# Water Quality Program Permit Writer’s Manual

Revised December 2011 Publication no. 92

- 109

## Publication and Contact Information

This report is available on the Department of Ecology’s website at www.ecy.wa.gov/biblio/92109.html

For more information contact:

Water Quality Program
P.O. Box 476 96 Program Development Services Section Olympia, WA 98504

- 76 96

Phone: 360

- 407

- 6 600

Washington State Department of Ecology

- www.ecy.wa.gov

o Headquarters, Olympia 360

- 407

- 6000

o Northwest Regional Office, Bellevue 425

- 649

- 7000

o Southwest Regional Office, Olympia 360

- 407

- 6300

o Central Regional Office, Yakima 509

- 575

- 2490

o Eastern Regional Office, Spokane 509

- 329

- 3400

If you need this document in a format for the visually impaired , call the Water Quality Program

at 360

- 407

- 6600. Persons with hearing loss can call 71 1 for Washington Relay Service. Persons with a speech disabili ty can call 877

- 833

- 6341.

# Water Quality Program Permit Writer’s Manual

Prepared by: Gary Bailey

Water Quality Program Washington State Department of Ecology Olympia, WashingtonTABLE OF CONTENTS (December 2011)

Permit Writer’ s Manual
iii 

# TABLE OF CONTENTS

TABLE OF CONTENTS

................................ ................................ ................................ . III

ACKNOWLEDGEMENTS

................................ ................................ ............................. XII

NOTE TO PERMIT WRITE RS

................................ ................................ ..................... XIII

NOTE TO OTHER READER S

................................ ................................ ..................... XIII

GLOSSARY

................................ ................................ ................................ ................ G

- 1

CHAPTER I. INTRODUC TION

................................ ................................ .................... I

- 1

1. OBJECTIVES AND FUNCTIONS

................................ ................................ ................................ .............. 1

2. FORMAT FOLLOWS PROCESS

................................ ................................ ................................ ............... 2 2.1 Other References

................................ ................................ ................................ ................................ ... 2

3. SCOPE

................................ ................................ ................................ ................................ ............................ 3

4. INSPECTIONS AND ENFORCEMENT

................................ ................................ ................................ ..... 3

5. NOT REGULATION

................................ ................................ ................................ ................................ ..... 3

6. A SHORT HISTORY LESSON

................................ ................................ ................................ .................... 4

7. THE CLEAN WATER ACT

................................ ................................ ................................ ......................... 5

8. TECHN OLOGY

- BASED CONTROL

................................ ................................ ................................ ......... 6
9. WATER QUALITY BASED CONTROL

................................ ................................ ................................ .... 7

10. PERMIT WRITERS IMPLEMENT THESE LAWS AND REGULATIONS

................................ ....... 7

11. PERMIT TOOLS

................................ ................................ ................................ ................................ ......... 8
CHAPTER II. AN OVER VIEW OF THE PERMITTI NG PROCESS

............................. II

- 1

1 . WHAT TYPE OF WASTEWATER DISCHARGE PERMIT?

................................ ................................ .. 1 1.1 State Wastewater Discharge Permit

................................ ................................ ................................ ........ 1 1.2 NPDES Wastewater Discharge Permit

................................ ................................ ................................ ... 1 1.3 General Wastewater Discharge Permit

................................ ................................ ................................ ... 2 1.4 Hydraulic Continuity

................................ ................................ ................................ .............................. 2

2. WHAT IS A WASTEWATER DISCHARGE PERMIT?

................................ ................................ ........... 2

3. THE PERMITTING PROCESS

................................ ................................ ................................ .................... 3

4. MODIFICATION OF PERMITS

................................ ................................ ................................ .................. 8

5. GENERAL PERMITS

- NEW AND RENEWAL

................................ ................................ ........................ 9

6. THE GENERAL PERMIT DEVELOPMENT PROCESS

................................ ................................ ...... 10

7. QA/QC PROCESS

................................ ................................ ................................ ................................ ....... 17 8. PERMITTEE REVIEW (also see Chapter XV, Section 4)

................................ ................................ ....... 20

9. PUBLIC REVIEW

................................ ................................ ................................ ................................ ....... 20

10. EPA REVIEW

................................ ................................ ................................ ................................ ............ 21

11. AN EXAMPLE PERMIT

................................ ................................ ................................ .......................... 21

12. PERMIT SHIELD POLICY

................................ ................................ ................................ ..................... 21Permit Writer’ s Manual
iv 13. CWA JURISDICTION ON TRIBAL LANDS

................................ ................................ ........................ 22

14. STATE AUTHORITY ON FOREST SERVICE LAND

................................ ................................ ........ 2 2

15. ANTIBACKSLIDING

................................ ................................ ................................ ............................... 23
CHAPTER III. THE AP PLICATION AND BACKGR OUND REVIEW

......................... III

- 1

1. WHO NEEDS PERMITS

................................ ................................ ................................ .............................. 1 1.1 NPDES Permit Requirements for Non

- discharging Facilities Which Have Zero Discharge
Limitations in Effluent Limitation Guidelines

................................ ................................ ..................... 3 1.2 Indepen dent Leaking Underground Storage Tank (LUST) Cleanup Sites

................................ ............ 4 1.3. Vehicle And Equipment Washing

................................ ................................ ................................ ........ 8 1.4. Petroleum Bulk Plants, S IC 5171

................................ ................................ ................................ .......... 8

2. APPLICATION FORMS FOR INDIVIDUAL PERMITS

................................ ................................ ........ 8

3. APPLICATION PROCESS

................................ ................................ ................................ ........................ 12 3.1 Analytical Requirements

................................ ................................ ................................ ...................... 16 3.2 Reviewing an Application

................................ ................................ ................................ .................... 17

4. APPLICATION AND EXPIRED PERMITS

................................ ................................ ............................ 18
4.1 NPDES

................................ ................................ ................................ ................................ ................. 18
4.2 State

................................ ................................ ................................ ................................ ...................... 19

5. APPLICATION FOR NEW PERMITS

................................ ................................ ................................ ..... 22
5.1 NPDES

................................ ................................ ................................ ................................ ................. 22
5.2 STATE

................................ ................................ ................................ ................................ .................. 22

6. TIME OF REAPPLICATION

................................ ................................ ................................ .................... 22

7. CONFIDENTIALITY OF INFORMATION

................................ ................................ ............................ 22

8. DOMESTIC SEWAGE EXCLUSION

................................ ................................ ................................ ....... 23

9. OWNER/O PERATOR AGREEMENTS

................................ ................................ ................................ ... 26 9.1. Ecology Must Review Agreements

................................ ................................ ................................ ..... 26 9.2 NPDES Permittee under Owner/Operator Agreement

................................ ................................ ......... 26 9.3 State Permittee under Owner/Operator Agreement

................................ ................................ .............. 29
CHAPTER IV. DERIVIN G TECHNOLOGY

- BASED EFFLUENT LIMIT S

.................. IV

- 1

1. EFFLUENT LIMITATION GUIDELINES

................................ ................................ ................................ 2 1.1 A Summary of Some Treatment Standards as Currently Defined

................................ ......................... 3 1.2 Steps for Using Effluent Guidelines

................................ ................................ ................................ ....... 4 1.3 Multiple Processes

................................ ................................ ................................ ................................ .. 6 1.4 Mass vs. Concentration

................................ ................................ ................................ .......................... 7
1.5 Some Solutions

................................ ................................ ................................ ................................ ....... 7 1.6 Outdated Effluent Guidelines

................................ ................................ ................................ ................. 8 1.7 Integrated Facilities

................................ ................................ ................................ .............................. 17 1.8 Converting Performance to Limits

................................ ................................ ................................ ....... 17

2. CASE

- BY

- CASE DERIVATION OF TECHNOLOGY

- BASED EFFLUENT LIMITS

....................... 21
3. ALL KNOWN, AVAILABLE, AND REASONABLE METHODS OF TREATMENT (AKART)

...... 26 3.1. A Summary of AKART

................................ ................................ ................................ ...................... 26
3.2. AKART As Given In Law

................................ ................................ ................................ .................. 27 3.3. AKART As Given In Regulation

................................ ................................ ................................ ....... 28
3.4. AKART as State Treatment Standards

................................ ................................ ............................... 32 3.5. AKART As Defined By the Pollution Control Hearings Board (PCHB) And Other Courts

............. 32
3.6. Direct Definitions of AKART

................................ ................................ ................................ ............ 35
3.7. AKART Defined In Individual Permits

................................ ................................ .............................. 35Permit Writer’ s Manual

v 3.8. AKART Versus Case

- by

- Case

................................ ................................ ................................ ........... 36 3.9. Zero Discharge

................................ ................................ ................................ ................................ ... 37
3.10. AKART For Pretreatment

................................ ................................ ................................ ................ 37 3.11. Engineering Analysis for All Known and Availabl e

................................ ................................ ........ 37
3.12. Economic Tests Define Reasonable

................................ ................................ ................................ . 38

4. ADJUSTMENT OF EFFLUENT LIMITS FOR AUTOCORRELATION

................................ ............ 72
CHAPTER V. MUNICIPA L EFFLUENT LIMITATIO NS AND OTHER REQUIREMENTS

................................ ................................ ........................... V

- 1

1. INTRODUCTION

................................ ................................ ................................ ................................ .......... 1

2. TECHNOLOGY

- BASED WASTEWATER DISCHARGE STANDARDS

................................ ............. 3

3. ALTERNATIVE WASTEWATER DISCHARGE STANDARDS

................................ ............................ 5
3.1 Conditions for Rece iving Alternative Effluent Limitations

................................ ................................ .... 5 3.2 Trickling Filters

................................ ................................ ................................ ................................ ..... 6 3.3 Waste Stabilization Ponds

................................ ................................ ................................ ..................... 9
3.4 Facilities with Combined Sewers

................................ ................................ ................................ ........ 14
3.5 Facilities with Less Concentrated Influent Wastewater

................................ ................................ ....... 25
3.6 Substitution of CBOD5 For BOD5

................................ ................................ ................................ ....... 28 3.7 Defining Compliance with 85% Removal

................................ ................................ ........................... 30 3.8 Operation and Maintenance (O & M) Manual

................................ ................................ ..................... 32 3.9 Maintaining Adequate Capacity

................................ ................................ ................................ ........... 34 3.10 Operator Certification

................................ ................................ ................................ ......................... 35 3.11 Loading Calculation for intermittent discharges

................................ ................................ ................. 36 4.1 The State Program

................................ ................................ ................................ ............................... 37 4.2 The Federal Program

................................ ................................ ................................ ............................ 39 4.3 Delegation

................................ ................................ ................................ ................................ ............ 39 4.4 Overlap With Wastewater Permits

................................ ................................ ................................ ....... 39

CHAPTER V I. WATER QUALITY

- BASED EFFLUENT LIMIT S FOR SURFACE WATERS

................................ ................................ ................................ ........ VI

- 1

1. WATER QUALITY CRITERIA AND STANDARDS

................................ ................................ ............... 1 1.1 The Water Qualit y Standards Define the Designated Uses and Incorporate Criteria

............................ 3
1.2 Conversion Factors and Translators for Metal Criteria

................................ ................................ ......... 5
1 .3 Site

- Specific Water Effect Ratio

................................ ................................ ................................ ........... 6

2. THE POINT OF COMPLIANCE OF THE WATER QUALITY STANDARDS

................................ 6
2.1 General Considerations fo r Authorizing Mixing Zones

................................ ................................ ......... 7

3. PREDICTING IMPACTS AND DEFINING EFFLUENT LIMITS FOR NUMERIC CRITERIA

.... 16 3.1 The Water Quality Impact Of BOD And Nutrients

................................ ................................ ............. 16 3.2 Other Specific Pollutants

- Conventional and Nonconventional

................................ ......................... 18 3.3 Deriving Effluent Limit s for Toxic Pollutants, as Seasonal Limits and for Impaired Waters

............. 25

4. ANALYTICAL LEVELS

................................ ................................ ................................ ............................ 49
4.1 Introduction

................................ ................................ ................................ ................................ .......... 49 4.2 Background Information

................................ ................................ ................................ ....................... 50 4.3 Implementation

- NPDES and State Permits

................................ ................................ ........................ 52 4.4 Choosing a Quantitation Level

................................ ................................ ................................ ............. 52
5. WHOLE EFFLUENT TOXICITY (WET)

................................ ................................ ................................ 61 5.1 Permit Writer's Task Summary

................................ ................................ ................................ ............. 61
5.2 Introduction

................................ ................................ ................................ ................................ .......... 61 5.3 The Purpose of Effluent Characterization

................................ ................................ ............................ 66Permit Writer’ s Manual
vi 5.4 Determini ng the Need for Effluent Characterization

................................ ................................ ............ 66 5.5 Determining Compliance with WET Limits

................................ ................................ ......................... 67 5.6 Noncompliance, Transient Toxicity Reports, and TI/RE Plans

................................ ............................ 69 5.7 Removal of WET Limits

................................ ................................ ................................ ...................... 71 5.8 Determining the Need for Rapid Screening Tests

................................ ................................ ................ 71 5.9 Technology

- Based WET Limits

................................ ................................ ................................ ........... 72 5.10 Options for Permittees

................................ ................................ ................................ ........................ 73 5.11 Species S election for WET Testing

................................ ................................ ................................ .... 74 5.12 Rapid Screening Test Selection

................................ ................................ ................................ .......... 77 5.13 Samples for WET Testing

................................ ................................ ................................ .................. 78 5.14 Managing Effluent Characterization Results

................................ ................................ ...................... 80
CHAPTER VII. DERIVI NG WATER QUALITY

- BASED EFFLUENT LIMIT S FOR PROTECTION OF HUMAN HEALTH

................................ ........................... VII

- 1

1. WATER QUALITY CRITERIA

- BACKGROUND

................................ ................................ .................. 1

2. IMPLEMENTATION

- OVERVIEW

................................ ................................ ................................ .......... 6

3. SCREENING AND PRIORITIZATION

................................ ................................ ................................ ..... 7

4. THE REASONABLE POTENTIAL DETERMINATION

................................ ................................ ........ 8 4.1 Which Criteria?

................................ ................................ ................................ ................................ ...... 8 4.2 Effluent and Background Concentration

................................ ................................ ................................ 8 4.3 Mixing Zones

................................ ................................ ................................ ................................ ......... 8 4.4 Plant Design Flows

................................ ................................ ................................ ............................... 10
4.5 Critical Flow Conditions

................................ ................................ ................................ ...................... 10
4.6 Coefficient of Variation of Effluent Concentration

................................ ................................ ............. 11
4.7 Dilution Factor

................................ ................................ ................................ ................................ ..... 11
4.8 Statistical Confidence Level

................................ ................................ ................................ ................. 11 4.9 Background Data on Chemical Concentrati ons

................................ ................................ .................... 11

5. RESULTS OF THE REASONABLE POTENTIAL DETERMINATION

................................ ............. 15 5.1 Yes, a Reasonable Potential Exists to Exceed Water Quality Standards

................................ ............. 15 5.2 No, a Reasonable Potential Does Not Exist to Exceed Water Quality Standards

................................ 16
5.3 The Result of the Reasonab le Potential Determination is Ambiguous, or, "Can't Determine".

........... 17

6. ANALYTICAL METHODS

................................ ................................ ................................ ....................... 17
CHAPTER VIII. DERIV ING WATER QUALI TY

- BASED EFFLUENT LIMIT ATIONS FOR THE PROTECTION O F GROUND WATER QUALI TY

........................ VIII

- 1

1. GROUND WATER CRITERIA AND STANDARDS

................................ ................................ ................ 1
1.1 Nu meric Criteria

................................ ................................ ................................ ................................ ..... 1

2. De MINIMIS APPLICATION OF FOOD PROCESS WASTEWATER

................................ ................. 1
CHAPTER IX. DERIVIN G EFFLUENT LIMITS FO R THE PROTECTIO N OF AQUATIC SEDIMENTS

................................ ................................ ................. IX

- 1

1. PERMIT WRITER'S TASKS

................................ ................................ ................................ ....................... 1 For permits to Puget Sound

................................ ................................ ................................ .......................... 1 For permits to other marine waters

................................ ................................ ................................ ............... 2 For permits to low saline waters

................................ ................................ ................................ ................... 2 For permits to fresh water

................................ ................................ ................................ ............................. 2

2. THE SEDIMENT MANAGEMENT STANDARDS

................................ ................................ ................... 2

3. OVERVIEW OF THE PROCESS

................................ ................................ ................................ ................ 7 3.1 Evaluation of the Potential for a Discharge to Impact Receiving Sediments (WAC 173

- 204

-Permit Writer’ s Manual
vii 400(1)(a))

................................ ................................ ................................ ................................ ............. 8 3.2 Application for a SIZ (WAC 173

- 204

- 400(1)(b))

................................ ................................ ................ 11 3.3 SIZ Eligibility Requirements (WAC 173

- 204

- 400(1)(c) and (f))

................................ ........................ 11 3.4 Development of SIZ Specifications (WAC 173

- 204

- 400(1)(d),(e), and (g))

................................ ..... 12 3.5 SIZ Monitoring and Maintenance Requirements (WAC 173

- 204

- 400(1)(i))

................................ ...... 13 3.6 Public Notice and Landowner Notification Procedures (WAC 17 3

- 204

- 400(1)(h))

........................... 13 3.7 Renewal, Modification, and Elimination of Authorized SIZs Over Time (WAC 173

- 204

- 400(1)(j)) 14
3.8 Clos ure and Restoration of SIZs (WAC 173

- 204

- 400(1)(I))

................................ ................................ 15

4. SCREENING

- LEVEL EVALUATION OF POTENTIAL FOR SEDIMENT IMPACTS

.................... 15
4.1 Initiation of Activities

................................ ................................ ................................ ...................... 15 4.2 Narrative Evaluation of the Potential for Sediment Impacts

................................ ............................... 20
4.3. Technical Evaluation of th e Potential for Sediment Impacts

................................ ............................. 20
4.4 Alternative Procedures for the Technical Evaluation of the Potential for Sediment Impacts in Freshwater, low Salinity, and Non

- Puget Sound Marine Env ironments

................................ ............ 38

CHAPTER X. PRETREAT MENT PROGRAM

................................ ............................ X

- 1

1. OVERVIEW

................................ ................................ ................................ ................................ ............... 1
1.1. Federal Pretreatment Rules

................................ ................................ ................................ .................. 1
1.2. Washington State’s rules for non

- domestic wastewater

................................ ................................ ...... 2
1.3. Philosophy of Washington Stat e’s Pretreatment Program

................................ ................................ ... 3

2. NPDES PERMITS FOR POTWS:

................................ ................................ ................................ ............... 4
2.1. Requiring a POTW to Develop a Pretreatment Program:

................................ ................................ .... 5
2.2. NPDES Permit Conditions for Delegated Programs

................................ ................................ .......... 10
2.3. Requiring and Recognizing changes to Delegated Programs

................................ ............................ 10
2.4. NPDES Permit Conditions for Non

- Delegated Programs

................................ ................................ .. 11
2.5. Pretreatment Related NPDES Permit Fact Sheet Language for POTWs

................................ ........... 12

3. STATE WASTE DISCHARGE PERMITS FOR NON

- DOMESTIC WASTE

................................ ...... 13
3.1. Overview of the Permitting Process

................................ ................................ ................................ ... 13
3.2. Pretreatment Standards

................................ ................................ ................................ ...................... 14
3.3. Other Pretreatment Requirements

................................ ................................ ................................ ...... 16
3.4. State Waste Discharge Permit F act Sheet Contents

................................ ................................ ........... 18

4. REGIONAL PRETREATMENT ENGINEER STAFF EXPERTISE AREAS

................................ ...... 19
4.1. Conducting Industrial User Surveys

................................ ................................ ................................ .. 20
4.2. Developing “Technically Based” Local Limits

................................ ................................ ................. 21
4.3. Providing Model Pretreatment Ordinance Language

................................ ................................ ......... 22
4.4. Inspecting and Auditing Delegated Programs

................................ ................................ .................... 23
4.5. Reviewing Pretreatment Related Submittals from POTWs

................................ ............................... 24
4.6. Reviewing Pretreatment Permits

................................ ................................ ................................ ........ 24
4.7. Providing Organized Pretreatment Related Training Events

................................ ............................. 24

CHAPTER XI. RECLAIM ED WATER USE

................................ ................................ XI

- 1

1. LEARNING THE LANGUAGE

................................ ................................ ................................ ................... 1 1.1 Working Definitions:

................................ ................................ ................................ .............................. 1 1.2 Abbreviations and Acronyms

................................ ................................ ................................ ................. 4

2. STATUTORY REQUIREMENTS

................................ ................................ ................................ ........... 4
2.1 Reclaimed Water Standards

................................ ................................ ................................ .................... 5
2.2 Industrial Process Reuse Water

................................ ................................ ................................ .............. 5 2.3 Water Resources Permitting

................................ ................................ ................................ ................... 5
2.4Guidance for Coordinated Permits

................................ ................................ ................................ .......... 6 2.5 Wetlands

................................ ................................ ................................ ................................ ................. 9Permit Writer’ s Manual
viii 2.6 Stormwater

................................ ................................ ................................ ................................ ........... 10 2.7. Department of Health Provisions

................................ ................................ ................................ ........ 10

3. THE PERMITTING PROCESS

................................ ................................ ................................ ............. 10 3.1. Ecology Water Quality Program Role

................................ ................................ ................................ 11 3.2. Department of Health Role

................................ ................................ ................................ ................. 12 3.3. Ecology Water Resources Program Role

................................ ................................ ........................... 13
3.4 Fact Sheets and Documentation

................................ ................................ ................................ ........... 19
3.5 Public Involvement

................................ ................................ ................................ ............................... 20
4. TREATMENT TECHNOLOGY REQUIREMENTS

................................ ................................ .............. 20
4.1 Source Control and Pre

- treatment

................................ ................................ ................................ ........ 20
4.2 Four Basic Classes

................................ ................................ ................................ ................................ 20
4. 3 Distri bution Line Chlorine Residual

................................ ................................ ................................ .... 22 4.4 Advanced Treatment Techniques

................................ ................................ ................................ ......... 22 4.5 Water Quality Technology Limits

................................ ................................ ................................ ........ 23 4.6 Monitoring Requirements

................................ ................................ ................................ ..................... 27

5. DISTRIBUTION AND USE

................................ ................................ ................................ ........................ 31
5.1 Use

- Based Water Qual ity Limits

................................ ................................ ................................ .......... 31 5.2 Discharges from Distribution Maintenance

................................ ................................ .......................... 31

6. IRRIGATION

................................ ................................ ................................ ................................ ............... 32 6.1. Class of Reclaimed Water Required for Use.

................................ ................................ ..................... 32 6.2 Other Considerations for Irrigation Water Quality

................................ ................................ ............... 33
6.3 Incidental Site Runoff

................................ ................................ ................................ ........................... 36 6.4 Incidental Percolation and Ground Water Monitoring

................................ ................................ ......... 37

7. IMPOUNDMENTS

................................ ................................ ................................ ................................ ...... 38 7.1. Class of Reclaimed Water Required for Use.

................................ ................................ ..................... 38 7.2 Relationship to Stormwater Ponds

................................ ................................ ................................ ........ 38 7.3 Incidental Runoff from Impoundments

................................ ................................ ................................ 38
7.4 Releases from Reclaimed Water Ponds

................................ ................................ ................................ 39

8. COMMERCIAL AND INDUSTRIAL USES

................................ ................................ ............................ 40 8.1. Class of Reclaimed Water Required for Use.

................................ ................................ ...................... 40

9. GROUND WATER RECHARGE BY SURFACE PERCOLATION

................................ ..................... 41 9.1 Water Quality Limitations

................................ ................................ ................................ .................... 42 9.2 Ground Water Recharge Criteria

................................ ................................ ................................ .......... 43 9.3 Additional Co ntaminants of Concern

................................ ................................ ................................ ... 48 9.4 Ground Water Monitoring

................................ ................................ ................................ .................... 50 9.5 Blended Flows for Groundwater Recharge

................................ ................................ .......................... 51

CHAPTER XII. ALTERN ATIVES AND ADDITIONS TO NUMERICAL EFFLUEN T LIMITS

................................ ................................ ................................ ........... XII

- 1

1. GENERAL CONDITIONS

................................ ................................ ................................ ........................... 1 1.1 The General Conditions for NPDES Permits

................................ ................................ ........................ 1
1.2 The General Conditions for State Permits

................................ ................................ ........................... 16

2. SPECIAL CONDITIO NS

................................ ................................ ................................ ............................ 19
3. POLLUTION PREVENTION AND BEST MANAGEMENT PRACTICES (BMPs)

........................... 20
3.1 Pollution Prevention

................................ ................................ ................................ ............................. 20 3.2 Best Management Practices

................................ ................................ ................................ .................. 21 3.3 Scope of BMPs

................................ ................................ ................................ ................................ .... 21 3.4 Minimum Requirements for the BMP Plan

................................ ................................ ......................... 23Permit Writer’ s Manual
ix 4. CERTIFIED OPERATORS AT INDUSTRIAL SITES WITH DOMESTIC WASTEWATER TREATMENT FACILITIES

................................ ................................ ................................ .................. 36

XIII. MONITORING GU IDELINE S

................................ ................................ ............ XIII

- 1

1. GENERAL CONSIDERATIONS OF A SELF

- MONITORING PROGRAM

................................ ......... 4 1.1 Establish Monitoring Objectives

................................ ................................ ................................ ........... 4
1.2 Parameters to Monitor

................................ ................................ ................................ ........................... 5 1.3 Monitoring Frequency

................................ ................................ ................................ ........................... 9 1.4. Baseline Monitoring Fre quencies

................................ ................................ ................................ ....... 16 1.5 Special Monitoring Strategies

................................ ................................ ................................ .............. 17 1.6 Sampling and Testing Methods

................................ ................................ ................................ ............ 18 1.7 Determining the Sampling Location

................................ ................................ ................................ ..... 21 1.8 Quality Assurance/Quality Control

................................ ................................ ................................ ...... 22 1.9 Data Management

................................ ................................ ................................ ................................ . 25

2. POTW MONITORING

................................ ................................ ................................ ................................ 26 2.1 Influent and Effluent Monitoring of POTWs

................................ ................................ ....................... 27 2.2 Process Control Monitoring

................................ ................................ ................................ .................. 42 2.3 POTW Sludge Monitoring and Special Conditions

................................ ................................ ............. 69 2.4 Combined Sewer Overflows

................................ ................................ ................................ ................ 70 2.5 Monitoring Bypasses

................................ ................................ ................................ ............................ 71

3. INDUSTRIAL AND COMMERCIAL FACILITY MONITORING

................................ ....................... 71 3.1 Influent Monitoring

................................ ................................ ................................ ............................. 72 3.2 Effluent Monitoring

................................ ................................ ................................ .............................. 73

4. WET TESTING MONITORING

................................ ................................ ................................ ................ 74 4.1 Recommended Test Frequency for Characterization

................................ ................................ ........... 74 4.2 Sampling

................................ ................................ ................................ ................................ .............. 79

5. STORM WATER MONITOR ING

................................ ................................ ................................ .............. 79 5.1 Types of Storm Water Permits

................................ ................................ ................................ ............. 80
5.2 Wastewater Characterization for Industrial Storm Water

................................ ................................ ..... 82 5.3 Compliance Monitoring

................................ ................................ ................................ ........................ 84

6. RECEIVING ENVIRONMENT MONITORING

................................ ................................ ...................... 89 6.1 General Conside rations for Monitoring Receiving Environments

................................ ....................... 90 6.2 Surface Water Monitoring

................................ ................................ ................................ .................. 106 6.3 Sediment Monitoring

................................ ................................ ................................ .......................... 112 6.4 Crop/Soil/Vadose Monitoring

................................ ................................ ................................ ............ 112 6.5 Groundwater Monitoring

................................ ................................ ................................ .................... 113 6.6 Biological Surveys

................................ ................................ ................................ .............................. 113 6.7 Data Compatibility

................................ ................................ ................................ ............................. 113

7. SEDIMENT MONITORING

................................ ................................ ................................ .................... 113 7.1. General Types of Monitoring in the Sediment Source Control Process

................................ ........... 114 7.2 Monitoring Objectives

................................ ................................ ................................ ........................ 115 7.3. Types of Moni toring Data

................................ ................................ ................................ ................. 116 7.4. Methods for Collecting Monitoring Data

................................ ................................ ......................... 120 7.5. Development of Appropriate Monitoring Requirements

................................ ................................ ... 130 7.6. Interpretation of Monitoring Results

................................ ................................ ................................ 133

8. SUMMARY CHECKLIST

................................ ................................ ................................ ........................ 135
CHAPTER XIV. FACT S HEETS AND DOCUMENTAT ION

................................ .... XIV

- 1

1. FEDERALLY REQUIRED FOR SELECTED PERMITS

................................ ................................ ........ 1Permit Writer’ s Manual

x 2. STATE REQUIREMENTS FOR ALL PERMITS

................................ ................................ ..................... 1
3. PUGET SOUND PLAN REQUIREMENTS

................................ ................................ ............................... 2
4. FEDERALLY REQUIRED DETAILS

................................ ................................ ................................ ........ 3

5. FACT SHEET CONSIDERATIONS

................................ ................................ ................................ ........... 3

6. FACT SHEET FORMATS

................................ ................................ ................................ ............................ 4
CHAPTER XV. PUBLIC INVOLVEMENT

................................ ................................ XV

- 1

1. SEPA

................................ ................................ ................................ ................................ ............................... 1

2. PUBLIC NOTICE OF PERMIT ACTIONS

................................ ................................ ............................... 2

3. PUBLIC NOTICE OF APPLICAT ION (PNOA)

................................ ................................ ........................ 2

4. PERMITTEE REVIEW

................................ ................................ ................................ ................................ 3
5. PUBLIC NOTICE OF DRAFT PERMIT (PNOD)

................................ ................................ ..................... 4

6. DISTRIBUTION OF DRAFT AND FINAL PERMIT MATERIALS

................................ ...................... 4

7. PUBLIC INFORMATIONAL MEETINGS AND WORKSHOPS

................................ ........................... 5 7.1. Inf ormational Meetings Preceding Hearings

................................ ................................ ......................... 5 7.2. Public Notice of Informational Meetings

................................ ................................ .............................. 6

8. HEARINGS

................................ ................................ ................................ ................................ .................... 6 8.1. Public Notice of Hearing

................................ ................................ ................................ ....................... 6 8.2. Hearing Officer

................................ ................................ ................................ ................................ ...... 7

9. PUBLIC NOTICE OF PERMIT ISSUAN CE

................................ ................................ ............................. 7

10. PUBLIC NOTICES OF OTHER ACTIONS

................................ ................................ ............................. 7

11. WHEN TO GO BACK TO PUBLIC NOTICE WITH A REVISED DRAFT PERMIT

....................... 8
CHAPTER XVI. APPEAL S AND VARIANCES

................................ ...................... XVI

- 1

1. APPEAL OF THE FINAL PERMIT TO THE POLLUTION CONTROL HEARINGS BOARD (PCHB)

................................ ................................ ................................ ................................ ........................ 1 1.1 The PCHB

................................ ................................ ................................ ................................ ............. 1 1.2 Appeal Process

................................ ................................ ................................ ................................ ...... 1

2. VARIANCES

................................ ................................ ................................ ................................ .................. 3
2.1 The Federal Variances

................................ ................................ ................................ ........................... 3 2.2 The State Requirements

................................ ................................ ................................ .......................... 5
REFERENCES

................................ ................................ ................................ ................ 1

CHAPTER I.

................................ ................................ ................................ ................................ ....................... 1

CHAPTER II.

................................ ................................ ................................ ................................ ...................... 1

CHAPTER IV

................................ ................................ ................................ ................................ ...................... 1

CHAPTER V

................................ ................................ ................................ ................................ ....................... 1

CHAPTER VI.

................................ ................................ ................................ ................................ ..................... 2

CHAPTER VIII

................................ ................................ ................................ ................................ .................. 3

CHAPTER IX.

................................ ................................ ................................ ................................ ..................... 4

CHAPTER XIII.

................................ ................................ ................................ ................................ ................. 7

APPENDIX 1

................................ ................................ ................................ ......... APP1

- 1

1. INDEX TO NPDES REGUL ATIONS

................................ ................................ ................................ .......... 1

APPENDIX 4

................................ ................................ ................................ ......... APP4

- 1Permit Writer’ s Manual
xi I. AUTOCORRELATION

................................ ................................ ................................ ................................ 1

II. NEW SOURCE

................................ ................................ ................................ ................................ ........... 10

APPENDIX 6

................................ ................................ ................................ ......... APP6

- 1

1. GUIDANCE FOR CONDUCTING MIXING ZONE ANALYSES

................................ ........................... 1
1.1 SELECTING VALUES FOR MODEL INPUT PARAMETERS

................................ ......................... 1
1.2 UNDERSTANDING INITIAL DILUTION THEORY

................................ ................................ ........ 9
1.3 CHOOSING AN INITIA L DILUTION MODEL

................................ ................................ ............... 13
1.4 UNDERSTANDING FARFIELD THEORY

................................ ................................ ...................... 21
1.5 CHOOSING A FARFIELD MODEL

................................ ................................ ................................ . 22
1.6 CONDUCTING A DYE STUDY

................................ ................................ ................................ ....... 25
1.7 REFERENCES

................................ ................................ ................................ ................................ .... 32
2.0 SPREADSHEETS FOR WATER QUALITY

- BASED NPDES PE RMIT CALCULATIONS

.......... 37
2.1. DETAILED DESCRIPTIONS AND USER INSTRUCTIONS

................................ .......................... 38
2.2 GUIDELINES FOR USING TSDCALC.XLW

................................ ................................ .................. 49
3. AN ALTERNATE METHOD FOR ESTIMATING UPPER QUANTILES

................................ .......... 54
4. GUIDANCE ON THE APPROPRIATE SIZE MIXING ZONE FOR A UNIQUE OUTFALL
CONFIGURATION

................................ ................................ ................................ ................................ . 56 5. DERIVING THE 7Q10 HIGH FLOW (HF) AND THE DESIGN SPILL

................................ .............. 57 5.1. Guidelines for Deriving the 7QHF

................................ ................................ ................................ ..... 57 5.2. Determining Design Spill for Gas Abatement

................................ ................................ .................... 58

APPENDIX 13

................................ ................................ ................................ ..... APP13

- 1

1. SUPPORTIN G STATISTICAL STUDY FOR PERFORMANCE

- BASED REDUCTION OF MONITORING (from EPA, April 96)

................................ ................................ ................................ ...... 1
2. DETERMINING THE NUMBER OF SAMPLES REQUIRED FOR COMPLIANCE MONITORING

................................ ................................ ................................ ................................ .......... 9Permit Writer’ s Manual
xii 

# Acknowledgements

This manual represents an effort by the Water Quality Program to improve its point source pollution control program. Numerous people have contributed to the manual.

Mike Herold, Dewey Weaver, Ed O'Brien, Ray Henneke, Randy Mars hall, Cheryl Neimi, Carl Tonge, Foroozan Labib, Kathy Cupps

, and Norm Glenn have contributed directly by writing parts of the manual.

Many of the regional and industrial section permit staff were involved in a manual workgroup that formulated direction and processes in the manual.

An advisory group representing those with an active interest in the permit program helped to provide direction for the first edition of this manual. The members of this group are :

Roger Von Gohren, Association of Washington Business, Mike Meeuwsen, Texaco Andre Caron, National Council for Air and Stream Improvement Vallana Piccolo, Puget Sound Water Quality Authority Lincoln Loehr, NW Pulp and Paper Association Dan Cheney, Bay Center Mariculture Dan Curry, City of Wenatchee Diane Lefevre, SEH America Jack Lilja, DSHS Shellfish Program John Magill, City of Stanwood Jim Matsuyama, Northeast Tri

- County Health District Mary Lou Mills, Dep artment of Fisheries Pat Romberg, METRO M. Pat Wennekens, Sierra Club Kerrie Schurr, EPA Mil es Beach, City of Ocean Shores Paul Schissler, Swinomish Tribal Community Darrell Turner, Washington Farm Bureau Stephen Vincent, Columbia Analytical Services

Many support staff in the Program Development Services Section have assisted with typing and

com position.

Everyone's efforts are appreciated.

Gary C. Bailey Project LeaderPermit Writer’ s Manual
xiii 

# Note to Permit Writers

There are visuals of a computer throughout the text of the manual. This indicates that there is some computer

- related assis tance available such as model permit language, model fact sheet language or spreadsheets to assist in calculations. The model language and spreadsheets are available on the network or from the Program Development Services Section.

The manual is designed to be used in a binder and is formatted to
accommodate revisions. The current version of the manual will be noted as the version date on the cover page and the Table of Contents
header.

Please direct any comments or requests for the manual to the Progra m Development Services
Section.



# Note to Other Readers

This manual is a working document for people in the Department of Ecology who write wastewater discharge permits. It is available to the public on the Ecology Web site. The manual will be updated p eriodically.

Appendices numbers reflect the related chapter. For example, Appendix 6 covers mixing zones and other topics which supplement the information in Chapter VI. Water Quality

- Based Effluent Limits For Surface Waters

.

The Department of Ecology is interested in your comments on this manual. Please address your

comments to PERMIT WRITERS MANUAL , DEPT OF ECOLOGY, PO BOX 476 96

, OLYMPIA WA 98504

- 76 96

.

C omments may also be posted at www. ecy.wa.gov/programs/wq/comments.htmlPermit Writer’ s Manual
xiv This page is purposely left blankGLOSSARY (December 2011)

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- 1 

# GLOSSARY

DEFINING THE TERMS OF WASTEWATER PERMITS

401(a) CERTIFICATION

- A requirement of Section 401(a) of the Clean Water Act that all federally issued permits be certified b y the state in which the permit is issued. The state certifies that the proposed permit will comply with state water quality standards.

ACEC (ACUTE CRITICAL EFFLUENT CONCENTRATION)

- The maximum concentration of effluent during critical conditions at the boundary of the zone of acute criteria exceedance assigned in the permit. If no zone of acute criteria exceedance is specified the acute critical effluent concentration shall be one hundred percent effluent.

A CUTE T OXICITY

- The lethal effect of a compo und on an organism that occurs in a short period of time, usually 48 to 96 hours.

ACUTE TOXICITY TEST

- A toxicity test with the death of test organisms as the measured response.

AET (APPARENT EFFECTS THRESHOLD)

- For a given quality

- assured data set

app roved by the department, the highest sediment concentration of an individual chemical contaminant which is not associated with statistically significant biological effects (proposed WAC 173

- 204

- 020).

AKART

- Acronym for "all known available and reasonable methods"..."to prevent and control"..."pollution" (RCW 90.48.010, RCW 90.48.520). (see Chapter IV)

ANTI

- BACKSLIDING

- A provision in the Federal Regulations (40 CFR 122.44) which says a reissued permit must be as stringent as the previous permit with som e exceptions.

AVERAGE MONTHLY DISCHARGE LIMITATION

- The highest allowable average of "daily discharges" over a calendar month. Calculated as the sum of all daily discharges measured during a calendar month divided by the number of daily discharges measu red during that month (40 CFR 122.2).GLOSSARY (December 2011)

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- 2 AVERAGE WEEKLY DISCHARGE LIMITATION

- The highest allowable average of "daily discharges" over a calendar week. Calculated as the sum of all daily discharges measured during a calendar week divided by the number of d aily discharges measured during that week (40 CFR 122.2). Applicable only to municipal discharges.

BAT (BEST AVAILABLE TECHNOLOGY ECONOMICALLY ACHIEVABLE)

- The wastewater treatment technology required to control toxic pollutants. Required to be in plac e by July 1, 1984, however, EPA has not completed the guidelines for all
industries.

BCT (BEST CONVENTIONAL POLLUTANT CONTROL TECHNOLOGY)

- This was the second step in defining treatment technology for conventional pollutants. A candidate technology must pass 2 cost tests which compare industrial costs to municipal costs of treatment. BCT was to be in place by July 1, 1984

, but EPA did not complete guidelines for all industries.

BIOSOLIDS

- Biosolids is municipal sewage sludge that meets standards for ap plication
to the land.

BOILER PLATE LANGUAGE

- See GENERAL CONDITIONS.

BMP (BEST MANAGEMENT PRACTICE)

- Permit condition used in place of or in conjunction with effluent limits to prevent the discharge of pollutants. BMPs m ay include schedules of activi ties, prohibitions of practices, maintenance procedures, treatment requirements, operating procedures and practices.

BOD (BIOCHEMICAL OXYGEN DEMAND)

- The quantity of substances present in a water or wastewater that utilizes oxygen to decompose. The test for BOD is to put a sample of water or wastewater in a sealed bottle with sewage bacteria and measure how much oxygen is used in 5 days.

BPJ (BEST PROFESSIONAL JUDGMENT)

- The highest quality technical opinion developed by permit writer after considerati on of all reasonably available and pertinent data or information which forms the basis for the terms and conditions of an NPDES permit. BPJ m ay also be called BEJ (Best Engineering Judgment). Authorized by Sec tion 402(a)(1)(B) of the Clean Water Act.GLOSSARY (December 2011)

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- 3 BPT (BEST PRACTICABLE CONTROL TECHNOLOGY CURRENTLY AVAILABLE)

- The first step of treatment technology identified by EPA for 52 categorical industries. The technology was identified by surveying the treatment technology in use and defining the best averag e performance. See section 301(b)(1)(A) of CWA.

B YPASS

- The intentional diversion of waste streams from any portion of a treatment facility.

CCEC (CHRONIC CRITICAL EFFLUENT CONCENTRATION)

- The maximum concentration of effluent during critical conditio ns at the boundary of the mixing zone assigned in the permit. Where no mixing zone is specified, the chronic critical effluent is one hundred percent effluent.

CERTIFICATION, 401(a)

- See 401(a) CERTIFICATION.

CFR (CODE OF FEDERAL REGULATIONS)

- A codif ication of the general and permanent rules published in the Federal Register by the Executive departments and agencies of the Federal Government. Environmental regulations are found in Title 40.

CHRONIC TOXICITY TEST

- A toxicity test which measures a su blethal effect such as failed fertilization, development, growth, or reproduction. Organism survival is also a measured endpoint in some chronic toxicity tests.

COD (CHEMICAL OXYGEN DEMAND)

- A measure of the decomposable substances
in water or wastewate r which uses a chemical oxidant instead of bacteria as in the
BOD test.

C OMBINED S EWER O VERFLOW (CSO)

- The event during which excess combined sewage flow caused by inflow is discharged from a combined sewer, rather than conveyed to the sewage treatment p lant because either the capacity of the treatment plant or the combined sewer is exceeded.

COMPLIANCE SCHEDULE

- A schedule of remedial measures included in a permit or an enforcement order, including an enforceable sequence of actions or operations
leadi ng to compliance with an effluent limitation, other limitation, prohibition, or standard (CWA 502 , 40 CFR 122.47 )

.GLOSSARY (December 2011)

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- 4 CONVENTIONAL POLLUTANTS

- Pollutants typical of municipal sewage and defined by Federal Regulation (40 CFR 401.16) as BOD, total suspended s olids, fecal coliform, pH, and oil/grease.

CRITERIA

- The numeric values and the narrative standards that represent contaminant concentrations which are not to be exceeded in the receiving environmental media (surface water, ground water, sediment) to pro tect beneficial uses.

C RITICAL C ONDITION

- The time during which the combination of receiving water and waste discharge conditions have the highest potential for causing toxicity in the receiving water environment. This situation usually occurs when the flow within a water body is low, thus, its ability to dilute effluent is reduced.

DAILY DISCHARGE

- The discharge of a pollutant measured during any 24

- hour period that reasonably represents a calendar day for purposes of sampling. For pollutants
with li mitations expressed in units of mass, the daily discharge is calculated as the total mass of the pollutant discharged during the day. For pollutants with limitations expressed in other units of measurement, the daily discharge is calculated as the

average measurement of the pollutant throughout the day (40 CFR 122.2).

DEVELOPMENT DOCUMENT

- A document prepared during the development of effluent guidelines by EPA which explains the methodology and data which was used to develop the guidelines.

DETECTION L IMIT (DL)

- See METHOD DETECTION LIMIT

.

D ILUTION F ACTOR

- A measure of the amount of mixing of effluent and receiving water that occurs at the boundary of the mixing zone. Expressed as the inverse of the effluent fraction e.g., a dilution factor of 16 me ans the effluent comprises 6.25% by volume and the receiving water 9 3.75 % at the compliance boundary or volume
restriction (DF = 1/.0625)

. The applicable dilution factor is the minimum of
volume/volume fraction or effluent concentration at the distance bo undary.

DILUTION ZONE

- See MIXING ZONE

.

DISCRETE SAMPLE

- A single sample of wastewater taken at neither set time nor flow. Also known as a grab sample or single sample.GLOSSARY (December 2011)

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- 5 DMR (DISCHARGE MONITORING REPORT)

- A report submitted by a permittee, (usually m onthly or quarterly ) which gives the results of the effluent monitoring tests performed.

Do. or do.

- Within the effluent limits sections of 40 CFR means ditto or the same as
above.

DRAFT PERMIT

- A document which indicates a decision to issue, deny, mod ify, revoke and reissue, terminate or reissue a permit. Usually is in the form of a permit and indicates a decision to issue, reissue, or modify a permit.

EARLY WARNING VALUES

- Act as a trigger in the groundwater standards to detect increasing contamina nt concentrations prior to the degradation of a beneficial use.

EFFLUENT LIMITATION

- Any restriction established by a permitting authority on quantities, rates, and concentrations of chemical, physical, biological pollutants discharged to waters of the s tate.

ENFORCEMENT LIMITS

- The values assigned by the groundwater standards to a contaminant for the purposes of regulation. This limit assures that a criterion will
not be exceeded.

EPA EFFLUENT GUIDELINES

- (see Chapter IV of this Manual )

.

EXCURSIONS

- Violations of effluent limits or water quality standards.

FACT SHEET

- A document prepared and issued with every permit which summarizes the activities and decisions on the permit and tells how the public may comment (40 CFR 124.8, 124.56).

FR (FEDERA L REGISTER)

- The periodical of the U.S. government in which draft and final regulations are published.

GENERAL PERMIT

- A permit to regulate storm water point sources or other category of point sources. A general permit is developed for a category of di schargers and is not specifically tailored for an individual discharger (40 CFR 122.28).

INDIRECT DISCHARGER or INDUSTRIAL USER

- A discharger of wastewater to the sanitary sewer which is not sanitary wastewater or is not equivalent to sanitary

wastewater in character.GLOSSARY (December 2011)

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- 6 I NDUSTRIAL W ASTEWATER

- Water or liquid

- carried waste from industrial or commercial processes, as distinct from domestic wastewater. These wastes may result from any process or activity of industry, manufacture, trade or business, from
the development of any natural resource, or from animal operations such as feed lots, poultry houses, or dairies. The term includes contaminated storm water and, also,
leachate from solid waste facilities.

INSPECTION, COMPLIANCE

- WITHOUT SAMPLING

- A site v isit for the purpose of determining the compliance of a facility with the terms and conditions of its permit or with applicable statutes or regulations. The minimum requirements are specified in the Compliance Inspection Checklist ( August 15 , 19 96).

INSP ECTION, COMPLIANCE

- WITH SAMPLING

- Similar to INSPECTION,
COMPLIANCE

- WITHOUT SAMPLING but includes as a minimum sampling and analysis for all parameters with permit limits for the purpose o f ascertaining compliance with those limits. For municipal fac ilities this includes sampling of the influent to determine compliance with the 85% removal requirement. Additional sampling for other parameters may also be conducted.

INSPECTION, COMPLIANCE FOLLOW

- UP

- An inspection for the main purpose of verifying th at a compliance issue required by a previous action (inspection, NOC, order) has been completed or initiated.

INSPECTION, COVERAGE

- An inspection of an unpermitted facility for the purpose
of determining if a permit is required or an inspection of a perm itted facility to determine whether permit termination is appropriate.

INSPECTION, MULTIMEDIA COMPLIANCE

- An INSPECTION, COMPLIANCE

- WITHOUT SAMPLING or an INSPECTION, COMPLIANCE

- WITH SAMPLING which is conducted on a metals mining facility that includ es an assessment of dam safety and air permit compliance in accordance with the multimedia inspection
checklist.

INSPECTION, OPERATOR OUTREACH

- An inspection for the purpose of providing assistance to municipal treatment plant operators conducted by a Te chnical Assistance Officer designated under RCW 43.21A.085.GLOSSARY (December 2011)

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- 7 INSPECTION , OPERATION AND MAINTENANCE

- A scheduled on

- site visit to a sewage treatment plant to review operations, record keeping, personnel information
and to make visual observations on the condition of a plant and its discharge. Any documented operations deficiencies will be noted and used to provide a basis for making recommendations for future operation and maintenance programs and activities at the plant.

INSPECTION, PRETREATMENT AUDIT

- An audit of a municipal treatment facility and system for municipalities that have been delegated pretreatment program responsibilities . Conducted at least once every five years. The primary purposes are to determine compliance with the requirements of the municipalities’ approved program and to assess the need for program improvements. Audits are conducted using EPA’s “Control Authority Pretreatment Audit Checklist and Instruction.”

INSPECTION, PRETREATMENT COMPLIANCE

- An annual inspection of a
muni cipal treatment facility and system for municipalities that have been delegated pretreatment program responsibilities. The primary purpose is to determine compliance with the requirements of the municipalities’ approved pretreatment program. Inspections are conducted using the PCT Checklist and EPA’s “Guidance for Conducting a Pretreatment Compliance Inspection.”

INSPECTION, TECHNICAL ASSISTANCE VISIT

- An inspection on a permitted facility for the sole purpose of providing compliance assistance to the p ermittee and where the permittee and the inspector have agreed to this purpose prior to or at the initiation of the inspection.

I NTERFERENCE

- A discharge which, alone or in conjunction with a discharge or discharges from other sources, both:

Inhibits or disrupts the POTW, its treatment processes or operations, or its sludge processes, use or disposal ; and

, Therefore is a cause of a violation of any requirement of the POTW's NPDES permit (including an increase in the magnitude or duration of a violation) o r of the prevention of sewage sludge use or disposal in compliance with the following statutory provisions and regulations or permits issued there under (or more stringent State or local regulations): Section 405 of the Clean Water Act, the Solid Waste
Dis posal Act (SWDA) (including title II, more commonly referred to as the Resource Conservation and Recovery Act (RCRA), and including State regulations contained in any State sludge management plan prepared pursuant to subtitle D of the SWDA), sludge regulat ions appearing in 40 CFR Part 507, the Clean Air Act, the Toxic Substances Control Act, and the Marine Protection, Research and Sanctuaries Act.GLOSSARY (December 2011)

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- 8 INTEGRATED FACILITY

- A primary industry with operations covered by more than one subcategory of operation.

LO AD ALLOCATION (LA)

- Within a TMDL, the allocation for the nonpoint sources of a pollutant.

LOCAL LIMITS

- Conditional discharge limits imposed by municipalities upon dischargers to their sewage treatment system.

MAJOR FACILITY (PERMIT)

- A facility disc harging to surface water with an EPA rating score of > 80 points based on such factors as flow volume, toxic pollutant potential, and public health impact. EPA reviews these major NPDES permits during issuance and tracks compliance with the permits.

MAXI MUM DAILY DISCHARGE LIMITATION

- The highest allowable daily discharge of a pollutant measured during a calendar day or any 24

- hour period that reasonably represents the calendar day for purposes of sampling. The daily discharge is calculated as the avera ge measurement of the pollutant over the day (40 CFR 122.2).

MCL (MAXIMUM CONTAMINANT LEVEL)

- are federally promulgated by the Environmental Protection Agency. These are enforceable health

- based standards

, which means the maximum permissible level for a contaminant in ground water. These values reflect the effect of certain risk management factors such as laboratory
confidence limits and economics.

MCLG (MAXIMUM CONTAMINANT LEVEL GOAL)

- are health goals for drinking

water which are set at a level at w hich no known or anticipated adverse effects on the health of persons should occur and which allows for an adequate margin of safety. These limits do not take into account treatment technology and economics as the
MCL's do.

MDL (METHOD DETECTION LIMIT)

- T he minimum concentration of a substance that can be measured and reported with 99% confidence that the analyte concentration is greater than zero and is determined from analysis of a sample in a given matrix containing the analyte. (40 CFR Part 136, Appe ndix B)

ALSO GIVEN AS: Detection Limit (DL ) : Smallest measured amount or concentration of analyte in a sample that gives rise to a Type I error tolerance of alpha underGLOSSARY (December 2011)

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- 9 the null hypothesis that the true amount or concentration of analyte in the sample is e qual to that of a blank. (The alternative hypothesis is that the true amount or concentration of analyte is greater than that of a blank).
Detection Limit (DL) : The minimum observed result such that the lower 100 (1

- α ) % confidence limit on the result is greater than the mean of the method blanks. ( Report of the Federal Advisory Committee on Detection and Quantitation Approaches and Uses in Clean Water Act Programs Submitted to the US Environmental Protection Agency December 2007 )

MGD (MILLION GALLONS P ER DAY)

- A unit of flow commonly used for wastewater discharges. One MGD is equivalent to 1.547 cubic feet/second.

MINIMUM LEVEL OF QUANTITATION (ML)

– See QUANTITATION LEVEL

MINOR PERMIT

- Any NPDES individual permit which is not a MAJOR PERMIT.

MIXI NG ZONE

- An area or a volume fraction of the receiving water , specified in a permit, which surrounds an effluent discharge point. This area is not required to

meet numeric water quality criteria but must allow passage of aquatic organisms and
not upset t he ecological balance of the receiving water. The mixing zone specifications and conditions for authorization are given in WAC 173

- 201A.

N EW D ISCHARGER

– See 40 CFR 122.2

NEW SOURCE

- Any building, structure, facility, or installation from which there i s or may be a discharge of pollutants, the construction of which commenced: (a) After promulgation of standards of performance under section 306 of CWA which are applicable to such source, or (b) After proposal of standards of performance in accordance wit h section 306 of CWA which are applicable to such source, but only if the standards are promulgated in accordance with section 306 within 120 days of their proposal (40 CFR 122.2).

NOEC (NO OBSERVED EFFECT CONCENTRATION)

- The highest measured
continuous concentration of an effluent or a toxicant that causes no observed effect on a test organism.

NONCONVENTIONAL POLLUTANTS

- Any pollutants which are not defined as CONVENTIONAL POLLUTANTS or TOXIC POLLUTANTS. Includes pollutants such as COD, nitrogen, ph osphorus, and fluoride.GLOSSARY (December 2011)

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- 10 NPDES

- National Pollutant Discharge Elimination System (Section 402 of the Clean Water Act). Permits issued under Section 402 of the Clean Water Act. The f ederal wastewater permitting system for discharges to navigable waters. T he authority for issuing these permits has been delegated to the State. NPDES permits issued by Washington permit writers are NPDES/state permits issued under both federal and
state law.

NSPS (NEW SOURCE PERFORMANCE STANDARDS)

- Effluent limitations that apply to those dischargers that qualify as new sources under 40 CFR 122.2 and
122.29.

PARTIES OF RECORD

- People who have indicated an interest in a particular permit during the public notice of application (PNOA) or public notice of draft (PNOD) and

are kept informed of progress of the pe rmit and future permit actions.

PASS THROUGH

- A discharge which exits the POTW into waters of the State in quantities or concentrations which, alone or in conjunction with a discharge or discharges from other sources, is a cause of a violation of any requirement of the POTW's NPDES permit (including an increase in the magnitude or duration of a violation), or which is a cause of a violation of State water quality standards.

PCHB (POLLUTION CONTROL HEARINGS BOARD)

- A 3

- member board appointed by the governor to hear and decide appeals of Ecology's permits and orders. See Chapter XVI of this manual and Chapter 371

- 08 WAC.

PERMIT

- An authorization, license, or equivalent control document issued by EPA or an approved sta te to implement the requirements of 40 CFR 122.2 and Parts 123 and 124. Permit includes any NPDES GENERAL permit. Permit does not include any proposed or draft permit which has not yet been the subject of public comment or EPA review, if necessary.

PERM IT, WASTEWATER DISCHARGE

- A document prepared by a permitting authority (Federal Government, State Government, Local Government) which limits the pollutants to be discharged by the holder of the permit (Permittee).

pH

- A measure of the acidity of water or wastewater. A pH of 7 is neutral , a pH less
than 7 is acidic

, and a pH greater than 7 is basic.GLOSSARY (December 2011)

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- 11 POINT SOURCE

- Any discernible, confined, and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete f ixture, container, rolling stock, concentrated animal feeding operation, vessel, or other floating craft from which pollutants are or may be discharged. This term does not include agricultural stormwater discharges and return flows from irrigated agricult ure. (See 40 CFR 122.3 for exclusions)

POLLUTANT

- Dredged soil, solid waste, incinerator residue, sewage, garbage, sewage sludge, munitions, chemical wastes, biological materials, radioactive materials, heat, wrecked or discarded equipment, rock, sand, c ellar dirt and industrial, municipal and agricultural waste discharged into water.

POLLUTANT, NON

- CONSERVATIVE

- Pollutants that are mitigated by natural biodegradation or other environmental decay or removal processes in the receiving
stream after in

- str eam mixing and dilution have occurred.

POLLUTION

- Contamination, or other alteration of the physical, chemical or biological properties, of any waters of the state, including change in temperature, taste, color, turbidity, or odor of the waters, or such discharge of any liquid, gaseous, solid, radioactive, or other substance into any waters of the state as will or is likely to create a nuisance or render such waters harmful, detrimental or injurious to the public health, safety or welfare, or to domestic, commercial, industrial, recreational, or other legitimate beneficial uses, or to livestock, wild animals, birds, fish or other aquatic life

.

POLLUTION PREVENTION

- Source reduction; or protection of natural resources by conservation; or increased efficie ncy in the use of raw materials, energy, water or
other resources.

P OTENTIAL S IGNIFICANT I NDUSTRIAL U SER

-- A potential significant industrial user is defined as an Industrial User which does not meet the criteria for a Significant Industrial User, but whic h discharges wastewater meeting one or more of the following criteria:

a. Exceeds 0.5 % of treatment plant design capacity criteria and discharges <25,000 gallons per day or;

b. Is a member of a group of similar industrial users which, taken together, ha ve the potential to cause pass through or interference at the POTW ( e.g., facilities which develop photographic film or paper, and car washes).GLOSSARY (December 2011)

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- 12 The Department may determine that a discharger initially classified as a potential significant industrial user s hould be managed as a significant industrial user.

POTW (PUBLICLY OWNED TREATMENT WORKS)

- A sewage treatment plant and the collection system (40 CFR 122.2).

PQL (PRACTICAL QUANTIFICATION LIMIT)

- is the lowest level that can be reliably achieved within specified limits of precision and accuracy during routine laboratory operating conditions.

PRECURSOR

- A substance present in effluent that is not toxic in its present form (not listed). However, a precursor could change into or react to form a toxic com pound.

PRETREATMENT

- The treatment of wastewater to remove or reduce the concentration of pollutants prior to discharge to a municipal sewage system. Pretreatment m ay denote a formal program (PRETREATMENT PROGRAM) which allows a municipality to issue pe rmits for discharges to its system under Federal and S tate authority.

PRIMARY INDUSTRY CATEGORIES

- A group of 34 industry groups for which EPA has or will develop effluent guidelines (40 CFR Part 122 Appendix A).

PRIORITY POLLUTANT (TOXIC POLLUTANT)

- A group of chemicals specifically listed in Federal Regulations and with priority for regulatory control (40 CFR 401.15).

PROCESS CONTROL MONITORING

- An internal program whereby the permittee performs intermediate checks on the plant's operations to asses s the efficiency of the

process

.

PROCESS WASTEWATER

- Any water which, during manufacturing or processing,
comes into direct contact with

, or results from

, the production or use of any raw material, intermediate product, finished product, byproduct, or wa ste product.

PROPOSED PERMIT

- A State NPDES permit prepared after the close of the public comment period (and, when applicable, any public hearing and administrative appeals) which is sent to EPA for review before fi nal issuance by the State.
A PROPOSED permit is not a DRAFT permit (40 CFR 122.2).GLOSSARY (December 2011)

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- 13 PSES (PRETREATMENT STANDARDS EXISTING SOURCE)

- Effluent limitations that apply to existing pretreatment dischargers.

PSNS (PRETREATMENT STANDARDS NEW SOURCE)

- Effluent limitations that apply to pretreatment dischargers qualifying as new sources under 40 CFR 122.2.
and 122.29.

QUANTITATION LEVEL (QL) also known as Minimum Level of Quantitation (ML)

- The lowest level at which the entire analytical system must give a recognizable signal and acceptable calibrat ion point for the analyte. It is equivalent to the concentration of the lowest calibration standard, assuming that all method

- specified sample weights, volumes, and cleanup procedures have been employed. The Q L is calculated by multiplying the MDL by 3.1 8 and rounding the result to the number nearest to (1, 2, or 5) x 10 n , where n i s an integer . (64 FR 30417).

ALSO GIVEN AS: The smallest detectable concentration of analyte greater than the Detection Limit (DL) where the accuracy (precision & bias) achiev es the objectives of the intended

purpose

. ( Report of the Federal Advisory Committee on Detection and Quantitation Approaches and Uses in Clean Water Act Programs Submitted to the US Environmental Protection Agency December 2007 )

SCHEDULE OF COMPLIANCE

- See COMPLIANCE SCHEDULE.

SECONDARY STANDARDS

- are numeric criteria within the groundwater standards designed to protect the public welfare. Limits established for those constituents will not adversely affect human health, but may affect the taste or od or of the water or cause discoloration of laundry or plumbing fixtures. Secondary standards are established for: chloride, color, copper, corrosivity, fluoride, foaming agents, iron, manganese, odor, pH, sulfate, total dissolved solids (TDS) and zinc.

SE DIMENT QUALITY STANDARDS

- These standards identify sediment chemical concentration criteria, and biological toxicity criteria which correspond to no observable acute or chronic adverse effects on biological resources, and which do not pose a significant h ealth threat to humans. The standards are used as a basis for identification of surface sediments that exceed these standards, and for limiting toxic discharges to waters of the state (WAC 173

- 204

- 010).

SELF

- MONITORING PROGRAM

- A program whereby a permi ttee is required through the NPDES permit system to maintain records and to report periodically on theGLOSSARY (December 2011)

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- 14 amount and nature of the waste components in the effluent. The required
information obtained by the Permittee’s self

- monitoring program is reported to the permitting agency using a DISCHARGE MONITORING REPORT (DMR) on a regular schedule delineated in the permit.

SEPA (STATE ENVIRONMENTAL POLICY ACT)

- A state law which requires an examination of the environmental effects of development projects. (RCW 4 3.21, Chapter 197

- 10 WAC)

SIGNIFICANT INDUSTRIAL USER (SIU)

- 1) All industrial users subject to Categorical Pretreatment Standards under 40 CFR 403.6 and 40 CFR Chapter I, Subchapter N ; and;

2) Any other industrial user that: discharges an average of 2 5,000 gallons per day or more of process wastewater to the POTW (excluding sanitary, noncontact cooling,
and boiler blow

- down wastewater); contributes a process wastestream that makes up
five percent or more of the average dry weather hydraulic or organic capacity of the POTW treatment plant; or is designated as such by the Control Authority on the basis that the industrial user has a reasonable potential for adversely affecting the POTW's operation or for violating any pretreatment standard or requirement (in accordance with 40 CFR 403.8(f)(6)).

Upon finding that the industrial user meeting the criteria in paragraph 2, above, has no reasonable potential for adversely affecting the POTW's operation or for violating any pretreatment standard or requirement, t he Control Authority may at any time, on its own initiative or in response to a petition received from an industrial user or POTW, and in accordance with 40 CFR 403.8(f)(6), determine that such industrial user is not a significant industrial user.

SINGLE SAMPLE

- (See DISCRETE SAMPLE).

SLUDGE

– Solids produced during wastewater treatment.

SOURCE REDUCTION

- Any practice which eliminates or reduces the amount or use of hazardous substances, pollutants or contaminants that enter a waste stream or are
relea sed into the environment, including fugitive emissions, prior to recycling, treatment or disposal, and thereby reduces adverse public health and environmental effects associated with the release of such substances, pollutants or contaminants

.GLOSSARY (December 2011)

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- 15 SANITARY SE WER OVERFLOW (SSO)

- Discharge of untreated sewage from a separate sanitary sewer collection system prior to the headworks of a sewage treatment plant.

STATE WASTE DISCHARGE PERMIT

- A wastewater discharge permit issued under State authority (Chapter 90.4 8 RCW) to control the discharge of pollutants to waters of the State. Generally issued for discharges to ground water and for industrial discharges to a municipal sewage system when that municipal system does not have

a delegated pretreatment program.

S T ATE W ATERS

- Lakes, rivers, ponds, streams, inland waters, underground waters, salt waters, and all other surface waters and watercourses within the jurisdiction of the state of Washington

S TORMWATER

- That portion of precipitation that does not naturally percolate into the ground or evaporate, but flows via overland flow, interflow, pipes, and other features of a storm water drainage system into a defined surface water body, or a constructed infiltration facility.

TDS

- See TOTAL DISSOLVED SOLIDS

TECHNO LOGY

- BASED EFFLUENT LIMIT

- A permit limit for a pollutant which is based on the capability of a treatment method to reduce the pollutant to a certain
concentration.

TI/RE (TOXICITY IDENTIFICATION/REDUCTION EVALUATION)

- A set of procedures to identify th e specific chemicals responsible for whole effluent toxicity.

TIERED TESTING

- Any of a series of tests that are conducted as a result of a previous test's findings.

TOTAL DISSOLVED SOLIDS (TDS)

- The material in water or wastewater that passes through a glass fiber filter. TDS is measured by Method 2540 C in Standard
Methods.

TOTAL MAXIMUM DAILY LOAD (TMDL)

- A determination of the amount of pollutant that a water body can receive and still meet water quality standards.GLOSSARY (December 2011)

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- 16 TOXIC

- Causing death, disease, behavioral abnormalities, cancer, genetic mutations, physiological malfunctions (including malfunctions in reproduction), or physical deformations in any organism or its offspring upon exposure, ingestion, inhalation,
or assimilation.

TOXIC POLLUTANT

- T hose pollutants, or combinations of pollutants, including
disease

- causing agents, which after discharge and upon exposure, ingestion, inhalation or assimilation into any organism, either directly from the environment or indirectly by ingestion through food chains, will, on the basis of information available to the Administrator, cause death, disease, behavioral abnormalities, cancer, genetic mutations, physiological malfunctions (including malfunctions in reproduction) or physical deformations, in such orga nisms or their offspring. (listed at 40 CFR 401.15).

TOXIC SUBSTANCE (TOXICANT or TOXICS)

- Poison or substance, which if present in sufficient quantity or concentration, is capable of producing a toxic response in a native or test organism.

TOXICITY

- T he quality or state of being TOXIC.

TOXICITY TEST

- A procedure to determine the toxicity of a chemical or an effluent using living organisms. A toxicity test measures the degree of effect a specific chemical or effluent has on exposed test organisms.

T RE (TOXICITY REDUCTION EVALUATION)

- A site

- specific study conducted in a stepwise process designed to iden tify the causative agents of effluent toxicity, isolate the sources of toxicity, evaluate the effectiveness of toxicity control options, and
then co nfirm the reduction in effluent toxicity.

TSD

- Abbreviation for Technical Support Document for water quality

- based toxics control (EPA/505/2

- 90

- 001), or

An a bbreviation for a facility which recycles, reuses, reclaims, transfers , stores, treats, or dispos es of dangerous wastes as defined in WAC 173

- 303.

TSS (TOTAL SUSPENDED SOLIDS)

- Particulates in water or wastewater retained by a glass fiber filter. TSS is measured by tests as given in 40 CFR Part 136 and
referenced as Residue

- nonfilterable (TSS) or as given in Standard Methods (17th ed.) method 2540 D.GLOSSARY (December 2011)

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- 17 TTO (TOTAL TOXIC ORGANICS)

- Organic chemicals listed within a specific category of discharge (such as electroplating Part 413). TTO is the summation of all quantifiable values of the organic chemica ls greater than 0.01 milligrams per liter.

U PSET

- An exceptional incident in which there is unintentional and temporary noncompliance with technology

- based permit effluent limitations because of factors beyond the reasonable control of the Permittee. An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, lack of preventative maintenance, or careless or improper operation.

WASTELOAD ALLOCATION (WLA)

- Within a TMDL, the allocation for point sources of a pollutant

. For an individual water quality

- based effluent limit, the WLA
is the numeric water quality criteria times the dilution factor.

WATER QUALITY

- BASED EFFLUENT LIMIT

- A permit limit for a pollutant which
limits the concentratio n such that it will not cause a violation of water quality
standards. The limit may include a dilution factor if AKART has been determined
and other restrictions are met.

WATER QUALITY STANDARDS

- Numerical and narrative criteria to protect the
beneficia l uses of the States' waters. Includes conventional and toxic pollutants. (Chapter 173

- 201A WAC)

WET (WHOLE EFFLUENT TOXICITY)

- The total toxic effect of an effluent measured directly with a toxicity test so that the interaction of all toxicants prese nt in the
effluent are assessed.GLOSSARY (December 2011)

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- 18 This page is purposely left blankCHAPTER I. INTRODUCTION (JULY 2011)

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- 1 

# CHAPTER I. INTRODUCTION

This manual is a technical guidance and policy manual for permit writers who develop wastewater discharge permits in Washington State. Developing this manual was specified as task element P5 in the 1987 Puget Sound Water Quality Management plan and subsequent amendments. Maintenance and improvement of the manual is recommended in the final report of the Commission for Efficiency and Accountability in Governme nt (1990).

The first version of this manual was issued in June, 1989. A 23

- member advisory committee assisted the Department of Ecology (Ecology) for one year on policy issues identified in the manual. The advisory committee represented those interested in wastewater permits. An internal work group also assisted in the development of this manual.

The primary purposes of this manual are to enhance the quality and consistency of the wastewater discharge permits issued by Ecology and to improve the effici ency of the permitting

process.



## 1. OBJECTIVES AND FUNCTIONS

The specific objectives and functions of this permit writer's manual are to:

Briefly review the legal history of wastewater permitting to provide permit writers with a perspective on their role.

Define the requirements for permits in Washington. This manual integrates state and federal law, state and federal regulation and Ecology implementation policies. Permits reviewed for 401(a) certification must be consistent with procedures in this manu al.

Ensure statewide consistency in permitting, especially for permits which require best professional judgment (BPJ) determinations.

Identify state and federal laws, regulations and policies relating to permitting.

Identify legal opinions of the Attorn ey General's Offices, rulings of the Pollution Control Hearing Board and rulings of other courts on permitting and permit related issues.

Gather collective knowledge of Ecology on permit writing.

Provide a central document to place new information, guida nce, and requirements related to permitting.CHAPTER I. INTRODUCTION (JULY 2011)

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- 2 Serve as a reference for experienced permit writers.

Train new permit writers. This manual is identified in the Permit Writers Training Strategy as a component of training for new permit writers. The manual will reduce the training time for new permit writers and the demand on experienced permit writers to train new permit writers.

Demonstrate to the regulated community and other interested public what the agency does in permitting a wastewater discharge.

T his manual is a technical and philosophical compendium of the experienced permit writers in Ecology

.

The manual is expected to be revised annually and therefore has been placed in a loose leaf
format to facilitate revision. Revisions or additions to the manual may occasionally be made
between annual revisions. These revisions and additions will be sent with a transmittal cover memo from the Program Manager explaining the need for revision and where the text is to be placed in the manual.



## 2. FORMAT FOLLO WS PROCESS

The manual's format follows the process of developing a wastewater discharge permit. Because of the complexity of the permitting process it is impossible to completely separate functions chronologically. For example, the public involvement cha pter is one of the later chapters in the manual because historically public involvement occurred after the permit conditions were drafted. Public involvement now begins upon permit application

.

In preparing the manual, we borrowed materials freely from E PA and from other states when appropriate. These materials are cited in the reference section. They are available from the Ecology library and on the Internet.



## 2.1 Other References

The new permit writer should read and have on hand some reference docume nts related to permitting. Specifically, the permit writer should have access to w ater p ollution l aws and

r egulations, the Code of Federal Regulations dealing with environmental regulation (40 CFR
Parts 100

- 149 and 400

- 471), and a current copy of the Clea n Water Act. The permit writer should read Chapters 173

- 220, 173

- 216 WAC and study Chapter 90.48 RCW. The Technical Support Document for Water Quality

- based Toxics Control (EPA 505/2

- 90

- 001) is required background reading for Chapters VI and VII.CHAPTER I. INTRODUCTION (JULY 2011)

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- 3 

## 3. SCO PE

The scope of this manual includes:



### • Joint State/NPDES permits as issued under Chapter 90.48 RCW and the Federal Water
Pollution Control Act.



### • Municipal wastewater treatment plants



### • Industrial/Commercial Facilities



### • General Permits



### • State waste discharge permits as issued under 90.48 RCW.



### • Discharges to groundwater



### • Discharges to municipal sanitary sewer systems as part of the state wide (undelegated) pretreatment program.



## 4. INSPECTIONS AND ENFORCEMENT

The issuance of a wastewater discharge permit leads to subsequent regulatory activities including inspections and enforcement. Guidance for those functions is provided in the Inspection Manual ( Ecology 92

- 76 ) and the Compliance Assurance M anual ( posted on the Intranet, under the Resources tab, Investigati ons, Compliance, and Docket Numbers )

.



## 5. NOT REGULATION

This manual is not regulation and should not be cited as regulatory authority for any permit condition. This manual describes law and regulation pertaining to permitting. These laws and regulations must be followed to issue a legal permit. Where those laws and regulations are not explicit on implementation the manual describes a process for implementation

. This process is a program decision (policy) for implementing the laws and regulations and ty pically has been subject to debate by permit writers and management. If the process does not fit a permitting circumstance, the permit writer can explore alternative processes as long as the law and regulation are met. Alternative processes require secti on supervisor app roval prior to implementation.CHAPTER I. INTRODUCTION (JULY 2011)

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- 4 

## 6. A SHORT HISTORY LESSON

The point source water pollution control program in this state is based on both Federal and State law which evolved concurrently. The state of Washington began a formal pollution

c ontrol program in 1945 with the creation of the Pollution Control Commission and enactment of RCW 90.48. The law did not allow strong enforcement. Pollution control was a negotiation process and required the state to demonstrate a water pollution problem and assign the cause of that pr oblem to a specific discharger.

In 1948 the federal government passed the Water Pollution Control Act (PL 80

- 845)

. This law provided some funds for the design of municipal wastewater treatment plants and for study of water pollution problems. This law also required the U.S. Surgeon General, in cooperation with the states, to develop water pollution control programs for interstate

waters. The Federal Water Pollution Control Act of 1956 (PL 84

- 660) and its 1961 amendments ( PL 87

- 88) established federal grants for construction of municipal treatment plants.

The Water Quality Act of 1965 (PL 89

- 234) required states to adopt water quality standards for interstate waters and created a small agency, the Federal Water Pollution C ontrol Administration ( FWPCA). These federal laws generally required the states or federal government to demonstrate that a water quality problem had implications for human health or violated water quality standards. Enforcement was minimal because the b urden of proof lay with the agencies: they had to demonstrate a direct link between a discharge and a water quality problem before enforcing on a discharger.

Meanwhile, Washington had adopted a waste water discharge permit system in 1955 (Chapter 90.48 RC W). This permit system was apparently not very effective in controlling pollution problems because in 1961 Washington requested assistance of the FWPCA in solving the problems with pulp mill discharges.

Increasing water pollution became apparent in the m id

- 1960's. Existing laws were not solving the problems. Two examples that reinforced this impression were Lake Erie, which suffered from severe eutrophication and toxic discharges, and the Cuyahoga River, which caught fire on several occasions. The Fede ral Government responded in 1970 by instituting a discharge permit system based on the authority of the Rivers and Harbors Act of 1899. This system was ineffective because it rapidly got tied up in litigation but it indicated
increased Federal interest in controlling wastewater discharges by means of a permit system.

In 1971, the State of Washington enacted legislation which required dischargers to use, "all known, available, and reasonable methods of treatment prior to", discharge regardless of the quali ty of the water to which the wastes are discharged. This law, the Pollution Disclosure Act of 1971 (Chapter 90.52 RCW), signaled a change of philosophy in water pollution law.CHAPTER I. INTRODUCTION (JULY 2011)

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- 5 Instead of trying to assign responsibility for water pollution problems to par ticular dischargers, the state would require that all dischargers provide a high level of wastewater treatment regardless of the quality of water to which they discharged (technology

- based control).



## 7. THE CLEAN WATER ACT

The Federal Government, in 1972, also adopted this philosophy of technology based pollution control when it enacted the Federal Water Pollution Control Act Amendments of 1972 (PL 92

- 500). Despite the name of the law, it was essentially a new law. Since 1977,
the law and its revisions ha ve been popularly called the Clean Water Act (CWA or the Act). This law, in conjunction with our state laws, forms the basis and framework for our water quality regulatory program today. The objective of the law was, "to restore and maintain the
chemical , physical, and biological integrity of the Nation's waters."

The Clean Water Act lists several goals and policies in Section 101 which show the Congressional intent for the Act. The best known is the goal that, "discharge of pollutants into navigable wa ters be eliminated by 1985." This goal wasn't reached, of course, but it still should be used as a principle for permitting. The Act had an interim goal for July 1, 1983: "water quality which provides for the protection and propagation of fish, shellfish

, and wildlife and provides for recreation in and on the water". This is known as the, "fishable, swimmable" goal.

Congress also recognized the issue of toxics and declared it "national policy that discharge of toxic pollutants in toxic amounts be prohib ited".

Other policies in the Act addressed Federal financial assistance, area wide waste management plans, research and demonstration projects.

The Act also contains 4 important principles:



### • Discharge of pollutants to navigable waters is not a right. A p ermit is required to use public resources for wastewater disposal.



### • The discharge permit limits the amount of pollutants to be discharged.



### • Wastewater must be treated with the best treatment technology which is economically
achievable

-- regardless of the co ndition of the receiving water.



### • Effluent limits are based on treatment technology but more stringent limits may be imposed if the technology

- based limits do not prevent violations of water quality standards in the receiving water.CHAPTER I. INTRODUCTION (JULY 2011)

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- 6 More specifically, the Act created a system for permitting wastewater discharges (Sec tion 402)

. This system is known as the National Pollutant Discharge Elimination System (NPDES)

. The objective of this system is to implement the goals and policies of the Act.

Section 306 pro vided for the creation of federal standards of performance for wastewater treatment. This eventually resulted in effluent guidelines for major categories of industries.

Enforcement is provided in Section 309 of the Act. Both procedures and penalty amoun ts were explicitly stated. This strong enforcement language was also a major departure from previous legislation.

In 1973, Washington State's water pollution control law (Chapter 90.48 RCW) was amended to enable the state to apply to EPA for authority to administer the NPDES program

. In November of 1973, Washington became one of the first states to be delegated the NPDES

program.

Congress amended the Clean Water Act in 1977, 1981, and 1987. In 1977 the construction grants program was reauthorized, and Congress clarified its intent and focus for toxic pollutants. The categories of conventional and toxic pollutants were defined. The 1987 amendments created a schedule to end the federal commitment to the construction grant program, addressed storm water permits, water quality problems due to toxics, and sludge management. The major philosophical change in these latest amendments is a greater emphasis on water quality based permitting for toxic pollutants. This assumed that all permits now comply with te chnology based requirements.



## 8. TECHNOLOGY

- BASED CONTROL

The permit writer should recognize that the environmental gains in point source pollution in this country in the 1970's and 1980's were largely due to the imposition of technology based
control and it remains the basis for both Federal and State law. There has been some discussion recently about utilizing the assimilative capacity of receiving waters to reduce the cost of wastewater treatment. This contradicts the legislative principles in the Clea n Water Act and Chapter 90.48 RCW. Legislative and Congressional Policy recognizes that a manageable and equitable clean water program requires a technology based program even though the treatment might be greater than required to meet water quality stand ards. Our stated public policy is to maintain the highest possible purity of public waters by minimizing pollutant discharges to the extent practicable

-- as opposed to allowing the maximum tolerable level of pollutant discharge.

Federal legislators also a dopted a goal of total elimination of the discharge of processCHAPTER I. INTRODUCTION (JULY 2011)

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- 7 pollutants. The time stated for achieving the goal has passed but the language remained through several major amendments to the Act. This "zero discharge" goal obviously requires treatment in excess of that necessary to meet water quality standards.

There is no regulatory mechanism in this state for limiting the number of dischargers on a water body until the cumulative effect of the pollutants cause an interference with a designated use of t hat water, in other words, a violation of water quality standards. Requiring technology based treatment, even though the treatment exceeds the requirements necessary to meet the water quality standards, may continually reduce the pollutant load from any s ource and postpone the necessity of allocating the waste load from each discharge to assure meeting water quality standards.

The technology based approach also functions as a buffer for our incomplete understanding of the fate and effects of pollutants.

For further discussion of the legal and regulatory background of the permit program see Bellingham v. Ecology PCHB No. 84

- 211, and the Clean Water Act of 1987 published by the Water Pollution Control Federation in 1987.



## 9. WATER QUALITY BASED CONTROL

The 1987 CWA and subsequent regulation clarified an earlier principle of the CWA. The principle is that when there is determined, by scientifically valid methods, to be a potential for the violation of the water quality standards from a discharge, then that d ischarge must
receive effluent limits. The effluent limits are to assure the effluent does not cause a violation of the water quality standards. The law does not require 100% certainty but requires a judgment of reasonable potential based on a rational p rocess in order to impose
limitations.



## 10. PERMIT WRITERS IMPLEMENT THESE LAWS AND REGULATIONS

The permit writers in the Department of Ecology are primarily located in the four regional
offices

, the Industrial Section and the Program Development Section

. Permit writers are engineers or environmental scientists. The regional staff is responsible for both industrial and municipal permits. The Industrial Section writes permits for the largest industrial dischargers such as pulp mills, petroleum refineries and aluminum smelters

. The Program Development Section primarily develops general permits.

Permit writers are actually point source pollution control managers with multipleCHAPTER I. INTRODUCTION (JULY 2011)

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- 8 responsibilities, therefore the terms permit writer and permit manager are used
i nterchangeably in this manual.

Permit writers represent the people of the state and the country in limiting the amount of pollutants discharged from point source discharges. They must exercise a considerable amount of discretional authority.

Permit writ ers should expect to receive criticism from all groups interested in the permit program. Environmental groups often charge Ecology permit writers with not writing strong enough permits, for not keeping permits current and for not enforcing on permits.
Th e regulated community often charges that permit requirements are unnecessary, overly stringent, and expensive.

Permit writers have a large amount of authority and responsibility, and this demands the exercise of good judgment . A good permit writer needs some things that are not in this manual, such as a strong commitment to the Department's mission, an internal sense of self
worth and self satisfaction , confidence, and a good sense of humor to make it through the
white water of the Water Quality permit pr ogram

.



## 11. PERMIT TOOLS

The Water Quality Program and the Environmental Assessment Program have developed several tools to assist permit writers. These tools include model permit language, model fact sheet language and spreadsheets for doing the calculat ions for water quality

- based permitting. These tools are available for permit writers from the Program Development Services Section and are available in Outlook. The spreadsheets and permit shells are
located at Outlook/Public Folders/All Public Folders/ ECY/Water Quality Shells/. The spreadsheets are also available to the public through the Ecology home page on the Internet

at www.ecy.wa.gov/programs/eap/pwspread/pwspread.html

.CHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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# CHA PTER II. AN OVERVIEW OF THE PERMITTING PROCESS

This chapter presents an overview of the several kinds of wastewater permits required in Washington State, the permitting process, and permit modification. The regulatory view of a permit and the components of a permit are described

. The process of writing a permit is described briefly in text and illustrated by the use of flow charts. The tasks identified within the flow charts are described in detail in subsequent chapters.



## 1. WHAT TYPE OF WASTEWATER DISC HARGE
PERMIT?

In Washington State anyone discharging wastewater (including contaminated stormwater) must have a wastewater discharge permit. There are 3 types of wastewater discharge permits:
1 ) State Waste Discharge Permit ; 2 ) NPDES/State Wastewater Disc harge Permit ; and
3 ) General Permit.



## 1.1 State Waste water Discharge Permit

A State Waste Discharge Permit is required for a discharge of wastewater to waters of the state which includes groundwater. A state waste discharge permit is also required for any industrial or commercial operators discharging solid or liquid waste material into sewerage systems operated by municipalities or public entities which in turn discharge to waters of the state. This permit is issued under authority of Chapter 90.48 RCW. A State Waste Discharge Permit is valid for a maximum of 5 years. An applicant for a State Waste Discharge Permit may receive a Temporary State Waste Discharge Permit if Ecology fails to act upon a complete application for a period of sixty days

. A tempo rary state waste discharge permit is valid for 5 years or until Ecology issues a state waste discharge permit. A temporary state waste discharge permit authorizes discharge as requested in the permit application. A facility covered under a temporary stat e waste discharge permit must reapply at least 60 days prior to expiration of the temporary permit.



## 1.2 NPDES Waste water Discharge Permit

An NPDES Permit is required for a discharge of wastewater to waters of the U.S (surface waters). This permit is issue d by Ecology by delegated authority of the Clean Water Act. Since waters of the U.S. are also waters of the state, NPDES permits are actually NPDES/State permits issued under dual authorities. NPDES permits are issued for a maximum of 5 years. Temporary permits are not allowed under the Clean Water Act.CHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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## 1.3 General Waste water Discharge Permit

General permits are wastewater discharge permits that are developed for a category of discharger instead of an individual facility. General permits may be issued u nder federal (NPDES) or State authority. General permits are issued for 5 years. Facilities which are eligible for coverage under the permit apply for coverage and then are covered for the remaining length of the permit.


## 1.4 Hydraulic Continuity

Permit w riters

, in some cases

, must decide if the discharge of a pollutant onto the ground near a surface water is subject to an NPDES permit or State Waste discharge permit. Ecology believes the best guidance on this issue comes from the United States District C ourt Eastern District of Washington (Washington Wilderness Coalition v. Hecla Mining, 870 F. Supp 983, 990). The court held that “since the goal of the CWA is to protect the quality of surface waters, any pollutant which enters such waters, whether directl y or through groundwater, is subject to regulation by NPDES permit.” The court went on to hold, “[I]t is not sufficient to allege groundwater pollution, and then to assert a general hydrological connection between all waters

. Rather, pollutants must be t raced from their source to surface waters, in order to come within the purview of the CWA.”

The decision on hydraulic continuity is dependent upon the pollutant (type and mobility in soils), the pollutant loading, the soils at the site, and the hydrology of the site. At sites where it is difficult to make a determination, a permit writer should require , by order, a discharger to do appropriate monitoring and analysis to determine whether pollutants discharged to the ground (water) can be traced to surface water. Ground water monitoring or other monitoring that will substantiate the analysis should be required.



## 2. WHAT IS A WASTEWATER DISCHARGE PERMIT?

In its simplest conceptual meaning a wastewater discharge permit is a legal document issued by a regulato ry body that allows some entity to discharge wastewater. In reality, a wastewater discharge permit represents a complex regulatory program that incorporates hundreds of legal, engineering, and scientific decisions. A simple permit may be just a few pages long but a complex permit may be dozens of pages. A permit package which would give a reviewer a complete picture of the discharge consists of the application, the permit, and the fact sheet

. The permit application documentation gives the permit writer most of the information necessary to produce the permit. The application requirements and detailed process are given in Chapter III. The body of the permit has 3 distinct components:



### • The cover page gives the name and location of the facility;



### • The efflue nt limitations, monitoring requirements and other special conditions are in the main body of the permit and are derived for each individual permit or general permit;CHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 3 

### • The general conditions are the last several pages of the permit.

Derivation of effluent limits, monitoring requirements and special conditions in permits is covered in detail in Chapters IV through XIII.

The general conditions, sometimes called standard conditions, are exactly the same within each category of permit. General conditions come directly from federal or state law or regulation or court interpretations of those laws and regulations. They are not subject to change by the permit
writer. Some general conditions may not be applicable to some Permittees because of the
circumstance of their discharge but they are not removed from the permit. State wastewater discharge permits for discharge to ground water have different general conditions from wastewater discharge permits for discharge to surface water.

The fact sheet describes the d ischarge, the regulatory basis of the permit, and the decisions made on the permit. The requirements of the fact sheet and a fact sheet check list are given in Chapter
XIV.

Permits are generally issued for the regulatory maximum period of 5 years. The p ermit writer may have occasion to issue a permit for less than 5 years and nothing prohibits this although dischargers generally prefer a 5

- year permit. Permits may be administratively extended past their expiration date for a period of five years if an a pplication for renewal has been properly submitted. The conditions of an extended permit remain in effect and are enforceable. A n extended permit may not be modified.



## 3. THE PERMITTING PROCESS

The major components of wastewater discharge permitting are i llustrated in Figure II

- 1. After receiving the application and making a decision to proceed on a permit, the permit writer reviews the application for completeness and accuracy. When the application is complete the permit writer derives the technology

- ba sed effluent limits. This is the core of the permit writer's task. Permit writers must always calculate technology

- based effluent limits because they may be more stringent than water quality

- based limits. The technology

- based effluent limits are compare d with effluent limits which are protective of surface or ground water or sediment quality standards (water quality

- based limits). The more stringent of the two is placed in the permit. The effluent monitoring requirements and other conditions are placed in the permit. This proposed permit and fact sheet are reviewed internally, by the permittee and the public, and the permit is subsequently issued as a final permit.

The permitting process is illustrated in more detail in Figure II

- 2. This flow chart i llustrates that the major steps of Figure II

- 1 are actually multistep processes. For example, the task of deriving technology

- based effluent limits is separated into BCT, BAT, BPJ and AKART. Figure II

- 2 alsoCHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 4 functions as an index to later chapters becaus e the sidebars list later chapters where the processes
are discussed.CHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 5 Figure II

- 1. Overview of the major components of the permitting process for all dischargers.

Receive Application

Review Application for Completeness and Accuracy

Derive Technology-based Effluent Limits

Will Effluent Cause Violation of Water Quality Standards with Technology-based Limits?

Derive Effluent Limits Necessary to Meet Water Quality Standards

Derive Monitoring Requirements

and Other Special Conditions

Conduct Review Process for Draft or Proposed Permit

Issue Final Permit yes

noCHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 6 Figure II

- 2. The permitting process for industrial dischargers.

IS APPLICANT A NEW SOURCE? REQUIRE ENGINEERING REPORT OR SUPPLEMENTAL INFORMATION THROUGH SEPA

REVIEW PERMIT

APPLICATION IS REPORT COMPLETE?

IS APPLICATION

COMPLETE? REQUEST NEW APPLICATION OR SUPPLEMENTAL INFORMATION

START PUBLIC NOTICE REVIEW BACKGROUND INFORMATION INSPECT EXISTING SOURCE

ARE COMPILED DATA ADEQUATE TO BEGIN PERMIT? REQUEST SUPPLEMENTAL INFORMATION

ARE CONVENTIONAL

POLLUTANTS

PRESENT? ARE BCT EFFLUENT GUIDELINES AVAILABLE?

DO BCT GUIDELINES MEET AKART? DEVELOP BCT LIMITS BY BPJ

USE BCT GUIDELINES DOES THE FACILITY HAVE KNOWN, PROBABLE, OR POTENTIAL PROBLEMS WITH SURFACE RUNOFF, SPILLS, OR LEAKS OF POLLUTANTS OR ARE HAZARDOUS WASTES STORED OR DISPOSED ON SITE?

ARE TOXIC POLLUTANTS PRESENT IN THE

EFFLUENT? REQUIRE A POLLUTION PREVENTION PLAN OR DEVELOP SPECIFIC BMPs GO TO A

GO TO B YES

NO

NO YES

NO

YES

NO

YES

YES

NO YES NO

YES NO

YES

NO CHAPTERS II AND III

CHAPTER IV

CHAPTER XIICHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

Per mit Writer’s Manual
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- 7 Figure II

- 2. ( Cont inued)

A

SELECT TOXIC POLLUTANTS TO

BE LIMITED ARE BAT GUIDELINES AVAILABLE FOR TOXICS? DEVELOP BAT LIMITS BY BPJ/AKART

DO THE BAT GUIDELINES MEET AKART? USE THE BAT GUIDELINES

ARE NONCONVENTIONAL POLLUTANTS PRESENT IN THE EFFLUENT?

ARE BAT GUIDELINES AVAILABLE FOR NONCONVENTIONALS?

DO THE BAT GUIDELINES MEET AKART?

DEVELOP BAT LIMITS BY BPJ/AKART

PERFORM WATER QUALITY MODELING AND REASONABLE POTENTIAL DETERMINATION WITH BCT/BAT/AKART LIMITS AND WET DATA USE BAT GUIDELINES

ARE ALL WATER QUALITY STANDARDS MET?

DEVELOP SPECIAL CONDITIONS

DEVELOP MONITORING REQUIREMENTS

PREPARE FACT

SHEET AND SUPPORTING DOCUMENTATION DRAFT PERMIT COMPLETE COMPLETE REVIEW AND

ISSUANCE PROCESS DEVELOP WATER QUALITY-BASED LIMITS YES NO

YES

NO YES

NO

NO YES

CHAPTERS XIVXVI CHAPTER XIII CHAPTER XII CHAPTERS VI - VII

CHAPTER IV YES NO NO

YES

BCHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 8 

## 4. MODIFICATION OF PERMITS

A permit modification may involve many of the same processes as developing a new permit. A term that has become synonymous with permit modification is “reopening the permit”. Permit
modifications m ay be initiated by Ecology, by the permittee, by the Pollution Control Hearings Board (PCHB), or by the public. Ecology may modify the permit for any of the causes listed in 40 CFR 122.62. Typically, Ecology modifies permits because of alterations of the facility (122.62 (a)(1)) or because of new information (122.62 (a)(2)) such as the effluent causing a violation of water quality standards

. Other causes for modification are listed in 122.62.

If the permittee or the public wants the permit modified, the y submit a letter to Ecology requesting
the modification and the reason for the request . Ecology may proceed with the modification as requested

, or not act on the request . When a permit is modified by Ecology, those portions of the permit that are modifi ed are subject to appeal to the PCHB

.

When the PCHB requests a permit modification, it is the result of a permit appeal and the PCHB remands the permit back to Ecology for change.

A permit modification may be minor or major. The definition of minor modi fication is found in 40 CFR 122.63. A permit modification is minor if it:



## • Corrects typographical errors ;



## • Requires more frequent monitoring or reporting ;



## • Changes an interim compliance date in a compliance schedule, provided the new date is
no more than 120 days later and it doesn't affect the final compliance date ;



## • Allows for a change of ownership or control of a facility ;



## • Changes the construction schedule for a new source discharger ;



## • Deletes a point source outfall when the discharge from that outfall stops, provided it doesn't cause a change at the other outfall(s) ; or ,



## • Incorporates conditions of a POTW pretreatment program if the pretreatment program has been subject to public hearing.CHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 9 Minor modifications do not require public notice but the modif ications should be sent to the parties of record. Any permit modification which goes beyond the above circumstances is a major modification and has the same requirements as a permit renewal including the public notice requirements. Modification does not change the expiration date of the permit.

A permit writer should consider revocation and reissuance of a permit when a major modification is required in order to extend the time until renewal. Anytime a permit is modified it may be revoked and reissued i f the permittee agrees. Regulations (40 CFR 122.64) allow a permit to be revoked and reissued without permittee agreement for any of the following causes:



## • Noncompliance with the permit



## • Misrepresentation or failure to disclose facts during application of the permit,



## • Discovery that the discharge is endangering human health or the environment,



## • A change in any condition that requires either a temporary or permanent reduction or elimination of any discharge or sludge use or disposal practice controlled by t he permit (for example, plant closure or termination of discharge by connection to a POTW).

When a permit is revoked and reissued the whole of the permit may be appealed.



## 5. GENERAL PERMITS

- NEW AND RENEWAL

General permits are NPDES/state or state wastew ater discharge permits that are developed for a category of discharger instead of an individual facility. General permits may be cost effective because of the large numbers of facilities that can be covered rapidly with a general permit. When deciding wh ether to do a general permit, consider the following:



## • Are there a large number of facilities to be covered?



## • Do they have similar production processes?



## • Do they have similar process pollutants?



## • Do es only a small percentage have a potential for water qual ity standards violations?

The decision to d evelop or reissue a general permit is made after section or program deliberationCHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 10 and a program management decision.



## 6. THE GENERAL PERMIT DEVELOPMENT PROCESS

The regulation covering general permits is Chapter 17 3

- 226 WAC. Many of the federal regulations in 40 CFR 122 and 125 are also applicable to NPDES general permits. The following is the step

- by

- step process for developing a general permit.

For a New general permi t

• Identify a category of dischargers for the development of a general permit. The permitting section and the Water Quality Program must concur on the development of the permit.

• Post a public notice of the department's intent to develop a general permit.

The scope of this public notice is largely left up to the permit manager, but must be done so as to inform interested and potentially affected persons.

All persons who express an interest in the permit may request to be placed on a mailing list to receive notices of the draft and final permit.

St art another mailing list. The list could be the same as the permit list above, or it could be composed of the existing regional "interested persons" mailing list s , or a new list specific to each general permit. The list will consist of people who want to know who is being covered under the general permit.

If Ecology decides not to develop a general permit after the public notice of intent to issue a general permit, then Ecology will publish a notice to that effect.

For New and Reissued General Permits



### • C haracterize the wastewater

– This may require EAP participation or issuance of
administrative orders if components of the wastewater are unknown.



### • Assemble the internal workgroup and, if necessary, a stakeholder advisory group

.



### • Start a web page for the perm it if there isn’t an existing page

. This page should be started shortly after the formation of the external advisory group. This page should tell people the process for renewal has started and if people want to be on a mail list for information to

contac t us. The people on this mail list must be notified when a draft permit is available.



### • Draft the application for coverage (if necessary), the g eneral permit, and the fact sheet.

The application for coverage becomes a problem when a permit is being renewed and it is determined that additional information is needed from existing Permittees ( the existing application form is inadequate ) . Existing Permittees must submit a renewal application priorCHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 11 to expiration of the existing general permit and the recommenda tion is to send out a renewal notice 12 months prior to expiration of the existing general permit. Applications must be received by Ecology at least 180 days prior to expiration of the general permit

. If the permit
is not re

- issued before expiration, onl y those Permittees who have submitted timely application will be covered in the interim and be deemed “existing discharger” for regulatory purposes. At the time the reapplication notice is sent, the permit development may be still formative and the inform ation requirements not known. The recommendation, in this case, is to continue development of the new application with development of the permit and request the new information as an order to existing Permittees at the time of issuance of coverage.

The t erms and conditions of a general permit are similar to those in an individual permit , and are developed in manner similar to the terms and conditions contained in an individual permit

. The process includes, at a minimum, characterization of pollutants in the wastewater and the development of technology

- based effluent limitations. Technology

based limitations in general permits may be the require ment for best management practices (BMPs). The Antidegradation Plan must be addressed in the fact sheet.

A fac t sheet is drafted on the general permit only, fact sheets will not be written for the facilities requesting coverage under a general permit. Antidegradation analysis is not required for individual coverages under a general permit.



### • Prepare a small busine ss economic impact analysis (SBEIS) on the general permit if required. Contact the Rules Unit early in permit development for assistance with the SBEIS

.

• A separate application for coverage will be developed for each new general permit. For renewal of ge neral permits the existing application should be reviewed for suitability and revised if necessary

.



### • For NPDES and combined NPDES / state waste discharge general permits only, the draft general permit, fact sheet and application for coverage must be submitte d to EPA for a 90

- day review. EPA does not review general permits issued solely under State authority.



### • Complete a public notice, fact sheet, and the revised application for coverage (if necessary)

. The public notice of the draft general permit includes:

- Publication of a short summary of the permit and the small business economic impact

statement in the state register.

- For new type of general permit with state

- wide coverage

, publish in the state register

and on the appropriate Ecology web page and consider p ublication of a notice in, at least, f ive local newspapers

. If the new general permit covers a category of dischargersCHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 12 which is highly localized, publication of notice in the major newspapers of one region may be sufficient. For renewals, plac e notice in the state register and on the Internet.

- Send individual notices of draft to the “interested persons” mailing list and “required”

governmental agencies and all tribes

. This mailing list and newspaper receipts must be saved as part of the pe rmit record.



### • Hold a minimum of one public hearing on the proposed general permit within the area covered by the general permit. Although only one public hearing is required, three or four hearings are recommended for a new type of state

- wide general perm it.



### • After the close of the public comment period, prepare a response to comments and make any required changes to the permit as a result of comments received on the general permit. The response to comments documentation must note where significant change s were made in the draft permit as a result of comments. This may be done as a separate summary section or by highlighting the response that notes a change in the draft permit. The response to comments
becomes an attachment to the fact sheet. The respon se to comments may also be published as a separate document

.



### • A public notice must be completed for the issuance of all general permits. A general permit is issued when signed by the program manager or appropriate regional water quality section
head. Pub lic notice of the issuance of a general permit must be done in a manner similar to the public notice of the draft permit, including publication in the state register.



### • A general permit may become effect ive 31 days after a notice of the issuance of the gene ral permit is published in the state register. The effective date should be set with consideration of the monitoring requirements of the permit and the Ecology permit data system.



### • If the reissued permit is significantly different than the previous permit then consider conducting state

- wide workshops on the permit.



### • Applications for new coverage under a general permit:

May be submitted any time following the public notice of the draft general permit, or at a later date as specified by the department.

Gen erally, d o not require public notice from facilities previously covered under the permit unless the facility has an increase in volume or a change in the character of the
effluent. A new application form may require that existing facilities may have to re apply

or provide additional information.CHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 13 

### • Coverage under a general permit is automatic on the latter of the following:

The effective date of the permit;

31 days following the end of any public notice and public comment period on an application for covera ge under the general permit;

31 days after receipt of a completed application for coverage; or

,

A date specified in the general permit.



### • Periodically, a list of facilities which have requested coverage under the general permit must be mailed out to peopl e who have expressed an interest in who is being cov ered under the general permit. Alternatively, the list may be posted on the web site for the general permit. The frequency for listing these facilities should be proportional to the number of applicants but should not be less than once a year. This listing is not required when the public gains access to our permit data system.

All of the requirements above must be documented and placed in the permit file. This includes
documentation of mail outs , publ ic notices and transmittal letter s to EPA and other required government agencies

.CHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 14 Figure II

- 3. General Permit Process GENERAL PERMITS PROCESS ( REISSUE )

Form Internal Team and Stakeholder Advisory Group

. Post reissue notice on web site

. 18 Months before expiration

Identify problem areas of current permit

. Review expected water quality impacts

, AKART and DMR data if available

. Write summary issue paper

. Identify expected direction of renewed permit

. Draft revised application form if necessary

. First meeting of Internal Team

– Discuss ground rules

, issues and problems

.

Send renewal notice to all existing permittees 12 Months before permit expiration

First meeting of stakeholders

. Introductions

, history of permit

, and presentation of summary issues

. Document issues as presented by stakeholders .( Invite the internal
team ). Start the permit web page

Meeting of Internal Permit Team to review stakeholder views and concerns

Permit writer prepares draft permit and fact sheet

- transmit to Internal Workgroup for review

Internal Workgroup meeting ( s )

- allow for 10 meetings
Present PMT Unresolved Issues for Decision Stakeholder Review and Meeting ( Entity Review )

Reconcile Stakeholder Review Comments with Internal Workgroup

, Management and AAG as necessary

. Revise as Directed ( Draft Permit )

– No Formal Reponse to Comments Required Here

. - Are you interested ? Let us know

- If selected you are expected to be a representative of your interest group

- There will be a limited number of meetings ( 2

- 3 )

- Come to the first meeting prepared to discuss problems with the current permit Letter to Potential Stakeholder Group Member

NEXT PAGE 30 days Regional visits to discuss current permit or data collection if necessary

20 weeks 4 weeks

2 weeks 2 weeks

2 weeks 2 weeks 2 weeks 2 weeks1yearCHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 15 PUBLIC NOTICE OF DRAFT AND HEARING ( S ) ( SEE NOTICE TEMPLATE )

- Publish notice of draft permit and hearing ( s ) in the

State Register *

- Place notice of hearings on agency calendar and sharepoint

- Send notice of draft by email to advisory group serving the area covered by the general permit

- Place the notice of draft
, draft permit
, and draft fact

sheet
, draft application form and economic analysis on the specific Internet site

- Issue news release
, focus sheet
, or newsletter

- Notify by letter everyone on the Program mailing lists or listserve wishing to be notified of draft permits and the required governmental agencies and tribes

- Send draft permit
, fact sheet and application to EPA for 90 day review ( This review may be waived by EPA ) * The Notice is delivered to the Code Revisors Office on or before the 1 st or 3 rd Wednesday of the month

. Publication in the Register is 2 weeks later

. The Governmental Relations Section

, Rules Unit can assist
you

. Deliver to the rules unit on Monday or Tuesday

. The draft comment period begins upon publication of Notice in the Register and extends a minimum of 30 days but must extend several

days past the date of last public hearing / workshop

. Allow about 45 days from time of publication to close of comment period

. During this

period conduct one ( minimum ) to four workshops / hearings on the draft permit

.

Prepare response to comment and revised permit

. The response to comments is attached as an appendix to the fact

sheet and as a stand alone document

. Circulate to permit team for review / comment

. Send to AAG review if recommended by Section Head

.

Post the Combined Comment Letters on the Website FROM PREVIOUS PAGE

The Comment Letters received as paper can be scanned to create an electronic file

.

Program Manager signs the permit ( 3 weeks minimum before expiration of current permit ). Schedule Program Manager appt

. 6 weeks before signing

.

Next Page Organize comments in preparation of response ( allow 1 to 3 weeks ). Similar comments may be consolidated120days

Comments received by email should be consolidated into a separate folder for future notice of issuance

.CHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 16 From previous page

PUBLIC NOTICE OF ISSUANCE ( SEE NOTICE TEMPLATE )

- Publish notice of issuance in the State Register *

- Send Tribal letter when notice goes to register

.

- Send permit and coverage letter to permittees

- Place the notice of issuance on the Internet site

.

- Issue news release
, focus sheet
, newsletter
, or FAQ

- Issue coverages with the permit to existing coverages on the issuance date

. The transmittal letter should inform of available fact sheet and any workshops

.

- Send copy of final permit
, fact sheet and application form to EPA

- Send a letter of issuance to all who commented by letter and those on the program mailing list wishing to be notified of issuance

. The letter includes links to web site with permit
, fact sheet and response to comments as separate documents

. The letter offers hard copies to be sent upon request

. Response to any requests as a result of this letter must be made within 3 days

.

- Send an email on the day of issuance to all who commented by email

. The email contains links to the web site containing the permit
, fact sheet and response to comments

.

- Notify other governmental agencies on the date of issuance

- Email advisory group one or two days before publication

Consolidate the permit file of record in preparation of appeal
Present workshops to explain requirements of the permitWAC173-220has somemandatory notificationparties

Required Governmental Agencies include : State of Idaho

, State of Oregon

, applicable Indian Tribes

, District Engineer Army Corp of Engineers

, US Fish and Wildlife

, National Marine Fisheries Service

, WA Dept

. Fish and Wildlife

, WA Dept

. of Health

, WA Dept

. of Social and Health Services

, and WA Dept of Archaeology and Historic Preservation

.2weeks from time of delivery to registerto publication(issuance)

The effective

date of the permit is a minimum of 30 days after publication in the registerCHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 17 

## 7. QA/QC PROCESS

The originati ng section and the Water Quality Program (WQP) Development Services Section (PDS Section ) will conduct a consistency check for all proposed and draft permits through a combination of pre

- issuance reviews.

The Water Quality Program Manager originally estab lished the following procedure for centralized quality control associated with permit issuance by a memorandum dated April 8, 1994. Each issuing office must establish the implementation details of the required procedures
for in

- office internal quality ass urance. All Ecology programs that issue wastewater permits under the authority of RCW 90.48 will adhere to the centralized quality control process for all NPDES and state waste discharge permits and major permit modifications issued. These programs typic ally include the Water Quality Program, Toxic Cleanup Program, Nuclear and Mixed Waste Management Program, Hazardous Waste and Toxics Reduction Program, and the Solid Waste and Financial Assistance Program (Industrial Section). The regions and Ecology
Pro grams identified above will also submit administrative orders establishing interim effluent limits issued under the authority of RCW 90.48 to the PDS Section for a quality control check. Actions initiated as "substantive requirements" of water quality per mit requirements under CERCLA or MTCA will also undergo centralized quality control. The signatory authority must approve any variations to this procedure and must convey the reason or cause for the variation to the WQP Manager prior to adopting the speci fic procedure and issuing of the permit.



### • Responsibility for Quality Permits

The ultimate responsibility for the content and quality of a permit rests with the supervisor signing the permit. The unit supervisor and the permit writer are responsible for b riefing the supervisor signing the permit on all significant issues raised from central QA/QC review, any EPA review, written review, and from an oral presentation. The unit supervisor and the permit writer will explain the resolution of these issues.



### • Re solution of Disagreements

Disagreements on significant issues may occur between the PDS Section Permit QA/QC Coordinator and the permit writer. The relevant unit supervisor, permit writer, and the QA/QC Coordinator will meet either directly or via a conf erence call as the first step towards resolution. If resolution does not occur, the relevant section supervisor and the PDS Section supervisor will discuss the issue. The final decision rests with the permit signature authority. The supervisor with sign ature authority and the PDS Section supervisor will determine the need for further management involvement in the decision.CHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 18 Pre

- Issuance Review

Internal peer review of all Water Quality Program draft permits, modifications, and
relevant orders must take place within the section or regional office. Each issuing office must establish the implementation details of the required procedures for in

- office internal quality assurance. The WQ Program encourages cross

- region and cross

- program review

. The paragrap hs below describe two in

- office internal approaches used by some of the regional WQ sections as well as the required PDS Section Permit QA/QC review and EPA
review.

Peer Review through Document Distribution: The unit supervisor may assign the draft permi t and fact sheet to one or more other permit managers for comments, suggested changes and additions.

Peer Review through Oral Presentations: Peer review of industrial and municipal permits through an oral presentation may occur at the local regional offi ce, at a permit writer training session, or other suitable forum prior to issuance of the permit.

PDS Section Central Permit QA/QC Review : This PDS Section central review should occur after regional peer and unit supervisor review. The permit coordinato rs must submit the draft permit, any associated compliance order, fact sheet and appendices to the PDS Section Permit QA/QC Coordinator for Central Permit QA/QC Review prior to entity review and the Public Notice of Draft (PNOD). Permit writers can expect that the Permit QA/QC coordinator will complete the quality control check of minors and state permits within ten days (two weeks) and within three weeks for major permits.

EPA Review : Permit writers must send all major and general permits to EPA R egion 10 for review concurrent with public review

. If the PDS Section Permit QA/QC reviewer believes that EPA may have concerns with a permit he/she will recommend that the region forward the permit to EPA during entity review so that Ecology and EPA have an

op portunity to work out any issues prior to public review

. Permit writers may contact the EPA reviewer at any time while drafting a permit to discuss issues if they foresee an objection by EPA of the permit terms and conditions.

The Permit QA/QC Coordinato r will review as many permits as possible for consistency and fulfillment of policy, procedural, and legal requirements. The Permit QA/QC Coordinator will provide assistance to the permit writer in the form of constructive suggestions and advice on
addres sing relevant policy issues. The Permit QA/QC Coordinator will identify areas of inconsistency requiring new or revised policies, procedures, and guidance and will identify areas where lack of policies, procedures, and guidance cause permit issuance ineff iciencies. The PDS Section supervisor will relay these issues to the Permit Writer’s Workgroup (PWG) and/or as necessary to the Program Management Team for discussion and resolution.CHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 19 The originating region/Program may publish the PNOD after consideration of comments received from the peer reviews, central QC check, any EPA review peer reviews and compliance with the pre

- issuance review procedures.

Post Issuance PDS Section Central Review

The Permit QA/QC Coordinator will randomly review final permits aft er issuance for consistency, use of common guidelines, and incorporation of internal and external comments. The Permit QA/QC Coordinator will give special attention to review of permit elements driven by new requirements.

Communication of Findings

When issues emerge that are of interest to permit managers, the Permit QA/QC Coordinator will communicate the issues to permit managers through emails, newsletters, PWG discussions, videoconferences, training sessions, and other appropriate methods.

The Permit QA/QC Coordinator will route recommendations for changes to the permit shells to the chair of the PWG for inclusion in the shell update process.

The Permit QA/QC Coordinator will discuss issues that require supervisory attention first with the appropriat e unit supervisor and, when necessary, elevate issues to the PDS Section supervisor for resolution.

The PDS Section Supervisor will elevate issues involving the efficiency of permit writing and issues needing policy determinations or procedural guidance t o program management.

The Permit QA/QC Coordinator will, as necessary, prepare and distribute a summary of issues prior to each permit writer training session for discussion at the session.

PDS Central Permit QA/QC Review : Submittal of draft permit, an y associated compliance order, fact sheet, and the permit application for PDS Section Central Permit QA/QC Review to the QA Coordinator in the PDS Section will occur prior to the Public Notice of Draft (PNOD). Ten days (two weeks) will be allowed for the quality control check of minor permits and three weeks will be allowed for major permits. The EPA review and PDS quality control check period should take place concurrently and before entity review for majors and general permits. Central quality control review will take place during

, or prior to

, any entity review period for state and minor permits. The permit QA Coordinator will be reviewing as many permits as possible for consistency and fulfillment of policy, procedural, and legal requirements. The p ermit QA Coordinator will provide assistance to the permit writer in the form of constructive suggestions and advice on addressing relevant policy issues. A key role of the QA Coordinator will be to identify areas of inconsistency requiring new or revised policies, procedures, and guidance. Areas where lack ofCHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 20 policies, procedures, and guidance are causing inefficiencies in permit issuance will be identified for management attention. The PNOD may proceed after consideration of comments received from the peer reviews, central QC check, any EPA review peer reviews and compliance with the pre

- issuance review procedures.



## 8. PERMITTEE REVIEW (also see Chapter XV, Section 4)

Procedures

1. Permit writers shall inform Permittees of significant changes to their renewed permits as early as possible in the permitting process.

2. The proposed fact sheet , permit, or permit and fact sheet should be forwarded to the Permittee for comment on factual content 30 days prior to the beginning of the formal public review per iod

. A shorter review period may be used when acceptable to the Permittee or if permit deadlines require a shorter review period.

3. The Permittee shall be made aware that the proposed permit conditions could be changed during the public review process.

4. The draft permit transmittal letter shall specify a date certain by which comments are due, and be clear that the permit issuance process will not be delayed if the date is not met.

5. For permit renewals with significant changes, the permit writer ma y offer the Permittee an opportunity to meet two weeks or more after forwarding the proposed permit or fact sheet. The purpose of the meeting is to explain new or changed requirements, receive comments on factual content, and to discuss the practicality o f compliance schedules

.

Waste discharge permits are now very complex documents, and new more complex requirements in reissued permits have become the norm. It is extremely important that Ecology inform s Permittees of significant changes proposed in their permit as soon as possible. It is also important that the proposed permit and fact sheet be factually correct with respect to facility information such as discharge locations, and process description before the public review.

The Permittee needs to know what the new permit requirements are and the basis for the requirements. The practicality of any proposed compliance schedules also needs to be discussed with the Permittee prior to setting a proposed schedule in the public review draft.



## 9

. PUBLIC REVIE W

Ecology is committed to implementing a more effective public involvement program and strongly supports public involvement in the review of and input on permit conditions during theCHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 21 public review.

If, during the public review period, members of the publi c wish to meet with Ecology staff to discuss new permit requirements and their basis, such a request should be granted

. Early Permittee involvement ensures a correct draft permit for public review and avoids unnecessary delays in the public issuance proce ss. It also ensures that Permittees are informed of the proposed permit requirements in a timely manner

. It’s also important that the public has full access and opportunity to participate in the permit process during the public notice process.



## 10 . EPA R EVIEW

Draft individual NPDES permits for major dischargers should be sent to the EPA Region 10 for review during the public review process.



## 1 1 . AN EXAMPLE PERMIT

New permit writers who are not familiar with permits should review several recent permits fro m their section files or posted on the Internet. The permit writer may contact the QA/QC person for some exemplary permits.



## 1 2 . PERMIT SHIELD POLICY

Permittees are afforded some protection of liability from enforcement and citizen suit by having
a discha rge permit. This protection comes from language in Section 402(k) of the Clean Water Act. This section of the CWA says “Compliance with a permit issued pursuant to this section, shall be deemed compliance, for purposes of sections 309 and 505, with secti ons 301, 302, 306, 307, and 403, except any standard imposed under section 307 for a toxic pollutant injurious to human health.” EPA has adopted a policy (EPA 1995) to clarify the circumstances of protection afforded by this policy. The policy states tha t if the pollutants in the discharge, the suspected pollutants in discharge and the manufacturing processes are fully disclosed during application,
the Permittee is shielded from enforcement if it’s subsequently discovered the discharge is causing a violat ion of water quality standards. Several courts have agreed with EPA on the legal interpretation of Section 402(k).

Occasionally, permit writers receive requests to place some explicit permit shield language in a permit. Ecology permit writers should not put permit shield language in permits. This is a protection afforded Permittees by the fact of receiving a permit and the circumstances surrounding the permit application and issuance. Nothing in the Clean Water Act or federal regulation or policy direc ts permit writers to place this language in permits. The language often suggested by Permittees grants far broader immunity than that afforded by Section 402(k).CHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 22 Permit writers who want to assure 402(k) protection for Permittees should require extensive analysis of the effluent for the permit application and be very explicit in the fact sheet about how each pollutant in the effluent was considered. Permittees who want the protection of 402(k) only have to make sure they disclose all relevant information on their discharge in their permit application

.



## 1 3

. CWA JURISDICTION ON TRIBAL LANDS

Jurisdiction within Indian Reservations is very mixed and is based on complex case law

. Also terminology can be confusing

. County

- issued permits are not evidence of sta te NPDES jurisdiction

.

The State does not have jurisdiction for any of the EPA delegated/approved programs on any lands (fee/trust, Indian owned/non

- Indian owned) within any Indian Reservation, except the Puyallup Reservation where we have received specif ic authorization.

EPA believes that it can only delegate/approve state programs within Indian Reservations if it makes a specific finding of state authority on those lands. On the Puyallup Reservation the tribe agreed and Congress approved a land claims settlement that provided that the state would have jurisdiction on fee lands within the Reservation

. On this basis, EPA has approved Ecology’s CWA, RCRA, and CAA programs on fee lands within the Puyallup Reservation.

On all of the other 25 reservations w ithin the state, EPA has retained CWA jurisdiction or has delegated specific programs to tribes under its “Treatment a s a State” (TAS) process. This is due to EPA’s read of its authority and EPA’s interpretation that tribes have inherent authority, for th e purposes of the federal environmental programs, over all tribal members and their land and all

non

- member residents and their land within reservations.

A county may have taxing jurisdiction on fee land within a reservation and may have (or assert)
zonin g and building code authority on fee land

. Ecology would still not have NPDES authority on fee land within the reservation unless EPA has specifically delegated CWA programs to the state within the reservation as it did on the Puyallup Reservation.



## 1 4

. S TATE AUTHORITY ON FOREST SERVICE LAND

Washington has concurrent jurisdiction with the US regarding both civil and criminal processes on national forest lands within the state (RCW 37.08.220). This means that the state has the authority to enforce our stat utes and regulations on national forest lands in the state. However, Ecology’s ability to take enforcement action against the federal government is limited. Consequently, if the federal government is the operator of the treatment plant discharging to
lan d, Ecology can issue a state waste discharge permit for the facility, but Ecology’s ability toCHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 23 enforce the permit may require a federal court action. If the plant is operated on USFS land by a private entity, Ecology can issue a permit to that entity and use all the usual enforcement tools (orders, penalties, etc) to enforce the permit.



## 1 5

. ANTIBACKSLIDING

In general, Ecology may not renew, reissue or modify an existing NPDES with effluent limits that are less stringent. The requirements and exceptions a re found in CWA 402(o), CWA 303(d)(4), and 40 CFR 122.44(l). The requirements are relatively straight forward but the exceptions are confusing.

Regardless of the exceptions given below, Ecology may not propose a less stringent effluent
limit if any of th e following apply : 1) It is less stringent than required by federal effluent guidelines. 2) It violates applicable water quality standards (including antidegradation requirements)

. 3) It violates State technology

- based treatment requirements that are more stringent than federal requirements (see discussion below).

State law is silent on antibacksliding so the following does not apply to limits in State permits ; however, the groundwater standards do have an antidegradation requirement which would apply
for increased limits.

Ecology may propose less stringent water quality

- based effluent limits if any of the following apply : 1) Material and substantial alterations to the permitted facility occurred after permit issuance justifying application of a less strin gent effluent limit. 2) Information, not available at the time of permit issuance (other than revised regulations, guidance, or test methods), would have justified applying a less stringent effluent limit at the time of permit issuance

. (This is available for listed waters only if the cumulative effect of these revisions assures attainment and the increase meets antidegradation requirements. This assumes that if limits for some dischargers to the impaired waters go up, others will go down
to assure attain ment of standards.) 3) Ecology made a mistake when it calculated limits or when it interpreted law or regulation when it issued the permit (available for listed waters only if the cumulative effect of these
revisions assures attainment and increase meets a ntidegradation requirements). 4) When Ecology revises a TMDL and transfers a WLA to increases the limits after it had based
limits on a TMDL in listed waters. Ecology must still ensure the water body attains water quality standards. 5) When Ecology change s the use designation so the criteria are less stringent after it had based
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- 24 Ecology believes that situations 2 and 3 would most commonly occur

. It’s not clear how situation 1 would apply to water quality

- based limit s un less the material and substantial alterations changed the character of the effluent.

EPA also stated in its guidance memo (Elder 1993) that exceptions 1 through 5 also apply to “any other State treatment requirements more stringent than required by the CW A (e.g., technology

- based State treatment requirements).

Ecology may increase technology

- based limits based on applicable EPA effluent guidelines if: 1) Material and substantial alterations to the permitted facility occurred after permit issuance justifyi ng the application of a less stringent effluent limitation.

Ecology may increase technology

- based limits determined on a case

- by

- case (BPJ) basis [40 CFR 125.3(d)] if any of the following apply:

1) Material and substantial alterations to the permitted fa cility occurred after permit issuance justifying the application of a less stringent effluent limitation.

2) Information, not available at the time of permit issuance (other than revised regulations, guidance, or test methods), would have justified applyi ng a less stringent effluent limit at the time of permit issuance

. (This is available for listed waters only if the cumulative effect of these revisions assures attainment and the increase meets antidegradation requirements.

3) Ecology made a mistake whe n it calculated limits or when it interpreted law or regulation when it issued the permit (available for listed waters only if the cumulative effect of these revisions assures attainment and increase meets antidegradation requirements).

4) Ecology determi nes a less stringent effluent limitation is necessary because of events over which the permittee has no control and for which there is no reasonably available remedy.

5) The permittee has received a variance or exception under CWA sections 316(a) or 301(c ), 301(g), 301(h), 301(i), 301(k), 301(m) and 301(n). These variances or exceptions are: 316(a)

– Thermal discharge, 301(c)

– Demonstration of maximum use of treatment technology, 301(g)

– Modification for certain nonconventional pollutants, 301(h)

– Ma rine waiver for secondary treatment, 301(i)

– Municipal time extension, 301(k)

– Innovative technology, 301(m)

– Deep sea industrial discharge of BOD and pH, and 301(n)

– Fundamentally different
factors.

6) The permittee has installed the treatment fac ilities required to meet the BPJ limits and has properly operated and maintained the facilities but has

, nevertheless

, been unable to achieve the effluent limit, in which case

, Ecology may revise the limits to reflect the level of pollutant
control actuall y achieved.CHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 25 Ecology believes antibacksliding applies to effluent limits developed on a case

- by

- case basis under authority of 90.48 (AKART) and placed in an NPDES permit. For example, Ecology develops a performance

- based limit for an industrial discharger with obsolete effluent guidelines

. The permit writer determines the treatment technology and the operation of that technology is AKART and develops appropriate technology

- based effluent limits based on the monitoring data from the facility

. EPA then revi ses the effluent guidelines for the industrial discharger

. The guidelines are less stringent than the AKART limit

. Even if antibacksliding did not apply, Ecology would still have an independent duty under state law to impose the more stringent
AKART limi t rather than the less stringent limit based on federal effluent guidelines.CHAPTER II. AN OVERVIEW OF THE PERMITTING PROCESS (JULY 2011)

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- 26 Figure II

- 4. Antibacksliding

IS THE LIMIT BASED ON WATER QUALITY CRITERIA ?

ANTIBACKSLIDING FOR TECHNOLOGY

BASED LIMITS IS DISCUSSED ABOVE [ SEE 40 CFR

122

. 44 ( l )]

ARE WQ STANDARDS ATTAINED ? 402 ( o )( 1 )/ 303 ( d )( 4 )

IS REVISION CONSISTENT WITH ANTIDEGRADATION ? 303 ( d )( 4 )( B ) IS LIMIT BASED ON A TMDL ? 303 ( d )( 4 )( A )

IS ATTAINMENT OF

WATER QUALITY STANDARDS ASSURED ( INCLUDING ANTIDEGRADATION ) IS A LISTED EXCEPTION MET ? 402 ( o )( 2 )

REVISION NOT ALLOWED

DOES REVISION COMPLY WITH EFFLUENT GUIDELINES AND WATER

QUALITY STANDARDS ? 402 ( o )( 3 )

REVISION ALLOWED NO YES

YES

YES

YES

YES NO NO

NO YES NO

YES NO

REFERENCES Elder, James 1989

. Draft Interim Guidance on Implementation of Section 402(o) Anti

backsliding Rules For Wa ter Quality

- Based Permits (Draft).CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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- 1 

# CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW

This chapter covers the process of permit application and background review including categories of application, forms, and time frames for application. A flow chart showing the tasks for permit writers is included at the end of the chapter. The objective of permit application and background review is for the permit writer to become as knowledgeable as possible about the circumstances of discharge and the characteris tics of the proposed effluent discharge.



## 1. WHO NEEDS PERMITS

Anyone who owns or operates a facility discharging or proposing to discharge wastewater (including some stormwaters) to the state waters must apply for a n individual wastewater discharge permit . State and Federal regulations require a facility to apply for a n individual permit to discharge to surface waters at least 180 days prior to the initial discharge. Ecology may allow a shorter time period by letter, however, 180 days is not enough time to work through engineering reports for new dischargers or complex issues for existing dischargers. Permit writers should alert their permit applicants to the realistic schedules for permit issuance and renewal. Major Permittees should be sent applicatio ns at the beginning of the fiscal year in which their permit expires. Permits should require reapplication one year prior to expiration.

Application for a n individual state waste discharge permit must be made 60 days prior to the date
on which it is desi red to begin discharge but for complex discharge situations 60 days is insufficient time to develop a permit. State permits should also require reapplication one year prior to expiration.

Application times for coverage under a general permit are develope d for the specific general permit.

Anyone who discharges wastewater or has a significant potential to discharge wastewater to the
surface waters of the state must obtain a joint NPDES/state wastewater discharge permit (40 CFR 122.3). Ecology issues joint federal/state permits because the state’s water pollution law requiring wastewater discharge permits preceded federal law

.

Those exempted from obtaining an NPDES individual permit include:



## • Anyone discharging domestic sewage only to a POTW,CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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- 2 

## • Anyone who i s covered by a general permit (see Section 5 of Chapter II and Section 9 of this chapter)

,



## • Anyone discharging industrial and commercial wastewater to a POTW,



## • Discharges of pollutants from nonpoint source agricultural and silvicultural activities,



## • Return flows from irrigated agriculture,



## • Any discharge in compliance with the instructions of an On Scene Coordinator, and



## • Any discharge occurring under CERCLA (but these discharges must meet substantive requirements)

State wastewater discharge permits are re quired by:



## • Anyone who discharges waste materials from a commercial or industrial operation to the waters of the state or to a municipal sewage system (RCW 90.48.160) ; and,



## • Any county or any municipal or public corporation operating or proposing to operat e a sewage system which results in the disposal of waste material into the waters of the state (RCW 90.48.162).



## • All lagoons containing wastewater, lined and unlined, require state waste discharge permits.

The exemptions for the requirement for state wast e discharge permits include:



## • Discharges to municipal sewerage systems of domestic wastewater (sanitary wastewater) from residential, commercial, or industrial structures

.



## • Any discharge to a municipal system which is already permitted (subject to review a nd limitation) by the local authority

.



## • Any discharge to a municipal system which is already permitted under a local pretreatment program (FWPCA section 307).



## • Discharges to municipal sewerage systems from commercial or industrial operations ifCHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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- 3 the waste s trength and characteristics are the same as domestic wastewater (if it's not easily degradable or if its high strength, then the permit writer should examine it in the permit process to assure the waste will not cause a n upset at the treatment plant).



## • Dis charges which have an NPDES/state individual or general discharge permit for discharge to surface water

.



## • Discharges from small domestic on

- site septic systems (design capacity less than or equal to 14,500 gallons per day) which discharge to the ground

.



## • D ischarges from small (less than or equal to 3,500 gallons per day) aerobic, domestic treatment plants which discharge to the ground.



## • Discharges during oil spill cleanup which have received prior authorization from Ecology.



## • Discharges under the State of W ashington Model Toxics Control Act.



## • Discharges from LUST sites and vehicle and equipment washing under some circumstances (see below).


## 1.1 NPDES Permit Requirements for Non

- discharging Facilities Which Have Zero Discharge Limitations in Effluent Limitati on Guidelines

Federal law is clear that any discharge of pollutants to surface waters of the United States requires an NPDES permit. Federal regulations [40 CFR § 122.21(a)] also impose on any facility that “discharges or proposes to discharge” a clear “d uty to apply” for an NPDES permit. EPA has issued guidance interpreting these regulations to impose a further duty to apply on certain facilities (such as concentrated animal feeding operations) that have a “potential to discharge.” However, facilities t hat do not discharge, do not propose to discharge, and do not have the potential to discharge have no obligation to apply for or to obtain NPDES permits.

EPA has developed categorical effluent limitation guidelines for a number of industries. The

purpose of these guidelines is to establish for these categories the minimum technology

- based requirements in terms of effluent limits in NPDES permits. A number of these federal effluent limitation guidelines (such as those for the Wood Preserving

– Boulton Sub category [40 CFR Part 429, Subpart H] and the Sawmills and Planing Mills Subcategory [40 CFR Part 429, Subpart K]) establish “zero discharge” requirements for process wastewater pollutants. Federal regulations require permits and permit applications from these facilities if they propose toCHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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- 4 discharge or have the potential to discharge to surface waters.

A facility subject to a “zero discharge” effluent limitation guideline may seek NPDES permit coverage to take advantage of the “unavoidable bypass” and “up set” defenses available to facilities with NPDES permit coverage. To the extent that the facility operator is “proposing to discharge” during these bypass and upset events, such a permit application is appropriate (and may in fact be required by 40 CFR § 122.21(a)).

However, some facilities subject to effluent limitation guidelines may (because of topography, process, etc.) have no potential to discharge pollutants to waters of the United States. For these facilities, Ecology has decided to follow the pr ocess demonstrated in practice by EPA Region 10. No permits will be issued solely because the facility falls within a zero discharge subcategory

. If the determination is made that there is a substantial probability of process water discharge to
surface w aters, an individual NPDES permit may be issued.


## 1.2 Independent Leaking Underground Storage Tank (LUST) Cleanup Sites

Sites that are classified as “non

- independent cleanup sites” are those under which cleanup activities are being conducted under the MTCA formal process of an agreed order or consent decree.

Sites that are classified as “independent cleanup sites” are those under which cleanup activities are being conducted under MTCA’s Voluntary Cleanup Program by choice through Ecology Toxic Cleanup Prog ram (TCP) involvement, and those cleanup activities being conducted voluntarily without involvement from TCP.

Both types, if they have a discharge resulting from their cleanup activities, must follow the guidance below or contact Ecology directly for case

- specific exemptions that may apply.

Independent Leaking Underground Storage Tank (LUST) cleanup sites are allowed an exemption from permits for short term discharges that meet high treatment standards. The following conditions apply:



### • The proponent must submit a letter to Ecology . If the discharge is to a POTW, a copy of the letter must be delivered to the POTW. The letter shall include the following items:

1. A project description, including treatment method, disposal method, rate of discharge (gpm), da tes of discharge s , and duration of discharge (days).
2. Analytical data from an accredited laboratory showing analysis of pollutants of concern (see Table C following) from the proposed treatment system.

3. A street map indicating the extent of the site, locati on of the treatment equipment,CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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- 5 address of the site, and point of discharge to the sewer or storm drain.

4. The name and telephone number of the project manager or person who should be contacted about the project.



### • All discharges to ground water at LUST clean up sites must also register with the state Underground Injection Control (UIC) program. The UIC coordinator will evaluate the registration and will refer the owner/operator to the regional permit coordinator if a permit is required.



### • All long term dischar ges (>60 days) to surface waters must contact the regional office.



### • All long term dischargers to ground water must submit an engineering report which includes a hydrogeological investigation.



### • The facility must notify Ecology when the discharge stops or ef fluent quality meets Level 2 and a permit is no longer required.



### • For Independent LUST sites involving gasoline or diesel (only) go to Table A if there is a
short

- term discharge (<60 days), otherwise go to Table B for discharges longer than 60 days.



### • A fac ility manager may require a permit in a situation that otherwise may be exempted if monitoring and reporting is required.CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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- 6 Table A Short Term <60 day Discharge Discharge Location Conditions Permit Requirement
Surface Water Meet Table C level 1

treatm ent Local approval required if discharge is to municipal stormwater system Generally no permit required.
Permit writers should make
determination based on circumstances ( e.g., if hydraulic capacity is a concern)

.

POTW Meet Table C level 3

treatment Local approval required Generally no permit required.
Permit writers should make
determination based on circumstances ( e.g., if hydraulic capacity is a concern). Ground Water by injection well or UIC, hydraulically
contained* on

- site Meet Table C level 1

treat ment UIC registration only No permit required

Ground Water, but not contained on

- site Option A: If meet Table C
level 2 treatment UIC registration only (if it meets UIC well definition) No permit Option B: Meet Table C
level 1 treatment Permit

- By

- Rul e Discharge to an injection well is
not allowed
*Hydraulically contained means that the aquifer is recharged in such a manner as to prevent the injected water from leaving the site.CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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- 7 Table B Long Term ≥ 60 day Discharge Discharge Locatio n Conditions Permit Type
Surface Water Meet Table C level 1

treatment Local approval required if discharge is to municipal stormwater system NPDES Permit

POTW Meet Table C level 1

treatment Local approval required State Industrial User (IU) Permit,
or P ermit

- By

- Rule

Ground Water by UCI, hydraulically contained on

site Option A: Meet Table C level
2 treatment UIC Registration

- No permit

Option B: Meet Table C level
1 treatment Permit

- By

- Rule

Ground Water by UCI, but
not contained on

- site Meet Table C level 2

treatment Temporary Permit

- By

- Rule

Table C Discharge Quality Maximum Concentration Levels
Parameter Level 1 (discharge to surface water) a Level 2 (discharge to groundwater) b Level 3 (discharge to POTW) c pH 6.0

- 9.0 6.5

- 8.5 6 to 9
TPH

- G 1 ppm 1 ppm 2 ppm
TPH

- D 5 ppm 1 ppm 10 ppm
Total Lead 15.0 ppb 15.0 ppb 20 ppb
BTEX 100 ppb N/A 200 ppb
Benzene 5.0 ppb 1.0 ppb 10 ppb
Toluene N/A (see BTEX) 40 ppb N/A Ethylbenzene N/A (see BTEX) 30 ppb N/A Xylene N/A (see BTEX) 20 ppb N/A

a. Level 1 limit s are based on the groundwater standards or MTCA method A value, whichever is more stringent.

b. Level 2 limit s are based on the ground water standards or MTCA method A value, whichever is more stringent

.
c Level 3 limits are based on King Count y pretreatment levels and best professional judgment to prevent explosives in the collection system and to prevent interference or upset at the wastewater treatment plant. Permit writers should confirm that these levels meet local pre

- treatment levels bef ore using in permit

.CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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## 1.3

. Vehicle And Equipment Washing

Ecology will generally not require discharge permits for vehicle or equipment wash water to ground, to POTW’s, or if it is non

- discharging or regulated by the hazardous waste program.
Instead of a permit, Ecology relies on education and outreach for these types of discharges. This education and outreach approach relies on the business community’s cooperation in using Best Management Practices identified in Vehicle and Equipment Washwater Discharge s (WQ

- R

- 95

- 56). Permit writers should observe the following:



### • A state wastewater discharge permit will not be issued to cover vehicle/equipment washing operations described in Vehicle and Equipment Washwater Discharges (WQ

- R

- 95

- 56) if they are using BMPs consistent with this document.



### • A state wastewater discharge permit may be issued under exceptional circumstances, such as, for a discharge to the ground over a sole source aquifer where there is reason to believe that the discharge needs to be controlled to protect the ground water resource. Also, where
there is an obvious non

- compliance with the appropriate BMPs, Ecology may require a wastewater discharge permit to prevent and/or control pollution from the discharge.



### • Discharges to surface waters or to s torm sewers require individual NPDES permits, however, in order to avoid the resource intensive process for an NPDES permit, alternatives to surface water or storm sewer discharges should be strongly encouraged where appropriate. Permits should only be is sued where absolutely necessary to control pollution.


## 1.4. Petroleum Bulk Plants, SIC 5171

Facilities with product storage over 100,000 gallons should be issued an individual NPDES or State wastewater discharge permit

Facilities with product storage under 100,000 gallons are usually covered by the industrial stormwater general permit with a companion order to cover any monitoring and reporting requirements. An individual permit may also be issued.



## 2. APPLICATION FORMS FOR INDIVIDUAL PERMITS

When it is de termined that a facility needs a permit, the facility must make an application for a permit ; however

, the facility must be allowed 30 days to submit. Applications are made on forms which are specific to the type of discharge. Discharges to surface waters are usually made
on federal NPDES forms as shown in Table III

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- 9 There are also application forms for state waste discharge permits. These include:



### • Application for POTW Discharges to Land,



### • Application for Industrial Discharge to Land, and



### • Application for Industrial Discharge to POTW (for POTWs without a delegated pretreatment program).

A general instruction page is used with each of these state application forms.

In the past an applicant could renew a permit by submitting a letter stating there had been no significant change at the facility during the term of the expiring permit. Federal Regulation changes in 1980 no longer allow the use of these letters for NPDES permits. An applicant must apply on a permit application form as given in Table III

- 1 or its equivalent.

There is nothing in regulation that prohibits alternative applications as long as the minimum amount of information submitted is equivalent to that required by the federal application form.
This is sometimes an issue for new facilitie s that submit engineering reports. An engineering report prepared in compliance with WAC 173

- 240 and Ecology supplementary guidance will have all of the information in the body of the report that is required on the permit form. In this
case it is allowab le to have the facility make out Form 1, the first page of the application , sign it, and attach it to the engineering report.CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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- 10 

### Table III

- 1. NPDES AND STATE PERMIT APPLICATION FORMS

TYPE OF FACILITY FORM

Municipally Owned Wast ewater Treatment Plants Form 2A

Commercial Facilities

1. New Source Forms 1 and 2D

2. New source with discharge Forms 1 and 2E

of non

- process waste water only and
follow

- up data

Industrial Fa cilities

1. New Source Forms 1 and 2D

2. New Source with discharge Forms 1 and 2E

of non

- process waste water and only follow

- up data

3. Existing Source Forms 1 and 2C

4. Reapplicatio n Forms 1 and 2C

Mining

1. New Source Forms 1 and 2D
and mining plan

2. Reapplication Forms 1 and 2C

Feedlot Forms 1 and 2B 

### Federal FormsCHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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### Table III

- 1. (Cont inued ).

Fish Hatchery Forms 1 and 2B

Water Treatment Forms 1 and 2D

Storm Water Form 2F

Industrial Discharge to Land Ecology form 040

- 179

Industrial Discharge to a POTW Ecology form 040

- 177

POTW Discharge to Land Ecology form 040

- 178

Industry to Industry Ecology form 040

- 177

All of the wastewater discharge permit application forms are available as electronic fill

- in forms

at w ww.ecy.wa.gov/programs/wq/permits/guidance.html

.



### State FormsCHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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## 3. APPLICATION PROCESS

The process of applying for a wastewater discharge permit is often frustrating for both the applicant and the permit writer. The key to making it go as smoothly as possible is to communicate the requirements for application as early and as in as much detail as possible. Many large industries are very knowledgeable about the permit process and only need direction on their specific application process. Smaller dischargers may requi re some background information on application requirements. For example, many smaller dischargers may not be familiar with the objective and process of whole effluent toxicity testing. The NPDES requirements for permit application are given in 40 CFR 122 .21. The processes of application and background review are illustrated in Figures III

- 1 and III

- 2.

The permit application is reviewed by the permit writer for completeness and accuracy. Reviewing an application for completeness is a fairly simple task but there's only one way to do it. Go over it item by item, making sure each blank is filled in. Each part of the form should have the requested information or an indication that it is not applicable. The instructions for both
the EPA forms and the stat e forms instruct the applicant to place an "NA" in a blank to show it
has been considered but the question is not applicable. Many times an application is incomplete and the question is how to deal with it. Do not fill in any information yourself unless it's information commonly available from public sources. Substantial time is saved by simply getting the information over the telephone and then writing in the answer. This information will not be certified as correct by the person who signed the applica tion. Send the application back to the applicant for completion if there is any uncertainty. This is the legally correct procedure.CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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- 13 Figure III

- 1. Permit Application Review

Review Permit Application

Is the application on

the correct form? Require new application on correct form

Does the application include all outfalls, priority pollutant, sludge and toxicity data when required? Establish schedule for submittal of required information

Does the application have all of the information

necessary to adequately characterize the nature and quantity of pollutants in the effluent and

their impact on the receiving water? Establish schedule for the submittal of the required information

Are all calculations and flow

diagrams correct Request recalculation and resubmittal

May begin public notice of application now or after facility inspection Go to Figure III-2 yes no

no

yes

no

yes

no

yes Data Received

c:\gary\manual1.195\iii-1.adsCHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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- 14 Figure III

- 2. Background Information Review

CONTINUED FROM FIGURE III-1 IS THE DISCHARGE A NEW SOURCE REVIEW THE CURRENT PERMIT AND FACT SHEET FOR DOCUMENTATION OF CURRENT PERMIT LIMITS

REVIEW ENGINEERING REPORT AND SUPPLEMENTAL INFORMATION DETERMINE WHAT FACILITY CHANGES SUCH AS PRODUCTION OR WASTEWATER TREATMENT HAVE OCCURRED SINCE THE LAST PERMIT WAS ISSUED

REVIEW THE RECENT DISCHARGE MONITORING REPORTS TO EVALUATE THE COMPLIANCE HISTORY AND OBVIOUS TREATMENT DEFICIENCIES

REVIEW HAZARDOUS WASTE AND WATER RIGHTS FILES

REVIEW INSPECTION REPORTS FOR GENERAL BACKGROUND AND COMPLIANCE PROBLEMS REVIEW DEVELOPMENT DOCUMENTS, VOLUME II OF THE TREATABILITY MANUAL, AND APPROPRIATE REFERENCE TEXTBOOKS TO DEFINE THE CHARACTERISTICS OF THE INDUSTRY TYPE INVOLVED

ARE ADDITIONAL DATA NEEDED FROM THE APPLICANT TO COMPLETE THE BACKGROUND INFORMATION? REQUEST SUPPLEMENTAL INFORMATION DATA RECEIVED

INSPECT THE FACILITY BEGIN PUBLIC NOTICE OF APPLICATION

DEFINE WHICH EFFLUENT GUIDELINES HAVE BEEN PROMULGATED FOR THIS FACILITY TYPE REQUEST SUPPLEMENTAL INFORMATION AND TECHNICAL ASSISTANCE FROM THE EPA EFFLUENT GUIDELINES DIVISION, IF NECESSARY

GO TO FIGURE IV-1 NO

YES

YES

NO

c:\gary\manual1.195\figiii-2.adsCHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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- 15 Some requirements that are of ten overlooked in applications are:



### • Grab samples must be used for pH, temperature, cyanide, total phenols, residual chlorine, oil and grease, fecal coliform, and fecal streptococcus. All others are collected by 24

- hour composite unless waived by Ecology. If the 24

- hour composite sampling is waived, the applicant is then required to collect a minimum of 4 grab samples which are representative of the effluent. The 4 grab samples can be combined for analysis.



### • Every applicant must submit data for BOD, COD , TOC, TSS, Temperature (winter and summer) and pH. Ecology may waive these test requirements if the applicant can demonstrate they are not necessary for characterizing the effluent.



### • Primary industries have some mandatory testing requirements for toxic p ollutants (40 CFR 122.21 Appendix D, Table I and Table II; also listed in Application Form 2C). Primary industries that are also small businesses [122.21(g)(8)] may be exempted from these testing requirements. Existing dischargers who believe certain pol lutants may be present in their effluent must test for those pollutants (122.21 Appendix D, Table IV, Table V).



### • Municipalities also have some mandatory application requirements for whole effluent toxicity and sludge. POTW's larger than 1 MGD or those wit h pretreatment programs are required to submit valid whole effluent biological toxicity testing. This requirement may be satisfied if the expiring permit contains a requirement for effluent characterization of whole effluent toxicity (see Chapter VI, Part 5). The permit writer should note the use of this option in the fact sheet

.

The following are application requirements for municipalities under the form 2A. Permits should contain the appropriate monitoring requirements to assure the data is available at time of reapplication.

NPDES Application Testing Requirements for municipalities with design flow < 0.1 MGD (a minimum of three values for each parameter collected within 4.5 years prior to submission of the application) pH (min and max)
Flow rate Temper ature ( winter and summer ) BOD (or CBOD)
Fecal Coliform Total Suspended SolidsCHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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- 16 Additional NPDES Application Testing Requirements for municipalities with design flow

≥ 0.1 MGD (a minimum of three values for each parameter collected within 4.5 years prior

t o submission of the application).

Ammonia
Total Residual Chlorine Dissolved Oxygen Total Kjeldahl Nitrogen Nitrate plus Nitrite Nitrogen
Oil and Grease Phosphorus (Total)
Total Dissolved Solids

NPDES Additional Application Requirements for municipalities with design flow ≥ 1.0 MGD or with Pretreatment Program (a minimum of three values for each parameter collected within 4.5 years prior to submission)

Metals, Cyanide, Phenols, and Hardness Volatile Organic Compounds
Acid

- extractable Compounds
Base

- neutra l Compounds Toxicity Testing: quarterly testing in past year using two species ;

or results from four acute or chronic tests performed at least annually within the four and one half years prior to application.

Upon request the applicant must submit other i nformation which may be needed in deciding whether to issue a permit. The requested information may include additional quantitative data on the effluent or receiving water.


## 3.1 Analytical Requirements

Ecology has defined the analytical requirements (detec tion and quantitation levels) for permit application and for compliance monitoring of effluent

. The objective is to reduce the number of

non

- detects when effluent is analyzed. The current table is posted with the other permit writer’s
materials in Outloo k.CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

Permit Writer’s Manual
III

- 17 

## 3. 2 Reviewing an Application

When a permit application is completed it must be reviewed for accuracy. The accuracy of the permit application can be assessed by checking the numbers on the application, and, for existing dischargers, by reviewing the f iles and inspecting the facility.



### • Everybody makes mistakes in arithmetic. Review the concentrations of pollutants reported in the effluent to make sure they're reasonable. Then add the flows to ensure the total is correct, and then do the mass loading c alculations.



### • Check the files for information. If the application is for an existing facility there is probably a large amount of information in the files. A reporting facility will have a previous permit file, discharge monitoring reports, correspondenc e and inspection reports.

In addition to the water quality files, there may be some good information in other files such as the Dangerous Waste files. The Dangerous Waste Regulations (Ch apter 173

- 303 WAC) require anyone who generates, transports or treat s dangerous waste to have an EPA/state identification number and to report their activities annually. There may also be some inspection reports in this file. The information in this file may indicate some pollutants or problems that need attention in
the permit process. (See Section 8, following, which discusses the domestic sewage exclusion for hazardous waste.)



## • Check to see if the facility has a water right and if it corresponds to the water use in the application.



## • If you're new to the office, check with the complaint inspectors to see if there is a history of complaints on the facility.



## • Check any additional information available on similar types of discharges (EPA Development Documents) to see if the reported effluent concentrations seem
reasonable.



## • Check with other permit writers in the agency who have permitted this type of facility to see if there are any special considerations in the application process.



## • Inspect the facility. An existing facility that is being permitted should be inspected at least once, except those being covered under a general permit. A facility inspection acquaints you with the facility, the people you'll be dealing with, and verifies the information in the permit application. If you're not an experienced inspector, revie w the Ecolog y Inspection Manual beforehand.CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

Permit Writer’s Manual
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- 18 The things you want to determine or verify during this inspection are:



## • The application's accuracy in describing the production processes ;



## • The number and type of outfalls (storm drains are frequently omitted) ;



## • The raw materials and chemicals used ;



## • The operation and maintenance of the treatment equipment ;



## • Production ; and

,



## • The company attitude toward environmental compliance

.

Go over the facility from roof to basement. Air pollution equipment may be dischargi ng pollutants to the roof, which washes off in the rain. Piping in basement areas may be neglected and have a potential for leakage. Pay particular attention to those things ( such as the need for spill prevention and housekeeping ) that can be used as pre ventative mechanisms in permits but

are n o t described very well in permit applications. Take photographs of key processing areas or problem areas.

For those permit managers who have been dealing with a facility for a long time, this is a good
time to tak e a fresh look and ask all the questions that you would ask if you were seeing the facility for the first time.

You may wish to include a sit

- down meeting at this time to discuss the general direction of the new permit and any new regulatory requirements that might be included in the permit. Avoid discussion of specific numbers at this time

.

If you have discovered inaccuracies in the application, point out the need to get correct information. Remind them of the statement on the signature block of the ap plication if

necessary.



## 4. APPLICATION AND EXPIRED PERMITS

4.1 NPDES

If a permittee has made "timely and sufficient application" for permit renewal, an expiring permit remains in effect until Ecology has either denied the application or issued a new permit (WACCHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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- 19 173

- 220

- 180(5)). Consequently, an expired NPDES permit remains in e ffect while Ecology reviews an application for a permit renewal, so long as the application is "timely and sufficient." Ecology must notify the permittee of the extension, by letter, that they have made timely and sufficient application and that the permi t remains in effect until the permit is reissued or for another five years, whichever comes first.



## 4.2 State

A permittee must submit a satisfactory application at least 60 days prior expiration of an existing permit (RCW 90.48.170 ) ( WAC 173

- 216

- 070) or as specified in the existing permit , unless the requirement is waived by Ecology . A satisfactory permit application consists of a completed form including the proper signature and any other information determined as necessary by the Department (WAC 173

- 216

- 0 70(4)). The existing permit remains in effect until the application has been finally determined by the Department (RCW 34.05.422(3)). In the event that Ecology takes no action on an application within 60 days, the applicant receives a temporary permit ba sed
on information in the application. The temporary permit is effective until Ecology acts on the application or for a period of five years. This process is illustrated for new and renewal state permits respectively in Figures III

- 3 and III

- 4.CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

Permit Writer’s Manual
III

- 20 Figure III

- 3. Application process for a new state wastewater discharge permit.

SEND APPLICATION AND

COVER LETTER REVIEW BY PERMIT COORDINATOR IS APPLICATION COMPLETE? SCREEN BY PERMIT MANAGER

IS APPLICATION ACCEPTABLE?

1. REJECT APPLICATION OR 2. CALL FOR INFORMATION OR 3. ISSUE ORDER FEES PAID? 60 DAYS START*

NO PERMIT POSSIBLE ENFORCEMENT

NEED PERMIT? ISSUE PUBLIC NOTICE OF APPLICATION

WILL THIS PERMIT HAVE RESTRICTIONS ON DISCHARGE AND REQUIRE MONITORING?

WILL THIS PERMIT HAVE

ONLY MONITORING REQUIREMENTS? ISSUE PERMIT AND FACT SHEET

SEND LETTER OF NOTIFICATION OF

TEMPORARY PERMIT (RCW

90.48.200) NO

SEND LETTER

SAYING NO

PERMIT NECESSARY YES

YES

NO NO

STAPNEW2.ADS IF PERMIT WILL TAKE LONGER THAN 60 DAYS SEND LETTER ESTIMATING TIME TO ISSUANCE YES 1. REJECT APPLICATION OR 2. CALL FOR INFORMATION OR 3. ISSUE ORDER

NO YES

NO

* SEPA PROCESS MUST BE COMPLETED NO YES

ISSUE PERMIT DETERMINE FEE CATEGORY AND SEND LETTER YESCHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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- 21 Figure III

- 4. Application process for renewal of a state wastewater discharge permit.

SEND APPLICATION

, COVER LETTER

, AND CERTIFICATION DOCUMENT RECEIVE APPLICATION AND CERTIFICATION INITIAL REVIEW OF APPLICATION BY PERMIT COORDINATOR

IS APPLICATION COMPLETE ? 1

. RETURN APPLICATION FOR COMPLETION OR 2

. CALL FOR MISSING INFO OR 3

. ISSUE ORDER FOR INFO

REVIEW BY PERMIT MANAGER IS APPLICATION ACCEPTABLE ? 60 DAY COUNT STARTS

IS THERE A CHANGE IN THE VOLUME OR CHARACTER OF THE WASTEWATER FROM THE

PREVIOUS APPLICATION ? SEND A LETTER WHICH SAYS ECOLOGY IS ACTING ON THE APPLICATION AND THE PERMIT ACTION IS EXPECTED

ON DATE

. THE CURRENT PERMIT WILL REMAIN IN

EFFECT UNTIL DATE ( TEMPORARY PERMIT ). THE LETTER MAY SAY AN UPDATED APPLICATION WILL BE REQUESTED

.

CONDUCT OR REQUIRE PNOA PREPARE AND ISSUE PERMIT NO

NO YES

YES NO

YESCHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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III

- 22 

## 5. APPLICATION FOR NEW PERMITS

5.1 NPDES

Applicants must sub mit an application at least 180 days before the date they wish to begin discharging or , with Ecology’s agreement, in sufficient time prior to commencement of discharge to allow the Department to formulate technology

- based and water quality

- based
limitation s. No discharge is authorized until the effective date of the permit.



## 5.2 STATE

Applicants must submit a satisfactory permit application at least 60 days before the date of the proposed discharge. The applicant will receive a temporary permit if Ecology fails to act upon the application within 60 days. The temporary permit is conditional upon the applicant having completed SEPA process. Any action within the 60

- day period from the time of filing also prevents the temporary permit from becoming effective

. Typically, this action would be a
notification to the applicant that the application was not satisfactory for Ecology to process the permit

.



## 6

. TIME OF REAPPLICATION

All Permittees must reapply for permits every five years (40 CFR 122.46(a)) (RCW 90.48 .180). This includes temporary permits and permits extended during application if the application period extends for five years. An NPDES permit extended for 5 years during application must be reissued upon the second application.



## 7. CONFIDENTIALITY OF INFORMATION

A permit writer is occasionally requested to keep confidential the informati on obtained during the permit application process. A permit writer cannot grant confidentiality because the authority is vested only to the director or those delegated the authority by the director.

The federal regulations (40 CFR 122.7(c)) state that in formation required by NPDES application forms may not be claimed as confidential. Information not explicitly required on the NPDES forms and information required on forms for state waste discharge permits is subject to the state
Public Disclosure Act codi fied in Chapter 42.17 RCW. Confidentiality is also addressed in Chapters 43.21A and 90.52 RCW.CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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- 23 The Public Disclosure Act generally makes all information normally submitted to Ecology as part of the permit process subject to public disclosure except "Val uable formulae, designs, drawings, and research data obtained by (Ecology) within 5 years of the request for disclosure when disclosure would produce private gain and public loss."

RCW 43.21A.160 provides that upon request, the director of Ecology may tre at certain information furnished as confidential if such information relates to processes unique to the person providing the information, or if such information might adversely affect the competitive position of that person if released to the public, provi ded that such action would not be detrimental to the public interest.

RCW 90.52.020 states that Ecology shall provide proper and adequate procedures to safeguard the confidentiality of manufacturing processes. The confidentiality shall not extend to wast e products discharged into the waters or air of the state.

The request for confidentiality must accompany the information for which the request is made. If the information is a part of the NPDES application form then no confidentiality can be granted. O ther information is considered by the appropriate section head, as a delegate of the Director, as to whether it may be deemed confidential. The AG's have not provided guidance as to the interpretation of "public loss" or "detrimental to the public interes t". Determination of "public loss" or "detrimental to the public interest" will therefore be made on a case

- by

- case basis.



## 8. DOMESTIC SEWAGE EXCLUSION

In some instances industrial dischargers to POTW’s are allowed to discharge dangerous waste if
the was te is treat ed in the POTW. The judgment on treatability is made by conferring with the regional hazardous waste and toxics reduction section.

Section E, question 8 of the state permit application for discharge to a POTW asks if the
wastewater to be disch arged designates as a dangerous waste according to procedures in Chapter
173

- 303 WAC. The applicant may answer yes, no, or don’t know. If the applicant answers yes they complete the following question 8 on the application which asks for the details on ho w the waste designated. In some cases it will be immediately apparent that some dangerous wastes cannot be discharged. For example, any wastewater that designates because of characteristics (ignitable, reactive, corrosive, TCLP) would not be allowed to b e discharged without treatment. In other cases, such as with dilute listed waste or state

- only toxic waste (see Appendix 3.1), it will not be immediately apparent if the discharge is allowable. In these instances the permit
writer should confer with the regional hazardous waste and toxics waste reduction section.CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

Permit Writer’s Manual
III

- 24 If the applicant answers question 7 “no” or “don’t know” the permit writer must use information from other parts of the application and from experience to judge the presence of dangerous waste
i n the wastewater. If dangerous waste potential exists the permit writer should confer with the regional hazardous waste and toxics waste reduction section about the course of action on the permit.

Dangerous waste discharges are subject to source reductio n (pollution prevention) measures
under :



## • HWTR interpretive policies for the Domestic Sewage Exclusion

.



## • 40 CFR Part 403.12(p)(4), referenced in WAC 173

- 208

.

The permit writer should confer with Regional Hazardous Waste and Toxics Reduction staff for
info rmation on source reduction opportunities. In many cases, source reduction can offer the applicant a variety of attractive benefits.

Case study examples for some common pollutants:

1. Formaldehyde

-- treatable Formaldehyde is an animal carcinogen, suspected human carcinogen, and mutagen which is a State toxic dangerous waste at 10% concentration. Fate modeling indicated that formaldehyde would probably be 84% biodegraded in an extended aeration activate sludge sewage treatment plant. King County has chosen to accept this waste based on its treatability (i.e., biodegradability) and low potential for interference.

2. Antifreeze

-- recyclable Ethylene glycol antifreeze is a State toxic waste that can be economically recycled through on

site filtration or off

- site r e

- refining. Rather than accept this high

- BOD waste, King County has established recycling of antifreeze as a best management practice.

3. Dry Cleaner Separator Water

-- dilute listed waste Dry cleaner separator water is saturated with perchlorethylene (tetrac hlorethene), a listed waste. Because the concentration of the solvent can range from 300 to 3000 mg/l, it does not meet the HWTR policy criteria for "dilute listed wastes" mentioned in the regulatory language of the domestic sewage exclusion. The WQ and HWTR programs have agreed not to allow disposal of separator water to the sewer.CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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- 25 WASTESTREAM IS IDENTIFIED BY INDUSTRIAL USER SURVEY, SITE VISIT, OR STATE PERMIT APPLICATION Figure III-5. Interpreting the domestic sewage exclusion (DSE).

IS THE DISCHARGE TO

A POTW? THE DSE

DOES NOT APPLY NO

DOES THE PROPOSED DISCHARGE/WASTESTREAM DESIGNATE AS A DANGEROUS WASTE? YES

NO

DOES THE PROPOSED WASTE EXHIBIT THE DANGEROUS WASTE

CHARACTERISTICS , SUCH AS IGNITABILITY, CORROSIVITY,

REACTIVITY OR TCLP?

I S THE WASTE A PERSISTENT DANGEROU S WASTE (HALOGENATED HYDROCARBONS >100 PPM) OR A PAH GENERATOR GREATER THAN > 10,000 PPM OR A

SOLI D /CORROSIVE WASTE? NO

THE WASTE IS A TREATED WASTE, A DILUTE LISTED WASTE OR A STATE ONLY DW DUE TO ITS TOXICITY NO YES

YES

HAVE AKART AND P2 BEEN APPLIED TO THE WASTE? NO

YES

IS THE WASTE SUITABLE FOR DISCHARGE TO

A POTW? NO

DOES THE POTW AGREE TO ACCEPT THE WASTE? YES

PROHIBIT THE DISCHARGE ISSUE STATE WASTEWATER

DISCHARGE PERMIT WITH APPROPRIATE LIMITATIONS NO

YES YES

IS TREATMENT AVAILABLE TO REDUCE

CHARACTERISTICS? DISCHARGE IS PROHIBITED UNDER THE DSE AND PRETREATMENT RULE. TALK TO HWTR STAFF ABOUT DISPOSAL OPTIONS APPLY TREATMENT/P2

YES

NOCHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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- 26 

## 9. OWNER/OPERATOR AGREEMENTS

Municipalities frequently contract the operation and maintenance of the wastewater treatment plant

. This requires some speci al consideration from Ecology.


## 9.1. Ecology Must Review Agreements

RCW 70.150 authorizes a public body to enter into service agreements to design, finance, construct, own, operate or maintain water pollution control facilities. Before a public body

enters into a service agreement to provide any of these services, the agreement "shall be reviewed by the department of ecology to ensure consistency with the purposes of chapters 90.46 and 90.48 RCW." RCW 70.150.040(9). Ecology does not have the resources to r eview all municipal agreements pertaining to water pollution control facilities ; therefore, Ecology will only review contracts for operation of wastewater treatment facilit ies

. 

## 9.2 NPDES Permittee under Owner/Operator Agreement

Under section 301(a) of the Clean Water Act, 33 USC section 1311(a), "the discharge of any pollutant by any person shall be unlawful" unless the discharge is authorized by an NPDES permit. This prohibition suggests that both the public owner and the private operator need to be permi tted since both the owner and operator are "persons" who will be discharging pollutants. However, under 40 CFR section 122.21(b), when a facility is owned by one person but operated by another, it is the operator's duty to obtain a permit. While this reg ulation suggests that only the private operator needs to be permitted, the regulation only says it is the operator’s duty to obtain a permit. It does not address who should be listed as permittee(s) on the permit

.

In general, it is the Water Quality Prog ram’s policy to identify contract operators as co

permittees on individual municipal NPDES permits, to address both state and federal requirements for permittees. The policy is based on advice from the Attorney Generals’ Office and was accepted by the PCH B in its Har t stene Opinion ( Order on Summary Judgment, PCHB
No. 09

- 152, WSUD and Har t stene Point e WSD v. Ecology).

However, in the Har t stene Opinion, the Board stopped short of stating that in every case, co

permittee status for owners and operators is ap propriate. As a result, Ecology must decide on a

case

- by

- case basis if identifying the operator as a co

- permittee is appropriate.

In reviewing any service agreement for wastewater operating services, Ecology staff should:

• Review the service agreement usi ng the recommended contract provisions following Section 9.3 as a guide.

• Discuss with a supervisor any need for AG assistance, and if necessary, request that an AAG review the service agreement. An AG review may be helpful for complicated

contracts

.CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

Permit Writer’s Manual
III

- 27 • Withi n 30 days of receipt of the agreement , respond in writing to the municipality. 1 2

In deciding whether to identify a contract operator as a co

- permittee, Ecology staff and managers
should:

• Consider the extent of the operator’s control over the treatment sys tem, as described in the service agreement

.

• Consider the experience and record of the operator at other facilities.

• Consider the performance and enforcement provisions in the service agreement between the owner and the operator.

• Review the recommendations or comments from the Attorney General’s office.

• Make a reasoned decision based on the facts

, Ecology guidance, and the manner in which the entities ’ service agreement define s the responsibilities each will have (see the Hartstene Opinion, pages 8 and 9).

The nature of these service agreement s is commonly one of shared responsibility for the facility. As a result, Ecology may commonly identify the operator as a co

- permittee. In the Har t stene decision (pages 7

- 8), the PCHB noted:

The undisputed facts esta blish that both Hartstene and West Sound are responsible for operation and maintenance of the plant.... Hartstene , as owner of the physical plant, is responsible for capital improvements and expenditures related to maintenance, and is “ultimately responsibl e for compliance” with permits issued by Ecology and other agencies. However, the Interlocal Agreement between Hartstene and West Sound for the operation of the Plant is premised on the fact that Hartstene lacks qualified employees to operate the plant, and therefore looks to West Sound to manage and operate the sewer system. Indeed, the very purpose of the agreement is to have West Sound provide its expertise and staff to Hartstene for Plant operation.... Both the owner and the operator
have duties in rel ation to Plant operations, and those operations result in discharges to state waters. Discharges must be consistent with permit terms, and both parties must ensure compliance with the same. Given the facts, and Ecology’s broad authority under the NPDES p rogram to control the discharges of pollutants to waters of the state, Ecology was well within its authority to require both entities to be named as permittees on the NPDES permit.

Ecology staff and managers should assume that co

- permittee status will be necessary to ensure

1 Ecology does not need to approve the contract. RCW 70.150.040 (9) reads in part: Before any service agreement is entered into by the public body, it shall be reviewed by the Department of Ecology to ensure consistency with the purposes of chapters
90.46 and 90.48 RCW. The Department of Ecology has thirty days from receipt of the proposed service agreement to complete its review and provide the public body with comments....

2 The Attorney General may not b e ab le to respond within Ecology’s 30

- day statutory deadline. In such cases, Ecology staff should respond within the 30

- day statutory deadline and if the agency has req uested review by the AG, note that the agency may
forward additional comments or make a decision on co

- permit t ee status once that review is complete.CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

Permit Writer’s Manual
III

- 28 permit compliance when inspections or compliance reviews reveal un

- resolved management, operation or maintenance issues, especially those that have caused permit violations. As with any “co

- permittee” designation, the service agreement must support the co

- permittee
determination.

There are also facilities where Ecology staff and managers may consider issuing the permit to the owner only, including facilities where:

1. Listing the contractor as a co

- permittee would create a disproportiona te burden for a small community to attract an operator, due to location or other factor; or 2. The service agreement is for a limited duration; for example, to provide temporary service until the owner can hire a permanent contractor, or to train staff; or 3. Th e need for enforcement has been or is expected to be low; for example, at larger facilities where owner resources and planning have historically addressed capacity or operational problems before they arise. 4. The operator has a superior record of compliance at the facility or other facilities ; and the service agreement allows the owner to enforce on permit requ irements as a matter of service agreement complian ce.

In cases were Ecology issues the permit to the owner only, the service agreement should address
the recommended provisions that follow Section 9.3 ( Recommended Service Agreement Provisions for Wastewater Treatment Plant Operations )

.

Naming a contract operator as a co

- permittee is an important decision with ramifications for both the operator and the owner. Operators that are co

- permit t ees:

• Are subject to Ecology enforcement and third party liability.

• Face potential capital expenditures (the contract should clearly identify the owner as responsible for capitol costs) that logically should fall on the owner.

• May turn down contracts that result in exposure, especially at small facilities where problems arise from a lack of resources.

Contract operators facing a greater risk may pass their risk

- related costs (including insurance)
onto the owner. While exposure can be handled via contract, there is a transactional cost associated with contract enforcement. C o

- permit t ee status complicates the owner

- contractor relationship in a manner that Ecology staff may not appreciate.

Accordingly, when Ecology is pr oposing co

- permittee status at a facility, Ecology staff and management ( i.e

. the Section o r Field Office Manager) should consider meeting with the facility owner and the contract operator, to discuss conce rns and consider alternatives.

In all cases, the decision to identify the operator as a co

- permit t ee resides with the Section or Field Office Manager, as delegated by the Program Manager.CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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III

- 29 Finally, it is critical that permit writers note the contractor’s responsibilities in the fact sheet (using the se rvice agreement as a reference) and document the decision to identify (or not) the operator as co

- permittee.


## 9.3 State Permittee under Owner/Operator Agreement

With respect to state waste discharge permits, under WAC 173

- 216

- 110(8), permits for domestic

wa stewater facilities shall be issued only to a public entity, however, if a domestic wastewater facility is owned by a nonpublic entity under contract to a public entity , a joint permit shall be issued to both the public and non

- public entity.

------------- --------------------------------------------------------------------------------------------- Recommended S ervice A greement Provisions for Wastewater Treatment Plant Operations

The service agreement should define the facilities covered by the agreement (e .g., treatment plant, pump stations, collection system, pretreatment program), and include provisions addressing:

• Responsibility for management, operations, maintenance, and capital improvements

• Permit compliance

• Permit renewal process (application and en tity review)

• Monitoring and reporting

• Record keeping

• Solids handling

• C overage including vacation coverage , emergency and non

- routine operations.

• Ordering and payment for supplies and equipment

• Capital improvements

• Communication between the contractor and owner addressing the state of the facility

• Contractor transitions

• Penalty responsibilities

• Responsibility for implementing pretreatment requirements

• C ompensation, insurance, indemnification, and Force Majeure.

Ecology recommends that the owner/operator wr ite the service agreement in the “active voice” to make it clear which party is responsible for each activity.

The service agreement should ensure that the contractor will:

1. Manage and operate the plant to meet permit requirements and prevent nuisance

con ditions. 2. Notify Ecology as required by the permit reporting conditions, in particular reporting for

non

- compliance. 3. Calibrate, maintain and repair all equipment to manufacturers’ specifications, and to preserve warranties.CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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- 30 4. Operate the facility according to the Ecology

- approved operation and maintenance manual. 5. Repair equipment in an expeditious manner to ensure that it is serviceable at all times. 6. Staff the plant with certified operators, at the appropriate level. 7. Obtain and maintain laboratory certificatio n for permit

- required analysis, unless the facility uses a contract laboratory; and use the appropriate test methods as defined in the permit and as accredited. 8. Prepare monthly DMRs and any other DMRS at the required permit frequency. The owner may retain or delegate signature authority, and may take responsibility for other reporting. 9. Allow Ecology to inspect the facility, inspect and copy records, and sample any substances or parameters necessary to determine compliance with the permit, at reasonable tim es, with or without prior notification. Reasonable times include after

hours site visits during non

- routine operations. 10. Cooperate with the owner on planning, design, construction and audits. 11. Keep permit

- related records for three years or longer for record s related to any unresolved litigation regarding the discharge of pollutants by the Permittee, or when requested by Ecology

. 12. Provide for termination of the service agreement for cause or convenience

.CHAPTER III. THE APPLICATION AND BACKGROUND REVIEW (JULY 2011)

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III

- 31 This page is purposely left blankCHAPTER IV. DERIVING TECHNOLOGY

- BASED EFFLUENT LIMITS (JULY 2011)

Permit Writer’s Manual
IV

- 1 

# CHAPTER IV. DERIV ING TECHNOLOGY

- BASED EFFLUENT LIMITS

This chapter, chapter VI and chapter VII discuss the major task of writing a wastewater discharge permit

- deriving the effluent limits. The effluent limits restrict the amount of pollutants that may be discharged. Ef fluent limits may be based on the technology which is available to treat the pollutants at a reasonable cost (technology

- based) or they may be based on the effect of the pollutants in the receiving water (water quality

- based), whichever is most stringent. Derivation of the effluent limits, whether they're based on technology, as discussed in this chapter or on water quality, as discussed in following chapters, is the core task of permit writing and often the most complex task.

Effluent limits are process control parameters or numbers which indicate that a process, which in this case is wastewater treatment, is functioning properly.

Not all of the pollutants in an effluent are limited with numeric limits. A pollutant may not require an effluent limitation if it meets all of the following:



### • Its concentration is too low to be treated at a reasonable cost; and

,



### • It can’t be eliminated by production changes or best management practices; and

,



### • There is no potential for causing surface or ground water quality or se diment quality standards violations; and

,



### • It is not listed in regulations, such as effluent guidelines.

There are two general approaches to deriving technology

- based effluent limits. A permit writer can use Federal effluent guidelines, if they are applic able and appropriate, or develop effluent limits specifically for an individual discharger or pollutant (case

- by

- case). In some cases a permit may contain both types of effluent limits.

This chapter discusses the derivation of technology

- based effluent l imits from the federal effluent guidelines, provides a step

- by

- step process on how they're used and details some problems with them. An example is provided to demonstrate the use of effluent guidelines. This chapter also discusses the development of techn ology based effluent limits on a case

- by

case basis under state (AKART) and federal authority.

Flow charts at the end of the chapter illustrate the process of developing technology

- based

effluent limits.

Adjustment of effluent limits to account for autoc orrelation is discussed in Part 4 of this chapter.CHAPTER IV. DERIVING TECHNOLOGY

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- 2 

## 1. EFFLUENT LIMITATION GUIDELINES

The Federal Water Pollution Control Act of 1972 (Clean Water Act) directed EPA to develop standards of performance (effluent limitations) for industrial categories. Spec ifically, the law required existing industrial dischargers to achieve "effluent limitations requiring the application of the best practicable control technology currently available (BPT)" by July 1, 1977. The law also required dischargers to achieve "effl uent limitations requiring the application of the best available technology economically achievable (BAT)" by July 1, 1983. Other performance standards to be developed were new source performance standards (NSPS) for new direct dischargers and pretreatmen t standards for indirect dischargers. The Administrator ( of EPA ) was given one year to develop and implement these performance standards.

EPA was unable to complete all effluent guidelines within the statutory deadline due to technical problems and press ure from various trade associations. In addition, EPA did not fully address toxic discharges in the guidelines it did promulgate. As a result, in 1976, EPA was sued by several environmental groups for failing to accomplish the promulgation of effluent gu idelines as directed in the Clean Water Act. The EPA and the environmental groups reached a settlement agreement which required EPA to develop a program and adhere to a schedule for promulgating BAT effluent guidelines, pretreatment standards and new sour ce performance standards for 65 priority pollutants and classes of pollutants. This agreement was limited to a group of 21 major categories of industries which became known as the primary industries. These are listed in 40 CFR 122 Appendix A. This settl ement was incorporated into the 1977 amendments of the Clean Water Act. The 1977 amendments also redefined BAT to include only toxic and nonconventional pollutants. The deadline for meeting BAT limits was 3 years after their promulgation but no later tha n July 1, 1987 (The 1987 amendments to the Clean Water Act have moved this deadline to March 31, 1989). The 1977 amendments also redefined BAT for conventional pollutants to become "best conventional pollutant control technology (BCT)." The

deadline for achieving BCT was July 1, 1984 but the date was amended to become March 31,

1989.

When Congress enacted the 1977 amendments

, they also required that a cost test be applied to any treatment that was proposed for BCT (more on the cost test later, in the cas e

- by

- case permits section). The EPA developed and published the regulations for BCT in 1979. At the same time the EPA published BCT limits for 41 industrial subcategories. This 1979 regulation was challenged and the final BCT methodology was not adopted until 1986.CHAPTER IV. DERIVING TECHNOLOGY

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- 3 All of the proceeding is to show some of the gyrations on the way to achieving the intent of Congress to develop technology

- based performance standards. It also helps to explain why some of the effluent guidelines, such as feedlots, contain BAT requirements for conventional pollutants or BCT limits that were never imposed. For more information on the history of the promulgation of effluent guidelines ( see Miller, et al. 1990 ) .Miller, L.A., R.S. Taylor, L.A. Monk. 1990. NPDES Permit Handbook . Government Institutes, Inc., Washington, D.C.


## 1.1 A Summary of Some Treatment Standards as Currently
Defined

BPT

- Best Practicable control Technology currently available

- applicable to conventional pollutants

- to be achieved by July 1, 1977

BCT

- Be st Conventional pollutant control Technology (BCT)

- the level of treatment that succeeds BPT for conventional pollutants. The deadline for achieving BCT was July 1, 1984 but was changed in the 1987 amendments to March 31, 1989.

BAT

- Best Available Tech nology economically achievable

- applicable to toxic pollutants

. The deadline for achieving BAT was July 1, 1983 but was changed by the 1987 amendments to March 31, 1989.

We now have performance standards (effluent limitation guidelines) for 52 groups or categories of industries and over 1,000 performance standards for all the subcategories. EPA typically developed these performance standards after completing the following tasks:



## • Performing a literature search to obtain the latest information on treatmen t processes;



## • Conversing with regional and state staff with experience pertaining to the industry;



## • Reviewing any comparable industrial limitations;



## • Conducting industrial plant surveys to collect statistical data on operations;



## • Conducting site visits, sampli ng, and evaluation of selected industrial sites;



## • Soliciting public comment from industrial representatives and the public at large;



## • Conducting an economic analysis of the impact of the identified treatment technology on the industry.

EPA estimated that i t required 2

- 5 years to develop each set of standards. The cost for each set of standards ranged from two million to 20 million dollars for technical contractors plus betweenCHAPTER IV. DERIVING TECHNOLOGY

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- 4 3 and 25 person

- years of EPA staff effort. The list of industries for which EPA has developed effluent guidelines is given in 40 CFR 122 Appendix A. The information that EPA developed is available in several forms. The most informative are the development documents prepared by

EPA. These documents contain the technical and economi c information from which the effluent guidelines were developed. The effluent guidelines are summarized in 40 CFR Parts 400

- 471.



## 1.2 Steps for Using Effluent Guidelines

STEP 1. Categorize the discharger. To be able to use the effluent guidelines it's nece ssary to know the processes at the facility you're permitting. Then if you're lucky, the facility will fit cleanly into a category and subcategory.

STEP 2. Learn about the category of discharger. To be able to write an effective permit, the permit writer must know the pollutants that are being discharged or have the potential to be discharged. This usually requires an understanding of the manufacturing processes that take place at a facility. There are several sources of information available to a permi t writer to learn about an industry.



## • The EPA Development Documents that were discussed previously are an excellent
source of information. More recent literature is sometimes available. Contact the Ecology library for a search.



## • EPA has industry experts lo cated in Washington, D.C. and in the regional offices

. EPA lists these experts in the training manual for the permit writing course. Call the
P rogram Development Services Section for assistance if you have difficulty finding or contacting these people.



## • T rade associations for the category of discharger can be sources of information.



## • The pre

- permit inspection of the facility being permitted is informative. This inspection is most valuable if the permit writer has done some background work before the inspec tion.

STEP 3. Decide on category. This is a decision point for the permit writer. The permit writer must decide after reading the development document, reviewing the application, and inspecting the facility whether the facility being permitted has essent ially the same kind of manufacturing processes as described in the development document. If the manufacturing process and the pollutants which are generated have changed to the extent that it is no longer described in the development document, the permit
writer must do case

- by

- case development of effluent limits. Outdated development documents may become more common as time goes by.CHAPTER IV. DERIVING TECHNOLOGY

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- 5 STEP 4. Decide on treatment. This is another decision point for the permit writer. The permit writer must decide if the

tr eatment process described in the development document is currently the best available. If it is not then the permit writer must do a case

- by

- case determination of the effluent limits.

STEP 5. Decide on the production base

. Most of the EPA effluent guidel ines are mass limits based on production as opposed to concentration limits (see the example at the end of the chapter). Production

- based limits cause a problem for permit writers in verifying the production base. The company may want to claim as high a production as possible to get higher effluent limits and thus not have to worry about compliance problems. The permit writer wants the production estimate to represent, as accurately as possible the production during the life of the permit. The Federal p ermit application asks the applicant for the facility maximum production but what the permit writer needs is an estimate of future average annual production. The derivation of the effluent guidelines incorporates an allowance for the daily and monthly var iations. The best estimate of future production is generally the production of the past year. In some cases the past year may have been a boomer for them and the next few are going to be bust. In that case, by basing the effluent limits on the past year s production you would be allocating more pounds of discharge than necessary. You may wish to use the highest year ly production of the last five years as the production base. If the company knows that there will be a substantial (25%) increase in product ion sometime during the course of the new permit, you may offer them alternate limits to be effective at the time they begin increased production. The company should have committed the capital expenditure and completed the design before alternate limits a re used, otherwise, modify the permit at the time of increased production.

Production levels may be verified by checking the previous year’s monitoring data. Assuming that water usage is proportional to production, you should be able to detect any change s

. The development document for the industry may have some water use/production data. The production data that you receive on the application is certified by the signature of the responsible official to be correct and subject to criminal enforcement if d eliberately false. This creates a strong incentive for not falsifying information. That person should understand that any information submitted subsequently during the permit process is also certified. If you have a basis to suspect that any production information is incorrect, you may ask to review their books
or ask for some other verification.

STEP 6. Apply the effluent guidelines to derive limits. The final calculations of the effluent limitations should be done from the effluent guideline

summaries found in 40 CFR Parts 400

- 471. Although the effluent limits in the developmentCHAPTER IV. DERIVING TECHNOLOGY

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- 6 documents and the CFR are usually the same, the CFR's are the most current regulatory version.

In this state there is another decision to be made at this point. The decision is whether the effluent guidelines also constitute all known, available and reasonable methods of treatment (AKART). AKART is discussed in detail in Part 3 of this Chapter. As a general rule, if the effluent guidelines for a particular category are 5 ye ars old or less they will be AKART and this will be immediately apparent in reviewing the development document. If the effluent guidelines are between 5 and 10 years old they are probably AKART but the permit writer should review the treatability data bas e for a determination. If the effluent guidelines are over 10 years old, the permit writer should

, at the minimum, conduct an analysis of unit processes design and

efficiencies at the facility to determine if the effluent guidelines constitute AKART.



## 1.3 Multiple Processes

For industries with only one process and relatively constant production, the production

- based effluent limits are simple to calculate and monitor. Now consider the Seafood Processors as a good example of some problems with production

- ba sed effluent limits. In our state, many seafood processors work on a variety of seafood. A typical processor in the coastal area might work on shrimp, salmon, bottom fish, and crab. On any given day the processor might be working on one or all of these products depending on what's available and the market demand

. Each of these products has production

- based effluent limits within Part 408

- Canned and Preserved Seafood Processing Point Source Category for the pollutants TSS, oil/grease, and pH

for existi ng sources. The treatment process identified as BPT treatment is screening of solids from the waste stream. Some product subcategories also include some management practices to reduce pollutants. To verify that the process is within the production

- based effluent limits requires daily monitoring of effluent and a daily production report. The purpose of monitoring is to verify that the treatment process is working properly; therefore, some permit writers have simply placed requirements in the seafood perm its for a daily check on the condition of the screen but with no effluent monitoring. This is contrary to regulations which require sampling at least once per year for those parameters in the effluent guidelines. This has also resulted in another problem because the permit writer has not built a data base to determine the potential for water quality standards violations from the discharges.

A similar difficulty exists with fruit and vegetable processors who run a mix of products and then

treat the wastew ater in a lagoon system with a 30

- day detention. The effluent which is analyzed is not representative of the production process for that month.CHAPTER IV. DERIVING TECHNOLOGY

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- 7 

## 1.4 Mass vs. Concentration

Effluent limits expressed as mass (pounds or kilograms per day) create an opportunit y for inefficient operation of a treatment process so a permit writer should consider using concentration limits (milligrams per liter) in addition to the mass limits.

An example would be a company that has effluent limits for pollutant X of 390 pounds/da y daily maximum and 260 pounds/day monthly average. These limits are based on annual production of widgets. The annual average flow is 0.9 MGD and the maximum daily flow is 1.6 MGD.

During periods of reduced production and flow (0.5 MGD) the company is able to reduce the efficiency of their treatment apparatus and still meet the monthly average mass limit of 260 pounds/day.

Under Average Production and Flow (0.9 MGD)

260 LBS/DAY /[(8.34)(0.9 MGD)] = 35 mg/L

Under Reduced Production and Flow (0.5 MGD) 260 LBS/DAY/[(8.34)(0.5 MGD)] = 62 mg/L

The number 8.34 in the formulas above is a conversion factor to get from pounds per million gallons to milligrams per liter. The first formula for Average Production and Flow with the units expressed as follows:

Unit cancellation results in mg/l. Note that MGD (millions of gallons per day), is expressed as MG divided by day(s) so day(s) will cancel correctly.



## 1.5 Some Solutions

The regulatory objective of effluent limits is to assure that the wastewater treatme nt process is being run as efficiently as possible and meeting the long term average (LTA) . Some solutions to the problems identified above include the use of concentration limits, requiring a statement of production, specifying the efficiency of the trea tment process and doing an annual balance. 260 lb

day 0.9 MG day x 1 MG mg 8.34 lb l = 34.64 mg l •

• • •

• • •CHAPTER IV. DERIVING TECHNOLOGY

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- 8 In the example above the permit writer could have specified an effluent limit of 35 mg/L in addition to the 260 lbs/day limit. This would have forced continued efficiency during periods of reduced production. I ncorporating concentration limits might discourage a facility from practicing water conservation. By reducing water usage in a process while continuing to provide good waste treatment the mass discharge might be reduced but the concentrations exceed

month ly and daily limits, therefore, a permit writer who places concentration limits in a permit in addition to the mass limits, should allow some exclusion from those concentration limits if there

is a demonstration of water conservation.

Another option for t he permit writer is to specify treatment efficiency by mass and concentration

. This is already incorporated into the municipal effluent limits for secondary treatment. The percent removal efficiency could be based on the design efficiency of the plant as specified in the approved engineering report.

A third option that is especially suitable for mixed production such as the seafood processors above is to require a statement of monthly production. This is commonly required in the permits for pulp mills w hich have a mix of products.

A fourth option to assure the efficient operation of the treatment process is to place some type of operating parameter as the daily control mechanism and then to run the balance sheet at the year end. This might be appropria te for the food processor example above. This option would be consistent with the way effluent limits were derived. As noted earlier, the production based effluent limits may have been derived on an annual basis and the monthly and daily limits

calculate d with the use of variability factors. This annual balance sheet creates a great deal of uncertainty for both the regulator and the regulated.



## 1.6 Outdated Effluent Guidelines

Frequently, the permit writer will find that the effluent guidelines are outdat ed such that the industrial processes or process pollutants are no longer accurately described. In this case the permit writer must derive effluent limits on a case

- by

- case basis as described previously in this chapter.CHAPTER IV. DERIVING TECHNOLOGY

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- 9 EXAMPLE IV

- 1 WOOL FINISHING EFF LUENT LIMITS This example is a company that receives cleaned wool, wool yarn, and wool fabric and produces finished wool yarn and fabric. This example is typical of the type of problems encountered when using effluent guidelines.

This company belongs to the category of industries called "textile mills". For this company the category is apparent. For some industries it's not so easy to determine the industrial group. For an industry that's not obvious, the permit writer may be able to use the SIC (Stan dard Industrial Classification) code information that the company supplies on the permit application form. The SIC numerical system was originally developed and used by the Federal government for tax and data gathering purposes. EPA adopted it as part of their categorization system

.

The Ecology library contains the EPA documents relating to the development of effluent limits

for textile mills.

For this industry there are several documents dated from 1974 to 1982. The earliest document is

called "Develo pment Document for Effluent Limitations Guidelines and New Source Performance Standards for the TEXTILE MILLS Point Source Category" (June 1974)

.

This 1974 document proposed BPT limits to be imposed by 1977, BAT limits to be imposed by
1983 and New Source Performance Standards (NSPS). The BAT parameters included fecal coliform and color (remember the discussion from the earlier section that BAT was initially for conventional pollutants). The proposed BAT guidelines were rescinded as a result of a

success ful challenge in court by the industry.

The next two documents were released by EPA in 1979. They are the "Proposed Effluent Limitations Guidelines, New Source Per formance Standards and Pretreatment Standards for TEXTILE MILLS Point Source Category" and "Economic Impact Analysis of Proposed Effluent Limitations Guidelines...". These guidelines redefined the industry and added some additional subcategories. BAT was now defined by the CWA as control of toxic pollutants. For

textiles BAT is defined as th e existing BPT. The NSPS is changed in this document and the pretreatment standards are given

.

These early documents are interesting from a historical perspective but the most pertinent and current document is the one released in 1982. This final "Devel opment Document for Effluent Limitations Guidelines and Standards for the Textile Mills Point Source Category" EPA 440/1

- 82/022 contained very few changes from the 1979 proposed guidelines

.CHAPTER IV. DERIVING TECHNOLOGY

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- 10 The effluent limitations are summarized in 40 CFR Part 410 which are reproduced on the following two pages. These regulations also include definitions that sometimes become important criteria for application of the regulations. Occasionally a question will arise that cannot be answered by reviewing the development doc ument or the regulations. In this case the permit writer should also review the Federal Register in which the effluent limits were promulgated. Many times, the EPA response to comments will clarify the regulatory intent. These effluent guidelines were p ublished in 47 FR 38819 on September 2, 1982 as noted in the CFR's.

The current development document describes how the industry was categorized and subcategorized. In addition, there are sections on wastewater characteristics, the pollutants of concern, control and treatment technology, non

- water quality aspects including costs, and recommendations for BPT, BAT, and NSPS effluent limits.

For more information about a particular aspect of the industry process, get the appropriate

references listed in the d evelopment document and request a computer search from the department library for more recent papers. Contact the Program Development Services Section to see if there is someone there or elsewhere in Ecology knowledgeable about the industry.

The producti on processes at this example facility fit the subcategory called wool finishing. In this case, it's particularly easy to determine because there is a flow chart describing the process (Figure IV

- 1). The other subcategories that are described are wool sco uring, low water use processing, woven fabric finishing, knit fabric finishing, carpet finishing, stock and yarn finishing, nonwoven manufacturing, and felted fabric processing.

The permit writer in this example reads the development document and inspects the facility. The permit writer decides that this particular woolen mill is adequately described by the development documents and the processes are essentially the same as described in the development document

.

The company claims they are an integrated facility because in addition to being covered under wool finishing they are covered under the woven fabric finishing subcategory. A review of the development document reveals that wool and wool blends are not covered in the woven fabric finishing subcateg ory because fabric finishing was included as a process in the wool finishing subcategory. There is no additional discharge allowance on that basis.CHAPTER IV. DERIVING TECHNOLOGY

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- 11 EXAMPLE IV

- 1 ( continued )

THIS PAGE CONTAINS A REPRODUCTION OF THE CFRCHAPTER IV. DERIVING TECHNOLOGY

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- 12 EXAMPLE IV

- 1 ( continued )CHAPTER IV. DERIVING TECHNOLOGY

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- 13 EXA MPLE IV

- 1 ( continued )

Figure IV

- 1

Wool Stock & Top Wool Yarn Wool Fabric

CARBONIZE AND SCOUR CARBONIZE AND SCOUR

FELT AND RINSE

BLEACH

AND RINSE

LIGHT SCOUR

DYE

WASH

FINAL FINISH BLEACH

AND RINSE

LIGHT SCOUR

DYE

WASH

SPIN OIL AND

CARD LIGHT SCOUR

DYE

WASH

SIZE (Warp Yarns)

KNIT OR WEAVE

Wool Yarn Wool Fabric Finished Fabric Water Liquid Waste

Liquid Waste

Liquid Waste

Liquid Waste

Liquid Waste

Liquid Waste

Liquid Waste H 2 SO 4 and Na 2 CO 3

Detergent: Acid and/or Alkali

H 2 O 2

Scouring Agents

Dyestuffs and Auxiliary Chemicals

Detergents

Lubricants, Sizing, and Finishing Agents

(TOP) (YARN) (FABRIC) (From Cleanup)CHAPTER IV. DERIVING TECHNOLOGY

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- 14 EXAMPLE IV

- 1 ( continued )

When industry requests to be included in a different category that would allow higher pollutant discharge and the permit writer determines that the request is not justified, the

reasons shoul d be explained in the fact sheet.

The effluent limits for the wool finishing subcategory are given as pounds of pollutant per 1000 pounds of fiber processed (this type of limit is called a production

- based effluent limit as opposed to a concentration limi t). The regulated pollutants for BPT are BOD5, COD, TSS, Sulfide, Phenol, Total Chromium and pH. The regulated pollutants for BAT are COD, Sulfide, Phenols, and Total Chromium with the same effluent limits as for BPT. The limits for BCT haven't been pro mulgated. This is noted in 40 CFR 410.27 by the words

"reserved"

.

A textile mill submits the following information on an application for permit renewal.CHAPTER IV. DERIVING TECHNOLOGY

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- 15CHAPTER IV. DERIVING TECHNOLOGY

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- 16 EXAMPLE IV

- 1 ( continued )

The company also indicates in their applicatio n that the maximum raw material usage at the facility is 19,500 pounds per day. The permit writer requests more information on the raw material usage, including some supporting data. The company replies that the 19,500 pounds includes the maximum daily u sage and a planned increase during the next 5 years. The permit writer requests detailed raw material usage and tells the company the permit will be based on current production with a permit modification later, if necessary to accommodate increased produc tion

. The typical materials taken in for processing in the wool finishing operation are washed and dried wool (stock), yarn, and fabric

. The applicant, mill X, submits information showing they receive and process 12,627 pounds of stock, 3,294 pounds of c loth, and 1,306 pounds of yarn per day

. It receives the cloth and yarn from company mill Y located in another state

. The applicant claims that the 3,294 pounds of cloth represent 3,765 pounds of original stock and the difference is wastage

. Similarly th ey claim the 1,306 pounds of yarn represents 1,606 pounds of stock

. The applicant claims 17,998 pounds as the production base (12,627 + 3,765 + 1,606)

. The permit writer allows 17,281 pounds as the production basis. The definition of fiber in 40 CFR 410 .21 is wool and other fiber as received at the mill. The production base for facility X does not include material processed or partially processed at facility Y.

The effluent limits for the permit are calculated as: 22.4 X 17.281 = 387 pounds per day ma ximum BOD 11.2 X 17.281 = 193.5 pounds per day average BOD

and so on for the other parameters. Note that BAT limits are the same as BPT and that BCT limits have not been promulgated for this industry.CHAPTER IV. DERIVING TECHNOLOGY

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- 17 

## 1.7 Integrated Facilities

In the previous example, if the facility X above also produced nonwoven fabric by an adhesive process, the facility would be an integrated facility and receive an additional effluent allowance in the nonwoven subcategory.

In the nonwoven subcategory, the limitation is based on p ounds of product produced. Therefore, the facility in the example would have to separately track that wool fiber used for nonwoven production so as not to get dual credit.



## 1.8 Converting Performance to Limits

EPA derived the BPT limits for wool finishing mills by determining the pollutants produced and the potential treatment methods available for treating those pollutants. EPA then examined the performance of two existing "exemplary" biological treatment plants at wool finishing mills (BPT = average of the best for conventional pollutants). The average effluent concentrations from the two treatment plants were then increased by 50% to derive the 30

- day average maximum limit. This 30

- day limit was multiplied by 2 to derive the maximum daily limit.

Somet imes more sophisticated statistical methods were used for deriving effluent limits when the data were available. The first step was to determine if the data was normally distributed and if not
then to do a transformation. The transformation if done corre ctly enabled the use of normal distribution statistical techniques. The data or transformed data were then used to calculate a mean and standard deviation. The effluent limits for daily maximum may be set at Z + 3s. The probability of any measurement ra ndomly exceeding this limit is 0.00135, so any exceedance means the treatment process is not functioning properly.

Another method used to arrive at daily maximum limits was to derive a variability factor V = (Z + 3s)/Z which was then multiplied by the ann ual average effluent concentration. The resultant number was the proposed daily maximum concentration. This variability factor may also be calculated by plotting the data on probit paper or using a computer program and finding the 50th and 99th percentil e concentration. The variability factor V = 99th percentile concentration/50th percentile concentration.

Monthly or 30

- day effluent limits may be set as Z + 2s or by determining variability factors on monthly data.

Performance

- based effluent limits may be derived using the formulas in Appendix E of the TSD (EPA 1991) and the observed data for the long term average (LTA).CHAPTER IV. DERIVING TECHNOLOGY

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- 18 EXAMPLE OF PERFORMANCE

- BASED LIMITS

A permit writer proposes to issue a permit with water quality

- based effluent limits for BOD and

w ants to derive performance

- based limits as interim limits for a compliance schedule. The data base consists of 169 effluent values collected once per week. The summary statistics (calculated
in Excel  ) are presented below.
UNTRANSFORMED LOGNORMAL(base e )
TRANSFORMED
Mean 32.9941 Mean 3.2783
Standard Error 2.00885 Standard Error 0.0492
Median 26 Median 3.2581
Mode 22 Mode 3.091
Standard Deviation 26.115 Standard Deviation 0.6396 Sample Variance 681.994 Sample Variance 0.4091
Kurtosis 7. 27301 Kurtosis 0.5068
Skewness 2.51836 Skewness 0.2898 Range 147 Range 3.2387
Minimum 6 Minimum 1.7918
Maximum 153 Maximum 5.0304
Sum 5576 Sum 554.03
Count 169 Count 169
Confidence Level (95.0%) 3.96584 Confidence Level (95.0%) 0.097 1

95th percentile 98 95th percentile 99th percentile 141 99th percentile Federal regulations require effluent limits be expressed as a maximum daily limit (MDL) and an average monthly limit (AML)(except municipal limits for conventional pollutants). The method for determining effluent limits from demonstrated performance is found in Appendix E of the TSD. The formulas have been incorporated into TSDCALC.CHAPTER IV. DERIVING TECHNOLOGY

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- 19 6396

. 0 log tan 2783

. 3 log 326

. 2 exp ) ( 99

.

= = = =    
   

+ =

data d transforme of deviation dard s data d transforme of mean where X LIMIT DAILY MAXIMUM

y y y y

σ μ σ μ



### Maximum Daily Limit (MDL) =exp(3.2783 + (2.326)(0.6396)) = 11 7.

The AVERAGE MONTHLY LIMIT (AML) depends on the number of samples that will be required per month for compliance monitoring. The following method is appropriate for 10 or fewer samples/month (Technical Support Document, Appendix E, Table E

- 2).



## ( ) ( )

( ) ( ) 

## [ ] [ ]

( ) 

# { }

( )

( )

08

. 54 ) 3447

. 0 645

. 1 4235

. 3 exp( 4235

. 3 1188

. 0 5

. 0 5524

. 32 ln 5

. 0 ) ( ln 3447

. 0 1188

. 0 1262

. 1 ln 1 ln 1 ln 126

. 535 505

. ) 9657

. 6 exp( 1 4091

. 0 exp 4091

. 0 2783

. 3 2 exp 1 exp 2 exp ) ( 5524

. 32 4091

. 0 5

. 0 2783

. 3 exp 5

. 0 exp ) ( 4091

. 0 data ed transform lognormal of variance 2783

. 3 data ed transform lognormal of mean 645

. 1 exp ) (

2 5524

. 32 4 126

. 535

) ( ) ( 2 2 2 2 2 95

.

2 2

= ⋅ + = = ⋅ − = −      

= = = = + =     

    

+ = = = − +
⋅ =    
   

−                

+ = = + =   

 

  

 

+ = = = = =   

 

  

 

+ =

  
 
  
       

AML X E X V X E where X LIMIT MONTHLY AVERAGE

n

n n X E n X

V

n y y y y y y y n n

σ μ σ σ σ σ μ σ μ σ μ σ μCHAPTER IV. DERIVING TECHNOLOGY

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- 20 The average monthly limit (AML) when there are more than 10 samples per month for compliance is calculated as follows:



## ( ) ( )

( ) ( ) ( ) ( )

( ) ( )



# ( ) 5

. 43 ) 653

. 44 ( 645

. 1 55

. 32 653

. 44 12 / 83

. 535 12 / 1 2 exp 2 2 exp / 55

. 32 4091

. 0 5

. 0 2783

. 3 exp 2 5

. 0 exp 12 = nth samples/mo of number 4091

. 0 data ed transform lognormal of variance 2 2783

. 3 data ed transform lognormal of mean 645

. 1 ) (

2 / 1
95

. 2 / 1

95

.

= + = = =   

 

  

 

−   

 

  

 

     

 

     

 

+ = = = + =   

 

  

 

+ = = = = = = =      
+ =



# X AML y y y n X V X V y y X E X E n y

y where X V X X AML

n n n n

σ σ μ σ μ σ μ

Effluent limits using these formulas can be calculated using TSDCALC

.

In this example for effl uent limits for BOD for a municipality the effluent limits would be as average monthly limits and average weekly limits instead of a daily maximum. The weekly average limit is the appropriate average monthly limit (44 or 54) times 1.5.CHAPTER IV. DERIVING TECHNOLOGY

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- 21 

## 2

. CAS E

- BY

- CASE DERIVATION OF TECHNOLOGY

BASED EFFLUENT LIMITS

Technology

- based effluent limits may be derived on an individual facility basis which is also called case

- by

- case or BPJ. Case

- by

case limits may be developed under federal authority (40 CFR 125.3) or they may be developed under authority of the state law RCW 90.48 (AKART).

Case

- by

- case derivation of effluent limits may be on a facility basis and cover all pollutants or may be on a n individual pollutant basis

.

Case

- by

- case development of effluent l imits for a n individual facility follow s the same process as EPA used for developing effluent guidelines for categories of dischargers. The permit writer can review any development document to reinforce the process described in this Part

. Case

- by

- case de velopment of effluent limits is a 2

- part determination. The first part is an engineering determination and the second part is an economic determination.

Case

- by

- case derivation of effluent limits is necessary in the following circumstances:



## • The facility being permitted has an effluent guideline but the industrial processes have changed to the extent that the process and the pollutants produced are no longer accurately described in the development document.



## • The facility type does not have federal effluen t guidelines. Some of the kind of facilities in Washington that do not have effluent guidelines are hazardous waste
treaters, some equipment manufacturers, waste oil reclaimers, industrial laundries, barrel reclaimers, transportation facilities, some min ing operations, water treatment plants, petroleum industry (other than refineries), chitin manufacturers, and some metallurgical manufacturers.



## • The facility being permitted has a n effluent guideline that accurately describes the manufacturing processes bu t has a pollutant or pollutants in the effluent that were not described in the development document.

The authority to develop and impose case

- by

- case or BPJ limits is given in the Clean Water Act

Sec tion 402(a)(1). This section authorizes the EPA adminis trator to issue permits containing "such conditions as the Administrator determines are necessary to carry out the provisions of the Act". Hap Thron - Former EPA Permit Writer ExpertCHAPTER IV. DERIVING TECHNOLOGY

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- 22 The process of deriving case

- by

- case (BPJ) effluent limits is not described in federal regulations but
the factors w hich must be considered are given in Sec tion 304(b) of the CWA and 40 CFR 125.3(c)(2) and 40 CFR 125.3(d).

The general factors to be considered for BPJ permit limits are:



## • The appropriate technology for the category or class of point sources of which the applicant is a member, based upon all available information; and



## • Any unique factors relating to the applicant.

The specific considerations are:

1. FOR BPT REQUIREMENTS (Conventional Pollutants)

i) The total cost of application of technology in relation t o the effluent reduction benefits to be achieved from such application;

ii) The age of equipment and facilities involved;

iii) The process employed;

iv) The engineering aspects of the application of various types of control techniques;

v) Process changes; and

vi) Non

- wat er quality environmental impact (including energy requirements)

.

2. FOR BCT REQUIREMENTS (Conventional Pollutants)

i) The reasonableness of the relationship between the costs of attaining a reduction in effluent and the effluent reduction benefits derived;

ii) The comparison of the cost and level of reduction of such pollutants from the discharge from publicly owned treatment works to the cost and level of reduction of such pollutants from a class or category of industrial sources;

iii) The age of equipment and fa cilities involved;CHAPTER IV. DERIVING TECHNOLOGY

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- 23 iv) The process employed;

v) The engineering aspects of the application of various types of control techniques;

vi) Process changes; and

vii) Non

- water quality environmental impact (including energy requirements).

3. FOR BAT REQUIREMENTS (Toxic Po llutants)

i) The age of equipment and facilities involved;

ii) The process employed;

iii) The engineering aspects of the application of various types of control techniques;

iv) Process changes;

v) The cost of achieving such effluent reduction; and

vi) Non

- water quality en vironmental impact (including energy requirements).

The BAT factors have been briefly defined in EPA guidance as:

AGE OF EQUIPMENT AND FACILITIES

- Age of the plant including manufacturing lines, sewer lines and wastewater treatment system.

PROCESS EMPL OYED

- The manufacturing process(es) used, and/or the wastewater treatment process employed.

ENGINEERING ASPECTS OF THE APPLICATION OF VARIOUS TYPES OF CONTROL TECHNIQUES

- The design, construction, cost, performance, reliability, etc., of the wastewater
treatment processes.

COST OF ACHIEVING THE EFFLUENT REDUCTION

- The capital and operating cost of attaining a specified effluent quality.CHAPTER IV. DERIVING TECHNOLOGY

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- 24 NON

- WATER QUALITY ENVIRONMENTAL IMPACTS

- The trade

- offs associated with achieving a specified effluent quality incl uding energy requirement; air pollution; hazardous waste generation; solid waste; etc.

There is no other federal guidance on case

- by

- case development of effluent limits

. The EPA permit writers training course makes several points on case

- by

- case limits.



## • These are best done with a team approach involving at least an engineer and an
economist.



## • Defensibility depends on a reasonable process and documentation of that process.

The permit writer has several useful tools for defining the appropriate treatment technology. These include engineering reports, the treatability manual, the abstracts of industrial permits, and a computerized literature review.

The permitting process for new facilities in Washington State includes a requirement of dischargers to prod uce an engineering report in conformance with Chapter 173

- 240 WAC. This regulation (173

- 240

- 130

- q) requires, "a statement, expressing sound engineering justification through the use of pilot plant data, results from other similar installations, and/or sci entific evidence from the literature, that the effluent from the proposed facility will meet applicable permit effluent limitations and/or pretreatment standards." This may seem like a catch

- 22 situation for those industries not covered by effluent guidel ines. The permit writer can't tell the industry what the permit limits will be until an engineering analysis is completed and the applicant can't make a statement as required until those limits are known. In these cases the permit writer should explicitl y instruct the applicant to review all possible treatment technologies, quantify the expected concentration of pollutants from each identified treatment, detail the cost of each identified
treatment and list the other environmental factors associated with each treatment method. This data in the engineering report will form the technical basis for the permit writer's BPJ determination of
effluent limits.

Another useful tool for determining the appropriate treatment technology or verifying an engineering re port is the Treatability Manual (EPA

- 600/2

- 82

- 001). The Treatability Manual is in 5 volumes. The individual volumes are;

Volume I

- Treatability Data
Vol ume II

- Industrial Descriptions
Vol ume III

- Technology for Control/Removal of Pollutants
Vol ume IV

- Cost Estimating
Vol ume V

- SummaryCHAPTER IV. DERIVING TECHNOLOGY

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- 25 Volume I provides physical data for 202 chemical compounds, their occurrence patterns, and methods of treatment and/or removal (with references to Vol ume III). Volume II is a summary of industrial descriptions fr om the development of effluent guidelines and describes only those industries for which there are guidelines. It describes manufacturing processes and the pollutants they produce. Volume III describes treatment technologies and their performance when tre ating industrial wastewater. The technologies include those which are widely used in treating industrial wastewater and those which are being used on a limited basis but have potential application in the removal of toxic pollutants from wastewater. The m anual does not specify final effluent concentrations because those would be dependent upon individual wastewater characteristics and
other factors.

The permit writer may request a computer search of the literature for any pollutants or process and

treatme nt methods from the Ecology library. The primary journals included in the search which include new treatment process data are the Journal of the Water Pollution Control Federation (now called Water Environment and Technology), the Sanitary Engineering Div ision of the ASCE, and
the Purdue Industrial Waste Conference.

Those permit writers who may need further technical assistance in developing BPJ permit limits may request it from the Water Quality Program Development Services Section. Although problems

un ique to a region will most likely be solved by that region, some, because of their complexity, political impact, etc. will be viewed as high enough state priority to require the Program Development Services Section involvement.

The second major part of BP J permitting is the task of determining the cost of the proposed treatment method. The cost is then subjected to a test for reasonableness. Reasonable is an economic test. The reasonable test for BCT is defined by federal regulation and the reasonable t est for BAT is defined by Federal guidelines. These economic tests are reviewed in the following Part 3

.CHAPTER IV. DERIVING TECHNOLOGY

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- 26 

## 3. ALL KNOWN, AVAILABLE, AND REASONABLE METHODS OF TREATMENT (AKART)

This part discusses the phrase, "all known, available, and reasonable methods o f treatment" or AKART, which occurs in state water quality law and regulation

. This part clarifies the meaning of AKART as used by Ecology in the process of permitting wastewater discharges

. Specifically, this part has sections which review law, regulati on, PCHB decisions and individual permit
instances in which AKART has been used or defined

. Subsequent sections discuss engineering analysis and other tests for AKART. This part does not specify in detail the process of engineering analysis because it is assumed that any engineering analysis will be cond ucted by a qualified engineer.



## 3.1

. A Summary of AKART

AKART is a statement of legislative intent directed toward the goal of clean water.

AKART has been interpreted as a technology

- based approach to lim iting pollutants from wastewater discharges which requires an engineering judgment and an economic judgment

. Because AKART encompasses a complex process of engineering and economic decision

- making there can be no simple definition.

AKART allows the state to be more stringent than federal effluent guidelines but actually parallels parts of the CWA.

AKART has been defined in state regulation for some categories of dischargers.

A determination of AKART may be the same process as case

- by

- case permitting as given in 40 CFR 125.3 if a proposed permittee has no effluent guidelines.

Production increases greater than 10% should be treated as new source for defining effluent limitations for those dischargers with new source performance standards.

The discharge o f pollutants already captured does not meet the intent of AKART.

AKART may be equivalent to the federal effluent guidelines or may be more stringent.

AKART means that effluent limits may be derived in consideration of the treatment performance of
a simil ar facility.CHAPTER IV. DERIVING TECHNOLOGY

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- 27 AKART may be a requirement to control pollutants at the source.

AKART may be zero discharge.

An industrial/commercial indirect discharger should not be required to treat for BOD and solids discharged to a POTW as long as the POTW has the ca pacity to treat the waste.

The general requirements of an engineering report are specified in WAC 173

- 240

. The actual analysis must be done by an engineer who is trained and experienced in wastewater treatment

. Other scientists may assist in determining whether the report meets the AKART criteria

. Case

- by

case decisions on technology

- based effluent limits for existing facilities must be reviewed and approved by an engineer.

Ecology has adopted EPA's BCT and BAT economic tests for AKART analysis.

The B CT economic reasonableness tests imply that the minimum treatment for conventional pollutants on a BPJ basis is secondary treatment with 85% removal of BOD and solids. A candidate treatment technology would be advanced secondary treatment. A new industry producing conventional pollutants similar in nature and strength to municipal wastewater, but not covered by effluent guidelines

, would be required at a minimum to treat with secondary treatment as BPT. A
candidate BCT treatment would be advanced seconda ry treatment.



## 3.2

. AKART As Given In Law

In the regulatory scheme of things legislative bodies express their intent through law

. Laws are generally not explicit as to how they should be implemented

. Therefore, regulations are promulgated to clarify the implementation of the law

. In some cases regulatory authorities must also provide guidance as an additional tool to implement the regulations.

AKART has not been explicitly defined in law

. AKART has been defined in certain regulations
and has been ruled upon by the Pollution Control Hearings Board (PCHB)

. The following discussion reviews the law and regulation in which the phrase AKART is used.

The phrase AKART is found in 3 statutes dealing with water pollution and water resources in Washington

. The context of these statutes in which the phrase AKART occurs gives some indication of the legislative intent.

The introduction to this manual reviewed some of the legislative history of Chapter 90.48 RCW,
Water Pollution Control

. Section 010 of 90.48 state s, "It is declared to be the public policy of the state of Washington to maintain the highest possible standards to insure the purity of all waters of the state consistent with public health and public enjoyment thereof, the propagation and protection
of w ild life, birds, game, fish and other aquatic life, and the industrial development of the state, andCHAPTER IV. DERIVING TECHNOLOGY

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- 28 to that end require the use of all known available and reasonable methods by industries and others to prevent and control the pollution of the waters of th e state of Washington. " AKART in this section of the law relates to industries and others preventing pollution so as not to affect other
water uses and intrinsic values.

Chapter 90.48 RCW, section 520 states, "In order to improve water quality by control ling toxicants in wastewater, the department of ecology shall in issuing and renewing state and federal wastewater discharge permits review the applicant's operations and incorporate permit conditions which require all known, available, and reasonable meth ods to control toxicants in the applicant's wastewater." This section ties AKART to the control of toxics, improvement of water quality, and the issuance of wastewater discharge permits.

In the Pollution Disclosure Act of 1971, Chapter 90.52 RCW, section 040 states "Except as provided in RCW 90.54.020(3)(b), in the administration of the provisions of chapter 90.48 RCW, the director of the department of ecology shall, regardless of the quality of the water of the state to which wastes are discharged or pr oposed for discharge, and regardless of the minimum water quality standards established by the director for said waters, require wastes to be provided with all known, available, and reasonable methods of treatment prior to their discharge or entry into wat ers of the state ." This statute introduces the concept that AKART is required regardless of the quality of the receiving water.

In the Water Resources Act of 1971, Chapter 90.54 RCW, section 020 (3)(b) states, "Waters of the state shall be of high quality

. Regardless of the quality of the waters of the state, all wastes and other materials and substances proposed for entry into said waters shall be provided with all known, available, and reasonable methods of treatment prior to entry. Notwithstanding tha t standards of quality established for the waters of the state would not be violated, wastes and other materials and substances shall not be allowed to enter such waters which will reduce the existing quality thereof, except in those situations where it is clear that overriding considerations of the public interest will be served. " This section of 90.54 continues on with technology

- based treatment exemp tions for wastewater discharges from municipal water treatment plants on the Chehalis, Columbia, Cowlitz , Lewis, and Skagit Rivers. This law explicitly states that AKART is required even if it results in more stringent treatment than required to meet water quality
standards. This is the basic philosophical approach found in the Clean Water Act

. Chapter 90 .54 also contains the caveat not found in other statutes of an exemption for, "overriding conside ration of the public interest."



## 3.3

. AKART As Given In Regulation

The phrase AKART is also found in the regulations that implement the laws reviewed above

. In these regulations the phrase may be defined, simply repeated or may be changed to indicate implementation process

. In some cases the context of the regulation also indicates implementation.

The state's surface water quality standards, Chapter 173

- 201A, define AKART as, "represent(ing)CHAPTER IV. DERIVING TECHNOLOGY

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- 29 the most current methodology that can be reasonably required for preventing, controlling, or abating the pollutants associated with a discharge." These water quality standards also require dischargers to
achieve AKART befor e receiving a mixing zone and require AKART as a condition for exemption to the antidegradation condition.

The state wastewater discharge permit program is implemented by Chapter 173

- 216 WAC, State Waste Discharge Permit Program

. WAC 173

- 216

- 020(1) state s, "It shall be the policy of the department in carrying out the requirements of this chapter, to maintain the highest possible standards to ensure the purity of all waters of the state and to require the use of all known,
available and reasonable methods to prevent and control the discharge of wastes into the waters of the state ."

WAC 173

- 216

- 050(3): "These exemptions" (to the requirement to obtain a state discharge permit) "shall not relieve any discharger from the requirement to apply all known, availab le, and reasonable methods to prevent and control waste discharges to the waters of the state ,"...

WAC 173

- 216

- 110(1): "Any permit issued by the department shall specify conditions necessary to prevent and control waste discharges into the waters of the s tate, including the following, whenever applicable: (a) All known, available, and reasonable methods of prevention, control, and treatment :"...

This regulation reiterates the phrase as found in law

. The regulation notes that a discharger may be exempted from getting a permit but they are not exempt from AKART.

The state's surface water discharge permit program is implemented through Chapter 173

- 220 WAC, National Pollutant Discharge Elimination System Permit Program

. This regulation refers to the

statute s covered above and the technology

- based processes of the CWA.

WAC 173

- 220

- 130(1): "Any permit issued by the department shall apply and insure compliance with all of the following, whenever applicable: (a) All known, available and reasonable methods of tr eatment required under RCW 90.52.040, 90.54.020(3)(b), and 90.48.520; including effluent limitations established under sections 301, 302, 306, and 307 of the FWPCA."

The state dangerous waste regulations, Chapter 173

- 303 WAC, which allow a (dangerous wast e) permit by rule

. T hat permit by rule is conditioned upon meeting AKART

. WAC 173

- 303

- 802 (5)(a): "The owner or operator of a totally enclosed treatment facility or an elementary neutralization or wastewater treatment unit that treats dangerous wastes sh all have a permit by rule, except as provided in (b) of this section, if he: (i) Has a NPDES permit, state waste discharge permit, pretreatment permit (or written discharge authorization from the local sewerage authority) and the permit or authorizationCHAPTER IV. DERIVING TECHNOLOGY

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- 30 pr ovides for the use of all known, available, and reasonable methods of prevention, control, and treatment of pollution pursuant to chapter 90.48 RCW, prior to discharge; "...

The underground injection control program, Chapter 173

- 218 WAC sets forth the proc edures and practices applicable to the injection of fluids through wells

. This regulation specifies in 173

- 218

- 100 that: (1) Any permit issued by the department shall specify conditions necessary to prevent and control injection of fluids into waters of t he state, including the following, whenever applicable: (a) All known, available, and reasonable methods of prevention, control, and treatment ;.

Other state standards are the ground water standards, Chapter 173

- 200, and Sediment Management Standards Chapt er 173

- 204 WAC

. These two regulations also use the phrase
AKART.

The Water Quality Standards for Ground Waters of the State of Washington, Chapter 173

- 200 WAC, implement Chapters 90.48 RCW and 90.54 RCW.

WAC 173

- 200

- 030 Antidegradation policy.
WAC 173

- 2 00

- 030(2)(c): "Whenever ground waters are of a higher quality than the criteria assigned for said waters, the existing water quality shall be protected, and contami nants that will reduce the existing quality thereof shall not be allowed to enter such wate rs, except in those in

stances where it can be demon strated to the department's satisfaction that: (i) An overriding consideration of the public interest will be served; and (ii) All contaminants proposed for entry into said ground waters shall be provid ed with all known, available, and reasonable methods of prevention, control, and treatment prior to entry ."

WAC 173

- 200

- 050 Enforcement limit
WAC 173

- 200

- 050(3): "All enforcement limits shall, at a minimum, be based on all known, available, and reasonable methods of prevention, control, and treatment ."

WAC 173

- 200

- 050(3)(b)(iv): "When naturally nonpotable ground water exceeds a secondary contaminant criterion, an enforcement limit for a secondary contaminant may exceed a criterion
when it can be demonstra ted to the department's satisfaction that:"..."(D) All known, available, and reasonable methods of prevention, control, and treatment will not result in concentrations less than the secondary contaminant criteria ."

The Sediment Management Standards, Chapt er 173

- 204 WAC expand the phrase to include best management practices.

WAC 173

- 204

- 120(c): "Whenever surface sediments are of a higher quality (i.e., lower chemical concentrations or adverse biological response) than the criteria assigned to said sediment s, the existing surface sediment quality shall be protected and waste and other materials and substancesCHAPTER IV. DERIVING TECHNOLOGY

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- 31 shall not be allowed to contaminate such sediments or reduce the existing sediment quality thereof, except in those instances where:"..."(ii) all waste s and other materials and substances proposed for discharge that may contaminate such sediments are provided with all known, available and reasonable methods of prevention, control, and treatment and/or best management practices ;"

WAC 173

- 204

- 400(2): "Per mits and other authorizations of wastewater, storm water, and nonpoint source discharges to surface waters of the state of Washington under authority of chapter 90.48 RCW shall be conditioned so that the discharge receives all known, available and reasonab le methods of prevention, control and treatment, and best management practices prior to discharge , as required by chapters 90.48, 90.52, and 90.54 RCW

. The department shall provide consistent guidance on the collection, analysis, and evaluation of wastewa ter, receiving

- water, and sediment samples to meet the intent of this section using consideration of the pertinent sections of
the Department of Ecology Permit Writer’s Manual , as amended, and other guidance approved by the department."

WAC 173

- 204

- 410(3) :"Except as identified in subsection (6)(d) of this section, any person may apply for a sediment impact zone under the following conditions: (a) The person's discharge is provided with all known, available and reasonable methods of prevention, control, an d treatment, and meets best management practices as stipulated by the department ;"...

WAC 173

- 204

- 410(6)(c): "Any person with a new or existing permitted storm water or nonpoint source discharge, which fully uses all known, available and reasonable method s of prevention, control, and treatment, and best management practices as stipulated by the department at the time of the person's application for a sediment impact zone, shall be required to meet the standards
of WAC 173

- 204

- 400 through 173

- 204

- 420;"...

It is apparent from the language in both law and regulation that AKART is meant to be a technology

- based requirement conditioned by a judgment of reasonableness

. In this respect it
shares the same characteristics of case

- by

- case or BPJ determinations spec ified in 40 CFR 125.3

. This is discussed in more detail later.CHAPTER IV. DERIVING TECHNOLOGY

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- 32 

## 3.4

. AKART a s State Treatment Standards

AKART has been defined explicitly as effluent limitations in some Ecology regulations for some categories of dischargers and some pollutants

.

For do mestic wastewater facilities the discharge standards are given in Chapter 173

- 221 WAC, Discharge Standards and Effluent Limitations for Domestic Wastewater Facilities

WAC 173

- 221

- 010(1): "The purpose of this chapter is to implement RCW 43.21A

- 010, 90.48.0 10, and 90.52.040 by setting discharge standards which represent “all known, available, and reasonable methods of prevention, control, and treatment for domestic wastewater facilities which discharge to
waters of the state.”

WAC 173

- 221 then defines treat ment standards (effluent limits) for domestic wastewater treatment plants for the parameters of BOD, TSS, pH, and fecal coliform

. This regulation was preceded by a PCHB decision regarding municipalities discharging to marine waters

, which is discussed bel ow.

Treatment standards are also defined in Chapter 173

- 221A WAC, Wastewater Discharge Standards
and Effluent Limitations.

WAC 173

- 221A

- 010: "This chapter implements chapters 43.12A, 90.48, 90.52, and 90.54 RCW by setting minimum discharge standards whic h represent "known, available, and reasonable methods" of prevention, control, and treatment for industrial wastewater facilities that discharge to waters of
the state."

This regulation currently defines treatment technology, treatment standards, and best management practices only for upland fin

- fish facilities.



## 3.5

. AKART As Defined By t he Pollution Control Hearings Board (PCHB) And Other Courts

The PCHB has confirmed some of the individual permit determinations which were based on
AKART

. The board look s to these past decisions as guidance for future decisions. Discussed below are decisions made on marine discharging municipalities, New Source Performance Standards (NSPS) for production increases and the discharge of captured pollutants.CHAPTER IV. DERIVING TECHNOLOGY

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- 33 

### 3.5.1

. Marin e Discharging Municipalities
The Clean Water Act Section 301(h) allows marine

- discharging municipalities to obtain a variance from the requirement of secondary treatment

. The variance is conditional upon 7 factors primarily dealing with water quality and upon concurrence of the state in which the discharge is located

. In anticipation of several Washington municipalities applying for marine waivers, Ecology requested a formal AG opinion to the question

, "Under state law may a municipality discharge wastes from its sewerage system into Puget Sound, or other marine waters, without providing secondary
treatment?" The response (AGO 1983 No. 23) reviewed the law as given previously in this section and then continued,
"Such statutory directions to the Department of Ecology, however, clearly do bring into play the expertise of the department as administrator of the state's water pollution control system

. Accord, Weyerhaeuser v. Southwest Air Pollution Control Authority , 91 Wn.2d 77, 586 p.2d 1163 (1978)

. The pre cise level of treatment required by those general standards involves, primarily, engineering determinations; i.e. , as to what treatment methods are "known," what treatment methods are "available," and what treatment methods are "reasonable" with respect to the particular installation in light of the factual circumstances surrounding it. 19 To make those determinations a review must be conducted by the department of existing engineering technologies in order to enable it to decide which
methods of treatment

-- including but not limited to "secondary treatment" as above defined

-- are suitable with respect to the waste situation involved in the particular case

. Cf

. , Weyerhaeuser

, supra

. 20

-------------------------------------------------------

19. The use o f the encompassing word "all" indicates to us that the existing "state of the art" or "best available" treatment technologies are required to be used

. Cf.

, Weyerhaeuser v. Southwest Air Pollution Control Authority

, supra

.

20. These determinations by the Department of Ecology are, of course, to be made in light of the foundation policy that "waters of the state" shall be of high quality and be maintained to the "highest possible standards to insure the purity of all waters of
the state" consistent with var ious environmental and economic objectives

. RCW 90.54.020(3)(b) and RCW 90.48.010.

Ecology denied the marine waivers on the basis that secondary treatment constituted all known, available and reasonable treatment for municipal dischargers

. Ecology determ ined reasonableness for each of the municipalities on 3 factors: (1) planning status, (2) environmental or siting constraints, and (3) economics

. The economics factor was an analysis of resulting rate structure after meeting secondary treatment and a comp arison to rates in other municipalities in the state and
nation

. The PCHB concurred with Ecology that secondary treatment for marine discharging municipal treatment plants was AKART

. The decision for Bellingham v. Ecology (PCHB No. 84

- 211) contains a goo d discussion on technology

- based treatment.CHAPTER IV. DERIVING TECHNOLOGY

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- 34 Footnote 20 above also mentions environmental objectives as a consideration of AKART. Environmental considerations are also a requirement given in federal regulations for case

- by

- case determinations. Unfortunat ely, there is no federal guidance on the process of making these environmental considerations. The environmental considerations required for BPT and BCT determinations were a consideration of the environmental effects of the pollutants in question.



### 3.5.2

. New Source Performance Standards for Production Increases
Federal effluent guidelines allow a permit writer to grant an increase in pollutant discharge for production increases because the guidelines are production

- based

. The new source performance

sta ndards in federal regulations are more stringent than standards for existing source because new facilities can take advantage of new treatment methods and equipment and incorporate these into the design of the facility

. In 1985 the Industrial Section issu ed a permit to Weyerhaeuser, Longview pulp mill complex which includes R

- W Paper and NORPAC

. The permit writer used new source performance standards to derive effluent limits for the 150 tons per day production increase at NORPAC and the 100 tons per day at R

- W Paper and used AKART as the basis

. Ecology argued that given the cost and planning required for anything except a marginal increase in production, a facility should also be planning and investing in its waste treatment to accommodate production inc reases

. In this case the company did not have to make any capital investment to meet the new effluent limitations. The appellant Weyerhaeuser argued that the
AKART standard was too uncertain

. The PCHB found that the limits were "more stringent than
fede rally required, but 'reasonable' as a matter of state law." As a general policy, wasteload increases greater than 10% at facilities with applicable effluent guidelines should be considered as new source loading when defining effluent limitations.



### 3.5.3

. Discharge of Captured Pollutants
In the early 1980's, Ecology discovered that an ITT Rayonier pulp mill was discharging clarifier solids to come up to its permitted effluent limit for TSS

. When Ecology reissued the permit, it contained a specific prohibit ion against discharge of sludge

. The facility appealed this provision (PCHB No. 85

- 218), arguing that as long as they were meeting their technology

- based effluent limits based on the federal effluent guidelines Ecology could not prohibit the discharge of sludge especially since Ecology could not prove water quality degradation

. The mill also argued that the cost to deal with all their solids was excessive. Ecology argued that the discharge of pollutants already captured did not meet the intent of AKART

. The PCHB ruled for Ecology.



### 3.5.4

. Source Control of Pollutants
Ecology issued a permit in 1998 to Shell Oil (Tesoro) that contained numeric effluent limits based on the current EPA effluent guidelines and narrative effluent limits for source control (po llution prevention). The narrative limits were based on authority of 90.48 as AKART. The PCHB (98

- 50) and the Court of Appeals (No. 44762

- 9

- 1) affirmed the narrative limits

. The Court of Appeals stated, “The Tesoro permit’s conditions, which directly ad dress the refinery’s pollution control methods, may in fact better satisfy AKART than numeric limits alone...”CHAPTER IV. DERIVING TECHNOLOGY

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- 35 

## 3.6

. Direct Definitions of AKART

Some legal rulings contain text that clarif ies the definitions of AKART

. In the footnote number 19 of the marine discharge section above, for example, the Attorney General's office has defined "all" as indicating that the existing "state of the art" or "best available" treatment technologies are required to be used.

In PCHB 85

- 218 (ITT Rayonier v. Ecology), also di scussed above, the board pointed to a decision by the Southwest Washington Air Pollution Control Authority (SWAPCA) for a definition of the

terms "known" and "available": " ...SWAPCA may not require an applicant to develop new technology to advance the ar t of

emission control

. The "advance" must be "known" in the sense that it has been tested and found to control emissions effectively and efficiently

. Under this test SWAPCA may not insist that an emission source be utilized as a proving ground for as yet untried control technology

. An applicant must, however, incorporate into its proposal those control systems previously developed and presently available

. 99 Wn.2nd at 81, 82."

The issue of reasonableness was addressed in PCHB 84

- 211 (Bellingham v. Ecol ogy) dealing with
the marine waivers

. The results of this case are discussed in the following section 3.1 2

.



## 3.7

. AKART Defined In Individual Permits

In individual permitting situations AKART may be equivalent or more stringent than the federal effluent g uidelines

. A permit manager may examine a development document and available treatment technologies for a particular category of discharger and make a determination that the
federal effluent limitations are AKART

. This becomes more difficult as the efflu ent guidelines become dated and the manufacturing processes change

. In some cases the manufacturing processes change to such an extent that they no longer fit those described in the development
documents

. As described in an earlier section, those effluen t guidelines less than 5 years old will always be AKART for the pollutants described in the development document. For effluent guidelines between 5 and 10 years old, the permit manager should compare production processes, pollutants generated and treatmen t efficiencies at the facility with those in the development document and in the treatability data base. For effluent guidelines older than 10 years, the permit writer should do the previous analysis and review unit p rocesses design if time
allows.

In so me cases Ecology permit writers have determined that a category of discharger is capable of better performance than specified under effluent guidelines

. An example is continuously

monitored pH

. Under federal regulations, if a pH limitation in a permit is technology

- based and is continuously monitored, then a discharger may receive an exclusion from the permit limits for a period of 1 hour per excursion and a maximum monthly excursion period of 7 hours and 26CHAPTER IV. DERIVING TECHNOLOGY

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- 36 minutes (40 CFR 401.17)

. The federal regulatio ns place no bounds on magnitude of the
excursions

. Ecology has issued permits which place outside limits on these excursions of 5.0

- 10.0 units for petroleum refineries and 4.0

- 9.5 units for pulp mills

. The justification for these
excursion limits was tha t water quality standards may be violated at extreme pH ranges, that extreme ranges would be a violation of the state's dangerous waste laws, and that the facilities were capable of achieving a narrower range (AKART)

. This determination was appealed but a
settl ement was reached on the issue.

An AKART determination may take into consideration the treatment performance at a similar manufacturing facility

. In this situation the permit writer must assess the costs to the facility to

achieve the increased tre atment efficiency

. Some of the factors to be analyzed are;

Are the production processes equivalent?

Does this facility have some site specific constraints that would prohibit the increased treatment efficiency?

And are the facilities of comparable ag e?



## 3.8

. AKART Versus Case

- by

- Case

In the cases above where proposed effluent limits are more stringent than those promulgated in the federal effluent guidelines, the effluent limits are based on the authority of RCW 90.48 (AKART). Federal regulations ar e not explicit as to whether or not case

- by

- case determinations should be made in every permitting circumstance, whereas, the language in 90.48 clearly indicates that all discharges are to be treated with all known, available and reasonable methods

. Techn ology

- based limitations based on AKART may have a compliance schedule placed in the permit instead of in a compliance order.

In the case of a facility without effluent guidelines , a permit writer must make concurrent decisions

on case

- by

- case under federa l regulations (40 CFR 125.3) for BCT (conventional pollutants), BAT (toxics/nonconventional pollut ants) and AKART

. This process is covered in the previous section of

this manual

. In this situation because the permit writer will be using the same cost te sts for economic achievability, case

- by

- case and AKART determinations are equivalent. In this situation the compliance schedule must be put in a companion enforcement order.CHAPTER IV. DERIVING TECHNOLOGY

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- 37 

## 3.9

. Zero Discharge

The permit writer may determine that for some permits AKART is zero discharge

. Although there is no explicit statement in RCW 90.48 equivalent to the "zero discharge" goal of the Clean Water Act, both of these laws have a technology

- based principle which, when followed to the logical conclusion lead to zero disch arge, when achievable and reasonable.



## 3.10

. AKART For Pretreatment

The pretreatment program parallels the surface discharge program. Municipal treatment plants are designed to treat domestic sewage. The uses to be protected at the treatment plant are
bi ological functioning of the biomass and uses of the biosolids (sludge). Local limits are designed in part to protect these uses and are equivalent to water quality

- based limits for surface discharges to prevent violations of the water quality standards. The categorical (pretreatment) effluent limitations are equivalent to the technology

- based effluent limitations in federal regulations for surface dischargers.

All indirect dischargers must be examined for AKART in the permitting process because there is no exemption in law for indirect dischargers. Determining AKART for indirect dischargers is the same process as described previously. If the discharger is a categorical discharger the permit writer must determine the applicability of the effluent guideli nes. A permit writer may derive limits that are more stringent than the effluent guidelines on the basis of AKART. If the discharger is not a categorical discharger the permit writer must do an engineering and economic analysis to determine appropriate t echnology

- based effluent limits on a case

- by

- case basis.

Since POTW's are designed to treat BOD and solids, an industrial/commercial discharger should not be required to treat for BOD and solids if the municipality has the capacity to treat the waste.



## 3.1 1

. Engineering Analysis for All Known and Available

The general requirements for the engineering analysis for all known and available are specified in
WAC 173

- 240 as requirements of an engineering report

. The process of engineering analysis is not given in Chapter 173

- 240 WAC, however, one of the requirements of this regulation is that the engineering report be prepared under the supervision of a licensed engineer unless the requirement is waived by Ecology

. The review and analysis of this report by Ecol ogy must also be done by an engineer who is trained and experienced in wastewater treatment

. Scientists in the permit unit may contribute to the determinations in an engineering report but an engineer must make the judgment on the question of whether the treatment system proposed meets the AKART criteria. Case

- by

- case decisions on technology

- based effluent limits for existing facilities must also be reviewed and approved by an engineer.CHAPTER IV. DERIVING TECHNOLOGY

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- 38 One point made earlier is important to review here. The PCHB in its citation of the SWAPCA decision indicated that Ecology cannot require Permittees to develop new treatment technology

. That does not mean that treatment methods must be demonstrated for each kind of discharger

. For example, if a discharger has a process not described in the effluent guidelines or elsewhere and which produces the pollutant BOD, and if the BOD concentration and degradation rates are similar to domestic wastewater, then biological treatment process and secondary treatment efficiencies are

ap plicable to that discharger.



## 3.12

. Economic Tests Define Reasonable

The section describes how to conduct the economic evaluation for deriving effluent limits by

case

- by

- case or by AKART.

Performing the economic reasonableness tests requires estimates of the costs of the proposed treatment technologies; estimates of pollutant removal levels; and profit, cost and revenue data. The permittee is responsible for providing any data needed by the permit writer to make a decision. For new dischargers the cost a nd pollutant removal estimates for the proposed treatment technologies should be included in the engineering report submitted under WAC 173

- 240. This section covers the information permit writers need from dischargers before deciding

on economic reasonabl eness.

Permit writers can use this section and the other reference documents to carry out economic reasonableness tests for BPJ permits.

As mentioned earlier, Ecology has adopted EPA's economic reasonableness tests. Ecology may develop its own tests in the future

. There are 3 federal economic reasonableness tests corresponding to 3 levels of treatment: (1) BPT (2) BCT, and (3) BAT. The New Source and

Pretreatment tests are identical to the BAT test.

For indirect dischargers, both AKART and federal pre treatment regulations define the effluent limits. The economic factors in setting pretreatment effluent limits are discussed later in this

section.

For dischargers to ground water, AKART alone defines the effluent limits. No Federal law or regulation de fines treatment standards for ground water dischargers.

BPT ECONOMIC REASONABLENESS TESTCHAPTER IV. DERIVING TECHNOLOGY

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- 39 BPT was the first level of treatment identified in the CWA and is applicable only to conventional pollutants. BPT costs are also used in the economic achievability tests for BCT and BAT levels

of treatment

. BPT treatment for conventional pollutants is used as the base cost for BAT treatment for toxics and nonconventional pollutants because treatment for conventional pollutants is effective in varying degrees for rem oving toxic pollutants

. The BPT economic reasonableness test is authorized by section 304(b)(1)(B) of the CWA. Among the factors that the permit writer must consider in setting BPT effluent limits is:

"...the total cost of application of technology in r elation to the effluent reduction benefits to be achieved from such application..." (40 CFR 125.3(d)(1).

The BPT economic reasonableness test is intended to be a cost

- benefit test and benefits are measured in terms of amounts of pollutants removed.

EPA w rites that:

"The cost

- benefit inquiry for BPT is a limited balancing, committed to EPA's discretion, which does not require the Agency to quantify benefits in monetary terms....In balancing costs in relation to effluent reduction benefits, EPA considers th e volume and nature of existing discharges, the volume and nature of discharges expected after application of BPT, the general environmental effects of the pollutants, and the cost and economic impact of the required pollution control level." (47 FR 23263)

.

Thus, there is no single, precisely

- defined BPT economic reasonableness test. The economic factors considered in determining BPT can vary from industry to industry.

According to an EPA economist, in setting BPT effluent limitations, EPA weighed the co st per pound of pollutants removed by the treatment technology more heavily than the effect of the annual cost of the treatment technology on the profitability of the plant (although some weight is given to the effect on profitability). The cost per pound of pollutants removed is intended to be a

cost

- benefit measure. By considering cost per pound, total cost in relation to pollution reduction
is considered.

The intent of the BPT cost

- benefit requirement is to avoid requiring wastewater treatment "where the additional degree of effluent reduction is wholly out of proportion to the costs of achieving such marginal level of reduction..." Costs cannot be wholly disproportionate to benefits.

For at l east a few industries EPA used the "inflection" or "knee of the curve" method as theCHAPTER IV. DERIVING TECHNOLOGY

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- 40 economic reasonableness test for BPT effluent limits. For each industry, "cost

- effectiveness" diagrams were constructed which graphed the total cost of various treatment technologies against the percentage of pollutants removed by each technology

. These graphs show that the marginal cost per percentage of pollutants removed rises as the total percentage of the pollutants removed
rises. The BPT effluent limitations "were set at the point where the costs per percent (of) pollutant reduction took a sharp break upward toward higher costs per percent of pollutant
removed"

. The cost per percent of pollutant reduction is called the marginal cost of pollut ant removal.

However, the "knee of the curve" test is not the BPT economic reasonableness test. The U.S. Fifth Circuit Court of Appeals rejected the argument that the CWA required the use of the "knee of the curve" cost test in setting BPT effluent limit s. The court wrote that:

"The CWA contains no specific statutory language e stablishing a BPT "knee of the curve" test or any other quantitative cost

- benefit ratio test for BPT.... The courts of appeal have consistently held that Congress intended Section 304(b) to give the EPA broad discretion in considering the cost of pollution abatement in relation to its benefits and to preclude the EPA from giving the cost of compliance primary importance."

S ection 304(b) of the CWA requires EPA to establish BPT effluent limits. The CWA does not require that the knee of the curve test be used

. The knee of the curve test can be used in
combination with other tests. EPA does have to consider costs in relation to benefits in some

manner. For each development document, an accompanying economic analysis is written. The economic analysis estimates the impact of the proposed effluent limits (BPT, BCT, BAT, NSPS, etc.) on the affected industry. The economic analys is includes estimates of the regulation's impact on prices, production, employment, profits, and the industry's ability to finance expansion. The ability of the industry to pass costs on to consumers through price increases is also considered.
The econom ic analysis is one of the determinants of the effluent limits (for an example, see 47 FR 23269).

For example, in setting BPT effluent limits, the development documents often make estimates of the impact of the cost of the BPT technology on product prices. The size of the price impact is one determinant of the BPT technology. Technologies with low price impacts are more economically achievable.

In conclusion, there is no single, precisely

- defined BPT economic reasonableness test.

BCT ECONOMIC REASONAB LENESS TEST
Best Conventional Technology (BCT) effluent limits only apply to the 5 conventional pollutants: BOD, TSS, pH, fecal coliform, and oil and grease.CHAPTER IV. DERIVING TECHNOLOGY

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- 41 BCT always provides control of conventional pollutants at least as stringent as that provided by BPT. BCT effluent limits cannot be less stringent that BPT limits. If no BCT treatment technology exists or if it is economically unreasonable, then BCT is set equal to BPT.

The BCT economic reasonableness test is the only federal or state test that is precisely defined in regulations.

The BCT economic reasonableness test is described in 40 CFR 125.3(d)(2)(i) and (ii). In writing

case

- by

- case or BPJ permits for BCT technology, among the factors that the permit writer must
consider are:

1. “ The reasona bleness of the relationship between the costs of attaining a reduction in effluent
and the effluent reduction benefits derived.

2. The comparison of the cost and level of reduction of such pollutants from the discharge from publicly owned treatment works (POTW) to the cost and level of reduction of such pollutants from a class or category of industrial sources. ” Sectio n 304(b)(4)(B) Clean Water Act.

The details of the BCT economic reasonableness test were published in 51 FR 24973

- 86 (July 9, 1986). This includes the BCT economic reasonableness test methodology.

The BCT economic reasonableness test considers whether it is “ cost

- reasonable ” for an industry to control conventional pollutants to a level more stringent than BPT effluent limitations. The

tes t compares a permit holder ’ s cost of removing conventional pollutants beyond BPT to a
POTW ’ s cost of removing conventional pollutants beyond secondary treatment. The test is a

cost

- benefit test because it compares costs and benefits (benefits are measured by the amount of pollutants removed).

The BCT economic reasonableness tests imply that the minimum treatment for conventional pollutants on a BPJ basis is secondary treatment with 85% removal of BOD and solids. A candidate treatment technology would be a dvanced secondary treatment. A new industry producing conventional pollutants but not covered by effluent guidelines would be required at a minimum to provide secondary treatment as BPT. A candidate BCT treatment would be advanced secondary treatment.

Co nducting the BCT Test

The following BCT test was promulgated as regulation to define a cost test

. EPA subsequently used the test to examine those industries that already had promulgated BPT effluent limits

. This test requires that BPT technology and cost s to have previously been calculated.

Conducting the BCT test as promulgated requires performing two tests:CHAPTER IV. DERIVING TECHNOLOGY

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- 42 1. POTW cost

- comparison test.

2. Industrial cost

- effectiveness test.

Both of these tests are intended to be cost

- reasonableness tests. They impl ement 40 CFR 125.3(d)(2)(i) and (ii) and section 304(b)(4)(B) of the Clean Water Act

. The tests are shown as flow charts in Figures IV

- 5, IV

- 6 and in Tables IV

- 1 and IV

- 2.

The proposed BCT technology must pass both tests for it to be economically reasona ble. If it passes one test but fails the other, then it is not economically reasonable.

Performing the two BCT tests requires the calculation of two marginal costs:

1. The annual marginal cost of the existing or proposed BPT treatment technology (MBPT).

2. The annual marginal cost of the proposed BCT treatment technology (MBCT). The marginal costs are in annual dollars per pound of BOD and TSS removed units (51 FR 24975).

To calculate these two marginal costs requires two annual total cost estimates:

1. The annual total cost of the existing or proposed BPT treatment technology (TBPT).

2. The annual total cost of upgrading the BPT technology to the proposed BCT treatment technology (TBCT).

The two total costs are annual costs.

In addition, the two annual pollutant removal amounts are estimated:

1. The amount of BOD and TSS removed annually by the BPT treatment technology in pounds (PBPT).

2. The additional amount of BOD and TSS removed annually by upgrading the BPT technology to the proposed BCT technology in pounds (PBCT).

To calculate marginal costs, the annual pounds of BOD and TSS removed by the BPT and BCT treatment technologies must be estimated. Annual amounts of BOD and TSS removed by the BPT and BCT treatment technologies are measured in pounds per year units. The pounds of BOD and TSS are added together.

In general, only the amounts of BOD and TSS removed by the various treatment technologies are used in calculating annual amounts of pollutants removed. The amounts of the other thre e conventional pollutants (oil and grease, pH, and fecal coliform) removed should not be included. They should not be included because when EPA calculated the cost benchmarks it only used theCHAPTER IV. DERIVING TECHNOLOGY

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- 43 amounts of BOD and TSS removed. The chief reason that EPA did not include fecal coliform and pH in the calculation is that these two pollutants cannot be measured in pounds.

However, EPA says that the pounds of oil and grease removed may also be included in the calculation of annual amounts pollutants removed when a ppropriate "in the context of the industry and technology" (51 FR 24973).

EPA calculated total annual amounts of BOD and TSS removed using the following method using actual data or the monthly maximum effluent limit.CHAPTER IV. DERIVING TECHNOLOGY

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- 44 FIGURE IV

- 2. The BCT Cost Test.

BCT TWO PART ECONOMIC TEST

CALCULATE ANNUAL TOTAL COST OF EXISTING OR PROPOSED BPT TREATMENT TECHNOLOGY (TBPT)

CALCULATE ANNUAL TOTAL COST OF PROPOSED BCT TREATMENT (TBCT)

CALCULATE POUNDS OF BOD AND TSS REMOVED ANNUALLY BY BPT (PBPT)

CALCULATE ADDITIONAL BOD AND TSS REMOVED BY PROPOSED BCT TREATMENT (PBCT)

CALCULATE BPT MARGINAL COST (MBPT) AS TBPT/PBPT

CALCULATE BCT MARGINAL COST (MBCT) AS TBCT/PBCT

CONDUCT POTW TEST AND CONDUCT INDUSTRY TEST IF NECESSARYCHAPTER IV. DERIVING TECHNOLOGY

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- 45 FI GURE IV

- 3. The POTW and Industrial Cost Tests for BCT.

THE POTW AND INDUSTRIAL TEST

COMPARE MBCT WITH BENCH MARK

COST OF $0.25 OR $0.14 (1976 BASIS)

FAILS COST TEST IS MBCT LESS THAN BENCH MARK COST? NO

PERFORM INDUSTRIAL

COST TEST YES

DIVIDE MBCT BY MBPT

IS RATIO LESS THAN 1.29 OR 0.68? PROPOSED TREATMENT IS ACHIEVABLE YES NOCHAPTER IV. DERIVING TECHNOLOGY

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- 46 Treatment processes for which long

- term pollutant removal data is available (long

- term means at least 12 months), actual long

- term pollutant removal data (or data on pollutant concentrations in
the effluent of the various treatment processes) should be used to calculate the amount of BOD and TSS removed annually.

For treatment processes for which long

- term pollutant removal data is unavailable, the maximum 30 day BPT effluent limits for BOD and TSS effluent limits should be used to calculate the amount of BOD and TSS removed annually.

For both types of processes (those with and those without long

- term data) pollutant loadings of the raw wastewater should be estimated from actual data. (For more inf ormation on how to calculate amounts of pollutants removed by treatment processes, see 51 FR 24983 and 51 FR 24985

- 6.)

Marginal Costs

The marginal costs are in annual dollars per pound of BOD and TSS removed units.

To calculate the marginal cost of BPT t reatment: divide the BPT annual costs by the BPT annual weight in pounds of conventional pollutants removed.

To calculate the marginal cost of BCT treatment

, compute the following ratio:

1. Numerator: The annual total cost of upgrading the BPT technology to the proposed BCT technology.

2. Denominator: The additional amount of BOD and TSS removed annually by upgrading the BPT technology to the proposed BCT technology.

The POTW Cost

- Comparison Test

The POTW cost

- comparison test is the first part of the cost

- reasonableness test. It compares the industry's cost of removing additional pounds of conventional pollutants (beyond BPT) to a POTW's cost of removing additional pounds of conventional pollutants (beyond secondary treatment).

The POTW benchmarks were c alculated in 1986. They are expressed in 1976 prices. These benchmarks must be updated to the year in which the proposed BCT technology cost estimate is made. If old benchmarks were used, the benchmarks would be too low (because construction and operati on costs are constantly rising) and too many proposed BCT treatment technologies would be rejected as economically not achievable.CHAPTER IV. DERIVING TECHNOLOGY

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- 47 EPA published a table that updated the benchmarks through 1985 (51 FR 24985). EPA has not formally updated the benchmarks p ast 1985. However, it can give help in upda ting them (cost indices, etc.).CHAPTER IV. DERIVING TECHNOLOGY

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- 48 TABLE IV

- 1. THE POTW COST

- COMPARISON TEST



### POTW COST

- COMPARISON TEST

TO PERFORM THE POTW COST

- COMPARISON TEST, COMPARE THE
FOLLOWING 2 MARGINAL COSTS:

1. The permit holder's annua l marginal cost per pound of pollutant removed when upgrading its treatment process from BPT to the proposed BCT treatment technology.

2. An average

- size POTW's annual marginal cost per pound of pollutant removed when upgrading from secondary treatment to ad vanced secondary treatment. Secondary treatment is defined as 30 mg/L of BOD and TSS. Advanced secondary treatment is defined as 20 mg/L of BOD and TSS.

Use the following figures for the POTW's annual marginal cost (51 FR 24985

- 6):

A. $.25 (in 197 6 dollars) when the proposed BCT treatment process has long

- term pollutant removal data (here, long term means at least 12 months). This figure is referred to as the "first tier POTW benchmark."

B. $.14 (in 1976 dollars) when the proposed BCT treatment process does not have long

- term pollutant removal data. This figure is referred to as
the "second tier POTW benchmark."

If the permit holder's marginal cost exceeds the appropriate POTW marginal cost benchmark, then the proposed BCT treatment process is not economically reasonable. If the permit holder's marginal cost is less than or equal to the appropriate POTW marginal cost threshold, then the proposed BCT treatment process is economically
reasonable.CHAPTER IV. DERIVING TECHNOLOGY

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- 49 The Industrial Cost

- Effectiveness Test

The industrial cost

- effectiveness test is intended to be a test of the proposed BCT technology's

cost

- effectiveness. It compares the industry's costs of attaining a reduction in pollution with the pollution reduction benefits derived. See the following Table IV

- 2 for the test.

The POTW benchmarks were calculated in 1986. They are expressed in 1976 prices. They do

not have to be updated to the year in which the proposed BCT technology's cost estimate is made. EPA (47 FR 49199) stated that the benchmar ks for the industrial cost

- effectiveness test would not be indexed for cost changes over time because any such changes would be small. The ratios are the ratios of the marginal cost of upgrading a secondary STP to advanced secondary to the marginal cost of building a secondary STP. It is unlikely that ratio will change much over time because the cost indices for secondary and advanced secondary STPs should be nearly
identical.

The proposed BCT technology must pass both tests for it to be economically reas onable. If it passes one test but fails the other, then it is not economically reasonable.

If the proposed technology fails one or both tests, then BCT is set equal to BPT.CHAPTER IV. DERIVING TECHNOLOGY

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- 50 Table IV

- 2. The Industrial Cost

- Effectiveness Test. 

## INDUSTRIAL COST

- EFFECTIVENES S TEST

TO PERFORM THE INDUSTRIAL COST

- EFFECTIVENESS TEST, COMPARE THE FOLLOWING

2 RATIOS OF MARGINAL COSTS:

1. The permit holder's ratio of marginal costs. This ratio is intended to be a measure of the
candidate BCT treatment's cost

- effectiveness. I t is the ratio of the following 2 marginal costs:

A. Numerator: The permit holder's marginal cost per pound of additional pollutants removed when upgrading its treatment process from BPT to the proposed BCT treatment process.

B. Denominator: The permit holder's marginal cost per pound of pollutant removed when upgrading its treatment process from no treatment (raw waste) to BPT.

2. A POTW benchmark ratio of marginal costs. This ratio is referred to as the "industry cost

benchmark." This is th e ratio of the following two marginal costs:

A. Numerator: The marginal cost per pound of pollutant removed when a POTW upgrades from secondary treatment to advanced secondary treatment.

B. Denominator: The marginal cost per pound of pollutant re moved when a POTW upgrades from no treatment (raw sewage) to second ary treatment.

Use the following figures for the POTW benchmark ratio (51 FR 24985

- 6):

A. 1.29 (calculated using 1976 dollars) when the proposed BCT treatment process has long

term pollutant removal data (here, long term means at least 12 months).

B. 0.68 (calculated using 1976 dollars) when the proposed BCT treatment process does not have long

- term pollutant removal data.

If the permit holder's ratio exceeds the POTW benchma rk ratio, then the proposed BCT treatment process is not economically reasonable. If the permit holder's ratio is less than or equal to the POTW benchmark ratio, then the proposed BCT treatment process is economically reasonable.CHAPTER IV. DERIVING TECHNOLOGY

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- 51 BAT ECONOMIC REASONABLENESS TEST

BAT is Best Available Technology Economically Achievable and is applicable to toxics and

non

- conventional pollutants

.

In setting BPJ effluent limits for BAT treatment technologies, 40 CFR 125.3(d)(3)(v) states that "the cost of achieving such effluent reduction" must be considered. This regulation repeats a portion of section 304(b)(2) of the Clean Water Act, which defines BAT. Even though the CWA does not list pollution reduction benefi ts among the factors that must be considered in determining BAT, they are considered by EPA when determining BAT

. Therefore, the relationship between the cost of BAT and the pollution reduction achieved by the installation of
BAT is also considered. An E PA permit writing expert has defined the cost of achieving the effluent reduction as the capital and operating cost of attaining a specified effluent quality.

The CWA does not require a comparison of costs and benefits. EPA writes:

"The statutory assess ment of BAT "considers" cost, but does not require a balancing of costs against pollution reduction benefits...In developing the BAT limitations, however, EPA has given substantial weight to the reasonableness of costs. The Agency has considered the
volum e and nature of discharges, the volume and nature of discharges expected after application of BAT, the general environmental effects of the pollutants, and the costs and economic impact of the required pollution control levels" (47 FR 23263).

Costs and be nefits do not have to be compared. However, EPA does consider the cost of the pollutant reduction achieved by BAT technology in setting BAT effluent limits. Thus, it does compare costs and benefits (as measured by pollutant reduction) in determining BAT. However, economic achievability is given more weight.

With regard to the BAT economic achievability test, the U.S. Fifth Circuit Court of Appeals

wrote: "Both Congress and the Supreme Court have made clear that in setting BAT,
the EPA is not required to compare the costs against the benefits of pollution
reduction in the same manner as the EPA is required to do in setting BPT standards". (p age 250, Chemical Manufacturers Association vs. USEPA)

The court also wrote that section 301(b)(2)(A), which define s BAT, differs from section 301(b)(1)(A), which defines BPT, in that it does not state that costs shall be considered in
relation to effluent reduction. No cost

- benefit test is required by the CWA (p age 250, Chemical Manufacturers Association vs. USEPA). In setting BAT effluent limits, EPA must only consider their "economic achievability."CHAPTER IV. DERIVING TECHNOLOGY

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- 52 BAT Economic Achievability Tests

The BAT economic achievability tests are described in federal guidelines

-- not in federal or state regulations . EPA's Guidance Manua l for Estimating the Economic Effects of Pollution Control
Costs describes these tests. EPA emphasizes that this manual is not regulation or policy

. Therefore, Ecology must determine the specific methods that it will use to evalu ate economic
achievabili ty and to justify those methods. Ecology could use methods other than the federal tests if it has legitimate reasons for using them.

EPA's Guidance Manual defines a treatment technology to be economically achievable if its use would not cause the plant t o shut down. That is, the technology is economically achievable if its annual cost is less than the plant's annual profits.

EPA's Guidance Manual uses a 3

- stage approach to determining economic achievability:

1. First, perform a firm

- level test.

2. If the co ntrol technology passes the firm

- level test, but the permit holder protests that the technology is not economically achievable, then perform a plant

- level test.

3. If the firm

- level test is inconclusive, then a plant closure analysis must be conducted.

The BAT economic achievability test is shown in Figure IV

- 7.

Figure IV

- 4. Sequence of Analysis for Determining Economic Achievability for BAT.CHAPTER IV. DERIVING TECHNOLOGY

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- 53 CONDUCT FIRM LEVEL ANALYSIS IF NECESSARY TO SUPPORT PLANT LEVEL ANALYSIS

DOES PROPOSED TREATMENT PASS FIRM LEVEL TEST ? TREATMENT IS NOT ECONOMICALLY

ACHIEVABLE

DOES THE FIRM CONTEST DECISION AND PROVIDE PLANT FINANCIAL DATA ? PROPOSED TREATMENT IS ECONOMICALLY

ACHIEVABLE

CONDUCT PLANT LEVEL

ANALYSIS

DOES PLANT PASS PLANT LEVEL TEST ?

PROPOSED TREATMENT IS ECONOMICALLY ACHIEVABLE TREATMENT IS NOT ECONOMICALLY

ACHIEVABLE NO

NO

NO NO YES

YESCHAPTER IV. DERIVING TECHNOLOGY

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- 54 The plant

- level test makes the most sense economically. It is more prec ise than the firm

- level test. However, plant

- level tests are difficult to do because plant

- level data is limited and confidential. Therefore, the Guidance Manual recommends doing the firm

- level test first because, in some cases, it is possible to conduct it with publicly

- available data on the firm's balance sheet, income statement, and stock prices.

However, in most cases it is either impossible or a waste of time to perform the firm

- level test
for two reasons:

1. For most permit holders, the firm

- level te st is difficult to do because few of them are publicly held corporations. Therefore, no publicly available balance sheet or stock market data exists. In many cases, because the firm is so small, the firm will equal the plant.

2. Any permit holder with any business sense will demand that the plant

- level economic achievability test be performed in any case, because he/she, as a profit

- maximizer, is interested in the profitability of the plant . A profit

- maximizing firm owner has no interest in subsidizing the wastewater treatment costs of one plant with profits earned by the remainder
of his/her firm.

The primary justification for conducting the firm

- level test is that the data needed to perform the test is publicly available from sources such as Moody's Indu strial Manual and from stock prices. However, very few Washington permit holders (especially small

- and medium

- sized companies) are publicly owned. Thus, few have stock that is publicly traded. Few permit holders are listed
in Moody's and similar public ations. There is no other publicly available data. Therefore, for these firms, permit holders must provide the data needed to conduct firm

- level tests.

In cases where the firm is identical to the plant, a plant

- level test is the same as a firm

- level tes t, therefore, call it a plant

- level test.

Even when there is publicly available data, a firm

- level test will usually yield a meaningless answer that will be immediately disputed by the permit holder. There is little point in estimating the impact of the annual cost of a proposed BAT treatment system for a Weyerhaeuser plant on the total worldwide profits of the Weyerhaeuser Co. It is obvious that the impact will be tiny. It is also obvious that Weyerhaeuser will immediately point out that it is concerned with the profitability of each of its facilities and is not interested in subsidizing one plant with profits from its other plants. Therefore, it will want a plant

- level test to be conducted.

Generally the firm

- level test should not be conducted except in the situation discussed below
where it is used to co mpliment the plant

- level test.CHAPTER IV. DERIVING TECHNOLOGY

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- 55 Firm

- Level Test

The firm

- level test examines whether the firm as a whole can afford the treatment technology. It is performed using publicly available balance sheet a nd stock market data.

There are 7 different firm

- level tests. They all estimate the impact of the cost of pollution control equipment on a financial ratio. Among the tests are: the current ratio, which is the ratio
of current assets to current liabilit ies; Beaver's ratio, which is the ratio of cash flow to total debt; the debt/equity ratio; and the market

- to

- book ratio.

The Guidance Manual suggests that if the firm

- level test shows that the proposed BAT treatment technology is not economically achievab le for the firm, then it is not economically achievable for the plant

. This is not always true because the firm

- level test may give misleading results. It is possible that the plant is making large profits, while the firm as a whole has low profits. Los ses in some of the firm's plants offset profits in others. In such a situation, the firm

- level test would indicate that the proposed BAT technology is economically unreasonable, when, in fact it was
reasonable.

If the firm

- level test shows that the propo sed BAT treatment technology is economically achievable, the owner may contest this determination. The owner may contend that the BAT technology will make the plant unprofitable to operate. If the determination is contested, the owner must provide plant

- level data for the plant

- level test.

In some cases (especially when the permit holder has only one plant), the firm

- level tests can be used to supplement the plant

- level test. They can provide information that the plant

- level test
does not. In most case s the data needed to perform the firm

- level tests will have to be provided by the permit holder. Because there are several firm

- level tests and because performing them is complicated, instructions for conducting them are not included here. See the Guidan ce Manual
for instructions.

As explained earlier, in most cases the firm

- level test is meaningless and will probably be disputed by the permit holder. In addition, for many firms, balance sheet and stock price data which is required to perform the firm

- l evel test is not publicly available. Therefore, the firm

level test should only be performed to compliment the plant

- level test.

Plant

- Level Test

There are three plant

- level tests. All the plant

- level tests ask the same question: would the plant's

earn ings before taxes be greater than zero if it installed the proposed BAT technology? That is, would the plant be driven out of business by the cost of the BAT technology?CHAPTER IV. DERIVING TECHNOLOGY

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- 56 The three plant

- level tests are:

1. Earnings test

. 2. Gross margin test

. 3. Revenue test

.

Ac cording to EPA, only 1 of the plant

- level tests needs to be done because the three tests are essentially the same, differing only in the amount of data that they require the firm to provide. The three tests require data from the plant's income statement a nd estimation of the annual cost of the proposed BAT treatment technology.

It is important to note that all three of the BAT plant

- level economic achievability tests are conservative. They assume that the permit holder cannot pass any portion of the cost of the BAT treatment equipment on to its customers. The cost is assumed to come completely out of its profits. The tests assume that the cost of the pollution control equipment is an additional cost but that revenue is constant. Generally, this assumpt ion is incorrect for many of the industries that hold permits because the permit holder will be able to pass along a portion or all of the cost, thus lowering the impact of the cost of the treatment equipment on its profits. The more that water pollution control regulations are consistent throughout the U.S., the easier it is for the permit holder to pass the costs on. Therefore, this economic achievability test is biased in favor of the permit holder.

The permit holders are responsible for providing the cost, earnings, and revenue data needed to perform the economic achievability test. If they refuse to supply the data, then it should be assumed that the treatment technology is economically achievable.

Plant Closure Analysis.

If the plant

- level tests do not provide conclusive answers, then a detailed plant closure analysis must be conducted. This is a much more detailed and therefore, more valid and expensive

-- examination of the impact of the cost of the treatment technology on the plant's economic
vi ability. It is a job for a consultant.

The EPA Guidance Manual states:

The plant

- level tests are intended and designed as screening tests rather than rigorous and definitive evaluations of a plant's ability to afford pollution control costs. If the tes t results indicate that pollution controls would impose severe economic impacts, then a more detailed plant closure analysis would be necessary. This would entail working closely with the plant and corporate accountants to gather information on a variety of costs, revenues, and accounting procedures. Information on salvage values of equipment as well as projections
of future economic condi tions may be desirable or required.CHAPTER IV. DERIVING TECHNOLOGY

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- 57 Data Requirements for Plant

- Level Test

If the owner does not think that a treatm ent technology proposed by Ecology is economically reasonable and wants a plant

- level test conducted, he/she must provide the data needed to conduct the economic achievability tests

.

The permit holders are responsible for providing all the data needed to perform the economic achievability tests. They must supply two types of data:

1. Cost estimate for upgrading the treatment technology from BPT to the proposed BAT technology.
2. Data from its income statement.

Pollution Control Equipment Cost Estimat e

All 3 BAT plant

- level economic achievability tests require estimates of the annual cost of the proposed BAT treatment technology. This cost is the cost of upgrading from BPT to BAT treatment. For the BAT test, the total annual cost of upgrading from B PT or proposed BPT to the proposed BAT treatment technology is used. Marginal costs per unit of pollutant removed
are not used in the BAT tests.

Ecology may propose a BAT treatment process based on the fact that a competitor of the permittee had a simila r process

. If the permittee disputes this type of comparison they must submit data to show why they are substantially different from their competitor.
The plant

- level tests use before

- tax annual costs.

Income Statement Data

The permit holder must provid e plant

- level income statement data

— revenue, costs, and earnings

— for the most recent three years ( the EPA Guidance Manual only uses data from the most recent year ’ s income statement). If it does not collect this data at the plant level, it must do
the bes t job it reasonably can in constructing accurate income statements for the plant.

The permit holder must provide the following income statement data:

1. Revenue

. 2. Cost of Goods Sold

. A. Cost of materials

. B. Direct labor costs

. C. Production overhead costs (indirect labor, rent, energy, etc.)

. D. Extraordinary costs should not be included.CHAPTER IV. DERIVING TECHNOLOGY

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- 58 3. Corporate Overhead Costs Assigned to the Plant A. Selling, general, and administrative expense. B. Interest expense

. C Depreciation on common property

. D. Etc.

The permit holder must supply documentation to verify the data. For example, state excise tax returns, federal income tax returns, tax schedules, etc.

For plants that are owned by companies with several facilities, income tax returns and schedules
will u sually lump together the revenue, cost, and earnings data for all the facilities. In such cases, income tax forms will be worthless for verifying plant

- level revenue and cost data. Ecology will then have to rely on accounting records. Such records might be biased by the permit holder. There is little Ecology can do about this, short of auditing the firm.

There are several problems that will be faced in obtaining accurate plant

- level data:



## • P l ant

- level data is usually confidential.



## • Sometimes firms do n ot collect plant

- level revenue and cost data. Many companies do not keep revenue data at the plant level. Instead, they maintain some cost records at the plant level but record revenues at the division or firm level.



## • Corporate overhead costs are not usu ally allocated to individual plants. And when they are, biases may exist in the allocation method.



## • Non

- standard accounting procedures used internally by the firm can make it difficult to verify cost and revenue data.



## • Firms may bias the plant's costs and revenues. It is essentially impossible to audit the cost and revenue data for accuracy.



## • Transfer prices for inputs purchased by the plant from other parts of the firm can be biased upward in order to increase costs.



## • Transfer prices for goods sold by th e plant to other parts of the firm may be biased
downward in order to reduce revenue.

The BAT plant

- level economic achievability tests are performed using the following tests which are calculated using income statement data:CHAPTER IV. DERIVING TECHNOLOGY

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- 59 

## • Earnings before taxes test (E BT) = revenues minus the costs of goods sold and corporate overhead



## • Gross margin test = revenues minus costs of goods sold



## • Revenue test

Performing the Plant

- Level Tests

The earnings test is the most accurate plant

- level BAT test. Therefore, if the data is available, it is the test that should be performed. The earnings test asks the question: would the plant's earnings before taxes be greater than zero if it installed the proposed BAT technology?

The earnings test analyzes a plant's earnings before ta xes (EBT) and determines if the EBT would be positive after installation of pollution control equipment.

The earnings test requires data that may not normally be collected at the plant level. Therefore, its application may be limited. The gross margin t est and the revenue test require less data and, therefore, can be used in more situations.CHAPTER IV. DERIVING TECHNOLOGY

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- 60 Table IV

- 3. The BAT Earnings Test.



### EARNINGS TEST

TO PERFORM THIS TEST CALCULATE:

Earnings before taxes minus the annual cost of proposed BAT technology

• If this number is greater than zero, the proposed BAT treatment technology is economically achievable.

• If this number is less than zero, the proposed BAT technology is not economically

achievable.

• If this number is equal to zero (or near zero), th en the test is inconclusive. A plant closure analysis must be carried out.

If the earnings test is inconclusive, the other two plant

- level tests will not help to determine whether or not the proposed technology is economically achievable. All three t ests are identical except that the gross margin and revenue test use less accurate data than the earnings test uses. Tests performed using less accurate data cannot help provide a conclusive answer when the test using the most accurate data (the earnings test) does not provide a conclusive answer.

Gross Margin Test

According to the EPA Guidance Manual , if the earnings test cannot be performed because cost data that allocates corporate overhead costs to individual plants is not available, then either the

g ross margin test or the revenue test should be performed. There is no need to perform both. As explained below the two tests are equivalent except for the data requirements.

Gross margin is equal to revenue minus the cost of goods sold. It is a measure of the plant's profit before deducting corporate overhead costs. The gross margin test avoids the problem of accurately allocating corporate overhead to the plant

. This test is a less accurate test of economicCHAPTER IV. DERIVING TECHNOLOGY

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- 61 achievability than the earnings test becaus e an estimate of the plant's corporate overhead is used
instead of actual data.

The gross margin test assumes that the firm's EBT

- to

- gross margin ratio is equal to its industry's
EBT

- to

- gross margin ratio. The test uses the firm's gross margin and the in dustry's EBT

- to

- gross margin ratio to estimate the firm's EBT (multiply the firm's gross margin by the industry's EBT/gross margin to yield the estimate of the firm's EBT). It then compares the cost of the BAT technology to the firm's estimated EBT. So, the gross margin test is an earnings test that uses estimated earnings rather than actual earnings.

Table IV

- 4. The Gross Margin Test for BAT.



### GROSS MARGIN TEST

TO PERFORM THE GROSS MARGIN TEST CALCULATE:

1. Ratio of the annual cost of the proposed BA T technology to the firm's gross margin.

2. Ratio of the industry ’ s average EBT to the industry ’ s average gross margin.

The industry average EBT and gross margin are obtained from Robert Morris

Associates ’ Annual Statement Studies . They are available for 4

- digit SIC

codes.

• If the first ratio is less than the second ratio, then the proposed BAT treatment technology is economically achievable.

• If the first ratio is greater than the second ratio, then the proposed BAT treatment technology is not econ omically achievable.

• If the first ratio is equal (or approximately equal) to the second ratio, then the test is inconclusive. A plant closure analysis must be carried out.CHAPTER IV. DERIVING TECHNOLOGY

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- 62 If the gross margin test is inconclusive, the revenue test will not help to determine whether or not the proposed technology is economically achievable. Both tests are essentially the same except that the revenue test uses less accurate data than the gross margin test does. A test performed using less accurate data cannot help p rovide a conclusive answer when the test using the more accurate data (the gross margin test) does not provide a conclusive answer

. However, if not enough data is available for the BAT earnings test or the gross margin test, then the revenue test
can be u sed.

Revenue Test

The EPA Guidance Manual suggests that if the earnings test cannot be performed because accurate cost data for the plant is not available, then the revenue test should be performed. This test has easy

- to

- meet data requirements.

The reve nue test completely avoids the problem of collecting accurate cost data for the plant. It does not require any data on production or overhead costs. It only uses the plant ’ s revenue. The disadvantage of this is that the revenue test is a less accurate t est of economic achievability than either the earnings test or the gross margin test.

The revenue test assumes that the firm ’ s EBT

- to

- revenue ratio is equal to its industry ’ s EBT

- to

revenue ratio. The test uses the firm ’ s revenue and the industry ’ s EBT

- t o

- revenue ratio to
estimate the firm ’ s EBT (multiply the firm ’ s revenue by the industry ’ s EBT/revenue to yield the
estimate of the firm ’ s EBT). It then compares the cost of the BAT technology to the firm ’ s estimated EBT. So, the revenue test is an earnin gs test that uses estimated earnings rather than actual earnings.CHAPTER IV. DERIVING TECHNOLOGY

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- 63 Table IV

- 5. The Revenue Test for BAT.



### REVENUE TEST

TO PERFORM THE REVENUE TEST CALCULATE:

1. Ratio of the annual cost of the proposed BAT technology to the firm ’ s revenue.

2. Ratio o f the industry's average EBT to the industry's average revenue.

The industry average EBT and revenue are obtained from Robert Morris

Associates' Annual Statement Studies . They are available for 4

- digit SIC

codes.

• If the first ratio is less than the s econd ratio, then the proposed BAT treatment technology is economically achievable.

• If the first ratio is greater than the second ratio, then the proposed BAT treatment technology is not economically achievable.

• If the first ratio is equal (or approximat ely equal) to the second ratio, then the test is inconclusive. A plant closure analysis must be carried out.

NSPS ECONO MIC REASONABLENESS TEST

In setting New Source Performance Standards (NSPS), section 306(b)(1)(B) of the CWA requires that EPA "take into consideration the cost of achieving such effluent reduction." This language is identical to that which specifies how costs are to be considered in defining BAT.

In setting NSPS effluent limits for toxic and conventional pollutants discharged by chemical manufacturers, EPA used the BAT economic test. The U.S. Fifth Circuit Court of Appeals agreed with EPA that use of th e BAT test in setting NSPS effluent limits was required by the CWA (p age 262, Chemical Manufacturers Association vs. USEPA).CHAPTER IV. DERIVING TECHNOLOGY

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- 64 Therefore, BAT economic achievability analysis is also applicable to NSPS.

The cost of installing a given level of treatment in a new plant (NSPS) should be less than the cost of installing it in an existing plant (BCT and BAT). Therefore, the economic reason ableness test for NSPS should be easier to pass than the test for BPT and BAT.

PRETREATMENT ECONOMIC REASONABLENESS TEST

In setting Pretreatment Standards for Existing Sources (PSES) and Pretreatment Standards for New Sources (PSNS), EPA stated:

"The le gislative history of the 1977 Act ( i.e., the CWA) indicates that pretreatment standards are to be tech nology

- based and analogous to the best available technology for removal of toxic pollutants" (47 FR 23264).

That is, PSES and PSNS are analogous to BAT.

However, in setting PSES and PSNS effluent limits, EPA also considered: The cost of application of technology in relation to the effluent reduction and other benefits achieved from such application (47 FR 23264).

This criterion is similar to that used i n setting BPT effluent limits. It is a cost

- benefit test.

The U.S. Fifth Circuit Court of Appeals wrote that the CWA requires that pretreatment standards be "based on BAT or more stringent criteria" (p age 196, Chemical Manufacturers Association vs.
USEPA ). The court also wrote that the PSES pretreatment standards are:

..."technology

- based and are analogous to the BAT effluent

- limitation guidelines for the removal of toxic pollutants

-- that is, they are intended to represent the best available technology that is economically achievable by indirect dischargers" (p age 244, Chemical Manufacturers Association vs. USEPA).

In addition, the court wrote that the PSES standards are equivalent to BAT standards and, therefore, are to be set in accordance with sectio n 304(b)(2)(B) of the CWA, which lists the factors that must be considered in determining BAT (p age 249, Chemical Manufacturers Association vs. USEPA).

Therefore, the BAT economic achievability test is applicable for pretreatment effluent limits.CHAPTER IV. DERIVING TECHNOLOGY

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- 65 The cos t of installing a given level of treatment in a new plant (PSNS) should be less than the cost of installing it in an existing plant (PSES). Therefore, the economic reasonableness test for PSNS should be easier to pass than the test for PSES.CHAPTER IV. DERIVING TECHNOLOGY

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- 66 ECONOMIC REASONABLENESS TESTS FOR SEWAGE TREATMENT PLANTS REQUESTING MARINE WAIVERS

In denying the municipal sewage treatment plants' (POTWs) applications for marine waivers discussed earlier, Ecology u sed the following criteria to determine "reasonable methods of treatment" for AKART for municipal POTWs' discharges to marine waters:



## • Status of planning needed to proceed with the proposed method of treatment.



## • Environmental or siting constraints.



## • Economic factors.

The PCHB accepted Ecology's use of these 3 criteria to determine reasonableness. The PCHB
also wrote:

"The economic aspect of the reasonableness criterion of the State Standard is, we conclude, defined by two propositions: (1) whether seconda ry treatment for the source would involve significantly greater costs than for others obliged to obtain the same levels of treatment, and (2) whether secondary treatment is within the economic ability of the source to meet the costs of treatment.

EPA's re fusal to consider the second of these propositions in industrial variances was upheld in National Crushed Stone Association, supra

. But, underlying this conclusion was the realization that a single plant unable to come up to industry

- wide standards can si mply cease operations

. This is a luxury municipal sewage treatment facilities do not enjoy

. The sewage must go someplace

. Therefore, in interpreting the state law requirement for reasonableness as to municipalities, we think it is appropriate to include "ability to pay" factor

. Cf. Weyerhaeuser v. Southwest Air Pollution Control Authority , 91 Wn.2nd 77, 586 P.2d 1163 (1978)."

Here the PCHB is defining a test for economic reasonableness.

The first proposition (1) applies to both industrial and municipa l permit holders. A proposed treatment technology is economically reasonable if its cost is "similar" to the cost to other dischargers with the same level of treatment (the other dischargers may or may not be in the same industry). One measure of cost is cost per pound of pollutants removed. Another measure

-

- which is applicable to STPs

-- is cost per user.

"Similar" is not precisely defined. It does not mean identical. Costs can be either above or below other dischargers' costs. If they are below, then they are definitely reasonable. And even if they are above other dischargers' costs they can still be reasonable as long as they are not too
far above.CHAPTER IV. DERIVING TECHNOLOGY

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- 67 The second of the PCHB's propositions (2) considers whether the cost of the treatment technology is wi thin the permit holder's ability to pay. For an industrial discharger, the impact of the cost of the treatment technology on the discharger's profitability is examined. Impact on profitability may be considered in BAT analysis, but not in BCT or BPT anal ysis. The PCHB held that only the first proposition is relevant in determining economic reasonableness for industrial dischargers when the AKART level is the same as the BCT level. For municipalities, ability to pay is measured by the impact of the treat ment technology's cost on user rates.

In setting AKART effluent limits, pollution reduction benefits (as measured by amounts of pollution reduction) are also to be considered

. Greater amounts of pollution reduction make a given level of cost more reasona ble.

Water Quality Financial Assistance

Ecology takes economic factors into account when dealing with municipal POTWs in the Centennial Clean Water Fund (CCWF) and the State Revolving Fund (SRF). Ecology's Water Quality Financ ial Assistance Program (WQFAP) administers both these funds.

The CCWF makes grants and loans to public bodies for water pollution control activities and facilities. Economic achievability or ability to pay is one of the determinants of the size of loan

o r grant that a municipality may receive.

Among the rating criteria for allocating CCWF grants and loans to marine dischargers (this includes POTWs, CSOs, and storm water dischargers) is the monthly residential user charge that
would result from constructi on of the project without any state assistance (see Chapter IV of WQFAP's Centennial Clean Water Fund: Program Guidelines ).

In addition, under the CCWF, public bodies may receive "supplemental financial hardship assistance" when project costs cause user charges to exceed 1.5% of the municipality's median
household income. In some cases, other information

-- for example, unemployment rates

-- may be used to establish financial hardship. Chapter IV of the Centennial Clean Water Fund: Program
Guidelines cont ains more detailed information on how economic factors determine loan and grant amounts.

The impact of project costs on rate payers is also a rating criterion for making loans from the State Revolving Fund. If project costs without financial assistance w ould cause a municipality's user charges to exceed 1.5% of its median household income, WQFAP will try to award sufficient funding to bring the user charge down to 1.5 %.CHAPTER IV. DERIVING TECHNOLOGY

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- 68 EPA Affordability Guidelines. EPA's Construction Grants Program had several afforda bility guidelines for municipal sewer user charges. They ranged from 1.0% of median household
income for low

- income communities to 1.75% of median household income for high income communities. The guidelines were used to determine whether a project was a "high cost" project. The guidelines are the source of the 1.5% threshold used by WQFAP.CHAPTER IV. DERIVING TECHNOLOGY

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- 69 Figure IV

- 5. Deriving BCT Limits for Conventional Pollutants.

CONTINUED FROM FIGURE III-2

ARE CONVENTIONAL POLLUTANTS PRESENT IN THE EFFLUENT AT TREATABLE CONCENTRATIONS?

ARE BCT GUIDELINES AVAILABLE?

DOES BCT=BPT FOR THIS INDUSTRY TYPE?

DOES BCT=BAT FOR THIS INDUSTRY TYPE?

DEFINE THE LEVEL OF BPT TREATMENT FOR

THE FACILITY ARE BCT GUIDELINES EQUIVALENT TO AKART? USE BCT GUIDELINES

ARE BPT GUIDELINES EQUIVALENT TO AKART? USE BPT GUIDELINES

ARE BAT GUIDELINES EQUIVALENT TO AKART?

SELECT A CANDIDATE BCT/AKART TREATMENT SYSTEM

CONDUCT THE BCT/AKART COST TEST IS THE COST OF THE SELECTED BCT/AKART SYSTEM REASONABLE? IS BCT MORE STRINGENT THAN BPT?

SET BCT/AKART LIMITS USE BPT GUIDELINES FOR LIMITS

GO TO FIGURE IV-6 USE BAT GUIDELINES NO

YES

YES

NO YES NO

YES

YES NO NO

YES

NO

NO YES

NO

YES YES

NOCHAPTER IV. DERIVING TECHNOLOGY

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- 70 Figure IV

- 6. Deriving BAT Limits for Toxic Pollutants.

CONTINUED FROM FIGURE IV-5

ARE THERE PRIORITY POLLUTANTS IN THE EFFLUENT? DETERMINE CONCENTRATIONS OF PRIORITY POLLUTANTS IN THE EFFLUENT COMPARE WITH KNOWN BAT LEVELS, AND TREATABILITY MANUAL DATA

SELECT POLLUTANTS TO BE LIMITED

ARE BAT GUIDELINES AVAILABLE? DO BAT GUIDELINES MEET AKART? USE BAT GUIDELINES

ARE THERE OTHER TOXIC POLLUTANTS PRESENT THAT NEED TO BE LIMITED? GO TO FIGURE VI-4

IS BCT TREATMENT SELECTED IN FIGURE IV-1 EQUIVALENT TO BAT FOR TOXICS? SELECT A CANDIDATE BAT TREATMENT SYSTEM USING BPJ

IS THE SELECTED BAT SYSTEM ECONOMICALLY ACHIEVABLE?

HAVE SEVERAL BAT

SYSTEMS BEEN CONSIDERED? CHOOSE THE MOST PRACTICAL/ECONOMICAL ALTERNATIVE WITH ACCEPTABLE POLLUTANT REMOVAL LEVELS SELECT INDICATOR PARAMETERS IF APPROPRIATE

SELECT A NEW CANDIDATE BAT SYSTEM GO TO IV-7 DEVELOP AKART LIMITS YES

NO

YES

NO NO YES

YES NO

NO

YES

YES

NO

YES

NO DEVELOP BPJ-BAT LIMITSCHAPTER IV. DERIVING TECHNOLOGY

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- 71 Figure IV

- 7. Deriving BAT Limits for Nonconventional Pollutants

CONTINUED FROM FIGURE IV-6

ARE THERE NONCONVENTIONAL POLLUTANTS IN THE EFFLUENT AT TREATABLE CONCENTRATIONS? SELECT POLLUTANTS TO BE LIMITED

GO TO FIGURE VI-4

ARE BAT GUIDELINES AVAILABLE FOR THE NONCONVENTIONAL POLLUTANTS? USE BAT GUIDELINES

ARE OTHER NONCONVENTIONAL POLLUTANTS PRESENT THAT NEED TO BE LIMITED?

IS BCT SELECTED IN FIGURE IV-2 EQUIVALENT TO BAT FOR NONCONVENTIONALS? SELECT A CANDIDATE BAT TREATMENT SYSTEM USING BPJ

IS THE SELECTED

BAT SYSTEM ECONOMICALLY ACHIEVABLE?

CHOOSE THE MOST PRACTICAL/ECONOMICAL ALTERNATIVE WITH ACCEPTABLE POLLUTANT REMOVAL LEVELS SELECT INDICATOR PARAMETERS IF APPROPRIATE

SELECT A NEW CANDIDATE BAT SYSTEM YES NO YES

NO

YES

GO TO FIGURE VI-4 NO

HAVE SEVERAL BAT SYSTEMS BEEN CONSIDERED? YES

NO NO DEVELOP BPJ-BAT LIMITSCHAPTER IV. DERIVING TECHNOLOGY

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- 72 

## 4. ADJUSTMENT OF EFFLUENT LIMITS FOR AUTOCO RRELATION

This part discusses the process of adjustment to the monthly average effluent limit in cases where the effluent data is not independent. This part is based on two technical memoranda from Jeanette L. Kranacs, Mathematical Statistician, and Henr y Kahn, Chief, Statistical Analysis Section of the Engineering and Analysis Division, U.S.E.P.A

. (March 20, 1996, June 25, 1996). Background material is presented in Gilbert (1987) and Box and Jenkins (1976). The example in Appendix 4 is from a request to the Ecology Industrial Section.

Applicability

- This adjustment is applicable only to water quality

- based effluent limits and case

by

- case technology

- based effluent limits. It is not applicable to effluent limits derived from effluent guidelines. It is applicable only to the average monthly limitation.

Process

- The permit writer may evaluate effluent data for autocorrelation in the course of developing effluent limits or a permittee may request an adjustment of an effluent limitation.
The P DS Secti on will provide assistance in evaluating autocorrelation.

Background The Technical Support Document for Water Quality

- based Toxics Control (EPA 505/2

- 90

- 001, Appendix E) discusses the problem of correlated effluent data when deriving effluent limits and

p resents techniques for adjusting monthly average effluent limitations based upon an analysis of
autocorrelation.

What is autocorrelation and why does it result in an increase in effluent limits When calculating statistics such as mean and variance from a data set there is a presumption of normal distribution and independence. If the data are not normally distributed they can be transformed to approximate a normal distribution so that statistics may be derived using techniques based on normal theory. If the data are not independent (i.e.

, each value is correlated to the value preceding and following) then the calculated mean will be lower than the true mean of the sample distribution. In wastewater treatment processes with hydraulic detention times of

se veral days, the daily sample values are usually correlated. If sample values are correlated then a correction process must be used to derive the correct mean. Monthly average effluent limits developed on a case

- by

- case basis (water quality or technology based) are dependent on the mean so that an adjustment to the mean results in a different monthly average effluent limitation. Correction for autocorrelation results in a smaller effective sample size, a numerically higher mean and corresponding higher mo nthly effluent limitation.
When EPA develops effluent guidelines they conduct an analysis for autocorrelation and adjustCHAPTER IV. DERIVING TECHNOLOGY

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- 73 the effluent limitations accordingly.
Accurate Estimates of Autocorrelation

If x 1 . x 2 , ....., x n denotes a series of equally spaced me asurements, Box and Jenkins (1976) indicate that the most satisfactory method of estimating the l th lag autocorrelation, ρ l is



# ( ) ( )
( ) ∑

− − ∑

−

=

= + −

=

n

t t t l n

t t

l



### x x x x x x

1 2 1 1 

### ρ

In practice, at least n=50 measurements are needed to obtain accurate estimates of the ρ l for lags
l = 1, 2, ...., K, where K should not exceed n/4 (Gilbert 1987). Therefore, a 30 day lag requires a data base (n) of 30 x 4 = 120. Because it’s difficult to predict what the maximum lag will be before data collection and because a 30 day autocorrelation may be allowed, the permit writer should specify a data requirement of 120 data points collected over a year. These should be collected as daily samples for a month and the 4 months should be seasonally representative. This will allow for an analysis of sea sonally effected autocorrelation.

Most of the time we would expect significant autocorrelation to occur in biological treatment plants rather than physical/chemical treatment because of the longer hydraulic residence time. The significant autocorrelation should be within the range of one to three times the hydraulic residence time. Autocorrelation that occurs at lag periods longer than three times the hydraulic residence time should be suspect and may simply be a characteristic of the data set

. Gilbert (1987) cautions that the analysis for autocorrelation assumes that the underlying process being measured does not cycle, does not have long

- term trends, does not make sudden jumps in magnitude or change its autocorrelation coefficient over time. If the si gnificant autocorrelation factors are not continuous (i.e.

, one day, two days, three days, and up to the maximum significant lag) the facility must provide some engineering explanation of why the autocorrelation is discontinuous, otherwise Ecology will not approve it. Discontinuous autocorrelation lags indicates some periodicity (cycling) that is process related.

Monitoring Frequency
The collection of data to assess autocorrelation and the autocorrelation coefficient allows the permit writer to derive a monitoring frequency which is characteristic of the discharge. The procedure is illustrated in the example in Appendix 4. The number of measurements, n, required
to estimate the mean μ by the sample mean X with the prescribed accuracy, d, and 100(1

- α )%CHAPTER IV. DERIVING TECHNOLOGY

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- 74 c onfidence is



###      
+ = 

# ∑ −

= 1

1 

### 2 1 n

l l 

### D n ρ

where ρ l includes only the significant autocorrelations

and

2

2 1 

###   

 

  

 

= − 

### d z
D σ α

with σ 2 estimated by



## ( ) 2

1 2 

### 1 1 

# ∑

= 

### −

− = n

i i 

### x x n s and 

###      

− =      

− 

### 2 1

2 1 

### α

α 

### z percentile of the standard normal distribution.CHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 1 

# CHAP TER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS

1. INTRODUCTION

The largest category of discharger which has technology

- based effluent limits is the municipal treatment plants. This chapter discusses the technology

- based effluent limits for municipal plants and some other requirements for municipalities such as biosolids, and CSO control.

The Department of Ecology has quantitative discharge standards for domestic wastewater facilities (i.e.

, municipal sewage treatment plants) which discharg e to surface waters. The standards are codified in chapter 173

- 221 WAC. Prior to this rule, Washington state generally used federal standards as published first on August 17, 1973 [38 FR 22298] and codified in 40 CFR Part 133. The regulation was extensi vely revised in 1984, and amended again in 1985 and
1989. See Table V

- l for a history of the federal rule.

In 1984, when the federal government amended its secondary treatment requirements, individual states had the option of applying those regulations or establishing more stringent requirements. Ecology decided to establish an ad hoc committee to study the opt ions and make
recommendations.

After hearing committee recommendations, Ecology adopted a state regulation defining

sec ondary treatment requirem ents.

This section explains how to determine technology

- based permit limits for conventional pollutants (BOD5, TSS, pH, fecal coliform) discharged by domestic wastewater treatment facilities. When reviewing a permit application or renewal, the permit wri ter must first determine the proper technology

- based limits. Then the writer must decide if these limits are stringent enough to ensure that water quality standards are not violated in the receiving water. If they are not, then water quality

- based limits must be developed. Guidance for making that
decis ion is provided in chapter VI.

Domestic Wastewater treatment facilities are also subject to other permitting requirements such as whole effluent toxicity testing and monitoring of receiving water and sedi ments. Please refer to other chapters for these topics.CHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 2 

### Table V

- 1. SECONDARY TREATMENT REGULATION

- 40 CFR 133

Date ( Federal Register) Applicability Action Parameter Limit Citation

August 17, 1973 (38 FR 22298) All secondary facilities initial defini tion BOD5 30 mg/L, 30

- day avg 45 mg/L, 7

- day avg 85% removal, 30 day avg 133.102(a)

SS 30 mg/L, 30

- day avg, 45 mg/L, 7

- day avg 85% removal, 7

- day avg 133.102(b)

FC 200/100 ML, 30

- day avg 400/100 ML, 7

- day avg 133.102(c)

pH 6.0 to 9.0 133.102(d)

Secondary facilities with combined sewers, during
wet weather revise limits BOD5
SS % removal discretionary % removal discretionary 133.103(a) 133.103(a)

Secondary facilities with
industrial wastes revise limits BOD5 Proportional adjustment of 30

- day and 7

- day concentration and load limits, but not % removal 133.103(b)

SS Proportional adjustment of 30

- day and 7

- day concentration and load limits, but not % removal 133.103(b)

July 26, 1976 (41 FR 30788) All secondary facilities delete FC

--

revi se definition pH

--

October 7, 1977 (42 FR 54665) WSP less than 2 mgd revise limit SS State

- determined,
EPA

- adopted 133.103(c)

September 20, 1984 (49 FR 36986) TF, WSP revise limits BOD5 45 mg/L, 30

- day avg 65 mg/L, 7

- day avg 133.105(a)(1)&(2)

SS 45 /mg/L, 30

- day avg 65 mg/L, 7

- day avg 133.105(b)(1)&(2)

September 20, 1984 (49 FR 36986) allow ASR's BOD5 State

- determined
EPA

- approved 133.105(d)

SS State

- determined
EPA

- approved 133.105(d)

All WSP remove 2 mgd cap SS State

- determined,
EPA

- adopted 133.103(c)

All secondary facilities allow use of
CBOD5 for BOD5 CBOD5 25 mg/L, 30

- day avg 40 mg/L, 7

- day avg 85% removal, 30

- day avg 133.102(a)(4)

June 3, 1985 (50 FR 23382) TF, WSP revise limits BOD5
SS 65% removal, 30

- day avg 65% removal, 30

- day avg 1 33.105(a)(3) 133.105(b)(3)

Secondary facilities with separate sewers, less
concentrated influent during wet or dry weather revise limits BOD5
SS % removal discretionary % removal discretionary 133.103(d) 133.103(d)

January 27, 1989 54 FR 4224) Secondary facilities with combined sewers, less
concentrated influent during dry weather revise limits BOD5
SS % removal discretionary % removal discretionary 133.103(e) 133.103(e)

Before writing domestic wastewater permits, a permit writer should be familiar with WAC 173

- 221 Sections 10

- 50.CHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 3 

## 2. TECHNOLOGY

- BASED WASTEWATER DISCHARGE STANDARDS

TASK OUTLINE FOR STANDARD TECHNOLOGY

- BASED PERMIT LIMITS (Following the rules in WAC 173

- 221

- 040.)

1. Unless a facility qualifies for an alternative discharge standard or e ffluent limitation, listed in Section 050, its discharge mus t meet the following standards.

7

- and 30

- day
Pollutant 30

- day Average 7

- day Average Average
Parameter Concentration Concentration Daily Load Limits

Biological Oxygen Demand (BOD5) 30 mg/L 45 mg/L NA * lbs/day (see Step 3) Total Suspended Solids (TSS) 30 mg/L 45 mg/L NA lbs/day (see Step 3)
Fecal Coliform (geometric means) 200 organisms/ 400 organisms/ NA NA
100 mL 100 mL pH 6

- 9 standard NA
uni ts

* Not applicable.

2. In addition, the 30

- day average percent removal for BOD5 and TSS shall not be less than
85%.

3. Determine the maximum allowable 30

- day (monthly) average pounds per day of BOD5 and
TSS as follows:

Influent:

Refer to the Ecology approved plans and specifications. They should include a table which specifies the design, maximum month influent BOD5 and TSS loadings. Include those in the permit. If no record exists, consider requiring an engineering report to determine the design

c apacity of the plant. Alternatively, use the historical capacity listed in previous permits or set a capacity based on the historical discharge monitoring reports (DMRs). Task outline (cont inued )CHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 4 • Effluent:

Specify the lower number obtained by one of these two methods:

a) Multiply 30 mg/L by 8.34 and by the design flow as expressed in million gallons per day (mgd) for the maximum flow month in the design year. The result is in lbs./day.

b) Multiply the Ecology approved, design maximum mo nth influent loading (lbs/day) by .15 (fifteen/hundredths).

Method (b) results in a lower number when, for example, the influent BOD5 is below 200 mg/L or CBOD5 is used in place of BOD5.

Permit writers may apply the less stringent method if the follo wing factors apply:

• The facility designed its treatment facility based on weak influent strength (<200 mg/L TSS or BOD as noted in the engineering report).

• The actual influent concentrations are higher than the influent concentrations assumed in the design report (i.e.

, infiltration and inflow is not excessive).

• The facility consistently treats and achieves greater that 85% removal. The permit writer must explain, in the fact sheet , the reason for the use of the less stringent
method.

Refer to the most rec ent engineering report and plans and specifications which Ecology has approved for the maximum month design flow and loading

. For permit compliance, remember that the permittee must still achieve 85% removal of every monthly average influent
concentration and every monthly influent mass loading. Therefore a permittee may discharge
less than the maximum allowable 30

- day average lbs/day and still violate its permit.

4. Determine the 7

- day (weekly) average load limits by multiplying the 30

- day limits by 1. 5. The result is expressed in lbs/day.

5. Finally, Permittees can qualify for pH effluent limits outside the allowable range of 6

- 9, if they can meet all 3 conditions listed in Subsection 040(3).

6. Determine whether the technology

- based limits deriv ed above (including pH) will cause water quality standards violations in the receiving water (Chapter VI).

Note: Federal and state regulations refer to 30

- day and 7

- day average limits, not monthly and weekly average limits. For ease of permit writing an d compliance monitoring, permits are typically written in terms of monthly and weekly averages.CHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 5 

## 3. ALTERNATIVE WASTEWATER DISCHARGE STANDARDS

The secondary treatment regulation (WAC 173

- 221

- 050) allows alternative effluent limitations
in 5 cases:



## • Trick ling filters



## • Waste stabilization ponds



## • Facilities with combined sewers



## • Weak influent sewage



## • CBOD5 in lieu of BOD5

The state rule also includes alternative discharge standards for the above, but adds additional restrictions in each case. The next pag e describes conditions a municipality must meet to qualify for any alternative limit. Following that are background and explanations for each alternative discharge standard and a task outline for determining the appropriate alternative effluent
limitation . The permit writer should be familiar with the background section before using the corresponding task outline.


## 3.1 Conditions for Receiving Alternative Effluent Limitations

3.1.1 Discussion of Section 050(5) In order to qualify for any of the alternative effluent limitations of WAC 173

- 221

- 050(1

- 4), a municipality must prove compliance with the 6 conditions in 050(5). Therefore, those conditions, a, b, and d are explicitly required by federal regulation. Condition a requires that the
alternative limit n ot cause a water quality violation. For condition b, note that the phrase "effluent concentrations consistently achievable through proper operation and maintenance" is defined in Section 030 (Definition #11). For condition d, check the design criteria sh eet of the facility's plans and specifications.

Ecology has added condition c to the list. This prevents issuing alternative limits to a facility which cannot achieve 30/30 mg/L BOD5/TSS because of interference by industrial wastewater.
USEPA did not in tend alternative limits for such cases. The federal industrial pretreatment regulation, 40 CFR Part 403, allows states to require a pretreatment program for any size facility if industrial wastewater interferes with attaining permit effluent limitations.

Condition e requires the permittee to analyze whether alternative limits should be seasonal ratherCHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 6 than year

- round. Here are two examples.



## • Facilities may have less concentrated influent wastewater only during certain winter months. Any reduced percent removal limit should be applied only to those months

.



## • Some ponds may have difficulty meeting the 30 mg/L BOD5 limit during certain months (e.g.

, winter time when biological activity is slow)

. If a review of the historical record shows a consistent patter n, consider alternative limits just for those months.

Finally, condition f requires a municipality to meet all other permit requirements and conditions.


## 3.2 Trickling Filters

3.2.1 Discussion of Section 050(1)
The trickling filters which were constructe d and/or expanded prior to November 1984 can qualify for alternative effluent limitations. In this case, the effluent limitations for BOD and TSS

are set on a case

- by

- case basis, according to past performance. However, effluent limitations

must not excee d 45 mg/L BOD5 and 45 mg/L TSS on a 30

- day average.

Rule 050(1) is more restrictive than the federal rule in two ways.

First, it applies only to trickling filters which meet definition #23 in Section 030

. The definition excludes trickling filters which have a supplemental biological treatment system, other than waste stabilization ponds, for th e principal wastewater stream.

In recent years, engineers have developed various ways of combining trickling filters with suspended growth ; i.e.

, activated sludge systems. These systems have proven to be cost effective and reliable. When designed properly, they are capable of achieving 30/30 mg/L BOD5/TSS effluent and better. Ecology requires that such systems achieve those limits. Note that trickling
filter/wa ste stabilization pond combinations (built before November 19 84) can qualify for alternative effluent limitations allowed under Section 030. Any trickling filter may still qualify for alternative limits as allowed under Section 050(3), (4), and (6). Thes e systems will still have periodic problems with algae in the effluent. The algae are reported as suspended solids.

Secondly, the rule does not allow alternative limits for trickling filters constructed and/or expanded after November 1984. That is the e ffective date of the 1984 federal secondary treatment rule revisions. Recent advances in trickling filter design and technology have made these systems more efficient pollutant removers. Synthetic media, and proper hydraulic and organic loading designs a re examples of these advances. New trickling filters are capable of achieving 30/30 mg/L BOD5/TSS and thus should not be eligible for alternative discharge standards. This position is consistent with the USEPA Science Advisory Board.CHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 7 The November 1984 c utoff date is appropriate because it coincided with the effective date of USEPA's regulations. When Ecology was proposing its secondary treatment rule, no municipalities in the state had expanded or constructed trickli ng filters since November 1984.

Most of the existing trickling filters in the state were built between 1930 and 1960

. Some of these qualify for alternative effluent limitations because they are not consistently achieving 30/30 mg/L BOD5/TSS and 85% removal. However, most are achieving thos e limits the majority of the time and Ecology expects them to continue to do so. When these facilities need replacing because of population growth or age, the new systems should meet the 30/30 and 85% standards. The permit writer must use judgment when d eciding whether a rehabilitation project at such a facility is sufficiently extensive t hat 30/30 and 85% should apply.

One reason for requiring new trickling filters to achieve 30/30 is the recent concern about toxicants in effluents. In general, the am ount of toxicant removal by a conventional secondary treatment plant is proportional to its removal of conventional (BOD, TSS) pollutants. Trickling filters designed for 30/30 will be better suited to d eal with toxicity

- based limits.



### 3.2.2 TASK OUTLINE F OR DETERMINING TRICKLING FILTER BOD5/TSS EFFLUENT LIMITS
1. Does the facility meet definition #23 of Section 030?

Yes

- Go to 2

No

- Use Section 040

. Sections 050(3), 050(4), and (6) may also apply if requested by the applicant.
2. Was the facility cons tructed or did it have its most recent significant rehabilitation before
November 1984?

Yes

- Go to 3

.
No

- Use Section 040

. Sections 050(3), (4), and (6) may also apply if requested by the applicant.

3. Determine BOD5 and TSS "effluent concentrations co nsistently achievable.." per definition #11 of Section 030, then find the percent removal value.

Procedure:

Examine at least the last few years of discharge monitoring reports for average monthly effluent concentrations and percent removals. Do not use effluent data for months during which the facility had equipment failure, operator error, overloading, or other extenuating circumstances. Review the permit file for any information which may indicate that certain data are inaccurate. Do not use those da ta. Class I and II inspection reports, Roving Operator Trainer reports, and memos of conversations are examples of information sources.CHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 8 Determine the effluent concentration and percent removal that have been achieved 95% of the time. The following tabl e indicates which data points represent the 95th percentile values.

Number of Acceptable 95 th Percentile Values Monthly Average Values Percent Removal Concentration

24

- 35 2nd lowest value 2nd highest value 36

- 59 3rd lowest value 3rd highest value above 60 4th lowest value 4th highest value

4a. Is the 95th percentile value for TSS or BOD5 less than 45 mg/L?

Yes

- Propose the 95th percentile value as the monthly effluent limit. Proceed to 4b.

No

- Propose 45 mg/L as the limit . Proceed to 4b.

4b. Is the 95th percentile value for percent removal greater than 65%?

Yes

- Use the percent removal value as the monthly effluent limit. Proceed to 5.

No

- Use 65% as the monthly effluent limit. Proceed to 5.

Note: You can have different percent removal limits for BOD5 and TSS.

5. Does the facility meet all 6 requirements of Section 050(5)? (See above.)

Task outline ( continued )

Yes

- Use the limits obtained in 4. Proceed to 6.

No

- Use Section 040 or Section 050(6)(a)

.

6. Determine maximum monthly average weight per day of BOD5 and TSS effluent loading by:

a) Multiplying the facility's approved design year maximum month flow as expressed in million gallons per day by the concen trations determined in 4, and by 8.34; or,

b) M ultiplying the Ecology approved, design maximum month influent loading by the quantity (1 minus the % removal limit (from 4b and expressed as a decimal)). The result is expressed in lbs/day. Use the lower number (6a or 6b) as the effluent limit. ProceedCHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 9 to 7.

7. Determine the effluent weekly average concentration and loading limits by multiplying the monthly values by 1.5. However, the maximum acceptable weekly concentration limits are 65/65 mg/L BOD5/TSS.

8. Determine whether the technology

- based lim its derived above will cause water quality standard violations in the receiving water. If they will, see Chapter VI on water quality

- based
effluent limits.



## 3.3 Waste Stabilization Ponds

3.3.1 Discussion of Section 050(2) Waste stabilization ponds which have design capacity below 2 million gallons per day (mgd) or have received the Department of Ecology's approval for a greater design capacity, prior to the effective date of the regulation (11/12/87), can qualify for alternative limits. Permit writers
sh ould determine effluent limitations for individual waste stabilization ponds on a case

- by

- case basis according to past performance. However, effluent limitations shall not be set higher than 45 mg/L BOD5 and 75 mg/L TSS on a 30

- day average, and 65 mg/L BO D5 and 11 2 mg/L TSS
on a 7

- day average.

The USEPA secondary treatment regulation applies to all ponds. It does not include design capacity restrictions. Ecology added 4 conditions:

a. In 1977, USEPA published a regulation (see Table V

- 1) which allowe d ponds under 2 million gallons per day (mgd) capacity to exceed the 30 mg/L TSS requirement. By that regulation, USEPA established the TSS requirement for such ponds on a state

- by

- state basis. For each state, USEPA made the TSS limit a concentration whi ch 90% of the ponds in that state were achieving. In 1977, a survey of lagoon effluent quality set that concentration limit at 75 mg/L.

USEPA figured that ponds under 2 mgd probably served towns of under 10,000 population. Such towns, they reasoned, sh ould not be required to operate and maintain a treatment system more complex than a simple pond system. However, those ponds could not always achieve 30 mg/L TSS. Rather than requiring each small town which had a pond treatment system to change to a diff erent system, EPA allow ed higher TSS limits for ponds.

Ecology agrees with this approach, and will continue to allow small municipalities the option of constructing and keeping ponds as their treatment system. Forcing these communities to more complex s ystems would be counterproductive. Such systems would require more intensive operation and maintenance (highly qualified operators working longer hours). In the short run, lack of qualified operators and funds would result in poor operation,CHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 10 maintenance, and poor effluent quality. Ultimately it would mean a financial burden which USEPA and Ecology contend is not necessary or reasonable.

b. USEPA used similar arguments for justifying alternative BOD5 limits for ponds. Ecology

concurs, and will continue to require engineers to design ponds using state of the art techniques to achieve 30 mg/L BOD5 . However, if despite proper design a pond under 2 mgd design capacity does not achieve 30 mg/L BOD5, the permit writer can change the
effluent limits for that facility. The permit writer should require the facility to achieve that which it has proven it can achieve. No permit should have an average monthly discharge
eff luent limit above 45 mg/l BOD5.

c. USEPA now allows these higher effluent limits for all p onds regardless of size. They have done so because the Clean Water Act legislative history does not necessarily indicate that Congress intended to limit alternative standards to small communities.

Ecology is not constrained by the federal congressional record. Municipalities over 10,000 population should have the ability and the financial wherewithal to construct and operate a facility which can achieve 30/30 mg/L BOD5/TSS. Therefore, any new ponds with design capacity equal to or greater tha n 2 mgd mu st meet those limits.

In addition, if a municipality with a pond system expands such that it exceeds the 2 mgd ceiling, it must treat that portion of the flow over 2 mgd to the 30/30 mg/L BOD5/TSS standard. However, if a municipality expands its total tr eatment capacity above 2 mgd by replacing the old pond system with a new pond system, it must treat all of the flow to the 30/30 mg/L BOD5/TSS. These various permitting situations are described in steps 1 to 9 of the next section ( 3.3.2, Task outline for determining waste stabilization ponds BOD5/TSS effluent limits ).

d. Municipalities which have Ecology

- approved pond systems of greater than 2 mgd design capacity can also qualify for alternative effluent limitations. Again, Ecology wants to allow
those municipalities which have invested in a pond treatment system to continue to use that investment. However, the provisions of state law which require all known available and reasonable technology (AKART) dictate that more complex treatment systems capable of achieving 30/30 mg/L BOD5/TSS are reasonable for larger municipalities. Therefore, any flows exceeding the pond system design capacity approved prior to December 12, 1987, must
be treated to meet th e 30/30 mg/L BOD5/TSS standard.CHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 11 

### 3.3.2 TASK OUTLINE F OR DETERMINING WASTE STABILIZATION PONDS' BOD5/TSS EFFLUENT LIMITS

Permitting Situation Start at this Step

New Pond under 2 mgd, Step 1 Existing Pond under 2 mgd, renewal application for same capacity Step 3 renewal applicat ion for greater capacity < 2 mgd Step 1 renewal application for greater capacity > 2 mgd Step 8
Pond > 2 mgd, capacity approval by Ecology after 12/87 Step 2 Existing Pond > 2 mgd, renewal application for capacity > 2 mgd Step 9

1. The first 5

- year permit limits shall be 30 mg/L BOD5 and the TSS concentration which Ecology is using to satisfy definition #25. Until notified otherwise, use 75 mg/L TSS for the
30

- day average, and 112 mg/L TSS for the 7

- day average. The applicant should submit a design based on achieving 30 mg/L BOD5 and minimizing TSS. The design review should
use the Criteria for Sewage Works Design and nationally recognized design manuals as standards for proper design.

Percent removal limits for BOD5 or CBOD5 shall be 85% unless Section 050(3) and/or (4) apply. No percent removal applies to TSS.

2. Use Section 040 for this and all renewal permits

. Section 050(3), (4), and (6) may also apply if requested by the applicant.

3. Determine BOD5 and TSS "effluent concentratio ns consistently achievable..." per definition
#11 of Section 030.

Procedure:

Examine at least the last 2 years of discharge monitoring reports for average monthly effluent and percent removals. Do not use effluent data for months during which the facili ty had equipment failure, operator error, overloading, or other extenuating circumstances. Review the permit file for any information which may indicate that certain data are inaccurate. Do not use those data. Examples of information sources are Class I and II inspection reports, Roving Operator Trainer reports, and memos of conversations.

Determine the effluent concentration and percent removal that have been achieved 95% of the time. The table below indicates which data points repres ent the 95th perc entile values.CHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 12 Task outline (cont inued )

Number of Acceptable 95 th Percentile Values Monthly Av erage Values Percent Removal Concentration

24

- 35 2nd lowest value 2nd highest value
36

- 59 3rd l owest value 3rd highest value
above 60 4th lowest value 4th highest value Alternatively, place the values in Excel and use the Data Analysis to calculate the 95 th percentile.

4a. Is the BOD5 value less than 45 mg/L?

Yes

- Propose that value as the monthly ef fluent limit and proceed to 4b.

No

- Propose 45 mg/L as the limit and proceed to step 4b

.

4b. Is the TSS value less than 75 mg/L?

Yes

- Propose it as the monthly effluent limit and proceed to 4c

.

No

- Propose 75 mg/L as th e limit and proceed to step 4(c).

4c. Is the percent BOD5 removal determined in 5, greater than 65%?

Yes

- Propose it as the monthly limit.

No

- Propose 65%.

5. Does the facility meet all 6 requirements of Section 050(5)? (See review of that sectio n.)

Yes

- Use the limits obtained above in 4

. Proceed to 6.

No

- Use Section 040, or Section 050(6)(a) if requested by applicant.

Note: One of the conditions of Section 050(5) is the identification of effluent concentrations consistently achievable t hrough proper operation and maintenance. The permit writer should have already checked the permit file, as explained in Step 3 above, for indications of inaccurate data. The permit writer should also check whether the facility is being operated in accord ance with the Operation and Maintenance Manual.CHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 13 Task outline (continued)

For pond systems, the writer should particularly note whether the manual includes any recommendation for frequency of sludge removal from the ponds, or whether it indicates an

acc eptable sludge depth. Prior to considering any alternative limits, the permit writer should require the applicant to verify the extent of sludge accumulation. Significant accumulations can be the reason for declining performance.

If the Operation and Ma intenance Manual is silent on sludge accumulation and dredging, the permit writer will have to use judgment in deciding when dredging of the pond is necessary

. If the existing pond system has extensive accumulations in one or more ponds which are likely

a ffecting the quality of the effluent, require dredging as soon as possible. Review the long term effluent quality records to note if a gradual decrease (corresponding to the sludge accumulation) in treatment efficiency has occurred. If so, give the pond system higher effluent limits (based on the last few years of data) for the time period up to the dredging, and lower limits (based on pond performance years when sludge accumulations were low) for the remaining time of the 5

- year permit. Permit limits at the next renewal should be based on pond performance after the dredging.

Finally, the permit writer should include periodic sludge depth monitoring in the pond system as a condition of the permit. Such a condition is included in the recommended monitori ng schedule for lagoons.

6. Determine maximum monthly average (lbs/day) of BOD5 and TSS effluent loading limits by:

(a) Multiplying the facility's approved design year maximum month flow (as expressed in million gallons per day) by the concentrations d etermined in 4 above, and by 8.34; or,

(b) for BOD5 only, multiplying the Ecology approved, design maximum month influent loading by the quantity (1 minus the % removal limit [expressed as a decimal] determined in 4(c) above). The result is expressed in lbs./day. For BOD5, use the lower number obtained by method a or b.

7. Determine the weekly average concentration and loading limits by multiplying the monthly values by 1.5

. However, the weekly average BOD5 concentration limits should not exceed 65 mg /L; and the weekly average TSS concentration limits should not exceed 112 mg/L.

8. Case I: If all the flow is treated by the ponds, use Section 040. Sections 050(3), (4), and (6) may also apply, if requested by the applicant.

Case II: The applicant pla ns to use its existing ponds for its previously approved flow capacity. In this case, follow the instructions in Steps 3 through 7 to determine the permit limits. TheCHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 14 Task outline (cont inued )

remaining flow must be treated in a separate facility which m eets the requirements of Section 040. Section 050(3), (4), and (6) may also apply if requested by the applicant.

Case III: The applicant plans to expand the existing pond capacity up to 2 mgd and take higher flows to a separate facility. Design the pon d for 30 mg/L BOD5. The first 5

- year permit limits
should be a 30

- day average of 30 mg/L BOD5, 75 mg/L TSS; and a 7

- day average of 45 mg/L BOD5, 112 mg/L TSS for the pond. The separate facility shall have permit limits required under
Section 040

. Sectio n 050(3), (4), or (6) may also apply if requested by the applicant. The pond may qualify for alternative effluent limitations in subsequent permits.

9. This step applies only to the following pond systems:

Everett Longview
Montesan o Marysville

The applicant has the option of proposing a system(s) which meets limits under Case A or Case
B.

Case A: If the proposal is to use the existing ponds within the previously approved design capacity, use the procedure outlined in Steps 3 through 7 above. Any additional flow over the previously approved capacity must be treated in a separate facility whose effluent limits shall be based upon Section 040

. Section 050(3), (4), and (6) may also apply if requested by the applicant.

Case B: If the proposal is to expand the design capacity of the pond system, use Section 040

. Section 050(3), (4), and (6) may also apply if requested by the applicant.

10. Determine whether the technology

- based limits derived above will cause water quality

sta ndard violations in the receiving water. If they will, see Chapter VI on water quality

based effluent limits.



## 3.4 Facilities with Combined Sewers

3.4.1 Discussion of Section 050(3)
Facilities which receive flow from combined sewers during wet weather ca n qualify for alternative monthly percent removal limits. During such wet weather conditions, the facility may be excused from achieving any predetermined percent removal requirement or may have a percent removal limit which is lower than otherwise allowe d.CHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 15 During rainfall events, sewage treatment facilities which serve combined sewers can receive widely fluctuating influent flow rates and influent pollutant concentrations. These fluctuations are due to the intrusion of storm water to the sewer system. In some situations the influent concentrations are so dilute that achieving 85% or any other predetermined percent removal per Section 050(1) or (2) is not possible. The fluctuations can also cause inaccurate computation of the 85% removal requirement. In many cases, the wide fluctuations prevent the establishment of a minimum (below 85%) percent removal requirement which the treatment system would be expected to achieve re gardless of any flow situation.

This section of the regulation differs from USEP A's rule because we define "wet weather" (See
definition #30 in WAC 173

- 221

- 030). We want the option to restrict application of this waiver to the time period immediately surrounding rainfall events.

In all cases first verify whether the applicant has a significant combined sewer area in its collection system. Refer to the definition of combined sewers (#5). Verify that the sewers were originally designed to serve a storm water and sanitary sewage function; and that the combined sewer area is allowed by local ordinance. The following is an inclusive list of those which to have combined sewer systems as of December 1988

. Please contact the Program Development Services Section if any municipalities re quest to be added to this list.

Seattle Port An geles
METRO Mt. Vernon
Everett Bremerton Spokane Olympia Bellingham Anacortes
Snohomish

Note that municipalities should not build, nor should Ecology approve, any new combined sewers. All new construction must have separate sani tary and storm sewers. New building construction in a combined sewer area can place storm water into the combined system. However, all municipalities with combined sewers must comply with Chapter 173

- 245 WAC for reducing combined sewer overflows. Any ne w storm drainage from new construction must not delay achievement of compliance with Chapter 173

- 245 WAC. The municipality should have an Ecology approved CSO plan with a schedule for CSO control compliance.

For communities with secondary treatment, rev iew the DMRs to see if a minimum percent removal requirement for wet weather months is identifiable. For municipalities still at primary treatment, consider no percent removal requirement for the traditional wet weather months until secondary treatment is on line for at least a couple years

. This should give sufficient data to identify plant capabilities.CHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 16 A municipality may choose to comply with Chapter 173

- 245 WAC regarding CSO control by transporting and treating high wet weather flows at the central d omestic wastewater treatment plant. For these situations in particular, the permit writer can grant relief from the monthly percent removal requirement. However, federal rules do not allow relief from the monthly and weekly concentration limits. If any municipality wishes to control their CSOs in this way, but is concerned about meeting their monthly concentration limits, please consult the Program Development Services Section about making inquiries to USEPA. 

### 3.4.2 CSO Treatment Facilities (173

- 245

- 090 ) (1) (a) (ii)) If the municipality has chosen at

- site treatment facilities (e.g.

, primary treatment and disinfection) for CSO control, the permit writer can choose to permit the facility under the same permit as that for the secondary treatment plant, or wr ite a separate permit. In either case, the permit should include numerical limits for the discharge, flow capacity limits for the facility, and reporting requirements.

The numerical limits must at a minimum address the definition of "primary treatment” g iven in
WAC 173

- 245

- 020 ; i.e.

, settleable solids not exceeding 0.3 ml/l/hr and not less than 50% removal of total suspended solids. The permit writer has some discretion in how to write the numerical permit limits. They can apply and be enforced on a yea rly, monthly, or per event basis. That which is reasonable to achieve should be required. Refer to Chapter XII

- 2.4 for monitoring guidance.

The permit should also note that "the total treated and untreated annual discharge from an at

- site treatment plan t shall not increase above the baseline annual" level (WAC 173

- 245

- 090 ) (1)(a)(ii).



### 3.4.3 TASK OUTLINE FOR DETERMINING PERCENT REMOVAL LIMITS FOR COMBINED SEWER SYSTEMS

1. The applicant may request the alternative limit and submit supporting documentation for that request. The permit writer is not obliged to initiate any adjustment without a r equest.

2. Determine whether the applicant meets the requirements of Section 050(5) (discussed earlier in this chapter).

Yes

- Proceed to 3.

No

- Use Section 040, or Section 050(6)(a) if requested by the applicant.

3. Determine whether the facility is capable of 85% removal on a monthly basis in spi te of the combined sewage flow.

Yes

- Use 85%. Go to 6.CHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 17 No

- Go to 4.

4. If 85% removal is not reasonable, determi ne whether a lower percent remo val is consistently achievable.

Yes

- Use the lower, consistent percent removal as the limit. Go to 5.

No

- Delete the percent removal requirement during wet weather conditions. Go to 5.

5. Include a condition which list s the specific months for which a lower or no percent removal limit applies. For example, delete the requirement for November through April,
the rainiest months.

Word the condition such that the percent removal requirement does apply for any
month which does not receive significant rainfall or snow melt, (e.g.

, a dry December).

Also state that this condition does not relieve the permittee from operating the treatment facility as efficiently as possible. Cross reference the standard condition that requir es this.

6. Determine whether the percent removal limit determined above will be sufficient to prevent water quality standard violations in the receiving water. If not, determine

Task outline (cont in ued )

what percent removal will achieve the standard s. Chapter VI on water quality

- based effluent limits may be helpful.



### 3.4.4. Definition of a CSO Event
RCW 90.48.480 requires “the greatest reasonable reduction of combined sewer overflows at the earliest possible date”. Chapter 173

- 245 WAC defines the g reatest reasonable reduction as “the control of each CSO such that an average of one untreated discharge may occur per year”.

The process of CSO control is given in the Criteria for Sewage Works Design (Ecology 98

- 37 WQ) ; however, that document does not d efine storm (event), overflow event or averaging period. A definition of event is necessary for large communities with numerous overflow sites and frequent overflows to design facilities for collection and treatment.

• A CSO event may be defined as the ove rflow or multiple overflows of a CSO outfall occurring within a 24 hour period (option 1 below).

• A CSO event may be defined by a 24 hour minimum inter

- event time for a CSO outfall (option 5 below).CHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 18 • One rainfall storm event causes only one CSO event.

• The averaging period may be one year or the five year permit term.

Defining Some Terms

Combined Sewer Overflow (CSO)

– an event during which excess combined sewage flow caused by inflow is discharged from a combined sewer, rather than conveyed to the sewage treatment plant because either the capacity of the treatment plant or the combined sewer is
exceeded.

Inter

- Event Time (IET)

– The dry period or time steps between storm or CSO events.

Minimum Inter

- Event Time (MIET)

– The amount of dry time or non

- overfl ow time required to indicate a storm event or CSO event is independent (CV ≈ 1).

Storm Duration

– The time from the first wet time step at the beginning of the storm event to the last wet time step ending the event.

Storm Event

– A period of rainfall sep arated from other wet time steps by a dry period equal to or greater than the minimum precipitation inter

- event time.

Storm Inter

- Arrival Time

– The time from the beginning of one storm event to the beginning of the next storm event. (Equal to one storm duration and one inter

- event time).

Threshold Rainfall

– The amount of rainfall necessary to cause runoff. In the Portland Oregon area this varies from 0.05 to 0.1 inch, depending on length of the storm.

Wet Time Steps

– A time increment in a precipitat ion record in which a measurable amount of precipitation occurs. The measurable amount may be defined as threshold rainfall.

Options Considered For Defining Event

1. Any overflow or multiple overflows in a specific interval of time (e.g. , 24 hours) is

c onsidered an event. This is the simplest option and may be appropriate for small CSO communities with few overflows and that are close to compliance with the one per year requirement. This option may be applicable where the engineering analysis is relativ ely straight forward and the solution may be as simple as additional storage or I and I correction. The advantage of this option is that it does not require analysis of regional precipitation, CSO system response to storm events and derivation of a design storm.CHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 19 This option doesn’t provide the statistical tools to predict the return period (probability) of a storm event of a certain mag nitude.

The current regulatory practice for larger sewer systems required to design to a certain return period is to li nk the definition of overflow event to the definition of storm event. Linking overflow events to storm events provides engineers with a mechanism for determining return periods of storm events and subsequent design of control structures

. The following op tions 2 through 5 (based on Nicholson and Adderley, 1994) are contingent upon linking the
definition of a CSO event to the definition of a storm event.

2. Sewer System

- Based Definition : Under this definition, a storm event is considered to end when the sewer system has processed or discharged the wet weather flows.

It is difficult to justify use of this definition for facilities planning because the system performance will change as controls are put in place. Systems with storage or systems affected by rain

- induced infiltration also cause difficulties with using this system because the overflow may continue long past the end of the precipitation. This problem is discussed in
more detail later.
3

. Best Professional Judgment IET: This definition relies heavily on the expertise, local knowledge, and preferences of the individual(s) developing the event definition. Typical values recommended for various projects include 1 hour, 3 hours, 6 hours, 12 hours, 24 hours, and 48 hours of dry time
between storms (precipitation IET) or outfall discharges (CSO IET).

4

. Duration

- Volume Design Criteria : An event is considered over when a specific amount of time has elapsed (6 hours to 3 days) since the rainfall stopped, or when a certain depth or volume of rainfall has occurred (0.5 inch to 3 inches).

The problem with this definition is that design storms based on return periods developed from this storm definition may be misleading. A 10

- year, 24

- hour design storm may generate a 100

- year CSO or a 1

- year CSO depen ding on the soil moisture conditions and available storage in the system at the time the design storm occurred.

5

. Statistical Independence : This definition is used when the probabilistic return frequency of events is important to the design, operation, or evaluation of the system. A frequency analysis has as its underlying assumption that the events (storms, CSO flows) are independent of one another ; i.e., there is no joint probability linking one event to any other event. Such a definition helps prev ent facilities from being undersized. The drawback of this definition is that the methods required to determine the statistical independence are somewhat difficult to use. This method has been used for the City of Portland (Nicholson and Adderley 1994) a nd for the EPA national modelCHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 20 (Woodward

- Clyde Consultants 1989). This method has also been examined for use in Seattle (Lukas and Merrill, 1996) and Spokane (Mau, 1999). The method is based on a paper by Restrepo

- Posada and Eagleson (1982).

Additional d esirable criteria considered for selecting the most appropriate storm/CSO event
definition are:
1. Incorporates the local hydrology patterns

. 2. Provides results that are appropriate for use in frequency analysis

. 3. Is objective and defensible

. 4. Provides results that are reasonable and useful.

Why Not Use The EPA National Definition Of Storm Event? An analysis of 40 years of rainfall data from 138 gages across the U.S. was conducted by
Woodward

- Clyde (1989). This analysis defined precipitation inter

- event times r equired to define independent storm events. The IET for the Eastern US was six hours, 20 hours for the mid

country, and 300 hours for the arid southwest. This analysis did not specify an IET for the
Pacific Northwest. Woodward

- Clyde (1989) recommended t hat a uniform 6

- hour minimum IET be used nationwide to assure a common basis throughout the country. Nicholson and Adderly (1994) say that a 6

- hour IET may be used for the design of small

- scale storm water facilities but should not be used for design of l arge

- scale CSO control facilities in the Pacific Northwest.

Precipitation events in the Pacific Northwest have different characteristics than events in other parts of the country. Rainfall in the Pacific Northwest is characterized by long

- duration, low

i ntensity storms and it may be difficult to identify individual storms

. Several analysts have
demonstrated a 6

- hour IET is not applicable for defining a storm event in the Pacific Northwest.

Defining CSO Event by Defining Storm Event (Option 5 Statistical Independence) The process as described in the paper by Restrepo

- Posado and Eagleson (1982) utilizes long

term precipitation data, typically hourly records. The following description of the process is taken from Nicholson and Adderley (1994).

In rainfall frequency analysis, the return period of a storm of a given volume or peak intensity is based on the assumption that the volume or peak intensity of each storm is independent. A sufficient condition that assures independence between peak storm volumes and peak intensities
is when the inter

- event times (dry times) between storms is independent as well. Establishing independence between storm events is done by assuming the rainfall data represent continuous time (t) divided into a sequence (i = 1 to n) of di screte subintervals of duration ( ∆ t, 1 hour if hourly record). The variable X i (i = 1 to n) is defined as depth of rainfall occurring in each interval i. At each time interval, a test is made to determine if rain occurred (X i > 0) or no rain occurred (X i = 0). Then a second variable that characterizes the occurrence of rain or event function, Y i , is defined as:CHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 21 Y i = 1 for X i > 0
Y i = 0 for X i = 0

If the storm events as represented by Y i are independent of each other, then the series will fit a

Poisson distribution, ! x e P x

x λ λ

− = , and the dry periods between the events (the precipitation

inter

- event times) are exponentially distributed. One of the characteristics of a Poisson distribution is that the mean (m) and the standard deviation (s) are the same, and the coefficient of variation (CV = s/m) equals one. The test for independent storm events is conducted by calculating the coefficient of variation (CV) of the IETs and comparing it to one.

This simplified method is applicable up to the poi nt where overlapping begins to occur. Overlapping means that the storm as modeled actually contains several storms grouped into one large event. Overlapping is prevented by keeping the ratio of the storm duration and the storm
inter

- arrival rate (time fr om the beginning of one storm to the beginning of the next storm) much
less than 1.0:

(Storm Duration)/(Storm Duration + Inter

- Event Time) << 1.0

An additional requirement is that the method must be applied to data that are homogenous or belong to the sa me seasonal weather patterns. The data must be analyzed by months and grouped into seasons with similar patterns.

The authors of this procedure noted that it was empirical and inexact but useful in many design
situations.

The statistical independence te chnique for defining event resulted in a precipitation MIET for the Portland area of 18 hours for winter and 48 hours for summer. A combined precipitation MIET of 24 hours was recommended (Nicholson and Adderley, 1994) for the Portland area.

An analysis of rainfall from the SeaTac Airport resulted in a precipitation MIET of 15 hours for winter and 36 hours for summer. A combined precipitation MIET of 18 hours was recommended (Lukas and Merrill, 1996).

An analysis of the Spokane rainfall record showed in dependent events at a MIET of 24 hours (Mau, 1999).

The basic assumption of this procedure is that the definition of an independent storm event also defines a CSO event and that only one CSO event will occur during one storm event. Therefore,
if the rain fall event is defined, then a CSO event is also defined. During a storm event, the rainfall intensity will vary over the duration of the storm. At certain times in the storm when the rain falls at an intense rate, CSO discharges may occur. A discharge m ay occur at the beginningCHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 22 of the storm, stop, and then begin again at the end of the storm. The assumption that a rainfall
event defines a CSO event means that these intermittent flows are considered one CSO event.

Defining Event b y Overflows The simplest method to define a CSO using the statistical

- based procedure is to define a CSO by equating the CSO IET to the precipitation MIET so that any CSO’s that were separated by a period longer than the precipitation MIET would be deemed separate events (one sto rm event can only cause one CSO event). CSO communities would measure compliance by measuring the beginning and ending of each CSO.

Lucas and Merrill (1996) point out a potential problem with this approach as illustrated in the following figure of actual precipitation record and resulting computer simulated overflows at the Martin Luther King Way (MLK) CSO.

Figure 1. An illustration from Lucas and Merrill (1996) comparing rainfall and CSO inter

- event periods.

This figure show s a series of precipitation events that have been classed as one event based on an
18

- hour precipitation MIET. The three CSO overflows are separated by more than 18 hours and would be classified as three overflow events if we simply used the precipitation MIET as the CSO MIET. Lucas and Merrill (1996) propose an alternative in which they use the simulation model to predict the number of overflows for the MLK overflow for the period of the precipitation record (Table V

- 2 ). The CSO IET is analyzed for vary ing periodicity (3 hours, 6CHAPTER V. MUNICIPAL EFFLUENT LIMITATIONS AND OTHER REQUIREMENTS (JULY 2011)

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- 23 hours, etc.) and the resulting number of overflows. For the SeaTac precipitation data, an 18

- hour precipitation MIET caused a simulated 3805 precipitation events (81.8/year) for the 46.5 period of record. Of these 3805 precipi tation events, 802 (17.3/year) caused simulated overflow events. The analysis of the CSO IETs showed that a 40

- hour (interpolated) CSO IET caused an equivalent number (802) overflow events for the period of record. They recommend, for the MLK overflow, t he use of 48

- hour CSO MIET for administrative convenience. A 48

- hour CSO MIET results in an average of 17 CSO events/year at MLK. This CSO process and the inter

event number were based on the assumptions that the Carkeek CSO permit had defined Ecology’s future processes for CSO’s. Specifically, that future CSO permits would be written to require reporting of CSO discharge without regard to the causative rainfall and Ecology would require reporting of CSO discharges on a calendar day basis.

Table V

- 2

. Inter

- Event Analysis Results

– Martin Luther King Way CSO and SeaTac Airport Rainfall (from Lukas and Merrill, 1996).
Minim

um inter

event ,

hr. MLK Overflow SeaTac Rainfall Rainfall Events Causing
Overflow (Simulated ) No. of
Events in 46.5

year record Ev ents
per
year No. of
Events in 46.5

year record Events

per
year Summer
inter

event C.V. Winter
inter

event C.V. No. of
Events in 46.5

year record Events

per
year

3 1196 25.72 9458 203.40 1.87 1.63 1048 22.54
6 1103 23.72 6668 143.40 1.57 1.32 961 20.67
9 1047 22.52 5448 117.16 1.42 1.17 900 19.35
12 999 21.48 4706 101.20 1.33 1.07 862 18.54
15 967 20.8 4202 90.37 1.26 1.00 836 17.98
18 943 20.28 3805 81.83 1.21 0.94 802 17.25
24 884 19.01 3216 69.16 1.12 0.85 742 15.96
30 849 18.26 2744 59.01 1.06 0 .78 687 14.77
33 831 17.87 2555 54.95 1.02 0.75 660 14.19
36 821 17.66 2409 51.81 1.00 0.73 639 13.74
48 771 16.58 1904 40.95 0.92 0.63 571 12.28
60 725 15.59 1533 32.97 0.84 0.57 497 10.69
72 679 14.60 1311 28.19 0.79 0.52 450 9.68
84 633 13.61 1138 24.47 0.75 0.49 408 8.77
96 600 12.90 999 21.48 0.72 0.46 379 8.15
120 559 12.02 751 16.15 0.65 0.41 314 6.75
144 527 11.33 589 12.67 0.59 0.39 270 5.81
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- 24 Note that the precipitation IET of 18 hours contains 17 storm events/year but a predicted 20 CSO events/year. While this analysis may be valid for counting the number of overflows now, this analysis is not applicable to other systems and does not predict the probability of this problem when overflows approa ch the required one per year. Ecology believes this difference between events will become negligible as CSO frequency approaches one per year and therefore no adjustment on a policy basis is necessary for overflows into the inter

- event period.

Definition of Event For smaller communities with few overflow points and infrequent overflows a CSO event may be counted as any 24

- hour period when a CSO discharge or multiple discharges occur. This prevents having to do a regional precipitation analysis and modeli ng of the CSO system to derive a design storm.

For large communities with numerous overflow points and frequent overflows, a CSO event is
defined as a 24 hour minimum inter

- event time for a CSO outfall

Averaging Period and Compliance Options (Reserved)CHAPTER V. MUNICIPAL EFFLUENT LIMITATIO NS AND OTHER REQUIREMENTS (JULY 2011)

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- 25 

## 3.5 Facilities with Less Concentrated Influent Wastewater

3.5.1 Discussion of Section 050(4) The facilities which receive less concentrated influent wastewater than normally received by domestic wastewater facilities can qualify for alternative limit s. The influent wastewater must have a BOD5 concentration less than 167 mg/L. In such cases, the facility may apply for a lower percent removal requirement than the 85% from Section 040 or the minimum 65% for trickling filters and waste stabilization pon ds (BOD5 only).

The 85% removal requirement was originally established to achieve 2 basic objectives:

1. to encourage municipalities to remove high quantities of infiltration and inflow (I/I) from their sanitary sewer systems, and

2. to prevent inten tional dilution of influent wastewater

. However, in facilities with dilute influent which is not attributable to high quantities of I/I or intentional dilution, the percent removal requirement will result in forcing "advanced treatment". Advanced

treatme nt generally refers to additional treatment processes (e.g., filtration, chemical addition, or 2

- stage biological treatment) which achieve significantly greater pollutant removals than secondary treatment processes alone. Ecology concurs with USEPA, that it is not reasonable or cost effective to require advanced treatment in these cases.

However, the USEPA regulation does not accomplish objective (1) above. Despite establishing 3 conditions (see 40 CFR 133.103(d) and WAC 173

- 221

- 050(4)(b)(i

- iii)) to qual ify, a municipality could still qualify despite grossly high levels of I/I. The federal regulation would allow such a municipality to claim that it is more effective to transport and treat such flows

-- at a reduced percent removal

-- than to correct. This c ould result in increasing total weight of pollutants discharged and neglecting adequate sewer system maintenance. To prevent this situation, Ecology has added a fourth condition (See 050(4)(b)(iv). That condition requires a municipality to submit a progr am aimed at controlling I/I. Ecology has approval authority over the program. The permit writer should incorporate the program into the conditions of the NPDES permit.CHAPTER V. MUNICIPAL EFFLUENT LIMITATIO NS AND OTHER REQUIREMENTS (JULY 2011)

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- 26 

### 3.5.2 TASK OUTLINE FOR DETERMINING LOWER PERCENT REMOVAL LIMITS FOR LESS CONCE NTRATED INFLUENT WASTEWATER
1. The permittee must request and submit supporting documentation for the permit writer's review. The documentation should include I/I analyses, and sewer system surveys, performed to meet federal requirements (as referred to i n 2.c. below). The daily historical rainfall record and historical daily sewage flows should be provided with these studies.

2. Determine whether the permittee qualifies under Section 050(4)(b).

a. Does the facility meet its effluent concentration limit s and the mass loading limits based on

those effluent concentration limits for BOD5 (or CBOD5) and TSS as established in Section 040 and 050(1) and (2)?

Yes. Proceed to b.

No. Does not qualify. The permit should include the requirements of Section 040 or section 050(1) or (2). If the permittee cannot immediately comply, issue an administrative order requiring submission of a plan and schedule to achieve compliance (e.g.

, build more capacity).

b. Have the average influent concentrations of BOD5 and TS S generally been below 167 mg/L in the months for which the permittee has requested lower percent removal limits? (Review at least a few years worth of data.)

Yes. Proceed to c.

No. Does not qualify. Section 040, or Section 050(1) or (2) applies.

c. Is the less concentrated influent the result of "excessive" I/I?

The permit applicant must use the USEPA pamphlet document "I/I Analysis and Project Certification" for proposing what is "excessive" I/I. When computing the costs of transporting
and treat ing the sewage, include the present cost (capital and operation and maintenance) of whatever technology would be necessary to achieve the limits allowed by Section 040, or Section 050(1), or (2), whichever is applicable. Any overflow of sewage is deemed e xcessive
I/I.

If the answer to c. is Yes , the applicant does not qualify for a lower percent removal limit. Issue a permit with the standard percent removal requirement (Section 040 or Section 050(1) or (2)), and propose a sewer rehabilitation program a nd schedule as a condition of the permit or withinCHAPTER V. MUNICIPAL EFFLUENT LIMITATIO NS AND OTHER REQUIREMENTS (JULY 2011)

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- 27 an administrative order. You will probably need additional guidance for determining reasonable rehabilitation schedules. The minimum goal of the rehabilitation program would be to eliminate
"excessive" I /I.

When the "excessive" I/I is eliminated, the applicant can get lower percent removal limits in accordance with #4 below, if they agree to further sewer rehabilitation as outlined in #4.

If the answer to c. is No , proceed to 3.

3. Does the facility me et all the requirements of Section 050(5)? (See task outline for this earlier in this chapter.)

Yes, proceed to 4.

No, does not qualify.

4. Propose a lower percent removal effluent limitation which the applicant has demonstrated it can meet 95% of the time. This % removal limit can be less than 65% for certain lagoons and trickling filters. Use DMR data as explained in Step 3 of the task outline for determining trickling filler BOD5/TSS effluent limits. Make a note in the permit that whenever the

mo nthly influent concentration exceeds 167 mg/L, 85% removal is the permit limit.

5. If the applicant ever exceeds the USEPA screening criteria of 120 gallons per capita per day (7

- 14 day average for sewage plus infiltration) or 275 gallons per day (highes t daily flow recorded during a storm event

-- includes sewage flow plus I/I), propose a sewer rehabilitation program and schedule as conditions of the permit. Alternatively, keep the permit condition worded in general terms and place the specific schedule o f activities in an administrative
order.

The goal must be to eliminate sufficient I/I quantities such that the influent sewage BOD5 and TSS concentrations exceed 167 mg/L. Thereafter, the standard percent removal requirements of Sections 040 and 050(1) a nd (2) would once again apply and should be written into the next permit renewal.

If the permittee rehabilitates the sewer and gets flows below the USEPA screening criteria, yet the BOD5 and TSS concentrations do not exceed 167 mg/L on a monthly average, propose a lower percent removal effluent limitation.

For trickling filters (BOD5 and TSS) and waste stabilization ponds (BOD5) which also qualify for percent removal limitations between 85 and 65% under Sections 050(1) and (2), the sewer rehabilitation go al should be to reduce I/I below the USEPA screening criteria, or to raise the influent concentrations such that the facility no longer meets 050(4)(b)(ii) ; i

. e. , theCHAPTER V. MUNICIPAL EFFLUENT LIMITATIO NS AND OTHER REQUIREMENTS (JULY 2011)

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- 28 influent concentrations are above 167 mg/L and therefore Section 040 or Section 050(1) o r (2) applies. If during the rehabilitation program, the flows are reduced below the USEPA screening criteria, yet the BOD5 and TSS concentrations do not rise above 167 mg/L, propose a lower percent removal limitation based on Section 050(1) or (2).



## 3.6 S ubstitution of CBOD5 For BOD5

3.6.1 Discussion of Section 050(6) The facility owner/operator can request and the Department can approve substitution of
carbonaceous BOD5 (CBOD5) for the standard BOD5 limitation. In such cases, the Department may substit ute a 25 mg/L CBOD5 limit for a 30 mg/L BOD5 limit.

USEPA has extensively studied the use of a CBOD5 limit in lieu of a BOD5 limit. They concluded that a 25 mg/L CBOD5 limit is effectively equivalent to a 30 mg/L BOD5 limit. We agree. A detailed expla nation for this substitution is in the preamble to 40 CFR part 133 as published on September 20, 1984

.

Using CBOD5, a municipality could discharge more oxygen

- demanding nitrogenous material than when using BOD5. This is likely if a facility can't prevent partial nitrification.

Nitrification is the conversion of organic nitrogen and ammonia

- nitrogen (nonoxidized) to nitrate (oxidized). It occurs by chemical action or by certain microorganisms which consume nonoxidized nitrogen getting into the water. Th ese organisms use large amounts of oxygen when consuming organic nitrogen and ammonia

- nitrogen (both unoxidized) and converting them to nitrate (oxidized). When this process is underway (partial nitrification), it creates a high BOD.
Once nitrification i s complete, there is very little oxygen

- demanding nitrogenous material left.

Using the BOD5 test, facilities have to either keep nitrifying microorganisms out (prevent partial nitrification), or wait for them to completely nitrify the water before dischar ge. Using CBOD5 however, facilities can discharge partially nitrified water, even with its high nitrogenous oxygen

demand.

Notably, unless Ecology identified a problem in receiving water quality, a facility has no obligation to remove nitrogenous oxygen

- demanding substances from its wastewater. USEPA's longstanding 30 mg/L BOD5 effluent limit was not intended to force removal of nitrogenous pollutants. It was intended for carbonaceous pollutants. The newer federal rule and Chapter
173

- 221 WAC clarify t hat intent, and eliminate the need for facilities to remove these nitrogenous pollutants. This need exists at some facilities only because the nitrogenous pollutants gave a false indicatio n of poor facility performance.CHAPTER V. MUNICIPAL EFFLUENT LIMITATIO NS AND OTHER REQUIREMENTS (JULY 2011)

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- 29 

### 3.6.2 TASK OUTLINE FOR DETERMININ G CBOD5 LIMITS 1. The per mittee must request the change.

2. Is the facility a waste stabilization pond or trickling filter as defined in Section 030, which has requested or received alternative BOD5 or CBOD5 limits?

Yes

- Go to 3.

No

- Issue new permit limits of 25 mg/L CBOD5 for the monthly average; and 40 mg/L for the weekly average. Refer to the explanation (earlier in this chapter) of Section 040 to determine monthly and weekly load limits. Percent removals are based on CBOD in
the influent and effluent.
The Average Monthly Mass Effluent Limit (CBOD) = The maximum monthly design flow (MGD) x Concentration Limit (mg/L) x 8.34 = _____MGD x 25 mg/L CBOD x 8.34 = lb/day CBOD

The Average Weekly Mass Effluent Limit (CBOD) = 1.5 x Average Monthly M ass Limit

3. Have the permittee submit at least one year's worth of influent and effluent data for CBO D5, BOD5, and ammonia nitrogen.
a. Try to establish a ratio between BOD5 and CBOD5, (for example, the BOD5/CBOD5 could be 1.2/1) for months with low or m oderate nitrification.

b. Determine the "effluent BOD5 concentration consistently achievable through proper operation and maintenance." See task outlines for Section 050(1) or (2).

c. Determine corresponding CBOD5 concentration for the BOD5 value determ ined above by using the ratio established in 3a.

d. Is the corresponding monthly average CBOD5 concentration limit less than 40 mg/L?

Yes

- Use it as the new CBOD5 limit.

No

- Use 40 mg/L as the new CBOD5 limit.

e. Determine the weekly average CBOD5 lim it by multiplying the number obtained in d. by
1.5.
f. Refer to the explanation in this chapter for Section 040 for guidance in determining
influent and effluent load limits for CBOD5. Remember to use the CBOD5 influent and
effluent concentrations determi ned above.

g. Determine percent removal requirements similarly to the procedures explained earlier forCHAPTER V. MUNICIPAL EFFLUENT LIMITATIO NS AND OTHER REQUIREMENTS (JULY 2011)

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- 30 trickling filters and waste stabilization ponds respectively.
NOTE: Whenever effluent CBOD5 limits are given, the permit must also be changed to require influent CBOD5. The 85% removal requirement applies to the CBOD5 effluent as compared to
the CBOD5 influent.

When designing biological aeration tanks, it's still appropriate to use BOD5, and in many cases,
nitrification

- demand requirements for determini ng aeration capacity. 

## 3.7 Defining Compliance with 85% Removal Compliance with the 85% removal standard of secondary treatment is defined as the 30

- day average influent concentration (AIC) minus the 30

- day average effluent concentration (AEC) divided by the 30

- day influent concentration (AIC):

(AIC

- AEC)/ AIC.
This method of calculation is consistent with the regulatory intent of the performance standard as a long

- term average performance standard. This method gives a percentage that is a fraction of a percent higher than if calculated as the average of the daily percent removals.

This determination comes from federal regulations, 40 CFR Part 133 (definitions).

40 CFR 133.101(b) 30

- day average. The arithmetic mean of pollutant parameter values of

samp les collected in a period of 30 consecutive days.

40 CFR 133.101(j) percent removal. A percentage expression of the removal efficiency across a treatment plant for a given pollutant parameter, as determined from the 30

- day average values of
the raw waste water influent pollutant concentrations to the facility and the 30

- day average values of the effluent pollutant concentratio ns for a given period of time.

40 CFR 133.102 Secondary treatment (a) BOD 5 (3) The 30

- day average percent removal shall not be less than 85% (b) SS (3) The 30

- day average percent removal shall not be less than 85%



### 3.7.1. STEP Systems
Section 2 of this chapter pointed out that federal and state regulations require POTW's to remove 85% of BOD and solids of the influent wastewat er. This removal requirement is difficult to assess in a STEP systems which utilize septic tanks as part of the treatment system

. This part presents a process for dealing with STEP systems.CHAPTER V. MUNICIPAL EFFLUENT LIMITATIO NS AND OTHER REQUIREMENTS (JULY 2011)

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- 31 RECOMMENDATIONS

A NPDES discharge permit and fact sheet for a POTW with a STEP system should include the following:

1. The permit should contain the appropriate effluent concentration limits and percent removal requirements from WAC 173

- 221

- 040 or 050 (1) or (2).

2. The 85% BOD 5 removal requirement in the permit should be footnoted with the following:
The permittee will be presumed to be in compliance with the percent removal requirement in the permit if the permit effluent concentration limit is met and there is no excessive inflow and infiltration (I/I). Infiltration is excessive when the highest 7

- 14 day average daily dry weather flow is greater than 120 gallons per capita per day. Inflow is excessive when the highest recorded daily flow during a storm event is greater than 275 gallons per capita per day or when hydrau lic overloading of the treatment plant occurs.

3. The permit should require monitoring and reporting of the influent BOD 5 and the percent BOD 5 removal accomplished at the central treatment plant.

4. The fact sheet should explain that as long as the permit efflue nt concentration is met and neither USEPA criteria (120 gallons per capita per day for the highest 7

- 14 day average, and 275 gallons per capita per day for the highest 24

- hour average) are exceeded, the permittee will be presumed to be in compliance with t he percent removal requirement in the permit.

5. The fact sheet should also explain that if either USEPA criteria are exceeded the permittee will be required to implement a rehabilitation program to reduce I/I. The program will be agreed upon between Ecology and the permittee and the details (schedule, work plan, financial commitment) will be incorporated into an administrative
order.

6. The permit should require annual reporting of the highest 7

- 14 day average daily dry weather flow rate and the highest 24

- h our per capita daily flow rate.

7. The permit should require the permittee to institute or continue an adequate operation and maintenance program for the entire sewage system including the septic tanks in the STEP system.

BACKGROUND Septic tanks remove set tleable solids and provide a limited amount of digestion of organic matter of domestic wastewater. When used as part of a STEP system, properly operated and maintained septic tanks can achieve some degree of BOD 5 removal and thus reduce wastewater BOD 5 lo ading to the sewage treatment plant downstream. The reported mean effluent BOD 5 concentrations from domestic septic tanks range from 120 to 240 mg/l (USEPA 1980). Based onCHAPTER V. MUNICIPAL EFFLUENT LIMITATIO NS AND OTHER REQUIREMENTS (JULY 2011)

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- 32 limited data, the influent BOD 5 concentration to the central sewage treatment plan t of a Western Washington municipality (Montesano) with septic tank effluent pumps discharging to a pressure conveyance system was found to be around 180 mg/l.

For POTWs that receive domestic sewage after treatment in septic tanks (STEP system), the
BOD 5 removal in the septic tanks is considered an integral part of the treatment process for
BOD 5 removal. Since it is impractical to measure the actual influent BOD 5 to the septic tanks, compliance with the 85 percent BOD 5 removal requirement of the secondary treatment rule may be assumed if the effluent concentration meets 30 mg/l, and if there is no excessive inflow and infiltration (I/I). In this case excessive infiltration is defined as exceedance of the USEPA screening criterion of 120 gallons per capita per day (average daily dry weather flow

- highest average daily flow recorded over 7

- 14 day period of seasonal high ground water); excessive inflow is exceedance of the USEPA criterion of 275 gallons per capita per day (highest daily flow recorded during a storm event for wastewater plus I/I); or any occurrence of treatment plant hydraulic overload. If the USEPA screening criteria for I/I are not exceeded, the presumption is that the raw sewage influent would be at least 200 mg/L if the septic tanks were not present. These screening criteria apply regardless of whether the I/I can be cost

- effectively removed (see section 3.5 of this chapter).Therefore, complying with the 30 mg/L effluent BOD5 concentration limit means that the 85% removal requirement is a lso achieved.

Since the sewage conveyance system is under pressure, ground water intrusion (infiltration) into the public sewer should not be a factor for weak influent. However infiltration can occur through sewers connecting the buildings to the septic tanks and through possible cracks in the tanks. The report required under (6) above should be sufficient to allow the permit writer to
make an assessment of excessive infiltration.


## 3.8 Operation and Maintenance (O & M) Manual

The NPDES permit special co ndition "Operation and Maintenance of Municipal Facilities" requires the permittee to keep an approved O & M manual at the treatment plant. The approved O & M manual must be updated as needed and a copy of the updated portions be submitted to the Departme nt for review and approval. Failure to keep an approved and updated O & M manual at the treatment plant is a permit violation and subject to enforcement. The permit writer should talk with his/her supervisor concerning the appropria te enforcement measure s needed.



### 3.8.1

. O & M Requirements for Collection Systems
The collection system ( that is the network of sewers and pump s or lift stations ) is an integral part
of the wastewater treatment works . For the most part these are buried and distant from the

tre atment facilities, so that small leaks often go unnoticed for long periods. Leaks of untreated sewage constitute a discharge of wastewater which is not allowed under the terms of the permit.

Small leaks, especially if numerous or under pressure, can resu lt in significant impacts on theCHAPTER V. MUNICIPAL EFFLUENT LIMITATIO NS AND OTHER REQUIREMENTS (JULY 2011)

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- 33 environment

. Leaks can adversely impact the treatment plant if they result in excessively dilute sewage (infiltration or inflow). For these reason s , maintenance of the collection system should be considered part of the Op erations and Maintenance for the wastewater treatment system, even if they are managed by different de partments of the municipality.

If the existing O&M manual for the facility does not include the collection system, the permit will require preparation an d implementation of a section on the collection system. If the collection system is included in the O&M Manual for the facility, a periodic review will be required and an update for all modifications of the system (e.g.

, extensions) required.

Mechanical systems (lift stations and pumps)

• There needs to be a regular schedule for reviewing the performance of mechanical systems which are part of the collection system. This includes schedules for lubrication, testing pump and motor performance, testing the op eration of level switches and alarms, call out systems and cleaning any screens, floating material and sediments. If there is excessive corrosion of the interior walls of wet wells, then leak testing may be warranted. Planning for power failures or unant icipated overflows needs to be implemented.

Gravity sewers

• Sewer pipes which operate partly full have low internal pressures (nearly atmospheric), which allows ground water to enter the sewer through leaks whenever the water table is above the level of the sewage and the leak . T his is called infiltration . The water table typically fluctuates seasonally (high during wet weather or irrigation season) so that leaks which result in infiltration during part of the year may result in exfiltration, leakage of raw sewage out of the sewer, at another time during the year. Excessive infiltration dilutes the sewage, increases the costs of treatment and potentially interferes with the complete treatment of the sewage. Exfiltration is a discharge of pollutants to groundwater.

• Testing sewers designed to operate at atmospheric pressure is more difficult than testing piping systems intend ed for operation under pressure, since the re are more openings to close and less strength for resisting leakage without failing. A lthough pressure testing of individual pipe segments is possible

, t esting sewers for infiltration (and by implication exfiltration) is usually done by measuring flows or other character s of the sewage such as temperature or conductivity

. Temporal pattern s of varying temperature and conductivity might be indicative of infiltration of groundwater into the sewer pipes. If the temperature or conductivity show values closer to groundwater during the low flow period in the early morning, infiltration is suspec ted and needs to be further characterized as to how much and where the leaks are occurring

. Also, smoke testing of sewers can be an effective technique for detecting leaks.

• Sewers may also collect water such as stormwater through holes in the covers for the access points to the sewer, direct connection of downspouts to the sanitary sewer, etc.CHAPTER V. MUNICIPAL EFFLUENT LIMITATIO NS AND OTHER REQUIREMENTS (JULY 2011)

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- 34 Th is result s in increased flows associated with storms and can cause some of the same problems as infiltration for treatment. This is referred to as i nflow

. Once inflow has been identified, it needs to be characterized for how much and where it enters; the techniques and tools used are often the same as those used for infiltration.

Pressurized sewers:

• These are sewers with pressures significantly greater than atm ospheric pressure, in which case leaks will almost always result in exfiltration. Sewers which operate at greater than atmospheric pressure include force mains where the pressure is generated by a pump operating against gravity and friction, and inverted siphons where the pressure results from gravity acting on the column of water between the invert of the siphon and the free surface in the gravity sewer.

• Pressurized sewers can be tested, if they can be taken out of service, by closing all of the valves, pressurizing the sys t em and measuring the loss of pressure with time

.

L eaks can be especially problematic i f the collection system contains segments which cross surface water or follow the low lying land along surface water (river

, stream , or lake)

. A re gular schedule of inspections and testing of the collection system on those segments in sensit ive environments is required.

Once a leak has been determined to be present and its location narrowed down

, ( for instance between two manholes ) , confirmation of the type of leak and location can often be done by passing a television camera through the sewer.


## 3.9 Maintaining Adequate Capacity

Ecology has observed over the years that it takes municipalities several years to plan and fund expansions of the wastewater treatment plant. Permit writers should note the population growth of a municipality when redrafting their wastewater discharge permit. For those nearing capacity or with rapid population growth, the permit writer should put a requirement in the permit t hat causes the municipality to submit a report on capacity. The triggers for submitting a report are when the peak flows waste load exceeds 85% of the design criteria for three months in a row or if flows or loads are expected to reach design capacity dur ing the life of the permit. The plan should include a schedule for continuing to maintain capacity. The capacity as outlined in the plan must be sufficient to achieve the effluent limitations and other conditions of this permit. This plan should address any of the following actions or any others necessary to meet the objective of maintaining capacity.

1. Analysis of the present design including the introduction of any process modifications that would establish the ability of the existing facility to achiev e the effluent limits and other requirements of this permit at specific levels in excess of the existing design
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- 35 2. Reduction or elimination of excessive infiltration and inflow of uncontaminated ground and surface water into the sewer system.

3. Limita tion on future sewer extensions or connections or additional waste loads.

4. Modification or expansion of facilities necessary to accommodate increased flow or
waste load.

5. Reduction of industrial or commercial flows or waste loads to allow for increasing
sani tary flow or waste load.


## 3.10 Operator Certification

Anyone operating a wastewater treatment plant in Washington State is required to be a certified operator

. Certification requires a combination of training and experience as described below

. A higher cer tification is required to operate higher discharge or more complex treatment plants

. The complete requirements for Operator Certification are given in Chapter 173

- 230 WAC.
Table V

- 3 below gives the operator level required for various treatment processes a nd flow
volumes.

Table V

- 3 Treatment Plant Classification Criteria

Treatment type Design flow MGD Operator Classification r equired

Primary ≤1 I >1, ≤10 II >10, ≤20 III
>20 IV Lagoon (Nonaerated) All I Lagoon (Aerated) ≤1 I
>1 II

Biofiltration ≤1 II >1, ≤10 III
>10 IV

Extended aeration ≤5 II
>5 III

Activated sludge ≤1 II >1, ≤10 III
>10 IV

Wetlands ≤1 I >1, ≤5 II
>5 III

Tertiary ≤5 III
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- 36 Treatment type Design flow MGD Operator Classification r equired

Membrane bioreactor a 

### ( Operators of these facilities must have an expert on call when needed as determined by the department) For any size facility discharging to a sensitive with effluent limits beyond secondary treat ment, Ecology will decide on the certification
level on a case

- by

- case basis using engineering judgment , the complexity of the operation, the record of permit compliance and the risk to humans
and the environment. ≤1 II ≤1 Class A reuse III ≤1 with c hemical addition
for nutrient removal III

>1, ≤10 III
>10 IV Any size discharge with water quality

- based limits with limits more stringent than technology

- based secondary treatment Determined on a case

- by case basis using engineering judgment based o n the complexity of the operation, the record of compliance, and
the risk to humans and the
environment.

a. C lassification levels have been determined by policy

Plants may be classified in a group different than indicated in this section if: 1) They have characteristics that make operation less complex or more difficult than other similar plants of the same flow range; or 2) The conditions of flow or the use of the receiving waters require an unusually high degree of plant operational control; or 3) They use an approved method of wastewater treatment that is not included in this section.


## 3.11 Loading Calculation for intermittent discharges

The following method is recommended for calculating loading for intermittent discharges: Multiply the month’s average daily flow (gpd) x average of sampled daily concentrations x [0.00000834]. Days with zero flow are included in the average daily flow calculation.

The federal definition (40 CFR Part 122.2 is “ Average monthly discharge limitation means the highest allow able average of ‘‘daily discharges’’ over a calendar month, calculated as the sum of all ‘‘daily discharges’’ measured during a calendar month divided by the number of ‘‘daily discharges’’ measured during that month.

Ecology notes that if a facility disc harges intermittently, this definition does not adequately represent the discharge loading particularly for discharges to land and for TMDL compliance. EPA’s definition was intended to apply to technology based limits and continuous discharges

. We can di rect facilities with intermittent discharges to calculate compliance with limits using aCHAPTER V. MUNICIPAL EFFLUENT LIMITATIO NS AND OTHER REQUIREMENTS (JULY 2011)

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- 37 different method specific to the situation. 

## 4 . BIOSOLIDS (SLUDGE) Important points for permit writers

• The Waste 2 Resources Program has the lead for biosolids managem ent, inclu ding permitting and regulation. There is a biosolids coordinator in each regional office and at headquarters.

• Treatment plant upgrades are a critical control point for effective biosolids management. When an upgrade or significant change in t reatment technology is contemplated, it is essential to be sure the regional biosolids coordinator is in the loop. Rather than attempting to decipher the options for biosolids management available under the regulations, it is often more helpful for operat ors to ask themselves, “What do we want to do with our biosolids,” and then investigate the requirements and feasibility.

• Virtually all sewage treatment facilities (and some others) come under the state

biosolids program, including lagoons

. Lagoons ofte n neglect biosolids management and find themselves with a very short time frame for decision making on costly projects. The recommended planning horizon for removing biosolids from a lagoon is two years.

• Biosolids are not a solid waste. State law says t hey are a valuable commodity and directs Ecology to implement a program maximizing beneficial use. The Waste 2 Resources Program generally does not support management options that lead to disposal.

• Ecology does not have delegation of federal program aut hority. This does not affect state program implementation because we have independent statutory authority, however, Ecology’s program must meet federal program requirements. Lack of federal delegation means that treatment works continue to have dual
obli gation of submitting permit applications and annual reports to both agencies. It also means that EPA can initiate unilateral permitting or enforcement actions, although this has not occurred. In some cases Ecology has delegated certain
authorities to loc al health jurisdictions (LHJs). It can be helpful to know the extent of local delegation agreements.



## 4.1 The State Program
1992 Legislation directed the Department of Ecology to implement a program maximizing the beneficial use of biosolids, a valuable c ommodity (Chapter 70.95 J RCW). This Legislation was significant because it was the first in the nation to recognize “biosolids” in statute, it gave authority for program development and implementation to Ecology, and it removed biosolids from regulation as a solid waste, declaring instead the product was a valuable commodity

.CHAPTER V. MUNICIPAL EFFLUENT LIMITATIO NS AND OTHER REQUIREMENTS (JULY 2011)

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- 38 Ecology adopted new rules for biosolids management in Chapter 173

- 308 WAC and issued a statewide general permit for biosolids management in the spring of 1998

. New general permits were issued in 2005 and 2010, and a revised rule was adopted in 2007

. The Waste 2 Resources Program is the regulatory authority responsible for authorizing and permitting the use of biosolids throughout the state. In some cases delegation agreements are in place with LHJs. Ecology’s biosolids program is intended to meet or exceed federal program requirements of the Clean Water Act, 40 CFR Part 503, and various other federal regulations. There is a program coordinator in the headquarters office and a coo rdinator in each regional office.

The term biosolids was adopted by the state Legislature in 1992 in Chapter 70.95J RCW. Biosolids is municipal sewage sludge that meets the quality standards allowing it to be beneficially used. The standards for qualit y are defined in Chapter 173

- 308

- WAC. Biosolids which do not meet these standards may not be applied to the land (even under a solid waste permit). Disposal options include incineration and landfill disposal. Chapter 70.95J recognizes biosolids as a va luable commodity and directs Ecology to develop a program to maximize beneficial use. Landfill disposal is discouraged, but may be allowed in some cases on an emergency or short

- term basis, or even as a long

- term management option. Ecology does not
suppo rt incineration but recognizes the importance of incineration to a few communities in the state who have incineration facilities in place. We have encouraged these communities to operate their incinerators as efficiently as they can for as long as they ar e serviceable. As these units need significant upgrades or replacements, Ecology will advocate strongly for abandonment and a shift to beneficial use.

The state rule includes a permitting program, the key to which is identification of a facility as a Tr eatment Works Treating Domestic Sewage (TWTDS)

. TWTDS is a term adopted from federal rules and essentially refers to any treatment facility which changes the quality of biosolids. The vast majority of TWTDS are publicly owned treatment works. Privately owned treatment works qualify only if there is no industrial influent component. Other facilities may also meet the definition of TWTDS. Biosolids compost facilities are TWTDS as are facilities which simply combine biosolids from two different sources, b ecause they both change the quality of biosolids they receive. Certain land application sites, called Beneficial Use Facilities, are also TWTDS. Facilities that treat or land apply septage are also TWTDS

. Ecology can also use its authority to designate TWTDS and bring facilities under the permit program that would not typically require permitting.

The state biosolids rule is directly enforceable. All facilities and persons subject to the rule must comply with its requirements, regardless of their sta nding under the permit program

. There are several steps to the permitting process which includes SEPA review, public notice, an application process and potentially public hearings. The first step involves submission of a Notice of Intent form at least 6 months before an existing general permit expires. The notice of intent acknowledges the facility’s intention of applying for coverage under the general permit. In the second step of permitting, the facility submits a complete permit application. The per mit application must be submitted within 180 days following the issuance of a new general permit. Complete review by Ecology may not occur for some time. In the third step Ecology reviews the application and current practices. Once final conditions have been established, the facility is notified with a letter of final approval; this letter may include additional or more stringentCHAPTER V. MUNICIPAL EFFLUENT LIMITATIO NS AND OTHER REQUIREMENTS (JULY 2011)

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- 3 9 requirements if needed. The facility must then comply with all final plans and any additional or more stringent requirements stipulated in their final approval letter.


## 4.2 The Federal Program
The Environmental Protection Agency (EPA) has responsibility for implementing biosolids program requirements on Indian lands and in states which have not taken delegation of federal
program authorities. EPA does not consider the federal program to be a high priority and in recent years has significantly disinvested from the biosolids program. This has left EPA Regions in a very difficult position to implement federal requirements. In Regi on X the primary focus has been on facilities in Alaska and Idaho which have fewer resources for implementing state
programs. EPA has also worked with some facilities on Indian lands and federal facilities

. EPA has chosen two approaches to implementing t he biosolids program at the federal level. The initial focus was on inclusion of requirements in federal NPDES permits. This effort is continuing at some level in Region X. After a time, EPA began using a general permit approach in some regions. EPA’s expectations of Washington facilities appear to be fairly reasonable and minimal at this point in time. Facilities with NPDES permits should have complete (and updated) federal biosolids permit applications on file with Region X. Other Treatment Works Tr eating Domestic Sewage (mostly state waste discharge permitted treatment works) should have Part 1 of the federal application on file. All major facilities should submit annual reports to EPA. EPA does not have an annual report form and has stressed that content of the report is the critical issue. Washington’s form has been determined to be acceptable. Beyond these requirements, EPA has a fundamental expectation of compliance with the rules.


## 4.3 Delegation
Ecology originally intended to pursue delegati on of federal program authority, but staff cannot set aside implementation activities in order to pursue federal delegation without compromising the state program. Consequently, the Waste 2 Resources Program has elected not to pursue delegation until adeq uate resources are available for the task. Ecology’s authority to implement the state program, however, is independent of federal delegation. A lack of federal delegation does not in any way invalidate the state program. The benefits of federal delegati on are marginal for Ecology. Delegation would relieve the regulated community of certain duplicative processes, particularly permit applications and annual report submittals. It would also clarify the first line of authority for regulatory decisions. EP A, however, has not played an active role in biosolids management with Washington facilities to date, although they have been helpful to Ecology. Nationwide only a handful of states have received delegation of federal authority.

Ecology may delegate cer tain responsibilities to LHJs. Typically this delegation will at a minimum include review of applications and site plans and routine inspections. A few LHJs around the state have delegation agreements in place with Ecology.


## 4.4 Overlap With Wastewater Pe rmits

Generally, Water Quality Program permit writers and managers should consult with the biosolids permit managers in the Waste 2 Resources Program regularly, as there is the potential for signi ficant overlap between permits.CHAPTER V. MUNICIPAL EFFLUENT LIMITATIO NS AND OTHER REQUIREMENTS (JULY 2011)

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- 40 One of the most critical p oints of overlap with wastewater permits are biosolids sampling and analysis requirements. All TWTDS which apply biosolids or sell or give away biosolids for application must conduct a minimum amount of sampling on an annual basis. The pollutants and

mon itoring schedules are the same in the federal and state rules, although permit requirements may extend those requirements. Both rules have provisions that require representative sampling as well. Many times the minimum specified sampling frequency may be inadequate. This is an area where Ecology’s biosolids permit program must fill the gap. While sampling methods are specified in the rules, the specific vehicle directing them is not critical to the biosolids program. For example, samples obtained in su pport of a pretreatment program may also be acceptable for biosolids program compliance. Water Quality permit managers should check with their counterparts in the Waste 2 Resources Program as monitoring requirements come under review.

Facility upgrades a nd new construction are areas of critical concern to both programs . Facilities should have a clear vision of future biosolids management practices when contemplating upgrades. For example, the biosolids treatment systems designed to produce Class A biosol ids (a measure of pathogen reduction) are different than those w hich produce a Class B product. Both products are acceptable, but there are markedly different implications for permitting in the biosolids program as well as for end uses. Also, the Waste 2 Resources Program would likely oppose a proposed management system which would depend either on incineration or landfilling of biosolids.

Finally, a delegation agreement between Ecology and a LHJ may be important in terms of Water Quality Program permitti ng. Permit managers should specifically inquire about current delegation agreements in both the area where the biosolids are generated, and where they are used.CHAPTER VI. WATER QUALITY

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- 1 

# CHAPTER VI. WATER QUALITY

- BASED EFFLUENT LIMITS FOR SURFACE WATERS

Permit writers must con sider the impact of every proposed discharge to surface waters on the quality of the receiving water and specifically consider how the discharge may affect the use of the receiving water. In some cases, this consideration may reveal that permit limits bas ed on a treatment technology are not sufficiently stringent to protect water quality even with a mixing
allowance . In these cases, additional permit limits must be developed, or alternative disposal methods or locations must be found. This chapter deals with conducting an analysis of reasonable potential and developing effluent limits for the protection of aquatic life for individual permits

. Human health protection is covered in Chapter VII.

To evaluate the effect an effluent has on receiving water, a permit manager must use:

• the water quality criteria and standards described below in Section 1,

• the mixing zone criteria described below in Section 2, and

• a method for predicting impact and defining effluent limits for numeric criteria
described below in Section 3.

The permit writer should keep in mind that the requirement for imposing effluent limitations for the protection of water quality does not require a demonstration of impact beyond any doubt but only that there is a determination of reasonable po tential determined by a rational and scientific

process.

Section 4 of this Chapter describes analytical levels for permit application and effluent limits

.

Evaluating an effluent's effect on receiving water includes an evaluation of whole effluent
toxicit y (WET). Section 5 presents Ecology's approach for dealing with whole effluent toxicity.

Additional guidance on determining effluent mixing is presented in Appendix 6.



## 1. WATER QUALITY CRITERIA AND STANDARDS

Water quality criteria are estimated threshol d concentrations for specific pollutants which are based on scientific data about adverse effects to aquatic life or human health. These criteria address human health effects, toxicity to aquatic organisms, bioaccumulation potential, or an
adverse effect on some other beneficial water use. These criteria may be single numbers, a concentration range, or a narrative statement.CHAPTER VI. WATER QUALITY

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- 2 The first water quality criteria developed by direction of the Water Quality Act of 1965 and the
Federal Water Pollution Control Ac t (Clean Water Act) have since been revised several times.

The methods used for deriving the criteria have changed over the years. The different methods that EPA has used are published as appendices to the Gold Book EPA 440/5

- 86

- 001. EPA
maintains a site dedicated to criteria development http://water.epa.gov/scitech/swguidance/standards/policy.cfm

. The criteria have become increasingly complex as EPA tries to incorporate all the factors which affect toxicity including exposure patterns or characteristics. The Criteria sheet of TSDCALC contains the current
criteria.

Many of the numeric criteria for aquatic life protection have 3 components:



## • magnitude or concentration,



## • duration

- averaging period for exposure to the chemical in question, and



## • frequency

- the number of times that the criteria may be exceeded within a given time frame without permanently affecting the aquatic communities. Three years is used as the per iod of time for aquatic community reestablishment.

Each of these components is defined for short

- term (acute) and long

- term (chronic or sub

- lethal)
effects.

The current EPA aquatic life criteria for zinc, for example, are: "freshwater aquatic organisms and their uses should not be affected unacceptably

if the 4

- day average (duration) concentration of zinc (in μg/L) does not exceed the numerical value given by (.986)(e (0.8473[ln(hardness)]+0.7614) ) (concentration) more than once every three years on the a verage (frequency) and if the 1

- hour average (duration) concentration (in μg/L) does not exceed the numerical value given by (.978)(e (0.8473[ln(hardness)]+0.8604) ) (concentration) more than once every three years on the average (frequency). For example, a t hardness of 50, 100, and 200 mg/L as CaCO 3 , the 4

- day average concentrations of zinc are 32, 105, and 188 μg/L respectively, and the 1

- hour average concentrations are 64 , 114, and 206 μg/L. If the striped bass is as sensitive as some data indicate, it w ill not be protected by this criterion... Saltwater aquatic organisms and their uses should not be affected unacceptably if the four

- day average concentration of zinc does not exceed 81 μg/L more than once every 3 years on the average and if the 1

- hour ave rage concentration does not exceed 90 μg/L more than once every 3 years on the average."(Values are from FR Vol ume 60, No. 86, May 4, 1995)

The criteria for toxic pollutants, including zinc, have separate development documents which provide a detailed rev iew of the data used to develop the criteria. These documents are available from the Department of Ecology Library, the Environmental Assessment Program, and from theCHAPTER VI. WATER QUALITY

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- 3 EPA Region 10 library in Seattle

. New or revised criteria are published in the Federal Register.

The criteria for toxic pollutants are not static

. EPA continues to refine these numbers to incorporate new research data and risk methods.


## 1.1 The Water Quality Standards Define the Designated Uses and Incorporate Criteria

Water quality stand ards for Washington's surface waters are codified in Chapter 173

- 201A WAC, Water Quality Standards for Surface Waters of the State of Washington

, Amended November 20, 2006 (Water Quality Standards) and in 40 CFR Part 131 Water Quality Standards

, Section 13 1.36, known as the National Toxics Rule. The National Toxics Rule does not apply to
those substances which were already included in our Water Quality Standards at the time the
R ule was adopted

. The Water Quality Standards consist of 3 key parts.

Part I of the standards contains the purpose and definitions.

P art II of the standards defines the designated uses of surface waters and the in

- stream criteria

necessary to protect those designated uses

. The four categories of uses are aquatic life, shellfish
h arvesting, recreational uses, and miscellaneous

. Within these categories there are subcategories and the criteria necessary to support those uses. The criteria within a subcategory or
classification are numerical values or narrative statements. The conv entional and historical parameters are dissolved oxygen, fecal coliform, dissolved gas saturation, temperature, pH, and turbidity. A map application assists Ecology staff in identifying the designated uses on a water body and their associated numeric crit eria

. The application and instructions are found at: http://aww.ecology/programs/wq/swqs/index.html

.

Toxic substances are addressed through both narratives statement and numerical criteria. T oxic criteria apply to all uses of waters. Note that in this section footnotes aa and bb to Table 240(3)
contain small typographical errors in the formulas as published , however, TSDCALC (discussed later) calculate s the criteria correctly.

Many of the numerical values of the criteria are dependent on other water quality parameters such as pH, temperature and hardness. Some values have duration periods specified as instantaneous values, 1

- hour averages, 24

- hour averages or 4

- day averages.

Silver is giv en in our standards as an instantaneous value not to be exceeded. Implementation of
silver is the same as an a cute one hour average exposure.

The chronic aquatic life criteri on for mercury is based on accumulation of methylmercury in aquatic organisms. Permit writers should use the chronic criteri on for mercury just like all other
chronic criteria

.CHAPTER VI. WATER QUALITY

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- 4 In addition to the specific numerical criteria, the State Water Quality Standards state that the Gold Book may be used as a source of information for determin ing the toxicity of substances not specifically listed in the standards [(173

- 201A

- 240(4) and (5)]

.

The key narrative criteria of the Water Quality Standards are:



## • Toxic, radioactive, or deleterious material concentrations must be below those which have

t he potential, either singularly or cumulatively, to adversely affect characteristic water uses, cause acute or chronic conditions to the most sensitive biota dependent upon those waters, or adversely affect public health (see WAC 173

- 201A

- 240, toxic substa nces, and 173

- 201A

250, radioactive substances)

.



## • Aesthetic values must not be impaired by the presence of materials or their effects, excluding those of natural origin, which offend the senses of sight, smell, touch, or taste (see WAC 173

- 201A

- 230 for gu idance on establishing lake nutrient standards to protect aesthetics).

Part III of the Water Quality Standards is the antidegradation policy and process. Three levels of protection are described

. Tier 1 is a statement of policy that existing and designa ted uses will be protected. Tier 2 is most applicable to permit writers

. Tier 2 is applicable to new dischargers or any discharger increasing pollutant loading which then causes a measurable degradation (concentration exceeding detection levels) of the r eceiving water ( boundary of the chronic zone for those pollutants with near field effects)

. Measurable degradation is defined in regulation for temperature, dissolved oxygen, bacteria, pH, and turbidity

. The increase in pollutant loading
must be shown to be necessary and in the overriding public interest. Generally, the tier II analysis should be conducted by the permittee as a companion to an engineering report. Implementation of antidegradation for general permits requires Ecology to describe in the f act sheet how new stormwater pollutant control technologies will be incorporated into the permit [(WAC 173

- 201A

- 320(6)]. The detailed guidance for antidegradation is posted in Outlook.

The Water Quality Standards also contain some specific directives for permit managers. These include the requirements that:



### • Permits be conditioned such that the discharge will not cause a violation of the standards [WAC 173

- 201A

- 510 ( 1 )],



### • Permits are subject to modification if a permitted discharge is discovered to be causi ng a violation of the standards [WAC 173

- 201A

- 510 ( 1 )(b)], and



### • No waste discharge is allowed to: the Cedar River (RM 21.6 to headwaters), the Green River (RM 59.1 to headwaters), Mill Creek (RM 25.2 to headwaters), the Sultan River (RM 9.4 to headwaters), t he Tolt River (RM 6.9 to the headwaters), the Union river and tributaries (RM 6.9 to the headwaters), and the Wishkah River and tributaries (RM 32.0 to the headwaters) [WAC 173

- 201A

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- 5 T here are also many other special waterbody

- specific special conditions listed in Sections 602
and 612 concerning fecal coliform, temperature and dissolved oxygen.

EPA has promulgated criteria to protect human health for 91 substances. These criteria appl y to the states waters and are found in 40 CFR Part 131.36 (see Chapter VII)

. These criteria are given
in TSDCALC.



## 1.2 Conversion Factors and Translators for Metal Criteria

In the 1992 revision of the Washington Water Quality Standards, the metals criter ia were changed from being expressed as total recoverable to expression as dissolved. The conversion was accomplished using the conversion factors recommended by EPA at the time. The conversion factors recommended by EPA were ratios observed in laborator y testing

. The conversion did not make the criteria more or less stringent but simply expressed them in the form believed to be toxic. These conversion factors become part of the formula for calculating the criteria. The current criteria are given in pe rmit tool TSDCALC.XLW.

Conversion of the metal criteria to the dissolved form created a problem for permit writers because federal regulation (40 CFR 122.45(c)) requires that effluent limitations for metals be in the form of total recoverable. The permit writer then needs a translator to conduct a determination of reasonable potential or derive effluent limits. The translator is used to predict the dissolved to total recoverable fraction that will occur in the receiving water from the total
recoverable m etal in the effluent.

Ecology permit writers should use one of the following as a translator, in the following order of priority depending on the circumstances: 1). Use the measured fraction of dissolved to total recoverable measured in the receiving wat er during critical condition

. 2). If there is no data on the dissolved fraction in the receiving water but there is TSS data on the receiving water use the
TSS

- dissolved fraction relationship described in Table VI

- 1 below for copper and zinc. Use the

app ropriate fraction for Cd and Pb from Table VI

- 1. 3)

. If there is no receiving water data on ratios or data on TSS, use the appropriate dissolved fraction from Table VI

- 1 for cadmium, copper, lead and zinc. For other metals, use the conversion factor as the translator. TSDCALC.XLW will calculate the appropriate translator (see Appendix VI ). A facility /receiving water

- specific translator may be used if the appropriate experimentation is
conducted.

Table VI

- 1

. Recommended estimates of the 90th and 95th percentiles of ambient dissolved fractions (f d ) of Cd, Cu, Pb, and Zn based on data from rivers in Washington (regressions assume TSS in mg/l).(from Pelletier, 1996)CHAPTER VI. WATER QUALITY

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- 6 90th percentile of f d* 95th percentile of f d

Cd 0.898 0.943

Cu if seasonal TSS<6.7 m g/L: 1

if seasonal TSS ≥ 6.7 mg/L: 1.91*TSS - 0.341

if no TSS data: 0.968 if annual TSS<11.4 mg/L: 1

if annual TSS ≥ 11.4 mg/L: 2.29*TSS - 0.341

if no TSS data: 0.996

Pb 0.340 0.466

Zn if seasonal TSS<4.9 mg/L: 1

if seasonal TSS ≥ 4.9 mg/L: 1.44*TSS - 0.231

if no TSS data: 0.965 if annual TSS<12.5 mg/L: 1

if annual TSS ≥ 12.5 mg/L: 1.79*TSS - 0.231

if no TSS data: 0.996 *The 90th percentile values are used if the TSS data is from the critical season. The 95th percentile values are used if the data are not stratified by season.

Waste

- specific translator

The translators described above assume a near

- instantaneous equilibrium of the metal in the receiving water . This may be a valid assumption for metals bound to the light floc discharging from secondary treatment. Other wastewaters, such as from physical chemical treatment may have metals tightly bound in the solids fraction and the conversion to dissolved form occurs slowly. A discharger may be allowed to develop a waste

- specific translator if the perm it writer

agrees

. An example QAPP and experimental design for a waste

- specific translator is available

.


## 1.3 Site

- Specific Water Effect Ratio

Footnote dd to Table 240(3) mentions the use of the water effects ratio to adjust metal criteria on
a site

- specif ic basis. This adjustment currently requires an amendment to the Water Quality Standards and therefore can only be granted for exceptional circumstances. Permit writers should contact the Watershed Management Section for more information.



## 2. THE POINT OF COMPLIANCE OF THE WATER QUALITY STANDARDS

The Water Quality Standards allow the use of mixing zones for discharges that would otherwise exceed the water quality criteria for aquatic life. Mixing zones are areas where the water quality standards may be ex ceeded but the exceedances are small enough and short enough so as not to interfere with beneficial uses. Mixing zones are a regulatory recognition that the concentrations and effects of most pollutants diminishes rapidly after discharge due to dilution. They areCHAPTER VI. WATER QUALITY

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- 7 established in a manner which limits the duration of exposure for organisms passing through the effluent plume in order to minimize the risk from each discharge. The water quality standards for chronic protection must be met at the boundary of t his zone and beyond. A smaller zone in which acute criteria may be exceeded can also be authorized. This zone must be small enough to limit exposure times and therefore not cause acute mortalities or interfere with passage of aquat ic organisms in the wat er body.

An intermediate goal in point source pollution control which is consistent with the CWA goal of zero discharge is the elimination of the need for a mixing zone.

The water quality standards do not prohibit a permit writer from granting a mixing z one for a shore discharge, but shore areas are important biological areas

. A permit writer should be sure that granting of the mixing zone on a shoreline will not cause biological effects as specified in the regulation. This may require a demonstration o n the part of the permittee in some cases.



## 2.1 G eneral C onsiderations for Authorizing M ixing Z ones

The authorization of a mixing zone (chronic) is subject to some conditions, as given in the Water Quality Standards.

1. The allowable size and location shal l be established in discharge permits or orders. A discharger does not receive a mixing zone unless it is specifically authorized in a permit or order . Any discharger whose effluent exceeds the water quality criteria and has not been authorized a mixing z one is in violation of the water quality standards. For marine waters the permit writer should authorize, as necessary, some distance around the point of discharge and place this in the permit. The fact sheet should discuss the distance, the dilution fac tor that results from this distance and the method of deriving the dilution factor. A diagram of the mixing zone and a map of location are helpful for the fact sheet reader

. For fresh water, the permit writer
should authorize some distance or some volume fraction of the receiving water, whichever is more stringent, and discuss the selection in the fact sheet.

2. The discharger shall be required to fully apply AKART pri or to being authorized a mixing

zone. This is the technology

- based limit process descri bed in Chapter IV. In some instances a pollutant may not have been addressed in the derivation of the technology

- based limits for a discharger. For example, municipal discharges have technology

- based limits for BOD, TSS, fecal coliform and pH in regulati on and this has been determined to be AKART (Chapter 173

- 221 WAC). This regulation does not address ammonia or chlorine and therefore ammonia and chlorine should be addressed on the design basi s or on a water quality basis.

3. Consider critical discharge conditions. The receiving water critical condition is generally defined in the Water Quality Standards.CHAPTER VI. WATER QUALITY

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- 8 Design conditions are discussed in more detail later in this section.

4. Not cause loss of sensitive or important habitat, Generally, permit managers have little data on the physical and biological characteristics of the receiving water and must meet the intent of this section by limiting the size of the mixing zone and conditioning permits to meet water quality standards.

5. Not exceed criteria past the boundary of the mixing zone The process of deriving effluent limits described later in this chapter will ensure the water quality standards are not exceeded past the mixing zone boundary or flow restriction.

6. The mixing zone size and the pollutant c oncentrations shall be minimized. Mixing zones are minimized by the design factors given in Table VI

- 2

.

A mixing zone is typically sized for the pollutant with the largest potential to violate water quality standards. Mixing zones may be authorized and s ized for individual pollutants.

7. Maximum size specifications (Chronic) In rivers and streams the maximum mixing zone boundary is 300 feet downstream plus water depth
at critical condition

. The dilution factor to use in calculating effluent limits for p rotection of the chronic criteria is the more restrictive of 1) twenty

- five percent (25%) of the flow at critical condition or 2) the center line dilution factor occurring at the downstream boundary of the
authorized mixing zone (Figure VI

- 1) as determine d by use of a hydraulic mixing model.

In estuaries the maximum mixing zone boundary is 200 feet plus water depth at MLLW in any horizontal direction (Fig ure VI

- 2).

In oceanic waters the maximum mixing zone boundary is 300 feet plus water depth at MLLW in any horizontal direction (Fig ure VI

- 3).

8. Zone of acute criteria exceedance

. This zone can only be authorized if it will not create a barrier to the migration or translocation of indigenous organisms to a degree that has the potential to cause damage to the ecosystem. If a permit is conditioned such that acute criteria are not exceeded past the boundary of this zone it can be assumed in the absence of information to the contrary that it will not cause a barrier.

In rivers and streams the maximum size o f this zone is the more restrictive of the mixing occurring at 10% of the mixing zone distance (centerline) or 2.5% of the flow at critical
condition.

In estuaries and oceanic waters the maximum size of this zone is 10% of the mixing zone
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- 9 

### 2.1.1 D etermining M ixing
A mixing zone may be a boundary around a point of discharge and a permit writer must know or be able to estimate the amount of mixing which occurs inside that area to determine th e potential for a violation of the water quality standards and to derive effluent limitations if necessary.

The permit writer has 3 basic options for determining the amount of mixing occurring within a mixing zone:

1. Use a computer hydraulic simulatio n model to predict the amount of mixing. A permit writer has several models available for use if the input data is available or can be reasonably
estimated

. These models are discussed in Appendix 6 of this Manual and Section 4.4 of the TSD. The EA Progr am must be consulted before using these models unless the permit writer has a strong background in modeling.

2. Require the mixing analysis to be done within the permit. A permit writer may run a model using the best available data for determination of reasonable potential but also require a permittee to do a mixing analysis as a requirement of a regulatory order or as a requirement in the permit.
3. Require the mixing analysis as a part of the permit application. If a permit writer knows that

a perm it will be done in the next fiscal year, the mixing and other data necessary for making water quality determinations can be requested well in advance. The data that could be requested are mixing data, effluent data and ambient receiving water data. Produ cing this data may be beneficial to the discharger

. For example, the multiplication factor for making a "reasonable potential" determination decreases with increasing number of data points.

Requiring the analysis as an order or permit application will sl ow the issuance of the permit. Requiring the analysis as a permit condition may mean the permit will have to be modified when the analysis is completed if it leads to a different conclusion than what the permit conditions are
based.

Saltwater discharges are modeled using steady state analysis and hydraulic models. These models require data on discharge depth, effluent flow rates, density of effluent, density gradients in the receiving water, ambient current speed, ambient current direction and outfall
ch aracteristics such as port size, spacing and orientation. The model output includes the dimensions of the plume at each integration step, time of travel to points along the plume centerline, and the average dilution at each point.

Mixing models are chang ing rapidly. The currently recommended models for most situations is the EPA PLUMES, CORMIX, UDKHDEN and site specific analysis using the formulas in Chapter 5 of Fisher, et al (1979). Guidelines for the selection of the appropriate model are given in Ap pendix VI.CHAPTER VI. WATER QUALITY

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- 10 In those permitting situations where input data is not available, the permit manager should require the permittee to develop the data and run the appropriate model. The requirements may be in an order, as a part of the permit application or wi thin the permit

. The EAP program can also do this as a requested project.

Where the hydraulic conditions at the discharge point are complex such as in the tidal reach of a river, a dye or tracer study should be used to confirm the model output at the chr onic compliance boundary.

The mixing analysis should determine centerline or minimum mixing at the compliance zone boundaries for unidirectional flow situations and flux average for multidirectional flow situations
such as tidal areas.

For flowing fresh water the water quality standards require, for chronic mixing, the more stringent of the dilution factor that results from the mixing at the boundary of the assigned mixing zone at critical condition (usually 7Q10 flow) or effluent mixing with 25% of the 7 Q10
flow

. For acute mixing, the allowed mixing is the more stringent of the modeled mixing that occurs at the boundary of the acute compliance zone (10% of the chronic zone) at 7Q10 condition or 2.5% of the 7Q10. Exceptions to the size criteria for mixin g zones (including the percent flow limitation) may be made in those circumstances where:

• the engineering report for the discharge was approved before November 24, 1992, or

• where altering the size configuration would result in greater protection, or

• where the effluent provides a greater benefit than removing it, if removing it is the only option, or

• where the exceedance is clearly necessary to accommodate important social or economic development.

Before an exception can be made, it mus t be demonstrated to Ecology that

• AKART is applied

• all other options that are economically achievable are being utilized and

• granting the exception would not have the reasonable potential to cause a loss of sensitive or important habitat, su bstantially interfere with the existing or characteristic uses of the water body, result in damage to the ecosystem, or adversely affect public health.CHAPTER VI. WATER QUALITY

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- 11 AKART is covered in Chapter IV, Part 3. A permit writer who makes a determination that a larger mixin g zone is required or the percent of flow limitations are not applicable should discuss, in the fact sheet, the determinations of AKART, economically achievable options, and receiving water impacts. This determination should be discussed with the Watershe d Planning
Section.



### 2.1.2 Shellfish Protection
Ecology has a shellfish protection strategy in cooperation with the Department of Health (Ecology 1984). Permit writers for marine dischargers should consult with DOH Shellfish Program to determine if the out fall is located in the general vicinity of shellfish resources, to gather other information about the discharge site, an d to discuss dilution modeling.

The Shellfish Program of the Department of Health (DOH) is responsible for establishing prohibited area s around the outfalls of wastewater dischargers in waters located near shellfish production areas. DOH utilizes many of the same assumptions used by Ecology in the selection of critical receiving water and effluent flow conditions. However, the area of i nterest to DOH for such discharges is far

- field. Therefore, the results of modeling or field studies which stop at the edge of dilution zones are often inadequate in providing appropriate information to DOH in establishing shellfish prohibited areas in th e far field. Where shellfish beds are in the area of the discharge, the results from computer models or field studies should be extended to the farther field (usually in terms of several hundreds of yards). This initial screening may indicate a need

to r equire the permittee to obtain additional information on receiving water conditions beyond the boundary of the dilution zone.

The Department of Health is also concerned about the discharge of human viral pathogens to shellfish beds from municipal treatmen t plants. They have asked that Ecology permit writers consider the following in developing municipal wastewater discharge permits:

The efficiency of UV disinfection decreases with increasing tube age.

The standard UV dosage is 16 milliwatt

- seconds per s quare centimeter, however, some reactivation of bacteria occurs with dosages less than 30 milliwatt

- seconds per square centimeter.

The use of detention time in the discharge pipe may be considered when deriving effluent limits
for chlorine.



### 2.1.3. M iscell aneous Water Quality Standards in Tidal Rivers

- In tidal rivers in which the salt water wedge reaches the discharge point, the permit manager may apply the salt water criteria.CHAPTER VI. WATER QUALITY

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- 12 Alternatively the permit writer may apply the following process if the infor mation is available:

Where 95 percent of the vertically averaged daily maximum salinity values are less than or equal to one part per thousand the freshwater criteria are applied. Exceptions to this include dissolved oxygen in which the marine criteria apply at any point where the salinity is one ppt or greater and fecal coliform in which the marine criteria apply where the salinity is 10 ppt or greater.

Reflux in Tidal Rivers

- In tidal rivers, some of the effluent that is discharged is carried back

up stream during the flood tide (reflux). In conducting a mixing analysis for a tidal river, the permit manager should model as an outgoing current and then assume reflux reduces the dilution factor by 1/2

. This is based on Ecology's studies of these situat ions. The permittee may supply information to show the factor is something else in their situation.CHAPTER VI. WATER QUALITY

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- 13 Figure VI

- 1. Mixing zones in rivers.CHAPTER VI. WATER QUALITY

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- 14 Figure VI

- 2. Mixing zones in estuaries.CHAPTER VI. WATER QUALITY

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- 15 Figure VI

- 3. Mixing zones for oceanic discharges.CHAPTER VI. WATER QUALITY

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- 16 

## 3. PREDICTING IMP ACTS AND DEFINING EFFLUENT LIMITS FOR NUMERIC CRITERIA

The permit manager must make several decisions when developing effluent limits for a permit. One decision, noted previously, is whether or not technology

- based effluent limits for a pollutant will pro tect the quality of the receiving water.

Generally, 2 types of analyses are done by the permit manager to predict impacts. One type of analysis is for pollutants such as BOD or nutrients which may cause an impact some distance from the point of discharge and for which mixing zones are not applicable. The other type of analysis examines the concentrations of specific pollutants or effects of pollutants within or at the edge of the mixing zone or the assigned dilution factor. These pollutants may be speci fic conventional, non

- conventional, or toxic compounds.



## 3.1 T he W ater Q uality I mpact O f BOD A nd N utrients

3.1.1 BOD
Biochemical oxygen demand (BOD) causes a depletion of dissolved oxygen in receiving water and consequently causes negative impacts on aqua tic life and water quality in general. Many of the existing municipal and industrial permit conditions in Washington are based upon consideration of the water quality impact of BOD. In these cases, the treated effluent met the technology

- based limitation s but the small volume of receiving water warranted additional
consideration.

In some cases, the dischargers were required to install advanced treatment to produce a lower effluent concentration of BOD. In other cases, they were required to change their point of discharge to new outfall locations or to land application during low flow periods.

The model used to predict dissolved oxygen deficit from BOD is the Streeter

- Phelps equation

. The Streeter

- Phelps equation has the basic form as follows: DOSAGCHAPTER VI. WATER QUALITY

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- 17 The impact of BOD is determined at the critical condition

. The critical condition (design flow) for flowing freshwater is usually the 7

- day average low flow with a recurrence interval of 10 years (7Q10)

. The critical period for marine waters is determine d on a site

- specific basis. The effluent design flow for industrial discharges is the highest monthly average flow for the past three years over the months when the 7Q10 is likely to occur. The effluent design flow for municipalities depends on how close to the design flow the facility is operating. For those municipalities that are operating within 15% of the design capacity or are experiencing a rapid population growth use the dry weather design flow. For those facilities that are operating well
below design flow and are expected to have a stable population over the permit cycle, use a projected average dry weather flow for the five year period. The projected flow can be estimated from trend analysis or population projectio ns from the engineering repo rt.

This model is for a determination of reasonable potential for violation of the dissolved oxygen
criteria

. If the model indicates a probable violation of the dissolved oxygen criteria in the receiving water, the permit writer should contact the EA Pro gram for assistance in verification of the model or confirmation with more sophisticated models.



### 3.1.2 Nutrients
Nutrients are another class of pollutants which would be examined for impacts at some point away from the discharge. The special concern is f or those water bodies quiescent enough to produce strong algae blooms. The algae blooms create nuisance conditions, dissolved oxygen depletion, and toxicity problems (i.e.

, red tides or blue

- green algae). High nutrient
concentrations can also create nuis ance conditions in flowing waters. The impact of nutrients is very difficult to predict and usually there are several point and nonpoint sources contributing to a Street er - Phelps Equation:

D t = DO sat - DO t = [K 2 BOD u ÷ (K 1 - K 2 )](10 - K 2 t

- 10 - K 1 t ) + D o (10 - K 1 t )

where:
D t = dissolved oxygen deficit at any time t (days).
DO sat = the dissolved oxygen level at saturation
DO t = the dissolved oxygen level at any ti me t (days)
BOD u = ultimate carbonaceous BOD of the stream immediately after mixing.
K 1 = reoxygenation rate constant (K r ).
K 2 = deoxygenation rate constant (K d ).
D o = dissolved oxygen deficit immediately after mixing.CHAPTER VI. WATER QUALITY

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- 18 nutrient problem. The Water Quality Standards contain recommendations for total phosphorus
concentrations for lakes in several ecoregions of the state

. The Gold Book also contains some guidelines for phosphorus loading to freshwater streams and reservoirs. A permit manager should point out any suspected nutrient problems to the unit and sectio n supervisor. Suspected water quality problems due to nutrients are best handled by a TMDL process conducted by the
EAP.



## 3.2 Other Specific Pollutants

- Conventional and Nonconventional

This section addresses dissolved oxygen, fecal coliform, pH, turbidi ty, temperature, total dissolved gas and aesthetics. The design flow for dissolved oxygen, fecal coliform, pH, turbidity, and temperature is the maximum monthly flow which may be estimated for existing facilities by using the discharge data for a period o f the last three years for the months in which
the cr itical flow is likely to occur.



### 3.2.1 Dissolved Oxygen
An effluent may cause a violation of the dissolved oxygen criteria near the point of discharge from 2 components. If the effluent is low in dissolved oxygen it may cause a violation of the dissolved oxygen criteria near the point of discharge from mixing with receiving water. The effluent may also have chemical components which cause rapid oxygen depletion called Immediate Oxygen Demand (I DOD). For most discharges the IDOD is not significant relative to the effect of mixing of the effluent, containing a low concentration of dissolved oxygen, with the receiving water.

The process for calculating dissolved oxygen concentration following ini tial dilution is a simple mixing calculation found in TSDCALC . This process requires data on the dissolved oxygen
concentration of the effluent

, the receiving water at the critical period and the dilution factor

. The point of compliance is the chronic mi xing zone boundary and the receiving water design concentration is the 10th percentile dissolved oxygen concentration.



### 3.2.2 Pathogenic Bacteria
Ecology uses fecal coliform (fc) and enterococci bacteria (en) as indicator organisms for the control of patho genic bacteria in wastewater effluent. Fecal coliform is limited on a technology basis in municipal permits to 200 colonies/100 ml as a monthly geometric mean and 400 as a weekly geometric mean. This limit is based on the performance of standard disinfec tion treatment processes. It is a promulgated performance standard in Chapter 173

- 221 WAC.

The water quality criteria for fecal coliform are quantified on a geometric mean of the number of colonies per 100 mL with an additional 10% or single sample limit (in parenthesis below) . They are based on the probable exposure to pathogenic bacteria causing intestinal upset

. These criteria are currently under review by EPA. IDODCHAPTER VI. WATER QUALITY

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- 19 The criteria are:

Extraordinary Primary Contact Recreation , freshwater

- 50 (100) /100 mL fc Shellfish and Primary Contact Recreation, marine

- 14 (43) /100 mL fc

Primary Contact Recreation

, freshwater

- 100 (200) /100 mL fc

Secondary Contact Recreation

, freshwater

- 200 (400) /100 mL fc
marine

- 70 (208) /100 mL en

The point of compliance for the fecal coliform standard is at the boundary of the chronic mixing zone if one is allowed. The design flow for application of the standard is the 7Q10 low flow for flowing freshwater and the 50th percentile current velocity for marine.

A municipal permittee meeting the technology

- based limitations would require minimal dilution to be able to meet the water quality standards for fecal coliform. Permit writers must address any human exposure within the mixing zone

. Alternatively, the per mit writer may impose a limit of 100 cfu/100mL as a daily maximum and then no mixing allowance is necessary.



### 3.2.3 pH
The pH in most permits in Washington is limited to a range of 6 to 9 unless pH has been defined by the federal effluent guidelines as a process pollutant. The range of pH 6 to 9 in permits for most dischargers is based on the demonstrated performance of simple equalization or neutralization. Unless pH is a process pollutant, the discharge of effluent outside this range generally indicate s s pills or treatment plant upset.

The criteria for pH in the water quality standards restrict the pH change caused by a source to 0. 2 units for core summer salmonid habitat and within a range of
6.5 to 8.5 . The point of compliance with the pH standard i s the boundary of the chronic dilution zone at 7Q10 or critical condition.

The resultant pH of a mixture of 2 flows is calculated by processes described in EPA (1988). A spreadsheet for the calculation in found in PWSPREAD.

Modeling of freshwater dischar ges is usually unnecessary unless the effluent pH is above 8 and the receiving water is poorly buffered or unless the volume of the discharge is very large.

Source

- caused pH changes are seldom a problem in salt water because of the high buffering capacity of sea water

. A spreadsheet in PWSPREAD is available to predict pH effects of a point source discharge. PHMIX2CHAPTER VI. WATER QUALITY

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- 20 

### 3.2.4 Turbidity
Turbidity is not a parameter generally considered in point source discharges except for water
treatment back flush wastewater. Contr ol of particulates as total suspended solids in an effluent usually results in low turbidity, however, depending on the size of the particulates and the pore size of the filter media used to determine TSS, some effluents may cause some turbidity in the

rec eiving waters while meeting TSS limits. Turbidity does not have a linear response to dilution. Any data that indicates a violation of water quality standards should be verified in the receiving

water.



### 3.2.5 Dissolved Gas Supersaturation

The Watershed Ma nagement Section monitors compliance with dissolved gas supersaturation. Dam operators can control dissolved gas by controlling the amount of spillage. The design condition for dissolved gas is the 7Q10 high flow (7Q10hf). During these very large natura l runoff events, the resulting high flows make it impossible for dam operators to abate for dissolved gas. Guidelines for deriving the 7Q10 high flow are presented in Appendix 6.7.



### 3.2.6 Temperature
Temperature in the water quality standards has multiple criteria and requirements. These
include:

1. Annual summer maximum threshold criteria

. 2. Supplemental spawning

- season criteria

. 3. Incremental warming restrictions

. 4. Protections against acute effects

. 5. Antidegradation requirements

.

1. Annual summer maximum threshold criteria

. In freshwater, each of 8 categories has a 7 day average daily maximum (7

- DADmax) upper temperature limit and a maximum allowable
rise. See the table below from WAC 173

- 201A

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- 21 Table 200 (1)(c)

Aquatic Life Temperature Criteria in Fresh Water

Category Highest 7

- DADMax Char Spawning 9°C (48.2°F) Char Spawning and Rearing 12°C (53.6°F) Salmon and Trout Spawning 13°C (55.4°F)

Core Summer Salmonid Habitat 16°C (60.8°F) Salmonid Spawning, Rearing, and Migration 17.5°C ( 63.5°F)

Salmonid Rearing and Migration Only 17.5°C (63.5°F)

Non

- anadromous Interior Redband Trout 18°C (64.4°F)

Indigenous Warm Water Species 20°C (68°F)

In marine water the categories have a 1 day maximum (1

- DMax)

.

Aquatic Life Temperature Criteria in Marine Water

Category Highest 1

- DMax Extraordinary quality 13°C (55.4°F) Excellent quality 16°C (60.8°F) Good quality 19°C (66.2°F) Fair quality 22°C (71.6°F)

2. Supplemental spawning

- season criteria. In some waters, a second threshold criterio n is assigned to protect the spawning and incubation of salmonids (9°C for char and 13°C for salmon and trout) [WAC 173

- 201A

- 200(1)(c)(iv) ] , and Ecology publication [ 06

- 10

- 038]. These criteria include explicit date

- windows for application, and must be app lied in addition
to the annual summer maximum criteria discussed above

. For fresh water bodies identified in Part VI of the standards the following are applicable:

- Maximum 7

- DADMax temperatures of 9°C (48.2°F) at the initiation of spawning and at fry

emergence for char; and

,

- Maximum 7

- DADMax temperatures of 13°C (55.4°F) at the initiation of spawning for

salmon and at fry emergence for salmon and trout.

3. Incremental warming restrictions. In addition to the criteria discussed above, the water

qu ality standards limit the amount of warming human sources can cause at any time water temperatures are cooler than the assigned threshold criteria. This criteria is designed to provide protection for the overall temperature regime [See WAC 173

- 201A

- 200(1) (c)(ii), 210(1)(c)(ii)].CHAPTER VI. WATER QUALITY

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- 22 At any time the background temperature is cooler than the assigned threshold criterion, point sources are permitted to warm the water by only a defined increment, t

.

Calculate t as follows:

o t = 28/(T ambient + 7) in freshwaters

, or

o t = 12/(T ambient – 2) in marine waters

.

4. Protection against acute effects A. Moderately acclimated (16

- 20°C, or 60.8

- 68°F) adult and juvenile salmonids will generally be protected from acute lethality resulting from discrete human actions by
mainta ining the 7

- DADMax temperature at or below 22°C (71.6°F) and the 1

- day maximum (1

- DMax) temperature at or below 23°C (73.4°F). B. Lethality to developing fish embryos can be expected to occur at a 1

- DMax temperature greater than 17.5°C (63.5°F). C. To pro tect aquatic organisms, discharge plume temperatures must be maintained such that fish could not be entrained (based on plume time of travel) for more than two seconds at temperatures above 33°C (91.4°F) to avoid creating areas that will cause near
instant aneous lethality.

3.2.6.1 Determining Reasonable Potential for Temperature. The process of determining reasonable potential is similar to other pollutants except no transformation or prediction of the 95 th percentile is required

. Figure VI

- 4 below illust rates the administrative process. TSDCALC contains spreadsheets for determining reasonable potential and effluent limits for temperature , when required. A companion document explaining temperature implementation is availabl e on the Water Quality web site and is also posted in Outlook.

Guidance for permittees to conduct temperature sampling and a model QAPP are available.

Permit writers should realize that in cases where dilution factors are approximately 6 or less,
an effluent limit derived for the crit ical mid

- summer or supplemental period may cause a slight exceedance of the incremental allowance during the winter time . This probability of exceedance depends on changes in dilution factor and effluent temperature from summer to
winter

. Th e incremental restriction was formulated to prevent a change of temperature regime in situations where the ambient temperature was well below the criteria

. An incremental rise of 1 or 2 degrees is well within the normal daily fluctuation in mid

- winter
and will not cau se a change in the temperature regime.CHAPTER VI. WATER QUALITY

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- 23 Table VI

- 2

. Effluent and receiving water design conditions for temperature

Chronic criteria Ambient background temperature 1 90 th percentile annual maximum 7DADMax, or
90 th percentile of annual maximum 1DMax; whichever matches the
criterion.
Ambient flow 7Q10 for critical periods:

 July

- Aug for summer criteria

 First month of any fall supplemental spawning criterion and last month of any spring supplemental spawning criterion. Effluent temperature 2 95 th percen tile (0.05 probability) of 7DADMax, or
95 th percentile of 1DMax; whichever matches the criterion.
Effluent flow Selected from Table VI

- 3 of the permit writer’s manual.

Acute criteria Ambient background temperature 1 90 th percentile annual maximum 1DMax , or 90 th percentile annual maximum 7DADMax; whichever matches criterion.
Ambient flow 7Q10 for critical periods:

 July

- Aug for summer criteria

 First month of any fall supplemental spawning criterion and last month of any spring supplemental spawning crite rion. Effluent temperature 2 99 th percentile (0.01 probability) of 1DMax, or
99 th percentile of 7DADMax; whichever matches the criterion.
Effluent flow Selected from Table VI

- 3 of the permit writer’s manual.

Notes to Table VI

- 2 : 1. The highest annual upst ream ambient temperature (1

- DMax or 7

- DADMax, whichever

matches the criterion) observed from 3 or more years of monitoring (1/2 hour measurement for the period) should be used to represent both the 95 th and 99 th percentile background receiving water temper ature

. 2. The highest annual effluent temperature (1

- DMax or 7

- DADMax, whichever matches the

criterion) observed from 3 or more years of monitoring should be used to represent both the 95 th and 99 th percentile effluent temperature

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- 24 Figure VI

- 4

. De cision process for temperature

Is there adequate data to determine a reasonable potential to violate the temperature standards ?

Is there a reasonable potential to exceed the standards ? Ensure adequate data to characterize effluent and

background receiving water temperatures and

the available dilution

during the critical conditions

.

The permit language requires an evaluation of reasonable potential in an engineering reportNext permit issuance No Limit in

Permit

– Consider continued monitoring

Place an effluent limit in the permit that meets the

temperature standards

Can the Permittee immediately comply with the limit ? Require effluent monitoring to

assure compliance with the liimit

Will the Permittee require two permit cycles to comply with the water quality

- based limit ? Place the compliance schedule and a performance

- based interim limit in the permit

Place the compliance schedule in an order and place a performance

- based limit in the permit

. Permit condition to collect the necessary data during the permit

no yes yes

no yes

no no

yes



### 3.2.7 Aesthetics
The Water Quality Standards require that aesthetic values shall not be impaired by the presence of materials or their effects, excluding those of natural origin, which offend the senses of sight,CHAPTER VI. WATER QUALITY

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- 25 smell, touch, or taste. These values will, of course, be mostly considered for new discharges or when a complaint has been received on an existing discharge. Examples of measures that could be required of a discharger to preserve aesthe tic values include:

• control of oil sheens,

• submerged discharges, and

• locating the discharge away from sensitive locations/persons.



## 3.3 Deriving Effluent Limits for Toxic Pollutants, as Seasonal Limits and for Impaired Waters

Defining water quality impacts and developing effluent limits is usually more complex for toxic pollutants than for the other pollutants. As noted in the earlier discussion on water quality criteria and standards, the toxic numerical criteria are given at 2 levels (acut e and chronic) each of which contains 3 components (magnitude, duration, and frequency). The analysis to predict water quality impacts and thus to define effluent limits must be conducted for both acute and
chronic criteria in order to define the most lim iting criteria . Many of the criteria for toxic pollutants are variable and depend on receiving water conditions. This section covers these subjects and others and presents an example of how to develop effluent limits for toxic pollutants.

Whole effluent toxicity (WET) is evaluated separately and explained in Section 5 of this chapter

. After determining a technology

- based limit for a toxic pollutant, the permit manager must decide if the limit will cause the discharge to meet the water quality standards

. Federal regulations require the permit manager to determine whether a discharge has a reasonable potential to violate water quality standards and if so to place a water quality

- based effluent limit in the permit (40 CFR 122.44). To determine this, the pe rmit manager must know the criteria, the background
concentration , the point of compliance, design flows for the receiving water and effluent flow, how to deal with multiple pollutants and effluent variability and the process of developing an
effluent limi t.

The EPA document, Technical Support Document for Water Quality

- based Toxics Control
EPA/505/2

- 90

- 001, is the basic reference document for the rest of this chapter and it is assumed that the permit manager has read it. The rest of this chapter will foc us on Washington's process and will not review the background material which is presented in the Technical Support
Document.



### 3.3.1 Point s of Compliance
The points of compliance for toxic pollutants are the same as discussed previously in this chapter

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- 26 restrictions as specified in the water quality standards for acute and chronic criteria.



### 3.3.2 Design Flows
The design flows for effluent and receiving water has been discussed above for some pollutant parameters. They are summarized in Table VI

- 3

.

The traditional receiving water design flow or critical condition for steady state modeling of pollutant discharge such as BOD to freshwater is the 7

- day low flow period with a recur rence interval of 10 years (7Q10)

. This flow is typically when the least amount of mixing occurs, temperature is the highest, and dissolved oxygen is the lowest. Ecology will use the 7Q10 as the design flow for the acute and chronic toxic criteria also. The permit manager should use this design flow unless another design flow is more suitable because of the nature of a particular pollutant or receiving water

.

For saltwater discharges the critical mixing condition is defined according to the characterist ics of the receiving water such as tidal exchange, river inflow, stratification by temperature and salinity, the characteristics of the outfall location, and the characteristics of the effluent such as temperature and salinity. It may be necessary to run a computer simulation of the discharge and receiving water to determine critical condition.



### 3.3.3 Criteria Vary With Background Conditions
Some criteria vary with other chemical or physical parameters. For example, the aquatic life criteria for some meta ls in freshwater vary with hardness of the receiving water. The criteri on for ammonia varies with temperature and pH. The critical period for ammonia is often difficult to calculate because
the criteri on varies on the 2 parameters. The EA Program or the Program Development Services Section can assist if the permit manager has difficulty.



### 3.3.4 Multiple Pollutants
Each toxic pollutant in a single discharge is considered independently. Many toxic pollutants are interactive but any additive or synergistic effects are difficult to predict

. Interactive effects in a single effluent will be detected with whole effluent toxicity testing. The chance for interactive effects is reduced by not allowing overlap of acute compliance zones and by not allowing the

ove rlap of mixing zones for the same parameters.



### 3.3.5 Effluent Variability (Coefficient of Variation)
A permit manager must have an estimate of variability to determine reasonable potential and to
calculate a permit limit. The estimator of variability which is most commonly used is the coefficient of variation (CV). The CV is the ratio of the standard deviation to the mean. The best estimate of effluent variability can be derived from a set of results from random effluent samples for the toxic parameter. As a general rule of thumb, because the distribution of values
from wastewater treatment is non

- normally distributed, any number of samples less than 2 0 is AMMONIA
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- 27 probably not valid as a predictor of distribution

. The number of samples required depends on the

tr ue variance of the population being sampled which is usually not predictable except by sampling

. For sample sizes less than 20 use the default CV of 0.6, which was derived by EPA on a large database of municipal effluent . The spreadsheet TSDCALC has a de fault CV of 0.6.

A permit writer may be able to obtain a value for variability from the development document for the category of discharger.

The permit writer may calculate a n effluent CV if data is available. Non

- detect concentrations in
the data set may be estimated by using one half of the detection level or estimation techniques described by Gilbert (1987) or EPA (1991).



### 3.3.6 Background (Receiving Water) Data
Permit writers and watershed coordinators, during the watershed scoping process should id entify the need for background water quality data for the basin waters. Information and data necessary to develop a water quality

- based permit should be requested from the discharger by letter or order in year two of the basin cycle. This gives ample tim e to budget and hire a contractor, if

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- 28 Table VI

- 3 . Applicable criteria/design conditions for determining the acute and chronic dilution factors for aquatic life.

Design Conditions for Mixing Zone/Ratio Analysis

- Aquatic life Criteria

Paramete r Mixing Zone Critical Design Condition

Plant Effluent Flow

- Municipal Acute The critical plant effluent flow, for those plants operating at less than 85% of the dry weather design flow during the critical period, is defined as the highest daily ma ximum plant effluent flow for the past three years during the critical flow or when the critical condition is likely to occur. If the facility is operating between 85 and 100% of dry weather design flow during the critical period then use a peaking factor applied to dry weather design to determine acute design flow. The peaking factor is a ratio of daily maximum to monthly average flows derived from actual plant data during critical period. A peaking factor may also be available in the engineering report for the facility.

Chronic The critical plant effluent flow is defined as the dry weather design flow if the facility is operating between 85 and 100% of design during the critical period

. If the facility is operating at less than 85% of design flow du ring the critical period the critical plant effluent flow is defined as the highest monthly average plant effluent flow for the past three years during the critical flow or when the critical condition is likely to occur.

Plant Effluent Flow

- Industri al Acute The critical plant effluent flow is defined as the highest daily maximum plant effluent flow for the past three years during the critical flow or condition is likely to occur. If plant effluent flows are expected to increase during the life of t he permit, the highest daily maximum flow must be estimated.

Chronic The critical plant effluent flow is defined as the highest monthly average plant effluent flow for the past three years during the critical flow or condition is likely to occur. If pl ant effluent flows are expected to increase during the life of the permit, the highest average monthly flow must be estimated.

Receiving Water (Characteristics) Acute and Chronic

Freshwater The critical receiving water current velocity is defined as the current velocity at both the
7

- day low flow and high flow periods with a recurrence interval of 10 years (7Q10 by the appropriate statistical method).

The diffuser depth is defined as the depth at the 7Q10 low flow period.

Acute

- Saltwater The critical receiving water current velocity is defined as the critical 10 th and 90 th percentile current velocities derived from a cumulative frequency distribution analysis. The current velocity frequency distribution analysis should be conducted, at minim um, over one neap and spring tide cycle.

The critical ambient density profile is defined as the density profile that results in the lowest mixing.

The diffuser depth is defined as the depth at MLLW. For estuaries, the diffuser depth is defined for low

- w ater slack and low river flow conditions.

Chronic

- Saltwater The critical receiving water current velocity is defined as the 50 th percentile current velocity derived from a cumulative frequency distribution analysis. The current velocity frequency di stribution analysis should be conducted, at minimum, over one tidal cycle.

The critical ambient density profile is defined as the density profile that results in the lowest mixing.

The diffuser depth is defined as the depth at MLLW.CHAPTER VI. WATER QUALITY

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- 29 Miscellaneous De sign Conditions for Mixing Zone/Ratio Analysis

Parameter No. of Data Points Methodology

Maximum expected Receiving Water Concentration
(Analytical Data) 1 to 20 The geometric mean of the receiving water values at time of critical condition should be multiplied by a factor of 1.74 to estimate the 90th percentile. This value should then be used in conjunction with the plant effluent data to evaluate reasonable potential to cause an exceedance of the criteria for aquatic life protection and derive efflu ent limits.

Over 20 The critical background receiving water value is defined as the 90 th percentile value derived from a cumulative frequency distribution analysis of data from time of critical condition. This 90 th percentile background value should b e used in conjunction with the plant effluent data to evaluate reasonable potential to cause a violation of the criteria for aquatic life protection and derive effluent limits.

Maximum Expected Effluent

Concentration (Analytical Data) 1 to 20 Use the highest single effluent concentration, assume a coefficient of variation (CV) of 0.6 and use the reasonable potential multiplying factors from Table 3

- 2 of the TSD (page 57) to estimate the maximum expected effluent concentration (TSDCALC does this by for mula) . This value should then be used in conjunction with the background receiving water data to evaluate a reasonable potential to cause a violation of the criteria for aquatic life/human health protection and derive effluent limits.

Over 20 Calculate CV and use the reasonable potential multiplying factors from Table
3

- 2 of the TSD to estimate the maximum expected effluent concentration. This derived effluent value should then be used in conjunction with the background receiving water data to evaluate a reasonable potential to cause a violation of the criteria for aquatic life/human health protection and derive effluent limits.

Dilution Factor unidirectional flows N/A Centerline for acute and chronic dilution.

Dilution Factor

marine and rotating dire ction N/A Flux average for acute and chronic

Reflux N/A Assume reflux reduces the dilution factor by 1/2 in the absence of site

- specific data.

Mixing Zone/Ratio Analysis

- Point of Compliance

Parameter Point of Compliance

pH, DO, Fecal Coliform, Tempe rature Compliance at the edge of the chronic mixing zone.

Human Health Criteria Compliance at the edge of the chronic mixing zone.

Whole Effluent Toxicity and Numeric Criteria Compliance at the edge of the acute dilution zone for acute WET/numeric criter ia and at the edge of the mixing zone for chronic WET/numeric criteria.

Chronic design conditions are used for both the initial mixing and the far

- field mixing calculations.CHAPTER VI. WATER QUALITY

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- 30 

### 3.3.7 Determining Reasonable Potential
Ecology has adopted EPA's (1991) process of determining reasonable potential including their statistical assumptions for estimating the 95th percentile effluent concentration from a limited data set of effluent data.

The current version of the TSD (1991) documents EPA's assumptions in
determini ng the multipliers to derive the 95th percentile effluent concentra tion based on a limited sample.

An alternate method for estimating quantiles from limited data sets with an assumed log normal distribution is presented in Gilbert (1987). This method pro duces an estimate of an upper percentile value that is a maximum likelihood estimator which is proportional to the geometric
mean. This estimator is lower for limited data sets than the EPA estimator and is used for estimating the 90th percentile receivin g water concentration when making determinations of reasonable potential for aquatic life criteria. The details of this method are given in Appendix 6.



### 3.3.8 Calculating the Effluent Limits
Water quality

- based effluent limits are calculated by the two

- va lue wasteload allocation process as described on page 100 of the TS D (EPA, 1991) and shown
below.

1. Calculate the acute wasteload allocation WLA a by multiplying the acute criteria by the acute dilution factor and subtracting the background concentration . Calculate the chronic wasteload allocation (WLA c ) by multiplying the chronic criteria by the chronic
dilution factor and subtracting the background concentration

.

WLA a = (acute criteria × acute zone dilution factor)

- (background concentration × (acut e zone dilution factor

- 1))

WLA c = (chronic criteria × chronic zone dilution factor)

- (background concentration × (chronic zone dilution factor

- 1))

2. Calculate the long term averages (LTA a and LTA c ) which will comply with the wasteload
allocations WLA a and WLA c .

LTA a = (WLA a ) ( e [0.5 σ 2

- z σ ] )

where:

σ 2 = ln(CV2 + 1)
z = 2.326 TSDCALC
REASPOT

TSDCALCCHAPTER VI. WATER QUALITY

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- 31 LTA c = (WLA c ) ( e (0.5 σ 2

- z σ ) )

where:

σ 2 = ln[(CV2 + 4) + 1]
z = 2.326

3. Use the smallest LTA of the LTA a or LTA c to calculate the maximum daily effluent limit and the monthly average effluent limit.

Maximum Daily Limit = MDL

where:

σ 2 = ln[CV2 + 1] z = 2.326 (99th percentile occurrence probability)
LTA min = smallest lo ng term average (LTA a or LTA c )

Average Monthly Limit = AML

where:

2

n 

### σ = ln[(CV2 ÷ n) + 1] n = number of samples/month z = 1.645 (95th percentile occurrence proba bility)
LTA min = smallest long term average (LTA a or LTA c ) 2 ( 0.5 ) min 

### ( )( ) z 

### MDL LTA e σ σ

− 

### =

2 ( 0.5 ) min 

### ( )( ) n n z 

### AML LTA e σ σ

− 

### =CHAPTER VI. WATER QUALITY

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- 32 The numeric water quality standards and the dilution factors define wasteload allocations (WLA) for pollutants. The WLA's are numbers not to be exceeded in order to protect aquatic life. In the statistical world, however, there is no such thing as 100% certainty. Ecology uses an estimate of variability (coefficient of variation or CV) for these parameters in the effluent to define a distribution of values with a long term average (LTA) such that there is a one percent probability (0.01) of exceedance of the WLA. There are two long term averages defined for each parameter

. One is for acute and one is for chronic. Effluent limits for each parameter are defined for the more limiting of the ac ute LTA or the chronic LTA. Effluent limits are control parameters to determine when a process is out of control. A process is deemed out of control when the extreme values are higher than expected (expressed as the daily maximum limit) or the average
is higher than expected (expressed as the monthly average limit). The 95% percentile (0.05 probability) used in calculating the average limit and the 99% percentile (0.01 probability) is used in calculating the daily maximum. These probabilities are the pr obability of determining the process is out of control when in fact the process is still in control.

The 95th percentile (0.05 probability) is used for calculating the average limit for the following reasons:

1. Exceedance of an average (average limit ) indicates a more serious potential for environmental harm than exceedance of a daily maximum. Even so, the Department rarely enforces the occasional exceedance of monthly average limit. Typically,
enforcement occurs after several consecutive violations of the monthly average limit or when both the daily maximum and the monthly average have been exceeded. This effectively reduces the probability of false noncompliance to something far less than 0.05.

2. The Department also uses the 95th percentile (0 .05 probability) because this is a recommendation of EPA in the Technical Support Document.

3. The 95th percentile (0.05 probability) for monthly average was used for development of technology

- based effluent limits when EPA developed the industrial effl uent guidelines and secondary treatment standards.

The above formulas may also be used to derive performance

- based limitations where the long term average (LTA) is the demonstrated performance and assuming the data is log normally
distributed.CHAPTER VI. WATER QUALITY

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- 33 

### 3.3.9 Sea sonal Effluent Limitations
The permit writer may elect to develop seasonal effluent limitations for a discharger, especially in those situations where meeting water quality

- based effluent limitations has a high operational
cost and there is a considerable difference of magnitude between the seasonal limits

. Generally, seasonal effluent limitations are developed on a semi

- annual or quarterly basis.



### 3.3.10 Dynamic Modeling
The use of dynamic modeling is an acceptable alternative to the static modeling discus sed above in those situations where the discharger is willing to meet the data requirements and submit the analysis for approval. A discussion of the three main type s of dynamic modeling techniques i s given in the TSD (EPA 1991).



### 3.3.11 TMDL'S, WLA'S and 303(d)

– Discharges to Impaired Waters
Discharges to impaired waters require additional consideration when issuing permits. The wasteload allocations (WLA's) which are used to derive effluent limits may be derived on an individual permit basis or they may be determined by a basin TMDL allocation.

In the absence of a basin TMDL and the resultant WLA, the permit writer must do an individual
WLA.

The general principles of this section are:
1. A water body listed on the 303(d) list is not a presumption of impai rment unless the listed section is the point of discharge.
2. A point source discharging to a water body with multiple sources (point and nonpoint) of impairment, which is a minor source of the impairment, and may gain relief from a TMDL is not required to ha ve a final limitation as the numeric water quality criteria before a TMDL is completed.

No TMDL and No 303(d) Listing

– Existing Discharge Occasionally, the permit writer, in the course of renewing a permit, will have information that the receiving water c oncentration (background) at the point of discharge during critical condition does not meet the aquatic life or human health criteria and that the receiving water is not listed on the 303(d) list ( http://www.ecy.wa.gov/programs/wq/303d/index.html ).

The applicable federal regulations in this case are 40 CFR 122.44(d)(1)(i), (ii), (iii) and (vii).

In these cases, where the excursion is documented with data that meets the criteria for 303(d) listing (see the 303(d) listing policy), the permit writer should develop interim effluent limits based on existing performance (no increase in loading) to be placed in the permit (see EPA 1991 and Chapter IV of this Manual for development of limits based on existing performance). These interim limits are effective on the effective date of the permit. A final limit based on the waterCHAPTER VI. WATER QUALITY

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- 34 quality criteria is calculated and placed in the permit (with a compliance schedule) if compliance is expected in the term of the permit. The compliance schedule must be as short as practicable and must include specified required actions that demonstrate reasonable progress toward attainment of the final limit or water quality criteria. The final limit is placed in the fact sheet if compliance with those limits is expected to exceed five years

. If technology

- based limits have not been established for the pollutant the permit must also cause the permittee to investigate the feasibility and reasonableness of meeting the final limit with technology and cost tests established for BCT or BAT. This is accomplished by requiring an engineering report completed in accordance with current Ecology guidance. In some cases, where the final limits are placed in the fact sheet, additional source control investigation may be productive and should be included in the permit.

At this point the permit writer should consider how the effluent pollutants would be permitted if the background was not exceeding the criteria. This analysis is for ne ar

- field pollutants. If an analysis of reasonable potential shows an exceedance of the numeric criteria with a background of zero (for human health pollutants), the effluent quality must be improved regardless of the
outcome of the TMDL. For other chemic al pollutants, use an expected reduction of 50% of observed background (this is probably more than can be achieved in a TMDL). A determination of reasonable potential in these cases requires a reduction of effluent pollutant concentration during the permi t term. For temperature, the permit writer should target an effluent temperature
that will meet a 0.3 ° C rise at the boundary of the chronic mixing zone. The two likely outcomes of a temperature TMDL are 1) that the natural condition exceeds the current numeric water quality criteria or 2) that with non

- point controls in place there may be some small amount of dilution. In either case, a 0.3 ° C increase at the boundary of the mixing zone is a reasonable target. The permits in the situations described ab ove should contain requirements for source control or evaluating treatment options to reduce the effluent pollutants regardless of the status of
a TMDL.

Receiving water data received by the permit writer that meets the listing criteria should be given

to the Watershed Management Section

. This data must be in Storet or Ecology’s EIM format. The water body will subsequently then be listed on the 303(d) list and prioritized for a TMDL.

If the data on the excursion is likely to be valid but does not meet th e 303(d) listing criteria, the permittee should be required, usually by compliance order, to investigate receiving water quality to determine if the receiving water exceeds water quality standards at the time of critical condition. A quality assurance pla n (QAPP) must be prepared by the permittee and approved by Ecology. The final data must be suitable for entry into Storet or the Ecology EIM database. No interim limits are necessary in this situation, however, if technology

- based limitations have not
be en explored for the pollutant, the order should also include the requirement for an engineering report on treatment options and costs (see Ecology engineering report guidance). If the receiving water study does show impairment, the decisions on final limi ts, interim limits and compliance schedules are the same as discussed above. Depending on the timing of the receipt of the data,CHAPTER VI. WATER QUALITY

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- 35 the permit may be modified or adjusted at the next renewal. If the data shows no impairment and
dilution is available then re asonable potential analysis and effluent limits are developed as discussed elsewhere in this chapter. The data from the receiving water is given to the Watershed Section for 303(d) listing.

Figure VI

- 5 . Discharges to water bodies not meeting standards b ut not yet listed on 303(d).

No TMDL

– 303(d) Listed

– Existing Discharge It’s more likely that a permit writer will be renewing a permit and discover the receiving water body is on the 303(d) list. The applicable federal regulations in this case are the same as the previous case

.

If the pollutant that caused the listing is not present in the discharge no limit is required.

If the pollutant is a far

- field pollutant, is present in the discharge and is the subject of a TMDL in progress, the permit writ er may defer any water quality

- based limits on the pollutant until the TMDL is completed and a WLA is assigned. When the WLA is assigned the permit writer may modify the permit or incorporate the WLA at the next reissuance, depending on timing.CHAPTER VI. WATER QUALITY

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- 36 If the po llutant is present in the discharge and the TMDL is not started the options are given below in Figure VI

- 6 and the text that follows.

IS LISTING DATA VALID ( is water quality impaired ) AT THE POINT AND TIME OF DISCHARGE ? REQUIRE RECEIVING WATER STUDY

, MAY REQUIRE INTERIM LIMITS DEVELOP EFFUENT LIMITS NORMALLY

CAN THE EFFLUENT BE TREATED OR CAN THE EFFLUENT OR POLLUTANT ( S ) BE REMOVED SEASONALLY AT A COST WHICH IS ECONOMICALLY ACHIEVABLE OR REASONABLE ? PERMIT HAS INTERIM LIMIT ( NO ADDITIONAL LOADING ) AND

REQUIRES ENGINEERING

REPORT ON OPTIONS AND COST FINAL LIMITS AS

THE WATER

QUALITY CRITERIA OR

LOWER

, A COMPLIANCE SCHEDULE AS NECESSARY

, AND

INTERIM LIMITS

BASED ON CURRENT DISCHARGE ( NO

ADDITIONAL LOADING )

ARE THERE OPTIONS FOR EFFLUENT TRADING OR MITIGATION BY TREATING UNCONTROLLED SOURCES ? PERMIT CONTAINS INTERIM LIMITS

TO PREVENT INCREASE IN LOADING AND FINAL LIMITS IN

FACT SHEET PERMIT CONTAINS FINAL EFFLUENT LIMITS AS THE WATER QUALITY CRITERIA

, A COMPLIANCE SCHEDULE TO ACCOMODATE TRADING AND MEETING FINAL LIMITS

, AND INTERIM

EFFLUENT LIMITS BASED ON CURRENT DISCHARGE

TMDL COMPLETED NO UNSURE

YES DATA IS VALID

( no dilution is

available ) DATA NOT VALID ( dilution is available )

YES

YES NO

NO UNSURE Figure VI

- 6

. Permitting discharges to a 303 ( d ) listed waterbody with no TMDL

. If an AKART analysis has not been completed for the pollutants at issue

, decision boxes 1 and 2 are conducted concurrently

.

1

2

3CHAPTER VI. WATER QUALITY

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- 37 Figure VI

- 6

. (continued)

DOES THE TMDL PREDICT ACHIEVEMENT OF THE WATER QUALITY STANDARDS BY A SIGNIFICANT MARGIN

AFTER IMPLEMENTATION OF POINT SOURCE AND NON-POINT SOURCE

CONTROLS AND/OR EFFLUENT TRADING?

TMDL COMPLETED

WASTELOAD ALLOCATION MAY INCLUDE

DILUTION

SEE WER, UAA, AND VARIANCE PROCESSES YES

NO

Decision box 1 (Is Listing Data Valid?)

– Non

- conservative Pollu tants. The permit writer must make a judgment, based on the circumstances of the 303(d) data on how to proceed with the listed pollutant in the effluent. This judgment is influenced by the proximity of the listed section to the point of discharge. The ju dgment is also influenced by the type of pollutant and whether it is a conservative or non

- conservative pollutant. Non

- conservative pollutants are pollutants that degrade in the receiving water. Some typical non

- conservative pollutants are BOD, ammonia n itrogen, and fecal coliform.

If the discharge is to a listed section, the receiving water is impaired

. If the listing is for one station at some distance from the point of discharge then there may be some uncertainty about the water quality at the point of discharge for non

- conservative pollutants. If there are station listings above and below the point of discharge or one station close to the point of discharge then there is more certainty that the water quality does not meet the criteria at the point o f discharge. Another judgment must be made regarding the degradation rate of the pollutant in relation to the point of discharge and the listing station(s). Some volatile pollutants may degrade in a matter of
hours in a turbulent river but others such as BOD may not reach full effect on dissolved oxygen until several days travel time down

- river. A permit writer who is unsure of the dynamics of the water quality at the point of discharge may wish to consult with someone in the EA Program.CHAPTER VI. WATER QUALITY

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- 38 Decision box 1 (Is Listing Data Valid?)

– Conservative Pollutants Conservative pollutants do not degrade in the receiving water, however, they may change form or their media association. Metals are a common conservative pollutant. They may be in a
bound or dissolved fo rm in the water column or go to the sediments. The decision

- making process is much the same as for non

- conservative pollutants except that if the listing station is downstream of the discharge, the effluent is assumed to be contributing to the impairment.

A factor of uncertainty with metals is the correctness of the data if the receiving water or effluent data wasn’t collected using ultra

- clean sampling and analysis. In this case, the concentrations of metals in the receiving water and the effluent shoul d be confirmed using clean sampling and analytical techniques.

Decision box 1 (Is Listing Data Valid?)

– Human Health Pollutants The listing for human health pollutants may be made on the basis of water column concentration
or on the basis of fish tissue an alysis. If the listing is on the basis of resident fish tissue concentration above or below the point of discharge assume the effluent is contributing to the impairment (assuming the pollutant is present in the effluent). If the listing is on the basis o f water column concentration the decision criteria given above for other pollutants are applicable.

Decision box 1 (Is Listing Data Valid?)

- Water Quality Studies If there is some uncertainty about the conditions at the point of discharge and whether dilu tion is available, the permit writer may require a receiving water study. A water quality

- based effluent limit is not always required in the permit that requires the study (see the following discussion on timing), but an effluent limit based on demonstrat ed performance should be placed in the permit. This limits the discharger to their current loading until the uncertainty about the receiving water
condition is resolved.

Permit conditions which require receiving water studies should require that the stud y plan be submitted as a QAPP to be approved by Ecology before the study proceeds. The permit should require the data from the study be submitted in a Storet format. The permit should also require that the critical conditions be determined for the 10 yea r critical condition. This can be done for some parameters by correlating the site data to a long

- term monitoring station. For other parameters where long

- term data is not available, the techniques for estimating 90 th (or 10 th ) percentile values from a s mall data set are given in appendix 6.

If receiving water data indicates there is no dilution available for part or all of the year, then other options can be explored as indicated on the flow chart. If no dilution is available, however,
a final effluent limitation of the criteria concentration (amount) is placed in the permit if compliance is expected within five years. The final limit is placed in the fact sheet if compliance is longer than five years and an interim limit based on existing performance is placed in the permit. A compliance schedule may be authorized for meeting the final limit but it must be as short as possible and must require demonstration of reasonable progress toward meeting theCHAPTER VI. WATER QUALITY

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- 39 water quality criteria or final limit.

Decision box 2 . Once the water quality impairment is confirmed or verified the following principle is in effect:

• There can be no additional loading or higher concentration allowed for the listed pollutants at times of impairment until the TMDL is completed and it sho ws dilution available at full implementation of the TMDL.

Ceasing discharge to surface waters may be an option for some small dischargers especially for summer discharges with high temperatures and low dilution. Other options include using the

wastewater for irrigation or simply storing the wastewater. In some cases there may be opportunities for seasonal pollutant removal. These options are explored in an engineering report required as part of the compliance schedule if these options were not originall y explored in the AKART analysis. If seasonal removal appears feasible for a facility, the final effluent
limit should be either:

• the water quality criteria or

• no discharge during critical period. The final limit is placed in the permit, if achievable in five years, or in the fact sheet, if a longer period is required for compliance. If longer than five years, an interim limit, based on existing performance, is placed in the permit. For some pollutants, treatment may be available that is
within the fina ncial capability of the facility. If the treatment option is used the permit should contain a final effluent limitation of the criteria concentration (amount) and an interim limit based on existing performance or a compliance schedule to meet final limita tions.

Decision box 3 . For some limited number of pollutants and discharges there may be some options for pollutant trading in which a discharger would pay some upstream point source or

non

- point source for treatment in order to gain some allowable dilut ion at the dischargers
location

. If this option is used, the permit should contain a final effluent limitation of the criteria concentration (amount) and an interim limit based on existing performance or a compliance
schedule to meet final limitations. I f this option is considered, there must be available data on the upstream source that would be used for the trade. This option is administratively very time consuming.

Timing for Decision Boxes 1, 2, and 3 . The permit language requiring examination of t he options in boxes 1, 2, and 3 in Figure VI

- 6 may be sequential within one permit term depending on the size and priority of the discharge. For example, a permit for a large industrial source which is being required to do a water quality study in the ini tial years of the permit, should also require an engineering report for treatment options in the later years of the permit if the studies show violations of water quality standards. In other cases, such as small municipalities, which may require several y ears to fund a water quality study, the initial permit may only require the water quality study. The next permit would then require the engineering report.CHAPTER VI. WATER QUALITY

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- 40 New Discharges To Listed Water B odies

No TMDL The applicable regulation is 122.4(i)
Sec tion 122. 4 P rohibitions

. No permit may be issued: i) To a new source or a new discharger, if the discharge from its construction or operation will cause or contribute to the violation of water quality standards. ...

A new discharge to a listed water body can not be a llowed (issuance of permit is prohibited) if the discharge will cause or contribute to a violation of water quality standards. A new discharge may be allowed to discharge at the water quality criteria (for those pollutants with criteria) or at the quantit ation level for those pollutants without criteria, such as BOD.

A permit applicant may be allowed to demonstrate that the listed water body has the ability to accept additional loading at the proposed point of discharge without measurable impairment or

me asurable increased impairment to the water body

.

In some cases a new discharger may be allowed to discharge listed pollutants by trading effluent reduction (effluent trading) or discharging seasonally. Effluent trading may entail treating a previously un treated but quantified pollutant source, such as a stormwater outfall such that the net effect of the new discharge is zero. Water reuse is encouraged by Ecology and it may be a good option for new dischargers to avoid discharge during the critical condit ion, typically the low flow period.

TMDL Completed The applicable regulation is 122.4(i) ...The owner or operator of a new source or new discharger proposing to discharge into a water segment which does not meet applicable water quality standards or is not e xpected to meet those standards even after the application of the effluent limitations required by sections 301(b)(1)(A) (BPT) and 301(b)(1)(B) (Secondary treatment) of CWA, and for which the State or interstate agency has performed a pollutants load alloc ation for the pollutant to be discharged, must demonstrate, before the close of the public comment period, that: (1) There are sufficient remaining pollutant load allocations to allow for the discharge; and (2) The existing dischargers into that segment ar e subject to compliance schedules designed to bring the segment into compliance with applicable water quality standards

. The Director may waive the submission of information by the new source or new discharger required by paragraph (i) of this section if the Director determines that the Director already has adequate information to evaluate the request

. An explanation of the development of limitations to meet the criteria of this paragraph (i)(2) is to be included in the fact sheet to the permit under Sect ion 124.56(b)(1) of this chapter.

A new source or new discharger proposing to discharge to a listed water body for which a TMDL has been completed and WLA’s assigned may obtain a permit for discharge into a waterCHAPTER VI. WATER QUALITY

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- 41 segment which does not meet applicable wat er quality standards by submitting information demonstrating that there is sufficient loading capacity remaining in the waste load allocations for the stream segment to accommodate the new discharge and that existing dischargers to that segment are subject to compliance schedules designed to bring the segment into compliance with the appli cable water quality standards.

General Permits General permits are issued under the same laws and regulations as individual permits but Ecology is unable to invest the t ime necessary to make the site

- specific decisions regarding the water quality at the point of discharge for the large number of permittees wanting coverage under general permits. Existing discharges to impaired waters will receive the same limitations as dischargers to non

- impaired waters

. The permit coverages should include monitoring for the impairment pollutant for use in the TMDL. The application for coverage under the General
Permit for new facilities will ask if the discharge is to a listed water b ody and will provide information for the applicant to determine if they will be discharging to a listed water body

. When possible, the pollutants specific to the type of discharge covered by the general permit will be identified in the permit application materials. If the permit applicant indicates they will be discharging a named pollutant to listed water body at or near the impaired section, the applicant

may receive an individual permit or special limits in the permit coverage

.
TMDL Completed

If the TM DL has been completed at the location, the steps for compliance may be similar to those given above especially when the WLA doesn’t allow for any significant dilution. The permit may contain a compliance schedule if necessary to meet a WLA.

Natural Condi tions

A determination that natural conditions in a water body exceeded water quality standards can only be made from: 1) data from the water body prior to any human disturbance in the watershed, 2) correlation of the water body to a nearby undisturbed wate r body , or 3) a model o f
the water body and watershed.

In some cases the permittee or applicant may try to demonstrate that conditions in the water body were not meeting standards before the addition of wastewater and therefore are natural
conditions or n atural background levels. Natural conditions are defined in the Water Quality Standards as the surface water quality that was present before any human

- caused pollution (WAC 173

- 201A

- 020). Human

- caused pollution includes non

- point sources such as timber
h arvesting and farming. Therefore, unless data is available from the watershed before there was any human disturbance or from a nearby less disturbed watershed showing exceedance of standards, a determination of natural conditions should not be made by the permit writer. An estimate of natural conditions can be made by modeling

. This may be developed as part of a TMDL or may be conducted by Permittees using methods approved by Ecology.CHAPTER VI. WATER QUALITY

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- 42 

### 3.3.1 2 . EFFLUENT LIMITS
Derive effluent limits for those pollutants th at are determined to have a reasonable potential (to violate the water quality standards). Effluent limits are also derived using the criteria as total recoverable. The process for deriving limits was described earlier and the calculations are
available in spreadsheets. Figure VI

- 7 illustrates the process of compliance.



### 3.3.1 3 . COMPLIANCE SCHEDULES
If an existing permittee can not immediately comply with the water quality

- based effluent limits the permit writer may allow a compliance schedule with interi m limits. The interim limits and compliance schedule are placed in the permit. The interim limits may be based on existing performance and calculated by using PERFORMLIM in TSDCALC.XLW.

If the schedule for permit issuance schedule allows, the permit wri ter may request the permittee to do the following analysis on a voluntary basis as a part of the permit application.

The compliance schedule will direct the permittee to do ultra

- clean sampling and analysis of effluent and receiving water. The guidance f or ultra

- clean sampling and analysis is available from EPA (1995). The receiving water sampling is necessary because historic data on metals may be biased on the high side. For industrial dischargers and municipal dischargers that receive
industrial wast ewater, the compliance schedule should also require a determination of the source of the metals and opportunities for reduction

.

The ultra

- clean analysis of effluent and receiving water and any source reduction may result in
lower concentrations of metals . If this results in a determination of no "reasonable potential", then the effluent limits and interim limits may be removed from the permit by permit
modification

. This will not violate the anti

- backsliding provision of the Clean Water Act
because this constitutes new information which if available at the time of permit issuance would have caused a different action (no limits).



### 3.3.1 5 . LARGER MIXING ZONES
If the permittee cannot meet the final effluent limits then the permittee may request an exception to the mixing zone size as allowed and conditioned by WAC 173

- 201A

- 4 00(12)

, (13) , and (14)

.

The permittee may also conduct a Use Attainability Analysis to demonstrate the classification for
the water body is inappropriate. This option will require a set o f studies to demonstrate the natural potential of the water body to support beneficial uses and the ability of the point and nonpoint source dischargers to control pollutants to those waters. It is unlikely that a single discharger would elect to conduct this type of analysis.CHAPTER VI. WATER QUALITY

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- 43 

### 3.3.1 6 INTERIM INTERPRETATION OF WATER QUALITY STANDARDS FOR EXISTING MUNICIPAL DISCHARGES (less than 0.5 MGD) TO INTERMITTENT STREAMS
Section 1 of this chapter discussed the use

- based water quality standards that were adopted in
2 006. Numeric criteria are associated with the designated uses for each water body . In most cases, waters receive the same designated uses as it is downstream receiving stream, regardless if it is shown on the map application. To view the designates uses and link to the numeric criteria use one of the applications available through this web site: http://aww.ecology/programs/wq/swqs/map

- apps.html

At this time, the WQ Standards do not addres s the “permanency” of streams, such as perennial intermittent or ephemeral. If a stream is isolated (does not contribute water to another stream) it would receive a Salmonid Spawning and Rearing Use.

Facility managers should evaluate the impacts of a mun icipal effluent upon the characteristic
uses of a stream and its water volume, including seasonal fluctuations. The impacts are compared to the beneficial effects of the effluent going to a stream reach that would otherwise be dry. In order to protect ch aracteristic uses associated with streams during flow and non

- flow periods, and to provide small municipal dischargers with options for treatment and disposal, the facility manager should require the facility to evaluate the following alternatives treatmen t options. 1. A treatment/disposal system that meets all numeric criteria and characteristic uses for the receiving water body

. This may require removal of the discharge from the stream either seasonally or completely. 2. A treatment/disposal system that protects the characteristic uses in the stream during seasonal fluctuations, including nonflow periods

. This option requires the evaluation of treatment technology commonly available which exceeds secondary treatment and which produces the following efflu ent quality (as monthly averages):
BOD and TSS

- 15 mg/l
Total Ammonia

- 1 mg/l if costs for achieving 1 mg/l are disproportionate to costs for achieving BOD and TSS Ecology may allow total ammonia average of 2 mg/l. If Chlorine is used for disinfection, d echlorination is required

. The facility should evaluate other
disinfection methods. If treatment option 2 is chosen, the discharge should be modeled or instream sampling required of the facility to demonstrate that all numeric criteria are met at the poin t of perennial flow.CHAPTER VI. WATER QUALITY

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- 44 EFFLUENT

LIMITS Figure VI

- 7

. Compliance with water quality

- based effluent limits

CAN PERMITTEE COMPLY WITH THE LIMITS ? ISSUE PERMIT WITH NO COMPLIANCE SCHEDULE

DOES BETTER DATA SHOW LOWER EFFLUENT CONCENTRATIONS OR

RESULT IN A NO REASONABLE POTENTIAL DETERMINATION ? ISSUE PERMIT WITH COMPLIANCE SCHEDULE OR IF TIME PERMITS REQUIRE ADDITIONAL ANALYSIS

BEFORE ISSUING THE PERMIT

PERMITTEE IS ABLE TO COMPLY WITH LIMITS OR PERMIT

IS MODIFIED TO REMOVE LIMIT

PERMITTEE MAY REQUEST A LARGER MIXING ZONE NO

YES

NO YES



### 3.3.1 7 . Flow Adjusted Effluent Limits
Typically, effluent limits are derived using a static model at the time of critical condition (discussed elsewhere in this Chapter). Critical condition is typically at time of low flow beca use of the reduced dilution. Many people have considered that limits derived from a static model were more conservative than those from a dynamic model or a Monte Carlo simulation. The
static model was considered conservative beca use of the many probability factors or design conditions considered in deriving limits. These probabilities for an industrial discharge to freshwater are given in Table VI

- 4 below.CHAPTER VI. WATER QUALITY

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- 45 Table VI

- 4. Statistical probabilities in static model effluent limits.

D esign Parameter Design Condition Probability of Occurrence
or exceedance

Effluent Flow (Acute) Highest daily maximum effluent flow for past 3 years 1 day in 1080 days (assuming daily effluent monitoring)
Effluent Flow (Chronic) Highest monthly average e ffluent flow for the past three years. 1 month in 36 months

Receiving Water Flow (Fresh Water) Typically 7Q10 low flow. (7 day average daily low flow with an

expected return period of 10 years based on historical record) 1 year in 10 (as a 7 day average). Flows with a smaller averaging period will occur more frequently.

Acute Criteria (metals) One hour exposure concentration not
to be exceeded more than once in three years

Chronic Criteria (metals) Four day exposure concentration not
to be exceeded mo re than once in three years
Effluent
Concentration 95 th percentile 5% for period of data
collection Receiving Water
Concentration 90 th percentile 10% for period of data
collection
Waste Load
Allocation Water Quality Criteria times the
dilution factor o r from TMDL Long Term Averages (Acute and Chronic) Based on WLA and CV 1% exceedance of WLA (Water Quality Criteria) Daily Maximum
Effluent Limit Based on limiting LTA Type 1* error = 1% Type II error = ?

Monthly Average
Effluent Limit Based on limitin g LTA Type I er r or = 5% Type II error ≈ 20% with
d=0.2 and CV = 0.6 * Type I error in this case is the probability that the facility will violate the limit but actually be in compliance with

the expected long term average. Type II error is the probabilit y that the facility will be meeting effluent limits but not meeting the expected long term average.

The derivation of effluent limits is typically done by static modeling for conditions existing at
the time of critical condition. Critical condition is us ually at times of low flow because the
amount of dilution is lowest at that time.

Some elements of the process of deriving water quality

- based effluent limits by the static process are conservative (cause effluent limits to go down) while other are libera l (cause effluent limits to increase) and some people have argued that the combination of extreme probabilities causesCHAPTER VI. WATER QUALITY

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- 46 unnecessary conservatism. On the other hand, many toxic water quality criteria are expressed as one hour or four day exposure and our ty pical definition of critical flow is a seven day average low flow. In addition, effluent monitoring for toxic pollutants is typically weekly or monthly and is rarely conducted on an hourly basis.

Alternates to the static model are the dynamic models as d iscussed in the TSD (1991). These models require large amounts of data to model properly. It had been assumed that dynamic models more accurately predicted water quality conditions and did not compound probabilities.
It was also assumed that effluent li mits derived from dynamic models would be higher than if derived from a static model, however, a paper (Dilks and Pendergast 2000) demonstrated that limits from static models are generally higher.

Some permittees have requested effluent limits which would vary based on the amount of flow and subsequent dilution occurring at the point of discharge. These permittees have the ability to modify their flow or pollutant loading within a short time period. There are two major difficulties with these types of fl ow

- based limits. One problem is simply the administrative problem of trying to keep track of the effluent limits so as to assess compliance

. Any flexible process for formulating effluent limits increases the difficulty of measuring compliance. Difficult y with measuring compliance means difficulty assuring compliance with the water quality standards and enforcing the provisions of the permit.

The second difficulty with flow based limits is maintaining the margin of safety. With the static model, it is a ssumed that the combination of probabilities described above would result in a probability of violating the water quality standards in any given year during the critical period to be 10% or less. When effluent limits are based on the existing receiving wa ter flows (and resulting dilution factor) there is no margin of safety.

Options for Flow Based Limits Case 1. Continuously Variable

– Continuously variable limits, if allowed, would only be applicable for a very small group of dischargers who are able to vary production on a short term basis. In this case effluent limits would be fixed to the data produced by a nearby hydrograph on the receiving water. The margin of safety would have to be explicitly set at 10% by reducing the calculated limit or dilutio n factor by 10%. This case would be virtually impossible to track for compliance because effluent limits, calculated on a daily basis, would have to be entered individually into the data base. In consideration of the limited applicability of this case an d the impossible data management, Ecology will not consider continuously variable effluent limits.

Case 2. Step Variable

– In this case effluent limits are increased or decreased in a stepwise manner as actual river flows increase or decrease respectivel y. This option affords flexibility but reduces the administrative burden if the number of increments is limited. The margin of safety can be set explicitly at 10% or by introducing a one step lag. This option is not feasible on an individual basis becau se of the difficulty of developing limits that retain a margin of safety with a falling hydrograph ( Fig ure VI

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- 47 Case 3. Seasonally Variable Limits based on historical flows or predicted flows.

- In this case (a variation of stepped limits) the seasonal effluent limits are based on a seasonal flow with a return frequency adjusted to give an annual probability of exceedance of 10%. For example, for two season limits the 7Q20 flows would be determined for each season and used for determining the
effluent limits. For three season limits the 7Q38 flows would be determined for each season and for quarterly limits the 7Q114 flows would be determined for each season. Determining these flows requires a good historical record of flows for the water body to accu rately predict these
flows . In reviewing cases where seasonal effluent limits have been proposed, it’s apparent that
there is little difference between 3

- season limits and 4

- season limits.

In some cases, the seasonal high and low flows are predicted from snow pack measurements. These are primarily for hydropower management, however, they could be used for determining seasonal effluent limits for the water year. The margin of safety is adjusted on the basis of the historical error rate of predicted flows to actual observed flows to an annual 10% probability of
exceedance.

Case 4. Seasonal Removal of Effluent

- In some cases there will not be any assimilative capacity in the receiving water at low flows. In this case the only option (other than administ rative) is to remove the effluent by land applying, reusing or storing the effluent. The margin of safety is applied by selection of the dates of removing and re

- discharging the effluent. The dates should be chosen such that the annual probability of exc eeding the water quality standards is 10% or
less.

Considerations for flow adjusted limits Permit writers who are considering flow

- adjusted limits need to take into account the fluctuation in other variables that affect the compliance with water quality st andards. For example, the dilution factor and background pollutant concentration will typically change seasonally and may be higher or lower than low flow measurements depending upon the specific water body

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- 48 TIME

TIME

TIMEMAGNITUDE FLOW

EFFLUENT LIMIT

X X X

X X SEASONAL
EFFLUENT LIMIT FLOW X X X X

X

X FLOW

x EFFLUENT LIMIT CASE 1

CASE 2

CASE 3MAGNITUDEMAGNITUDE

Figure VI

- 8. Flow

- based effluent limitationsCHAPTER VI. WATER QUALITY

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- 49 Hardness, pH, and temperature which affect the numeric criteria for some metals and ammonia will also vary seasonally and must be accounted for in setting limits. The information on these variables should be develo ped by the permittee. The permit writer should also consider the difficulty of accounting for upstream dischargers if there are multiple dischargers to a reach. Where conditions become too complex to authorize flow adjusted limitations, the permit writer should consider doing static water quality

- based limits and authorizing a compliance schedule to incorporate the time necessary to do the TMDL.



## 4. ANALYTICAL LEVELS

This part discusses detection and quantitation levels and outlines an approach to assess compliance with water quality standards and with effluent limits that are near or below the levels of quantitation. The approach is primarily for organic and metal pollutants where criteria and effluent limits may be very low . Chemical

- specific concentra tion levels that can be used for compliance assessment are presented, as well as guidance on how to tailor those levels to fit regulatory concerns regarding the possible impacts of the discharge

. Compliance levels are expected to change over time as analy tical methods improve and as we gather more dat a on laboratory performance.

T he permit writer should require EPA Methods as given in Part 136 and specify the specific method to achieve detection and quantitation levels for permit application or permit com pliance monitoring

.


## 4.1 Introduction

Effluent limits based on water quality criteria may be set at very low concentrations (in the range of parts per billion to parts per quadrillion). Laboratory analytical methods approved for use in the NPDES program ar e often not capable of measuring chemical concentrations at the concentrations of the permit limits. In many cases we are unable to determine if pollutants contained in discharges are at concentrations that merit concern, and when we set an effluent
limit , we are often unable to determine if that limit is being exceeded.

Historically, the method detection limit (MDL) was used to determine compliance (all data at or above the MDL were considered adequate for assessing compliance and supporting
enforcement actions). The MDL, however, is the level at which a chemical's presence or absence can be detected, and provides limited information with regard to actual concentration . The low concentrations of many of the aquatic life

- based and human health

- based crit eria ha ve made the issue of quantitation important to both the regulator and the discharger. This section uses the
term “ quantitation level ” as equivalent to the term “ minimum level of quantitation (ML) ” which is used by EPA. The ML is defined by EPA as the lowest concentration of an analyte thatCHAPTER VI. WATER QUALITY

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- 50 can be measured with a defined level of confidence (see further discussion below)

. This may
also be called the reporting level by some laboratories.

Historically, analytical results of wastewater effluent testi ng w ere only used only to demonstrate compliance with effluent limits

. The analytical results are now being used to determine loading of pollutants to receiving waters and compliance with human health criteria

. This requires the
use of lower detection an d quantitation levels.


## 4.2 Background Informati on

Two types of analytical levels are in common use. The first type is the Method Detection Limit (MDL) or Detection Level which is defined as the minimum concentration of a substance that
can be measured and reported with 99% confidence that the analyte concentration is greater than zero and is determined from analysis of a sample in a given matrix containing the analyte

. This may be called the Instrument Detection Level (IDL) for some analyses

. The Quantif ication Level (QL) or Minimum Level is defined as the practical quantitation level ( PQL ) in Ecology's groundwater quality standards. Another type of quantitation level commonly used is the Contract Required Quantitation Levels (CRQLs) listed in the EPA Co ntract Laboratory Program (CLP). The CRQLs are a list used historically in EPA's groundwater and waste programs for laboratory contracts, and have been routinely used to measure concentrations at waste sites. The advantage of these levels is that numerous laboratories throughout the country provide the services, but the levels specified are not always based on the use of the most sensitive analytical test methods that EPA has approved for the NPDES permitting program. Both quantitation types have advantag es in a regulatory program. Using the Method Detection Limit times a safety factor is straight forward and easy to understand, and is widely used in many regulatory programs throughout the country. The CLP values are also well known to the regulatory

com munity, and are attainable for most labs. However, with each quantitation type, certain regulatory issues can increase or decrease the cost of the compliance monitoring program for dischargers and regulators.

The minimum level of quantitation (ML) has no t been formally defined except as a component of the specific analytical method. EPA has proposed adopting a definition and procedure for defining a ML (FR 3/12/2003)

. The text of the proposal is reprinted below. EPA also convened an advisory committee on this issue

. A committee report is available ( Report of the Federal Advisory Committee on Detection and Quantitation Approaches and Uses in Clean Water Act Programs, December 2007)

.CHAPTER VI. WATER QUALITY

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- 51 The definition of ML as proposed by EPA in th e text above is still controversial among chemists, including some chemists within Ecology.CHAPTER VI. WATER QUALITY

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- 52 

## 4.3 Implementation

- NPDES and State Permits

An analytical result below the MDL means there can be no judgment regarding the presence of analyte in the sample

. The actual concentration may fall from 0 to just below the detection level

. Given this uncertainty

, single analytical results below the MDL may be treated as 0

. A few measurements below the MDL may be set equal to half of the detection level to calculate an average if the data set also contains measurements above the QL.

An analytical result that falls between the MDL and the QL means there is a level of certainty that the analyte is in the sample. The actual concentration may lie anywhere between the MDL and the QL. These values may be reported by the laboratory but are accompanied by a qualifier. Ecology’s Manchester Laboratory uses a J qualifier in this case. A value falling between the MDL and the QL may be used for calculating averages (daily maximu m and monthly average) but should not be used for enforcing the daily maximum if the daily maximum value consists of a single daily analysis.

All analytical result above the QL may be used as valid single values for assessing compliance with the daily max imum and for use in the monthly averages.

The objective in wastewater characterization (permit application) is to quantify at or below
criteria levels.


## 4.4 Choosing a Quantitation Level

Table VI

- 5 below lists the detection and quantitation levels recommen ded by Ecology for wastewater analysis in permitting . These should be used for application and permit requirements unless the Ecology laboratory advises differently for a particular pollutant

.

Effluent matrices (interfering substances) may affect the MDL of an analysis. If a discharger cannot provide a required Method Detection Limit or quantitation level because the matrix of their particular effluent causes interferences with the analysis, the discharger also could face non

compliance because of inabil ity to provide a quantitation level required in a permit. This situation can be addressed by allowing the discharger to develop a matrix

- specific quantitation level. If a discharger suspects that the quantitation level cannot be attained in its effluent because of matrix effects (e.g., high salinity), the discharger could run a laboratory spike of their sample matrix along

- side an unspiked sample. If the recovery in the laboratory spike is poor, the discharger may need to develop an effluent specific MDL and quantitation level. Based on data from Wisconsin and communication with the State of New York, matrix effects are not a common problem, however, dischargers should be allowed time schedules in permits to provide required quantitation levels if local labs cannot provide them, and should be allowed to develop matrix specific quantitation levels if their effluent matrices cause analytical interference. InCHAPTER VI. WATER QUALITY

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- 53 order to qualify for development of a matrix specific quantitation level, the discharger must show that it is matrix effects, and not lack of a laboratory's ability to perform a method, that is affecting the MDL. This demonstration can be made by providing laboratory performance data showing all information needed to calculate the needed MDL, as define d in 40 CFR 136. All sample measurements and supporting QA/QC data should be submitted to Ecology.

Metals. Method detection limits have not been developed for metals. Instead, instrument detection limits (IDLs) are available for each method. The method detection levels for metals
listed in Table VI

- 5 a re typically given as IDLs in 40 CFR Part 136. The quantitation levels for
metals w ere estimated by multiplying the IDL by a factor of 4.

Organics

- The quantitation levels recommended here should prove attainable by most dischargers, and protective of most surface waters. Those dischargers unable to attain the recommended QLs may be allowed to develop matrix specific quantitation levels or given time schedules to attain appropriate laboratory services.

The approach outlined above will (1) reduce the uncertainty dischargers are faced with if data below quantitation levels were used to assess compliance, (2) provide dischargers with schedules to provide laboratory services and the ability to determine mat rix specific effects from their effluents, (3) promote high quality laboratory services in a reasonable time frame, (4) provide the agency with data reasonable to use in enforcement, and (5) provide receiving waters with protection by specifying the best a pproved methods for measuring compliance.CHAPTER VI. WATER QUALITY

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- 54 Table VI

- 5

. Methods, d etection and quantitation levels recommended for effluent characterization and effluent monitoring. T his list includes EPA

- required pollutants (priority pollutants) and some ecolo gy priority toxic chemicals ( PBTs )

.

The following table with analytical levels is to be used as guidance for effluent characterization in NPDES

new permit applications and applications for permit renewal. The table should also be used as a guide for

rout ine effluent monitoring

. This table contains values which have been shown to be consistent for wastewater analysis and may be slightly higher or lower than published values in 40 CFR Part 136

. The objectives are to reduce the number of analytical “non

- de tects” in applications and monitoring reports and to measure effluent concentrations near or below criteria values where possible at a reasonable cost

. If an applicant or Permittee knows that an alternate method from 40 CFR Part 136 is sufficient to produ ce measureable results in their effluent, that method may be used for analysis.

Chemical name in bold d enotes a State of Washington priority pollutant

. (Table Oct ober 2011)

Pollutant & CAS No. **(if available)** Recommended Analytical

Protocol Detection ( DL) 1

**μ**

**g/L unless specified**  Quantitation Level (QL) 2

**μ**

**g/L unless specified** 
CONVENTIONALS Biochemical Oxygen Demand SM 5210

- B 2 mg/L Chemical Oxygen Demand SM5220

- D 10 mg/L Total Organic Carbon SM 5310

- B / C / D 1 mg/L Total Suspended Solids SM 2540

- D 5 mg/L Total Ammonia (as N) SM 4500

- NH3

- G H 0.3 mg/L

Flow Calibrated device Dissolved oxygen 4500

- OC /OG 0.2 mg/L Temperature (max. 7

- day avg.) Analog recorder or Use micro

recording devices known as thermistors 0.2 o C

pH SM4500

- H + B N/A N /A NONCONVENTIONALS Total Alkalinity SM2320

- B 5 mg/L as CaCo3 Chlorine, Total Residual 4500 Cl G 5 0.0
Color SM2120 B/C/E 10 color unit
Fecal Coliform SM 9221 D/ E ,9222 N/A N/A

Fluoride (16984

- 48

- 8) SM 4500

- F E 25 100CHAPTER VI. WATER QUALITY

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- 55 Pollutant & CAS No. **(if available)** Recommended Analytical

Protocol Detection ( DL) 1

**μ**

**g/L unless specified**  Quantitation Level (QL) 2

**μ**

**g/L unless specified** 

Nitrate

- Nitrite (as N) 45 00

- NO 3

- E/F/H 100 Nitrogen, Total Kjeldahl (as N) 4500

- N H 3

- C/E/FG 300

Soluble Reactive Phosphorus ( as P) 4500

- P E/PF 3 10 Phosphorus, Total (as P) 4500

- P E/PF and SM4500

- PE/PF 3 1 0

Oil and Grease (HEM) 1664A 1,400 5,000 Salinity SM2520

- B 3 PSS
Settleable Solids SM2540

- F 100 Sulfate (as mg/ L SO 4 ) SM4110

- B 200 Sulfide (as mg/ L S) 4500

- S 2 F/D/E/G 2 00 Sulfite (as mg/ L SO 3 ) SM 4500

- SO3B 2000
Total dissolved solids SM 2540 C 20 mg/L
Total Hardness 2340B 200 as CaCO3 Aluminum, Total (7429

- 90

- 5) 200.8 2.0 10 Barium Total (7440

- 39

- 3) 200.8 0.5 2.0 BTEX (benzene +toluene + ethylbenzene + m,o,p xylenes) EPA SW 846 8021/8260 1 2

Boron Total (7440

- 42

- 8) 200.8 2 .0 10.0 Cobalt, Total (7440

- 48

- 4) 200.8 0.0 5 0. 25 Iron, Total (7439

- 89

- 6 ) 200. 7 12.5 50 Magnesium, Total (7439

- 95

- 4) 200. 7 10 50 Molybdenum, Total (7439

- 98

- 7) 200.8 0.1 0. 5 Manganese, Total (7439

- 96

- 5) 200.8 0. 1 0. 5

NWTPH Dx 4 Ecology NWTPH Dx 250 250

NWTPH Gx 5 Ecology NWTPH Gx 250 250

Tin, Total (7440

- 31

- 5) 200.8 0. 3 1.5 METALS, CYANIDE & TOTAL PHENOLS Antimony, Total (7440

- 36

- 0) 200.8 0. 3 1.0 Arsenic, Total (7440

- 38

- 2) 200.8 0.1 0.5 Beryllium, Total (7440

- 4 1

- 7 ) 200.8 0.1 0.5 Cadmium, Total (7440

- 43

- 9) 200.8 0.05 0.25 Chromium (hex) dissolved (18540

- 29

- 9) SM3500

- Cr EC 0. 3 1.2

Chromium, Total (7440

- 47

- 3) 200.8 0.2 1.0 Copper, Total (7440

- 50

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- 56 Pollutant & CAS No. **(if available)** Recommended Analytical

Protocol Detection ( DL) 1

**μ**

**g/L unless specified**  Quantitation Level (QL) 2

**μ**

**g/L unless specified**  Lead, Total (7439

- 92

- 1) 200.8 0.1 0.5 Mercury, Total (7439

- 97

- 6) 1631E 0.000 2 0.0005 Nickel, Total (7440

- 02

- 0) 200.8 0.1 0.5 Selenium, Total (7782

- 49

- 2) 200.8 1.0 1.0 Silver, Total (7440

- 22

- 4) 200.8 0.04 0.2 Thallium, Total (7440

- 28

- 0) 200.8 0.09 0.36 Zinc, Total (7440

- 66

- 6) 200.8 0.5 2.5 Cyanide, Total ( 57

- 12

- 5 ) 335.4 2 10 Cyanide, Weak Acid Dissociable SM4500

- CN I 2 10 Cyan ide, Free Amenable to Chlorination (Available Cyanide) SM4500

- CN G 5 10

Phenols, Total EPA 420.1 50
DIOXIN 2,3,7,8

- Tetra

- Chlorodibenzo

- P

- Dioxin (176

- 40

- 16) 1613B 1.3 pg/L 5 pg/L

VOLATILE COMPOUNDS Acrolein (107

- 02

- 8) 624 5 10 Acrylonitrile (10 7

- 13

- 1) 624 1.0 2.0 Benzene (71

- 43

- 2) 624 1.0 2.0 Bromoform (75

- 25

- 2) 624 1.0 2.0 Carbon tetrachloride ( 56

- 23

- 5 ) 624/601 or SM6230B 1.0 2.0

Chlorobenzene (108

- 90

- 7) 624 1.0 2.0 Chloroethane (75

- 00

- 3) 624/601 1.0 2.0
2

- Chloroethylvinyl Ether (11 0

- 75

- 8) 624 1.0 2.0 Chloroform (67

- 66

- 3) 624 or SM6210B 1.0 2.0 Dibromochloromethane (124

- 48

- 1) 624 1.0 2.0 1,2

- Dichlorobenzene (95

- 50

- 1) 624 1.9 7.6 1,3

- Dichlorobenzene (541

- 73

- 1) 624 1.9 7.6 1,4

- Dichlorobenzene (106

- 46

- 7) 624 4.4 17.6
Dichlor obromomethane (75

- 27

- 4) 624 1.0 2.0 1,1

- Dichloroethane (75

- 34

- 3) 624 1.0 2.0 1,2

- Dichloroethane (107

- 06

- 2) 624 1.0 2.0 1,1

- Dichloroethylene (75

- 35

- 4) 624 1.0 2.0 1,2

- Dichloropropane (78

- 87

- 5) 624 1.0 2.0 1,3

- dichloropropylene (mixed isomers) (542

- 75

- 6) 6 624 1.0 2.0

Ethylbenzene (100

- 41

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- 57 Pollutant & CAS No. **(if available)** Recommended Analytical

Protocol Detection ( DL) 1

**μ**

**g/L unless specified**  Quantitation Level (QL) 2

**μ**

**g/L unless specified**  Methyl bromide (74

- 83

- 9) ( Bromomethane ) 624/601 5.0 10.0 Methyl chloride (74

- 87

- 3) (Chloromethane) 624 1.0 2.0 Methylene chloride (75

- 09

- 2) 624 5.0 10.0 1,1,2,2

- Tetrachloroethane (79

- 34

- 5) 6 24 1.9 2.0 Tetrachloroethylene (127

- 18

- 4) 624 1.0 2.0 Toulene (108

- 88

- 3) 624 1.0 2.0 1,2

- Trans

- Dichloroethylene (156

- 60

- 5) (Ethylene dichloride) 624 1.0 2.0

1,1,1

- Trichloroethane (71

- 55

- 6) 624 1.0 2.0 1,1,2

- Trichloroethane (79

- 00

- 5) 624 1.0 2.0 Trichloroethylene (79

- 01

- 6) 624 1.0 2.0 Vinyl chloride (75

- 01

- 4) 624/SM6200B 1.0 2.0 ACID COMPOUNDS
2

- Chlorophenol (95

- 57

- 8) 625 1.0 2.0 2,4

- Dichlorophenol (120

- 83

- 2) 625 0.5 1.0 2,4

- Dimethylphenol (105

- 67

- 9) 625 0.5 1.0 4,6

- dinitro

- o

- cresol ( 534

- 52

- 1) (2

- methyl

- 4,6,

- dinitrophenol) 625/1625B 1.0 2.0

2,4 dinitrophenol (51

- 28

- 5) 625 1.0 2.0
2

- Nitrophenol (88

- 75

- 5) 625 0.5 1.0
4

- nitrophenol (100

- 02

- 7) 625 0.5 1.0
Parachlorometa cresol (59

- 50

- 7) (4

- chloro

- 3

- methylphenol) 625 1.0 2.0

Pen tachlorophenol (87

- 86

- 5) 625 0.5 1.0 Phenol (108

- 95

- 2) 625 2.0 4.0 2,4,6

- Trichlorophenol (88

- 06

- 2) 625 2.0 4.0 BASE/NEUTRAL COMPOUNDS (compounds in bold are Ecology PBTs) Acenaphthene (83

- 32

- 9) 625 0.2 0.4 Acenapht h ylene (208

- 96

- 8) 625 0.3 0.6 Anthracene (120

- 12

- 7) 625 0.3 0.6 Benzidine (92

- 87

- 5) 625 12 24 Benzyl butyl phthalate (85

- 68

- 7) 625 0.3 0.6 Benzo( a )anthracene (56

- 55

- 3) 625 0.3 0.6 Benzo(b)fluoranthene ( 3,4

- benzofluoranthene ) (205

- 99

- 2) 7 610/625 0.8 1.6

Benzo(j)fluoranthene ( 205

- 82

- 3) 7 625 0. 5 1.0 Benzo(k)fluoranthene ( 11,12

- benzofluoranthene ) (207

- 08

- 9) 7 610/625 0.8 1.6

Benzo(r,s,t)pentaphene (189

- 55

- 9) 625 0.5 1.0CHAPTER VI. WATER QUALITY

- BASED EFFLUENT LIMITS FOR SURFACE WA TERS (JULY 2008)

Permit Writer’s Manual
VI

- 58 Pollutant & CAS No. **(if available)** Recommended Analytical

Protocol Detection ( DL) 1

**μ**

**g/L unless specified**  Quantitation Level (QL) 2

**μ**

**g/L unless specified**  Benzo( a )pyrene (50

- 32

- 8) 610/625 0.5 1.0 Benzo( ghi )Perylene (191

- 24

- 2) 610/625 0.5 1.0 Bis( 2

- chloroet hoxy) methane (111

- 91

- 1) 625 5.3 21.2

Bis( 2

- chloroethyl )ether (111

- 44

- 4) 611/625 0.3 1.0 Bis( 2

- chloroisopropyl )ether ( 39638

- 32

- 9 ) 625 0.3 0.6

Bis( 2

- ethylhexyl )phthalate (117

- 81

- 7) 625 0.1 0.5
4

- Bromophenyl phenyl ether (101

- 55

- 3) 625 0.2 0.4

2

- Chl oronaphthalene (91

- 58

- 7) 625 0.3 0.6
4

- Chlorophenyl phenyl ether (7005

- 72

- 3) 625 0.3 0.5

Chrysene (218

- 01

- 9) 610/625 0.3 0.6 Dibenzo (a,j)acridine ( 224

- 42

- 0) 610M/625M 2.5 1 0. 0 Dibenzo (a,h)acridine ( 226

- 36

- 8) 610M/625M 2.5 1 0. 0 Dibenzo( a

- h )anthr acene (53

- 70

- 3 ) (1,2,5,6

- dibenzanthracene) 625 0.8 1.6

Dibenzo( a,e )pyrene (192

- 65

- 4) 610M/625M 2.5 10.0 Dibenzo( a,h )pyrene (189

- 64

- 0) 625M 2.5 10.0 3,3

- Dichlorobenzidine (91

- 94

- 1) 605/625 0.5 1.0 Diethyl phthalate (84

- 66

- 2) 625 1.9 7.6 Dimethyl ph thalate (131

- 11

- 3) 625 1.6 6.4
Di

- n

- butyl phthalate (84

- 74

- 2) 625 0.5 1.0 2,4

- dinitrotoluene (121

- 14

- 2) 609 /625 0.2 0.4 2,6

- dinitrotoluene (606

- 20

- 2) 609/625 0.2 0.4
Di

- n

- octyl phthalate (117

- 84

- 0) 625 0.3 0.6 1,2

- Diphenylhydrazine ( as Azobenzene ) ( 103

- 33

- 3 ) 1 625 B 5.0 20

Fluoranthene (206

- 44

- 0) 625 0.3 0.6 Fluorene (86

- 73

- 7) 625 0.3 0.6 Hexachlorobenzene (118

- 74

- 1) 612/625 0.3 0.6 Hexachlorobutadiene (87

- 68

- 3) 625 0.5 1.0 Hexachlorocyclopentadiene (77

- 47

- 4) 1625B/625 0.5 1.0
Hexachl oroethane (67

- 72

- 1) 625 0.5 1.0 Indeno( 1,2,3

- cd )Pyrene (193

- 39

- 5) 610/625 0.5 1.0 Isophorone (78

- 59

- 1) 625 0.5 1.0
3

- Methyl cholanthrene (56

- 49

- 5) 625 2.0 8.0CHAPTER VI. WATER QUALITY

- BASED EFFLUENT LIMITS FOR SURFACE WA TERS (JULY 2008)

Permit Writer’s Manual
VI

- 59 Pollutant & CAS No. **(if available)** Recommended Analytical

Protocol Detection ( DL) 1

**μ**

**g/L unless specified**  Quantitation Level (QL) 2

**μ**

**g/L unless specified**  Naphthalene (91

- 20

- 3) 625 0.3 0.6 Nitrobenzene (98

- 95

- 3) 625 0.5 1.0
N

- Nitrosodimethy lamine (62

- 75

- 9) 607/625 2.0 4.0
N

- Nitrosodi

- n

- propylamine (621

- 64

- 7) 607/625 0.5 1.0
N

- Nitrosodiphenylamine (86

- 30

- 6) 625 0.5 1.0 Perylene (198

- 55

- 0) 625 1.9 7.6 Phenanthrene (85

- 01

- 8) 625 0.3 0.6 Pyrene (129

- 00

- 0) 625 0.3 0.6 1,2,4

- Trichloro benzene (120

- 82

- 1) 625 0.3 0.6 PESTICIDES/PCBs Aldrin (309

- 00

- 2) 608 0.025 0.05 alpha

- BHC (319

- 84

- 6) 608 0.025 0.05
beta

- BHC (319

- 85

- 7) 608 0.025 0.05

gamma

- BHC (58

- 89

- 9) 608 0.025 0.05
delta

- BHC (319

- 86

- 8) 608 0.025 0.05 Chlordane (57

- 74

- 9) 8 608 0.025 0.05 4,4’

- DDT (50

- 29

- 3) 608 0. 025 0.05 4,4’

- DDE (72

- 55

- 9) 608 0.025 0.05 4,4’ DDD (72

- 54

- 8) 608 0.025 0.05 Dieldrin (60

- 57

- 1) 608 0.025 0.05 alpha

- Endosulfan (959

- 98

- 8) 608 0.025 0.05
beta

- Endosulfan (33213

- 65

- 9) 608 0.025 0.05
End osulfan Sulfate (1031

- 07

- 8) 608 0.025 0.05 Endrin (72

- 20

- 8) 608 0.025 0.05 Endrin Aldehyde (7421

- 93

- 4) 608 0.025 0.05 Heptachlor (76

- 44

- 8) 608 0.025 0.05 Heptachlor Epoxide (1024

- 57

- 3) 608 0.025 0.05
PCB

- 1242 (53469

- 21

- 9) 9 608 0.25 0.5
PCB

- 12 54 (11097

- 69

- 1) 608 0.25 0.5
PCB

- 1221 (11104

- 28

- 2) 608 0.25 0.5
PCB

- 1232 (11141

- 16

- 5) 608 0.25 0.5
PCB

- 1248 (12672

- 29

- 6) 608 0.25 0.5
PCB

- 1260 (11096

- 82

- 5) 608 0.13 0.5
PCB

- 1016 (12674

- 11

- 2) 9 608 0.13 0.5 Toxaphene (8001

- 35

- 2) 608 0.24 0.5CHAPTER VI. WATER QUALITY

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Permit Writer’s Manual
VI

- 60 1

. Detection level (DL) or detection limit means the minimum concentration of an analyte (substance) that can be measured and reported with a 99% confidence that the analyte concentration is greater than zero as determined by the procedure given in 40 CFR p art 136, Appendix B.
2. Quantitation Level (QL) also known as Minimum Level of Quantitation (ML)

– The lowest level at which the entire analytical system must give a recognizable signal and acceptable calibration point for the analyte. It is equivalent to the concentration of the lowest calibration standard, assuming that all method

specified sample weights, volumes, and cleanup procedures have been employed

. The QL is calculated by multiplying the MDL by 3.18 and rounding the result to the number nearest to (1,2,or 5) x 10 n , where n is an integer

. (64 FR 30417)

. ALSO GIVEN AS: The smallest detectable concentration of analyte greater than the Detection Limit (DL) where the accuracy (precision & bias) achieves the objectives of the intended purpose

. ( Rep ort of the Federal Advisory Committee on Detection and Quantitation Approaches and Uses in Clean Water Act Programs
Submitted to the US Environmental Protection Agency December 2007

.CHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

Permit Writer’s Manual
VI

- 61 

## 5

. WHOLE EFFLUENT TOXICITY (WET)

5.1 Permit Writer's Task Summary

Th is Section is a summary of how permit writers implement Chapter 173

- 205 WAC, Whole Effluent Toxicity Testing and Limits for different permitting situations

. The following subsections of 5.2 through 5.14 describe the rule and implementation processes in mo re detail

. Additional detail on test species, statistics, anomalous tests, and sampling is found in Ecology Publication WQ

- R

- 95

- 80 (Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria) which is available from agency libraries or from http ://www.ecy.wa.gov/programs/wq/wet

.

New Permits

Permit managers should:

♦ Evaluate the discharge for need for effluent characterization (See subsection 5.4.)

. ♦ Decide on species to require in the permit (See subsection 5.11.)

. ♦ Decide on the monitori ng frequency (See Chapter XIII, Section 4.)

. ♦ Decide on the use of rapid screening tests (See subsection 5.8.)

. ♦ Use model language in the permit

. ♦ Contact the PDS Section for assistance with non

- compliance or reviewing a TI/RE plan

.

Permit Renewals wi th Previous Effluent Characterization

Permit managers should:

♦ Contact the PDS Section for the WET data record (See subsection 5.14.)

. ♦ Decide if additional characterization is required (See subsection 5.4.)

. ♦ Decide if a permittee with a WET limit no longer needs that limit (See subsection 5.7.).

♦ Decide on species to require in the permit (See subsection 5.11.)

. ♦ Decide on the monitoring frequency (See Chapter XIII, Section 4.)

. ♦ Decide on the use of rapid screening tests (See subsection 5.8.)

. ♦ Use model language in the permit

. ♦ Contact the PDS Section for assistance with non

- compliance or reviewing a TI/RE plan

. 

## 5.2 Introduction

Whole effluent toxicity is the total toxicity of an effluent measured directly with a toxicity test

. WET testing is necessary because EPA cannot develop water quality criteria for every one of the thousands of toxic pollutants possibly found in wastewater discharges

. WET testing is also the only method available to permit managers for assessing the toxic interaction o f pollutants.

Chapter 173

- 205 WAC, Whole Effluent Toxicity Testing and Limits (the WET rule), became effective November 6, 1993

. The goal of the WET rule is the eventual elimination of the discharge of toxics in toxic amounts

. The WET rule establishes a procedure for deriving whole effluentCHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

Permit Writer’s Manual
VI

- 62 toxicity limits in accordance with RCW 90.48.520, 40 CFR 122.44(d), and 40 CFR 122.44(e) for inclusion into NPDES permits

. The rule implements the requirement for all known, available, and reasonable methods of preve ntion, control, and treatment of toxicants and assures the attainment of state water quality standards

.
This guidance explains WET requirements and helps readers locate WET rule sections pertinent to each issue

. It will be helpful to refer to the text of the WET rule while using this Section of the Permit Writer's Manual

. The WET rule contains the authoritative language on the WET requirements and should be consulted directly in order to make correct decisions

. This guidance directs the reader to the se ction of the WET rule applicable t o each subject discussed below.

WET testing is used in NPDES permits for the following purposes:
♦ To serve as a broad spectrum indicator of increases in effluent toxicity

. Analyzing effluents regularly for every possible toxic chemical would be expensive

. WET tests provide an assessment of the overall toxicity of every toxicant and toxicant combina ti on. ♦ To assess and limit WET to levels allowable under the state Water Quality Standards

. The state's water quality standards prohibit ambient toxicity (WAC 173

- 201A

- 040(1), WAC 173

- 201A

- 030)

. The water quality standards also establish the point of co mpliance; there is no ambient toxicity allowed past the edge of an approved mixing zone (WAC 173

- 201A

- 100)

. The main purpose of Chapter 173

- 205 WAC is to characterize effluents for WET in order to establish whether a reasonable potential exists to violate this prohibition against ambient toxicity

. If a reasonable potential exists, a permit limit is required on WET (WAC 173

- 205

- 050(2)(a))

. The WET rule also describes how to monitor for WET limits based on the prohibition against ambient toxicity outside o f approved mixing zone s (WAC 173

- 205

- 070(1) and (2)).
♦ To assess and limit WET on a technology basis

. Technology

- based limits on acute WET may be placed into permits on a case

- by

- case basis (WAC 173

- 205

- 130)

. WAC 173

-

205

- 130 does not provide for techn ology

- based WET limits for categories of dischargers or for chronic WET.

The regulatory process for WET in NPDES permits is shown in Figure VI

- 8 and Figure VI

- 9. Figure VI

- 10 illustrates the compliance process for WET

. The steps in the process in Figure VI

- 8 are described below.

1. The process begins with NPDES permit application

. The application can be for a new NPDES permit or for renewal of an existing permit

. If a previous permit required an effluent characterization, the permittee will either be at STEP 5 and STEP 6 will determine the new permit requirements or the permittee will be at STEP 7 and STEP 8 will determine the new permit requirements.

2. Section 173

- 205

- 040 of the WET rule contains a list of circumstances under which a discharge is required to be characterized for WET

. These circumstances define discharges with a risk for aquatic toxicity

. The permits for a discharge which fits any of these circumstances will contain a requirement for WET characterization

. Unless section 173

- 205

- 0 60 applies, effluent characterization will only happen once in the lifetime of a discharge

. Permits for discharges which do not fit any of the circumstances will not require WET testing

. If circumstances change so that a facility no longer has a risk for aquatic toxicity pursuant to WAC 173

- 205

- 040(1), a permit writer may make a determination in accordance with WAC 173

- 205

- 040(2)(h) to stop WET testing.CHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

Permit Writer’s Manual
VI

- 63 3. An effluent characterization usually occurs during the first year of the permit term

. Effluent cha racterization establishes the baseline toxicity level and determines the need for WET limits. Every sample during effluent characterization will be tested with all of the WET tests listed in the permit (multiple species testing).

4. The permit will requi re that the permittee determines

, at the end of effluent characterization

, whether the WET performance standards have been met for acute and chronic toxicity

. The performance standard for acute toxicity is a median of at least 80% survival in 100% effluen t with no single test showing less than 65% survival in 100% effluent

. The performance standard for chronic toxicity is no toxicity in a concentration of effluent representing the edge of the acute mixing zone

. Permittees meeting performance standards wi ll get no WET limits or compliance monitoring and go straight to STEP 7 on the diagram.

5. Those permittees not meeting a performance standard during effluent characterization will receive WET limits

. The permit will require monitoring to determine comp liance with the WET limit

. Failing to comply with a WET limit will trigger additional WET testing and possibly other enforcement actions as described in subsection 5.6 and Figure VI

- 10 below.

6. The WET rule does not intend that WET limits are permanent

. If a permittee with a WET limit meets the performance standard during compliance monitoring for a permit term, then the WET limit will not be placed into subsequent permits

. By controlling toxicity well enough to meet the performance standard, the perm ittee has allowed the limit and routine monitoring to be removed from the permit

. The permittee's cost and liability are lower.

7. Permittees who have attained the performance standards can remain indefinitely without WET limits or compliance monitoring

. The only requirement will be WET test results submitted with each permit application or rapid screening testing during the permit term

. The results of the WET tests done for permit application or routine rapid screening testing will be used to determin e if another effluent characterization is needed

. (In addition, there is a requirement in 40 CFR 122.21(j) that POTWs with design influent flows greater than or equal to 1 mgd and POTWs required to develop pretreatment programs must submit WET test result s with each permit application in Part E of the 2A permit application form.)

8. If changes have occurred that might increase toxicity , then the next permit will require a new effluent characterization in accordance with WAC 173

- 205

- 060 and start the proc ess over again at STEP 3

. WET limits could result from a new effluent characterization or the permittee could go directly back to STEP 7 with no WET limits

. If changes have occurred that decrease the chance for effluent toxicity , then the permit applicat ion should be reviewed as in STEP 2 to see if any of the risk criteria in WAC 173

- 205

- 040 still apply

. If none of the risk criteria apply, WET testing requirements can be removed from the next permit

. If any of the risk criteria still apply, the permit

s hould keep the requirement to submit a set of WET test results with the next permit application as in STEP 7 even though there is a reduced risk.CHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

Permit Writer’s Manual
VI

- 64 Figure VI

- 8. The WET implementation process.CHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

Permit Writer’s Manual
VI

- 65 Figure VI

- 9. WET requirements for permits

HAS THE APPLICANT ALREADY CHARACTERIZED EFFLUENT FOR WET? CONTINUE LIMIT AND COMPLIANCE MONITORING OR CONTINUE APPLICATION REQUIREMENT OR REMOVE REQUIREMENTS YES

DOES THE APPLICANT MEET

CRITERIA FOR

EXCLUSION? NO

NO REQUIREMENT YES

CONDUCT EFFLUENT CHARACTERIZATION

FOR ACUTE AND CHRONIC TOXICITY NO

MEET ACUTE PERFORMANCE STANDARD

OF SURVIVAL MEDIAN OF 80% WITH NONE < 65% IN 100% EFFLUENT? MEET CHRONIC PERFORMANCE OF NO CHRONIC EFFECT AT THE ACEC?

NO LIMIT, MONITORING AND

RECHARACTERIZATION IF NECESSARY YES YES

LIMIT OF NO CHRONIC EFFECTS AT THE CCEC LIMIT OF NO ACUTE EFFECTS

AT THE ACEC

MEET PERFORMANCE STANDARD FOR ONE TERM? YES NO NO

NO NO PERMIT APPLICATION

CHRONIC ACUTECHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

Permit Writer’s Manual
VI

- 66 

## 5.3 The Purpose of Effluent Characterization

Effluent characterization is used to establish whether a reasonable potential exists pursuant to 40 CFR 122.44(d)(1)(v) which would require a WET limit

. Acute and chronic WET are evaluated separately for a reasonable potential to violate the water quality standards

. Permittees who cannot meet the WET performance standards have demonstrated a reasonable potential for ambient toxicity and need WET limits (WAC 173

- 205

- 020 and in WAC 173

- 205

- 05 0(2)(a))

. Effluent characterization is also used to establish a baseline toxicity level (WAC 173

- 205

- 050(2)(b))

. The effluent characterization process lasts for one year (WAC 173

- 205

- 020 and WAC 173

- 205

- 050(1))

. During the year of effluent characterizat ion, each effluent sample is tested with all WET test species listed in the permit

. This multiple species testing provides an assessment of effluent toxicity in order to provide protection to as many different types of receiving water organisms as possibl e

. See subsection 5.11 for guidance on WET test species selection.


## 5.4 Determining the Need for Effluent Characterization

Effluent characterizations for WET are required when:

♦ A discharge has never before been characterized for WET and has one or more of the risk factors in WAC 173

- 205

- 040(1)

. These factors include the presence of hazardous substances (Table VI

- 3) at the facility which could be released to the wastewater syst em, the presence of toxic pollutants in the effluent for which there are no water quality criteria, being an industry listed in Table VI

- 4, or toxicity detected in past WET testing.
♦ A discharge that has been previously characterized for WET experiences changes in process or discharge characteristics (WAC 173

- 205

- 060(1)) and has not made the demonstration pursuant to WAC 173

- 205

- 060(2) that the changes have not increased effluent toxicity.
♦ Either a rapid screening test result during the permit term or a WET test result submitted with the permit application has shown toxicity at levels of regulatory concern (WAC 173

- 205

- 060(3)).
♦ A new WET test has been approved pursuant to WAC 173

- 205

- 050(1)(d) that would measure effluent toxicity better than the WET tests used in the original effluent characterization

. The discharge will then be characterized using only the new WET test (WAC 173

- 205

- 060(5) and (6)).

Effluent characterizations for WET are not required when:

♦ The discharge has none of the risk fac tors in WAC 173

- 205

- 040(1) and is excluded by WAC 173

- 205

- 040(2).
♦ The discharge has none of the risk factors in WAC 173

- 205

- 040(1) and the permit manager has made a determination the effluent doesn't have the potential to contain toxic substances in toxi c amounts (WAC 173

- 205

- 040(2)(h)).
♦ If the effluent receives at least 1000:1 dilution at the edge of an approved mixing zone, the chronic testing is skipped but characterization for acute toxicity is still done

. (WAC 173

- 205

- 040(3))
♦ If the permittee is monitoring for compliance with a WET limit using species rotation, additional characterizations for WET are not required (WAC 173

- 205

- 060(4)) for the type of toxicity (acute or chronic) covered by that WET limit.
♦ No additional effluent characterizati on is required for a discharge that has experienced a change if the permittee has made a demonstration that the change has not increased toxicity (WAC 173

- 205

- 060(2))

. The demonstration might include toxicity testing, chemical analysis, or both.CHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

Permit Writer’s Manual
VI

- 67 Other e ffluent characterization requirements:

♦ Characterization for WET may be delayed for existing facilities that are under a compliance schedule to implement technology

- based controls or to achieve compliance with water quality

- based effluent limits (WAC 173

- 205

- 030(4)).
♦ Unless WAC 173

- 205

- 060 applies, effluent characterizations conducted in a previous permit need not be repeated as long as the information is adequate to make all determinations in WAC 173

- 205

- 050(2) and meet the permitting requirement in WAC 173

- 205

- 030(5)(b)

. The determination s in WAC 173

- 205

- 050(2)(a) can be made as long as the results of the effluent characterization include the percent survival in 100% effluent for every acute test and the NOEC for every chronic test

. WAC 173

- 205

- 050(2)(b) also requires that an effluent cha racterization generate point estimates (LC 50 , EC 50 , etc.) to use in establishing a baseline toxicity level

. WET tests conducted for effluent characterization must be from EPA manuals (WAC 173

- 205

- 050(1)(d)) or listed in 40 CFR Part 136.
♦ The determinati on in WAC 173

- 205

- 050(2)(a)(ii) can be complicated, or perhaps even inconclusive, if the acute critical effluent concentration (ACEC) is not specified in the permit and included in the concentration series of chronic WET tests conducted for effluent charac terization.
♦ Effluent characterization may include WET tests conducted on ambient water collected downstream of the discharge or using ambient water collected upstream of the discharge as dilution water (WAC 173

- 205

- 030(6))

. Testing downstream samples has already be en done in one permit and has withstood challenge in front of the Pollution Control Hearings Board (PCHB).


## 5.5 Determining Compliance with WET Limits

SPECIES ROTATION. Because changes in an effluent can change the relative sensitivity of the WET test spe cies listed in the permit, species will be rotated during compliance monitoring

. The rotation schedule need not have an equal testing frequency for all of the species

. If one species was clearly the most sensitive during effluent characterization, then t he rotation schedule should use the most sensitive species for all monitoring

. The model permit language allows Ecology to notify a permittee of the rotation schedule

. If the rotation schedule is not specified by Ecology, then the permit language directs the permittee to test the species in the order listed in the permit.

ACUTE WET LIMITS. Compliance with an acute WET limit requires a demonstration of no acute toxicity in a concentration of effluent equal to the acute critical effluent concentration (AC EC)(WAC 173

- 205

- 070(1))

. The ACEC is defined as the maximum concentration of effluent during critical conditions at the boundary of the zone of acute criteria exceedance (WAC 173

- 205

- 020)

. A demonstration of no acute toxicity at the ACEC means that the ef fluent is not at a concentration above acute toxicity thresholds outside of the zone of acute criteria exceedance.

CHRONIC WET LIMITS. Compliance with a chronic WET limit requires a demonstration of no chronic toxicity in a concentration of effluent equa l to the chronic critical effluent concentration (CCEC) (WAC 173

- 205

- 070(2))

. The CCEC is defined as the maximum concentration of effluent during critical conditions at the boundary of the mixing zone (WAC 173

- 205

- 020)

. A demonstration of no chronic toxi city at the CCEC means that the effluent is not at a concentration above chronic toxicity thresholds outside of the mixing zone.

STATISTICALLY SIGNIFICANT DIFFERENCES IN RESPONSE. The scientifically valid way to make a demonstration of no toxicity is to demonstrate that the ACEC or the CCEC in a WET test has no statistically significant difference in organism response from the control

. The control isCHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

Permit Writer’s Manual
VI

- 68 laboratory water that is known to be nontoxic to test organisms

. If there is a statistically significant difference in response between the ACEC or CCEC and the control, then toxicity has been demonstrated

. If there is no statistically significant difference in response, then it can be assumed that there is no toxicity at the ACEC or CCEC and that the permi ttee has complied with the performance standard or the WET limit.

HYPOTHESIS TESTING. Statistical significance means that the difference in response between a control and the ACEC or CCEC is likely to be due to toxicity and not to test variability

. The statistical technique for making this determination is a hypothesis test

. A hypothesis test compares the average response of the replicates of the ACEC or CCEC to the average response of the control replicates in order to determine if there is a statistic ally significant difference in response at some level of confidence such as 95%

. There is a 5% chance for some test results at the 95% level of confidence that a difference will be due to chance and not toxicity

. There is a 1% chance for some test result s at the 99% level of confidence that a difference will be due to chance and not toxicity

. Differences due to chance are called false positives or Type I errors.

FALSE POSITIVE TEST RESULTS. When a statistically significant difference in response is due to test variability and not to toxicity, the WET test has produced a false positive result

. However, a confidence level of 95% does not mean that 1 in 20 (5%) of failed WET tests is a false positive

. The confidence level only approximates the worst case false positive rate which exists when the two values being compared are relatively close together

. The further apart these values are, the less likely are false positive results

. In other words, if all of the organisms in the ACEC die and none die in th e control, the probability that the statistically significant difference in response is a false positive is closer to 0 than 1 in 20

. The overall false positive rate is less than 1 in 20 and is almost always less than the overall false negative rate

. To prevent most false positive test results, the model permit language raises the confidence level to 99% when the differences in response are small.

DEFINITION OF INVALID TESTS AND ANOMALOUS TEST RESULTS. Invalid WET tests occur when the lab does not follo w the test method or when the results do not meet the validation criteria in the test method

. Permittees are obligated to assure that all tests are valid because the permit requires that only the results of valid tests be submitted

. The Program Developme nt Services Section reviews WET test results to see that they are based on valid tests.

Anomalous test results happen when the lab appears to have conducted the WET test in accordance with the test method, but the results are unreliable according to revi ew criteria

. There is no requirement for Permittees to attempt to identify anomalous WET test results

. All valid WET test results must be submitted whether anomalous or not

. See subsection 5.10.2 for a discussion of permittee identification of anomalous test results.

The Program Development Services Section will be reviewing WET test results and screening out anomalous test results

. Anomalous test results will not be used for compliance determinations (WAC 173

- 205

- 070(5)(c))

. Most anomalous test resu lts will be identified by the lack of a good concentration

- response relationship

. If the toxic response does not increase as the concentration of effluent increases, then the test is considered to be anomalous in most cases

. Permittees will usually be re quired to take another sample and repeat the WET test when results are anomalous.

FALSE NEGATIVE TEST RESULTS AND THE POWER STANDARDS. Sometimes variability across replicates will prevent a large difference in response (in other words, a toxic effluent) from being detected as statistically significant

. False negatives happen easily when the number of replicates isCHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

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- 69 low and the lab is not careful in conducting the WET test

. Chapter 173

- 205 WAC handles false negatives through the establishment of power sta ndards

. Several parts of the WET rule require that toxicity tests meet the power standards (WAC 173

- 205

- 050(1)(f)(ii), WAC 173

- 205

- 050(2)(a)(iii)(A), WAC 173

- 205

- 070(4), and WAC 173

- 205

- 120(2)(c))

. The acute statistical power standard and the chronic sta tistical power standard are defined in WAC 173

- 205

- 020

. The acute statistical power standard says that acute toxicity tests must be able to detect a minimum of a 30% difference in survival between the ACEC and a control as statistically significant

. The chronic statistical power standard says that chronic toxicity tests must be able to detect a minimum of a 40% difference in response between the ACEC or CCEC and a control as statistically significant

. If a WET test does not meet the appropriate statistic al power standard, then the permittee will be required to immediately resample the effluent and repeat the toxicity test with the number of replicates increased in order to meet the statistical power standard.


## 5.6 Noncompliance, Transient Toxicity Reports , and TI/RE Plans

ADDITIONAL TESTING AND TRANSIENT TOXICITY REPORTS

. ( Figure VI

- 10). When a permittee fails a routine compliance test for a WET limit, then additional testing is immediately required to assess and confirm the continuing presence of toxicit y (WAC 173

- 205

- 090(1))

. WET testing of 4 additional weekly samples are required following noncompliance with an acute WET limit and 3 additional monthly samples following noncompliance with a chronic WET limit (WAC 173

- 205

- 090(1))

. If only the routine co mpliance test is failed, then the permittee is required to prepare a transient toxicity report on the possible causes and prevention of the toxicity

. Compliance with the permit limit is restored with the first additional sample that passes the compliance test

. Compliance with all WET testing provisions of the permit is accomplished by passing all of the additional testing following a routine compliance test failure and submitting an acceptable transient toxicity report

. The contents of a transient toxici ty report are described in WAC 173

- 205

- 100(1).

TI/RE PLANS. If any toxicity test fails the compliance test during the additional monitoring, then the permittee must submit a TI/RE plan to Ecology within sixty days of the last additional sample (WAC 173

- 2 05

- 100(2))

. The TI/RE plan will be based on procedures in the latest versions of the EPA guidance documents for conducting toxicity reduction evaluations or toxicity identification evaluations (WAC 173

- 205

- 100(2)(b))

. However, the TI/RE plan need not inc lude any procedure from the EPA manuals that is not necessary to the goal of controlling the discharge of WET by the permittee (WAC 173

- 205

- 100(2)(b)(i))

. Ecology may approve any modifications or additions to the EPA procedures that will improve the abili ty to identify or reduce toxicity (WAC 173

- 205

- 100(2)(b)(ii))

. The permittee is required to implement the TI/RE plan immediately upon notification by Ecology of plan approval (WAC 173

- 205

- 100(3))

. Model permit language specifies an administrative order a s the means to notify a permittee to implement a TI/RE

. The Program Development Services Section will assist in reviewing TI/RE plans and in writing administrative orders to implement TI/RE plans.CHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

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- 70 Figure VI

- 10 Compliance Process for WET

Testing as specified in the permit for acute and chronic toxicity

Meet performance standards ?

Meet effluent limits ? Consider removal of requirements after one permit term of compliance

Does permittee

acknowledge effluent is toxic ? Increased WET

testing to 4 weekly acute and 3 monthly chronic Prepare TI / RE plan and submit to Ecology

Does toxicity occur again ?

Prepare transient

toxicity report and submit to Ecology

Resume monitoring Is reduction effort successful ? 2 to 6 months to confirm and eliminate source of

toxicity

Implement TI / RE plan Is there an apparent source of toxicity ? yes

yes

yes

yes

yes yes no

no

no

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## 5.7 Removal of WET Limits

A WET limit is eligible for removal upon permit renewal if the permittee has demonstrated compliance with the WET performance standard associated with that limit for at least the last three consecutive t est years following effluent characterization or for an entire subsequent permit term, and has not made any changes within the last three years which would otherwise require additional effluent characterization (WAC 173

- 205

- 120(1)). Removing a WET limit u nder this provision of Chapter 173

- 205 WAC is a good idea for the following reasons:

♦ It protects the environment. Concentration

- response curves are steep and toxicity decreases rapidly with dilution

. As a consequence, toxicity is often undetectable at the ACEC or CCEC

. This means that WET limits will be easily met by most dischargers

. However, when the concentration of toxic chemicals increases in the effluent, then toxicity increases quickly

. Toxicity (especially acute toxicity) tends to behave as if there was a threshold where one side is safe and the other side is lethal to aquatic organisms

. A larger margin of safety is a good idea under these circumstances

. Offering to remove these WET limits provides a strong incentive to do more to control toxicity than is required to meet the water quality standards

. The performance standards provide a margin of safety for the environment and move toward the goal of RCW 90.48.520.
♦ It is fair. Other permittees conducted a similar or smaller amount of WET testing during effluent characterization and did not receive a WET limit in the first place

. If a permittee can meet the same performance standard measured with at least as much WET testing over a longer period of time as other permittees who received no WET limits did, then that permittee also has no reasonable potential to violate the water quality standards.
♦ It fits into the system for regulating WET in Chapter 173

- 205 WAC. Chapter 173

- 205 WAC recognizes that the evaluation of WET is an ongoing process that encompasses more than just dividing permittees into two groups: those with WET limits and those withou t WET limits

. Chapter 173

- 205 WAC also has provisions for rapid screening tests, for additional effluent characterizations, for permittee evaluations of facility changes, and for technology

- based acute WET limits

. All of these provisions are enhanced by or dependant on WET limit removal.


## 5.8 Determining the Need for Rapid Screening Tests

RAPID SCREENING TESTS. A rapid screening test is a screening toxicity test on one hundred percent effluent or some other high concentration of effluent in order to dete ct unanticipated increases in toxicity

. Examples of rapid screening tests include twenty

- four hour EPA acute tests, acute toxicity tests using rotifers produced from cysts, bacterial bioluminescence tests (Microtox®), and two

- day life cycle tests with rot ifers

. See subsection 5.12 for guidance on rapid screening test selection.

RAPID SCREENING TESTS WHEN WET LIMITS ARE NOT ASSIGNED OR ARE REMOVED. Permit managers may condition the nonassignment of a WET limit with a requirement for routine monitoring wi th a rapid screening test (WAC 173

- 205

- 120(2))

. A permit manager must place rapid screening tests into a permit if there is the potential for an event at the facility which could result in a toxic discharge that would otherwise go unnoticed (WAC 173

- 205

- 1 20(2)(a)(ii))

. The permit manager should consider the potential for treatment system upsets, control equipment failures, spills, accidental releases to the wastewater system, or any other event which could result in a toxic discharge

. If a permittee refu ses to accept rapid screening tests in the permit, leave the WET limit inCHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

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- 72 place

. Chemical monitoring may also be required to assess increases in effluent toxicity when adequate for that purpose.

RAPID SCREENING TESTS AND ADDITIONAL EFFLUENT CHARACTERIZA TIONS. Rapid screening testing can be beneficial for the permit manager and the permittee

. Toxicity caused by a facility change can be determined if a permittee is routinely doing rapid screening tests with a known sensitivity relative to the regular WET tests

. Additional effluent characterizations are then
unnecessary.

THE RESULT OF RAPID SCREENING TESTING. Whenever a rapid screening test is failed, the permittee must immediately retest with all of the acute or chronic toxicity tests used in the last p ermit with WET (WAC 173

- 205

- 120(2)(d))

. Toxicity detected by a rapid screening test must be confirmed by the traditional EPA WET tests

. The results of these acute or chronic toxicity tests conducted in response to a rapid screening test will be evaluated to determine the need for a new WET characterization in the next permit or the need for immediate administrative orders to implement the regulatory process which begins in WAC 173

- 205

- 090.

OTHER USES OF RAPID SCREENING TESTS. Rapid screening tests may b e required of any permittee (WAC 173

- 205

- 030(5))

. This means that, in addition to evaluating changes in the toxicity of discharges which have no WET limits, rapid screening tests can be used during effluent characterization to develop a correlation with t he WET tests or in a permit with WET limits to raise the monitoring frequency

. Compliance with WET limits is never measured with a rapid screening test

. They can be required at a higher monitoring frequency than the WET tests and are used to trigger the WET tests when needed.


## 5.9 Technology

- Based WET Limits

PROCESS. A permit manager may place the WET performance standard for acute toxicity into permits as a limit on a case

- by

- case basis pursuant to 40 CFR 125.3(d)(3) (WAC 173

- 205

- 130(2))

. 40 CFR 125.3(d )(3) contains the list of factors which must be considered in setting case

- by

- case BAT limits

. There are six of these site

- specific factors

. These include: the age of equipment, the process employed at the facility, changes to the process required to mee t the performance

- based limit, engineering aspects of the control techniques, and the cost of achieving the performance

- based limit

. These considerations require the assistance of the Program Development Services Section.

TIMING. The performance

- based a cute toxicity limit in WAC 173

- 205

- 130(2) will not be automatically applied to all permittees in a category, but will only be imposed on a case

- by

- case basis after several years have passed during which permittees are encouraged to meet the performance sta ndards solely through the incentive of offering to remove WET limits and compliance monitoring from the permit

. The determination to impose a performance

- based WET limit will not occur until after a water quality

- based acute WET limit has been assigned, a fter at least one permit term of monitoring for compliance with the water quality

- based WET limit, after a similar permittee has met the acute toxicity performance standard, and after consideration of the site

- specific factors listed in 40 CFR 125.3(d)(3)

. Because these steps must occur before the determination is made to impose a performance

- based limit, the delay will be at least five years before such a limit is placed in a permit unless such a limit was already in place before Chapter 173

- 205 WAC becam e effective.CHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

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## 5.10 Options for Permittees

5.10.1 Conducting WET Tests
There are three options for permittees:

♦ Permittees may conduct toxicity tests using a full dilution series (WAC 173

- 205

- 030(9))

. A full dilution series would protect the permitte e by allowing anomalous test results to be identified by examining the concentration

- response relationship

. It also allows our database to contain a better record of baseline effluent toxicity, compare the toxicity of different discharges, and evaluate th e response of different WET tests.
♦ A permit manager may approve the request of a POTW discharging less than 0.5 mgd or a small business as defined in RCW 43.31.025(4) to conduct WET testing as effluent screening tests using 100% effluent for the acute toxicity tests and the ACEC for the c hronic toxicity tests (WAC 173

- 205

- 050(1)(f))

. A small business is defined as a business entity which is owned and operated independently from all other businesses, which has the purpose of making a profit, and which has 50 or fewer employees (RCW 43.31.0 25)

. Effluent screening tests are WET tests that are conducted as a screen for toxicity in 100% effluent (acute tests) or the ACEC (chronic tests)

. No other effluent concentrations (except the control) are tested until toxicity has been detected in the e ffluent screening

test

. This saves the permittee money as long as the effluent is nontoxic

. The effluent screening tests are about two

- thirds to one

- half the cost of a full dilution WET test

. However, since the quality of the information is lower and re peating tests ends up being more expensive, it would be best to limit this option to dischargers that are likely to be nontoxic.
♦ The WET rule requires that samples, dilution water, and test solutions be handled as specified in the test method or the permit (WAC 173

- 205

- 080(1)

. Permittees who received permit language which is not consistent with the test method, Ecology Publicatio n WQ

- R

- 95

- 80 (Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria), or model permit language may request approval of alternative samples, dilution water, or test solutions (WAC 173

- 205

- 080(1)(c)).



### 5.10.2 Notification of an Anomalous Test Result
Ecology will be reviewing WET test results to see if these results are anomalous and should not be used for compliance determinations (WAC 173

- 205

- 070(5)(b))

. Examples of anomalous WET test results include tests with a lower toxic response at high er effluent concentrations or a concentration

response which has no slope

. A review for these kinds of WET test results will protect permittees from the consequences of noncompliance with a WET limit when the WET test itself was responsible for the appear ance of noncompliance.

If the permittee believes that a compliance test failure will be identified by Ecology as an anomalous test result, the permittee may send Ecology notification with the compliance test result that the compliance test result might b e anomalous and that the permittee intends to take only one additional sample for toxicity testing and wait for notification from Ecology before completing the additional monitoring required in WAC 173

- 205

- 090(1)

. The notification must identify the reason for considering the compliance test result to be anomalous

. Our definitions of anomalous tests are published in Ecology Publication WQ

- R

- 95

- 80 (Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria)

. The permittee must complete all of the additional monitoring required by WAC 173

- 205

- 090(1) as soon as possible after notification by Ecology that the compliance test result was not anomalous

. Ecology will review all compliance test results to determine if they areCHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

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- 74 anomalous regardless of whe ther or not they are accompanied by permittee notification that they may be anomalous.


### 5.10.3 Conducting a TI/RE
There are three options for permittees:
♦ A permittee may proceed directly to a TI/RE and not perform the additional testing (WAC 173

- 205

- 090(4))

. Permittees that choose this option save themselves the expense of the additional monitoring and lessen the time between first detecting WET in exces s of a limit and taking action to achieve compliance.
♦ If any WET test fails the compliance test during the additional monitoring conducted in accordance with WAC 173

- 205

- 090(1), then the permittee shall submit a plan for a TI/RE (WAC 173

- 205

- 100(2))

. A s a part of this plan, the permittee may request that Ecology allow up to six months before beginning the TI/RE for facility personnel to attempt to control the most likely sources of toxicity through efforts such as changes in plant operation, replacement of a toxic material used in the facility, or improvement of best management practices (WAC 173

- 205

- 100(2)(a))

. Ecology approves the request in writing, and if the attempt is successful, then the permittee and Ecology are saved the time and expense of TI/ RE plan review and implementation

. However, since time and effort will be wasted if the attempt is unsuccessful, requests should only be approved for attempts that have a good chance of success.
♦ Ecology may approve the interruption of a TI/RE if toxici ty has disappeared (WAC 173

- 205

- 110(1))

. The permittee then returns to the routine monitoring schedule and takes enough extra sample each time to begin a TI/RE if the effluent fails the compliance test

. If toxicity testing shows compliance with WET limit s for one year after interruption of the TI/RE, then the permittee may cease taking the extra sample (WAC 173

- 205

- 110(2))

. The approval letter for the TI/RE interruption should inform the permittee of the option to cease taking the extra sample after one year of compliance.


## 5.11 Species Selection for WET Testing

5.11.1 Acute WET Test Species
Selecting acute WET test species is fairly simple

. Effluents with a risk for aquatic toxicity are tested at a minimum for toxicity to a fish, an invertebrate, and any appropriate plant (WAC 173

- 205

- 050(1)(a))

. Because EPA has not provided any test for acute toxicity to plants, effluents can only be tested for acute toxicity using a fish and an invertebrate

. If the effluent itself is freshwater, freshwater species are generally used for acute WET testing

. Freshwater WET tests are more readily available and more convenient for TI/REs

. The saltwater and freshwater acute WET tests do not differ significantly in sensitivity

. However, discharges to saltwater of low ha rdness (< 50 mg/L) freshwater might be best tested using acute tests with saltwater organisms

. Contact the Program Development Services Section if you want permit language for using acute tests with saltwater organisms

.

CHOICE OF INVERTEBRATE. Daphnids are the standard freshwater invertebrate test organisms

. The permittee or lab may choose the most convenient species ( Daphnia pulex

, Daphnia magna , or Ceriodaphnia dubia )

. The sensitivity to toxicity of these species is similar

. WAC 173

- 205

- 050(1)(c)

r equires daphnid (or mysid) acute tests to be 48 hours in duration.CHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

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- 75 CHOICE OF FISH. WAC 173

- 205

- 050(1)(c) requires fish acute tests to be 96 hours in duration

. Fathead minnow are recommended for acute WET testing for several reasons

. Fathead minnows are sensitive test organisms; they were more sensitive than rainbow trout tested using the DOE 80

- 12 procedure

. EPA has developed the freshwater WET testing program around the use of fathead minnows for fish testing

. More labs around the country have experie nce with fathead minnow WET testing or fathead minnow toxicity identification/reduction evaluations (TI/REs) than any other fish

. The national experience with fathead minnow TI/REs is much more extensive than with rainbow

trout.

TI/REs will be more diff icult and expensive with rainbow trout

. The volume of effluent that must be sampled, shipped, and fractionated is much larger for a rainbow trout WET test or TI/RE than it is for fathead minnow

. EPA protocols require about 20 times the volume of effluent for rainbow trout testing than fathead minnow testing

. For example, it might require 5 liters of effluent for a fathead minnow TI/RE and 100 liters for a rainbow trout TI/RE

. Taking a representative sample of 100 liters of effluent, shipping it, and per forming the chemical manipulations required in a TI/RE will be more difficult and expensive to accomplish than it would be with 5 liters of effluent.

If you have decided to require acute WET testing with rainbow trout in order to provide direct protectio n of salmonids, it is recommended that you also require fathead minnow testing so that any TI/RE can be performed with fathead minnow

. Each sample during effluent characterization will be tested using both of the fish and this information can be used to g uide the fathead minnow TI/RE so that it also protects rainbow trout.

ACUTE TESTING OF SALINE EFFLUENTS. If the effluent is too saline for freshwater organisms, contact the Program Development Services Section to discuss acute WET tests with saltwater

or ganisms.


### 5.11.2 Chronic WET Test Species
Unlike the situation with acute WET testing, permits for discharges to freshwater should have requirements for freshwater chronic WET tests, and permits for discharges to saltwater or brackish water should have re quirements for saltwater chronic WET tests

. Exceptions to this recommendation are allowable but should be discussed with the Program Development Services Section

. Ecology Publication WQ

- R

- 95

- 80 (Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria) has important extra detail on the chronic tests and their sublethal endpoints such as development, biomass, growth, reproduction, intrinsic rate of population increase, germination, etc

. It also describes in detail the new supplemental chronic tests described below in subsection 5.11.3.

FRESHWATER CHRONIC WET TEST SPECIES. Chronic WET test species selection is fairly simple for discharges to freshwater

. EPA recommends testing with a fish, an invertebrate, and a plant and has provided only one of each for freshwater chronic WET testing (fathead minnow, Ceriodaphnia

, and Selenastrum )

. The new species name for Selenastrum is Pseudokirchneriella subcapitata

. Effluents with a risk for aquatic toxicity should be tested for toxicity to a fish, an in vertebrate, and if appropriate, a plant (WAC 173

- 205

- 050(1)(a)).

The WET Rule required testing with a plant only when deemed appropriate because the plant tests available in the early 1990s had deficiencies

. Most of these deficiencies have now been reso lved by improvements in the Selenastrum test and by inclusion in the EPA west coast manual of a good kelpCHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

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- 76 test

. If you have the slightest suspicion that an effluent might be toxic to plants, use the model permit language that requires these plant tests.

SALTWATER CHRONIC WET TEST SPECIES. The selection of chronic WET test species for discharges to saltwater is complex for two main reasons:

♦ The reproduction of multicellular organisms in a marine environment usually begins with broadcast fertilization resulting in very small embryos and larvae which drift with the plankton

. These early life stages of marine organisms are very sensitive to toxicity, and are part of the life cycle of most marine organisms including examples such as oysters, kelp, halibut , and crab

. EPA has provided a larger list of chronic WET tests for protecting marine waters so effects on these sensitive early life stages could be assessed.
♦ The transition to west coast organisms is complete except for the mysid

. The mysid in the EPA west coast manual cannot be cultured and must be caught in the wild for use in toxicity testing

. Wild

- caught organisms are less readily available, more expens ive, and have an uncertain history

. The east coast mysid is one of the more reliable test organisms and has been retained in the model permit language

. All other saltwater test species are from the west coast manual.

Standard Fish and Invertebrate Top smelt ( Atherinops affinis ) and east coast mysid ( Americamysis bahia ) The chronic WET tests with these two species should be included in all permits for discharges to saltwater

. The level of protection provided by these two tests is similar to the protecti on provided by the freshwater chronic tests

. The mysid test is an excellent test

. When EPA studied the toxicity of 13 effluents from a wide variety of sources, they found the Americamysis bahia test to be the most sensitive of the tests in the marine chr onic toxicity test manual 31% of the time

. Another study found the Americamysis bahia test to be 42

- times more sensitive than the average fish and crustacean in EPA's database of toxicity test results used in the development of the marine water quality cr iteria

. When the minnow and mysid provide less than adequate protection, the permit should also contain a fertilization test, an embryo

- larval development test, or the kelp germination and growth test

. Permits containing WET testing requirements for only the fish and mysid meet the minimum requirement of WAC 173

- 205

- 050(1)(a).

Bivalve Embryo

- Larval Survival and Development Test Pacific oyster ( Crassostrea gigas ) or blue mussel ( Mytilus sp. ) The bivalve embryo

- larval development test is recommended for discharges to ecosystems of special importance or fragility

. Put this chronic WET test into a permit along with the standard fish and invertebrate test when there is a risk of toxicity to sensitive larval life

- stages of marine organisms

. This test is es pecially appropriate for discharges to areas where mollusks are being cultivated or for discharges to breeding grounds for important marine organisms

. This chronic WET test is often the most sensitive of all the tests, except to polycyclic aromatic hydroc arbons (PAHs).

Echinoderm Embryo

- Larval Survival and Development Test Sea urchin ( Strongylocentrotus purpuratus ) or sand dollar ( Dendraster excentricus ) Put this chronic WET test into a permit along with the standard fish and invertebrate test when the re is a risk of toxicity to sensitive larval life

- stages of marine organisms

. This chronic WET test is the most sensitive test to polycyclic aromatic hydrocarbons (PAHs)

. If an effluent contains PAHs and is discharged to a marine ecosystem of special imp ortance or fragility, then the echinoderm development test should be required.CHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

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- 77 Echinoderm Fertilization Test Sea urchin ( Strongylocentrotus purpuratus ) or sand dollar ( Dendraster excentricus ) The echinoderm fertilization test has some advantages over th e other WET tests

. The combination of high sensitivity and short duration (forty minutes) is unique to this test

. Very small volumes of effluent can be tested successfully and one spawning yields enough material for many tests

. TI/REs with the echinoder m fertilization test are likely to be more convenient and successful than with other WET tests because of these advantages

. The echinoderm fertilization test is an excellent rapid screening test

. It is recommended that permit managers require the echinod erm fertilization test when both high sensitivity and ease of use are important.

Kelp Germination and Growth Test Giant kelp ( Macrocystis pyrifera ) If the discharge is to an area with kelp beds, water shallow enough to admit sunlight, or to a rocky

are a that should be capable of supporting kelp, then the kelp germination and growth test should be considered

. This plant test is a sensitive and reliable test.


### 5.11.3 Supplemental Chronic WET Test Species
The Environment Canada Trout Embryo Viability and EPA Rainbow Trout 7

- day Survival and Growth test methods are used in the evaluation of stormwater treatment chemicals and can be used in permits

. The trout embryo test has withstood challenge in front of the PCHB

. Because they do not qualify under WAC 1 73

- 205

- 050(1)(d), they cannot be used for effluent characterization or monitoring for compliance with any WET limit

. They can be used in permits as monitoring tools for effluents or receiving waters and trigger TI/REs if needed

. The TI/RE requirement has also withstood PCHB challenge

. Contact the PDS Section if you want advice or permit language for these two trout tests.

Three Pacific herring ( Clupea pallasi ) toxicity tests have been developed for us at the Shannon Point Marine Center (SPMC) of Wester n Washington University

. The three tests are a 16

- day (7

- day toxicant exposure) embryo development test, a 4

- day acute test with yolk sac larvae, and a 7

- day larval survival and growth test

. These methods do not meet the conditions in WAC 173

- 205

- 050(1)( d) and cannot be used for compliance monitoring but have been put into several permits in order to assess the potential impacts of wastewater on the early life stages of Pacific herring

. The herring tests are also used in the evaluation of ballast water b iocides

. Contact the PDS Section if you want advice or permit language for any of these herring tests.



## 5.12 Rapid Screening Test Selection

5.12.1 Acute Rapid Screening Tests

Rotifer, Brachionus sp. (ASTM E 1440

- 91)

. This test is a 24

- hr acute test us ing rotifers hatched from cysts

. Tests with organisms hatched from cysts are less expensive because no time or materials are consumed by maintaining a culture

. This rotifer test is common in Europe and is accepted by ASTM

. The rotifer test is a sensitiv e test (except to insecticides) and can be used in freshwater or saltwater

.CHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

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- 78 24

- hr EPA screening tests

. If the permittee is uncomfortable with the rotifer test, you might consider the EPA 24

- hr screening tests instead of the rotifer

. The 24

- hr EPA acut e tests are conducted using the same EPA manual and species that were used for effluent characterization.



### 5.12.2 Chronic Rapid Screening Tests
Bacterial bioluminescence test (Microtox® or approved alternate). Microtox® can screen more than one effluent sample at a time

. The ability to test samples from several permittees at one time will lower the cost of Microtox®

. Microtox® is a relatively inexpensive test and an economy of scale within any lab which tests frequent samples will bring the cost down ev en lower

. This low cost will allow very high monitoring frequencies if necessary to catch episodes of effluent toxicity.

Snell, Terry W. 1992. A 2

- d Life Cycle Test With The Rotifer Brachionus calyciflorus

. Environ. Toxicol. Chem. 11:1249

- 1257. The ch ronic rotifer test has good ecological relevance

. The rotifer test measures the intrinsic rate of population increase

. Measuring the intrinsic rate of population increase simultaneously assesses both mortality and reproduction

. The chronic rotifer test is as ecologically relevant as any EPA chronic tests and about as sensitive as the Ceriodaphnia chronic test

. Because it starts with rotifer cysts, uses small volumes of effluent, and only takes two days, it will be less expensive than EPA chronic tests

. The rotifer test may not be sensitive to insecticides.

Echinoderm Fertilization Test The combination of high sensitivity and short duration (40 minutes) is unique

. Very small volumes of effluent can be tested successfully

. Because the echinoderm fert ilization test uses the same test protocol whether conducted for effluent characterization, compliance monitoring, or rapid screening, it is especially useful

. It would be a very good rapid screening test.


## 5.13 Samples for WET Testing

5.13.1 Advantages o f Grab Samples
The toxicity of an effluent sample begins changing at the time of sampling

. Often the toxicity decreases, but it can also increase

. These changes continue throughout the holding time

. Composite sampling lengthens the holding time by 24 h ours and allows more changes in toxicity to occur

. In addition, composite samplers contain a large amount of surface area which enhances toxicant adsorption or reaction

. Composite samplers must be cleaned frequently to prevent toxicant adsorption or reac tion and the growth of bacteria which can infect the test organisms

. The compositing process increases the opportunity for the escape of volatile toxicants

. Changes in dissolved gases during compositing cause changes in pH which ultimately affect the che mistry and toxicity of the sample.

Properly taken grab samples minimize changes in chemistry and provide the most accurate measurement of toxicity

. Grab samples can be taken quickly with a minimum of equipment, sealed in a container with no void space, cooled to 4o C, and sent directly to the lab for testing.CHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

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- 79 

### 5.13.2 Advantages of Composite Samples
If toxicity varies unpredictably during a day, grab samples will not be representative unless the monitoring frequency is increased to compensate

. (If toxi city varies over a time period longer than a day or produces a huge peak of toxicity for only a few hours out of twenty

- four, then 24

- hr composite sampling will also not be representative.) In addition, permittees can sometimes deliberately schedule grab s ampling for times of day when the effluent is less likely to be toxic. 24

- hr composites usually provide a representative sample of effluent toxicity

. The toxicity highs and lows over a day are all represented in the sample

. Composite samples are sometim es more difficult for permittees to schedule for times predicted to have low toxicity.


### 5.13.3 Recommended Sampling Technique
If the effluent chemistry or toxicity is consistent over time, use grab samples

. If sampling can be scheduled for times of typic al or peak effluent toxicity, use grab samples.
If grab samples will not be representative of effluent toxicity, use 24

- hr composite sampling.


### 5.13.4 Sampling Chlorinated Effluents

For all chlorinated effluents, review WAC 173

- 205

- 080 to determine whethe r to test unmodified final effluent, test dechlorinated final effluent, or test a sample taken just prior to the chlorinator

. Samples for WET should be taken before the chlorinator for discharges which can meet water quality

- based effluent limits for chlo rine and have an ACEC below 25% effluent

. If the ACEC is 25% effluent or higher, the effluent is sampled after the chlorinator because extra control on chlorine is needed due to the effluent

- dominated receiving water

. If the treatment plant will begin de chlorination within two years, then the sample may be dechlorinated at the lab.


### 5.13.5 Low Hardness Samples
Model permit language now contains an option to allow dischargers of low hardness (< 50 mg/L) effluent to sample receiving water at the same time and instruct the lab to increase the hardness of the effluent sample to match the hardness of the receiving water sample prior to beginning the toxicity

test

. If hardness is significantly lower in a sample than in the receiving water, metals toxicity in t he test will be significantly greater than in the environment

. Low hardness by itself might reduce Ceriodaphnia reproduction or increase sporadic mortalities due to disease in fathead minnows. The use of a low hardness sample will produce a hardness gradi ent in the test concentrations with hardness declining as effluent concentration increases and make it difficult to screen for adverse effects due to low hardness

. In other words, adverse effects due to the hardness gradient will mimic toxicity.

If you are managing a permit that does not yet have the language allowing low hardness samples to have hardness increased to match the receiving water, the permit likely says to “test an unmodified sample of final effluent.” Keep in mind that effluent samples fro m discharges to saltwater have always had salinity increased to about 30‰ to avoid adverse effects due to a declining salinity gradient across test concentrations even though the permit said to test an unmodified effluent sample

. Therefore, it is probably OK to allow any discharger of low hardness effluent to adjust the hardness to match the receiving water

. This both makes sense for low hardness discharges to freshwater and provides consistency with the standard practice for saltwater testing.CHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

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## 5.14 Man aging Effluent Characterization Results

5.14.1 Whole Effluent Toxicity Information Assistance
As a service to permit managers and permittees, the Water Quality Program purchased CETIS in order to be able to provide quality assurance of WET test results a nd maintain a database able to support permitting decisions

. CETIS is computer software that creates a record in a database of each toxicity test and can automatically perform the statistical procedures in the EPA test manuals

. CETIS also allows queries of the database to produce tables of the WET test results for each permittee.

The step of the information management system is getting quality records of each permittee's WET test results into the database

. Achieving quality records requires a review of each WET test, entry of the test into CETIS, and performance of the proper statistics

. After the record of WET test results is completed for a permittee, then the database can be queried to produce a table of effluent characterization test results that w ill assist permittees and permit managers during permit renewal

. The production of an accurate table of the numbers to be used for regulatory determinations for each permittee is the ultimate goal of the information management system.

Permit managers sh ould utilize the services of the Program Development Services Section for information management of WET

. The PDS Section evaluates every test before entering into the data base

. Data entered into CETIS is assured of using the proper statistics

. Only WET test results produced from CETIS should be considered accurate.

The PDS Section will, upon request, provide summary data of their test results to permittees

. Therefore, it is essential that all WET data be entered into CETIS and that permittees and per mit managers receive the same summary information.


### 5.14.2 Getting Complete Effluent Characterizations
If an effluent characterization is not adequate for making regulatory determinations under the WET rule, there are several possible solutions

. For exam ple, every permittee who is regulated under the WET rule, has no WET limits, and conducts no rapid screening testing is required to submit a set of WET tests with each permit application [WAC 173

- 205

- 030(8)]

. Most of the permittees currently fit this situ ation, and when they are informed of the requirement to submit a set of WET tests with the permit application, the WET tests could be chosen to complete any inadequate effluent characterization

. The PDS Section can advise permit managers on how to use thi s requirement to supplement inadequate effluent characterizations with a minimum of extra effort by permittees

. This assistance will be most valuable if permit managers contact the PDS Section six months prior to the application time.CHAPTER VI. WATER QUALITY BASED LIMITS FOR SURFACE WATER (July 20 11)

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- 81 Table VI

- 6 . Chemic al screening list for WET testing. (40 CFR 403, Appendix C)

Acenaphthene Acenaphthylene Acetaldehyde
Acetic acid Acetic acid (2,4

- dichlorophenoxy) Acetic acid, lead(2+) salt Acetic acid, (2,4,5

- trichlorophenoxy) Acetic anhydride Acetone cyanohydrin
Acet yl bromide Acetyl chloride
Acrolein Acrylonitrile
Aldrin Allyl alcohol Allyl chloride
Aluminum sulfate
Ammonia
Ammonium acetate
Ammonium benzoate
Ammonium bicarbonate
Ammonium bichromate
Ammonium bifluoride
Ammonium bisulfite
Ammonium carbamate
Ammonium ca rbonate
Ammonium chloride
Ammonium chromate Ammonium citrate, dibasic
Ammonium fluoborate
Ammonium fluoride Ammonium hydroxide
Ammonium oxalate
Ammonium silicofluoride
Ammonium sulfamate
Ammonium sulfide
Ammonium sulfite
Ammonium tartrate Ammonium thiocyan ate Amyl acetate
Aniline Antimony pentachloride Antimony potassium tartrate Antimony tribromide Antimony trichloride Antimony trifluoride Antimony trioxide
Aroclor 1016
Aroclor 1221 Aroclor 1232
Aroclor 1242
Aroclor 1248
Aroclor 1254
Aroclor 1260
Arsenic
Arsenic disulfide
Arsenic oxide As2O3
Arsenic oxide As2O5 Arsenic pentoxide
Arsenic trichloride
Arsenic trioxide
Arsenic trisulfide
Asbestos Barium cyanide Benz[a]anthracene 1,2

- Benzanthracene
Benzenamine
Benzene Benzene, 1

- bromo

- 4

- phenoxy

Benzene, chlor o

Benzene, chloromethyl

1,2

- Benzenedicarboxylic acid,

dioctyl ester 1,2

- Benzenedicarboxylic acid,

[bis(2

- ethylhexyl)]

- 1,2

- Benzenedicarboxylic acid,

dibutyl ester 1,2

- Benzenedicarboxylic acid,

diethyl ester 1,2

- Benzenedicarboxylic acid,

dimeth yl ester Benzene, 1,2

- dichloro

Benzene, 1,3

- dichloro

Benzene, 1,4

- dichloro

Benzene,

1,1'

- (2,2

- dichloroethylidene)bis[4

- chloro

Benzene, dimethyl 1,3

- Benzenediol Benzene, hexachloro

Benzene, hexahydro

Benzene, hydroxy

Benzene, methyl

Benzene, 2

- met hyl

- 1,3

- dinitro

Benzene, 1

- methyl

- 2,4

- dinitro

Benzene, nitro

Benzene, 1,1'

- (2,2,2

- tri

- chloroethylidene)bis[4

- chloro

Benzene,CHAPTER VI. WATER QUALITY

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- 82 1,1'

- (2,2,2

- trichloroethylidene) bis[4

- methoxy

Benzidine Benzol[a]anthracene Benzo[b]fluoranthene Benzo(k)fluoranthene
Benzo [j,k]fluorene
Benzoic acid
Benzonitrile Benzo[ghi]perylene Benzo[a]pyrene 3,4

- Benzopyrene Benzoyl chloride 1,2

- Benzphenanthrene Benzyl chloride Beryllium Beryllium chloride Beryllium fluoride Beryllium nitrate alpha

- BHC
beta

- BHC
delta

- BHC

gamma

- BHC (1,1'

- Biphenyl)

- 4,4'diamine [1,1'

- Biphenyl]

- 4,4'diamine, 3,3'dichloro

Bis (2

- chloroethyl) ether Bis (2

- ethylhexyl)phthalate
Bromoform
4

- Bromphenyl phenyl ether 1,3

- Butadiene, 1,1,2,3,4,4

- hexachloro

2

- Butenal Butyl acetate Butylamine Butyl benzyl phthalate

n

- Bu tyl phthalate Butyric acid
Cadmium
Cadmium acetate
Cadmium bromide
Cadmium chloride
Calcium arsenate
Calcium arsenite
Calcium carbide
Calcium chromate Calcium cyanide Calcium cyanide Ca(CN)2 Calcium dodecylbenzenesulfonate Calcium hypochlorite Camphene, o ctachloro

Carbaryl
Carbofuran Carbon disulfide
Carbon tetrachloride
Carbonic dichloride
Chlordane Chlordane, alpha & gamma isomers Chlordane, technical
CHLORINATED BENZENES
CHLORINATED ETHANES
CHLORINATED NAPHTHALENE
CHLORINATED PHENOLS
Chlorine
CHLOROALK YL ETHERS
Chlorobenzene
4

- Chloro

- m

- cresol

p

- Chloro

- m

- cresol
Chlorodibromomethane
Chloroethane
2

- Chloroethyl vinyl ether
Chloroform
beta

- Chloronaphthalene
2

- Chloronaphthalene
2

- Chlorophenol

o

- Chlorophenol
4

- Chlorophenyl phenyl ether
Chlorosulfonic acid
Chlo rpyrifos
Chromic acetate
Chromic acid Chromic acid H2CrO4, calcium salt
Chromic sulfate
Chromium
Chromous chloride Chrysene
Cobaltous bromide
Cobaltous formate
Cobaltous sulfamate Copper Coumaphos Cresol(s) Cresylic acid Crotonaldehyde Cupric acetate Cup ric acetoarsenite Cupric chloride Cupric nitrate Cupric oxalate Cupric sulfate Cupric sulfate, ammoniated Cupric tartrate Cyanogen chlorideCHAPTER VI. WATER QUALITY

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- 83 Cyanogen chloride (CN)Cl Cyclohexane Cyclohexane, 1,2,3,4,5,6

- hexachloro

- ,

(1 alpha,2alpha,3beta,4alpha,5alpha,6be ta)

- 1,3

- Cyclopentadiene, 1,2,3,4,5,5

- hexachloro

2,4

- D Acid 2,4

- D Ester 2,4

- D, salts and esters
DDD 4,4' DDD
DDE 4,4' DDE
DDT 4,4'DDT
Diazinon Dibenz[a,h]anthracene 1,2:5,6

- Dibenzanthracene Dibenzo[a,h]anthracene Dibutyl phthalate
Di

- n

- butyl phthalate
Dic amba
Dichlobenil
Dichlone
Dichlorobenzene 1,2

- Dichlorobenzene 1,3

- Dichlorobenzene 1,4

- Dichlorobenzene

m

- Dichlorobenzene

o

- Dichlorobenzene

p

- Dichlorobenzene 3,3'

- Dichlorobenzidine
Dichlorobromomethane 1,1

- Dichloroethane 1,2

- Dichloroethane 1,1

- Dichloroethyle ne 1,2

- Dichloroethylene Dichloroethyl ether Dichloroisopropyl ether Dichloromethoxy ethane 2,4

- Dichlorophenol Dichloropropane 1,2

- Dichloropropane Dichloropropane

- Dichloropropene (mixture) Dichloropropene 1,3

- Dichloropropene 2,2

- Dichloropropionic acid
Dichl orvos Dicofol
Dieldrin Diethylamine Diethylhexyl phthalate Diethyl phthalate Dimethylamine 2,4

- Dimethylphenol Dimethyl phthalate Dinitrobenzene (mixed) 4,6

- Dinitro

- o

- cresol and salts Dinitrophenol
Dinitrotoluene 2,4

- Dinitrotoluene 2,6

- Dinitrotoluene
Di

- n

- o ctyl phthalate 1,2

- Diphenylhydrazine Diphosphoric acid, tetraethyl ester
Di

- n

- propylnitrosamine Diquat
Diuron Dodecylbenzenesulfonic acid
Endosulfan alpha

- Endosulfan
beta

- Endosulfan
Endosulfan sulfate
Endrin Endrin aldehyde Endrin, & metabolites Epichl orohydrin
Ethanal Ethane, 1,2

- dibromo

Ethane, 1,1

- dichloro

Ethane, 1,2

- dichloro

Ethane, 1,1'

- oxybis[2

- chloro

Ethane, 1,1,2,2

- tetrachloro

Ethane, 1,1,1

- trichloro

Ethane, 1,1,2

- trichloro

Ethene, chloro

Ethene, 2

- chloroethoxy

Ethene, 1,1

- dichloro

Et hene, 1,2

- dichloro

- (E) Ethene, tetrachloro

Ethene, trichloro

Ethion Ethylbenzene Ethylenediamine Ethylenediamine

- tetraacetic acid (EDTA) Ethylene dibromide Ethylene dichloride Ethylidene dichloride
Ferric ammonium citrate
Ferric ammonium oxalate
Ferric chlorideCHAPTER VI. WATER QUALITY

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- 84 Ferric fluoride
Ferric nitrate
Ferric sulfate
Ferrous ammonium sulfate
Ferrous chloride
Ferrous sulfate
Fluoranthene
Fluorene Formaldehyde
Formic acid
Fumaric acid
2

- Furancarboxaldehyde 2,5

- Furandione
Furtural
Guthion Heptachlor Heptachlor epoxide
Hexachlorobenzene
Hexachlorobutadiene HEXACHLOROCYCLOHEXANE (all isomers) Hexachlorocyclohexane (gamma isomer) Hexachlorocyclopentadiene
Hexachloroethane Hydrazine, 1,2

- diphenyl

Hydrochloric acid Hydrocyanic acid Hydrofluoric acid Hydrogen chloride Hydro gen cyanide Hydrogen fluoride Hydrogen sulfide Hydrogen sulfide H2S Indeno(1,2,3

- cd)pyrene Isophorone Isoprene Isopropanolamine dodecylbenzenesulfonate Kepone
Lead
Lead acetate
Lead arsenate
Lead chloride
Lead fluoborate
Lead fluoride
Lead iodide
Lead nit rate Lead stearate
Lead sulfate
Lead sulfide Lead thiocyanate
Lindane Lithium chromate
Malathion
Maleic acid Maleic anhydride Mercaptodimethur Mercuric cyanide
Mercuric nitrate
Mercuric sulfate Mercuric thiocyanate
Mercurous nitrate Mercury Methanamine, N

- methyl

Methanamine, N

- methyl

- N

- nitroso

Methane, bromo

Methane, chloro

Methane, dichloro

Methane, tetrachloro

Methane, tribromo

Methane, trichloro

Methanethiol Methoxychlor Methyl bromide Methyl chloride Methyl chloroform Methylene chloride
2

- Methyl lactonitrile Methylmercaptan Methyl methacrylate Methyl parathion Mevinphos
Mexacarbate Monoethylamine
Naled Naphthalene Naphthalene, 2

- chloro

Naphthenic acid
Nickel
Nickel ammonium sulfate
Nickel chloride Nickel hydroxide
Nickel nitrate
Nickel sulfate
N itric acid
Nitrobenzene Nitrogen dioxide Nitrogen oxide NO2 Nitrophenol (mixed)

o

- Nitrophenol

p

- Nitrophenol
2

- NitrophenolCHAPTER VI. WATER QUALITY

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- 85 4

- Nitrophenol
N

- Nitrosodimethylamine
N

- Nitrosodiphenylamine
Nitrotoluene Oxirane, (chloromethyl)

- Paraformaldehyde
Parathion
Pentachlo rophenol Perchloroethylene
Phenanthrene
Phenol Phenol, 2

- chloro

Phenol, 4

- chloro

- 3

- methyl

Phenol, 2,4

- dichloro

Phenol, 2,4

- dimethyl

Phenol, 2,4

- dinitro

Phenol, methyl

Phenol, 2

- methyl

- 4,6

- dinitro

Phenol, 4

- nitro

Phenol, pentachloro

Phenol, 2,4,5

- t richloro

Phenol, 2,4,6

- trichloro

Phosgene Phosphoric acid Phosphorothioic acid,

O,O

- dimethyl O

- (4

- nitrophenyl) ester Phosphorus Phosphorus oxycloride Phosphorus pentasulfide Phosphorus sulfide Phosphorus trichloride Plumbane, tetraethyl

Potassium ars enate Potassium arsenite
Potassium bichromate
Potassium chromate Potassium cyanide Potassium cyanide (K(CN) Potassium hydroxide potassium permanganate
1

- Propanamine, N

- nitroso

- N

- propyl

Propane, 1,2

- dichloro

Propanenitrile, 2

- hydroxy

- 2

- methyl

Propane, 2, 2'

- oxybis[2

- chloro

Propargite
2

- Propenal
1

- Propene, 1,3

- dichloro

2

- Propenenitrile
2

- Propenoic acid, 2

- methyl

- , methyl ester
2

- Propen

- 1

- o1 Propionic acid Propionic anhydride Propylene dichloride Propylene oxide Pyrene Pyrethrins Quinoline
Resorcinol
Selen ium
Selenium dioxide
Selenium oxide
Silver
Silver nitrate Silvex (2,4,5

- TP)
Sodium
Sodium arsenate
Sodium arsenite
Sodium bichromate
Sodium bifluoride
Sodium bisulfite
sodium chromate Sodium cyanide Sodium cyanide Na (CN) Sodium dodecylbenzenesulfonate
S odium fluoride Sodium hydrosulfide Sodium hydroxide Sodium hypochlorite Sodium methylate
Sodium nitrite Sodium phosphate, dibasic Sodium phosphate, tribasic
Sodium selenite
Strontium chromate Strychnidin

- 10

- one Strychnine, & salts Styrene
Sulfur monochlori de Sulfur phosphide
Sulfuric acid Sulfuric acid, dithallium (1+) salt 2,4,5

- T acid 2,4,5

- T amines 2,4,5

- T esters 2,4,5

- T salts 2,4,5

- T
TDE Tetraethyl lead Tetraethyl pyrophosphate
ThalliumCHAPTER VI. WATER QUALITY

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- 86 Thallium (1) sulfate
Thiomethanol
Toluene Toxaphene 2,4,5

- TP acid 2,4,5

- TP esters
Trichlorfon 1,2,4

- Trichlorobenzene 1,1,1

- Trichloroethane 1,1,2

- Trichloroethane
Trichloroethene Trichloroethylene Trichlorophenol 2,4,5

- Trichlorophenol 2,4,6

- Trichlorophenol 2,4,5

- Trichlorophenol 2,4,6

- Trichlorophenol Triethanolamine dodecyl benzenesulfonate Triethylamine Trimethylamine Uranyl acetate Uranyl nitrate
Vanadium oxide V205 Vanadium pentoxide Vanadyl sulfate Vinyl chloride Vinyl acetate Vinyl acetate monomer Vinylidene chloride Xylene (mixed) Xylenol
Zinc
Zinc acetate
Zinc ammoniu m chloride
Zinc borate
Zinc bromide
Zinc carbonate
Zinc chloride Zinc cyanide Zinc cyanide Zn(CN)2
Zinc fluoride
Zinc formate Zinc hydrosulfite
Zinc nitrate Zinc phenosulfonate Zinc phosphide
Zinc silicofluoride
Zinc sulfate
Zirconium nitrate Zirconium pot assium fluoride
Zirconium sulfate
Zirconium tetrachlorideCHAPTER VI. WATER QUALITY

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- 87 Table VI

- 11. Industry Categories of 40 CFR Part 122, Appendix A. Industrial Category 40 CFR part Aluminum Forming 467 Asbestos Manufacturing 427 Battery Manufacturing 461 Builder’s Paper and Board Mills 431 Carbon Black Manufacturing 458 Centralized Waste Treatment 437 Coil Coating and Canmaking 465 Copper Forming 468 Electrical and Electronic Components 469 Electroplating 413 Feedlots 412 Ferroalloy Manufacturing 424 Fertilizer Manu facturing 418 Glass Manufacturing 426 Grain Mills 406 Ink Formulation 447 Industrial Laundries 441 Inorganic Chemicals 415 Iron and Steel Manufacturing 420 Landfills and Incinerators 437 Leather Tanning and Finishing 425 Metal Finishing 433 Metal Molding and Casting 464 Metal Products and Machinery Phase 1 438 Metal Products and Machinery Phase 2 438 Nonferrous Metal Forming and Metal Powders 471 Nonferrous Metals Manufacturing 421 Organic Chemicals, Plastics, and Synthetic Fibers 414 Paint Formulation 446 Paving and Roofing Material 443 Pesticide Formulation, Packaging and Repacking 455 Petroleum Refining 419 Pharmaceutical Manufacturing 439 Porcelain Enameling 466 Pulp, Paper and Paperboard 430/431 Rubber Manufacturing 428 Soap and Detergent Manufacturing 417 Steam Electric Power Generating 423 Sugar Processing 409 Timber Products Processing 429 Transportation Equipment Cleaning 442CHAPTER VI. WATER QUALITY

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- 88 This page is purposely left blankCHAPTER VII. WATER QUALITY

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– HUMAN HEALTH (JULY 04)

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- 1 

# CHAPTER VII. DERIVING WATER QUALITY

BASED EFFLUENT LIMITS FOR PROTECTION OF HUMAN HEALTH

Our water quality standards now include 91 numeric human health

- based criteria that permit writers must consider when drafting an NPDES permit. These criteria were promulgated for the state by the U.S.EPA in its' National To xics Rule (40 CFR 131.36) . Permit writers must consider whether a discharge has a reasonable potential to violate these criteria. The criteria are
listed in TSDCALC

. ( NOTE: At the time of this publication Ecology is revising the fish consumption estimat e
. This will result in changes in the human health criteria and the implementation process .)

This section outlines the process of conducting an initial screening and conducting a reasonable potential determination for these chemicals, as well as how to d etermine monitoring requirements and compliance schedules. This guidance complies with the NTR. The process of determining a reasonable potential for human health

- based criteria exceedances parallels the procedure currently used for aquatic life

- based cr iteria (Chapter VI). The decision path for
human health

- based permitting is illustrated in Figure VII

- 1.



## 1. WATER QUALITY CRITERIA

- BACKGROUND

The human health

- based water quality criteria incorporate several exposure and risk assumptions. These includ e (1) a 70

- year lifetime of daily exposures, (2) a n ingestion rate for
fish or shellfish in kg/day , (3) 2 liters/day ingestion rate for drinking water, and a one

- in

- one

million excess cancer risk for carcinogenic chemicals. In general, these exposure assu mptions will provide a safe level of protection for most individuals. On the other hand, the criteria do not account for additive or synergistic effects of multiple contaminants on human health, and they contain the assumption that 100% of exposures come from ingesting fish, shellfish, or waters from surface water sources, thus no account is taken of exposures resulting from air, other foodstuffs, or groundwater

- derived or public drinking water supplies.

Human health criteria are derived by equations that reflect both technical information and policy decisions. Many issues associated with establishing human health criteria are complex and controversial, but the basic equation and concepts used to derive the criteria are simple. EPA changed the methodolog y for calculating human health criteria in 2000. This resulted in changes to some human health criteria, however, EPA did not revise the National Toxic Rule based on the new methodology. The following text is from the EPA fact sheet on the revised
method ology.CHAPTER VII. WATER QUALITY

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– HUMAN HEALTH (JULY 04)

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- 2 

## Revised Methodology for Deriving Health

- Based Ambient Water Quality Criteria (2000)

Fact Sheet; October 2000

We have published revisions to the 1980 Ambient Water Quality Criteria National Guidelines to better protect human health

. The 1980 Ambien t Water Quality Criteria National Guidelines outline the methodology used by states and tribes to develop human health water quality criteria

. Revisions to the 1980 guidelines incorporate significant scientific advances in key areas such as cancer and non

- cancer risk assessments, exposure assessments, and bioaccumulation in fish

. The revised methodology will provide more flexibility for decision

- making at the state, tribal and EPA regional levels

. It is most likely that the methodology will result in mor e stringent criteria for bioaccumulatives and generally similar values of nonbioaccumulatives.

Human Health Water Quality Criteria

Human health ambient water quality criteria (AWQC) are numeric values limiting the amount of chemicals present in our nation 's waters

. Human health criteria are developed under Section 304(a) of the Clean Water Act of 1972 and are designed to protect human health

. Water quality criteria are developed by assessing the relationship between pollutants and their effect on human h ealth and the environment

. These criteria are used by states and Indian tribes to establish water quality standards and ultimately provide a basis for controlling discharges or releases of pollutants.

The Clean Water Act (CWA) requires EPA to develop, pu blish and revise ambient water quality criteria (AWQC)

. In 1980, EPA published AWQC for 64 pollutants/pollutant classes and provided a methodology for deriving the criteria

. These national guidelines addressed three types of endpoints: noncancer, cancer and organoleptic (taste and odor) effects.

The states and tribes use these criteria to develop water quality standards for each water body

. EPA is required to review periodically criteria adopted by states and tribes

. The revisions to the EPA's 1980 met hodology will help states and tribes establish water quality criteria and standards that protect human health

. They provide detailed means for developing water quality criteria, including systematic procedures for evaluating cancer risk, noncancer health effects, human exposure, and bioaccumulation potential in fish.



### EPA Methodology for Deriving Criteria

States and tribes must develop water quality standards that include designated uses and water quality criteria necessary to support those uses

. The Meth odology is the guidance for states and tribes to help them establish water quality criteria and standards to protect human health

. It provides detailed means for developing the water quality criteria, including systematic procedures for evaluating cancer risk, noncancer health effects, human exposure, and bioaccumulation potential in fish.CHAPTER VII. WATER QUALITY

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- 3 Risk assessment practices have evolved significantly since 1980, particularly in the areas of cancer and noncancer risk assessments (with new information, procedures, a nd numerous published Agency guidelines), exposure assessments (with new studies on human intake and exposure patterns, and new science policy guidelines) and methodologies on accounting for bioaccumulation in fish.



### General Background of the Revision Proc ess

Revisions began with a national workshop in 1992, where participants discussed critical issues

. Based on individual expertise, attendees were assigned to technical workgroups including cancer risk, noncancer risk, exposure, and bioaccumulation in fish

.
EPA submitted recommendations from the workshop for review and comment by the EPA Science Advisory Board

. EPA created a workgroup in 1994, including program office and regional participants, to revise the methodology

. Numerous stakeholder participatio n activities were conducted between 1995 and 1998, including presentations to the Federal

- State Toxicology and Risk Analysis Committee and several multi

- regional water quality coordinator's meetings in 1996 and 1997, which included participants from EPA re gions, states, tribes and some industry.

Following publication of the draft Methodology revisions, written public comments were accepted

. Further presentations included the 1998 Annual Meeting of the Society For Risk Analysis and the 1999 Annual Meeting of the Society of Toxicology

. In May 1999, a peer review workshop was held

. A public stakeholders meeting was also held then

. EPA received extensive input on the Methodology from each of these groups

. EPA considered all comments and incorporated a subs tantial portion of them into the final AWQC Methodology Revisions.



### Major Methodology Revisions

Publication of final revisions satisfies the requirements of the CWA that EPA periodically revise criteria for water quality to reflect accurately the latest sc ientific knowledge on the kind and extent of all identifiable effects on health and welfare that may be expected from the presence of pollutants in any body of water

. These Final AWQC Methodology Revisions to the 1980 AWQC National Guidelines are necessit ated by the many significant scientific advances made during the past 20 years in the key areas of cancer and noncancer assessments, exposure assessments, and bioaccumulation in fish.

The major revisions are in four assessment areas: cancer, non

- cancer, e xposure, and bioaccumulation.

For carcinogen (cancer) risk assessment:

• Recommend more sophisticated methods to comprehensively determine the likely mechanism of human carcinogenicity.

• Recommend a mode of action (MOA) approach to determine the most appro priate low

- dose extrapolation for carcinogenic agents.CHAPTER VII. WATER QUALITY

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- 4 For noncarcinogens:

• Use EPA guidance on assessing noncarcinogenic effects of chemicals and for the Reference Dose (RfD) derivation.

• Recommend consideration of other issues related to the RfD proces s including: integrating reproductive/ developmental, immunotoxicity, and neurotoxicity data into the calculation.

• Recommend the use of quantitative dose

- response modeling for the derivation of RfDs.

• Provide guidance for states and tribes on the use of a n alternative value from the RfD point estimate, within a limited range, to reflect the inherent imprecision of the RfD.

For exposure assessment:

• Encourage states and tribes to use local studies on fish consumption that better reflect local intake patter ns and choices.

• Recommend default fish consumption values for the general population, recreational fishers and subsistence fishers.

• Account for other sources of exposure, such as food and air, when deriving AWQC for noncarcinogens and nonlinear carcinoge ns.

For bioaccumulation:

• Focus on the use of bioaccumulation factors (BAFs), instead of bioconcentration factors (BCFs) for estimating potential human exposure to contaminants via the consumption of contaminated fish and shellfish.

• Use high quality fiel d data over laboratory or model

- derived estimates for deriving BAFs, since field data best reflect factors which can affect the extent of bioaccumlation (e.g., chemical metabolism, food web structure).

EPA does not plan to completely revise all of the cri teria developed in 1980 or those updated as part of the 1992 National Toxics Rule

. Partial updates of all criteria may be necessary

. EPA will continue to develop and update toxicology and exposure data needed in the derivation of AWQC that may be impract ical for the states and regions to obtain.



### Methodology Revisions Implementation by EPA/States

EPA's future role in developing AWQC for the protection of human health will include:

• The development of revised criteria for chemicals of high priority and nat ional importance (including, but not limited to, chemicals that bioaccumulate, such as PCBs, dioxin, and mercury).

• The development or revision of AWQC for some additional priority chemicals.

• Technical assistance to states and tribes on the toxicology, ex posure and bioaccumulation methods, and review of state/tribal water quality standards.

EPA encourages states and tribes to use the revised methodology to develop or revise AWQC to reflect local conditions appropriately

. EPA believes that AWQC inherently require several risk management decisions that are, in many cases, better made at the state and regional level (e.g., fish consumption rates, target risk levels).CHAPTER VII. WATER QUALITY

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### Effect on State and EPA Regional Offices

The revised methodology will provide more flexibil ity for decision

- making at state, tribal and EPA regional levels

. EPA believes the AWQC require several risk management decisions that are often better made at the state, tribal and regional level

. The methodology will probably result in more stringent c riteria for bioaccumulatives (due to the use of BAFs instead of BCFs) and generally similar, or less stringent, values of nonbioaccumulatives.

The formulas for calculating human health criteria are presented below.

The generalized equations for deriving AWQC based on noncancer effects are:
Noncancer Effects 2



## ( ) 4

2 i i i BW AWQC RfD RSC
DI FI BAF

=    

=• •

+ •   

# ∑

2. Although appearing in this equation as a factor to be multiplied, the RSC can also be an amount subtracted

. Refer to the explanation key below.

Cancer Effects: Non linear Low

- Dose Extrapolation



## ( ) 4

2 i i i POD BW AWQC RSC UF DI FI BAF

=    

= ••

+ •   

# ∑

Cancer Effects: Linear Low

- Dose Extrapolation



## ( ) 4

2 i i i BW AWQC RfD
DI FI BAF

=    

= •

+ •   

# ∑

where: AWQC = Ambient Water Quality Criterion (mg/L) RfD = Reference dose for noncancer effects (mg/kg

- day)
POD = Point o f departure for carcinogens based on a nonlinear low

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- 6 extrapolation (mg/kg

- day), usually a LOAEL, NOAEL, or LED 10 UF = Uncertainty Factor for carcinogens based on a nonlinear low

- dose extrapolation (unitless)
RSD = Risk

- specific dose for carcinogens ba sed on a linear low

- dose extrapolation (mg/kg

- day) (dose associated with a target risk, such
as 10 - 6 ) (Note: The RSD for Washington State is 10 - 6 )
RSC = Relative source contribution factor to account for non

- water sources of exposure

. (Not used for linear carcinogens.) May be either a percentage (multiplied) or amount subtracted, depending on whether multiple criteria are relevant to the chemical. BW = Human body weight (default = 70 kg for adults) DI = Drinking water intake (default = 2 L/day for adults)
FI i = Fish intake at trophic level (TL) I (I = 2, 3, and 4) (defaults for total intake = 0.0175 kg/day for general adult population and sport anglers, and 0.1424 kg/day for subsistence fishers)

. Trophic level breakouts for the general adult population and sport anglers are: TL2 = 0.0038 kg/day; TL3 = 0.0080 kg/day; and TL4 = 0.0057 kg/day.
BAF i = Bioaccumulation factor at trophic level I (I=2, 3 and 4), lipid normalized (L/kg)



## 2. IMPLEMENTATION

- OVERVIEW

The process for developing an effluent limit based on human health (Fig ure VII

- 1) parallels the existing process for developing aquatic life

- based limits. However, there are some differences in the procedures used to determine whether a discharge will have a reasonable potential
determination made for th e human health

- based criteria. These include two steps where the discharge is evaluated for (1) likelihood of discharging chemicals of concern, and (2) an evaluation by the agency of whether that discharge is a high priority in the permitting scheme or

no t.

The process of performing a reasonable potential determination is similar to that used for evaluating aquatic impacts as indicated by chronic aquatic life

- based criteria. The differences between the two are the model inputs used to represent the criti cal flow conditions, the criterion values, and the probability values. Other input data, such as the default value for the coefficient of variation of effluent variability and statistical confidence level remain the same.CHAPTER VII. WATER QUALITY

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## 3. SCREENING AND PRIORITIZAT ION

Screening and prioritizing discharges to determine whether a reasonable potential determination should be made is a two step process.

Step 1 . After receipt of an NPDES application, the application should be screened t o determine
if it is a "low risk" discharge or a discharge undergoing modification. These discharges will be omitted from implementation at the present time. "Low risk" discharges include non

- process cooling waters without biocides, gravel mining operations without asphalt processes, or other facilities where the permit writer has data or process knowledge to indicate that chemicals regulated under the human health criteria are absent. This determination must be made based on data or process information pointing to absence of chemicals, and cannot be based on a lack of data indicating the presence of chemicals. Discharges undergoing technology

- based upgrades or improvements that are required by an Ecology order or permit (as specified below) will be
omitted in order to allow the effluen t to stabilize under the new treatment regime. These discharges will be considered for human health

- based limits after their upgrades are completed. These discharges include all industrial storm water dischargers covered under the department's general in dustrial storm water permit and all municipal storm water discharges. If a discharger is in the planning phase of upgrades in response to an Ecology requirement, the discharger should be told that the effluent will be evaluated for impacts to human health after the upgrades are completed. This will allow the discharger to make plans for more extensive upgrades or process changes earlier on, if desired, and may result in cost savings. After a discharge has been evaluated based on the above criteria, the a pplicant will either be given no further consideration
for human health

- based permitting at the present time, or will go on to a second prioritization step.

Step 2 . If the screening step results in a "likelihood" finding, the application should be review ed to determine whether the discharge is a high priority in agency permitting. Those discharges termed "high priority" will go on to have a full reasonable potential determination made on them. The following discharges are classed as high priorities:

1. All major dischargers

.

2. Discharges for which existing data or knowledge of processes indicates the known or probable presence of chemicals with human health

- based criteria

.

3. Facilities discharging to a receiving water that is 303(d)

- listed for a ch emical with human
health

- based criteria, and that chemical is expected to be in the effluent.

If a discharge fits into any of the three groups described above, a reasonable potential determination must be conducted for that discharge. If a discharge does not fit into the groups described above, the application should not be considered further for human health

- basedCHAPTER VII. WATER QUALITY

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- 8 effluent limits, but the permit writer should consider requiring submittal of a priority pollutant scan with the next permit application.



## 4. THE REASONABLE POTENTIAL DETERMINATION

The following section reviews the design criteria for making a determination of reasonable potential of a violation of the water quality criteria for human health. A summary of these is presented in Table VII

- 2.



## 4.1 Which Criteria?

A reasonable potential determination is conducted for each chemical in a discharge that (1) has
an associated human health

- based criterion, and (2) has been found (or is known to exist) in the discharge during the last permit cycle or upon application.


## 4.2 Effluent and Background Concentration

Use the 50th percentile effluent concentration for reasonable potential analysis . If there is less than 10 effluent data points use a multiplier on the highest effluent concentration to estimate the 50th percentile concentration

. If there is more than 10 values use the cumulative percentile calculation at a 95% confidence to derive the 50th percentile (Excel).

For background concentration(s), use 0 for measured value(s) below the MDL and use the MDL for values between the MDL and the QL. For multiple data points use the geometric mean


## 4.3 Mixing Zones

The NTR allows states to use mixing zones already placed in state standards, or to default to an application of the criteria at the "end

- of

- pipe"(40 C FR 131.36(c)(2)(i).

Washington's Water Quality Standards (Chapter 173

- 201A WAC) specifies mixing zone sizes for acute and chronic criteria. The mixing zone specified for chronic aquatic life

- based criteria
will be used for the human health

- based criteria . This mixing zone allows for some dilution when calculating effluent limits, but is still protective of human health.CHAPTER VII. WATER QUALITY

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- 9 Figure VII-1. Process for Implementing Human Health Criteria

NPDES PERMIT APPLICATION RECEIVED

IS THIS DISCHARGE A LOW RISK OR IN THE PROCESS OF INSTALLING TECHNOLOGY-BASED TREATMENT? THESE INCLUDE: 1. FACILITIES UNDER A COMPLIANCE SCHEDULE FOR UPGRADES OR TREATMENT MODIFICATIONS 2. NON-PROCESS COOLING WATER WITHOUT BIOCIDES

3. GRAVEL MINING WITHOUT ASPHALT OPERATIONS 4. INDUSTRIAL AND MUNICIPAL STORMWATER DISCHARGES 5. FACILITIES WITH PROCESS OR EFFLUENT DATA WHICH

INDICATES NONE OF THE 91 CHEMICALS WITH HUMAN HEALTH CRITERIA ARE PRESENT.

NO FURTHER CONSIDERATION

IS THIS DISCHARGE A HIGH AGENCY PRIORITY: - A MAJOR DISCHARGER - THE EFFLUENT OR PROCESS DATA INDICATES PROBABLE DISCHARGE OF CHEMICALS WITH HUMAN HEALTH CRITERIA, OR - A FACILITY WHICH DISCHARGES TO A RECEIVING WATER LISTED ON THE 303(d) LIST FOR HUMAN HEALTH CHEMICAL(S) EXPECTED TO BE IN THE EFFLUENT? * NO FURTHER CONSIDERATION

FOR CURRENT PERMIT CYCLE. CONSIDER PP SCAN IN THE PERMIT OR AT NEXT APPLCATION

CONDUCT ANALYSIS FOR REASONABLE POTENTIAL TO VIOLATE THE WATER QUALITY STANDARDS FOR HUMAN HEALTH

REASONABLE POTENTIAL ?

REQUIRE EFFLUENT MONITORING FOR POLLUTANTS WITH HH CRITERIA PLACE EFFLUENT LIMITS AND COMPLIANCE MONITORING IN THE PERMIT, GRANT COMPLIANCE SCHEDULE AND REQUIRE SOURCE CONTROL AS NECESSARY YES

NO

NO

NO OR UNCERTAIN

YES

* SEE CH VI, SECT. 3.3.11CHAPTER VII. WATER QUALITY

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- 10 

## 4.4 Plant Design Flows

The following plant design flows should be used when conducting a human health

- b ased reasonable potential determination. Note that the flows differ depending on whether the criterion
is based on cancer or non

- cancer effects (see Table VII

- 1 to determine this).

Carcinogens

Municipal Effluent

- Use the annual average design flow as specified in the engineering report, permit application, or a projection of the average annual flow over the life of the permit.

Industrial Effluents

- Use the annual average flow based on the permit application or DMR analysis.

Non

- carcinogens

Munici pal Effluent

- Use the dry weather design flow if the facility flows are within 15% of design capacity. If the facility is operating well below design during the critical receiving water period, and there is no substantial projected increase in flows for the period of the next permit, then use the historical flow as defined by the highest monthly average flow for the past three years during the time of year when the critical receiving water period is likely to

occur.

Industrial Effluents

- Use the histor ical flow as defined by the highest monthly average flow for the past three years during the period when the critical receiving water flow is most likely to occur. If flows are expected to increase during the life of the permit the highest average monthly flow must be estimated.



## 4.5 Critical Flow Conditions

The NTR specifies that critical receiving water flow conditions in a state's standards may be used
to determine effluent limits for human health criteria. WAC 173

- 201A

- 020 allows the state flexibility when determining the critical condition for riverine systems ("...may be assumed equal to the 7Q10 flow event unless determined otherwise by the department") and contains a narrative
statement that can be used to determine a marine critical condition.

The flows used to conduct a reasonable potential determination are specified below, and follow the guidance in the NTR as closely as possible. Note that different flows are specified for
criteria based on cancer effects and non

- cancer effects.CHAPTER VII. WATER QUALITY

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### Carcinogens

Fr eshwater Critical Condition

- Use the harmonic mean flow for the representative period of record. The representative period is the period that best represents flows as they now exist. For instance, if a dam was constructed that modified flows, use data f rom the time
after the dam was constructed to determine the critical flow.

Marine/Estuarine Critical Condition

- Use the median velocity taken over one tidal cycle or from as many tidal cycles as are available in the period of record.



### Non

- carcinogens

Fres hwater Critical Condition

- Use the 30Q5 if available or use the 7Q10 as an estimate of the 30Q5.

Marine/Estuarine Critical Condition

- Use the median velocity taken over one tidal cycle or from as many tidal cycles as are available in the period of recor d.



## 4.6 Coefficient of Variation of Effluent Concentration

Use 0.6, as is used for aquatic life

- based permitting, or the best available estimate (see Chapter VI)

.


## 4.7 Dilution Factor

Use a value derived from a reliable model (as is used for aquatic life

- ba sed permitting) or from an ambient dilution study or use percent of flow if that is more stringent. If reliable values are not available, estimate flows or use percent of flow to determine reasonable potential and then insert a requirement in the permit f or the discharger to provide a reliable dilution value to the department no later than the next permit reapplication (see Chapter XIII, Monitoring).



## 4.8 Statistical Confidence Level

Use an alpha equal to 0.05 when calculating reasonable potential.



## 4.9 Back ground Data on Chemical Concentrations

Use available background data on chemical concentrations in the water column, or use zero as a
default value if reliable data are not available.CHAPTER VII. WATER QUALITY

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- 12 Table VII

- 1 . Design conditions for water quality

- based permitting of human health criteria.

Design Conditions for Mixing Zone/Ratio Analysis

- Human Health Criteria
Parameter Pollutant Critical Design Condition Carcinogen The design effluent flow is defined as the annual average flow based on the engineering report,

perm it application or DMR analysis. Facility Effluent (Flow) Non

carcinogen The design effluent flow is defined as the highest monthly average plant effluent flow for the past three years during the critical flow or when critical condition is likely to occur. If plant effluent flows are expected to increase during the life of the permit, the highest average monthly flow must be estimated. Carcinogen

- Freshwater The design receiving water current velocity is defined as the current velocity at the harmonic

m ean flow for the representative period of record.

The diffuser depth is defined as the depth at the harmonic mean flow.

Receiving
Water (Characteris tics) Non

carcinogen

- Freshwater The design receiving water current velocity is defined as the current v elocity at the 30

- day low flow period with a recurrence interval of 5 years (30Q5) if available or at 7Q10.

The diffuser depth is defined as the depth at the 30Q5 or 7Q10 low flow period. Carcinogen

- Saltwater The design receiving water current velocit y is defined as the 50 th percentile current velocity derived from a cumulative frequency distribution analysis. The current velocity frequently distribution analysis should be conducted, at minimum, over one tidal cycle.

The design ambient density profil e is defined as the density profile that results in average mixing.

The diffuser depth is defined as the depth at MLLW. For estuaries, the diffuser depth is defined as the smaller of the median water depth at eitherCHAPTER VII. WATER QUALITY

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- 13 Design Conditions for Mixing Zone/Ratio Analysis

- Human Health Criteria
Parameter Pollutant Critical Design Condition the ebb tide or the flood tide during the critical receiving water period.
Non

carcinogen

- Saltwater The design receiving water current velocity is defined as the 50 th percentile current velocity derived from a cumulative frequency distribution analysis. The current velocity frequency
dist ribution analysis should be conducted, at minimum, over one tidal cycle.

The design ambient density profile is defined as the density profile that results in average mixing.

The diffuser depth is defined as the depth at MLLW. For estuaries, the diffuser depth is defined as the smaller of the median water depth at either the ebb tide or the flood tide during the critical receiving water period.CHAPTER VII. WATER QUALITY

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- 14 Miscellaneous Design Conditions for Mixing Zone/Ratio Analysis

Parameter No. of
Data Points Methodology

Re ceiving

Water Background Concentration (Human Health) N/A The geometric mean of receiving water concentrations is used to determine reasonable potential. If background is between the MDL and the QL use the MDL

. If the background concentration is below the MDL, use 0. If no background data is available use 0.

Effluent Concentration (Human Health) N/A Use the 50th percentile effluent concentration. If there is less than 10 effluent data points use the following multipliers (see box following) on the highe st effluent concentration to estimate the 50th percentile concentration

. If there is more than 10 values use the cumulative percentile calculation at a 95% confidence to derive the 50th percentile (Excel).

Dilution Ratio Unidirectional flow (freshwater) N/A Flux average

Dilution Ratio Multidirection al flow (marine) N/A Flux average

Reflux N/A Assume reflux reduces the dilution factor by 1/2 or use site

- specific data.

The point of compliance with the human health criteria is the boundary of the chronic mixing zone.

Chronic design conditions are used for both the initial mixing and the far

- field mixing calculations.CHAPTER VII. WATER QUALITY

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- 15 NUMBER OF EFFLUENT SAMPLES FOR DETERMINING REASONABLE POTENTIAL FOR HUMAN HEALTH CRITERIA FACTORS BY WHICH TO
MULTIPLY THE H IGHEST EFFLUENT CONCENTRATION VALUE TO ESTIMATE THE 50TH

PERCENTILE VALUE (CV = 0.6, 95% CONFIDENCE)

1 2.5

2 1.5

3 1.2

4 1.0

5 0.9

6 0.9

7 0.8

8 0.8

9 0.7

10 0.7

The values in this table were calculated using EPA's method (TSD, Section 3.3.2) of estimating quantile values from a limited data set presumed to be log normally distributed.



## 5. RESULTS OF THE REASONABLE POTENTIAL DETERMINATION

The reasonable potential determination will result in three possible outcomes. These are "yes", "no", or "c an't determine". The following paragraphs explain how to set up permit requirements for the three possible results.


## 5.1 Yes, a Reasonable Potential Exists to Exceed Water Quality Standards

If the reasonable potential determination shows that there is a potential for one or more water quality criteria to be exceeded, then effluent limits should be placed in the permit for the constituent(s) of concern (TSDCALC). The effluent limits are calculated by setting the averageCHAPTER VII. WATER QUALITY

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- 16 monthly limit equal to the WLA and using Table 5

- 3 of the TSD (99 th and 95 th percentile) to calculate the maximum daily limit. The HUMAN

- H spreadsheet in TSDCALC will perform a determination of reasonable potential and calculate limits if there is a reasonable potential. The permit should also contain a compliance schedule if one is needed. The length of the compliance schedule should be evaluated individually for each facility. The permit should also contain source control requirements in order to ensure that efforts to comply with the permit limits in a timely manner are being made. These source control requirements should be set out in a phased approach. For instance, initial requirements should be to evaluate sources of pollutants, and examine ways to control those sources. That ph ase should be followed by requirements to implement methods of control. The timing of the requirements will differ from facility to facility. In some cases, where sources are already known and may be easily controllable, short compliance schedules may be appropriate. In other cases, unknown sources or reduction issues may make a longer compliance schedule appropriate. Source reduction requirements should be aimed at pollution prevention, and, if possible, not be aimed at treatment methods that would
inv olve large capital expenditures by dischargers. Compliance schedules should be shorter if fishing, shellfishing, or drinking water uses of the receiving water body are known or suspected to be impaired.



### 5.1.1

. Compliance Monitoring

Permits with effluent limits should also contain requirements for priority pollutant scan monitoring during wet and dry seasons of years three and four of the permit. Effluent limits must be monitored at least once yearly

. The recommended frequency is one/month.


## 5.2 No, a Re asonable Potential Does Not Exist to Exceed Water Quality Standards

If the results of the reasonable potential indicate that an exceedance of water quality standards is unlikely to occur, the permit should not contain effluent limits. The permit should, h owever, contain requirements for priority pollutant scan monitoring once during the wet and once during the dry seasons of year three of the permit. This information should be submitted with the next permit application. In addition, other information may be needed to more clearly make a reasonable potential determination at the next permit reissuance. These will be factors that are acceptable for decision making at this time, but about which valid biological or engineering
issues still need to be address ed. For instance, using a river model program to estimate dilution is frequently acceptable, but in some cases the physical characteristics of the river (e.g., river bottom topography, curvature of river) make a field dilution study desirable to validate the model. In this case, although a reasonable potential determination can be made with the available data, the permit should contain requirements for a field dilution study to calibrate or verify modeling work.CHAPTER VII. WATER QUALITY

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## 5.3 The Result of the Reasonable Potentia l Determination is Ambiguous, or, "Can't Determine".

The result "can't determine" will likely result from poor or incomplete effluent data, background data or unreliable dilution estimates. If this outcome occurs the permit should be issued with requireme nts to conduct two priority pollutant scans during year three of the permit, one during the wet season and one during the dry season. These data should be submitted with the appropriate DMRs. In addition, the permit should contain requirements to provide data to clarify any other factors leading to the "can't determine" finding. For instance, if the reasonable potential determination does not yield a reliable "yes" or "no" result because of unreliable dilution information, the permit should require that a dilution study be performed during the permit cycle, with data available, at latest, with the next permit application.



## 6. ANALYTICAL METHODS

See Table VI

- 5 for the analytical methods that should be used for general priority pollutant scans. In general, it is not effective to require an individual and different method for each chemical in a priority pollutant scan. Instead, the usual default will be to require the most sensitive analytical method for a particular chemical analysis that will measure a su ite of chemicals (e.g., Method 608 for pesticides).CHAPTER VII. WATER QUALITY

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- 18 This page is purposely left blankCHAPTER VIII. WATER QUALITY

- BASED LIMITS FOR GROUND WATER (JULY 2011)

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- 1 

# CHAPTER VIII. DERIVING WATER QUALITY

BASED EFFLUENT LIMITATIONS FOR THE PROTECTION OF GROUND WATER QUALITY

In Washington, any commercial or industrial operation disch arging wastewater to ground must have a discharge permit

. The permit writer, in developing that permit, must consider the effect of the discharge on the quality of ground water.



## 1

. GROUND WATER CRITERIA AND STANDARDS

The Water Quality Standards for Groun d Waters of the State of Washington (Chapter 173

- 200 WAC) are similar to the water quality standards for surface waters

. They define the beneficial uses to be protected, they specify the concentrations of chemicals to protect the beneficial uses, they hav e an antidegradation section, and they generally define the point of compliance.

The implementation process for the ground water standards is found in Implementation Guidance for the Ground Water Quality Standards , Ecology Publication 96

- 02. Other guidan ce documents for those wanting to apply for discharges to land are given in Section 3 below.



## 1.1 Numeric Criteria

The numeric criteria within the ground water standards are divided into I. Primary and Secondary Contaminants and Radionuclides and II. Carcin ogens.



## 2 . De MINIM I S APPLICATION OF FOOD PROCESS WASTEWATER

General: De minimis application of food process wastewater to land via irrigation for the purpose of treatment is an application that occurs infrequently (e.g

., once per year), on a limited are a (e.g

.,
one

- time applications to a specific field), and/or at a nutrient loading rate that is well below the crop requirement. If managed properly, de minimis applications of food process wastewater benefits both the discharger and the environment by pr olonging the viability of wastewater disposal sites, and providing nutrient benefit for crops. To qualify as a de minimis discharge, the permittee must clearly demonstrate in an Engineering Report that the discharge will have minimal potential to impact g round water. All de minimis discharges will be authorized by conditions set forth in a state waste discharge permit. To make this type of operation viable, a process and permit language was developed to allow these types of applications.CHAPTER VIII. WATER QUALITY

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- 2 

### Review Process: If a food processing facility intends to propose a de minimis discharge at the time it submits a discharge permit application, an Engineering Report, as per Chapter 173

- 240 WAC, or an addendum to an existing approved engineering report must accompany the permit application

. At a minimum the engineering report must include a description of soil and crop types, depth to ground water, distance to any surface water, proposed wastewater irrigation schedule, percent of nutrient crop need per year provided by t he wastewater, and a statement that the proposed de minimis application will be protective of the existing and future beneficial uses of the ground water. This is similar to the requirements for submission of an “Abbreviated Engineering Report” detailed i n Chapter 3 of Guidelines for Preparation of Engineering Reports for Industrial Wastewater Land Application Systems (Ecology Pub lication 93

- 36). An addendum to an existing engineering report must give details of the proposed de minimis application and

eva luate hydrogeologic conditions at the proposed sites

. The facility manager

, in coordination with the project proponent

, will determine if additional evaluation is required for a proposal for de minimis application. Adequate guidance currently exists ( Imp lementation Guidance for the Ground Water Quality Standards (Ecology Pub lication 96

- 02)

, Guidance for Submission of an Engineering Report for Industrial Wastewater Land Treatment Systems , and the Irrigation Management Practices Manual , etc.) that allows Ec ology to evaluate de minimis application proposals from food processors. These manuals provide enough flexibility for Ecology to evaluate the need for additional hydrogeologic information and to determine what type of monitoring is needed

. Review of the Engineering Report will help determine if additional hydrogeologic evaluation is needed and what type of monitoring (e.g

., effluent quality, application monitoring, farm plan evaluation, etc.) is needed to insure the protection of the state's ground water resource. After Ecology’s approval of the Engineering Report or addendum, permit language should be included to condition the application of wastewater in accordance with that described in the Engineering Report or addendum and to address monitoring needs (See the following permit language section)

Facilities that decide to make de minimis applications while their current permit is in effect must request a permit modification and submit the same type of engineering report or addendum discussed above. App roval of the engineering report will result in the permit being modified to include new de minimis permit language (See the following permit language section)



### Permit Language: The following is sample permit language to address de minimis wastewater applic ations of food process wastewater to ground. Some sections or conditions may need to be modified by the permit writer to address the exact discharge proposal.CHAPTER VIII. WATER QUALITY

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### Section S1 (Discharge Limitations)
Beginning on the effective date of this permit and lasting t hrough the expiration date of this permit, the Permittee is authorized to apply (state type or source of wastewater) during the months of (state month or months of application) to varied crop production acreages located (give general location) via ________ (state method of application) _________ subject to the following limitations:

Hydraulic Loading not to exceed (give condition) and shall not cause ponding or runoff
of wastewater Nitrogen (e.g

., Total, Nitrate, Ammonia, etc.) Loading not to exceed ____(give condition)_____ BOD (e.g

., 5

- day, soluble, etc.) Loading not to exceed ___(give condition)_____ Solids (e.g

., total dissolved, total volatile, etc.) Loading not to exceed ___(give
cond ition)______ Chloride not to exceed ____(give condition)______ Other design limiting parameter(s) (give condition)

(Optional text) Beginning on the effective date of the permit and lasting through the expiration date of this permit, the Permittee is authorized to use wastewater for dust control subject to the provisions of the BMPs in their Dust Abatement and Road Management Plan*. The water cannot be used on publicly owned lands or roads. *See Fresh Fruit Packing General Permit, S5.B.3 and S5.B. 5 for guidance.



### Section S2 (Monitoring Requirements)

Wastewater

(Monitoring requirements will be site specific and dependent on wastewater characterization information presented in the engineering report. The following is an example of wastewater
monitor ing requirements and conditions.)CHAPTER VIII. WATER QUALITY

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- 4 Parameter Units Sampling Frequency Sample Type

Flow 1 gallons/acre; inches/acre; gallons/day Site specific measured

TKN (as N) mg/L; lbs/acre; lbs/day Site specific grab
NH 3 - N mg/L; lbs/acre; lbs/day Site specif ic grab Nitrate (as N) mg/L; lbs/acre; lbs/day Site specific grab BOD (5

- day; total; soluble) mg/L; lbs/acre;lbs/day Site specific grab

Solids (total dissolved; dissolved; dissolved inorganic) mg/L; lbs/acre; lbs/day Site specific grab

COD mg/L; lbs/ac re; lbs/day Site specific grab Conductivity umhos/cm Site specific grab
Chloride mg/L; lbs/acre; lbs/day Site specific grab

1 The total amount of wastewater applied to the crop production field and for dust control shall be reported each month.



### Sectio n S_ . IRRIGATION AND CROP PLAN

Annual Summary of Farm Operations for Previous year

This summary shall include:

1.

- 5.: Use existing permit language 6.. (Depending on site specific conditions and wastewater characteristics in the engineering report, add any appropriate reporting conditions for the annual summary submittal)CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 1 

# CHAPTER IX

. DERIVING EFFLUENT LIMITS FOR THE PROTECTION OF AQUATIC SEDIMENTS

Permit managers must consider the effect of a proposed discharge to surface waters on the quality of aquatic sediments and limit the concentrations of pollutants that cause an exceedance of the sediment quality standards (SQS).

This chapter acquaints the permit writer with the basis of the sediment quality standards and defines the permit writer's initi al tasks of implementing the standards. This chapter is derived from a more comprehensive document called the Sediment Source Control Standards User
Manual (Ecology 1993). Permit managers who become involved in authorizing sediment impact zones (SIZ) or deriving effluent limits based on the sediment quality standards should read the
Sediment Source Control Standards User Manual to understand those procedures.

This chapter outlines the permit writers tasks for implementing the sediment management
standard s, discusses the sediment quality standards, presents the overall approach for implementing the sediment source control standards including the authorization of the SIZ and then discusses in more detail the narrative and technical screening conducted by pe rmit writers. Sediment monitoring guidance is located in Section 7 of Chapter XIII Monitoring Guidelines.

Permit writers should realize that the processes described here are only for assessment and control of sediment contamination near the point of dis charge. Protection from farfield contamination relies on customary technology

- based and surface water quality

- based pollutant
controls.



## 1. PERMIT WRITER'S TASKS

For permits to Puget Sound

Complete the narrative evaluation sheet and the technical evaluat ion sheets, send a copy of the completed sheets when submitting the draft permit for QA review, and discuss the results in the fact sheet. Require baseline monitoring or monitoring for model runs if indicated by the
evaluation. Consult with the Sediment Management Unit (SMU) on the specifics of the monitoring requirements. Compare monitoring results with the sediment quality standards.CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 2 

## For permits to other marine waters

Complete the narrative evaluation sheets and the technical evaluation sheets, attach copies of the completed sheets to the draft permit for QA review, and discuss the results in the fact sheet. Require baseline monitoring or monitoring for model runs if indicated by the evaluation. Consult with the Sediment Management Unit on the specif ics of the monitoring requirements. Compare sediment quality data with the sediment quality standards on a case

- by

- case basis.


## For permits to low saline waters

Complete the narrative and technical evaluation sheets and send a copy of the completed sheets with the draft permit for QA review. Require sediment

- related monitoring or other sediment requirements only after consultation with the SMU.


## For permits to fresh water

Evaluate the possibility of sediment contamination on a pollutant

- specific and facili ty

- specific basis. Contact the SMU before placing any sediment

- related requirements in permits.



## 2. THE SEDIMENT MANAGEMENT STANDARDS

Several state laws provide Ecology with the authority to address sediment contamination issues in Washington State waters . The most important of these laws, for purposes of implementing the Sediment Management Standards, is the Water Pollution Control Act, Chapter 90.48 of the Revised Code of Washington (RCW). The Water Pollution Control Act provides Ecology with
the autho rity to regulate point and nonpoint source discharges in order to limit discharge

- related impacts to sediment quality. The Sediment Manage ment Standards rule (Chapter 173

- 204 WAC) was developed by Ecology to:



### • Establish chemical, biological, and other cr iteria as standards for the quality of sediments to protect beneficial uses and human health. These specific criteria values within the Sediment Management Standards are called the Sediment Quality Standards (SQS). The SQS are equivalent to the numerical criteria in the surface water quality standards.



### • Apply the sediment quality standards (SQS) as the basis for the management and reduction of pollutant discharges



### • Provide a management and decision process for the cleanup of contaminated sediments.

Addit ional background information on the development of and rationale for the SedimentCHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 3 Management Standards is available in the Final Environmental Impact Statement for the Washington State Sediment Management Standards (Ecology 1990).

The Sediment Management Standards address three main issues.

First, the rule establishes a narrative sediment quality goal defined as no acute or chronic adverse effects on biological resources and no significant health risk to humans caused by sediment contamination. The SQS establish the long

- term management goal for the quality of sediments throughout the state. The SQS are defined by:



### • Numerical chemical concentration criteria (chemical concentration criteria for Puget Sound marine sediment quality are provided in WAC 173

- 204

- 320(2))



### • Biological effects criteria (biological effects criteria for Puget Sound marine sediment quality are provided in WAC 173

- 204

- 320(3))



### • Human health criteria (currently under development); WAC 173

- 204

- 320(4) and (5)).

Sediments that exceed the SQS criteria are predicted to have adverse effects on biological resources or to pose significant human health risks. The SQS criteria may be revised as new data are developed regarding the toxicity of contaminants in sediments to human health and the

en vironment.

A significant difference between the SQS and the surface water quality standards is that the SQS
can be superseded by a demonstration that no significant biological effects are occurring. A discharger who finds that the SQS are exceeded at the point of discharge may elect to let the results stand as an exceedance of the criteria or, alternatively, to conduct biological testing to show compliance with the standards.CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 4 TABLE IX

- 1. MARINE SEDIMENT QUALITY STANDARDS AND SEDIMENT IMPACT ZONE MAXIM UM ALLOWABLE CONTAMINATION LEVELS FOR PUGET SOUND a

Chemical Parameter SQS SIZ max

Metals (mg/kg dry weight)

Arsenic 57 93
Cadmium 5.1 6.7
Chromium 260 270 Copper 390 390
Lead 450 530 Mercury 0.41 0.59
Silver 6.1 6.1
Zinc 41 0 960

Nonionizable Organic Compounds (mg/kg organic carbon b ) Aromatic Hydrocarbons

Total LPAH c 370 780 Naphthalene 99 170 Acenaphthylene 66 66 Acenaphthene 16 57
Fluorene 23 79
Phenanthrene 100 480
Anthracene 220 1,200

2

- Methylnaphthalene 38 64
Total HPAH d 960 5,300
Fluoranthene 160 1,200 Pyrene 1,000 1,400 Benz[a]anthracene 110 270 Chrysene 110 460
Total benzofluoranthenes e 230 450 Benzo[a]py rene 99 210 Indeno[1,2,3

- c,d]pyrene 34 88 Dibenzo[a,h]anthracene 12 33 Benzo[g,h,i]perylene 31 78
Chlorinated Benzenes

1,2

- Dichlorobenzene 2.3 2.3 1,4

- Dichlorobenzene 3.1 9 1,2,4

- Trichlorobenzene 0.81 1.8CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 5 Chemical Parameter SQS SIZ max

Hexachlorobenzene 0.38 2.3

Phthalate Esters

Dimethyl phthalate 53 53 Diethyl phthalate 61 110

Di

- n

- butyl phthalate 220 1,700 Butyl benzyl phthalate 4.9 64 Bis[2

- ethylhexyl]phthalate 47 78

Di

- n

- octyl phtha late 58 4,500
Miscellaneous

Dibenzofuran 15 58
Hexachlorobutadiene 3.9 6.2

N

- nitrosodiphenylamine 11 11
PCBs 12 65

Ionizable Organic Compounds ( μ g/kg dry weight; parts per billion)

Phenol 420 1,200

2

- Methylphenol 63 63

4

- Methylphenol 670 670 2,4

- Dimethylphenol 29 29 Pentachlorophenol 360 690 Benzyl alcohol 57 73
Benzoic acid 650 650

Note: HPAH

- high molecular weight polycyclic aromatic hydrocarbon LPAH

- low molecular weight polycyclic arom atic hydrocarbon PCB

- polychlorinated biphenyl SIZ max - Sediment Impact Zone maximum allowable contamination level (WAC 173

- 204

- 420) SQS

- Sediment Quality Standards (WAC 173

- 204

- 320)

a Where laboratory analysis indicates a chemical is not detected in a sediment sample, the detection limit should be reported. Where chemical criteria in this table represent the sums of individual compounds (e.g., total LPAHs and total HPAHs) or groups of isomers (e.g., total PCBs), and a chemical analysis identifies an undetected value for one or more individual compounds or groups of isomers, the detection limit should be used for calculat ing the sum of the respective compounds or groups of isomers.

b The listed values represent concentrations in par ts per million "normalized" on a total organic carbon basis. To normalize to total organic carbon, the dry

- weight concentration for each parameter is divided by the decimal fraction representing the percent total organic carbon content of the sediment.CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 6 c The total LPAH criteria are to be compared to the sum of the concentrations of the following LPAH compounds: naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, and anthracene. 2

- Methylnaphthalene is not included in the LPAH definition . The total LPAH criteria are not the sums of the corresponding criteria listed for the individual LPAH compounds.

d The total HPAH criteria are to be compared to the sum of the concentrations of the following HPAH compounds: fluoranthene, pyrene, benz[ a]anthracene, chrysene, total benzofluoranthenes, benzo[a]pyrene, indeno[1,2,3

- c,d]pyrene, dibenzo[a,h]anthracene, and benzo[g,h,i]perylene. The total HPAH criteria are not the sums of the corresponding criteria listed for the individual HPAH compounds.

e The total benzofluoranthenes criteria are to be compared to the sums of the concentrations of the b, j, and k isomers of benzofluoranthene.

The numerical chemical concentration criteria and biological effects criteria presently containe d in the rule (WAC 173

- 204

- 320(2) and (3)) apply only to marine sediments in Puget Sound.
Similar criteria for other marine sediments and for freshwater and low

- salinity sediments of Washington State are currently being developed by Ecology (WAC 173

- 204

- 3 20(1)(c), 173

- 204

- 330, and 173

- 204

- 340). Until such criteria are adopted into the Sediment Management Standards, rule compliance with the narrative standard for other marine, freshwater, and low

salinity sediments will be determined on a case

- by

- case basi s. This document presents a process
for such case

- by

- case determinations in Part 4.4.

Second, the Sediment Management Standards set forth a process for managing sources of sediment contamination (WAC 173

- 204

- 400 through 173

- 204

- 420). The SSCS specifical ly address the following aspects of this process:



### • A requirement that discharges with the potential to impact receiving sediments have received all known, available, and reasonable methods of prevention, control, and treatment (AKART) prior to discharge, a nd/or the application of best management practices (BMPs), as appropriate



### • Monitoring procedures for evaluating the potential for a discharge to impact the receiving
sediments



### • Procedures for determining whether a discharge is eligible for a sediment impac t zone (SIZ), which would allow contamination in the receiving sediments to exceed the SQS



### • If a SIZ is to be authorized, methods for determining appropriate restrictions (e.g., on the allowable areal extent or level of contamination and biological effects )



### • SIZ renewal, maintenance, and closure requirements.CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 7 Although the SSCS allow eligible discharges to cause receiving sediments to exceed the SQS, the SSCS also set forth specific chemical and biological criteria (WAC 173

- 204

- 420) that define
the maximum level of chemical contamination or biological effects above the SQS that will be allowed within an authorized SIZ. This ceiling on chemical contamination and biological effects is referred to as the SIZ maximum allowable contamination level, or SIZ max .

T hird, the Sediment Management Standards set forth a decision process for identifying contaminated sediment sites and determining appropriate cleanup responses (WAC 173

- 204

- 500 through 173

- 204

- 590). Natural recovery is recognized as a viable response optio n for sediments that are expected to recover unaided to at least the minimum cleanup level within a 10

- year time frame. Natural recovery to the SQS may take more than 10 years.

There should be consistency in the levels of sediment contamination and biolo gical effects that will be allowed to remain in the environment following source control measures and cleanup at contaminated sediment sites. For this reason, the same numerical chemical concentration criteria and biological effects criteria have been est ablished for the maximum level of chemical contamination or biological effects allowable within an authorized SIZ (i.e., SIZ max ; WAC 173

- 204

- 420) and the maximum level of chemical contamination or biological effects allowable once cleanup is complete (i.e. , MCUL; WAC 173

- 204

- 520). These standards have been set at chemical concentrations or biological effects levels established by the narrative sediment quality regulatory goals that correspond to a “minor adverse effects level” (equal to or higher than the SQS).

The narrative goal of the Sediment Management Standards has also been formulated to be consistent and compatible with the sediment quality goals of the Puget Sound Dredged Disposal Analysis (PSDDA) program, which addresses the management and disposa l of sediments dredged as part of navigational maintenance or construction activities. Consistency is established by setting the SIZ max , CSL, and MCUL at chemical concentrations and biological effects levels that are as similar as possible to the PSDDA gu idelines for unconfined, open

- water disposal of dredged material (i.e., PSDDA Site Condition II). Exact correspondence is currently not possible because slightly different sets of biological tests and test interpretation guidelines are used for the two pr ograms. For the purpose of testing sediments under the various sediment management programs, the Puget Sound Estuary Program protocols (PSEP 1991c) provide consistent procedures for sediment sampling, chemical analyses, and biological testing, but the
int erpretation of the results is program

- specific.



## 3

. OVERVIEW OF THE PROCESS

Figure IX

- 1 provides an overview of the permitting process and authorization of a SIZ. For the sake of simplicity, the process depicted in Figure IX

- 1 is linear. However, the act ual decision

-CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 8 making process followed by permit managers and SMU staff has multiple decision points and pathways, which are described in greater detail in subsequent sections of this chapter and in the
Sediment Source Control Standards Users Manual . In add ition, some of the steps illustrated in Figure IX

- 1 are actually implemented in a phased or iterative manner, which is not easily represented in this linear flowchart (e.g., the evaluation of the potential for sediment impacts may include both generalized and site

- specific computer model runs, which are conducted before and after, respectively, the request for a SIZ application). This section only discusses in detail the part of the process up to the application of the SIZ.

In the following subsections, t he primary provisions and requirements of the SSCS with respect to the sediment source control standards permitting process are described. This process generally follows the 10

- step process outlined in WAC 173

- 204

- 400(1)(a)

– (j), but the order of
discussio n in the following subsections has been modified slightly to correspond to the permitting process as implemented by the WQP. The subsections of the rule corresponding to each step are indicated. When appropriate, reference is made to subsequent chapters of this manual for implementation guidance.


## 3.1 Evaluation of the Potential for a Discharge to Impact Receiving Sediments (WAC 173

- 204

- 400(1)(a))

A screening

- level evaluation of the potential for a discharge to cause sediment impact is conducted when a pe rmit application is accepted for a new or existing discharge. The screening

level evaluation, which consists of both narrative and technical evaluations, is described in
Section 4.

If the screening

- level evaluation indicates that it is unlikely that the discharge would adversely impact the receiving sediments, the permit is issued or renewed without sediment monitoring, a SIZ authorization, or sediment quality

- based effluent limits. The evaluation sheets are sent to the
SMU.

If the screening

- level evalu ation indicates a potential for a discharge to adversely impact receiving sediments the sediment

- related information is forwarded to the SMU with the evaluation sheets. The SMU then runs a generalized SIZ computer model(s) (such as the Cornell Mixing Zone Expert System [CORMIX], or Water Quality Analysis Simulation Program [WASP]) using readily available information. The purpose of this generalized model run is to determine whether the discharge has the potential to cause an exceedance of the SQS numerica l criteria (Table IX

- 1) within a 10

- year period from the date of Ecology's evaluation of the ongoing discharge or the starting date of the proposed discharge, whichever is later (WAC 173

- 204

- 415(2)).

If there is evidence of an SQS violation, if sufficient data are available, and if the discharge is from a priority facility (see Figure IX

- 1), a site

- specific model run will also be performed.CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 9 Additional data required for either the generalized or site

- specific model runs may be requested from the discharger . The results of these model runs and application of the SMU's best professional judgment provide the basis for predicting the potential for a discharge to result in sediment impacts. The generalized and site

- specific model runs are described in the Sedi ment Source Control User Manual . In some cases, a compliance schedule may be established during the period required for collection of additional data to support application of the models.

In addition to the modeling data, monitoring data may be used to e valuate the potential for a discharge to cause an exceedance of the SQS. Guidance on the use of monitoring data for this purpose is provided in Chapter XIII Section 7.CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 10 Figure IX

- 1. Overview of process and responsibilities for the protection of aquatic sediments.

TASK RESPONSIBILITY

Wastewater Discharge Permit Application Discharger

Screening-level Evaluation of the

Potential for Sediment Impacts Water Quality Program

Detailed Evaluation of the Potential for Sediment Impacts Sediment Management Unit (SMU)

Application for sediment impact zone (SIZ) Sediment Management Unit

Assess Eligibility for SIZ Sediment Management Unit

Sediment Management Unit Develop SIZ Specifications and Sediment Quality-Based Effluent Limits

Develop Monitoring Requirements

Notify Public and Affected Landowners Sediment Management Unit/ Water Quality

Water Quality

Authorize SIZ (if appropriate) Water Quality

Monitoring of SIZ Sediment Management/Water Quality

Renewal or Modification of SIZ Sediment Management Unit/Water Quality

Closure of SIZ Sediment Management Unit/Water Quality TASK RESPONSIBILITY

Wastewater Discharge Permit Application Discharger

Screening-level Evaluation of the

Potential for Sediment Impacts Water Quality Program

Detailed Evaluation of the Potential for Sediment Impacts Sediment Management Unit (SMU)

Application for sediment impact zone (SIZ) Sediment Management Unit

Assess Eligibility for SIZ Sediment Management Unit

Sediment Management Unit Develop SIZ Specifications and Sediment Quality-Based Effluent Limits

Develop Monitoring Requirements

Notify Public and Affected Landowners Sediment Management Unit/ Water Quality

Water Quality

Authorize SIZ (if appropriate) Water Quality

Monitoring of SIZ Sediment Management/Water Quality

Renewal or Modification of SIZ Sediment Management Unit/Water Quality

Closure of SIZ Sediment Management Unit/Water QualityCHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 11 

## 3.2 Application for a SIZ (WAC 173

- 204

- 400(1)(b))

If the results of the generalized SIZ computer model run indicate that the discharge has the potential to impact sediments, Ecology will require an application for a SIZ. W AC 173

- 204

- 200(22) defines a SIZ as:

...an area where the applicable sediment quality standards of WAC
173

- 204

- 320 through 173

- 204

- 340 are exceeded due to ongoing permitted or otherwise authorized wastewater, storm water, or nonpoint source discharges, an d authorized by the department within a federal or state wastewater or storm water discharge permit, or other formal department authorization.

By the authority of WAC 173

- 204

- 415(4)(a), Ecology may require a discharger to submit any
information needed to run the SIZ models (simulating sediment contamination over a 10

- year period) to determine whether a SIZ is necessary and to determine the areal extent and location of the SIZ associated with the discharge. The SMU is responsible for requesting and evaluat ing applications for SIZs. SIZ application procedures are described in the Sediment Source Control
Standards Users Manual . When an application is received, the SMU will notify the Washington Department of Natural Resources (DNR) Division of Aquatic Lands , U.S. Army Corps of Engineers (Corps), and any port districts whose aquatic lands may be included within the proposed SIZ (WAC 173

- 204

- 415(2)(f)).



## 3.3 SIZ Eligibility Requirements (WAC 173

- 204

- 400(1)(c) and (f))

Once a SIZ application is received, the di scharge must be evaluated to determine whether it is eligible for a SIZ. The SMU is responsible for the eligibility evaluation.

All discharges are required to be operating with AKART and/or BMPs in place, as appropriate, or to be on a compliance schedule to meet these requirements, as a condition of a discharge authorization (Chapters 90.48, 90.52, and 90.54 RCW). This issue will, therefore, be addressed early in the discharge permitting process, regardless of the potential for the discharge to cause an impact to receiving sediments. However, to determine whether a new discharge or one not yet operating with AKART/BMPs in place will adversely impact receiving sediments, AKART/BMPs must be identified and assessed in the initial screening evaluation. Chap ter IV of this manual should be consulted for guidance on the process of determining AKART/BMPs for a given discharge. This evaluation will be conducted before a permit application is forwarded to
the SMU for SIZ evaluation.
WAC 173

- 204

- 415(3) requires th e discharger to submit to Ecology information concerning the location of the proposed SIZ. This section also requires that SIZs authorized by Ecology avoid whenever possible, and minimize adverse impacts to, areas of special importance. A SIZ mustCHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 12 also b e authorized in a manner consistent with the antidegradation policy of the state, as set forth
in WAC 173

- 204

- 120.

The areal extent of a SIZ will be determined based on the results of the modeling and the application of the SMU's best professional judgmen t. When the model results indicate that a SIZ may impact an area of special importance or property owned by someone other than the discharger, it may be necessary to alter the discharge characteristics (e.g., by relocating the discharge, reducing effluent loading) to avoid impacting such areas.


## 3.4 Development of SIZ Specifications

(WAC 173

- 204

- 400(1)(d),(e), and (g))

After determining that the discharge is eligible for a SIZ, detailed model simulations are run using site

- specific information provided in the SIZ application. The CORMIX and WASP models, or other SIZ model(s) can be used. The SMU is responsible for application of contaminant fate and transport modeling to the discharge.

The site

- specific model run is used to reduce the uncertainty associ ated with the generalized model run, develop SIZ specifications, and evaluate the potential for the discharge to exceed the
SIZ max numerical criteria over a 10

- year period from the date of Ecology's evaluation of an ongoing discharge or the start date of a proposed discharge, whichever is later (WAC 173

- 204

- 415(4)). The site

- specific model may also be used to establish sediment quality

- based effluent limits necessary to achieve acceptable levels of sediment quality. WAC 173

- 204

- 415(4) specifies that the m odels be run by Ecology or by the discharger, as required by Ecology.

In addition to the modeling data, monitoring data may be used to evaluate the potential for a discharge to cause an exceedance of the SIZ max numerical criteria. Guidance on the use of monitoring data for this purpose is provided in Chapter XIII Section 7.

As stated in WAC 173

- 204

- 415(1)(e), SIZs authorized by Ecology shall include the minimum practicable surface area, not to exceed the surface area allowed by WAC 173

- 204

- 415(4). WAC
1 73

- 204

- 415(4) in turn requires that the location of the SIZ, its areal extent, and the degree of allowable effects within the SIZ be determined by applying the SIZ models (CORMIX, WASP, and/or other SIZ model[s] approved by Ecology) as limited by the stand ards of that section, and by application of best professional judgment.

Any overlap of the SIZs for two or more discharges predicted through the use of the SIZ models or based on best professional judgment will be authorized only in the event that the SIZ max chemical and biological criteria are not exceeded as a result of the overlap. If multiple discharges would result in sediment contamination above the SIZ max , a wasteload allocation process would be necessary (WAC 173

- 204

- 415(4)(b)(ii)). The SMU is re sponsible for running the SIZ models for this purpose and will work with Ecology's Environmental AssessmentCHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 13 Program and the WQP in developing wasteload allocations.

WAC 173

- 204

- 415(1)(f) also requires that the chemical concentrations and biological effect s levels within an authorized SIZ be maintained at the lowest levels possible. Ecology is required to consider the relationship between environmental effects, technical feasibility, and cost in determining the minimum practicable chemical concentration an d biological effects levels, within the range of contamination that will be allowed in an authorized SIZ. In no case should the adverse effects to biological resources within an authorized SIZ exceed the minor adverse
effects level as a result of the disc harge, as determined by the procedures set forth in WAC 173

- 204

- 415(5). This activity is the responsibility of the SMU.



## 3.5 SIZ Monitori ng and Maintenance Requirements (WAC 173

- 204

- 400(1)(i))

All SIZ authorizations should include monitoring and maintenan ce requirements designed to ensure that the specifications included in the authorization are not violated. Such requirements should include sediment and effluent monitoring and procedures for maintenance restoration of sediments (i.e., if the discharge re sults in sediment contamination or biological effects that exceed the maximum levels allowed in the SIZ authorization, capping or dredging of the contaminated sediments may be required). Permit managers and SMU staff jointly develop monitoring and mainten ance requirements.



## 3.6 Public Notice and Landowner Notification Procedures (WAC 173

- 204

- 400(1)(h))

In accordance with WAC 173

- 204

- 415(1)(j), all proposed SIZ authorizations are subject to public notice, comment, and hearing procedures as required by the s tate laws and regulations applicable to the specific discharge. When determining the need for, location, and/or design of the SIZ, Ecology is required to consider all comments received during public review of the application. The permit manager is respon sible for public notice and landowner notifications. However, as discussed above, the SMU will also notify DNR, the Corps, and affected port districts early in the process of reviewing a SIZ application. The discharger should also be encouraged to make a n early effort to identify and coordinate with the potentially affected landowner(s).

In some cases, an authorized SIZ will be located on property owned or used by someone other than the source discharger. Recognizing that the potential sediment impact r esulting from the discharge may be of concern to the other individual(s), WAC 173

- 204

- 415(2)(e) requires that Ecology and the discharger make a reasonable effort to identify and notify all landowners, adjacent landowners, and lessees potentially affected b y the proposed SIZ. Under the authority
of WAC 173

- 204

- 415(2)(e)(viii), affected landowners, adjacent landowners, and lessees may comment on a proposed SIZ. Any such comments are to be submitted in writing to EcologyCHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 14 within 30 days from the date of recei pt of the notification letter, or by an extended due date approved by Ecology. WAC 173

- 204

- 415(5)(e) also requires that affected landowners be given the opportunity to review all SIZ maintenance action plans before the action is implemented.



## 3.7 Renewa l, Modification, and Elimination of Authorized SIZs Over Time (WAC 173

- 204

- 400(1)(j))

The goal of Ecology is to manage source control activities to reduce and ultimately eliminate adverse effects on biological resources and significant threats to human hea lth resulting from sediment contamination (WAC 173

- 204

- 410(1)(a)). In support of that goal, it is Ecology's policy to minimize the number, areal extent, and adverse effects of all authorized SIZs, with the
intent to eliminate the existence of all SIZs whe never practica ble (WAC 173

- 204

- 410(1)(b)). This goal will be achieved through modification of existing SIZ specifications and by limiting the renewal of SIZs when possible. However, the rule addresses exceptions to this general policy by requiring that Ecology consider environmental effects, technical feasibility, and cost in determining when it is practicable to minimize or eliminate a SIZ.

WAC 173

- 204

- 415(8) sets forth the conditions under which a SIZ authorization may be renewed

. These conditions in clude:



### • When the discharge is operating with AKART/BMPs in place



### • When the discharger demonstrates that the discharge activities comply with the SSCS and with the existing SIZ authorization



### • When the disch arger demonstrates that a reduction in the areal extent of the SIZ and/or the level of contamination within the SIZ is not practicable, and therefore the SIZ cannot be
reduced or eliminated.

WAC 173

- 204

- 415(7) specifically authorizes Ecology to modify a S IZ authorization under the following conditions:

* When the nature of the discharge activity has changed

* When new information indicates that a modification of the SIZ authorization is appropriate

* When the standards or regulations upon which the permit was based have changed

* When there is advancement in technology that applies to the discharge under
consideration.CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 15 This section should be interpreted to provide Ecology with the authority to both restrict and relax SIZ specifications, as appropriate, based o n a consideration of environmental effects, technical feasibility, and cost, consistent with the requirements of the SSCS.

Guidance for determining whether it is practicable to modify or eliminate a SIZ, whether SIZ maintenance activities should be requir ed, or whether a SIZ should be renewed at the end of the permit cycle without modification is provided in the Sediment Source Control Standards Users
Manual . SMU staff and permit managers share the responsibility for this determination. Permit

managers w ill conduct an initial screening of the renewal application. If it appears that a SIZ authorization should be modified, the renewal application will be forwarded to the SMU for a
detailed evaluation.


## 3.8 Closure and Restoration of SIZs (WAC 173

- 204

- 400(1) (I))

WAC 173

- 204

- 415(6) requires that all SIZ authorizations include a SIZ closure plan. The purpose of this plan is to identify the method or methods of cleanup that the discharger will implement upon closure of the SIZ. The responsibility for overseein g SIZ closure and restoration activities will be determined by Ecology on a case

- by

- case basis.



## 4. SCREENING

- LEVEL EVALUATION OF POTENTIAL FOR SEDIMENT IMPACTS

The general process for determining whether a SIZ is needed and for developing SIZ specificatio ns is illustrated in Figure IX

- 2. The first step in this process is for the permit manager to perform a screening

- level evaluation of whether the discharge has the potential to impact sediment quality. This chapter describes the screening

- level evaluatio n, which includes
both narrative and technical evaluations

. The WQ Program has determined that all major dischargers to Puget Sound will conduct sediment sampling.

Screening

- level evaluations are required for all marine surface water discharges to determ ine their potential to cause an exceedance of the SQS numerical criteria.



## 4.1 Initiation of Activities

In the initial stages of the permitting process, three general categories of activities that relate to sediment quality impacts are initiated by the pe rmit manager:



## • Assess Status of Source Control

— The status of source control activities is routinely assessed to determine whether AKART and BMPs are in place. If the facility has not yet achieved AKART/BMPs, a compliance schedule should be developed, andCHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 16 estimates should be made of effluent characteristics (including contaminant concentrations) to be achieved with AKART/BMPs.



## • Perform Screening

- Level Evaluation of the Potential for Sediment Impacts

— Existing information on the qualitative and quantitative c haracteristics of the facility, discharge, and receiving environment is reviewed to determine whether there is a potential for a discharge to cause sediment quality impacts.



## • Evaluate Baseline Monitoring Data

— Available baseline monitoring data for
sediment s and receiving water in the vicinity of the discharge should be identified and reviewed. If the screening

- level evaluation indicates the potential for a discharge to cause sediment impacts, and if available baseline data are inadequate, additional
baseli ne monitoring may be necessary. Monitoring data and other local sediment data (e.g., data in the SMU SEDQUAL database) will also be used at a number of decision points in the SIZ development process.

These activities are discussed on the following page

.CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 17 Figure IX

- 2. Screening

- level Evaluation of Potential for Sediment Impacts

Permit Application

Conduct Narrative Evaluation

Does Narrative Evaluation Indicate a Potential for Violation of the SQS? - No baseline monitoring - Discuss lack of potential in the fact sheet - Send evaluation sheets

with draft permit to QA reviewer No

Are Data Available to Conduct Technical Evaluation? Yes

- Require baseline sediment monitoring in the permit or by order and discuss in the fact sheet

Conduct Technical Evaluation No

Yes

Does Technical Evaluation Indicate Potential for Sediment Contamination?

- No Baseline Monitoring or other Sediment Requirements. - Identify the Lack of Potential in the Fact Sheet - Send Worksheet with the draft permit to QA reviewer No

Are Data Available for a General Computer Run? Yes

SMU runs the General Model Require Data Collection in the

Permit or by Order.

Consult SMU Regarding Further Requirements Yes

NoCHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 18 

### 4.1.1 Assess Status of Source Control

WAC 173

- 204

- 400(2) requires all permits or other authorizations for wastewater, stormwater, and nonpoint source disc harges to surface waters of the state to be conditioned so that the discharger is operating with AKART and/or BMPs prior to discharge, as required by Chapters 90.48, 90.52, and 90.54 RCW. Thus, all regulatory actions taken under the Sediment Management St andards are based on the assumption that the discharger either is operating with AKART and/or BMPs in place, or is on a compliance schedule to meet these requirements. Chapter IV should be consulted for guidance on the process of identifying AKART/BMPs fo r the various types of discharges.

Ecology recognizes that it may take some time for an existing discharge to come into compliance with the requirements of AKART. If a discharge of this type has the potential to impact receiving sediments before coming i nto compliance with AKART, a SIZ may be authorized while a compliance schedule is being implemented. If receiving sediments become contaminated above the level allowed within the SIZ before AKART is in place, Ecology may require the discharger to conduct mainte nance restoration of the impacted sediments before or as part of the SIZ authorization.

The permit manager should also document recent changes in treatment processes and assess time trends in discharge loading characteristics. If a compliance sche dule is to be implemented for the achievement of AKART/BMPs, it will be necessary to estimate effluent characteristics (including contaminant concentrations) to be achieved with AKART/BMPs for SIZ modeling
and authorization.

In addition to the AKART/BMP r equirement, WAC 173

- 204

- 415(1)(d) requires that the discharger adequately addresses alternative waste reduction, recycling, and disposal options. The permit manager is responsible for verifying this requirement, which would normally be
addressed in the di scharger's solid waste plan, spill plan, and/or pollution prevention plan.



### 4.1.2

. Perform Screening

- Level Evaluation of the Potential for Sediment Impacts
The initial screening

- level evaluation of the potential for a discharge to impact receiving
sediment s is based primarily on readily available qualitative and quantitative information. The evaluation consists of two parts, a narrative evaluation and a technical evaluation.

In general, facilities handling or producing known contaminants that are commonly associated with pollution problems are considered to have a potential for causing sediment contamination and will generally undergo a detailed evaluation by the SMU. If relevant contaminant loading data are available for the discharge, screening equation s can be applied as part of the technical evaluation, and a preliminary assessment of the potential for sediment impacts can be made.

Facilities that have been in place and discharging wastewater at a steady rate for several years
can also be evaluated th rough direct measurement of chemical concentrations or biologicalCHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 19 effects in the receiving sediments. If no sediment contamination or biological effects are found, it may be assumed that there is little potential for sediment contamination to occur in the future unless the loading rate is expected to increase. Alternatively, if a discharger is being granted an increase in permitted contaminant loading rates, evaluation of existing sediment conditions may not be sufficient, and the detailed evaluation may be necessary.

Once the screening

- level evaluation is complete, the worksheets should be filed with the permit application and a copy of the worksheets forwarded to the SMU. If the screening

- level evaluation indicates that there is little or no potential for sediment impacts, the permit manager may determine that no specific sediment

- related provisions need to be included in the discharge permit. If there is considered to be a potential for sediment impacts, the permit manager should
evaluate available ba seline monitoring data, or, if available baseline monitoring data are inadequate, the discharger should be required to collect the necessary baseline monitoring data (see Part 4.1.3).

The narrative and technical evaluation steps are described in detail in subsections 4.2 and 4.3,
which include worksheets that can be used in the evaluation.



### 4.1.3

. Evaluate Baseline Monitoring Data
The results of any baseline sediment quality monitoring, if available, should be reviewed by the permit manager to establish ba seline sediment quality conditions. These monitoring data, as well as available regional monitoring data from other programs (e.g., data in the SMU SEDQUAL database), should be reviewed early in the permitting process to identify any additional monitoring that may be required and to identify data that may be used to evaluate the need for a
SIZ.

In the sediment source control process, early evaluation of available baseline monitoring data is important because it assists in identifying sediment contaminants that may have been contributed by other permitted or unpermitted (and possibly historical) discharges. In addition, this evaluation may enable Ecology to identify the single or multiple ongoing discharges contributing to sediment contamination in a given area, and thus to regulate these discharges as appropriate.

In cases where no baseline monitoring has previously been conducted and the result of the screening

- level evaluation is a judgment that the discharge has the potential to cause sediment impacts, a requirement for baseline monitoring should be included in the permit. The permit manager is responsible for developing baseline monitoring requirements, where appropriate, with
assistance of the SMU. In cases where there are also insufficient data ava ilable to run even the generalized SIZ model, additional monitoring requirements should be included in the permit for the collection of the necessary data. Guidance on the development of monitoring requirements to support use of the models is also provide d in Chapter XIII.CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 20 In cases where there is a potential for sediment impacts and the needed monitoring data have not yet been collected, the permit may be issued or renewed without a SIZ authorization, but with the requirement for appropriate monitoring t o be conducted early in the permit cycle. Once the necessary monitoring has been completed, the data can be used to complete the detailed evaluation of the potential to cause sediment impacts. If the result of the detailed evaluation is
that a SIZ is nee ded, the permit can then be modified to authorize a SIZ.


## 4.2 Narrative Evaluation of the Potential for Sediment Impacts

The narrative evaluation may be used to identify facilities that have a low potential for sediment impacts, based on the general charac teristics of the facility and the nature of the discharge. Facilities identified as having a low potential for sediment impacts by the narrative evaluation need not be evaluated using the more detailed technical evaluation. The permit manager should
cond uct the narrative evaluation by filling out the narrative evaluation worksheet (Figure IX

- 3). If the facility has any of the characteristics identified in Item 1 of the worksheet, its discharge is considered to have the potential for causing adverse sedim ent impacts. If the discharge is one of the types identified in Item 2 of the worksheet, or if the facility has none of the characteristics identified in Item 1 of the worksheet, the discharge is not considered to have a potential for causing adverse sedi ment impacts. The permit manager should indicate in response to Item 3 whether or not the discharge is considered to have the potential to cause adverse sediment impacts.

Although a definitive assessment of a discharge's eligibility for a SIZ can only be made after the development of SIZ specifications, it is appropriate as part of the narrative evaluation to provide a preliminary indication of whether the discharge would be eligible for a SIZ. One of the criteria
for authorization of a SIZ is that it no t adversely affect an area of special importance and that it be in the public interest. The permit manager should make this determination during the narrative evaluation and indicate to the SMU if the discharge is eligible for a SIZ.



## 4.3

. Technical Evalu ation of the Potential for Sediment Impacts

If the narrative evaluation identified the facility as having the potential for sediment impacts and if the necessary data are available, the screening

- level evaluation should also include a technical
evaluation , as described below. This evaluation uses readily available information on the discharge, along with any baseline monitoring data, to determine whether there is a potential for the SQS numerical criteria to be exceeded in the receiving sediments. If the re are insufficient data to conduct the technical evaluation, the discharger will be required to provide the data necessary to further evaluate the need for a SIZ (see Chapter XIII, Section 7).

To date, SQS numerical criteria have only been promulgated fo r marine sediments within Puget Sound. Hence, the technical evaluation procedures described in this section currently apply onlyCHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 21 to discharges to Puget Sound marine environments. Use of these procedures for evaluating discharges to non

- Puget Sound marine environments may be appropriate based on the case

- by

case application of best professional judgment by the permit manager, with guidance from the SMU. Until SQS numerical criteria for sediments in freshwater and low

- salinity environments are developed, o ther evaluation procedures will have to be used for discharges to those environments (see Subsection 3.4).

If there are chemicals of concern in a marine discharge that have SQS numerical criteria (see
Table IX

- 1), the permit manager should complete the te chnical evaluation worksheets and attach them to the narrative evaluation. If the discharge is of concern, but not enough data are available to complete the technical evaluation or the chemicals of concern do not have SQS numerical criteria, the permit ap plication should be forwarded to the SMU for a case

- by

- case evaluation.



### 4.3.1 Methods of Evaluation
Sediment contaminant concentrations can be measured directly or can be estimated using a variety of sampling methods. These methods include sampling parti cles or sediments in sumps, drains, or the receiving environment, or sampling suspended particulate matter in the water column or suspended solids in an effluent entering the receiving water. In addition, the results of biological tests may be used to eva luate the potential for impacts to sediments. Alternatively,
data on the total chemical concentrations in an effluent can be used to estimate the chemical concentrations associated with discharged particles. Once sediment or particle chemistry has
been d etermined, the concentrations can be compared directly to the SQS numerical criteria to evaluate whether a discharge has the potential to cause an exceedance of the standards. Methods for sampling sediment and suspended particulate matter are described in greater detail in Chapter
XIII.

Figures IX

- 3 through IX

- 7 provide worksheets for completing the technical evaluation. In addition to information provided in the permit application, existing effluent monitoring data and baseline monitoring data should be reviewed and used in the evaluation. The following four types of data may be used (see Sections 1

– 4 of the technical evaluation worksheet):

* Chemical Concentrations in Source Sediments and Effluent Suspended Solids

— These data include the concentrations of chemicals in sediments that may accumulate at points within the facility downstream of any treatment processes (e.g., ditch, outfall, sump) or the concentrations of chemicals associated with suspended solids in the effluent. Because these data

are mos t closely related to source characteristics, this section of the worksheet should always be completed if such data are available.

* Chemical Concentrations in Receiving Sediments and Settling Particulate Matter in the Water Column

— Baseline monitoring data or other data on receiving sediments near the point of discharge are most useful in evaluating potential impacts from a source that has been ongoing at a similar level of discharge for 5 years or more. If such data are available nearCHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 22 existing outfalls, t his section of the worksheet should be completed, unless there is sufficient reason to believe that receiving sediments would only be contaminated due to historical or ongoing sources unrelated to the discharge. This section of the worksheet should also b e completed if there are data available on the chemistry of settling particulate matter obtained from sediment traps in the receiving water column, and if there is sufficient reason to believe that the material obtained from those sediment traps is associa ted with the discharge.

* Biological Test Data for Receiving Sediments

— These data include baseline monitoring data or other biological tests performed on sediments collected near the outfall. This section of the worksheet should be completed if the appro priate types of biological tests have been conducted, unless there is sufficient reason to believe that receiving sediments would only be contaminated due to historical or ongoing sources unrelated to the discharge.

* Effluent Monitoring Data

— Effluent mon itoring data (i.e., total chemical concentrations in the effluent) can also be used to estimate the potential for sediment impacts, although the relationship between these data and the potential for sediment impacts is less direct than for the types of dat a described above. This section of the worksheet should be completed if representative effluent data are available, and may be especially useful if the discharger proposes a new or substantially different type of discharge than has been present in the pas t.

Each of the sections of the worksheet is independent, and any one of the sections alone may indicate the potential for sediment contamination. However, if more than one type of data is available, each applicable section of the worksheet should be comp leted. This additional information will assist the SMU in performing the subsequent detailed evaluation.

Figures IX

- 3 through IX

- 8 are on the following pages IX

- 24 through IX

- 30.

Figure IX

- 3

. Screening

- Level Evaluation of the Potential for Sediment Im pacts. Part A.
Narrative Evaluation.

Figure IX

- 4. Screening

- Level Evaluation of the Potential for Sediment Impacts

. Part B. Technical Evaluation

. Summary Sheet.

Figure IX

- 5

. Screening

- Level Evaluation of the Potential for Sediment Impacts

. Sectio n 1. Chemical Concentration in Source Sediments and Effluent Suspended Solids.

Figure IX

- 6

. Screening

- Level Evaluation of the Potential for Sediment Impacts. Section 2. Chemical Concentrations in Receiving Sediments and Settling Particulate Mat ter in the
Water Column.

Figure IX

- 7. Screening

- Level Evaluation of the Potential for Sediment Impacts. Section 3. Biological Test Data for Receiving Sediments.CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 23 Figure IX

- 8. Screening

- Level Evaluation of the Potential for Sediment Impacts. Section 4. Effluent Monitoring Data.CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 24 

### Screening

- Level Evaluation of the Potential for Sediment Impacts

Part A. Narrative Evaluation

Applicant:
Waste Discharge Permit No.:

Location:

1. A discharge is generally considered not to have a risk for causing adverse sediment impacts if the facility has all of the following three characteristics:  a freshwater discharge to marine water, and  has secondary wastewater treatment or equivalent and  discharges to an area with an average tidal velocity of 1 cm/sec or greater. If any one of these three factors is not applicable proceed to 2.

2. A d ischarge is generally considered to have a risk for causing adverse sediment impacts if the facility meets any of the following criteria (check any that apply and attach a brief explanation):

 Uses, stores, produces as a product or waste, or transfers a ny hazardous substance listed in 40 CFR 302.4, with a statutory code of 1 or 2, [referring to Sections 311(b)(4) or 307(a) of the Clean Water Act] unless: The facility is designed and managed so that these substances are kept fully physically separated at all times, including spills or any other accidental release, from any part of the wastewater collection, treatment, or discharge system or stormwater system; or
The amount of any hazardous substance at the facility is never more than the statutory repo rtable quantity listed in 40 CFR 302.4.

 Discharges any chemical pollutant listed in Appendix D of 40 CFR Part 122, Table II, in its effluent (attach a list of any such pollutants known to be discharged)

.  Has a reasonable potential to violate water quality standards for any pollutant in Appendix D of 40 CFR Part 122, Table III (attach a list of any such pollutant known to be discharged)

.  Discharges other potentially deleterious substances, such as any of the following (check any that apply) :

_

____ Solid inorganic materials (e.g., paint chips, slag) _____ Radionuclides _____ Other (describe)

 Belongs to any industry category identified in 40 CRF Part 122, Appendix A.

 Is a municipal facility that receives a discharge from any industry category identified in 40 CFR Part 403, Appendix C.

 Any facility with whole effluent toxicity detected during the last five years based on:

• Less than 80 percent survival in 100 percent effluent; or

• The no observed effects concentration for ch ronic toxicity being less than or equal to the acute critical effluent concentration; and

• Not attributable to a known chemical

 Any facility with suspected sediment toxicity because of apparent damage to aquatic biota in the immediate vicinity of t he discharge.

 Any other discharge that Ecology determines has the potential to include toxic substances that may accumulate in the sediment.

3. The following types of discharges (check if applicable) are generally not believed to have a potential for causing adverse sediment impacts unless one of the above factors, in item 2, applies:

 Once

- through noncontact cooling water without biocidesCHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 25  Municipal plants discharging less than one

- half million gallons per day of effluent that are regulated only for conventional pollutants

 Drinking water treatment plants

 Sand and gravel mining operations

 Sump pump discharges of ground water or rainwater

 Construction dewatering

 Fish hatcheries and other aquaculture

 Boiler blowdown

 Any o ther discharger that Ecology determines does not have the potential to discharge toxic pollutants

3. Based on the narrative evaluation above, is there a potential for sediment impacts from this discharge?

 Yes. If yes, answer the following question.

 No

4. Is there a preliminary indication that the discharge would be eligible for a SIZ?

 Yes

 No. If no, describe the reason(s) the discharge may be ineligible.

Permit Manager:

___________________________________________ Date: (print n ame)

________________________________________ (Signature)CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 26 

### Screening

- Level Evaluation of the Potential for Sediment Impacts

Part B. Technical Evaluation

Applicant:
Waste Discharge Permit No.:

Location:

SUMMARY

Potential for Sediment Im pact? No Available Data

Worksheets Attached: YES NO

 Section 1. Source Sediments   

 Section 2. Sediment Chemistry   

 Section 3. Sediment Biological Tests   

 Section 4. Effluent Chemistry   

Permit Manager:

___________________________________________ Date: (print name)

________________________________________ (Signature)CHAPTER IX. AQUATIC SED IMENTS (JULY 2002)

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- 27 

### Section 1

Chemical Concentrations in Source Sediments and Effluent Suspended Solids

Types of Data: Number of Samples:

 Ditch Sediments Analyte Groups:

 Sump Sediments

 Outfall Sediments

 Effluent Suspended Solids

Detected Analytes Maximum Concentration (mg/kg) a SQS (mg/kg) a Exceeds SQS?

YES NO Number of Samples Exceeding SQS

1.  

2.  

3.  

4.  

5.  

6.  

7.  

8.  

9.  

10.  

11.  

12.  

13.  

14.  

15.  

16.  

17.  

18.  

19.  

20.  

a mg/kg dry weight or organic carbon normalized, as appropriate (see Section 3. 3.3).CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 28 

### Section 2

Chemical Concentrations in Receiving Sediments and Settling Particulate Matter in the Water Column

Types of Data: Number of Samples:

 Receiving Sediments Analyte Groups:

 Settling Particulate Matter in the Water Column

Detected Analytes Maximum Concentration (mg/kg) a SQS (mg/kg) a Exceeds SQS?

YES NO Number of Samples Exceeding SQS

1.  

2.  

3.  

4.  

5.  

6.  

7.  

8.  

9.  

10.  

11.  

12.  

13.  

14.  

15.  

16.  

17.  

18.  

19.  

20.  

Is there reason to believe that historical or other ongoing sources of contamination unrelated to the discharge may have contributed to the excee dances of SQS shown? If so, explain below:

a mg/kg dry weight or organic carbon normalized, as appropriate (see Section 3.3.3).CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 29 

### Section 3

Biological Test Data for Receiving Sediments

Type of Test Total Number of Stations Exceeds SQS? YES NO Number of Stations Exceeding SQS

 Amphipod Bioassay  

 Larval Bioassay

Type  

 

 

 

 Benthic Infauna  

 Neanthes Bioassay  

 Microtox® Bioas say  

Is there reason to bel ieve that historical or other ongoing sources of contamination unrelated to the discharge may have contributed to the exceedances of SQS shown? If so, explain below:CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 30 

### Section 4

Effluent Monitoring Data

Number of Samples:

Average TSS (mg/L):

Analyte Groups:

Detected Analytes Average Concentration ( μ g/L) C p (mg/kg) a SQS (mg/kg) a Exceeds SQS?

YES NO

1.  

2.  

3.  

4.  

5.  

6.  

7.  

8.  

9.  

10.  

11.  

12.  

13.  

14.  

15.  

16.  

17.  

18.  

19.  

20.  

C p Concentration of a contaminant associated with suspended solids in the effluent

a mg/kg dry weight or organic carbon normalized, as appropriate (see Section 3.3.3).CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 31 

### 4.3.2. Instructions for the Technical Evaluation Worksheet
The following sections provide further explanations and instructions for completing each section of the technical evaluation worksheet. This worksheet should be completed along with the
narrative evaluation workshee t and filed with the permit application. A copy of the worksheet should be forwarded to the SMU. Any data used in the screening

- level evaluation should also be forwarded to the SMU with the worksheet; these data will be used in the subsequent detailed

ev aluation. The permit manager should also provide the SMU with electronic and hard copies of water quality dilution zone model runs, spreadsheets, and any other data and information used to assess compliance with water quality and sediment quality standard s.

If neither the narrative nor the technical evaluations indicate that a discharge has the potential to cause sediment impacts, the permit should be issued or renewed by the permit manager without a SIZ authorization or sediment quality

- based effluent li mits. No sediment monitoring should be required in the permit. The permit manager should identify the lack of potential for sediment impacts in the fact sheet accompanying the permit.

Because the screening

- level evaluation (including the narrative and t echnical evaluations) is highly conservative, it may indicate the potential for impacts for certain facilities where no actual impact would occur. Therefore, if either the narrative or technical evaluation indicates that a discharge has a potential for se diment impacts, the discharge will be further evaluated by the
SMU.

Summary Page

The summary page is shown in Figure IX

- 4. To complete the summary page, the permit manager should perform the following steps:

1. In the space provided, fill in the name of t he applicant, the waste discharge permit number, and the location of the existing or proposed discharge (e.g., latitude and longitude or state plane coordinates; attach a map showing the discharge, if available) or attach those from the
fact sheet.

Review available data for the permit, including data provided in the permit application, existing effluent monitoring data, and baseline monitoring data, to determine what types of data are available for the evaluation. Check the appropriate boxes to indicate w hich types of data
are used in the evaluation.

Fill out and attach the appropriate worksheets.

Summarize the results of the evaluation on the summary sheet by checking the “yes,” “no,” or
“no available data” box for each worksheet used.CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 32 Sign and date th e worksheet.

Attach all data used in the evaluation and forward the worksheet to the SMU. Include a copy of the worksheet in the permit file for the applicant.

Section 1. Chemical Concentrations in Source Sediments and Effluent Suspended Solids The poten tial for a discharge to cause an exceedance of the SQS in adjacent sediments can be evaluated by directly comparing SQS numerical criteria with concentrations of contaminants in sediments that may accumulate at points within the facility downstream of any treatment processes (e.g., ditch, sump, outfall). Sediments collected from such locations are likely to be more indicative of source characteristics than are receiving sediments in the immediate vicinity of the point of discharge, because the latter may b e affected by other factors, including historical contamination, contributions from other sources, and burial by and mixing with natural
sediments.

If there are no sediments present in ditches, sumps, or outfalls, or if these sediments have not been sampl ed, it may be possible to collect suspended solids in the effluent and determine their chemical concentrations. Methods for the collection of suspended solids in the effluent are discussed in Chapter XIII Sect i on 7. Care must be taken to collect a sample that is representative
of the effluent.

The worksheet for Section 1 is shown in Figure IX

- 4. To complete the worksheet for Section 1, the permit manager should perform the following steps:

1. Indicate the type of data available and the number of samples c ollected. Also note the analyte groups (e.g., metals, semi

- volatile organic com pounds) that were analyzed. If source sediments were analyzed, any available information (qualitative or quantitative) on the grain size of the sediments sampled should be ap pended to the worksheet.

2. In the first column, list the detected analytes for which SQS numerical criteria are available (Table IX

- 1).

List the maximum concentration mea sured for each analyte. If the SQS numerical criteria for
the contaminants measured are listed in mg/kg organic carbon, the organic carbon normalization procedure described in Part 4.3.3 must be completed before comparing the data to the criteria. Otherwise, concen trations should be listed in mg/kg dry weight.

Compare the maximum conce ntrations detected to the SQS numerical criteria listed in Table
IX

- 1. Check the appropriate boxes to indicate whether the criteria are exceeded. For each contaminant, also indicate the number of samples for which the contaminant exceeds the
criteria. I f any of the sample concentrations exceed the SQS numerical criteria, there is a potential for sediment impacts from the discharge.CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 33 Attach the completed worksheet to the summary page.

Section 2. Chemical Concentrations in Receiving Sediments and Suspended Particulate Matter in the Water Column

If there are no sediments associated with the source pathway (e.g., sediments do not accumulate at points within the facility downstream of any treatment processes), surface sediments near the point of discharge can be collected and analyzed. If surface sediment sampling is used to assess contaminant concentrations, only the uppermost sediment horizon ( i.e. , 0

– 2 cm), reflecting the most recently deposited sediments, should be collected. Because receiving sediments respond relatively slowly to changes in source characteristics, receiving sediment data should not be used unless the discharge being evaluated is an existing source that has been discharging at a similar rate for at least 5 years.

Because bottom sediment s respond slowly to changes in source characteristics, sampling of suspended particulate matter in the water column may provide a more reliable method for verifying the effects of a discharge on receiving sediments. However, suspended particulate
matter i n the water column (receiving environment) may also be mixed with particles from other sources or facilities (potentially including resuspended bottom sediments). Sampling of suspended particulate matter in the water column can be performed over a period of time using a sediment trap. Because sediment traps collect only settling particles in the water column, use of sediment traps is the most appropriate sampling method for evaluating the impact on sediment quality of particulate matter settling out of th e water column. This sampling technique is discussed in greater detail in Chapter XIII Section 7.

The worksheet for Section 2 is shown in Figure IX

- 5. To complete the worksheet for Section 2, the permit manager should perform the following steps:

1. Indic ate the type of data available and the number of stations at which samples were collected. Also note the analyte groups (e.g., metals, semivolatile organic compounds) that were analyzed.

3. In the first column, list the detected analytes for which SQS numer ical criteria are available (Table IX

- 1).

List the maximum concentration measured for each analyte. If the SQS numerical criteria for the contaminants measured are listed in mg/kg organic carbon, the organic carbon normalization procedure described in Pa rt 4.3.3 must be completed before comparing the data to the criteria. Otherwise, concentrations should be listed in mg/kg dry weight.

Compare the maximum concentrations de tected to the SQS numerical criteria listed in TableCHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 34 IX

- 1. Check the appropriate boxes to indicate whether the criteria are exceeded. For each contaminant, also indicate the number of stations at which the contaminant exceeds the criteria. If any of the sample concentrations exceed the SQS numerical criteria, there is a potential for sediment impacts from the discharge.

Explain in the space provided whether there is any reason to believe that historical contamination and/or the presence of other ongoing sources may have contributed to the SQS exceedances listed.

Attach the completed worksheet to the summary page.

Section 3. Biological Test Data for Receiving Sediments Use of biological test data for receiving sediments is the most direct way of evaluating whether sediment impacts are occurring, because such tests directly measure adv erse effects on organisms of interest. However, because receiving sediments respond relatively slowly to changes in source characteristics, this section of the worksheet should only be used if the discharge being evaluated is an existing source that has b een discharging at a similar rate for at least 5 years.

SQS biological effects criteria for Puget Sound have been established for the following types of tests (WAC 173

- 204

- 315):



### • Amphipod bioassay ( Rhepoxynius abronius )



### • Larval bioassays:

– Pacific oyster ( Crassostrea gigas )

– Blue mussel ( Mytilus edulis )

– Purple sea urchin ( Strongylocentrotus purpuratus )

– Sand dollar ( Dendraster excentricus )



### • Benthic infauna



### • Juvenile polych aete bioassay ( Neanthes arenaceodentata )



### • Microtox  bioassay ( Photobacterium phosphoreum )
Therefore, only these types of biological data can be used in the screening

- level evaluation.CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 35 The worksheet for Section 3 is shown in Figure IX

- 6. To complete the w orksheet for Section 3, the permit manager should perform the following steps:

1. Indicate the type(s) of biological tests for which data are available. List the number of stations at which samples were collected for each test.

2. Compare the results of each t est to the SQS biological effects criteria for that test listed in
Table IX

- 2. To compare observed adverse effects to the SQS biological effects criteria, it must first be determined whether the effects observed are statistically significant. The permit applicant should perform this test. If this information is not provided, contact the SMU for instructions or assistance in interpreting the results of biological tests.

Check the appropriate boxes to indicate whether the SQS biological effects criteria a re exceeded. For each test, also indicate the number of stations that exceed the SQS biological effects criteria. If the sediments exceed the SQS biological effects criteria for one or more of the tests, there is a potential for sediment quality impacts.

Explain in the space provided whether there is any reason to believe that historical contamination and/or the presence of other ongoing sources may have contributed to the SQS exceedances listed.

Attach the completed worksheet to the summary page.



### Secti on 4. Effluent Monitoring Data
If appropriate data are not available to conduct the evaluations in worksheet Sections 1

– 3, the results of effluent chemical analyses can be used as an indicator of whether that discharge has the potential to result in exceed ance of the SQS numerical criteria near the outfall. Because effluent sampling and analysis is a standard part of NPDES permit requirements, such data may be available when sediment quality data are not. To use effluent data as an indicator of potential contamination in sediments, a relationship must be derived between effluent and sediment quality. This part of the evaluation uses effluent monitoring data to provide an estimate of potential sediment quality near a point of discharge. The equation used i n the evaluation is based on the assumption that for contaminants likely to accumulate in the sediments, and for which there are SQS numerical criteria, most of the total contaminant concentration in an effluent (or in the receiving water) will be found on the suspended solids fraction. This assumption may not be applicable to certain classes of contaminants (i.e., highly soluble contaminants). Furthermore, this equation does not directly predict the impact of the effluent on sediments around the point of discharge, and it does not account for dilution of the effluent by ambient water during initial mixing or for dilution of effluent suspended solids by particles from other sediment sources.CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 36 However, the concentration of a contaminant associated with sus pended solids in the effluent (C p ) derived using this equation can be directly compared with the SQS numerical criterion for that contaminant. For chemicals with SQS numerical criteria that are normalized to organic carbon (i.e., nonpolar, nonionizable or ganic compounds), the additional normalization for organic carbon (i.e., dividing the dry

- weight contaminant concentration for the suspended solids fraction by the organic carbon content of the suspended solids fraction) should be applied (see Part 4.3.3.)

.

C p can be estimated from effluent monitoring data as follows:

where:

C p = concentration of contaminant associated with suspended solids in the effluent (mg/kg dry weight)

C t = total concentration of contaminant in the effluent (mg/L)

TSS = total suspended solids in the effluent (mg/L)

10 6
= conversion factor (mg/kg).

If all contaminant concentrations on th e suspended solids in the effluent are less than or equal to the SQS numerical criteria, the screening criterion is passed.

This equation incorporates the assumption that all contaminants are associated with suspended solids (or particulate organic carbon ) in the effluent. This is a conservative assumption intended to provide an environmentally protective analysis; therefore, it may be possible using this equation to screen out a number of discharges with very little expenditure of time and resources.

Th ere are two scenarios in which this equation may be overly conservative. First, if most of the contaminants are expected to be in the dissolved form, this equation could greatly overestimate the concentration of a contaminant associated with suspended sol ids. Second, if the concentration of TSS is very low, the concentrations of contaminants associated with the suspended solids may appear to be very high, and the screening criterion may be failed. However, in the latter scenario there may or may not be s ignificant loading of contaminants to 10 x TSS

C

= C 6 t pCHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 37 the sediments in the immediate vicinity of the point of discharge. In either of these two scenarios, the permit manager should contact the SMU for guidance on the appropriate course of
action.

It should be noted that this equation may be of only limited applicability for effluents that have very low TSS concentrations (e.g., biological treatment of municipal wastewater may yield a TSS concentration of only 10

– 30 mg/L). Depending on the magnitude of the SQS numerical criteria for individual contaminants, the total contaminant concentration in the effluent necessary to cause an exceedance of the criteria may be at or below commonly achievable detection limits
in cases of low TSS concen trations (e.g., at a TSS concentra tion of 30 mg/L, a total arsenic concentration of greater than 1.7 μ g/L would cause exceedance of the SQS numerical criterion for arsenic). For contaminants with higher SQS numerical criteria, use of the equation may still
be valuable for effluents with l ow TSS concentrations.

The worksheet Section 4 is shown in Figure IX

- 7. To complete the worksheet Section 4, the permit manager should perform the following steps:

1. Indicate the number of samples collected and the analyte groups (e.g., metals, semivo latile organic compounds) that were analyzed. The WQP typically recommends that 10 samples be collected over a period of time to adequately characterize the nature and variability of a discharge's effluent quality. For the purposes of this screening

- leve l evaluation, the results of the analysis of at least 10 samples should be evaluated. If fewer samples are available, they should still be evaluated, although the conclusion should be qualified.

2. Determine the average concentration of TSS in the efflu ent and note it in the space provided.

3. In the first column, list the detected analytes for which SQS numerical criteria are available (Table IX

- 1).

4. Determine the average concentration of each contaminant in the effluent samples and write
the aver ages in the space provided.

5. For each contaminant, divide the average concentration by the average TSS to get C p . For

con taminants whose SQS numerical criteria are in mg/kg organic carbon, convert C p from mg/kg dry weight to mg/kg organic carbon, as described in Part 3.3.3. Fill in the C p values in the space provided.

6. Compare C p values to the SQS numerical criteria listed in Table IX

- 1. Check the appropriate box for any contaminants for which C p exceeds the criteria. If any of the contaminants exceed SQS nu merical criteria, there is a potential for sediment quality impacts.

7. Attach the completed worksheet to the summary page.CHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 38 

### 4.3.3. Organic Carbon Normalization
The SQS numerical criteria for nonpolar, nonionizable, organic contaminants are listed in units of mg/kg organic carbon. However, sediment data are often reported in mg/kg dry weight. C p is also derived in units of mg/kg dry weight. To convert chemical concentrations expressed as mg/kg dry weight to mg/kg organic carbon for compar ison to SQS, the following equation is
used:

where:

TOC = percent total organic carbon of sediments or suspended solids (expressed as a decimal; i.e., 1% TOC = 0.01).

For this screening

- level analysis , a total organic carbon (TOC) value of 1 percent may be assumed in the absence of discharge

- specific TOC data. In Puget Sound reference area sediments, TOC values range from 0 to 6.1 percent, with a median of 1.4 percent (Pastorok et al. 1989).



## 4.4 Alt ernative Procedures for the Technical Evaluation of the Potential for Sediment Impacts in Freshwater, low Salinity, and Non

Puget Sound Marine Environments

As described in Subsection 3.3, the current absence of promulgated SQS numerical criteria for
sedime nts in freshwater, low

- salinity, and non

- Puget Sound marine environments necessitates the use of alternative procedures for the technical evaluation of the potential for sediment impacts. This section describes technical evaluation procedures for discharg es into each of those environments. After SQS numerical criteria are promulgated for those environments, other evaluation procedures will be developed by Ecology.



### 4.4.1. Technical Evaluation Procedures for Discharges to Freshwater
Environments
Currently, the Sediment Management Standards have neither SQS numerical criteria nor biological effects criteria for freshwater sediments. However, sediment quality values are available from other sources (e.g., Ecology's FSEDCRIT report, Appendix D of the Sediment
Source Control Standards User Manual ), and Ecology has two recommended freshwater sediment bioassays for evaluating sediment impacts around existing discharges to freshwater environments. Therefore, there are tools available for use, on a case

- by

- case bas is using best 

### TOC dry weight mg/kg

= carbon organic mg/kgCHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 39 profes sional judgment, in evaluating the potential for sediment impacts in the vicinity of discharges to freshwater environments. These tools require sediment monitoring data from the depositional environment in the vicinity of the discharg e.

Ecology's FSEDCRIT report includes numerical sediment quality values for a number of metals and organic compounds in freshwater sediments. These values were assembled from several sources, including the U.S. Environmental Protection Agency (EPA), othe r states, and Canadian agencies. While not directly applicable to Washington State freshwater sediments, they can be used, with supporting documentation, on a case

- by

- case basis using best professional judgment with the assistance of the SMU for identifyi ng sediments likely to exhibit adverse effects.

Ecology currently recommends the following sediment bioassays for identifying biological impacts in freshwater sediments (Bennett and Cubbage, 1992):

 Amphipod bioassay ( Hyalella azteca )

 Microtox® bioas say ( Photobacterium phosphoreum ).

The protocols for these bioassays (ASTM 1990; PSEP 1991a) do not include test sediment interpretation values. For the amphipod bioassay, the SMU recommends that to be considered indicative of a potential sediment impact, the test sediment should exhibit mortality that is significantly higher ( t

- test, P ≤ 0.05) than the reference sedi ment and the test sediment mortality should exceed 25 percent (on an absolute basis). For the Microtox® bioassay, to be considered indicative of a potential sediment impact, the mean light output of the highest concentration of the test sediment should be less than 80 percent of the mean light output of the reference sediment, and the two means should be significantly different ( t

- test, P ≤ 0.05).

In cases where there are existing sediment data (either sediment concentrations of chemicals for which there are sediment quality values in the FSEDCRIT report, or the results of sediment bioassays), the permit manager has the option of conducting the technical evaluation on a case

by

- case basis using best professional judgment or for warding the permit application materials to the SMU for them to perform the technical evaluation. If the permit manager elects to conduct
the technical evalua tion, the concentrations of sediment contaminants (if available) can be compared with the approp riate FSEDCRIT sediment quality values (selected with guidance from the SMU) using the worksheet Section 2 (Figure IX

- 5), modified accordingly. If the results of one or both sediment bioassays are available, they can be reported on the worksheet Section 3 (Figure IX

- 6), modified accordingly . The permit applicant should generally perform the tests of statistical significance for these bioassays. If this information is not provided, the permit manager should contact the SMU for instructions or assistance i n interpreting the results.

In the absence of existing sediment data from the vicinity of a discharge to a freshwater environment, there are no technical procedures (equivalent to those used for screen ing PugetCHAPTER IX. AQUATIC SEDIMENTS (JULY 2002)

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- 40 Sound marine sediments) for evaluating the potential for sediment impacts based only on chemical concentrations in source sediments and particles (i.e., worksheet Section 1; Figure IX

4) or on effluent monitoring data (i.e., worksheet Section 4; Figure IX

- 7). If the narrative
evaluation indicated the potential for sediment impacts, and if only those data types are available (or if no data at all are available), the permit manager should issue or renew the permit with a requirement for the collection of baseline monitoring data (including sediment c hemistry and sediment bioassays) so that an evaluation of sediment impacts can be made at a later date.

After the baseline monitoring data become available, the technical evaluation can be completed by the permit manager or by the SMU. This may occur dur ing the next permit review cycle or at an earlier date, at the discretion of the permit manager.



### 4.4.2. Technical Evaluation Procedures for Discharg es to Low

- Salinity
Environments
Currently, the Sediment Management Standards have neither SQS numerical cri teria nor biological effects criteria for low

- salinity sediments. Unlike the situation for freshwater sediments, however, there are no sediment quality values currently available from other sources. Application of the SQS numerical criteria for Puget Sou nd marine sediments to low

- salinity sediments may be inappropriate. Similarly, the biological effects tests applicable to Puget Sound marine sediments may not be applicable to low

- salinity sediments. Therefore, there are currently
no technical evaluation procedures applicable to low

- salinity sediments that can be performed by the permit manager. Hence, all permit applications received for discharges to such environments should be forwarded to the SMU for further evaluation, until such time as appropriate criteria and technical evaluation procedures are developed. On a case

- by

- case basis using best professional judgment, the SMU may choose to apply the Puget Sound marine sediment chemical criteria or biological effects tests to low

- salinity sediments.



### 4.4 .3. Technical Evaluation Procedures for Discharges to Non

- Puget Sound
Marine Environments
Currently, the Sediment Management Standards have neither SQS numerical criteria nor biological effects criteria for non

- Puget Sound marine sediments. As in the case of low

- salinity sediments, there are also no sediment quality values currently available from other sources. However, the SMU is of the opinion that, until such time as criteria are developed specifically
for non

- Puget Sound marine sediments, the corresp onding criteria developed for Puget Sound marine sediments can be used, on a case

- by

- case basis using best professional judgment, for evaluating the potential for sediment im pacts in those environments. Hence, the technical evaluation for discharges to n on

- Puget Sound marine environments can in the interim be conducted by the permit manager using the same procedures as developed for Puget Sound marine sediments (see Subsection 4.3).CHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 1 

# CHAPTER X. PRETREATMENT PROGRAM

1. OVERVIEW

Cities have long recognized t he need to control tributary industries to keep them from harming their sewer systems. After passage of the Clean Water Act, EPA standardized these controls and set “categorical” limits for pollution from specific processes of certain types of major indus tries. Both municipal and industrial permit writers implement the pretreatment program. Municipal permit writers must add appropriate pretreatment related conditions in permits for Publicly Owned Treatment Works (POTWs) and other Treatment Works Treating Domestic Sewage (TWTDS). These conditions compel the participation of sewerage agencies in carrying out this program. Ecology may require sewerage agencies to develop a program, properly run their approved program, or do things to support and reinforce Ecology’s control of their tributary industries. Industrial to POTW permit writers must know how to apply categorical standards and other applicable pretreatment standards and requirements. The following sections provide an overview of pretreatment speci fic concerns for permit writer in both cases.



## 1.1. Federal Pretreatment Rules

Pretreatment Requirements: Federal Regulations describing appropriate controls for non

domestic wastewater are found at 40 CFR§403. These regulations are intended to prevent non

do mestic wastewater from having undesirable effects at a POTW. These rules prohibit discharges that cause “Pass Through” or “Interference” at the POTW, explosion, vapor toxicity, emergency conditions, and sludge contamination. You can find definitions of p retreatment related terms at 40 CFR §403.3, and these prohibitions at 40 CFR §403.5. The rules at §403.8 require POTWs that have a design flow capacity of over 5.0 MGD to develop programs to prevent such undesirable effects if they have any industries.

The rules at §403.8 describe (in general) the required components of an approvable program. EPA guidance (See EPA’s Pretreatment Website) significantly augments and refines the brief descriptions found there. EPA’s manual “Introduction to the National P retreatment Program” summarizes some of the most important guidance. Staff seeking to run a pretreatment program
must be conversant with much of this.

The rules beginning at §403.9 describe the process of delegating a pretreatment program. Rules at §403 .10(e) allow states to take responsibility for the POTW’s program and issue permits to control discharges from Industrial Users.CHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 2 Categorical Pretreatment Standards: Under the Clean Water Act (CWA), EPA established uniform national standards for some s pecific industry categories. These are found in sections §405 to §471. Where these standards specify Pretreatment Standards for Existing Sources (PSES) or Pretreatment Standards for New Sources (PSNS) for processes conducted by the industry, and the indu stry is connected to a POTW, the industry is considered a “Categorical Industrial User” (CIU). Where PSNS or PSES standards merely require compliance with the general pretreatment regulations (formerly 40 CFR §128, now 40 CFR §403), the industry is not

co nsidered to be subject to categorical standards or a CIU.

EPA publishes each categorical pretreatment standard as a separate regulation. The standards contain limitations for pollutants commonly discharged within each specific industrial category

. All i ndustries regulated by a particular category are required to comply with these standards, no matter where they are located in the United States. Facilities covered by categorical standards must comply with any more stringent local limits, state standards, or prohibitive standards.

Local Limits: EPA has constructed the Pretreatment Regulation to recognize technically based local limits as pretreatment standards under section 307(c) of the Clean Water Act. EPA’s pretreatment regulations also reinforce th at pretreatment permits must require compliance with any more stringent state or local requirement.

Pretreatment Streamlining: EPA revised several sections of the pretreatment rules in November 2005 in what they termed “streamlining”. The preamble to t he rule change, which can be found on EPA’s pretreatment web site, provides the best source of information on the scope and EPA’s intentions for those changes. EPA has produced nine “fact sheets” that describe the various required changes, options allowed , and particulars of each change or new allowance. Permit writers should familiarize themselves with this rule change. They should understand the need to carefully document, in fact sheets, decisions with respect to the sample type (grab or composite),

r equirements for a slug discharge control plan, and best management practices (BMPs)

. Permits need to include, as enforceable provisions, requirements to develop and follow a slug discharge control plan, keep records that show compliance with BMPs, and prov ide any periodic
certifications or characterizations.



## 1.2. Washington State’s rules for non

- domestic wastewater

EPA delegated Ecology the authority to issue NPDES permits in 1973 and to administer the federal pretreatment program in 1986. Ecology derives its a uthority to include pretreatment related requirements in NPDES permits issued to POTW's through RCW 90.48 and Ch apter 173

- 220 WAC. These rules allow (at 173

- 220

- 150(g)) Ecology to give full or partial delegation to POTWs and requires their programs be as stringent as the Department’s. Rules allowing delegation of local pretreatment programs are at Ch apter 173

- 208 WAC.

The authority to directly regulate industries discharging to a POTW comes from 90.48 RCW and
Ch apter 173

- 216 WAC. Ecology’s rules are for permit writers to include all relevant state andCHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 3 federal requirements in such permits. In addition to reinforcing EPA requirements, Washington State rules require industries to:

• Obtain approval for plans for construction of wastewater facilities (as des cribed in
Ch apter 173

- 240 WAC).

• Provide All Known, Available, and Reasonab le means of Treatment (AKART). [Note: Ecology determined that AKART prohibits approval of removal credits (described at 40 CFR §403.7)].

• Use an accredited laboratory for their monito ring.

• Comply with Dangerous Waste rules (found at Chapter 173

- 303 WAC). These rules (173

- 303

- 071 WAC) exempt discharges to the sewer from DW rules if they identify the waste streams that would otherwise be DW in their permit application, and their pretrea tment permit includes certain language.



## 1.3. Philosophy of Washington State’s Pretreatment Program

Federal regulations require POTWs with design flows of 5.0 MGD and SIU’s to develop a pretreatment program unless the state assumes this responsibility. These rules also allow Ecology to require a smaller POTW to develop a program when they receive wastes that are causing problems such as pass through at the POTW, when their problems are most amenable to local solutions. On a functional level, Ecology may also have to require a local program when the POTW is not providing Ecology the support needed to manage the program for them. Ecology would have to rely on Best Professional Judgment (BPJ) to require other TWTDS to develop a program. Washington State is one of only a handful of states that has a permit program to allow the state to implement the pretreatment program in lieu of a POTW.

Ecology’s decision to require a municipality to develop a pretreatment program is a regional one. The decision should weig ht the benefits of each option. One of the main factors is whether it is less work to permit significant industrial users (SIUs) or to delegate and oversee a local program. Permit writers should describe the rationale for delegation decisions in the perm it fact sheet when the municipality’s permit (State Waste Discharge for TWTDS, and NPDES for POTWs ) is (re)issued.

Where Ecology does not delegate full responsibility to implement the pretreatment program, Ecology will issue permits to SIUs. The POTW ma y still be required, in its NPDES permit, to do a variety of supporting tasks as described in section 2.D. (Similarly, Ecology permits writers may place equivalent requirements in TWTDS permits based on BPJ.)

Ecology oversees the approved POTW pretreatm ent programs of municipalities that have been delegated pretreatment program authority. As of 2010, ten Washington municipalities have approved POTW pretreatment programs and have been delegated pretreatment authority

. TheseCHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 4 include: METRO (Seattle metro politan area including Renton and Bellevue), Everett, Lynnwood, Pierce County, Spokane, Vancouver, Richland, LOTT (Lacey, Olympia, Tumwater and Thurston County), Tacoma, and Yakima.



## 2. NPDES PERMITS FOR POTWS:

Ecology’s approved program manual from 1986 describes how Ecology and municipal sewerage agencies are to work in concert to carry out the responsibilities of the pretreatment program. POTWs and TWTDS, with staff at the local level, may be better situated to carry out certain pretreatment related ta sks. In such cases, Ecology should assign them the responsibility for doing so as an NPDES permit condition.

The first step in crafting pretreatment related permit conditions is to evaluate the situation and decide what pretreatment related needs are. To do this, the permit writer must know what problems are symptomatic of poor pretreatment oversight. These include the observation either at the POTW or at some point in the collection system of certain conditions as listed below.

Symptoms of Uncontr olled Industrial Waste Sources Tributary to a POTW :

1. Corrosion to sewer lines, manholes, pump stations, or the POTW headworks
2. Noxious or chemical odors in the collection or treatment system
3. Oil, grease, fuel, solvents, or explosivity alarms
4. Unusual color
5. Excessive foaming
6. Unexplained reductions in treatment efficiency
7. Toxicity in WET tests, or periodic reduction in the oxygen uptake rate in aeration basins
8. Poor settling sludges
9. High temperatures in sewer lines or at the headworks
10. High or low pH or unu sual pH swings
11. Poor UV transmissivity or loss of the effectiveness of UV disinfection
12. High or unusual variation in conventional pollutant loading rates (BOD, TSS, ammonia)
13. High metals concentrations in the influent, effluent, or sludges
14. High levels of t otal dissolved solids (e.g

., from uncontrolled sources of brines)
15. Debris, sand, or unusual sludges in sewer lines or excessive solids at the headworks
16. Unusual levels of priority pollutants in the effluent or biosolids

In revisiting a POTW’s NPDES permit, the permit writer should both review the POTW’s monitoring reports for these symptoms and ask representatives of the POTW (including staff
who oversee the collection system) about such occurrences. If the POTW shows evidence of
adverse effects from non

- do mestic wastes, then the permit writer must decide two things: What actions should be taken in response, and the respective roles of Ecology and the POTW in taking
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- 5 The Permit Writer’s challenge will be to develop permit conditions that su pport and reinforce Ecology’s partnership with the POTW. Conditions must compel the POTW to provide the support needed for Ecology to, in turn, properly administer the pretreatment program.

The major divisions of this section describe how permit writers craft permit language that requires a POTW to: Develop a pretreatment program; Implement their previously delegated program; Implement a modified program, or; Support Ecology’s pretreatment program. Of these options, the permit writer has the greatest la titude in requiring tasks in support of Ecology’s program. Whatever pretreatment related conditions are decided upon, the permit writer will typically need to properly document the basis for the conditions in the fact sheet.

Ecology has developed standar d language for requiring a POTW to develop a delegated program, or to implement their previously delegated or modified program. This wording is in the NPDES Permit shell for POTWs

. Regional pretreatment specialists are available to help permit managers d ecide what conditions to impose and evaluate whether the POTW has complied with their permit requirements (Section 4 of this chapter describes regional pretreatment engineer expertise areas).



## 2.1. Requiring a POTW to Develop a Pretreatment Program:

2. 1 .1 Reso urces Requiring a POTW to develop a pretreatment program is an involved process. If you are n o t doing it, you can (merciful ly) skip to the next section. If you are, it is best to anticipate the level of effort required from the outset (about 0.5 FTE*year s). Then you can adjust your work plan accordingly. Permit writers should never require a POTW to develop a pretreatment program without the concurrence of the regional pretreatment engineer and regional manager. Either a POTW or a TWTDS may request aut hority to administer a permit program for their tributary IU’s. Ecology is not obliged to approve such requests, and should ensure that any decision enhances the protection of waters of the state.



### 2. 1 .2 Drivers
Most states that administer the NPDES permit program also operate as the “Approval Authority” to require, approve, and oversee local POTW pretreatment programs. EPA rules at 40 CFR 403.8(a) require certain POTWs to develop a pretreatment program. This includes any POTW or group of POTWs owned by t he same municipality with a design capacity of 5.0 MGD and receiving wastewater subject to pretreatment standards or requirements. State rules at RCW 90.48.165 and Chapter 173

- 208 WAC expand on this, empowering Ecology to also delegate ANY municipal body the authority to issue permits for the discharge of wastes into their system provided Ecology finds the program will protect the quality of the state’s waters (“Waters of the State” includes both surface and ground water).CHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 6 Federal rules at 40 CFR 403.10 (e) allow states that have developed a permitting program to assume the role of the Control Authority instead of requiring the POTW to develop a pretreatment program. Ecology developed such a program and received EPA approval of it in 1986. Ecology there fore may permit the industries that discharge to a municipal sewerage system ( either a POTW or TWTDS) rather than require a local pretreatment program. When Ecology decides to do this, permit writers must document this decision, and clarify which tasks
Ec ology still expects the municipality to carry out (to facilitate Ecology’s permitting program) in the municipality’s NPDES or State Waste Discharge permit and fact sheet.



### 2. 1 .3 Selection Process The final responsibility for the selection and scope of a new full or partial program delegation rests with the Regional Section Manager. Ecology regional offices are to notify POTWs when they are required to develop local pretreatment programs (40 CFR 403.10(f)(2)(i))

. To support that decision, the regional pretr eatment engineer must assess whether:

1. The POTW is willing to assume pretreatment program responsibilities. 2. The POTW is capable of assuming pretreatment program responsibilities. 3. The POTW can overcome challenges posed by the inter

- jurisdictional situation. 4. Delegating (in whole or part) the pretreatment program will better achieve the goals of pretreatment (better protect the public, the treatment works, and receiving waters). 5. For full program delegations, whether the review, approval, and oversight of the pr ogram will be less work to Ecology than the continued oversight of Industrial Users, or other feasible collaborative options.
Where Ecology decides to require a pretreatment program, Ecology should transmit this requirement by NPDES permit condition (per 4 03.8(a

- e), 122.44(j), and 122.62(a)(9)). Upon approval of a local program, Ecology will provide an approval letter or Order delegating authority to the POTW. Ecology then must amend the POTW’s NPDES permit (under authority of 403.8(a

- e) and 122.63(g) to include the requirement to implement their approved pretreatment

program.



### 2. 1 .4 How Long Do We Allow to Develop a Program Federal Regulations at 40 CFR 403.8(b) require municipalities to develop a local program within a year of being notified in writing th at they are required to have a program by the Approval Authority (which in Washington State is Ecology). While EPA has not objected to a longer schedule, permit writers should understand that a third party might successfully challenge it. On the other han d, some believe that properly developing a well

- considered pretreatment program may take up to three years.



### 2. 1 .5 Including A Schedule f or Delegation Where Ecology finds a pretreatment program is necessary, Ecology should include a compliance schedule i n the POTW’s NPDES permit when it is reissued or modified (403.10(f)(2)(iii)). The compliance schedule outlines milestones and dates for program completion. Federal rules at 40CHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 7 CFR 403.8(e)(5) also specifically permit Ecology to invoke the authority of se ction 402(b)(1)(C) of the Act to modify or revoke and reissue a POTW's Permit to include a compliance schedule to develop a Pretreatment Program.

The compliance schedule should require the POTW to develop and document the necessary authorities, informat ion, and procedures to implement its local program

. The next two sections describe the typical program elements specified in the compliance schedule for a fully delegated program, and the general process for “partial” delegation.



### 2. 1 .6 Contents f or Full Delegations
EPA describes the requisite contents for a POTW’s submission for approval of their proposed program in 40 CFR 403.9. If the Permit Writer, in concert with the regional Pretreatment Specialist, determines that the POTW should develop a program, Ecology must require this in the POTW’s NPDES permit or an Order. All delegated pretreatment programs must have the basic elements required by regulations. Each permit or Order to develop a local program must require the POTW to:

1. Develop a list of User s that will be subject to the proposed Pretreatment Program.
2. Estimate the resources and staff needed to carry out the program and propose a schedule for obtaining resources and qualified staff prior to program approval.
3. Develop technically defensible local limits for all pollutants of concern.
4. Obtain the legal authority to apply and to enforce the re quirements of the program C/O:

a. An Ordinance that provides requisite authorities and codifies the local limits,
b. Inter

- jurisdictional agreements that app ly the program to outlying areas, and

c. An assessment by the POTW’s counsel that the POTW’s authorities and IJA’s allow them to legally defend applying the program throughout their service area.
5. Develop procedures to ensure compliance with the requiremen ts of a pretreatment program. These procedures must include the means to:

a. Locate all Users potentially subject to the program through both periodic efforts and continuous systems,
b. Properly permit users subject to their program,

c. Develop a Slug Discharge Control Program,
d. Develop a system for evaluating compliance with permit conditions,

e. Provide direct oversight including inspecting and sampling,
f. Take timely and effective enforcement against violations of the program through the applic ation of an Enforcement Response Plan, and

g. Provide for public participation and transparency, and
h. Modify the program to keep pace with Federal and State rule changes.



### 2. 1 .7 Stepwise Process f or Delegating Programs : NOTE: The procedures for partial programs will be similar to the procedures developed for fully delegated pretreatment programs with the exception that Ecology will not require and review anyCHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 8 functions which Ecology is not delegating. The regional pretreatment engineer will typically be the lead in carrying out these steps:

1. Ecology determines which pretreatment functions to delegate to the POTW and formally
notifies the POTW of this determination.
2. Ecology puts the POTW on a compliance schedule to complete development of the procedures or includes the requirements in their NPDES permit.
3. The POTW takes the measures necessary to develop a program as described in items 1

- 5 above (or the functions required by the Order) and sends three copies to Ecology who has 60 days to review the submittal. Ecology sends one copy to EPA for review.
4. Ecology provides comments back to the POTW on any areas that they have not adequately addressed. The POTW must address all deficiencies to Ecology’s satisfaction before going on to the next step.
5. Ecology provi des public notice of delegation of a pretreatment program. Public notice provisions of the POTW’s NPDES permit are adequate for a partial delegation.
6. Ecology notifies IUs of the transfer of responsibilities that result from full or partial delegation.
7. E cology revises the POTW’s NPDES permit to reflect the municipality's delegated status or additional roles and responsibilities.
8. Ecology cancels or the State Waste Discharge Permits of tributary Users when a delegated program issues a permit (upon the effec tive date of that permit).
9. Ecology modifies permits for IU’s discharging to POTWs which need to reflect additional reporting or oversight by POTWs with partial programs

.



### 2. 1 .8 EPA Role
EPA oversees program delegations as described in 40 CFR 403.9 through being sent a copy of the proposed program and objecting within 30 days if it does not meet their standards. There is no formal role for the EPA in the selection and delegation of a partial program under the federal pretreatment regulations

. There are no regulatory requirements that specify the involvement of the EPA in partial program delegation other than their right to review and comment on permit conditions in NPDES permits issued by Ecology

. The municipality is simply acting as Ecology's duly appoint ed agent as provided for in Chapter 90.48 RCW.

EPA also has the opportunity to comment on any partial delegation when we place the partial program conditions in a municipality's NPDES permit.



### 2. 1 .9 Tribal and Federal Treatment Works or Tributary Faciliti es

Tribal and Federal Owned Treatment Works: Washington State’s delegation of the NPDES

permit program in 1973 did not include delegation of the authority to permit tribal or federal facilities. Ecology did not seek such delegated responsibility since Ec ology’s interpretation ofCHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 9 the CWA was that it did not allow delegation of authority c ommensurate with it. The Clean
Water Act, unlike RCRA, does not give States authority over federal facilities. Ecology concluded it may well have less authority to compe l compliance with an NPDES permit it issues to a federal facility than to compel compliance with an EPA issued permit as a third party. Ecology also has the ability to issue 401 certifications, adding state specific requirements.

Federal Facilities Trib utary t o POTWs : Ecology expects POTWs, as utility providers, to ensure any person using their utility does so in accordance with the rules established to protect the POTW. Where federal facilities are discharging to a POTW, the POTW should condition its services to require compliance with local pretreatment program requirements as a condition of discharge. This must be in an enforceable contract with the tributary facility. Ecology should include language in the NPDES permit for delegated POTWs requirin g the POTW to establish such contractual relationships. Where the POTW is not delegated, Ecology has written permits for tributary federal facilities which impose requirements on point sources tributary to a POTW. This can be done by requiring the federa l facility to sample and meet appropriate criteria at intermediate discharge points

.

Industries o n Tribal Lands Tributary t o a POTW : Permits for facilities on tribal lands are discussed in Chapter II, section 13 of Permit Writer’s Manual. That section di scusses discharges on tribal lands, but not the rules for a discharge from Tribal Lands to a POTW that is not on tribal lands. No law gives tribal activities the right to connect to a POTW without permission of that POTW, or to be exempt from categorical standards for indirect discharges. Since the POTW would have to construct a pipeline that extends to the tribal lands, such discharges can only be initiated with the concurrence of the POTW. POTWs must be VERY careful about agreeing to accept any such di scharges without appropriate safeguards. A POTW may have no authority to enter and inspect such sources of wastewater (which may change over time) unless this right is established as a condition of their service. Ecology has been extremely reluctant to a ssert its authorities to require tribal activities discharging to a POTW to obtain a State Waste Discharge Permit. Unless and until this changes, Ecology permit writers should be clear with POTWs that this puts the burden squarely on their shoulders.

Pr oblems f rom Federal a nd Tribal Industries : Where the POTW doesn’t establish the appropriate controls before agreeing to accept the flows from any such activities such discharges may cause damage to the POTW, including its treatment process. When Ecology finds this happening, they should require the POTW to take action to fulfill its obligation to protect the public’s interest in the POTW. If the POTW does not have a pretreatment program, and Ecology believes that a pretreatment permit is necessary, Ecolo gy might need to require the POTW to develop one.



### 2. 1 .10 Discharges t o Ground

E cology’s municipal permit writers also oversee POTWs and other treatment works treating domestic sewage (TWTDS) which discharge to ground. Such facilities and their tributaryCHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 10 industries are not subject to the federal pretreatment program at 40 CFR 403. Ecology may, however, require such facilities to essentially do the same things a pretreatment POTWs would do. The pretreatment program provides a number of important safeguard s to protect the sewers, treatment process, biosolids, and effluent. These goals are important for discharges to ground as well. The difference is that for a discharge to ground, the standards for discharge of the effluent are not designed to meet our wa ter quality criteria, but rather our groundwater criteria.



## 2.2. NPDES Permit Conditions for Delegated Programs

For delegated programs, pretreatment requirements in the municipal NPDES permit must include conditions requiring the POTW to properly implement its p rogram, submit an annual report, and do proper oversight, enforcement, and verification. All permit writers should be familiar with the requirements of the Pretreatment Program because the requirements will become an integral part of some municipal NPDES permits.

The Municipal NPDES permit shell contains standard language for requiring a POTW to carry out the requirements of its approved program and pretreat ment rules of EPA and Ecology. These sections were written to be as self

- explanatory as possible. However, since each situation is unique, it’s best to consult your regional pretreatment engineer when there is any doubt about whether a condition is appropriate or not.

Special conditions that may be applicable to delegated programs include additional t asks supporting single industry campaigns such as dental amalgam or photo processors. Tasks supporting information gathering efforts also may be included.



## 2.3. Requiring and Recognizing changes to Delegated Programs

As Federal and State regulations change, d elegated pretreatment programs need to be required to change in turn. 40 CFR 403.18 describes when POTWs (control authorities) must submit changes to Ecology (the approval authority) and when they are substantial enough to require approval by Ecology and public notice and opportunity for comment.

Ecology, through its oversight (PCI’s and Audits) may also find that some aspects of the program are insufficient or inadequately described. In such cases, POTWs may need to modify their program to correct the d eficiencies. POTWs should follow the rules of 40 CFR 403.18 whenever they change their program.

Ecology may also modify pretreatment permits to require monitoring or controls on any pollutant for which criteria have been newly promulgated or revised.CHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 11 

## 2.4. NP DES Permit Conditions for Non

- Delegated Programs

Ecology applies and enforces pretreatment requirements on IUs when Ecology has not delegated the authority to run a local pretreatment program to the municipality

. Ecology's program for direct inspection an d control of IUs includes processes and procedures for developing local limits, updating and maintaining user inventories, permitting, reviewing reports and plans, compliance tracking and monitoring, inspections, and enforcement.

However, Ecology cannot c arry out these tasks without the assistance of the municipalities that run the treatment works and control discharges to the collection system. Permit writers must require domestic treatment works without pretreatment programs to develop and implement pol icies and procedures to support Ecology’s pretreatment program administration as enforceable conditions of their NPDES or State Waste Discharge permit

. While Ecology will maintain the NPDES municipal permit shell with the most up

- to

- date source of these c onditions, typically they include requirements for each municipality which owns a portion of the collection system

to:

• Conduct Industrial User Surveys at a frequency commensurate with the treatment works’ design flows. Such surveys must provide Ecology e nough information to know whether a potential industrial user requires a permit.

• Prohibit IU’s from discharging either without a permit (where an Ecology “IU to POTW” permit is warranted), or in violation of the prohibitions applicable to all discharges;

• Develop local pollutant discharge limits specific to the treatment works where Ecology finds such limits are needed to enable Ecology to, in turn, issue permits with a reasonable assurance they will protect the treatment works;

• Codify a pretreatment ordina nce (including local limits where developed) that gives affected users notice and opportunity for comment, gives authorities to the municipality to compel certain actions (such as completing survey forms, obtaining a permit, and meeting local limits).

• Deve lop a spill prevention program that protects against spills and slug discharges to the
treatment works.

Additional tasks which Ecology may require of local POTWs to ensure proper administration of the pretreatment program include to:

• Develop and impleme nt a grease control program for food service establishments.

• Develop and require (through ordinance provisions ) Best Management Practices (BMPs) for small flow industries whose combined contribution to the POTW is a significant source of pollutants. These may include photo

- processors, dental offices, stormwater sources, car washes, dry cleaners, medical service industries, laboratories, and such.

• Issue control mechanisms for such “Minor Industrial Users” (above) that compel periodicCHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 12 certification they are adhering to the BMP’s required by the program.

• Develop “end of process” limits for small flow pretreatment processes such as silver limits from silver recovery units used by photo processors (e.g

., 5 mg/l) or mercury from dental amalgam separators to suppo rt appropriate maintenance practices and BMP’s.

• Develop capacity management strategies and annually report on the flows and loadings allocated to industries as a proportion of the total flow and loading capacity available to the POTW (may be included with the annual waste load assessment report requirement).

• Collect and tabulate data from industries, trunk lines, biosolids, and POTW influent and effluent to show where loadings are coming from and how much reserve capacity is
available at the POTW. POTWs m ay be required to report such data annually, and compile the results of monitoring from tributary users permitted by Ecology.

• Maintain signed IU Survey forms from all businesses with the potential to discharge non

domestic wastewater. Hold IU’s accountabl e for obtaining a permit prior to discharging wastewater that they should reasonable know is subject to State Waste Discharge permit
or local BMP’s.

• Undertake sampling and inspection of IU’s permitted by Ecology.

• Review duplicates of the monitoring reports sent by IU’s permitted by Ecology, alert Ecology to non

- compliance, help develop a response strategy, and tabulate compliance data annually.

• Review and ensure the adequacy of Slug Discharge Control Plans that Ecology requires
of IUs.

• Respond to reports of spills or slug discharges at IU’s permitted by Ecology.

• Issue permits to Industries with compatible pollutants only, or below the flow and loading
thresholds which would make them SIUs.



## 2.5. Pr etreatment Related NPDES Permit Fact Sheet Language for POTWs

The m unicipal NPDES permit fact sheet shell contains standard language explaining the basis for common pretreatment related POTW conditions. These address the basis for requiring the POTW to run a pretreatment program, or do some of the more common pretreatmen t tasks. This language should be included in the permit to the extent it is applicable.

When additional pretreatment related requirements are added to the permit (such as those list in the section immediately preceding this one), the permit writer must document the basis in the fact sheet. This is important for the POTW, future permit managers, and others seeking to understand the basis and intent of the requirement.CHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 13 

## 3. STATE WASTE DISCHARGE PERMITS FOR NON

DOMESTIC WASTE

3.1. Overview of the Permitting P rocess

Permit writers use State Waste Discharge Permits to control discharges to sewage treatment systems (both POTWs and TWTDS). Where the receiving treatment works is owned by a municipal corporation and discharges to waters of the United States, the sy stem is termed a Publicly Owned Treatment Works (POTW). Federal rules on permit contents found at 40 CFR part 403 apply to permits for industries tributary to POTWs.
When the receiving treatment works discharges to ground or other waters of the state, o r is not publicly owned, it may not meet the federal definition of a POTW (found at 40 CFR 403.3(q)). In such cases, the treatment works is termed a Treatment Works Treating Domestic Sewage (TWTDS). Discharges from industries that would be subject to cat egorical standards if discharging to a POTW, but discharge s to a TWTDS are not technically CIUs, or subject to categorical standards. The same logic applies to industries that would be SIUs if discharging to a POTW. While not considered SIUs or CIUs, Eco logy can impose equivalent conditions on sources of indirect discharges to a TWTDS to similarly protect receiving treatment works based on the particular situation.
However, state laws at chapter 173

- 216 WAC impose the same requirements for discharge to a domestic sewage system regardless of whether it is a POTW or a TWTDS. Permit writers permitting a sewer customer or “Industrial User” therefore can use the same “IU to POTW” permit shell to issue a permit under the authority of that chapter. A number of the conditions in the permit shell stem from federal pretreatment requirements applicable to discharges to a POTW. Because of this, where discharge is to a TWTDS, the permit writer may have greater latitude in imposing such requirements.

Sources of non

- d omestic wastewater enter the permitting process through various means. The permit assistance center is one means. Their identification by a POTW or TWTDS is another. That is why it is so important to include (per the prior section) conditions in NPDES p ermits for POTWs, and State Waste Discharge Permits for other TWTDS that require municipalities have a system for identifying such sources and (in turn) requiring them to apply for permits before providing sewer service.
Ecology begins the permitting pro cess for a tributary industry when we hear of a source that may be subject to “categorical” standards or may otherwise be an SIU or require a permit. The first step in the permitting process is to gather information. Through review of the permit applicat ion and inspection of the User, the permit writer’s second step is to decide how to categorize the User (as a SIU, CIU, or MIU). After categorizing the User, the third step is for the permit writer to notify the User of theirCHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 14 status. The notification let ter should document their categorization, the basis, the status of their permit application (if one has been received) and their reporting requirements per 40 CFR 403.12. These reporting requirements vary depending on whether the User is subject to catego rical pretreatment standards or not. Both SIU’s and CIU’s must provide a one

- time notification of discharges of any wastes that would otherwise be hazardous (see 403.12(p)). CIUs must be advised that their permit application must satisfy requirements of a baseline monitoring report (403.12(b)) and they will need to provide an initial compliance report (per 403.12(d)) within 90

- days after commencing discharge. CIUs should be advised that they lose their right to request a categorical determination from EP A once they commence discharge (per 403.6.(a)(4)) and that this is a requisite step in requesting alternate limits due to fundamentally different factors (per 403.13(g)(3)).

The fourth step is to review the industry’s permit application and collect enough information to write the permit. Chapter III of the Permit Writer’s Manual and the flow charts of figure III

- 1,
III

- 2, and III

- 3 describe this process in good detail. Please refer to those areas of this manual. The permit writer will need to include ap propriate pretreatment standards (below section 3.B), and requirements (section 3.C).

Section 8 of Chapter III of the Permit Writer’s Manual discusses the “Domestic Sewage Exclusion” in good detail, and permit writers need to review this section and fig ure III

- 5 before writing a permit for discharge to a POTW of a waste which would otherwise be a hazardous waste. In such cases, the permit writer should ensure that the permit application adequately describes the waste (if a permit is not going to be issu ed), and should specifically authorize the discharge of the hazardous constituents in the permit, including a mass or concentration limit for the pollutants when feasible

. (reference 173

- 303

- 070(b)(iii)(G), 173

- 303

- 071(3)(a) and 173

- 303

- 803(5))



## 3.2. Pretreatm ent Standards

The general pretreatment regulations establish three types of pretreatment standards: Discharge prohibitions, categorical pretreatment standards, and local limits. The State adds a fourth type of
standard known as AKART.

Each is importan t to properly controlling pollutant discharges into POTW's

. Prohibited discharge standards (40 CFR 403.5 and 173

- 216

- 060 WAC) apply to all sources of non

- domestic wastewater (industrial and commercial establishments) connected to POTW's

. Categorical pret reatment standards (40 CFR parts 405

– 471) requiring zero discharge or compliance with concentration or production based limits apply to the users in 37 sp ecific industrial categories.

When tasked to write a permit for an industry conducting an operati on covered by categorical standards, permit writers must apply the more stringent of the categorical standards, local limits,CHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 15 or AKART. All permit writers writing industrial permits should be able to recognize industry sectors subject to national categori cal standards, and know how to research what specific industrial processes are covered by the standards.

Pollutants subject to categorical limits are not candidates for a “reasonable potential” determination. Federal rules require CIU’s to confirm at l east semi

- annually through self

monitoring they are meeting the limits for all pollutants limited by the categorical standards. Also, a “reasonable potential” determination may not be used to justify removing pollutant limits where treatment reduces pollu tant levels to below the “reasonable potential” threshold. In such cases, the application of AKART requires permit writers to continue to apply the pollutant limits. This is necessary to ensure the Permittee continues to provide appropriate treatment (AK ART).

Chapter IV, section 1.2 of this manual describes the process for applying categorical standards when permitting a Categorical Industrial User. Permit writers should apply this methodology for indirect dischargers subject to categorical standards as well. Permit writers looking to review development documents should consult their regional pretreatment coordinator. The pretreatment workgroup has compiled references on the “Pot

- O

- Gold” CD under the folder “Categorical Standards”. This compilation includes all published pretreatment standards, a list of early development documents, and subdirectories for each categorical standard. The development documents which EPA has scanned are included as well. Permit writers can probably locate all of these o n EPA’s internet web site but it may take longer. Ecology’s library also includes a substantial number of development documents.

Local limits are considered “pretreatment standards” under the clean water act when approved by Ecology. Local limits may be codified such that they only apply to SIU’s, apply to all users, apply to the combined discharge, or apply to the discharge from specific processes. Section 2 discusses the reasons for Ecology requiring POTWs receiving non

- domestic wastewater to codify s uch limits. After approval, Permit Writers should use them to write permits that protect the environment, sludge use, and the proper functioning of the collection system and treatment works.

EPA, in 2004 refined their guidance on local limit developmen t, and asks all POTWs which require local limits to develop them for all pollutants of concern, and at least the following pollutants: Arsenic, Cadmium, Chromium, Copper, Cyanide, Lead, Mercury, Molybdenum, Nickel, Selenium, Silver, Zinc, BOD, TSS, and wh ere the POTW is providing nitrification, Ammonia. Technically based local limits must consider the pollutant level that would cause adverse effects to the POTW (or TWTDS) including: its biological processes, sludge processes, sludge use options, and recei ving environment (surface waters, groundwater, or air for POTWs which incinerate their sludges). In writing permits for industrial users, permit writers should consider requiring information on “pollutants of concern” in order to facilitate developing or confirming local limits.CHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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## 3.3. Other Pretreatment Requirements

Permits must include notification of one time reporting requirements, determination of the User’s classification, requirements to submit baseline monitoring and final compliance reports, plans for

wa stewater facilities, and a complete permit application. Permits must contain requisite

contents.

Discharge Prohibitions: Federal rules at 40 CFR 403.5(A) prohibit discharge of any pollutants that cause p ass through or i nterference , and at 403.5(B) speci fically prohibit a number of discharges. These prohibitions are reinforced in Chapter 173

- 216 WAC under section 173

- 216

- 060. Permit writers must be conversant with these prohibitions and therefore should read and understand these sections. Ecology’s rul es for indirect discharges to POTWs goes beyond the requirements of 40 CFR 403 in prohibiting:

• Clean storm water, non

- contact cooling water in significant volumes, and other clean wastewaters that could significantly affect hydraulic loading

.

• Wastes with a pH greater than 11.0

.

• Dangerous wastes, as prohibited by chapter 173

- 303 WAC.

Local Prohibitions: Local POTWs may, at their discretion, prohibit the discharge of pollutants which they find are not amenable to their treatment process, have a potential t o disrupt the POTW or pose a threat, or that have caused or contributed to pass through or interference.

Permit Contents (in general) will cover the following topics:

• Permittee Rights to :

o Discharge the waste streams and pollutants identified in the permi t application subject to the pretreatment standards and requirements of the permit.

o Discharge specific waste streams (identify) at specific outfall locations (describe or show).

• Pretreatment Requirements to :

o Properly treat all wastewater and apply AKART.

o Meet the specific (listed) effluent limits (flow and pollutant concentration or loading limits) applicable to each outfall.

o Average monitoring results over specific time frames (e.g

., daily, weekly, monthly).

• Monitoring Requirements to :

o Monitor flows and specific pollutants on a specific schedule,

o Take representative samples (grab(s) or composite) using approved (40 CFR 136) methods and an accredited laboratory.

• Reporting Requirements to :

o Send periodic reports (at least semi

- annually) that include al l applicable documentation and monitoring results to a specific person and address.

• Record Keeping Requirements to record for each sample and keep at the facility for atCHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 17 least three years :

o Who took the sample, where the sample is from, when it was taken (date and time), and how it was preserved,

o Who else had control of the sample,

o Who analyzed the sample, when it was analyzed, and what analysis method they used,

o What the sample results were, when they were obtained, and when they were reported.

• Notific ation Requirements to :

o Immediately notify the CA and POTW upon discovering noncompliance (including failure of continuous flow or monitoring equipment),

o Resample on discovering limits were exceeded and promptly report the results of re

sampling.

o Notify be fore any scheduled bypass, or planned changes to production, chemicals, waste streams, water use, and flows.

o Notify before a new or increased discharge of a substance which would be a dangerous waste if otherwise disposed of.

• General Permittee Responsibili ties to :

o Immediately halt any discharge that threatens to harm any person or the POTW.

o Take actions needed to maintain compliance with permit limits, and act promptly to restore compliance.

o Comply with the other permit terms and applicable Laws and Statute s.

o Properly operate and maintain pretreatment systems, follow your approved O&M manual, and keep any checklists or log books it describes on site.

o Obtain Ecology review and concurrence before making changes to processes creating wastewater or any pretreatm ent systems.

o Properly handle and dispose of removed substances, retaining records of any waste characterization and disposal.

o Provide information relevant to discharges to the control authority or receiving POTW upon request.

o Reimburse all costs incurred b y Ecology and the POTW due to noncompliance including additional monitoring.

o Support any assertion of an affirmative defense with contemporaneous documentation.

• Prohibitions Requiring the Permittee to :

o Comply with any general and specific discharge prohibi tions.

o Discharge only waste streams from activities or processes identified in this permit.

o Obtain Ecology approval prior to discharge of any unforeseen wastes (e.g

., rinse tanks, resin regeneration, or periodic maintenance).

o Not use dilution as a substit ute for treatment, and not bypass any treatment component except in accordance with an approved O&M Manual.

• Administrative Requirements Pertaining to :

o How reports must be certified and who can sign them.CHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 18 o Requirements to pay for sewer use, capacity, and e xtra strength charges, any costs arising from non

- compliance, and penalties assessed under this permit.

o How to request and how Ecology will process changes to the permit.

o Requirements to re

- apply for the permit a certain length of time before expiration.

o R ules for transferring the permit to new owner or operator.

o Rules for appealing a permit term or condition.

o Notice that permit conditions are severable, property rights are not established by the permit, and enforcement remedies are not exclusive.

• Control A uthority Rights :

o To modify the permit in certain situations and cancel it in other specific situations

.
o To enter the facility without delay.

o To sample any waste stream and copy any records pertaining to wastes.

o To inspect the facility and take notes and pi ctures of activities subject to the permit.

o To apply injunctive relief to halt any discharge that poses a threat.

o To apply civil penalties for violations.

o To pursue criminal prosecution for knowing or willful violations.

o To determine and annually publish U sers in Significant Non

- Compliance.

o To require the Permittee to provide any information needed to make permit decisions.

o To increase the scope and frequency of monitoring in response to changed conditions or noncompliance.

o And to extend an expired permit.

• Liabilities : General civil and criminal liabilities apply to noncompliance with the permit.

• Special Requirements :

o To develop and follow a Slug Discharge Control Plan as a requirement of this permit, and promptly modify the plan as changes occur.

o To report whether compliance schedule milestones have been met when such are established by this permit.

o To provide any plans developed to comply with other environmental media such as spills, solid waste, dangerous waste, air pollution, & stormwater.



## 3.4. State Waste D ischarge Permit Fact Sheet Contents

The following topics are typical of a pretreatment permit fact sheet.

• Summary of information in the permit application relevant to permit terms and conditions

• Compliance status with the prior permit if this is a permit renewal.

• Processes producing wastewater and their flow volumes and characteristics (pollutants).

• Whether composite samples or grab samples are appropriate for each pollutant and why.

• Observations from the last inspection of the facility.

• Pretreatment syste ms, the waste streams they treat, their capacities, and approval status of these systems and any O&M manuals per chapter 173

- 240 WAC.

• Whether reinforcement of O&M manuals or procedures are needed to ensure compliance.CHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 19 • Specific processes (if any) subject to categorical standards.

• For CIU’s that combine categorical and non

- categorical waste streams for treatment before the monitoring point, whether each non

- categorical wastestreams is “unregulated” or “dilute” (as defined by EPA for use in the combined wastes tream formula)

• Applicable pretreatment standards (categorical, local limits, AKART) and how the most stringent limitations are applied.

• Whether the Permittee has identified any wastestreams which would otherwise be dangerous waste and therefore need to be allowed to discharge under the Domestic Sewage Exclusion.

• Whether a compliance schedule is needed for the Permittee to install additional treatment to reasonably meet the limits or other requirements of the permit.

• Prohibitions that the discharger has the potential to violate and safeguards to ensure that they do not occur.

• Whether the Permittee needs a new or updated slug discharge control plan or any other special condition.

• Other permits which the User reasonably needs to obtain in order to comply with
N PDES, stormwater, Dangerous Waste, or other Ecology permit programs.

• Public involvement documentation (public notice, comments, responses)

• Process Piping and Site Layout

• Definitions of terms used in the permit



## 4. REGIONAL PRETREATMENT ENGINEER STAFF
EXPER TISE AREAS

Overview
Federal Regulations at section 40 CFR 403.10(f)(2) require Ecology to provide technical and legal assistance to POTWs in developing Pretreatment programs. As a functional necessity, Ecology must also provide training and oversight of t he non

- delegated POTWs that we rely upon to implement parts of the pretreatment program where there is no local program.



### Division o f Duties
Each region determines how to divide the responsibilities of implementing and overseeing the diverse municipal and industrial components of the pretreatment program between their pretreatment engineer and municipal and industrial permit writers and facility managers.



### Training Ecology provides training and oversight through the pretreatment workgroup, its chairperson, and regional pretreatment engineers. Pretreatment staff support and speak at pretreatment training events such as the Northwest Pretreatment Conference, and more general forums such as PNCWA meetings. The Pretreatment Workgroup chairperson, in conjunctio n with regionalCHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 20 pretreatment engineers, also arranges separate training events that focus on one or more non

delegated POTW areas of responsibility. These are typically one day events held every two or three years at a couple locations.



### Delegated Program Oversight Regional pretreatment engineers support delegated pretreatment programs on both an informal and formal level. Informally, they support POTW requests for engineering assistance in plan review (Engineering Reports, Plans and Specifications, and O& M Manuals). They also help by reviewing permit applications and draft permits when requested. Formal oversight of delegated pretreatment programs is provided by conducting pretreatment compliance inspections (PCIs), audits, and reviewing the POTW’s annua l pretreatment report. Pretreatment reports are required and reviewed annually from each delegated municipality



### EPA Oversight The Ecology

– EPA Performance Partnership Agreement establishes several pretreatment requirements. Ecology performs PCI’s and A udits at the frequency described in that document. As of 2010, that document committed Ecology to conducting PCIs every two years and Audits once every five years. Ecology submits copies of PCI’s and Audits to EPA. Ecology will also provide the pretreat ment related data in EPA’s Required ICIS Database Elements (RIDE) when those protocols are established by rule. Ecology will require delegated POTWs to include this information in annual reports then as well.



### Non

- Delegated Program Oversight Regional pretr eatment engineers provide non

- delegated POTWs with oversight, guidance, and assistance as needed to fulfill their role as partners with Ecology carrying out the pretreatment program in their service area. The duties of non

- delegated POTWs can vary, but al l are charged with locating industry that should be subject to the pretreatment program. They must also all prohibit industrial discharges until properly controlled by Ecology, and control the myriad diffuse sources such as restaurants that collectively p ose a threat.



### Expanded Responsibilities Ecology’s staffing and resource limitations are severe. Accordingly, some POTWs must do more than just locate industries. Ecology may need the POTW to develop pretreatment standards (local limits) that protect th eir POTW from adverse effects from non

- domestic wastes, codify these limits in an Ordinance, and provide an expanded oversight “presence” to businesses. The regional pretreatment engineers evaluate the situation and recommend POTW responsibilities commens urate with the situation. This may require changes to NPDES permit requirements and activities preparatory to developing a local program.



## 4.1. Conducting Industrial User Surveys

Local POTWs are ideally situated to identify the sources of non

- domestic wastewate r potentially subject to pretreatment standards and requirements. They have direct access to water records,CHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 21 utility billing records for water use, planning department staff and records, tax and business license records, and building code enforcement staff

. For this reason, Ecology’s permit shell assigns this task to non

- delegated POTWs at a frequency commensurate with the threat. Important factors in evaluating the threat include whether the POTW serves an industrial area, if there have been incidents a t the POTW that may have been caused by non

- domestic discharges, and how much flow the POTW receives.

Part of the information POTWs collect includes the flow and concentrations of pollutants of concern. This allows the POTW to estimate the loadings from all their non

- domestic dischargers which is an important part of developing “technically based” local limits (next section).

The POTW’s procedures should describe how they keep their survey list updated (through ongoing systems such as applications for new business licenses or approval or plans), and the interval for periodically re

- surveying sewer customers to locate new or changed discharges with should be subject to pretreatment requirements.

To assist in this task, Ecology has developed an Industri al User Survey guidance manual. Permit writers and regional pretreatment engineers should provide this to POTWs that need technical
assistance.



## 4.2. Developing “Technically Based” Local Limits

POTWs must develop local limits for all pollutants of concern to pr otect the POTW, its solids, workers, and the public from harm. To be legally defensible these limits must describe their basis. This is referred to as “technically based”.

Local limits for indirect dischargers are analogous to water quality based limits derived by Ecology for direct dischargers

. Both types of limits are developed protect the receiving environment (surface water, groundwater, or POTW). Both also intend to ensure healthy water quality in the receiving environment. POTWs must develop Loc al limits where they have SIU’s that are not limited by categorical standards, or when applicable categorical standards do not limit pollutants well enough to protect the POTW. This latter case is increasingly common as categorical industries use more che micals that were unavailable when such standards were set.

Federal regulations at 40 CFR 403.5(d) state that where specific limits on pollutant parameters are developed by a POTW according to 403.5(c) (which includes notice to affected Users), such
limits are deemed Pretreatment Standards for the purposes of section 307(d) of the Clean Water Act. Ecology should require, as an NPDES permit condition, that any new or revised local limits be reviewed and approved by Ecology. This is important as Ecology wil l have to defend the limits should they ever be challenged by a Permittee.CHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 22 Categorical standards and local limits are distinct and complementary types of pretreatment
standards

. Categorical standards provide a nationally uniform degree of water pollutio n control

. Local limits provide an additional degree of control based on site specific requirements. EPA has published guidance on how to develop local limits in their July 2004 manual “Local Limits Development Guidance” Ecology has developed and will pr ovide a spreadsheet for tabulating and analysis of the data collected during the local limits development process. Ecology has also developed a checklist for verifying the completeness of the local limits development document.

Where Permit Writers have q uestions on how to develop local limits, they should contact their regional pretreatment engineers, who can answer these questions or pass them on to the state pretreatment engineer. See the monitoring chapter of this manual for a discussion of what
monit oring requirements should be included in a POTW's NPDES permit for developing and updating local limits.

Some municipalities may elect to develop local pollutant discharge limits without being required by Ecology

. Industrial permit writers should always ask knowledgeable POTW staff about local limits when writing a permit for an industry discharging to a POTW

. If those local limits satisfy the requirements of 403.5(c) they are applicable to all indirect discharges. Permit writers should
document their f indings in such cases in the fact sheet of the permit they are writing. Permit writers must apply the most stringent of local limits, categorical standa rds, BPJ, and AKART.



## 4.3. Providing Model Pretreatment Ordinance Language

POTWs that have or are developing delegated programs must first develop a Sewer Use Ordinance that allow the POTW to legally apply and enforce the local limits, requirements of the General Pretreatment Regulations and any other federal, state, or local pretreatment standards and requiremen ts needed to control non

- domestic dischargers to all tributary users.

POTWs which support Ecology’s administration of a pretreatment program also need to have the authorities to carry out the functions which we require of them. See Section 2.D for a fai rly comprehensive list of such possible requirements. Where Ecology has approved the technical basis for local limits, the POTW needs to codify these local limits in their ordinance so that Ecology can support and reinforce them in permits issued by Ecolo gy to indirect dischargers.

Ecology has develop ed a model pretreatment ordinance for delegated POTWs. This has been used in updating pretreatment programs after EPA’s streamlining of 2006. This language will be periodically revised when federal and st ate rules change. Ecology is working on an adaptation of this Ordinance for non

- delegated POTWs. One complication is that the range of responsibilities for non

- delegated POTWs may vary. Until such time as that is published, non

- delegated POTWs can codif y the model ordinance for delegated POTWs, but instead of requiring Users to obtain a permit from the POTW, reinforce the requirement for them to obtain a permit from Ecology for indirect discharge.CHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 23 

## 4.4. Inspecting and Auditing Delegated Programs

Ecology is ob liged to ensure that delegated POTWs implement the Federal Pretreatment Program and State Waste Discharge permit program for tributary users and do so in accordance with their approved program and applicable rules. Two types of inspections of delegated pr etreatment programs are the “Pretreatment Compliance Inspection” (PCI) and “Pretreatment Audit”. Definitions of these terms, and the current philosophy for their use and scope is found in Chapter 9 “Pretreatment” of EPA’s July 2004 NPDES Compliance Inspec tion Manual. EPA has also published instructions and checklists for both types of inspections.

During an Audit, Ecology reviews whether the POTW’s program satisfies all applicable state and federal rules. This including reviewing whether they have adopt ed provisions that incorporate any revisions to rules since the program was developed. Where Ecology finds that a program is not carrying out its approved program, or it needs to amend its approved program to incorporate changes to rules or a changed situ ation, Ecology will apply escalating enforcement measures to
correct the situation.

During a PCI, Ecology focuses on assessing whether the POTW is properly implementing its approved program. The PCI starts with assessing whether the local program locates all industries potentially subject to the program, notifies them of appropriate pretreatment related requirements, issues appropriate permits, provides proper oversight (frequency and scope of inspections and sampling), properly reviews reports, manages f iles, and effectively responds to

non

- compliance. As part of the PCI, Ecology must assess whether the POTW has sufficient staffing to carry out their approved program. Often inspectors will review the annual pretreatment report in preparation for conduct ing a PCI. This report can reveal problems at the POTW or continuing non

- compliance that needs to be addressed during the PCI.

As part of either an Audit or PCI, Ecology may inspect one or more tributary users. There are several purposes for such oversi ght. First, it allows Ecology to confirm that the IU is properly classified, and that pretreatment controls of its permit are appropriate. It also provides an assessment of the POTW’s ability to do inspections. And it allows Ecology to provide some
trai ning for local inspectors that may have few opportunities for such training.

For POTWs without a delegated program, Ecology staff responsible for managing compliance with the municipal permit would typically also assess whether the POTW has met the pretre atment related permit requirements. This may be done during POTW compliance inspections, or based on the POTW not meeting the submittal dates of its permit. The regional pretreatment specialist should be asked to assist in this assessment process when th e permit manager is unsure of the requirements.CHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 2 4 

## 4.5. Reviewing Pretreatment Related Submittals from POTWs

There are two major types of pretreatment related submittals

— t hose we have required under the POTWs permit and those we haven’t. Pretreatment related s ubmittals that arrive unsolicited can range from Engineering Reports and O&M Manuals for tributary Users, to program changes that
the POTW would like to make.

Most regions have recognized the value of having an engineer oversee implementation of local
P OTWs so that they can review plans for wastewater facilities.

Processing NPDES Permit Modifications When a local pretreatment program has been developed or modified, it must be reviewed and approved by Ecology and EPA. Ecology must then issue a public n otice of the proposed approval and allow for public involvement (a comment period). Ecology must then modify the municipal NPDES permit so it incorporates the approved program as an enforceable part of the permit

. Ecology must also delegate State Waste D ischarge permitting authority to the municipality while retaining an oversight function

. This is required under RCW 90.48.165

. These procedures should happen concurrently.



## 4.6. Reviewing Pretreatment Permits

Ecology regional pretreatment engineers have differ ent assigned duties in different regions. In some regions they may write all the indirect discharge permits. In others they may provide technical assistance to Ecology permit writers writing indirect discharge permits. Ecology also provides review of dr aft permits for delegated programs. Delegation rules at Chapter 173

- 208 WAC specify that delegated programs will send all permits to Ecology upon issuance. While Ecology has developed other means of ensuring consistency of permits, some POTWs choose to

c ontinue to use this opportunity to validate their permits.



## 4.7. Providing Organized Pretreatment Related Training Events

While much training is done “one

- on

- one” with POTW staff, another important way that Ecology assists POTWs is to provide training events wh ere Ecology staff review our guidance and answer common implementation questions. Ecology, as part of pretreatment training, should periodically review Ecology guidance and tools for carrying out IU surveys, developing local limits, codifying these limits , and should develop instruction around these topic areas.

Ecology pretreatment training should be focused on reviewing the basics of how the program works, how to use available tools, and what references to go to for additional clarifications.

EPA has produced quite a few EPA guidance manuals relating to pretreatment. Ecology’s training should provide an overview of these manuals so POTWs can locate guidance in specificCHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 25 areas. The Pretreatment coordinator will maintain a compilation of these EPA manu als, Ecology manuals, and other referenced materials that form the basis for pretreatment permit condition and program procedures on DVD format. Part of organized training events will include disseminating this compendium, and ensuring that regional coord inator s have copies for distribution within their region s

.CHAPTER X. PR ETREATMENT (NOVEMBER 2010)

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- 26 This page is purposely left blank9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 1 

# CHAPTER XI. RECLAIMED WATER USE

The Washington State Legislature passed the Reclaimed Water Use Act (chapter 90.46 RCW) in 1992

. This law promotes the be neficial use of a new water supply derived from highly treated

wastewaters

. Categories include reclaimed water, greywater and two types of industrial process

water reuse

. This Chapter provides the permit writer with information needed to write these

perm its.

Permits are issued to the owner of the facility generating the reclaimed water and govern the water quality, distribution and use of the water supply

. Reclaimed Water Act permits are much broader than state or NPDES wastewater discharge permits. S tate law requires a single comprehensive permit integrating Ecology Water Quality Program, Water Resource Program and Department of Health (DOH) requirements. Agencies and programs must coordinate as early in the process as possible. For most projects, E cology’s Water Quality Program issues the permit and includes all requirements. DOH may issue the permit for projects with only commercial and industrial uses. Amendments to Chapter 90.46 RCW in 2009 created a “lead agency” designation for either Ecology or DOH, whichever agency issues the facility permit. The lead agency is required to refer all permit applications to the “nonlead agency” for review and consultation, but the nonlead agency may choose to limit the scope of its review.
A reclaimed water p ermit grants an exclusive right to the use and distribution of the water and has stringent requirements for treatment reliability and disinfection

. Although a facility may produce and discharge a highly treated wastewater effluent (and may even call itsel f a water reclamation facility), the state does not consider a facility a “reclaimed water facility” until a permit is issued under Ch apter 90.46 RCW.



## 1

. LEARNING THE LANGUAGE

The permit writer should become familiar with the specialized terms in the Rec laimed Water Use statute and the Water Reclamation and Reuse Standards. Consult these sources directly for the complete legal definitions:

Reclaimed Water Use Act (chapter 90.46 RCW) Water Reclamation and Reuse Standards, Publication # 97

- 23

We provide plain English working translations of these definitions below:



## 1 .1 Working Definitions:

Agricultural Indust rial Process water is a special subset of industrial reuse water and refers to adequately and reliably treated water supplies derived from food processing wastewaters for use on agricultural lands.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 2 Beneficial use refers to the direct use of reclaimed wa ter for specifically stated and permitted

uses without an intervening discharge to waters of the State

. Beneficial use refers to conveyance of reclaimed water through pumps and pipes for irrigation, industry, urban non

- potable purposes,

or for planned env ironmental benefits such as wetlands, maintaining instream flows, lakes or aquifer levels. Beneficial use does not include discharge to public waters for planned recovery of the reclaimed water.

Constructed beneficial use wetlands (also called created w etlands) are wetlands created on non

wetland sites to produce or replace (mitigate for) lost natural wetland functions and values. They are considered waters of the state.

Constructed treatment wetlands (also called constructed wetlands) are wetlands co nstructed with reclaimed water for additional polishing of the water or providing public educational or aesthetic water features

. They are not considered waters of the state. This category does not include wetlands used for primary or secondary wastewate r treatment.

Controlled use refers to the indirect use of reclaimed water for specifically stated and permitted

uses. Controlled use involves the discharge of reclaimed water to public waters (lakes, rivers and aquifers) for storage or conveyance follow ed by the subsequent recovery and beneficial use of the reclaimed water.

Direct ground water recharge refers to subsurface injection of reclaimed water directly to the ground water basin

. Reclaimed water may be used for in situ environmental benefits such as maintaining geological structure or providing base flows to surface waters. The water many also be planned for subsequent recovery and use. Ground water recharge may also be used to mitigate impacts from other water withdrawals.

Drainfield , as used in this Chapter, refers to the network of subsurface pipes or tiles through which reclaimed water is dispersed into the soil for the purpose of ground water recharge through infiltration in undisturbed native soil

. This use of drainfields must meet a ll requirements for ground water recharge by surface percolation. If the drainfields do not provide adequate separation from the ground water basins, direct ground water recharge requirements apply.

Greywater refers to domestic wastewater including the wastewater from sinks, showers and laundry fixtures but not from toilets and urinals

. Standards, procedures and guidelines for reuse of greywater are developed by the Department of Health, Office of Environmental Health and Safety. Statute requires that the reuse greywater be permitted by Department of Health or local health officers based on rules adopted by Department of Health

. Contact or refer requests to the Large On

- site System Program Lead at DOH. Greywater may only be used below the surface (suc h as for drip irrigation). For surface uses, the greywater must be treated to meet the state reclaimed water standards appropriate for the use. After treatment, it is considered reclaimed water rather than greywater.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 3 Ground water recharge criteria are s pecifically defined in the reclaimed water act as the official state drinking water standards. For ground water recharge by surface percolation, the law requires reclaimed water to meet these criteria in the ground water beneath the recharge site.

Impair ment refers to a condition caused by someone or something other than a natural condition where a water right holder cannot accomplish the beneficial use(s) for which the right was perfected using reasonable care and diligence. Ecology considers a reclaime d water impairment analysis in the same context as the issuance of a new water right pursuant to RCW 90.03.290 and RCW 90.44.060.

Industrial Reuse Water was added to the statute in 2002. This refers to water supplies derived from industrial processing wa stewaters that are adequately and reliably treated to a quality suitable for another use. This is a very broad category and water quality limitations must frequently be decided on a case

- by

- case basis.

Land application refers to the beneficial use of re claimed water for crop or urban landscape irrigation. It includes both surface and sub

- surface (drip) irrigation methods

. It does not include dedicated sprayfields used for land treatment and disposal of wastewater.

Reclaimed water is the original cat egory in the 1992 statute. It is specifically defined as a new water supply derived from the adequate and reliable treatment of wastewater containing a sewage (or human waste) component. This is most frequently domestic or municipal wastewater but also i ncludes any wastewater that contains any amount of sanitary sewage.

Recycling means the capture and redirection of used water back to the same uses. This may be with or without additional treatment

. Recycling most frequently occurs in an industrial sett ing.

Reuse is a more general term referring to the subsequent use of any used water including reclaimed water , greywater , stormwater and wastewater. These used waters do not always require treatment to be re

- used

. This becomes confusing because the term water reuse also describes the use of reclaimed water (which requires treatment). Under state law, reclaimed water is considered a new water supply

- not used water

- and the more precise term is reclaimed

water use.

Surface percolation refers to the a pplication of reclaimed water to the ground surface for the planned replenishment of ground water. Reclaimed water may be planned for in situ environmental benefits or for subsequent recovery and use. Ground water recharge may also be used to mitigate im pacts from other water withdrawals. Streamflow augmentation means the planned and permitted release of reclaimed water to lakes, rivers, streams. The reclaimed water may be used for in situ environmental benefits or planned for subsequent recovery and us e. Streamflow augmentation may be used to mitigate impacts from other water withdrawals.

Water of the State or State Waters refers to lakes, rivers, ponds, streams, inland waters,9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 4 underground waters, salt waters, and all other surface waters and waterco urses within the jurisdiction of the state of Washington.

Water of the United States is defined by the U.S. E.P.A. as navigable waters, tributaries to navigable waters, interstate waters, the oceans out to 200 miles, and intrastate waters which are
used by interstate travelers for recreation or other purposes, as a source of fish or shellfish sold in interstate commerce, or for industrial purposes by industries engaged in interstate commerce.



## 1 .2 Abbreviations and Acronyms

AKART

– All known available and reasonable methods of prevention, control and

treatment. ART

– Adequate and reliable treatment
DOH

– State Department of Health WQP

– Water Quality Program
WRP

– Water Resources Program
SEA

– Shorelands and Environmental Assistance Program
ODW

– Office of Drinking Water (DOH)



## 2. STATUTORY REQUIREMENTS

The permit writer should understand the basic statutory differences between reclaimed water permits, wastewater discharge permits and water rights.

Wastewater discharge permits include the National Discharge E limination System (NPDES) and state waste discharge permits . They are regulated under Ch apter 90.48 RCW, the Water Pollution Control Act. These permits include treatment, monitoring and siting conditions providing for the least harmful disposal of treate d wastewater effluent. Wastewater discharges must be treated to protect existing beneficial uses in ground or surface water discharges, but the wastewater is not planned for a specific beneficial use

. This is true even when there is some
incidental benef it.

Water right permits are regulated under Ch apter 90.03 Water Code and Ch apter 90.44 Ground
Water Code govern the quantity, location and purpose of water use and relation to other water

uses. Reclaimed water permits are regulated under a different la w, Ch 90.46 RCW, the Reclaimed
Water Use Act. Reclaimed water is considered a new water supply planned for beneficial use.
The law requires issuance of a single comprehensive permit governing the water quality, the rate, location, and purpose of use

. Th e owner of the permitted facility receives an exclusive right to
the use and distribution of the reclaimed water and exemption from the Water Code appropriative water right permit requirements. The permit is usually issued by Ecology through9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 5 the Water Qua lity Program with close coordination with the Water Resources Program and
DOH

. DOH may issue permits that are not under Ecology jurisdiction

. Combining various permits into the single reclaimed water permit quickly becomes complex

. Reclaimed water facil ities with no wastewater effluent discharges are still issued permits under
Ch apter 90.46 RCW. However, m any facilities that generate reclaimed water also have wastewater effluent discharge s . Effluent discharge may be an alternative when reclaimed water quality standards are not met or when there are uses for only some of the treated water

. An NPDES permit is required under federal law (The Clean Water Act ) whenever the water is discharged to a water of the United States . When the reclaimed water permit is combined with
an NPDES or state waste discharge permit, the reclaimed water requirements are usually designated as a separate section (calle d R conditions for reclaimed).



## 2.1 Reclaimed Water Standards

Ch apter 90.46 RCW funded and required the development of a single set of standards for
reclaimed water

- Water Reclamation and Reuse Standards , 1997. The standards were developed cooperatively between the Departments of Ecology and Health. Alth ough authorized by statute,
i t is very important to remember that the standards are not in regulation and must be incorporated
into the permit to be enforceable.
The 1997 standards define adequate and reliable treatment (ART) requirements to be met at al l
times

. This “at all times” requirement is included because reclaimed water is no longer
considered a wastewater. ART requirements are in addition to ( and generally more stringent
than ) the AKART requirements for wastewater treatment. Although all proj ects must meet state requirements, r eclaimed water released to a water of the United States must also meet all federal Clean Water Act requirements for discharge.



## 2.2 Industrial Process Reuse Wat er

In 2001 and 2002

, amendments to Ch apter 90.46 RCW added provisions for two additional types
of industrial water reuse: agricultural

- industrial process water and industrial reuse water

. The law did not specifically require or fund development of either new standards or regulations for the new categories

. The wide variety of potential wastewater sources and uses require most
i ndustrial reuse water decisions to be made on a case

- by

- case basis. All existing requirements for water quality and human health protection under Ch apter 90.48 RCW still apply. In addition

, the permit must assure that the new water supply meets the ART requirements for the intended

uses.



## 2 .3 Water Resource s Permitting

Reclaimed water act permits also differ from wastewater disc harge permits regarding the legal status of the water following discharge from the treatment facility. RCW 90.46 .120 gives the9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 6 owner of a permitted reclamation treatment facility the exclusive right to the use and distribution of the reclaimed water gener ated by the facility. The law specifically exempts the owner from
the appropriative water right permitting requirements of the state water code 4 . The exclusive right and exemption intends to streamline the permitting process by providing for only one sta te permit with conditions regulating the water quality as well as the location, the rate and the purpose of water use.

Some projects may propose the indirect or controlled use of reclaimed water following discharge to waters of the state. As long as the intent of subsequent withdrawal or diversion is recovery of the reclaimed water and a portion of the reclaimed water is actually recovered, the complete project may be permitted under a single reclaimed water permit. When the reclaimed water is discharge d as mitigation for withdrawal or diversion of waters of the State (no portion of the reclaimed water is recovered), two permits are required: a reclaimed water permit for groundwater recharge or streamflow augmentation and a new appropriative water right under Chapter 90.03/90.44 RCW.

When wastewater that has been traditionally discharged to waters of the State is planned to be diverted for other uses, the Permittee must also meet provisions in RCW 90.46.130. This section
of the Reclaimed Water Use Act requires that existing water rights not be impaired by the water reuse project. For reclaimed water , RCW 90.46.130(1) provides that any compensation or mitigation of impairment must be agreeable to the holder of the affected water right

. The Water
Resour ces Program (WRP) is available to assist the water reuse project proponent in assessing the potential to impair existing water rights. WRP also review s the impairment analysis and provides a recommendation to the permit writer and water quality facility m anager for p roject approvals and permit conditions necessary to avoid impairment of existing water rights

. 

## 2.4 Guidance for Coordinated Permits

In some cases it is not possible to issue a single permit that covers both treatment of the
reclaimed water and the eventual beneficial use. One example of this is an appropriation of state water in exchange for groundwater recharge or stream flow augmentation where the appropriation does not capture any of the reclaimed water. Examples of this would be an

approp riation up stream, or upgradient in the same aquifer. The Department does not possess statutory authority to grant a single permit for these types of reclaimed water projects, and a separate water right ( 90.03/90.44 RCW ) permit must be issued for the appr opriation in addition to the reclaimed water permit

.

4 RCW 90.46.120 specifically exem pts use and distribution of reclaimed water by the owner of the facility from the permit requirements of RCW 90.03.250 and 90.44.060. However, it will be appropriate for the permit writer to consider permit conditions and analyses from other portions of t he water code when issuing the single combined reclaimed water permit. These would include an evaluation of impairment pursuant to RCW 90.46.130, well construction standards, metering and reporting requirements, screening provisions and others.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 7 These types of reclaimed water projects must still demonstrate that no existing water right is impaired by their actions and that water quality standards are met.

Additionally, the statutory tests for issuing a new water right must also be met including that water is available for appropriation, that the proposed purpose must be a beneficial use of the water, and that the application will not impair existing water rights or be detrimental to the public welfare. Ecology must process new water right application in the order they are received unless they qualify for expedited processing. Reclaimed water projects proposing mitigated use of state water may qualify for expedited processing if they meet the r equirements in the WAC
173

- 152

- 050 (2)(b) and Ecologies water Budget Neutral Policy (Pol icy

- 1021)



### 2 .4.1 Timing Issues
Because the water right permit and the reuse permit are issued on different time cycles coordination between the two permitting programs will be necessary.

For a new reuse facility, discharging reclaimed water (e.g

., beneficial use for groundwater recharge or instream flows) and seeking a “credit” for a commensurate (or lesser) amount of state resources in a different location, the follow ing schedule will typically apply:

1. A 20

- year planning projection is completed in a water system plan update.
2. The water resources permit issues for the 20

- year planning projection.
3. The water quality permit issues for the first 5

- year cycle, and then ever y 5 years thereafter (4 total reuse permits over the life of a single water right permit).
4. At the end of the 20

- year cycle, if the facility has not grown as fast as that projected initially, the permit could be extended for another 5

- year term under RCW 9 0.03.320.
5. If the permitted quantity has been put to beneficial use a new water resources permit application is required of additional growth. Because use of water under the water resources permit is always contingent on equivalent discharge of reclaimed water a certificate is not issued.



### 2 .4.2 Water Resources Permit Content
The water right permit would have the following characteristics inherent to every water right
issued under Ch apter 90.03/90.44 RCW, including:9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 8 1. Qi (Instantaneous withdrawal rate)
2. Qa (Annual withdrawal rate)
3. Point of diversion/point of withdrawal
4. Place of use
5. Season of use
6. Purpose of use
7. Priority Date

Additionally, it would include provisions that would “marry” it to the reclaimed water permit.

Provision 1: “No withdrawal is a u thorized under this permit unless mitigation is provided consistent with the terms outlined in the DATE Water System Plan or an update thereto approved by the Department of Ecology.” Note that this plan will need to include the description
of the other wa ter rights in play, and contingencies for what happens when the system doesn’t meet a water quality parameter (e.g

., is not reclaimed water discharge, but rather disposal). This is largely a paper exercise because the discharge would typically have occurr ed, so there would not necessarily be a wet water impact. However, there is no “credit” for disposal.

Provision 2: Source metering.

Provision 3: Monitoring data shall be submitted each year. The annual submittal will include a monthly accounting of r eclaimed water discharged and source water diverted (e.g

., debits and credits).



### 2 .4.3 Reuse (Water Quality/Health) Permit Content
The Reuse Permit Fact Sheet would include a narrative of the project in the including the use of reclaimed water as mitigat ion for a subsequent state water diversion.

The Reuse Permit would be slightly modified to reflect the two permit format.

1. R1

– Limits. Standard (Class A, B, C, or D as appropriate) limits would apply. For surface water, include limits for the dischar ge (disposal) of off specification water. Include language that treated wastewater that does not meet the reclaimed water limits is effluent, not reclaimed water. This is important for the water right ‘credit’ accounting.
2. R2

– Monitoring. Include monit oring of the flow meter for the diversion of state water to dovetail with the WATER RIGHT permit.
3. R3

– Reporting. An additional reporting requirement to submit the accounting of the water diverted and the reclaimed water produced. The exact accounting w ould be project specific ; i.e

. , the accounting method described in the approved facility plan, and assumed in the impairment analysis. The reuse permit would have the same language as ‘Provision 3’ from the water rights permit. Water Resources would be o n the distribution
list for this submittal.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 9 4. R4

– Use and Distribution. The authorized use would be ground water percolation or flow augmentation. The reuse plan, use area agreement and other permit requirements would regulate how the water was discharge d or percolated. The reclaimed water permit would put no conditions on the use of the water appropriated through the water right permit.



### 2 .4.4 Changes to the Water Resources Permit
Because the development schedule for the permit will be 20 years, it i s very possible that changes could occur during that time, including:

1. Point of withdrawal. Pursuant to RCW 90.44.100, such a change could be made through a Showing of Compliance, or a formal change application submitted to Ecology or a Conservancy Board.
2. Point of diversion. Point of diversion changes are limited to those authorized by RCW
90.03.350

- 370 and for municipalities, under RCW 90.03.570. Once perfected changes may be made pursuant to RCW 90.03.380.
3. Place of use. For municipalities, the place of use would likely change every 6 years with a water system plan update by operation of law.
4. Purpose of use. Most permits would issue for municipal water supply. Purpose of use cannot be changed on inchoate permits. Purpose of use may be changed purs uant to RCW 90.03.380 once perfected.

The above changes to a water right permit would generally not necessitate an immediate change to the reuse permit, rather it could be addressed (e.g

., in the narrative) at the next 5 year update.



### 2 .4.5 Changes to t he Reuse (Water Quality/Health) Permit
Reuse permit changes could cause a change in the water right permit authority if the nature of the discharge changed (e.g

., location, timing, duration, or other type that could affect the underlying

no

- impairment det ermination).



## 2

. 5 Wetlands

Site specific permit provisions in addition to the requirements in the Water Reclamation and Reuse Standards may be required for wetlands projects. All p rojects that propose wetlands
creation or enhancement should be coordinate d with the regional wetlands specialists in the Ecology SEA Program. The field of wetland science and the wetland regulatory framework are constantly changing. Wetlands are dynamic and highly variable ecosystems and Ecology has developed general wetland regulation guidelines that allow the agency to incorporate current wetland science, tailor the level of regulation to the type of wetland being affected, and respond
to site

- specific situations.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 10 

## 2

. 6 Stormwater

Stormwater use is generally not covered unde r Ch 90.46 RCW. However, t here are two basic

ways in which storm flows may be considered part of reclaimed water. In both cases , the stormwater is introduced prior to treatment.

1. Normal infiltration and inflow to sanitary sewer systems

.

2. Stormwater con sidered as industrial process wastewater

.

Some projects also propose blending stormwater with reclaimed water after treatment

. Due to the differences in regulatory requirements, combined applications can quickly become complex

. The blending of stormwate r and reclaimed water is discussed under the various categories for use
of reclaimed water.



## 2.7

. Department of Health Provisions

Early coordination or consultation between the Department of Ecology and DOH is needed for all significant issues related to public health protection. RCW 90.46 .030 gives DOH the lead for
industrial and commercial uses of reclaimed water such as toilet flushing and cooling tower use.
The DOH review focuses on reliability, advanced treatment and distribution and use
considerat ions for disease prevention, particularly from pathogens such as protozoa, bacteria and
viruses.



## 3. THE PERMITTING PROCESS

4. This section discusses the general permitting proces s for most reclaimed water projects. Chapter 90.46 RCW requires Ecology to issue a single permit which is essentially a combination of a water quality permit, DOH requirements and water right provisions governing the location, the rate and purpose of use of the water

. A single combined permit is issued by the Water Quality Program to the owner of the reclaimed water facility. Since the permit requirements for reclaimed water facilities extend beyond the Water Quality Program, it is important for the permit writer to coordinate efforts between Ecology Water Quality and Water Resources p rograms and DOH early in the permit process

. Failure to do so results in project delays and strained relationships. Regional staff should also notify the State Lead in Ecology’s Water Quality Program

. This is needed for project tracking and is helpful in obtaining assistance with the water reuse elements of the proposal.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 11 

## 3.1

. Ecology Water Quality Program Role

The Ecology Water Quality program has the largest regulatory burden for permit administration

. Under Chapter 90.46 RCW, Ecology has the primar y permitting responsibility for land application; ground water recharge, wetlands, and streamflow augmentation of reclaimed water and for all treatment and uses of agricultural industrial and industrial reuse water (see definitions). To streamline procedu res, Ecology also has authority under RCW 90.46.030(5) to issue permits including commercial and industrial uses of reclaimed water through a formal agreement with DOH. Ecology uses the authority under Chapter 90.46 RCW and Chapter 90.48
RCW to review, ap prove, permit and inspect the water reclamation and reuse facilities.



### 3 .1.1 Reclaimed Water Permits
Reclaimed water is, by definition, derived from wastewater with a domestic wastewater component

. Ch apter 90.46 RCW authorizes Ecology to issue a single p ermit for the treatment and beneficial use of reclaimed water. The statute and the Water Reclamation and Reuse Standards (1997) specify the treatment and monitoring require d for various uses of the reclaimed
water. These must always be incorporated into the permit to assure that they will be enforceable. The Water Quality program is also the lead for coordinating with both DOH and Water Resources Program (WRP) during the development of the permit. Both WRP and DOH may also include conditions within the permit.



### 3 .1.2 Agricultural Industrial Process Water Reuse Permits
Beginning in 2001, RCW 90.46.150 authorized Ecology to issue a single permit for agricultural reuse of water derived from food processing wastewater. As long as there is no sewage prese nt in the wastewater, the requirement for adequate and reliable treatment should be considered equal to or higher than the AKART treatment technology requirements for wastewater discharge permits from food processing facilities. If the wastewater has a se wage component, then it must meet the requirements for reclaimed water under 4.1.1 above

. In either case, the treatment must assure that the water is safe and appropriate for use as a water supply. Section 14 (under development) of this Chapter will prov ide additional detail on water quality considerations for various uses. The permit writer should coordinate with the WRP regarding the potential for water right impairment and any additional permit conditions

. The law requires Ecology to refer the permit application to DOH for review and consultation if a significant risk to public health exists in the proposed use of the water. Public health risks that may warrant referral to DOH are included under section 4.2.2. If you are uncertain regarding the pote ntial for public health risk in a project, contact DOH early in the permitting process.



### 3 .1.3 Industrial Process Water Reuse Permits
In 2002, RCW 90.46.160 authorized Ecology to issue a single permit for water reuse projects derived from industrial pro cess wastewaters

. If the i ndustrial wastewater is co

- mingled with any amount of human sewage, it is considered reclaimed water and as discussed in 4.1.1 above

. The9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 12 law is very broad regarding the types of industrial wastewaters and potential use

. Projec ts are likely to be very case specific and no specific standards or regulations have been written to cover this category. ART (adequate and reliable treatment) is required in the law to assure that the water is safe and appropriate for the proposed uses o n sites which are not dedicated for wastewater disposal. Ecology has several sets of standards and regulations for industrial wastewaters that can be applied on a case

- by

- case basis to meet this requirement. These include:

• AKART and Industrial Pre

- treatment Standards

• Surface water standards

• Ground water standards

• Water Reclamation and Reuse Standards

• Section 14 of this Chapter (under development) When Ecology determines that a significant risk to public health exists in the use of the water, the ag ency is required to refer the application to DOH for review and consultation. Public health risks that may warrant referral to DOH are included in Section 4.2.2 of this Chapter. If you are uncertain regarding the potential for public health risk in a pro ject, contact DOH early in the permitting process

. The permit writer should coordinate with the WRP regarding the potential for water right impairment and any additional permit conditions.



## 3.2

. Department of Health Role

DOH under RCW 43.70.80 and Chapter s 246

- 271 and 246

- 272 WAC has the authority to protect public health and approve, inspect, and permit municipal wastewater disposal systems. DOH also has the permitting lead for commercial and industrial uses of reclaimed water although RCW 90.46.030 allo ws Ecology to issue the permit through interagency agreement.



### 3 .2.1 Memorandum of Understanding (MOU)
Ecology Water Quality Program and DOH Office of Drinking Water completed an MOU (May 25, 1995) to more clearly delineate responsibilities

. Under the in teragency MOU, DOH has responsibility for the following:

o Cross

- connection control measures and public health requirements for reclaimed water permits.

o Notify Ecology of any reclaimed water permit violations through copies of inspections, monitoring record s or correspondence with Permittee, distributors or

users.

o Report any other alleged permit violation to Ecology that is found as a result of a DOH inspection or notification. The MOU also provides that Ecology will:

o Institute a consistent, statewide pro cedure for DOH to include appropriate public health conditions for reclaimed water projects within the permits.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 13 o Notify DOH of initial permit applications, renewals or modifications that contain reclaimed water provisions.

o Consult with DOH to assure that p ublic health is adequately addressed in engineering approvals, permits and enforcement orders.

o Report to DOH any permit violations of public health significance that may affect reclaimed water permits including copies of inspections, monitoring records o r correspondence with Permittee, distributors or users.

o Notify DOH of any complaints of public health significance on reclaimed water permits



### 3 .2.2 Public Health Risk Consultation

Public health risks in the use of reclaimed water or industrial reuse water that may be of interest to DOH include the following:

• Irrigation or other direct reclaimed water use within areas served by public water systems.

• Installation of non

- potable pipelines in a public right

- of

- way that also incorporates potable water lines w hen pipe separation requirements are not met.

• Projects creating cross connections between reclaimed water and potable water in all public water supply systems.

• Projects where aerosols are introduced into public areas.

• Projects with ground water recharge oc curring in areas adjacent to or contiguous with existing potable source water protection areas.

• Projects where uses might be compromised by microbial pathogens or other contaminants in the reclaimed or industrial reuse water.

• Projects where reclaimed water quality for public contact uses could be contaminated from other non

- potable pipelines such as sanitary sewers.



## 3.3

. Ecology Water Resources Program Role

Chapter 90.46 RCW requires Ecology to issue a single reclaimed water permit. This permit combines the water quality permit with the water right provisions governing the location, the rate and purpose of use of the water

. Although reclaimed water use is exempt from the permitting requirements of the water code, there are several areas where the two pro grams overlap and coordination must occur

. In addition, it is important for the water resources program to have knowledge of and access to information where water reuse supplies offset the need for other

water sources.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 14 Consideration must be given to t he following:

• Impairment of Existing Water Rights

.

• Location, rate and purpose of use

.

• Controlled Use

.

• Blending with other flows

.

• Mitigation for New Water Rights

.


### 3 .3.1 Impairment of Existing Water Rights The guidance below is applicable to reclaimed water facilities under RCW 90.46.130(1) which are primarily municipal facilities. It may not always apply to the non

- impairment provisions under RCW 90.46.130(2) for industrial reuse water. Additional guidance will be included in Section 14 at a future update . If you have an industrial reuse project, consult the WRP for specific help with impairment determination requirements.

Impairment is defined in Section 2 of this Chapter. RCW 90.46.130(1) indicates that a reclaimed water permit should only be issue d if there is no impairment of existing downstream water rights or if adequate compensation or mitigation is provided for the impairment. To mitigate for impairment, the reclaimed water permit may therefore include specific permit conditions such as restr ictions on the amount of flow that may be diverted at critical times. Figure 4.1 on the following page illustrates the importance of the impairment analysis in the reclaimed water permitting process.

Assessing the potential for impairment is an essential step in determining the feasibility and cost of a reclaimed water project

. The purpose of the impairment analysis is to evaluate whether existing water right holders will be impaired when a reclaimed water facility decreases or eliminates its existing di scharge of wastewater and begins to reclaim the water for beneficial uses. All downstream water right holders must be considered in the analysis

. (See Impairment Analysis is required for All Projects below).

Generally, the analysis will be completed a nd approved as part of the SEPA process

. Compliance with SEPA is required for approval of the facility plan or engineering report. It is important for the proponent to identify and notify all potentially impaired water right holders

. Public notice requi rements are included in Section 4.6 of this Chapter.

T he Water Quality facility manager or permit writer should arrange a meeting with the Permittee and the Water Resources Program to discuss the project and the level of technical assistance
available as the Permittee prepares the impairment analysis

. The following topics are intended to assist the permit writer when working with the Permittee and with the Water Resources Program.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 15 Figure 3 .1 Permitting Flow Chart for Reclaim ed Water Projects

Complete The Impairment Analysis Early. Ecology recommends submitting the impairment analysis as early as possible in the planning process

. Depending on the status of a community’s sewer planning efforts, a n iterative process may be m ost appropriate

. The proponent completes a scoping analysis at the initial stages of a reclaimed water project, followed by a more detailed assessment when
reclaimed water appears feasible

. Typically, an impairment analysis must be completed to comply wi th SEPA and is submitted to the department as a component of an approved facility plan or engineering report.

Impairment Analysis Is Required For All Projects. Although an analysis is always required, in some cases the scope of the analysis may be simp le. When no water rights have historically used the wastewater return flow (such as
marine discharges and wastewater land treatment and disposal facilities that consume the water) a short paragraph may be sufficient documentation. For all projects, docum entation of the impairment analysis must be included in the fact sheet accompanying the draft permit. Proponent submits Reclaimed Water Permit application

Has WR previously reviewed

an impairment

Was an impairment

analysis submitted wi th

the permit

WQ can proceed with review of the application, and if complete develop Reclaimed Water Permit The application is not complete. Provide proponent a list of deficiencies including the need for an impairment analysis. WR 75 day review of impairment analysis

The application is not complete Is the impairment

analysis adequate? YES

YES

YES NO

NO

NO9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 16 Evaluate All Existing Downstream Water Right Holders (6 Steps). For reclaimed water projects other than a historic marine discharge or land disposal, se veral steps must be completed in evaluating the potential for impairment associated with a proposed water reclamation project.

The first step in evaluating impairment is to determine an initial study area based on the maximum possible geographic and geo logic boundaries for the analysis. Geologic boundaries should be based on hydraulic barriers to water flow, including faults, folds, impermeable layers and other geologic features. Geographic boundaries should be based on topography, watershed boundaries , and (in surface water settings) a downstream control point that is sufficiently separated by distance as to make impairment extremely unlikely.

The second step in evaluating impairment is to establish the location of this downstream control point. A good way to do this is to compare the maximum instantaneous quantity of wastewater to be reclaimed with the minimum annual flow in the receiving water body at the historical point of waste discharge. If the amount of water to be reclaimed is small

compare d to this minimum flow, it can be argued that this control point is essentially at the point of discharge, and impairment of downstream rights is highly unlikely 5 . As the ratio of reclaimed wastewater to minimum annual stream flow increases however, it be comes increasingly likely that this control point is further downstream, and one or more intervening downstream water right holders may be impaired. Natural surface and ground water inputs between the historical point of discharge and the downstream right s may bring the control point closer to the discharge point.

The goal of this step is to shrink the size of the initial study area from a whole geological basin to a smaller portion therein, if at all possible. Outside of this final study area, it is
h ighly likely that no water rights will be impaired.

The third step in evaluating impairment is to identify all existing rights within the final study

area. Any downstream water right holder in this area whose exercise of a water right relies

, in whole or in part, on the water body to which wastewater has historically been discharged
should be evaluated. Ecology has interpreted downstream to mean down gradient in the context of groundwater. Ecology water resources staff can assist the project proponen t in determining the location and characteristics of study area water rights.

The fourth step in evaluating impairment is to determine whether any of those rights may be removed from further consideration because they never relied upon the historic wastew ater

5 One exce ption is the potential for impairment of an instream flow adopted by the Department in rule, for which any reduction may be considered to be impairment (see Instream Flow Water Rights section).9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 17 discharge. In many cases, the project proponent may not be able to exclude any water right holders at this step. However, in some areas where water rights have been adjudicated, it may be appropriate to exclude water rights that were perfected befor e the wastewater discharge began and no impairment is likely. In areas where the original source water for the wastewater discharge is in another basin or aquifer, such flow may be considered foreign and water right holders downstream of the discharge may not have had a right to rely upon such flows. Ecology encourages the project proponent to work closely with water resources staff where such situations are present.

The fifth step is to determine the most appropriate water right to use as an “indicator right” for the impairment evaluation. Often times this is the closest water right to the historic discharge.

The sixth step is to evaluate whether the reduced discharge, including timing and frequency of occurrence, will impair the indicator water right under the impairment definition. Technical evaluations, analytical formulae or modeling may be necessary to make such a determination. If no impairment of the indicator right is found, then it may be appropriate to determine no impairment will occur to a ny right in the study area based on this worst

- case evaluation. If the indicator water right is impaired, further evaluation may be necessary to determine how many rights would be impaired in the event that compensation or mitigation is proposed.

Instr eam Flow Water Rights Are Included. The State is the holder of instream flow “rights” adopted by rule and is required to protect these minimum instream flows. Reduction of stream flow that prevents the legal purpose(s) of the adopted in

- stream flow is considered an impairment of a water right

. When instream flows c ould be impaired by the continuous diversion of water for a proposed project, the Ecology issued water right is typically conditioned as an interruptible right to assure that instream flow pr ovisions are met.

It may be possible to provide compensation or mitigation to ameliorate the impairment of the State instream flow water “right”

. Ecology has prepared a mitigation digest of past projects that have included this type of mitigation. In g eneral, in

- kind (e.g

., drop for drop) mitigation

- in both space and time to the impact

- is preferred. Ecology may also determine that a project is in the overriding consideration of the public interest (OCPI) and elect to not enforce the State’s right a gainst the proposed project. However, compensation/mitigation or
OCPI are rare exceptions.

Surface Water/Groundwater Continuity Must Be Considered. The rule governing protection of ground water withdrawal facilities

, Ch apter 173

- 150 WAC

, identifies how qualifying withdrawal facilities for groundwat er rights may be impacted by a project

. In general, a well must fully penetrate an aquifer in order to qualify for impairment protection.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 18 Indicat ors of More Complex Impairment Analysis

. A project whose historic discharge exhibits one or more of the following characteristics generally indicates that impairment may occur and that compensation or mitigation may be necessary. Impairment may occur if the discharge is:

• To a basin closed to further appropriations by Ecology

.

• To a basin with instream flows adopted by rule

.

• To an aquifer with declining water levels

.

• To a designated groundwater management area

.

• To a stream that goes dry

.

• To a stream that is managed each year according to priority date.

• To a basin with Federal Energy Regulatory Commission (FERC) projects with flow requirements.



### 3.3.2 Location, Rate and Purpose of Use
The reclaimed water permit must include conditions identifying the locati on, rate and purpose of use of the reclaimed water. These may be generally defined ( similar to requirements in a municipal water right ) or may be very site specific. The Water Resources Program must be
aware of reclaimed water use as it makes water resou rce management decisions . The
coordinat ed permit conditions provide a method to track reclaimed water use

. The Water Reuse Workgroup also maintains a summary of existing projects which is updated as new facilities
come on line.



### 3 .3. 3 Controlled Use

Contr olled uses are indirect uses involving the release of the reclaimed water to waters of the State, with subsequent recovery of the reclaimed water. A single Ch apter 90.46 RCW permit is required to authorize the project.

When reclaimed water is commingled with waters of the State for indirect use, it does not necessarily lose its character as reclaimed water. The owner of the permitted reclamation facility may retain the exclusive right to some of the reclaimed water for storage or conveyance and subsequen t recovery. The intent to retain this exclusive right must be clearly documented in the facility plan and regulatory language included in both the fact sheet and the permit.



### 3

. 3.4 Combin ing With Other Withdrawals or Diverted Water Supplies.

When reclaimed water is combined with other diversionary water supplies for an approved use, the owner still retains the exclusive right to the reclaimed water. However the combined water supply must be consistent with the uses and conditions authorized in the diversio nary water right. The volumes (rates) of water authorized in the appropriative water right are restricted to the9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 19 authorized purpose and place of use in the water right. The volume (rate), water quality,
locations and uses of the reclaimed water must be i ncluded in the reclaimed water permit

. This does not necessarily preclude the use of the combined water for uses or locations not included in the appropriative water right. However, it does complicate administrative details. For example

– the use of the combined water at another location along the same pipe route could be authorized under the reclaimed water permit provided that the combined water still meets the requirements for the proposed use. If each supply is separately determined to be of adequat e quality for the beneficial use, the combined flow is generally also adequate quality for the use. The specific water chemistry of the combined flow should be considered in making this determination during the facility planning process.



### 3.3.5 Mitigation for New Appropriative Water Rights
Ecology encourages the beneficial use of reclaimed water. However, for some projects it may be prohibitively expensive to use the reclaimed water either directly through pumps and pipes or indirectly through controlled storage and recovery. Under such circumstances, it may be possible to return the reclaimed water to waters of the State in exchange for the use of new state

water.

Using reclaimed water as mitigation for state water may be appropriate when the proposed use site is geographically or geologically removed from the reclaimed water facility so that withdrawal of any of the reclaimed water for use is impractical.

In this case, the permit must describe the beneficial use of reclaimed water that is proposed ( streamflow augmentation, groundwater recharge) and identify the appropriative right under
Ch apter 90.03 or 90.44 RCW that is mitigated by the Ch apter 90.46 RCW reclaimed water permit. Permit language must provide for contingency planning either enforcing interruption of the dependent water right or providing an approved, alternate source of water when the
reclaimed water is not available.



## 3

. 4 Fact Sheets and Documentation

Fact sheets are used to document provisions for reclaimed water and industrial wat er reuse permits. Chapter XIV of the permit writer’s manual contains information on federal and state water quality requirements for fact sheet documentation. The permit writer should use this chapter as a guide and also include the following types of in formation which are specific to reclaimed water or industrial process water reuse permits. Additional information includes:
1. Document the water rights impairment analysis and any mitigation or compensation
measures taken.
2. DOH requirements
Fact sheet boile rplates for reclaimed water permits are included on the Ecology website.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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## 3

. 5 Public Involvement

There are several requirements for notification of the public of a Permittee’s intent to reclaim water. These include SEPA notifications as part of sewer ut ility planning, application for a
reclaimed water or NPDES permit and issuance of a permit by Ecology. Ecology recommends full and repeated disclosure detailing the project plans relative to historic wastewater discharges in public notices . This will min imize the risk associated with legal action following construction
and use of the reclaimed water facility. Whenever possible, the permit writer should plan to issue reclaimed water use permits prior to the beginning of facility construction. This will h elp prevent last minute objections that could hold up or prevent the use of the reclaimed water.



## 4 . TREATMENT TECHNOLOGY REQUIREMENTS

This section provides the more specific permit requirements for assuring adequate treatment and water quality for use. T he WQP issues the permit governing the quality of the water for public health protection, environmental protection and suitability of the water for the intended
beneficial uses authorized in the reclaimed water law. Reclaimed water must meet the ART

treat ment method and reliability requirements, technology

- based water quality limits and specific

use

- based standards. The Water Reclamation and Reuse Standards, 1997 , govern the use.



## 4

. 1 Source Control and Pre

- treatment

Source Control is the first line of defense

. An effective industrial pretreatment program is necessary to provide a high quality of influent so that the resulting product will be suitable for
use. The Water Reclamatio n and Reuse Standards require the Permittee to either have an Ecology delegated industrial wastewater pretreatment program or to assure that all industries discharging into the collection system have current waste discharge permits issued by Ecology

. Reg ular monitoring of industrial users is required.



## 4 .2 Four Basic Classes

There are four basic classes of reclaimed water

– A, B, C and D

– with Class A as the highest
level

. These levels are appropriate for the more traditional direct beneficial uses of r eclaimed water for irrigation and various commercial and industrial uses

. Similar to surface water quality

use

- based standards, the degree of treatment required varies according to the specific use

. Additional treatment is required for ground water recha rge, streamflow augmentation or wetlands projects

The w ater reclamation treatment systems are derived from requirements for both conventional wastewater treatment and drinking water treatment systems. The effectiveness and reliability of
these measures is considered a critical element of the system

. It is not feasible or cost

- effective9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 21 to measure the wide variety of pathogens and pollutants that may be present in the wastewater at any given time.

To assure final quality, the wastewater flows through a series of sequential treatment processes. This provides multiple opportunities to remove pollutants and provides a high level of reliability to final water quality. None of the required treatment steps may be eliminated and still produce
reclaimed wate r. The treatment steps must occur in the order given below:

All reclaimed water requires a minimum level of oxidized, secondary treatment and a high level
of disinfection (Steps 1 and 4 below). For uses with public contact requiring Class A reclaimed

wa ter or higher, all 4 treatment techniques are required

. Some uses (or source waters) also require biological nitrogen removal or other processes to remove specific contaminants. The treatment steps must occur in the order given below.

1. Oxidation

– Oxid ation refers to the biological secondary treatment process designed to remove dissolved organic contaminants. The actual process design depends on requirements for nutrient removal or for subsequent advanced treatment processes. The goal is to produce

a wastewater that has been stabilized to the point that the biochemical oxygen demand (BOD 5 ) and the total suspended solids (TSS) do not exceed 30 mg/L on a monthly average

. Dissolved oxygen is also required to be present following this step. The dissolved oxygen is considered necessary to assure that biological oxygen demand remaining after treatment will not cause the water to go anoxic or anaerobic which may result in operational problems or disinfection (usually chlorine) demand that might reduce the fi nal water quality. Although the presence of dissolved oxygen is required for all levels of reclaimed water, the biological stabilization it represents is particularly important prior to filtration when nitrogen has not
been removed to low levels. If the water becomes anoxic, nitrification can begin leading to denitrification in the filters, gas bubble formation and clogging or preferential flow paths leading to short circuiting in the filter beds.

2. Coagulation

- Class A or higher

. This process promot es the aggregation of fine waste particles and colloids to improve their removal by settling and filtration. Coagulation usually is done by the addition of chemicals such as metallic salts (alum or ferric chloride) and polymers. The Water Reclamation and Reuse Standards will allow other equally effective methods in standard engineering practice.

3. Filtration

– Class A or higher

. Filtration removes suspended particles. Because pathogenic organisms are often associated with particles, filtration reduces th e concentration of pathogenic organisms in the water. Filtration also removes particles that can interfere with disinfection processes.

Conventional filtration methods such as sand or cloth filters are considered adequate when9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 22 on

- line average operating turbidity does not exceed 2 nephelometric turbidity units (NTU) or 5 NTU at any time.

4. Disinfection

- Disinfection is essential to destroy waterborne pathogenic organisms such as bacteria, viruses, and protozoa

. Each Class of reclaimed water has a diff erent total coliform standard to indicate that disinfection has occurred to the level appropriate for the allowed

uses.



## 4

. 3 Distribution Line Chlorine Residual

Chlorine residual is required in distribution lines that convey reclaimed water from the trea tment facility to the use area. This can be considered as an additional pathogen protection barrier but is
also used to avoid regrowth that results in fouling or plugging of the distribution pipeline. A minimum 0.5 mg/L residual is required unless waived for a specific application by both Ecology

WQ and DOH

- ODW

. Beneficial uses that may justify a waiver of chlorine residual include wetlands enhancements and groundwater recharge,



## 4 .4 Advanced Treatment Techniques

4 .4.1 Microfiltration and ultrafiltration membranes

Membranes remove particles to very low levels. This treatment technology is increasingly popular as membrane quality improves and cost goes down. Our water reuse standards do not currently provide an equivalent standard to determine adequate m embrane filtration for Class A
reclaimed water. California has established a technology based membrane filtration standard requiring the effluent turbidity to be at or below 0.2 NTU more than 95% of the time and never
to exceed 0.5 NTU

. A properly mainta ined and operated membrane would consistently achieve these levels. Turbidity above these levels could indicate a breach or bypass of the membrane process. Therefore, until the adoption of a reclaimed water rule , Ecology and DOH have agreed to apply an a verage turbidity of less than or equal to 0.2 NTU “at all times” and a maximum turbidity value of 0.5 NTU. Turbidity spikes above the 0.5 NTU level during the first 5 minutes following filter start

- up may be acceptable if the permittee can demonstrate tha t these spikes are not due to breaching, bypass, or lack of membrane integrity

. For membrane filters, meeting these turbidity criteria will be considered equivalent to meet ing the coagulation and filtration steps required for Class A applications of recla imed water.



### 4

. 4.2 Nitrogen Removal Nitrogen removal is generally considered a use

- based rather than a technology

- based requirement. However , for ground water recharge, the removal of nitrogen in the biological
oxidation treatment process step of the rec lamation process is a required treatment technology

.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 23 Most nitrogen in reclaimed water readily converts to nitrate, which is very soluble and mobile in the ground water. Ecology therefore limits nitrogen in the final reclaimed water to 10 mg/L of
total nitrogen to assure ground water protection.



### 4 .4.3 Reverse Osmosis Reverse osmosis (RO) is required as a treatment technique for direct ground water recharge as defined in Section 2 of this Chapter. RO is a membrane system that removes dissolved salts a nd minerals from solution based on reversing osmotic pressure differentials. RO is also effective for pathogen removal.



## 4 .5 Water Quality Technology Limits

Table 4 .5.1 provides a general summary of the requirements for Class A, B, C, and D reclaimed

wa ter. Note that disinfection requirements are measured in total coliform and use a 7

- day median rather than a geometric mean calculation for compliance.



### 4 .5.1 Water Quality Technology Limits Class A

- D Reclaimed Water

Table 4 .5.1 Summary of Treatment Req uirements
Class
Level Oxidized Secondary

(BOD/TSS

---- mg/L ) Coagulated Filtered

(Turbidity in NTU) Disinfection (Total Coliform/ 100 MPN mL)

7

- Day Median Single Sample
A 30 YES 2 NTU

average < 2.2 23

5 NTU
maximum

B 30 NO NO < 2.2 23

C 30 NO NO < 23 240

D 30 NO NO < 240 No
standard9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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### 4 .5 .2 Class B, C or D Reclaimed Water Quality Limit s

Table 4 .5.2 provides the basic reclaimed water quality limits and sampling points for Class B, C or D water.

Water Quality L imits For Class B, C or D Reclaimed Water

Parameter Average Monthly a

Flow MGD (Point of Compliance)

Oxidized Wastewater

– Secondary Effluent c

Parameter Average Monthly a Average Weekly b

BOD 5 30 mg/L 45 mg/L

TSS 30 mg/L 45 mg/L

Dissolved Oxyge n Shall be measurably present in secondary effluent at all times

Disinfected

- Reclaimed Water

Total Nitrogen as N Average Monthly a
mg/L (engineering report) Sample Maximum d
mg/L (engineering report)

Total Coliform

Class D 7

- day Media n e

240 MPN/ 100 ml Sample Maximum f

Not defined

Class C 23 MPN/ 100 ml 240 MPN/100ml

Class B 2.2 MPN/ 100 ml 23 MPN/ 100 ml

pH Shall be between 6 and 9 standard units at all times

Distribution System

Chlorine Residual Min imum Daily
0.5 mg/L Point of compliance g

a 30 mg/L is the highest value allowable under this permit limit

. The average monthly value for compliance is calculated as the sum of all daily samples measured during a calendar month divided by the number of sa mple measured that month

b 45 mg/L is the highest allowable value under this permit limit. The average weekly value for compliance is calculated as the sum of all daily samples measured during a calendar week divided by the number of daily samples measu red during that week.

c The compliance point for BOD and TSS will be in the secondary effluent.

d The sample maximum is defined as the value not to be exceeded by any single sample.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 25 Water Quality L imits For Class B, C or D Reclaimed Water

e The median number of total coliform organisms in the reclaimed wate r after disinfection is determined from the bacteriological results of the last 7 days of analyses.

f This limit denotes the maximum number of total coliform organisms per 100 milliliters allowable in any single sample.

g A chlorine residual of at least 0.5 mg/L shall be maintained in the reclaimed water during conveyance to the location of use or to the storage pond if reclaimed water is not directly piped to the location of use.



### 4 .5.3 Water Quality Limits for Class A Reclaimed Water

Table 4 .5.3 prov ides the basic reclaimed water quality limits and sampling points for Class A

water. Note that the BOD, TSS, and dissolved oxygen limits are met after the secondary treatment step rather than in the final reclaimed water. This assures the effectiveness o f the treatment technique

. Turbidity is regulated after filtration and prior to disinfection.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 26 Table 4 .5.3 Reclaimed Water Limitations for Class A

Parameter Average Monthly a

Flow MGD (Point of Compliance)

Oxidized Wastewater

– Secondary Effluen t c

Parameter Average Monthly a Average Weekly b

BOD 5 30 mg/L 45 mg/L

TSS 30 mg/L 45 mg/L

Dissolved Oxygen Shall be measurably present in secondary effluent at all times

Coagulated/ Filtered Wastewater

– Prior to Disinfection

Turbidity Average Month ly a

2 NTU Sample Maximum d

5 NTU

Disinfected

- Reclaimed Water

Total Nitrogen as N Average Monthly a
10 mg/L Sample Maximum d
15 mg/L

Total Coliform 7

- day Median e

2.2 MPN/ 100 ml Sample Maximum f

23 MP N/100 ml

pH Shall be between 6 and 9 standard units at all times

Distribution System

Chlorine Residual Minimum Daily
0.5 mg/L Point of compliance g

a 30 mg/L is the highest value allowable under this permit limit

. The average monthly value for comp liance is calculated as the sum of all daily samples measured during a calendar month divided by the number of sample measured that month

b 45 mg/L is the highest allowable value under this permit limit. The average weekly value for compliance is calcul ated as the sum of all daily samples measured during a calendar week divided by the number of daily samples measured during that week.

c The compliance point for BOD and TSS will be in the secondary effluent.

d The sample maximum is defined as the value not to be exceeded by any single sample.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 27 Table 4 .5.3 Reclaimed Water Limitations for Class A

e The median number of total coliform organisms in the reclaimed water after disinfection is determined from the bacteriological results of the last 7 days of analyses.

f This limit denotes the maximum number o f total coliform organisms per 100 milliliters allowable in any single sample.

g A chlorine residual of at least 0.5 mg/L shall be maintained in the reclaimed water during conveyance to the location of use or to the storage pond if reclaimed water is not directly piped to the location of use.



## 4 .6 Monitoring Requirements

4 .6.1 Class B, C or D Reclaimed water Monitoring

Table 4 .6.1 lists the minimum monitoring requirements for reclaimed water. Note that flow, turbidity and chlorine residual must be mon itored continuously.

Table 4 .6.1 Class B, C or D Reclaimed Water Monitoring Requirements

Parameter Units Sample Point a Sampling Frequency Sample Type

Flow MGD Continuous Recording

meter

BOD 5 mg/l Influent Weekly b 24

- hour composite

Final reclaimed

water Weekly b 24

- hour composite

TSS mg/l Influent Weekly b 24

- hour
composite

Final reclaimed

water Daily 24

- hour
composite

pH Standard
Units Influent Daily Measurement

Disinfected
reclaimed water Daily Measurement

Dissolved Oxygen mg/L Final r eclaimed

water Daily Grab c9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 28 Table 4 .6.1 Class B, C or D Reclaimed Water Monitoring Requirements

Parameter Units Sample Point a Sampling Frequency Sample Type

Temperature Celsius Final reclaimed

water Daily Grab c

Total Nitrogen (as N)

- Optional mg/l Disinfected
reclaimed water Monthly 24

- hour
composite

Ammonia (as N)

- Optional mg/L Disinfected
reclaimed water Monthly 24

- hour

compos ite

Nitrate (as N)

- Optional mg/L Disinfected reclaimed water Monthly 24

- hour
composite

Total
Coliform d No. of org. per 100 ml Disinfected reclaimed water Daily Grab c

Priority
Pollutants ug/L Disinfected
reclaimed water Once per permit cycle

– minimum

– see Ch XIII. 24

- hour composite

Total
Chlorine
Residual mg/L Water Reuse
Distribution
Line Daily (when in use) Grab c

a Samples shall be taken at (describe location).

b Weekly is the minimum allowable monitoring requirement. More frequent monitoring is appropriate when based on the wastewater treatment facility sizes and

processes

. See Chapter XIII for minimum requirements for most secondary facilities.

c Grab samples shall be taken at the same time daily when wastewater characteristics
are the most de manding on the treatment facilities and disinfection processes.

d As an alternate method, total coliform bacteria may be monitored using the
ONPUG

- MUG test (also called Autoanalysis Colilert System) per latest edition of
standard methods.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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### 4 .6.2 Class A Reclaimed W ater Monitoring

Table 4 .6.2 lists the minimum requirements for Class A reclaimed water monitoring. Note that flow, turbidity and chlorine residual must be monitored continuously.

.
Table 4 .6.2 Class A Reclaimed Water Monitoring Requirements

Parameter Units Sample Point a Sampling Frequency Sample Type

Flow MGD Continuous Recording

meter

BOD 5 mg/l Influent Weekly b 24

- hour composite
Secondary
effluent Weekly b 24

- hour composite

TSS mg/l Influent Weekly b 24

- hour composite
Secondary
effluent Daily 24

- hour composite
pH Standard
Units Influent Daily Measurement
Secondary
effluent Daily Measurement

Disinfected
reclaimed water Daily Measurement

Dissolved Oxygen mg/L Secondary
effluent Daily Grab c

Disinfected
reclaimed wate r Daily Grab c

Temperature Celsius Secondary
effluent Daily Grab c

Disinfected
reclaimed water Daily Grab c

Turbidity NTU Secondary
effluent a Daily Grab c9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 30 Table 4 .6.2 Class A Reclaimed Water Monitoring Requirements

Parameter Units Sample Point a Sampling Frequency Sample Type

NTU Filter effluent prior to
disinfection Continuous recording

meter d

Coagulant Lbs. Coagulant feed Daily Metered usage
Coagulant
Aid Lbs. Coagulant feed Daily Metered usage

Total Nitrogen (as N) mg/l Disinfected
reclaimed water Monthly 24

- hour composite

Ammonia (as N) mg/L Disinfected
reclaimed water Monthly 24

- hour composite
Nitrate (as N) m g/L Disinfected reclaimed water Monthly 24

- hour composite

Total
Coliform e No. of org. per 100 ml Disinfected reclaimed water Daily Grab c

Priority
Pollutants ug/L Disinfected
reclaimed water Once per permit cycle 24

- hour composite

Total
Chlorine
Resid ual mg/L Water Reuse
Distribution
Line Daily (when in use) Grab c

a Secondary effluent shall be taken at (describe location) Disinfected reclaimed water samples shall be taken at (describe locations)

b Weekly is the minimum allowable monitoring requiremen t. More frequent monitoring is appropriate when based on the wastewater treatment facility sizes and

processes

. See Chapter XIII for minimum requirements for most secondary facilities.

c Grab samples shall be taken at the same time daily when wastewater characteristics are the most demanding on the treatment facilities and disinfection processes.

d Filter effluent turbidity analysis shall be performed by a continuous recording turbidimeter and shall also be read and recorded at least every four hours.

e As an alternate method, total coliform bacteria may be monitored using the ONPUG

MUG test (also called Autoanalysis Colilert System) per latest edition of standard
methods.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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### 4 .6.3 Process Operational Monitoring
Since process monitoring is used as a bar rier to assure the quality of the water at all times, it is more important than in wastewater discharge permits. Appropriate process monitoring protocols for disinfection should be included as permit conditions to protect the quality of the reclaimed

wate r. (Guidance under development)



## 5

. DISTRIBUTION AND USE

This section covers permit requirements for the distribution of reclaimed water as well as requirements common to various uses. The remaining sections discuss the specific requirements for each ty pe of reclaimed water use

. This section is currently under construction and the permit
writer is referred to the Water Reclamation and Reuse Standards and the Reclaimed Water Permit Boilerplate for guidance on permit language.



## 5 .1 Use

- Based Water Quality Limits

All reclaimed water supplies must meet requirements protecting public health and environmental quality. In addition, permit requirements should also assure the suitability of the water for the planned direct beneficial use s

. This does not mean th at all contaminants believed present must be included as limits or monitoring requirements in every permit. D etection of chemicals at low levels does not automatically translate into imp acts on human or aquatic health or the suitability
of the water for t he proposed use

. For example, USGS water quality assessments may be done at the parts

- per

- trillion levels, which is an amount that can be up to 100 times lower than the threshold used for setting standards and guidelines

. The permit writer should use be st professional judgment in determining when additional parameters should be added to the permit for limits or environmental monitoring.



## 5 .2 Discharges from Distribution Maintenance

5 .2.1 Flushing Reclaimed Water Lines
Incidental or planned discharges of reclaimed water from distribution system maintenance procedures must conform to the permit conditions regarding notification to the regulatory agencies and the public. The permit should specify the methods of control, discharge or disposal
of this water as approved in the engineering report.



### 5 .2.2 Pipeline Repair Discharges
Reclaimed water discharge or drainage resulting from pipeline repair activities is considered an unanticipated discharge. Management and disposal of this water must be addressed withi n the Permittee’s operations and maintenance plan.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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## 6

. IRRIGATION

Irrigation is the most common use of reclaimed water. This section describes the parameters the permit writer should consider in permitting irrigation use.



## 6 .1

. Class of Reclaimed Water Required for Use.

Table 6 .1 lists the minimum class of reclaimed water that may be used for the various types of irrigation uses

. For uses not listed, consult the Water Reuse Workgroup.

Table 6 .1 Class of Reclaimed Water Required for Irrigation Use

Class of Reclaimed Water Required

Use A B C D
Irrigation of nonfood Crops Trees and Fodder, Fiber, and Seed Crops YES YES YES YES

Sod, Ornamental Plants for Commercial Use, and Pasture to Which Milking Cows or Goats Have Access YES YES YES NO

Ir rigation of Food Crops Spray Irrigation

- All Food Crops YES NO NO NO Spray Irrigation

- Food Crops Which Undergo Physical or Chemical Processing Sufficient to Destroy All Pathogenic Agents YES YES YES YES

Surface Irrigation

- Food Crops Wher e There is No Reclaimed Water Contact With Edible Portion of Crop YES YES NO NO

Surface Irrigation

– Root crops YES NO NO NO Surface Irrigation

- Orchards and vineyards YES YES YES YES Surface Irrigation

- Food Crops Which Undergo Physical or C hemical Processing Sufficient to Destroy All Pathogenic Agents YES YES YES YES

Landscape Irrigation
Restricted Access Areas (e.g., Cemeteries and Freeway Landscapes) YES YES YES NO Open Access Areas (e.g., Golf Courses, Parks, Playgrounds,
Schoo lyards, and Residential Landscapes) YES NO NO NO

Impoundments
Landscape Impoundments YES YES YES NO Restricted Recreational Impoundments YES YES NO NO Nonrestricted Recreational Impoundments YES NO NO NO Fish Hatchery Basins YES YES NO NO
Dec orative Fountains YES NO NO NO9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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## 6 .2 Other Considerations for Irrigation Water Quality

The feasibility of using reclaimed water for irrigation is based on several factors beyond those listed in the Water Reclamation and Reuse Standards. Problems that may arise from irrigation can be broadly classified as follows:

1. Those caused by materials which accumulate in, or leach from, the soil with potentially harmful effects on the soil, groundwater or surface waters

. The problems that fall into this group include those caused by heavy metals and dissolved salts, particularly sodium

. The severity of the problem depends on water quality, soil characteristics and management approach

. Salinity can be a particular concern in that it influences the soil osmotic potent ial and specific ion toxicity. This can result in degradation of the soil conditions. Sodium, boron and chloride are soluble constituents that can interfere with plant growth. Chloride and sodium increase in domestic and industrial water usage, especial ly when water softeners are used

2. Those which cause changes to crop or landscape condition or kill vegetation but can be readily
corrected.

The problems described in the first group are serious when the toxicity to plants, animals or humans is involved. When the water will be used for irrigation purposes, the wastes discharged to sewers must be treatable to the quality required for irrigation waters and this should be reflected in the pre

- treatment permits and local ordinances. Source control may be nec essary to assure that wastewaters can be suitably
treated for beneficial use. Wastewater with significant levels of the following types of contaminants may not be able to be reclaimed to a level usable for use in any irrigation projects without advanced t reatment capable of removing the compounds.

• Radioactive materials with a half life of more than a few days;

• Pharmacologically active compounds;

• Non

- biodegradable toxic organic compounds;

• Wastes containing elevated levels of total dissolved salts;

• Wastes containing high concentrations of metals; and

,

• Petrochemical and mining industries output.

Soils which are naturally saline may also not be good candidates for longer term use of reclaimed water without additional treatment (such as reverse osmosis) to r emove excess salts

.

In many parts of Washington, winter rains frequently saturate the soil profile allowing accumulated salts
to be leached from the root zone. The effectiveness of winter rains to leach salts from the root zone can be approximated by de termining whether rainfall over the winter period is sufficient to overfill the crop
root zone on at least one occasion.

Table 6 .2 .1 and 6 .2.2 below provide the EPA recommended guidelines for maximum levels of various
contaminants in reclaimed water used for irrigation purposes.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 34 Table 6 .2 .1 Recommended Limits for Trace Heavy Metals for Reclaimed Water Irrigation

Constituents Long

- Term Use (mg/L) Short

- Term Use (mg/L) Remarks

Aluminum 5.0 20 Can cause nonproductiveness in acid soils, but soils at pH 5.5 to 8.0 will precipitate the ion and eliminate toxicity

Arsenic 0.10 2.0 Toxicity to plants varies widely, ranging from 5 mg/L for Sudan grass to less than 0.05 mg/L for rice
Beryllium 0.10 0.5 Toxicity to plants varies widely, ranging from 5 mg/L
fo r Kale to 0.5 mg/L for bush beans

Boron 0.75 2.0 Essential to plant growth, with optimum yields for many obtained at a few tenths mg/L nutrient solutions. Toxic to many sensitive plants (e.g., citrus) at 1 mg/L. Usually sufficient quantities in reclaimed water to correct soil deficiencies, Most grasses are relatively tolerant at 2.0 mg/L to 10 mg/L

Cadmium 0.01 0.05 Toxic to beans, beets, and turnips at concentrations as low as 0.1 mg/L in nutrient solution. Conservative limits
recommended.

Chromium 0.1 1.0 Not generally recognized as an essential growth element
Conservative limits recommended due to lack o knowledge on toxicity to plants

Cobalt 0.05 5.0 Toxic to tomato plants at 0.1 mg/L in nutrient solution. Tends to be inactivated by neutral and al kaline soils
Copper 0.2 5.0 Toxic to a number of plants at 0.1 mg/L to 1.0 mg/l in
nutrient solution.

Fluoride 1.0 15.0 Inactivated by neutral and alkaline soils

Iron 5.0 20.0 Not toxic to plants in aerated soils. But can contribute to
soil acidificatio n and loss of essential phosphorus and molybdenum

Lead 5.0 10.0 Can inhibit plant cell growth at very high concentrations

Lithium 2.5 2.5 Tolerated by most crops at up to 5 mg/l and is mobile in
soil. Toxic to citrus at low doses: recommended limit is
0. 075 mg/L
Manganese 0.2 10.0 Toxic to a number of crops at a few tenths to a few mg/L9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 35 in acid soils
Molybdenum 0.01 0.05 Non toxic to plants at normal concentrations in soil and water. Can be toxic to livestock if forage is grown in soils with high levels of available molybdenum

Nickel 0.2 2.0 Toxic to a number of plants at 0.5 mg/L to 1.0 mg/l; reduced toxicity at neutral or alkaline pH

Selenium 0.02 0.02 Toxic to plants at low concentrations and to livestock if forage is grown in soils with low levels of added
selenium
Tin, Tungsten,
& Titanium Effectively executed by plants; specific tolerance levels
unknown

Vanadium 0.1 1.0 Toxic to many plants at relatively low concentrations

Zinc 2.0 10.0 Toxic to many plants at widely varying concentrations; reduced toxicity at increased pH (6 or above) and in
fine

- textured or organic soils.

Table 6 .2.2 Recommended Limits for Other Constituents for Reclaimed Water Irrigation

Constituent Recommended Limit Remarks
pH 6.0 Most effects of pH on plant growth ar e indirect (e.g., pH effects on heavy metals toxicity described above)

TDS 500

- 2000 mg/L Below 500 mg/L, no detrimental effects are usually noticed. Between 500 and 1,000 mg/l, TDS in irrigation water can affect sensitive plants. At 1,000 to 2,000 mg/L, TDS levels can affect many crops and careful management practices should be followed. Above 2,000 mg/L, water can be used regularly only for tolerant plants on permeable soils

Free Chlorine
Residual < 1 mg/L

Source: "Handbook of Wastewater Reclamation & Reuse" by Donald R. Rowe and Isam Mohamed Abdel Magid, July 1995"9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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## 6

. 3 Incidental Site Runoff

Incidental runoff refers to small amounts of runoff from intended reclaimed water use areas,

over

- spray from sprinklers drifting out of the intended use ar ea, and overflow of reclaimed water ponds (see Section 8). Runoff generally does not include water that percolates into the ground although a minimal amount could be considered incidental runoff.

Class A reclaimed water is permitted for unrestricted publ ic contact uses and buffers are not required or always available. Although reclaimed water applied for irrigation is intended to remain on the irrigated areas, incidental runoff or over

- spray of minor amounts of reclaimed water cannot always be completely prevented. Similarly, it is not possible to entirely prevent the runoff of rainwater from areas irrigated with Class A reclaimed water particularly during major

storm events.

Although Washington state law no longer regards reclaimed water as wastewate r, any amount of incidental runoff to waters of the United States could be interpreted to require an NPDES permit.
This is undesirable since incidental runoff would be of small volumes and individual wastewater discharge permits for incidental runoff woul d be difficult to administer. Customers would not be willing to use reclaimed water given the cost and the potential liability associated with either securing an individual NPDES permit or ensuring that no incidental runoff will ever leave the permitted ar ea. Reclaimed water quality has already been regulated by Ecology and DOH under the reclaimed water permit. Once reclaimed, Class A water should be subject to the same requirements as other nonpotable water supplies.



### 6

. 3.1 Interpreting Water Quality Law s for Incidental Runoff
Water quality laws should be interpreted consistent with the intent of the Legislature to promote reclaimed water use. Consequently, incidental runoff from reclaimed water projects should be
handled as follows:

1. Where reclamation requirements prohibit the discharge of waste to waters of the US and discharges are not expected to occur, occasional runoff should not trigger the need for either an individual NPDES permit or enforcement action.

2. If discharges from reclamation project ar ea occur routinely, such discharges would usually be regulated under a municipal storm water NPDES permit

. What if they are not a Phase 1 or 2 city?

3. An individual NPDES permit should be issued only if necessary to achieve water quality objectives.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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### 6

. 3.2 Incidental Runoff Associated with Reclaimed Water Irrigation
Reclaimed water use facilities should be designed and operated to avoid runoff to waters of the State. Nonetheless, incidental runoff is likely to occur at many facilities. The following

perm it language is recommended: The incidental discharge of reclaimed water to waters of the State is not a violation of these requirements if the incidental discharge does not unreasonably affect the beneficial uses of the water, and does not result in exceed ing an applicable water quality objective in the receiving water.



## 6

. 4 Incidental Percolation and Ground Water Monitoring

Many irrigation projects use reclaimed water at or below agronomic rates and do not require additional ground water monitoring. The re claimed water is considered suitable for the beneficial use when it complies with the treatment and water quality requirements before distribution. Ecology promotes water use efficiency through both conservation practices and

water reuse

. A small amount of deep percolation from an efficient and well maintained spray irrigation system should not penalized by requiring more monitoring than would be required for other water supplies.

Deep percolation of excess irrigation water to the groundwater table from some irrigation practices (such as rill or flood irrigation) can be significant. When the beneficial use is irrigation, t he potential impact of excess percolation to ground water quality should be evaluated.

When reclaimed water irrigation projects are p roposed that may adversely impact groundwater, the permit writer should consult with the Water Reuse Workgroup and agency hydrogeologists regarding permit conditions for ground water protection

. Best m anagement practices, additional

treatment and monitori ng requirements should be included in the permit when needed for groundwater quality protection. Since these requirements may impact the feasibility of the project, the requirements to protect ground water should be established early in the project and
in cluded in the approved facility plan or engineering report.

When establishing permit conditions, t he permit writer should consider existing irrigation practices, the crop, site features and hydrogeology as well as the reclaimed water quality (Class A, B, C or D), the amount of reclaimed water used, and the percentage of reclaimed water in the total irrigation water supply

. Groundwater monitoring programs , if required, may be as simple as a series of surficial wells or as complex as an arrangement of well s sampling at various depths.

Refer to Section 10, Groundwater Recharge by Surface Percolation for additional assistance with ground water monitoring requirements.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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## 7

. IMPOUNDMENTS

This section describes the parameters the permit writer should consider in permitting irrigation

use.



## 7 .1

. Class of Reclaimed Water Required for Use.

Table 7 .1 lists the minimum class of reclaimed water that may be used for the various types of impoundment use. For uses not listed, consult the Water Reuse Workgroup.

Tabl e 7 .1 Class of Reclaimed Water Required for I mpoundment Use

Class of Reclaimed

Water Required

Use A B C D

Impoundments
Landscape Impoundments YES YES YES NO Restricted Recreational Impoundments YES YES NO NO Nonrestricted Recreational Impoundme nts YES NO NO NO Fish Hatchery Basins YES YES NO NO
Decorative Fountains YES NO NO NO



## 7 .2 Relationship to Stormwater Ponds

Incidental precipitation falling directly on impoundments or water features storing reclaimed
water is considered reclaimed water

. Stormwater p onds

, ( designed specifically for the diversion,
retention or treatment of storm water ) are not included under Ch 90.46 RCW

. Stormwater must meet the applicable storm water quality requirements and (if put to beneficial use) obtain appropria tive water rights.



## 7 .3 Incidental Runoff from Impoundments

It is not possible to entirely prevent the runoff of rainwater from decorative or storage ponds filled with Class A reclaimed water, particularly during major storm events.

Although Washington state law no longer regards reclaimed water as wastewater, any amount of incidental runoff to waters of the United States could be interpreted to require an NPDES permit.
This is undesirable for several reasons

. Incidental runoff would be of small volum es and individual customer permits would be difficult to administer

. Customers would not be willing to use reclaimed water given the cost and the potential liability associated with either securing an9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 39 individual NPDES permit or ensuring that no incidental runoff will ever leave the permitted area. Reclaimed water quality has already been regulated by Ecology and DOH under the reclaimed water permit. Once reclaimed, Class A water should be subject to essentially the same requirements as other nonpotable w ater supplies.

Water quality laws should be interpreted consistent with the intent of the Legislature to promote reclaimed water use. Consequently, incidental runoff from reclaimed water projects should be
handled as follows:

1. Where reclamation require ments prohibit the discharge of waste to waters of the US and discharges are not expected to occur, occasional runoff should not trigger the need for either an individual NPDES permit or enforcement action.

2. If discharges from reclamation project area occu r routinely, such discharges would usually be regulated under a municipal storm water NPDES permit.

3. An individual NPDES permit should be issued only if necessary to achieve water quality objectives.



## 7 .4 Releases from Reclaimed Water Ponds

A principal wa ter quality concern with reclaimed water ponds is the presence of locally added pollutants, such as fertilizers and algaecides. These same issues exist with potable water ponds.

Reclaimed water ponds should be designed and operated not to spill during dr y months. Spills should be prohibited during these times. Generally, wet weather regulatory strategies that do not require individual NPDES permits fall within the following categories.

1. The reclaimed water pond is designed not to spill during wet mont hs. Under this circumstance, spills that occur under extreme weather conditions or emergencies should
not be considered for enforcement.

2. Reclaimed water ponds can be drained and refilled with potable water or flushed with potable water prior to the onset of the wet season. Flushing will not displace all of the reclaimed water but the water quality threat is minimal.

Reclaimed water ponds designed to spill reclaimed water during the wet season must be regulated under an NPDES permit.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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## 8

. COMMERCIAL AND INDUSTRIAL USES

This section describes the parameters the permit writer should consider in permitting commercial
and industrial uses of reclaimed water

. (Under development)



## 8 .1. Class of Reclaimed Water Required for Use.

Table 8 .1 lists the minimum class of reclaimed water that may be used for the most common
commercial and industrial uses

. For uses not listed, consult the DOH and the Water Reuse Workgroup.

Table 8 .1 Class of Reclaimed Water Required for Commercial and Industrial Uses

Class of Recl aimed

Water Required

Use A B C D

Commercial
Flushing of Sanitary Sewers YES YES YES YES Street Sweeping, Brush Dampening YES YES YES NO Street Washing, Spray YES NO NO NO Washing of Corporation Yards, Lots, and Sidewalks YES YES NO NO
Dust Contr ol (Dampening Unpaved Roads and Other Surfaces) YES YES YES NO Dampening of Soil for Compaction (at Construction Sites, Landfills, etc.) YES YES YES NO

Water Jetting for Consolidation of Backfill around Pipelines YES YES YES NO Fire Fighting and Protec tion

- Dumping from Aircraft YES YES YES NO Fire Hydrants or Sprinkler Systems in Buildings YES NO NO NO

Toilet and Urinal Flushing YES NO NO NO

Ship Ballast YES YES YES NO

Washing Aggregate and Making Concrete YES YES YES NO

Industrial

Boiler Fee d YES YES YES NO

Cooling

– No Creation of Aerosols or Other Mist YES YES YES NO Cooling Aerosols or Other Mist Created (e.g., Use in Cooling Towers, Forced Air Evaporation, or Spraying) YES NO NO NO
Process Water

- Without Exposure of Workers YES YES YES NO
Process Water

- With Exposure of Workers YES NO NO NO9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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## 9

. GROUND WATER RECHARGE BY SURFACE PERCOLATION

Reclaimed water (a new water supply) is permitted differently from wastewater effluent disposal to ground. The intent of ground water recha rge is planned replenishment of the ground water either for an in situ value (salt water intrusion barrier, base flows for instream flows, maintain geologic structure), for recovery for beneficial uses, or as mitigation for other water withdrawals. Ch 90. 46 RCW states that reclaimed water use is consistent with the anti

- degradation requirements in Ecology’s ground water quality regulations, Ch 173

- 200 WAC . Reclaimed water use (by definition) is b eneficial use in the public interest and some water quality degradation may be allowed. However, the Permittee must demonstrate that the use of reclaimed water is in the public interest. This documentation must be included in sufficient detail within

gen eral sewer plans and facility plans

. RCW 90.46.120 also requires documentation in water supply plans when the uses will augment or replace potable supplies or create potential for development of additional potable supplies.

Reclaimed water used for grou ndwater recharge by surface percolation must meet all of the following requirements:

• Class A reclaimed water requirements including source control, reliability, emergency storage, and water quality

. (See Section 4 of this chapter).

• Reduction of total ni trogen in the biological oxidation process.

• State drinking water quality standards in the ground water beneath the recharge site

. This is usually interpreted to mean in the ground water mound directly beneath the recharge
site.

• Any additional quality limi ts established for other contaminants required by Ecology. These may be limits either in the reclaimed water or in the ground water.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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## 9 .1 Water Quality Limitations

Table 9 .1 Reclaimed Water Limitations for Ground Water Recharge By Surface Percolation

P arameter Average Monthly a

Flow MGD (Point of Compliance)

Oxidized Wastewater

– Secondary Effluent c

Parameter Average Monthly a Average Weekly b

BOD 5 20 mg/L 30 mg/L

TSS 30 mg/L 45 mg/L

Dissolved Oxygen Shall be measurably present in secondary e ffluent at all times

Coagulated/ Filtered Wastewater

– Prior to Disinfection

Turbidity Average Monthly a

2 NTU Sample Maximum d

5 NTU

Disinfected

- Reclaimed Water

Total Nitrogen
as N Average Monthly a
10 mg/L Sample Maximum d

15 mg /L

Total Coliform 7

- day Median e

2.2 MPN/ 100 ml Sample Maximum f

23 MPN/100 ml

pH Shall be between 6 and 9 standard units at all times

Distribution Line

Chlorine
Residual Minimum Daily
0.5 mg/L Point of compliance g

a The average monthly effluent limitation is defined as the highest allowable average of daily discharges over a calendar month, calculated as the sum of all daily discharges measured during a calendar month divided by the number of daily discharges measured during that month.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 43 Table 9 .1 Reclaimed Water Limitations for Ground Water Recharge By Surface Percolation

b The average weekly effluent limitation is defined as the highest allowable average of daily discharges over a calendar week, calculated as the sum of all daily discharges measured during a calendar week divided by the number of daily discharges measured during that week.

c The sampling point for BOD and TSS will be the secondary effluent.

d The sample maximum is defined as the value not to be exceeded by any single sample.

e The median number of total coliform organisms in the re claimed water after disinfection does not exceed 2.2 per 100 milliliters, as determined from the bacteriological results of the last 7 days for which analyses have been completed.

f The number of total coliform organisms shall not exceed 23 per 100 milli liters in any single sample.

g A chlorine residual of at least 0.5 mg/L shall be maintained in the reclaimed water during conveyance to the use area, or to the storage pond if reclaimed water is not directly piped to the use area.



## 9 .2 Ground Water Rechar ge Criteria

Reclaimed water permits are issued under the authority of both C hapter 90.46 RCW and C hapter 90.48 RCW. RCW 90.46. 080 requires reclaimed water to meet state drinking water contaminant criteria which are defined as the state drinking water stan dards

. The state drinking water standards are established by the state Board of Health and are listed in Table 9.2 below. These ground water recharge criteria are generally consistent with Ecology’s ground water standards (chapter 173

- 200 WAC) as drinkin g water is often, but not always, the most stringent requirement.

Permit writers are also required to apply the broad mandate to protect and preserve the quality of state waters under chapter 90.48 RCW when writing a permit. The provisions of chapter 1 73

- 200 WAC, Water Quality Standards for Groundwaters of the State of Washington must be considered on a case by case basis when issuing any reclaimed water permit for groundwater recharge. T he possible risk to people and to aquatic life can only be partia lly addressed by drinking water standards. Drinking water standards lack criteria for many chemicals and their degradation or

- breakdown

- products

. In addition, criteria were developed for individual chemicals and do not take into account exposure to mix tures or seasonal high pulses in concentrations

. Some ground waters also support environmental systems requiring more stringent protection than that provided by the board of health criteria. If a more stringent standard is considered necessary for a cont aminant listed under the state board of health criteria, the permit writer must be able to specifically justify and defend the basis for that requirement.9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 44 For contaminants not included in the state drinking water standards, the law (RCW 90.46.180(2)) al lows Ecology to establish discharge limits, when justified. These may be in the reclaimed water or in the ground water mound. Not all contaminants listed in of the ground water standards must be listed in every permit. The permit writer should make a re asonable potential determination as to whether or not the parameters are likely to be present in the reclaimed water before requiring additional monitoring.

RCW 90.46.080(3) also authorizes Ecology and DOH to jointly authorize a lower ground water quality standard

. Procedures for authorizing less stringent standards should be generally consistent with the overriding public interest processes Ecology uses in justifying exceptions to the ground water criteria in WAC 173

- 200

- 050(3)(a)(ix). The permit writer should consider aquifer vulnerability, the reclaimed water source water characteristics, proposed uses of the water and previous water quality information in establishing these requirements. Information on potential sources and health impacts in found at the EPA Ground and Drinking Water website.

Table 9 .2 Ground Water Recharge Criteria (Drinking Water Standards)
MCL = maximum contaminant level (DOH enforceable standard for human health prote ction)

. Secondary contaminant

– may impact the quality and suitability of the water for certain uses but is not considered a human health concern for drinking water

. (Not a DOH enforceable
standard ).
Contaminant Criterion (MCL) Notes Comparison to Ecol ogy WAC (173

- 200

- 040) Inorganic Chemicals: Nitrate (as N) 10 mg/L same Nitrite (as N) 1 mg/L same Antimony (Sb) 6 μ g/L not listed Arsenic (As) 10 μ g/L 10 μ g/L effective January 23, 2006. 0.050 μ g/L
Asbestos 7 * * million fibers/L not listed Barium (Ba) 2 mg/L 1 mg/L Beryllium (Be) 4 μ g/L not listed Cadmium (Cd) 5 μ g/L 10 μ g/L Chromium (Cr) 100 μ g/L 50 μ g/L Copper (Cu) * * *No MCL

- known health significance. EPA action level is 1.3 mg/L 1 mg/L

Cyanide (HCN) 200 μ g/L not listed

F luoride (F) 4 mg/L Also listed as secondary contaminant at 2.0 mg/L 4 mg/L

Lead (Pb) * * *No MCL

- known health significance

. EPA action level is 50 μ g/L9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 45 0.015 mg/L. Mercury (Hg) 2 μ g/L same Nickel (Ni) 100 μ g/L not listed Selenium (Se) 50 μ g/L 10 μ g/L Sodium (Na) * * *No MCL

- known health significance. EPA action level is 20 mg/L. not listed

Thallium (Tl) 2 μ g/L not listed
Chloride 250 mg/L Secondary contaminant 250 mg/L Iron (Fe) 2 mg/L Secondary contaminant 300 μ g/L Manganese(Mn) 50 μ g/L Secondary contaminant 50 μ g/L Silver (Ag) 100 μ g/L Secondary contaminant. 50 μ g/L Sulfate (SO 4 ) 250 mg/L Secondary contaminant 250 mg/L
Zinc 5 mg/L Secondary contaminant same Physical Characteristics:
Color 15 Color
units Secondary conta minant. same

Total Dissolved
Solids 500 mg/L Secondary contaminant same

Specific Conductivity 700 μ mhos/

cm Secondary contaminant Not listed

Disinfection Bi

- products:
Total
Trihalomethanes (TTHM) = the
sum of the mass
concentrations of chloroform(CH Cl 3 ), BDCM(CHCl 2 Br) DBCM(CHClBr 2 ) bromoform(CHBr 3 ). 80 μ g/L BDCM (bromodichloromethane) DBCM (dibromochloromethane) Carcinogenic THM levels tend to increase with pH, temperature, time, and the level of organic matter present. individually listed ( μ g/ L) : CHCl 3 - 7.0
BDCM

– 0.3
DBCM

– 0.5
Bromoform

– 5

Haloacetic acids (HAA5) are: monochloroacetic
dichloroacetic
trichloroacetic
monobromoacetic
dibromoacetic 60 μ g/L At high enough concentrations, they are poisonous to plants, and some are

susp ected carcinogens. not listed

Bromate 10 μ g/L Only systems using ozone not listed
Chlorite 1.0 mg/L Only systems using chlorine dioxide not listed
Disinfectant Residuals:
Free Chlorine 4.0 mg/L not listed
Chloramines 4.0 mg/L not listed
Chlorine dioxide 0.8 mg/L not listed9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 46 Radionuclides:
Radium 226/228 5 pCi/L May increase cancer risk over long

exposure 226

- 3 pCi /L
226/228

– 5 Gross Alpha Particle Activity 15 pCi/L May increase cancer risk over long exposure. Does not include radon or

ura nium same

Beta Particle
and Photons 4 mrem Calculated on 2 liter water intake/day

– average annual dose Tritium(Total body)

-- 20,000 pCi/L Strontium

- 90(Bone marrow)

-- 8 pCi/L May increase cancer risk over long

exposure. same

Uranium 30 μg/L May produc e toxic effects to the kidney. May increase cancer risk over long exposure. none

Organic Chemicals TT = treatment technique required for contaminant removal. MGLG = maximum contaminant level goal

– level below know or expected health risk.(not DOH
enfo rceable) Acrylamide TT MCLG = zero 0.02 μg/L

Alachlor 2 μg/L MCLG = zero not listed

Atrazine 3 μg/L not listed

Benzene 5 μg/L MCLG = zero 1 μg/L
Benzidine 0.0004 μg/L Benzo(a)pyrene (PAHs) 0.2 μg/L MCLG = zero 0.008 μg/L

BCDM See disinfection byproducts

Bromoform See disinfection byproducts

Carbofuran 40 μg/L

Carbon
tetrachloride 5 μg/L MCLG=zero 0.3 μg/L

Chlordane 2 μg/L MCLG=zero

CDBM = DBCM

- See disinfection byproducts

Chloroform See disinfection byproducts

4 Chloro

- 2

- methyl aniline 0.1 μ g/L

4 Chloro

- 2

- methyl aniline hydrochloride 0.2 μ g/L

o

- Chloro

nitrobenzene 3 μ g/L

p

- Chloro

nitrobenzene 5 μ g/L

Chlorthalonil 30 μ g/L 2,4 D 70 μ g/L 0.1 μ g/L9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 47 Dalapon 200 μg/L

DBCP 0.2 μg/L DCBP = 1,2 dibromo

- 3

- ch loropropane
MCLG = zero

o

dichlorobenzene 600 μg/L

p

dichlorobenzene 75 μg/L

1,2

- dichloroethane 5 μg/L Ethelene chloride 0.5 μg/L

1,1

- dichloroethylene 7 μg/L

Cis and trans 1,2 dichloroethylene 7 μg/L

Dichloromethane 5 μg/L MCLG = zero
1,2 dicholopropane 5 μg/L MCLG = zero 0.6 μg/L

Di(2

- ethylhexyl) adipate 400 μg/L

Di(2

- ethylhexyl) phthalate 6 μg/L MCLG = zero

Dinoseb 7 μg/L
Dioxin (2,3,7,8

- TCDD) * μg/L * 0.00003 μg/L 0.0000006 μg/L

Diquat 20 μg/L

Endothall 100 μg/L

Endrin 2 μg/L Epichlorohydrin TT μg/L TT =
MCLG = zero 8 μg/L

Ethylbenzene 700 μg/L Ethylene
dibromide 0.05 μg/L MCLG = zero 0.001 μg/L

Glyphosate 700 μg/L Heptachlor 0.4 μg/L MCLG = zero 0.02 μg/L Heptachlor epoxide 0.2 μg/L MCLG = zero 0.009 μg/L

Hex achloroenzene 1 μg/L MCLG = zero 0.05 μg/L Hexachlorocyclo

pentadiene 50 μg/L

Lindane 0.2 μg/L 0.06 μg/L Methoxychlor 40 μg/L
Oxamyl (Vydate) 200 μg/L

PCBs (polychlorinated biphenyls) 0.5 μg/L MCLG = zero 0.01 μg/L

Pentachlorophenol 1 μg/L

Picloram 500 μg/L9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 48 Simazine 4 μg/L
Styrene 100 μg/L

Tetrachloro

ethylene 5 μg/L MCGL = zero 0.8 μg/L

Toluene 1 mg/L
Toxaphene 3 μg/L MCLG = zero 0.08 μg/L
2,4,5

- TP (Silvex) 50 μg/L

1,2,4

- Trichlorobenezene 70 μg/L

1,1,1

- Trichloroethane 3 μg/L

Trichloroethylene 5 μg/L MCLG = zero 3 μg/L Vinyl chloride 2 μg/L MCLG = zero 0.02 μg/L
Xylenes(total) 10 mg/L



## 9 .3 Additional Contaminants of Concern

Ecology may add additional parameters of concern (not listed in the ground water recharge

c riteria above) if there is reason to believe that they are present in the reclaimed water at levels that would not adequately protect the beneficial uses of the water.

Table 9 .3 lists Parameters from Ecology Ground Water Standards (WAC 173

- 200

- 140). Thes e are not included in the Ground Water Recharge Criteria.

Table 9 .3 Other Parameters of Concern (WAC 173

- 200

- 140) Physical Characteristics
Parameter Criterion Notes Corrosivity Noncorrosive (narrative) EPA secondary drinking water contaminant.

F oaming Agents 0.5 mg/L EPA secondary drinking water contaminant.
Odor 3 threshold odor units EPA secondary drinking water contaminant. pH 6.5

- 8.5 standard
units. EPA secondary contaminant. Organic Chemicals

- Carcinogens
Contaminant Criterion ( μg/L) N otes (under development)

Aldine 0.005

Aniline 14

Azobenzene 0.7

Benzidine 0.0004

Benzotrichloride 0.007 Benzyl chloride 0.5 Bis(chloroethyl)

- ether 0.07
Bis(Chloro

- methyl)ether 0.0004

Carbazole 59CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 49 4 Chloro

- 2

- methyl aniline 0.1

4 Chloro

- 2

- methyl aniline hydrochloride 0.2

o

- Chloro

- nitrobenzene 3

p

- Chloro

- nitrobenzene 5

Chlorthalonil 30

Diallate 1
DDT (includes DDE and DDD) 0.3
1,2 Dibromoethane 0.001
3,3' Dichlorobenzidine 0.2
1,1 Dichloroethane 1.0
1,3 Dichl oropropene 0.2

Dichlorvos 0.3

Dieldrin 0.005 3,3' Dimethoxybenzidine 6 3,3 Dimethylbenzidine 0.007 1,2 Dimethylhydrazine 60
2,4 Dinitrotoluene 0.1
2,6 Dinitrotoluene 0.1
1,4 Dioxane 7.0 1,2 Diphenylhydrazine 0.09

Direct Black 38 0.009

Direct Blue 6 0.009

Direct Brown 95 0.009 Epichlorohydrin 8 Ethyl acrylate 2 Ethylene thiourea 2 Folpet 20

Furazolidone 0.02

Furium 0.002 Furmecyclox 3 Hexachlorocyclohexane (alpha) 0.001 Hexachlorocyclohexane (technical) 0.05
H exachlorodibenzo

- p

- dioxin,
mix 0.00001 Hydrazine/Hydrazine sulfate 0.03 2 Methoxy

- 5

- nitroaniline 2 2 Methylaniline 0.2 2 Methylaniline hydrochloride 0.5 4,4' Methylene bis(N,N'

- dimethyl) aniline 2 Methylene chloride (dichloromethane) 5
M irex 0.05

Nitrofurazone 0.069CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 50 N

- Nitrosodiethanolamine 0.03

N

- Nitrosodiethylamine 0.0005

N

- Nitrosodimethylamine 0.002

N

- Nitrosodiphenylamine 17

N

- Nitroso

- di

- n

- propylamine 0.01

N

- Nitrosopyrrolidine 0.04

N

- Nitroso

- di

- n

- butylamine 0.02

N

- Nitro so

- N

- methylethylamine 0.004

PAH 0.01

PBBs 0.01

o

- Phenylenediamine 0.005 Propylene oxide 0.01 Tetrachloroethylene (perchloroethylene) 0.8 P,a,a,a

- Tetrachlorotoluene 0.004
2,4 Toluenediamine 0.002

o

- Toluidine 0.2 Trichloroethylene 3 2,4,6

- Trichlorophenol 4 Trimethyl phosphate 2



## 9 .4 Ground Water Monitoring

Frequency of monitoring should take into account the size of the facility and the impact to ground water.

Table 9

. 4 Suggested Ground Water Monitoring for Recharge by Surface Percolation
Parameter Units Minimum Sampling Frequency Sample Type

Static well water
elevation Feet above sea
level Quarterly (1) Measurement

Temperature ° C Quarterly (1) Measurement Dissolved Oxygen mg/L Quarterly (1) Grab pH Standard Units Quar terly (1) Measurement Conductivity umhos/cm Quarterly (1) Grab
Nitrate NO 3 (as N) mg/L Quarterly (1) Grab
Nitrite NO 2 (as N) mg/L Quarterly (1) Grab TKN (as N) mg/L Quarterly (1) Grab
Total Dissolved Solids mg/L Quarterly (1) Grab
Total Coliform
Bacteria c fu/100 ml Quarterly (1) Grab

Chloride mg/L Quarterly (1) Grab
Cations/Anions: Calcium, Magnesium, mg/L Yearly (2) Grab9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 51 Table 9

. 4 Suggested Ground Water Monitoring for Recharge by Surface Percolation
Parameter Units Minimum Sampling Frequency Sample Type

Potassium, Sodium, Bicarbonate, Carbonate, Fluoride,
sulfate
Total Metals: Arsenic, Cadmium, Chromium, Copper, Lead, Mercury, Nickel, S ilver, Zinc (3) μ g/L Yearly (2) Grab

Total Trihalomethanes (TTHM) mg/L Quarterly (1) Grab

(1) Quarterly is defined as every three months. (2) Yearly is defined as once within twelve consecutive months. (3) Analytical method: Arsenic, EPA 206.3 or 206.2; Cadm ium, EPA 2007.7 or 213.2; Chromium, EPA 200.7 or 218.2; Copper, EPA 200.7 or 220.2; Lead, EPA 239.2; Mercury, EPA 245.1 or 245.2; Nickel, EPA 249.2; Silver, EPA 272.2; Zinc, EPA 200.7 or 289.1.

Permittees may prefer to monitor contaminants in the reclaimed water in lieu of ground water monitoring

. For any parameters monitored in the reclaimed water prior to recharge, the permit writer should consider deleting duplicative ground water monitoring requirements

. This option should be based on site specific co nditions

- considering the potential for the recharge project to adversely impact the quality of the ground water. In some cases, recharging aquifers may improve water quality. In others, large volumes of recharge water may cause chemical changes
directl y or indirectly degrading the ground water quality. Ground water monitoring should continue in cases where there is concern that the recharge may result in ground water quality trends toward higher contaminant concentrations impacting the suitability of t he water for
beneficial use.



## 9 .5 Blended Flows f or Groundwater Recharge

It is more straightforward when stormwater and reclaimed water are not deliberately mixed either temporally or sequentially into the same infiltration basin. A stormwater infiltratio n basin should be used only for stormwater

. A reclaimed water surface percolation basin should be used only for reclaimed water

. Historically, the laws governing state water, stormwater, wastewater,

on

- site systems, reclaimed water, conservation and pota ble and non

- potable supply have developed independently. Existing laws do not provide equivalent levels of health protection, environmental resource protection, and water management.

i. Existing requirements for treatment and infiltration of stormwater ar e not sufficiently protective for planned recharge of a potable aquifer. Stormwater runoff contains many contaminants (oil, particulates, pesticides, pathogens). The9CHAPTER XI. RECLAIMED WATER USE (JULY 2011)

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- 52 quality is not reliable or predictable.

ii. Reclaimed water recharge is voluntary for speci fied beneficial use of the water. Stormwater management practices are meant to reduce contamination and runoff
from human activities.

iii. The generator of the reclaimed water has an exclusive right to the water.
Stormwater is state water

- when stormwater is put to a beneficial use, a water right is required. Exceptions:

Despite the complications, there are cases where it may be desirable to blend stormwater with reclaimed water for ground water recharge.

i. The commingled stormwater and wastewater may be jointly treated to meet the more stringent reclaimed water recharge requirements prior to infiltration. It is not sufficient to treat the stormwater to stormwater BMP requirements and the reclaimed water to reclaimed water requirements.

ii. A combined in filtration system could potentially recharge a designated non

- potable groundwater with the stormwater treated to stormwater requirements and reclaimed water to water reclamation requirements

. There must be no chance of potable water supply contamination. Examples: A salt water intrusion barrier, a fully contained

non

- potable ASR project, recharge flowing directly to surface waters or wetlands through hydraulic continuity. Under state law, only the reclaimed water would have an exclusive right attached

. If the stormwater is recovered for beneficial use, it would require an appropriative water right.

iii. A combined infiltration system could also be considered where adequate stormwater source control (essentially uncontaminated stormwater) or treatment

assure s water quality control. This would be coupled with sufficient soils and travel time for natural attenuation and degradation of pollutants through soil

- aquifer treatment (SAT) for potable water quality protection. Again, only the reclaimed
water could be recovered under the exclusive right provisions of Ch 90.46 RCW.

iv. The reclaimed water is not meant for beneficial use and is disposed to ground under a waste discharge permit regulating both the wastewater effluent and the storm
water. The combined disch arge must meet Ecology ground water standards and wastewater permit requirements.CHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2008)

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- 1 

# CHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS

There are alternative mechanisms to numerical effluent limits which can be used in permits to regulat e the discharge of pollutants

. These alternative mechanisms are authorized by federal and state law for use in both NPDES and state permits

. These mechanisms include general conditions, special conditions and best management practices.



## 1. GENERAL CONDIT IONS

The general conditions, standard conditions, or boilerplate of a permit are those permit conditions that are based on federal or state law or regulation

. They delineate the legal, administrative, and procedural requirements of the permit

. In many ca ses they are direct quotes of the regulations

. Most of the federal regulations for the General Conditions are found in 40
CFR 122.41 and 122.42

. In the Washington State permit format most of the General Conditions are placed in the back of a permit which is customary. Because Ecology uses standardized permit wording some of the direct regulatory requirements have been placed in S1 and S2. The General Conditions are the same for every type of NPDES permit and are not to be changed by permit writers

. The General Conditions and changes to those conditions are reviewed and approved by the AAG. If a General Condition is not applicable to a particular discharger, they are free to disregard that condition. The General Conditions for state discharge permits a re based on state law and regulation

. The importance of the General Conditions should not be underestimated just because they are standardized

. The general conditions are very stringent permit conditions.



## 1.1 The General Conditions for NPDES Permits

T he following text is the wording found in individual NPDES permits

. Some of these conditions are required by regulation

. They were placed in the main body of the permit for consistency. Permit writers should not alter this text in the permit templates.

S1. DISCHARGE LIMITS
A. Process Wastewater Discharges All discharges and activities authorized by this permit must be consistent with the terms and conditions of this permit.

The discharge of any of the following pollutants more frequently than, or at a l evel in excess of that identified and authorized by this permit violates the terms and conditions of this permit.CHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2008)

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- 2 Beginning on the effective date of this permit and lasting through the expiration date, the Permittee is authorized to discharge specify allow ed waste stream at the permitted location subject to complying with the following limits:

S2. MONITORING REQUIREMENTS
B. Sampling and Analytical Procedures Samples and measurements taken to meet the requirements of this permit must represent the volume and nature of the monitored parameters, including representative sampling of any unusual discharge or discharge condition, including bypasses, upsets, and maintenance

- related conditions affecting effluent quality.

Sampling and analytical methods used to meet the monitoring requirements specified in this permit must conform to the latest revision of the Guidelines Establishing Test Procedures for the Analysis of Pollutants contained in 40 CFR Part 136.

S3. REPORTING AND RECORDKEEPING REQUIREMENTS
The Permittee must monitor and report in accordance with the following conditions. The falsification of information submitted to Ecology is a violation of the terms and conditions of this permit.

A. Reporting The first monitoring period begins on the effective date of the permit. The Permittee

must:

1. Submit monitoring results each month. 2. Summarize, report, and submit monitoring data obtained during each monitoring period on a Discharge Monitoring Report (DMR) form provided, or otherwise approved, by Ecology. 3. Submit DMR forms monthly whether or not the facility was discharging. If the facility did not discharge during a given monitoring period, submit the form as required with the words " NO DISCHARGE " entered in place of the monitoring results. 4. Ensure that DMR forms a re postmarked or received by Ecology no later than the 15 th day of the month following the completed monitoring period, unless otherwise specified in this permit. 5. Submit priority pollutant analysis data no later than forty

- five (45) days following the mo nitoring. 6. Send report(s) to Ecology at:

Water Quality Permit Coordinator Department of Ecology
PO Box 47696 Olympia, WA 98504

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- 3 All laboratory reports providing data for organic and metal parameters must include the following information: samplin g date, sample location, date of analysis, parameter name, CAS number, analytical method/ number, method detection limit (MDL) or laboratory quantitation limit (QL or ML), reporting units, and concentration detected. Analytical results from samples sent t o a contract laboratory must have information on the chain of custody, the analytical method, QA/QC results, and documentation of accreditation for the parameter.

B. Records Retention The Permittee must retain records of all monitoring information for a mi nimum of three (3) years. Such information must include all calibration and maintenance records and all original recordings for continuous monitoring instrumentation, copies of all reports required by this permit, and records of all data used to complete the application for this permit

. The Permittee must extend this period of retention during the course of any unresolved litigation regarding the discharge of pollutants by the Permittee or when requested by Ecology.

C. Recording of Results
For each meas urement or sample taken, the Permittee must record the following information:

1. The date, exact place, method, and time of sampling or measurement.
2. The individual who performed the sampling or measurement.
3. The dates the analyses were performed.
4. The individual who performed the analyses.
5. The analytical techniques or methods used.

6. The results of all analyses.

D. Additional Monitoring by the Permittee If the Permittee monitors any pollutant more frequently than required by Condition S2

o f this permit, then the Permittee must include the results of such monitoring in the calculation and reporting of the data submitted in the Permittee's DMR.

E. Reporting Permit Violations
The P ermittee must take the following action s when it violates or is unable to comply with any permit condition:

a. Immediately take action to stop, contain, and cleanup unauthorized discharges or otherwise stop the noncompliance and correct the problem. b. If applicable, immediately repeat sampling and analysis. Submit the re sults of any repeat sampling to Ecology within thirty (30) days of sampling.

1. Immediate Reporting The Permittee must report any failure of the disinfection system immediately to the Department of Ecology's Regional Office 24

- hr. number listed below:CHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2008)

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- 4 For discharges to marine waters :

The Permittee must report any failure of the disinfection system, any collection system overflows which may reach surface waters or any plant bypass discharging to a shellfish area immediately to the Department of Ecology and the Department of Health, Shellfish Program at the numbers listed below:

For discharges to fresh water

The Permittee must report any failure of the disinfection system, any collection system overflows, or any plant bypass discharging to a water body used as a source of drinking water immediately to the Department of Ecology and the Department of Health, Drinking Water Program at the numbers listed below:

Department of Health, Drinking Water Program 360

- 521

- 0323 (business hours) 360

- 481

- 4901 ( after business hours)

2. Twenty

- four

- hour Reporting

The Permittee must report the following occurrences of noncompliance by telephone, to Ecology at

_____ within 24 hours from the time the Permittee becomes aware of any of the following circumstances:

a. Any noncompliance that may endanger health or the environment, unless previously reported under subpart 1, above.

b. Any unanticipated bypass that exceeds any effluent limitation in the permit (See Part S4.B., “Bypass Procedures”).

c. Any upset that e xceeds any effluent limitation in the permit (See G.15, “Upset”).

d. Any violation of a maximum daily or instantaneous maximum discharge limitation for any of the pollutants in Section S1.A of this permit.

e. Any overflow prior to the treatment works, wh ether or not such overflow endangers health or the environment or exceeds any effluent limitation in the permit.

3

. Report within Five Days

The Permittee must also provide a written submission within five days of the time that the Permittee becomes awar e of any event required to be reported under subparts 1 or 2, above. The written submission must contain:

a

. A description of the noncompliance and its cause.CHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2008)

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- 5 b. The period of noncompliance, including exact dates and times.

c. The estimated time noncom pliance is expected to continue if it has not been corrected. d. Steps taken or planned to reduce, eliminate, and prevent recurrence of the noncompliance.

e. If the noncompliance involves an overflow prior to the treatment works, an estimate of the quanti ty (in gallons) of untreated overflow.

4. Waiver of Written Reports

Ecology may waive the written report required in subpart 3, above, on a case

- by

case basis upon request if a timely oral report has been received.

5

. All Other Permit Violation Reportin g

The Permittee must report all permit violations, which do not require immediate or within 24 hours reporting, when it submits monitoring reports for S3.A ("Reporting"). The reports must contain the information listed in paragraph E.3, above. Complianc e with these requirements does not relieve the Permittee from responsibility to maintain continuous compliance with the terms and conditions of this permit or the resulting liability for failure to comply.

6. Report Submittal

The Permittee must submit rep orts to the address listed in S3.

F. Other Reporting The Permittee must report a spill of oil or hazardous materials in accordance with the requirements of RCW 90.56.280 and chapter 173

- 303

- 145. You can obtain further instructions at the following websit e: http://www.ecy.wa.gov/programs/spills/other/reportaspill.htm

. Where the Permittee becomes aware that it failed to submit any relevant facts in a permit application, or submitt ed incorrect information in a permit application, or in any report to Ecology, it must submit such facts or information promptly.

The Permittee must submit a new application or supplement at least one hundred eighty (180) days prior to commencement of di scharges, resulting from the activities listed below, which may result in permit violations. These activities include: any facility expansions, production increases, or other planned changes, such as process modifications, in the permitted facility.CHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2008)

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- 6 Th e Permittee must keep a copy of this permit at the facility and make it available upon request to Ecology inspectors.

S4 (INDUSTRIAL, S5 MUNICIPAL). OPERATION AND MAINTENANCE The Permittee must, at all times, properly operate and maintain all facilities or systems of treatment and control (and related appurtenances) which are installed to achieve compliance with the terms and conditions of this permit. Proper operation and maintenance includes adequate laboratory controls and appropriate quality assuranc e procedures. This provision requires the operation of back

- up or auxiliary facilities or similar systems, which are installed by a Permittee only when the operation is necessary to achieve compliance with the conditions of this permit.

B. Bypass Procedu res This permit prohibits a bypass which is the intentional diversion of waste streams from any portion of a treatment facility. Ecology may take enforcement action against a Permittee for a bypass unless one of the following circumstances (1, 2, or 3) ap plies.

1. Bypass for Essential Maintenance without the Potential to Cause Violation of Permit Limits or Conditions.

Bypass is authorized if it is for essential maintenance and does not have the potential to cause violations of limits or other conditions of th is permit, or adversely impact public health as determined by Ecology prior to the bypass. The Permittee must submit prior notice, if possible, at least ten (10) days before the date of the bypass.

2. Bypass which is Unavoidable, Unanticipated, and Results i n Noncompliance of this Permit.

This bypass is permitted only if:

a. Bypass is unavoidable to prevent loss of life, personal injury, or severe property damage

. “Severe property damage” means substantial physical damage to property, damage to the treatment fa cilities which would cause them to become inoperable, or substantial and permanent loss of natural resources which can reasonably be expected to occur in the absence of a bypass.

b. No feasible alternatives to the bypass exist, such as:

• The use of auxiliary t reatment facilities.

• Retention of untreated wastes.

• Stopping production.

• Maintenance during normal periods of equipment downtime, but not if the Permittee should have installed adequate backup equipment in the exercise of reasonable engineering judgment to prevent a bypass.CHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2008)

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- 7 • Transport of untreated wastes to another treatment facility or preventative maintenance), or transport of untreated wastes to another treatment facility.

c. Ecology is properly notified of the bypass as required in condition S3E of this permit.

3. If bypass is anticipated and has the potential to result in noncompliance of this permit.

a. The Permittee must notify Ecology at least thirty (30) days before the planned date of bypass. The notice must contain:

• A description of the bypass and its cause.

• An analysis of all known alternatives which would eliminate, reduce, or mitigate the need for bypassing.

• A cost

- effectiveness analysis of alternatives including comparative resource damage assessment.

• The minimum and maximum duration of bypass u nder each alternative.

• A recommendation as to the preferred alternative for conducting the bypass.

• The projected date of bypass initiation.

• A statement of compliance with SEPA.

• A request for modification of water quality standards as provided for in WAC 173

- 201A

- 410, if an exceedance of any water quality standard is anticipated.

• Details of the steps taken or planned to reduce, eliminate, and prevent reoccurrence of the bypass.

b. For probable construction bypasses, the Permittee must notify Ecology of the need to bypass as early in the planning process as possible. The Permittee must consider the analysis required above during preparation of the engineering report or facilities plan and plans and specifications and must include these to the extent practic al. In cases where the Permittee determines the probable need to bypass early, the Permittee must continue to analyze conditions up to and including the construction period in an effort to minimize or eliminate the bypass.

c. Ecology will consider the follow ing prior to issuing an administrative order for this type of bypass:

• If the bypass is necessary to perform construction or maintenance

- related activities essential to meet the requirements of this permit.

• If feasible alternatives to bypass exist, such as the use of auxiliary treatment facilities, retention of untreated wastes, stopping production,CHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2008)

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- 8 maintenance during normal periods of equipment down time, or transport of untreated wastes to another treatment facility.

• If the Permittee planned and scheduled the bypass to minimize adverse effects on the public and the environment.

After consideration of the above and the adverse effects of the proposed bypass and any other relevant factors, Ecology will approve or deny the request. Ecology will give the publ ic an opportunity to comment on bypass incidents of significant duration, to the extent feasible. Ecology will approve a request to bypass by issuing
an administrative order under RCW 90.48.120.

C. Duty to Mitigate The Permittee is required to take all r easonable steps to minimize or prevent any discharge or sludge use or disposal in violation of this permit that has a reasonable likelihood of adversely affecting human health or the environment.

S4.D. Notification of New or Altered Sources (POTW only)
The Permittee shall submit written notice to the Department whenever any new discharge or a substantial change in volume or character of an existing discharge into the POTW is proposed which: (1) would interfere with the operation of, or exceed the design cap acity of, any portion of the POTW; (2) is not part of an approved general sewer plan or approved plans and specifications; or (3) would be subject to pretreatment standards under 40 CFR Part 403 and Section 307(b) of the Clean Water Act. This notice shall include an evaluation of the POTW's ability to adequately transport and treat the added flow and/or wasteload, the quality and volume of effluent to be discharged to the POTW, and the anticipated impact on the Permittee’s effluent.(40 CFR 122.42(b)).

Th e following are general conditions for NPDES individual permits

. These are taken directly from federal or state regulation

. The text may have been changed slightly to improve clarity.

G1. SIGNATORY REQUIREMENTS A. All applications, reports, or informati on submitted to Ecology must be signed and
certified. (a) In the case of corporations, by a responsible corporate officer. For the purpose of this section, a responsible corporate officer means: (i) A president, secretary, treasurer, or vice

- president of the corporation in charge of a principal business function, or any other person who performs similar policy

- or decision making functions for the corporation, or (ii) the manager of one or more manufacturing, production, or operating facilities, provided, the manager is authorized to make management decisions which govern the operation of the regulated facility including having the explicit or implicit duty of making major capital investment recommendations, and initiating and directing other comprehensive measures to assure long term environmental compliance with environmental laws and regulations; the manager can ensure that the necessaryCHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2008)

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- 9 systems are established or actions taken to gather complete and accurate information for permit application requirement s; and where authority to sign documents has been assigned or delegated to the manager in accordance with corporate procedures. (b) In the case of a partnership, by a general partner. (c) In the case of sole proprietorship, by the proprietor. (d) In the c ase of a municipal, state, or other public facility, by either a principal executive officer or ranking elected official. Applications for permits for domestic wastewater facilities that are either owned or operated by, or under contract to, a public entit y shall be submitted by the public entity

. B. All reports required by this permit and other information requested by Ecology must be signed by a person described above or by a duly authorized representative of that person. A person is a duly authorized r epresentative only if:

1. The authorization is made in writing by a person described above and submitted to Ecology.

2. The authorization specifies either an individual or a position having responsibility for the overall operation of the regulated facility , such as the position of plant manager, superintendent, position of equivalent responsibility, or an individual or position having overall responsibility for environmental matters. (A duly authorized representative may thus be
either a named individual o r any individual occupying a named position.)

C. Changes to authorization. If an authorization under paragraph B.2 above is no longer accurate because a different individual or position has responsibility for the overall operation of the facility, a new a uthorization satisfying the requirements of paragraph
B.2 above must be submitted to Ecology prior to or together with any reports, information, or applications to be signed by an authorized representative.

D. Certification. Any person signing a document und er this section must make the following certification:

I certify under penalty of law, that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly g athered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering information, the information submitted is, to the best of my knowledge and belief, tru e, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations.CHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2008)

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- 10 G2. RIGHT OF INSPECTION AND ENTRY The Permittee must allow an authorize d representative of Ecology, upon the presentation of credentials and such other documents as may be required by law:

A. To enter upon the premises where a discharge is located or where any records must be kept under the terms and conditions of this permit.

B. T o have access to and copy

- at reasonable times and at reasonable cost

- any records required to be kept under the terms and conditions of this permit.

C. To inspect

- at reasonable times

- any facilities, equipment (including monitoring and control equipment ), practices, methods, or operations regulated or required under this permit.

D. To sample or monitor

- at reasonable times

- any substances or parameters at any location for purposes of assuring permit compliance or as otherwise authorized by the Clean Water Act.

G3. PERMIT ACTIONS Note: This section derived from 40 CFR 124.5, RCW 90.48.190, 195 and 173

- 220

- 150.
This permit may be modified, revoked and reissued, or terminated either at the request of any interested person (including the permittee) or upon E cology’s initiative. However, the permit may only be modified, revoked and reissued, or terminated for the reasons specified in 40 CFR 122.62, 122.64 or WAC 173

- 220

- 150 according to the procedures of
40 CFR 124.5.

A. The following are causes for terminatin g this permit during its term, or for denying a permit renewal application:

1. Violation of any permit term or condition.

2. Obtaining a permit by misrepresentation or failure to disclose all relevant facts.

3. A material change in quantity or type of waste disposa l.

4. A determination that the permitted activity endangers human health or the environment or contributes to water quality standards violations and can only be regulated to acceptable levels by permit modification or termination [40 CFR part 122.64(3)].

5. A ch ange in any condition that requires either a temporary or permanent reduction or elimination of any discharge or sludge use or disposal practice controlled by the permit [40 CFR part 122.64(4)].

6. Nonpayment of fees assessed pursuant to RCW 90.48.465.

7. Failur e or refusal of the permittee to allow entry as required in RCW 90.48.090.CHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2008)

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- 11 B. The following are causes for modification but not revocation and reissuance except when the permittee requests or agrees:

1. A material change in the condition of the waters of the sta te.

2. New information not available at the time of permit issuance that would have justified the application of different permit conditions.

3. Material and substantial alterations or additions to the permitted facility or activities which occurred after this p ermit issuance.

4. Promulgation of new or amended standards or regulations having a direct bearing upon permit conditions, or requiring permit revision.

5. The Permittee has requested a modification based on other rationale meeting the criteria of 40 CFR Part 12 2.62.

6. Ecology has determined that good cause exists for modification of a compliance schedule, and the modification will not violate statutory deadlines.

7. Incorporation of an approved local pretreatment program into a municipality’s permit.

C. The following ar e causes for modification or alternatively revocation and reissuance:

1. Cause exists for termination for reasons listed in A1 through A7, of this section, and Ecology determines that modification or revocation and reissuance is appropriate.

2. Ecology has recei ved notification of a proposed transfer of the permit. A permit may also be modified to reflect a transfer after the effective date of an automatic transfer (General Condition G8) but will not be revoked and reissued after the effective date of the transf er except upon the request of the new permittee.

G4. REPORTING PLANNED CHANGES The Permittee must, as soon as possible, but no later than sixty (60) days prior to the proposed changes, give notice to Ecology of planned physical alterations or additions to the permitted facility, production increases, or process modification which will result in: 1) the permitted facility being determined to be a new source pursuant to 40 CFR 122.29(b); 2) a significant change in the nature or an increase in quantity of pol lutants discharged; or 3) a significant change in the Permittee’s sludge use or disposal practices. Following such notice, and the submittal of a new application or supplement to the existing application, along with required engineering plans and reports, this permit may be modified, or revoked and reissued pursuant to 40 CFR 122.62(a) to specify and limit any pollutants not previously limited. Until such modification is effective, any new or increased discharge in excess of permit limits or not specifica lly authorized by this permit
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- 12 G5. PLAN REVIEW REQUIRED Note: The following is derived from RCW 90.48.110 and WAC 173

- 240

- 110(1)
Prior to constructing or modifying any wastewater control facilities, an engineering report
and detai led plans and specifications must be submitted to Ecology for approval in accordance with Chapter 173

- 240 WAC. Engineering reports, plans, and specifications must be submitted at least one hundred eighty (180) days prior to the planned start of
constructi on unless a shorter time is approved by Ecology. Facilities must be constructed and operated in accordance with the approved plans.

G6. COMPLIANCE WITH OTHER LAWS AND STATUTES Nothing in this permit must be construed as excusing the Permittee from complia nce with any applicable federal, state, or local statutes, ordinances, or regulations.

G7. TRANSFER OF THIS PERMIT In the event of any change in control or ownership of facilities from which the authorized discharge emanate, the Permittee must notify the s ucceeding owner or controller of the existence of this permit by letter, a copy of which must be forwarded to Ecology.

A. Transfers by Modification

Except as provided in paragraph B below, this permit may be transferred by the
Permittee to a new owner or o perator only if this permit has been modified or revoked and reissued under 40 CFR 122.62(b)(2), or a minor modification made under 40 CFR 122.63(d), to identify the new Permittee and incorporate such other requirements as may be necessary under the Clean Water Act.

B. Automatic Transfers

This permit may be automatically transferred to a new Permittee if:

1. The Permittee notifies Ecology at least 30 days in advance of the proposed transfer
date.
2. The notice includes a written agreement between the existing and new Permittee’s containing a specific date transfer of permit responsibility, coverage, and liability
between them.
3. Ecology does not notify the existing Permittee and the proposed new Permittee of its intent to modify or revoke and reissue this permit. A modification under the subparagraph may also be minor modification under 40 CFR 122.63. If this notice is not received, the transfer is effective on the date specified in the written agreement.

G8. REDUCED PRODUCTION FOR COMPLIANCE The Permittee, in or der to maintain compliance with its permit, must control production and/or all discharges upon reduction, loss, failure, or bypass of the treatment facility untilCHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2008)

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- 13 the facility is restored or an alternative method of treatment is provided. This requirement applies in the situation where, among other things, the primary source of power of the treatment facility is reduced, lost, or fails.

G9. REMOVED SUBSTANCES Collected screenings, grit, solids, sludges, filter backwash, or other pollutants removed in
th e course of treatment or control of wastewaters must not be resuspended or reintroduced to the final effluent stream for discharge to state waters.

G10. DUTY TO PROVIDE INFORMATION The Permittee must submit to Ecology, within a reasonable time, all inform ation which Ecology may request to determine whether cause exists for modifying, revoking and reissuing, or terminating this permit or to determine compliance with this permit. The Permittee must also submit to Ecology upon request, copies of records requ ired to be kept by this permit.

G11. OTHER REQUIREMENTS OF 40 CFR All other requirements of 40 CFR 122.41 and 122.42 are incorporated in this permit by
reference.

G12. ADDITIONAL MONITORING Ecology may establish specific monitoring requirements in addition to those contained in this permit by administrative order or permit modification.

G13. PAYMENT OF FEES The Permittee must submit payment of fees associated with this permit as assessed by Ecology.

G14. PENALTIES FOR VIOLATING PERMIT CONDITIONS Any person who is found guilty of willfully violating the terms and conditions of this permit is deemed guilty of a crime, and upon conviction thereof will be punished by a fine of up to ten thousand dollars ($10,000) and costs of prosecution, or by imprisonment
in t he discretion of the court. Each day upon which a willful violation occurs is a separate and additional violation.

Any person who violates the terms and conditions of a waste discharge permit must incur, in addition to any other penalty as provided by la w, a civil penalty in the amount of up to ten thousand dollars ($10,000) for every such violation. Each and every such violation is a separate and distinct offense, and in case of a continuing violation, every day's continuance is deemed to be a separate and distinct violation.

G15. UPSET
Definition

– “Upset” means an exceptional incident in which there is unintentional and temporary noncompliance with technology

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- 14 factors beyond the reasonable control of the Permittee . An upset does not include noncompliance to the extent caused by operational error, improperly designed treatment facilities, inadequate treatment facilities, lack of preventive maintenance, or careless or improper operation.

An upset constitutes an affi rmative defense to an action brought for noncompliance with such technology

- based permit effluent limits if the requirements of the following paragraph are met.

A Permittee who wishes to establish the affirmative defense of upset must demonstrate, through properly signed, contemporaneous operating logs or other relevant evidence that: 1) an upset occurred and that the Permittee can identify the cause(s) of the upset; 2) the permitted facility was being properly operated at the time of the upset; 3) the Per mittee submitted notice of the upset as required in condition S3.E; and 4) the Permittee complied with any remedial measures required under S4.C of this permit.

In any enforcement proceedings the Permittee seeking to establish the occurrence of an upset ha s the burden of proof.

G16. PROPERTY RIGHTS This permit does not convey any property rights of any sort, or any exclusive privilege.

G17. DUTY TO COMPLY The Permittee must comply with all conditions of this permit. Any permit noncompliance constitutes a v iolation of the Clean Water Act and is grounds for enforcement action; for permit termination, revocation and reissuance, or modification; or denial of a permit renewal application.

G18. TOXIC POLLUTANTS The Permittee must comply with effluent standards or prohibitions established under Section 307(a) of the Clean Water Act for toxic pollutants within the time provided in the regulations that establish those standards or prohibitions, even if this permit has not yet been modified to incorporate the requirem ent.

G19. PENALTIES FOR TAMPERING The Clean Water Act provides that any person who falsifies, tampers with, or knowingly renders inaccurate any monitoring device or method required to be maintained under this permit will, upon conviction, be punished by a fine of not more than $10,000 per violation, or by imprisonment for not more than two years per violation, or by both. If a conviction of a person is for a violation committed after a first conviction of such person under this Condition, punishment will b e a fine of not more than $20,000 per day of violation, or by imprisonment of not more than four (4) years, or by both.

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- 15 MANUFACTURING, COMMERCIAL, MINING, AND SILVICULTURAL DISCHARGERS (Industrial only)
Th e Permittee belonging to the categories of existing manufacturing, commercial, mining, or silviculture must notify Ecology as soon as they know or have reason to
believe:

A. That any activity has occurred or will occur which would result in the discharge, on a routine or frequent basis, of any toxic pollutant which is not limited in this permit, if that discharge will exceed the highest of the following “notification levels:”

1. One hundred micrograms per liter (100 μ g/L).

2. Two hundred micrograms per liter (200 μ g /L) for acrolein and acrylonitrile; five hundred micrograms per liter (500 μ g/L) for 2,4

- dinitrophenol and for 2

- methyl

4,6

- dinitrophenol; and one milligram per liter (1 mg/L) for antimony.

3. Five (5) times the maximum concentration value reported for that p ollutant in the permit application in accordance with 40 CFR 122.21(g)(7).

4. The level established by the Director in accordance with 40 CFR 122.44(f).

B. That any activity has occurred or will occur which would result in any discharge, on a

non

- routine or inf requent basis, of a toxic pollutant which is not limited in this permit, if that discharge will exceed the highest of the following “notification levels:”

1. Five hundred micrograms per liter (500 μ g/L).

2. One milligram per liter (1 mg/L) for antimony

.

3. Ten (10) times the maximum concentration value reported for that pollutant in the permit application in accordance with 40 CFR 122.21(g)(7).

4. The level established by the Director in accordance with 40 CFR 122.44(f).

G21. COMPLIANCE SCHEDULES Reports of compliance o r noncompliance with, or any progress reports on, interim and final requirements contained in any compliance schedule of this permit must be submitted no later than fourteen (14) days following each schedule date.

G21. CONTRACT REVIEW (municipal only)
The Permittee must submit to Ecology any proposed contract for the operation of any wastewater treatment facility covered by this permit. The review is to ensure consistency with chapters 90.46 and 90.48 RCW. In the event that Ecology does not comment within a thirty (30)

- day period, the Permittee may assume consistency and proceed with the contract.CHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 16 

## 1.2 The General Conditions for State Permits

As with the NPDES permits some required conditions have been moved to other sections of the permit.

G1. SIGNATOR Y REQUIREMENTS All applications, reports, or information submitted to Ecology must be signed as follows:

A. All permit applications must be signed by either a principal executive officer or ranking elected official.

B. All reports required by this permit a nd other information requested by Ecology must be signed by a person described above or by a duly authorized representative of that person. A person is a duly authorized representative only if:

1. The authorization is made in writing by the person describ ed above and is submitted to Ecology at the time of authorization, and

2. The authorization specifies either a named individual or any individual occupying a named position.

C. Changes to authorization. If an authorization under paragraph B.2. above is no longer accurate because a different individual or position has responsibility for the overall operation of the facility, a new authorization must be submitted to Ecology prior to or together with any reports, information, or applications to be signed by a n authorized representative.

D. Certification. Any person signing a document under this section must make the following certification:

"I certify under penalty of law, that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted. Based on my inquiry of the person or persons who manage the system or those persons directly responsible for gathering info rmation, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing v iolations."

G2. RIGHT OF ENTRY Note: Right of Entry derived from RCW 90.48.090. Also see

WAC 173

- 216

- 110(3), and WAC 173

- 220

- 150(1)(e).
Representatives of Ecology must have the right to enter at all reasonable times in or uponCHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 17 any property, public or pri vate for the purpose of inspecting and investigating conditions relating to the pollution or the possible pollution of any waters of the state. Reasonable times includes normal business hours; hours during which production, treatment, or discharge occurs; or times when Ecology suspects a violation requiring immediate inspection. Representatives of Ecology must be allowed to have access to, and copy at reasonable cost, any records required to be kept under terms and conditions of the permit; to inspect any monitoring equipment or method required in the permit; and to sample the discharge, waste treatment processes, or internal waste streams.

G3. PERMIT ACTIONS Note: This section derived from RCW 90.48.190, 195 and 173

- 216

- 130.
This permit is subject to mod ification, suspension, or termination, in whole or in part by Ecology for any of the following causes:

A. Violation of any permit term or condition;

B. Obtaining a permit by misrepresentation or failure to disclose all relevant facts;

C. A material chan ge in quantity or type of waste disposal;

D. A material change in the condition of the waters of the state; or

,
E. Nonpayment of fees assessed pursuant to RCW 90.48.465.
Ecology may also modify this permit, including the schedule of compliance or other conditions, if it determines good and valid cause exists, including promulgation or revisions of regulations or new information.

G4. REPORTING A CAUSE FOR MODIFICATION Note: The following section derived from WAC 173

- 216

- 110(5) and

- 040(1)

The Permittee m ust submit a new application at least 60 days before it wants to discharge more of any pollutant, a new pollutant, or more flow than allowed under this permit. The Permittee should use the State Waste Discharge Permit application, and submit required pla ns at the same time. Required plans include an Engineering Report, Plans and Specifications, and an Operations and Maintenance manual, (see Chapter 173

- 240 WAC). Ecology may waive these plan requirements for small changes, so contact Ecology if they do n ot appear necessary. The Permittee must obtain the written concurrence of the receiving POTW on the application before submitting it to Ecology. The Permittee must continue to comply with the existing permit until it is modified or reissued. Submitting a notice of dangerous waste discharge (to comply with Pretreatment or Dangerous Waste rules) triggers this requirement as well.

G5. PLAN REVIEW REQUIRED Note: The following is derived from RCW 90.48.110 and WAC 173

- 240

- 110(1) and WAC 173

- 216

- 040(2).CHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 18 Pri or to constructing or modifying any wastewater control facilities, an engineering report and detailed plans and specifications must be submitted to Ecology for approval in accordance with Chapter 173

- 240 WAC. Engineering reports, plans, and specifications should be submitted at least 180 days prior to the planned start of construction. Facilities must be constructed and operated in accordance with the approved plans.

G6. COMPLIANCE WITH OTHER LAWS AND STATUTES Nothing in the permit must be construed as ex cusing the Permittee from compliance with any applicable federal, state, or local statutes, ordinances, or regulations.

G7. TRANSFER OF THIS PERMIT Note: This section derived from WAC 173

- 216

- 120.
This permit is automatically transferred to a new owner or operator if:

A. A written agreement between the old and new owner or operator containing a specific date for transfer of permit responsibility, coverage, and liability is submitted to Ecology;

B. A copy of the permit is provided to the new owner and;

C

. Ecology does not notify the Permittee of the need to modify the permit.
Unless this permit is automatically transferred according to section A. above, this permit may be transferred only if it is modified to identify the new Permittee and to incorporate such other requirements as determined necessary by Ecology.

G8. PAYMENT OF FEES The Permittee must submit payment of fees associated with this permit as assessed by Ecology. Ecology may revoke this permit if the permit fees established under Chapter
173

- 224 WAC are not paid.

G9. PENALTIES FOR VIOLATING PERMIT CONDITIONS Any person who is found guilty of willfully violating the terms and conditions of this permit is guilty of a crime, and upon conviction thereof will be punished by a fine of up
to ten thou sand dollars and costs of prosecution, or by imprisonment in the discretion of the court. Each day upon which a willful violation occurs may be deemed a separate and
additional violation.

Any person who violates the terms and conditions of a waste discha rge permit incurs, in addition to any other penalty as provided by law, a civil penalty in the amount of up to ten thousand dollars for every such violation. Each and every such violation is a separate and distinct offense, and in case of a continuing vio lation, every day’s continuance is a separate and distinct violation.

G10. DUTY TO PROVIDE INFORMATION The Permittee must submit to Ecology, within a reasonable time, all information whichCHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 19 Ecology may request to determine whether cause exists for modifying , revoking and reissuing, or terminating this permit or to determine compliance with this permit. The Permittee must also submit to Ecology upon request, copies of records required to be kept by this permit.

G11. DUTY TO COMPLY The Permittee must comply with all conditions of this permit. Any permit noncompliance constitutes a violation of the Clean Water Act and is grounds for enforcement action; for permit termination, revocation and reissuance, or modification; or denial of a permit renewal applicatio n.



## 2

. SPECIAL CONDITIONS

Special conditions are requirements placed in permits without limits

. They may be similar to Best Management Practices (discussed in the next part) but are generally smaller in scope and may lead to permit limits

. Special condit ions are enforceable.

Since special conditions are specific to individual permits, it's difficult to define them in general

terms

. Some examples of special conditions follow.

1. An old complex industrial facility was found on one occasion to be leaking pro cess wastewater under the building which then flowed to a small stream

. The plumbing at the facility was old and in need of repair

. In one instance at this facility, process wastewater was plumbed to a line carrying and discharging non

- contact cooling wa ter

. This error occurred because the maintenance people were unsure of which pipes were carrying wastewater

. These problems occurred near permit renewal time

. The permit writer wrote a spe cial condition in the new permit that required the facility to u pgrade the piping in some areas, to produce a pipe routing diagram, and to conduct a weekly inspection for leaky wastewater plumbing to prevent any further discharges.

2. A sawmill discharged yard runoff and non

- contact cooling water which went to a ditch an d
then to a small stream

. There was no receiving water data on the temperature or flow for the

stream

. The permit writer placed a special condition in the permit which required a temperature study in the receiving water during the summer low flow to dete rmine if the discharge was violating water quality standards

. The special condition included language to alert the permittee that the new information could be used as a basis to modify the permit and place temperature limits in it if necessary to meet wat er quality standards

. (See also Chapter
XIII

- Receiving Environment Monitoring)CHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 20 

## 3. POLLUTION PREVENTION AND BEST MANAGEMENT PRACTICES (BMPs)

This section describes Ecology's process of pollution prevention within the Water Quality Program and how to i ncorporate best management practices into permits.



## 3.1 Pollution Prevention

Pollution prevention is a priority for the agency and the Water Quality Program. It is inherent in the goals of the Clean Water Act (zero discharge) and was one of the five goals in the strategic plan the Water Quality Program adopted in 1992.

Pollution prevention has been defined by Ecology as source control of pollutants.

The implementation of pollution prevention into the permit program is based on the premise that pollution p revention makes both environmental and economic sense. People will choose to make their products or provide their services in less polluting ways if they know they have a choice and it appears economical. Permits can be used to nudge people to look at vi able alternatives, to provide incentives for prevention over treatment or to provide a legally binding framework for a project of interest to both the department and the permittee. Permits should not be used to mandate expensive studies of impractical alt ernatives or to mandate zero discharge where it is not required and it is not cost effective. The permit should be used as a tool to drive practical economical preventative approaches.

Implementation measures include:

Zero Discharge

- Permit managers sh ould require permittees to consider and investigate options for zero discharge in engineering reports where that option appears viable.

Reduced Monitoring

- Reward exemplary performance, especially as a result of source control efforts, by reducing monito ring requirements (see Chapter XIII, Section 1.3.2).

Cross Media Shift of Pollutants

- Coordinate your actions at facilities with other Ecology and local government actions to prevent cross media shifts of pollutants when feasible.

When developing techno logy

- based effluent limits on a case

- by

- case basis or when developing water quality

- based limits, the permit manager should identify those situations where there is a significant shift of pollutants to some other media such as air or land. These situation s should be discussed and documented with the appropriate Ecology media programs to look for a mutual
solution.CHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 21 Watershed Scoping

- Include a pollution prevention section in watershed scoping documents and in watershed workshops with Shorelands and Water Resources look for source reduction and water conservation opportunities.


## 3.2 Best Management Practices

NPDES permits have traditionally focused on chemical

- specific numerical effluent limits. To improve water quality, the Act provides for water pollutio n controls, such as Best Management Practices, to supplement effluent limitations guidelines. Pursuant to RCW 90.48 and sections 304 and 402 of the Act, BMPs may be incorporated as permit conditions. In the context of the NPDES program, BMPs are actions or procedures to prevent or minimize the potential for the release of pollutants or hazardous substances in significant amounts to surface waters. BMPs, although normally qualitative, are most effective when used in conjunction with numerical
effluent lim its in NPDES permits.

Section 402(a)(1) of the Act allows the Administrator to prescribe conditions in a permit determined necessary to carry out the provisions of the Act, such as BMPs. The discharges to be controlled by BMPs are plant site runoff, sp illage or leaks, sludge or waste disposal, and drainage from raw material storage.

BMPS are intended to complement other regulatory requirements imposed by RCRA, OSHA, the Clean Air Act, and SPCC plans for hazardous substances

. Pursuant to section 311 of the Act, EPA has promulgated (40 CFR Part 151) requirements that SPCC plans prevent discharges of hazardous substances from facilities subject to NPDES permitting requirements. The guidelines

pro posed for hazardous substances SPCC plans are very similar to those required for oil SPCC plans in the Oil Pollution Prevention Regulations (40 CFR Part 112). The NPDES BMP regulation has also been structured to be similar to the highly successful oil SPCC regulation. Even though the State of Washington has no statutory authority to enforce federal SPCC plan requirements, the NPDES permitting program and state law (RCW 90.48.010 and RCW 90.48.520) allow state permit writers to address appropriate spill prevention requirements as permit conditions.

EPA has promu lgated the BMP regulation as 40 CFR Subpart K (44 FR 32954

- 5). Industries regulated by Subpart K must develop a BMP program and submit it with their permit application.


## 3.3 Scope of BMPs

Any activity which is associated with the industrial manufacturing or treatment process is subject to BMPs. The federal BMP program is only concerned with toxic or hazardous chemical discharges. The State of Washington's BMP program is broader and covers the discharge or potential discharge of any substance which would affect water quality. All activities or sources at the plant should be examined to determine if there is a reasonable potential for equipmentCHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 22 failure (e.g., spillage or leakage), natural conditions (e.g., plant site runoff or drainage from raw
material st orage), or other circumstances (e.g., sludge or waste disposal) which could result in the discharge of a significant amount of pollutants or hazardous substances to receiving waters. For the State of Washington, receiving waters include both surface water s and ground water. These activities or sources usually include: material storage areas, loading and unloading areas; plant site runoff; in

- plant transfer, process, and material handling areas; and sludge disposal

areas.

Material storage areas include st orage areas for toxic and hazardous chemicals which may be raw materials, intermediates, final products or by

- products. Included are liquid storage vessels that range in size from large tanks to 55

- gallon drums; dry storage in bags, piles, bins, silos, an d boxes; and gas storage in tanks and vessels.

Loading and unloading operations involve the transfer of materials to and fro m trucks or railcars
but not in

- plant transfers. These operations include pumping of liquids or gases from truck or
railcar to a s torage facility or vice versa, pneumatic transfer of dry chemicals to or from the loading or unloading vehicle, transfer by mechanical conveyor systems, and transfer of bags, boxes, drums, or other containers from vehicles by forklift trucks or other mater ials handling equipment.

Plant runoff is generated principally from rainfall on a plant site. Runoff from material storage areas, in

- plant transfer areas, loading and unloading areas, and sludge disposal sites potentially
could become contaminated with t oxic pollutants and hazardous substances. Heavy metals from sludge (disposal sites are of special concern). Fallout, resulting from the plant air emissions which settle on the plant site, may also contribute to contaminated runoff. Contaminated runoff

m ay reach a receiving body of water through overland flow, drainage ditches, storm or noncontact cooling water sewers, or overflows from combined sewer systems. Contaminated runoff can enter ground water by infil trating through the soil or through recharg e zones in
surface waters.

In

- plant transfer areas, process areas, and material handling areas encompass all in

- plant transfer operations from raw material to final product. Various operations could include transfer of liquids or gases by pipelines inclu ding devices such as pumps, valves and fittings; movement of bulk materials by mechanical conveyor belt systems; and forklift truck transport of bags, drums, and bins. All transfer operations within the process area with a potential for release of toxic

p ollutants and hazardous substances to other than the process wastewater system are addressed in this grouping.

Sludge and other waste handling areas are potential sources of contamination of receiving waters. These operations include landfills, pits, pon ds, lagoons, and deep

- well injection sites. Depending on the construction and operation of these sites there may be a potential for leachate containing toxic pollutants or hazardous substances to seep into the ground water, or for liq uidsCHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 23 to overflow to surface waters from these disposal operations. BMP requirements are not intended to duplicate the requirements of RCRA. Actions taken for compliance with RCRA may be referenced in the BMP plan submitted with the permit application.

Any facility with an RCRA permit will already have plans addressing BMP requirements (e.g., contingency plans, personnel training plans, inspections and maintenance, security, reporting and records, compatibility testing, and housekeeping procedures). However, the RCRA requir ements will usually be applied only to areas involved in the treatment, storage or disposal of hazardous waste. So these RCRA procedures may need to be expanded to meet BMP requirements.


## 3.4 Minimum Requirements for the BMP Plan

BMPs may include some of the same practices used by industry for pollution control, SPCC plans for oil and hazardous substances, safety programs, fire protection, protection against loss of valuable raw materials or products, insurance policy requirements or public relations. The minimum requirements of a BMP Plan are listed in Table 1 and are divided into 2 categories: general requirements and specific requirements.



### Table XI

- 1. MINIMUM REQUIREMENTS OF A BMP PLAN

A. General Requirements

1. Name and location of facility
Statement of BMP policy and objectives Review by plant manager

B. Specific Requirements

1. BMP Committee
2. Risk Identification and Assessment
Structural Modifications Reporting of BMP Incidents Materials Compatibility Good Housekeeping
Preventive Maintenance Inspection s and Records Security Employee Training



### 3.4.1 General Requirements
The BMP plan should be organized and described in an orderly narrative format. A description of the facility, including the plant name, the type of plant, processes used, and the product sCHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 24 manufactured should be included in the BMP plan. A map showing the location of the facility and the adjacent receiving waters also should be part of the plan. Any available data about site soils or ground water conditions should also be included. Spec ific objectives for the control of toxic pollutants and hazardous substances should be included in a statement of corporate policy. The plan should be reviewed by the plant manager.



### 3.4.2 Specific Requirements
Each of the 9 specific requirements listed i n Table IV

- 1 should be addressed in the BMP plan

. The size and complexity of the BMP plan will vary with the size, complexity, and location of the facility. It is anticipated that the length and detail of the BMP plan will be commensurate with the quanti ty of toxic and hazardous chemicals on site and their opportunity for discharge

. The fundamental goal of the BMP plan is determining the potential for toxic and hazardous chemicals to reach receiving waters, and taking appropriate preventive measures.



### 3. 4.3 BMP Committee
The BMP Committee is a group of individuals within the plant organization which is responsible for developing the BMP plan and assisting the plant management in its implementation, maintenance and updating. The scope of activities and r esponsibilities of the BMP Committee should include all aspects of the facility's BMP plan, such as identifying toxic and hazardous materials handled in the plant; identifying potential spill sources; establishing incident reporting procedures; developing BMP inspection and records procedures; reviewing environmental incidents to determine and implement necessary changes to the BMP plan; coordinating plant incident response cleanup and notifying authorities; establishing BMP training for plant personnel; an d aiding interdepartmental coordination in carrying out the BMP plan. Other committee duties could include reviewing both new construction and changes in processes or procedures at the facility relative to spill prevention and control.

The plan should co ntain a clear statement of the management's policies and responsibilities related to BMPs. Authority and responsibility for immediate action in the event of a spill should be clearly established and documented in the BMP plan, with the Committee indirectl y involved in that responsibility

. The Committee should advise management on the technical aspects of environmental incident control, but should not impede the decision

- making process for preventing or mitigating spills and incidents. Management should, of course, review and support the BMP plan.

The size and composition of the BMP Committee should be appropriate to the size and complexity of the plant, and to the specific toxic and hazardous chemicals handled at the plant. Facility personnel knowledgea ble in spill control and waste treatment such as environmental specialists, production foreman, safety and health specialists, and any treatment plant supervisor should be included. In some small plants, the committee might consist of the one manager or

e ngineer assigned responsibility for environmental control. For very small facilities, theCHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 25 Committee function might even have to be fulfilled by competent engineers or managers from the corporate staff or the nearest large plant.

A list of personnel on th e BMP Committee should be included in the BMP plan. The list should have the office and home telephone numbers of the Committee members, and the names and phone numbers of backup or alternate people.



### 3.4.4 Risk Identification and Assessment

The areas of the plant that are subject to BMP requirements should be identified by the BMP
Committee. Each such area should be exam ined for the potential risks for discharges of toxic pollutants or hazardous substances to receiving waters. Any existing physical mean s (dikes, diversion ditches, etc.) of controlling such discharges also should be identified.

The areas described above should be clearly indicated on a plant plot plan or drawing. A simplified materials flowsheet showing major process operations can be u sed to indicate the direction and quantity of materials flowing from one area to another. Areas with the potential for ground water contamination via subsurface infiltration or surface water recharge after spills
should be identified and indicated on site drawings. The direction of flow of potential spills and surface runoff should also be estimated based on site topography and indicated on the plant site drawings. Dry chemicals that are either toxic pollutants or hazardous substances should be
evaluated if they have the potential to reach surface or ground waters in significant quantities via rainfall runoff, for example.

A hazardous substance and toxic chemical inventory (materials inventory) should be developed as part of the "Risk Identification and Assessment." The detail of the materials inventory should be pro portionate to the quantity of toxic pollutants and hazardous substances on site and their potential for reaching the receiving waters (both surface and ground water). For example:

1. The plant has determined that materials stored in bulk quantities at a tank farm have a high potential for reaching the receiving waters via surface runoff or subsurface infiltration in the event of structural failure or overfills. Therefore, the materials in ventory for the tank farm should be detailed, and should provide the identity, quantities, and locations of each material.

2. The plant has determined that materials stored in small quantities at the research laboratory have a low potential for reaching the receiving waters. Therefore, the materials inventory for the laboratory could be minimally detailed, and may not include the identity, quantity, or location of each material but might include an estimate of the total quantity of toxic and hazardous ma terials stored and would provide the location of the laboratory. The rationale for the "low risk" nature of the laboratory would be provided in this part of the BMP plan.CHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 26 3. The plant has determined that materials used in a batch operation in the manufa cturing process have a high potential for reaching the receiving water. The plant supplies a variety of products through the batch operation process to accommodate fluctuations in public demand. Consequently, the materials used for the batch process vary from week to week, often times unexpectedly. Therefore, the materials inventory for the batch operation should be detailed but remain flexible. The inventory might include the identification of each material expected for use, the maximum quantity of mat erial expected for use, and the maximum quantity of material that the batch process can handle. The materials inventory could be updated to include any material substitutions unanticipated at the time of the original inventory.

The examples above illustr ate the flexibility of the materials inventory. A materials inventory should be part of the "Risk Identification and Assessment" of every BMP plan but the detail of the inventory will vary with the size and complexity of the plant, the quantities of toxic and
hazardous chemicals on

- site, and the potential for those materials to reach surface waters.

The materials inventory and other useful technical information should be made available to the BMP Committee but may require separate filing from the BMP plan documents to protect proprietary information or trade secrets. This data may include physical, chemical, toxicological and health information (e.g., technical bulletins or material safety data sheets) on the toxic pollutants and hazardous substances hand led; the quantities involved in various operations; and the prevention, containment, mitigation, and cleanup techniques that would be used in the event of a discharge.

Materials planned for future use in the plant should be evaluated for their potential t o be discharged in significant amounts to receiving waters. Where the potential is high, the same type
of technical data described above should be obtained.



### 3.4.5 Structural Modifications
An important element of BMP implementation involves actual physica l changes to the facility
that prevent the potential release of a pollutant. These physical changes include overflow and overfill controls, secondary containment systems, ground water protection barriers, and emergency cut

- offs

. The purpose of these stru ctural modifications to the facility is to confine potential pollutants to those portions of the facility where they belong by preventing spills, stopping spills that have started, or containing spills that have already happened. Because these
structural modifications are physical changes, they do not need human intervention to work effectively. However, this does not mean that these devices are "fool proof" and do not need to be a part of other elements of BMP such as facility inspection programs, employ ee training or spill drills.

Overflow and overfill controls prevent spills in pipes, process vessels or storage tanks by stopping or rerouting flow when the unit is full or flow is blocked. The principle is the same as the pumps in gas stations which sen se the level of gasoline in your car and shut

- off when theCHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 27 tank is full. These devices sense the fluid level or the line pressure and automatically stop or reroute flow before the point of spillage. Liquids can be re routed back to their source, to anoth er vessel such as a process or storage tank or to secondary containment.

Secondary containment is a facility's extra storage capacity that automatically receives a spill from a process or storage unit. This extra storage capacity can be provided by earth en dikes, concrete pads, walls or curbing, concrete sumps, or a tank connected down gradient of the potential spill source. Secondary containment holds a spill safely until facility person nel can recover or dispose of the spilled material. A secondary c ontainment device must be capable of holding more than the vol ume of the largest spill possible at the facility (for example, capable of holding more than the volume of the largest tank in a tank farm or 40% of the total volume of all
drums which can be s tored in a drum storage area). The permit writer should realize that other environmental programs such as SPCC or RCRA will have specific requirements on the volumes of many secondary containment systems.

Ground water protection barriers are made of natu ral or artificial materials designed to stop spills from infiltrating through the soil to contaminate ground water. Natural materials used as ground water protection barriers are usually clays that are placed in a layer between the source of the spill and the soil overlaying the ground water. Artificial materials take the form of impermeable synthetic liners which are placed under the spill source. These ground water protection barriers
can be used as back

- up for secondary containment in the event of an overflow or a structural failure such as a crack in a concrete drum storage pad, or they can be used in combination with secondary containment such as lining the bottom of a diked area around a tank farm. These devices are also useful for lining containme nt ba sins for stormwater which could be contaminated or for areas such as loading docks which are subject to frequent small spillage. Of course, ground water protection barriers are routinely installed under surface impoundments, waste piles and landfill s.

Emergency cutoffs include many of the overflow/overfill control devices, but also include other types of control. One such device is the emergency cutoff for an entire industrial process that occurs when the wastewater or air pollution control system fails. A related type of emergency cutoff shuts down an industrial operation when internal pressures, chemical reactions or ambient vapors threaten an explosion at a facility. Other emergency cutoff systems shut storm sewer systems when a monitor has det ected gasoline vapors or when special organic absorbents swell and block a sewer in reaction to solvents. Emergency cutoffs can also be installed to stop the discharge from a failed pollution control device such as a wastewater plant or air pollution

scru bber.

Any of these structural modifications made to physically prevent the release of pollutants from a facility must be included in all of the related BMP activities such as inspections, maintenance, personnel training, and spill drills. A disconnected or neglected device will not work in the event of a spill. If facility personnel do not know about the functioning of the device, they cannotCHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 28 properly maintain or inspect it. Without training and spill drills which include the devices, personnel may misi nterpret the cause of an emergency cutoff or may release material from secondary containment prematurely. Just because these structural devices operate automatically, does not mean that they can be left out of all other BMP elements. The BMP plan must de scribe these physical devices and outline their routine inspection and maintenance in addition to including them in personnel training and spill drills.



### 3.4.6 Reporting of BMP Incidents
A BMP incident reporting system is used to keep records of incidents such as spills, leaks, runoff and other improper discharges. The system minimizes recurrence, expedites containment or cleanup activities, and complies with legal requirements. Reporting procedures defined by the
BMP Committee should include these 3 elem ents upon discharge:

1. Immediately notify appropriate plant personnel so they can initiate prompt action.

2. Write formal reports for management to review. Management should evaluate the BMP incident and consider revising the BMP plan accordingly.

3

. (By law) Notify governmental and environmental agencies if a spill or other discharge reaches surface water or ground water.

The reporting system should designate the means for reporting incidents to responsible company and government officials. The names, office telephone numbers, and home telephone numbers of key employees ranked in order of responsibility should be listed for immediate reporting of BMP incidents to plant management personnel involved in implementation of emergency response plans.

The communications system should be described which is available for notification of an impending or actual BMP incident. Reliable communications with the person directly responsible is necessary to expedite immediate action for preventing, containing, o r initiating cleanup of a discharge. Such a communication system could include telephone, radio, or alarm systems that could signal the location of an incident. Provisions to maintain communications in the event of a power failure must be addressed.

Wri tten reports on all BMP incidents should be submitted to the plant's BMP Committee and plant management for review. Written reports should include the date and time of the discharge, weather conditions, nature of the materials involved, duration, volume, cause, environmental problems, countermeasures taken, people and agencies notified, and recommended revisions to the BMP plan involving changes to the plant operating procedures and/or equipment to prevent

recurrence.

Procedures and important information should be outlined in the BMP plan for inclusion in reports of BMP incidents to federal, state, and local regulatory authorities. In someCHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 29 circumstances, notifying authorities such as municipal sewage treatment works, drinking water treatment plants, and f ish and wildlife commissions may be desirable. The BMP plan should list the individuals who are responsible for notifying these authorities. The telephone numbers of these authorities and of people in the plant who need to be notified should also be list ed in the BMP plan. The phone numbers should be reviewed periodically for accuracy and might actually be used in the course of a "spill drill."



### 3.4.7 Materials Compatibility
Incompatibility of materials can cause equipment failure through corrosion, fire , or explosion. Equipment failure can be prevented by ensuring that the materials of construction for containers handling hazardous substances or toxic pollutants are compatible with the containers' contents and surrounding environment.

Materials compati bility encompasses 3 aspects: compatibility of the chemicals being handled with the materials of construction of the container, compatibility of different chemicals upon mixing in a container, and compatibility of the container with its environment. The specific requirement of "Materials Compatibility" in the BMP plan should provide procedures to address these aspects in the design and operation of the equipment on site handling toxic and hazardous
materials.

The BMP plan documentation on materials compa tibility should describe the engineering practices already used in the plant, and should summarize these existing practices with regard to corrosion and other aspects of material compatibility. Specific consideration should be given to procedures and prac tices for the mixing of chemicals which might result in fire, explosion or unusual corrosion. Thorough cleaning of storage vessels and equipment before use with another chemical should be standard practice to avoid unexpected reactions or releases of haza rdous material. Coatings or cathodic protection should be considered for protecting a buried pipeline or storage tank from corrosion.

Where applicable, material testing procedures should be described in the BMP plan. Proposed substitutions for currently used toxic or hazardous chemicals should be studied to determine whether they are compatible with the construction materials of the existing containers. The procedures utilized by the plant or an outside contractor to perform the materials compatibility study should be documented. Materials compatibility situations which are covered by the RCRA hazardous waste regulations should be referred to in the BMP plan.



### 3.4.8 Good Housekeeping
Good housekeeping is essentially the maintenance of a clean, orderly w ork environment and contributes to the overall facility pollution control effort. Periodic training of employees on housekeeping techniques for those plant areas where the potential exists for discharges reduces the possibility of incidents caused by mish andling of chemicals or equipment.CHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 30 Examples of good housekeeping include neat and orderly storage of bags, drums, and piles of chemicals; prompt cleanup of spilled liquids to prevent significant runoff to surface water or infiltration to ground water; swe eping, vacuuming, or other cleanup of accumulations of dry chemicals as necessary to prevent them from reaching receiving waters; and provisions for storage of contain ers or drums to keep them from protruding into open walkways or pathways.

Maintaining e mployee interest in good housekeeping is a vital part of the BMP plan. Methods for maintaining good housekeeping goals could include regular housekeeping inspections by supervisors and higher management; discussions of housekeeping at meetings; and public ity through posters, suggestion boxes, bulletin boards, slogans, incentive programs, and employee publications.



### 3.4.9 Preventive Maintenance (PM)
An effective preventive maintenance (PM) program is important to prevent spills or releases. A PM program in volves inspection and testing of plant equipment and systems to uncover conditions which could cause breakdowns or failures which result in significant discharges of chemicals to receiving waters. The program should prevent breakdowns and failures by adju stment, repair, or replacement of items. A PM program should include a suitable records system for scheduling tests and inspections, recording test results, and facilitating corrective action. Most plants have existing PM programs which provide a degree of environmental protection. It is not the intent of the BMP plan to require development of a redundant PM program. Instead, the objective is to have qualified plant personnel and the BMP Committee evaluate the existing plant PM program and recommend to management those changes, if any, needed to address BMP requirements.

A good PM program should include the following: (1) identification of equipment or systems to which the PM program should apply; (2) periodic inspections or tests of identified equipmen t and systems; (3) appropriate adjustment, repair, or replacement of items; and (4) maintenance of complete PM records on the applicable equipment and systems.

The BMP plan documentation on PM may include a list of procedures, examples of record keeping, a list of the principal systems to which the PM program is applicable, and directions for obtaining the records for any particular system included or referred to in the BMP plan. In general, it will be adequate to refer to the scope of existing PM procedu res and location of PM
records.



### 3.4.10 Inspections and Records
The purpose of the inspection and records system is to detect actual or potential BMP incidents. The BMP plan should include written inspection procedures and optimum time intervals between
i nspections. Records to show the completion date and results of each inspection should be signed by the appropriate supervisor and maintained for a period of 3 years. A tracking ( follow

up ) procedure should be instituted to assure that adequate response a nd corrective action haveCHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 31 been taken. The record keeping portion of this system can be combined with the existing spill reporting system in the plant.

While plant security and other personnel may frequently and routinely inspect the plant for BMP
inciden ts, these people are not necessarily capable of assessing the potential for such incidents. Certain inspections should be assigned to designated qualified individuals, such as maintenance personnel or environmental engineering staff.

The inspection and r ecords system should include those equipment and plant areas identified in the "Risk Identification and Assessment" portion of the BMP plan as having the potential for significant discharges. To determine the inspection frequency and inspection procedures

, competent environmental personnel should evaluate the causes of previous incidents and assess the probable risks for incidents. Furthermore, the nature of chemicals handled, materials of construction, and site

- specific factors including age, inspection techniques, and cost

effectiveness should be considered.

Qualified plant personnel should be identified to inspect designated equipment and plant areas. Typical inspections should include examination of pipes, pumps, tanks, supports, foundations, dikes, and drainage ditches. Records should be kept to determine if changes in preventive maintenance or good housekeeping procedures are necessary.

Material storage areas for dry chemicals should be inspected for evidence of, or the potential for, wind blowing which might result in significant discharges.

Liquid storage areas should be inspected for leaks in tanks, for corrosion of tanks, for deterioration of foundations or supports, and for closure of drain valves in containment facilities. Inspections cou ld include the examination of seams, rivets, nozzle connections, valves, and connecting pipelines. Storage tanks should be inspected for evidence of corrosion, pitting, cracks, abnormalities, and deformation and such evidence should then be evaluated.

Fo r in

- plant transfer and materials handling of liquids, inspections should include visual examination for evidence of deterioration of pipelines, pumps, valves, seals and fittings. The general condition of items such as flange and expansion joints, pipelin e supports, locking valves, catch or drip pans, and metal surfaces also should be assessed.

For loading and unloading operations, inspections during transfer of materials would permit immediate response if an incident occurred. The conditions of pipeline s, pump, valves, and fittings for liquid transfer systems and pneumatic conveying systems used for transferring dry chemicals should be inspected. Inspections (together with monitoring) should be used to ensure that the transfer of material is complete be fore flexible or fixed transfer lines are disconnected prior to vehicular departure. Before any tank car or tank truck is filled, the lower most drain valve and all outlets of such vehicles should be closely examined for evidence of leakage and, if

necess ary, tightened, adjusted, or replaced. Before departure, all tank cars or tank trucks shouldCHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 32 be closely examined to ensure that all transfer lines are disconnected and that there is no evidence of leakage from any outlet.

For plant runoff, inspect the in tegrity of the stormwater collection system and the diversion or overflow structures, and ensure that the drain valves and pump for diked areas are properly closed. The plant sewer and storm sewer system should be periodically surveyed to ensure that
toxi c and hazardous pollutants are not discharged in significant amounts. Inspections also should include diked areas to ensure that hazardous and toxic chemicals are not discharged from inside diked areas to waterways. Any liquid, including rainwater runoff , should be examined, and where necessary, analyzed, before being released from the diked areas to a receiving water. The permit should include site

- specific methods for determining whether rainwater has received contamination. For examples, a facility ha ndling acids could check to see that the pH of the rainwater is close to neutral, or a facility handling oils could check for sheen on the rainwater before discharge. If inspection reveals any indication of contamination, then the rainwater must be analyz ed and properly treated before discharge.

Visual inspections should include examinations for leaks, seepage, and overflows from land disposal sites such as spray fields, pits, ponds, lagoons, and landfills. Other procedures and inspection techniques shou ld be considered on a site

- specific basis. Any inspections made or records kept to comply with a solid waste permit may be included in the BMP plan by reference.

Emergency equipment and supplies for spill control or fire fighting must be inspected to ens ure that equipment is in good condition and supplies are adequate. The communication system must also be inspected.



### 3.4.11 Security
A security system is needed to prevent accidental or intentional entry to a plant which might result in vandalism, theft, sabotage or other improper or illegal use of plan facilities that could possibly cause a BMP incident. Most plants have security system to prevent unauthorized entry leading to theft, vandalism, sabotage or a spill. The BMP plan should describe those por tions of the existing security system which ensure that chemicals or other pollutants are not discharged either accidentally or deliberately to receiving waters in significant quantities.

The BMP Committee, plant security manager, plant engineer or other qualified plant personnel should evaluate the coverage of the existing security system over those areas of the plant identified by the "Risk Identification and Assessment" as having the potential for significant discharges. They should recommend to plant management any changes necessary to improve the security system.

Examples of security measures include: routine patrol of the plant by security guards in vehicles or on foot; fencing to prevent intruders from entering the plant site, good lighting; vehic ular traffic control; a guardhouse or main entrance gate, where all visitors are required to sign in andCHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 33 obtain a visitor's pass; secured or locked entrances to the plant; locks on certain valves or pump starters; and television surveillance of appropriate plant sites, such as plant entrance, and loading and unloading areas.

Whenever possible, security personnel should be instructed to observe leaks from tanks, valves, or pipelines while patrolling the plant and also be informed of the procedures to follow when a spill or other discharge is detected. Many plants use contractor or plant security personnel who may not be qualified or may not have time to carry out such surveillance. In such cases, the surveillance can be incorporated in the "Inspection and Records" specific requirement and should be conducted by production or environmental staff.



### 3.4.12 Employee Training
Employee training programs should result in personnel, at all levels of responsibility, having a complete understanding of the BMP plan. Employee training meetings should be conducted at least annually to ensure adequate understanding of the objectives of the BMP plan and the individual responsibilities of each employee. Typically, these meetings could be a part of routine employee meeting s for safety or fire protection. Such meetings should highlight previous spill events or failures, malfunction ing equipment components, and recently developed BMP precautionary measures. Training sessions should review the BMP plan and associated proced ures. Just as fire drills are used to improve an employee's reaction to a fire emergency, spill or environmental incident drills may serve to improve the employee's reactions to BMP incidents. Large or complex facilities are required to conduct spil l dri lls on a quarterly or semi

annual basis. Smaller facilities are strongly encouraged to conduct spill drills too. Spill drills
also serve to evaluate the employees' knowledge of BMP

- related procedures, and are a fundamental part of employee training.

Ade quate training in a particular job and process operation is essential for understanding potential discharge problems. Knowledge of specific manufacturing operations and how discharges could occur, or have occurred in the past, is important in reducing hum an error that
can lead to BMP incidents.

The training program must include the protocol used to report discharges to the people responsible for implementing countermeasures. In addition, personnel involved in spill response
should be trained to use clean up materials such as sorbents, gelling agents, foams, and neutralizing agents. They should also be educated in safety precautions, in the side effects of the chemicals they are working with, and in possible chemical reactions. Operating manuals and
stand ard procedures for process operations should include appropriate sections on the BMP plan and the spill control program and must be readily available for reference.

The BMP plan must contain records showing the dates, names and positions of the employees trained and also include the lesson plans, subject material covered, and instructors' names and positions. BMP

- related training may be combined with other forms of training, such as safety,CHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 34 fire prevention, or RCRA required training.

In addition to per manent personnel, contractors or temporary personnel should be trained in procedures for preventing BMP incidents since these individuals may be unfamiliar with the normal operating procedures or location of equipment (pipelines, tanks etc.) at the facilit y. Adequate supervision of contractor maintenance personnel should be provided to minimize the possibility of BMP incidents resulting from damaging equipment such as buried pipelines. This supervision or training must be described in the BMP plan.



### 3.5 Sp ecific BMPs
Ecology has developed specific BMPs for vehicle and equipment washing (WQ

- R

- 95

- 56) and for prevention of pollution from storm water discharge in the Puget Sound Basin (Ecology 91

- 75)



### 3.6 Spill Plans Required by Others
Some facilities are requi red by other laws to have spill plans

. The following Table XII

- 1 lists the facilities that are required to have spill plans for oil and petroleum products under RCW
90.56

. These spill plans are reviewed by the Spill Program.CHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 35 Table XII

- 1. Facilities C overed by the Spill Program's Facility Oil Handling Regulation , for oil spill prevention planning/Chapter 173

- 180 WAC Plan ID* Facility Name NW006 BP West Coast Products Terminal, Seattle NW029 Rainier Petroleum, Seattle NW008 BP Cherry Point Refinery, B laine NW011 ConocoPhillips Refinery, Ferndale SW004 Tesoro Terminal, Port Angeles NW005 ConocoPhillips Terminal, Renton SW002 ConocoPhillips Terminal, Tacoma NW002 Tesoro Northwest, Anacortes NW020 Shell, Seattle SW003 NuStar, Vancouver
SW013 Sound Re fining, Tacoma ER006 Chevron Pipeline, Pasco SW010 ST Services, Tacoma NW007 Paramount Petroleum Richmond Beach Terminal, Seattle SW005 Tesoro Terminal, Vancouver ER002 Chevron USA, Pasco NW003 Shell Refinery, Anacortes ER003 Tidewater Terminal, Clarkst on ER004 Tidewater Terminal, Pasco NW009Kinder Morgan Energy Partners Terminal, Seattle NW016 Terasen Pipeline, Bellingham SW009 US Oil & Refining, Tacoma SW007 Weyerha e user, Longview NW004 Manchester Naval Fuel Depot, Manchester
SW017 McNeil Island Corr ections Center, Steilacoom NW014 Naval Air Station, Whidbey Island ER007 Yellowstone Pipeline, Spokane

* The plan ID indicates which region is reviewing the plan. Copies of those plans are available at

that regional office. Copies o f all plans are available at HQ by contacting the Spills Program.CHAPTER XII. ALTERNATIVES AND ADDITIONS TO NUMERICAL EFFLUENT LIMITS (JULY 2002)

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- 36 

## 4. CERTIFIED OPERATORS AT INDUSTRIAL SITES WITH DOMESTIC WASTEWATER TREATMENT FACILITIES

Many industrial facilities have small domestic wastewater treatment facilities at the si te or treat small quantities of domestic wastewater with the industrial wastewater. The personnel who work at these treatment facilities must be certified in accordance Chapter 173

- 230 WAC (Certification of Operators of Wastewater Treatment Plants). This regulation was primarily intended for municipal wastewater treatment plants but it applies to any wastewater treatment plant treating domestic wastewater. The level of certification ranges from OIT (operator

- in

- training) to Group IV. The
level of certif ication required is in accordance with the size and complexity of the wastewater treatment facility. Wastewater discharge permits for industrial facilities treating domestic wastewater should include a requirement for a certified operator. Permit manager s who are uncertain of the classification of a facility should call the operator certification coordinator, for assistance. Inspections of these facilities should verify the operator is certified and that the certification is of the proper level.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 1 

# XIII. MONITORING GUIDELINES

This chapter presents guidance and provides the technical references and the few statutory references which a permit writer should consider when establishing the special permit conditions for frequency of sampling, sample types, sam pling locations and the analytical methods in a wastewater discharge permit. The seven sections of this chapter include:

1. The general considerations of self monitoring.

2. POTW monitoring (excluding land application).

3. Industrial and commercial facility monit oring.

4. WET testing monitoring.

5. Storm water monitoring.

6. Receiving environment monitoring.

7. Sediment monitoring

. 8. Summary checklist.

"Monitoring is truly the cornerstone of the NPDES program. It is the primary means of ensuring that the permit limitations are met. It is also the basis for enforcement actions against permittees who are in violation of their permit
limits."

Having so stated in the opening of its primary permit

- writing training manual, EPA dedicates four pages of a 100 page training manual to the topic of monitoring (EPA, 1987d). There is little explicit guidance which provides the permit writer with a framework for decisions relating to monitoring. This chapter informs the permit writer of what methods to follow to establish monitoring cond itions in a permit.

EPA directed the states to require recording and reporting of monitoring results:

"All permits shall specify requirements concerning the proper use, maintenance, and installation, when appropriate, of monitoring equipment or
methods (including biological monitoring methods when appropriate). All permits shall specify required monitoring including type, intervals, and frequency sufficient to yield data which are representative of the monitored activity including when appropriate, cont inuous monitoring" (40 CFR 122.48).CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 2 "In addition to §122.48, the following monitoring requirements:

(1) To assure compliance with permit limitations, requirements to monitor:

(i) The mass (or other measurement specified in the permit) for each pollutant limited in the permit;

(ii) The volume of effluent discharged from each outfall;

(iii) Other measurements as appropriate including pollutants in internal waste streams under §122.45(i); pollutants in intake water for net limitations under §122.45(f); frequency,
rate of di scharge, etc., for noncontinuous discharges under §122.45(e); pollutants subject to notification requirements under 122.42(a); and pollutants in sewage sludge or other monitoring as specified in 40 CFR part 503; or as determined to be necessary on a

case

- b y

- case basis pursuant to section 405(d)(4) of the CWA.

(iv) According to test procedures approved under 40 CFR part 136 for the analyses of pollutants having approved methods under that part, and according to a test procedure specified in the permit for p ollutants with no approved methods.

(2) Requirements to report monitoring results with a frequency dependent on the nature and effect of the discharge, but in no case less than once a year..." (40 CFR 122.44[i])

The two citations quoted above give the p ermit writer extreme flexibility in monitoring, from yearly to continuous. The most important requirement is that the data "are representative of the monitored activity."

Washington State regulations provide more detailed requirements.

" (1) Monito ring.

(a) Any discharge authorized by a permit may be subject to such monitoring requirements as may be reasonably required by the department, including the installation, use, and maintenance of monitoring equipment or methods (including, where appropr iate, biological monitoring methods)

. These monitoring requirements would normally include:

(i) Flow (in gallons per day);

(ii) Pollutants (either directly or indirectly through the use of accepted correlation coefficients or equivalent measurements) whic h are subject to reduction or elimination under the terms and conditions of the permit;CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 3 (iii) Pollutants which the department finds could have a significant impact on the quality of surface waters; and

(iv) Pollutants specified by the administrator, in r egulations issued pursuant to the FWPCA, as subject to monitoring.

(b) Each effluent flow or pollutant required to be monitored pursuant to (a) of this subsection shall be monitored at intervals sufficiently frequent to yield data which reasonably chara cterizes the nature of the discharge of the monitore d effluent flow or pollutant. Variable effluent flows and pollutant levels may be monitored at more frequent intervals than relatively constant effluent flows and pollutant levels which may be monitored at less frequent intervals.

(c) Monitoring of intake water, influent to treatment facilities, internal waste streams, and/or receiving waters may be required when determined necessary by the department to verify compliance with net discharge limitations or removal requirements, to verify that proper waste treatment or control practices are being maintained, or to determine the effects of the discharge on the surface waters of the state...

(3) Reporting of monitoring results.

(a) The permittee shall periodically report (at a frequency of not less than once per year) on the proper reporting form, the monitoring results obtained pursuant to monitoring requirements in a permit

. In addition to the required reporting form, the department at its discretio n may require submission of such other results as it determines to be necessary." [WAC 173

- 220

- 210]

"(1) Any permit issued by the department shall specify conditions necessary to prevent and control waste discharges into the waters of the state, includin g the following, whenever applicable:

(g) Any appropriate monitoring, reporting and recordkeeping requirements as specified by the department, including applicable requirements under sections 307 and 308 of FWPCA" [WAC 173

- 216

- 110]”.

The nature and effec t of the discharge are important factors in determining monitoring frequency and so it is important that the discharge be adequately characterized. The permit writer should recognize the costs of monitoring while deciding how much is enough for an adequat e characterization.

Consulting with individuals, including the permittee, who are knowledgeable about the facility or type of operation will save time on appeals, enforcement and future permit renewal or modification efforts. A prime source of informatio n about a facility is the inspector who deals with the facility or similar facilities.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 4 

## 1. GENERAL CONSIDERATIONS OF A SELF

MONITORING PROGRAM

The general considerations apply to all facilities in the wastewater permit program administered by the Washingt on State Department of Ecology. Exceptions and additional considerations are explained in the chapter sections for POTWs, industrial facilities, storm water and for receiving environment monitoring. The general considerations are presented in this sectio n in the following sequence:



### • Objectives of monitoring.



### • Parameters to monitor.



### • Frequency of monitoring.



### • Special monitoring strategies.



### • Sampling and testing methods.



### • Sampling locations.



### • Data validation, management and reporting.



### • Quality assurance and qualit y control.

All permits must require monitoring of effluent in order to determine if the facility is in compliance with the permit. The permit must state the sampling location, frequency, methods of analyses, and sample type for each parameter with limits . Parameters without limits may be monitored as required by the department. Internal process control monitoring may be required of dischargers exhibiting noncompliance. Tiered monitoring and indicator parameters should be used when appropriate.

The var iability of the effluent is one of the most important factors in establishing monitoring frequency, particularly for industrial dischargers, and therefore the degree of monitoring frequency is dependent on the characterization of the effluent. The charact erization should ideally occur as a part of the renewal or application process. A high frequency monitoring study is presented as a means of effluent characterization. High frequency monitoring, usually within a tiered framework or as a special study, is recommended to characterize effluent.


## 1.1 Establish Monitoring Objectives

The main purpose of self monitoring requirements is to determine compliance with effluent limits and other permit conditions. Monitoring may also be required in order to gather
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- 5 impacts on the receiving environment.

The parameters, frequency of monitoring, and sampling locations for POTWs are listed in Tables
XIII

- 1(A

- E) and XIII

- 2(A

- M). The limits and monitoring strategies for POTWs are standardized and based on Best Conventional Treatment for pollutants generally associated with municipal sewage treatment plants (Section 2. POTW Monitoring). Industrial or commercial facilities which have the same type of treatment system, in particular a secondary biological process, should receive similar monitoring requirements for the pollutants listed. POTW monitoring frequency for permit conditions based on water quality standards and toxi c discharges must be derived separately.

Discussion and guidance on requirements for monitoring compliance with whole effluent toxicity are found in Section XIII

- 4. The permit writer should use the guidance presented in this chapter to determine the moni toring frequency, the level of detail required and the relevancy of the testing results toward evaluating the potential for environmental harm from the effluent.

The permit writer should be able to justify the monitoring requirements on the basis of the v alue of the data. Know how the data may be used. The most useful, valid and cost

- effective data are generated when the purpose or monitoring objectives of monitoring are understood. Some general objectives include:



## • To determine compliance with technolo gy

- based and water quality

- based effluent limits.



## • To determine adequacy of 0 & M procedures.



## • To determine specific impacts on water or sediment quality.



## • To determine effectiveness of source control measures and BMPs.



## • To determine baseline or background con ditions in the receiving environment.



## • To determine the variability of the wastewater as a prerequisite to establishment of monitoring schedules.



## • To characterize the wastewater for determining the need for additional limits.



## 1.2 Parameters to Monitor

All p arameters with effluent limits must have monitoring requirements. Additional parameters to monitor will depend on the monitoring objectives explained previously.

Monitoring flow rates is important for determining loading and is required in all NPDES perm its [40 CFR 122.44(i)]. Methods and techniques of flow measurement are explained in the Water Quality Inspection Manual , Ecology, 1992.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 6 

### 1.2.1 Effluent Monitoring
The pollutant parameters to be monitored in effluent are based on application data, history of the facility discharge, pollutants discharged from similar facilities and any applicable EPA development documents. Minimum parameters for POTWs are outlined in Section XIII

- 2.

The permit may require monitoring of pollutants in the effluent for reas ons other than to determine compliance with effluent limits. The general objectives stated in section 1.1 contain many objectives other than the compliance objective. For example, the objective "to determine effectiveness of source control measures" only indirectly determines compliance. BMPs may be followed as required in the permit but the BMPs may not be adequate to prevent undesirable effects. The monitoring becomes a feedback mechanism to fine tune the BMPs. Another important objective is to gathe r information to determine if further effluent limits are necessary. The authority to require monitoring is derived from Section 308 of the FWPCA and 90.48.260 RCW.

The discharger may be required to monitor for pollutants which the permit writer knows or suspects to be present in the discharge, even those not listed in the permit application. Additional parameters to monitor include toxic chemicals or substances that could upset the treatment system.
These substances could be introduced from raw materia ls, compounds resulting from chemical interactions, or impurities in raw materials including solvents.



### 1.2.2 Process Control and In

- Plant Monitoring
"Monitoring of intake water, influent to treatment facilities, internal waste streams, and/or receiving wa ters may be required when determined necessary by the department to verify compliance with net discharge limitations or removal requirements, to verify that proper waste treatment or control practices are being maintained, or to determine the effects of a discharge on the surface waters of the state." (WAC 173

- 220

- 210[1][c])

Process control monitoring refers to monitoring of internal waste streams in order to verify that proper waste treatment or control practices are being maintained. In

- plant monitoring refers to monitoring at internal sample points due to the inability or impracticality to apply limits or conditions at the typical point of compliance.

Process Control Monitoring

-- Process control monitoring may be included in an enforcement order
when a facility has been out of compliance with its permit. Process control monitoring should not be a requirement in the permit in most circumstances. The permit manager may select certain internal waste streams for monitoring which can generate data to assist the discharger in efficient operation of the treatment system. An enforcement order may also specify monitoring to assist in identifying pollutant sources. Reasonable cause for internal process control monitoring includes:



### • Enforcement action for permit noncompliance when the monitoring is intended to identify the source or cause of noncompliance.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 7 

### • Evaluating pollutant inputs from various functional areas of the facility as part of a Toxicity Identification Evaluation (TIE), a BMP for pollutant identific ation or quantification or the application of a performance standard for a process employed.



### • Other circumstances to verify that proper waste treatment or control practices are being maintained ( e.g. , the certification period for a grant related project or as a condition of a demonstration or experimental project)

The wastewater treatment process will determine the types of process control monitoring needed. For industries with biological treatment systems and wastewater characteristics and flows that ar e similar to comparable POTWs, the monitoring frequency can follow the schedules of Table XIII

2(A

- M). For physical and chemical treatment systems, the permit manager should review any development document for the industrial category, the treatability man uals and other engineering literature for information regarding parameters to use for process control monitoring.

In

- Plant Monitoring

-- Under both federal (40 CFR 122.45[h]) and state regulation (Ch apter 173

- 220

- 210 [1][c] WAC), in

- plant monitoring may be required as a permit condition. In

- plant monitoring for industries may be required at the discretion of the permit writer when reasonable cause exists and the cause is explained in the fact sheet. In

- plant monitoring may be required:



### • When the sample at final discharge is not characteristic of undiluted effluent because of dilution from other parts of the plant (and to determine whether the waste flow is being diluted to meet effluent limits).



### • When interferences among pollutants at the point of discharge would make detection or quantification impractical.



### • When the final discharge point is inaccessible (but make every effort to require accessibility).



### • When determining chlorination efficiency.



### 1.2.3 Indicator Parameters
Indicator parameters may be used i n certain instances when a close correlation exists between concentrations of pollutants in a wastestream. Indicator tests or observations can be useful in determining the effectiveness of the treatment process. Indicator parameters can be used only for well documented processes where the effluent concentration of an easily measured component parallels the concentration of a component more difficult to measure or detect. The correlation must be consistent over the range of varying raw material input to t he system. A treatment process that reduces the concentration of the indicator in equal or less proportion to the
contaminant of concern is essential.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 8 Limits on indicators may not be used as a substitute for federally promulgated technology

- based
limits or limits developed on a case

- by

- case basis on parameters in the discharge. Contaminants of interest in the effluent for which no limits are specified can be monitored by an indicator when a positive correlation is established. There are correlations bet ween some parameters which allow tests for one parameter to indicate the relative value of another parameter. A procedure for calculating correlations is located in the Handbook for Sampling and Sample Preservation of
Water and Wastewater , EPA, 1982b, p.1 46. Computer software packages such as Excel  , the agency standard spreadsheet software calculates correlation coefficients. In many cases significant correlations exist between the following parameters:



### • BOD and TOC



### • Chlorides and Conductivity



### • Total Dissolved Solids and Conductivity



### • Acidity, Alkalin ity and pH



### • Hardness, Calcium, and Magnesium

Besides the cost considerations, indicator tests are also advantageous if they give quicker feedback for process control testing. An example would be analyzing TOC instead of 5 day BOD if a reasonably consisten t mathematical relationship is established through special comparison studies. BOD is not always the most useful indicator of oxygen demand because of the long incubation time required to obtain a meaningful result. Once a correlation has been establishe d, the TOC
measurements can be translated to BOD. Monitoring the effluent for an indicator cannot substitute for monitoring on a parameter which has an established effluent limitation.

The utility of an indicator must be explained in the fact sheet. The explanation should be based

on:



## • Similarities between causative pollutants and a convenient monitoring parameter (e.g

. , monitoring Total Petroleum Hydrocarbon to indicate control of polynuclear aromatic hydrocarbons where the removal technology equally re duces the concentration of both or preferentially reduces the PAH component).



## • The effectiveness of a particular treatment process and a control parameter for that process (e.g., limits on TOC to ensure proper performance of an activated carbon process).

Indicators might be appropriate for an industry that generates a waste stream containing metals in which the relative concentration of metal pollutants does not vary because of consistent raw material composition and internal process control. An internal process control parameter could be monitored to assure process stability. One metal could serve as an indicator for most other metals. TSS has been used by EPA as an indicator of toxics for some effluent guidelines.

Where there is no water quality crite rion for a specific pollutant which causes or contributes to an excursion above a narrative criterion, the permit writer may establish effluent limits and monitorCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 9 an indicator parameter. The permit should require all effluent and ambient monitoring necess ary to show that the limit on the indicator continues to attain and maintain applicable water quality standards [40 CFR 122.44(d)(1)(vi)(C)].


## 1.3 Monitoring Frequency

"Each effluent flow or pollutant...shall be monitored at intervals sufficiently frequent to yield data which reasonably characterizes the nature of the discharge of the monitored effluent flow or pollutant. Variable effluent flows and variable pollutant concentrations may be monitored at more frequent intervals than relatively constant efflu ent flows and pollutant concentrations which may be monitored at less frequent intervals" [WAC 173

- 220

- 210(1)(b)].

The frequency of sampling should result in the production of data that provide a reasonable characterization of the effluent. Reasonablenes s can be demonstrated on the basis of the value of data collected. A primary value of the data is the establishment of effluent variability, an important factor in calculating discharge limits, determining compliance and establishing the basis for monitor ing frequency. Routine compliance monitoring frequency may be adjusted to reflect the variability. The intent is to establish a frequency of monitoring which will detect most events of noncompliance without requiring needless or burdensome monitoring.

F or example, at equivalent average flow rates, a large lagoon system which is not susceptible to short circuiting requires less frequent monitoring than an overloaded treatment facility which experiences fluctuating flow rates due to infiltration or large b atch discharges from an industrial user on the system. The large lagoon should have a relatively low coefficient of variation (CV = population standard deviation divided by the population mean: sd/mean) compared to the facility receiving batch discharges.



### 1.3.1 Establishing Monitoring Frequency The frequencies for monitoring pollutants from a POTW with limits based on a performance standard are presented in Section 2 of this chapter. The permit writer should consider these as minimum frequencies.

The f requencies for monitoring pollutants for informational purposes, for performance

- based limited pollutants from non

- POTWs or for water quality

- based effluent parameters from any facility should be derived at the discretion of the permit

- writer by one of the two following methods.

Method 1. Estimate the variability of the concentration of the parameter by reviewing DMRs and the record of similar dischargers. In addition to the estimated variability, other factors for determining sampling frequency include:



## • Size and design capacity of facility



## • Type of treatmentCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 10 

## • Compliance history



## • Number of pollutant sources from a facility



## • Cost of monitoring relative to the discharger's capability and benefits obtained



## • Environmental significance of pollutants



## • Receiving water quality (including dilution effects)



## • Detection limits and analytical precision/accuracy



## • Production schedule of the facility (seasonal, daily, etc.)



## • Plant wash down or cleanup schedule



## • Number of monthly samples used in developing the permit limit



## • Batch typ e process and discharge or continuous operation

These factors and other facility

- specific factors used to determine monitoring frequency should be presented and discussed in the permit fact sheet.

Method 2

. See Appendix 13.2



### 1.3.2 Tiered Monitoring

The Puget Sound Water Quality Management Plan , Puget Sound Water Quality Authority, 1991

states:

"Monitoring requirements included in permits shall be tiered so that if initial (baseline) sampling discloses no problems, a reduced monitoring scheme may
then a pply. Likewise, if initial (baseline) sampling indicates the possibility of problems, a more frequent and/or more comprehensive monitoring schedule would apply. Initial monitoring schemes shall be set to ensure that enough
data is collected to determine if additional discharge limits should be set."

The concept of tiered monitoring should be considered for all permits. It is a permit program goal to require sufficient monitoring to meet the objectives mentioned earlier but to avoid excessive monitoring. Tiered monitoring requires that implementation of additional monitoring methods or reduction of certain monitoring frequencies be based on the results of previous monitoring. This step

- wise approach could lead to lower monitoring costs for the permittee while still providing an adequate degree of protection for the receiving environment and human health. The term "tiering" for this chapter means a reduction or increase in frequency of monitoring within a permit cycle. The conditions for increase and dec rease are explained in the permit.

The recommendation at this time is to consider tiering only for parameters with established limits. Monitoring for information should be done in the context of a "Special Study" with a definite beginning and ending esta blished in the permit.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 11 The use of tiering should be restricted to a one

- time reduction in monitoring frequency with no provision for reversion to the high frequency in the permit. If the permit manager feels that a reversion to high frequency is warrante d, require the reversion through an administrative order or a subsequent permit modification (minor modification).

The application of tiering will generally be left to the judgment of the permit writer. Justification for the level or degree of monitori ng required in the permit should be presented in the fact sheet. The time frames associated with establishment of the baseline monitoring period should be determined by the permit writer. The initial (baseline) monitoring period should reflect the
enviro nmental consequence and the likelihood of presence of the pollutant(s). If tiering is also used to generate variability and LTA data, these needs should be considered in establishing the
schedule.

Until there is sufficient data available by the methods s tated previously, require a minimum of 10 observations every month for all pollutants of concern for which there are limits specified as explained in the TSD (EPA, 1991). The permit writer should require that data be accumulated
until the level of variabi lity is established. One approach would be to request that semi

- weekly to daily monitoring results of effluent parameters be submitted in addition to the routine DMRs during the early months of the permit cycle. Analysis of this data would indicate wheth er monitoring frequency can be reduced while maintaining adequate characterization of the effluent. This strategy should be explained briefly in the fact sheet. Once variability is established, monitoring frequency should be based on the confidence that effluent limit excursions will be
detected.

The total cost of monitoring for toxic pollutants could be reduced by requiring a high initial monitoring frequency that is reduced if the permittee consistently meets the limit. The overall purpose of such req uirements is to first establish a compliance history using a relatively high monitoring frequency and then reduce the frequency if they routinely comply with permit conditions. The requirements should be specified in the permit.

An example of a decrease in monitoring is a requirement to test for chemicals such as volatile organics monthly or bimonthly in the first year of a permit cycle, then reduction to annually if no volatiles of concern as specified in the permit are detected. This strategy may suff ice if the permit writer has doubts about information presented in an application or if improvements in pollutant control are expected which reduce the likelihood of discharge of volatiles.

The triggers for the tiered elements of a permit must be well def ined in the permit and explained in the fact sheet. For the above example, the simplest approach is to state the trigger in a footnote in the special condition for monitoring frequencies. The footnote should explain to what frequency the tiered parameter will revert if not detected or not found to be at a level of concern. The numeric "level of concern" must be defined in the permit and explained in the fact sheet. The reduction or elimination of monitoring should also be contingent upon the permittee r equestingCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 12 approval from Ecology. The regional DMR data input coordinator must be in the paper trail loop of "approval of frequency or parameter

- change" in order to be able to track these changes.

It is convenient to begin the permit cycle with baseline m onitoring which specifies a high frequency of monitoring for the wide variety of pollutants suspected to be present. Elimination or reduction of monitoring can be accomplished through compliance and discharge at levels of non

concern and after written app roval from the permit manager.

An increase in monitoring frequency or scope of monitoring is usually more difficult to administer. The trigger for increased monitoring would need to be established and explained. Except for relatively simple triggers f or additional types of monitoring or increased frequency, the recommended approach for an additional monitoring schedule is to issue an administrative order based on noncompliance with the permit. The few instances where additional monitoring may be requi red do not justify the resource investment involved in satisfying all possibilities or contingencies in the permit text.
A common example of an increase in monitoring is a requirement to test an effluent for toxic
chemicals when the effluent violates a WET limit. This is discussed further in Chapter VI.



### 1.3.3 Monitoring Reduction for Exemplary Performance
Another concept related to tiered monitoring is the reduction of monitoring frequency for demonstrated good performance. This process is generally appli ed at the time of permit renewal and the monitoring frequency is reduced from some baseline frequency. The following guidance is adopted from EPA guidance (EPA memorandum from Robert Perciasepe and Steven A. Herman to Regional Administrators, April, 1996) . The guidance is applicable to NPDES permitted discharges, State permitted discharges, and discharges to a POTW.

Criteria for Exclusion Facilities whose owners or operators have been criminally convicted under any Federal or State environmental statute o f falsifying monitoring data or of committing violations which presented an imminent and substantial endangerment to public health or welfare will not receive any reductions. These facilities may be eligible at any time Ecology determines there has been a wholesale change in ownership and management from those convicted.

Facilities whose owners or operators have been convicted of any other criminal violation under any Federal or State environmental statue will not receive any reductions for at least 5 yea rs from the time of conviction.

Facilities where an individual employed by the permittee, but not the permittee itself, was convicted of a criminal violation under any Federal or State environmental statute, will be eligible for reduced monitoring frequen cy provided the permittee discovered and self

- disclosed the violation, and took prompt action to correct the root cause in order to prevent future criminal violations.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 13 Facilities involved in civil environmental, judicial actions brought by the State are e ligible for consideration of reduction 1 year after completion of injunctive relief and payment of penalty.

Facilities involved in administrative actions are eligible for consideration after the permittee has complied with Administrative Order (AO) requir ements, and payment of any assessed penalty. A permittee that is issued an AO, in conjunction with reissuance of its permit, to extend a compliance schedule, may be eligible if the permittee is in compliance with the interim
milestones and schedule in the AO.

For example, in order to comply with a newly promulgated effluent guideline, an industrial sector may be required to install a new technology. Some facilities may not be able to attain the new technology immediately so an AO is issued at the time th e facility’s permit is reissued. The AO sets a compliance schedule to allow the permittee additional time to install the technology needed to meet the new effluent guideline limitation.

Facilities are not eligible for monitoring reduction for any paramet er that exceeds a one percent noncompliance during the past two years. Noncompliance includes monthly average, weekly average or daily maximum.

Other permit noncompliance such as failure to submit a DMR or other permit submittals should
be considered bef ore authorizing a reduction.

Facilities are not eligible for monitoring reduction until at least one permit cycle from the time of restoration of lab accreditation if the accreditation was lost for not performing to standards.

Facilities are not eligible for monitoring reduction until at least two years from the time of a Class II inspection in which it was found the facility was submitting invalid results.

Monitoring reduction for effluent data which has not been continuously reported over the two

year period, interrupted or discontinuous data, intermittent, short

- term, and batch discharges must be considered on a case by case basis. These will require performance data for longer than two years to determine a long term average.

New dischargers will be eligible for reduced monitoring after meeting the two year compliance requirement. Normally, the reduced monitoring provisions would be applied after one permit cycle of five years and at permit reissuance.

Permit writers should evaluate the discharge si tuation when considering monitoring reduction. For example, discharges to a shellfish area should generally not be considered for reduction in fecal coliform monitoring and discharge to an AA water body generally should not be considered
for reduction in t oxics monitoring. Permit writers should also evaluate the prospect of theCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 14 permittee maintaining good performance during the life of the permit. A municipal treatment plant that is lightly loaded but is expected to be near capacity by the end of the permi t term would probably not be meeting the performance criteria by the end of the permit term. Similarly, an industrial facility which demonstrates good performance for the past two years because of greatly reduced production would not be a good prospect fo r maintaining good performance if production increased during the term of the permit.

Procedures Reduction of monitoring frequency will generally be granted at time of permit renewal by examination of performance in the two years preceding renewal. The a mount of reduction is dependent upon the ratio of performance for the last two years to the monthly average effluent limitation (Table XIII

- 1A1). The baseline monitoring frequency is discussed in Section 1.4
below.

Monitoring reduction will be granted du ring the permit term at the request of the permittee and as appropriate. Monitoring reduction during a permit term is a major modification and requires public notice. Each request for modification must include documentation from the permittee
demonstrati ng eligibility. Permit managers will track the number of requests for modification and the disposition of those requests.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 15 Table XIII

- 1A1. Allowable Monitoring Frequency Based on Ratio of Long Term Effluent Average to the Average Monthly Limit (AML)

Ba seline Ratio of Long Term Average to the AML Monitoring 75

- 66% 65

- 50% 49

- 25% <25%
7/wk 5/wk 4/wk 3/wk 1/wk
6/wk 4/wk 3/wk 2/wk 1/wk
5/wk 4/wk 3/wk 2/wk 1/wk
4/wk 3/wk 2/wk 1/wk 1/wk
3/wk 3/wk 2/wk 1/wk 1/wk
2/wk 2/wk 1/wk 2/mo 1/mo
1/wk 1/wk 1/wk 2/mo 1/2mos
2/month 2/mo 2/mo 2/mo 1/quarter
1/month 1/mo 1/mo 1/quarter 1/6mos Note: See above eligibility requirements.

Facilities which satisfy the ent ry criteria but are not experiencing discharges of 75% or less of their permitted levels of water quality

- based parameters may still be eligible for reductions in monitoring/reporting frequencies. Monitoring will only be reduced for such parameters if the applicant can demonstrate a coefficient of variation (ratio of standard deviation to the mean) of 0.20 or less and no monthly average limit violation for the two year averaging period. Reduction
will be allowed as shown in Table XIII

- 1A2 below.

Table XI II

- 1A2. Allowable Monitoring Reduction with a Ratio of Long Term Effluent Average to Monthly Average Limit 100

- 76% and a CV of 0.2 or Less.

Baseline Reduced Monitoring Monitoring
7/wk 6/wk
6/wk 5/wk
5/wk 4/wk
4/wk 4/wk
3/wk 3/wk
2/wk 2/wk
1/wk 1/wk
2/month 2/month
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- 16 Permittees that receive monitoring frequency reductions in accordance with Table XIII

- 1A1 or
Table XIII

- 1A2 are still expected to take all appropriate measures to control bot h the average level of pollutants of concern in their discharge (mean) as well as the variability of such parameters in the discharge (variance), regardless of any reductions in monitoring frequencies granted from the baseline levels. To remain eligible f or these reductions, the permittee may not have any violations for effluent limitations of the parameters for which reductions have been granted or failure to submit DMRs, or may not be subject to a new formal enforcement action.
For facilities that do no t maintain performance levels, Ecology may require increased monitoring by minor permit modification or Administrative Order.

Background material on the statistical derivation of the reduction allowance is presented in the original EPA memo. This materia l is reproduced in Appendix XIII. Permit writers may wish to alert permittees that this background material points out that the probability of reporting a violation increases as the monitoring frequency decreases in some cases.


## 1.4. Baseline Monitoring F requencies

The permit writer must establish a baseline monitoring frequency in order to determine any allowable reduction for good performance. The baseline monitoring frequency may be established by using:

1. The POTW monitoring frequencies given in Sectio n 2 of this chapter.

2. The original monitoring frequency in the permit before any reduction for performance was granted.

3. The statistical formulas given in Appendix 13 Part 2.

A baseline must be established each time a reduction in monitoring frequency is granted (usually at time of renewal). For example, the first time POTW is granted a reduction in monitoring, the baseline is the monitoring frequency in the expiring permit (assuming that the monitoring frequency is consistent with Section 2 of this Chapt er ). At the time of next renewal the baseline frequency would be based on the appropriate tables in Section 2 and not on the reduced monitoring frequency in the permit. Similarly

, if an industrial discharger is granted a reduction in monitoring, then at the time of the next renewal the reduction is based on the original frequency before the reduction was granted or on a frequency calculated by the statistical formulas in Appendix 13.

Monitoring reductions should be stated in the fact sheet for future re ference.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 17 

## 1.5 Special Monitoring Strategies

Routine effluent and facility monitoring can meet some of the objectives stated at the beginning of this chapter but some objectives are best met through the use of special timing strategies and studies. Special studies are typically for a single purpose and are conducted during a limited time frame within the permit cycle. Section XIII

- 6 on receiving environment monitoring also discusses considerations relevant to special studies of the receiving environment.



### 1 .5.1 Stratified Sampling
Uniform sampling intervals may not always be the best approach, considering the cyclic variations in water quality and effluent variability. Stratifying a sampling program into different time periods may result data more suited to characterizing the impact of the discharge.

An example is to require increased monitoring frequency during critical receiving water periods to measure potential impacts to water quality. Seasonal monitoring schedules could be applied. This type of samp ling scheme has been used by Ecology for determining compliance with some water quality based effluent limits. More frequent sampling may be required during the receiving water's critical flow, with less intensive monitoring during the rest of the year. Such an approach could be taken for scheduling toxicity testing. Variable sampling frequency could also be used to allocate sampling to periods of peak production or times of largest effluent variation.



### 1.5.2 Unusual Sampling Frequencies
A unique approach is to require that certain parameters traditionally monitored at a frequency of quarterly or twice annually be monitored under a non

- traditional schedule such as "once every fifth month," which results in one monitoring event for each calendar month of a five year permit cycle. This method of scheduling frequencies supplies a degree of randomness. True random sampling is usually difficult to administer.



### 1.5.3 Studies to Determine Effluent Variability, A High Frequency Study
The variability can be establi shed by a special monitoring study conducted prior to permit renewal or during an early portion of the permit cycle. The survey should cover a span of discharge which represents the range of effluent quality and quantity. The sampling frequency on which the data are based should be frequent enough to cover a time span of discharge which considers the swings in effluent quality and quantity. A high frequency study required by the permit should specify the time frame within which the study is to be conduct ed.

An alternative to a specific permit requirement is to require that the same type of data be generated through a permit

- required engineering report. The report should involve an intense analysis that demonstrates the variation or CV, the co

- dependence of variables and the mean or LTA of the pollutant concentrations in the discharge.

The generic factors available for estimating variability listed in section 1.3.1.A should beCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 18 considered in establishing the schedule for the high frequency study.

This strategy should be explained briefly in the fact sheet. Once variability is established, monitoring frequency should be based on the confidence that effluent limit excursions will be
detected.


## 1.6 Sampling and Testing Methods

Monitoring requirements in th e permit should specify the sampling frequency, the sample type (grab, composite or continuous) and the analytical methods for each parameter. A permit condition should require the use of sampling and analytical methods conforming to 40 CFR Part
136.

Det ailed information for developing the sampling program is found in the publication, Monitoring Industrial Wastewater , EPA, 1973. The information is also applicable to POTWs. Test procedures which are approved for NPDES monitoring are listed in Tables IA

- I F of 40 CFR 136 ( 7/1/2003 update). The tables include methods published in:

Methods for the Chemical Analysis of Water and Wastewater , EPA 600/4

- 79

- 020.

Standard Methods for the Examination of Water and Wastewater

, 20 th Edition, APHA.

Annual Book of AS TM Standards , Volumes 11.01 and 11.02.

Methods for Analysis of Inorganic Substances in Water and Fluvial Sediments , USGS, 1989.

Methods for the analysis of organic chemicals are published in 40 CFR 136, Appendix A. Specific requirements and guidance for toxicity testing (bioassays) are included in Chapter 173

- 205 WAC, Whole Effluent Toxicity Testing and Limits and are explained in section XIII

- 4.

Some parameters and samples may require special considerations. Parameters which have no approved testing method in Part 136 can be tested and reported. The permit should specify the test method and include a reference. Contact the EA program for assistance in selecting test methods. The method itself should be included as an appendix to the fact sheet if th e method is not readily available to the permittee. An example is saltwater samples, which may require modifications to the approved methods to avoid matrix interferences from the high salt content.

Approved analytical methods for parameters usually incl ude sampling and handling requirements. Refer to Ecology's Laboratory User's Manual for information regarding sample preservation and handling. The sample type will depend on:CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 19 

## • The parameter to be monitored. To determine appropriate sample types consult 40 CFR Part 136, Standard Methods or other approved methods;



## • The temporal and pollutant concentration variability of the discharge; and



## • The type of limit. Limits based on instantaneous or one hour values may be sampled using grab sampling techniques. L imits based on average values or daily maximums may be sampled using time or flow proportional composite samples. This is acceptable for certain conventional pollutants, nutrients, and bioaccumulative pollutants, for which percent
removal and total loadin g to the receiving water are of concern.



### 1.6.1 Discrete Grab or Sequential Grab Samples
A grab sample is an individual sample collected in less than 15 minutes time. It represents more
or less "instantaneous" conditions.
Use grab samples when:



### • The wast ewater characteristics are relatively constant.



### • The parameters to be analyzed are likely to change with storage such as temperature, residual chlorine, soluble sulfide, cyanides, phenols, microbiological parameters and pH.



### • The parameters to be analyzed a re likely to be affected by the compositing process such as oil & grease and volatiles.



### • Information on variability over a short time period is desired.



### • Composite sampling is impractical or the compositing process is liable to introduce artifacts of sampl ing.



### • The spatial parameter variability is to be determined. For example, variability through the cross section and/or depth of a stream or a large body of water.



### • Effluent flows are intermittent from well

- mixed batch process tanks. Sample each batch dump ing event.
Grab samples can measure maximum effect only when the sample is collected during flows containing the maximum concentration of pollutants toxic to the test organism. Another type of grab sample is sequential sampling. A special type of automati c sampling device collects relatively small amounts of a sampled waste stream, with the interval between sampling either time or flow proportioned. Unlike the automatic composite sampler, the sequentialCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 20 sampling device automatically retrieves a sample and holds it in a bottle separate from other automatically retrieved samples. Many individual samples can be stored separately in the unit, unlike the composite sampler which combines aliquots in a common bottle. This type of sampling is effective for deter mining variations in effluent characteristics over short periods of time.



### 1.6.2 Composite Samples A composite sample consists of a series of individual samples collected over time into a single container, and analyzed as one sample. There are two general types of composites and the permit writer should clearly express which type is required in the permit:



### • Time composite samples collect a fixed volume at equal time intervals and are acceptable when flow variability is not excessive. Automatically timed co mposited samples are usually preferred over manually collected composites. Composite samples collected by hand are appropriate for infrequent analyses and screening.



### • Composite samples can be collected manually if subsamples have a fixed volume at equal

t ime intervals when flow variability is not excessive.



### • Flow proportional compositing is usually preferred when effluent flow volume varies appreciably over time. The equipment and instrumentation for flow

- proportional compositing have more downtime due to maintenance problems.



### • When manually compositing effluent samples according to flow where no flow measuring device exists, use the influent flow measurement without any correction for time lag. The error in the influent and effluent flow measurement is insignificant except in those cases where extremely large volumes of water are impounded, as in reservoirs.

Use composite samples when:

1. Determining average concentrations, or

2. Calculating mass loading/unit of time.

There are numerous cases where compos ites are inappropriate. Samples for some parameters such as pH, residual chlorine, temperature, cyanides, volatile organics, microbiological tests, oil and grease, and total phenols should not be composited. They are also not recommended for sampling batc h or intermittent processes. Grab samples are needed in these cases to determine fluctuations in effluent quality. For bioassays, composite samples are used unless it is known that the effluent is most toxic at a particular time. Some toxic chemicals are short

- lived, degrading rapidly, and will not be present in the most toxic form after lengthy compositing even with refrigeration or other forms of preservation. Require grab samples for bioassays to be taken under those circumstances.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 21 In the absence of an expressed sampling protocol in regulation, the duration of the compositing time period and frequency of aliquot collection is established by the permit writer. Whether collected by hand or by an automatic device, the time frame within which the sample is collected should be specified in the permit. The number of individual aliquots which compose the composite should also be specified. NPDES application requirements specify a minimum of four aliquots for non

- stormwater discharges lasting four or more h ours. The sampling procedures for general pretreatment specify a minimum of twelve aliquots for 24

- hour composites.



### 1.6.3 Continuous Monitoring
Continuous monitoring is another option for a limited number of parameters such as TOC, temperature, pH, conduc tivity, fluoride and dissolved oxygen.

Reliability, accuracy and cost vary with the parameter. Continuous monitoring can be expensive, so continuous monitoring will usually only be an appropriate requirement for the most significant dischargers with vari able effluent. The environmental significance of the variation of any of these parameters in the effluent should be compared to the cost of continuous monitoring equipment
available.

The regulations concerning pH limits allow for a period of excursion wh en the effluent is being continuously monitored (40 CFR 401.17). Continuous monitoring or labor

- intensive periodic monitoring by grab sampling is necessary where pH excursions are allowed.


## 1.7 Determining the Sampling Location

The permit writer must deter mine permanent sampling locations, and identify them in the monitoring requirements. The permit applicant should provide a description of the effluent outfall location and in most cases, a line drawing and description of the flows and processes involved i n
wastewater treatment.

The point at which a sample is collected can make a large difference in the monitoring results. Important factors to consider in selecting the sampling station are:



### • The flow at the sampling station should be measurable.



### • The sampl ing station should be easily and safely accessible.



### • The sample must be truly representative of the effluent during the time period which is monitored. The wastewater should be well mixed, such as near a Parshall flume or at a location in a sewer with hydr aulic turbulence. Weirs tend to enhance the settling of solids immediately upstream and the accumulation of floating oil or grease immediately downstream. Such locations should be avoided for sampling.

It is often convenient to combine a flow measurement station with a sampling station. When flumes are used for flow measurement, the sample is usually well mixed.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 22 Effluent samples should be collected at the most representative site downstream from all entering waste streams. Sampling of POTWs for convent ional pollutants and nutrients (except for BOD) should be collected downstream of any chlorination or disinfection units.

Separate samples should be taken if two outfalls are used and the effluent which enters the outfalls comes from different parts of th e plant.

If there is no practical way to sample the effluent, the permit must require that the permittee establish an appropriate effluent monitoring station for determining flow rates and compliance
with effluent limits.

The location of sample sites for receiving environment and benthos testing vary with each discharger and the dimensions of any mixing or sediment impact zone. More detail can be found
in Section 6.


## 1.8 Quality Assurance/Quality Control

The data gathered in self monitoring programs provi des information to decision makers on the quantity and quality of the effluent, the adequacy of operation and maintenance procedures, and the potential for discharges to affect receiving waters. Given the importance of monitoring data in assessing complia nce and in assessing whether receiving waters may be affected, it is important that the processes involved in generating monitoring data be standardized, comparable among dischargers, and free from practices that would generate inaccurate or faulty data. A quality assurance or quality control program can help to ensure that data meet the above requirements.

"Quality assurance (QA) has been described as a system of activities that assures the producer or user of a product or a service that defined standard s of quality with a stated level of confidence are met. Quality control (QC) differs in that it is an overall system of activities that controls the quality of a product or service so that it meets the needs of users. In other words, QC consists of the i nternal (technical), day to day activities, such as use of QC check samples, spikes, etc., to control and assess the quality of the measurements, while QA is the management system that ensures an effective QC system is in place and working as intended." (K eith, 1991)

The objective of quality assurance for a self

- monitoring program is to ensure the production and reporting of valid results. Valid and useful results are those that answer a question or provide a basis on which a decision can be made (Keith, 1991). Within Ecology's regulation of self

monitoring data, the QA of a discharger's self

- monitoring program is examined by different groups within Ecology. The EA Program's laboratory accreditation group oversees the QA/QC program for laboratories. Per mitted dischargers are required to have their samples analyzed by labs accredited by the state. As part of the laboratory accreditation process, labs must develop an approved QA/QC plan that addresses laboratory operations. In addition, with few exceptio ns,CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 23 dischargers will use specified and standardized methods (40 CFR 136) to measure compliance with permit limitations. These methods are specified in discharge permits by reference to use of Part 136 methods.

In most cases, dischargers are not required to submit formal QA plans addressing sampling technique because sampling technique is generally uncomplicated, and can be easily checked by inspectors during Ecology inspections. Poor sampling technique is likely to result in sample contamination, which i s generally to the disadvantage of dischargers. However, because some dischargers with low dilution now have water quality based effluent limits that are in the low parts per billion range, it is important to ensure that sample collection techniques do no t introduce contamination, and that data can be verified (e.g., by use of appropriate blank samples).

Contamination can be introduced by improper cleaning of sampling vessels, during sampling, or during handling and analysis of the sample in the lab. T he laboratory that is preparing sampling bottles and analyzing samples will generally depend on the person who does samples to minimize contamination in the field. If you suspect that sample contamination is occurring at any point in the process of sampli ng and analysis, you should first discuss your concerns with the discharger. In most cases, since sample contamination is not to the benefit of the discharger, they will try to determine on their own if a problem exists (e.g. , a small corroded area on a c omposite sampler at one municipal discharge was adding from 10

- 20 ppb of excess nickel to effluent samples, but was found after several weeks of examining all possible sources of contamination). If this is not effective, you may need to require a formal E cology inspection with split samples analyzed by the state, or even a formal requirement for a full QA/QC sampling plan. When assessing potential sample contamination, it is also a good idea to discuss the contaminants with the staff at the Manchester Env ironmental Laboratory to attempt to rule out common laboratory contaminants as being present in the discharge.

Flow data is not compromised by sample contamination, but data verification is important to consider when collecting flow measurements during inspections. In some cases flow measurements cannot be safely verified because of the position of the flow measurement device. In other cases the flow measurement device may not be properly constructed, so there is doubt about the measurements produced b y the device (e.g., a weir may not be level, thus the original engineering calculations used to gauge flow on the weir may not be appropriate for use with the structure as built). Data verification for flow devices should be approached carefully, because in many cases the cost of verification can be great. In some cases documentation showing proper calibration can be presented as a flow verification (inexpensive option), but in other cases complex models may be the only way to provide verification. If th ere is reason to believe that flow data is suspect, the permit manager should evaluate whether flow data is a highly critical parameter to verify for the discharger at the time. If the discharge is nearing capacity, approaching a water quality based

conce ntration limit, or mass loading limits (total mass per day or year) have been imposed on the discharge, measurement of flow may be critical. In those cases, flow verification, even if costly, should be strongly considered, and may be required. The permit writer should use his/her best professional judgment when making the determination of whether a flow verification is needed.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 24 If there is a need for the discharger to submit a QA/QC plan for all or a portion of a self

monitoring program (e.g., if contam ination is suspected), the following elements should be included in the plan:

1. Project Description

- Outlines the scope of the monitoring project.

2. Responsibilities

- Identifies the responsibilities of personnel in implementing the QA plan.

3. Quality Assura nce Objectives

- Identifies the monitoring objectives including quantitative objectives for generating and measuring data in terms of accuracy, precision, completeness, representativeness, and compatibility.

4. Sampling Procedures

- Describes the following f or each measurable variable:



## • Guideline used to select sample site.



## • Specific sampling procedures (including chain of custody requirements).



## • Information for special containers, conditions for preparation of sampling equipment
and containers.



## • Sampling pres ervation methods and holding times.

5. Calibration Procedures, References, and Frequencies

- Identifies the procedures for properly maintaining the accuracy and precision of field and laboratory equipment, and for properly obtaining, using, and storing analy tical standards.

6. Analytical Procedures

- Identifies standard procedures for sample analysis by reference, and describes specialized procedures in detail.

7. Data Reduction, Validation, and Reporting

- Provides the data reduction scheme for measurement data, including equations used for calculations, criteria used to validate data integrity, and methods used to identify and treat abnormal data or statistical outliers.

8. Internal Quality Control Checks and Frequency

- Identifies all procedures used to assess

qu ality during sample collection and analysis, including the uses and frequency of replicates, spikes, blanks, surrogate samples or reference materials, control charts, and calibration
materials.

9. Quality Assurance Audits

- Describes procedures used to deter mine the effectiveness of the QA program and its implementation.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 25 10. Preventative Maintenance Procedures and Schedules

- Details procedures for maintaining equipment in a ready state, including lists of critical spare parts.

11. Procedures and Deliverables for D ata Validation

- Provides a compilation of routine data analysis techniques used to assess data precision and accuracy, representativeness, comparability, and completeness of the measured parameters.

12. Corrective Action

- Identifies predetermined limits for data acceptability beyond which corrective action is necessary

, the specific corrective action to be taken for out

- of

- control data (including action in response to system and performance audits), and the individual responsible for each corrective action.

Additionally, the QA Section of the EA Program has prepared an Ecology publication "Guidelines and Specifications for Preparing Quality Assurance project Plans", which specifically addresses issues faced by Ecology when sampling in Washington State. Perm it writers should consult these guidelines as well as consider the items listed above.

Federal regulations require laboratories used by major NPDES dischargers to analyze proficiency testing (PT) samples (i.e., they must participate in the DMR

- QA program) using the analytical methods in 40 CFR Part 136. The EA Program’s Lab Accreditation Section can provide a list of accredited laboratories and the analyses they are accredited for to the permit writer. Alternatively, Scopes of Accreditation for accredite d labs can be accessed at http://www.ecy.wa.gov/apps/eap/acclabs/labquery.asp . Additional sampling information is given
in Handbook for Sampling and Sample Preservation of Water and Waste water , EPA
600/4

- 82

- 029). Flow measurement is discussed in Monitoring Industrial Wastewater (EPA, 1973). By specifying, in a permit, a particular method to use for self

- monitoring, any QA/QC procedures included in that method become permit requirements. Whenever QA/QC standards are not met, the analyses should be repeated until the specified level of performance is met. The reasons for inadequate QA/QC should be explained by the permittee when retesting is not possible. The EA Program or Headquarters s taff should be contacted to help review this
information.


## 1.9 Data Management

The format of data submitted to Ecology can directly influence how that data is interpreted, therefore it is critical that data be given to Ecology in a format most suitable for the data's intended use. The information obtained by the permittee's self

- monitoring program is submitted to the permitting agency using a Discharge Monitoring Report (DMR) with a standardized format. The DMR is submitted to Ecology on a regular schedule stated in the permit. Special reports may be required in a permit, in which case the permit writer must designate the frequency and format of the report. In all cases, the data must be presented in an organized and clear manner, and ifCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 26 necessary, suppor ting data may be required (e.g., duplicate measures, spike recoveries, etc.). These reporting requirements should be specified in the special conditions section of the permit, enforcement order, or application requirements notification.

Reporting require ments for WET are given in the canary book (Ecology Publication No. WQ

- R

95

- 80, Laboratory Guidance and Whole Effluent Toxicity Test Review Criteria ). This manual which provides instructions to labs and includes our detailed test review criteria, and is n ow referenced in the acute and chronic WET language in the permit shells. Dischargers should instruct labs to follow the instructions for both testing and reporting in the canary book and in the EPA toxicity test manuals referenced in the permit language. WET test reports are rejected for serious omissions or deviations from these instructions. The test review system has been in place for several years now and the labs are familiar with it and its consequences.

The other routine monitoring data require d in the permit will be entered into a computerized database located at each Region's office. This database is called the Water Permit Life Cycle System (WPLCS). The WPLCS will generate compliance reports determining whether or not dischargers are in com pliance. Even though the WPLCS will generate compliance reports, the permit manager may still find it useful to inspect the DMRs because of the information they contain, including data on effluent variability and trends in changing effluent quality. All special reports should be reviewed by the permit writer or appropriate staff at Headquarters or at the EA Program.

Other considerations concerning data interpretation (e.g., quantitation levels) are discussed in Chapter VI

- 4 Effluent Limits Below Quantita tion.



## 2. POTW MONITORING

Regulatory agencies are more involved in the day

- to

- day operation of POTWs than with industrial plants. Some examples of this are the regulatory requirements for operation and maintenance (O&M) plans and O&M inspections, operator certification requirements, and historical process control monitoring requirements. This involvement is largely due to the history of public funding for construction of POTWs and the protection of that investment.

POTWs are a single, large category of di scharger for which monitoring guidance has evolved over time. The tests, sample points, frequencies, and sample types listed in the accompanying tables represent the level of monitoring which seeks to balance the minimum cost to the discharger while

assur ing the permit manager that the POTW is being operated correctly and is meeting the conditions of its permit.

This section builds on the previous General Considerations section to provide the permit writer more specific guidance for writing a permit for a POTW. Land application monitoring
information is covered in Implementation Guidance for the Ground Water Quality StandardsCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 27 (Ecology 96

- 02). The following information is included in this section:



### • Influent and Effluent Monitoring for:

- Compliance with l imits, treatment efficiency,

- Sludge,

- Pretreatment requirements, and

- Whole Effluent Toxicity Testing



### • Process Control

- Use in response to significant noncompliance with limits

- If required, implement in a permit, with an Order or as a requirement f or O&M Manual update



### • Sludge Monitoring

- Satisfy new Part 503 Regulation requirements

- Satisfy pretreatment requirements



### • Combined Sewer Overflows

- Provides guidance on CSOs monitoring

- Defines CSO event



### • Monitoring Bypasses

- Provides guidance on sampli ng bypassed flows


## 2.1 Influent and Effluent Monitoring of POTWs

2.1.1 General

Tables XIII

- 2 (A

- E) contain the recommended minimum influent, effluent, and sludge monitoring frequencies for various types of POTWs. These tables are organized according to trea tment method and design flow. For clarity, each table is divided into several types of monitoring such as compliance, sludge, WET testing, and pretreatment.

For conventional pollutants, the minimum recommended frequency for compliance monitoring in
Tab les XIII

- 2 (A

- E) is 1/week. This minimum frequency is suggested for two reasons:

1. It is a reasonable minimum frequency for monitoring compliance with effluent limits.

2. It fulfills the implicit weekly reporting requirement associated with the seven

- day a verage discharge standards described in Chapter 173

- 221 WAC and 40 CFR 133.102. ""Seven

- day average" means the arithmetic mean of pollutant parameter values for samples collected in a period of seven consecutive days."CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 28 Since the tables represent the mini mum recommended frequencies rather than the median recommended frequencies, it is more likely that more monitoring will be required than less. If significantly more or less than the recommended monitoring is required for a particular facility,
this should be discussed in the fact sheet. Reasons for more monitoring may include:



### • Frequent upset.



### • Poor O&M performance.



### • Discharge to a sensitive environment.



### • A coefficient of variation is greater than 0.6 (EPA , 1991 ).



### • Periods of significant non

- compliance.

Reas ons for less monitoring may include:



### • POTW operating significantly below effluent limits



### • Non

- continuous discharge (seasonal)



### • Long detention time ( e.g., lagoons)



### • Good O&M performance



### • Good history of compliance with limits (inspection reports, DMRs)

POTWs ar e required to sample both the influent and effluent streams for BOD 5 and Total Suspended Solids in order to determine the removal efficiencies. Secondary treatment is generally defined as 85% removal of TSS and BOD 5 with a maximum limit of 30 μ g/l each although exceptions do exist for waste stabilization ponds and trickling filters as discussed in Chapter V, Municipal Effluent Limitations and Other Requirements.

Flow may be measured as either inflow or outflow. The sampling point chosen shoul d be specified in the permit. However, for some lagoon systems, due to rainfall or evaporation, both influent and effluent flow measurement may be required. Also for lagoons, effluent flow measurements are preferred for determining compliance with efflue nt limits.

The permit writer should attempt to identify the period of peak discharge into the POTW from the commercial and industrial users expected to be discharging any pollutants of concern and then specify monitoring frequencies and sample types that will include the period of peak industrial discharge. Monitoring during times of peak commercial and industrial discharge will increase the likelihood of detecting the presence of any toxic pollutants which are or maybe of

concern.

The choice of sampling techniques for chemical

- specific analyses is dependent on the type of compounds to be measured (e.g., grab sampling for volatile organic compounds, pH, cyanide, oil and grease, dissolved oxygen and phenols). More guidance is provided in the Laboratory Us ers Manual , Ecology, 1991b, the Handbook for Sampling and Sample Preservation of Water andCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 29 Wastewater , EPA

- 600/4

- 82

- 029, EPA, 1982b, the Water Quality Program Inspection Manual

, Ecology, 1992, Standard Methods for Examination of Water and Wastewaters , 17th Edition, pp.
1

- 37 and 1

- 38, and Chapter XIII

- 1.5 & 1.6 of this manual.



### 2.1.2 Influent Monitoring
The influent must be sampled (BOD 5 ,TSS) and measured (flow) ahead of the point of entry of recycle flows such as digester supernatant, filter backwash, sludge thickener subnatant o r supernatant, and any other in

- plant recycle flows. Also, influent samples should generally be collected just downstream of the coarse screens or grit chamber but may include sampling points
such as:

• The upflow siphon following a c omminutor (in absence of grit chamber).

• The upflow distribution box following pumping from main plant wet well.

• Aerated grit chamber.

• Flume throat (assuming no impact on flow measurement).

• Pump wet well.

BOD 5 and TSS monitoring frequency in the influent s hould usually correspond with effluent monitoring frequency to determine compliance with percent removal requirements. However, influent monitoring may sometimes be at a higher frequency than effluent monitoring such as when influent flows into a lagoon c annot match the evaporative loss.

For parameters other than BOD 5 and TSS, any influent monitoring frequency should consider the variabilities in wastewater flow and characteristics, the quantity and quality of industrial input to the facility, and if the influent monitoring is being required for local pretreatment limits development or updating.

If multiple waste streams enter the plant and a representative sample cannot be collected, a flow

proportional composite sample of the various inflows may be used for influent analysis.



### 2.1.3 Effluent Monitoring
Effluent samples for POTWs should be collected downstream of any chlorination/dechlorination units or other disinfection units, with the exception of BOD and perhaps WET testing.

Post

- chlorination BOD 5 sam ples should be dechlorinated and reseeded as described in Standard Methods for the Examination of Water and Wastewater , 18 th , 19 th , or 20 th Edition . The sample for
the BOD 5 test, usually a refrigerated composite, may be drawn prior to chlorination to avoi d the inhibiting effect of chlorine on biological oxidation. This would require two effluent composite samplers (pre

- and post

- chlorination) which may represent a significant expense for some smaller
POTWs.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 30 WET testing samples should be taken following the protocols in Section 4 of this Chapter.

Separate samples should be taken if multiple effluent outfalls representing different treatment modes are present. For example, a parallel system with several treatment processes with different
treatment effici ency requirements such as a trickling filter or lagoons and aeration basin, RBC, etc. Multiple discharges from equivalent treatment processes need not be analyzed separately provided there is a common effluent outfall that represents the combined total ef fluent discharge.

A lagoon with a long retention time may require lagged collection of effluent samples relative to influent samples for the purpose of determining compliance with the percent removal requirement, particularly if a review of historical dat a indicates a wide seasonal or periodic variation in influent concentrations ( e.g., seasonal industrial input). A dye study should be used to decide whether it makes sense to require a lag time or not.

Samples should be collected during "typical" dischar ge periods. An evaluation of the condition of the facility's treatment system can be made by comparing the effluent sample concentrations of BOD, TSS, and other pollutants to long

- term historical averages and/or permitted values for these parameters.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 31 

### Table XIII

- 2 A. RECOMMENDED MINIMUM MONITORING FOR POTWs
DISCHARGING TO SURFACE WATERS

For: 1. All Treatment Plants < 0.1 MGD Average Design Flow

Monitoring Type (Plant category) Test Sample Pt. Frequency Sample Type

Compliance

(1) Flow, mgd Infl. or F in. Eff. Continuous Measurement

" pH Final effluent 5/week Grab

" BOD 5 Infl.; Fin. Eff. a 1/week;
1/week 24

- hr. Composite

" TSS Infl.; Fin. Eff. 1/week;
1/week 24

- hr. Composite

" Tot. Res. Cl 2 Chlorinated Eff. f

, Fin. Eff. g 5/week Grab

" Fecal
Coliform Fin. Eff. 1/week c Grab

Sludge See Chapter
XIII

- 2.3, See Chapter XIII

2.3, Table XIII

- 3 See Chapter
XIII

- 2.3,

WET Test. See Chap.
XIII

- 4 Final Eff.

(See also reapplication requirements for NH3, TKN, NO2+NO3, O+G, Total P, and TDS in
Cha pter III, Section 3)CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 32 

### Table XIII

- 2 B. RECOMMENDED MINIMUM MONITORING FOR
POTWs DISCHARGING TO SURFACE WATERS

--

For: 1. Trickling Filter Plants < 0.5 MGD Average Design Flow 

### 2. RBC Plants < 0.5 MGD Average Design Flow 3. Sewage Lagoons < 0.5 MGD Average Design Flow

Monitoring Type

(Plant category) Test Sample Pt. Frequency Sample Type

Compliance (1,2,3) Flow, mgd Infl. or Fin. Eff. Continuous Measurement

" pH Final effluent Daily Grab

" BOD 5 Infl.; Fin. Eff. a 1/week;
1/week 24

- hr. Composit e

" TSS Infl.; Fin. Eff. 1/week;
1/week 24

- hr. Composite

" Tot. Res. Cl 2 Chlorinated Eff. f

, Fin. Eff. g Daily Grab

" Fecal
Coliform Fin. Eff. 1/week c Grab

Sludge

(1,2,3) See Chapter
XIII

- 2.3, See Chapter XIII

2.3, Table XIII

- 3 See Chapter
XIII

- 2. 3,

Sludge

(3) Sludge Depth Each Cell,

numerous locations 2/year Measurement

WET Test. See Chap.
XIII

- 4 Final Eff.

(See also reapplication requirements for NH3, TKN, NO2+NO3, O+G, Total P, and TDS in Chapter III, Section 3)CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 33 

### Table XIII

- 2 C. RECO MMENDED MINIMUM MONITORING FOR
POTWs DISCHARGING TO SURFACE WATERS

-- For: 1. Trickling Filter Plants 0.5

- 2.0 MGD Average Design Flow 2. RBC Plants 0.5

- 2.0 MGD Average Design Flow 3. Sewage Lagoons > 0.5 MGD Average Design Flow 4. Activated Sludge Plant < 2.0 MGD Average Design Flow 5. Oxidation Ditches

Monitoring Type
(Plant category) Test Sample Pt. Frequency Sample Type

Compliance (1,2,3,4,5) Flow, mgd Infl. or Fin. Eff. b Continuous Measurement

" pH Final effluent Daily Grab

" BOD 5 Infl.; Fin. Eff. a 2/week; 2/week 24

- hr. Composite

" TSS Infl.; Fin. Eff. 2/week; 2/week 24

- hr. Composite

" Tot. Res. Cl 2 Chlorinated Eff. f , Fin. Eff. g Daily Grab

" Fecal Coliform Fin. Eff. 2/week c Grab

Sludge (1,2,3,4,5) See Chapter XIII

2.3 See Chapte r XIII

- 2.3, See Chapter XIII

- 2.3,

Sludge (3) Sludge Depth Each Cell, numerous locations 2/year Measurement

WET Test.

(1,2,3,4,5) See Chapter XIII

- 4 Final Eff.

(See also reapplication requirements for NH3, TKN, NO2+NO3, O+G, Total P, and TDS in Ch III, Section 6)

Pretreatment (1,2,3,4,5) (see 2.1.4) Oil and grease, pH, priority pollutant metals, and cyanide

Priority pollutant Influent

Final effluent

Sludge Quarterly d

Quarterly d

1 taken within 30 days after influent sample 24 hour composite e except grab for O&G

24 hour composite e

Grab

24 hour composite eCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 34 Monitoring Type
(Plant category) Test Sample Pt. Frequency Sample Type

organics and other toxic pollutants likely to be present Influent

Final effluent

Sludge Annually d

Annually d

1 taken within 30 days after influent sample 24 hour composite e

GrabCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 35 

### Table XIII

- 2 D. RECOMMENDED MINIMUM MONITORING FOR
POTWs DISCHARGING TO SURFACE WATERS

--

For: 1. Trickling Filter Plants > 2.0 MGD Average Design Flow 2. RBC Plants > 2.0 MGD Average Design Flow 3. Activated Sludge Plant 2.0

- 5.0 MGD Average Design Flow

Monitoring Type

(Plant category) Test Sample Pt. Frequency Sample Type

Compliance
(1,2,3) Flow, mgd Infl. or Fin. Eff. Continuous Measurement

" pH Final effluent Daily/
Continuous Grab/
Measurement

" BOD 5 Infl.; Fin. Eff. a 3/week;
3/week 24

- hr. Com posite

" TSS Infl.; Fin. Eff. 3/week;
3/week 24

- hr. Composite

" Tot. Res. Cl 2 Chlorinated
Eff. f , Fin. Eff. g Daily Grab

" Fecal Coliform Fin. Eff. 3/week c Grab

Sludge
(1,2,3) See Chapter
XIII

- 2.3, See Chapter
XIII

- 2.3, See Chapter
XIII

- 2.3,

WET Test.

(1,2,3) See Chapter
XIII

- 4 Final Eff.

(See also reapplication requirements for NH3, TKN, NO2+NO3, O+G, Total P, and TDS in
Ch III, Section 3)

Pretreatment

(1,2,3) (see 2.1.4) Oil and grease, pH, prior ity pollutant metals, and cyanide Influent

Final effluent Quarterly d

Quarterly d 24 hour composite e

, except grab for
O&GCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 36 Monitoring Type

(Plant category) Test Sample Pt. Frequency Sample Type

Pretreatment

(1,2,3) (see 2.1.4) Priority pollutant organics and
other toxic pollutants likely to be present Sludge

Influent

Final effluent

Sludge 1 taken
within 30 days after
influent sample

Annually d

Annually d

1 taken
within 30 days after
influent sample 24 hour composite e

Grab

24 hour composite e

24 hour composite e

GrabCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 37 

### Table XIII

- 2 E. RECOMMENDED MINIMUM MONITORI NG FOR
POTWs DISCHARGING TO SURFACE WATERS

FOR: 1. ACTIVATED SLUDGE PLANTS > 5.0 MGD AVERAGE DESIGN FLOW Monitoring Type
(Plant category) Test Sample Pt. Frequency Sample Type

Compliance
(1) Flow, mgd Infl. or Fin. Eff. Continuous Measurement

" pH Final effluent Continuous Measurement

" BOD 5 Infl.; Fin. Eff. a 5/week; 5/week 24

- hr. Composite

" TSS Infl.; Fin. Eff. 5/week; 5/week 24

- hr. Composite

" Tot. Res. Cl 2 Chlorinated Eff. f

, Fin. Eff. g Daily Grab

" Fecal Coliform Fin. Eff. Daily c Grab

Slud ge

(1) See Chapter XIII

2.3, See Chapter XIII

2.3, See Chapter
XIII

- 2.3,

WET Test.

(1) See Chapter XIII

4 Final Eff.

(See also reapplication requirements for NH3, TKN, NO2+NO3, O+G, Total P, and TDS in Ch III, Section 3)

Pretreatment

(1) (see 2.1.4) Oil and grease, pH, priority pollutant metals, and cyanide

Priority pollutant Influent

Final effluent

Sludge Q uarterly d

Quarterly d

1 taken within 24 hour composite e

, except grab
for O&G.
24 hour composite e

GrabCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 38 Monitoring Type
(Plant category) Test Sample Pt. Frequency Sample Type

Pretreatment

(1) (see 2.1.4) organics and
other toxic pollutants likely to be present
Influent

Final effluent

Sludge 30 days after influent sample

Annually d

Annually d

1 taken within 30 days after influent sample 24 hour composite e

24 hour composite e

Gr ab

NOTES:

a

. Samples for BOD 5 analysis may be taken before or after the disinfection process. If taken after, the sample must be dechlorinated and reseeded.

b

. Influent flow must be provided if the permittee requests relief from 85% removal requirement as allowed in WAC 173

- 221

- 050. Influent flow monitoring is recommended for all lagoons to track influent loading.

c

. Sampled concurrently with Total Residual Chlorine (before dechlorination, if applicable).

d

. The days selected for sampling shall be ro tated annually or quarterly (e.g., first quarter sample Monday, second quarter sample Tuesday, etc.). If the facility has undergone screening and prioritization for human health criteria the testing must be done during a wet season and a dry season.

e

. C yanide, Volatile Organics and Phenols must be taken as a minimum of 4 grab samples and separately analyzed in place of each 24 hour composite.

f

. Sampled before dechlorination, if applicable.

g

. Sampled after dechlorination, if applicable.

DEFINITIONS:

"Continuous" means readings are being taken and recorded at all times.

"Daily" in these tables is equivalent to 7 days/week.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 39 "Final Effluent" means wastewater which is exiting, or has exited, the last treatment process or operation. Typically, this is after or at the exit from the chlorine contact chamber or other disinfection process.

"Grab" means an individual sample collected in less than fifteen minutes.

"Influent" means the raw sewage flow excluding any sidestreams returned to the headworks of th e plant.

"24

- hour composite" means a series of individual samples collected over a 24 hour period into a single container, and analyzed as one sample.



### 2.1.4 Pretreatment

2.1.4. 1 Monitoring for local limit development The federal pretreatment regulation 403.8(f)(4) requires pretreatment POTWs to develop local pollutant discharge limitations for any pollutants which cause Pass Through or Interference, or demonstrate they are not necessary. This requirement to develop local limits becomes Ecology's
in the non

- delegated pretreatment POTWs.

All pretreatment POTWs, both delegated and non

- delegated, are required to have influent, effluent, and sludge sampled for toxic pollutants in order to characterize the industrial input and to determine if pollutants are o r have the potential to interfere with the treatment process or pass through the plant to sludge or the receiving water. The monitoring data are used by Ecology or the municipality to develop technically defensible local limits which commercial and indust rial users

must meet.

A delegated POTW must conduct monitoring to support the development of local limits as a
condition of its POTW Pretreatment Program. For non

- delegated pretreatment POTWs, the permit writer may choose to have the POTW conduct the mon itoring for Ecology so that local limits can be developed by Ecology for the non

- delegated POTWs. Measurement of pH, Oil and Grease, priority pollutants (metals and organics), and any other pollutants likely to be present from
commercial or industrial use rs are used as indicators to determine the need for local limits.

The list of priority pollutants to be monitored for is contained in 40 CFR part 122, Appendix D, Table II (organics) and Table III (metals and cyanide). Other toxic pollutants that should be monitored for if likely to be present are listed in 40 CFR part 122, Appendix D, Table V.

In addition to quantifying pH, oil and grease, and all priority pollutants, a reasonable attempt should be made to identify all other substances and quantify all organic pollutants shown to be present by gas chromatograph/mass spectrometer (GC/MS) analysis per 40 CFR 136, Appendix. A, Methods 624 and 625. Determinations of pollutants should be attempted for each fraction which produces identifiable spectra on tota l ion plots (reconstructed gas chromatograms). Determinations should be attempted from all peaks with responses 5% or greater than the nearestCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 40 internal standard. The 5% value is based on internal standard concentrations of 30 μ g/l, and must be adjusted d ownward if higher internal standard concentrations are used or adjusted upward if
lower internal standard concentrations are used. Non

- substituted aliphatic compounds may be expressed as total hydrocarbon content. Identification shall be attempted by a l aboratory whose computer data processing programs are capable of comparing sample mass spectra to a computerized library of mass spectra containing at least sixty

- thousand (60,000) compounds, with visual confirmation by an experienced analyst. (Note: The current National Institute of Standards and Technology GC/MS computerized library of mass spectra, covers 62,000 compounds. The phone number of the NIST Office of Standards Data is 301

- 975

- 2208). For all detected substances which are determined to be pol lutants, additional sampling and appropriate testing shall be conducted to determine concentration and variability, and to evaluate trends (refer to "Determining Reasonable Potential", Chapter VI).

Local limits development requires one year of data collec tion. To develop local limits, the permit writer should require that each pretreatment POTW establish a data base from sampling and analysis over one year. Sampling will include both wet and dry weather flows. The sample locations, types, and frequencie s are specified in the matrix below and apply to all pollutants as discussed in this section on monitoring for local limit development.

Matrix of monitoring requirements for local limits development

Location Sample Type Frequency b

Raw Influent 24 hour composite a Once quarterly

Primary Clarifier

Effluent 24 hour composite a Once quarterly concurrently
with influent

Final Effluent 24 hour composite a Once quarterly concurrently
with influent

Sludge Grab Taken within 30 days following influ ent sampling

*a. Cyanide, Volatile Organics, and Phenols must be taken as a minimum of 4 grab samples and separately analyzed in place of each 24 hour composite.
*b. The days selected for sampling shall be on days when industrial flow to the POTW is expe cted to be at a maximum and rotated quarterly (e.g., first quarter sample Monday, second quarter sample Tuesday, etc.).

At a minimum, Ecology should require all pretreatment POTWs to establish local limits for pH, oil and grease, the priority pollutant me tals, cyanide, and phenols.

A pretreatment POTW is required to analyze for priority pollutants and any other toxic pollutants likely to be present. After local limits have been established, it is recommended that the monitoring frequency for toxic pollut ants not be less than annually for toxic organics and not lessCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 41 than quarterly for toxic metals, unless reduced monitoring can be justified.

For additional information of identifying pollutants of concern, the permit writer is encouraged to
consult the EP A Guidance Manual of the Development and Implementation of Local Discharge Limitations Under the Pretreatment Program , (EPA, 1987a).

2.1.4. 2 Monitoring for updating of local limits The federal pretreatment regulation 403.5(c) requires pretreatment POTWs to continue to update local pollutant discharge limitations for any pollutants which cause Pass Through or Interference. This requirement to update local limits becomes Ecology's in the non

- delegated pretreatment POTWs.

The POTW should continue to survey i ts commercial and industrial users to find out what toxic metals and organics are reasonably expected to be present in its influent at detectable levels and then analyze its plant influent, effluent, and sludge for those pollutants. A reasonable attempt

s hould be made to identify all other substances and quantify all pollutants shown to be present by GC/MS analysis per 40 CFR 136, Appendix. A, Methods 624 and 625. Determinations of pollutants should be attempted for each fraction which produces identifiab le spectra on total ion plots (reconstructed gas chromatograms). Determinations should be attempted from all peaks with responses 5% or greater than the nearest internal standard. The 5% value is based on internal
standard concentrations of 30 μ g/l, and must be adjusted downward if higher internal standard concentrations are used or adjusted upward if lower internal standard concentrations are used.
Non

- substituted aliphatic compounds may be expressed as total hydrocarbon content.
Identificati on shall be attempted by a laboratory whose computer data processing programs are capable of comparing sample mass spectra to a computerized library of mass spectra containing at least sixty

- thousand (60,000) compounds with visual confirmation by an experi enced analyst. (Note: The current National Institute of Standards and Technology GC/MS computerized library of mass spectra, covers 62,000 compounds. The phone number of the NIST Office of Standards
Data is 301

- 975

- 2208). For all detected substances whic h are determined to be pollutants, additional sampling and appropriate testing shall be conducted to determine concentration and variability, and to evaluate trends (refer to "Determining Reasonable Potential", Chapter VI).

All pretreatment POTWs, both de legated and non

- delegated, are required to continue monitoring influent, effluent, and sludge for toxic pollutants in order to characterize the industrial input and to determine if pollutants are or have the potential to interfere with the treatment proces s or pass through the plant to sludge or the receiving water. The monitoring data is used by Ecology or the municipality to update the local limits for commercial and industrial users. The remainder of this section on pretreatment monitoring will focus o n the monitoring requirements for pretreatment
POTWs with established local limits.

A delegated POTW must conduct monitoring to support the update of its local limits as a condition of its POTW Pretreatment Program. For non

- delegated pretreatment POTWs, the permit writer may choose to have the POTW conduct the monitoring for Ecology so the localCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 42 limits can be updated. This section, including Tables XIII

- 1C, D, and E, establishes the monitoring that should be conducted for updating of local limits. Measu rement of pH, Oil and Grease, priority pollutants (metals and organics), or any other pollutants of concern that are likely to be present from commercial or industrial users are used as indicators to determine compliance with local limits or the need for a dditional local limits.

The list of priority pollutants to be monitored for is contained in 40 CFR part 122, Appendix D, Table II (organics) and Table III (metals and cyanide). Other toxic pollutants which should be monitored for if likely to be present are listed in 40 CFR part 122, Appendix D, Table V. A pretreatment POTW is required to analyze for priority pollutants and any other toxic pollutants likely to be present. After local limits have been established, it is recommended that the monitoring fre quency for toxic pollutants not be less than annually for toxic organics and not less than quarterly for toxic metals, unless reduced monitoring can be justified.

For additional information of identifying pollutants of concern, the permit writer is encou raged to consult the EPA Guidance Manual of the Development and Implementation of Local Discharge Limitations Under the Pretreatment Program , (EPA, 1987a).


## 2.2 Process Control Monitoring

2.2.1 General
Process control monitoring provides a check on the effi ciency of the treatment process and it allows the operator to make adjustments to optimize the process efficiency. It was commonly required as a permit condition in the past, especially for those facilities having difficulty complying with their permit li mitations. Recently however, several factors have combined to limit the use of process control monitoring in permits:

1. Workload considerations emphasizing effluent limit compliance.

2. A general reluctance to initiate enforcement for noncompliance with per mit process control parameters.

3. An internal policy memorandum suggesting process control monitoring be left out of permits (Stan Springer, July, 1990).

4. Language in Puget Sound Water Quality Plan Element P

- 8 suggesting that permit managers "leave most of the in

- plant process control monitoring to the discretion of the discharger except in cases of significant non

- compliance, as necessary to meet permit effluent limits."

Process control monitoring should not be required in permits. This type of monitoring is best implemented as part of an enforcement action for non

- compliance and may be placed in an order. Routine process control monitoring may also be implemented through the submission of an updated O&M Manual.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 43 

### 2.2.2 Tables XIII

- 3 (A

- M)
These tables pre sent suggested process control monitoring for POTWs applicable to O&M manual revision and administrative orders. Because process control monitoring is applicable to relatively few facilities and tends to be facility specific, it should be a matter of the professional judgment of the permit manager in consultation with the permittee. Frequencies should be established that allow for the minimum amount of resource investment for the discharger while assuring the best available treatment.

It may be advantag eous to require a short

- term intensive survey in order to determine appropriate sampling times and frequencies, and to establish possible correlations between parameters such
as TOC and BOD 5 , or BOD 5 and CBOD 5 . Daily sampling for one to two months during both the wet season and dry season is recommended for short

- term studies. In the long run, conducting a
short

- term study may save the POTW from sampling more frequently than necessary or sampling during non

- representative times. If a correlation is deter mined between TOC and
BOD 5 , the permit writer may allow the permittee to substitute TOC tests for BOD 5 for process control. This allows the operator to respond quickly with process adjustments. The COD can also be related empirically to BOD 5 or TOC but t he Manchester Laboratory has recommended the use of alternative equivalent methods (BOD 5 and TOC) to eliminate the generation of highly toxic hazardous waste. A method for determining a correlation between parameters may be found in chapter four of the Ha ndbook for Sampling and Sample Preservation of Water and
Wastewater , EPA , 1982b . The topic of indicators is presented in Chapter XIII

- 1.

POTWs with industrial pretreatment programs or significant industrial input require more
extensive in plant testing i f current or expected concentrations of pollutants in the influent are detrimental to the secondary process. (e.g., priority pollutant analysis of primary effluent, in addition to the influent, is warranted to determine whether interference will result).

When sampling waste streams within the POTW, sampling points that are most representative of the process area (e.g., the common channel for secondary clarifiers) should be chosen and unwanted waste streams should be avoided. For branching flows, samples s hould be taken ahead of the branching point or from each stream after the branching point.

Samples on the aeration basin influent in the activated sludge process must be taken ahead of the point of entry of the recycle sludge. Sampling points should be l ocated where the flow stream is
well mixed.

In addition to sampling at the established process control locations, other unit processes may be sampled periodically when the variability of a parameter adversely affects the efficiency of a unit process. The basis for additional monitoring should be explained in the fact sheet.

Samples should be collected from channels at mid

- channel and mid

- depth where the flow is turbulent, well

- mixed, and the settling of solids is minimal. Sampling should avoid skimming theCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 44 water surface, or dragging the channel bottom. The sampling of wastewater for immiscible liquids, such as oil and grease, requires special attention and no specific rule can be given for selection of the most representative site because of wide range of conditions encountered in the field.

Sampling locations may be specified in an order or O&M Manual using a schematic flow diagram of the treatment process that shows the direction of flow between the processes, and shows all recycle flows. All samplin g points should be identified on the schematic diagram. Include final sludge and/or other solids disposal where applicable. List all tests, sampling methods, frequencies, and sample types with the monitoring requirements.

The timing and frequency of sam pling should be based on the relative complexity of the influent and the processes, as opposed to the design capacity of the facility.

If additional information is needed for process control monitoring for individual processes, Table
5.2 in the Handbook for Sampling and Sample Preservation of Water and Wastewater , EPA, 1982b, includes minimum sampling recommendations for each treatment process.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 45 

### Table XIII

- 3 A. SUGGESTED PROCESS CONTROL MONITORING
FOR POTWs APPLICABLE TO O&M MANUAL REVISION AND
ADMINISTRAT IVE ORDERS

–

FOR: ACTIVATED SLUDGE PLANTS < 2 MGD AVERAGE DESIGN FLOW

Test Sample Pt. Frequency Sample Type

Flow, mgd
Instantaneous RAS 2/week Measurement

pH Primary Effluent
Aeration Basin Digester(s) (An/A) a Digester Feed Sludge (An/A) 5/week
5/week
5 /week Daily Grab

BOD 5 Primary Effluent 2/week Grab

TSS Primary Effluent Aeration Basin(MLSS)
RAS
WAS 2/week
2/week
2/week
1/event Grab

Dissolved O 2 Influent
Final Effluent Aeration Basin(s) Primary Effluent Digester (A) Daily Daily Daily
5/week Daily Gr ab

Temperature Influent Digester(s) (An/A) Daily Daily Measurement

Chlorine Usage (Effluent Disinfection) Daily Measurement

30 Minute
Settleometer Activated Sludge 2/week Grab

SVI, Loading Index Aeration Basin 2/week Grab

Mean Cell Res. Time Calcula tion 2/week

Volatile Acids Digester (An) 1/week Grab

Alkalinity Digester (An) 1/week Grab

Gas Analysis & Vol.:CO 2 Digester(s) (An) Daily Grab

% Total Solids Digester Feed Sludge Digester (An/A) Stabilized Sludge 1/week a
1/week a
1/week a GrabCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 46 Test Sample Pt. Frequency Sample Type

Volum e & lbs. to Waste WAS Primary Sludge Per Event
Per Event Measurement

Sludge Blanket Depth Secondary Clarifiers Daily Measurement

Additional Process Control Monitoring To Consider

Ammonia Influent Aerators (Mixed Liquor)
Final Effluent 1/week
1/week
2/ week Grab

Nitrate Aerators (Mixed Liquor) 1/week Grab

Settleable Solids Influent
Final Effluent 2/week
2/week Grab

Vol. Suspended Solids Aeration Basin 2/week Grab

Food/Mass Calculation 2/week

Centrifuge Spin Aeration Tank Conc. Return Sludge Conc.
W aste Sludge Conc. 3/week
3/week
3/week GrabCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 47 

### Table XIII

- 3 B. SUGGESTED PROCESS CONTROL MONITORING FOR
POTWs APPLICABLE TO O&M MANUAL REVISION
AND ADMINISTRATIVE ORDERS

FOR: ACTIVATED SLUDG PLANTS BETWEEN 2 AND 5 MGD AVERAGE DESIGN
FLOW

Test Sample Pt. Fre quency Sample Type

Flow, mgd
Instantaneous RAS Daily Measurement

pH Primary Effluent
Aeration Basin Digester(s) (An/A) Digester Feed Sludge (An/A) Daily Daily Daily Daily Grab

BOD 5 Primary Effluent 3/week Grab

TSS Primary Effluent
Aeration Basin(MLSS)
RAS
WAS 3/week
3/week
3/week
1/event Grab

Dissolved O 2 Influent
Final Effluent Aeration Basin(s) Primary Effluent Daily Daily Daily Daily Grab

Temperature Influent Digester(s) (An/A) Daily Daily Measurement

Chlorine Usage (Effluent Disinfection) Daily M easurement

30 Minute
Settleometer Activated Sludge 5/week Grab

SVI, Loading Index Aeration Basin 3/week Grab

Mean Cell Res. Time Calculation 5/week

Vol. Acids Digester (An) 2/week Grab

Alkalinity Digester (An) 2/week Grab

Gas Analysis & Vol.: CO 2 Digester(s) (An) Daily Grab

% Total Solids Digester Feed Sludge 3/week b GrabCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 48 Test Sample Pt. Fre quency Sample Type Digester(s) (An/A) Stabilized Sludge 3/week b

3/week b

Volume & lbs. to
Waste WAS Primary Sludge Per Event
Per Event Measurement

Sludge Blanket Depth Secondary Clarifiers Dail y Measurement

Additional Process Control Monitoring To Consider

Ammonia Influent Aerators (Mixed Liquor)
Final Effluent 2/week
2/week

Daily Grab

Nitrate Aerators (Mixed Liquor)
Clarifier Effluent 2/week

2/week Grab

Settleable Solids Influent
Final Effluent 5/week
5/week Grab

Vol. Suspended Solids Aeration Basin 2/week Grab

Food/Mass Calculation 3/week

Centrifuge Spin Aeration Tank Conc. Return Sludge Conc. Waste Sludge Conc. 5/week
5/week 5/week GrabCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 49 

### Table XIII

- 3 C. SUGGESTED PROCESS CONTROL MO NITORING FOR
POTWs APPLICABLE TO O&M MANUAL REVISION
AND ADMINISTRATIVE ORDERS

—

FOR: ACTIVATED SLUDGE PLANTS > 5 MGD AVERAGE DESIGN FLOW

Test Sample Pt. Frequency Sample Type

Flow, mgd
Instantaneous RAS Daily Measurement

pH Primary Effluent
Aeration Bas in Digester(s) (An/A) Digester Feed Sludge (An/A) Daily Daily Daily Daily Grab

BOD 5 Primary Effluent 5/week Grab

TSS Primary Effluent
Aeration Basin(MLSS)
RAS
WAS 5/week
5/week
5/week
1/event Composite
Grab
Grab
Grab

Dissolved O 2 Influent
Final Effluent Aeration Basin(s) Primary Effluent Daily Daily Daily Daily Grab

Temperature Influent Digester(s) (An/A) Daily Daily Measurement

Chlorine Usage (Effluent Disinfection) Daily Measurement

30 Minute
Settleometer Activated Sludge Daily Grab

SVI, Loading Index Aeration Basin 5/week Grab

Mean Cell Res. Time Calculation 5/week

Volatile Acids Digester(s) (An) 3/week Grab

Alkalinity Digester (An) 3/week Grab

Gas Analysis & Vol.: CO 2 Digester(s) (An) Daily Grab

% Total Solids Digester Feed Sludge Digeste r(s) (An/A) 5/week b

5/week b GrabCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 50 Test Sample Pt. Frequency Sample Type Stabilized Sludge 5/week b

Volume & lbs. to
Waste WAS Primary Sludge Per Event or Daily Measurement

Sludge Blanket Depth Secondary Clarifiers Daily Measurement

Additional Process Control Monitoring To Consider

Ammo nia Influent Aerators (Mixed Liquor)
Final Effluent 2/week
2/week

Daily Grab

Nitrate Aerators (Mixed Liquor)
Clarifier Effluent 2/week

2/week Grab

Settleable Solids Influent
Final Effluent Daily Daily Grab

Vol. Suspended Solids Aeration Basin 2/week G rab

Food/Mass Calculation 5/week

Centrifuge Spin Aeration Tank Conc. Return Sludge Conc. Waste Sludge Conc. Daily Daily Daily GrabCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 51 

### Table XIII

- 3 D. SUGGESTED PROCESS CONTROL MONITORING
FOR POTWs APPLICABLE TO O&M MANUAL
REVISION AND ADMINISTRATIVE ORDER S

--

For: Package Aeration Plants < 0.1 MGD Average Design Flow

Test Sample Pt. Frequency Sample Type

Flow, mgd
Instantaneous RAS 2/week Measurement

TSS Mixed Liquor
RAS
WAS 2/week
2/week
1/event Grab

Dissolved O 2 Influent
Final Effluent
Aeration Basin (s) Digester (A) 5/week
5/week
5/week
5/week Grab

Temperature Aeration Basin(s) 5/week Measurement

Chlorine Usage (Effluent Disinfection) 5/week Measurement

30 Minute
Settleometer Mixed Liquor 2/week Grab

SVI, Loading Index Aeration Basin 2/week Grab

Mean Cell Res. Time Calculation 2/week

% Total Solids Unstabilized Sludge Digester(s) (An/A) Stabilized Sludge 1/month b

1/month b

1/month b Grab

Volume & lbs. to
Waste WAS Primary Sludge Per Event
Per Event Measurement

Sludge Blanket Depth Secondary Clarifiers Daily MeasurementCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 52 Additional Process Control Monitoring To Consider

Ammonia Influent Aerators (Mixed Liquor)
Final Effluent 1/week
1/week 2/week Grab

Settleable Solids Final Effluent 2/week Grab

Food/Mass Calculation 2/week

Centrif uge Spin Aeration Tank Conc. Return Sludge Conc. Waste Sludge Conc. 2/week
2/week
2/week GrabCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 53 

### Table XIII

- 3 E. SUGGESTED PROCESS CONTROL MONITORING FOR
POTWs APPLICABLE TO O&M MANUAL REVISION
AND ADMINISTRATIVE ORDERS

For: Oxidation Ditches

Test Sample P t. Frequency Sample Type

Flow, mgd
Instantaneous RAS
WAS 2/week per event Measurement

pH Ditch Digester(s) (An/A) Daily
3/week Grab

TSS Aeration Basin (MLSS)
RAS
WAS 2/week
2/week per event Grab

Dissolved O 2 Influent
Final Effluent Aeration Basin(s)
Di gester (A) Daily Daily Daily
2/week Grab

Temperature Influent Daily Measurement

Chlorine Usage (Effluent Disinfection) Daily Measurement

30 Minute
Settleometer Activated Sludge 2/week Grab

SVI, Loading Index Aeration Basin 2/week Grab

Mean Cell Res. Time Calculation 2/week

% Total Solids Unstabilized Sludge Digester(s) (An/A) Stabilized Sludge 1/week b

1/week b

1/week b Grab

Volume & lbs. to
Waste WAS Primary Sludge Per Event
Per Event Measurement

Sludge Blanket Depth Secondary Clarifiers Daily M easurementCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 54 Additional Process Control Monitoring To Consider

Ammonia Influent Aerators (Mixed Liquor)
Final Effluent 1/week
1/week 2/week Grab

Nitrate Mixed Liquor
Clarifier Effluent 1/week
1/week Grab

Settleable Solids Final Effluent 2/week Grab

Food/Mass Calculation 2/week

Centrifuge Spin Aeration Tank Conc. Return Sludge Conc. Waste Sludge Conc. 3/week
3/week 3/week Grab

Alkalinity Influent
Clarifier Effluent 1/week
1/week GrabCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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### Table XIII

- 3 F. SUGGESTED PROCESS CONTROL MONITORING FOR
POTWs APPLICABLE TO O&M MANUAL REVISION
AND ADMINISTRATIVE ORDERS

— FOR: TRICKLING FILTER PLANTS ≤0.5 MGD AVERAGE DESIGN FLOW

Test Sample Pt. Frequency Sample Type

Flow, mgd
Instantaneous Trickling Filter Recycle Daily Measurement

pH Primary Effluent
Filter Eff luent Digester(s) (An/A) Digester Feed Sludge (An/A) 5/week
5/week
5/week
1/week Grab

TSS Aeration Basin (MLSS)
RAS
WAS 2/week
2/week per event Grab

Dissolved O 2 Influent
Final Effluent Primary Effluent
Filter Effluent Aerobic Digester (A) Daily Daily
2/ week
2/week Daily Grab

Temperature Influent Digesters (An/A) Daily Daily Measurement

Chlorine Usage (Effluent Disinfection) Daily Measurement

30 Minute
Settleometer Activated Sludge 2/week Grab

SVI, Loading Index Aeration Basin 2/week Grab

Mean Cell Res. Time Calculation 2/week

Volatile Acids Digester (An) 1/week Grab

Alkalinity Digester (An) 1/week Grab

Gas Analysis & Vol.: CO 2 Digester(s) (An) 5/week Grab

% Total Solids Digester Feed Sludge Digester(s) (An/A) Stabilized Sludge 1/week b

1/week b

1/week b Grab

Volume & lbs. to
Waste Waste Primary Sludge Filter Sludge Per Event
Per Event MeasurementCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 56 Test Sample Pt. Frequency Sample Type

Sludge Blanket Depth Secondary Clarifiers Daily Measurement

Recirculation Ratio Filter Effluent/
Filter Influent 1/week Measurement

Additional Process Control Monitoring To Consider

Ammonia Influent
Final Effluent 1/week
2/week Grab

Settleable Solids Trickling Filter Eff.
Final Effluent 2/week
2/week GrabCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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### Table XIII

- 3 G. SUGGESTED PROCESS CONTROL MONITORING
FOR POTWs APPLICABLE TO O&M MANUAL
REVISION AND ADMINISTRATIVE ORDERS

— FOR: TRICKLING FILTER PLANTS 0.5 TO 2.0 MGD AVERAGE DESIGN FLOW

Test Sample Pt. Frequency Sample Type

Flow, mgd
Instantaneous Trickling Filter Recycle Daily Measurement

pH Primary Effluent
Filter Effluent Digester(s) (An/A) Digester Feed Sludge (An/A) 5/week Daily
5/week Daily Grab

TSS Aeration Basin (MLSS)
RAS
WAS 2/week
2/week per event Grab

Dissolved O 2 Influent
Final Effluent Primary Effluent
Filter Effluent Digester (A) Daily Daily
2/week
2/week Daily Grab

Tem perature Influent Digesters (An/A) Daily Daily Measurement

Chlorine Usage (Effluent Disinfection) Daily Measurement

30 Minute
Settleometer Activated Sludge 2/week Grab

SVI, Loading Index Aeration Basin 2/week Grab

Mean Cell Res. Time Calculation 2/we ek

Volatile Acids Digester (An) 1/week Grab

Alkalinity Digester (An) 1/week Grab

Gas Analysis & Vol.: CO 2 Digester(s) (An) Daily Grab

% Total Solids Digester Feed Sludge Digester(s) (An/A) Stabilized Sludge 1/week b

1/week b

1/week b Grab

Volume & l bs. to
Waste Waste Primary Sludge Filter Sludge Per Event
Per Event MeasurementCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 58 Test Sample Pt. Frequency Sample Type

Sludge Blanket Depth Secondary Clarifiers Daily Measurement

Recirculation Ratio Filter Effluent/
Filter Influent Daily Measurement

Additional Process Control Monitoring T o Consider

Ammonia Influent
Final Effluent 1/week
2/week Grab

Nitrate Influent
Final Effluent 1/week
1/week Grab

Settleable Solids Trickling Filter Eff.
Final Effluent 2/week
2/week GrabCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 59 

### Table XIII

- 3 H. SUGGESTED PROCESS CONTROL MONITORING
FOR POTWs A PPLICABLE TO O&M MANUAL
REVISION AND ADMINISTRATIVE ORDERS

For: Trickling Filter Plants > 2.0 MGD Average Design Flow

Test Sample Pt. Frequency Sample Type

Flow, mgd
Instantaneous Trickling Filter Recycle Daily Measurement

pH Primary Effluent
Filter Eff luent Digester(s) (An/A) Digester Feed Sludge Daily Daily Daily Daily Grab

BOD 5 Primary Effluent 3/week Grab

TSS Primary Effluent 3/week Grab

Dissolved O 2 Influent
Final Effluent Primary Effluent
Filter Effluent Daily Daily Daily Daily Grab

Temperature Influent Digesters (An/A) Daily Daily Measurement

Chlorine Usage (Effluent Disinfection) Daily Measurement

Volatile Acids Digester (An) 2/week Grab

Alkalinity Digester (An) 2/week Grab

Gas Analysis & Vol.: CO 2 Digester(s) (An) Daily Grab

% Total Sol ids Digester Feed Sludge Digester(s) (An/A) Stabilized Sludge 3/week b

3/week b

3/week b Grab

Volume & lbs. to Waste Waste Primary Sludge Filter Sludge Per Event
Per Event Measurement

Sludge Blanket Depth Secondary Clarifiers Daily MeasurementCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 60 Addi tional Process Control Monitoring To Consider

Ammonia Influent
Final Effluent 2/week Daily Grab

Nitrate Influent
Final Effluent 2/week
2/week Grab

Settleable Solids Trickling Filter Eff.
Final Effluent 3/week Daily Grab

Total Solids Supernatant 3/week GrabCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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### Table XIII

- 3 I. SUGGESTED PROCESS CONTROL MONITORING FOR
POTWs APPLICABLE TO O&M MANUAL REVISION
AND ADMINISTRATIVE ORDERS

For: Sewage Lagoons < 0.5 MGD Average Design Flow

Test Sample Pt. Frequency Sample Type

pH Each Cell 1/week Grab

Dissolved O 2 Influent
Final Effluent
Each Cell 2/week
2/week
1/week Grab

Temperature Influent
Each Cell 2/week
1/week Measurement

Chlorine Usage (Effluent Disinfection) Daily Measurement

Lagoon Depth Each Cell 1/week Measurement

Additional Process Control Moni toring To Consider

Ammonia Influent
Final Effluent 1/week
2/week Grab

Settleable Solids Final Effluent 1/week Grab

Dissolved O 2 Lagoon Profile 1/month

Precipitation/Evaporation On

- site DailyCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 62 

### Table XIII

- 3 J. SUGGESTED PROCESS CONTROL MONITORING FOR
POTWs APPLICABLE TO O&M MANUAL REVISION
AND ADMINISTRATIVE ORDERS

--

For: Sewage Lagoons > 0.5 MGD Average Design Flow

Test Sample Pt. Frequency Sample Type

pH Each Cell Daily Grab

Dissolved O 2 Influent
Final Effluent
Each Cell Lagoon Profile 2/week
2/we ek
1/week 1/month Grab

Temperature Influent
Each Cell 2/week
1/week Measurement

Chlorine Usage (Effluent Disinfection) Daily Measurement

Lagoon Depth Each Cell 1/week Measurement

Additional Process Control Monitoring To Consider

Ammonia Influent
Fi nal Effluent 1/week
2/week Grab

Nitrate Influent
Final Effluent 1/week
1/week Grab

Settleable Solids Final Effluent 2/week Grab

Precipitation/Evaporation On

- site DailyCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 63 

### Table XIII

- 3 K. SUGGESTED PROCESS CONTROL MONITORING
FOR POTWs APPLICABLE TO O&M MA NUAL
REVISION AND ADMINISTRATIVE ORDERS

--

For: RBC Plants < 0.5 MGD Average Design Flow

Test Sample Pt. Frequency Sample Type

pH Primary Effluent
RBC Tank Digester(s) (An/A) Digester Feed Sludge 5/week
5/week
5/week 1/week Grab

Dissolved O 2 Influent
Fin al Effluent Primary Effluent
RBC Tank Effluent Daily Daily
2/week
2/week Grab

Temperature Influent Digester(s) (An/A) Daily Daily Measurement

Chlorine Usage (Effluent Disinfection) Daily Measurement

Volatile Acids Digester (An) 1/week Grab

Alkalinity Digester (An) 1/week Grab

Gas Analysis & Vol.: CO 2 Digester(s) (An) 5/week Grab

% Total Solids Digester Feed Sludge Digester(s) (An/A) Stabilized Sludge 1/week b

1/week b

1/week b Grab

Volume & lbs. to Waste Waste Primary Sludge Waste RBC Sludge Per Eve nt Per Event Measurement

Sludge Blanket Depth Secondary Clarifiers Daily MeasurementCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 64 Additional Process Control Monitoring To Consider

Ammonia Influent
Final Effluent 1/week
2/week Grab

Settleable Solids Final Effluent 2/week Grab

Soluble BO D 5 Primary Effluent
RBC Tank Effluent 1/week
1/week Grab

Load Cell 1/week Report

Dissolved O 2 Profile RBC Tank 1/week Grab

Bio

- Growth
Observations RBC 1/weekCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 65 

## Table XIII

- 3 L. SUGGESTED PROCESS CONTROL MONITORING
FOR POTWs APPLICABLE TO O&M MANUAL REV ISION AND
ADMINISTRATIVE ORDERS

--

For: RBC Plants 0.5

- 2.0 MGD Average Design Flow

Test Sample Pt. Frequency Sample Type

pH Primary Effluent
RBC Tank Digester(s) (An/A) Digester Feed Sludge (An/A) Daily Daily Daily
1/week Grab

Dissolved O 2 Influent
Final Effluent Primary Effluent
RBC Tank Effluent Daily Daily
2/week
2/week Grab

Temperature Influent Digester(s) (An/A) Daily Daily Measurement

Chlorine Usage (Effluent Disinfection) Daily Measurement

Volatile Acids Digester (An) 2/week Grab

Alkalinity Di gester (An) 2/week Grab

Gas Analysis & Vol.: CO 2 Digester(s) (An) Daily Grab

% Total Solids Digester Feed Sludge Digester(s) (An/A) Stabilized Sludge 3/week b

3/week b

3/week b Grab

Volume & lbs. to Waste Waste Primary Sludge Waste RBC Sludge Per Event
Per Event Measurement

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- 66 Additional Process Control Monitoring To Consider

Ammonia Influent
Final Effluent 1/week
2/week Grab

Settleable Solids Final Effluent 2/week Grab

Soluble BOD 5 P rimary Effluent
RBC Tank Effluent 1/week
1/week Grab

Load Cell 1/week Report

Dissolved O 2 Profile RBC Tank 1/week Grab

Bio

- Growth
Observations RBC 1/weekCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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## Table XIII

- 3 M. SUGGESTED PROCESS CONTROL MONITORING
FOR POTWs APPLICABLE TO O&M MANUAL REVISIO N AND
ADMINISTRATIVE ORDERS

--

For: RBC Plants > 2.0 MGD Average Design Flow

Test Sample Pt. Frequency Sample Type

pH Primary Effluent
RBC Tank Digester(s) (An/A) Digester Feed Sludge Daily Daily Daily
1/week Grab

BOD 5 Primary Effluent 3/week Grab

TSS P rimary Effluent 3/week Grab

Dissolved O 2 Influent
Final Effluent Primary Effluent
RBC Tank Effluent Daily Daily Daily Daily Grab

Temperature Influent Digester(s) (An/A) Daily Daily Measurement

Chlorine Usage (Effluent Disinfection) Daily Measurement

Vo latile Acids Digester (An) 2/week Grab

Alkalinity Digester (An) 2/week Grab

Gas Analysis & Vol.: CO 2 Digester(s) (An) Daily Grab

% Total Solids Digester Feed Sludge Digester(s) (An/A) Stabilized Sludge 3/week b

3/week b

3/week b Grab

Volume & lbs. to Waste Waste Primary Sludge Waste RBC Sludge Per Event
Per Event Measurement

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- 68 Additional Process Control Monitoring To Consider

Ammonia Influent
Final Effluent 1/week
2/week Grab

Settlea ble Solids Final Effluent 2/week Grab

Soluble BOD 5 Primary Effluent
RBC Tank Effluent 1/week
1/week Grab

Load Cell 1/week Report

Dissolved O 2 Profile RBC Tank 1/week Grab

Bio

- Growth
Observations RBC 1/week

NOTE:

a . An = anaerobic, A = aerobic

b

. "Digester feed" or "unstabilized" sludge samples may be taken when wasting from primary and secondary clarifiers to an aerobic digester, anaerobic digester, or sludge drying beds. "Stabilized sludge" samples can be taken when wasting from the sludge tre atment recommended in the schedule.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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## 2.3 POTW Sludge Monitoring and Special Conditions

Sludge (biosolids) disposal and the associated monitoring is a program separate from the NPDES permit process and codified in 40 CFR 503. See Chapter V, Section 5. Bi osolids for the current status of sludge and biosolids. Ecology may require sludge monitoring in permits in order to develop local limits under authority of 40 CFR 403 (see Chapter X, Section 6).



### 2.3. 1 Sampling of Sewage Sludge
For flowing sludge, collect samples at the measuring weirs, or at another point where the sludge is well mixed.

Recommended sludge sampling locations are:



### • Primary Sludge

-- Draw sludge from the settling tank hoppers into a well or pit before pumping, mix well and then collect a repre sentative sample directly from this well. Alternatively, collect samples from openings in pipe near the sludge pumps or from the pump itself.



### • Activated Sludge

-- Collect samples at the pump suction well, the pump or adjacent piping or the point of discharg e of the return sludge to the primary effluent. The sample point should be located in a region of good agitation to maintain the suspension of solids.



### • Digested Sludge

-- Collect samples at the point of the discharge of the digester drawoff pipe to the dryi ng beds or the drying equipment. For batch sludges in digesters, collect samples from a mixed sink which is fed through lines attached at different levels in the digester. Be certain to remove sludge accumulated in the lines prior to sampling. For batch sludges in tanks, mix thoroughly if possible and collect samples. Collect samples at various depths and locations in the tank. Mix samples together prior to analysis.



### • Bed Dried Sludge

-- Collect equal sized samples at several points within the bed withou t including sand. M ix thoroughly.



### • Filtered Sludge

-- Collect equal size portions at the filter discharge.

The variability of sludge creates a need for frequent initial sampling in order to determine sampling frequencies. Samples should be composited, and should consist of at least 3 individually obtained samples. Batch operations should be sampled at the beginning, middle and end of a discharge, or more frequently if high variability is suspected. Tapped lines should also be sampled in three separate int ervals because of variations in the sludge at the drawoff source (i.e., clarifier, digester, etc.). Sludges treated in aerobic or anaerobic digesters have long detention times within the digesters. Therefore, sampling should be no more frequent than the detention time of the digester.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 70 Collect grab samples when analyzing for a parameter which is unstable, for example ammonia, or when analysis is required as soon as possible (e.g., sludge volume index test for activated sludge samples).

Analysis of compos ite samples is recommended in all other situations to reduce effects of sludge variability. Use at least three individual samples to form the composite. Wherever possible, collect frequent grab samples and composite according to flow rate.

Use manual sa mpling techniques in most situations unless special adaptations can be made for reliable automatic samplers. Automatic samplers have problems because of high fouling potential due to the solids content of the wastewater.



## 2.4 Combined Sewer Overflows

WAC 173

- 245

- 090(1) requires municipalities with combined sewer overflows (CSO's) to make an annual report to Ecology. The annual report must discuss three topics:

1. The past year's frequency and volume of combined sewage discharged from each CSO site,

or grou p of CSO sites in close proximity.

2. The past year's CSO reduction accomplishments.

3. The projects planned for the next year.

To report on #1 above, the WAC requires field monitoring. The extent of field monitoring necessary should be agreed upon in advanc e by Ecology and the municipality. The agreement should be formalized by incorporating the monitoring schedule within the appropriate NPDES permit when it is renewed.

The purposes of the monitoring are to determine whether any CSO is increasing in volume or frequency over the "baseline annual" condition (see WAC 173

- 245

- 020), and to determine the success of CSO reduction efforts. Any increase triggers a requirement to accomplish additional CSO reduction (WAC 173

- 245

- 090(1)(a).

Actual flow recording eq uipment in each discharge location is preferable. If the discharge is not accessible to flow recording equipment, establish a relationship between flow in the sewer trunkline and flow in the discharge pipe to which the trunk overflows. If the discharger can establish a relationship between frequencies and quantities of overflows among a group of CSO's, then monitoring at one of the locations can suffice. Note that all parties should agree to these indirect measurements as satisfactory to determine compli ance with the requirements of
WAC 173

- 245

- 090(1).CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 71 As described in Chapter V, Section 3.4.2, if the municipality has chosen at

- site treatment facilities ( e.g., primary treatment and disinfection) for CSO control, the permit writer can choose to permit th e facility under the same permit as that for the secondary treatment plant, or write a separate permit. In either case, the permit should include numerical limits for the discharge, flow capacity limits for the facility, and reporting requirements. The i nfluent and effluent during each storm event must be sampled for total suspended solids. The effluent during each storm event must be sampled for settleable solids. The sample types can be flow

- or time

- weighted composites for the time of the discharge. Flow

- weighted is preferable since it will more accurately estimate actual discharge quality and quantity over the discharge.


## 2.5 Monitoring Bypasses

When emergency bypasses are made to a different outfall or discharge point, due to high inflows

or treatme nt plant problems, separate samples of the bypassed flows should be taken ( Design of 301(h) Monitoring Programs for Municipal Wastewater Discharges to Marine Waters , EPA
430/9

- 82

- 010, EPA, 1982a).

Reporting of bypasses (and by implication monitoring) is r equired in 40 CFR 122.41 (l) and (m). Noncompliance that endangers health or the environment must be reported including "any unanticipated bypass which exceeds any effluent limitation in the permit." In certain emergency situations, when all available ma npower is required to correct the problem, monitoring the bypass may be difficult or even impossible. However, data on the total amount of wastewater bypassed and limited conventional pollutants such as BOD 5 and TSS may be helpful in understanding the eff ects of a bypass. Fecal coliforms in particular should be sampled because this test can provide both an indication of the concern to public health and, in certain situations, the amount of dilution afforded to the raw sewage by I/I. If the bypass occurs at a location where sampling is difficult, grab samples may substitute for composite samples.



## 3. INDUSTRIAL AND COMMERCIAL FACILITY MONITORING

The general considerations from part 1 of this chapter apply to all facilities discharging under the
terms of was tewater permits issued by the department. Knowledge of the general considerations is necessary in order to write a permit in accordance with department guidelines. The topics which are expanded and exceptional for industrial and commercial facilities are presented in this section. This section is not intended to absolutely apply to indirect dischargers (industrial users) although some of the principles will apply. The topics discussed are:CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 72 1. Influent monitoring

2. Effluent monitoring frequency

The monito ring strategy of industrial and commercial wastewaters, because of the many different types of facilities, is less amenable to categorization than POTW monitoring. The operational processes that generate wastewater and the resultant effluents are much mor e diverse in industrial and commercial facilities. Individual wastewaters vary significantly with industry type and facility. Also, the influent pollutants may not be treated by biological treatment. Toxic and nonconventional pollutants are often the fa ctors limiting the efficiency of wastewater treatment
for industries.

For facilities with conventional pollutants that have biological treatment similar to POTWs, use the monitoring frequencies of Tables XIII

- 1(A

- E) for facilities of comparable flows. Da iry products and other food processors may fit this approach.

The permit must contain monitoring requirements for all pollutants in the effluent with limits. Regulation states that the frequency of monitoring must result in a reasonable characterization of the nature of the discharge. A reasonable characterization should produce the variability and quantity of pollutant concentrations or loadings in the effluent as described earlier in Chapter
XIII

- 1.3.


## 3.1 Influent Monitoring

Depending on the treatment process used, it may be beneficial to require an industry to monitor influent to the treatment process and the facility. Influent monitoring may be necessary when there is a change in process or treatment technology, when the source of effluent toxicity or violations of permit conditions are unknown, or when the influent process water is known or suspected to contain unusually high concentrations of a contaminant. Evaluating the removal efficiencies for certain pollutants may help to trace the sources of problems, and may be used to determine whether a facility is meeting AKART by comparing with treatment efficiencies of
similar facilities or treatment systems

.

Effluent limits based on treatment technology can be influenced by the quality of influent. U pon request of the discharger, credits for input water under certain conditions may be applied to the calculation of pollutants generated by the industrial process. This is only the case for technology

- based limits and does not apply to water quality base d limits. The permit must specify the frequency and sample point for data on input water. This should be concurrent with sampling frequencies for effluent sampling parameters where this is a factor. (40 CFR 122.45[g])CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 73 

## 3.2 Effluent Monitoring

The most p revalent monitoring required by wastewater discharge permits is the monitoring at point of compliance, the effluent outfall. Until recently this was usually the only monitoring required for industries. There are virtually no regulations and little guidan ce for establishing frequency of monitoring.

An exception is found in the pretreatment regulations, 40 CFR Part 403.12. Significant Industrial Users (SIUs) must report results of wastewater analyses at least semi

- annually to the Control Authority. The C ontrol Authority is Ecology for all state waste discharge permits issued
to Industrial Users.

Generally the permit writer is faced with a decision to either increase frequency over past permits and face the wrath of the permittee or imitate the monitoring requirements from other accepted permits.

Other than the SIUs, there is no fixed guidance from EPA on establishment of monitoring frequencies for industrial or commercial facilities.

"The decision on the monitoring frequency is case

- specific and needs to consider a number of factors, including those listed below:



### • Type of treatment process, including retention time



### • Environmental significance and nature of the pollutant or pollutant parameter



### • Cost of monitoring relative to the discharger's capabilitie s and benefit obtained



### • Compliance history



### • Number of monthly samples used in developing the permit limit



### • Effluent variability

Based upon an array of data analyzed for both individual chemicals and whole effluent toxicity, and independent of other consid erations, EPA has observed that ideally 10 or more samples per month provides the greatest statistical likelihood that the average of the various monthly values will approach the true monthly LTA value. In practice, however, selection of monitoring freque ncies will need to consider the previously mentioned factors and arrive at a reasonable compromise of the appropriate considerations" ( TSD, page 113, EPA, 1991)CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 74 A facility not given to extreme fluctuations can be adequately regulated by selecting a freque ncy based on the single high

- frequency monitoring study explained in Section XIII

- 1.4.3. Armed with enough data, the permit writer can calculate limits, establish the projected LTA, and determine a protective monitoring frequency capable of detecting a vi olation of the limits within a certain degree of confidence.

When needed to establish frequency of monitoring, the single high frequency monitoring study should occur during the application phase of the permit but this is not always possible. Some
disch argers are too slow or lack the initiative to supply the data outside the structure of the permit. In these cases the permit writer should include a requirement in the permit which requires the discharger to conduct the high

- frequency study during a criti cal phase of production. The high frequency monitoring study should be conducted at each permit cycle for some dischargers, unless other factors are present. The use of DMR and other data in lieu of the high frequency monitoring study is explained in Sec tion 1.3.1. High frequency monitoring during the fourth year of a typical five year permit cycle will supply variability information for the renewal of the permit.



## 4. WET TESTING MONITORING

4.1 Recommended Test Frequency for Characterization

Whole efflue nt toxicity tests are relatively expensive. Therefore, the test frequency should be related to the probability of any discharger having whole effluent toxicity. The following table ranks some factors associated with the discharger or the receiving water. A permit manager may use other factors to increase or decrease the rank of any discharge. A permit manager may also change the relative weight of the factors listed. All factors considered should be explained in the
fact sheet.

The EPA application form 2A for municipal dischargers requires WET testing data with the application. The specific requirements are based on the size of the discharge. The requirements are given at the end of Table XIII

- 4.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 75 Table XIII

- 4 DISCHARGE RANKING SYSTEM

Applicant: NPDES Permit #

A. Toxicity Likelihood (Circle the scores for all that apply.)

1. 5 points Uses, stor es, produces as a product or waste, or transfers hazardous substances listed in 40 CFR 302.4 with a statutory code of 1 or 2 with adequate Best Management Practices (adequate secondary containment, good housekeeping, good employee training, thorough self

- i nspection, sufficient emergency planning and spill control equipment, etc.)

2. 20 points Uses, stores, produces as a product or waste, or transfers hazardous substances listed in 40 CFR 302.4 with a statutory code of 1 or 2 with inadequate Best Managemen t Practices (no or undersized secondary containment, poor house

keeping, little employee training, poor self

- inspection, little emergency planning, insufficient spill control equipment, history of spills which have reached receiving water, etc.)

3. 15 po ints Discharges in the effluent any toxic pollutant listed in Appendix D of 40 CFR
Part 122

4. 15 points Discharger belongs in an industry category identified in 40 CFR Part 122, Appendix A

5. 15 points Discharger is a municipal facility which receives a discharge from any industry category identified in 40 CFR

, Part s 40 5

- 471 , unless the municipality has an adequate pretreatment program which establishes and enforces local
limits

6. 10 points Any facility with toxicity detected during past acute toxicity testing based on less than 80% survival in 100% effluent

7. 15 points Any facility with known or suspected receiving water impacts

Sum of scores in part A:CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 76 Table XIII

- 4 . Continued

B. Potential For Impact

1. Average Annual Discharge Flow Volume (Circle one score.)*

a. 5 points Flow < 0.5 mgd

b. 10 points Flow 0.5 mgd to 12.5 mgd

c. 15 points Flow 12.5 mgd to 25 mgd

d. 20 points Flow 25 mgd to 37.5 mgd

e. 25 points Flow 37.5 mgd to 50 mgd

f. 30 points Flow > 50 mgd

2. Chronic Criti cal Effluent Concentration at Edge of Mixing Zone (Circle one score. If not known, estimate or double the score in category B)*

a. 1 point CCEC < 0.1% effluent

b. 5 points CCEC = 0.1% effluent to 2% effluent

c. 10 points CCEC = 2% effluent to 4% eff luent

d. 15 points CCEC = 4% effluent to 6% effluent

e. 20 points CCEC = 6% effluent to 8% effluent

f. 25 points CCEC = 8% effluent to 10% effluent

g. 30 points CCEC > 10% effluent

Sum of scores in part B:

C. Multiply the sum of scores fr om part A by the sum of scores in part B to rank the discharge:CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 77 Table XIII

- 4 Continued

D. Discharge Ranks*

Rank 1

- greater than 2500 points

Rank 2

- 1500 points to 2500 points

Rank 3

- 750 points to 1500 points

Rank 4

- 100 points to 75 0 points

Rank 5

- less than 100 points

*Borderline values go to any adjacent group at the discretion of the permit manager.

EPA Form 2a Requirements for Part E

- WET data at the time of application

. Part E is required for all municipal dischargers with a design flow of 1 MGD or more, treatment works with an approved pretreatment program (and those that should have one), and any other municipal discharger directed by Ecology to submit WET data. Part E requirements

• If chronic dilution factor ≥ 1000

– acute t esting only with 2 species quarterly for a minimum of one year.

• If chronic dilution factor is between 100 and 1000

– acute or chronic testing with 2 species quarterly for a minimum of one year.

• If chronic dilution factor < 100

– chronic testing with 2 spec ies quarterly for a minimum of

one year.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 78 Table XIII

- 4 . Continued

TESTING FREQUENCY

DISCHARGE
RANK EFFLUENT CHARACTERIZATION

Acute Toxicity Chronic Toxicity

RANK 1 6/year,
1 fish
1 invert. 6/year,
1 fish
1 invert. 1 algal*

RANK 2 6/year,
1 fis h
1 invert. 4/year,
1 fish
1 invert. 1 algal*

RANK 3 4/year,
1 fish
1 invert. 4/year,
1 fish
1 invert.

RANK 4 4/year,
1 fish
1 invert. 2/year,
1 fish
1 invert.

RANK 5 2/year,
1 fish
1 invert. 2/year,
1 fish
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## 4.2 Sampling

Samples for whole effluent toxicity testing may be composite or grab samples. Twenty four hour composite samples are recommended except:

a. when the permit manager has reason to believe that the effluent is signific antly more toxic at a certain time of day,

b. when the permit manager suspects that toxicity may be lost by the compositing process (for example, chlorine or volatile organics vaporizing out of solution, or surfactants adsorbing to the composite sampler),

c. o r when the toxicity testing will require a sample volume in excess of composite sampler volume which is usually about five gallons. Grab samples can be composited in these cases.

Samples taken for toxicity testing should be cooled to 4 degrees Celsius an d sent to the lab immediately. The lab should begin the toxicity testing as soon as possible but no later than 36 hours after the time that sampling was begun.

Sampling should be evenly spaced during the year and timed to catch the maximum seasonal
varia tion. For example, if sampling frequency is 2/year, then these should be taken in the
summer and winter.



## 5. STORM WATER MONITORING

The Clean Water Act did not exempt storm water from regulation. Storm water is considered
wastewater and if it flows in a co nveyance it is a point source discharge. Storm water discharges have not been regulated in a consistent manner under the Clean Water Act because of funding limitations and because control mechanisms and monitoring requirements are different from other poin t sources.

As other point source pollution sources came under control, it was apparent that storm water was
often the cause of non

- attainment of the water quality standards. The 1987 amendments to the Act explicitly required storm water permits. These s torm water requirements have been clarified in EPA rule making. The regulatory history of storm water pollution control is reviewed in 56 FR 40948 (August 16, 1991). Storm water is unique in that EPA has established that the implementation of best manage ment practices constitutes BCT/BAT for storm water discharges associated with industrial activity. The fact sheet to the EPA industrial storm water permit says that BMP's identified in pollution prevention plans substitute for numeric limitations for the general class of industrial storm water.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 80 Ecology has several types of storm water permits and the monitoring requirements are different for each type.


## 5.1 Types of Storm Water Permits

5.1.1 Industries with Effluent Guidelines That Include Storm Water

EPA has promulgated effluent guidelines for some industries which include storm water requirements. The following industrial categories have storm water requirements:



### • Cement Manufacturing



### • Feedlots



### • Fertilizer Manufacturing



### • Petroleum Manufacturing



### • Steam Electri c



### • Coal Mining



### • Ore Mining and Dressing



### • Mineral Mining and Processing



### • Asphalt Emulsion

These categories of dischargers have effluent limitations in regulation and they address either
"non

- process wastewater" or wastewater from material storage piles. Even though some of these limitations specify the design storm ( i.e., 10 year 24 hour storm) they do not specify monitoring frequency. Therefore the only regulatory monitoring requirement is the minimum of once per year as specified in 40 CFR 122.44(i)(2). The se categories of dischargers receive individual permits which cover storm water discharges. The permit writer for one of these categories of discharge must review the development document to determine which waste streams are covered
in the effluent limita tions. If a permit writer finds that a waste stream in one of these categories of discharge is not covered by the effluent guidelines, the effluent limitations for that waste stream are developed on a case

- by

- case basis.



### 5.1.2 Industries With Effluent Gu idelines
Some industries with effluent guidelines for the process wastewater have storm water that mixes with the process wastewater before the point of discharge. The permit typically includes both types of wastewater. An example of this type is the timb er products processing category. These categories of dischargers would generally receive individual permits that include effluent limitations developed on a case

- by

- case basis for the storm water component.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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### 5.1.3 Industries Without Effluent Guidelines bu t With Existing Individual
Permits
These are usually industries that have permits because of some demonstrated water quality problem from storm water runoff or because they are a remedial cleanup site. This category of discharger has an individual permit that contains storm water effluent limitations developed a

case

- by

- case basis.



### 5.1.4 Industrial Stormwater General Permit
Ecology re issued a general permit for industrial storm water on Octo ber 21

, 2009 . This general permit requires the permittees to deve lop and implement a pollutant reduction plan (SWPPP) and
conduct quarterly effluent monitoring.



### 5.1.5 Municipal General Permit
Ecology has issued a general storm water permits to municipalities with a population greater than 250,000 (Phase 1) and to muni cipalities with populations between 100,000 and 250,000.



### 5.1.6 Dual Permits
A permit writer who is permitting an industrial facility may find the previous permit or the effluent guidelines do not cover storm water discharge at the facility. This facility must have submitted a Notification of Intent (NOI) to be covered under the Industrial Baseline Storm Water General permit if it is included in the regulations. Most industries are included in the SIC codes that require storm water permits.

A facility sho uld not be removed from coverage under the Baseline General Permit unless the permit manager considers the pollution control approach or the timing of the general permit to be inappropriate for that facility. Ecology will not charge a facility a fee for co verage under the storm water general permit if they have an individual permit. The Baseline Storm Water permit may be inappropriate for facilities which the permit manager has reason to believe may be having significant water quality impacts, or where the discharge is a "significant contributor of pollutants" (40 CFR 122.28(b)(2)(i)(G)).

Some industries may not be required to be covered under the general permit but the permit manager has reason to believe the storm water discharge from the facility is ca using pollution and therefore requires control. These facilities would be issued an individual permit.

If the permit manager decides to remove a facility from dual coverage and address the storm water discharge within an individual permit, the wastewater characterization process must meet the requirements in federal regulations.

Federal regulations require submission of form 2F (40 CFR 122.26(c)) for characterizing theCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 82 amount and nature of the storm water. This form requires submission of sampling data and an assessment of the site. This form is appropriate for facilities which the permit writer wants to obtain storm water quality data now rather than waiting until about 1997 under the Baseline
Storm Water General Permit.

If the permit manager wants t o include stormwater in an individual process waste water permit, but doesn't want to wait until the form 2F is submitted before issuing the permit, the monitoring requirements of form 2F should be included in the monitoring requirements of the permit. The other option is a permit requirement to submit a form 2F and to comply with the sampling requirements of the storm water regulations.



## 5.2 Wastewater Characterization for Industrial Storm Water

The storm water regulations contain some specific requirement s for characterizing storm water pollutant concentrations and loading. Permit managers should require these sampling processes in individual permits so as to be consistent with the regulations. The requirements for storm water sampling are contained in N PDES Storm Water Sampling Guidance Document (EPA 833

- B

- 92

- 001). This document should be referenced in permits requiring storm water
characterization.

The regulations require a grab sample for the first flush of the precipitation event during the first
30 minutes of a discharge and a flow

- weighted composite for the rest of the storm event. The first flush grab sample is not required if the storm water is from a detention basin with a detention time of 24 hours or more. The flow weighted composite samples must be collected during the first three hours of the discharge or the entire period of discharge if less than three hours in length.

The regulations also specify the pollutants to be analyzed in each sample.

The first flush sample must be analyzed for :



## • Oil/grease,



## • pH,



## • BOD,



## • COD,



## • TSS,



## • Total P,



## • Nitrate and nitrite nitrogen,



## • Total Kjeldahl nitrogen,CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 83 

## • Any pollutant in the facilities effluent guideline,



## • Any additional pollutants that are in the facility's permit including those for the purpose of

c haracterization of the process waste stream, and



## • Any pollutant that the applicant denotes as believed to be present on the form 2F.

The composite sample must be analyzed for all the parameters in the first flush sample except oil/grease and pH unless the y happen to be parameters given in the permittees individual permit. For certain industries EPA's General Industrial Storm Water Permit specifies pollutant parameters to be monitored (refer to Table XIII

- 5).

The storm water regulations are explicit on th e storm event to be sampled to characterize the storm water discharge. The storm event must produce 0.1 inch of precipitation and occur at least 72 hours from the last 0.1 inch of precipitation. The duration and total precipitation for the storm
event sh ould be from 0.5 to 1.5 times the average or median storm event for the area.

The regulations also require that the permittee measure flow rate, estimate volume for the storm event sampled and provide the method of flow estimation. The permittee must also provide:



## • The date and duration (in hours) of the storm event(s) sampled.



## • The rainfall measurements or estimates of the storm event (in inches) which generated the sampled runoff.



## • The duration between the storm event sampled and the end of the previo us measurable storm

event.

The sample volume is not specified in regulation but is contingent upon the number of pollutants to be analyzed. The samples generally should be a minimum of four liters for the first grab and three liters for the composite sa mple.

The regulations do not require an automatic sampler for storm water but they do place a restriction on manual sampling. Samples collected manually for composite samples must be taken once in each hour for three hours and at least 15 minutes apart. The EPA guidance document contains a good discussion of the advantages and disadvantages of automatic versus manual sampling. The document also presents several strategies for sampling to meet the intent of the regulations.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 84 

## 5.3 Compliance Monitoring

The frequency of compliance monitoring is based upon the permit manager’s best professional judgment . The permit manager should review the general considerations for determining the frequency of compliance monitoring given in the earlier sections of this chap ter. For industries
listed in Table XIII

- 5, the permit writer should use the monitoring frequencies required by EPA as the minimum monitoring frequencies.

For some storm water discharges the first flush flow may contain many times the concentration of pol lutants than sometime later in the storm event. The first flush concentration may also be dependent upon the season. An industry that has a large amount of deposition from air pollutants would have the highest concentration of pollutants in the first hea vy rain of the fall. This time of the year is also a low flow period for streams that are dependent upon ground water recharge. The short term biological impact (acute toxicity) would be greatest at this time and a grab sample of the first heavy fall rain would be the best predictor of impact. Grab samples are not as important in facilities with storm water storage basins with long detention times.

For effluent limits based on treatment, composite samples are important for determining average performance . Composite samples are better at predicting loading of pollutants to a water body.

The permit manager should consider using tiered monitoring as discussed in an earlier section of this chapter. The reduction of monitoring frequency could be based upon compliance with effluent limits or upon a demonstrated reduction of pollutants attributable to implementation of Best Management Plans.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 85 Table XIII

- 5. EPA STORM WATER GENERAL PERMIT POLLUTANT
PARAMETERS

Type of Facility Type of Storm Water Discharge Param eters Monitoring Frequency Reporting Frequency

EPCRA,
Section 313 Facilities subject to Reporting Requirements for Water Priority
Chemicals Storm water discharges
that come into contact with any equipment, tank, container, or other vessel
or area used for storage of
a Section 313 water priority chemical, or
located at a truck or rail car loading or unloading
area where a section 313 water priority chemical is
handled Oil and Grease, BOD5, COD, TSS, Total Kjeldahl Nitrogen 1 , (NH 3 - N 1 NO 3 +NO 2 - N) 3 Total Phosph orus, pH, acute whole effluent toxicity 2

, any Section 313 water priority chemical for which the facility reports. Semi

- annual Annual

Primary Metal Industries (SIC 33) All storm water discharges associated with industrial activity Oil and Grease, COD, TSS, pH, acute whole effluent toxicity 2 , Total Recoverable Lead, Total Recoverable Cadmium, Total Recoverable Copper,
Total Recoverable Arsenic, Total Recoverable Chromium, and any pollutant limited in an effluent guideline to which the facility is subject. Se mi

- annual Annual

Land Disposal
Units/Incinerators/
BIFs Storm water discharges
from active or inactive land disposal units
without a stabilized cover that have received any
waste from industrial
facilities other than construction sites; and
storm water di scharges
from incinerators and
BIFs that burn hazardous

waste Total Recoverable Magnesium, Magnesium (dissolved), Total Kjeldahl Nitrogen, COD, TDS, TOC, Oil and Grease, pH,
Total Recoverable Arsenic, Total Recoverable Barium, Total Recoverable Cadmium,
To tal Recoverable Chromium, Total Cyanide, Total Recoverable Lead, Total Mercury, Total Recoverable Selenium, Total Recoverable Silver,
acute WET 2 Semi

- annual AnnualCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 86 Table XIII

- 5. EPA STORM WATER GENERAL PERMIT POLLUTANT
PARAMETERS

Type of Facility Type of Storm Water Discharge Parameters Monitoring Frequency Reporting Frequency

Animal Handling/ Meat Packing
Facilities Storm water discharges from animal handling areas, manure management areas, production waste management areas exposed to precipitation at meat packing plants, poultry packing plants, facilities that
manufacture animal and marine
fats or oils. BOD5, Oil and Grease, COD, TSS, Total Kjeldahl Nitrogen (TKN), (NH 3 , NO 3 ,NO 2 ) 3 , Total Phosphorus, pH, Fecal
Coliform Annual Retain on
site.

Chemical and
allied Product
Manufacturers/Ru
bber
Manufacturers (SIC 28 & 30) Storm water discharges that
come into contact with solid chemical storage piles Oil and Grease, COD, TSS, pH, any pollutant
limited in an effluent guideline to which the facility is subjec t. Annual Retain on
site.

Automobile Junkyards Storm water discharges exposed to: a) over 250 auto/truck bodies with drivelines, 250 drivelines, or any combination thereof b) over 500 auto/truck units c) over 100 units dismantled per year where automotiv e fluids are drained or stored. Oil and Grease, COD, TSS, pH, any pollutant
limited in an effluent guideline to which the facility is subject. Annual Retain on
site.

Lime Manufacturing
Facilities Storm water discharges that
have come into contact with
li me storage piles Oil and Grease, COD, TSS, pH, any pollutant
limited in an effluent guideline to which the facility is subject. Annual Retain on
site.

Oil

- Fired Steam
Electric Power Generating
Facilities Storm water discharges from oil handling sites Oil and Grease, COD, TSS, pH, any pollutant
limited in an effluent guideline to which the facility is subject. Annual Retain on
site.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 87 Table XIII

- 5. EPA STORM WATER GENERAL PERMIT POLLUTANT
PARAMETERS

Type of Facility Type of Storm Water Discharge Parameters Monitoring Frequency Reporting Frequency

Cement Manufacturing
Facilities and
Cement Kilns All storm water discharges associated with industrial activity (except those from material storage piles that are not eligible for coverage under this permit) Oil a nd Grease, COD, TSS, pH, any pollutant limited in an effluent guideline to which the facility is subject. Annual Retain on site.

Wood
Treatment Facilities

Industrial
Facilities with
Coal Piles Storm water discharges from coal pile runoff Oil and Gre ase, pH, TSS (TOC) 3 , Total Recoverable Copper,
Total Recoverable Nickel, Total
Recoverable Zinc Semi

- annual Annual

Battery
Reclaimers Storm water discharges from areas for storage of lead acid batteries, reclamation products, or waste products, and

areas used for lead acid battery
reclamation Oil and Grease, COD, TSS, pH, Total Recoverable Copper,
Total Recoverable Lead, (Cd) 3 Semi

- annual Annual

Airports (with over 50,000 flight operations per year) Storm water discharges from aircraft or airport
deicin g areas Oil and Grease, BOD5, COD, TSS, pH, and the primary ingredient used in the deicing materials Annual Retain on siteCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 88 Table XIII

- 5. EPA STORM WATER GENERAL PERMIT POLLUTANT
PARAMETERS

Type of Facility Type of Storm Water Discharges Parameters M onitoring Frequency Reporting Frequency

Coal

- fired Steam Electric Facility Storm water discharges from coal handling sites (other than runoff from coal piles which is not eligible for coverage under this permit) Oil and Grease, pH, TSS, Total
Recoverable Copper,
Total Recoverable Nickel, Total
Recoverable Zinc Annual Retain on site.

Ready

- mix
Concrete
Facilities All storm water discharges associated with industrial activity Oil and Grease, COD, TSS, pH, any pollutant
limited in an effluent guideline to wh ich the facility is subject Annual Retain on site.

Ship Building and Repairing
Facilities All storm water discharges associated with industrial activity Oil and Grease, COD, TSS, pH, any pollutant
limited in an effluent guideline to which the facility is subject, (Total Recoverable Copper, Organo

- tins) 3 Annual Retain on site.

Notes:

1 A discharger is not subject to the monitoring requirements provided the discharger

makes a certification for a given outfall, on an annual basis, under penalty of law, t hat material handling equipment or activities, raw materials, intermediate products, final products, waste materials, by

- products, industrial machinery or operations, significant materials from past industrial activities, or, in the case of airports, deici ng activities, that are located in areas of the facility that are within the drainage area of the outfall are not presently exposed to storm water and will not be exposed to storm water for the certification period.

2 A discharger may, in lieu of monitor ing for acute whole effluent toxicity, monitor for

pollutants identified in Tables II and II of Appendix D of 40 CFR Part 122 that the discharger knows or has reason to believe are present at the facility site. Such
determinations are to be based on reaso nable best efforts to identify significant quantities of materials or chemicals present at the facility.

3 Recommendations by the Washington Department of Ecology.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 89 

## 6. RECEIVING ENVIRONMENT MONITORING

Requirements to monitor receiving environments are a necessary component of some NPDES permits. Most receiving environment monitoring programs will be aimed at determining (1) the background concentrations of parameters in the receiving environment, and (2) the dilution
available in the ambient environment for a proposed or existing discharge. A much less common need will be the requirement for assessment of impacts in receiving environments (please refer to the specific section on the media you are concerned with to determine when this need may exist).
E ffluent limits that are calculated using appropriate data from dilution studies and ambient background level studies should not cause impacts to the aquatic life, drinking water, or sediment uses upon which the state's Water Quality Criteria are based. Ho wever, in some cases concerns will arise that prompt the permit writer to consider whether a monitoring survey to assess impacts is necessary. These cases are most likely to occur when beneficial uses that are not yet assigned protective criteria are conc erned ( e.g., wildlife uses).

The arrangement of this chapter is as follows:

1. The regulatory authority Ecology can use to require monitoring (6.1 General Considerations for Monitoring Receiving Environments);

2. Guidance to use when determining when and ho w to require effluent dilution and ambient background monitoring (6.1 General Considerations for Monitoring Receiving Environments); and,

3. Considerations to be aware of when a study to assess impacts to receiving environments may be necessary (in almost al l circumstances the permit writer will work with the E.A. Program and the appropriate headquarters section to develop these requirements).

a. What circumstances may prompt you to consider monitoring (6.1.1).

b. How to determine if monitoring is needed (6.1.1 a nd 6.1.2).

c. The steps needed to logically develop or review a receiving environment survey to get the greatest amount of useful data in the most cost effective way (6.1.3 through 6.1.5). This section also advises on when the E AP Program and Headquarters s hould be consulted within the course of determining environmental monitoring requirements, and what type of assistance you can expect from those groups.

Note : Throughout this section the permit manager is directed to contact both EAP and headquarters whe n determining the specifics of simple or complex receiving environment surveys. This has been emphasized because of the need to assure thorough understanding of the goals of surveys by all parties participating in their design. During the design of compl exCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 90 surveys, headquarters will assist the permit manager to clearly transmit the goals of a receiving environment monitoring project to EAP, and will work to ensure that EAP understands the regulatory need for studies, and the way in which data will be used . This process is recommended as one way of "translating" survey needs between the more regulatory requirement

- based permit managers and the environmental assessment

- based group at EAP. This should expedite a more thorough review of survey proposals and result in more effective monitoring programs.


## 6.1 General Considerations for Monitoring Receiving Environments

Environmental monitoring commonly includes surveys of surface and ground water, sediments and soils, and biota. In the State of Washington, ma jor NPDES dischargers are likely to be required to perform some type of receiving environment monitoring. Minor dischargers may also be required to monitor receiving waters. By far the most frequent need for monitoring will be prompted by a lack of infor mation of discharge specific dilution and ambient background concentrations of pollutants or other water quality parameters (e.g., hardness or pH). Other factors that could prompt the need for additional monitoring would likely be founded on a
concern tha t the existing water quality criteria (based on toxicity to aquatic life and benthic invertebrates, and, drinking water concerns) are not providing adequate protection for other designated beneficial uses in waters of the state.

The decision to require or not require receiving environment monitoring must be explained in the fact sheet. Ecology has the regulatory authority to require surface water, sediment, soil, and groundwater monitoring. Regulatory authority for receiving environment monitoring is
des cribed below.



### STATE AUTHORITY
Our state authority derives from RCW 90.48 and is expressed in Chapters 173

- 220 and 173

- 216
WAC.

Chapter 173

- 220 is explicit in the authorization to require receiving water monitoring.

WAC 173

- 220

- 210(1)(c).

"(c) Monito ring of intake water, influent to treatment facilities, internal waste streams, and/or receiving waters may be required when determined necessary by the Department to verify compliance with net discharge limitations or removal requirements, to verify that proper waste treatment or control practices are being maintained, or to determine the effects of the discharge on the surface waters of the
state."CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 91 The state regulatory authority for receiving environment monitoring for ground discharges is
clear but not explicit.

WAC 173

- 216

- 110 (1)(g).

"(1) Any permit issued by the Department shall specify conditions necessary to prevent and control waste discharges into the waters of the state, including the following, whenever applicable:

(g) Any appropriate moni toring, reporting and record keeping requirements as specified by the Department, including applicable requirements under sections 307 and 308 of FWPCA;"

The WAC includes language that specifically allows Ecology to require environmental monitoring inform ation as part of a permit application:

WAC 173

- 216

- 070 (4)(c).

"(4) The requirement for a permit application will be satisfied, if the discharger files:

(c) Any other information determined as necessary by the Department."

WAC 173

- 216

- 080 (1)(c) and ( d).

"(1) Any information submitted pursuant to this chapter may be claimed as confidential.... Claims of confidentiality for the following information will be
denied:

(c) description of proposed receiving waters;

(d) description of quality and quanti ty of receiving water; and..."



### FEDERAL AUTHORITY
Ecology is authorized to implement the Clean Water Act by RCW 90.48.260 which states:

"The Department of Ecology is hereby designated as the State Water Pollution Control Agency for all purposes of the Fed eral Clean Water Act as it exists on February 4, 1987, and is hereby authorized to participate fully in the programs of the act as well as take all action necessary to secure to the state the benefits and to meet the requirements of the act."CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 92 Ecology's au thority under RCW 90.48.260 allows it to exercise whatever powers it needs "to meet the requirements" of the Clean Water Act. Whenever the Clean Water Act requires certain authority of an NPDES state, Ecology has that authority. The Clean Water Act, in 3 3 U.S.C. § 1342, requires that states be able to issue permits which apply federal effluent limitations and "[t]o inspect, monitor, enter, and require reports to at least the same extent as required in Section 1318..." 33 U.S.C. § 1342(b).

Section 308 of The Clean Water Act as Amended by the Water Quality Act of 1987, Public Law
100

- 4 [33 U.S.C. § 1318] states, in part:

"Whenever required to carry out the objective of this Act, including but not limited to (1) developing or assisting in the development of any effluent limitation, or other limitation, prohibition, or effluent standard, pretreat ment standard, or standard of performance under this Act; (2) determining whether any person is in violation of any effluent limitation, or other limitation...

(a) the Administrator shall require the owner or operator of any point source to (i) establish and maintain such records, (ii) make such reports, (iii) install, use, and maintain such monitoring equipment or methods (including, where appropriate, biologica l monitoring methods), (iv) sample such effluent (in accordance with such methods, at such locations, at such intervals, and in such
manner as the Administra tor shall prescribe), and (v) provide such other information as he may reasonably require;"

The f ederal regulation which comes from this section of law is 40 CFR 122.41(h) which states:

"(h) Duty to provide information. The permittee shall furnish to the Director, within a reasonable time, any information which the Director may request to
determin e whether cause exists for modifying, revoking and reissuing, or terminating this permit or to determine compliance with this permit."

The legal test of monitoring and testing under the federal Clean Water Act demands only that the monitoring or testing be reasonably required for some purpose under the Act

- including that of developing any new effluent limitation.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 93 

### COURT OPINIONS ON SECTION 308
Referring to Section 308 , the circuit court in Natural Resources Defense Council v. U.S.
Environmental Protec tion Agency , 822 F.2d at 119, (D.C. Cir. 1987) commented upon the broad discretion granted by the statute:

The breadth of this statutory grant of authority is obvious. In our view, the statute's sweep is sufficient to justify broad information disclosure requirements relating to the Administrator's duties, as long as the disclosure demands which he imposes are "reasonable."

In United States Steel v. Train , 556 F.2d 822, 850 (7th Cir. 1977), the company argued that an NPDES permit provision requiring a st udy of the impact of cooling water intake structures on aquatic life was unreasonable. The court rejected the argument saying:

U.S. Steel's argument that, even if applicable, the permit provision is unreasonable must also be rejected. Not even a "rough cost

- benefit analysis" is necessary as a basis for the requirement that the company conduct a study of the impact of the present cooling

- water intake structures on aquatic life in Lake Michigan. Such a study, intended to assist EPA in developing 316(b) ef fluent limitations, is well within the agency's 308 [33 U.S.C. § 1318] authority.

The court's reasoning that "not even a 'rough cost

- benefit analysis' is necessary" is important, because it confirms that there is no requirement in the statute that the cos t of the monitoring must somehow be proportional to the value of the data expected to be obtained. These determinations are left to the discretion of the permitting agency.

Permitting agencies not only have broad discretion on whether to require monitori ng, but the choice of what particular test to require is perhaps even more a matter of agency discretion. Courts only require that the agency's choices in the scientific arena be "rational"

- that is, that these choices have some scientific support. If t he agency's choice has scientific support, a court will not attempt to substitute its judgment for that of the agency by weighing the merits and demerits of competing scientific approaches. These limitations on review of Clean Water Act
scientific judgmen ts are discussed in Reynolds Metals Company v. U.S. Environmental Protection Agency , 760 F.2d 549, 558

- 59 (4th Cir. 1985):

The scope of our review is further colored by the policy of the Clean Water Act and the sophisticated data evaluations mandated by t hat lengthy and complicated statute. The Act expresses a congressional insistence to eliminate water pollution within a short time

- span... Further, technological and scientific issues, such as those presented in this case, are by their very nature difficu lt toCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 94 resolve by traditional principles of judicial decision making. For this reason "[w]e must look at the decision not as the chemist, biologist or statistician that we are qualified neither by training nor experience to be, but as a reviewing

court exe rcising our narrowly defined duty of holding agencies to certain minimal standards of rationality." More specifically, we note that an agency's data selection and choice of statistical methods are entitled to great deference, and its conclusions with resp ect to data and analysis need only fall within a
"zone of reasonableness."

The court went on to note, "[a]s frequently has been written, we do not sit as a scientific body minutely comparing competing research methods and results." 760 F.2d at 560.

This e choes the sentiments expressed in the earlier opinion in Weyerhaeuser Company v. Costle

, 590 F.2d 1011, 1026 (D.C. Cir. 1978):

Where existing methodology or research in a new area of regulation is deficient, the agency necessarily enjoys [a] broad discret ion to attempt to formulate a solution to the best of its ability on the basis of available information.". . . Indeed, the mere fact that the counsel on both sides in this suit could draw upon the opinions of diverse experts sitting virtually at their
elb ows during preparation of their briefs, while we are faced to decide between their resulting arguments on the basis of our "generalists" judicial backgrounds, argues for restraint on our part. In sum, unless we are quite certain of our basis for doing so, we must be slow to overturn the Agency's judgment , whichever way it may incline, when Congress has required it to act quickly and decisively despite the lack of exact data.[Citations omitted; footnotes omitted.]

The cases provide some "real world" exampl es of how these standards of review are applied. In Natural Resources Defense Council v. U.S. Environmental Protection Agency

, supra , the court was reviewing an EPA requirement that each NPDES permit applicant provide EPA with a list of "any toxic polluta nt which the applicant currently uses or manufactures as an intermediate or final product or byproduct." Industry argued that this requirement was invalid because EPA was authorized only to regulate toxic discharges and not toxics which may be involved on ly in some intermediate manufacturing step. The court stated, "[t]he indications are abundant that EPA was intended to possess broad latitude in identifying and regulating suspected toxics." EPA had identified three reasons for requiring the information: (1) to make sure that the effluent limitations in the permit covered the right toxicants; (2) to provide guidance on what to test for in the effluent; and (3) to aid setting "best management practices" that might be imposed to prevent spills. The

court found these reasons sufficient to require the information under 33 U.S.C. § 1318. A final example of a federal case construing 33 U.S.C. § 1318 is American Petroleum InstituteCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 95 vs. Environmental Protection Agency, 787 F.2d 965, 978 (5th Cir. 1986). In th is case, the court rejected a challenge to use of a bioassay test in making NPDES permit determinations:

The nub of the industry's contention is that the bioassay test, based on a four

day long exposure of critical marine fauna to drilling mud, creates a completely unrealistic situation which would never occur in nature because of the rapid dispersion of drilling mud from an offshore platform as a result of simple dilution, currents, and storms...

API's suggestion that the dynamic ocean environment would never result in the extended exposure to drilling mud contemplated by the 96

- hour LC

- 50 test commends itself to common sense. On the other hand, API concedes that test to be perhaps the most widely accepted benchmark for toxicity evaluations by
EPA. Ther efore, EPA has not selected a patently irrational methodology to measure the relative toxicity of generic Mud No.1. Under such circumstances, we are required to resist API's attempts to substitute our judgment for that of the agency...and must sustain its choice.[Citations omitted.]

The court in American Petroleum Institute, supra, used the approach which Ecology believes defines the criteria for determining if receiving environment is appropriate. These criteria are: (1) Are the test(s) required in the permit or as part of the permit application being imposed for an allowable purpose under state law or under 33 U.S.C. § 1318 (that is, to carry out some objective of the Clean Water Act)? Typically these purposes are to require the permittee to monitor fo r information for permit development or to demonstrate the discharge is not causing harm. (2) Are the specific test methods "reasonable," in that they have scientific support?

The permit writer should be clear these questions are answered in the fact shee t when requiring receiving environment monitoring.



### Common Monitoring Requirements:
The two most common reasons to consider and require receiving environment monitoring are:



### • To attain data on ambient conditions in receiving waters for use in calculating ef fluent limits, and;



### • To determine flows and dilution in the vicinity of the discharge (i.e., field verification of mixing zone models).

By far the most common reason to require receiving environment monitoring is to provide background data to use when perm it limits are calculated. These data can be required upon application, or can be specified in the preceding permit as a special study. Both options haveCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 96 advantages and disadvantages. Requesting ambient data upon application, especially if the request is not specific as to detection limits, QA/QC, and sampling locations and depths, can result in submittal of data that are not appropriate to use in limit calculation. Requiring background data within a permit can result in an additional work

- load for the p ermit manager if study plans need review and approval. The recommended approach is to require a special study as a permit requirement. Ideally, as many of the data reporting requirements as possible should be incorporated into the requirement. Studies s hould address the most necessary types of data needed for effluent limit calculation, including temperature, hardness, and/or toxins measures. Copies of all data and reports should be submitted to the Basin Planning and Standards Section for incorporation into statewide reports.

There are two general ways to place receiving water studies in permits, permit applications, and enforcement orders. The first method is to describe the sampling program in detail in the permit. In many cases this is the best me thod for simple studies that will be conducted by the permittee ( e.g., measuring copper concentration at one ambient background site to determine the concentration of copper in ambient water during critical flow conditions, or, estimating dilution
near the discharge point). When using this method, the permit manager should specify any applicable sampling and analytical protocols to be used, as well as sample location and timing. The specific protocols for these simple studies, for different environmental media, can be found
in the media

- specific sections at the end of this chapter.

The second method is to specify the study objectives and to allow the permittee to submit draft and final study plans, acceptable to Ecology, within a specified time period (e. g., within 90 days of permit issuance). It is important to note that discussing the need to conduct receiving monitoring studies with the discharger and other interested parties during the permitting process can help to formulate survey objectives early

- o n, and will help the discharger by giving them early warning that they must start to budget for a sampling program. This is the best approach for studies that are conducted by a consultant for the permittee. If the permit manager requires the permittee t o submit a sample plan, the qualifications of the people doing the work should be submitted for approval. The study plan should address the variables and information needs associated with fulfilling the objective. All study plans must be approved by Ecol ogy. When the second method of requiring a study is used, the permit manager should discuss the specific problem, the study objectives, and any constraints of the study with the Program Development Services Section (or other appropriate headquarters group ) and EAP. Experts on commercial laboratory and permittee analytical capabilities are in the Quality Assurance Section in the EA Program.



### Infrequent Monitoring Requirements:
The third and least common reason to consider requiring receiving environment mon itoring is to determine whether the permitted discharge is causing a detrimental impact to the environment in the vicinity of the discharge (i.e., environmental assessment).

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- 97 damage due to discharges, thus effluent quality should be characterized before a receiving environment study is required. Environmental monitoring should focus on effects that could be caused by chemicals and other properties that are present in the effluent. In some cases biological or chemical effects may already be identified in a receiving water (e.g., abnormal
blooms or die

- off of algae, deleterious concentrations of toxins in wildlife, or, exceedances of
state standards and associated am bient toxicity). If any of these occur, the main focus of a receiving water survey will be to gather data to assist Ecology to identify the cause(s) of the impact. Studies that can determine cause and effect in natural systems are generally difficult to design, and expensive to finance. Studies to determine complex cause and effect issues should always be discussed with the PSMS and the EILS Program in order to clarify objectives and determine the most effective sampling design. In addition, the permit writer may wish to consult the following documents when planning and considering a monitoring program: Guidelines and Specifications for Preparing Quality Assurance Plans , (Ecology, 1991a) and, Technical Guidance for Assessing the Quality of Aquatic Envir onments in Washington State , (Ecology, 1990a)

A general process for deciding whether to require a receiving environment study to determine impacts consists of the following steps (Baker and Wolff, 1987):

1. Define and clarify the problem (what is the major concern you are interested in?) (Section 6.1.1)

Specify objectives and constraints (Section 6.1.2)

Develop alternative strategies (solutions) that address objectives and constraints (alternative sample designs including parameters to be monitored, sampli ng locations, methodologies for sample collection and analysis, and timing and frequency of sampling) (Section 6.1.3)

Evaluate the alternative sampling designs (Section 6.1.4)

Choose the best sampling design (Section 6.1.5)

This process is discussed in more detail below (Sections 6.1.1 through 6.1.5).



### 6.1.1 Define and Clarify the Problem
For our purposes, an environmental study is a way of addressing a problem with one or more effluents. Defining the specific problem you are concerned with is critical to the success of the project. Some examples of problems you may find include:



### • High levels of fecal coliform in publicly used shellfish beds near a municipal discharge point.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 98 

### • Detectable mercury concentrations in an effluent that discharges to a quiesce nt and organic

rich environment, leading you to suspect sediment or organismal accumulation.



### • You do not have background data to use when calculating effluent limits for copper and
nickel.



### • Repeated acute toxicity violations lead you to suspect that ambien t effects are occurring outside the mixing zone for acute toxicity.



### • You discover that effluent conveyed through a storm drain is directly entering a rocky intertidal area at low tide, and you wish to determine the areal extent of the effluent in the
inte rtidal zone.



### • Fish kills or other events occur downstream of a discharge.



### • Dredge spoils from a ditch contain elevated concentrations of certain pollutants.



### • Contamination that is characteristic of dairy farms is found in a drinking water well located
down gradient from a large dairy.

Sampling should focus directly on the suspected or observed problems. Sampling of surface waters and sediments is discussed below. More details on sampling these and other media can be found in sections 6.3 through 6.6.

The decision to require the permittee to monitor the receiving environment should be based on a knowledge or indication that the discharge may be adversely affecting the receiving environment. This knowledge or indication will generally come from effluent mo nitoring data or from observable impairment of the environment. The following are cases for which receiving environment monitoring could be considered:

1. Problem: The facility discharges to a 304(1) water body.

Comment: Point source discharges that cont ribute to Water Quality Standards violations will be identified in technical reports being prepared for each of the water bodies on the 304(l) short list. The "short list" is comprised of water bodies that do not meet the Water Quality Standards due to po int source discharges of toxins. Facilities that discharge to these water bodies, and especially those facilities identified as contributing to these standards violations, could be required to perform receiving environment monitoring that
is focused on ef fects caused by the toxin of concern. This could include ambient toxicity testing, water chemistry, bioaccumulation studies, and others. When deciding if impactCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 99 assessment is necessary, the permit writer should consider whether monies spent on addressing the listing are better spent in clarifying the problem (monitoring) or on reducing discharges of problem pollutants.

Problem: The facility discharges chemicals that meet technology

- and water quality

- based limits but is suspected of causing problems bec ause of the high sensitivity of an indigenous species in the receiving environment.

Comment: A facility may be meeting technology

- and water quality

- based limits but be discharging to a receiving water which traditionally serves as a spawning habitat for a species which is particularly sensitive to a component of the effluent. If environmental surveys are proposed, monitoring may be concentrated on seasons in which resident organisms are particularly sensitive to effluent. With this particular problem, however, it may be possible to satisfy concerns with the receiving water by doing toxicity tests with species that are closely related ( e.g., same genus and habit) to the indigenous species of concern, instead of trying to identify impacts in the receiving environment. Although toxicity tests are costly, environmental monitoring programs that adequately address both physical and biological variability in a natural system ( i.e., the data is good enough to answer the original question instead of yielding an ambiguous result because of high variability) can be much more expensive.

Problem: The facility is associated with periodic spills or the discharge of high
concentrations of toxins.

Comment: The purpose of sediment and water column monitoring in this c ase would be to determine whether degradation of the receiving environment has occurred due to occasional discharge of highly concentrated contaminants. Permits issued for combined sewer overflows and storm drains would fall into this category. The timin g of receiving water sampling is critical for detecting effects from storm events. Of particular interest are violations of acute criteria associated with storm water in well flushed areas, and violations of chronic criteria that last days, weeks, or long er in poorly flushed areas (e.g., estuarine areas removed from major flushing currents or lacking significant riverine inflow).

Problem: Facility expansions, production increases, or process modifications are proposed that may result in new or substanti ally increased discharges of pollutants or a change in the nature of the discharge.

Comment: Permittees in this category are required to submit a new application or supplement to the previous application. The information submitted with the application

o r supplement should indicate expected changes in effluent quality or quantity. Permit managers will use that information to determine if the change in the facility could resultCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 100 in discharge of effluent that could potentially impact the environment. The p roper receiving environment data collected before and after the proposed change occurs could help to identify environmental impacts caused by the change. If an environmental survey is required, the sampling program should focus on effects that are expecte d to occur due to the changes in effluent. In many cases the use of dilution information and ambient background data to calculate effluent limits will provide enough reassurance to reduce the need for impact assessment.

Problem: A facility is suspected of discharging effluent that may be causing or contributing to observed environmental impacts such as recurring algae blooms or fish kills. A facility is discharging to a water body on the 305(b) list or suspected of contributing to violations of water q uality standards in the receiving environment.

Comment: When trying to draw cause and effect relationships (e.g., fish kill caused by a specific effluent discharge) it is critical to gather as much operational data on the discharge as possible. Review o f operational data may indicate periodic presence of toxins in effluent that are not caught by self monitoring (e.g., filter backflush and disinfection that has not been dechlorinated prior to discharge), and review of monitoring data may indicate levels o f chemicals that could drive receiving water to develop toxic conditions during critical periods or in certain downstream areas (e.g., depletion of oxygen caused by excessive BOD). This information can sometimes lower the cost of environmental surveys by focusing the objectives toward the effects most likely to occur.

Problem: A facility's discharge is a source of ongoing public concern regarding the actual or potential effects on the biota of the receiving environment.

Comment: When the concern i s due to the location of the discharge in or near a sensitive receiving environment, benthic biota, sediment, bioaccumulation, or water column studies may be appropriate. If the public is concerned, the permit manager should try to clarify the specific co ncerns of the public (e.g., mercury uptake and toxicity to wildlife; uptake of toxins by fish and shellfish that may cause a hazard to human health; public believes the environment in the area of discharge does not get any flushing, and consequently toxi ns may be accumulating to levels dangerous to either humans or other biota). In some cases, these fears may be allayed by reviews of existing information. Sometimes a review of existing information will prompt the permit manager to suspect that the publi c concerns are based on realities, or will bring up other concerns with the area. In that case environmental surveys should be required. Because of the environmental and political complexities associated with surveys prompted by widespread public involve ment, the permit manager should confer with the Program Development Services Section, EAP, and any applicable resource agenciesCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 101 before formulating specific sampling objectives.

Complex receiving environment monitoring should not be required of facilities t hat discharge effluents that have little potential to impact the environment and do not fall under a category listed above. For example, facilities that discharge into areas with strong currents would have no accumulated bottom sediments. However, even t hese facilities may be required to sample background water chemistry to establish data on which to base permit limits, or to measure bioaccumulation of toxins, or to perform other specific studies.



### 6.1.2 Specify Monitoring Objectives and Constraints
Speci fic monitoring objectives state the variables that are to be observed, and the time frame or time period during which the observations should occur. Several objectives may develop from thoughtful consideration of the initial problem. Clearly expressed an d specific objectives are critical to proper sampling design and use of data. In addition, when you define monitoring objectives and constraints, it is important to determine what the regulatory outcome of the monitoring will be. If the data you gather i s intended to result in modification of a discharge permit, then you should clearly define the result that will trigger a permit modification. Examples of objectives include:



## • To determine the concentrations of priority pollutant metals in the receiving w ater before a new facility commences discharging.



## • To determine if concentrations of lead and zinc in the receiving water are exceeding water quality criteria during low flow months.

The following is an example of a specific monitoring objective to determ ine compliance with sediment quality standards:



## • To determine if the concentrations of cadmium, lead, zinc and mercury in sediments near the outfall are exceeding the sediment quality standards during year four of the issued permit.

Other constraining fac tors can limit the way in which specific objectives are addressed and may be both scientific and operational (Baker and Wolff, 1987). An example of an objective and some discharge

- specific constraints are illustrated in the following example:

Objective: Determine a background copper concentration in ambient waters to use when calculating an effluent limit.

Constraints: Sampling must occur during critical conditions (low flow).

Data must be collected and analyzed using ultra

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- 102 Preconcent ration of samples must be done if copper concentrations are below the levels of detection using graphite furnace AA.

Because of time constraints, the permit manager is willing to calculate the limit based on samples collected over one summer that occurs d uring a drought period.

In some cases you will address problems that deal with more than one environmental media, such as assessing sediments and water in the same area, or determining sediment toxicity and sediment chemistry. If more than one media is b eing tested, be sure to formulate your objectives and constraints in such a way as to best address all media. In many cases you will use data from one media to interpret the data from another media (sediment chemistry data can help interpret
causes of sed iment toxicity). In such cases try to coordinate the sample sites, sampling times, and choice of parameters for measurement to make them as useful and comparable as possible.



### 6.1.3 Develop Alternative Sampling Strategies that Address Objectives and Constr aints.
When the problem has been defined, and the objectives and their constraints have been clearly and precisely set out, alternative sampling strategies to address the objectives and constraints should be developed. In effect, this means that several d ifferent ways of answering the same question may exist, and these should be developed and designed in detail. If you require the discharger to submit a sampling plan, they will submit one or more of the potential sampling designs. In most cases you will first consider the chemical and physical parameters you want to sample, the analytical methods to measure them, and then the general location of the sample sites. Are you interested in sediment toxicity caused by cadmium accumulation in sediments? Is
the area subject to dredging, currents, navigation, or high winds? Can the area be safely sampled? Are there rip tides, can divers be used, or can benthic grabs be safely used in the area? What are the windows of safety for sampling (not at maximum tid al e xchange , not during afternoon high winds, etc...) ? What is the direction and speed of groundwater flow? In other words, how will you design your sampling program to fit the environment and environmental compartment you are interested in (i.e., determine its statistical design to fit your specific sampling objectives)? Some of these concerns are discussed below:

Chemical and Physical Parameters

-- The choice of the appropriate physical and chemical parameters to sample for in a particular study are direct ly dependent on the problem, objectives, and constraints that have been previously defined. It is important that sampling be focused in order to (1) produce data adequate to answer the question you are asking, and (2) to minimize the
amount of useless or ambiguous data collected in the study. It is also important to enhance the comparability of the data that is collected with data collected in other sampling programs. In order to enhance data comparability, there are specific chemical and physical measur ements that should be taken with each sample that you collect. Lists of required analyses for each samplingCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 103 media (receiving waters on surface, receiving waters in subsurface, sediments, etc....) are
described in sections 6.2 through 6.6. In some cases t he parameter you are monitoring will be included in the list of required analyses. At other times the usefulness of the data you are interested in will be enhanced by collecting data on all parameters in the required list of analyses.

Sampling and Analyt ical Methods

-- After you decide on the parameters you wish to measure in the samples, decide the specific methods to be used for sample collection and chemical analysis. These include preparation of sampling containers, detailed field protocols, and specif ying analytical methods. Specific protocols have been developed for most media (e.g., Recommended Protocols for Measuring Metals in Puget Sound Water, Sediment and Tissue Samples , Tetra Tech, Inc., 1986a). The protocols that should be used for specific t ypes of receiving environment monitoring are described in sections 6.2 through 6.6. In some cases you may want to use different methods than those in the specified sampling protocol (e.g., ultra

- clean sampling for metals in surface waters, preconcentratio n of metals in order to yield lower detection limits). In those cases the analytical methods you wish to use should be referenced. The practical aspects of finding labs that can perform alternative analytical methods should be discussed with the PDS
secti on and the EA Program. In other cases you may wish to specify changes in sample replication or collection methods to fit the particular media, site, and statistical analysis of a particular survey. Any changes in sample collection methods should be clear ly described.

Sampling Locations

-- In most cases, such as sampling for background data, it will not be difficult to choose sampling sites. The sites will be in "clean" areas of water bodies (or other media), or they will be at the edge or just outside of a designated mixing zone. The size of the mixing zone will be determined during effluent limit calculation. In many cases the study you require may be a field verification of a mixing zone model that has been used to calculate limits. These types of

stu dies have straight

- forward survey designs. However, some surveys will address more complex objectives, in which case the design should always be discussed with the PDS Section (or other appropriate sections at headquarters) and with the EA Program. In ma ny cases those groups will help formulate or review alternative test designs for the permit manager.

Consider the Statistical Analyses

-- In some cases no statistical analyses will be necessary, as in cases where one sample is being collected for direct com parison of chemical concentrations in
the environment with state standards.

If you are considering a complex monitoring survey, the sample locations you choose, and the spatial configuration of those sites, will in large part depend on the statistical a nalysis you choose to use. For example, if you are comparing a far

- field station to a near

- field station, you might
choose to use the Student's t

- test to distinguish between stations. If you are interested in looking at a larger area with numerous statio ns, you might choose to use one of the many analysis of variance tests, followed by multiple comparison testing, and your station locations would be set up with proper replication and siting. A consideration of which statistical analyses to use will
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- 104 the discharge point as compared to surrounding "clean" areas at the p=0.05 level), and choose the proper statistical procedure to interpret the data you collect (e.g., T

- test, parametric two

- way ANOVA for use with random box design). Specific design considerations for each media (surface waters, ground waters, sediments, etc....) are discussed in sections 6.2 through 6.6. (Note: You may wish to refer to a stat istical text when determining a sample design. Sokal and Rohlff, 1981, Biometry , Second Edition, has good coverage of most statistics you will be interested in.) Remember that complex designs should always be discussed with the EA Program, and the headqu arters section that addresses the media you are sampling. In many cases these groups will assist you to formulate and review test designs.

Your consideration of statistical analyses will include review of other similar studies whose data may indicate the likely distributions or variability of data in certain areas. For instance, you may discover from looking at USGS sediment monitoring data from an area you are interested in that (1) mercury data are log normally distributed, (2) that mercury concentrati ons should be normalized for organic carbon, and (3) that three replicates of superficial sediments per station will adequately assess variability so that station to station differences can be determined. Existing data can prove invaluable when designing sampling programs. In most cases, however, existing data will not be available for you to use, in which case you will have to decide how to handle the unknown variability of the parameter you are measuring.

Variability: Variability can be caused by seve ral factors, including variability introduced during sampling and sample analysis, and by temporal and spatial components.

Sources of temporal variability include cyclic flow patterns of municipal treatment plants, tidal cycles, seasonal cycles, El Nino s outhern oscillation cycles, and dredging schedules. Spatial variability occurs over small (e.g., within one scoop of sediment) to large (e.g., within Puget Sound) distances, with both vertical and horizontal components.

When dealing with sources of var iability it is best to minimize the variability by controlling (equalizing) as many factors as possible. Variability introduced during sampling and analysis can be controlled to a large degree by standardizing the sampling and analytical techniques used

w ithin and among sampling surveys. Use of the Puget Sound Protocols will help to reduce variability and enhance comparability of data. Reducing variability can also take the form of including temporal controls (e.g., collect all samples at high slack tide on the same day or on consecutive days) or spatial controls (e.g., sample unpolluted reference sites to determine "background " conditions, take enough replicates to characterize each station, and only collect oxidized sediment layer). These types of con trols will all result in more useful data by limiting variability and enhancing comparability. Ideally, your sampling design will control for as many variables as possible. In the long run, a thorough consideration of sources of variability and ways to t ry to minimize variability is likely to save money, either by pointing out effective ways to sample, or by pointing out that some problems may be too complex to affordably answer. Sample replication is frequently a point of controversy when designing surv eys.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 105 Sample replication is often necessary to adequately characterize the variability at a site and is often expensive, thus it is a source of controversy. Remember that reducing the number of replicates can lead to collection of data that yields ambig uous interpretations, and is frequently useless for regulatory decisions. If it turns out that a monitoring program that can adequately answer a question is too costly to consider, then the permit manager should rethink the original problem and objectives . At this point communication with other parties is particularly important. The permit manager should consider discussion with the EA Program, the appropriate headquarters section, other state and federal regulatory agencies, state and federal resource

a gencies, academia, and any other interested party. Brainstorming with other persons can lead to new perspectives on how to address a question, or can lead to solutions that could be found more easily in other environmental compartments, or at less cost. In many cases other monitoring options may exist that can adequately respond to the concern.



### 6.1.4 Examine the Alternative Sampling Designs
After generating detailed sampling designs, the permit manager should evaluate the effectiveness
and cost of the di fferent designs, whether submitted by a discharger or developed by Ecology. It is critical at this point to first weed out any designs that appear to have a likelihood of yielding ambiguous data (i.e., that may not give you enough data to answer the quest ion you are asking). Secondly, consider cost. Will two studies yield equally useful data on which to base a decision, but one is much less costly than the other? If so, recommend the one of lesser cost. In most cases ( e.g., gathering background ambient data to use in the calculation of permit limits) cost will not be prohibitive. However, if the cost of the survey that will yield useful data is out of proportion to the magnitude of the problem being addressed, try to find another way to "ask the questio n" (e.g., can less frequent tissue accumulation studies be substituted for frequent water column monitoring for mercury?), and generate sampling designs for use with the new question. Can a less expensive study be done in a lab that will also address the real problem being considered? And will the public, resource agencies, and Ecology feel comfortable with the data generated? Ecology has a regulatory mandate, as part of their NPDES delegation, to fulfill the pertinent requirements of the Clean Water Act and to assure compliance with permit limits, and Ecology must ensure that it has appropriate data to make regulatory decisions that will be protective of water quality and beneficial uses.



### 6.1.5 Choose the Best Sampling Design
At this point in the five

- step process of planning/reviewing an environmental survey, the permit manager should have already examined the problem thoroughly, developed precise and well thought out objectives and criteria, evaluated effluent quality and operations, and be familiar with the advantages and disadvantages of alternative sampling designs. The permit manager, after conferring with the EA Program and the appropriate Ecology headquarters section, should choose the best study design, and require that study as part of a perm it application, as a permit requirement, or in an enforcement order.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 106 

## 6.2 Surface Water Monitoring

6.2.1 Parameters
When requiring receiving water monitoring, all samples should be measured for the following
characteristics:

Temperature, Dissolved oxyge n, Conductivity if freshwater or, salinity if estuarine/marine Turbidity or light transmittance at depths, pH Salinity or Hardness

These data will add to the comparability of data collected in monitoring programs conducted throughout the state. Other par ameters that you choose for measurement should be directly related to the objective and the specific conditions of the study. These may include the following:

Nutrients
Fecal coliform Chlorophyll

- a BOD 5 , COD or TOC Water column profiles Ambient toxicity t ests Toxic pollutants (metals, volatile organics, priority pollutants, other) Water column dilution, currents, etc.
Others In many cases receiving water studies will be required to determine if the Water Quality Standards are being met in the water column . Each water body classification has water quality standards for the following parameters:

Temperature Dissolved oxygen pH Turbidity
Fecal coliform Total dissolved gas

In addition, water quality standards based on aquatic toxicity have been developed fo r the following toxic substances:

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- 107 Ammonia Lindane
Cadmium Lead
Chlordane Mercury Chlorine Nickel Chloropygifos Parathion
Chromium 3+ PCBs
Chromium Pentachlorophenol Copper Selenium Cy anide Silver
DDT & metabolites Toxaphene
Endosulfan Zinc
Endrin

All water body classifications are required to meet standards based on aquatic toxicity. Human
health

- based criteria for 91 toxic compounds have been issued to the state by the EPA. If those chemicals are detected in effluent at concentrations that merit concern, either tissue bioaccumulation or water column studies may be required. Guidance on setting limits based on human health is given in Chapter VII.

Ambient toxicity sho uld be measured with organisms that tolerate the natural salinity of the water body. This will allow a truer measure of toxicity in the water column than if samples undergo salinity modification. For example, ambient brackish waters should be measured wi th organisms tolerant of brackish salinities, instead of requiring addition of artificial salts to enable use of a marine organism not tolerant of brackish salinities. Always choose the test organism that will require the smallest amount of sample modific ation.



### 6.2.2 Sampling Locations
Water quality criteria apply at the end

- of

- pipe unless a mixing zone is established. If a mixing zone is established, its spatial boundaries will be specified in the permit. The mixing zone boundary can be set between t he discharge point and the distance limits specified in WAC 173

- 201A. If the objective of the receiving water survey is to determine background concentrations of toxins (or other characteristics) to use in the calculation of effluent limits, locate the sa mpling station as near to the discharge as possible, but in an area not affected by the discharge of any effluents. In most circumstances this will be an easy and straightforward task. However, the task may become complex in poorly flushed areas of estua rine circulation (tidal cycles that dilute effluent with previously discharged effluent from the same source), or where multiple effluents are discharged into the same water body. In complex areas, waste

- load allocations may be necessary to allocate disch arge capacity to numerous discharges. If this type of situation exists, contact the Program Development Services Section at headquarters.

In order to accurately set sampling station locations that address the survey objectives, it may be necessary to fie ld

- verify computer models of mixing and dilution in receiving waters. TypicalCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 108 situations where this could occur are in shallow areas a ffected by both tidal currents and regularly occurring strong winds (e.g., wind may move effluent plume into areas that a re not predicted by models), in rivers with "side bank" discharges, or in areas where accumulation of toxins in sediments does not match the pattern of effluent flow predicted by models. A dilution study can include use of floats, dyes, salts, and other d evices, can include samples from all depths, and can last from hours to weeks (or longer). A natural component of the effluent may be used if the differential between the concentration in the effluent and receiving water is large. In most cases, however, a dye is added to the effluent in proportion to the effluent flow. The specific type of study you choose to require will depend directly on the types of questions you plan to ask in any future receiving water surveys, and on the physical characteristics of the discharge area. The EA Program should be contacted before specific dilution study methods are determined. The information from dilution studies will prove useful when used to locate sampling stations.

Depending on the specific objectives of the r eceiving water survey, the following sampling location considerations may apply:

Rivers

--

Reference or control stations may be located upstream from the discharge point, but downstream from other sources of pollutants or dilution (e.g., other discharge s or tributaries). Data from reference or control stations can be compared to data collected from stations at or below the point of discharge, or for calculating effluent limits.

Stations chosen to assess the effectiveness of effluent limits (i.e., wheth er or not Water Quality Standards are being exceeded) are generally located downstream of the discharge point, in an area where complete mix of the effluent occurs. The boundaries of the mixing zone used in setting effluent limits will be specified in the permit and fact sheet. Sampling this area is important when determining whether narrative criteria, as measured by ambient toxicity, are being met.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 109 Stations located downstream from the discharge point and mixing zone can provide data to
assess the inst ream effects caused by discharges. Your list of considerations when selecting downstream sampling stations and depths might include the following:

• The different densities of the wastewater constituents, such as floating oils, or settling suspended solids

.

• The distribution of the wastewater constituents in the receiving water, resulting from either poor mixing or stratification (for example, vertical distribution patterns which may need to be determined).

• Public beaches, shellfish beds, eelgrass beds or other biologically productive areas that may be affected by the discharge of pollutants.

• Chemical or biological reactions, such as growth of algae in upper layers of the water which may cause changes in pH, or exertion of a BOD sag miles downstream
of the discharge.

• The convenience and accessibility for sampling the area.

These types of information will help focus your choice of sampling site to a particular place and time that best address the objectives and constraints of the survey. In general, only complex receiving water surveys will require the use of sample stations located downstream of mixing

zones.

Marine or Estuarine Systems

--

Sampling tidally influenced environments is almost always more complex than sampling
unidirectional

- flow river sys tems. In most cases the selection of sampling stations for marine or estuarine receiving waters will follow the same general riverine principles of control stations and full mix station, with practices adapted to the tidal marine environment. Additional factors to consider include tidal cycles, current patterns, bottom currents and counter

- currents, stratification, climatic conditions, seasonal fluctuations, dispersion of discharges, wind induced surface currents, and multi

- depth sampling. If a problem d evelops that may be caused by a marine/estuarine discharger, and that problem can only be addressed by a complex receiving water survey, it is appropriate to perform a dilution study prior to choosing sample sites.

Water current and chemical data for some areas of Puget Sound exist. It would be worthwhile to consult any studies conducted by the Coast Guard, the Corps of Engineers, NOAA, USGS, universities, or private research done in areas you are focusing on. That data can help you
determine whether ini tial surveys (preliminary surveys that will give you enough information to set up the real receiving water survey) are necessary. The EA Program may be able to provideCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 110 some references. Marine and estuarine sampling will require some kind of station posit ioning
method.

Considerable stratification can occur in estuaries because of the differing densities of saltwater and freshwater. Freshwater flows enter estuaries as point source discharges, as sheets of storm water runoff, and in rivers and other small er tributaries. Freshwater is more buoyant than salt water, and will rise to the surface unless it is entrained in a current underneath a salt water layer. It is essential to determine the extent of stratification when starting a survey of an unknown

est uarine area. This can be done by determining salinity at different locations and depths over tidal cycles and over seasons. Because stratification is important to know about when calculating effluent limits and when designing a field survey, it should al ways be considered during survey design. Stratification is not difficult to measure, but the field time and gear needed to measure stratification can be expensive. If data indicating the extent of stratification is not available, the permit writer should require the discharge to provide the information only for
times of maximum concern.

It is possible for stratification to occur in one part of an estuary and not in another. A wedge of fresh river water overriding more dense saltwater is a specific mec hanism of stratification commonly seen at and in the vicinity of river mouths. In that situation, when the discharge of pollution is in the saltwater layer, the contamination will be concentrated near the bottom of the freshwater wedge at the flood tide. Where stratification is suspected, samples at different depths will be needed to measure vertical distribution. Dilution studies will generally be needed to determine plume movement and dispersion during times of stratification. These studies should

gen erally be conducted under the perceived "worst case" dilution conditions (e.g., time of least flushing flows, accounting for low slack tides and ebb tides).



### 6.2.3 Specify Methods for Sample Collection and Analysis
The general sampling methods for receiv ing water surveys conducted within Puget Sound are
detailed in the Puget Sound Protocols

. The analytical methods chosen for a specific survey should, as far as possible, be consistent with both the Puget Sound Protocols and the Ambient Monitoring Program. In some cases other methods may be more appropriate to address the survey's objective.

The choice of specific field methods and equipment used to collect samples will in large part be determined by the type of representative sample required to address the survey objectives, and the chosen analytical methods. In almost all cases grab samples will be collected because of the limited availability, expense, and vandalism problems associated with in

- situ composite samplers. Determine the depth of sampling based on the position of the plume and the particular chemicals or physical properties you are interested in. Equipment preparation and type should follow the guidance in the Puget Sound Protocols. If you are planning to measure many different
constitue nts of the sample, make sure that the sample collection gear fulfills the specifications of all the different analyses. This might mean collecting more than one sample per station. In allCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 111 cases, parameters that are subject to change during storage (disso lved gases, residual chlorine, soluble sulfide, temperature and pH) should be determined in the field.

Unless a special data need arises, samples collected from Puget Sound for metals determinations should follow the sample collection, analytical methods and the QA/QC procedures outlined in
the Recommended Protocols for Measuring Metals in Puget Sound Water, Sediment and Tissue Samples (1986a). The sample collection methods for water column samples provides guidance for using water bottle samplers that al so applies to sampling the water column of fresh waters.

In general, water column samples collected for analysis of toxins have not been collected with replication. This has in large part been due to cost considerations. In situations where water
colum n concentrations are compared to the Water Quality Standards, lack of replication may not be particularly important. However, in more complex surveys the statistical design of the survey will drive any data interpretation. An estimate of the sample varia nce is frequently needed for a statistical test powerful enough to yield useful data, and more than one sample is needed to estimate the sample variance. The needed replication cannot accurately be known without a characterization of the variability of the constituent of concern in the water body, which can be a prohibitively expensive task. Additionally, other sources of variability that affect the system are often uncharacterized (e.g., local currents). The Permit Manager should be aware that small

scal e spatial variability of toxins in waters are not well characterized, and studies conducted without replication lack an estimate of the sample variance of the parameter, which can hinder interpretation of sampling results. Always discuss the design of com plex receiving water studies with the EA Program and the appropriate headquarters unit

.

Dilution studies should be conducted using methods in the following references:
USGS. 1985. Kilpatrick, F.A., and Cobb, E.D., Measurement of Discharge Using Tracers.
C hapter A16. Techniques of Water

- Resources Investigations of the USGS , Book 3, Applica

tion of Hydraulics. U.S. Department of the Interior. Reston, VA.

USGS. 1986. Wilson, J.F., Cobb, E.D., Kilpatrick, F.A. Fluorometric Procedures for Dye Tracing. Chapter A12. Techniques of Water

- Resources Investigations of the USGS , Book 3, Application of Hydraulics. U.S. Department of the Interior. Reston, VA.

Doneker, R.L. and Jirka, G.H. 1990. Cormix1: An expert system for Hydrodynamic mixing zone analysis of Conventio nal and Toxic Sub merged Single Port Discharges. USEPA, Environmental Research Laboratory, Athens, GA. EPA/600

- 3

- 90/012.

Akar, P.J. and Jirka, G.H. 1990. Cormix2: An Expert System for Hydrodynamic Mixing Zone Analysis of Conventional and Toxic Multiport D iffuser Discharges. USEPA Environmental Research Laboratory, Athens, GA. Draft, July 1990.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 112 Yearsley, J. 1991. Diffusion in near

- shore and riverine environments . USEPA Region 10. EPA
910/9

- 87

- 168.

Also review the material in Appendix 6.



### 6.2.4 Specify the Timing and Frequency for Sampling
Predictable variations in the quantity and quality of effluent, as well as seasonal variations in the receiving water, will help to establish the timing and frequency for a receiving water sampling program. In most cases a "worst case" scenario will be of interest, which for the majority of river dischargers will be at low summertime flows. For estuarine dischargers worst case could correspond to times of minimum flushing and maximum stratification.

Some data interpreta tion difficulties may occur when determining compliance with water quality standards that were developed with toxicity test exposure periods ranging from instantaneous maximum (silver) to 4

- day averages (e.g., zinc). If you collect one grab sample on one day, is that sufficient to determine compliance with a standard that was developed with a 4

- day average exposure? In general, because one

- time grab samples are the type of data which is most practical and least expensive to collect, those data will be dir ectly compared to Water Quality Standards to assess compliance. If the discharger is not willing to use one sample to measure water body compliance, the discharger should be allowed and encouraged to sample multiple times over an appropriate time period t o collect data that is even more representative for comparison to the Water Quality Standards.


## 6.3 Sediment Monitoring

The protocols for sediment monitoring, as well as when sediment monitoring is necessary, are
discussed in Section 7.


## 6.4 Crop/Soil/Vadose Monitoring

The Criteria for Sewage Works Design states that for land application, background soil samples sufficient to characterize the field area shall be tested prior to land application. Additional soil samples shall be collected and retained permane ntly to allow the original soil to be physically compared with the soil after application begins. The depth to the permanent ground water table
shall be determined.

Chemical data on the soil will be analyzed on an annual basis for a possible build

- up of heavy metals, salts, a pH change, or any other parametric change that may indicate a reduction in soil renovation capacity or fertility.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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## 6.5 Groundwater Monitoring

See Chapter VIII


## 6.6 Biological Surveys

Some of the various types of surveys commonly used t o assess effects of pollution on biota include ambient water and sediment toxicity testing, analyses of benthic infaunal populations and communities, measures of bioaccumulation in resident or transplanted organisms, analyses of fish populations, and a var iety of sub

- lethal physiological, histopathological, and biochemical biomarkers (e.g., production of metallothionen and metal binding proteins, or, lesions in skin, ovary, liver, or other organs). The types of monitoring commonly encountered in NPDES
moni toring programs include toxicity testing, benthic infaunal surveys, and measures of
bioaccumulation.

Guidance for monitoring sediment toxicity and benthic infaunal populations and communities is given in the Sediment Source Control Users Manual , Ecology , 1993. Guidance addressing bioaccumulation testing will be addressed during an upcoming rule

- making on human health

based water quality criteria. Bioaccumulation testing guidance for purposes other than to address human health are currently being develo ped, and will be inserted in this section when they are complete. Before that time, if characteristics of an effluent lead to the conclusion that problems exist that can most efficiently be addressed using bioaccumulation testing, the permit writer
should contact the Program Development Services Section to discuss appropriate sample designs and organisms.


## 6.7 Data Compatibility

As required in the 1991 Puget Sound Water Quality Plan, monitoring data shall be gathered using the " Puget Sound Protocols (Tetra Tech, 1986b) when available". In addition, dischargers
shall use data formats compatible with Storet.



## 7. SEDIMENT MONITORING

This section discusses the monitoring associated with the protection of aquatic sediments from waste water discharges. Specifica lly this section discusses:



### • The general types of monitoring that may be conducted in support of the sediment source control process



### • The different types of monitoring data that are applicable to the sediment source control process and their differing object ives



### • Methods for the collection of monitoring dataCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 114 

### • Factors to be considered in the development of appropriate monitoring requirements



### • Interpretation of the monitoring results in light of the monitoring objectives.

Permit managers who have permittees which require sediment impact zones (SIZ) should review
the Sediment Source Control Standards User Manual for more detail on monitoring associat ed with sediment impact zones.



## 7.1. Gen eral Types of Monitoring in the Sediment Source Control Process

There are fo ur general types of monitoring that may be conducted in support of the sediment source control process:



### • Baseline monitoring

— Conducted prior to authorization of a SIZ to collect information that will be used in determining whether such an authorization i s likely to be necessary.



### • SIZ application monitoring

— Conducted to collect information to support application of
the SIZ models.



### • Maintenance monitoring

— Conducted during the term of a permit that includes an authorized SIZ, with the intent to determine whether the SIZ should be renewed, reduced, or eliminated; to determine whether areas of special importance have been adversely impacted by the discharge; and to determine the conditions for SIZ reauthorization.



### • Closure monitoring

— Conducted following c losure of a SIZ to demonstrate successful restoration of sediment quality.

Baseline monitoring, SIZ application monitoring, maintenance monitoring, and closure monitoring are the responsibility of the discharger. The need for and extent of each of these types of monitoring will vary depending on discharge

- and site

- specific characteristics. In certain cases, it may be possible for the discharger to use data previously collected in other monitoring programs in lieu of conducting baseline monitoring.

In a ddition to these four general types of monitoring conducted in support of the sediment source control process, there are other situations in which additional monitoring may be appropriate. For example, Ecology or an interested third party may conduct addi tional monitoring to assess discharge or receiving environment conditions independent of the assessment provided by the discharger. In the event Ecology determines that modification of the conditions of the SIZ authorization is necessary, the discharger m ay also conduct additional monitoring to rebut the conclusions of Ecology's determination.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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## 7.2 Monitoring Objectives

Monitoring objectives vary with the type of monitoring being conducted. The objectives for the four general types of monitoring are descri bed below.



### 7.2.1. Baseline Monitoring
The primary objective of baseline monitoring is to collect information to confirm a best professional judgment decision of the potential to violate the SQS. The data will be used in determining whether a SIZ authoriza tion is likely to be necessary. Such data may be used for:



### • Application of simple screening tools (e.g., information on the nature of the wastewater to be discharged, based either on knowledge of the type of facility or on actual chemical analyses of the wastewater)



### • Definition of baseline environmental conditions in the vicinity of the discharge (e.g., chemical or biological characteristics of the sediments).

Baseline monitoring data can also be used to identify other potential contaminant sources in the area or to relieve the discharger from liability for sediment contamination contributed by other permitted or unpermitted (and possibly historical) discharges.



### 7.2.2. SIZ Application Monitoring
The objective of SIZ application monitoring is to collect th e necessary data to support the use of generalized or site

- specific models to predict future sediment conditions under specific discharge scenarios (e.g., more detailed information on characteristics of the wastewater as well as on physical and chemical co nditions in the receiving environment). In cases where an existing, permitted point source has been discharging at a similar flow and wastewater quality for a sufficiently long period (e.g., 10 years), there is reason to believe steady

- state contaminant

c oncentrations may have been reached. In such cases, existing sediment conditions alone may indicate whether there is a need for a SIZ in the absence of detailed modeling.



### 7.2.3 Maintenance Monitoring
The objectives of maintenance monitoring are to collec t data necessary to:



### • Determine whether the SIZ should be renewed, reduced, or eliminated



### • Determine whether areas of special importance have been adversely impacted by the discharge



### • Determine the conditions for SIZ reauthorization.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 116 Such monitoring may i nclude chemical and/or biological assessments of conditions within the SIZ to demonstrate that the maximum allowable contaminant concentrations and/or biological effects levels have not been exceeded within the SIZ. Assessments of chemical and/or biologic al conditions in areas beyond the SIZ may also be used to demonstrate that the spatial limits of the
authorized SIZ have not been exceeded.



### 7.2.4. Closure Monitoring
For instances of SIZ closure that involve active cleanup, the objective of closure monito ring is to demonstrate that the cleanup was successful at restoring sediment quality to acceptable levels (i.e., to contaminant concentrations and/or biological effects levels below SQS) within the SIZ.
For instances of SIZ closure that involve natural re covery of the sediments, the objective of closure monitoring is to verify predictions regarding the efficacy of natural processes in restoring sediment quality to acceptable levels within the SIZ.


## 7.3. Types of Monitoring Data

There are several types of mo nitoring data that are applicable to the sediment source control

process:



### • Physical data on the receiving environment



### • Chemical data on the receiving environment



### • Biological data on the receiv ing environment



### • Physical data on the waste water discharge



### • Ch emical data on the wastewater discharge



### • Whole

- effluent toxicity test data.

Some types of monitoring data may be useful for only one phase of the sediment source control process. For example, physical monitoring of the receiving environment may be requir ed to provide input for the SIZ models used to determine whether a SIZ should be authorized for a given discharge, but may not be necessary after a SIZ is authorized. Other types of monitoring data may be useful for all phases of the sediment source contr ol process. For example, chemical or biological monitoring of the receiving environment may be required to determine whether a SIZ should be authorized, to demonstrate compliance with conditions of an authorized SIZ, or to
document successful remediation of sediment contamination following SIZ closure. The various types of monitoring data and the potential uses of the data are described in greater detail below.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 117 

### 7.3.1. Physical Data on the Receiving Environment
Data on physical conditions in the receivin g environment may be useful in determining whether sediment impacts are likely to occur. For example, physical evidence of a high

- energy, nondepositional receiving environment in the vicinity of the discharge would suggest that sediment impacts are unlike ly to occur.

Data on physical conditions in the receiving environment are also collected to support application of the SIZ models. The types of physical data that may need to be collected include vertical profiles of the density of the receiving water (g enerally calculated from the temperature and salinity of the receiving water), water depth, bottom topography, ambient current velocities, particulate concentrations in the water column, ambient sedimentation rates, and physical
characteristics of the sedi ments (e.g., sediment grain size). The SIZ models can be run with varying degrees of site

- specific data. In some cases, default values for many of the model input parameters can be used, while in other cases, detailed site

- specific data are required to r un the models. Guidance on the appropriate data requirements for various types of SIZ model runs is provided in the WASP Application Guidance Manual (Ecology, in preparation).



### 7.3.2. Chemical Data on the Receiving Environment

The collection of sediment c hemistry data may be important for several reasons. Data on contaminant concentrations in the sediments around an existing discharge that are collected during baseline monitoring can be compared with the SQS numerical criteria to determine
wheth er there is a need for a SIZ. If none of the contaminants exceed the SQS numerical criteria, and there has been neither a substantial change in the wastewater composition or flow over the past several years nor an expected change in the next 10 years, then it is u nlikely that a SIZ will be needed. Exceedances of the SQS numerical criteria, however, suggest the need for further analyses to determine whether a SIZ will be required. Exceedances of the SQS numerical criteria would not necessarily require authorizatio n of a SIZ because:



### • The exceedances of SQS numerical criteria may be historical or otherwise unrelated to the discharge in question



### • Modeling may indicate that sediment contaminant concentrations are expected to be below SQS numerical criteria within 10 y ears



### • The discharge may not be eligible for a SIZ.

In the event that site

- specific data are needed for running the SIZ model(s), it will likely be necessary to measure existing sediment contaminant concentrations.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 118 In certain circumstances, it may be appr opriate to collect data on subsurface as well as surface sediment quality conditions. Contaminant concen trations in subsurface sediments may be used to investigate changes associated with increases or decreases in contaminant loading over time, and may b e important in establishing sedimentation rates that may be used in evaluating the efficacy of natural recovery.

Sediment chemistry data will also be useful for both maintenance and closure monitoring. The
contaminant concentrations in sediments within a n authorized SIZ will be monitored to determine whether there are any exceedances of applicable limits (i.e., SIZ max or other limits established specifically for that SIZ). Contaminant concentrations in sediments beyond the
authorized SIZ will also be mon itored to determine whether there are any exceedances of SQS numerical criteria. Finally, contaminant concentrations in the sediments following SIZ closure will be monitored to evaluate whether the predicted reductions in contaminant concentrations
follow ing natural recovery, or the target contaminant concentrations following active restoration,
are achieved.



### 7.3.3. Biological Data on the Receiving Environment
Biological monitoring data, which consist of information on the abundances of naturally
occurrin g benthic infaunal organisms and the results of sediment bioassays, are used for two basic purposes in the sediment source control process. First, WAC 173

- 204

- 315 allows for the use of acute and chronic effects biological tests to confirm designation of P uget Sound marine sediments using the procedures described in WAC 173

- 204

- 310(2). Sediments that have either passed or failed the initial designation procedures based on compliance with the SQS numerical criteria may be subject to confirmatory designation using these biological tests. The results of these biological tests may override the initial designation based on sediment chemistry alone. Hence, confirmatory testing using these biological tests may be important in determining the potential need for a SIZ. If the sediments around a wastewater discharge have one or more
chemicals that exceed the criteria of WAC 173

- 204

- 320(2), these sediments would be designated as failing the SQS and the discharge would be considered for authorization of a SIZ, unless the results of the biologi cal tests indicate the absence of adverse effects. Conversely, even if the sediments pass the chemical criteria of WAC 173

- 204

- 320(2), there may be reason(s) to conduct biological tests on the sediments (e.g., if there are pote ntially toxic chemicals known to be present in the sediments for which there are no SQS numerical criteria). Failure of one or more of the biological tests would result in the designation of the sediments as failing the SQS, and the discharge would be con sidered for authorization of a SIZ.

Second, biological tests are used in the sediment source control process to identify the maximum biological effects level that may be authorized within a SIZ. The SIZ

max biological effects levels
can be established usi ng one of two methods (see Table IX

- 2). While designation of sediments as failing the SQS requires only one of the biological tests of WAC 173

- 204

- 315 to be failed by
the criteria of WAC 173

- 204

- 320(3), the SIZ

max biological effects level is exceeded when any two of the biological tests exceed the criteria of WAC 173

- 204

- 320(3). Alternatively, the SIZ

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- 119 biological effects level is also considered to be exceeded when any one of the biological tests
exceeds the criteria of WAC 173

- 204

- 420(3), each of which requires a greater biological effect than the corresponding criteria of WAC 173

- 204

- 320(3).



### 7.3.4. Physical Data on the Wastewater Discharge
The collection of physical data on the wastewater discharge will likely be necessary to provide input for the SIZ models. The types of physical data likely to be needed include:



### • the flow of the discharge (to estimate total loading to the receiving water),



### • the density of the wastewater (generally calculated from the measured or estimated temperature of the wastewa ter if the salinity of the wastewater approximates that of fresh water, or from both the temperature and salinity if it does not), and



### • the concentration of suspended solids in the wastewater. Physical processes such as flocculation and coagulation may a ffect the concentration of suspended solids following discharge to the receiving environment, but these processes are not presently addressed in
the SIZ models.

As previously indicated, the SIZ models can be run with varying degrees of site

- specific data. In some cases, default values for many of the model input variables can be used, while in other cases, detailed site

- specific data are required to run the models. Guidance on the appropriate data requirements for various types of SIZ model runs is provi ded in the WASP Application

Guidance Manual (Ecology, in preparation).


### 7.3.5. Chemical Data on the Wastewater Discharge
Data on the chemical characteristics of the wastewater may be used for several purposes. Data
on the concentrations of chemical contami nants in the wastewater that are routinely collected as part of NPDES monitoring may be used in simple screening tools to determine whether the discharge has the potential to cause exceedances of the SQS numerical criteria. The data required for this purp ose include the concentrations of any of the contaminants in the wastewater for which there are SQS numerical criteria, as well as the concentration of suspended solids in the wastewater. These data may also be used in the SIZ models to evaluate the need for a SIZ. Data on the concentrations of chemical contaminants in the wastewater may also be used to verify that the discharge is achieving AKART or some other level of required treatment defined
on the basis of achievable wastewater concentrations. Fina lly, data on the concentrations of chemical contaminants in the wastewater may be used to identify contaminants that may be targeted for investigation in monitoring of the receiving water or sediments.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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### 7.3.6. Whole

- Effluent Toxicity Test Data

Data on who le

- effluent toxicity may be useful for assessing the likelihood of adverse biological effects in the sediments. This is especially true when the same organisms (e.g., bivalve larvae)
were used in the whole

- effluent toxicity tests as would be used in asses sing sediment impacts. If
a toxic effect was demonstrated in a whole

- effluent toxicity test, this may suggest the need for biological testing of the sediments in the vicinity of the discharge, especially if the cause of the toxicity is not apparent.



## 7.4. Methods for Collecting Monitoring Data

This section briefly describes the methods appropriate for collecting various types of monitoring data. In cases where the methods have been described in other documents, appropriate
references to those documents ar e provided. For methods that are not well documented, additional details are provided, although the level of detail is necessarily brief.



### 7.4.1. Physical Monitoring of the Receiving Environment
Data on physical conditions in the receiving environment col lected to support application of the SIZ models may include vertical density profiles, ambient current velocities, ambient suspended particulate matter concentrations, sedimentation rates, sediment grain size, water depth, and bottom topography. Methods f or collecting these data are described briefly in the following
sections.

Vertical Density Profiles Vertical density profiles, which may be necessary for detailed discharge modeling, are typically generated from temperature and salinity data. Temperature and salinity (or conductivity) are generally measured electronically using submersible probes (e.g., conductivity

- temperature

depth devices, or CTD) lowered from a boat. In some cases, temperature may be measured using reversing thermometers, and salinity may be determined by returning the samples to the laboratory for measurement with a salinometer. Recommended procedures for measuring temperature and salinity are described in PSEP (1991b). Measurements should be made over the
entire water column at the site of the discharge and at sufficient intervals to provide representative data for periods of maximum and minimum stratification.

Ambient Current Velocities Ambient current velocities are typically measured using current meters. Multiple current meters are usually arrayed along a taut

- line mooring, which is deployed in the immediate vicinity of an outfall. Records of currents are typically made over periods of several weeks; the period of monitoring should take into account the possible effects of vari ations in both tidal influences and nontidal influences (e.g., wind

- induced currents), and should be scheduled to include periods of both spring and neap tides.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 121 Ambient Suspended Particulate Matter Concentrations Determination of ambient suspended particul ate matter concentrations normally entails collection of water samples from the water column and analysis for TSS. Sample collection and analytical procedures are described in PSEP (1991b). If ambient TSS data are required, the sampling strategy should a ddress the temporal and spatial variability of this variable, which is likely to be high.

Sedimentation Rates The most common method of estimating sedimentation rates is through the use of sediment traps, which are cylinders, closed at the bottom, that are placed vertically in the water column to collect settling particulate matter (see U.S. GOFS [1989] and Norton [1990] for descriptions of sediment trap design and use). Sedimentation rates (i.e., the rate at which particulate matter settles out of
the wat er column) should not be confused with sediment accumulation rates (i.e., the rate at which sediments accumulate on the bottom after accounting for loss functions such as resuspension and biodegradation). Because sediment traps are routinely left in place for up to 3 months and occasionally for up to 6 months, they are useful for characterizing average loadings of suspended solids from an intermittent or variable source, such as a storm drain, as well as for characterizing local area sedimentation rates. The advantage of sediment traps is that they collect particulate matter settling out of the water column before it is commingled with sediments on the bottom. The primary disadvantage is that the particulate matter collected is from all sources, both natu ral and anthropogenic, and not just from the discharge of interest.

Sediment traps should be used in areas that do not receive heavy boat traffic. The traps should be placed close to the source, far enough above the bottom that sediment resuspension will not substantially dilute the particulate matter from the source that is found in the trap. Traps are typically poisoned with sodium azide, mercuric chloride, or salt to minimize biotransformation of organic chemicals. However, a poison should be selecte d that does not interfere with the analytes of interest. To minimize preservation concerns, valves that prevent entry of zooplankton into the traps have been incorporated into recent sediment trap designs.

Sediment Grain Size Determination of sediment gra in size may be important in assessing the potential for sediment deposition and in modeling sediment resuspension. Sample collection and analysis procedures are described in PSEP (1986). The sampling strategy should take into account spatial differences in sediment grain size, as well as temporal differences that may occur, especially in areas with seasonal differences in flow regime.

Water Depth and Bottom Topography In cases where relatively detailed bathymetric charts exist for the vicinity of a discha rge, sufficient information on water depth and bottom topography may already be available. In other cases, it may be necessary to conduct a bathymetric survey, generally using echosounding equipment, to provide such information.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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### 7.4.2. Chemical Monitori ng of the Receiving Environment
Chemical monitoring of the receiving environment may be used to evaluate existing sediment quality, to provide input for the SIZ models, to evaluate historical changes in contaminant loading, and to use for both maintenance and closure monitoring. Chemical monitoring includes conventional sediment variables, sediment contaminant concentrations, and concentrations of contaminants associated with suspended particulate matter. Methods for the collection of these
data are descr ibed briefly in the following sections.

Conventional Sediment Variables Measurement of conventional sediment variables is valuable to help interpret the concentrations of sediment contaminants. TOC, for instance, should be measured whenever the concentrat ions of nonionizable organic compounds are to be measured, because the SQS numerical criteria for those compounds are TOC

- normalized. Acid

- volatile sulfides (AVS) should be measured whenever the concentrations of metals are to be measured, because AVS dat a are useful for interpreting the toxicity of metals in sediments. Analysis of ammonia is also potentially useful for interpreting bioassay results. Guidelines for the collection of sediment samples and for the analyses of conventional sediment variables are provided in PSEP (1986).

Sediment Contaminant Concentrations To determine whether sediment samples contain any contaminants at concentrations above the SQS or to use contaminant concentrations for input to the SIZ models, the sediments should be analy zed for all contaminants for which there are SQS numerical criteria and for all contaminants that are either known or suspected to be present in the wastewater of a subject discharge. There may be other potentially toxic contaminants known or suspected to be in the subject wastewater for which there are presently no criteria (i.e., “other toxic, radioactive, biological, or deleterious substances,” see WAC 173

- 204

- 320(5)). These contaminants should also be analyzed for, using
methods to be determined on a case

- by

- case basis, because their presence in the sediments may necessitate the assessment of the concentration below which they would have no adverse effects.

Guidelines for the collection of sediment samples are provided in PSEP (1986). Metals should
b e analyzed according to the guidelines provided in PSEP (1989a), and organic compounds should be analyzed according to the guidelines provided in PSEP (1989b). Recommended sample preparation methods, cleanup methods, analytical methods, and detection limi ts for sediments are presented in Table XIII

- 6. It is important that subsamples of sediment samples analyzed for nonionizable organic compounds be analyzed for TOC as well in order to normalize the resulting concentrations by their TOC contents. It is al so important that the analytical laboratory be instructed to employ all necessary methods to attempt to achieve the recommended
detection limits.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 123 Concentrations of Contaminants Associated with Suspended Particulate Matter It is expected that it will rarel y be necessary to directly measure the concentrations of contaminants associated with suspended particulate matter in the receiving environment. This information might be necessary in cases where it is not practical to directly measure the
concentrations of contaminants in wastewater suspended solids and the information is needed for the application of screening procedures or modeling techniques. If such information is necessary, the use of filtration or continuous centrifugation may be considered to coll ect the suspended solids, although neither method may be practical because of the large volumes of water that must be filtered or centrifuged. Alternatively, concentrations of contaminants associated with suspended particulate matter in the receiving wate r may be measured using sediment traps to collect the particulate matter; these methods have been successfully employed in Commencement Bay waterways by Norton (1990).CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 12 4 Table XIII

- 6 . Recommended Sample Preparation Methods, Cleanup Methods, Analytical
M ethods and Detection Levels for Sediments.

Chemical Recommended Sample Preparation

Methods a Recommended Sample Cleanup Methods b Recommended Analytical Methods c Recomme nded Detection

Limits d (  g

**Metals**
Arsenic PSEP

-- 7060/7061 100
Cadmiu m PSEP

-- 7130/7131 100
Chromium PSEP

-- 7190/7191 5,000 Copper PSEP

-- 7210 100
Lead PSEP

-- 7420/7421 100 Mercury

-- e

-- 7471 10
Silver PSEP

-- 7760 100
Zinc PSEP

-- 7950 200 **Nonionizable Organic Compounds LPAH Compounds** 
Na phthalene 3540/3550 3640/3660 8270/1625C 10 Acenaphthylene 3540/3550 3640/3660 8270/1625C 10 Acenaphthene 3540/3550 3640/3660 8270/1625C 10
Fluorene 3540/3550 3640/3660 8270/1625C 10
Phenanthrene 3540/3550 3640/3660 8270/1625C 10
Anthracene 3540/3550 3640/3660 8270/1625C 10
3540/3550 3640/3660 8270/1625C 10 **HPAH Compounds**
Fluoranthene 3540/3550 3640/3660 8270/1625C 10 Pyrene 3540/3550 3640/3660 8270/1625C 10
3540/3550 3640/3660 8270/1625 C 10 Chrysene 3540/3550 3640/3660 8270/1625C 10
Total 3540/3550 3640/3660 8270/1625C 10 Benzo[a]pyrene 3540/3550 3640/3660 8270/1625C 10
3540/3550 3640/3660 8270/1625C 10
3540 /3550 3640/3660 8270/1625C 10
3540/3550 3640/3660 8270/1625C 10
**Chlorinated** 1,2

- Dichlorobenzene 3540/3550 3640/3660 8270/1625C/8240 10CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 125 Chemical Recommended Sample Preparation

Methods a Recommended Sample Cleanup Methods b Recommended Analytical Methods c Recomme nded Detection

Limits d (  g

3540/3550 3640/3660 8270/1625C/8240 10
3540/3550 3640/3660 8270/1625C/8240 10
3540/3550 3640/3660 8270/1625C 10
**Phthalate Esters** Dimethyl 3540/3550 3640/3660 8270/1625C 10 Diethyl phthalate 3540/3550 3640/3660 8270/1625C 10
Di

- n

- butyl phthal ate 3540/3550 3640/3660 8270/1625C 10 Butyl benzyl 3540/3550 3640/3660 8270/1625C 10
3540/3550 3640/3660 8270/1625C 10
Di

- n

- octyl phthalate 3540/3550 3640/3660 8270/1625C 10
**Miscellaneous Extractable Com poun**  **ds**
Dibenzofuran 3540/3550 3640/3660 8270/1625C 10
3540/3550 3640/3660 8270/1625C 10
3540/3550 3640/3660 8270/1625C 10
**PCBs**
PCB Aroclors 3540/3550 3620/364

- 8080 1 **Ionizable Organic**
Phenol 3540/3550 3640/3660 8270/1625C 10
2

- Methylphenol 3540/3550 3640/3660 8270/1625C 10

4

- Methylphenol 3540/3550 3640/3660 8270/1625C 10
3540/3550 3640/3660 8270/1625C 10
3540/3550 3640/3660 8270/1625C 50 Benzyl alcohol 3540/3550 3640/3660 8270/1625C 50
Benzoic acid 3540/3550 3640/3660 8270/1625C 50 **Other Analyses**
Ammonia

- - g

-- Plumb (1981) 100
Grain size

- - g

-- Plumb (1981) 1% Organic carbon,

- - g

-- 9060 0.1%
Sul fides, acid

- - g

-- U.S. EPA (1991) 0.1 Sulfides, total

- - g

-- Plumb 100 Oil and grease

- - g

-- PSEP 10,000CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 126 Chemical Recommended Sample Preparation

Methods a Recommended Sample Cleanup Methods b Recommended Analytical Methods c Recomme nded Detection

Limits d (  g

Total solids

- - g

-- PSEP 0.1% (wet wt)

Total volatile solids - - g

-- PSEP 0.1%

a Recommended sample preparat ion methods are: PSEP

- Puget Sound Estuary Program (PSEP 1989a) Method 3500 series

- sample preparation methods from SW

- 846 (U.S. EPA 1986) and updates.

b Recommended sample cleanup methods are: Method 3600 series

- sample cleanup methods from SW

- 8 46 (U.S. EPA 1986) and updates.

c Recommended analytical methods are: Method 7000, 8000, and 9000 series

- analytical methods from SW

- 846 (U.S. EPA 1986) and updates Method 1625C

- isotope dilution method (U.S. EPA 1989) Plumb (1 981)

- U.S. EPA/U.S. Army Corps of Engineers Technical Report EPA/CE

- 81

- 1 PSEP

- Puget Sound Estuary Program (PSEP 1986) Acid volatile sulfide method for sediment (U.S. EPA 1991).

d In order to achieve the recommended detection limits for organic c ompounds, it may be necessary to use a larger sample size (approximately 100 g), a smaller extract volume for gas chromatography/mass spectrometry analyses (0.5 mL), and one of the recommended sample cleanup methods, as necessary, to reduce interference. Detection limits are on a dry weight basis unless otherwise indicated.

e The sample digestion method for mercury is described in the analytical method (Method 7471, SW

- 846 [U.S. EPA 1986] and updates).

f Total benzofluoranthenes represent the sum of the b, j, and k isomers.

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- 127 

### 7.4.3. Biological Monitoring of the Receiving Environment
Biological testing to assess existing sediment quality, to establish the maximum biological effects level within an authorized SIZ, or to assess compliance with the SIZ authorization may include the conduct of sediment bioassays or the assessment of the naturally occurring community of benthic infauna in sediment samples. Met hods for conducting these biological tests are described briefly in the following sections.

Sediment Bioassays Four of the biological tests that can be applied to assessments of marine sediment quality in the sediment source control process are sediment bi oassays, including:

**Acute Effects Tests**



## • Amphipod

— A 10

- day acute sediment bioassay that assesses mortality of the amphipod Rhepoxynius abronius



## • Larval

— Any one of several acute sediment bioassays that assess mortality and/or abnormality of larvae of the f ollowing organisms:

- Pacific oyster, Crassostrea gigas

- Blue mussel, Mytilus edulis

- Purple sea urchin, Strongylocentrotus purpuratus

- Sand dollar, Dendraster excentricus

**Chronic Effects Tests**



## • Juvenile polychaete

— A 20

- day sublethal sediment bioas say that assesses decreases in growth of the juvenile polychaete Neanthes arenaceodentata



## • Microtox® saline extract

— A 15

- minute bioassay that assesses decreased bioluminescence
of the bacteria Photobacterium phosphoreum exposed to a saline extract of the s ediment sample. Although conducted for a relatively short period of time and therefore generally considered to be an acute test, the Sediment Management Standards consider the Microtox® bioassay to be a surrogate chronic test because of its high sensitivi ty.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 128 Guidelines for the collection of sediment samples and for the conduct of these bioassays are provided in PSEP (1991a).

In addition to the chronic sediment bioassays listed above, the assessment of benthic infaunal abundance (see below) is also consi dered to be a chronic biological test.

For confirmatory designation of marine sediments, WAC 173

- 204

- 310(2)(a) requires that the sediments be tested using two of the acute effects biological tests and one of the chronic effects biological tests. For esta blishing the SIZ

max biological effects level, WAC 173

- 204

- 420(3)(a) also requires that the sediments be tested using two of the acute effects biological tests and one of the chronic biological effects tests. In establishing the SIZ

max biological effects l evel, however, the only applicable chronic effects tests to choose from are the benthic infaunal abundance and juvenile polychaete tests.

Assessment of Benthic Infauna As indicated above, the fifth biological test that can be applied to assessments of sedi ment quality in the sediment source control process is assessment of the naturally occurring community of benthic infauna in samples of the sediment of interest. This chronic effects test assesses statistically significant alterations in the abundances of the following major taxa: Crustacea, Mollusca, and Polychaeta. Guidelines for the collection and analysis of benthic infaunal samples are provided in PSEP (1987b).



### 7.4.4. Physical Monitoring of the Wastewater
Physical data on the wastewater to be collec ted to support application of the SIZ models may include the concentration of suspended solids in the wastewater, discharge flow, and wastewater density. Methods for collecting and analyzing these data are described briefly in the following
sections.

Conc entration of Suspended Solids in the Wastewater The concentration of suspended solids in the wastewater may be needed for the use of simple screening tools and as input to the SIZ models. It is typically reported as the TSS content. The
collection of sam ples for analysis of TSS should reflect knowledge of discharge conditions that are likely to result in temporal variability of the TSS content of the wastewater. Multiple samples are recommended to gain some idea of the variability of TSS content, which f or some types of discharges may be extremely high. The analysis of TSS is conducted by filtering a sample of the wastewater, drying the filter, and weighing the filter by standard methods (APHA 1989; Method 209C).

Discharge Flow

Information on the flow of the discharge is needed to estimate contaminant loading to the receiving environment and for use in the SIZ models. Flow is typically monitored and reported for most permitted wastewater discharges, regardless of whether they are under consideration forCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 129 authorization of a SIZ. Flow can be measured in situ using a variety of methods. There are two major categories of methods for measuring flow: direct

- discharge and velocity

- discharge (Metcalf & Eddy 1979). The direct

- discharge methods are used most freq uently, and relate the rate of discharge to one or two easily measured variables, employing devices such as weirs, Parshall flumes, Venturi meters, and magnetic flow meters. Flow should preferably be measured downstream of all treatment processes, althoug h flow measurements upstream of the treatment processes are common for municipal wastewater treatment plants and may be used in the absence of downstream measurements. The most useful flow measurements are those made continuously
and recorded automaticall y because they provide a temporal record of flow variations.

Wastewater Density Wastewater density is needed as input for the modeling of initial dilution (e.g., in PLUMES or CORMIX). Although wastewater density could be measured directly, it is more typi cally calculated based on the temperature of the wastewater, assuming the salinity of the wastewater approximates that of fresh water. Unless the characteristics of an individual discharge suggest otherwise (e.g., for a brine discharge), wastewater densit y may be calculated based on temperature alone. Temperature may be measured using either a thermometer or a thermistor. Methods are discussed in APHA (1989; Method 212). Measurements of temperature should take into account any temporal variability that is likely to occur (e.g., based on seasonal changes or changes in treatment processes).



### 7.4.5. Chemical Monitoring of the Wastewater
Data on the chemical characteristics of the wastewater may include both contaminant
concentrations in whole wastewater sam ples as well as contaminant concentrations in wastewater suspended solids. Such data may be used in simple screening procedures, as input to the SIZ models, as verification of achievement of specific wastewater treatment levels, or as evidence of
contamin ants that should be investigated in the receiving environment. Methods for the collection of these data are described briefly in the following sections.

Contaminant Concentrations in Whole Wastewater Samples

Contaminant concentrations in whole wastewater samples may be used in simple screening tools (see Chapter 4) or to estimate contaminant loading to the receiving environment. Routine analyses of EPA priority pollutant metals and organic compounds are included as monitoring requirements for many permitt ed discharges, regardless of whether they are under consideration for authorization of a SIZ. Wastewater samples may be collected as grabs, or as time

- averaged
or flow

- weighted composites; the latter are generally preferred because they integrate variatio ns in contaminant concentrations over short time scales (e.g., 24 hours). If there is likely to be substantial variability in wastewater quality over a longer time period (e.g., because of seasonal variations in stormwater runoff), it may be desirable to sample at various time intervals to gain an understanding of the range of wastewater quality. Methods for the analysis of EPA priority pollutant metals are presented in U.S. EPA (1987); methods for the analysis of EPA priority pollutant organic compounds are presented in U.S. EPA (1988a).CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 130 Contaminant Concentrations in Wastewater Suspended Solids If data are needed on the contaminant concentrations associated with wastewater suspended solids, sufficient solid sample must be collected to analyze for the cont aminants of interest, and this may represent a technical challenge if the concentration of suspended solids is relatively low. One method under development for obtaining a sample of suspended solids from a wastewater sample is to pass the water through a high

- speed, continuous centrifuge. This method is capable of retaining all the suspended solids present in the water. The use of a centrifuge will normally require continuous collection at the discharge facility for greater than a
24

- hr period. Because this procedure would involve collection of suspended solids over a relatively short time period, its best use would be to characterize sources that are continuous and relatively stable. Alternatively, a periodic monitoring program could be employed. Use of a continuous centrifuge for the collection of wastewater suspended solids is still under development by Ecology, and there is currently no approved protocol for this procedure.

A less costly method of obtaining suspended solids from wastewater is filtr ation. However, compared to the centrifuge method, filtration is time consuming, technically difficult, and may not be appropriate for use when a large water sample is needed to collect the required amount of solids for analysis. A discussion of the rela tive merits of the centrifuge and filtration methods can be found in Horowitz (1986). Methods for analysis of suspended solids samples are discussed in Tetra Tech (1986). Ecology (1991a) provides details on collection and analysis of suspended solids usi ng a centrifuge.


## 7.5. Development of Appropriate Monitoring Requirements

This subsection describes the factors to be considered in the development of baseline, SIZ application, maintenance, and closure monitoring requirements.

Pursuant to WAC 173

- 204

- 400 (5), Ecology is authorized to specify in discharge permits the locations and methods for collection and analysis of representative samples of wastewater, receiving water, and sediments that will be required of the discharger. In determining the appropriat e monitoring requirements, WAC 173

- 204

- 400(6) requires Ecology to consider the following factors as they relate to the potential for the discharge to violate the SQS:



### • Discharge suspended solids characteristics



### • Discharge contaminant concentrations, flow, and loading rates



### • Sediment chemical concentrations and biological effects levels



### • Receiving water characteristics (e.g., vertical density profiles, ambient current velocities)CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 131 

### • The geomorphology of sediments



### • Cost mitigating factors such as the available resources of the discharger



### • Other factors determined necessary by Ecology.

General issues to be considered in the development of monitoring requirements for all permitted discharges are discussed in other sections of this chapter.

The process for estab lishing monitoring requirements described in the other sections applies to all permitted discharges, whether or not they have the potential for impacting sediments or they are being considered for authorization of a SIZ. Certain aspects of the monitoring requirements pertinent to the sediment source control process overlap with aspects of the monitoring requirements for permitted discharges in general, and, in fact, certain information needs in the sediment source control process may already have been fill ed through the collection of monitoring data under an existing permit. In other cases, the information needs of the sediment source control process may be distinct and therefore require the collection of new and/or different types of monitoring data.



### 7.5. 1. Development of Baseline Monitoring Requirements
The development of baseline monitoring requirements is the responsibility of the permit manager, with guidance and assistance from the SMU, as necessary. The baseline monitoring requirements should be de scribed in detail in the discharge permit, or, in some cases, in a companion order.

If the result of the narrative and technical evaluations (Chapter IX) is a judgment that the discharge does not have the potential for causing sediment impacts, collection of baseline monitoring data may not be necessary. For discharges identified by the narrative and technical evaluations as having the potential for sediment impacts, there is expected to be a range of required baseline monitoring. In some cases, although there may be a potential for sediment impacts, the combination of discharge and receiving environment characteristics (e.g., a relatively small discharge with low levels of most priority pollutants, discharging to an
environment not known to have sediment impacts, in the absence of other nearby discharges) is such that any sediment impacts would not likely be severe or widespread. In such cases, the only required baseline monitoring may be chemical analyses of sediments in the immediate vicinity of
a mari ne discharge, or chemical analyses of sediments and sediment bioassays in the immediate vicinity of a freshwater discharge. In cases where sediment impacts might be expected to be more severe or widespread (e.g., a relatively large discharge with high lev els of a number of priority pollutants, discharging to an environment known to have water and/or sediment quality problems, in the presence of other nearby discharges), more extensive baseline monitoring may be required.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 132 Under certain circumstances, the n eed for baseline monitoring data may already have been satisfied by previous studies. In such cases, the evaluation of the need for a SIZ can proceed without further data collection. In other cases, the collection of additional baseline monitoring
data w ill be necessary to confirm whether there are exceedances of SQS in the vicinity of the discharge. If the data needs are relatively minor (e.g., collection and chemical analysis of a few surface sediment samples), the discharger may be required to collect the data prior to evaluation of the need for a SIZ. If, however, the data needs are extensive, the baseline monitoring requirements should be specified in the renewed permit (in the case of previously permitted discharges) or in the initial permit (for p reviously unpermitted discharges). By including the baseline monitoring require ments in the permit, issuance of the permit will not be unnecessarily delayed while an evaluation of the need for a SIZ is conducted. Authorization of a SIZ, if deemed approp riate, can then occur at a later time after the baseline monitoring data become
available and are evaluated.

In developing baseline monitoring requirements for an individual discharge, it is important to understand that the intent is only to determine whe ther currently there are exceedances of SQS in the vicinity of the discharge, and whether they appear to be caused by the discharge. Baseline monitoring is not intended to accurately delimit the area over which there are exceedances of SQS, or to definiti vely tie those exceedances to the discharge. Baseline monitoring should therefore be able to detect exceedances of SQS near the discharge and then to determine whether such exceedances are of greater magnitude near the discharge or of a more general, area wide nature, which might suggest contaminant inputs from other local sources.

For small discharges with only a low likelihood of sediment impacts, an array of only six stations may suffice if they are located along a transect extending from the point of discharge to a point downstream (in the direction of predominant current flow) sufficiently far away from the discharge to be beyond likely effects of the discharge. If flow is unidirectional (e.g., in a river), it may suffice to have one station of the t ransect upstream of the discharge to define ambient conditions. If flow is bidirectional (e.g., as in many Puget Sound marine environments where tidal currents predominate), the six stations might be arranged along a transect spanning the discharge along the axis of predominant current flow. Given the diversity of possible discharge scenarios, it is not appropriate to give generic guidance on the appropriate spacing of the stations along a transect. However, the spacing should take into account both the volume of the discharge and the velocity of currents in the vicinity of the discharge.

For larger discharges with a high likelihood of sediment impacts, or for discharges to more complex receiving environments, it may be necessary to have two to three tra nsects, each with six stations extending out from the point of discharge. Once again, it is not appropriate to give generic guidance on the appropriate spacing of the stations along a transect, but the spacing
should take into account both the volume of t he discharge and the velocity of currents in the vicinity of the discharge.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 133 Selection of appropriate baseline monitoring parameters is dependent on the nature of the discharge. For most marine discharges, it will be appropriate to collect surface sedimen t samples and analyze them for the contaminants for which there are SQS numerical criteria. Depending on how thoroughly the effluent has been characterized, it may be appropriate to analyze the surface sediments for additional contaminants, especially any known to be present in the effluent and considered potentially toxic to aquatic life. The sediment samples from the various stations should be analyzed individually and not composited with those from other stations, so that it will be possible to investi gate contaminant gradients as evidence of the source of the contaminants.

If chemical analysis of the sediments in the vicinity of a marine discharge reveals exceedance(s) of the SQS numerical criteria, consideration should be given to requiring biologica l testing, because the results of biological tests may override a decision based on sediment chemistry alone. Biological testing may also be appropriate for marine discharges if there are potentially
toxic chemicals in the effluent for which there are no SQS numerical criteria. In Puget Sound marine environments, the biological testing should include two acute tests and one chronic test (see Part 7.4.3) for the available tests to choose from). In non

- Puget Sound marine environ

ments, it may be appropriat e to use the same tests as for Puget Sound marine environments, but this decision should only be made on a case

- by

- case basis, with guidance from the SMU. In freshwater environments, baseline monitoring should always include biological testing with the Hy alella azteca and Microtox® sediment bioassays. Appropriate biological tests for low

- salinity environments have not yet been identified, but may be selected by the SMU on a case

- by

- case basis.



### 7.5.2. Development of SIZ Application Monitoring Requirements
The development of SIZ application monitoring requirements is the responsibility of the SMU. A detailed description of the SIZ application monitoring requirements will be provided to the permit manager by the SMU, to be forwarded to the discharger.



### 7.5.3 . Development of Maintenance Monitoring Requirements
The development of maintenance monitoring requirements is the responsibility of the SMU. A detailed description of the maintenance monitoring requirements will be provided to the permit manager by the SMU for inclusion in the permit.


## 7.6. Interpretation of Monitoring Results

This section describes procedures for interpreting monitoring results for various purposes in the sediment source control process.



### 7.6.1. Evaluation Criteria for Designation of Se diments as Passing or Failing the Sediment Quality Standards
Initial designation of sediments as passing or failing the SQS is made on the basis of chemical contaminant concentrations (WAC 173

- 204

- 310(1)). Sediments with chemical contaminantCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 134 concentration s equal to or less than all the applicable chemical and human health criteria are designated as not having adverse effects on biological resources or posing a significant threat to human health. Sediments having one or more chemical contaminants at concen trations greater than the applicable chemical or human health criteria are designated as having adverse effects on biological resources or posing a significant threat to human health.

Whether the sediments pass or fail the initial designation based on che mical criteria alone, they are potentially subject to confirmatory designation (see WAC 173

- 204

- 310(2)) using the applicable biological testing procedures of WAC 173

- 204

- 315. To confirm the designation of these sediments, they should be tested using two o f the acute effects biological tests and one of the chronic effects biological tests (for brief descriptions of these tests, see Part 7.4.3 above). The biological test results for control and reference sediments must meet the performance
standards of WAC 173

- 204

- 315(2). A sediment sample is determined to have an adverse effect on biological resources, and therefore is designated as failing the SQS, when any one of the biological tests demonstrates the results listed in the SQS column of Table IX

- 2, notwit hstanding the initial designation based on sediment contaminant concentrations alone. If the sediment sample does not demonstrate any of the results listed in the SQS column of Table IX

- 2, it is designated as passing the SQS, notwithstanding the initial d esignation based on sediment
contaminant concentrations alone.

For marine sediments containing other toxic, radioactive, biological, or deleterious substances, Ecology will identify appropriate test interpretation standards for initial and confirmatory
de signation. Because these procedures have not yet been developed by Ecology, they are not currently discussed in this manual.



### 7.6.2. Evaluation Criteria for SIZ
max 

### Biological Effects Level

The maximum sediment contaminant concentrations allowed within an authorized SIZ as a result of a permitted or otherwise authorized discharge are presented in Table IX

- 1, and are referred to
as SIZ max . Biological effects within an authorized SIZ are also not to exceed a “minor adverse effects level,” which is defined on the basis of the results of biological tests. To determine compliance with the SIZ

max biological effects criteria, the sediment should be tested using two of the acute effects biological tests and one of the chronic effects biological tests (see Part 7.4 .3). The biological tests employed for demonstrating compliance with the SIZ

max biological effects
criteria of WAC 173

- 204

- 420(3) are the same as those used in biological testing for confirmatory designation, except that the Microtox® test is omitted as o ne of the options for a chronic test. The biological test results for control and reference sediments must meet the performance
standards of WAC 173

- 204

- 315(2). The sediments are determined to exceed the SIZ

max biological effects criteria when any two of the biological tests exceed the criteria of WAC 173

- 204

- 320(3) or when any one of the tests demonstrates the results shown in the SIZ

max biological
effects criteria column of Table IX

- 2.CHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 135 If, in a given area, the nonanthropogenically affected (i.e., natu ral background) sediment quality is of a lower quality (i.e., having higher contaminant concentrations, causing an adverse biological response, or posing a greater threat to human health) than allowed within an authorized SIZ, the existing sediment chemica l and biological quality criteria will be identified on an area wide basis, as determined by Ecology, and used in place of the SIZ

max criteria of WAC 173

- 204

- 420.



## 8. SUMMARY CHECKLIST

Monitoring Program Checklist

1. Have all the possible sampling matrice s been considered?

- Influent

- Internal waste streams

- Treated process wastewater (effluent)

- Particulates

- Nonprocess wastewater

- Sludge

- Storm water

- Receiving environment

- Water

- Sediment

- Biota

- Groundwater

- CSOs

- Bypasses

2. Are there a ny water

- quality based limits or considerations?

- Numerical criteria

- Narrative criteria (toxicity)

- Beneficial uses (fishable, swimmable)

3. Where do the process wastes end up?

- Surface waters

- Land (application)

- Ground water

- Underground injec tion

- LandfillsCHAPTER XIII. MONITORING GUIDELINES (JULY 2008)

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- 136 4. Is there sufficient data to characterize the effluent? Are any special studies needed?

- For statistical comparisons (temporal and spatial)?

- To establish sampling frequencies?

- Are all constituents characterized?

- How variable is the effluent?

5. Is there sufficient data to characterize the potential impact on the receiving environment?

- Is there existing ambient data?

- Is data needed for modeling?

6. Specify parameters to be monitored

- To meet limits

- To create baseline d ata

- For surveys

- Indicators

- Evaluate acute/chronic toxicity

7. Specify in permit:

- Sampling locations

- Timing and frequency for sampling

- Sample collection and analytical methodologies

- QA/QC

- Data reporting requirements.

8. Will any of the mo nitoring data be used to trigger an action?

- Effluent biomonitoring

- Survey results

- Receiving environment monitoring

- Local limits policy

- Tiered sampling

- Increase/decrease

- monitoring frequency

- Add/eliminate parameters from sampling program

9. What is the size, treatment technology and compliance history of the facility?

10. Does the facility discharge into Puget Sound?

- Plan elements for majorsCHAPTER XIV. FACT SHEETS AND DOCUMENTATION (JULY 20 02)

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# CHAPTER XIV. FACT SHEETS AND DOCUMENTATION

This chapter discusses the regulatory requirements fo r fact sheets.

As in any process of complex decisions and calculations, documentation is valuable. In the permit process the documentation occurs in a fact sheet. A fact sheet sets forth the principal facts and the significant legal, procedural and pol icy decisions considered in preparing the permit. Some of the content of fact sheets is directed by federal and state regulation and some content is dictated by good project management.



## 1. FEDERALLY REQUIRED FOR SELECTED PERMITS

The federal NPDES regulat ions (40 CFR 124.8, 124.56) require a fact sheet for



### • every major NPDES facility or activity,



### • every draft permit that incorporates a variance or requires an explanation under 124.56(b),



### • every draft permit which is the subject of widespread public interest or raises major issues,



### • every Class I sludge management facility,



### • every permit that includes a sewage sludge land application plan, and for



### • every permit that includes a variance.



## 2. STATE REQUIREMENTS FOR ALL PERMITS

The State regulations for surface dis charge (WAC 173

- 220

- 060) are much simpler

- every permit
must have a fact sheet.

The state regulation requires that fact sheets at a minimum will summarize the following:



### • The type of facility or activity which is the subject of the application;



### • The locat ion of the discharge in the form of a sketch or detailed description;



### • The type and quantity of the discharge, including at least the following:



## ♦ The rate or frequency of the proposed discharge,


## ♦ For thermal discharges, the average summer and winter tempera tures, and


## ♦ The average discharge in pounds per day, or other appropriate units, of any pollutants which are present in significant quantities or which are subject to limitations orCHAPTER XIV. FACT SHEETS AND DOCUMENTATION (JULY 20 02)

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- 2 prohibition by state or federal regulation;



### • The conditions in the proposed permit;



### • The legal and technical grounds for the draft permit determination, including an explanation of how conditions meet both the technology

- based and water quality

- based requirements of state and federal law;



### • The effluent standards and limitations app lied to the proposed discharge;



### • The applicable water quality standards, including identification of the uses for which receiving waters have been classified;



### • How the draft permit addresses use or disposal of residual solids generated by wastewater

treatmen t;



### • The procedures for the formulation of final determinations (in more detailed form than that given in the public notice) including:


## ♦ The 30

- day comment period required by WAC 173

- 220

- 050(2);


## ♦ Procedures for requesting a public hearing and the nature thereo f; and


## ♦ Any other procedures by which the public may participate in the formulation of the final
determinations.



### • RCW 90.48.520 requires the control of toxicants (specific chemicals and overall toxicity) in permits. This should be discussed in the fact sheet

.



## 3. PUGET SOUND PLAN REQUIREMENTS

The Puget Sound Water Quality Management Plan (11/90) requires that in the fact sheet accompanying each draft major permit:

"Ecology shall clearly explain how the draft permit fulfills the goal of reducing
and eventua lly eliminating harm from toxic contaminants in Puget Sound, including a summary of the information used to determine which limits on specific toxicants and/or overall effluent toxicity should be included in the permit."

The plan also requires a discussio n in the fact sheet of 4 types of monitoring;



### • sediments in the vicinity of every significant outfall,



### • particulate fraction of the effluent,



### • acute and chronic toxicity of the effluent and sediments near the outfall,



### • biota surveys in the vicinity of each s ignificant outfall,



### • water quality at the boundary of the dilution zone.CHAPTER XIV. FACT SHEETS AND DOCUMENTATION (JULY 20 02)

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- 3 The plan requires a discussion of why these 5 monitoring requirements were not included if applicable.



## 4. FEDERALLY REQUIRED DETAILS

The Federal Regulations also require:



### • The name and telephone number of a person to contact for more information



### • Any calculations or other necessary explanation of the derivation of specific effluent limitations and conditions, including a citation to the applicable effluent limitation guideline
and the reasons why they are applicable or an explanation of how the alternate effluent limitations were developed.



### • An explanation of the reasons for including any of the following conditions in a permit:

∗ Limitations to control toxic pollutants

∗ Limitations on int ernal waste streams

∗ Limitations on indicator pollutants

∗ Limitations set on a case

- by

- case basis



### • For every permit to be issued to a treatment works owned by a person other than a State or municipality, an explanation of the decision on regulation of the use rs (whether to issue a separate permit)



### • For every permit that includes a sewage sludge land application plan, a brief description of how each of the required elements of the land application plan are addressed in the permit.



## 5. FACT SHEET CONSIDERATIONS

T he fact sheet serves a legal requirement and informs a new permit writer of the history of the permit. Since the fact sheet is a summary, the permit writer may also wish to submit an internal memorandum to the file on some issues too lengthy or not approp riate for the fact sheet but which may be useful in the next permitting period. Ecology often spends a considerable amount of time debating a permit issue which then becomes an assumption upon which the permit conditions are based. Documenting the decisi on process may prevent a repeat of the debate in 5 years when the permit is up for reissuance.

EPA is required to maintain an administrative record on their permits to document the decision process. This type of procedure is useful for all permit writers . The permit writer should document every permit as if it were going to an appeal hearing and as if someone new would be reissuing the permit in 5 years.CHAPTER XIV. FACT SHEETS AND DOCUMENTATION (JULY 20 02)

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- 4 The time of writing the fact sheet is an individual preference. Some experienced permit writers
wri te a fact sheet before actually drafting the permit conditions, others do it after drafting the permit.

The permit writer should use language in the fact sheet that is understandable to a non

- technical person. Public and permittee support for Ecology's p ermitting actions is increased if the issues are clearly presented in the fact sheet.

Significant comments made on a draft permit in writing or by comment at a public hearing must receive a response. The response is presented in a document called a Respon se to Comments. The Response to Comments becomes an addendum to the fact sheet. The original fact sheet may or may not be modified to reflect permit changes as a result of comment.



## 6. FACT SHEET FORMATS

The Permit Workgroup maintains model fact sheets fo r NPDES and State permits. These are
available on Outlook.CHAPTER XV. PUBLIC INVOLVEMENT (JULY 20 02)

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- 1 

# CHAPTER XV. PUBLIC INVOLVEMENT

The permit writer must allow the public to observe and influence the decision

- making process involved in developing a permit. The timing of public involveme nt was discussed in Chapters II and III. Some of the mechanisms for public involvement are the State Environmental Policy Act (SEPA), public notice of permits, and public hearings. The public involvement processes may
be difficult and time

- consuming but the permit writer is a public representative and the process is an opportunity to demonstrate that we are doing a good job of representing the public interest. Some public involvement tasks are required by law.



## 1. SEPA

A permit writer may become involve d in the SEPA process and may occasionally become the lead for new dischargers. SEPA requirements are given in Chapter 43.21C RCW and Chapter
197

- 11 WAC.

Regulation exempts reissuance or modification of any wastewater discharge permit from the SEPA proc ess as long as the permit contains conditions no less stringent than federal effluent limitations and/or state rules and regulations. The exemption applies only to existing discharges, not to new source discharges. To conform with the intent of SEPA, an existing, unpermitted discharge must undergo SEPA review during the permitting process.

The environmental review process under SEPA generally begins when someone submits a permit application to an agency or when an agency proposes some activity, policy, p lan, ordinance, or regulation. A typical situation for a new discharger is to submit a request for a building permit to a municipality or county. That municipality or county then becomes the lead agency on SEPA. However, if they feel the environmental i ssues are too complex, they may request some other agency such as Ecology to take the SEPA lead. Most small projects are covered by a checklist and a Determination of Nonsignificance. These projects go into a review list circulated by the
SEPA office. L arge projects may require an Environmental Impact Statement.

If a discharger moves into an existing facility and doesn't need a building permit, the permit writer may become the lead on SEPA. If the only environmental issue is a proposed wastewater
disch arge which is controlled by treatment, there should not be a need for an environmental impact statement. The permit applicant will complete an environmental checklist and determination of nonsignificance. The signatory authority on the determination of

n onsignificance is the person responsible for signing the permit. For multi

- program situations in the regional offices, the regional director may be the lead and signatory. The permit writer
should consult Ecology's Responsible Offical's Notebook for SEPA

- February 1989 for more
information on SEPA.CHAPTER XV. PUBLIC INVOLVEM ENT (JULY 2002)

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## 2. PUBLIC NOTICE OF PERMIT ACTIONS

Ecology uses a common public involvement process for NPDES permits, new state wastewater discharge permits, and renewal of state wastewater discharge permits for facilities w ith an increase in volume or change in nature of the wastewater.

Public notices of permit actions will be widely circulated to increase public awareness and encourage public participation early in the permit process.

Ecology assumes that costs associat ed with public notifications of permit actions and other costs of administering the public involvement procedures constitute a portion of the total costs incurred to administer the water quality permit program and are, therefore, fee eligible expenses.

E cology will administer all public notices and advertisements to ensure that they are published in a timely and consistent manner.

Public notices of application and of draft permit may be done on a batch basis for applications and permits associated with b asin permitting.



## 3. PUBLIC NOTICE OF APPLICATION (PNOA)

RCW 90.48.170 requires that certain applications be made known through a public notice in a news publication.

...Upon receipt of a proper application relating to a new operation, or an operation previously under permit for which an increase in volume of wastes or change in character of effluent is requested over that previously authorized, the department shall instruct the applicant t o publish notices thereof by such means and within such time as the department shall prescribe. The department shall require that the notice so prescribed shall be published twice in a newspaper of general circulation within the county in which the disposa l of waste material is proposed to be made and in such other appropriate information media as the department may direct. ...

Based on the above law, the following process has been adopted for PNOAs:

PNOA is required

• for new NPDES and State Waste Discharge Permits and

• for renewal of NPDES permit and State Waste Discharge permit if an increase in the

volume of waste or change in character is requested.CHAPTER XV. PUBLIC INVOLVEM ENT (JULY 2002)

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- 3 To assess whether there has been an increase in volume, the permit writer must confirm that the current f lows are consistent (within 10%) with those used in the reasonable potential calculation performed for the previous permit.

PNOA is not required

• for renewal of NPDES and State Waste Discharge permit when no increase in volume

of waste or change in chara cter is requested.

When PNOA is required, PNOAs will be published by Ecology as a

• legal classified advertisement, to be published at least once each week for 2

consecutive weeks, and as

• mailings of PNOAs sent to persons on the general mailing list w ho have indicated an interest in receiving such information.

• A PNOA may also be a display advertisement, to be published one time, concurrent

with the first legal classified advertisement

, for permits likely to have a high degree of public interest.

PN OAs will use consistent wording and format to identify the types of information that Ecology would like to receive from the public and is able to consider in permit decision

making.

In addition to public notice, Ecology is required to notify the director of the Department of Fisheries and Wildlife and the secretary of Department of Social and Health Services of the application for a permit.



## 4. PERMITTEE REVIEW

Ecology must send the preliminary draft permit and fact sheet to the permittee for comment.
Ide ally, Ecology will allow the P ermittee 30 days to review the documents before the public notice of draft (PNOD) period begins. Ecology must specify a date by which comments are due and notify the P ermittee that the permit issuance process will not be delay ed if the date is not met. Ecology must notify the Permittee that the draft permit conditions could change as a result of the public review process. If the draft permit is substantially different than the existing permit, Ecology should offer the Permittee an opportunity to meet. The purpose of the meeting would be to explain the new or changed requirements, accept comments from the Permittee on factual content, and to discuss the practicality of the monitoring requirements and compliance schedules.
If the permittee requests substantial changes beyond factual comment and the permit writer agrees with those requests, the permit writer should document the discussion and his/her decision
in the fact sheet.CHAPTER XV. PUBLIC INVOLVEM ENT (JULY 2002)

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## 5. PUBLIC NOTICE OF DRAFT PERMIT (PNOD)

A public notice of draft is required for :

• all NPDES permits (including reauthorizations)

• renew ed state permits which have an increase in volume o f discharge or a change in the characteristics of the discharge and for

• all new state permits

.

Ecology will publish PNODs as legal classified advertisements at least once in the same major paper in which the PNOA was published.

PNOD's will also be distr ibuted by mail to "parties of record." Parties of record are those persons who responded to the PNOA or who have otherwise requested that they be informed about the development of a specific permit.

Ecology may also issue news releases and other informat ional materials to announce the availability of the draft permit for public review.

The comment period following a PNOD will normally be 30 days from the date of the latest notice. The comment period can be extended any time the permit section supervisor determines that an extension of the comment period will result in greater or more meaningful public input, or in any other circumstances the permit section supervisor deems appropriate.



## 6. DISTRIBUTION OF DRAFT AND FINAL PERMIT MATERIALS

Ecology will mai l 1 copy of the draft permit, final permit, and fact sheet to parties of record or to any other party requesting such information. One copy of the application will be mailed upon request.

Draft and final permits, fact sheets, and other permit

- related inf ormation will be made available for public review and copying at the Ecology office from which the draft or final permit was
issued.CHAPTER XV. PUBLIC INVOLVEM ENT (JULY 2002)

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## • Draft permits will normally be retained in the permit file and made available for review and comment only until the Final Permit has been issued.

Ecology will bear the cost of copying and mailing draft or final permits and accompanying fact sheets to parties of record or others requesting copies of the same as part of its public outreach/education program on a 1

- copy

- per

- re questor basis only. Additional copies will be supplied as specified in Ecology Policy 10

- 30, Requests for Ecology Records . Free copies are available only for permits which are being developed or considered for renewal.



## • Copies of permit

- related informati on other than draft or final permits and accompany ing fact sheets will be made available for viewing and copying at the Ecology regional office which developed the permit. Copies of permit

- related materials will be provided by mail as long as requests cle arly specify the materials desired.

Draft and final permits and fact sheets and other permit

- related materials will also be made available, at the discretion of the permit section supervisor, at repositories in appropriate public buildings (e.g., librari es, town hall) for the duration of the comment period.



## 7. PUBLIC INFORMATIONAL MEETINGS AND WORKSHOPS

Informational meetings or workshops will be held any time the permit section supervisor deems them appropriate to inform the public about a permit or pe rmit

- related issues, to facilitate public discussion of permit issues, and to generate more informed, more pertinent public comment on permit issues.

Holding discretionary informational meetings neither precludes the need for formal hearings, nor

creates a demand that formal hearings be held.



## • Informational meetings are not required permit procedures. Therefore, informational meetings require no extension of the public comment period. However, the comment period can be extended at the discretion of the p ermit section supervisor.


## 7.1. Informational Meetings Preceding Hearings

Informational meetings are required prior to holding public hearings.CHAPTER XV. PUBLIC INVOLVEM ENT (JULY 2002)

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### • Meetings should be held at least 1 week prior to a hearing to allow the public time to study the information pr ovided in meetings and to allow the public time to prepare well

considered formal comments or responses.



### • A brief meeting should also be held immediately prior to a hearing to answer ques tions and address unresolved issues prior to accepting formal testim ony, including those hearings for which informational meetings are held at an earlier date.


## 7.2. Public Notice of Informational Meetings

Public Notices of Informational Meetings will normally be included within Notices of Public Hearing. However, when a P ublic Hearing is not planned or when inclusive notices are not practical, a Public Notice of Informational Meeting will be



## • published at least 1 time in a major newspaper with circulation in the geographic area of the discharge, and



## • distributed to parties of record by mail.

The content and format of Public Notices of Informational Meetings will be essentially the same as that used to advertise Notice of Public Hearing.



## 8. HEARINGS

Ecology will hold formal public hearings whenever the permit section supe rvisor deems that there is sufficient interest and a likelihood of meaningful public comment on a permit to warrant hearings. (Note that regulations may require public hearings under some circumstances.)


## 8.1. Public Notice of Hearing

A Public Notice of H earing will be published at least once in a major newspaper with circulation in the geographical area of the discharge. The public notice will be published at least 30 days prior to the hearing.

The Notice of Hearing will also be mailed to parties of re cord at least 30 days prior to the hearing.

Notices of Hearing will use a standard format and language which will, at a minimum



### • outline permit issues to be discussed,



### • establish time and place of hearings,CHAPTER XV. PUBLIC INVOLVEM ENT (JULY 2002)

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### • include the name of a contact person at Ecolog y who can supply information or assistance,



### • clearly state that testimony can be considered only if it pertains to the condi tions of the named permit,



### • outline the extent of Ecology's authority and interest in the permit, and



### • instruct interested parties o n getting their issues placed on the hearing agenda.

Whenever practical, a second Notice of Hearing should be issued l0

- l4 days prior to the meeting to encourage greater participation.


## 8.2. Hearing Officer

A hearing officer will be appointed by the permi t section supervisor for each hearing. It will be the hearing officer's responsibility, in cooperation with the permit manager, to prepare the agenda, and conduct the meeting according to the agenda and the established procedures for holding a hearing (di stributed by the Ecology Office of Education and Information).



## 9. PUBLIC NOTICE OF PERMIT ISSUANCE

Notices of issuance will be mailed by Ecology to parties of record.



## 10. PUBLIC NOTICES OF OTHER ACTIONS

Notices of appeals of permits will be mailed to pa rties of record, as will decisions on appeals.

Major modification, suspension (state permits), and revocation (for cause other than cessation of discharge), of a wastewater discharge permit each require public review and comment.
Therefore:



### • Ecology will publish a notice of intent to modify, suspend, or terminate a permit as a legal classified advertisement in a major newspaper with general circulation in the geographical area of discharge.



### • Ecology will notify parties of record, by mail, of the departme nt's intent to make a major modification to, or to suspend or revoke a permit.



### • All subsequent public notification will be implemented using the same procedures as outlined for new discharges and permit renewals in the previous sections. This includes

not ice of draft major modifications and may include informational meetings or public hearings and notice of resolution of the permit action taken.CHAPTER XV. PUBLIC INVOLVEM ENT (JULY 2002)

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## 11. WHEN TO GO BACK TO PUBLIC NOTICE WITH A REVISED DRAFT PERMIT

There are no regulations requiring Ecology to repeat public notice on a draft permit after it has been revised, however, to meet the intent of public notice requirements a revised draft permit should go back to public notice under either of the following conditions:

1. When a significant revision to the draft originally public noticed has taken more than 9 months to complete and there were comments from the first public notice. The draft should also go back to EPA for approval if the permit is a major.

or

2. If new information causes the effluent limits or loading to increase.

If an issue is discussed in the first draft and new information submitted by the public causes changes in the permit conditions, then another public notice is not necessary. However, if the change is lower limitations, the permit writer should inform the permittee before issuing the permit.CHAPTER XVI. APPEALS AND VARIANCES (JULY 2002)

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# CHAPTER XVI. APPEALS AND VARIANCES

A wastewater discharge permit is an administrative action of the Department of Ecology and is subject to both state administrative hearings and court appea ls.

Variances are exceptions within the law.



## 1. APPEAL OF THE FINAL PERMIT TO THE POLLUTION CONTROL HEARINGS BOARD (PCHB)

1.1 The PCHB

The PCHB is an independent agency of the state of Washington, composed of 3 members appointed by the governor for term s of 6 years. The members are qualified by experience or training in environmental matters. At least 1 member is a lawyer, and not more than 2 members are of the same political party.

The function of the board is to hear appeals of permit actions (issua nce, modification, denial), orders, rules, or regulations of Ecology or the air pollution control board. The regulatory requirements of the PCHB are given in Chapter 371

- 08 WAC.


## 1.2 Appeal Process

A permit writer may be involved in PCHB appeals of permit s, orders, and penalties.

The general process of appeal is:

1. The permit, order, or penalty is issued by the Department

2. The recipient has 30 days to appeal to the PCHB with a copy served to Ecology

3. Upon receipt of a correct appeal the board will set a he aring date. The hearing date is usually 4 to 6 months from the time of appeal. The filing of an appeal does not stop the requirements of the permit or order. However, the appealing party may also request a stay of the requirements of the permit or order until the time the appeal is decided. The PCHB will ask Ecology to respond to the request for stay and may schedule a separate hearing on the request. The PCHB has the option of moving the appeal hearing date up and hearing
both issues.

4. The hearing is held and a decision is issued.CHAPTER XVI. APPEALS AND VARIANCES (JULY 2002)

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### 1.2.1 AG Cooperation
The Attorney General's office will assign an assistant AG to work on the appeal. The assistant AG is the state's representative in the appeal and the permit writer serves as the technical
consultant. T he permit writer should be aware that the assistant AGs have a very heavy case load and they work with a large body of federal and state laws in several programs. The permit writer may first have to convince the assistant AG of the technical and legal meri ts of the appealed permit. If the permit fact sheet and other decision documentation are done correctly (see Chapter XIV) this should be an easy task. The attorney is the legal expert but you are the permit and water quality expert. The permit writer ma y have to teach the assistant AG about water quality in the process of justifying the permit. Preparation of a good permit fact sheet will save time here. The permit writer will also be responsible for preparing the submittals of evidence (documents and photos). A complete permit file will expedite this task.



### 1.2.2 Conferences Before the Hearing
Two types of conferences may be held before the hearing. One type is an optional informal conference in which a PCHB member is a facilitator. The purpose of th e meeting is to see if an agreement can be reached before going to hearing. The outcome of the meeting may be a settlement, no settlement, or an agreement to continue settlement proceedings. The PCHB has the authority to order these meetings, but they us ually do so only if requested by one of the parties.

If the case proceeds to hearing, a prehearing conference will be held to lay the legal ground rules for the hearing. This conference may be held at the end of an informal conference or by telephone.



### 1. 2.3 Deposition and Testimony
A permit writer may be required to give a deposition, in which the appellant attorney conducts the questioning that would otherwise occur in the hearing. The deposition is transcribed and presented as evidence. The appellant attorney may ask some of the same questions at the hearing.

After your deposition is transcribed, you'll have an opportunity to read it and make any corrections you believe are appropriate. It's extra work but worth the effort. There are no perfect

tra nscripts and some are absolute disasters, especially if they concern technical matters. Never waive the right to read and sign your transcript.CHAPTER XVI. APPEALS AND VARIANCES (JULY 2002)

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- 3 During the hearing in front of the PCHB, the permit writer will be examined and cross

- examined by the appellant attorney and the assistant AG.



### 1.2.4 PCHB Determination
Sometime after the conclusion of the hearing the PCHB will
issue a final det ermination and order. This may take up to a year. Either party in the hearing may then request a
reconsideration of the final determination. After review of the
case the PCHB will issue a decision and order. This decision and order may be appealed to a state superior court and thence appealed to the Federal Supreme Court , if necessary.

The PCHB has specific regulatory authority for wastewater discharge permits. If the PCHB determines, upon appeal, that a permit is invalid in any respect it will direct Ecology to reissue the permit in accordance with the directive and any applicable federal or state law.



### 1.2.5. Assistance
Staff in the Program Development Services Section have time allotted to assist in permit appeals.



## 2. VARIANCES

2.1 The Federal Va riances

The Clean Water Act provides a mechanism for modifying requirements of the Act in exceptional cases. These modifications are called variances. There are very specific provisions which must be met by an applicant before a variance may be granted. As the term implies, a variance is an exceptional situation. A permit writer might never work on a variance but should know what they are and the general procedure for handling them.

Variances are requested during the rulemaking period or during the fir st permit period after completion of the rulemaking.



### 2.1.1 Economic 301(c) (No guidance developed by EPA)
Section 301 (c) provides for a variance for non

- conventional pollutants from BAT effluent guidelines due to economic factors. The variance may also apply to non

- guideline limits (40 CFR 122.21(m)(2)(ii). The request for the variance from effluent limitations developed from BAT guidelines is normally filed by the discharger during the public notice period for the draft permit. Other filing time peri ods may apply as specified in 40 CFR 122.21(m)(2). The The AG's office and the Program Development Services Section have material to assist you in depositions
and hearings.CHAPTER XVI. APPEALS AND VARIANCES (JULY 2002)

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- 4 application for the variance must show that the modified requirements will



### • represent the maximum use of technology within the economic capability of the owner/operator, and



### • result in further progre ss toward the "no discharge goal".

The cost tests for evaluating this variance request are the same as given in the BPJ permitting for BAT. The applicant must pass these cost tests and, in addition, show compliance with BPT limitations and water quality standards.



### 2.1.2 Water Quality 301(g) (No guidance developed by EPA)
The CWA provides for a variance from BAT effluent guidelines for ammonia, chlorine, color, iron, and total phenols. The discharger must file a variance application which meets the
fol lowing requirements:



### • The modified requirements must result in compliance with BPT limits, pretreatment guidelines, or water quality standards of the receiving stream, whichever is applicable.



### • No additional treatment will be required of other point or non

- point source dischargers as a result of the variance approval.



### • And the modified requirements will not interfere with attain ment or maintenance of water quality to protect public water supplies, protection and propagation of a balanced population
of she llfish, fish, and wildfowl, and allow recreational activities in and on the water. Also, the modified requirements will not result in quantities of pollutants which may reasonably be anticipated to pose an unacceptable risk to human health or the environm ent, acute or chronic toxicity, or synergistic properties.

This variance request requires the discharger to perform water quality monitoring for toxicity, human health effects and dilution. It may also require the development of site

- specific water quali ty criteria.

If a discharger wants both a 301(g) variance and a 301 c variance, the requests must be submitted and considered together.



### 2.1.3 POTW Discharge to Marine Waters 301(h) (40 CFR Part 125, Subpart G)
This section allows POTW'S that discharge t o marine waters a conditional exemption from secondary treatment. The variance is conditional upon meeting water quality standards, conducting receiving water monitoring, limiting the discharge of toxics through pretreatment ofCHAPTER XVI. APPEALS AND VARIANCES (JULY 2002)

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- 5 industrial wastes, and prov iding primary treatment.



### 2.1.4 Innovative Technology 301(k) (40 CFR Part 125, Subpart C)
This section provides an extension of the deadline for compliance with effluent guidelines for up to 2 years if the discharger meets the following criteria:



### • Uses an innovative production process that will result in an effluent reduction greater than required.



### • Installs an innovative control technique that is likely to reduce the effluent below required
levels.



### • Achieves the required BAT effluent limits with an innovati ve system which is expected to cost significantly less.



### • This system must also have the potential for industry

- wide application.
A process should have been used less than 5 years to qualify as innovative. Industry

- wide application is defined as being appli cable to 2 or more facilities in 1 or more industrial category.



### 2.1.5 Fundamentally Different Factors 301(n) (40 CFR Part 125, Subpart D)
This section provides for variances based upon fundamentally different factors (FDF). FDF
variances for direct disch argers are available from effluent guidelines for BPT, BCT, and BAT if the individual facility is found to be fundamentally different from the factors considered in establishing the effluent guidelines. Approval of a FDF variance can result in an effluent limitation which is less stringent for a particular pollutant than would result from application of the national effluent guidelines. The FDF variance must be requested by the discharger within 180 days from the time an effluent limit is promulgated or r evised. No FDF variance can be approved if it results in violations of water quality standards.


## 2.2 The State Requirements

The Clean Water Act allows state requirements to be more stringent than federal requirements. The State of Washington has language in its water pollution law which is technology

- based (see discussion of all known, available, and reasonable treatment (AKART) in Chapter IV). This language may negate the use of the CWA variances in this state. A good example is the 301(h)
variance for municipal discharges to marine waters. Several Puget Sound municipalities were preparing to apply for marine waivers (authorized by the 1977 amendments to the CWA) and were discharging to marine waters with primary treatment. In 1984, the Department of Ec ology determined that primary treatment did not conform to state law, specifically, the discharges did not provide AKART. That decision was appealed by the cities to the PCHB. The PCHB ruled that AKART for municipal discharges was secondary treatment.CHAPTER XVI. APPEALS AND VARIANCES (JULY 2002)

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- 6 This page is purposely left blankREFERENCES (JULY 20 02)

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R

- 1 

# REFERENCES

Chapter references include references from corresponding appendices.



## CHAPTER I.

Puget Sound Water Quality Authority. 1987. Puget Sound Water Quality Management Plan. Amended in 1989 and 1991. 318 p.

Water Po llution Control Federation. 1987. The Clean Water Act of 1987 . 318 p.

Miller, L.A., R.S. Taylor, L.A. Monk. 1990. NPDES Permit Handbook . Government Institutes, Inc., Washington, D.C. 271 p.



## CHAPTER II.

U. S. Environmental Protection Agency. 1995. Revised Policy Statement on Scope of Discharge Authorization and Shield Associated with NPDES permits. Memo from Perciasepe, Herman and Nelson to Regional Administrators.



## CHAPTER IV

Miller, L.A., R.S. Taylor, L.A. Monk. 1990. NPDES Permit Handbook . Government Ins titutes, Inc., Washington, D.C. 271 p.



## CHAPTER V

Ecology 1998. Criteria for Sewage Works Design . Ecology publication #98

- 37 WQ.

Restrepo

- Postada, P.J. and Peter S. Eagleson, 1982. Identification of Independent Rainstorms

, Journal of Hydrology, 55, 303

- 31 9

Lukas, Andy and M. Steve Merrill, 1996, CSO Event Definition (Task 16.01 Technical Memorandum) , Brown and Caldwell.

Mau, Russell, 1999, Design Storm Statistical Analysis (Draft Memo to ERO), CTE Consultants.

Nicholson, G. and Adderley, V. 1994, TM 7.1 : Rainfall Analysis for CSO Facilities Planning

,REFERENCES (JULY 20 02)

Permit Writer’s Manual
R

- 2 CH2M Hill Technical Memorandum 7.1.

Woodward

- Clyde Consultants. 1989. Analysis of Storm Event Characteristics for Selected Rainfall Gages Throughout the United States (Draft ) prepared for the U.S. Environme ntal Protection Agency.

OTAK, Inc. 1989 . Columbia Slough Planning Study, Task 7.2, Representative Year Rainfall Analysis . Prepared for OTAK, Inc. for Brown and Caldwell and submitted to the City of Portland, Bureau of Environmental Services.



## CHAPTER VI.

D ilks, David and James Pendergast. 2000. Comparison of Dynamic and Steady

- State Models for Determining Water Quality Based National Pollutant Discharge Elimination System for Toxics

, Water Environment Research, March/April, 225

- 229.

Ecology. 1984. Shellfi sh Protection Strategy. Washington State Department of Ecology, April
1984. WDOE 84

- 4.

Fisher H.B., E.J. List, C.Y. Koh, J. Imberger, and N.H. Brooks. 1979. Mixing in Inland and
Coastal Waters . Academic Press. New York.

Gilbert, R.O. 1987. Statistical Methods for Environmental Pollution Monitoring. Van Nostrand Reinhold Company. New York.

Pelletier, G. 1996. Applying Metals Criteria to Water Quality

- Based Discharge Limits , EPA Project Completion Report (Grant No. CP990497

- 01

- 0), Watershed Assessments S ection, Environmental Assessment Program, Washington State Department of Ecology.

U. S. Environmental Protection Agency. 1982. Revised Section 301(h) Technical Support
Document. 430/9

- 82

- 001.

U. S. Environmental Protection Agency, Office of Water. 1985a. Technical Support Document for Water Quality

- based Toxics Control

.

U. S. Environmental Protection Agency. 1985b. Water Quality Assessment: A Screening Procedure for Toxic and Conventional Pollutants (Revised 1985). Part II. EPA/600/6

- 85/002b.
U. S. Envi ronmental Protection Agency. 1986. Quality Criteria for Water. EPA 440/5

- 86

- 001.

U. S. Environmental Protection Agency. 1988. Technical Guidance on Supplementary Stream Design Conditions for Steady State Modeling . EPA Office of Water. Washington, D.C.REFERENCES (JULY 20 02)

Permit Writer’s Manual
R

- 3 U . S. Environmental Protection Agency, Office of Water. 1991. Technical Support Document for Water Quality

- based Toxics Control . EPA/505/2

- 90

- 001.

U. S. Environmental Protection Agency, 1993. Memorandum from Martha Prothro, Acting
Assistant Administrator f or Water. Office of Water Policy and Technical Guidance on Interpretation and Implementation of Aquatic Life Metals Criteria . Office of Water, Washington, D.C.

U. S. Environmental Protection Agency, 1995. Method 1669: Sampling Ambient Water for Trace
Me tals at EPA Water Quality Criteria Levels . EPA 821

- R

- 95034.

U. S. Environmental Protection Agency, 1996a. Memorandum from Jeanette L. Kranacs and Henry D. Kahn, USEPA to Gary Bailey, Ecology, Autocorrelation of Cyanide in Anacortes Refinery Effluent, Mar ch 20, 1996.

U. S. Environmental Protection Agency, 1996b. Memorandum from Jeanette L. Kranacs and Henry D. Kahn, USEPA, to Gary Bailey, Ecology, Data Requirements for Analysis of Autocorrelation in Effluent Discharge, June 25, 1996



## CHAPTER VIII

Canter, LW, and Knox, RC, 1985, Septic Tank System Effects on Ground Water Quality, Lewis Publishers, Chelsea, MI, 336p.

Hantzsche, N., Finnemore, E. J., 1992, Predicting Ground

- Water Nitrate

- Nitrogen Impacts, Ground Water, Volume 30, No. 4, July

- August, pp 490

- 4 99.

Hem, J.D., 1985, Study and Interpretation of the Chemical Characteristics of Natural Water, US Geological Survey Water

- Supply Paper 2254, Washington DC, 263 p.

Kaplan, O.B., 1987, Septic Systems Handbook, Lewis Publishers, Chelsea, MI, 290 p.

Kramer , R., 1987, Report on Septic Tank Systems in Arizona, Report to the Legislature, Arizona Department of Health Services, 26 p.

Miller, DW, 1980, Waste Disposal Effects on Ground Water, Premier Press, Berkeley, CA, 512p.

Nelson, M.E. et al, 1988, Predictin g Nitrogen Concentrations in Ground Water: An Analytical Model, Matopma; Water Well Association, Focus Conference on Eastern Ground Water Issues, pp. 16

- 39.REFERENCES (JULY 20 02)

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- 4 Perkins, R.J., 1984, Septic Tanks, Lot Size and Pollution of Water Table Aquifers, Journal of
Envi ronmental Health, (May/June) Volume 46, No. 6, pp 298

- 304.

Office of Financial Management, 1991, 1991 Population, Trends for Washington State, Olympia, WA, 128 p.

US Environmental Protection Agency, 1980, Design Manual Onsite Wastewater Treatment and
Dis posal Systems, Technology Transfer Publication 1012, Cincinnati, OH, 392p.



## CHAPTER IX.

Akar, P.J. 1989. CORMIX2: an expert system for hydrodynamic mixing zone analysis of conventional and toxic submerged multiport discharges . Thesis. Cornell Universit y, School of Civil and Environmental Engineering, Ithaca, NY.

APHA. 1989. Standard methods for the examination of water and wastewater . Seventeenth Edition. American Public Health Association, Washington, DC. 1,268 pp.

ASTM. 1990. Standard guide f or conducting sediment toxicity tests with freshwater
invertebrates. ASTM Standard E1383

- 90. American Society for Testing and Materials, Philadelphia, PA.

Baumgartner, D.J., W.E. Frick, P.J.W. Roberts, and C.A. Bodeen. 1992. Dilution models for efflue nt discharges . U.S. Environmental Protection Agency, Pacific Ecosystems Branch,
ERL

- N, Newport, OR. 168 pp.

Bennett, J., and J. Cubbage. 1992. Evaluation of Bioassay Organisms for Freshwater Sediment Toxicity Testing . Washington Department of Ecology , Environmental Investigations and Laboratory Services, Olympia, WA.

Doneker, R.L., and G.H. Jirka. 1989. CORMIX1: an expert system for hydrodynamic mixing zone analysis of conventional and toxic submerged single port discharges . Technical Report.
U. S. Environmental Protection Agency, Environmental Research Laboratory, Athens, GA.

Ecology. In preparation. WASP application guidance manual . Washington Department of Ecology, Sediment Management Unit, Olympia, WA.

Ecology 1990. Final environmental i mpact statement for the Washington State Sediment Management Standards. Chapter 173

- 204 WAC. Washington Department of Ecology, Olympia,
WA.REFERENCES (JULY 20 02)

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R

- 5 Ecology. 1991a. Evaluation of high

- speed centrifugation for the characterization of municipal
and industrial was tewater particulates . Report in progress. Washington Department of Ecology, Compliance Monitoring Section, Olympia, WA.

Ecology. 1991b. Guidance for determination and allocation of total maximum daily loads (TMDL) in Washington State . Washington Depa rtment of Ecology, Watershed Assessments Section, Environmental Investigations and Laboratory Services Program, Olympia, WA.

Ecology. 1991c. Sediment cleanup standards user manual . Washington Department of Ecology, Sediment Management Unit, Olympia, WA

.

Ecology. 1991d. Sediment site ranking, SEDRANK guidance document . Prepared for Washington Department of Ecology by PTI Environmental Services, Bellevue, WA. Washington Department of Ecology, Sediment Management Unit, Olympia, WA.

Ecology. 1992b. Procedures for public involvement, NPDES and state wastewater discharge permits . October 1, 1992 policy statement. Washington Department of Ecology, Olympia, WA.

Ecology 1993. Sediment Source Control Standards User Manual

.

Horowitz, A.J. 1986. Comp arison of methods for the concentration of suspended sediment in river water for subsequent chemical analysis . Environmental Science and Technology 20(2):155

- 160.

Metcalf & Eddy. 1979. Wastewater engineering: treatment/disposal/reuse . Second Edition. McGraw Hill Book Company, New York, NY. 920 pp.

Norton, D. 1990. Use of sediment traps to monitor contaminant flux to City Waterway sediments: interim report . Washington Department of Ecology, Environmental Investigations and Laboratory Services Pr ogram, Olympia, WA. 32 pp.

Pastorok, R.A., R. Sonnerup, J.J. Greene, M.A. Jacobson, L.B. Read, and R.C. Barrick. 1989. Interim performance standards for Puget Sound reference areas . Prepared for Washington Department of Ecology, Olympia, WA. PTI Envi ronmental Services, Bellevue, WA.

Plumb, R.H., Jr. 1981. Procedure for handling and chemical analysis of sediment and water samples . Technical Report EPA/CE

- 81

- 1. U.S. Environmental Protection Agency and U.S. Army Corps of Engineers, Waterways Experi ment Station, Vicks burg, MS.

PSEP. 1986. Recommended protocols for measuring conventional sediment variables in Puget
Sound . Prepared for Puget Sound Estuary Program by Tetra Tech, Inc. In: RecommendedREFERENCES (JULY 20 02)

Permit Writer’s Manual
R

- 6 Protocols for Measuring Selected Environmental Variables in Puget Sound. U.S. Environmental Protection Agency Region 10, Seattle, WA.

PSEP. 1987a. Puget Sound environmental atlas . Prepared for U.S. Environ mental Protection Agency, Puget Sound Estuary Program; Puget Sound Water Quality Authority; and U.S. Army Corps of Engineers. Evans

- Hamilton, Inc. and D.R. Systems, Inc., Seattle, WA.

PSEP. 1987b. Recommended protocols for sampling and analyzing subtidal benthic macroinvertebrate assemblages in Puget Sound . Prepared for Puget Sound Estuary P rogram by Tetra Tech, Inc. In: Recommended Protocols for Measuring Selected Environmental Variables in Puget Sound . U.S. Environmental Protection Agency Region 10, Seattle, WA.

PSEP. 1989a. Recommended guidelines for measuring metals in Puget Sound w ater, sediment, and tissue samples . Prepared for Puget Sound Estuary Program by PTI Environmental Services.
In: Recommended Protocols for Measuring Selected Environmental Variables in Puget Sound

. U.S. Environmental Protection Agency Region 10, Seattle , WA.

PSEP. 1989b. Recommended guidelines for measuring organic compounds in Puget Sound sediment and tissue samples . Prepared for Puget Sound Estuary Program by PTI Environmental
Services. In: Recommended Protocols for Measuring Selected Environment al Variables in Puget Sound . U.S. Environmental Protection Agency Region 10, Seattle, WA.

PSEP. 1991a. Recommended guidelines for conducting laboratory bioassays on Puget Sound
sediments . In: Recommended Protocols for Measuring Selected Environmental Variables in Puget Sound . U.S. Environmental Protection Agency Region 10, Puget Sound Estuary Program, Seattle, WA.

PSEP. 1991b. Recommended guidelines for measuring conventional marine water

- column variables in Puget Sound . Prepared for Puget Sound Estuary Program by PTI Environmental
Services. In: Recommended Protocols for Measuring Selected Environmental Variables in Puget Sound . U.S. Environmental Protection Agency Region 10, Seattle, WA.

PSEP. 1991c. Recommended protocols for measuring sele cted environmental variables in Puget Sound . U.S. Environmental Protection Agency Region 10, Office of Puget Sound, Puget Sound Estuary Program, Seattle, WA.

PTI. 1991. Recommended sediment impact and recovery zone models and case study analysis

. Prep ared for Washington Department of Ecology, Olympia, WA. PTI Environmental Services, Bellevue, WA.

Tetra Tech. 1986. Analytical methods for U.S. EPA priority pollutants in particulate matter from discharges and receiving waters . Prepared for Washington Department of Ecology andREFERENCES (JULY 20 02)

Permit Writer’s Manual
R

- 7 U.S. Environmental Protection Agency. Tetra Tech, Inc., Bellevue, WA. 75 pp. + appendices.

U.S. EPA. 1986. Test methods for evaluating solid waste (SW

- 846): physical/chemical
methods . U.S. Environmental Protection Agency, Office of Solid Waste, Washington, DC.

U.S. EPA. 1987. U.S. EPA Contract Laboratory Program statement of work for inorganic analysis, multi

- media, multi

- concentration . U.S. Environmental Protection Agency, Washington, DC.

U.S. EPA. 1988a. U.S. EPA Contract Laboratory Program statement of work for organic analysis, multi

- media, multi

- concentration . U.S. Environmental Protection Agency, Washington, DC.

U.S. EPA. 1988b. WASP4: a hydrodynamic and water quality model. Model theory

- users manual a nd programmers guide . EPA/600/3

- 87/039. U.S. Environmental Protection Agency, Washington, DC.

U.S. EPA. 1989. Method 1625C: semivolatile organic compounds by isotope dilution GC/MS

. U.S. Environmental Protection Agency, Office of Water Regulations a nd Standards, Industrial Technology Division, Washington, DC.

U.S. EPA. 1991. Analytical method for determination of acid volatile sulfide in sediment . U.S. Environmental Protection Agency, Office of Science and Technology, Health and Ecological
Criter ia Division, Washington, DC.

U.S. GOFS. 1989. Sediment trap technology and sampling . U.S. Global Ocean Flux Study Planning Report Number 10. G. Knauer and V. Asper (eds). University of Southern Mississippi,
Center for Marine Science.



## CHAPTER XIII.

Ak ar, P.J. and Jirka, G.H. 1990. Cormix2: An Expert System for Hydrodynamic Mixing Zone Analysis of Conventional and Toxic Multiport Diffuser Discharges . USEPA Environmental Research Laboratory, Athens, GA. Draft.

American Public Health Assoc., American Water Works Assoc., and Water Pollution Control
Federation. 1985. Standard Methods for the Examination of Water and Wastewater , Sixteenth
Edition.

American Society for Testing and Materials. 1992. Annual Book of ASTM Standards , Volumes
11.04.REFERENCES (JULY 20 02)

Permit Writer’s Manual
R

- 8 Baker, J.M. and W.J. Wolff. 1987. Biological Surveys of Estuaries and Coasts.

Doneker, R.L. and Jirka, G.H. 1990. Cormix1: An expert system for Hydrodynamic mixing zone analysis of Conventi on al and Toxic Submerged Single Port Discharges . USEPA, Environmental Research Laboratory, Athens, GA. EPA/600

- 3

- 90/012.

Ecology 1993. Sediment Source Control Standards User Manual

.

Keith, L.H. 1991. Environmental Sampling and Analysis: A Practical Guide . Lewis Pub. Inc.,
ISBN 0

- 87371

- 381

- 8, 129 pp.

Puget Sound Water Quality Authority. 1991. Puget Sound Water Quality Management Plan

.

Tetra Tech. 1986a. Recommended Protocols for Measuring Metals in Puget Sound Water, Sediment and Tissue Samples

.

Tetra Tech. 1986b. Recommended Protocols for Measuring Selected En vironmental Variables in Puget Sound

.

U.S. Environmental Protection Agency. 1973. Handbook for Monitoring Industrial Wastewater

.

U.S. Environmental Protection Agency. 1979. Methods for the Chemical Analysis of Water and
Wastewater , EPA 600/4

- 79

- 020.

U.S. Environmental Protection Agency. 1982a. Design of 301(h) Monitoring Programs for Municipal Wastewater Discharges to Marine Waters . EPA 430/9

- 82

- 010.

U.S. Environmental Protection Agency. 1982b. Handbook for Sampling and Sample Preservation of Water and Wastewater . EPA

- 600/4

- 82

- 029.

U.S. Environmental Protection Agency. 1984. NPDES Compliance Inspection Manual

.

U.S. Environmental Protection Agency. 1987a. Guidance Manual for the Development and Implementation of Local Discharge Limitati ons Under the Pretreatment Program

.

U.S. Environmental Protection Agency. 1987b. Short

- Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Marine and Estuarine Organisms , EPA/600/4

- 87/028.

U.S. Environmental Protection Agency. 1987c. Permit Writer's Guide to Water Quality

- Based Permitting for Toxic Pollutants . EPA 440/4

- 87

- 005.REFERENCES (JULY 20 02)

Permit Writer’s Manual
R

- 9 U.S. Environmental Protection Agency. 1987d. Training Manual for NPDES Permit Writers

.
U.S. Environmental Protection Agency. 1989. Sho rt

- Term Methods for Estimating the Chronic Toxicity of Effluents and Receiving Waters to Freshwater Organisms , EPA/600/4

- 89/001.

U.S. Environmental Protection Agency. 1990. Methods for Measuring the Acute Toxicity of Effluents to Freshwater and Marine O rgan isms , EPA/600/4

- 90/027.

U.S. Environmental Protection Agency. 1991. Technical Support Document for Water Quality Based Toxics Control

.
U.S. Environmental Protection Agency. 1992. NPDES Storm Water Sampling Guidance Document , EPA 833

- B

- 92

- 001.

U .S. Geological Survey. 1989. Methods for Analysis of Inorganic Substances in Water and Fluvial Sediments

.
U.S. Geological Survey. Kilpatrick, F.A., and Cobb, E.D. 1985. Measurement of Discharge Using Tracers. Chapter A16. Techniques of Water

- Resources Investigations of the USGS , Book 3, Application of Hydraulics. U.S. Department of the Interior. Reston, VA.

U.S. Geological Survey. Wilson, J.F., Cobb, E.D., Kilpatrick, F.A. 1986. Fluorometric Procedures for Dye Tracing. Chapter A12. Techniques of W ater

- Resources Investigations of the USGS , Book 3, Application of Hydraulics. U.S. Department of the Interior. Reston, VA.

Washington State Department of Ecology. 1998. Criteria for Sewage Works Design . Ecology Publication No. 98

- 37WQ.

Washington State Department of Ecology. 1991a. Guidelines and Specifications for Preparing Quality Assurance Plans

.
Washington State Department of Ecology. 1991b. Laboratory Users Manual

.
Washington State Department of Ecology. 1990a. Technical Guidance for Asse ssing the Quality of Aquatic Environments in Washington State

.
Washington State Department of Ecology. 1992. Water Quality Program Inspection Manual

.
Washington State Department of Ecology. 1990b. Water Quality Technical Guidance Manual.

Yearsley, J. 1991. Diffusion in near

- shore and riverine environments. USEPA Region 10. EPA 910/9

- 87

- 168.REFERENCES (JULY 20 02)

Permit Writer’s Manual
R

- 10 This page is purposely left blankAPPENDIX 1. (JULY 20 04)

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APP1

- 1 

# APPENDIX 1

1. INDEX TO NPDES REGULATIONS

SUBJECT CFR NUMBER

301(b)

- see Fundamentally Different Factors 301(c).....

........................................................................... ............................... 122.21(1)(2) 301(g)................................................................................

............................... 122.21(1)(2) 301(h)

- Secondary treatment waiver................................

............ ................... 122.21(m)(1)
122.56 301(k).................................................................................

.............................. 122.21(m)(2) 122.21(l)(3)
122.90

301(k)................................................................................

............................... 122.21(l)( 4)
125.20 316(a)................................................................................

............................... 122.21(l)(6)
125.70 124.51(7)(a)
124.66 401(a) State Certification.........................................................

...................... 124.54
124.65
Administrat ive Procedures Act
Permit Continuation......................................................

...................... 122.6
Administrative Record.............................................................

........................ 124.9
Alternate Test Procedures

................................ ................................ ................ 136.4
Anti

- Backsliding (Reissued Permits)

............................................ ................... 122.44(l) Application..........................................................................

............................. 122.21 Completeness..............................................................

............................... 122.21(e) 124.3(c)

- (g) Existing Facilities.........................................................

.............................. 122.21(g) Municipal...................................................................

................................ 122.21(j) Submittal Deadline (Time to Apply)...................................

...................... 122.21(c) Aquaculture

......................................................................... ............................. 122.25
125.10 Aquatic Animal Production Facilities Application.................................................................

........................ 122.21(h)(2)
Definition...........................

........................................ ......................... 122.24 Appendix AAPPENDIX 1. (JULY 20 04)

Permi t Writer’s Manual
APP1

- 2 Average Monthly Discharge Limitation

................................ .......................... 122.2

Average Weekly Discharge Limitation (POTW)...........................

................. 122.2 Backsliding...............................................................

........... ............................ 122.62(a)(15) 122.62(a)(17) Best Management Practices
Definition...................................................................

......................... 122.2 122.44(k)
125.100
Best Professional Judgment (Case

- by

- Case).................................

.................. 125.3 Boilerplate (General) Permit Conditions........................................

................. 122.41

- 122.44 Bypass...............................................................................

............................... 122.41(m) Calculating NPDES Permit Conditions.............................

........... ................... 122.45
Case

- by

- Case Limitations.........................................................

....................... 122.44(a), 125.3
Case

- by

- Case Permits.............................................................

......................... 124.52
Coast Guard......................................

................................... ............................ 122.44 Coastal Zone Management Act...................................................

..................... 122.49(d) Combined Sewers (stormwater/wastewater....................................

................. 133.103(a) Combined Wastes (municipal/industrial)

....................................... ................. 133.103(b) Comments During Public Notice Period........................................

.................. 124.13 Compliance Schedules.............................................................

........................ 122.41(l)(5)
122.47 122.62(a)(13)
C omputation of Time..............................................................

......................... 124.20 Concentrated Animal Feeding Operations Application.................................................................

................................ 122.23
Definition...................................

................................ ................................ 122 Appendix B Concentrated Aquatic Animal Production...........

................................ ............ See Aquatic Animal Production Conditions applicable to all Permits

................................ ................................ 122.41 Confidentiality of Information...................................................

...................... 12 2.7 Consolidation of Permit Processing.............................................

.................... 124.4 Continuation of Expiring Permits................................................

.................... 122.6
Conventional Pollutants........................................................

... ........................ 401.16
DMR

- See Discharge Monitoring Report Daily Average

- See Average Monthly Daily Maximum

- See Maximum Daily
Definitions..........................................................................

.............................. 122.2
124.2
401.11
Denial of Permit............

........................................................ ........................... 124.6(b)
Public Notice...............................................................

............................... 124.10(a)(i)APPENDIX 1. (JULY 20 04)

Permi t Writer’s Manual
APP1

- 3 Design Flow (POTW).............................................................

......................... 122.45(b)
Dilution/ Ocean..................................................................

............................... 125.123(d)(1)(i)
Dilution/Pollution..................................................................

.......................... 122.45(f)(1)(iii) Discharge Monitoring Report (DMR)...............................

............ .................. 122.41(l)(4)(i) Discharge of Pollutants

- Definition.............................................

................... 122.2 Disposal into well, POTW, or land application..............................

................. 122.50 122.45(i)
Draft Permit................................

........................................ ............................. 124.6
Duration of Permits................................................................

.......................... 122.46 Duty to Comply....................................................................

............................ 122.41(a) Duty to Mitigate.........

........................................................... ........................... 122.41(d) Duty to Provide Information.....................................................

....................... 122.41(h) Duty to Reapply....................................................................

........................... 122.41(b)
E ffective Date......................................................................

............................ 124.15 Effluent Limits for Continuous Discharges....................................... 122.45(d)
EIS

- Public Notice for New Source............................................

.................... 124.10(b)(1)
EIS

- Fi nal..........................................................................

.............................. 124.61 Endangered Species Act...........................................................

....................... 122.49(c) EPA Review and Objection to State Issued NPDES Permits.........................

.. 123.44 Environmental Impact Statement
New Source................................................................

................................ 122.29(c)
NEPA.......................................................................

................................ .. 40 CFR Part 6 Evidentiary Hearing Procedures..........

....................................... ..................... 124.71

- 124.91
Ex Parte Communication.........................................................

........................ 124.78 Exclusions (from NPDES permits).................................................................. 122.3 Existing Source

- Definition......................................................

...................... 122.29(a)(3) Expiration Dates (Duration of Permits).........................................

.................. 122.46, 124.20
Extension of Public Comment Period........................................

... ................... 124.12(c)
Extension of Permits..............................................................

.......................... 122.46(b)
122.6
Fact Sheets..........................................................................

............................. 124.8
124.56 Feedlots (see concentrated animal feedin g operations)
Filter Backwash....................................................................

........................... 125.3(g)
Fish and Wildlife Coordination Act............................................

..................... 122.49(e) Fish Farms (see aquatic animal production facilities)
Flow M onitoring Required....................................................................

.......... 122.44(i)(1)(ii) 403.12(b)(4) Fundamentally Different Factors................................................

..................... 122.21(l)(1)
125.30 122.44(d)(8)
General Permits.....

............................................................... ............................ 122.28APPENDIX 1. (JULY 20 04)

Permi t Writer’s Manual
APP1

- 4 Public Notice..............................................................

................................ 124.10(c)(2)(i) Special Procedures........................................................

............................. 124.58
Innovative Technology

- see 301(k) Inspection and Entry...............................................................

......................... 122.41(i) Intake Credits (technology

- based)

................................ ................................ ... 122.45(g)
Instream Aeration..................................................................

........................... 125.3(f)
I nternal Waste Streams............................................................

........................ 122.45(h)
Introduction of New Pollutants

- POTW.......................................

.................. 122.42(b)
Issuance and Effective Dates.................................................

.... ...................... 124.15
124.60
Mass Limitations...................................................................

........................... 122.45(f) Maximum Daily Discharge Limitations........................................

.................. 122.2
Metals.....................................................

........................... ............................... 122.45(c)
Minor Modifications...............................................................

......................... 122.62
Modifications.......................................................................

............................ 122.62
122.5 Monitoring and Recording....

.................................................... ....................... 122.48(b) Monitoring and Records..........................................................

........................ 122.41(j) Monitoring Reports.......................................................

............................. 122.41(l)(4) Requirements...

............................................................ .............................. 122.44(i) Record keeping............................................................

.............................. 122.21(o) Monitoring Waiver (for guideline

- listed pollutants)

................................ ........ 122.44(a)(2)
NPDES

- Definition.................

............................................. ........................... 122.2 National Environmental Policy Act.............................................

.................... 122.49(g)
National Historic Preservation Act..............................................

.................... 122.49(b) Navigation..............

............................................................. ............................. 122.44(q)
124.58 Need to Halt or Reduce Activity Not a Defense..............................

................ 122.41(c)
Net/Gross............................................................................

............................. 122 .45(g) New Discharger

- Definition.....................................................

....................... 122.2
New Source

- Application POTW...............................................

.................... 122.21(j) Application industrial.....................................................

............................ 122.21(k)
Criteria......................................................................

................................ . 122.29(b)
Definition...................................................................

................................ 122.2 Mitigation Measures.....................................................

. ............................ 122.44(d)(9) Prohibited Discharges....................................................

............................ 122.4(i)
Public Notice...............................................................

............................... 124.10(a)(1)(vi) No Discharge Zones (Vessels)

................................ ................................ ......... 140.4
Non

- Advisory Panel Procedures

................................................ ...................... 124.111

- 124.128
Non

- Continuous Discharges......................................................

...................... 122.45(e) Noncompliance

- Anticipated.....................................................

..................... 122.41(l)(2)
Other

........................................................................ ................................ .. 122.41(l)(7)APPENDIX 1. (JULY 20 04)

Permi t Writer’s Manual
APP1

- 5 Notification Levels.................................................................

.......................... 122.42(a) 122.44(f) Ocean Discharge Criteria.......................................

.................. ........................ 125. 1 20
Offshore Oil and Gas Facilities..................................................

...................... 122.28(c)
On

- Site Construction (New Source).............................................

................... 122.29(c)(4) Operation and Maintenance....................

................................... ...................... 122.41(e) Permit Application Forms........................................................

........................ 122.1(d)(1)
Permit Shield

................................ ................................ ................................ .... 122.5(a)(1) pH

- Continuous Monitoring.....................................................

....................... 401.17
Plan ned Changes...................................................................

........................... 122.41(l)(1)
Pollutant

- Definition..............................................................

......................... 122.2 Pollutants in Intake Water (Net/Gross)...................................

...... ................... 122.45(g)
POTW

- Applications..............................................................

........................ 122.21(j)
Pretreatment........................................................................

............................. 122.44(j)
40 CFR 403 Primary Industry.......................

............................................ ........................... 122 Appendix A Privately Owned Treatment Works..............................................

................... 122.44(m)
Production

- Based Limits..........................................................

....................... 122.45(b) Prohibitions (No permit may be issued)........................................................... 122.4 Proper Operation and Maintenance..............................................

................... 122.41(e) Property Rights................................................................

..... ........................... 122.41(g) Public Hearings (Public Notice).................................................

..................... 124.10(b)(2) 124.10(d)(2)
124.12
Public Notice.......................................................................

............................. 124.10(d)
Contents...................

................................................. ................................ . 124.10(d) Reapplication.......................................................................

............................ 122.21(d) Reasonable Potential (violation of WQ standards)............................

.............. 122.44(d)(1)(i)

- (vi)
Rec ord Keeping....................................................................

..................... 122.21(o) 122.41(j)(2) Reopener Clause....................................................................

.......................... 122.44(c) Reopening of Public Comment Period.......................

................... .................. 124.14 Response to Comments............................................................

........................ 124.17
Retention of Records..............................................................

.......................... 122.41(j)(2)
Revocation and Reissuance....................

................................... ....................... 122.62
124.5 Secondary Treatment Requirements.............................................

................... 133 Secondary Treatment Variance (see 301(h)) Sewage Sludge....................................................................

.. ........................... 122.44(o) Signatory Requirements...........................................................

........................ 122.22
Silviculture..........................................................................

............................. 122.27 Small Business Exemption....................................

.................... ...................... 122.21(g)(8)APPENDIX 1. (JULY 20 04)

Permi t Writer’s Manual
APP1

- 6 Standard Conditions

................................ ................................ ......................... 122.41
State Certification .................................................................

.......................... 124.53 State Certification (301(h)).......................................................

....................... 124.54
124.55
St ates more Restrictive............................................................

........................ 122.1(f)
Statement of Basis..................................................................

.......................... 124.7 Statutory Deadlines for POTW..............................................

.... ...................... 125.3(a)(1) Statutory Deadlines for non

- POTW.............................................

.................... 125.3(a)(2) Statutory Variances and Extensions.............................................

.................... 125.3(b) Stays of Contested Permit Conditions........................

................... .................. 124.16
124.60
Storm Water........................................................................

............................. 122.26 Application and Deadline

................................ ................................ ... 122.26(e) Technology Based Effluent Limits...............................................

................... 122.44(a)
Ten Year Protection Period for New Sources and Dischargers............

........... 122.29(d)
Termination of Permit.............................................................

......................... 122.64 Thermal Dischargers (see 316(a))
TMDL......................................................

................................ ...... 130.7 Toxic Pollutants (definiti on)....................................................................

........ 122.2
Toxic Pollutants

- List...............................................................

......................... 401.15
Transfer of Permit.................................................................

........................... 12 2.41(l)(3)
122.61 Total Toxic Organics (TTO)

................................ ................................ ............ varies by category

see 413.02(i) for an example Twenty

- four hour Reporting......................................................

...................... 122.41(l)(6) 122.44(g) Upset............................................

..................................... ............................... 122.41(n)

Water Quality Standards..........................................................

........................ 122.44(d) Federally Promulgated..................................................

............................. 131 Waters of the U.S. (and Wetlands)

- defi nition...............................

................. 122.2 Whole Effluent Toxicity

- definition............................................

................... 122.2
Wild and Scenic Rivers Act......................................................

....................... 122.49(a)APPENDIX 4. TECHNOLOGY

- BASED LIMITS (JULY 20 02)

Permit Writer’s Manual
APP4

- 1 

# APPENDIX 4

I. AUTOCORRELATIO N

The background material for this example is presented in Chapter IV, Part 4.

Adjustment of Monthly Average Effluent Limitations for Autocorrelation

. The Department of Ecology required an industrial discharger to monitor its cyanide discharge for

severa l years prior to permit renewal. The data is presented below in Table AP4

- 1. The data indicated a reasonable potential for violation of the water quality standards and the necessity of a water quality

- based effluent limit in the new permit. The facility requested an adjustment of the average monthly effluent limit due to autocorrelation. The request and data were passed on to USEPA for assistance in evaluating the autocorrelation. Calculation of autocorrelation involves two steps: 1. calculation of aut ocovariance and then 2. using the autocovariance to calculate the significant autocorrelation coefficients. These coefficients are used in calculating the monthly average effluent limitation.

An example is presented to show the process but the example sh ows a one week cycle and would probably not be granted an adjustment to the effluent limit. The facility used in this example applied for an autocorrelation adjustment but also provided the data for a higher site

- specific water quality criteria for cyanid e. With the higher criteria, they no longer showed a reasonable potential or required an effluent limit.

Table AP4

- 1. Effluent cyanide data.

DATE Cyanide ug/ l DATE Cyanide ug/ l DATE Cyanide ug/ l 3/2/90 38 7/3/90 15 12/16/93 79 3/3/90 70 7/5/90 10 12/22/93 38 3/4/90 50 7/10/90 11 12/29/93 47 3/5/90 66 7/12/90 10 01/05/94 27 3/6/90 52 7/17/90 3 01/12/94 33 3/7/90 35 7/19/90 5 01/19/94 28 3/14/90 40 7/24/90 3 01/26/94 42 3/15/90 47 7/26/90 4 02/02/94 29 3/22/90 3 8/1/90 5 02/09/94 37 3/23/90 23 8/2/90 5 02/16/94 87 3/27/90 2 8/7/90 5 02/23/94 44APPENDIX 4. TECHNOLOGY

- BASED LIMITS (JULY 20 02)

Permit Writer’s Manual
APP4

- 2 3/30/90 18 8/16/90 3 03/01/94* 70 4/3/90 35 8/20/90 4 03/02/94 45 4/4/90 30 8/23/90 4 03/09/94 43 4/5/90 32 8/28/90 3 04/06/94 20 4/6/90 34 8/30/90 5 04/13/94 12 4/9/90 39 4/1/91 6 0 04/19/94 15 4/12/90 44 4/8/91 10 04/27/94 26 4/17/90 48 03/26/93 60 05/04/94 22 4/19/90 51 03/30/93 56 05/11/94 23 4/25/90 64 04/02/93 58 05/18/94 16 4/26/90 33 04/06/93 40 05/25/94 21 4/29/90 70 04/08/93 74 06/01/94 19 4/30/90 34 04 /12/93 66 06/08/94 17 5/8/90 15 04/19/93 52 06/15/94 15 5/10/90 13 04/22/93 37 06/30/94 23 5/15/90 20 04/25/93 39 07/06/94 20 5/17/90 20 05/10/93 21 07/13/94 15 5/22/90 23 05/12/93 13 7/20/94 11 5/24/90 18 05/14/93 12 7/27/94 10 5/29/9 0 8 6/1/93* 20 8/3/94 14 5/31/90 12 06/16/93 13 8/10/94 10 6/5/90 10 06/18/93 11 8/17/94 4 6/7/90 2 06/21/93 9 8/24/94 13 6/12/90 2 06/24/93 13 8/31/94 8 6/14/90 2 07/10/93 19 9/7/94 35 6/19/90 23 07/12/93 18 9/14/94 26 6/21/90 17 07/14/93 12 9/21/94 38 6/26/90 13 07/16/93 15 9/28/94 46 6/28/90 14 07/29/93 20 10/5/94 5 08/04/93 13 10/11/94 6

DATE Cyanide ug/ l 10/18/94 4 10/26/94 4 11/2/94 35 11/9/97 44 11/17/94 34 11/22/94 35 11/30/94 26APPENDIX 4. TECHNOLOGY

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- 3 12/7/94 4 3 12/14/94 53 12/21/94 30 12/28/94 34

1/5/95 34 1/11/95 53 1/26/95 46 2/1/95 41 2/8/95 49 2/15/95 24 2/22/95 19 3/1/95 32 3/8/95 33 3/15/95 22 3/29/95 23

Calculation of Autocovariance Estimates The cyanide data consists of 144 individual d aily composite samples representing concentration measurements taken during the period March 2, 1990 to March 29, 1995. Days with no samples are considered missing observations. For purposes of calculating the autocovariances, let z 1 , z 2 , ..., z N denote the N concentration measurements. The following formula (Box & Jenkins, 1976, p.32) was used to calculate the estimate of the autocovariance:

C N Z Z Z Z

k t

t N k

t k = − −

= −

+ 

## ∑ 1

1 ( )( )

where,

N = number of observations = 144
k = lag between observations in days = 0, 1,...,30

t = the day, where t = 1 = March 2,1990 t = 2 = March 3,1990 t = 3 = March 4,1990

•

•

• t = 1854 = March 29,1995

Days on which concentration amounts were not reported are considered to be missing observations. Therefore only thos e values of t where data has been reported will be used toAPPENDIX 4. TECHNOLOGY

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- 4 calculate autocovariances.

The following lists t=1 through t=13 and gives some calculation examples:

value of t date concentration amount
1 3/2/90 38
2 3/3/90 70
3 3/4/90 50
4 3/5/90 66 5 3/6/90 52
6 3/7/90 35
7

– 12 3/8/90

- 3/13/90 missing

13 3/14/90 40

The mean of the concentration amounts for the entire data set is:

Z N Z
t

t N k

= =

= − 

## ∑ 1 26 9653

1 .

Note: Only use those values of t w here concentration amounts exist.APPENDIX 4. TECHNOLOGY

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- 5 Calculations for a lag of one day using all measurements one day apart (i.e., k=1). For example:

value of t calculation
1 (38

- 26.9653)(70

- 26.9653) = 474.875
2 (70

- 26.9653)(50

- 26.9653) = 991.291
3 (50

- 2 6.9653)(66

- 26.9653) = 899.153
4 (66

- 26.9653)(52

- 26.9653) = 977.222
6

- 13 *

• •

• •

• • 1853 *
N = 144 Sum of contributions = 5759.7696

Autocovariance of lag two = 8784.0864/144 = 61.0006

* concentra tion amount two days from this value of t is missing and therefore cannot contribute toward an autocovariance for a lag of two. Concentration values two days apart must exist to be included in the calculation of the autocovariance for lag two.

It is reco mmended (Box & Jenkins, 1976, p.33) that k not be larger than N/4. In our case, we recommend that k not be larger than 30 since the limits are calculated on a monthly basis. The
estimate of the k th lag autocorrelation is

r k = C

C

k

o

The number of observations used to estimate r k and c k need not be equal. Therefore missing data are not a problem, however missing data does prevent standard time series modeling. Estimates of autocovariance and autocorrelation for lags 1

- 30 are given in Table AP4

- 2.

A lag of 7 indicates the autocorrelation for observations 7 days apart. (For example, successive Mondays would have a lag of 7, successive Tuesdays would have a lag of 7, etc.)APPENDIX 4. TECHNOLOGY

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- 6 Table AP4

- 2. Estimates of Autocovariance and Autocorrela tion: Lags 0

- 30
Lag Autocovariance Autocorrelation

0 367.117

1 39.9984 0.10895

2 61.0006 0.16616

3 33.7574 0.09195

4 44.5250 0.12128

5 37.6707 0.10261

6 49.7120 0.13541

7 101.503 0.27649

8 27.0599 0.07371

9 39.8864 0.10865

10 28.6923 0.07816

1 1 16.0746 0.04379

12 32.0776 0.08738

13 61.6921 0.16804

14 75.6883 0.20617

15 8.7124 0.02373

16 18.3915 0.05010

17 16.0578 0.04374

18

- 4.7897

- 0.01305

19 17.2813 0.04707

20 9.6339 0.02624

21 68.9943 0.18794

22 0.4231 0.00115

23 19.9909 0.05445

24

- 0.0996

- 0.00027

25

- 1.4486

- 0.00395

26 18.0623 0.04920

27 9.7315 0.02651

28 57.6594 0.15706

29

- 0.4159

- 0.00113

30 14.6503 0.03991APPENDIX 4. TECHNOLOGY

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- 7 Significance of Autocovariances

Using

var[r k ] = 1

N

to approximate the variance of the autocorrelations (Box & Jenkins, 1976, p.35), where N = 144, the approximate variance is 0.006944. The corresponding approximate standard error is 0.083307. The approximate standard error is compared to the autocorrelations (Box & Jenkins, 1976, p .36). In cases where the autocorrelation is greater than two standard deviations (0.166614) the autocovariance was considered significant. Autocovariances for lags 2, 7, 13, 14, and 21 were significant. Adjustment for the lag 2 autocorrelation was not m ade in our limitation calculations because daily monitoring would be required to implement such limits properly and the permit writer had indicated a requirement of weekly monitoring.

Calculation of Limits

Calculation for limits using the covariance of lags 7, 14, and 21 days follows:

Var[Mean(X)] = (1/16)[4 * Var(X) + 6 * 0.27649 Var(X) + 4 * 0.20617 Var(X) + 2 * 0.18794 Var(X)]

= .25 Var (X) + 0.10368 VAR (X) + 0.05154 Var (X) + 0.02349 Var (X)
= 0.42871

1. Performance

- based Li mit

a. Calculate μ and σ as above as the mean and standard deviation of the ln(CN) values.

μ y = 2.96442

σ y = 0.91308

σ y 2 = 0.83372

b. Calculate the estimated mean and standard deviation of the CN values as:

E(X) = exp ( μ y + σ y 2 /2)APPENDIX 4. TECHNOLOGY

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- 8 = exp (2.96442 + 0.83372/2) = exp (3.38128)
= 29.40839

Var(X) = exp (2 * μ y + σ y 2 ) * [exp ( σ y 2 )

- 1] = exp (2 * 2.96442 + 0.83372) * [exp (0.83372)

- 1] = exp (6.76256) * [exp (0.83372)

- 1] = (864.85339) * (1.30187)
= 1125.9266

c. Calculate the estimated mean and variance of the average of 4 weekly CN values used in a monthly average. Include the autocovariance effect.

n = 4

σ 4 2 = ln {0.42871 * Var(X) / E[(X)] 2 + 1} = ln {(0.42871 * 1126 / [29.4] 2 ) + 1}
= ln 1.55848
= 0.44371

μ 4 = ln (E(X))

- 0.5 σ 4 2 = ln (29.4)

- 0.5 * (0.44371)
= 3.38099

- 0.22186
= 3.15913

d. Calculate the 95th percentile monthly average limit

X .95 = exp { μ 4 + 1. 645 σ 4 } = exp {3.15913 + 1.645 (0.66611)} = exp {4.25488}
= 70.44836

e. Calculate the 99th percentile daily average limit

X .99 = exp { μ y + 2.326 σ y } = exp {2.96442 + 2.326(0.91308)} = exp {5.08824}
= 162.10496

2. Calculating th e limit based on the proposed site specific acute water quality standard for CN
of 9.85 μ g/l.

a. WLA = (9.85 μ g/l)(13) = 128 μ g/1APPENDIX 4. TECHNOLOGY

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- 9 b. Calculate the LTA using the CV calculated from the lognormal distribution

CV = [exp( σ y 2 )

- 1] 0.5 = [exp(0.8 3372)

- 1] 0.5
= 1.30187] 0.5

= 1.14100

σ 2 = ln(CV 2 + 1) = ln(1.14100 2 + 1) = ln(2.30188)
= 0.83373

LTA = WLA {exp[0.5 σ 2

- z σ ]} = 128 {exp[0.5(0.83373)

- 2.326(0.91309)]} = 128 {exp[

- 1.70698]} = 128 {0.18141}
= 23.22048

c. Calculate the MDL and the AML

MDL = LTA {exp[z σ

- 0.5 σ 2 ]} = 23.22048 {exp [2.326(0.91309)

- 0.5(.83373)] = 23.22048 {exp [1.70698]} = 23.22048 {5.51229}
= 127.99801

AML = LTA {exp[z σ 4 - 0.5 σ 4 2 ]}

σ 4 2 = ln [(0.42871)CV 2 + 1] = ln [(0.42871)(1.14100) 2 + 1] = ln [1.55813]
= 0.44349

AML = 23.22048 {exp[(1.645)(0.66595)

- (0.5)(0.44349)] = 23.22048 {exp[0.87375]} = 23.22048 {2.39 588}
= 55.63348

Table AP4

- 3 illustrates the different results obtained when considering no autocorrelation, autocorrelation at lag 7, autocorrelation at lags 7 and 14, and autocorrelation at lags 7, 14, andAPPENDIX 4. TECHNOLOGY

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- 10 21. The limits increase with the amount of autocorrelation included in the calculation. Positive
autocorrelation increases the variance which increases the limit.

Table AP4

- 3. Comparison of Limit

Lags Considered Significant Performance

Based AML Water Quality

- Based
AML σ 4 2

None (Independe nt) 47.3 48.5 .282

Lag 7 66.9 52.8 .378
Lags 7 and 14 69.4 54.8 .424
Lags 7,14,21 70.5 55.6 .444

Note: MDL’s are the same no matter how many lags are considered significant. For the Performance based limit it would be 159.3 and the water quality

- bas ed limit is 128



## II. NEW SOURCEAPPENDIX 6. (JULY 20 02)

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- 1 

# APPENDIX 6

1. GUIDANCE FOR CONDUCTING MIXING ZONE ANALYSES

The key products from a mixing zone analysis are the dilution factors. They are used in conjunction with the water quality criteria for calculating re asonable potentials and effluent limits. There are aquatic life

- based water quality criteria and human health

- based water quality criteria. The former are applied at the acute and chronic mixing zone boundaries; the latter are (presently) applied at the chronic boundary. The methodology for conducting aquatic life

- based analyses and human health

- based analyses are similar. The permit manager should be consulted
about the need for a human health

- based analysis.

It is essential to have a working knowledg e of how water quality

- based effluent limits are developed in Washington state. This knowledge can be gained through reading and understanding the Water Quality Standards for Surface Waters of the State of Washington (in particular the subparts on Toxic S ubstances and Mixing Zones ), EPA’s Technical Support
Document (EPA, 1991), and the Department of Ecology’s Permit Writer’s Manual (in particular Chapters VI and VII)

- and through experience. This Guidance provides the specific, detailed
information that i s needed to select the correct values for the effluent and receiving water parameters, select the appropriate model, and determine when a dye study should be used. As
with the Permit Writer’s Manual, it’s expected that ample justification will be provided whenever the guidance is not followed.



## 1.1 SELECTING VALUES FOR MODEL INPUT PARAMETERS

Steady

- state models are the most frequently used tools for conducting mixing zone analyses. The value(s) chosen for each effluent and receiving water variable (parame ter) is derived from a data subset, which corresponds to a specified period of time. The specified period of time should encompass and be limited to the most likely occurrence of the critical condition, as defined in the Water Quality Standards ( e.g., a s eason when a 7Q10 is most likely to occur or the time when a particular stage of tide occurs). The term ‘reasonable worst

- case’ is applied to the value(s).

The durations established for the aquatic life

- based water quality criteria are one

- hour (acute)

a nd four

- day (chronic). There are two types of human health

- based water quality criteria: Those
based on non

- cancer effects and those based on cancer effects. The same concept of reasonable

worst

- case applies in non

- cancer analyses as applies in aquatic life

- based analyses. The concept of average values applies to carcinogenic human health

- based analyses because the duration established for these criteria is the expected life span.APPENDIX 6. (JULY 20 02)

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- 2 Critical condition scenario refers to a scenario containing reasonable w orst

- case parameters, which has been set up to run in a mixing zone model ( e.g., critical condition scenario to determine mixing at the chronic boundary). Steady

- state mixing zone models are applied using a combination of these parameters ( e.g. , effluent flow, current speed, depth, density, etc.) packaged to simulate either a critical condition or (in the case of carcinogenic human health

- based) an average condition. It’s understood that each critical condition scenario (by itself) has a low probability o f occurrence. [Discharges to tidally

- influenced rivers where a saltwater wedge is present are an exception. In these situations there is usually a high probability of occurrence because some of the parameters in the critical condition are known to occur simultaneously ( e.g. , during low tides, the predominance of freshwater may always create a minimum depth and
well

- mixed profile; while during high tides a stratified profile may always exist)].

A mixing zone analysis conducted with a steady

- state model s hould include a sensitivity analysis. A sensitivity analysis is a series of scenarios organized such that only one reasonable

worst

- case value in each scenario is changed while all others are held constant in a logical progression. Figure 1 is an example of a sensitivity analysis.

The state

- of

- the

- art mixing zone models accept time

- series data. They are referred to as dynamic models, but it’s still necessary to calculate reasonable worst

- case values for most of the parameters. These models are assuming more importance as expanded data sets become
available.

In some circumstances the primary tool in a mixing zone analysis may be a dye study

- with a model filling a secondary role. One such circumstance would be when it’s apparent that an effluent plume doesn’t develop normally (for any number of reasons). The dilution factors must then be measured directly in the field. However, these are the dilution factors for one set of effluent and receiving water conditions only, and a model may still be necessa ry for analyzing other sets of conditions that are quite different from those present during the dye study.

Those reasonable worst

- case and average parameters that are required input to the critical
condition scenarios are discussed in subsections 1.1.1

- 1 .1.8. Subsections 1.1.9 and 1.1.10 discuss other parameters which aren’t essential to using the models, but are essential ingredients in a complete mixing zone analysis. Subsection 1.1.11 addresses two other factors which must
be considered before arrivi ng at the correct dilution factors for the acute and chronic boundaries: The Standards require that mixing zones not occupy more than a certain percentage of the channel width and that, in rivers and streams, the effluent flowrate not utilize more than a certain percentage of the available receiving water flowrate in the process of dilution. So actually, the dilution factor to use when determining whether the effluent contributes to acute or chronic toxicity must be the lowest one of three that can be gen erated for both the acute and chronic
boundaries.APPENDIX 6. (JULY 20 02)

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- 3 

### 1.1.1 Municipal Effluent Flowrate
For critical condition scenarios at the acute boundary, the flow

- rate to use depends on how close to design capacity the plant is presently operating. If the plant is op erating at less than 85% of the dry weather design flow during the critical condition, then the flow

- rate to use is the highest daily maximum plant effluent flow for the past three years during the season in which the critical condition is likely to occur. If the facility is operating between 85 and 100% of dry weather design flow during the critical condition, then use a peaking factor applied to dry weather design to determine acute design flow. The peaking factor is a ratio of daily maximum to monthly average flows derived from actual plant data during the critical season. A peaking factor may also be available in the engineering report for the facility.

For critical condition scenarios at the chronic boundary, the flow

- rate to use depends on how
clos e to design capacity the plant is presently operating. If the plant is operating at less than 85% of dry weather design flow during the critical condition, then the flowrate to use is the highest monthly average plant effluent flow for the past three year s during the season in which the critical condition is likely to occur. If the facility is operating between 85 and 100% of dry weather design flow during the critical condition, then use the dry weather design flow. For average condition (human health

- b ased) scenarios, the flow

- rate to use is the annual average design flow as specified in the engineering report, permit application, or projection of annual average flow over the life of the permit by analyzing D ischarge M onitoring R eport (DMR) data.



### 1.1.2 Industrial Effluent Flowrate
For critical condition scenarios at the acute boundary, the flowrate to use is the highest daily maximum flow for the past three years during the season in which the critical condition is likely to occur. If plant effluent fl ows are expected to increase during the life of the permit, the highest daily maximum flow must be estimated.

For critical condition scenarios at the chronic boundary, the flowrate to use is the highest monthly average flow for the past three years during the season in which the critical condition is likely to occur. If plant effluent flows are expected to increase during the life of the permit, the highest average monthly flow must be estimated. For average condition (human health

- based) scenarios, the flow

- rate to use is the annual average design flow based on permit application or DMR analysis.



### 1.1.3 CSO Flowrate
For critical condition scenarios at the acute boundary, the flowrate to use is the highest equivalent twenty

- four hour average for the past three years during the season in which the critical condition is likely to occur. If plant influent flows are expected to increase during the life of the permit, the highest daily maximum flow must be estimated.

For critical condition scenarios at the c hronic boundary, the flowrate to use is the highest equivalent monthly average flow (total volume of all discharge events in a month divided by theAPPENDIX 6. (JULY 20 02)

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- 4 total hours of discharge in that month) for the past three years during the season in which the
critical co ndition is likely to occur. If plant influent flows are expected to increase during the life of the permit, the highest average monthly flow must be estimated. For average condition (human health

- based) scenarios, the flowrate to use is the annual equiva lent average flow based on data provided in the permit application or DMR analysis.



### 1.1.4 Intermittent Effluent Flowrate
For analyses at both the acute and chronic boundaries, it is necessary to use an instantaneous
flow when the effluent flowrate is inte rmittent. (Steady

- state (averaged) effluent flowrates are a commonly accepted approximation of inherent variability

- but only for continuous discharges).
The reasonable worst

- case flowrate to use is the maximum that can occur

- whether through

pumps or gravity flow. The resultant model generated dilution factor for the acute boundary must then be adjusted upward by a ratio of maximum flowrate to one

- hour, time

- averaged flowrate (if the maximum flowrate occurs for less than one hour); and the resultant d ilution factor for the chronic boundary must then be adjusted upward by a ratio of maximum flowrate to
four

- day, time

- averaged flowrate.



### 1.1.5 Stormwater Flowrate
For analyses at the acute boundary, the flowrate to use in western Washington is the average of the peak one

- hour flowrate generated by the two

- year, six

- hour storm event. For analyses at the chronic boundary, the flowrate to use in western Washington is an estimate of the average run

off generated by the two

- year, 72

- hour storm event (Ecology, 1993) (Ecology, 1995). Guidance for other areas of the state is evolving.



### 1.1.6 Current
For aquatic life

- based analyses at both the acute and chronic boundaries in unidirectional waters, both low flow and high flow condition currents should be used. Th e low flow velocity to use is
that which occurs with the 7

- day low flow period with a recurrence interval of 10 years (7Q10 by the appropriate statistical method). The high flow velocity to use is that which occurs with the 7Q10 high flow. For non

- carcino genic human health

- based analyses, the current velocity associated with a 30Q5 flow should be used if available

- or a 7Q10. For carcinogenic human
health

- based analyses, the velocity associated with the harmonic mean flow for the representative period of record should be used. These can usually be calculated if a cross

sectional profile of the channel bottom has been measured.

Determining the reasonable worst

- case current in tidally

- influenced water is deceptively
difficult. It is true that dilution fac tors at the hydrodynamic mixing zone boundary (also referred
to as the end of initial dilution or near

- field) are increased by increased current velocities (assuming other variables are held constant). Conversely, the lower the current velocity, the
lower the dilution factor at the end of initial dilution. Early EPA guidance ( e.g. , that guidance written for the 301(h) waiver application process) suggested that currents approaching zero contributed to critical condition scenarios. However, what is true at the hydrodynamic mixingAPPENDIX 6. (JULY 20 02)

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- 5 zone boundary is not necessarily true at a regulatory mixing zone boundary

- because the two are not synonymous. (Refer to Figure 5 in the 3PLUMES User's Manual (EPA, 1994) for confirmation of this statement).

Roberts’ Froude num ber (F) is a dimensionless number which characterizes the importance of current velocity relative to the buoyancy flux. It evolved from research into plume behavior and mixing in marine waters. As a dependent variable, it is calculated automatically when ever a case is set up in the DOS PLUMES model and appears in the [ Roberts’ F ] cell on the 3PLUMES interface. Small values of the Roberts' Froude number signify little effect of current on mixing. According to Roberts (1991) the current exerts no effect o n dilution if Roberts’ F < 0.1. (Refer
to section 1.3.2 Range of the Experiments for additional information).

For analyses at the acute boundary in tidally

- influenced water, the velocity to use in a model operating in the steady

- state is the 10th perce ntile velocity. This is defined as both the 10th and the 90th percentile velocities derived from a cumulative frequency distribution analysis. The distribution analysis should be produced from a data set consisting of periodic readings taken by
an instrum ent deployed over a neap and spring tide cycle. A field data set this comprehensive
could also be used as a time

- series file in the newer version models. In the absence of a comprehensive field data set, a sensitivity analysis should be run using a wide range of possible velocities which could reasonably occur for any 1

- hour duration. The velocity which produces
the lowest dilution should be considered the reasonable worst

- case velocity.

For analyses at the chronic boundary in tidally

- influenced water, the reasonable worst

- case velocity is defined as the 50th percentile current velocity derived from a cumulative frequency distribution analysis. In the absence of a comprehensive field data set, a sensitivity analysis should be run using a wide range of v elocities, any of which could reasonably occur as the average velocity for any 4

- day duration. The velocity which produces the lowest dilution should
be considered the reasonable worst

- case velocity.



### 1.1.7 Depth
For aquatic life

- based analyses at both th e acute and chronic boundaries in unidirectional water, use the depth of the port(s) during a 7Q10 low flow period. For non

- carcinogenic human health

based analyses, use the depth at 30Q5 or 7Q10. For carcinogenic human health

- based analyses, use the dep th at the harmonic mean flow. These can usually be calculated if a cross

- sectional profile of the channel bottom has been measured.

For analyses at both the acute and chronic boundaries in marine water (sea level), use the depth of the port(s) at Mean Lo wer Low Water (MLLW)

- the depth given on most nautical charts.

For analyses at both the acute and chronic boundaries in upstream tidally

- influenced riverine waters, use the depth of the port(s) at MLLW during a 7Q10 low flow period. (Salt water wedges and a situation wherein the elevation of the river bottom at the outfall location is lowerAPPENDIX 6. (JULY 20 02)

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- 6 than the surface elevation of the MLLW will require special considerations).

[Note: EPA mixing zone models should be used advisedly when the depth is less than 5 times the plume diameter. Refer to section 1.3.5 Boundary Conditions .]



### 1.1.8 Stratification
The density profile to use in aquatic life

- based analyses is the one that results in the least mixing. Generally, this is either the minimum or maximum stratific ation, defined as follows: "Minimums" are characterized by profiles that extend to the same depth as the outfall with (1) the smallest differential between sigma

- t values at the bottom and top of the profile; and (2) collectively, the highest sigma

- t valu es. "Maximums" are characterized by profiles that extend to the same depth as the outfall with (1) the largest differential between sigma

- t values at the bottom and the plume trapping depth; and (2) collectively, the lowest sigma

- t values. Some profiles w hich are profoundly nonlinear warrant special consideration ( e.g., saltwater wedges and nascent densities (Refer to section 1.3.8 Nascent Density and Buoyancy )).

[Note: Sigma

- t is defined as (mass density (kg/m 3 )

– 1000)]

The density profile to use in human health

- based analyses is the one that results in average mixing. This is determined as follows: (1) Generate the dilution factors for the two profiles (minimum and maximum), (2) calculate the reciprocal of the dilution factors to convert them to
ef

fluent concentrations, (3) calculate the average of the reciprocal dilution factors (average effluent concentration), and (4) calculate the reciprocal of the average effluent concentration and
use that as the harmonic mean dilution factor.

In Puget Sound, changes in density correlate most closely to changes in season. Minimum stratifications frequently occur in October, while maximum stratifications frequently occur from May 1

- July 15 (NOAA, 1981). There is little or no correlation between changes in sta ges of tide and changes in profiles. For this reason, one day of field measurements conducted during a neap or spring tide is of limited value

– even though it may be in close proximity to the outfall. There is probably more value in the long

- term, month ly salinity

- temperature

- depth (STD) data from Ecology’s Ambient Monitoring Program

– even though it may not be in close proximity. Ecology’s data are available on the Internet at the Ecology website (www.ecy.wa.gov/programs/eap/env

- info.html)

[Note: T he manufacturer of SEABIRD field monitoring equipment has proprietary software for downloading, analyzing, and presenting STD data. SEAPLOT is a module of this software which may prove useful for quickly reviewing the graphs of stratification profiles fro m a large
STD data set

– such as a station from Ecology’s Ambient Monitoring Program.]APPENDIX 6. (JULY 20 02)

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- 7 

### 1.1.9 Pollutants of Concern
All toxic effects testing has some degree of uncertainty associated with it. The more limited the amount of test data available, the large r the uncertainty. A statistical approach has been developed to better characterize the effects of receiving water and effluent variability and reduce uncertainty in the process of deciding whether to require an effluent limit.

The statistical approach t o use when determining the background concentration in the receiving water for aquatic life

- based analyses depends on the number of data points. For 20 or fewer samples, the geometric mean of the receiving water values should be multiplied by a factor of 1.74 to estimate the 90th percentile. This estimated background value should then be used in conjunction with the plant effluent data to evaluate reasonable potential to cause an exceedance of the criteria for aquatic life protection and to derive effluen t limits.

For 21 or more samples, the reasonable worst

- case value is the 90th percentile value derived from a cumulative frequency distribution analysis of a complete data set. A complete data set should include at least three years of ambient data from the critical season. This derived background value should be used in conjunction with the plant effluent data to evaluate reasonable potential to cause a violation of the criteria for aquatic life protection and to derive
effluent limits.

The statistical approach to use when determining the background concentration for human
health

- based analyses when there are multiple data points is the geometric mean. Use 0 for value(s) below the MDL and use the MDL for values between the MDL and the QL (Refer to

sect ion 4. Effluent Limits Below Quantitation in Chapter VI of the Permit Writer’s Manual )

.

The statistical approach to use when determining the concentration in the plant effluent for aquatic life

- based analyses also depends on the number of data points. For 20 or fewer samples, assume a coefficient of variation (CV) of 0.6 and use the reasonable potential multiplying factors
to calculate the estimated 95 th percentile value. These factors can be found in Table 3

- 2 of the TSD (EPA, 1991) or calculated usi ng the algorithm in Ecology’s Excel spreadsheet called
TSDCALC.XLW

– which is available at the Ecology website ( http://www.ecy.wa.gov/programs/eap/pwspread/pwspread.html ). This estim ated value should then be used in conjunction with the background receiving water data to evaluate a reasonable potential to cause a violation of the criteria for aquatic life/human health protection and to derive
effluent limits.

For 21 or more samples, calculate the CV and the 95 th percentile effluent value. . This effluent value should then be used in conjunction with the background receiving water data to evaluate a reasonable potential to cause a violation of the criteria for aquatic life/human heal th protection
and to derive effluent limits.

The statistical approach to use when determining the concentration in the plant effluent forAPPENDIX 6. (JULY 20 02)

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- 8 human health

- based analyses is to use the 50th percentile concentration. If there are less than 10 data points use a multiplier on the highest concentration to estimate the 50th percentile concentration. (The multipliers can be found in Table VII

- 2 of the Permit Writer’s Manual ). If there are more than 10 values use the cumulative percentile calculation at a 95% confi dence to derive the 50th percentile. (a statistical routine in a spreadsheet software such as Excel  can do these calculations)..

The present temperature standards are as ‘not to exceed’ values (no averaging period). The 95 th percentile effluent and hi ghest observed or expected receiving water values for the critical season should be used. The criterion must be met at the edge of the chronic boundary. Addressing the second part of the standard pertaining to ‘incremental temperature rise’ is beyond the scope of this guidance.

It may be necessary to do an analysis of immediate dissolved oxygen demand (IDOD) when effluent becomes a relatively high percentage of the receiving water flowrate. The 10th percentile value for effluent D.O. concentration and 1 0 th percentile receiving water value for the critical season and time of day should be input to a mass

- balance equation. Such an equation is available from Ecology in the Excel workbook called PWSPREAD (the particular spreadsheet is IDOD2). The D.O. crit erion must be met at the edge of the chronic boundary.



### 1.1.10 Other Parameters
Temperature, pH, and hardness are the most noteworthy examples of other parameters, which may not be considered pollutants of concern, but are required to determine the toxic effects of other pollutants ( e.g., ammonia). When selecting a reasonable worst

- case value for temperature and pH, use the 90th percentile value derived from a cumulative frequency distribution analysis of a complete data set. For hardness, use the 10 th p ercentile value. A complete data set should include at least three years of DMR or ambient data corresponding to the critical season. If annual data (from all months) are used to select the value, then the 95th or 5th percentile value from the frequency distribution should be used. For limited data sets (n<20) the upper or lower percentile values can be estimated by methods in Gilbert (1987).



### 1.1.11 Other Factors
The subpart pertaining to mixing zones in the Water Quality Standards restricts the width o f a water body that can be “occupied” by both the acute and chronic mixing zones to twenty

- five percent. Implementation of this restriction involves generating a dilution factor (DF) at a lateral boundary, which is located such that the width of the speci fied mixing zone does not occupy more than 25% of the channel width. The Channel width must be determined during a 7Q10 (in freshwater), MLLW (in sea level marine water), or combination thereof (in upstream tidally

influenced riverine waters). The diluti on factor can be generated in one of two ways: (1) Use a model and note the DF associated with the plume diameter at the point where the plume has spread to one of the lateral boundaries; or (2) use dye and measure the DF at the lateral boundary(ies).APPENDIX 6. (JULY 20 02)

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- 9 Thi s same subpart of the Standards restricts the flowrate in rivers and streams that can be “utilized” by an effluent flowrate to 25% at the chronic mixing zone boundary and to 2.5%at the acute mixing zone boundary. Formulation of this dilution factor for a receiving water involves solving the volume fraction equation: 

## ( ) DF Q Q Q amb e

e 

### = + (1)

where Q amb is the receiving (ambient) water flowrate; and Q e is the effluent flowrate.

The ambient portion must first be reduced by the appropriate percentage to g ive the amount available for dilution before the equation is solved for DF.

The dilution factor then for freshwater and narrow estuaries is the lesser of the factors calculated as % of flow or dilution at the spatial boundary as determined by modeling.



## 1. 2 UNDERSTANDING INITIAL DILUTION THEORY

The general theory behind wastefield formation is easily understood. Visualize wastewater discharged horizontally as a jet from a single round port or a series of jets from ports spaced at equal distances along a d iffuser. If the wastewater has a lower density than the surrounding water, then the resulting buoyancy force deflects the jet(s) upward forming plumes which are swept downstream by the current. The plume(s) entrain ambient water as they rise, causing the m to be diluted and decreasing the density difference between them and the ambient. If the ambient is stratified, then its density at the depth of the ports is greater than near the surface. The greater density ambient water is entrained initially, and t he rising, expanding plumes can reach a level where their density is the same as the surrounding water ( i.e.

, neutral buoyancy). This is the trapping depth.

If the receiving water is unstratified, then its density is the same throughout the water column. In marine water the plume will always surface

- if it remains intact. In freshwater the plume will nearly always surface. (Ambient temperatures equal to or less than 4 degrees Centigrade may generate exceptions. Refer to section 1.3.8 Nascent Density a nd Buoyancy ).

The more specific theory behind initial dilution is less easily understood. It applies downstream from the port(s) until the turbulent kinetic energy generated by the buoyancy and momentum of the discharge dissipates. This is commonly refe rred to as the hydrodynamic mixing zone, initial dilution, or the near

- field. (The term initial dilution will be used because near

- field is defined and used differently in section 1.6 Conducting a Dye Study ). Generally, initial dilution ceases
because a layer boundary (water surface or trapping depth) is encountered. At the end of initial dilution, the wastefield is said to be established. The established wastefield then passes into "far

field". Designers of the outfall can usually affect what occurs i n the hydrodynamic mixing zone,APPENDIX 6. (JULY 20 02)

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- 10 but have little or no control over what occurs in the far

- field.

All initial dilution models are based on the conservation principles of mass, momenta, and energy. The most important principle is that of conservation of ma ss

- the equation of continuity. In mixing zone modeling it’s better understood as the entrainment equation. Different models use different conceptual "building blocks" for constructing their plumes along the trajectory. But regardless, the initial mass of the plume building block plus that added, or entrained, over some discrete period of time has to be conserved ( i.e. , there has to be a mass balance).

Another important aspect of a mass balance involves knowing the effect of water movement,
which is de termined with the conservation of momentum principle. Like the mass balance approach, accounting is undertaken for fluid momentum in a defined building block. Horizontal momentum is conserved. It is the product of building block mass and horizontal velo city and is increased by the horizontal momentum of the fluid that is entrained in the same period of time. Vertical momentum is not conserved but is altered by buoyancy, which arises from the density difference between the building block and the ambient water. Kinetic and thermal energy are
conserved.



### 1.2.1 The Conceptual Dilution Factor
The volume fraction equation (Refer to section 1.1.11 Other Factors, equation (1)) is the simplest formulation of the dilution factor. Q amb was defined somewhat diffe rently in equation (1) than it will be defined here; it is replaced by Q a in the following equation:


## ( ) DF Q Q Q a e

e 

### = + (1a)

where,

Q a is the volume flux of receiving (ambient) water entrained in the plume from an outfall at some sampling point i n the plume; and Q e is the volume flux of effluent in the plume.

The Q a value is easier to visualize than to obtain directly ; i.e.

, it is extremely difficult to measure at any sampling point that might be chosen in the plume. What can be measured direc tly in the plume is the concentration of a pollutant of concern (or a dye tracer) at any sampling point whose location is a known measured distance from the outfall. Call this concentration (C p ). The background concentration in the ambient water (C a ) and the concentration being discharged in effluent (C e ) can
also be measured.APPENDIX 6. (JULY 20 02)

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- 11 To understand initial dilution theory it is necessary to formulate the dilution factor using the basic mass balance equation:


## ( ) ( ) ( )

Q C Q C Q Q C

a a e e a e p



### ∗ + ∗ = + (2)

The volume fluxes (includ ing the Q a that’s so difficult to measure) can be factored out of the equation by algebraic manipulation:

If the % effluent is represented by the term X; then the % ambient water which has been entrained in the plume of effluent that emerged from the ou tfall must be (1

- X), because the sum of the two is 100% of the water in the plume. Substituting (1

- X) for Q a and X for Q e (and understanding from equation (1) that 1 / X = DF) gives


## ( ) 

# ( ) DF C C

C C

e a

p a = −

− (3)

A DF calculated using equation (3) is an emp irical result for the particular sampling point where the
C p value is measured.

An initial dilution model generates dilution factors using outfall, effluent, and receiving water characteristics supplied to it. Each DF that prints out is for a particular calculated distance as the model iterates along the plume trajectory away from the outfall. Depending on the model used, the DF (and C p ) may be calculated simply using the volume fraction equation, or the C p may be calculated as an actual, effective dilut ed concentration (depending on whether the model accepts C e and C a as inputs).

Rearranging equation (3) gives

C C DF C DF

p e a

=     

 +

−     

     

 1 1 1 (4)

Again depending on the model used, the printout may occur repeatedly refl ecting the model’s iterative process along the plume trajectory or it may occur only upon completion of initial dilution. Whatever the capability of the model, it is imperative that its generated C p s can be validated ; i.e.

, compared to measured C p s at the same distance from the outfall to establish how well the model is simulating the plume. A dye tracer is generally better for this task because dye can be measured in
situ with a fluorometer.APPENDIX 6. (JULY 20 02)

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- 12 

### 1.2.2 Theoretical Models

The two theoretical models mentioned in this Guidance are UM (or UM3) and UDKHDEN (or DKHW). They both solve the equations of fluid motion and mass transport using an integration scheme in which they march forward in discrete increments along the trajectory of the buoyant jet (prompting the phrase “jet

- integral models”, which often appears in the literature). UM is a Lagrangian model and uses a time increment; UDKHDEN is an Eulerian model and uses a
distance increment.

The basic model building block in UM is the wafer

- shaped plume element; in UDKHDEN it’s the control volume. In theoretical modeling terms the building block mass is incremented by the amount of fluid that flows over the outside boundary of the building block during each time or distance increment. The theoretical models, us ing these analytical tools, are capable of yielding fair approximations for the turbulent

- flow problems encountered in mixing zone analyses. But, this particular field ( i. e., the field of fluid mechanics) is more heavily involved with empirical
work than are other fields because these analytical tools are not capable of yielding exact solutions to many of the problems.



### 1.2.3 Empirical Models
A considerable amount of experimental evaluation has been done using dynamic similitude (models and towing tanks i n the laboratory) and dimensional analysis. This led to the development of empirically

- derived curve fit equations to make dilution predictions and verify accuracy of the theoretical models. Eventually, the graphs and equations in the original papers

wer e codified and became useful models in their own right.

The empirical models, like RSB (or NRFIELD) and CORMIX, predict initial dilution by stringing together a series of building blocks called length scales. Each length scale evolves from an empirically

- derived curve

- fit equation and is, literally, a distance along the trajectory where one parameter predominates ( i.e. , controls the flow). Once strung together by this analysis, the length scales should describe the relative importance of all parameters

- discharge volume flux, momentum flux, buoyancy flux, ambient crossflow, and density stratification

- throughout the trajectory. For example, the solution for a pure jet can be applied as an approximate solution to that portion of a buoyant jet in a cross flow where jet momentum dominates the flow. Likewise, the results for a pure plume can be applied to the buoyancy

dominated regions for the buoyant jet. The length scales are linked by "appropriate transition conditions" to create a path for the trajecto ry through completion of initial dilution. These
transition conditions are relative unknowns and a cause for concern.



### 1.2.4 Average Versus Centerline
When conducting mixing zone analyses it is necessary to have an elementary understanding of
the differen ce between average and centerline plume concentrations (and dilutions) and the role of each in modeling. In theoretical models average concentrations are integral to the integrationAPPENDIX 6. (JULY 20 02)

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- 13 scheme, center

- of

- mass of the building block, and total mass flux. Cente rline concentrations become important when determining the potential for acute toxicity to organisms.

Plume velocities in a cross section of each building block (perpendicular to the path of the trajectory) resemble a bell

- shaped curve. Concentrations, o n the other hand, do not resemble a
bell

- shaped curve ( i.e. , peak concentrations do not occur at the same location as the center

- of

mass). Therefore, an average concentration involves weighting the concentration distribution by the velocity distribution. This average may be referred to as either a “top hat” or “flux

- average”, depending upon how it is formulated in a particular model. It is the value to be multiplied by the total plume volume flux to get total mass flux, which is passed on to the farfield algorithm.

In theoretical models, the ratio between centerline and average concentration varies between 2 (1.44) (for a fully

- merged line plume) and 1.94 (for round plumes). It depends on a number of factors: The type of bell

- shap ed curve employed by a particular model (two examples are 3/2 power profile and Gaussian), the plume geometry, where the building block is on the trajectory relative to the point of discharge, and whether the individual plumes have merged. Models employin g the 3/2 power profile may deliver more accurate ratios because that curve better
“feathers” the cross

- section into complete ambient.

It is difficult to quantify the relationship between average and centerline values based on empirical measurements. Ave rage dilution is difficult to measure in the laboratory, and virtually impossible to measure in the field since it is necessary to define the plume boundary and know the velocity distribution over the plume cross

- section. Some direct measurements of avera ge dilutions by Roberts (1991) indicate that the average may differ by only 10 to 20% from the centerline in stagnant currents and is 0% when Roberts’ F < 0.1. Suffice it to say, these peak

- to

mean ratios are still the subject of research in the plume mod eling community (Frick, et al

, 2000). When initial dilution ends due to contact with a layer boundary the distinction between average and centerline ends soon afterward. There is no longer an elliptical plume

- it becomes more rectangular.

For aquatic l ife

- based analyses at both the acute and chronic boundaries in unidirectional water, centerline values should be used. For all other analyses flux

- average values should be used. All comparisons of outputs between models must use centerline values.



## 1.3 C HOOSING AN INITIAL DILUTION MODEL

1.3.1 Descriptions
Steady

- state models have been the most frequently used tools for conducting mixing zone analyses. Three of the more commonly used models are theoretical: UM, UDKHDEN, and VSW. Two are empirical: RSB and CORMIX. Three were included in the DOS

- based interface (platform) called 3PLUMES which was released by EPA in about 1993: UM, VSW, and RSB.APPENDIX 6. (JULY 20 02)

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- 14 Dynamic models with the capability of using time

- series data are rapidly coming of age as more
effluent and re ceiving water data become available. In 2000 EPA released a new Windows

based platform called Visual Plumes which houses the DOS PLUMES interface but also provides a dynamic model capability for three of these models: UM (renamed UM3, UDKHDEN (renamed DK HW), and RSB (renamed NRFIELD). In 2000 a Windows

- based version of CORMIX with dynamic model capability was also released.

UM3 is the current version of the earlier models UOUTPLM (vintage 1979), UMERGE (vintage 1985), and UM (vintage 1993). It is a thr ee

- dimensional model ( e.g., it simulates plumes that
bend in a three

- dimensional trajectory). It uses the 3/2 power profile to calculate the ratio and determine the centerline concentration as a function of the top hat concentration that it predicts.
The ratio changes continuously with each integration step along the trajectory (EPA, 1994). Merging is simulated with the reflection technique (Turner, 1970). It is not able to recognize and address lateral boundary constraints (Refer to section 1

. 3.5 Bou ndary Condition(s) ) It transitions smoothly to a farfield algorithm (Refer to section 1

. 5.1 FARFIELD ).

DKHW is a three

- dimensional model. It considers either single or multiport discharges at an arbitrary horizontal angle into a stratified, flowing cu rrent. The current speed and density can vary with depth. The dilution factor generated is the flux

- averaged which is, at all points on the trajectory, 1.15 times the centerline dilution factor. It terminates when the surface is reached, the plume reach es its maximum rise height, or when errors are encountered. It does not transition to a farfield algorithm, but this is not a problem (Refer to section 1.5 CHOOSING A FARFIELD MODEL ).

VSW stands for V ery S hallow W ater. It is the only initial dilution model that will provide reliable results when the depth approaches three pipe diameters

- or less. VSW employs the reflection technique (Turner, 1970), which is the same algorithm employed by UM to simulate merging of multiple plumes. A user's manual for VSW can be found at Appendix 6.2 of the
Permit Writer’s Manual.

NRFIELD is an updated version of RSB and ULINE which is based on experimental studies of multiport diffusers in marine water as described in Roberts (1991). It requires at least four ports. Its strengths are: (1) It is set up and run through both the DOS PLUMES and Visual Plumes interfaces, so that many cases can be run quickly and compared to UM3 results; (2) it simulates opposing

- port diffusers; and (3) the user is advised whenever the m odel is operating outside the range of the experiments. (Refer to section 1

. 3.2 Range of the Experiments ). One present shortcoming of RSB is that it does not provide dilution factors for distances prior to the end of initial dilution, although it does t ransition smoothly to the same farfield algorithm employed by
UM3. It uses a constant centerline

- to

- flux

- average ratio of 1.15.

CORMIX stands for CORnell MIXing zone models. The package consists of CORMIX1, CORMIX2, and CORMIX3 for the analysis of subme rged single port discharges, submergedAPPENDIX 6. (JULY 20 02)

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- 15 diffusers, and surface discharges, respectively. EPA's decision to proceed with the development of CORMIX was an attempt to utilize accumulated laboratory and field experience to compile a set of methods and empirica l models to bridge the gaps that were evident in theoretical modeling at that time. The original system was designed for the non

- specialist model user, so that plume predictions could be made without having prior knowledge about dilution modeling.

A conc ern is its infrequent, but unpredictable, creation of plume trajectories with discontinuities. These may be due to the transition conditions. (Refer to section 1.2.3 Empirical Models ).
“CORMIX1 & CORMIX2 near

- field simulations now use the jet integral model CORJET for simulations. A few simulation modules still do use ‘empirical’ approach, but these cases are now in the minority” (Doneker, 1997). The strengths of this model are its ability to acknowledge the effects of boundary constraints and gravita tional collapse. CORMIX2 uses the “equivalent slot diffuser” concept and thus neglects the details of the individual jets issuing from each diffuser port and their merging process. It assumes that the flow emerges from a long slot discharge with equivalen t dynamic characteristics (Jirka et al , 1996b). Thus, mixing is based on the plume characteristics after the individual ports have merged. The initial dilution modules in CORMIX generate only centerline values.

UM3 should perform well for a majority of the critical condition scenarios encountered

- particularly in tidally

- influenced waters. It can also be used frequently for the purpose of comparing dilutions with the other models. The following sections ( 1.3.2

– 1.3.8) discuss specific circumstances a nd outfall configurations which might influence which model is selected or how a particular mixing zone analysis is conducted.



### 1.3.2 Range of the Experiments
“Empirical models are most effective when prototype and model variables and conditions match
clos ely. When they do not, the predictions can degrade substantially. In other words, it is often difficult to extrapolate to conditions which were not included in the experimental design [range of experiments] on which the models are based. Since it is oft en not clear to the user when extrapolation occurs, this can be a real problem” (EPA, 1994). Inaccurate extrapolations are manifested in the form of discontinuities in the plume trajectory.

The authors of RSB (NRFIELD) went through a careful consideratio n of the possible critical condition scenarios which their model might be expected to analyze before choosing the range of experiments (Roberts et al , 1989). The studies were conducted with the following experimental configuration: (1) A straight diffuse r consisting of horizontally discharging round ports which were uniformly spaced; (2) ports discharging from both sides of the diffuser through T

- shaped risers; (3) marine water

- both density

- stratified and well

- mixed; (4) current at an arbitrary angle

re lative to the diffuser axis; and (5) individual plumes merging rapidly. As a result, there is a straightforward approach to determining whether the model will be operating within this range:APPENDIX 6. (JULY 20 02)

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- 16 The two length scale ratios l

l m

b and s l b are diffuser parameters which characterize the

significance of source momentum flux and port spacing, respectively. (Refer to
section 1.2 UNDERSTANDING INITIAL DILUTION THEORY for an explanation of length scales and fluxes). Note that thes e length scale ratios encompass all of the "diffuser" parameters: jet exit velocity, port diameter, port spacing, effluent density, and ambient stratification. The model is operating within its range of "diffuser" parameters
when:

0.31 < s l b < 1.92 , and

0.078 < l

l m

b < 0.5

Roberts' Froude number (F) is a more important parameter. The tests were run at differing current speeds to obtain F in the range 0 (zero current speed) to 100. As was
stated in section 1.1.6 C urrent , values of F < 0.1 signify no effect of current on dilution.

The effect of current also depends on its direction relative to the diffuser axis ( Θ is the horizontal angle). Tests were run with Θ = 90 o , 45 o and 0 o (parallel to the current).

The le ngth scale ratios, F, and Θ for each scenario are included in the output for each RSB model run. It then becomes a simple matter to determine whether the model is operating within its capability. Consideration should be given to using Figure 13 in Robert s (1991) (included as

Figure 2) if the length scale ratios l

l m

b and s l b are less than 0.2 and 0.3, respectively. The

normalized equation on the x

- axis of the graph must be solved for S m - the minimum initial
dilution.

[Note: The volume flux per unit length of diffuser (q) is easily calculated. The Roberts Froude number (F)[Roberts F], buoyancy flux per unit length of diffuser (b)[buoy flux], and Brunt

Vaisalla frequency (N)[N (freq)] needed to solve for S m are includ ed on the DOS PLUMES interface among the "red" cells. The “red” cells can also be used to calculate other fluxes, length scales, and length scale ratios].APPENDIX 6. (JULY 20 02)

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- 17 

### 1.3.3 Densimetric Froude Number Less Than 1 or Negative

The densimetric Froude number is the ratio of the momentum to the buoyancy of the plume. It is an important number when analyzing plume performance in marine water. It is of less importance in freshwater because the buoyancy of the plume is often near zero.

If the Froude number is less than 1, t hen the plume separates from the bottom of the port orifices allowing ambient water to flow into the diffuser. This may also occur in marine waters if the total area of the port orifices exceeds 70% of the diffuser cross

- section area. Either of these two conditions will result in unbalanced flows, and the diffuser section must be evaluated hydraulically as a manifold prior to completing the mixing zone analysis (Ecology, 1998). Tide

flex valves are being used with more frequency under these conditions. Red Valve Company is a good source of information on how to simulate these valves in UM3 and DKHW.

UM and UM3 signal this condition in several ways: (1) The input cell [Froude #] contains the number; and (2) the output from the run may contain the messag e "absolute value Froude # < 1, potential diffuser intrusion", or the message "begin overlap". UM3 should generate accurate results as the Froude Number approaches zero

- provided the correct conditions are described to it. RIVPLUM5 or FARFIELD may be a better choice in most freshwater ambients whenever the plume has very little momentum. (Refer to section 1.5 CHOOSING A FARFIELD MODEL ).

[Note: UDKHDEN has a built

- in safeguard which causes it to terminate and display an “IHLF

11” error message when th e Froude number is less than 2.5 and it cannot provide an accurate answer.]

If the Froude Number is negative, then the effluent is more dense than the ambient water. The plume may hit bottom (Refer to section 1.3.5 Boundary Condition(s) ); or perform eve n more atypical (Refer to section 1.3.8 Nascent Density and Buoyancy ).



### 1.3.4 Overlap Condition

This condition is associated with low momentum/high buoyancy plumes ( i.e. , when the upward curvature of the plume is great). As UM3 iterates through the curva ture the bottom portions of consecutive plume building blocks (elements) actually overlap, resulting in physically unreal negative volume and negative mass. The radius of each element, and entrainment, are over

estimated. Plumes that perform in this mann er and surface will usually protrude upstream from the outfall. Output from a UM3 run which is performing through this condition will contain the error message "begin overlap". The results from UM should not be used unless the following information appea rs in the output after the message: (1) An "end overlap" message indicating the cessation of the condition causing the error, and (2) relatively little change in the dilution between the "begin overlap" and "end overlap" messages.

[Note: It may be neces sary to invoke the ^R command in DOS PLUMES in order to force theAPPENDIX 6. (JULY 20 02)

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- 18 model to simulate through the "end overlap" message to maximum rise. This will allow the comparison to be made between dilutions at the beginning and end of overlap.]

Refer to section 1.3. 2 Range of the Experiments to determine whether NRFIELD can be used
under those conditions when UM3 should not be used.



### 1.3.5 Boundary Condition(s)
Boundary conditions are side, surface, and/or bottom constraints which interfere with
entrainment of recei ving water into the plume. Banks, levees, docks, shallow water, port(s) discharging directly on the bottom, and confined embayments are all examples. The concern is whether the model will reflect these interferences accurately by limiting the entrainment . An additional consideration is whether the constraints are more likely to affect initial dilution or
farfield entrainment.

If side boundaries are in close proximity such that initial dilution entrainment is likely to be affected, then CORMIX should be used exclusively

- provided there do not appear to be discontinuities. CORMIX simply gives a cautionary message acknowledging attachment to the side boundary, but does not proceed to calculate adjusted dilutions. Side boundaries may
become interferences in the farfield phase of the plume, such as when the plume attaches to the bank downstream in a unidirectional river or stream. Then it may be appropriate to use RIVPLUM5, if the attachment (or close proximity) affects horizontally transverse spreading of the mixed effluent. Otherwise, the Constant Eddy algorithm may be appropriate. (Refer to
section 1.5 CHOOSING A FARFIELD MODEL).

It is suggested that all of the models except VSW be used with caution in shallow waters ( i.e.

, , less than five pipe diame ters deep) and not be used at all if it is very shallow water ( i.e. , less than three plume diameters deep). VSW (in DOS PLUMES) is the best choice. If UM (in DOS PLUMES) is used, consideration should be given to using the “Pause” command to force the
mod el to terminate initial dilution when the plume width is the same as the depth of water (The plume is no longer entraining properly). RIVPLUM5 is a very good alternative in unidirectional waters. (Refer to section 1.5 CHOOSING A FARFIELD MODEL ). If the discharge is actually to the surface of the receiving water ( e.g. , during mean lower low water (MLLW)), then either VSW or CORMIX3 should be used. Justifying the model chosen is advised.

Plumes that surface inside one or both of the two regulatory bounda ries are a common occurrence in estuarine receiving waters because of the additional buoyancy. The surface is the one boundary condition that all five models signal decisively. However, simulations from that point to either or both of the regulatory boun daries may be suspect. (Refer to section 1.4 UNDERSTANDING FARFIELD THEORY ).

UM3 will issue a "

- > bottom hit" message when the extremities of the plume element intersect the bottom. The bottom is assumed to be either (1) at a distance below the port eq ual to the portAPPENDIX 6. (JULY 20 02)

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- 19 elevation [port elev], or (2) at the deepest ambient depth (in the column headed [depth] on the interface)

- whichever is greater. Often times this constraint can be ignored or eliminated. Frequently it is the downstream portion of the pl ume which hits the bottom. Since this is not the primary entraining surface of the plume, the condition can be ignored, as long as it isn't violated excessively. The condition can be eliminated by increasing the deepest ambient depth (in the [depth] colu mn), as long as it is reasonable to do so ( e.g., anytime there is a positive gradient to the bottom in the direction of the plume trajectory).



### 1.3.6 Extreme Horizontal Angle
The horizontal angle is defined in UM as the angle between the axis of the diffus er and the current ( i.e.

, an angle of 90 degrees simulates a situation where the effluent plume(s) and current

are co

- flowing). The dialogue box on the DOS PLUMES interface indicates that UM is valid over angles ranging from 45 to 135 degrees; it can also be used advisedly for angles between 20 and 45 degrees, and 135 and 160 degrees. It's most accurate at 90 degrees because UM is a two

dimensional model. The effect of changing the direction of the current simply reduces the spacing between ports, invoki ng a pseudo

- three

- dimensional version. UDKHDEN may be a better choice the further away from 90 degrees the horizontal angle is because it's a true three

dimensional model.

In the Windows

- based version (Visual Plumes), UM3 is a three

- dimensional model. T he horizontal angle is determined using the scientific convention, in which zero degrees is to the east. The angle increases in the counter

- clockwise direction; thus north is 90 degrees. Extreme horizontal angles are less of a concern than with UM.

It i s recommended that RSB (NRFIELD) be used for multi

- port diffusers in marine water

- particularly if the diffuser is an opposing

- port configuration. (Refer to section 1.3.7 Opposing

port Diffuser Configuration) . It evolved from an EPA model (ULINE), whic h was designed to simulate multi

- port configurations where upstream plumes are bent over by the current to interact with downstream plumes. (These zero and 180 degree horizontal angle situations are termed line plumes). It may also be the model of choice for many other horizontal angles, including negative ( i.e. , a counter

- flowing situation). . However, it must perform within its range of experiments. (Refer to section 1.3.2 Range of the Experiments ).

UM3 can be adapted to simulate line plumes in fres hwater

- and in marine water when NRFIELD is not appropriate. The procedure to follow is relatively straightforward: Run UM to simulate one plume (using the actual flowrate from only one of the ports in the diffuser). Assume that it is the most upstream plume. The output from this case will provide enough information about the plume trajectory so that an estimate can be made of the horizontal distance this plume will travel before merging with the plume from the next downstream port. The output will al so provide the average concentration within the plume at this point of merging. This concentration is then input as the ambient pollutant concentration [amb conc] to the UM case for the next downstream port. The procedure is completed for this particular critical condition scenario when the last downstream port in the sequence is simulated.APPENDIX 6. (JULY 20 02)

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- 20 In order for this procedure to accurately simulate line plumes, the interaction among upstream and downstream plumes must be quite thorough. This can be determined b y examining the output from the first UM run to see whether the plume is sufficiently strongly bent over to envelop most of the downstream plume’s trajectory. This procedure is explained in a citation by Frick (1996). It may sometimes be advisable to com pare dilutions from several models and provide justification for the one chosen.



### 1.3.7 Opposing

- port Diffuser Configuration
Opposing

- port diffuser configurations have ports discharging in opposite directions. The configuration may consist of paired ports which are directly opposite each other or staggered ports, which are all equal distance apart but alternate from one side to the other.

In a current, the upstream plumes create a counter

- flowing situation wherein they frequently bend over and merge with downstream plumes. UM3 assumes that the diffuser is configured with all ports on one side, the downstream side, creating a co

- flowing situation. The counter

flowing situation resulting in cross

- diffuser merging is not simulated explicitly.

The preferred approach to modeling these configurations in freshwater is to simply divide the diffuser length by the total number of segments ( i.e. , total number of ports minus one). The quotient is the appropriate spacing; this number should be entered in the cell [s pacing] on the DOS or Visual PLUMES interface. The number of ports is entered in the cell [# ports]. The simulation offered by UM will be quite good if the Roberts' Froude number (F) is > 0.1 because at this current speed the plumes from opposite sides o f the diffuser merge rapidly.

The preferred approach in marine water is to use RSB

- if it will be operating within its range of experiments. (Refer to section 1.3.2 Range of the Experiments )

. It is based on experiments conducted in the lab using oppo sing

- port diffusers. However, RSB does require a minimum of 3 ports in the diffuser; and it presently does not provide dilution factors for intermediate points prior to the end of initial dilution. The latter will not be a problem when initial dilution e nds inside the acute boundary.

An alternative approach, that represents a major simplification and that appears to be fairly accurate based on the results of informal modeling trials, is to treat the diffuser as if all ports are
on one side with half the spacing. This approach works well when the regulatory boundaries are beyond the point of merging.

Another acceptable approach for either fresh or marine water involves simulating only downstream ports. However, it is best used with paired port configura tions. This necessitates doubling the flow per port (assuming there is an even number of ports in the diffuser) and increasing the diameter of the ports to maintain approximately the same densimetric Froude number. With this approach only the downstream ports would be used when determiningAPPENDIX 6. (JULY 20 02)

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- 21 spacing and number of ports. This method may give better simulations than the preferred freshwater approach if the Roberts' Froude number (F) is < 0.1. However, a cautionary message will sometimes appear stating that far

- field results are unreliable because the plumes did not merge prior to the end of initial dilution.

All models assume that the ports point perpendicular to the axis of the diffuser. Staged diffusers have ports pointing at an acute angle to the diffus er. Therefore, staged diffusers can only be modeled by making additional assumptions, which must be explained in the analysis.



### 1.3.8 Nascent Density and Buoyancy
It is well understood that the density of water is not a linear function of temperature or s alinity,

e.g. , water expands below about four degrees Celsius. However, it is not well understood that
the non

- linear response of water density to changes in temperature and salinity can cause surprising and unanticipated changes in plume behavior. A the rmally buoyant freshwater plume discharged to unstratified freezing freshwater will initially rise, as expected, before unexpectedly sinking to the bottom. The plume will rise only briefly before becoming denser than the ambient and beginning to sink beca use, as the plume entrains ambient water and cools, it eventually acquires a temperature at which fresh water is at or near maximum density. In another situation, a highly buoyant plume may rise less than a less buoyant plume. These phenomena are known

a s the nascent density effect.

Nascent buoyancy effects also occur under many combinations of ambient and effluent salinities and temperatures. A high salinity plume, e.g. , a blended effluent such as desalination brine and sewage, may sink briefly before becoming less dense than the ambient and beginning to rise

- reversing buoyancy. The citation mentioned below contains several additional examples involving freshwater discharges to the Columbia River.

The linear density assumption is a popular theoretic al and empirical simplification in most models. The latest version of UM (8/7/95) is a non

- linear model which will simulate nascent conditions. A draft citation by Frick et al (1995) is an excellent reference on this subject.



## 1.4 UNDERSTANDING FARFIELD THEORY

It is reasonable to always assume that the plume’s motion in the ambient receiving water is turbulent. Spreading takes place much faster in turbulent flow than in laminar flow. Farfield begins with gravitational collapse (also referred to as buoya nt spreading or density current). This is characterized by lateral spreading of the plume along the layer boundary while it is being advected by the ambient current. Plume thickness probably decreases during this phase; the mixing rate is relatively smal l.

Following gravitational collapse, the remainder of farfield mixing is best explained by either the theory of turbulent diffusion or shear flow dispersion. Turbulent diffusion employs the turbulentAPPENDIX 6. (JULY 20 02)

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APP6

- 22 mixing equation of Brooks (1960), wherein the coeffici ent describing the rate of spread of the plume increases with the size of the plume. The best known facet of this theory is the celebrated
“4/3 Power Law”

- which says that the diffusion coefficient is proportional to the 4/3 power of the size of the plum e. In reality, the Law only applies in homogeneous turbulence far from any boundaries.

Shear flow dispersion employs the longitudinal dispersion equation of Taylor (1954) by the method of Fischer et al (1979). The theory common to all shear flow is that spreading in the direction of flow is caused primarily by the velocity profile in the cross

- section. The mechanism Taylor analyzed is often referred to as the “shear effect”. It gives a reasonably accurate estimate of the rate of longitudinal dispersion in rivers, and a partial estimate of longitudinal in estuaries.



## 1.5 CHOOSING A FARFIELD MODEL

There are two farfield models which are presently recommended for use. They are code named FARFIELD and RIVPLUM5. Each can serve as a stand

- alone mixing zone model when warranted by the situation and has been set up in spreadsheet format to accommodate this ( http://www.ecy.wa.gov/programs/eap/pwspread.html ).

FARFIELD also serves as the farfiel d algorithm in the 3PLUMES interface, so that it operates in conjunction with UM and RSB by taking the plume diameter delivered to it at the cessation of initial dilution. This may change in the future, since RSB presently accounts for gravitational colla pse and the UM/FARFIELD interface does not.

The appropriate farfield model to use in a particular mixing zone analysis depends on the combination of conditions involved:

1. The receiving water is sufficiently deep such that a plume will form and pass th rough the initial dilution phase without "Froude number less than 1", "overlap", or "boundary constraint" problems. Use FARFIELD as the algorithm ( i.e. , the version in 3PLUMES interface). (Refer to 1.5.1 FARFIELD .)

2. The receiving water is shallow and unidirectional; the effluent is thoroughly mixed surface to depth ( i.e.

, no defined plume); and the discharge is a single port or short diffuser. Use RIVPLUM5. (Refer to 1.5.2 RIVPLUM5 .)

3. There is/are bank constraint(s). Use RIVPLUM5, provided the conditions in 2. above are also met. (Refer to 1.5.2 RIVPLUM5 .)

4. Other shallow receiving waters (with no bank constraints) which occur with all other combinations of effluent plumes and discharger configurations. Use FARFIELD as a stand

- alone model . (Refer to 1.5.1 FARFIELD ). A three

- dimensional advective dispersion equation may also be appropriate.APPENDIX 6. (JULY 20 02)

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- 23 Gravitational collapse is not accounted for in the three theoretical, initial dilution models or the
two farfield models discussed in this section. It may be included in a later version of UM3 in the Windows interface (Visual Plumes). The two empirical, initial dilution models (CORMIX and NRFIELD) do account for gravitational collapse. This phenomenon was observed during the

tow

- tank experiments, a nd plume performance during this phase was measured and factored into the empirical equations. The interface allows the modeler to choose the diffusivity coefficient (the [far dif] cell.



### 1.5.1 FARFIELD
FARFIELD calculates dilution using the method of N.H. Brooks (1960). Four variations have been set up as spreadsheets in an EXCEL workbook

- FARFIELD.XLS. The spreadsheets are:

- 3PLUMES algorithms;

- Brook’s exponential diffusivity (4/3 power law);

- Brook’s linear diffusivity; and

- Brook’s constant (e ddy) diffusivity.

The "3PLUMES algorithms" spreadsheet calculates dilutions by assuming either an exponential increase, a linear increase, or a constant diffusivity

- just as the other three spreadsheets do. Linear diffusivity was added to the two algori thms already incorporated in the 3PLUMES interface in order to make it the same package that is offered by the other three spreadsheets. Its utility is in allowing direct comparisons to be made between dilutions at the regulatory boundaries as generated b y one or the other of the models in 3PLUMES and dilutions generated by other initial dilution models which have no far

- field algorithm, e.g. , UDKHDEN.

The default value for the dispersion coefficient in the 3PLUMES interface, the [far dif] cell, is
0.0003 m 2/3 /sec. For areas of high energy dissipation and where there are no constraints, e.g., a large, relatively deep embayment, then the value 0.000453 m 2/3 /sec can be used. In less turbulent situations, it may be as low as 0.0001 m 2/3 /sec.

The exponentia l increase is referred to as the 4/3 Power Law in the output from 3PLUMES. It is Richardson's Law, which is basically only applicable in situations where there is unobstructed spread of the plume. It is reasonable to assume that the spread is unobstructe d if the plume diameter at all locations on its trajectory is less than 1/10 the distance to the nearest side boundary. It is unreasonable to assume that diffusivity will increase exponentially when the plume can only spread along a nearby side boundary. Provided this boundary does not act as a constraint (as discussed in section 1.3.5 Boundary Condition(s )), it is reasonable to assume that it will increase as the first power of the plume width ( i.e. , linearly). Dilutions generated by the Constant Eddy Diffusion algorithm should be used in all other situations.APPENDIX 6. (JULY 20 02)

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- 24 To understand why "3PLUMES algorithms" differs from the other spreadsheets, it is necessary to understand the motivation of the authors of the interface. They felt it was important that users

o f the interface should have to input only one dispersion coefficient in the [far dif] cell; but still be able to receive the output from two far

- field algorithms

- the 4/3 Power Law and the Constant Eddy. This resulted in some coding changes in the initia l steps of the algorithms (including linear diffusivity), where the dispersion coefficient in the [far dif] cell is converted for the first and only time to the diffusivity coefficient used in the Brook's equation. The dispersion coefficient is multiplied by (the width of the plume field at the end of initial dilution) 4/3 . The 4/3 Power Law is described by R.A. Grace (1978).

Following these initial steps, the diffusivity coefficient is either (1) continuously increased according to the 4/3 power of the w idth of the plume field at the end of the previous iteration, (2) continuously increased according to the first power of the width of the plume field at the end of the previous iteration, or (3) held constant according to the zero power of the width of the plume field at the end of the previous iteration. Each algorithm then inserts its coefficient into a modified Brooks' Equation, as described in the text associated with equations 66

- 73 of the User's Manual (EPA, 1994).

Each of the other three spreadshee ts contains one of the algorithms; they are also based on Brook's Equation. Their utility is that they're purer forms, unencumbered by the slight inaccuracies associated with the need to input a single dispersion coefficient to an interface. All
of these far

- field algorithms are much simpler and rudimentary than the initial dilution models. The quality of the estimates should not, in general, be expected to be as high as the initial dilution models. Consequently, if better methods for estimating the far

- field dilutions are available they should be used.

User instructions for the input section of FARFIELD.XLS are available in another appendix to this chapter and on the Internet (http:/www.ecy.wa.gov/programs/eap/pwspread). The user does
not need to ente r or change any values or formulas in the Output section. The spreadsheets calculate dilution along the trajectory of the plume and at the specified mixing zone boundary. Optional calculation of pollutant concentrations assuming first

- order decay rates i s also provided.



### 1.5.2 RIVPLUM5
The spreadsheet RIVPLUM5.XLS calculates dilution using the theory of Taylor (1954) by the
method described in Fischer et al, (1979) and referred to in EPA's Technical Support Document (1991). The analysis considers two

- dim ensional plume spread ( i.e.

, longitudinal and transverse directions), but not vertical mixing (assumed instantaneous). It calculates dilution at a specified point of interest downstream in a river. The calculation for dilution factors incorporates the
bo undary effect of shore lines using the method of superposition. This model is based on the assumption that: (1) the discharge is a single point source, which is most appropriate for single port or short diffusers, or side

- bank discharges; (2) the dischar ge is completely and rapidly mixed vertically, which usually only occurs in shallow rivers; (3) the velocity at all points in theAPPENDIX 6. (JULY 20 02)

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- 25 channel is equal to mean cross

- sectional velocity ( i.e. , there is no transverse variation in velocity); and the transverse dis persion coefficient constant is equal to 0.6 ( i.e.

, a slowly meandering river channel). Table 5.3 in Fischer et al , (1979) contains a number of these coefficients based on experimental measurements.

If the diffuser length occupies a substantial portion of the stream width, or the discharge is not vertically mixed over the entire water column within the acute mixing zone, an alternative model should be used. The spreadsheet also includes optional calculation of the effective origin of a

wastewater source . User instructions for the input section are available in another appendix to this chapter and on the Internet.



## 1.6 CONDUCTING A DYE STUDY

There are four primary objectives that justify conducting a dye study:

1. Confirm the presence of an eddy.

2. Quantify dilution.

3. Quantify far

- field accumulation (reflux).

4. Develop a far

- field diffusivity coefficient.

It is advisable to conduct a reconnaissance survey before the main field work. If the receiving water is tidally

- influenced, then the surv ey should be conducted at the same time in the neap or spring tide cycle and covering the same stages of tide as will be covered during the dye injection. Consideration should be given to deploying a meter to record time, current speed and direction,
and depth of water during the survey in order to develop a thorough understanding of anomalies that may be occurring between published tide data and actual field data. Consider taking a cross

section of the channel bottom, if appropriate. These data will all ow accurate times to be established for dye injection and measurement. It will also afford an opportunity to set up and run some preliminary cases; which, in turn, will provide some early estimates of plume performance, e.g. , trapping depth and horizontal distance to the end of initial dilution.

Concentration of dye in effluent, total loading, and duration of injection deserve careful consideration. Each varies in importance depending upon the objectives of the study, and is discussed below for each obje ctive. A draft plan of study explaining the methods and QA/QC to be employed should be submitted to the Department for review and approval following the reconnaissance survey and prior to initiation of the study.APPENDIX 6. (JULY 20 02)

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- 26 

### 1.6.1 Confirm the Presence of an Eddy

If the objective of the study is to simply confirm the presence of an eddy, then concentration, loading, and duration of injection are all relatively unimportant. It’s only necessary that the path of the plume can be traced. If, on the other hand, it is ne cessary to know the mixing ratio in the eddy in order to determine its contribution, then concentration, loading and duration may all be important.



### 1.6.2 Quantify Dilution
Sometimes dilution factors must be measured directly in the field. However, these are dilution factors for one set of effluent and receiving water conditions only, and a model may still be necessary for analyzing other sets of conditions that are quite different from those present during the dye study. ( e.g. , future growth). Calibrati on , while admittedly an unpredictable exercise, may serve to increase confidence in model performance.

A constant dye concentration in effluent is important. Total loading is not important per se; however, it is important that effluent flowrate be at or near its reasonable worst

- case. Duration is relatively unimportant. In tidally

- influenced waters, injection and measurements should begin after the start of an ebb tide stage. By using this timing it may be possible to capture one critical
condition sc enario.

The most appropriate location to take the measurements for comparing dilutions from the dye study and a model is at the end of the hydrodynamic mixing zone, particularly if the end follows rapid surfacing of the plume in shallow water. (Refer to section 1.3.5 Boundary Condition(s) ). The best way of determining the location is via a reconnaissance survey in conjunction with preliminary model runs, using the set of conditions that will be encountered during the field
work.

A dye study may be the only reliable way to quantify dilutions if boundary constraints are such that all model results will be suspect. A critical condition scenario may include a rapidly surfacing plume with upstream protrusion and/or side boundaries that are affecting entrain ment and dilution. (Refer to 1.3.5 Boundary Condition(s) ). Measurements would be taken at both
the acute and chronic boundaries.

A dye study may also be the most reliable way to quantify dilutions at a lateral boundary when the width of a mixing zone i s restricted to 25% of the channel width. (Refer to section 1.1.11 Other Factors ). The field work should be conducted when conditions are as close as possible to a critical condition, as defined in the Water Quality Standards.

In this situation, a const ant concentration in effluent and duration of injection are important. Total loading is relatively unimportant, per se ; however, it is important that effluent flowrate be
at or near its reasonable worst

- case. In tidally

- influenced waters, injection and m easurementsAPPENDIX 6. (JULY 20 02)

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APP6

- 27 should begin soon after the start of a Lower Low Water slack at sea level during a neap tide or soon after a small flood if it’s riverine. This affords the best opportunity to capture a critical
condition scenario.

[Note: It can be assumed that upstream protrusion does not occur whenever the Roberts’ F is > 0.1.]



### 1.6.3 Quantify Far

- field Accumulation (Reflux)
This objective warrants considerable discussion because it's difficult to accomplish. Tidal currents may cause effluent to accumulat e in the receiving water surrounding an outfall in a tidal river or estuary. The receiving water may also contain background concentrations of pollutants
from sources other than effluent. Various methods are available to account for the accumulation
of e ffluent and ambient background sources when determining potential to exceed water quality criteria or estimating waste load allocations.

There are three methods which are acceptable to Ecology. Two of the methods involve a dye study. Total loading and d uration are important factors in both methods; concentration in the effluent can vary during application. The third method involves simply accepting a default value for reflux in lieu of conducting a dye study. Detailed guidance for conducting the methods and

mass

- balance equations follow.

Far

- field accumulation of effluent may be estimated based on either of two methods:

• Method 1: the USGS superposition method (Hubbard and Stamper, 1972) may be used by injecting the tracer during one tidal day and me asuring continuously at a fixed monitoring station to determine maximum concentrations during succeeding days until the tracer is undetectable; or

• Method 2: the Jirka method (EPA, 1992) may be used by injecting the tracer over several tidal cycles (usu ally five or more) until a quasi

- maximum steady state is reached. Concentrations of the tracer are usually monitored continuously at a fixed monitoring
station.

In addition to two methods of tracer injection, two alternative schemes for locating monitori ng stations are acceptable:

• Alternative 1: tracer concentrations are measured in the near

- field at the mixing zone boundary in the approximate centerline of the effluent plume; or

• Alternative 2: tracer concentrations are measured in the far

- field a t some considerable distance from the effluent plume at a position that is representative of the source of dilution water for the plume.APPENDIX 6. (JULY 20 02)

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- 28 Either the superposition or Jirka methods may be used to conduct the tracer studies for both
Alternatives 1 and 2. A third method is also proposed if a tracer study is not conducted:

• Method 3: A default correction which can be used as an approximation of far

- field accumulation will be based on recommendations by EPA (1992).

A number of terms which will be used duri ng this discussion need to be defined.

near

- field: at the chronic mixing zone boundary in the approximate center

- line of the effluent plume.

far

- field: at some considerable distance from the effluent plume at a position that is representative of the source of dilution water for the plume.

V: initial maximum effluent concentration (volume fraction of effluent ; e.g., 5 percent effluent corresponds to V of 0.05) during first tidal cycle prior to
influence of far

- field accumulation from previous tidal c ycles.



### V : quasi

- steady

- state maximum effluent concentration (volume fraction of

effluent ; e.g., 5 percent effluent corresponds to 

### V of 0.05) after several tidal cycles result in equilibrium with far

- fiel d accumulation.

r d: return rate of dye or effluent mass discharged in the previous tidal cycle as defined in EPA (1992).

DF: initial effluent dilution factor (reciprocal of volume fraction of effluent ; e.g., 5 percent effluent corresponds to DF of 20) du ring first tidal cycle prior to
influence of far

- field accumulation from previous tidal cycles. DF may be estimated using a model ( e.g., PLUMES) or by near

- field tracer measurement. DF is usually determined at a critical condition.



### DF : quasi

- steady

- state effluent dilution factor (reciprocal of volume fraction of

effluent ; e.g., 5 percent effluent corresponds to 

### DF of 20) after several tidal cycles (usually 5 or more cycles) result in equilibrium w ith far

- field

accumulation. 

### DF is usually determined at a critical condition.

C p : pollutant concentration measured as a flux

- average value in the plume at the mixing zone boundary. (Refer to section 1.2.4 Average versus Centerline ).

C e pollutant concentration in effluent discharged from the outfall pipe.APPENDIX 6. (JULY 20 02)

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- 29 C a : pollutant concentration in upstream ambient receiving water ( i.e.

, away from
the influence of far

- field accumulation).

WLA: effluent concentration to use for Waste Load Alloca tion (acute or chronic) for derivation of water quality

- based permit limits.

WQC: pollutant concentration for water quality criteria (acute or chronic).

Mass Balance Equations for Alternative 1

If the tracer monitoring station is located in the near

- field, then the following mass

- balance equations are appropriate:

• calculate Jirka's r d from near

- field 

### V and V (based on equation 22 in (EPA, 1992)): 

# ( )

r V V

V d = − (5)

• calculate the near

- field 

### DF (acute or chronic boundary), including the effect of far

- field accumulation of effluent, from model or tracer estimates of DF and estimated r d in the previous step (based on equation 22 in (EPA, 1992)):


## ( ) DF DF r d 

### = − 1 (6)

• The following equation is appropriate to calculate pollutant concentrations (C p ) at the mixing zone boundaries for comparisons with water quality criteria. Near

- field dilution
is corrected for far

- field accumulation of efflue nt in the previous step. The following equation incorporates the effect of ambient background (C a ) from sources of pollutants
other than effluent. Estimates of C e may also include a reasonable potential multiplier using methods in chapter VI of this Manu al. Pollutant concentrations (C p ) are estimated as follows (based on equation 9 in (EPA, 1994):



### C C DF C DF

p e a



### =     

 +

−     

     

 1 1 1 (4a)APPENDIX 6. (JULY 20 02)

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- 30 • calculate acute and chronic WLAs: 

# ( ) WLA WQC DF C DF

a = ∗

− − 1 (7)

Example :

Given: near

- field V = .02 (2 percent effluent); near

- field 

### V = .07 (7 percent effluent).

Calculation of near

- field 

### DF including far

- field accumulation of effluent:


## ( )

r d = −

= . .

. . 07 02

07 7143 ; DF = = 1
02 50

. ; therefore, near

- field 

## ( ) DF = − = 50 1 7143 14 3

. .

Mass Balance Equations for Alternative 2

If the tracer monitoring station is located in the far

- field, then the following mass

- balance equations are applicable:

• calculate near

- field DF, excluding the far

- field accumulation of effl uent, from a mixing zone
model or from an additional near

- field tracer monitoring station ( e.g., near

- field DF = reciprocal of near

- field V)

• calculate the near

- field 

### DF (acute or chronic boundary), including the effect of far

- field

a ccumulation of effluent, by mass balance with near

- field DF from the previous step and

far

- field 

### V (based on equation 8 in (EPA, 1994)):



## ( ) 

# ( ) DF DF

V DF = +

− 1 1 (8)

• The following equation is appropriate to calculate pollutant concen trations (C p ) at the mixing zone boundaries for comparisons with water quality criteria. Near

- field dilution
is corrected for far

- field accumulation of effluent in the previous step. The following equation incorporates the effect of ambient background (C a ) from sources of pollutants
other than effluent. Estimates of C e may also include a reasonable potential multiplier using methods in chapter VI of this Manual. Pollutant concentrations (C p ) are estimated as follows (based on equation 9 in (EPA, 1994)):



### C C DF C DF

p e a



### =     

 +

−     

     

 1 1 1 (4a)APPENDIX 6. (JULY 20 02)

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- 31 • calculate acute and chronic WLAs: 

# ( ) WLA WQC DF C DF

a = ∗

− − 1 (7)

Example:

Given : near

- field DF=50 from PLUMES model excluding far

- field accumulation of
effluent; far

- field 

### V =.051 (5.1 percent effluent) from tracer study using super

- position
method.

Calculation of near

- field 

### DF including far

- field accumulation of effluent :

N ear

- field 

## ( ) 

# ( ) DF = +

− = 50

1 051 50 1 14 3

. .

Mass Balance Equations for Meth od 3

If it is decided to use a default correction for far

- field accumulation, then the following mass balance equations are applicable:

• estimate default for Jirka's r d = 0.5 from EPA (1992).

• calculate the near

- field 

### DF (acute or chronic boundary), including the effect of far

- field accumulation of effluent, from model or tracer estimates of DF and estimated r d in the previous step (based on equation 22 in (EPA, 1992)):


## ( ) DF DF r d 

### = − 1 (6)

• The following equation is appropriate to calculate pollutant concentrations (C p ) at the mixing zone boundaries for comparisons with water quality criteria. Near

- field dilution
is corrected for far

- field accumulation of efflu ent in the previous step. The following equation incorporates the effect of ambient background (C a ) from sources of pollutants
other than effluent. Estimates of C e may also include a reasonable potential multiplier using methods in chapter VI of this Man ual. Pollutant concentrations (C p ) are estimated as follows (based on equation 9 in (EPA, 1994):



### C C DF C DF

p e a



### =     

 +

−     

     

 1 1 1 (4a)APPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 32 • calculate acute and chronic WLAs: 

# ( ) WLA WQC DF C DF

a = ∗

− − 1 (7)

Example:

Given : r d =0.5; DF=50

Calc ulation of 

### DF : 

## ( ) DF = − = 50 1 0 5 25

. .


### 1.6.4 Develop a Farfield Diffusion Coefficient
[RESERVED].



## 1.7 REFERENCES

Brooks, N. H., 1960. Diffusion of Sewage Effluent in an Ocean Current, Proceedings of the First Conference on Waste Disp osal in the Marine Environment, pages 246

- 267, edited by E.A. Pearson, Pergamon Press, New York, NY.

Davis, L. R., 1996. Personal communication, Oregon State University, Department of Mechanical Engineering, Corvalis OR 97331

- 6001, July.

Doneker, R. L. , 1997. Personal communication, Oregon Graduate Institute, Department of Environmental Science and Engineering, Portland OR 97291

- 1000, July.

Ecology, 1993. Dam Safety Guidelines, Technical Note 3: Design Storm Construction, Washington state Department of Ecology, Olympia WA, Publication # 92

- 55G, April.

Ecology, 1995. An Analysis of Regulatory Issues Raised by Application of the NPDES Permit Program to Municipal and Industrial Stormwater Discharges (draft issue paper)

, Washington State Department o f Ecology, Water Quality Program, Olympia WA,
December.

Ecology, 1996. An Analysis of the Effect of Discharged Wastewater on the Stillaguamish River
at Stanwood , Washington state Department of Ecology, Environmental Investigations and Laboratory Services Program, Olympia WA 98504

- 7710, July.

Ecology, 1998. Criteria for Sewage Works Design (the “Orange Book”), as revised, Washington state Department of Ecology, Water Quality Program, Olympia WA, Publication # 98

- 37 WQ, chapter E2.APPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 33 EPA, 1991. Technical Support Document for Water Quality

- based Toxics Control , U.S. Environmental Protection Agency, EPA/505/2

- 90

- 001, pages 77

- 78.

EPA, 1992. Technical Guidance Manual for Performing Waste Load Allocations Book III: Estuaries Part 3: Use of Mixing Zone M odels in Estuarine Waste Load Allocations , U.S. Environmental Protection Agency, EPA/823/R

- 92/004, section 2.6.

EPA, 1994. Dilution Models for Effluent Discharges

, U.S. Environmental Protection Agency,
EPA/600/R

- 94/086, Washington, D.C.

Fischer, H.B., E .F. List, R.C.Y. Koh, J. Imberger, and N.H. Brooks, 1979. Mixing in Inland and Coastal Waters, Academic Press, Inc., Harcourt Brace Jovanovich Publishers, New York NY, pp. 126

- 127.

Frick, W.E., et al , 1995. Nascent Buoyancy Effects on Blended and Exotic Effluents

, Draft, U.S. Environmental Protection Agency, Center for Environmental Assessment Modeling, Athens GA, April 16.

Frick, W. E., 1996. Estimating Parallel Diffuser Dilutions Using PLUMES UM , U.S. Environmental Protection Agency, Center for Envi ronmental Assessment Modeling, Athens GA, July 11.

Gilbert, R.O., 1987. Statistical Methods for Environmental Pollution Monitoring , Van Nostrand Reinhold, New York.

Glenn, N. L. and D. Giglio, 1997. Kitsap County Mixing Zone Study , Washington state Dep artment of Ecology, Environmental Investigations and Laboratory Services Program, Olympia WA 98504

- 7710, July.

Grace, R.A., 1978. Marine Outfall Systems: Planning, Design, and Construction

, Prentice

- Hall, Englewood Cliffs NJ, Chapter 7.

Hubbard, E.F. a nd W.G. Stamper, 1972. Movement and Dispersion of Soluble Pollutants in the Northeast Cape Fear Estuary, North Carolina , Water

- supply paper 1873

- E, U.S. Geological Survey, United States Department of the Interior.

Jirka, G.H., P.K. Akar and J.D. Nash, 19 96a. Enhancements to the CORMIX Mixing Zone Expert System: Technical Background , Technical report, DeFrees Hydraulics Laboratory, School of Civil and Environmental Engineering, Cornell University, Ithaca
NY 14853

- 3501.APPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 34 Jirka, G.H., R.L. Doneker and S.W . Hinton, 1996b. User’s Manual for CORMIX: A Mixing Zone Expert System for Pollutant Discharges into Surface Waters , draft, DeFrees Hydraulics Laboratory, School of Civil and Environmental Engineering, Cornell University, Ithaca NY 14853

- 3501, page 16.

NOAA, 1981. A Summary of Knowledge of Puget Sound Related to Chemical Contaminants

, National Oceanic and Atmospheric Administration, Office of Marine Pollution Assessment, Technical Memorandum OMPA

- 13, Boulder, CO.

Roberts, P.J.W., 1991. Ocean Outfalls

, Critical Reviews in Environmental Control , Volume 20, Issues 5 & 6, pages 311

- 339.

Roberts, P.J.W., W.H. Snyder, and D.J. Baumgartner, 1989. Ocean Outfalls. I: Submerged Wastefield Formation

, Journal of Hydraulic Engineering , Volume 115, No. 1, January

.

Taylor, G.I., 1954. The d ispersion of matter in turbulent flow through a pipe, Proceedings of R.
Soc. London Ser. , A223, 446

- 468, Sci. Pap. 2, 466

- 488.

Turner, D.B., 1970. Workbook of atmospheric dispersion estimates . Office of Air Programs,
Publica tion No. AP

- 26, USEPA, Research Triangle Park, North Carolina.APPENDIX 6. (JULY 20 02)

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APP6

- 35APPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 36APPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 37 

## 2.0 SPREADSHEETS FOR WATER QUALITY

- BASED NPDES PERMIT CALCULATIONS

Updated July 2000 by Greg Pelletier

Several spreadsheets were developed by the Washington State Department of Ecol ogy to aid NPDES permit writers. These spreadsheets are referred to in Ecology's Permit Writer's Manual (Department of Ecology Publication Number 92

- 109). Several of the spreadsheets are in separate
Lotus 1

- 2

- 3 WK1 files and also have been combined and ref ormatted into an Excel 5 workbook.

• DOSAG2.WK1: This spreadsheet calculates critical sag of dissolved oxygen downstream from a point source using the Streeter

- Phelps equation.

• IDOD2.WK1: This spreadsheet calculates concentrations of dissolved oxygen at a mixing zone boundary accounting for dilution of dissolved oxygen and initial dissolved oxygen
demand.

• NH3FRES2.WK1: This spreadsheet calculates freshwater un

- ionized and total ammonia criteria from temperature and pH from the formulas modified by EPA whic h were adopted in the 1995 revision to the state water quality standards.

• NH3SALT.WK1: This spreadsheet calculates saltwater total ammonia criteria from temperature, pH, and salinity to meet the un

- ionized ammonia criteria.

• PHMIX2.WK1: This spreadsheet c alculates the pH of a mixture of two sources for temperature, pH, and alkalinity.

• RIVPLUM5.WK1: This is a simple dilution model for rivers based on the method in chapter 5 of the book "Mixing in Inland and Coastal Waters" by H.B. Fischer et al. (1979,
Aca demic Press Inc.)

• PWSPREAD.XLS: This Excel 5 file contains the following spreadsheets as described
above:

• dosag2

• idod2

• nh3fres2

• nh3fresh

• nh3salt

• phmix2

• rivplum5APPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 38 • FARFIELD.XLS (requires the Analysis ToolPak Add

- In under the "Tools/Add

- Ins" menu) : T his Excel 5 workbook calculates far

- field mixing of a plume using the method of N.H. Brooks (1959, "Diffusion of Sewage Effluent in an Ocean Current," in "Waste Disposal in the Marine Environment", edited by E.A. Pearson, pp, 246

- 267, Pergamon Press, New Y ork, NY.) This workbook is useful for estimating dilution beyond the range
of near

- field models such as UDKHDEN or PLUMES/UM using Brook's 4/3

- power law, linear diffusivity, and constant diffusivity algorithms.

• TSDCALC.XLW is a workbook composed of severa l spreadsheets. It is used for reference and for developing water quality

- based permit limits. The individual spreadsheets contained in TSDCALC are:

• criteria.xls

• ammoniafw.xls

• reaspot.xls

• limit.xls

• performlim.xls

• human

- h.xls

The spreadsheets CRITERI A.XLS and AMMONIA.XLS contain or calculate water quality criteria. REASPOT.XLS and LIMIT.XLS determine reasonable potential (to violate the water quality standards) and calculate effluent limits. PERFORMLIM.XLS calculates performance

- based effluent limitat ions and accounts for autocorrelation if
known. HUMAN

- H.XLS determines reasonable potential and calculates effluent limits for human health pollutants.



## 2.1. DETAILED DESCRIPTIONS AND USER INSTRUCTIONS

Spreadsheet DOSAG2.WK1

Revised October 19, 1993

This spreadsheet calculates the critical dissolved oxygen sag and concentration downstream from a point source load of BOD in a river using the Streeter

- Phelps equations. The method used is
documented in EPA/600/6

- 85/002a (Water Quality Assessment: A Screening Procedure for Toxic and Conventional Pollutants in Surface and Ground Water). This spreadsheet is recommended for use as a screening tool to determine the potential for dissolved oxygen standards to be violated. DOSAG2.WK1 may be overly simplistic for deri ving limits for effluent BOD. If DOSAG2.WK1 suggests the dissolved oxygen sag is close to or below the water quality standard, then a more sophisticated model such as QUAL2E or WASP5 should be used to derive appropriate effluent limits. Those water quality models are designed to more accurately simulate water movements, mass transport, and water column processes.APPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 39 

### User Instructions for the Input Section
Step 1: Enter the permittees effluent characteristics, including permitted discharge and maximum ( e.g. , we ekly) 5

- day BOD (referred to as CBOD5 for "carbonaceous" 5

- day BOD).
Carbonaceous 5

- day BOD is less than the total 5

- day BOD if nitrification occurs during the test.
The minimum national standards for carbonaceous 5

- day BOD in effluent after secondary

trea tment are a monthly average of 25 mg/L and weekly average of 40 mg/L (40 CFR Part 133). Guidance for determining if carbonaceous 5

- day BOD should be substituted for total 5

- day BOD is contained in Ecology's Permit Writer's Manual (section V

- 3.6).

Nitrogen ous BOD (NBOD) should also be estimated if it is significant ( e.g., if nitrification is not significant during secondary treatment). NBOD can be estimated as:

NBOD = 4.57 * (Ammonia N + Organic N)

where concentrations of NBOD, ammonia N and organic N are expressed in mg/L. Effluent temperature and dissolved oxygen for the analysis are also entered at this step. The spreadsheet may be used to estimate the maximum permissible effluent CBOD5 and NBOD that will meet the water quality standards for dissolved oxygen. A trial and error solution is necessary for this purpose. Trial values of effluent CBOD5 and NBOD may be entered until the dissolved oxygen at the critical sag meets the water quality standard.

Step 2: Enter receiving water characteristics. These will generally be conditions at the 7Q10 discharge. Upstream CBOD5, NBOD, dissolved oxygen and temperature at the design river flow ( e.g. , 7Q10) should be entered. The local channel elevation and channel slope ( e.g. , from USGS topographic maps) downstream from the discharge should also be entered. Downstream average channel depth and velocity at the design flow should be entered also.

If no receiving water data are available, it would be desirable to collect data. Channel cross

sections of depth and veloci ty can be measured during the critical season. If measurements are not taken near critical conditions, then Manning's equation may be used to estimate velocity and depths from the measurements. Several cross

- sections proceeding downstream from the discharg e may be needed to characterize the river to the point of critical sag if velocities and depths are not uniform. Dye studies to measure travel time may be useful if velocities are variable. If significant tributaries, groundwater inflows, or other pollutan t loads occur before the predicted critical sag point, then a more sophisticated model should be used ( e.g., QUAL2E).

Measurements of water quality ( e.g., dissolved oxygen, ammonia, BOD) in the receiving water from upstream and at intervals downstream to the critical sag point are also desirable for model calibration. If the model is applied without sufficient data to demonstrate calibration, then the model should mainly be used to screen for potential violation of standards. If effluent BOD is required to be more restrictive than current technology

- based limits, then calibration data are probably needed. Separate calibration and verification data sets taken on different dates may beAPPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 40 needed in many cases where the accuracy of the model is in question.

Ste p 3: Enter the reaeration rate (base e) at 20 degrees C in cell D27. Suggested values using empirical equations referenced in EPA/600/6

- 85/002a are given below cell D27 for guidance in selecting an appropriate value. If the calculated values are used, sele ct the most appropriate equation based on applicable depth and velocity ( e.g. , if depth is <1 to 2 feet, then use the value shown from the Tsivoglou

- Wallace equation).

Step 4: Enter the BOD decay rate (base e) at 20 degrees C in cell D36. A calculated val ue based on the Wright and McDonnell equation referenced in EPA/600/6

- 85/002a is provided and may be entered in cell D36 at Step 4 if desired. 

### User Instructions for the Output Section
The user does not need to change or enter any values or formulas in the Output Section. The travel time and distance to critical sag, deficit at critical sag, and dissolved oxygen concentration at critical sag are displayed in the Output Section.



### Spreadsheet IDOD2.WK1

Revised October 19, 1993 This spreadsheet calculates the di ssolved oxygen concentration at a mixing zone boundary from dilution of dissolved oxygen in the effluent and ambient background and immediate dissolved oxygen demand of the effluent. The method used is presented in EPA/600/6

- 85

- 002b (Water Quality Assessme nt: A Screening Procedure for Toxic and Conventional Pollutants in Surface and Ground Water

- Part II Revised 1985) and EPA/430/9

- 82

- 011 (Revised Section 301(h) Technical Support Document).



### User Instructions for the Input Section

Step 1: Specify the dilu tion factor for effluent at the chronic mixing zone boundary. This value should represent dilution at critical conditions if the spreadsheet is being used for developing NPDES permit limits. The dilution factor used should represent the reciprocal of the v olume fraction of effluent present at the mixing zone boundary (see Permit Writer's Manual section VI

2.1).

Step 2: Enter the background dissolved oxygen concentration in the receiving water. The 10th percentile during the critical season is recommended a s a reasonable worst case. If no data are available it would be desirable to collect data describing background dissolved oxygen concentrations during the critical season ( e.g., upstream from the discharge to a river).

Step 3: Enter the effluent dissolved oxygen concentration. The 10th percentile during the critical
season is recommended as a reasonable worst case.

Step 4: Enter the immediate dissolved oxygen demand (IDOD) of the effluent if known. TheAPPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 41 IDOD represents the oxygen demand of reduced substan ces which are rapidly oxidized ( e.g., sulfides to sulfates). If the effluent contains measurable dissolved oxygen, then the IDOD may be negligible. If IDOD is to be determined experimentally, the procedures in Standard Methods 1979 edition could be followe d. However, the method was omitted from Standard Methods in the 1985 edition because of concerns about the accuracy of the test. 

### User Instructions for the Output Section
The user should not enter or change the value or formula in the output section. The d issolved oxygen at the mixing zone boundary is presented in the output section.



### Spreadsheet NH3FRES2.WK1
Revised December 12, 1994 (NH3FRES2.WK1)

NH3FRES2.WK1 contains the formulas modified by EPA that were adopted in the 1995 revision
of the state water quality standards. The spreadsheet also calculates the amount of un

- ionized ammonia present in a sample if total ammonia, temperature, and pH are known. 

### User Instructions for the Input Section
Step 1: Specify the temperature (design condition at the mixing zone boundary) for which un

ionized ammonia criteria or concentrations are to be estimated. If the spreadsheet is being used to calculate criteria for a NPDES permit limit, the 90th percentile temperature during the critical
season is recommended for a re asonable worst

- case condition. If no data are available it may be desirable to collect data during the critical season to describe temperature at the mixing zone boundary.

Step 2: Specify the pH (design condition at the mixing zone boundary) for which un

- ionized ammonia criteria or concentrations are to be estimated. If the spreadsheet is being used to calculate criteria for a NPDES permit limit, the 90th percentile pH during the critical season is
recommended for a reasonable worst

- case condition. If no data are available it may be desirable to collect data during the critical season to describe pH at the mixing zone boundary.

Step 3: Specify the sample total ammonia concentration if known. Entering a value here only affects Output Step 2 (calculation o f un

- ionized ammonia present in a sample). No input is required at this step if the spreadsheet is being used only to calculate criteria from temperature and pH ( i.e., values entered at this step do not affect criteria calculations).

Step 4: Specify "Acut e TCAP" according to the Gold Book (enter 20 if salmonids are present; 25 if salmonids are absent).

Step 5: Specify "Chronic TCAP" according to the Gold Book (enter 15 if salmonids are present; 20 if salmonids are absent).APPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 42 

### User Instructions for the Output Section
The user should not enter or change any values or formulas in the Output Section. The spreadsheet calculates the amount of un

- ionized ammonia present in a sample at Output Step 2 if the sample total ammonia was specified at Input Step 3. Output St ep 3 provides the acute and chronic criteria for un

- ionized ammonia expressed in ug/L as NH3

- N. Output Step 4 provides the acute and chronic criteria for total ammonia expressed in ug/L as NH3

- N.



### Spreadsheet NH3SALT.WK1

Revised October 19, 1993 This spread sheet calculates water quality criteria for ammonia in saltwater using the method specified in EPA 440/5

- 88

- 004 (Ambient Water Quality Criteria for Ammonia (Saltwater)

- 1989). 

### User Instructions for the Input Section
Step 1: Specify the temperature (design c ondition at the mixing zone boundary) for which un

ionized ammonia criteria are to be estimated. If the spreadsheet is being used to calculate criteria for a NPDES permit limit, the 90th percentile temperature during the critical season is
recommended for a reasonable worst

- case condition. If no data are available it may be desirable to collect data during the critical season to describe temperature at the mixing zone boundary.

Step 2: Specify the pH (design condition at the mixing zone boundary) for which un

- ionized ammonia criteria to be estimated. If the spreadsheet is being used to calculate criteria for a NPDES permit limit, the 90th percentile pH during the critical season is recommended for a
reasonable worst

- case condition. If no data are available it may be desirable to collect data during the critical season to describe pH at the mixing zone boundary.

Step 3: Specify the salinity (design condition at the mixing zone boundary) for which un

- ionized ammonia criteria are to be estimated. If the spread sheet is being used to calculate criteria for a NPDES permit limit, the 10th percentile salinity during the critical season is recommended for a
reasonable worst

- case condition. If no data are available it may be desirable to collect data during the critic al season to describe salinity at the mixing zone boundary. 

### User Instructions for the Output Section
The user should not enter or change any values or formulas in the output section. The acute and chronic criteria are expressed three ways: 1) as unionized ammonia in mg/L as NH3 at Output Step 5; 2) as total ammonia in mg/L as NH3 at Output Step 6; and 3) as total ammonia in mg/L as NH3

- N at Output Step 7. For derivation of total ammonia waste load allocations and comparisons with effluent total ammonia data , it is recommended that the criteria be expressed as total ammonia in mg/L as NH3

- N for simplicity. [Note: the criteria in EPA 440/5

- 88

- 004 Tables 2 and 3 are for total ammonia as mg/L as NH3, which should be multiplied by 0.822 to convert to mg/L as NH3

- N.]APPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 43 

### Spreadsheet PHMIX2.WK1

Revised October 19, 1993 This spreadsheet calculates the pH of a mixture of two flows using the procedure in EPA's DESCON program (EPA, 1988. Technical Guidance on Supplementary Stream Design Conditions for Steady State Modeling. EPA Office of Water, Washington DC). The major form of alkalinity is assumed to be carbonate alkalinity. Also, alkalinity and total inorganic carbon are assumed to be conservative. 

### User Instructions for the Input Section
Step 1: Specify the dilution facto r for effluent at the mixing zone boundary. This value should represent dilution at critical conditions if the spreadsheet is being used for developing NPDES permit limits. The dilution factor used should represent the reciprocal of the volume fraction of effluent present at the mixing zone boundary (see Permit Writer's Manual section VI

- 2.1).

Step 2: Specify the upstream characteristics, including temperature, pH, and alkalinity. For development of NPDES permit limits for ammonia, the 90th percentiles dur ing the critical season are recommended. If no data are available, it is desirable to collect data describing upstream temperature, pH, and alkalinity during the critical season.

Step 3: Specify the effluent characteristics, including temperature, pH, and alkalinity. For NPDES permit limits, a reasonable worst case estimate of each may be estimated from DMR data ( e.g., for ammonia limits use 90th percentile values from the DMR data during the critical season). If effluent data are not available then data s hould be collected during the critical season. In many cases, pH in ambient receiving water (at Step 2 above) may be assumed to represent the pH in the mixing zone. 

### User Instructions for the Output Section
The user does not need to enter or change any valu es or formulas in the Output Section. The spreadsheet calculates and displays the pH at the mixing zone boundary at Output Step 4. Some important factors that can influence pH are not included in this calculation. For example, photosynthesis in the receivi ng water may increase pH downstream from the mixing zone. In many cases where dilution is relatively large ( e.g., greater than a dilution factor of 20) the pH in the mixing zone will be dominated by ambient conditions. This spreadsheet should be used
mainl y where effluent dilution is relatively low and effluent pH and alkalinity are much different than in the receiving water.



### Spreadsheet RIVPLUM5.WK1
Revised February 22, 1996

This spreadsheet calculates dilution at a specified point of interest downstream from a point discharge to a river. The procedure used is described in Fischer et al. , 1979 (Mixing in Inland and Coastal Waters, Academic Press) and referred to in EPA/505/2

- 90

- 001 (TSD for WQ

- basedAPPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 44 Toxics Control.) The calculation for dilution factors inc orporates the boundary effect of shorelines using the method of superposition (Fischer et al. , equation 5.9.)

This spreadsheet is based on the assumption that the discharge: 1) is a single point source, which is most appropriate for single port or short d iffusers, or side

- bank discharges; and 2) is completely and rapidly mixed vertically, which usually only occurs in shallow rivers. If the diffuser length occupies a substantial portion of the stream width, or the discharge is not vertically mixed over the entire water column within the acute mixing zone, an alternative model should be used such PLUMES or CORMIX. RIVPLUM5.WK1 is useful for estimating dilution
in shallow rivers for side

- bank discharges or single

- port outfalls. This spreadsheet replaces a

prev ious version called RIVPLUM4.WK1 RIVPLUM5.WK1 was modified to include optional calculation of the effective origin of a wastewater source. 

### User Instructions for the Input Section
Step 1: Enter the effluent design flow (see Permit Writer's Manual section VI

- 3.3.2).

Step 2: Specify the receiving water characteristics, including average channel depth, velocity and width downstream from the discharge at the design flow ( e.g. , at 7Q10. NOTE: The product of depth*width*velocity should equal the receiving water d ischarge rate downstream from the discharge).

Also enter either the channel slope downstream from the discharge ( e.g. , as measured from a USGS topographic map) or Manning's "n" coefficient for roughness. Finally, enter either 0 (if slope is entered above) or 1 (if Manning's "n" is entered above).

The slope or Manning's "n" are used to estimate shear velocity and transverse mixing coefficients. Either method may be used, depending on which data are more readily available. It is not necessary to specify bot h slope and Manning's "n". If comparisons are made between the two methods then care should be taken to be sure that slope and Manning's "n" values are consistent with velocity, depth, and width data since all are related by Manning's equation. In general, it is not desirable to overestimate Manning's "n" because a lower value will generally be more protective since it will predict a lower transverse mixing coefficient. If the Manning option is used, the following values may be appropriate estimates for Man ning's "n" (EPA/600/3

- 87

- 007 after Henderson, F.M., Open Channel Flow, Macmillan Co., New York, NY, 1966):

• Artificial channel, earth, smooth, no weeds: 0.020

• Artificial channel, earth, some stones and weeds: 0.025

• Natural channel, clean and straight: 0. 025

- 0.030

• Natural channel, winding with pools an shoals: 0.033

- 0.040

• Natural channel, very weedy, winding and overgrown: 0.075

- 0.150

If no receiving water data are available, then data collection would be desirable. MeasurementsAPPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 45 of channel cross

- sections of width, depth, and velocity should be collected within the mixing zone at conditions near critical low flow ( e.g., near 7Q10). If conditions are significantly different than 7Q10 during measurements, then data may need to be adjusted ( e.g., usin g Manning's equation).

Step 3: Enter the distance between the diffuser midpoint and the nearest shoreline of the river ( e.g. , for a side

- bank discharge enter 0).

Step 4: Enter the location of the downstream point at which dilution factors will be estimat ed, including the distance downstream from the diffuser and the distance from the nearest shoreline. The "point of interest" is the location at which dilution factors will be estimated in the Output Section. The highest concentration of effluent downstream from the outfall will be the same distance from shore as the point of discharge. Therefore, the distance from shore for the point of interest should be the same as for the diffuser midpoint in Step 3 for a worst case. However, the dilution at any point do wnstream may be estimated using any combination of distances downstream and from shore for the "point of interest."

Step 5: Enter the transverse mixing coefficient constant. A value of 0.6 is recommended for most natural channels. Fischer reports that the transverse mixing coefficient can range from 0.1 to 0.2 for straight artificial channels. Curves and sidewall irregularities increase the coefficient such that in natural streams it is rarely less than 0.4. If the stream is slowly meandering and the
sidew all irregularities are moderate, then the coefficient is usually in the range of 0.4 to 0.8. Therefore, a value of 0.6 is usually recommended in natural channels. Uncertainty in this constant is usually at least +/

- 50 percent.

Step 6: Enter 0 to use the original equations documented in Fischer et al. (1979), or enter 1 to account for the effective origin of the wastewater source in the Fischer et al. equations. Entering 0 will give results identical to the previous version of the spreadsheet (RIVPLUM4).
T he optional correction for effective origin is based on discussion in section 5.1.3 of the Fischer
et al. text. The dilution factors for some discharges may be underestimated without correction for effective origin.
The dilution model is based on consider ing a rectangular channel of depth (d) into which is discharged M units of mass of effluent per unit time in the form of a vertical line source. A line source of M units into a flow of depth (d) is equivalent to a point source of strength M/d in a

two

- dime nsional flow, for which the concentration (C) is as follows from equation 5.8 and 5.9 of
Fischer et al. (the nomenclature is as in Fischer et al. ; Qe=effluent flow (L^3/T); u=velocity (L/T); d=depth (L); Et=transverse mixing coefficient (L^2/T); x=distance downstream (L); y=distance across channel (L); W=channel width (L)):

C = k * C0 / (4*pi*x')^0.5 (eqn 1)

where

2APPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 46 k = SUM {exp[

- (y'

- 2n

- y0')^2/4x']+exp[

- (y'

- 2n+y0')^2/4x']}

n=

- 2

C0 = M / (u*d*W)

x' = x*Et /(u*W^2)

y' = y/W

y0' = y' at the source location y=y0

If C represents the effluent volume fraction, then the dilution factor is equal to 1/C. In order to apply this equation very close to the effluent outfall, the effective origin may be estimated as
f

ollows.

• If M is estimated as the product of effluent flow and concentration, then the effluent source concentration (Ce) is:

Ce=M/Qe (eqn 2)

• The offset or correction (x0) for the effective origin of ef fluent may be estimated as follows. First, substitute eqn 2 into eqn 1 for instream C=Ce:

M/Qe = k * C0 / (4*pi*x')^0.5 (eqn 3)

• Next, solve eqn 3 for x=x0, which is the distance downstream from the effective origin to
the ou tfall, such that in

- stream concentration equals the effluent concentration at the
actual outfall location:

x0 = (k*Qe/d)^2 / (u*4*pi*Et) (eqn 4)

• The effective distance downstream (x) in eqn 1 is then replaced by (x+x0) to ac count for the effective origin of the source. 

### User Instructions for the Output Section
The user does not need to enter or change any values or formulas in the Output Section. The plume characteristics incorporating the shoreline effect are displayed at Ste p 5 of the Output Section, including the approximate distance downstream to complete mix, theoretical maximum available dilution at complete mix of effluent with the receiving water, flux

- average dilution at the specified downstream distance, and the calcu lated dilution factor at the specified point of interest downstream from the discharge.

The distance downstream to complete mixing is often overestimated because most natural channels contain sharp bends or changes that increase mixing beyond the processe s included in the model. The model is most useful for predicting mixing where the channel is represented over a relatively short distance ( e.g., to the mixing zone boundary).APPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 47 

### Workbook PWSPREAD.XLS
Revised February 22, 1996
This Excel 5 workbook contains th e following spreadsheets:

• dosag2

• idod2

• nh3fres2

• nh3salt

• phmix2

• rivplum5

The spreadsheets in PWSPREAD.XLS perform the same calculations as the Lotus 1

- 2

- 3 .WK1
files of the same names. The instructions for each of the sheets in PWSPREAD.XLS are the

s ame as for the .WK1 files.



### Workbook FARFIELD.XLS
Revised February 22, 1996

[NOTE: This workbook requires the Analysis ToolPak Add

- In, which must be configured using
the "Tools/Add

- Ins" menu in Excel 5.]

This Excel 5 workbook calculates far

- field mixing o f a plume using the method of N.H. Brooks (1959, "Diffusion of Sewage Effluent in an Ocean Current," in "Waste Disposal in the Marine Environment", edited by E.A. Pearson, pp, 246

- 267, Pergamon Press, New York, NY.) This workbook is useful for estimating d ilution beyond the range of near

- field models such as UDKHDEN or PLUMES/UM using Brook's 4/3

- power law, linear diffusivity, and constant diffusivity algorithms.

Brooks' model is applied in this workbook using the algorithm of EPA's PLUMES model (1993,
"Di lution Models for Effluent Discharges," U.S. Environmental Protection Agency, EPA/600/R

93/139, Washington, DC.) with the addition of a linear diffusivity algorithm as described by R.A. Grace (1978, "Marine Outfall Systems: Planning, Design, and Constructi on," Prentice

- Hall Inc., Englewood Cliffs, NJ.)

FARFIELD.XLS contains the following four spreadsheets:

• PLUMES algorithm

• Brooks' four

- thirds power law

• Brooks' linear diffusivity

• Brooks' constant diffusivity

The "PLUMES algorithm" spreadsheet uses the same method as EPA's PLUMES model ("Dilution Models for Effluent Discharges," U.S. Environmental Protection Agency,APPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 48 EPA/600/R

- 94/086) to implement Brooks' far

- field models. The PLUMES algorithm is documented in equations 66

- 73 of EPA/600/R

- 94/086. The majo r difference between the "PLUMES algorithm" and the other spreadsheets is in the treatment of the parameter "alpha" in the following equation:

epsilon(0) = alpha * b ^n

where epsilon(0) is the lateral diffusion coefficient (L^2/T), b is the width of the plume (L), and n is an exponent used to estimate the initial value of epsilon. The PLUMES algorithm assumes that the initial value of epsilon(0) at the start of far

- field modeling is based on n=4/3 for both the 4/3 power law and constant diffusivity models . Therefore, the PLUMES algorithm assumes that "alpha" has units of L^(2/3)/T and n=4/3 regardless of which Brooks' model is used.

The "PLUMES algorithm" spreadsheet also includes Brooks' linear diffusivity model and uses
n=4/3 for the initial calculation of epsilon(0). The linear diffusivity model used in the spreadsheet is as presented by equation 7

- 65 of Grace (1978).

The "Brooks' four

- thirds power law", "Brooks' linear diffusivity", and "Brooks constant diffusivity" spreadsheets differ from the "PLUME S algorithm" spreadsheet by assuming different units for "alpha" and different values of n depending on the model being used. "Alpha" has units of L^(2/3)/T for the 4/3 power law (n=4/3), L/T for the linear diffusivity model (n=1),
and L^2/T for the consta nt diffusivity model (n=0). Brooks' equations as documented in equations 7

- 64, 7

- 65, and 7

- 66 of Grace (1978) were used to estimate dilution along the plume trajectory. 

### User Instructions for the Input Section
Step 1: Specify the plume and diffuser characte ristics at the start of far

- field mixing. The computations at the end of a near

- field mixing model such as UDKHDEN or PLUMES/UM is usually used to define the conditions at the start of far

- field mixing. The necessary parameters
are the flux

- average dilutio n factor at the end of near

- field model computations, the estimated
initial width at the start of far

- field mixing ( e.g., equation 70 as described in the PLUMES manual (EPA/600/R

- 94/086), and the horizontal distance that the plume travels during the near

f ield mixing phase.

Step 2: Specify the horizontal distance from the outfall to the mixing zone boundary along the trajectory of the plume ( e.g., as defined in WAC 173

- 201A

- 100).

Step 3: Specify the parameter "alpha" as described above. The units for "alp ha" depend on which spreadsheet is used, as discussed above.

Step 4: Specify the horizontal current speed along the far

- field plume trajectory.

Step 5 (optional): Specify the initial pollutant concentration and the first

- order decay rate. TheAPPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 49 initial con centration for far

- field mixing should be the final concentration at the end of near

- field mixing. 

### User Instructions for the Output Section
The user does not need to enter or change any values or formulas in the Output Section. The spreadsheets calculate d ilution along the trajectory of the plume and at the specified mixing zone boundary. Optional calculation of pollutant concentrations assuming first

- order decay rates is also provided.



## 2.2 GUIDELINES FOR USING TSDCALC.XLW

TSDCALC.XLW is a workbook compo sed of several spreadsheets. Several are duplicates of those given above. It is used for reference and for developing permit limits. The individual spreadsheets contained in TSDCALC are CRITERIA.XLS, AMMONIA.XLS, REASPOT.XLS, LIMIT.XLS, PERFORMLIM.XLS, HUMAN

- H.XLS , Fresh

- temp.XLS and Marine

- temp.XLS

. The spreadsheets CRITERIA.XLS and AMMONIA.XLS contain or calculate water quality criteria. The spreadsheets REASPOT.XLS, and LIMIT.XLS determine reasonable potential (to violate the aquatic life water qual ity standards) and calculate effluent limits. The spreadsheet PERFORMLIM.XLS calculates performance

- based effluent limitations and accounts for autocorrelation if known. The spreadsheet HUMAN

- H.XLS determines reasonable potential and calculates effluent limits for human health pollutants. The spreadsheets Fresh

- temp and Marine

temp determine reasonable potential and limits for temperature. The process and formulas for determining reasonable potential and effluent limits in these spreadsheets are taken dir ectly from the Technical Support Document for Water Quality

- based Toxics Control , (EPA 505/2

- 90

- 001). The adjustment for autocorrelation is from EPA (1996a) , and EPA (1996b)



### CRI TERIA.XLS
This spreadsheet is split for convenience of the permit writer. The pollutants of concern can be copied from the lower view and pasted in the upper view. The upper view can then be printed with only the pollutants of concern. Documentation text is found in rows 186

- 193.

Input

- Cell B199 is a fill

- in cell for receiving water TSS concentration, if known. TSS is used for calculating the partitioning translator for copper and zinc. If no TSS values are placed in this cell, the statewide 95th per centile ratio or the conversion factor is used as the default translator.

Input

- Cell B200 is a fill

- in cell, which characterizes the TSS data. Place an A in this cell if the TSS data is derived from several seasons. Place an S in this cell if the TS S data is only from the critical period.

Input

- Cell B201 is a fill

- in cell for hardness of the receiving water. Hardness is used to
calculate several of the metal criteria. The hardness value should be the lowest value from the critical period if the data set is less than 20, or the 10th percentile value if theAPPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 50 data set is 20 or greater. Column A contains the pollutant name, the CAS number, and where it is found on the table of effluent characteristics in the NPDES permit application.

Column B is lab eled “Priority Pollutant?” A Y in this column means the chemical is a priority pollutant (toxic pollutant).

Column C is labeled Carcinogen? A Y in this column means the chemical is a carcinogen.

Columns D through G are the aquatic life water quality cr iteria for fresh and marine waters.

Columns H and I are the human health criteria for fresh and salt water. These columns are more correctly stated as Criteria for consumption of water and organisms (typically fresh water) and Criteria for the consumptio n of organisms only (typically salt water).

Column J gives the source of the criteria and any additional comments. A notation of NTR

- HH means the human health criteria are from the National Toxics Rule and therefore part of our regulatory requirements. A notation of Gold Book means the criterion is a federal EPA criterion. These values should be treated as guidance. The “Gold Book” has been modified extensively by federal regulations such as the National Toxics Rule and others.

Columns K through N are translators for the metal criteria, which are used for determining reasonable potential. The translators for cadmium, copper, lead, and zinc are based on data presented by Pelletier (1996).



### AMMONIA.XLS
This spreadsheet calculates the freshwater ammonia c riteria. The inputs for this spreadsheet are temperature
, pH of the receiving water at the time of critical condition and whether the receiving
water is salmonid habitat

.



### REASPOT.XLS
This spreadsheet determines if there is a reasonable potential for vi olation of the aquatic life water quality standards based on the input values. There is an example for reasonable potential determination for metals in the PWM in Chapter VI.APPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 51 Input

- Column A

- enter the pollutant parameter.

Input

- Column B and C

– Th ese are the metal criteria translator values taken from Criteria.XLS. If there is no value placed here the default value is the
metal conversion factor.

Input

- Column D is the ambient background concentration. For metals use the dissolved
concentration . If you only have ambient total recoverable data, use the translator to convert
the total recoverable data to dissolved.

Input

- Columns E and F

- enter the appropriate acute and chronic water quality criteria for the parameter.

Columns G and H are the calculated expected concentrations at the edge of the acute and chronic mixing zones. They are calculated from expected effluent concentration, ambient concentration, dilution factors and, for metals, the translator.

Column I compares the expected acut e and chronic criteria with the concentration at the edge of the appropriate dilution zone. It returns a yes if the expected concentration is higher than the criteria or a no if not. Yes indicates a reasonable potential to violate the water quality crite ria.

Column J is the upper percentile estimate of the effluent concentration. The recommended value to enter is 0.95.

Column K is a calculated value

Input

- Column L

- Enter in the highest measured effluent concentration

Input

- Column M

- Enter the coe fficient of variation of the effluent parameter (standard deviation/mean). The default value is 0.6. If you have more than 10 effluent values this value should be calculated instead of using the default.

Input

- Column N

- Enter the number of data value s in the set from which the value entered in
Column L was taken.

Column P is the calculated value used as a multiplier. Column L is multiplied by this value (Column P) to estimate the 95th percentile value of a small data set lognormally distributed.
Th is value is equivalent to the multiplier in Table 3.2 95/95 in the TSD. If the permit writer has 20 or more data points for a parameter in the effluent, the 95th percentile effluent value can be calculated more accurately by transforming the data by log o r lognormal, finding the 95th percentile value and then converting the value back by taking antilog or natural antilog. This value is placed in Column L and the number of samples is varied by trial and error until theAPPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 52 multiplier in Column P equals 1.0. F or example, with a CV of 0.6 column P would have to be 58 for the multiplier to equal 1.



### LIMITS.XLS
This spreadsheet calculates effluent limits for aquatic life pollutants by use of formulas given in the Technical Support Document Box 5

- 2. Limits are requ ired for any parameters that show a reasonable potential in the preceding spreadsheet. If the parameter has an extensive database, the values should be lognormal transformed (see comment in G2 of PERFORMLIM) and then the spreadsheet PERFORMLIM.XLS used to calculate effluent limits.

Input

- Column A

- enter the parameter

Input

- Columns B and C

- enter the acute and chronic dilution factors

Input

- Columns F, G, and H can be copied from REASPOT.XLS

Column I is the calculated Average Monthly effluent lim it

Column J is the calculated Daily Maximum effluent limit

Columns L and M are the calculated wasteload allocations for acute and chronic criteria

Columns N and O are the acute and chronic long term averages necessary to meet the wasteload
allocations. The smaller of these two (the limiting LTA) is automatically placed in column R.

Column P is the expected coefficient of variation for the LTA. Use the effluent CV if available
or use the default CV of 0.6.

Column Q is the probability the LTA will meet the WLA (expectation that the water quality standards will be met). A value of 0.99 (recommended by EPA) means an expected probability of exceedance of 0.01 or 1%.

Column S is the effluent CV. Use the calculated value if available or a default of 0.6 i f an actual
value can’t be calculated.

Columns T and U are the expected probability of error for the effluent limits. The recommended values are 0.95 for the AML and 0.99 for the MDL (See the PWM page VI

- 28 for a discussion).

Input

- Column V

- The numb er of samples which will be required per month for compliance sampling. If sampling will be less than 1 per month use a value of 1 in this column.APPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 53 

### PERFORMLIM.XLS
This spreadsheet calculates performance

- based effluent limits. It will account for autocorr elation if the autocorrelation factor is known. The permit manager should assume effluent data is non

normally distributed and use EXCEL  to transform the data using a lognormal transformation. A note in cell G2 explains the procedure for lognormal data transformation. Rows 5 through 8

are input cells. The lognormal transformed mean and variance are placed in cell H5 and H6. The number of samples per month that will be required for compliance monitoring is placed in
cell H7. The autocorrelation factor is placed in cell H8 if it is known. Cells H9 through H13 are
calculated intermediate values. Cells H15 and H16 are the calculated effluent limits.



### HUMAN

- H.XLS
This spreadsheet calculates reasonable potential and the effluent limits for human health pol lutants. Reasonable potential for human health criteria is based on the 50 th percentile effluent value. This spreadsheet deals with the effluent values in two ways. In a situation where the permit writer has 10 or more data points for the effluent conce ntration, the 50 th percentile should be calculated by using the statistical calculation in EXCEL or some other software. Place this
calculated 50 th percentile value in column N. Any number in this column is always used for calculations if present so it mu st be 0 unless a calculated percentile value is placed here. In a situation with less than 10 data points, the 50 th percentile effluent concentration is estimated within the spreadsheet by placing the highest observed effluent concentration in column I. T he estimated coefficient of variation is placed in column J and the expected number of compliance monitoring samples is placed in column L. The 50 th percentile value is calculated and then is used to calculate the expected concentration at the edge of the mixing zone. The dilution factor is placed in the last column (o). Carcinogens and non

- carcinogens have different design criteria for effluent and receiving water flow so the dilution factors may be different for different human health pollutants. The spreadsheet calculates the expected concentration at the edge of the mixing zone, notes whether an effluent limit is required and, if so, calculates the limits using five and one percent error probabilities for average monthly and daily maximum, respective ly.

Input

- Column A

– Enter the pollutant parameter name

Input

– Column B

– Enter the ambient concentration as the geometric mean of the receiving
water values.

Input

– Column C

– Enter the human health criteria value.
Column D

– This column calculates the expected concentration at the edge of the chronic mixing

zone.

Column E

– This column returns a yes or no as a determination of reasonable potential. Input

- Column F

– The number of samples expected to be required in the permit for compliance
monito ring.APPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 54 Columns G and H

– the calculated monthly average and daily maximum limits. Note that the monthly average limit equals the WLA adjusted for the background concentration.

Column I

– The expected effluent percentile at 95% confidence. The recommende d value is 0.5
in this column.

Column J

– Internal calculation used to calculate multiplier (Col. O).

Input

- Column K

– The maximum effluent concentration measured.

Input

- Column L

– The coefficient of variation. The default value is 0.6 but this sho uld be calculated from the effluent data if there are 10 or more data points. The coefficient of variation
is the standard deviation ÷ the mean.

Column M

– An internal calculation used to calculate the multiplier (Col. O).

Column N

– The number of data points in the data set from which value in Column K was taken.

Column O

– The calculated value which is used to multiply the value in Column K to estimate
the 50 th percentile at the 95 th percent confidence level. The formula for this multiplier is taken
from the EPA TSD.

Input

- Column P

– The calculated 50 th percentile effluent concentration. With 10 or more effluent data points the 50 th percentile value should be calculated and placed in this column. A number in this column will take precedence over an estimated value. If the 50 th percentile value
isn’t calculated this column should be 0. Input

- Column Q

– The chronic mixing zone dilution factor.



### Fresh

- temp.XLS and Marine

- temp.XLS These sheets contain two columns for calculating RP during maximum s ummer temperature and the fall or spring spawning season. Blocks A, B, C and D are interim registers for lines 17 and
18.



## 3. AN ALTERNATE METHOD FOR ESTIMATING UPPER QUANTILES

This method estimates a selected upper percentile value from a distribution ass umed to be lognormally distributed. The most statistically valid estimate of an upper percentile value is a maximum likelihood estimator which is proportional to the population geometric mean. If one assumes the population of effluent concentrations to f it a lognormal distribution, this relationship is given by:APPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 55 C p = C mean * exp (Z p * σ

- 0.5 * σ 2)

Where: Z p = normal distribution factor at pth percentile

σ 2 = ln(CV2 + 1)

To calculate the maximum likelihood estimator of the 95th percentile, the speci fic relationship
becomes:

C 95 = C mean * exp (1.645* σ

- 0.5* σ 2)

if CV is assumed = 0.6,

σ 2 = .307

The ratio of the estimated 95th percentile value to the mean (C 95 /C mean ) = 2.13

A single effluent value or the geometric mean of a group of values is mul tiplied by the ratio to yield the estimate of the 95th percentile value.

The following table shows the ratio of the upper percentile to the mean for the 90th, 95th, and 99th percentiles

Ratio of Upper Percentiles to Geometric Mean

Percentile Z C p /C m ean

90 1.283 1.74
95 1.645 2.13
99 2.386 3.11

In use with limited data sets assumed to be lognormally distributed, the geometric mean is multipl i ed by the value in the right column above to estimate the percentile given in left column. This

e stimation technique results in lower estimates of upper percentile values than the technique
discussed in the TSD in Section 3.2.2. for n less than 6. At some number of values it becomes more accurate simply to calculate the desired percentile value. Mos t spreadsheets have this capability. The number of values at which this occurs can't be predicted because it depends on the characteristics of the population being sampled. Using the TSD upper quantile estimation technique on page 56 and calculating wher e the largest value is greater than the 90th percentile (at 95% Confidence), the value of n is 30. In other estimation techniques for lognormal distributions, Gilbert (1987) predicts a large sample as n = 20.APPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 56 

## 4. GUIDANCE ON THE APPROPRIATE SIZE MIXING ZONE FOR A UNIQUE OUTFALL CONFIGURATION

In this situation a 170

- foot diffuser runs parallel to the bank of a large river, rather than projecting across the river (see Figure 1). The 26 equally spaced eight

- inch ports discharge away
from the bank toward t he deeper water. Thus, the plumes are carried downstream by the current “one over the other” (serially), rather than adjacent to each other (in parallel). The depth of
water is 18 feet.

The regulations pertaining to sizing of mixing zones are in the Wat er Quality Standards for Surface Waters ..., WAC 173

- 201A

- 100. The freshwater rules apply (while this river is influenced by the tide, the flow simply slows but does not reverse). The regulation states that the chronic mixing zone shall:

“(i) Not exte nd in a downstream direction for a distance from the discharge port(s) greater than three hundred feet plus the depth of water over the discharge port(s), or extend upstream for a distance of over one hundred feet;

(ii) Not utilize greater than twenty

- five per cent of the flow;

(iii) Not occupy greater than twenty

- five percent of the width of the water body.”

This language does not address a serial discharge situation; ( i.e.

, it is not clear from which discharge port(s) the 300

- foot measurement begins).

The reason able solution is: If an outfall is configured such that the centerline of the diffuser lies parallel to the direction of current flow, then the distance to the downstream chronic mixing zone boundary is to be determined by beginning the measurement from t he most upstream port in the diffuser. The distance from the downstream port to the chronic mixing zone boundary will be:

300 ft. + depth of water

– length of diffuser. (1)

An acute boundary is 10 percent of the distance allowed for the chronic mixi ng zone. In this situation it will be 10 percent of the distance determined in equation (1). The width of these mixing zones will be addressed by subpart (iii) of the regulations mentioned above. This solution ensures that length of diffuser is not a factor in size of mixing zone and discourages the use of diffusers much longer than 170 feet in this type of configuration.APPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 57 The mixing zone will be 148 feet from the downstream port. The acute boundary will be 14.8 feet from the downstream port. Width o f the mixing zone will be very large since this outfall is to a large river.



## 5 . DERIVING THE 7Q10 HIGH FLOW (HF) AND THE DESIGN SPILL

5 .1. Guidelines for Deriving the 7 QHF

Use the record of observed flow data. For the Columbia River use the record from water year 1974 to the present. 1974 is the year when the last major storage reservoir was built in the
Columbia River Basin. If data is not available for the location of interest, make reasonable calculations based on an approved 7Q10hf for up

- river or down

- river locations or dams. Flow
data must include total river flow.

The period of record may be extended by including modeled or transformed data prior to 1974
that represents the current condition of the basin with all dams in place. If this is done, compare 

### Figure 1. Unique Outfall
Orientation CURRENT
DIRECTION

170 FEET

BANKAPPENDIX 6. (JULY 20 02)

Permit Writer’s Manual
APP6

- 58 results of using data from the observed period of record with the results of using the data from the extended period of record. This serves as a check to see i f the proposed method for extending the period of record gives comparable results.

To the extent possible, take into account any trends or anticipated changes of flows in the future.

Use daily average flows to calculate the 7Q10hf and then determine the highest 7

- consecutive

day average peak flow for each year.

Calculate frequency/return interval using standard hydrology methods (see USGS bulletin 17B, Guidelines for Determining Flood Flow Frequency , or any hydrology textbook)

Information submitted to E cology must include documentation of the methods of calculating 7Q10hf, including assumptions about data, current trends, anticipated changes, quality assurance, methods of measurement, methods of transforming historic data and comparisons of 7Q10hf
values for other dams.



## 5 .2. Determining Design Spill for Gas Abatement

To determine the design spill for gas abatement

, use the hourly spill data for high flow months of a high flow year (1997 for example) and extrapolate to the 7Q10hf. The high flow months fo r the Columbia River are May and June.APPENDIX 13 (December 2 0 01)

Permit Writer’s Manual
APP13

- 1 

# APPENDIX 13

1. SUPPORTING STATISTICAL STUDY FOR PERFORMANCE

- BASED REDUCTION OF MONITORING (from EPA, April 96)

Effect of Sample Size on Probability of Violation

EPA has done a statistical analysis on the effect of sampling frequency on compliance assessment. The basic premise underlying a performance

- based reduction approach is that maintaining a low average discharge relative to the permit limit results in a low probability of the
occurrence of a violation for a wide range of sampling frequencies.

The probability of the occurrence of a violation of a monthly average permit limit was
calculated. Tables 13

- 1,13

- 2 and 13

- 3 display the percentage of time that a monthly average permit violation will be reported gi ven sample size and a long

- term average to permit ratio. This probability is dependent on the true long

- term average of the discharge, the permit limit, and the monthly sampling frequency. The variables of long

- term average and permit limit are both
refle cted in the tables by expressing these as a ratio. Tables 13

- 1, 13

- 2, and 13

- 3 assume a normal distribution of monthly averages and show the effect of altering the assumed coefficient of variation, using 20%, 60%, and 80%, respectively.

Obviously, the best estimate of the true monthly average discharge is obtained by daily sampling. One can assess the true violation rate of a discharge by looking at the probability calculated assuming sampling was done daily (30 times per month). In order to maintain c ompliance with a permit limit, the long term average level of the discharge must be controlled at a level less than the permit limit. Reducing the sample size, while increasing the probability that a violation will be reported, does not change the underly ing probability of reporting a violation associated with a baseline estimate of the monthly average calculated with 30 samples. With a constant performance, the probabilities of reporting a permit violation increase as the sample size is
reduced from dai ly sampling because the variance of the average is inversely proportional to the sample size.

Looking at the true violation rate of a facility sampling daily and operating at 75% of their permit limit, these tables show that the probability of a violat ion in a given month is 1% or less. If the long

- term average discharge is 65% of the permit limit, the true percentage of violation is less than 1%. As sample size decreases for a given discharge/limit ratio, the expected percentage
of time that the aver age of the samples collected during the month will exceed the permit limit increases. For example, Table 13

- 3 demonstrates that at a ratio of 65%, the expected violation rate is effectively zero. If a subsample of 8 samples per month is taken instead of 30, the facilityAPPENDIX 13 (December 2 0 01)

Permit Writer’s Manual
APP13

- 2 has a 3% chance of reporting a violation. If only one sample per month is taken, the chances of reporting a violation increase to 25%. The facility performance (true monthly average discharge) has not changed, thus "missed" monthly avera ge violations are not an issue. The probabilities calculated for very low sampling frequencies reflects the risk assumed by the discharge operator that monthly average violations will be reported when in fact the process average is under permit
limit. If facility performance degrades during the permit term and sampling has been reduced, it can be seen that the facility will have probability of reporting violations at a higher rate, even if the long

- term average is still below the permit limit. An example will illustrate this point. Table
13

- 3 shows that if a facility was judged to be at 75% of their permit limit and reduced sampling from 16 to 12 times per month, the probability of violation would change from approximately 5% to 7%. If the long

- term aver age performance degraded to 90% of the permit limit, the 12 monthly samples would yield expected monthly average permit violations 32% of the time instead of 29% of the time if 16 samples were collected.

Table 13

- 3 shows probabilities calculated using a more conservative assumption of 80% coefficient of variation. The results show that facilities with a long term average of less than or equal to 75% have essentially no chance of violating a monthly average limit, hence facilities with this performance w ould be good candidates for performance

- based monitoring reductions.
The reductions in Table XIII

- 1A1 were designed to maintain approximately the same level of reported violations as that experienced with their current (baseline) sampling.APPENDIX 13 (December 2 0 01)

Permit Writer’s Manual
APP13

- 3 Table 13

- 1. Probability of Reporting Monthly Average Permit Violations at 20% Effluent Variability (CV = 0.20; Normal Distribution).

Monthly Sample Size

1 LTA/Permit 30 28 24 20 16 12 8 4 2 1

100% 50% 50% 50% 50% 50% 50% 50% 50% 50% 50%

95% 7% 8% 10% 1 2% 15% 18% 23% 30% 35% 40%

90% 0% 0% 0% 1% 1% 3% 6% 13% 22% 29%

85% 0% 0% 0% 0% 0% 0% 1% 4% 11% 19%

80% 0% 0% 0% 0% 0% 0% 0% 1% 4% 11%

75% 0% 0% 0% 0% 0% 0% 0% 0% 1% 5%

70% 0% 0% 0% 0% 0% 0% 0% 0% 0% 2%

65 % 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

60% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

55% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

50% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

40% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

30% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

20% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

1 Ratio of calculated average of at least 2 years of effluent data to monthly average permit limit.APPENDIX 13 (December 2 0 01)

Permit Writer’s Manual
APP13

- 4 Table 13

- 2. Probability of Reporting Monthly Average Permit Violations at 60% Effluent Variabi lity (CV = 0.60; Normal Distribution)

Monthly Sample Size

1 LTA/Permit 30 28 24 20 16 12 8 4 2 1

100% 50% 50% 50% 50% 50% 50% 50% 50% 50% 50%

95% 32% 32% 33% 35% 36% 38% 40% 43% 45% 47%

90% 16% 16% 18% 20% 23% 26% 30% 36% 40% 43%

85% 5% 6 % 7% 9% 12% 15% 20% 28% 34% 38%

80% 1% 1% 2% 3% 5% 7% 12% 20% 28% 34%

75% 0% 0% 0% 1% 1% 3% 6% 13% 22% 29%

70% 0% 0% 0% 0% 0% 1% 2% 8% 16% 24%

65% 0% 0% 0% 0% 0% 0% 1% 4% 10% 18%

60% 0% 0% 0% 0% 0% 0% 0% 1% 6% 1 3%

55% 0% 0% 0% 0% 0% 0% 0% 0% 3% 9%

50% 0% 0% 0% 0% 0% 0% 0% 0% 1% 5%

40% 0% 0% 0% 0% 0% 0% 0% 0% 0% 1%

30% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

20% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

1 Ratio of calculated aver age of at least 2 years of effluent data to monthly average permit limit.APPENDIX 13 (December 2 0 01)

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- 5 Table 13

- 3. Probability of Reporting Monthly Average Permit Violations at 80% Effluent Variability (CV = 0.80; Normal Distribution)

Monthly Sample Size

1 LTA/Permit 30 28 24 20 16 12 8 4 2 1

100% 50% 50% 50% 50% 50% 50% 50% 50% 50% 50%

95% 36% 36% 37% 38% 40% 41% 43% 45% 46% 47%

90% 22% 23% 25% 27% 29% 32% 35% 39% 42% 44%

85% 11% 12% 14% 16% 19% 22% 27% 33% 38% 41%

80% 4% 5% 6% 8% 11% 14% 19% 27% 33% 38%

75% 1% 1% 2% 3% 5% 7% 12% 20% 28% 34%

70% 0% 0% 0% 1% 2% 3% 6% 14% 22% 30%

65% 0% 0% 0% 0% 0% 1% 3% 9% 17% 25%

60% 0% 0% 0% 0% 0% 0% 1% 5% 12% 20%

55% 0% 0% 0% 0% 0% 0% 0% 2% 7% 15%

50% 0% 0% 0% 0% 0% 0% 0% 1% 4% 11%

40% 0% 0% 0% 0% 0% 0% 0% 0% 0% 3%

30% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

20% 0% 0% 0% 0% 0% 0% 0% 0% 0% 0%

1 Ratio of calculated average of at least 2 years of effluent data to monthly average permit limit.



### Detailed Protocol for Calculating Probability of Reporting Permit Violations

Calculation of probabilities for Tables 13

- 1 to 13

- 3

Probability distributions may be used to model effluent data and assess the probability of permit violations. The models provide a l ogical and consistent methodological framework for using observed performance data to assess permit limitations in an objective manner. The goal of the limitations is to establish performance levels that enforce good treatment and ensure that water qualit y objectives are met. In deriving limitations, sufficient allowance for variation in treatment performance is provided such that a well

- operated treatment system should be capable of compliance with the limitations at all times. In using probability mod els as the basis for limits, it is necessary to select a percentile value such that, within the context of the model, anyAPPENDIX 13 (December 2 0 01)

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APP13

- 6 meaningful limit will have a non

- zero probability of being exceeded.

The results shown in the tables here are derived from probabil ity distribution functions that may be used to model effluent data. That is, the processes are assumed to operate over time in a manner that is consistent with past performance. No intervention to change the process or exert
more or less control over the discharge is assumed.

Calculation of the probability that a reported permit violation will occur depends upon: the number of individual samples taken during the month, the long

- term discharge level, the variance of the discharge concentrations, the pro bability distribution of the individual samples during the month, and the permit limit. There are two probability distributions commonly used to model effluent data: the lognormal distribution and the normal distribution. The lognormal
distribution usual ly provides a good fit to data sets comprised of individual effluent measurements because such data typically have two critical lognormal characteristics: they are positive valued and positively skewed. Positive skewness means that the data are characteri zed by a tendency for a preponderance of measurements in the lower range of possible values with relatively fewer measurements stretched out over a wider range of possible upper values. The lognormal also has the property that the logarithms (natural or b ase 10) of the data are normally
distributed. The normal distribution has the well

- known "bell shape" and is mathematically straightforward so that working with the logarithms of effluent data is relatively uncomplicated.

The asymptotic distribution of s ample averages is normally distributed. That is, the average of a sample of individual measurements will have a distribution that is approximately normally distributed regardless of the distribution of the individual measurements. The quality of the

appr oximation depends on several factors i ncluding the number of individual measurements being averaged and the form of the underlying distribution. Although individual effluent measurements are rarely normally distributed, it is reasonable in many situations to approximate
the distribution of th e averages of effluent measurements with a normal distribution and thus the normal approximation is used in many cases as a model for monthly average effluent limitations.
The results in Tables 13

- 1 through 13

- 3 are based on the assumption of a normal dis tribution for
the averages of effluent measurements. Extensive discussion on the statistical modeling of effluent data and methodology for setting effluent limitations are contained in EPA's 1991 Technical Support Document for Water Quality

- based Toxics C ontrol (TSD).

The results of calculating probability of a reported violation of a monthly average permit limit
are shown in Tables 13

- 1 through 13

- 3 under different conditions. The purpose of these tables is to provide some insight into the effects of ch anging monitoring requirements. The probability of exceeding the monthly limit when the long

- term average of the discharge is at the desired value can be thought of as the Type I error rate (alpha

- level) of the monitoring program. When the long

- term aver age exceeds the desired limit, the probability of exceeding the monthly limit is now the monitoring program's ability to detect violation increases if the long

- term average increases over the desired level. It should be understood that if permit limits ar e held constantAPPENDIX 13 (December 2 0 01)

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APP13

- 7 and performance measures such as long term average discharge and variability of treatment do not change, then reducing the number of monitoring measurements used to calculate the monthly average causes the probability of a violation to inc rease for all values of the long term average less than the monthly average permit limit. This has a two

- fold effect: 1) the chances of reporting a violation even when the long term average is less than the desired level (the Type I error rate) go up 2) the sensitivity (ability to detect violations) of the program increases. The Tables also show that if the average discharge level is held well below the monthly average limit,
the chances of a violation are small. The thee tables reflect three differen t levels of variation in the underlying daily data as measured by the coefficient of variation. The coefficient of variation (CV) is the ratio of the standard deviation of the distribution to the mean and is often expressed as a percentage. The CV is a c onvenient measure for summarizing the relative variability in a
data set. The results in Tables 13

- 1, 13

- 2, and 13

- 3 use CVs of 20%, 60% and 80% respectively. A coefficient of variation of 60% was used in the TSD to describe a typical level of variation for lognormally distributed effluent data. CVs of 80% and 20% were used to show the effects of higher and lower levels of variability.

The probability distribution of the average of N daily measurements taken during a month, M N , is given by the followi ng normal probability density function:

where μ is the mean or long term average, and σ is the standard deviation of the daily discharges. If μ 1 is the maximum monthly average allowed by the permit , then the probability that the monthly average exceeds the permit maximum is given by P(M N > μ 1 ). Using simple algebra this probability can
be rewritten as:

where Φ (.) is the standard normal
cumulati ve probability function (the Microsoft®Excel built

- in function NORMDIST). g( M ) = 1

2

N e N - N ( M

- )
2 N 2

2 π σ μ

σ



### P( M > ) = P( M

-

N > -

N ) = 1

- ( -

N ), N 1 N 1 1 

### μ μ

σ μ μ

σ φ μ μ

σAPPENDIX 13 (December 2 0 01)

Permit Writer’s Manual
APP13

- 8 Since

where C is the coefficient of variation, then the probability of a monthly average exceeding the
maximum allowable can b e calculated using C, N, and the ratio of the long

- term average to the maximum allowable monthly average using NORMDIST. This is how the values in Tables 13

- 1,
13

- 2, and 13

- 3 were calculated.

Alternate approaches to probability calculations:

The prob abilities in Tables 13

- 1 to 13

- 3 were calculated with the assumption that the distribution of the sample means is normal. Individual sample values are generally best fit to a lognormal distribution. As discussed in the TSD, the mean of small samples from a lognormal distribution is in most cases approximately lognormal. Probabilities can be calculated assuming a lognormal distribution by two different methods, a Monte Carlo technique and the Microsoft Excel built

- in function LOGNORMDIST. The resulting probabilities will be very close to those in the normal distribution table for the sample sizes and discharge levels under consideration for monitoring reductions, although the probabilities calculated from these two distributions may not be comparable for all sample sizes and all discharge levels.

The statistical evaluations used in this analysis are intended for use only to illustrate the effect and benefits of this strategy, alternative statistical techniques and approaches may be utilized in
other si tuations. 1

1 -

N = N
C ( 1

( ) -1), μ μ

σ μ

μAPPENDIX 13 (December 2 0 01)

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APP13

- 9 

## 2. DETERMINING THE NUMBER OF SAMPLES REQUIRED FOR COMPLIANCE MONITORING

This section provides some statistical tools for selection of a monitoring frequency when effluent
data is available.

It is recommended that the permit writer use formul a 3 with a confidence level of 90% and a relative error (d r ) around the mean of no larger than 20% (0.20) to derive a baseline monitoring frequency. Table 1 is compiled from formula 3 for several combinations of confidence level,
relative error and coeffi cients of variation. The rest of this section provides background material.

An effluent limit is a control parameter to assure that the long term average (LTA) of a wastewater control device or practice is being maintained. The LTA may be derived from t he performance of a wastewater treatment device or from a wasteload allocation necessary to meet water quality standards. We assume the number of samples required to demonstrate compliance is the same as that necessary to determine a mean of a sample from a population.

For a sampled population which is normally distributed, in which the samples are not correlated over time or space, and in which the number of elements in the sampled population (N) is large relative to the standard deviation ( σ ), the numbe r of samples (n) required to estimate a population mean is:

n = (Z 1

- α / 2 

### σ / 

### d ) 2

where

Z 1

- α / 2 is the standard normal deviate that cuts off (100 α /2)% of the tails of a standard normal
distribution and

σ = standard deviation of the sampled populati on and

d = error around the mean.

This formula is for a two tailed test where the sample mean may be higher or lower than the true mean. In our situation we are only concerned with the situation in which the sample mean is higher than the true mean. T herefore, a one

- tailed test is appropriate.

n = (Z 1

- α 

### σ / 

### d ) 2 (1 (from Gilbert 1987)APPENDIX 13 (December 2 0 01)

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APP13

- 10 To estimate a population mean with a error (d) of 20 (plus or minus 10) with a 10% probability of type I error ( α )when the standard deviation ( σ ) of the population is 50 requires

n = (Z 0.10 50/20) 2 = (1.2816*50/20) 2 = 10.2 ≈ 10 samples.

This assumes the data are independently, normally distributed and not correlated over time or

space.

Effluent data is typically lognormally distributed (Schaeffer, et al. 1980 ) but parametric statistics
( 

### Χ and s 2 ) are the best estimators of the population parameters if the coefficient of variation ( 

### η ) is less than 1.2 (Gilbert 1987). A typical coefficient of variation ( 

### η ) for conventional pollutants from domestic wastewater treatment plants is 0.6. Other pollutants and industrial treatment processes typically have a higher CV of 1 to 1.5.

An adjustment for autocorrelation can be made to the formulas for sample numbers if nece ssary. This adjustment increases the number of samples required.

If the standard deviation is uncertain (because of limited previous sampling) then the t distribution should be used in the place of the standard normal distribution 

# ( ) n t d

n =

− − 1 1 2

α σ

, / (2

and the process of determining n becomes iterative.

Start with equation 1 above and use a Z value to approximate n, 

## ( ) n

n 1 2

1 1 2816 50 20

10 = ∗

≅ . /

then go to a t table to find t 0.90, 9 which is 1.383. Placing this value into equation 2 gives 12. 

## ( ) n = ∗ ÷ = ≅ 1 383 50 20 11 95 12 2



### . .

Placing the t value for t .90, 11 which is 1.363 into equation 2 gives 11.6 which is approximately
12 which then is the answer.

The margin of error can be expressed as relative error (d r ) of the mean instead of a absolute value
and th e coefficient of variation 

### ( η 

### = σ 

### / μ 

### ) can be used as the measure of variability. The formula
then becomes



## ( ) n Z d

r

=

− 1 2

α

η / (3
(from Gilbert 1987) and a table can be produced of some common values (Table 1).APPENDIX 13 (December 2 0 01)

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APP13

- 11 Table 1. Sample sizes required for E stimating the True Mean μ Coefficient of Variation ( η )
Confidence level (1

- α ) Relative Error
d r 0.60 1.00
.80 .10 26 72 (Z 0.80 = .846) .20 6 18
.30 3 8
.50 1 3
.85 .10 41 113 (Z 0.85 =1.062) .20 10 28
.30 5 13
.50 2 5
.90 .10 59 164 (Z 0.9 0 = 1.282) .20 15 41
.30 7 18
.50 2 7
.95 .10 97 271 (Z 0.95 = 1.645) .20 24 68
.30 11 30
.50 4 11
.99 .10 195 541 (Z 0.99 =2.326) .20 49 135
.30 22 60
.50 8 22 The permit writer may adjust sample sizes from Table 1 according to factors disc ussed in section 1.3.1 of Chapter XIII.

Formula 3 can be adjusted for uncertainty of the standard deviation by use of the t distribution and an iterative process as in formula 2. The number of samples required for a given confidence level, relative error and cv will be slightly higher using the t distribution, however, not significant for the extra effort.

Zar (1996) presents an alternative method for determining n, the number of samples to determine the mean with specified type I ( α ) and type II ( β ) err or probabilities, as;

n s t t

= + 2

2 1 1 2 δ α υ β υ ( ) ( ), ( ), (4

where

s 2 is the sample variance estimated with v degrees of freedomAPPENDIX 13 (December 2 0 01)

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APP13

- 12 β is the probability of type II error

δ is the size of the error around the mean (d from above)

α , and t are defined as above.

In t his equation the number of data required to calculate a confidence interval of a specified width depends upon: 1) the width desired

- narrow widths require more samples 2) the variability in the population

- larger variability requires larger sample size 3 ) the confidence level (type I error) and 4) the assurance that the confidence interval will be no larger than that specified (type II error).

This formula is also iterative.

To determine the number of samples required to estimate the mean of a sample wi th a 90% probability that the 95% confidence interval will be no wider than 3 mg/l (the effluent limit is 30 mg/l), then δ = 3 mg/l, β = 0.10, 1

- α = 0.95, and α = 0.05. Assume an estimate of the population variance from previous sampling : s 2 = 18.0388 wi th v = 24. If we start with a guess of 8 samples per month then

t 0.05(1),7 = 1.895 and t 0.10,(1),7 = 1.415

Using equation 4,

n s t t = + 2

2 1 1 2 δ α υ β υ ( ) ( ), ( ), n = (18.0388/9)(1.895+1.415) 2

n = 22
for n = 22 , t 0.05(1),21 = 1.721 and t 0.10,(1), 21 = 1.323

n = (18.0388/9)(1.721+1.323) 2

n = 19 for n = 19, t 0.05(1),18 = 1.734 and t 0.10(1), 18 = 1.330

n = (18.0388/9)(1.734+1.330) 2

n = 19

This formula gives a higher n because of the additional constraint of the type II erro r.

AN INDUSTRIAL EXAMPLEAPPENDIX 13 (December 2 0 01)

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APP13

- 13 A permit manager proposes to use the following data to derive performance

- based effluent limits for a discharge from a metal facility. The data are metal concentrations in mg/l from a settling basin. The permit writer wants to know the number of samples to determine the monthly average such that the type I error (false judgment of noncompliance) will be 5% with a 10%
interval around the mean.

Mean 0.627260274 Standard Error 0.010826197 Median 0.59 Mode 0.5 S tandard Deviation 0.206834198

Sample Variance 0.042780385 Kurtosis 5.752860027 Skewness 1.644693358 CV 0.33 Range 1.7 Minimum 0.29 Maximum 1.99 Sum 228.95 Count 365 Confidence Level(95.0%) 0.02128972

99th percentile = 0.2135155

A . Using formula 1 to determine the number of samples per month to determine a monthly average , with d = 0.06 (10% of the mean), and α =0.05. The data standard deviation s is

used as an estimator of 

### σ

.

n = (Z 1

- α / 2 

### σ / 

### d ) 2

n = (1.645 * 0.2068 / 0.06) 2 = 32 samples/monthAPPENDIX 13 (December 2 0 01)

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APP13

- 14 B. Using formula 2, d = 0.06 or 10% of the mean, α =0.05 and, the data standard deviation, s, as

an estimator of 

### σ

. 

# ( ) n t d
n 

### =

− − 1 2 1 2

α 

### σ

/

, 

### /

The Z value is used as an initial estimator for t. n = (Z .95 * 0.2068 / 0.06) 2 = (1.645 * 0.2068 / 0 .06) 2 = 32 n = (t .95,31 * 0.2068 / 0.06) 2 = (1.696 * 0.2068 / 0.06) 2 = 34 n = (t .95,33 * 0.2068 / 0.06) 2 = (1.693 * 0.2068 / 0.06) 2 = 34 samples/month.

C. Using formula 3 with the coefficient of variation ( η ) = 0.33, relative error (d r ) = 0.10 and α = 0.05.



## ( ) n Z d

r

=

− 1 2

α

η /
n = (1.645 * 0.33 / 0.10) 2 = 29 samples/month

Using t values in this formula will increase n slightly to 31.

D . Using formula 4 to determine n with β = 0.1 (probability noncompliance is occurring but not detected).

n s t t

= + 2

2 1 1 2 δ α υ β υ ( ) ( ), ( ),



## ( ) n

n = +

= 0 0428

0 0627 1 645 1 282

93 2 2 .

. (

. . )