United States 

Environmental Protection 

Agency 

Office of Water 

Washington, DC 

NPDES Permit Writers’ Manual 

December 1996 

The statements in this document are intended solely as guidance. This document is not intended, nor can it be 

relied on, to create any rights enforceable by any party in litigation with the United States. EPA and State 

officials may decide to follow the guidance provided in this document, or to act at variance with the guidance, 

based on an analysis of specific site circumstances. This guidance may be revised without public notice to 

reflect changes in EPA’s policy. 

Office of Wastewater Management 

U.S. Environmental Protection Agency 

Washington, DC 20460 
Acknowledgements 

The revisions to this manual were made possible through a cooperative team 

effort led by Dan Weese, Office of Wastewater Management. EPA gratefully 

acknowledges the contributions of the team members involved in this effort (Greg 

Currey and Pat Bradley) for the countless hours spent and determination in bringing 

this effort to completion. Their commitment and dedication to this product was key to 

the NPDES Program’s mission of providing comprehensive programmatic guidance 

and technical support to its stakeholders. The revisions to this manual would not have 

been realized without their assistance. EPA also wishes to thank Dave Hair and Jim 

Parker of Science Applications International Corporation for their contributions and 

invaluable support provided under contract 68-C4-0034. 

The primary contact regarding questions or comments to this manual is: 

Dan Weese, Environmental Engineer 

Off ice of Wastewater Management 

Permits Division (4203) 

U.S. Environmental Protection Agency 

401 M Street, SW 

Washington, DC 20460 

Cover Photo: 

Lower Yellowstone falls 

Yellowstone National Park 

Photograph by Dave Hall 
Foreword 

Since its establishment in the 1972 amendments to the Federal Water Pollution 

Control Act, the National Pollutant Discharge Elimination System (NPDES) Program 

has achieved significant reductions in pollutant discharges, which in turn has resulted 

in tremendous improvement to the quality of our Nation’s water resources. As we 

move into the 21st century, the objective of the national program will not only be to 

develop solutions which address remaining impacts to surface waters, but to do so in 

ways that continue to improve the effectiveness of the NPDES Program and allow us 

to measure environmental progress and results. 

As EPA and States take steps to improve the NPDES Program and how it is 

implemented, it is essential that all parties involved understand the fundamental basis 

of the NPDES Program. The NPDES Permit Writers’ Manual is principally designed to 

help permit writers prepare legally defensible and enforceable NPDES permits. Its 

purpose is to serve as a useful resource in providing the technical and legal 

considerations which support the development of NPDES permits. However, the 

manual is also intended to serve as a resource for others, including stakeholders and 

the regulated community, interested in the NPDES permitting process. Only after 

reaching some common level of understanding of the NPDES Program and the issues 

surrounding the permitting process, can EPA, State permitting authorities, and 

stakeholders develop optimal solutions to improve the quality of our surface water 

resources. To that end, I would like to take this opportunity to highlight some of the 

changes taking place within the NPDES Program: 

• Stakeholder involvement and Public Participation-EPA is committed to 

getting permittees and other interested parties involved at an early stage of 

the permit development and decision making process. For example, 

several NPDES authorities involve permittees and stakeholders in the 

permit development phase before the public notice process. This early 

involvement provides an opportunity for the permitting authorities, 

permittees and stakeholders to identify errors, address questions and 

develop optimal solutions. 

• Watershed Approach--The Watershed Approach is EPA’s renewed 

emphasis to address all stressors within a hydrologically defined drainage 

basin instead of viewing individual pollutant sources in isolation of other 

stressors. The watershed approach allows us to recognize that the health 

of our water resources are the result of complex interactions of various 

pollution sources, habitat conditions, flow and many other factors. EPA 

believes that these problems are best addressed through the development 

of watershed plans that integrate controls of point and nonpoint sources 

and provide decision-makers with an opportunity to consider issues such as 
Foreword 

protection and restoration of habitats, drinking water sources, ground water 

protection and other environmental and social objectives. EPA strongly 

encourages innovative approaches that implement NPDES requirements in 

ways that achieve greater environmental results at the least cost. 

• Refining of Point Source Focus-As we place greater emphasis on 

environmental results we realize that certain sources of pollution may 

require increased national attention to achieve local watershed goals. EPA 

is actively engaged with States, environmental groups and the regulated 

community to. address pollution problems from wet weather sources (CSOs, 

storm water and sanitary sewer overflows), mining operations, concentrated 

animal feeding operations and other key point sources where substantial 

pollution reduction may be possible. EPA is confident that involving 

stakeholders in the development of solutions for these remaining sources of 

pollution will provide optimal solutions. 

• Burden Reduction-EPA is also pursuing regulatory reforms to eliminate 

unnecessary regulations and to reduce administrative burdens. For 

example, in June 1995, EPA promulgated a rule to eliminate obsolete rules. 

In 1996, EPA finalized national guidance on ways to reduce reporting and 

monitoring for permittees that have good historical compliance records. 

As we move forward, we will continue to explore ways to promote watershed, 

streamlining, and reinvention concepts discussed above to facilitate the continual 

evolution and success of the NPDES Program. As such, this manual is expected to 

be revised periodically to reflect improvements, regulatory changes, and policy 

decisions. Thank you for using this permit writers’ guide. We hope that it serves as a 

valuable resource and tool for helping to achieve healthy water resources throughout 

the Nation. 

James F. Pendergast 

Acting Director 

Permits Division 
Contents 

Page 

List of Acronyms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A-1 

Glossary of Terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . G-1 

Chapter l-Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 

1.1 History and Evolution of the NPDES Program . . . . . . . . . . . . . . . . . . . 2 

Chapter 2 -Regulatory Framework and Scope of the NPDES Program . . . . . . . . 7 

2.1 Regulatory Framework of the NPDES Program . . . . . . . . . . . . . . . . . . 7 

2.2 Scope of the NPDES Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

2.3 NPDES Program Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 

2.3.1 NPDES Program Areas Applicable to Municipal Sources . . . . . 14 

2.3.2 NPDES Program Areas Applicable to Industrial Sources . . . . . 18 

Chapter 3 - Overview of the NPDES Permitting Process . . . . . . . . . . . . . . . . . . . 21 

3.1 Types of Permits ........................................ 21 

3.2 Major Components of a Permit ............................. 23 

3.3 Overview of the Development/Issuance Process for NPDES Individual 

Permits .............................................. 23 

3.4 Overview of the Development/Issuance Process for NPDES General 

Permits .............................................. 26 

3.5 Roles and Responsibilities of the Federal and State Authorities ...... 27 

Chapter 4 - The Permit Application Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 

4.1 NPDES Permit Application Forms ........................... 29 

4.1.1 Municipal Application Requirements 

(Form A and Short Form A) .................. 31 

4.1.2 Non-Municipal Permit Application Requirements ........... 32 

4.1.3 Application Requirements for NPDES General Permits ....... 36 

4.2 Application Deadlines .................................... 36 

4.3 Review of the Application ................................. 37 

4.3.1 The Complete Application ........................... 39 

4.3.2 Common Omissions and Errors in Applications ............ 39 

4.3.3 The Accurate Application ............................ 42 

EPA NPDES Permit Writers’ Manual - i 
Contents 

4.4 Facility Information Review . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 

4.4.1 Background Information Review . . . . . . . . . . . . . . . . . . . . . . . 43 

4.4.2 Facility Site Visits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 

4.5 Confidential Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 

Chapter 5 - Technology-Based Effluent Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 

5.1 Application of Technology-Based Effluent Limitations for Non-Municipal 

Dischargers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 

5.1.1 Statutory and Regulatory Foundation . . . . . . . . . . . . . . . . . . . 50 

5.1.2 Development of National Effluent Limitations Guidelines and 

Performance Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 

5.1.3 General Considerations Concerning the Use of Effluent 

Limitation Guidelines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 

5.1.4 Best Professional Judgment Permit Limits . . . . . . . . . . . . . . . . 68 

5.2 Application of Technology-Based Effluent Limitations for Municipal 

Dischargers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 

5.2.1 Secondary Treatment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75 

5.2.2 Equivalent-to-Secondary Treatment Definition . . . . . . . . . . . . . 79 

Chapter 6 - Water Quality-Based Effluent Limits . . . . . . . . . . . . . . . . . . . . . . . . . 87 

6.1 Overview of Water Quality Standards . . . . . . . . . . . . . . . . . . . . . . . . . 88 

6.7.1 Components of Water Quality Standards . . . . . . . . . . . . . . . . . 89 

6.1.2 Establishing Water Quality Criteria . . . . . . . . . . . . . . . . . . . . . 91 

6.1.3 Future Directions for Water Quality Standards . . . . . . . . . . . . . 93 

6.2 Approaches to Implementing Water Quality Standards . . . . . . . . . . . . 94 

6.2.1 Chemical-Specific Approach . . . . . . . . . . . . . . . . . . . . . . . . . . 94 

6.2.2 Whole Effluent Toxicity (WET) Approach . . . . . . . . . . . . . . . . . 94 

6.2.3 Biological Criteria or Biological Assessment Approach . . . . . . . 98 

6.3 Determining the Need for WQBELs . . . . . . . . . . . . . . . . . . . . . . . . . . 99 

6.3.1 Defining “Reasonable Potential” to Exceed Applicable Criteria . 99 

6.3.2 Determining Reasonable Potential With Effluent Monitoring 

Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 

6.3.3 Determining Reasonable Potential Without Effluent Monitoring 

Data.......................................... 103 

6.4 Exposure Assessment and Wasteload Allocation . . . . . . . . . . . . . . . 104 

6.4.1 Total Maximum Daily Loads . . . . . . . . . . . . . . . . . . . . . . . . . 104 

6.4.2 Calculating Wasteload Allocations . . . . . . . . . . . . . . . . . . . . 106 

6.4.3 Selecting a Water Quality Model . . . . . . . . . . . . . . . . . . . . . . 107 

6.5 Permit Limit Derivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 

6.5.1 Expression of Permit Limits . . . . . . . . . . . . . . . . . . . . . . . . . 112 

6.5.2 Limits Derived from Steady-State Model Outputs . . . . . . . . . . 112 

6.5.3 Limits Derived from Dynamic Model Outputs . . . . . . . . . . . . . 114 

6.5.4 Special Considerations Permits Protecting Human Health . . . 114 

ii - EPA NPDES Permit Writers’ Manual 
Chapter 7 - Monitoring and Reporting Conditions . . . . . . . . . . . . . . . . . . . . . . . 115 

7.1 Establishing Monitoring Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . 116 

7.1.1 Monitoring Location . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117 

7.1.2 Monitoring Frequency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119 

7.1.3 Sample Collection Methods . . . . . . . . . . . . . . . . . . . . . . . . . 122 

7.1.4 Analytical Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 

7.1.5 Other Considerations in Establishing Monitoring Requirement . 127 

7.1.6 Establishing Monitoring Conditions for Unique Discharges . . . 129 

7.2 Reporting and’ Recordkeeping Requirements . . . . . . . . . . . . . . . . . . 134 

Chapter 8 - Special Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 

8.1 General Types of Special Conditions . . . . . . . . . . . . . . . . . . . . . . . . 138 

8.1.1 Special Studies and Additional Monitoring . . . . . . . . . . . . . . . 138 

8.1.2 Best Management Practices (BMPs) . . . . . . . . . . . . . . . . . . . 141 

8.1.3 Pollution Prevention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 

8.1.4 Compliance Schedules . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 

8.2 Permit Conditions Addressing Storm Water Discharges Associated 

With Industrial Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 

8.3 Special Conditions for Municipal Facilities . . . . . . . . . . . . . . . . . . . . . 151 

8.3.1 The National Pretreatment Program . . . . . . . . . . . . . . . . . . . 151 

8.3.2 Municipal Sewage Sludge . . . . . . . . . . . . . . . . . . . . . . . . . . 156 

8.3.3 Combined Sewer Overflows (CSOs) . . . . . . . . . . . . . . . . . . . 159 

8.3.4 Sanitary Sewer Overflows . . . . . . . . . . . . . . . . . . . . . . . . . . 164 

8.3.5 Municipal Separate Storm Sewer Systems (MS4) . . . . . . . . . 164 

Chapter 9 - Standard Conditions of NPDES Permits . . . . . . . . . . . . . . . . . . . . . 167 

9.1 Types of Standard Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168 

9.2 Other Standard Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 

Chapter 10 - Variances to Permit Requirements and Other Regulatory 

Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 

10.1 Variances to Technology-Based Permit Requirements . . . . . . . . . . . . 171 

10.1.1 Economic Variances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172 

10.1.2 Variances Based on Localized Environmental Factors . . . . . . 173 

10.1.3 Marine Discharge Variances . . . . . . . . . . . . . . . . . . . . . . . . . 174 

10.1.4 Fundamentally Different Factors Variances . . . . . . . . . . . . . . 175 

10.1.5 Thermal Discharge Variances . . . . . . . . . . . . . . . . . . . . . . . . 175 

10.1.6 Net Credits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 

10.2 Variances to Water Quality-Based Permit Requirements . . . . . . . . . . 176 

10.2.1 Site-Specific Water Quality Criteria Modification . . . . . . . . . . . 177 

10.2.2 Designated Use Reclassification . . . . . . . . . . . . . . . . . . . . . . 177 

10.2.3 Water Quality Standard Variance . . . . . . . . . . . . . . . . . . . . . 177 

EPA NPDES Permit Writers’ Manual - iii 
Contents 

10.3 Additional Programmatic Considerations and Requirements ........ 178 

10.3.1 Anti-Backsliding .................................. 178 

10.3.2 Considerations for Other Federal Laws ................. 185 

Chapter 11 - Administrative Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191 

11.1 Documentation For Development of the Draft Permit ............. 192 

11.1.1 Administrative Record ............................. 193 

11.1.2 Fact Sheets and Statements of Basis .................. 194 

11.2 Items to Address Prior to Issuance of a Final Permit ............. 197 

11.2.1 Public Notice .................................... 198 

11.2.2 Public Comments ................................ 199 

11.2.3 Public Hearing ................................... 201 

11.2.4 State/Tribal Roles in Reviewing Draft Permit ............ 202 

11.2.5 Schedule for Final Permit Issuance .................... 203 

11.3 Administrative Actions After Final Permit Issuance .............. 203 

11.3.1 Permit Appeals .................................. 204 

11.3.2 Permit Modification, Revocation, Termination, and Transfer . . 206 

11.3.3 Termination of Permits ............................. 208 

11.3.4 Transfer of Permits ............................... 209 

Chapter 12 - Permit Compliance and Enforcement . . . . . . . . . . . . . . . . . . . . . . 211 

12.1 Overview ............................................ 211 

12.2 Compliance Monitoring .................................. 212 

12.2.1 Compliance Review ............................... 212 

12.2.2 Compliance Inspections ............................ 213 

12.3 Quarterly Noncompliance Reports .......................... 214 

12.4 Enforcement .......................................... 216 

12.5 Public Participation ..................................... 218 

12.6 Compliance Assistance and Voluntary Compliance Policies ........ 218 

Appendix A Index to NPDES Regulations 

Appendix B Effluent Guidelines and Standards 

Appendix C List of SIC Codes 

Appendix D How to Obtain Additional EPA Documents 

iv - EPA NPDES Permit Writers’ Manual 
List of Exhibits 

EXHIBIT 1-1 

EXHIBIT 2-1 

EXHIBIT 2-2 

EXHIBIT 2-3 

EXHIBIT 3-1 

EXHIBIT 3-2 

EXHIBIT 4-1 

EXHIBIT 4-2 

EXHIBIT 5-1 

EXHIBIT 5-2 

EXHIBIT 5-3 

EXHIBIT 5-4 

EXHIBIT 5-5 

EXHIBIT 5-6 

EXHIBIT 5-7 

EXHIBIT 6-1 

EXHIBIT 6-2 

EXHIBIT 6-3 

EXHIBIT 7-1 

EXHIBIT 7-2 

EXHIBIT 7-3 

EXHIBIT 7-4 

EXHIBIT 7-5 

EXHIBIT 8-1 

EXHIBIT 8-2 

EXHIBIT 8-3 

Page 

Organization of the Clean Water Act ...................... 4 

Federal NPDES Regulations (40 CFR Part 122) .............. 9 

Sources of Discharge to Waters of the United States .......... 11 

NPDES Program Areas and Applicable Regulations ........... 12 

NPDES Permit Components ............................ 24 

Major Steps Involved in Developing and Issuing an 

Individual NPDES Permit .............................. 25 

Applications Forms Required for NPDES Discharges .......... 30 

Permit Application Review ............................. 38 

Statutory Deadlines for BPT, BAT, and BCT ................ 53 

Effluent Guidelines Flowchart ........................... 54 

ELGs for Iron and Steel Manufacturing .................... 57 

OCPSF Effluent Limitations Guidelines .................... 62 

BPJ Permitting Tools ................................. 72 

Secondary Treatment Standards ......................... 76 

State-Specific ASRs .................................. 84 

Components of an Integrated Approach to Water Quality-Based 

Toxics Control ...................................... 95 

Basic Mass Balance Water Quality Equation ............... 102 

Components of a TMDL .............................. 105 

Examples of Specifying Sampling Locations in Permits ........ 120 

Cornpositing Methods ............................... 126 

Estimated Costs for Common Analytical Procedures .......... 128 

Minimum Requirements for Sewage Sludge Monitoring, 

Based on Method of Sludge Use or Disposal ............... 133 

Discharge Monitoring Report (DMR) ..................... 135 

Categories of CSO Permitting Conditions .................. 162 

Nine Minimum CSO Controls .......................... 163 

Elements of the Long-Term CSO Control Plan .............. 163 

EPA NPDES Permit Writers’ Manual - v 
List of Exhibits 

EXHIBIT 10-1 Anti-Backsliding Rules Relating to Water Quality-Based Effluent 

limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 

EXHIBIT 11-1 NPDES Permitting Administrative Process ................. 192 

EXHIBIT 11-2 Elements of the Draft NPDES Permit Administrative Record .... 194 

EXHIBIT 11-3 Elements of the Administrative Records for a Final Permit ..... 195 

EXHIBIT 11-4 Required Contents of a Fact Sheet ...................... 196 

EXHIBIT 11-5 Actions That Must Receive Public Notice .................. 198 

EXHIBIT 11-6 Contents of the Public Notice .......................... 199 

EXHIBIT 11-7 Conditions Requiring Major Modification .................. 207 

EXHIBIT 11-8 Conditions Requiring Minor Modification .................. 208 

vi - EPA NPDES Permit Writers’ Manual 
List of Acronyms 

Acronym 

ACR 

ANPRM 

ASR 

ASTM 

BAT 

BCT 

BMP 

BOD 

BOD, 

BPJ 

BPT 

CBOD 

CERCLA 

CERI 

CFR 

ChV 

COD 

CSO 

CSS 

CV 

CWA 

DMR 

DO 

DWO 

EIS 

ELG 

EMMI 

EPA 

ESA 

FDF 

FR 

FWS 

GC 

GC/MS 

gpd 

IC 

Full Phrase 

Acute-to-Chronic Ratio 

Advanced Notice of Proposed Rulemaking 

Alternative State Requirement 

American Society for Testing and Materials 

Best Available Technology Economically Achievable 

Best Conventional Pollutant Control Technology 

Best Management Practice 

Biochemical Oxygen Demand 

5-day BOD 

Best Professional Judgment 

Best Practicable Control Technology Currently Available 

Carbonaceous BOD 

Comprehensive Environmental Response, Compensation and 

Liabilities Act 

Center for Environmental Research Information 

Code of Federal Regulations 

Chronic Value 

Chemical Oxygen Demand 

Combined Sewer Overflow 

Combined Sewer System 

Coefficient of Variation 

Clean Water Act 

Discharge Monitoring Report 

Dissolved Oxygen 

Dry Weather Overflow 

Environmental Impact Statement 

Effluent Limitations Guidelines 

Environmental Monitoring Methods Index 

Environmental Protection Agency 

Endangered Species Act 

Fundamentally Different Factor 

Federal Register 

Fish and Wildlife Service 

Gas Chromatography 

Gas Chromatography/Mass Spectroscopy 

Gallons per Day 

Inhibition Concentration 

EPA NPDES Permit Writers’ Manual - A-1 
List of Acronyms 

l/l 

LA 

LC 

LC50 

LD50 

LOEC 

LTA 

LTCP 

MCL 

MDL 

MEP 

mg/l 

mgd 

MPN 

MS4 

NEPA 

NHPA 

NMC 

NMFS 

NOEC 

NOI 

NPDES 

NSPS 

NTIS 

O&M 

PCS 

PL 

POTW 

PPETS 

PPIC 

PQL 

PSD 

PSES 

PSNS 

QA 

QC 

QNCR 

RAPP 

R&D 

RCRA 

RNC 

SIC 

SIP 

SNC 

SPCC 

Infiltration/Inflow 

Load Allocation 

Lethal Concentration 

Concentration at which 50% of test organisms die in a specified 

time period 

Dose at which 50% of test organisms die in a specific time period 

Lowest Observed Effect Concentration 

Long Term Average 

Long Term Control Plan 

Maximum Contaminant Level 

Method Detection Limit 

Maximum Extent Practicable 

Milligram per Liter 

Million Gallons per Day 

Most Probable Number 

Municipal Separate Storm Sewer System 

National Environmental Policy Act 

National Historic Preservation Act 

Nine Minimum Controls 

National Marine Fisheries Service 

No Observable Effect Concentration 

Notice of Intent 

National Pollutant Discharge Elimination System 

New Source Performance Standards 

National Technical Information Service 

Operations and Maintenance 

Permit Compliance System 

Public Law 

Publicly Owned Treatment Works 

Pretreatment Permits and Enforcement Tracking System 

Pollution Prevention Information Clearinghouse 

Practical Quantification Limit 

Prevention Significant Deterioration 

Pretreatment Standards for Existing Sources 

Pretreatment Standards for New Sources 

Quality Assurance 

Quality Control 

Quarterly Noncompliance Report 

Refuse Act Permit Program 

Research and Development 

Resource Conservation and Recovery Act 

Reportable Noncompliance 

Standard Industrial Classification 

State Implementation Plan 

Significant Noncompliance 

Spill Prevention Control and Countermeasure Plan 

A-2 - EPA NPDES Permit Writers’ Manual 
List of Acronyms 

SS 

SSO 

STORET 

TCLP 

TIE 

TKN 

TOC 

TMDL 

TRC 

TRE 

TRI 

TS 

TSCA 

TSD 

TSDF 

TSS 

TTO 

TUa 

TUc 

TVS 

TWTDS 

USC 

USGS 

VOC 

WET 

WLA 

WQA 

WQBEL 

WQS 

Suspended Solids 

Sanitary Sewer Overflow 

EPA Storage and Retrieval Database 

Toxicity Characteristic Leaching Procedure 

Toxicity Identification Evaluation 

Total Kjeldahl Nitrogen 

Total Organic Carbon 

Total Maximum Daily Load 

Technical Review Criteria 

Toxicity Reduction Evaluation 

Toxic Release Inventory 

Total Solids 

Toxic Substances Control Act 

Technical Support Document 

Treatment, Storage, and Disposal Facility 

Total Suspended Solids 

Total Toxic Organics 

acute Toxic Units 

chronic Toxic Units 

Total Volatile Solids 

Treatment Works Treating Domestic Sewage 

United States Code 

United States Geological Survey 

Volatile Organic Compound 

Whole Effluent Toxicity 

Waste Load Allocation 

Water Quality Act of 1987 

Water Quality-Based Effluent Limit(s) 

Water Quality Standard(s) 

EPA NPDES Permit Writers’ Manual - A-3 
Glossary of Terms 

This glossary includes a collection of the terms used in this manual and an 

explanation of each term. To the extent that definitions and explanations provided 

in this glossary differ from those in EPA regulations or other official documents, 

they are intended for use in understanding this manual only. 

. 401(a) Certification-A requirement of Section 401(a) of the Clean Water 

Act that all federally issued permits be certified by the State in which the 

discharge occurs. The State certifies that the proposed permit will comply 

with State water quality standards and other State requirements. 

. Acute-A stimulus severe enough to rapidly induce an effect; in aquatic 

toxicity tests, an effect observed in 96 hours or less is typically considered 

acute. When referring to aquatic toxicology or human health, an acute 

effect is not always measured in terms of lethality. 

• Anti-backsliding-A provision in the Federal Regulations [CWA §303(d)(4); 

CWA §402(c); CFR §122.44(l)] that requires a reissued permit to be as 

stringent as the previous permit with some exceptions. 

. Antidegradation- Policies which ensure protection of water quality for a 

particular water body where the water quality exceeds levels necessary to 

protect fish and wildlife propagation and recreation on and in the water. 

This also includes special protection of waters designated as outstanding 

natural resource waters. Antidegradation plans are adopted by each State 

to minimize adverse effects on water. 

. Authorized Program or Authorized State-A State, Territorial, Tribal, or 

interstate NPDES program which has been approved or authorized by EPA 

under 40 CFR Part 123. 

. Average Monthly Discharge Limitations -The highest allowable average 

of daily discharges over a calendar month, calculated as the sum of all daily 

discharges measured during that month divided by the number of days on 

which monitoring was performed (except in the case of fecal coliform). 

. 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 

daily discharges measured during that week. 

EPA NPDES Permit Writer Training Manual - G-7 
Glossary of terms 

• Best Available Technology Economically Achievable (BAT)- 

Technology-based standard established by the Clean Water Act (CWA) as 

the most appropriate means available on a national basis for controlling the 

direct discharge of toxic and nonconventional pollutants to navigable 

waters. BAT effluent limitations guidelines, in general, represent the best 

existing performance of treatment technologies that are economically 

achievable within an industrial point source category or subcategory. 

• Best Conventional Pollutant Control Technology (BCT) - Technologybased standard for the discharge from existing industrial point sources of 

conventional pollutants including BOD, TSS, fecal coliform, pH, oil and 

grease. The BCT is established in light of a two-part “cost reasonableness” 

test which compares the cost for an industry to reduce its pollutant 

discharge with the cost to a POTW for similar levels of reduction of a 

pollutant loading. The second test examines the cost-effectiveness of 

additional industrial treatment beyond BPT. EPA must find limits which are 

reasonable under both tests before establishing them as BCT. 

• Best Management Practice (BMP) - Permit condition used in place of or in 

conjunction with effluent limitations to prevent or control the discharge of 

pollutants. May include schedule of activities, prohibition of practices, 

maintenance procedure, or other management practice. BMPs may 

include, but are not limited to, treatment requirements, operating 

procedures, or practices to control plant site runoff, spillage, leaks, sludge 

or waste disposal, or drainage from raw material storage. 

• Best Practicable Control Technology Currently Available (BPT) - The 

first level of technology-based standards established by the CWA to control 

pollutants discharged to waters of the U.S. BPT effluent limitations 

guidelines are generally based on the average of the best existing 

performance by plants within an industrial category or subcategory. 

• Best Professional Judgment (BPJ) - The method used by permit writers 

to develop technology-based NPDES permit conditions on a case-by-case 

basis using all reasonably available and relevant data. 

• Bioassay-A test used to evaluate the relative potency of a chemical or a 

mixture of chemicals by comparing its effect on a living organism with the 

effect of a standard preparation on the same type of organism. 

• Biochemical Oxygen Demand (BOD) - A measurement of the amount of 

oxygen utilized by the decomposition of organic material, over a specified 

time period (usually 5 days) in a wastewater sample; it is used as a 

measurement of the readily decomposable organic content of a wastewater. 

G-2 - EPA NPDES Permit Writer Training Manual 
Glossary of Terms 

. Bypass-The intentional diversion of wastestreams from any portion of a 

treatment (or pretreatment) facility. 

l Categorical Industrial User (CIU)-An industrial user subject to National 

categorical pretreatment standards. 

l Categorical Pretreatment Standards-Limitations on pollutant discharges 

to publicly owned treatment works promulgated by EPA in accordance with 

Section 307 of the Clean Water Act that apply to specified process 

wastewaters of particular industrial categories [40 CFR 5403.6 and Parts 

4054711. 

l Chemical Oxygen Demand (COD)-A measure of the oxygen-consuming 

capacity of inorganic and organic matter present in wastewater. COD is 

expressed as the amount of oxygen consumed in mg/t. Results do not 

necessarily correlate to the biochemical oxygen demand (BOD) because 

the chemical oxidant may react with substances that bacteria do not 

stabilize. 

l Chronic-A stimulus that lingers or continues for a relatively long period of 

time, often one-tenth of the life span or more. Chronic should be 

considered a relative term depending on the life span of an organism. The 

measurement of a chronic effect can be reduced growth, reduced 

reproduction, etc., in addition to lethality. 

. Clean Water Act (CWA)-The Clean Water Act is an act passed by the 

U.S. Congress to control water pollution. It was formerly referred to as the 

Federaj Water Pollution Control Act of 1972 or Federal Water Pollution 

Control Act Amendments of 1972 (Public Law 92-500), 33 U.S.C. 1251 et. 

seq., as amended by: Public Law 96-483; Public Law 97-117; Public Laws 

95-217, 97-l 17, 97440, and 100-04. 

. Code of Federal Regulations (CFR)-A codification of the final rules 

published daily in the Federal Register. Title 40 of the CFR contains the 

environmental regulations. 

l Combined Sewer Overflow (CSO)-A discharge of untreated wastewater 

from a combined sewer system at a point prior to the headworks of a 

publicly owned treatment works. CSOs generally occur during wet weather 

(rainfall or snowmelt). During periods of wet weather, these systems 

become overloaded, bypass treatment works, and discharge directly to 

receiving waters. 

66% NPDES Permit Writer Training Manual - G-3 
Glossary of Terms 

. Combined Sewer System (CSS)-A wastewater collection system which 

conveys sanitary wastewaters (domestic, commercial and industrial 

wastewaters) and storm water through a single pipe to a publicly owned 

treatment works for treatment prior to discharge to surface waters. 

. Compliance Schedule-A schedule of remedial measures included in a 

permit or an enforcement order, including a sequence of interim 

requirements (for example, actions, operations, or milestone events) that 

lead to compliance with the CWA and regulations. 

. Composite Sample-Sample composed of two or more discrete samples. 

The aggregate sample will reflect the average water quality covering the 

cornpositing or sample period. 

l Conventional Pollutants-Pollutants typical of municipal sewage, and for 

which municipal secondary treatment plants are typically designed; defined 

by Federal Regulation [40 CFR 9401 .16] as BOD, TSS, fecal coliform 

bacteria, oil and grease, and pH. 

. Criteria-The numeric values and the narrative standards that represent 

contaminant concentrations that are not to be exceeded in the receiving 

environmental media (surface water, ground water, sediment) to protect 

beneficial uses. 

. 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 limitations 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 (e.g., concentration) the daily discharge is calculated as the 

average measurement of the pollutant throughout the day (40 CFR 3122.2). 

. Daily Maximum Limit-The maximum allowable discharge of pollutant 

during a calendar day. Where daily maximum limitations are expressed in 

units of mass, the daily discharge is the total mass discharged over the 

course of the day. Where daily maximum limitations are expressed in 

terms of a concentration, the daily discharge is the arithmetic average 

measurement of the pollutant concentration derived from all measurements 

taken that day. 

. Development Document-A report prepared during the development of an 

effluent limitation guideline by EPA that provides the data and methodology 

used to develop limitations guidelines and categorical pretreatment 

standards for an industrial category. 

G-4 - BEPA NPDES Permit Writer Training Manual 
Glossary of Terms 

. 

. 

. 

Director-The Regional Administrator or State Director, as the context 

requires, or an authorized representative. When there is no approved State 

program, and there is an EPA administered program, Director means the 

Regional Administrator. When there is an approved State program, 

“Director” normally means the State Director. 

Discharge Monitoring Report (DMR)-The form used (including any 

subsequent additions, revisions, or modifications) to report self-monitoring 

results by NPOES permittees. OMRs must be used by approved States as 

well as by EPA. 

Draft Permit-A document prepared under 40 CFR 5124.6 indicating the 

Director’s tentative decision to issue, deny, modify, revoke and reissue, 

terminate, or reissue a permit. A notice of intent to terminate a permit, and 

a notice of intent to deny a permit application, as discussed in 

40 CFR 9124.5, are considered draft permits. A denial of a request for 

modification, revocation and reissuance, or termination, as discussed in 

40 CFR 5124.5, is not a draft permit. 

Effluent Limitation-Any restriction imposed by the Director on quantities, 

discharge rates, and concentrations of pollutants which are discharged from 

point sources into waters of the United States, the waters of the contiguous 

zone, or the ocean. 

Effluent Limitations Guidelines (ELG)-A regulation published by the 

Administrator under Section 304(b) of CWA that establishes national 

technology-based effluent requirements for a specific industrial category. 

Fact Sheet- A document that must be prepared for all draft individual 

permits for NPDES major dischargers, NPDES general permits, NPDES 

permits that contain variances, NPDES permits that contain sewage sludge 

land application plans and several other classes of permittees. The 

document summarizes the principal facts and the significant factual, legal, 

methodological and policy questions considered in preparing the draft 

permit and tells how the public may comment (40 CFR 5124.8 and 

9124.56). Where a fact sheet is not required, a statement of basis must be 

prepared (40 CFR 9124.7). 

Fundamentally Different Factors (FDF)-Those components of a 

petitioner’s facility that are determined to be so unlike those components 

considered by EPA during the effluent limitation guideline and pretreatment 

standards rulemaking that the facility is worthy of a variance from the 

effluent limitations guidelines or categorical pretreatment standards. 

General Permit-An NPDES permit issued under 40 CFR $122.28 that 

authorizes a category of discharges under the CWA within a geographical 

8fp# NPDES Permit Writer Training Manual - G-5 
Glossary of Terms 

area. A general permit is not specifically tailored for an individual 

discharger. 

l Grab Sample-A sample which is taken from a wastestream on a one-time 

basis without consideration of the flow rate of the wastestream and without 

consideration of time. 

. Hazardous Substance-Any substance, other than oil, which, when 

discharged in any quantities into waters of the U.S., presents an imminent 

and substantial danger to the public health or welfare, including but not 

limited to fish, shellfish, wildlife, shorelines and beaches (Section 311 of the 

CWA); identified by EPA as the pollutants listed under 40 CFR Part 116. 

. Indirect Discharge-The introduction of pollutants into a municipal sewage 

treatment system from any nondomestic source (i.e., any industrial or 

commercial facility) regulated under Section 307(b), (c), or (d) of the CWA. 

. Instantaneous Maximum Limit-The maximum allowable concentration of 

a pollutant determined from the analysis of any discrete or composite 

sample collected, independent of the flow rate and the duration of the 

sampling event. 

. Local Limits-Conditional discharge limits imposed by municipalities upon 

industrial or commercial facilities that discharge to the municipal sewage 

treatment system. 

. Major Facility-Any NPDES facility or activity classified as such by the 

Regional Administrator, or in the case of approved State programs, the 

Regional Administrator in conjunction with the State Director. Major 

municipal dischargers include all facilities with design flows of greater than 

one million gallons per day and facilities with EPA/State approved industrial 

pretreatment programs. Major industrial facilities are determined based on 

specific ratings criteria developed by EPA/State. 

. Mass-Based Standard-A discharge limit that is measured in a mass unit 

such as pounds per day. 

. Method Detection Limit (MDL)-Defined as the minimum concentration of a 

substance that can be measured and reported with 99 percent confidence 

that the analyte concentration is greater than zero and is determined from 

analysis of a sample in a given matrix containing the analyte. 

. Million Gallons per Day (mgd)-A unit of flow commonly used for 

wastewater discharges. One mgd is equivalent to 1.547 cubic feet per 

second. 

G-6 - 8B# NPDES Permit Writer Training Manual 
Glossary of Tern18 

l Mixing Zone-An area where an effluent discharge undergoes initial 

dilution and is extended to cover the secondary mixing in the ambient water 

body. A mixing zone is an allocated impact zone where water quality 

criteria can be exceeded as long as acutely toxic conditions are prevented. 

. Municipal Separate Storm Sewer System (MS4)-A conveyance or 

system of conveyances (including roads with drainage systems, municipal 

streets, catch basins, curbs, gutters, ditches, manmade channels, or storm 

drains) owned by a State, city, town or other public body, that is designed 

or used for collecting or conveying storm water, which is not a combined 

sewer, and which is not part of a publicly owned treatment works. 

Commonly referred to as an “MS4” [40 CFR $122.26(b)(8)]. 

. National Pollutant Discharge Elimination System (NPDESj-The 

national program for issuing, modifying, revoking and reissuing, terminating, 

monitoring and enforcing permits, and imposing and enforcing pretreatment 

requirements, under Sections 307, 318, 402, and 405 of CWA. 

. National Pretreatment Standard or Pretreatment Standard-Any 

regulation promulgated by the EPA in accordance with Sections 307(b) and 

(c) of the CWA that applies to a specific category of industrial users and 

provides limitations on the introduction of pollutants into publicly owned 

treatment works. This term includes the prohibited discharge standards 

under 40 CFR 5403.5, including local limits [40 CFR 9403.3(j)]. 

. New Discharger-Any building, structure, facility, or installation: 

a. From which there is or may be a discharge of pollutants; 

b. That did not commence the discharge of pollutants at that particular site 

prior to August 13, 1979; 

c. Which is not a new source; and 

d. Which has never received a finally effective NPDES permit for 

discharges at that site. 

. New Source-Any building, structure, facility, or installation from which 

there is or may be a discharge of pollutants, the construction of which 

commenced: 

a. After promulgation of standards of performance under Section 306 of 

the CWA which are applicable to such source; or 

8e# NPDES Permit Writer Training Manual - G-7 
Wcmsary of Terms 

b. After proposal of standards of performance in accordance with Section 

306 of the CWA which are applicable to such source, but only if the 

standards are promulgated in accordance with Section 306 of the CWA 

within 120 days of their proposal. 

c. Except as otherwise provided in an applicable new source performance 

standard, a source is a new source if it meets the definition in 

40 CFR 5122.2; and 

i. It is constructed at a site at which no other source is located; or 

ii. It totally replaces the process or production equipment that causes 

the discharge of pollutants at an existing source; or 

iii. Its processes are substantially independent of an existing source at 

the same site. In determining whether these processes are 

substantially independent, the Director shall consider such factors 

as the extent to which the new facility is integrated with the existing 

plant; and the extent to which the new facility is engaged in the 

same general type of activity as the existing source. 

. New Source Performance Standards (NSPS)-Technology-based 

standards for facilities that qualify as new sources under 40 CFR $122.2 

and 40 CFR 5122.29. Standards consider that the new source facility has 

an opportunity to design operations to more effectively control pollutant 

discharges. 

. Nonconventional Pollutants-All pollutants that are not included in the list 

of conventional or toxic pollutants in 40 CFR Pat-l 401. Includes pollutants 

such as chemical oxygen demand (COD), total organic carbon (TOC), 

nitrogen, and phosphorus. 

. pH-A measure of the hydrogen ion concentration of water or wastewater; 

expressed as the negative log of the hydrogen ion concentration in mg/l. A 

pH of 7 is neutral. A pH less than 7 is acidic, and a pH greater than 7 is 

basic. 

. Point Source-Any discernible, confined, and discrete conveyance, 

including but not limited to any pipe, ditch, channel, tunnel, conduit, well, 

discrete fixture, container, rolling stock, concentrated animal feeding 

operation, landfill leachate collection system, vessel, or other floating craft 

from which pollutants are or may be discharged. 

G-8 - &BY4 NPDES Permit Writer Training Manual 
Glossary of Terms 

. 

. 

. 

Pollutant-Dredged spoil, solid waste, incinerator residue, filter backwash, 

sewage, garbage, sewage sludge, munitions, chemical wastes, biological 

materials, radioactive materials (except those regulated under the Atomic 

Energy Act of 1954, as amended (42 U.S.C. 2011 et seq.)), heat, wrecked 

or discarded equipment, rock, sand, cellar dirt and industrial, municipal, and 

agricultural waste discharged into water. 

Pollutant, Conservative-Pollutants that do not readily degrade in the 

environment, and which are mitigated primarily by natural stream dilution 

after entering receiving bodies of waters. Included are pollutants such as 

metals. 

Pollutant, Non-Conservative-Pollutants that are mitigated by natural 

biodegradation or other environmental decay or removal processes in the 

receiving stream after in-stream mixing and dilution have occurred. 

Practical Quantification Limit (PQL)-The lowest level that can be reliably 

achieved within specified limits of precision and accuracy during routine 

laboratory operating conditions. 

Pretreatment-The reduction of the amount of pollutants, the elimination of 

pollutants, or the alteration of the nature of pollutant properties in 

wastewater prior to or in lieu of discharging or otherwise introducing such 

pollutants into a publicly owned treatment works [40 CFR 9403.3(q)]. 

Primary Industry Categories- Any industry category listed in the Natural 

Resources Defense Council (NRDC) settlement agreement [(NRDC et al. w. 

Train, 8 E.R.C. 2120 (O.O.C. 1976), modified 12 E.R.C. 1833 (O.O.C. 

1979)] for which EPA has or will develop effluent guidelines; also listed in 

Appendix A of 40 CFR Part 122. 

Primary Treatment-The practice of removing some portion of the 

suspended solids and organic matter in a wastewater through 

sedimentation. Common usage of this term also includes preliminary 

treatment to remove wastewater constituents that may cause maintenance 

or operational problems in the system (i.e., grit removal, screening for rags 

and debris, oil and grease removal, etc.). 

Priority Pollutants-Those pollutants considered to be of principal 

importance for control under the CWA based on the NRDC consent decree 

settlement [(NRDC et al. V. Train, 8 E.R.C. 2120 (D.D.C. 1976), modified 12 

E.R.C. 1833 (D.D.C. 1979)]; a list of these pollutants is provided as 

Appendix A to 40 CFR Part 423. 

8Ef% NPDES Permit Writer Training Manual - G-9 
Glossary of Terms 

. 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 waste product. 

. Production-Based Standard-A discharge standard expressed in terms of 

pollutant mass allowed in a discharge per unit of product manufactured. 

l 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 final 

issuance by the State. 

. Publicly Owned Treatment Works (POW)-A treatment works, as 

defined by Section 212 of the CWA, that is owned by the State or 

municipality. This definition includes any devices and systems used in the 

storage, treatment, recycling, and reclamation of municipal sewage or 

industrial wastes of a liquid nature. It also includes sewers, pipes, and 

other conveyances only if they convey wastewater to a POTW treatment 

plant [40 CFR $403.31. 

. Sanitary Sewer-A pipe or conduit (sewer) intended to carry wastewater or 

water-borne wastes from homes, businesses, and industries to the POTW. 

. Sanitary Sewer Overflows (SSOj-Untreated or partially treated sewage 

overflows from a sanitary sewer collection system. 

l Secondary Industry Category-Any industry category which is not a 

primary industry category. 

. Secondary Treatment-Technology-based requirements for direct 

discharging municipal sewage treatment facilities. Standard is based on a 

combination of physical and biological processes typical for the treatment of 

pollutants in municipal sewage. Standards are expressed as a minimum 

level of effluent quality in terms of: BOD,, suspended solids (SS), and pH 

(except as provided for special considerations and treatment equivalent to 

secondary treatment). 

l Self-Monitoring-Sampling and analyses performed by a facility to 

determine compliance with a permit or other regulatory requirements. 

l Spill Prevention Control and Countermeasure Plan (SPCC)-A plan 

prepared by a facility to minimize the likelihood of a spill and to expedite 

control and cleanup activities should a spill occur. 

G-10 - 8HY4 NPDES Permit Writer Training Manual 
Glossary of Tennrb 

. 

. 

Significant Industrial User (SIU)-An indirect discharger that is the focus 

of control efforts under the national pretreatment program; includes all 

indirect dischargers subject to national categorical pretreatment standards, 

and all other indirect dischargers that contribute 25,000 gpd or more of 

process wastewater, or which make up five percent or more of the hydraulic 

or organic loading to the municipal treatment plant, subject to certain 

exceptions [40 CFR $403.3(t)]. 

Standard Industrial Classification (SIC) Code-A code number system 

used to identify various types of industries. The code numbers are 

published by the Superintendent of Documents, U.S. Government Printing 

Office, Washington, D.C. 20402. A particular industry may have more than 

one SIC code if it conducts several types of commercial or manufacturing 

activities onsite. 

Statement of Basis-A document prepared for every draft NPDES permit 

for which a fact sheet is not required. A statement of basis briefly 

describes how permit conditions were derived and the reasons the 

conditions are necessary for the permit [40 CFR $124.71. 

STORET-EPA’s computerized STOrage and RETrieval water quality data 

base that includes physical, chemical, and biological data measured in 

waterbodies throughout the United States. 

Storm Water-Storm water runoff, snow melt runoff, and surface runoff 

and drainage [40 CFR §122.26(b)(13)]. 

Technology-Based Effluent Limit-A permit limit for a pollutant that is 

based on the capability of a treatment method to reduce the pollutant to a 

certain concentration. 

Tiered Permit Limits-Permit limits that only apply to the discharge when 

a certain threshold (e.g., production level), specific circumstance (e.g., 

batch discharge), or timeframe (e.g., after 6 months) triggers their use. 

Tiered Testing-Any of a series of tests that are conducted as a result of a 

previous test’s findings. 

Total Maximum Daily Load (TMDL)-The amount of pollutant, or property 

of a pollutant, from point, nonpoint, and natural background sources, that 

may be discharged to a water quality-limited receiving water. Any pollutant 

loading above the TMDL results in violation of applicable water quality 

standards. 

Total Organic Carbon (TOC)-Measures the amount of organic carbon in 

water. 

8ER4 NPDES Permit Writer Training Manual - G-l 1 
Glossary of Terms 

Total Suspended Solids (TSS)-A measure of the filterable solids present 

in a sample, as determined by the method specified in 40 CFR Part 136. 

Toxic Pollutant-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 of EPA, cause death, 

disease, behavioral abnormalities, cancer, genetic mutations, physiological 

malfunctions, (including malfunctions in reproduction) or physical 

deformations, in such organisms or their offspring. Toxic pollutants also 

include those pollutants listed by the Administrator under CWA Section 

307(a)(l) or any pollutant listed under Section 405(d) which relates to 

sludge management. 

Toxicity Reduction Evaluation (TRE)-A site-specific study conducted in 

a stepwise process designed to identify the causative agent(s) of effluent 

toxicity, isolate the sources of toxicity, evaluate the effectiveness of toxicity 

control options, and then confirm the reduction in effluent toxicity. 

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 on exposed test organisms of a specific chemical or effluent. 

Treatability Manual-Five-set library of EPA guidance manuals that 

contain information related to the treatability of many pollutants. This 

manual can be used in developing NPDES permit limitations for facilities 

and/or pollutants which, at the time of permit issuance, are not subject to 

industry-specific effluent guidelines. The five volumes that comprise this 

series include: Vol. I - Treatability Data (EPA-600/8-80-042a); Vol. /I - 

industrial Descriptions (EPA-600/8-80-042b); Vol. 111 - Technologies 

(EPA-600/8-80-042~); Vol. IV - Cost Estimating (EPA-600/8-80-042d); Vol. 

V - Summary (EPA-600/8-80-042e). 

TSD-Abbreviation for the Technical Support Document Water Qualitybased Toxics Control (EPA-505/2-90-OOl), EPA Office of Water 

Enforcement and Permits, 1991. It contains procedures for water qualitybased limitation development. 

TWTDS-Abbreviation for Treatment Works Treating Domestic Sewage. 

Includes all POlWs and other facilities that treat domestic wastewater, and 

facilities that do not treat domestic wastewater, but that treat or dispose of 

sewage sludge. 

Upset-An exceptional incident in which there is unintentional and 

temporary noncompliance with the permit limit because of factors beyond 

G-12 - iiElY4 NPDES Permit Writer Training Manual 
Glossary of Tmrr 

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. 

l Variance-Any mechanism or provision under Sections 301 or 316 of the 

CWA or under 40 CFR Part 125, or in the applicable “effluent limitations 

guidelines” which allows modification to or waiver of the generally applicable 

effluent limitations requirements or time deadlines of the CWA. This 

includes provisions which allow the establishment of alternative limitations 

based on fundamentally different factors. 

. Wastesload Allocation (WLA)-The proportion of a receiving water’s total 

maximum daily load that is allocated to one of its existing or future point 

sources of pollution. 

. Water Quality-Based Effluent Limit (WQBEL)-A value determined by 

selecting the most stringent of the effluent limits calculated using all 

applicable water quality criteria (e.g., aquatic life, human health, and 

wildlife) for a specific point source to a specific receiving water for a given 

pollutant. 

. Water Quality Criteria -Comprised of numeric and narrative criteria. 

Numeric criteria are scientifically derived ambient concentrations developed 

by EPA or States for various pollutants of concern to protect human health 

and aquatic life. Narrative criteria are statements that describe the desired 

water quality goal. 

. Water Quality Standard (WQS)-A law or regulation that consists of the 

beneficial use or uses of a waterbody, the numeric and narrative water 

quality criteria that are necessary to protect the use or uses of that 

particular waterbody, and an antidegradation statement. 

. Waters of the United States-All waters that are currently used, were 

used in the past, or may be susceptible to use in interstate or foreign 

commerce, including all waters subject to the ebb and flow of the tide. 

Waters of the United States include but are not limited to all interstate 

waters and intrastate lakes, rivers, streams (including intermittent streams), 

mudflats, sand flats, wetlands, sloughs, prairie potholes, wet meadows, play 

lakes, or natural ponds. [See 40 CFR 5122.2 for the complete definition.] 

. Whole Effluent Toxicity (WET)-The total toxic effect of an effluent 

measured directly with a toxicity test. 

&EM NPDES Permit Writer Training Manual - G-13 
Chapter 1 

Introduction 

The purpose of this manual is to provide the basic regulatory framework and 

technical considerations that support the development of wastewater discharge 

permits as required under the National Pollutant Discharge Elimination System 

(NPDES) Program. It is designed for new permit writers, but may also serve as a 

reference for experienced permit writers. In addition, the manual will serve as a useful 

source of information for anyone interested in learning about the legal process and 

technical aspects of developing NPDES permits. This manual updates the Training 

Manual for NPDES Permit Writers. 1 

It is recognized that each United States Environmental Protection Agency (EPA) 

Regional office or approved State will have NPDES permitting procedures adapted to 

address local situations. Therefore, it is the objective of this manual to explain the 

minimum national NPDES Program elements common to any State or Regional office 

that issues NPDES permits, The specific objectives and functions of this training 

manual are to: 

• Provide an overview of the scope and regulatory framework of the NPDES 

Program 

1 USEPA (1993). Training Manual for NPDES Permit Writers. EPA/B-93-003. Office of Wastewater 

Management. 

EPA NPDES Permit Writers’ Manual - 1 
Chapter 1 Introduction 

• Describe the components of a permit and provide an overview of the 

permitting process 

• Describe the different types of effluent limits and the legal and technical 

considerations involved in limit development 

• Describe other permit conditions including: 

- special conditions 

- standard conditions 

- monitoring and reporting requirements 

• Describe other permitting considerations including: 

- variances 

- anti-backsliding 

- other applicable statutes (e.g., National Environmental Policy Act, 

Endangered Species Act, National Historic Preservation Act) 

• Explain the administrative process for issuing, modifying, revoking and 

terminating NPDES permits. 

This manual is not intended to be a stand-alone reference document. Instead, 

it is intended to establish the framework for NPDES permit development and should 

be supplemented, where necessary, by additional EPA and State guidance applicable 

to specific types of dischargers and circumstances. To this end, the NPDES Permit 

Writers Manual identifies and references other guidance documents throughout the 

text and provides information on how these documents can be obtained. Appendix D 

of this manual provides the reader with detailed information on how to obtain 

comprehensive lists of available EPA publications and how these documents can be 

ordered. 

1.1 History and Evolution of the NPDES Program 

The NPDES Program has evolved from numerous legislative initiatives dating 

back to the mid-1960s. In 1965, Congress enacted legislation requiring States to 

develop water quality standards for all interstate waters by 1967. However, despite 

increasing public concern and increased Federal spending, only about 50 percent of 

the States had established water quality standards by 1971. Enforcement of the 

Federal legislation was minimal because the burden of proof lay with the regulatory 

agencies in demonstrating that a water quality problem had implications for human 

health or violated water quality standards. Specifically, the agencies had to 

demonstrate a direct link between a discharger and a water quality problem in order to 

enforce against a discharger. The lack of success in developing adequate water 

2 - EPA NPDES Permit Writers’ Manual 
btr0duction Chapter 1 

quality standards programs, combined with ineffective enforcement of Federal water 

pollution legislation prompted the Federal government to advance the 1970 Refuse Act 

Permit Program (RAPP), under the Rivers and Harbors Act of 1899, as a vehicle to 

control water pollution. 

RAPP,required any facility that discharged wastes into public waterways to 

obtain a Federal permit specifying abatement requirements from the United States 

Army Corps of Engineers. The Administrator of EPA endorsed the joint program with 

the Corps of Engineers, and on December 23, 1970, the permit program was 

mandated through Presidential Order. EPA and the Corps of Engineers rapidly began 

to prepare the administrative and technical basis for the permit program. However, in 

December 1971, RAPP was struck down by a decision of the Federal District Court in 

Ohio (Kalur v. Resofl, which held that the issuance of a permit for an individual facility 

could require the preparation of an environmental impact statement under the National 

Environmental Policy Act (NEPA) of 1969. The concept of a permit program survived, 

however, and, in November 1972, Congress passed a comprehensive recodification 

and revision of Federal water pollution control law, known as the Federal Water 

Pollution Control Act amendments of 1972. These amendments included the NPDES 

permit program as the centerpiece of the efforts for national water pollution control. 

The enactment of the 1972 amendments marked a distinct change in the 

philosophy of water pollution control in the United States. The amendments 

maintained the water quality-based controls, but added an equal emphasis on a 

technology-based, or end-of-pipe, control strategy. The 1972 Act established a series 

of goals or policies in Section 101 that illustrated Congressional intent. Perhaps the 

most notable was the goal that the discharge of pollutants into navigable waters be 

eliminated by 1985. This goal was not realized, but remains a principle for 

establishing permit requirements. The Act had an interim goal to achieve “water 

quality which provides for the protection and propagation of fish, shellfish, and wildlife 

and provides for recreation in and on the water” by July 1, 1983. This is more 

commonly known as the “fishable, swimmable” goal. The Act also contained four 

important principles: 

l The discharge of pollutants to navigable waters is not a right. 

l A discharge permit is required to use public resources for waste disposal 

and limits the amount of pollutants that may be discharged. 

88# NPDES Permit Writers’ Manual - 3 
. Wastewater must be treated with the best treatment technology 

economically achievable-regardless of the condition of the receiving water. 

. Effluent limits must be based on treatment technology performance, but 

more stringent limits may be imposed if the technology-based limits do not 

prevent violations of water quality standards in the receiving water. 

More specifically, Title IV of the Act created a system for permitting wastewater 

discharges (Section 402), known as the National Pollutant Discharge Elimination 

System (NPDES), with the objective to implement the goals and objectives of the Act. 

An outline of the Titles contained in the Act is provided as Exhibit 1-l. 

EXHIBIT l-l 

Organization of the Clean Water Act 

Title I - Research and Related Programs 

Title II - Grants for Construction of Treatment Works 

Title III - Standards and Enforcement 

l Section 301 Effluent Limitations 

l Section 302 Water Quality-Related Effluent Limitations 

l Section 303 Water Quality Standards and Implementation Plans 

l Section 304 Information and Guidelines [Effluent] 

l Section 305 Water Quality Inventory 

l Section 307 Toxic and Pretreatment Effluent Standards. 

Title IV - Permits and Licenses 

l Section 402 National Pollutant Discharge Elimination System (NPDES) 

l Section 405 Disposal of Sewage Sludge. 

Title V - General Provisions 

l Section 502 Definitions 

l Section 510 State Authority 

l Section 5 18 Indian Tribes. 

Title VI - State Water Pollution Control Revolving Funds 

4 - 8EfYJ NPDES Permit Writers’ Manual 
Chapter 1 

The first round of NPDES permits issued between 1972 and 1976 provided for 

control of a number of traditionally regulated pollutants, but focused on 5-&y 

biochemical oxygen demand (BOD,), total suspended solids (TSS), pH, oil and grease, 

and some metals, by requiring the use of the Best Practicable Control Technology 

currently available (BPT). The Act established a July 1, 1977, deadline for all facilities 

to be in compliance with BPT. Additionally, the Act established the compliance 

deadline for installing Best Available Technology Economically Achievable (BAT) as 

July 1, 1983. Most of the major permits issued to industrial facilities in the first round 

of NPDES permitting cdntained effluent limitations based on Best Professional 

Judgment (BPJ) because regulations prescribing nationally uniform, technology-based 

effluent limitations were generally unavailable. The second round of permitting in the 

late 1970s and early 1980s began to emphasize the control of toxics, but, due to a 

lack of information on treatability, failed to complete the task. 

EPA’s failure to develop adequate controls for toxic discharges under the 1972 

Act prompted the Natural Resources Defense Council (NRDC) to sue EPA. [NRDC v. 

Train, 8 E.R.C. 2120 (D.D.C. 1976)j. The suit was settled through a court supervised 

“consent decree” in 1976. The consent decree identified (1) the “priority” pollutants to 

be controlled; (2) the “primary industries” for technology-based control; and (3) the 

methods for regulating toxic discharges through the authorities of the 1972 Act. The 

provisions of the consent decree were incorporated into the framework of the 1977 

amendments of the Act, and resulted in the Act’s refocus toward toxics control. 

The 1977 amendments to the legislation, known formally as the Clean Water 

Act (CWA) of 1977, shifted emphasis from controlling conventional pollutants to 

controlling toxic discharges. This era of toxic pollutant control is referred to as the 

second round of permitting. The concept of BAT controls was clarified and expanded 

to include toxic pollutants. Hence, the compliance deadline for BAT was extended to 

July 1, 1984. The conventional pollutants (BOD,, TSS, pH, fecal coliform, and oil and 

grease) controlled by BPT in the first round of permitting were now subject to a new 

level of control, termed Best Conventional Pollutant Control Technology (BCT). The 

compliance deadline for meeting BCT was also July 1, 1984. 

On February 4, 1987, Congress amended the CWA with the Water Quality Act 

(WQA) of 1987. The amendments outlined a strategy to accomplish the goal of 

&BY4 NPDES Permft Writers’ Manual - 5 
Chepter 1 1lltlQdUGtl~ 

meeting water quality standards set by the States. The WQA required all States to 

identify waters that were not expected to meet water quality standards after 

technology-based controls on point sources have been imposed. The State must then 

prepare an individual control strategy to reduce toxics from point and nonpoint sources 

in order to meet the water quality standards. Among other measures, these plans 

were expected to address control of pollutants beyond technology-based levels. 

The WQA once again extended the time to meet BAT and BCT effluent 

limitations. The new compliance deadline was no later than March 31, 1989. The 

WQA also established new schedules for industrial and municipal storm water 

discharges to be regulated by NPDES permits. Industrial storm water discharges 

must meet the equivalent of BCT/BAT effluent quality. Discharges from municipal 

separate storm sewer systems (MS4) required controls to reduce the discharge of 

pollutants to the maximum extent practicable (MEP). Additionally, the WQA required 

EPA to identify toxics in sewage sludge and establish numerical limits to control these 

pollutants. The WQA also established a statutory anti-backsliding requirement that 

would not allow an existing permit to be modified or reissued with less stringent 

effluent limitations, standards, or conditions than those already imposed. There were 

a few exceptions for technology-based limits, but in no case could the limits be less 

stringent than existing effluent guidelines (unless a variance has been granted) or 

violate water quality standards. 

6 - 88# NPDES Permit Writers’ Manual 
Chapter 2 

Regulatory Framework and 

Scope of the NPDES Program 

This chapter provides a discussion of the regulatory framework of the NPDES 

Program, identifies the types of activities regulated under the NPDES Program, and 

discusses the program areas that address the various types of regulated activities. 

2.1 Regulatory Framework of the NPDES Program 

Chapter 1 discussed how Congress, in Section 402 of the CWA, required EPA 

to develop and implement the NPDES permit program. While Congress’ intent was 

established in the CWA, EPA had to develop specific regulations to carry out the 

congressional mandate. The primary regulations developed by EPA to implement and 

administer the NPDES Program are found in Title 40 of the Code of Federal 

Regulations (CFR) Part 122. 

The CFR is a set of documents listing all regulations issued by every United 

States government agency. The CFR is published by the National Archives and 

Records Service of the General Services Administration. The CFR is updated 

annually based on the regulations published daily in the Federal Register (FR). 

EPA NPDES Permit Writers’ Manual - 7 
Chapter 2 Regulatory Framework and Scope of the NPDES Program 

The FR is the vehicle by which EPA and other branches of the Federal 

government provide notice of, propose, and promulgate regulations. Although all of 

the regulations can be found in the CFR, the background and implementation 

information related to these regulations can be found in the preamble to the 

regulations contained in the FR. This information is important to the permit writer 

because it explains the regulatory basis upon which permitting decisions are made. 

An outline of the Federal NPDES regulations (40 CFR Part 122) is provided in 

Exhibit 2-1. Other parts of 40 CFR that are related to the NPDES Program include: 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

• 

40 CFR Part 123 (State requirements) 

40 CFR Part 124 (procedures for decision making) 

40 CFR Part 125 (technology-based standards) 

40 CFR Part 129 (toxic pollutant standards) 

40 CFR Part 130 (water quality management plans) 

40 CFR Part 131 (water quality-based standards) 

40 CFR Part 133 (sewage secondary treatment regulations) 

40 CFR Part 135 (citizen suits) 

40 CFR Part 136 (analytical procedures) 

40 CFR Part 257 (State sludge disposal regulations) 

40 CFR Part 401 (general effluent guidelines provisions) 

40 CFR Part 403 (general pretreatment regulations) 

40 CFR Parts 405-471 (effluent limitations guidelines) 

40 CFR Part 501 (State sludge permitting requirements) 

40 CFR Part 503 (sewage sludge disposal standards). 

An index to the NPDES regulations is provided in Appendix A. This index 

groups the regulatory requirements by subject area to provide the permit writer easier 

access to specific provisions. 

2.2 Scope of the NPDES Program 

Under the NPDES Program, all facilities which discharge pollutants from any 

point source into waters of the United States are required to obtain a NPDES permit. 

Understanding how each of the key terms (“pollutant,” *‘point source,” and “waters of 

8 - EPA NPDES Permit Writers’ Manual 
Regulatory Framework and Scope ot the NPDES Program Chapter 2 

EXHIBIT 2-l 

Federal NPDES Regulations (40 CFR Part 122) 

Subpart A - Definitions and General Program Requirements 

122.1 Purpose and Scope of NPDES Program 

122.2 Definitions 

122.3 Exclusions 

f 22.4 Prohibitions 

122.5 Effect of a Permit 

122.6 Continuation of Expired Permits 

122.7 Confidentiality of Information 

Subpart B - Permit Application .and Special NPDES Program Requirements 

122.21 .4pplications 

122.22 Signatures Rcquircments for Applications 

122.23 Animal Feeding Operations 

122.24 Aquatic Animal Production 

122.25 Aquaculture 

122.26 Storm Water Discharges 

122.27 Silviculture 

122.28 General Permits 

122.29 New Sources and New Discharges 

Subpart C - Permit Conditions 

122.41 Standard Conditions 

122.42 Standard Conditions Applicable to Specified Categories 

122.43 Permit Conditions 

122.44 Permit Limitations 

(a) Technology Basis 

(b) Other Basis (not WQ) 

(c) Reopeners 

id) Water Quality Basis 

(c) Priority Pollutants 

I f) Notification Levels 

t,g) 24 Hour Reporting 

fh) Duration of Permits 

(i) Monitoring 

(j) Pretreatment Program 

(k) Best Management Practices 

(1) Anti-Backsliding 

(m) Private Treatment Works 

(n) Grants 

(0) Sludge 

(p) Coast Guard 

(q) Navigation 

122.45 Calculating Limitations 

(a) Discharge Points 

(b) Production Basis 

(c) Metals 

(d) Continuous Discharges 

ie) Non-continuous Discharges 

(f) Mass Based Limits 

(g) Intake Water Pollutants 

(h) Internal Waste Streams 

(i) Discharge into Wells 

122.46 Duration of Permits 

122.47 Schedules of Compliance 

122.48 Reporting 

122.49 Considcratiun of Other Federal Laws 

122.50 Disposal 10 Other Points 

Subpart D - Transfer, Modification, Revocation and Reissuance, and Termination of Permit 

122.61 Transfer of Permits 

122.62 Modification or Revocation and Reissuance of Permits 

122.63 Minor Modifications of Permits 

122.64 Termination of Permits 

BEPA NPDES Permit Writers’ Manual - 9 
Chapter 2 Regulatory Framework and Scope of the NPDES Progna~l 

the United States”) have been defined and interpreted by the regulations is the key to 

defining the scope of the NPDES Program. 

Pollutant 

The term “pollutant” is defined very broadly by the NPDES regulations and 

includes any type of industrial, municipal, and agricultural waste discharged into water 

(see glossary). For regulatory purposes, pollutants have been grouped into three 

general categories under the NPDES Program: conventional, toxic, and 

nonconventional. By definition, there are five conventional pollutants: 5day 

biochemical oxygen demand (BOD,), total suspended solids (TSS), fecal coliform, pH, 

and oil and grease. Toxic or “priority” pollutants are those defined in Section 307(a)(l) 

of the CWA (and listed in 40 CFR 5401.15) and include metals and manmade organic 

compounds. Nonconventional pollutants are those which do not fall under either of 

the above categories and include such parameters as ammonia, nitrogen, phosphorus, 

chemical oxygen demand (COD), and whole effluent toxicity (WET). 

Point Source 

Pollutants can enter waters of the United States from a variety of pathways 

including agricultural, domestic and industrial sources (see Exhibit 2-2). For 

regulatory purposes these sources are generally categorized as either “point sources” 

or “non-point sources.” Typical point source discharges include discharges from 

publicly owned treatment works (POTWs), industrial facilities, and discharges 

associated with urban runoff. While provisions of the NPDES Program do address 

certain specific types of agricultural activities (i.e., concentrated animal feeding 

operations), the majority of agricultural facilities are defined as non-point sources and 

are exempt from NPDES regulation. 

Pollutant contributions to waters of the United States may come from both 

“direct” and “indirect” sources. “Direct” sources discharge wastewater directly into the 

receiving waterbody, whereas “indirect” sources discharge wastewater to a POTW, 

which in turn discharges into the receiving waterbody. Under the national program, 

NPDES permits are issued onJ to direct point source discharges. Industrial and 

commercial indirect dischargers are controlled by the national pretreatment program 

(see Section 8.3.1). 

10 - &EM NPDES Permit Writers’ Manual 
Regulatory Framework and Scqm of the NPDES Program Chapter 2 

EXHIBIT 2-2 

Sources of Discharge to Waters of the United States 

I- __ -.. 1 

As indicated above, the primary focus of the NPDES permitting program is 

municipal and non-municipal (industrial) direct dischargers. Within these major 

categories of dischargers, however, there are a number of more specific types of 

discharges that are regulated under the NPDES Program. Exhibit 2-3 provides an 

overview of the scope of the NPDES Program and identifies the program areas that 

control various categories of wastewater discharges. 

Municipalities (e.g., POTWs receive primarily domestic sewage from residential 

and commercial customers. Larger POTWs will also typically receive and treat 

wastewater from industrial facilities (indirect dischargers) connected to the POTW 

sewerage system. The types of pollutants treated by a POTW, therefore, will always 

include conventional pollutants (BOD,, TSS, pH, oil and grease, fecal coliform), and 

will include nonconventional and toxic pollutants depending on the unique 

characteristics of the commercial and industrial sources discharging to the POTW. 

The treatment typically provided by POTWs includes physical separation and settling 

(e.g., screening, grit removal, primary settling), biological treatment (e.g., trickling 

filters, activated sludge), and disinfection (e.g., chlorination, UV, ozone). These 

processes produce the treated effluent and a biosolids (sludge) residual. An additional 

&EPA NPDES Permit Writers’ Manual - 11 
Chapter 2 Regulatory Framework and Scope of the NPDES Program 

EXHIBIT 2-3 

NPDES Program Areas and Applicable Regulations 

source I AtZfh@? 1 

Municipal Effluent 

Discharge 

NPDES Point Source 

Control Program 

40 CFR 122 

40 CFR 125 

40 CFR 133 

Indirect Industrial/ Pretreatment 40 CFR 122 

Commercial Discharges Program 40 CFR 403 

40 CFR 405-499 

Municipal 

Municipal Sludge Use 

and Disposal 

Municipal Sewage 

Sludge Program 

40 CFR 122 

40 CFR 257 

40 CFR 501 

40 CFR 503 

Combined Sewer 

Overflow 

(CSO) Discharges 

CSO Control Program 40 CFR 122 

40 CFR 125 

Storm Water Discharges 

(Municipal) 

Storm Water 

Program 

40 CFR 122 

40 CFR 125 

Process Wastewater 

Discharges 

NPDES Point Source 

Control Program 

40 CFR 122 

40 CFR 125 

40 CFR 405-499 

Industrial Non-process Wastewater NPDES Point Source 40 CFR 122 

Discharges Control Program 40 CFR 125 

Storm Water Discharges Storm Water Program 40 CFR 122 

(Industrial) 40 CFR 125 

concern to some older POTWs are “combined sewer” systems (i.e., sewerage systems 

that are designed to collect both sanitary sewage and storm water). Exhibit 2-3 

illustrates how the NPDES Program is structured to control all of the various types of 

pollutant sources and wastestreams that contribute to municipal point sources. 

Non-municipal sources, which include industrial and commercial facilities, are 

unique with respect to the products and processes present at the facility. Unlike 

municipal sources, the types of raw materials, production processes, treatment 

technologies utilized, and pollutants discharged at industrial facilities vary widely and 

are dependent on the type of industry and specific facility characteristics. The 

12 - &EM NPDES Permit Writers’ Manual 
Chapter 2 

operations, however, are generally carried out within a more clearly defined plant area; 

thus, collection system considerations are generally much less complex than for 

POTWs. In addition, residuals (sludge) generated by industrial facilities are not 

currently regulated by the NPDES Program. Industrial facilities may have discharges 

of storm water that may be contaminated through contact with manufacturing activities, 

or raw material and product storage. Industrial facilities may also have non-process 

wastewater discharges such as non-contact cooling water. As illustrated in Exhibit 

2-3, the NPDES Program addresses each of these potential wastewater sources for 

industrial facilities. 

Waters of the United States 

The term “waters of the United States,” has been defined by EPA to include: 

. Navigable waters 

. Tributaries of navigable waters 

. Interstate waters 

l Intrastate lakes, rivers, and streams: 

- Used by interstate travelers for recreation and other purposes; or 

- Which are the source of fish or shellfish sold in interstate commerce; or 

- Which are utilized for industrial purposes by industries engaged in 

interstate commerce. 

The intent of this definition is to cover all possible waters within Federal jurisdiction 

under the framework of the Constitution (i.e., Federal versus State authorities). The 

definition has been interpreted to include virtually all surface waters in the United 

States, including wetlands and ephemeral streams. As a general matter, groundwater 

is not considered a waters of the United States: Therefore discharges to groundwater 

are not subject to NPDES requirements. If, on the other hand, there is a discharge to 

groundwater that results in a “hydrological connection” to a nearby surface water, the 

Director may require the discharger to apply for an NPDES permit. [Note: Because 

States maintain jurisdiction over groundwater resources, they may choose to require 

NPDES permits for discharges to groundwater.] 

BERA NPDES Permit Writers’ Manual - 13 
Chapter 2 Regulatory Framework and Scope of the NPDES Program 

2.3 NPDES Program Areas 

As indicated in Exhibit 2-3, the national NPDES Program includes provisions 

that address several different types of discharges from municipal and industrial 

sources. This section provides a brief description of how the NPDES Program 

addresses each of these program areas. 

2.3.1 NPDES Program Areas Applicable to Municipal Sources 

The NPDES permitting program focuses on the development of effluent limits 

and conditions for the discharge of treated effluent. The NPDES Program, however, 

also incorporates other control measures to address certain types and categories of 

discharges that may be present at some municipal facilities. A description of these 

control measures, and a discussion of how they are incorporated into the permitting 

process is provided below. 

National Pretreatment Program 

The national pretreatment program regulates the discharges of wastewater from 

non-domestic (i.e., industrial and commercial) facilities that discharge to POTWs (i.e., 

“indirect” discharges). The pretreatment program requires industrial and commercial 

indirect dischargers to “pretreat” their wastes, as necessary, prior to discharge to 

POTWs, to prevent interference or upset to the operation of the POTW. The Federal 

program also requires many indirect dischargers to meet technology-based 

requirements similar to those for direct dischargers. The pretreatment program is 

generally implemented directly by the POTW receiving indirect discharges, under 

authority granted through the NPDES permit. The Federal regulations specifying 

which POTWs must have pretreatment programs, and the authorities and procedures 

that must be developed by the POTW prior to program approval are found in 40 CFR 

Part 403. The implementation of a local pretreatment program is typically included as 

a special condition in NPDES permits issued to POTWs. The incorporation of 

pretreatment special conditions is discussed in Chapter 8. 

Municipal Sewage Sludge Program 

Section 405 of the CWA requires that all NPDES permits issued to POTWs and 

other Treatment Works Treating Domestic Sewage (TWTDS) contain conditions 

14 - GEM NPDES Permit Writers’ Manual 
Mgulatory Framework and Scope of the NPbES Program Chapter 2 

implementing 40 CFR Part 503 Standards for the Use and Disposal of Sewage 

Sludge. Thus, POTWs and other TWTDS must submit permit applications for their 

sludge use or disposal practices. TWTDS include sewage sludge incinerators, 

sewage sludge surface disposal sites, and facilities that do not discharge to waters of 

the United States (sludge-only facilities such as sludge composting facilities that treat 

sewage sludge). 

The permitting regulations can be found at 40 CFR Part 122 for the Federal 

program. Regulations for State program approval are found at 40 CFR Parts 123 or 

501 (depending on whether the State wishes to administer the sewage sludge 

program under its NPDES Program or under another program, e.g., a solid waste 

program). The technical regulations governing sewage sludge use and disposal are 

contained in 40 CFR Part 503. Where applicable, sludge management requirements 

are included as a special condition in permits issued to POTWs. The incorporation of 

special conditions that address sludge requirements is discussed in Chapter 8. 

Combined Sewer Overflows 

Combined sewer systems (CSS) are wastewater collection systems designed to 

carry sanitary wastewaters (commercial and industrial wastewaters) and storm water 

through a single conduit to a POTW. As of 1995, CSSs serve about 43 million people 

in approximately 1,100 communities nationwide. During dry weather, CSSs collect 

and convey domestic, commercial, and industrial wastewater to a POTW; however, 

during periods of rainfall or snowmelt, these systems can become overloaded. When 

this occurs, the CSS overflows at designed relief points, discharging a combination of 

untreated sanitary wastewaters and storm water directly to a surface water body. 

These overflows, called combined sewer overflows (CSOs), can be a major source of 

water pollution in communities served by CSSs. CSOs often contain high levels of 

suspended solids (SS), pathogenic microorganisms, toxic pollutants, floatables, 

nutrients, and other pollutants, causing exceedances of water quality standards. 

To address CSOs, EPA issued the National CSO Control Strategy on August 

10, 1989 (54 FR 37370). While the 1989 Strategy resulted in some progress in 

controlling CSOs, significant public health risks and water quality impacts remained. 

To expedite compliance with the CWA and to elaborate on the 1989 Strategy, EPA, in 

collaboration with other CSO stakeholders (communities with CSSs, State water 

&EM NPDES Permit Writers’ Manual - 15 
Chapter 2 Regulatory Framework and Scope of the NPDES Program 

quality authorities, and environmental groups), developed and published the CSO 

Control Policy on April 19, 1994 (59 FR 18688). The Policy establishes a uniform, 

nationally consistent approach to developing and issuing NPDES permits that address 

CSOs. With respect to NPDES permittees, State water quality standards authorities, 

and NPDES permitting and enforcement authorities, the CSO Policy states the 

following: 

. Permittees should immediately implement the nine minimum controls 

(NMCs), which are technology-based actions or measures designed to 

reduce CSOs and their effects on receiving water quality, as soon as 

practicable, but no later than January 1, 1997. 

. Permittees should give priority to environmentally sensitive areas. 

l Permittees should develop long-term control plans (LTCPs) for controlling 

CSOs. A permittee may use one of two approaches: (1) demonstrate that 

its plan is adequate to meet the water quality-based requirements of the 

CWA (“demonstration approach”), or (2) implement a minimum lavel of 

treatment (e.g., primary clarification of at least 85% of the collected 

combined sewage flows) that is presumed to meet the water quality-based 

requirements of the CWA, unless data indicate otherwise (“presumptive 

approach”). 

. Water quality standards authorities should review and revise, as 

appropriate, State water quality standards during the CSO long-term 

planning process. 

. NPDES permitting authorities should consider the financial capability of 

permittees when reviewing CSO control plans. 

The CSO Policy recommends that NPDES permitting authorities utilize a phased 

approach in addressing CSOs. Phase I permits should require the permittee to 

implement the NMC within two years of notice from the NPDES permitting authority 

and to develop a LTCP. Phase II permits should require continued implementation of 

the NMC and implementation of a LTCP. 

Prior to issuing a permit that requires conditions that address CSOs, permit 

writers should consult the CSO Control Policy and associated guidance materials. 

The incorporation of permit conditions that address CSOs is provided in Chapter 8. 

16 - &ERA NPDES Permit Writers’ Manual 
Regulatory Framework and Scope of the NPDES Program Chapter 2 

Storm Water Program (Municipal) 

EPA has determined that storm water runoff from major metropolitan areas is a 

significant source of pollutants discharged to waters of the United States. While 

rainfall and snow are natural events, the nature of runoff and its impact on receiving 

waters is highly dependent on human activities and use of the land. Runoff from 

lands modified by human activities (i.e., metropolitan areas) can affect surface water 

resources in two ways: (1) natural flow patterns can be modified; and (2) pollution 

concentrations and loadings can be elevated. 

To address these discharges, the 1987 amendments to the CWA added a 

provision [Section 402(p)] that directed EPA to establish phased NPDES requirements 

for storm water discharges. Section 402(p)(2) of the Act identifies discharges covered 

under Phase I of the Storm Water Program and includes discharges from municipal 

separate storm sewer systems (MS4s) serving a population of 100,000 or more. 

Section 402(p)(3) identifies the standards for MS4 permits. These standards mark the 

significant difference in permits that address storm water discharges from MS4s 

versus permits that address other more traditional sources (i.e., POTWs and nonmunicipal sources). In general, Congress provided that permits for discharges from 

MS4s: 

. May be issued on a system- or jurisdiction wide basis; 

l Shall effectively prohibit non-storm water discharges into the MS4; and 

l Shall require controls to reduce the discharge of pollutants to maximum 

extent practicable (MEP). 

In response, EPA published regulations addressing storm water discharges 

from municipal separate storm sewer systems on November 16, 1990 (55 FR 47990). 

The regulations define a MS4 as any conveyance or system of conveyances that is 

owned or operated by a State or local government entity designed for collecting and 

conveying storm water. Under Phase I of the Storm Water Program, only those MS4s 

which served a population of 100,000 or more were required to apply for a NPDES 

permit. Unlike permits that are developed and issued to individual POTWs (also 

referred to as “municipals”), permits that address storm water discharges from MS4s 

may be issued on a jurisdiction-wide basis to the operator of the storm water collection 

3H34 NPDES Permit Writers’ Manual - 17 
Chapter 2 Regulatory Framework and Scope of the NPDES Program 

system (e.g., a county or city public works department). Chapter 8 discusses 

considerations for developing NPDES permits for storm water discharges from MS4s. 

2.3.2 NPDES Program Areas Applicable to Industrial Sources 

In addition to the development of effluent limits and conditions for discharges of 

process and non-process wastewater from direct dischargers, the NPDES Program 

also includes provisions for control of storm water discharges from industrial sources. 

A description of this program area and a discussion of how it is incorporated into the 

permitting process is provided below. 

Storm Water Program (Industrial) 

All storm water discharges associated with industrial activity that discharge 

through municipal separate storm sewer systems or that discharge directly into the 

waters of the United States are required to obtain NPDES permit coverage, including 

those which discharge through MS4s located in municipalities with a population of less 

than 100,000. Discharges of storm water to a sanitary sewer system or to a POTW 

are excluded. As with the Municipal Storm Water Program discussed in Section 2.3.1 

above, EPA published the initial permit application requirements for certain categories 

of storm water discharges associated with industrial activity on November 16, 1990 

(55 FR 48065). 

The regulations define storm water discharges associated with industrial activity 

as discharges from any conveyance used for collecting and conveying storm water 

directly related to manufacturing, processing, or raw materials storage areas at an 

industrial plant. The NPDES permitting regulations at 40 CFR $122.26 were 

promulgated on November 16, 1990 (55 FR 48065) to identify the following 11 

industrial categories required to apply for NPDES permits for storm water discharges: 

. Facilities subject to storm water effluent limitations guidelines (ELG), new 

source performance standards (NSPS), or toxic pollutant effluent standards 

under 40 CFR Subchapter N 

. Certain heavy manufacturing facilities (lumber, paper, chemicals, petroleum 

refining, leather tanning, stone, clay, glass, concrete, ship construction) 

l Active and inactive mining operations and oil and gas operations with 

contaminated storm water 

18 - 8Ep# NPDES Permit Writers’ Manual 
Regulatory Framework and Scope of the NPDES Program Chapter 2 

. Hazardous waste treatment, storage, or disposal facilities, including 

Resource Conservation and Recovery Act (RCRA) Subtitle C facilities 

. Landfills, open dumps, and RCRA Subtitle D facilities 

. Recycling facilities, including metal scrapyards, battery reclaimers, salvage 

yards, and automotive junkyards 

. Steam electric power generating facilities, including coal handling sites 

. Transportation facilities that have vehicle maintenance shops, equipment 

cleaning operations, or airport de-icing operations 

. Major POTW sludge handling facilities, including onsite application of 

sewage sludge 

l Construction activities that disturb five acres or more 

. Light industrial manufacturing facilities. 

Operators of industrial facilities that are federally, state or municipally owned or 

operated that meet the description of the facilities listed in 40 CFR 122.26(b)(14)(1)- 

(xi) must also submit applications (note: the Transportation Act of 1991 provides 

exceptions for certain municipally owned or operated facilities). EPA published final 

rules regarding the NPDES Storm Water Regulations on both April 1, 1992 (57 FR 

11394) and December 18, 1992 (57 FR 60444). The rule promulgated on April 2, 

1992 was, in part, to codify provisions of the Transportation Act of 1991. The 

December 18, 1992 rule was in response to the mandate of the Ninth Circuit United 

States Court of Appeals in NRDC v. EPA (June 4, 1992). Each of these final rules 

are summarized below: 

l Transportation Act of 1992-The Transportation Act of 1991 provides an 

exemption from Phase I storm water permitting requirements for certain 

industrial activities owned or operated by municipalities with a population of 

less than 100,000 (note: population threshold not tied to a service 

population for a MS4). Such municipalities must submit storm water 

discharge permit applications only for airports, powerplants, and 

uncontrolled sanitary landfills that they own or operate. 

. Ninth Circuit Court Decision-The Ninth Circuit United States Court of 

Appeals’ opinion in NRDC v. EPA (June 4, 1992) invalidated and remanded 

for further proceedings two regulatory exemptions from the definition of 

“storm water discharges associated with industrial activity”: 

1. The exemption for construction sites disturbing less than five acres of 

land (category x), and 

2. The exemption of certain “light” manufacturing facilities without 

exposure of materials and activities to storm water (category xi). 

8fR4 NPDES Permit Writers’ Manual - 19 
Chapter 2 

In response to these two remands, EPA intends to conduct further 

rulemaking proceedings on construction activities under five acres and light 

industry without exposure. As ordered by the Court, EPA will not require 

permit applications for construction sites disturbing less than five acres of 

land and category xi facilities without exposure until this further rulemaking 

is completed. 

Generally, storm water discharges from industrial sources are regulated by 

Federal or State issued general permits (see Section 3.1 for a description of the types 

of NPDES permits). However, in some cases, storm water conditions may be 

incorporated into a comprehensive individual NPDES permit for a facility, or a storm 

water-specific individual NPDES permit. The incorporation of permit conditions that 

address storm water discharges from industrial facilities is provided in Chapter 8. For 

more information regarding the scope of the NPDES Storm Water Program, refer to 

EPA’s storm water regulations at 40 CFR 122.26 and the Overview of the Storm 

Water Proaram.2 

‘USEPA (1996). Ovewiew of the Storm Water Program. EPA 833-R-96-008. Office of Water. 

20 - 88R9 NPDES Permit Writers’ Manual 
Chapter 3 

Overview of the NPDES 

Permitting Process 

This chapter presents an overview of the different types of NPDES permits, 

permit components, the permitting development and issuance process, and the roles 

and responsibilities of the Federal and State governments. The intent of this chapter 

is to give the permit writer an introduction to the elements of a NPDES permit and to 

provide a brief overview of the process of writing a permit. The process is illustrated 

by the use of flow charts. The tasks identified within the flow charts are described in 

detail in subsequent chapters. 

3.1 Types of Permits 

A permit is typically a license for a facility to discharge a specified amount of a 

pollutant into a receiving water under certain conditions; however, permits may also 

authorize facilities to process, incinerate, landfill, or beneficially use sewage sludge. 

The two basic types of NPDES permits that can be issued are individual and general 

permits. 

An individual permit is a permit specifically tailored for an individual facility. 

Upon submitting the appropriate application(s), the permitting authority develops a 

permit for that particular facility based on the information contained in the permit 

EPA NPDES Permit Writers’ Manual - 21 
Chapter 3 Overview of the NPDES Permitting Process 

application (e.g., type of activity, nature of discharge, receiving water quality). The 

permit is then issued to the facility for a specific time period (not to exceed 5 years) 

with a requirement to reapply prior to the expiration date. 

A general permit is developed and issued by a permitting authority to cover 

multiple facilities within a specific category. General permits may offer a cost-effective 

option for agencies because of the large number of facilities that can be covered 

under a single permit. According to 40 CFR §122.28, general permits may be written 

to cover categories of point sources having common elements, such as: 

• Storm water point sources 

• Facilities that involve the same or substantially similar types of operations 

• Facilities that discharge the same types of wastes or engage in the same 

types of sludge use or disposal 

• Facilities that require the same effluent limitations or operating conditions, 

or standards for sewage sludge use or disposal 

• Facilities that require the same monitoring where tiered conditions may be 

used for minor differences within class (e.g., size or seasonal activity) 

• Facilities that are more appropriately regulated by a general permit. 

General permits, however, may only be issued to dischargers within a specific 

geographical area such as the following: 

• Designated planning area 

• Sewer district 

• City, county, or State boundary 

• State highway system 

• Standard metropolitan statistical area 

• Urbanized area. 

The use of general permits allows the permitting authority to allocate resources 

in a more efficient manner and to provide more timely permit coverage. For example, 

a large number of facilities that have certain elements in common may be covered 

under a general permit without expending the time and money necessary to issue an 

individual permit to each of these facilities. In addition, the use of a general permit 

ensures consistency of permit conditions for similar facilities. 

22 - EPA NPDES Permit Writers’ Manual 
Overview of the NPOES Pennltting Process Chapter 3 

3.2 Major Components of a Permit 

All NPDES permits, at a minimum, consist of five general sections: 

l Cover Page-Typically contains the name and location of the permittee, a 

statement authorizing the discharge, and a listing of the specific locations 

for which a discharge is authorized. 

l Effluent Limitations-The primary mechanism for controlling discharges of 

pollutants to receiving waters. The majority of the permit writer’s time is 

spent deriving appropriate effluent limitations based on applicable 

technology and water quality standards. 

. Monitoring and Reporting Requirements-Used to characterize 

wastestreams and receiving waters, evaluate wastewater treatment 

efficiency, and determine compliance with permit conditions. 

l Special Conditions-Conditions developed to supplement effluent 

limitations guidelines. Examples include best management practices 

(BMPs), additional monitoring activities, ambient stream surveys, toxicity 

reduction evaluations (TREs), etc. 

l Standard Conditions-Pre-established conditions that apply to all NPDES 

permits and that delineate the legal, administrative, and procedural 

requirements of the NPDES permit. 

Although these sections compose all permits, the contents of some of these 

sections will vary depending on whether the permit is to be issued to a municipal or 

industrial facility, and whether the permit will be issued to an individual facility or to 

multiple dischargers (Le., a general permit), Exhibit 3-l shows the components of a 

permit and highlights some of the distinctions between the contents of NPDES permits 

for industrial and municipal permits. 

3.3 Overview of the Development/Issuance Process for NPDES 

Individual Permits 

While the limits and conditions in an individual NPDES permit are unique to the 

permittee, the process used to develop the limits and conditions, and issue the permit, 

generally follows a common set of steps. Exhibit 3-2 illustrates the major steps 

involved in developing and issuing an individuai NPDES permit. Exhibit 3-2 also 

serves as an index for the subsequent chapters of this manual by identifying the 

chapters where more detailed information for each step is presented. 

BEPA NPDES Permit Writers’ Manual - 23 
Chapter 3 OvervIew of the NPDES Pemdtting Process 

EXHIBIT 3-1 

NPDES Permit Components 

Components of AU 

NPDES Permits 

cover Page 

Technology-Based: 

l Effluent Guidelines 

l Best Professional 

Judgment (BP&. 

EfIIuent Limitations: Technology Based: 

l Secondary Treatment 

- Technology-Based l Equivalent to 

- Water Quality-Based Secondary Treatment. 

Monitoring Luid 

Reporting 

Requirement6 

Other Requirements: 

l Best Management 

Practices (BMP). 

Spedal Conditions: Other Requirements: 

l Pretreatment Proaam 

- Compliance Schedules l Combined Sewer 

- Storm Water Overflow 

- Special Studies, l Municipal Sewage 

Evaluation, and Other Sludge. 

Requirements 

Standard Conditions 

The permitting process begins when an application is submitted by the operator 

of a facility. After receiving the application and making a decision to proceed with the 

permit, the permit writer reviews the application for completeness and accuracy. 

When the application is determined to be complete, the permit writer begins to 

develop the draft permit and the justification for the permit conditions (referred to as 

the fact sheet or statement of basis) based, in part, on the application data. 

The first major step in the permit development process is the derivation of 

technology-based effluent limits. Fotlowing this step, the permit writer derives effluent 

limits that are protective of State water quality standards (i.e., water quality-based 

effluent limits (WQBEL)). The permit writer then compares the technology-based limits 

with the WQBELs and applies the more stringent limits in the NPOES permit. The 

24 - 8HYi NPDES Permit Writers’ Manual 
OvervIew of the NPDES Pemdtting Process Chapter 3 

EXHIBIT 3-2 

Major Steps Involved in Developing and Issuing an 

Individual NPDES Permit 

Receive Appkation 

Chapter 4 

Review Application for completeness 

Using applrcation information and 

Chaptar 5 

I 

other dala sources, develop 

technology-based effluent limits I 

# 

r 

Compare between water 

quality-based effluent limits and 

technology-based effluent limits 

for each pollutant and choose 

more stringent of the two 

Chapter 8 

v 

Using application information and 

other data sources, develop water 

quaMy-based effluent limitations 

Develop monitoring requirements 

for each pollutant 

ChapW 9 

Prepare fact sheet and supporting 

documentation I 

Ctlqmll 

I 

Complete the review and 

issuance process I 

4 4 

8EFY4 NPOES Permit Writers’ Manual - 25 
Chapter3 Overview of the NPDES Pemftting Pfmm 

decision-making process for deriving limits is documented in the permit fact sheet. It 

is quite possible that a permit may have limitations that are technology-based for 

some parameters and water quality-based for others. For example, a permit may 

contain an effluent limit for TSS based on national effluent limitations guidelines 

(technology-based), a limit for ammonia based on prevention of aquatic toxicity (water 

quality-based), and a BOD, limit based for part of the year on effluent limitations 

guidelines (technology-based) and for the remainder of the year on water quality 

considerations. 

Following the development of effluent limits, the permit writer develops 

appropriate monitoring and reporting conditions, facility-specific special conditions, and 

includes standard conditions that are the same for atl permits. 

The next step is to provide an opportunity for public participation in the permit 

process. A public notice is issued announcing the permit and interested parties may 

submit comments regarding the draft permit. Based on the comments, the permitting 

authority then finalizes the permit, with careful attention to documenting the process 

and decisions for the administrative record, and issues the final permit to the facility. 

3.4 Overview of the Development/Issuance Process for NPDES 

General Permits 

The process for developing and issuing general NPDES permits is similar to the 

process for individual permits, however, there are certain differences. In the general 

permit development/issuance process, the permitting authority first identifies the need 

for a general permit, and collects data that demonstrate that a group or category of 

dischargers have similarities that warrant a general permit. In deciding whether to 

develop a general permit, permitting authorities should consider the following: 

l Are there a large number of facilities to be covered? 

. Do the facilities have similar production processes or activities? 

. Do the facilities generate similar pollutants? 

. Do only a small percentage of the facilities have the potential for water 

quality standards violations? 

26 - 8B# NPDES Permit Writers’ Manual 
Overvlew of the NPDES Permitting Process Chapter 3 

The remaining steps of the permit process are the same as the individual 

permits. A draft permit and fact sheet are developed, a public notice is issued and 

public comments are addressed, the issues are documented for the administrative 

record, and the final permit is issued. After the general permit has been issued, 

facilities that wish to be covered under the general permit then generally submit a 

Notice of Intent (NOI) to the permitting authority. The permitting authority may then 

either request additional information describing the facility, notify the facility that it is 

covered by the general permit, or require the facility to apply for an individual permit. 

3.5 Roles and Responsibilities of the Federal and State 

Authorities 

EPA is authorized under the CWA to directly implement the NPDES Program. 

EPA, however, may authorize States, Territories, or Tribes to implement all or parts of 

the national program. States, Territories, or Tribes applying for authorization may 

seek the authority to implement the base program (i.e., issue individual NPDES 

permits for industrial and municipal sources), and may seek authorization to implement 

other parts of the national program including, Federal facilities, the national 

pretreatment program, general permits, and/or the municipal sewage sludge program. 

If the State has only partial authority (e.g., only the base NPDES permits program), 

EPA will implement the other program activities (e.g., pretreatment program, Federal 

facilities, and sewage sludge program). For example, where a State has an approved 

NPDES Program but has not received EPA approval of its State sludge management 

program, the EPA Region is responsible for including conditions to implement the Part 

503 Standards for the Use or Disposal of Sewage Sludge in NPDES permits issued to 

treatment works in that State. EPA may issue a separate NPDES permit with the 

applicable sewage sludge standards and requirements, or negotiate with the State on 

joint issuance of NPDES permits containing the Part 503 sewage sludge standards. 

The same process also applies where a State has not received approval of its 

pretreatment program or Federal facilities. One exception to this process is where a 

NPDES-authorized State, Territory, or Tribe is not approved to implement the general 

permit program. In these cases, EPA may not issue a general permit in that State, 

Territory, or Tribe. 

In general, once a State, Territory, or Tribe is authorized to issue permits, EPA 

is prohibited from conducting these activities. However, EPA must be provided with 

BEPA NPDES Permit Writers’ Manual - 27 
Overvlew of the NPDES Pennittlng Process Chapter 3 

an opportunity to review each permit issued by the State, Territory, or Tribe and may 

formally object to elements that conflict with Federal requirements. If the permitting 

agency does not address the objection points, EPA will issue the permit directly. 

Once a permit is issued through a government agency, it is enforceable by the 

approved State, Territorial, and Federal agencies (including EPA) with legal authority 

to implement and enforce the permit, and by private citizens (in Federal court). 

28 - MfM NPDES Permit Writers’ Manual 
Chapter 4 

The Permit Application 

Process 

This chapter describes the NPDES permit application process including the 

permit writer’s role in reviewing the application and evaluating background information 

about the applicant. Through this process, the permit writer gains an understanding of 

the circumstances of the discharge and the characteristics of the proposed effluent 

that will allow proper development of permit limits and conditions. 

4.1 NPDES Permit Application Forms 

When it is determined that a facility needs an individual NPDES permit, the 

facility must submit an application for a permit. Application forms and requirements 

are specific to the type of facility and discharge. NPDES permit application regulations 

are contained in 40 CFR Part 122, Subpart B. Most application requirements are 

contained in forms developed by EPA. Exhibit 4-1 provides an overview of the types 

of dischargers required to submit NPDES application forms, identifies the form(s) that 

they must submit, and references the corresponding NPDES regulation citation. It 

should be noted that authorized States are not required to use the EPA application 

forms. However, any alternative form used by an authorized State must contain the 

information required in 40 CFR Part 122, Subpart B. An application form must also be 

submitted for permit renewals. Permits may no longer be renewed by submitting a 

EPA NPDES Permit Writers’ Manual - 29 
The Permit Application Process Chapter 4 

EXHIBIT 4-1 

Applications Forms Required for NPDES Discharges 

Regulatory 

Citation 

Type of Facility Status Forms (40 CFR Part 122) 

All NPDES Applicants (except MS4s) New and 

Existing Form 1 122.21(f) 

Municipal Facilities 

- Major POTWs (Facilities with flows 

greater than 1.0 mgd or populations New and Standard 122.21(j) 

greater than 10,000, or receive Existing A (reserved) 

industrial process wastewater) 

- Minor POTWs 

Industrial Facilities 

- Manufacturing Facilities 

- Commercial Facilities 

- Mining Activities 

- Silvicultural Activities 

- Water Treatment Facilities 

Concentrated Animal Production 

Facilities 

- Animal Feedlots 

- Hatcheries 

New and 

Existing 

New 

Existing 

Short A 

2D 

2c 

Non-Process 2E 

Wastewater 

New and 

Existing 2B 

122.21(j) 

(reserved) 

122.21(f) and (k) 

122.21(f) and (g) 

122.21(f) and (h) 

122.21(f) and 

122.21(i) 

Storm water discharges associated with 

industrial activities 

New and 

Existing 2F 122.26(c) 

Storm water discharges from MS4s 

serving a population greater than 

100,000 

New and 

Existing None 122.26(d) 

Key: Form 1 - General information. 

Standard Form A - Municipal (new and existing major municipal facilities). 

Short Form A - Municipal (new and existing minor municipal facilities). 

Form 2B - Concentrated Animal Feeding Operations and Aquatic Animal Production Facilities. 

Form 2C - Existing Manufacturing, Commercial, Mining, and Silvicultural Operations. 

Form 2D - New Sources and New Dischargers Application for Permit to Discharge Process Wastewater. 

Form 2E - Facilities Which Do Not Discharge Process Wastewater. 

Form 2F - Application for Permit To Discharge Storm Water Discharges Associated With Industrial 

Activity. 

30 - EPA NPDES Permit Writers’ Manual 
The Permit Application Process Chapter 4 

letter stating that no significant changes occurred at the facility during the term of the 

expiring permit. 

Form 1 - General Information 

All facilities applying for an individual NPDES permit, with the exception of 

MS4s applying for a municipal storm water permit, must submit Form 1. Form 1 

requires general facility information including: 

. Name, mailing address, facility contact, and facility location 

l Standard industrial classification (SIC) code and a brief description of 

nature of business 

l Topographic map showing the location of the existing or proposed intake 

and discharge structures. 

4.1.1 Municipal Application Requirements (Form A and Short Form A) 

Ail new and existing POTWs must submit Form A or Short Form A (used for 

minor POTWs). POTWs with design infiuent flows equal to or greater than 1 million 

gallons per day (mgd) and POTWs with approved pretreatment programs, or POTWs 

required to develop a pretreatment program are required to submit Form A. Form A 

requires submission of the following types of information: 

. Name, mailing address, authorized agent, and facility location 

l Collection system type, areas served, and total population served 

. Description of influent, including major industrial facilities discharging to the 

system 

. Description of treatment practices and plant design, schedule of 

improvements, number of discharge points, total volume discharged, and 

receiving water name. 

Although testing of the infiuent and effluent for specific pollutants is not 

required, Form A does request any available data on the following parameters: flow, 

pH, temperature, fecal coliform, BOD,, COD or total organic carbon (TOC), total 

residual chlorine, total solids, total dissolved solids, settleable matter, ammonia, 

Kjeidahl nitrogen, nitrate, nitrite, phosphorus, and dissolved oxygen. The municipal 

application regulations also require POTWs with design infiuent flows equal to or 

&EM NPDES Permit Writers’ Manual - 31 
The Permit Applhtion Process Chapter 4 

greater than 1 .O mgd, and POTWs with approved pretreatment programs, to submit 

results of whole effluent toxicity (WET) testing (40 CFR 9122,21(j)(l)). In addition, 

PO7Ws with approved pretreatment programs are also required to submit a written 

technical evaluation of the need to revise local limits (40 CFR 5122.21(j)(4)). 

POTWs with design flows of less than 1 .O mgd, and which are not required to 

have an approved pretreatment program, may generally use Short Form A. Short 

Form A requires only general information such as the name, mailing address, and 

facility location as well as a description of any major changes at the facility. 

Reg Update: 

On December 6, 1995, EPA proposed revisions to the municipal application requirements and 

accompanying application forms [60 FR 625451. The proposed regulation replaces Form 1, Form A, and 

Short Form A with a new Form 2A for use by all municipal dischargers. Form 2A is divided into five 

individual sections that must be completed depending on the characteristics of the municipal discharger. 

In the same proposal, EPA introduced Form 2s to obtain information on municipal sewage sludge such 

as volume, characteristics, and sludge use or disposal practices. The Form 2S regulations will replace 

the interim sludge use and disposal application requirements that are currently in use. 

4.1.2 Non-Municipal Permit Application Requirements 

in addition to Form 1, which requests general information, non-municipal 

dischargers applying for an individual NPDES permit are required to submit additional 

detailed facility information. The types of forms required depend upon the activities of 

the facility applying for a permit. Each of the forms and the types of activities for 

which they apply are briefly described below. 

Form 2B - New and Existing Animal Feeding Operations and Aquatic Animal 

Production Facilities 

Owners of new and existing animal feeding operations and aquatic animal 

production facilities must submit Application Form 28. The types of information 

required by Form 2B include: 

l Animal feeding operations 

- Type and number of animals in open confinement and housed under 

roof 

- Number of acres used for confinement feeding 

32 - 8ER9 NPDES Permit Writers’ Manual 
The Permit Application Process Chapter 4 

- Calendar month of maximum feeding and total mass of food fed during 

that month 

l Aquatic animal production facilities 

- Maximum daily and average monthly flow from each outfall 

- Number of ponds, raceways, and similar structures 

- Total yearly and maximum harvestable weight for each species of 

aquatic animal. 

Form 2C - Existing Manufacturing, Commercial, Mining, and Silvicultural 

Discharges 

Operators of existinq (i.e., currently pemritted) manufacturing, commercial, 

mining, and silvicultural discharges must submit Application Form 2C. The types of 

information required in Form 2C include: 

l Outfall location(s) 

. Flow characteristics 

l Sources of potlutants 

l tntake and effluent characteristics 

. Pollutants expected to be present 

. Treatment technologies 

l Production information (if applicable). 

Quantitative effluent data requirements for existing industrial dischargers varies 

depending on the facility’s discharge characteristics and the types of pollutants 

expected to be present in the discharge. 

Form 20 - New Manufacturing, Commercial, Mining, and Silvicultural Discharges 

Operators of new manufacturing, commercial, mining, and silvicultural 

discharges must submit Application Form 20. “New” dischargers are those that have 

not previously obtained permits for a discharge and have not commenced operation. 

The types of information required in Form 2D include: 

0 Expected outfall location(s) 

. Date of expected commencement of discharge 

0ER9 NPDES Permit Writers’ Manual - 33 
The Permit Application Process Chapter 4 

. Expected flow characteristics 

l Sources of pollutants 

l Treatment technologies 

. Production information (if applicable) 

. Expected intake and effluent characteristics. 

Form 2E - Manufacturing, Commercial, Mining, and Silvicultural Facilities that 

Discharge Only Nonprocess Wastewater 

Operators applying for an individual NPDES permit for manufacturing, 

commercial, mining, and silvicultural facilities that are not regulated by an effluent 

limitation guideline or new source performance standard, and which discharge only 

non-process wastewaters, must submit Application Form 2E. “Nonprocess 

wastewaters” include sanitary wastes, restaurant or cafeteria wastes, and non-contact 

cooling water, but do not include storm water. Storm water is specifically excluded 

from the definition of “non-process wastewater.” The types of information required in 

Form 2E include: 

l Outfall location(s) 

. Type of waste discharged 

. Effluent characteristics, including quantitative data for selected parameters 

. Flow characteristics 

. Treatment technologies. 

Form 2F - Storm Water Discharges Associated with Industrial Activities 

Operators applying for an individual NPDES permit for discharges of storm 

water associated with industrial activity must submit Application Form 2F. The types 

of information required in Form 2F include: 

l A topographic map and estimates of impervious surfaces 

. Descriptions of material management practices and control measures 

l A certification that outfalls have been evaluated for non-storm water 

discharges 

l Descriptions of past leaks and spills 

0 Analytical data from each outfall for several specified parameters. 

34 - 88# NPDES Permit Writers’ Manual 
fhe Permit Application Process Chapter 4 

Storm Water Discharges from Municipal Separate Storm Sewers Serving a 

Population of Greater Than 100,000 

The 1990 Storm Water application regulations (55 Ff? 48062), list the 

application requirements for operators of a large or medium MS4 to submit a two-part 

application. Part 1 application information was required to be submitted by large 

MS4s (serving a population >250,000) by November 18, 1991 and by medium MS4s 

(serving a population >lOO,OOO but < 250,000) by May 18, 1992. Part 2 application 

information was required to be submitted by large MS4s by November 16, 1992 and 

by medium MS4s by May 17, 1993. The following summarizes the key requirements 

of each part of the application: 

. Part 1 of the application must include: 

- General information (e.g., name, address) 

- Existing legal authorities and any additional authority required 

- Source identification information 

- Discharge characterization, including results from dry weather flow 

screening 

- Identification of 5 to 10 representative outfails for storm water sampling 

- Description of existing storm water management practices 

- Descriptions of existing financial budget and resources available to 

complete Part 2 of the application. 

. Part 2 of the application must include: 

- Demonstration of adequate legal authority 

- Identification of any major storm sewer outfalls 

- Discharge characterization data from sampling three representative 

storm events 

- Proposed storm water management program 

- Assessment of controls, including expected reductions in pollutant 

loadings 

- Fiscal analysis, including necessary capital and operation and 

maintenance expenditures for each year of the permit. 

Under the NPDES regulations, permittees are required to reapply for a new 

NPOES permit prior to the expiration of their existing permit. However, in the case of 

storm water permits for MS4s, Part 1 and Part 2 application requirements were 

intended only for the initial issuance of a MS4 permit and specific requirements for 

reapplication have not been defined in the regulations. On May 17, 1996, EPA issued 

8ep# NPDES Permit Writers’ Manual - 35 
fhe Permit Application Process Chapter 4 

a policy which sets forth a streamlined approach for reapplication requirements for 

operators of MS4s. tt allows municipalities to use recommended changes submitted in 

their fourth annual report as the principal component of their reapplication package. It 

also encourages changes to monitoring programs to make them appropriate and 

useful to storm water management decisions. With the policy, EPA seeks to improve 

municipal storm water management efforts by allowing municipalities to target their 

resources for the greatest environmental benefit. 

4.1.3 Application Requirements for NPDES General Permits 

As previously discussed, general permits (see 40 CFR 5122.28) are permits 

that are developed for storm water dischargers or a specific category of dischargers 

within a specified geographic or political boundary. The use of a general permit may 

simplify the permitting process for both EPA and the permittee. Unlike individual 

permits, however, operators can only apply for coverage under a general permit if one 

has been issued that is applicable to the type of facility for which coverage is sought 

and covers the facility’s activities. In addition, the permitting authority may determine 

that a general permit is not appropriate for a particular facility applying for coverage 

under the general permit, and can require the facility to apply for an individual permit. 

Furthermore, a facility that otherwise qualifies for a general permit may opt to apply for 

an individual permit. 

An applicant for a general permit, in almost all cases, must apply by submitting 

a Notice of Intent (NOI) to be covered under the permit. The contents of a NOI, and 

any additional information requirements, must be specified in the general permit and in 

the fact sheet or instructions, and at a minimum must include the following: 

. Name and address of the owner or operator 

. Name and address of the facility 

. Type of facility or discharges 

. The receiving stream(s). 

4.2 Application Deadlines 

The Federal regulations contained in 40 CFR $122.21 require that applications 

for new discharges be made no later than 180 days before discharges actually begin. 

36 - 88# NPDES Permit Writers’ Manual 
The Permit Application Process Chapter 4 

Appkations for permit renewals (Le., for existing dischargers) must be made at least 

180 days before the expiration of the existing NPDES permit. Authorized states, 

however, may have slightly different schedules but generally no less stringent. 

Furthermore, the State Director or the Regional Administrator may allow individual 

applications to be submitted at dates later than these but not later than the expiration 

date of the existing permit. 

It should be noted that according to 40 CFR 9122.6, an expired NPDES permit 

remains in effect until the new permit is issued as long as the application for permit 

renewal was submitted on time and complete (per 40 CFR 5122.21). However, if 

State law does not allow expired permits to remain in effect until a permit is reissued, 

or if the permit application is not on time and complete, the facility is considered to be 

discharging without a permit from the time the permit expired until the effective date of 

the new permit. 

4.3 Review of the Application 

The contents of individual NPDES permits are based in par? upon the 

information included in the application. Thus, the application must be complete and 

accurate before a permit writer can properly develop a permit. Exhibit 4-2 depicts a 

general process for reviewing a permit application. 

After the initial review of an application, the permit writer may request that an 

applicant submit other information which may be needed in deciding whether to issue 

a permit. The requested information may include: 

. Additional information, quantitative data, or recalculated data 

l Submission of a new form (if an inappropriate form was used) 

. Resubmission of application (if incomplete or outdated information was 

initially submitted). 

A considerable amount of correspondence, therefore, may be required before the 

permit writer obtains an application that can be considered complete and accurate. 

BEPA NPDES Permit Writers’ Manual - 37 
The Permit Applhtion Process Chapter 4 

Review Activities 

EXHIBIT 4-2 

Permit Application Review 

1 Review Permit+AppIication 1 

* 

Is the application on 

the correct form? 

1 \ 

No 

w 

Does the application include 

all outfalls, priority pollutant, sludge 

and toxicity data when required? 

No 

w 

Applicant Follow-Up * 

l (as necessary) 

Require new application on 

correct form 

Establish schedule for submittal of 

required information 

I 

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? 

No Establish schedule for submittal of 

required information 

L 

Are all calculation and flow 

diagrams correct 

May begin public notice of 

application now or after 

facility inspection 

Request recalculation and resubmittat I 

38 - 8Ef# NPDES Permit Wrfters’ Manual 
The Permit Applhtion Process Chapter 4 

4.3.1 The Complete Application 

Regulations under 40 CFR 5122.21 (e) state that the Director “shall not issue a 

permit before receiving a complete application....” At a minimum, the application form 

must have all applicable spaces filled in. Instructions for the apptication form states 

that all items must be completed and that the statement “not applicable” (NA) be used 

to indicate that the item had been considered by the applicant. Blanks on a form can 

occur for a number of reasons, such as: 

l The response was inadvertently left out; or 

l The applicant had difficulty determining the correct response and rather 

than provide misleading or incorrect information, left the space blank. 

A response to the blank items must be obtained by contacting the facility in 

writing or, in some cases, by telephone. Because of the administrative record 

(discussed in Chapter 11) that must be maintained in processing an application, and 

the possibility of legal challenges regarding permit decisions, it is recommended that 

only minor items be handled by telephone, and even these should be documented in 

writing. 

If the changes or corrections to any application are extensive, the permit writer 

may require the permit applicant to submit a new application. Supplementary 

information, such as more detailed production information or maintenance and 

operating data for a treatment system, may also be required to process the permit. 

Supplementary information can also be obtained at a later date when the permit writer 

is actually drafting the permit. According to 40 CFR 5122.21(e), an application is 

considered to be complete when the permit writer is satisfied that all required 

information has been submitted. 

4.3.2 Common Omissions and Errors in Applications 

This section identifies some of the most common omissions and errors found in 

NPDES permit applications. Examples of ways to identify missing information and of 

verifying the accuracy of some of the data are also provided. 

One of the most common items overlooked is the provision of a topographic 

map which is required as an attachment to Form 1. Other industrial or municipal8EFY4 NPDES Permit Writers’ Manual - 39 
The Permit Applhtion Process Chapter 4 

specific information is also often omitted. For example, industrial applicants 

sometimes fail to submit a process line diagram required by Part II-A of Form 2C. 

The process line diagram is important for ensuring that the location and description of 

the outfalls and the description of processes (Parts I and 11-B of Form 2C) given by the 

applicants are accurate. 

Often, applicants do not properly submit the effluent characterization data 

required for the permit applications. Applicants may fail to submit data necessary to 

properly characterize the facility. The following highlights some of the data 

requirements that are required in applications: 

. POTWs with design flows greater than 1 mgd or those with a pretreatment 

program are required to submit valid WET testing data. This requirement 

may be satisfied if the expiring permit contains a requirement for effluent 

characterization of WET. The permit writer should note the use of this 

option on the fact sheet. 

l POTWs and other treatment works treating domestic sewage (TWTDS) 

must submit any sludge monitoring data; a description of sludge use and 

disposal procedures at the facility; annual sludge production volumes; and 

for land application sites, information on the suitability of the site and a 

description of the site management. A land application plan is required for 

any sites not identified in the application. 

. Every non-POTW applicant must submit data for BOD, -COD, TOC, TSS, 

ammonia, temperature (winter and summer), and pH. 

. Non-municipal dischargers categorized as “primary industries” have some 

mandatory testing requirements for toxic pollutants (see 40 CFR 5122.21, 

Appendix D, Table I and Table II; also listed in Application Form 2C). 

Primary industries are identified in Appendix A of 40 CFR Part 122. 

Primary industries that are also small businesses [see 40 CFR 

$122.21 (g)(8)] may be exempted from these testing requirements. Existing 

dischargers who believe certain pollutants may be present in their effluent 

must test for those pollutants (40 CFR s122.21 Appendix D, Table IV and 

Table V). 

. Industrial facilities that are subject to production- or flow-based effluent 

guidelines must report production rates and flow data, using units of 

measure corresponding to applicable effluent limitations guidelines, that will 

allow calculation of effluent limits. 

l Sample types for all required pollutants and parameters must be 

appropriate for the parameter being analyzed (as per 40 CFR Part 136; see 

Sections 7.1.3 and 7.1.4 for more information). For example, only grab 

samples may be used for pH, temperature, cyanide, total phenols, volatile 

$0 - 8EW NPDES Permit Writers’ Manual 
The Permit Applhtion Process Chapter 4 

organics, residual chlorine, oil and grease, fecal coliform, and fecal 

streptococcus. 

Examples of the types of data that the permit writer will need to obtain before 

the application can be considered complete are given in the text boxes which follow. 

Are required toxic organic pollutants (gas chromatograph/mass spectrometer [GCIMS] fractions) listed? 

Example: 

An application from a plastics processor fails to list any GWMS fraction. 

Discussion: 

The plastics processor is required to test for the volatile GUMS fraction (Table 2C-2 in the application 

form instructions and 40 CFR §122.21(g)(7)(ii)(A) of the NPDES regulations). 

Are required heavy metals listed? 

Example: 

A primary felt producer marks thallium and beryllium as believed absent in the wastewater. 

Discussion: 

Although thallium and beryllium are not expected to be found in a felt producer’s discharge, page ZC-3 of 

the application form instructions and 40 CFR 9122.21 (g)(7)(ii)(B) require testing for these metals. 

Occasionally, unexpected contaminants will be present in a waste stream due to poor housekeeping, 

unusual production methods, etc. 

The comprehensive testing requirements that apply to the various categories of industry are designed to 

determine whether any unexpected contaminants are present in significant quantities, as well as to 

determine levels of pollutants that are known to be present. In the above example, the submission is 

incomplete because additional information is needed and “believed absent” is wrongly indicated. 

Are all expected pollutants listed? 

Example: 

A producer of wood-resin-based derivatives does not indicate the presence of zinc in his wastewater. 

Discussion: 

Testing for zinc is required. Zinc is used as a catalyst in the production of wood-resin-based derivatives. 

This type of information can be found in the effluent limitations guidelines development documents. 

&EM NPDES Permit Writers’ Manual - 41 
The Permit Applhtion Process Chapter 4 

What pollutant data are needed to characterize the industries above? 

Example: 

Consider the plastics processor, the felt producer, and the producer of wood-resin-based derivatives, 

mentioned above, and answer the following questions: 

. ‘For which toxic organic pollutants are they required to test? 

. For which heavy metals are they required to test? 

. Which metals would you expect to find in their wastewaters regardless of whether testing is 

required or not? 

Discussion: 

The application form in Table 2C-2 and 40 CFR @22.21(g)(7)(ii)(A) of the NPDES regulations require 

testing of the volatile GCMKi fraction by the plastics processor, and testing of all four GC/MS fractions by 

the felt producer and the producer of wood-resin-based derivatives. Page 2C-3 of the application 

instructions and 40 CFR 9122.21 (g)(7)(ii)(B) require testing of all of the metals listed in item V part Cl of 

the application form by all three manufacturers. For the expected metals, see the effluent limitations 

guidelines development documents for information. 

1.3.3 The Accurate Application 

All information submitted on a permit application should be accurate, in addition 

to being complete. Although it may be difficult to detect certain inaccuracies, a 

number of common mistakes can be readily detected. When mistakes are detected, 

they must be corrected. The permit writer should follow the same procedures for 

correcting inaccurate information as used for obtaining missing information. The 

following text boxes contain examples that reflect the types of questions that the 

permit writer may consider while reviewing the permit application. 

Can we verify flow data using a water balance calculation? 

Example: 

An industrial user has estimated a wastestream flow of 50,000 gpd using water usage records. However, a 

review of historical water usage records and an old permit application indicates wastewater flows ranged 

from 100,000 to 150,000 gpd. The facility had not instituted any water-reduction measures, significantly 

changed its process operations, or decreased its number of employees. 

I Discussion: 

An inspection of the facility revealed two separate water meters (one for sanitary and one for process water); 

the industrial user had overlooked the sanitary meter. Further, the process water meter was found to be 

defective. Subsequent flow monitoring of the total wastestream recorded a flow of 125,000 gpd. A new 

water meter was installed and concurrent wastestream flow monitoring and water meter readings resulted in 

the following water balances: 

. Water In (based on both water meter readings): 

17,000 gpd sanitary line) 

148,000 gpd (131,000 gpd process line and 

. Water Out (based on wastestream flow monitoring): 125,000 gpd total wastestream 

discharged to sewer system. Evaporative and consumption losses were estimated at 23,000 

gpd (15 percent of total water usage). 

42 - 8EfR NPDES Permit Writers’ Manual 
The Permit Applhtion Process Chapter 4 

Do the concentration, mass, and flow values correspond? 

Example: 

Suppose the maximum daily flow is shown as 1.2 million gallons per day (MGD), the maximum daily 

suspended solids concentration is 23 milligrams per liter (mg/l), and the maximum daily mass discharge 

is reported as 690 pounds per day (Ibs/day). 

23 mg/f x 8.34 x 1.2 MGD = 230 lb/d 

The mass corresponding to the solids concentration (23 mg/l) and flow (1.2 MGD) is 230 pounds per day. 

However, the maximum daily mass discharge is 690 pounds per day. 

Discussion: 

Assuming that the maximum daily flow and the maximum daily concentration occurred on the, same day 

(worst case scenario), the highest mass discharge should not exceed 230 pounds per day. Since the 

applicant reported a maximum mass discharge of 690 pounds per day, a significant discrepancy is 

indicated. The permit writer should contact the facility to resolve the discrepancy. 

Do concentration values correspond with analytical detection limits? 

Example: 

The acid GUMS fraction (phenols) compounds are all reported as less than 1 mgll. 

Discussion: 

According to 40 CFR Part 136, the detection limits for the compounds in this organic fraction are all near 

0.01 mg/l. Probably the 4AAP method for phenols was used, rather than the required testing procedure 

using GCYMS. 

4.4 Facility Information Review 

In addition to the submitted application form, the permit writer should consider 

collecting other information that could be utilized for development of permit limits and 

conditions. 

4.4.1 Background Information Review 

Prior to developing permit conditions, the permit writer should collect and review 

any additional background information on the facility. Much of this information may 

already be available in the permit file. In-house file information typically includes: 

l The current permit 

l The fact sheet or statement of basis for the current permit 

8EF# NPOES Permit Writers’ Manual - 43 
The Permit Applhtion Process Chapter 4 

. Discharge Monitoring Reports (DMRs) 

l Compliance inspection reports 

. Engineering reports 

l Correspondence or information on changes in plant conditions or problems, 

and compliance issues. 

Much of this information, particularly DMR data, may be already stored in an 

interoffice automated data tracking system such as the EPA Permit Compliance 

System (PCS). 

The permit writer may check with other permit writers who have permitted 

similar types of facilities to see if there are any special considerations related to the 

facility to be permitted. A permit writer also may wish to discuss compliance issues, 

changes, or history of complaints with compliance personnel who conducted previous 

inspections of the facility. Examples of some other sources of information that could 

be used by the permit writer include: 

. EPA development documents that contain detailed information that was 

collected by the EPA for the purpose of developing effluent guidelines and 

categorical pretreatment standards for a variety of industrial categories 

. Reference textbooks, which address specific industry categories and which 

are available from the National Technical Information Service (NTIS), United 

States EPA library and other libraries. These technical documents provide 

information about manufacturing processes and wastestreams. 

. EPA’s Treatability Man~a/,~ which is a five-volume guidance (also refer to 

glossary) and which provides detailed descriptions of industrial processes, 

potential pollutants from each process, appropriate treatment technologies, 

and cost estimating procedures 

. Receiving water quality data (e.g., the EPA Storage and Retrieval data 

base [STORETj) 

l Related environmental permits that could provide site-specific background 

information about the types of pollutants and wastestreams at a facility, 

including, for example: 

- RCRA permit-which regulates the management of hazardous waste 

from its generation through ultimate disposal for waste generators, 

3USEPA (1980). Treatability Manual, Volumes I - K EPA-600/8-80-042a-e. Office of Research 

and Development. 

44 - &EW NPOES Permit Writers’ Manual 
The Permit Applhtion Process Chapter 4 

transporters, and owners and operators of treatment, storage, and 

disposal facilities [42 USC 6901 et seq.1 

- Clean Air Act permit-which regulates the discharge of atmospheric 

pollutants. 

. The Toxic Release Inventory (TRI), which is accessible on EPA’s 

mainframe and through a public online service. TRI contains facility 

information on over 300 listed toxic chemicals released by specific facilities, 

including chemical identification, quantity of chemical released to various 

environmental media, offsite waste transfer and waste treatment and 

minimization information. 

If the permit writer must address special conditions in the permits for municipal 

dischargers for development or implementation of a pretreatment program, combined 

sewer overflows (CSOs), sanitary sewer overflows (SSOs), sewage sludge use or 

disposal, or storm water discharges, information relevant to these issues would need 

to be obtained. Such information may be found in: 

l Annual pretreatment reports, pretreatment compliance inspections and 

audits 

l CSO reports 

l Bypass notifications or SSOs reports 

l Storm water discharge applications or NOI for a general permit. 

4.4.2 Facility Site Visits 

Facility site visits can be invaluable to update information on manufacturing 

processes, obtain information about the facility’s operations, equipment or 

management, and to verify application information. A site visit also acquaints the 

permit writer with the people who will be operating under the permit and participating 

in the permit development process. 

Site visits may also allow the permit writer to gain a better understanding of 

more complex facilities. Site visits are especially warranted if significant pollution 

control or treatment improvements will be required, if there have been frequent 

problems in complying with the present permit, if there are known problems with spills 

or leaks or with contaminated surface runoff, or if there are other onsite activities that 

may impact the characteristics of the discharge from the facility. 

iiEpA NPOES Permit Writers’ Manual - 45 
The Permit Application Process Chapter 4 

The site visit should include a detailed review of production processes in order 

to evaluate the types of toxic or hazardous substances that may be present in raw 

materials, as well as in products and byproducts. The water uses, the resulting 

wastewater streams, and any in-process pollution controls should be reviewed. This 

review is needed to assist in selecting toxic and other pollutants to be limited and in 

evaluating possible in-process control improvements. 

In addition, the site visit should include a review of the performance, operation 

and maintenance practices of wastewater treatment facilities. This review is useful in 

evaluating the adequacy of existing treatment performance and assessing the 

feasibility of improvements and performance. Effluent monitoring points, sampling 

methods, and analytical techniques should also be examined to identify any needed 

changes to monitoring requirements and to evaluate the quality of DMR data. 

Raw material and product storage and loading areas, sludge storage and 

disposal areas, hazardous waste management facilities, including onsite disposal 

areas, and all process areas should be observed to determine the need for controls on 

surface runoff and for specific best management practices (BMPs). As noted 

previously, the information from other environmental programs (e.g., Comprehensive 

Environmental Response, Compensation, and Liabilities Act [CERCLA]; RCRA) may 

be important in this regard. 

While onsite, the permit writer should note any needs for spill prevention and 

housekeeping problems, which are not usually well-described in permit applications. If 

allowed, photographs of problem areas should be taken for future use during permit 

preparation. A meeting with management should be included if necessary to ask 

questions and clarify information on the permit application. If any inaccuracies in the 

application were found as a result of the site visit, corrected information should be 

requested at this time. 

The time required to conduct a site visit will vary according to the complexity of 

the facility. For facilities with only a few basic processes, one main waste treatment 

system, limited in-process controls, few surface runoff outfalls, and limited onsite 

management of sludges or hazardous wastes, an adequate site visit can most likely 

46 - 8El3l NPOES Permit Wrfters’ Manual 
The Permit Application Process Chapter 4 

be completed in 1 day. Complex, larger plants with several treatment systems, 

numerous outfalls, and extensive ancillary activities may require several days. 

Time spent on site visits often results in time savings during permit preparation. 

However, time and/or travel resources are generally not adequate to allow viewing of 

all facilities to be permitted. In such cases, the permit writer may be able to obtain 

much of the desired information from the next {or previous) compliance inspection 

performed at the facility. 

Aerial photographs are also an excellent aid for conducting a plant visit and 

may provide much of the needed information on the potential for contamination of 

surface runoff and on ancillary activities in the absence of a site visit or inspection. In 

addition, comparison of aerial photographs with site and process diagrams provided 

with the application may provide the permit writer with a complete visual description of 

the facility. Aerial photographs may be obtained from a variety of sources, including 

the United States Geological Survey (USGS), Environmental Services Division in some 

EPA Regions, the National Enforcement Investigation Center, Las Vegas, Nevada; the 

Environmental Photo Interpretation Lab, Vint Hill, Virginia; and private contractors. 

4.5 Confidential Information 

In accordance with 40 CFR Part 2, information submitted to EPA pursuant to 

the NPDES permitting regulations under 40 CFR Part 122 may be claimed as 

confidential by the submitter. However, EPA has determined that the following 

information will not be held confidential: 

. Name and address of the applicant 

. Permit applications and information submitted with applications 

. Permits 

. Effluent data. 

Any claims of confidentiality must be made at the time of submission or the 

information will not be considered confidential. 

Information that may be treated as confidential includes material related to 

manufacturing processes unique to the applicant, or if such information might 

8Ep# NPDES Permit Wrlters’ Manual - 47 
fhe Permit Application Process Chapter 4 

adversely affect the competitive position of the applicant if released to the public. 

Under these circumstances, the permit writer will be required to treat the information 

as confidential in accordance with the requirements in 40 CFR Part 2. 

48 - 8BY4 NPDES Permit Writers’ Manual 
Chapter 5 

Technology-Based Effluent 

Limits 

When developing effluent limits for a NPDES permit, a permit writer must 

consider limits based on both the technology available to treat the pollutants (i.e., 

technology-based effluent limits), and limits that are protective of the designated uses 

of the receiving water (water quality-based effluent limits). This chapter discusses 

considerations for deriving technology-based effluent limitations for both non-municipal 

(i.e., industrial) and municipal discharges. 

There are two general approaches for developing technology-based effluent 

limits for industrial facilities: (1) using national effluent limitations guidelines (ELGs) 

and (2) using Best Professional Judgment (BPJ) on a case-by-case basis (in the 

absence of ELGs). Technology-based effluent limits for municipal facilities (POTWs) 

are derived from secondary treatment standards. The intent of a technology-based 

effluent limitation is to require a minimum level of treatment for industrial/municipal 

point sources based on currently available treatment technologies while allowing the 

discharger to use any available control technique to meet the limitations. 

For industrial sources, the national ELGs are developed based on the 

demonstrated performance of a reasonable level of treatment that is within the 

EPA NPDES Permit Writers’ Manual - 49 
Chapter 5 Technology-Based Effluent Limits 

economic means of specific categories of industrial facilities. Where national ELGs 

have not been developed, the same performance-based approach is applied to a 

specific industrial facility based on the permit writer’s BPJ. In some cases, effluent 

limits based on ELGs and BPJ (as well as water quality considerations) may be 

included in a single permit. 

5.1 Application of Technology-Based Effluent Limitations for 

Non-Municipal Dischargers 

When developing technology-based effluent limitations for non-municipal 

dischargers, the permit writer must consider all applicable standards and requirements 

for&l pollutants discharged. As indicated above, applicable technology-based 

requirements may include national standards and requirements applicable to all 

facilities in specified industrial categories, or facility-specific technology-based 

requirements based on the permit writer’s BPJ. It is important, therefore, that permit 

writers understand the basis of the national standards and the differences between the 

various required levels of treatment performance. This section describes the statutory 

and regulatory foundation of the performance-based standards, and discusses 

considerations in the application of these standards for non-municipal dischargers. 

5.1.1 Statutory and Regulatory Foundation 

Originally, the Federal Water Pollution Control Act amendments of 1972 

directed EPA to develop standards of performance (effluent limitation guidelines) for 

industrial categories. Specifically, for “existing” industrial dischargers, the Act directed 

the achievement: 

“...by July 1, 1977, of effluent limitations which will require application of 

the best practicable control technology currently available [BPT], and by 

July 1, 1983, of effluent limitations which will require application of the 

best available technology economically achievable [BAT].” 

EPA defined BPT performance as the “average of the best existing performance by 

well operated plants within each industrial category or subcategory.” The BAT level of 

performance was defined as the “very best control and treatment measures that have 

been or are capable of being achieved.” The 1972 amendments, however, made no 

distinction regarding the application of BPT or BAT to different types of pollutants (i.e., 

50 - EPA NPDES Permit Writers’ Manual 
Chapter 5 Technology-Based Effluent Limits 

BPT and BAT applied to all pollutants). The CWA did provide additional guidance for 

determining the economic achievability of BPT and BAT, The BPT standards required 

that effluent limits be justified in terms of the “total cost of [industry wide] application of 

the technology in relation to the effluent reduction benefits to be achieved.” Thus, 

BPT required EPA to consider a cost-benefit test that considered a broad range of 

engineering factors relating to a category’s ability to achieve the limits. For BAT, the 

Agency must still consider the cost of attainability, however, it is not required to 

balance cost against the effluent reduction benefit. 

In addition to BPT and BAT requirements, Section 306 of the 1972 

amendments established more restrictive requirements for “new sources.” EPA has 

defined “new source” as any facility that commenced construction following the 

publication of the proposed standards of performance. The intent of this special set of 

guidelines is to set limitations that represent state-of-the-art treatment technology for 

new sources because these dischargers have the opportunity to install the latest in 

treatment technology at the time of start-up. These standards, identified as new 

source performance standards (NSPS), are described as the best available 

demonstrated control technology, processes, operating methods, or other alternatives 

including, where practicable, standards permitting no discharge of pollutants. NSPSs 

are effective on the date of the commencement of a new facility’s operation and the 

facility must demonstrate compliance within 90 days [see 40 CFR $122.29(d)]. A 

major difference between NSPS and either BPT or BAT, is the absence of the kind of 

requirements for a detailed consideration of costs and benefits when establishing the 

technology requirements. 

As noted above, the 1972 amendments tasked EPA with developing ELGs 

representing application of BPT, BAT, and NSPS; however, EPA was unable to 

complete development of all effluent guidelines within the statutory deadlines. In 

addition, EPA did not fully address toxic discharges in the guidelines it did promulgate. 

As a result, EPA was sued by several environmental groups for failing to accomplish 

the promulgation of effluent guidelines as directed by the 1972 amendments. As a 

consequence of the suit, EPA and the environmental groups entered into a settlement 

agreement that required EPA to develop a program and adhere to a schedule for 

promulgating BAT effluent guidelines, pretreatment standards, and NSPSs (NRDC v. 

Train, 1976). The standards focused on 65 toxic “priority pollutants” (including classes 

8i3Y4 NPDES Permit Writers’ Manual - 51 
Chapter 5 Technology-Based Effluent Limits 

of pollutants) for 21 major categories of industries (known as “primary” industries). 

This settlement was incorporated in the 1977 amendments to the Act. This settlement 

was further amended to include a total of 34 major categories of industries and 129 

priority pollutants (NRDC v. Costle, March 1979). [Note: The list of priority pollutants 

was subsequently revised to include 126 specific parameters which are listed in 

Appendix A of 40 CFR 5423.1 

In light of the settlement agreement, the 1977 amendments to the Federal 

Water Pollution Control Act (renamed the Clean Water Act [CWA]) revised the scope 

and application of BAT requirements to focus solely on toxic and nonconventional 

pollutants. The amendments also required the application of the best conventional 

pollutant control technology (BCT) for conventional pollutants. Both the BAT and BCT 

standards were defined to represent the best control and treatment measures that 

have been developed or that are capable of being developed within the industrial 

category or subcategory. With respect to the cost reasonableness, the 1977 CWA left 

the BAT definition relatively unchanged. For BCT, EPA was to consider the 

reasonableness of the relationship between the cost of attaining a reduction in effluent 

discharge and the benefits that would result. The cost of meeting BCT limits was 

expected by Congress to be comparable to the costs of achieving secondary 

treatment [see discussion in Section 5.21 for POTWs. 

As noted in the discussion of the statutory evolution of the technology-based 

standards, deadlines for development of the various standards were established by 

the CWA and amendments. Due to technical and administrative difficulties, most of 

the initial deadlines were postponed. A summary of final statutory deadlines for the 

different required levels of treatment technologies is provided in Exhibit 5-l. 

When applying applicable ELGs in permits, permit writers need to be aware that 

they do not have the authority to extend statutory deadlines in a NPDES permit; thus, 

all applicable technology-based requirements (i.e., ELGs and BPJ) must be applied in 

NPDES permits without the benefit of a compliance schedule. 

52 - 8ER9 NPDES Permit Writers’ Manual 
Chapter 5 Technology-Based Effluent Limits 

EXHIBIT 5-l 

Statutory Deadlines for BPT, BAT, and BCT 

Pollutant Level of Treatment Statutory Deadlines 

Conventional 

Conventional 

?Jonconventional 

Nonconventional 

Toxic 

Toxic 

BPT 

BCT 

BPT 

BAT 

BPT 

BAT 

July 1, 1977 

March 31, 1989 

July 1, 1977 

March 3 1, 1989 

July 1. 1977 

March 31, 1989 

51.2 Development of National Effluent Limitations Guidelines and 

Performance Standards 

Effluent limitations guidelines and performance standards are established by 

EPA for different industrial categories since the best control technology for one 

industry is not necessarily the best for another. These guidelines are developed 

based on the degree of pollutant reduction attainable by an industrial category through 

the application of control technologies, irrespective of the facility location. Using these 

factors, similar facilities are regulated in the same manner. In theory, for example, a 

pulp and paper mill on the west coast of the United States would be required to meet 

the same technology-based limitations as an identical plant located on the east coast 

(unless there were special site-specific concerns that had to be addressed). 

To date, EPA has established guidelines and standards for more than 50 

different industrial categories (e.g., metal finishing facilities, steam electric power 

plants, iron and steel manufacturing facilities). These guidelines appear in 40 CFR 

Parts 405499, a list of which is provided in Appendix B. Additionally, Section 304(m) 

of the 1987 Water Quality Act (WQA) requires EPA to publish a biennial plan for 

developing new ELGs and a schedule for the annual review and revision of existing 

promulgated guidelines. As such, EPA is constantly developing new guidelines, and 

revising or updating existing guidelines. 

Developing ELGs is a complicated and time-consuming effort. A schematic 

showing the general guidelines development process is presented in Exhibit 5-2. The 

regulations are based on complex engineering and economic studies that determine a 

subcategorization scheme for each industrial category and the wastewater 

&ER9 NPDES Permit Writers’ Manual - 53 
Chapter 5 Technology-Based Effluent Urn&s 

EXHIBIT 5-2 

Effluent Guidelines Flowchart 

Critiil Path 

b 

Non-Critiil Path 

mm==) 

Effluent Guideline Plan 

I Review available data 

- identify data gaps I I 

..........m..===~1=1=m=== 

. 

. 7 

Select Plants for Visits 

Plant Visits 

- Process 8 treatments assessment 

- In-process 8 stream sampling 

. 

. 

. 

. 

. 

. 

. 

. Statistical Analysis . 

. 

. 

. of field data . 

. H 

. 

. 

. 

. 

I~BB~=B==m~=~~~D~===~ l mmmmmmmmmmmmm1~~ 

I I I 

Assess Technology I 

I 

technology pertorrnance, water use. I 

costs, residuals, etc. I 

-------m---f------ s “““‘1 l 

Technology : Subcategorization : Economic I 

Costing I 1 Analysis I 

I I , I 

I 

. . . . . . . 

. 

9f.lE.10 

Select Preferred 

v Optrons 

jl 

54 - 86% NPDES Permit Writers’ Manual 
Chapter 5 Technology-Based Effluent Umits 

characteristics and treatment capabilities of each industrial category and/or 

subcategory. The CWA requires EPA to assess certain factors when establishing 

ELGs, including the following: 

. Age of the equipment and facilities involved 

. Manufacturing processes used 

. Engineering aspects of the application of recommended control 

technologies, including process changes and in-plant controls 

. Non-water quality impacts, including energy requirements 

l cost 

. Other factors, as deemed appropriate. 

Where necessary, EPA sets multiple ELGs for facilities within a given category, where 

data indicates varying conditions warranting different requirements. These 

subdivisions, known as subcategories, provide EPA with a second level of regulatory 

control to improve consistency of the guidelines within an industrial category. 

EPA develops both daily maximum and long-term average limitations for all 

ELGs, both of which must be included in the permit by the permit writer. The daily 

maximum limitations are based on the assumption that daily pollutant measurements 

are lognormally distributed. Long-term average limitations are based on the 

distribution of averages of measurements drawn from the distribution of daily 

measurements. When designing a treatment system, EPA recommends that the 

permittee target the design of its treatment system to meet the long-term average 

rather than the daily maximum. The daily maximum is intended to account for 

variation in effluent concentration above the long-term average. 

It should be noted that ELGs are not always established for every pollutant 

present in a point source discharge. In many instances, ELGs are established only for 

those pollutants that are necessary to ensure that industrial facilities comply with the 

technology-based requirements of the CWA (i.e., BPT, BCT, BAT, NSPS). These are 

often referred to as “indicator” pollutants. For example, EPA may choose to regulate 

only one of several metal pollutants that are present in the effluent from an industrial 

category; however, compliance with the ELG (i.e., implementation of technology-based 

controls) will ensure that all metals present in the discharge are adequately treated. 

8W4 NPDES Permit Writers’ Manual - 55 
Chapter 5 Technology-Bassd Effluent Llmlts 

EPA produces a number of documents that will prove useful to permit writers 

responsible for applying ELGs in permits. Most notable are the “Development 

Documents,” prepared by EPA for every industrial category with ELGs. Development 

Documents are produced by EPA as part of the development of ELGs and provide a 

detailed overview of the limitations development process, including decisions made on 

applicability of the regulations to various process operations. 

5.1.3 General Considerations Concerning the Use of Effluent Limitation 

Guidelines 

Derivation of effluent limits based on ELGs requires that the permit writer have 

a general understanding of the ELGs for all industrial categories, and detailed 

knowledge of the ELGs applicable to the permittee. In order to properly apply effluent 

guidelines, there are several considerations that a permit writer must take into 

account: 

l Categorization- Determination of the proper category and subcategory of 

the facility and proper use of the guidelines applicable to the category or 

subcategory under consideration 

l Multiple Products or Multiple Categories-Classification of plants that fall 

under more than one subcategory and/or have multiple products with 

multiple measures of production 

l Production/Flow-based Limitations-Determination of the appropriate 

measure of production or flow 

l Tiered Permit Limits-Use of alternate limits for varying production and 

flow scenarios 

. Mass Versus Concentration Limits-Considerations in the application of 

mass versus concentration limits. 

Each of these considerations is discussed further below. 

Once the appropriate ELGs have been identified, application of the limitations is 

relatively straightforward since it involves the application of a guideline that has 

already been technically derived (and sometimes litigated). Implementation of ELGs 

does require familiarity with several sources of information, particularly the CFR and 

the Federal Register (FR). As an example, two pages of the ELGs for the Iron and 

Steel Manufacturing industrial category are presented as Exhibit 5-3. 

56 - &El34 NPDES Permit Writers’ Manual 
Chapter 5 Technology-Based Effluent Limits 

EXHIBIT 5-3 

ELGs for Iron and Steel Manufacturing 

wo.u3 

SuepAm H-Gmtinmd 

. .““..... .“. ........... ...... -. D.oom9 

... . ... -. .... ..... I. ..... “,._. .... I I O.OOW9 ::Ei 

an .. ..... _.. ... I.. ... . . ...... .... ....... ..... PI 

4OcFRul.1(7-1*E8lbn) 

SUBPART H-continued 

IElPTd8mnl- 

-a-- !qqs 

....” ..“.......................... 0007w Qoo50) tudtd .. ..-..........-........................ ooow3 o#IpI OH ........................ .... ..... ............. I (‘1 I 1’1 

' WWn 2~ WIQ@ d 6.0 b 0.0. 

(4) ContinuouB. 

SUBPART H 

IePTamumthil#lam 

0.0984 

wtd ._._....--. _ . . ..-..-....-...... I. 

on .._.” ._..” _._......._........_......... I I 0.0413 

0.0013S a-1 

0.00124 o.cm413 

I’) r 1 

‘wmhm0mgmdhObO.a 

t; ~3albath doscaling, reducing. 

SUWARTH 

!(,tG!bW 

i!j%i&:::::::::::::::::: 

t-r 

00403 EE2 o:oamo w-....-...-...“-....-...- O.wl3e o.cm642. 

.------- . . . . . . . . - . . . . . . . . . o.om22 0.w 

on ..-...--........-...-..-........-... F) I’ t 

*v&n~~~e.oi09.a 

(2) Continuolls. 

-ART H 

1 BPTammtllmmbm 

. . ..-...--...I”...“......... - ““--...-^ .-. ..... “_...““. I EL I Ehl 

’ whh 6u - d 0.0 to 9.0. 

[47 FR 23284, May 27. 198!& 17 FR 11798. Sept. 

22.19e21 

0 420.88 EiYluent limItdons rqnwantZbC 

T 

of d!luent redaction 

the rppliation of the 

bd mmihb hchnology acoaomitally mhievnble (BAT). 

Except as provided in 40 CFR 126.30 

through 125.32. any existing point 

source subject to t&a subpart must 

achieve the following effluent lfmitetions repreeenting the degree of emuent reduction attainable by the app11- 

cation of the beet available technology 

economically achievable. 

(a) Salt bath descalfng. oxidizing. 

(1) Batch, sheet and plate. 

SUBPART H 

----- 

- ... ... .... .................. . 

N&d .. .._....I................................ 

( cl:lI ml& 

(2, Batch, rod and wire. 

SMI’ART H 

IB4T&UUllmWm 

. . . . . I . . . . . . . . ^ . . . . . . . . . . . . . . . . . . _. 

. . . . “...._ . . . . _...“._..... . . . . . “....... 

(3) Batch, pipe and tube. 

88# NPDES Permit Writers’ Manual - 57 
Chapter 5 Technology-Based Effluent Limits 

EXHIBIT 5-3 

ELGs for Iron and Steel Manufacturing (continued) 

The discharge of wastewetetr pollutante from any new eource subject to 

this subpart shall not exceed the steindarda set forth below. 

(a) Salt bath deecaling, oxidizing. 

(1) Batch, sheet and plate. 

SUBPART H 

- 

. . . ..-- . . . . . - . . . . . . . . . . . . . . . . . . . 

. . ..-..... . ..-.... . . . . . . . .._..... _ . . . . . . 

(4) Continuous. 

&WART H 

T!3s . . . . . . . . . . . . . . . . . . . . . . . ...” ,.......” .._.-._ 0.0878 chranilml .. . . . ^ . . . . . . . - . . ..-..-........- EL2 a001 17 N&al *.................................-......... oltxQs3 o.wo8?8 

pt4 . . . . . . . . . . . . . . . . . ..-.................-......... ('1 r') 

‘Wllhhlhorm@dLOb9.0. 

(2, Batch. rod and wire. 

~U~FW?T H 

aranbm 1...1...---..-. I_. 1 

?&ml ..-... - .-.-,...-....-. - II_.. 

(b) Salt bath dw. reducing. 

(1) Batch. 

SUBPMH 

. . ..---.-...-..- 

tz2zn .--.......-.--- 

omo2 aooo330 

o.oow. am 

-w...-_.....” 0.00122 o.mo4o7 

(2) Continuour. 

SUBPART H 

‘WllhhUm~dhOb9.O. 

(3) Batch, pipe and tube. 

SUBPART H

ZztL - O.WSW I I O.QOlOO 

om789 am04 

-I.-.-....-.-“. mom3 O.OOW8 

PH- A-e-...,..... 

‘Hlhhk~dbOb9.Q. 

58 - 8EFR NPDES Permit Writers’ Manual 
Chapter 5 Technology-Based Effluent Limlts 

Categorization 

To properly use and apply ELGs, the permit writer must first determine which 

industrial category(s) applies to the facility being permitted. In determining the 

appropriate category(s) into which a facility falls, the Standard Industrial Classification 

(SIC) code is often very helpful. SIC codes were developed and are maintained by 

the Federal government as a way to classify establishments by type of activity for 

comparing economic and other types of facility-specific data. A listing of SIC codes 

corresponding with ELG categories is provided in Appendix C and is useful for 

determining applicable industrial categories. 

Item V-II of NPDES Application Form I requires that the applicant provide the 

SIC code for the activity covered by the permit application. In some instances, the 

SIC code will identify both the industrial category and the subcategory of a particular 

facility. Often, the SIC code will identify the appropriate industrial category, but may 

not necessarily identify the subcategory. 

Example: 

A primary smelter of copper, SIC code 3331, falls under the Nonferrous Metals Manufacturing category 

listed in 40 CFR Part 421. In this particular case, SlC code 3331 also clearly identifies the facility in the 

Copper Smelting Subcategory. 

Example: 

A facility that manufactures acrylic acids and acrylic acid esters (SIC code 2869) can easily be classified 

as subject to the Organic Chemicals, Plastics and Synthetic Fibers (OCPSF) category based on its SIC 

code; however, determination of the applicable subcategory requires additional effort. In this example, 

the permit writer can determine from a review of the industrial categorization discussion in the 

Development Document for the OCPSF industry that facilities performing these manufacturing operations 

are subject to Subpart G (bulk organic chemicals). 

Although SIC codes provide a helpful starting point for categorizing a facility, 

the permit writer should be cautious of relying exclusively on SIC codes for 

determining the appropriate industrial category. SIC codes were not developed based 

on EPA’s industrial classification scheme, or vice versa, and, therefore, may not 

always correspond exactly with the categorization process. It is also important to note 

that more than one SIC code may apply to a facility. EPA’s Development Documents, 

&EM NPDES Permit Writers’ Manual - 59 
Chapter 5 Technology-Based Effluent Limits 

provide detailed information on the applicability of the regulations to specific types of 

facilities and are useful sources of information when categorizing a facility. Similarly, 

FR notices of the promulgated ELGs provide additional insight into applicability of the 

guideline to various types of facilities. 

When determining applicable ELGs, it is best to identify the categories first, and 

then, through a careful analysis of plant operations, determine the subcategories. The 

determination of applicable categories can be accomplished by quickly classifying the 

categories as “not applicable” or “potentially applicable.” 

Example: 

If a brewery is under consideration, the Iron and Steel Manufacturing category would obviously not be 

applicable but Organic Chemicals might be, depending on the extent of recovery and processing of 

byproducts. A careful analysis of the production of the plant and comparison to the subcategories under 

Organic Chemicals would establish which, if any, of the subcategories are applicable. 

In many cases, industrial facilities may not clearly fall into a category or a 

subcategory, thus requiring some research on the part of the permit writer to identify 

the applicable category and subcategory. 

Example: 

An integrated washing machine producer (SIC code 3633) would be categorized in the Household 

Laundry Equipment category (as specified under the SIC code system). However, depending on the 

activities occurring at the facility, it may also fall under the Porcelain Enameling, Metal Finishing, or 

Plastic Molding and Forming categories for purposes of regulation under effluent guidelines. 

After determination of potential categories, the permit writer can conduct a more 

detailed evaluation to narrow the list to only the applicable categories and 

subcategories using more detailed facility information. 

Multiple Products or Multiple Categories 

There are instances when one facility produces multiple products, or whose 

production process is covered by multiple categories and subcategories. In these 

cases, the permit writer must examine the applicable guidelines closely to ensure that 

(1) one guideline does not supersede another, and (2) the guidelines are properly 

60 - 8EM NPDES Permit Writers’ Manual 
Chapter 5 Technology-Based Effluent Limits 

applied. For example, as presented in Exhibit 5-4, the preamble to the final rule for 

the OCPSF ELGs (52 FR 42523) identified numerous circumstances where the 

OCPSF regulations are superseded by existing ELGs for other industrial categories. 

When a facility is subject to multiple effluent guidelines, the permit writer must 

apply each of the effluent guidelines in deriving the technology-based effluent limits for 

the particular facility. If all wastewaters regulated by effluent guidelines are combined 

prior to treatment and discharge to navigable waters, then the permit writer could 

simply combine the allowable pollutant loadings from each effluent guideline to arrive 

at a single technology-based effluent limit for the facility (i.e., a “building block” 

approach). 

Circumstances will also arise when an effluent guideline for one subcategory 

regulates a different set of pollutants than the effluent guidelines applicable to another 

subcategory. If all regulated wastestreams are combined, there are two approaches 

to ensure proper application of the effluent guidelines: 

. If one wastestream containing a pollutant that is not covered by an effluent 

guideline is combined with another wastestream that has applicable effluent 

guidelines for the same pollutant, then the permit writers must use BPJ to 

establish a technology-based effluent limit for the non-regulated wastewater 

(see Section 5.1.4). 

. If one wastestream that does not contain a pollutant is combined with 

another wastestream that has applicable effluent guidelines for the 

pollutant, the permit writer must ensure that the non-regulated wastestream 

does not dilute the regulated wastestream to the point where the pollutant is 

not analytically detectable. If this circumstance occurs, then the permit 

writer will most likely need to establish internal outfalls, as allowed under 40 

CFR 5122.45(h). 

Effluent guidelines may also specify inconsistent limit expressions that will have 

to be adjusted. For example, effluent guidelines for one category (e.g., porcelain 

enameling) may contain limits with a daily maximum limit, while effluent guidelines for 

another category (e.g., electroplating) sets a 4-day average limit for the same 

pollutant. In this case, both ELGs must be applied in the permit. If this situation 

arises, a permit writer has several alternatives such as: 

iiEpA NPDES Permit Writers’ Manual - 61 
Chapter 5 Technology-Based Effluent LImlt!s 

EXHIBIT 5-4 

OCPSF Effluent Limitations Guidelines 

Federal Register / Vol. 52. No. 214 1 Thursday, November 5. 1987 / Rules and Rrqularions 425-3 -

(OCPSF) manufacturing facdltlea. lt 

applics.to pmcers wasIcwatcr 

discharges from these faciliUes. 

For the purposes of This regulation. 

OCPSF process wsstewater discbarges 

are defined as dischanjes from all 

eatablishmcnls or poruons of 

establishments that manufacture 

pmduccs or product groups listed in rhe 

applicability sections of this regulation. 

and are mcluded within the following 

U.S. Deperlment of Commerce Bureau of 

rhe Censur Standard industrial 

Classdicalion (SIC) major groups: 

(1) SIC 3M-Cyclic Crudes and 

Intcrmediales. Dyes, and Organic 

Pigments. 

(2) SIC 2&3+fndustrisl Organic 

Chemicals. not Elsewhere Clas~&d 

(3) SIC z&?l-Plartlc Malcnals. 

Synthetic Resins. and Nonvulcanrxablo 

Elastomers. 

(4) SIC 2823-CeIlulosic Man-Made 

Fibers. and 

[S) SIC WCSynthetic Organic 

Fibers. Except Cellulosie. 

The CKXW regulation does not applyto process was!swstsr discharges from 

the msnufachur of oganic chemical 

wmpaunds solely by extraction from 

plant end animal NW materials or by 

fsrmentetion processes. 

Ttle OCPBF regulation wwm au 

OCPSP products or proceues WhOlhW 

or noI lhey am bated at facibtlem 

where the OCFSP covered operrtkma 

am a minor podoa of and analleq to 

the prim- production l cUviUea or l 

mrjor poruon of the JctMMes. 

The OCPSF mguldon does not eppl~ 

to &schuge8fromoCPSFpmduct) 

pmcesa operetlons which are coved 

by the pmvlsions of otbes utegoriul 

industry effluent UmiteUona guidek 

and sW if the wasWwater le 

treated in wmbiiation with the nonOUW hdwtrid atogory regulated 

wastewater. (Some pmduats at roduc4. 

grape are mumfactnmi by Lid ennt 

pmcesses and some proaeser withslrgbt-opentiqJ wndltloo vuleuaMgive cuHeNnt pfodnclh EFA usu tlu 

term “pfoduct/pmcese” to mean 

diffsrenl vuirtloM of the - hub 

pmceas to munlfecture &famM 

products as well aa to menufuture the 

mrmproblu~-~) 

However, the OCPSF re&Ucut doee 

apply to tha prodoctlwd 

by this N&UOB K the facility rep&n 

~~~s-~ 

wastewetm are treeled fn l separetr 

mdlllent systun at the frcility or 

dischqed sepuetely to l municipJ 

treebnent system 

For example. same vertluUy 

lntmted petroleum refllleries Mb 

ph~~centlcal manufduren diachugo 

wastewaters from the production of 

synthetic organic chemical products that 

are specifically regulated under the 

Petrochemical and Integrated 

Subcategories of the Petroleum Refining 

Foml Source Category (40 CFR Part 419. 

Fubparts C and E) or the Chernlcal 

Synthesis Productr Subcategory of Lhe 

Pharmaceuticals Manufacturing Point 

Source Category (40 CFR Part 439. 

Subpart CJ. The principles discussed in 

the preceding paragraph apply aa 

follows: The process wastewater 

discharges by petroleum mfineries and 

pharmaceutjcd manufacfuren from 

production of organic chemical products 

opeafically covered by 40 CFR Part 419 

Subpan, C and E and Part 439 Subpart 

C, respectively, that are treated in 

combination with other petroleum 

refinery or pharmaceuticel 

manufacturing wsstewatcr. mspectivrly. 

am not subject Lo the OCPSF regulation 

no matter what SIC code they use to 

report their pmducte. However. d the 

wasteweters from their OCPSP 

productioll are separately discharged to 

a POTW or ku ted in l sepuatr 

treebnent system and they mport their 

prodti (fmm these prousaes) under 

SICcode8ZW.Z8BXwUlZl.then 

discbugu fmm these mannfduring 

opamtione ue subject to regulatloo 

under the OCPSP regulation. regudlese 

of whether the OCPSF producta em 

coveredby4oCFRPart4laSubperteC 

andEandFut43&SubpertC 

Today’8 OCPSF cat 

applies Lo plestka mol z iii%= 

procesaee when pluuc msln 

nuncfactnrm mold 01 form (e.g.. 

extrude and peueuM) aude 

lntemediate plestio maLerial far 

1llipmMt off-sit.. -ma regukuM also 

applies to the extrusion of fibem. 

Auua molding and forming pmcrsu 

other tlm thou duulhed above am 

p&k% R”dte$? ud 

StMduda (40 cl@ puc4w 

fbblk mats requested 

relatiq to uu mvmge of o&treMucb and dewlopment fwiliur 

!5l~aoeocPsFmse~~ 

develwk pilot plant, teobnicek 

serda, and IdloNtory bench seek 

operaunas4Nllotmwredbytflo 

OCPSFwUoa However, 

wutewatsr frcm such opueuwu 

wnducted ia CcnllNctbnvrith uub 

relrti to exisung OCPSF 

manuhtuhg opemlo~ at OCIW 

fedllUn le cowred by rhe ocpsp 

mgulMlwt becMM these opueumu 

would mmt ukely genmto wutew~tr 

wall chulamlrua simiru to use 

commerdd q anufafdurlng frcllityk 

Rsseucb and development. pilot pla&. 

wbnial srrvke. and laboratory 

operations which are unrelated to 

existing OCPSF plant operations. even 

though conducted on-mite. arc not 

covered by the OCF’SF regula!ion 

because they may generate wastewater 

with characterirks dissimdar lo that 

from the commercial OCPSP 

manufacturing facility. 

Finally. as described in the folIowIng 

paragraphs, this mguiaUon does not 

cover certain production that has 

historically been mportsd to the Bureau 

of Census under a non-OCPSF SIC 

subgroup heading, even II such 

production could be reported under one 

of the five SIC code groups covered by 

today’s regulation 

The Settlement Agreemsnl (sse 

Section ILA) requues the Agency 10 

establish regulations for the Organic 

Chtmicals Manufsctving SIC codes 

~868 and 2864 and for Ihe Plastics and 

Synthetic MeterirIs manafacturing SIC 

code 282 SIC 282 includes the three 

codes covered by this regulation. Z&X. 

2823. and 2824 as well ae SIC 2822 

SyntheUc Rubber (Vulcenlzable 

Elastomers]. which is covered 

specifically in lhe SetUemsnt Agreement 

by another industrial category. Rubber 

Msnufactwing (49 CFR Pad 428). The 

Agency themfoon directsd its date 

coUwUoo efforts lo those facilltles that 

report mamfacturing l cUvities under 

SICwduMZl.2823.28242888and 

u#Q Resed 00 en assessment of this 

information and tbe integrated nature of 

the syntheUo organic chemicals. plastics 

and synthetic 5bere industry. Ihe 

Agency also defined the l Ppliubilily of 

the OCFSF re&Uoo by listing the 

spec& prod&e and product groups 

that pmvide the techaiul bares for the 

regulaum 

Sina many of the products may be 

qmrted under umre than one SIC code 

l wntbough(brJuroft~ 

m~nfwhued with the same maction 

cheaistry or enit operations. the Agency 

considered extendfng the applicability 

oftlleocF%Fmgnhuoa(soFRzsom 

July 17,lW or 51 PR 440W2 Dec8mber 

& 1988) to illclude OCPSP production 

reported ua&r the fouowtng SIC 

SUbqouP= 

1. SIC ZSll(#buomeU.c 

hydrcarho~ manufactured fmm 

pwcbsedh5nery product* 

2. SIC 291183z-eliph~uc 

hydrocubona manufactured fmm 

pucbued dnuy product* 

3. SIC 28@tkyntbeUo ruin and 

rubher l dheeives (k&d@ only those 

syatbetlc reelna listed under both SIC 

211914 and SIC 28~1 that em polymerized 

far we or ado by adldvo 

IWZlUfWUWS). 

62 - 4bEF% NPDES Permit Writers’ Manual 
Chapter 5 Technology-Based Effluent Limits 

. Place both limits in the permit (i.e., both the daily maximum and 4-&y 

average) 

. Apply the applicable effluent guidelines at internal outfalls [as allowed under 

40 CFR $122.45(h)]. 

Example 1: 

A facility with a newly constructed metal plating production line is added to a facility with an existing metal 

plating production line. Wastewater from both of these lines is commingled prior to treatment, treated, 

and then discharged. In this situation, the combination of the NSPS (for the new line) and BAT/BCT 

standards (for the older line) would be used to derive a limitation. 

Example 2: 

An integrated lamp maker conducts copper forming, aluminum forming, metal finishing, and porcelain 

enameling processes with wastewater combined prior to treatment and discharge. In this situation, the 

appropriate effluent guidelines for these categories must be applied to each waste stream and combined 

when developing limitations. 

Production/Flow-Based Limitations 

Most ELGs are expressed in terms of allowable pollutant discharge per unit of 

production (or some other measure of production) or are based on wastewater flow 

rates. In general, production/flow-based standards are developed for industries that 

incorporate flow reduction practices, and EPA considers this in the ELG development 

process. This methodology forces permittees to implement comparable measures to 

comply with the limitations. To determine permit limits, and in accordance with the 

requirements at 40 CFR 9122.45(b), these standards are multiplied by a reasonable 

measure of the facility’s actual production/flow rate (i.e., not the design production or 

flow rate). Thus, it is necessary for the permit writer to determine the facility’s actual 

production or flow, based on information supplied by the facility in the permit 

application. 

The ideal situation for the application of ELGs is where production or flow is 

constant from day-to-day and month-to-month. Production or flow for the purposes of 

calculating the limitations would then be the average rate. In actuality, production or 

flow rates are not as constant as this ideal situation. They vary based on factors such 

as the market demand, maintenance, product changes, down times, breakdowns, and 

facility modifications. As such, the production or flow rate of a facility will vary with 

time. 

HIT4 NPDES Permit Writers’ Manual - 63 
Chapter 5 Technology-Based Effluent Limits 

To apply production/flow-based ELGs to a facility with varying production or flow 

rates, the permit writer should determine a single estimate of the long-term average 

rate that is expected to exist during the term of the permit being prepared. It is 

recommended that the permit writer establish this average from the past 5 years of 

facility data. This single value is then multiplied by the ELGs to obtain permit limits. 

In certain instances, the permit writer may find that fewer than 5 years of data may 

better represent conditions that are anticipated for the next 5 years. This would be the 

case for a facility that has undergone major renovations that would impact production 

or flow; making use of data prior to this construction inappropriate to model future 

process options. 

The objective in determining a production or flow estimate for a facility is to 

develop a single estimate of the long-term average production rate (in terms of mass 

of product per day or volume of process wastewater per day), which can reasonably 

be expected to prevail during the next term of the permit. The following example 

illustrates the proper application of production-based guidelines: 

Example: 

Company A has produced 331,000 tons, 301,500 tons, 361,500 tons, 332,000 tons, and 331,500 tons per 

year for the previous 5 years operating 255 days per year. What would be a reasonable measure of 

production for permitting purposes? Assuming that pollutant X has an effluent limitation guideline of 0.1 

lbs/l,OOO Ibs for the monthly average and 0.15 lbs/l,OOO Ibs for the daily maximum, what would be the 

resulting effluent limitations? 

Discussion: 

The use of the long-term average production (i.e., average production over past 5 years = 331,500 tons 

per year) would be an appropriate and reasonable measure of production, if this figure represents the 

actual production expected to occur over the next term of the permit. Also, in evaluating these gross 

production figures, the number of production days must be considered. If the number of production days 

per year is not comparable, the numbers must be converted to production per day before they may be 

compared. To convert from the annual production rate to average daily rate, the annual production rate 

is divided by the number of production days per year. To determine the number of production days, the 

total number of normally scheduled nonproduction days are subtracted from the total days in a year. 

If Company A normally has 255 production days per year, the annual production rate of 331,500 tons per 

year would yield an average daily rate of 1,300 tons per day. 

Monthly average limit: 

1,300 tons/day x 2,000 lb&on x 0.10 tbs/l,OOO Ibs = 260 Ibs/day 

Daily maximum limit: 

1.300 tons/day x 2,000 Ibs/ton x 0.15 Ibs/l,OOO Ibs = 390 Ib.s/day 

64 - &EM NPDES Permit Writers’ Manual 
Chapter 5 Technology-Based Effluent Limits 

In the example above, the average production rate during the last 5 years was 

used as the estimate of production. This average rate is appropriate when production 

is not expected to change significantly during the permit term. However, if historical 

trends, market forces, or company plans indicate that a different level of production 

will prevail during the permit term, a different basis for estimating production should be 

used. 

Tiered Permit Limits 

If production rates are expected to change significantly during the life of the 

permit, the permit writer can include alternate or tiered limits. These tiered limits 

would become effective when production exceeds a threshold value, such as during 

seasonal production variations. As a general rule of thumb, up to a 20 percent 

fluctuation in production is within the range of normal variability, while changes in 

production higher than 20 percent could warrant consideration of alternate limits. The 

major characteristics of tiered limits are best described by illustration and example. 

Example: 

Plant B produced approximately 40 tons per day of product during spring and summer months (i.e., 

March through August) and 280 tons per day during fall and winter months during the previous 5 years. 

Production during the fall and winter months are significantly higher than during the off-season and the 

permittee has made a plausible argument that production is expected to continue at that level. The 

guideline for pollutant X is 0.08 Ibs/l ,000 Ibs for the monthly average and 0.14 Ibs/l,OOO Ibs for the daily 

maximum. What are the tiered effluent limitations? 

Discussion: 

The first tier or lower limits would be based on a production rate of 40 tons per day. These limits would 

apply between March and August. 

Monthly average limit: 

40 tons/day x 2,000 tbs./ton x 0.08 Ibs/l,OOO Ibs = 6.4 Ibs/day 

Daily maximum limit: 

40 tons/day x 2,000 lb&on x 0.14 Ibs/l ,000 lbs = 11.2 Ibs/day 

The second tier or higher limits would be based on a production rate of 280 tons per day. These limits 

would apply between September and February. 

Monthly average limit: 

280 tons/day x 2,000 lb&on x 0.08 Ibs/l,OOO Ibs = 44.8 Ibs/day 

Daily maximum limit: 

280 tons/day x 2,000 Ibs/ton x 0.14 Ibs/l,OOO Ibs = 78.4 Ibs/day 

8EV4 NPDES Permit Writers’ Manual - 65 
Chapter 5 Technology-Based Effluent Umlts 

Tiered permits with alternate limits should be used only after careful 

consideration of production data and only when a substantial increase or decrease in 

production is likely to occur. In the example above, the lower limits would be in effect 

when production was at “low” levels. During periods of significantly higher production, 

the higher limits would be in effect. In addition, alternate limits may also be 

appropriate in the case of special processes or product lines. The thresholds, 

measures of production, and special reporting requirements must be detailed in the 

permit. Special reporting requirements include provisions such as: 

l The permittee notifying the permitting authority at least two business days 

prior to the month they expect to be operating at a higher level of 

production and the duration this level of production is expected to continue 

. The permittee reporting, in the discharge monitoring report, the level of 

production and the limitation and standards applicable to that level. 

Mass Versus Concentration Limits 

The regulations at 40 CFR $122.45(f)(l) require that all permit limits, standards, 

or prohibitions be expressed in terms of mass units (e.g., pounds, kilograms, grams) 

except under the following conditions: 

1) For pH, temperature, radiation, or other pollutants that cannot appropriately 

be addressed by mass limits; 

2) When applicable standards and limitations are expressed in terms of other 

units of measurement; or 

3) If in establishing technology-based permit limitations on a case-by-case 

basis limitations based on mass are infeasible because the mass or 

pollutant cannot be related to a measure of production. The limitations, 

however, must ensure that dilution will not be used as a substitute for 

treatment. 

While the regulations require that limitations be expressed in terms of mass, a 

provision is included at 40 CFR $122.45(f)(2) that allows that permit writer, at his or 

her discretion, to express limits in additional units (e.g., concentration units). Where 

limits are expressed in more than one unit, the permittee must comply with both. 

As provided by the regulations, the permit writer may determine that expressing 

limits in more than one unit is appropriate under certain circumstances. For example, 

66 - 88R9 NPDES Permit Writers’ Manual 
Chapter 5 Technology-Based Effluent Limits 

expressing limitations in terms of concentration as well as mass encourages the 

proper operation of a treatment facility at all times. In the absence of concentration 

limits, a permittee would be able to increase its effluent concentration (i.e., reduce its 

level of treatment) during low flow periods and still meet its mass-based effluent limits. 

Concentration limits discourage the reduction in treatment efficiency during low flow 

periods, and require proper operation of treatment units at all times. 

The derivation of concentration limits should be based on evaluating historical 

monitoring data and using engineering judgment to be sure they are reasonable. In 

certain situations, the use of concentration limits may not be appropriate since they 

may discourage the use of innovative techniques, such as water conservation by the 

permittee. For example, if a facility had a history of providing efficient treatment of its 

wastewater and also wished to practice water conservation, inclusion of concentration 

limits would not be appropriate (i.e., concentration limits would prohibit decreases in 

flow that would concurrently result in an increase in pollutant concentration). To 

summarize, the applicability of concentration limits should be a case-by-case 

determination based upon the professional judgment of the permit writer. 

It should be noted that the long-term average flow should be used to calculate 

both the monthly average and daily maximum concentrations. The use of the longterm average flow is most appropriate for the calculation of concentration limits 

because it will reflect the range of concentrations that could be expected in a well 

operated plant. The use of the maximum daily flow is not appropriate to determine 

concentration limits from the mass limitations because it will reduce the concentration 

below the value which could be expected in a well operated plant. Alternatively, use 

of the lowest flow value will increase the concentration limit to levels above what 

would be expected in a well operated plant. 

Example 1: 

An industrial facility (leather tanner) is subject to effluent limitations guidelines based on its rate of 

production. The permit writer calculates the applicable mass-based limits based on the long-term 

production rate at the facility and incorporates the mass limits in accordance with 40 CFR $122.45(f)(l). 

In reviewing the past inspection records for the facility, the permit writer notes that while the facility is 

generally in compliance with its mass limits, the effluent flow and concentration vary widely. To ensure 

that the treatment unit is operated properly at all times, the permit writer determines that concentrationbased limits are also appropriate. The permit writer consults the EPA Development Document for the 

leather tanning effluent limitations guidelines and bases the concentration-based limits on the 

demonstrated performance of the treatment technology upon which the effluent guidelines were based. 

The concentration-based limits are then incorporated in the permit in accordance with 40 CFR 

$122.45(f)(2). 

QEM NPDES Permit Writers’ Manual - 67 
Chapter 5 Technology-Based Effluent Limits 

Example 2: 

For Company A, the mass limits for pollutant X have been set at 260 Ibs/day and 390 Ibs/day monthly 

average and daily maximum, respectively. What are the monthly average concentration limitations in 

milligrams per liter (mg/l) using both an average flow of 0.9 mgd and the low flow of 0.6 mgd? Note: 

8.34 is a conversion factor with the units (Ibs/day)/(mgd)(mg/l). 

Discussion: 

Monthly average limit (based on average flow): 

260 lbs/day/(8.34 x 0.9 mgdl = 35 mg/l 

Monthly average limit (based on low flow): 

260 lbs/dav/(8.34 x 0.6 mad1 = 52 rnti 

This is almost 150 percent more than the concentration during average flow! 

In determining applicable effluent concentration limitations, the monthly average and daily 

maximum mass limits divided by the average flow will provide appropriate concentrations. 

Monthly average limit: 

260 lbs/day/[8.34 x 0.9 mqdl= 35 mg/l 

Daily maximum limit: 

390 lbs/dav/(8.34 x 0.9 mqdl = 52 mg/l 

51.4 Best Professional Judgment Permit Limits 

Best Professional Judgment (BPJ)-based limits are technology-based limits 

derived on a case-by-case basis for non-municipal (industrial) facilities. BPJ limits are 

established in cases where ELGs are not available for, or do not regulate, a particular 

pollutant of concern. BPJ is defined as the highest quality technical opinion developed 

by a permit writer after consideration of all reasonably available and pertinent data or 

information that forms the basis for the terms and conditions of a NPDES permit. 

The authority for BPJ is contained in Section 402(a)(l) of the CWA, which 

authorizes the EPA Administrator to issue a permit containing “such conditions as the 

Administrator determines are necessary to cat-v out the provisions of this Act” prior to 

taking the necessary implementing actions, such as the establishment of ELGs. 

During the first round of NPDES permits in the early-to-mid-1970s, a majority of 

permits were based on the authority of Section 402(a)(l) of the CWA. These first 

round so-called best engineering judgment permits were drafted because effluent 

guidelines were not available for many industries. As effluent guidelines began to be 

promulgated, permit writers had to rely less on their best engineering judgment and 

could apply the ELGs in permits. As the implementation of the age of toxic pollutant 

68 - 88# NPDES Permit Writers’ Manual 
Chapter 5 Technology-Based Effluent Limits 

control continues, the use of BPJ conditions in permits has again become more 

common. However, the statutory deadline for compliance with technology-based 

effluent limits (including BPJ-based pollutant limits) was March 31, 1989. Therefore, 

compliance schedules cannot be placed in permits to allow for extensions in meeting 

BPJ pollutant limits. 

BPJ has proven to be a valuable tool for NPDES permit writers over the years. 

Because it is so broad in scope, BPJ allows the permit writer considerable flexibility in 

establishing permit terms and conditions. Inherent in this flexibility, however, is the 

burden on the permit writer to show that the BPJ is reasonable and based on sound 

engineering analysis. If this evaluation of reasonableness does not exist, the BPJ 

condition is vulnerable to a challenge by the permittee. Therefore, the need for and 

derivation of the permit condition, and the basis for its establishment, should be clearly 

defined and documented. References used to determine the BPJ condition should be 

identified. In short, the rationale for a BPJ permit must be carefully drafted to 

withstand the scrutiny of not only the permittee, but also the public and, ultimately, an 

administrative law judge. 

Establishment of BPJ Permit Limits 

The NPDES regulations in 40 CFR 5125.3 state that permits developed on a 

case-by-case basis under Section 402(a)(l) of the CWA must consider (1) the 

appropriate technology for the category class of point sources of which the applicant is 

a member, based on all available information, and (2) any unique factors relating to 

the applicant. To set BPJ limits, a permit writer must first determine a need for 

additional controls beyond existing ELGs. The need for additional controls may be the 

result of the facility not falling under any of the categories for which ELGs exist (e.g., 

barrel reclaimers, transportation equipment cleaning facilities, or industrial laundries) or 

discharging pollutants of concern that are not directly or indirectly addressed by the 

development of the ELGs (e.g., a pharmaceutical manufacturer or a petroleum refiner 

may discharge elevated levels of organic solvents for which category-specific 

guidelines do not exist). It should be noted that prior to establishing BPJ-based limits 

for a pollutant not regulated in an effluent guideline, the permit writer should ensure 

that the pollutant was not considered by EPA while developing the ELGs (i.e., BPJbased effluent limits are not required for pollutants that were considered by EPA for 

regulation under the effluent guidelines, but for which EPA determined that no ELG 

&EPA NPDES Permit Writers’ Manual - 69 
Chapter 5 Technology-Based Effluent Limits 

was necessary). Information contained in the appropriate “Development Document” 

should assist permit writers in making this determination. 

In setting BPJ limitations, the permit writer must consider several specific 

factors as they appear in 40 CFR 5125.3(d). These factors, which are enumerated 

below, are the same factors required to be considered by EPA in the development of 

ELGs and, therefore, are often referred to as the Section 304(b) factors: 

. For BPT requirements: 

- 

The total cost of application of technology in relation to the effluent 

reduction benefits to be achieved from such application 

The age of equipment and facilities involved* 

The process employed* 

The engineering aspects of the application of various types of control 

techniques* 

Process changes* 

Non-water quality environmental impact including energy requirements* 

. For BCT requirements: 

- All items in the BPT requirements indicated by an asterisk (*) above 

- The reasonableness of the relationship between the costs of attaining a 

reduction in effluent and the effluent reduction benefits derived 

- The comparison of the cost and level of reduction of such pollutants 

from the discharge of POTWs to the cost and level of reduction of such 

pollutants from a class or category of industrial sources 

. For BAT requirements: 

- All items in the BPT requirements indicated by an asterisk (*) above 

- The cost of achieving such effluent reduction. 

A permit writer must consider each of these factors in establishing BPJ-based 

conditions in permits. Since BPJ contains an element of judgment or educated 

opinion, a permit writer with the proper tools should be able to establish BPJ 

conditions in permits that are both technically sound and reasonable. 

A technically sound and reasonable permit is not likely to be successfully 

challenged by the permittee or a third party. In this context, “technically sound permit 

conditions” means that the conditions are achievable with existing technology. 

70 88# NPDES Permit Writers’ Manual 
Chapter 5 Technology-Based Effluent Limits 

“Reasonable” means that the conditions are achievable at a cost that the facility can 

afford. Historically, some of the other factors, such as age, process employed and 

non-water quality impacts have assumed lesser importance than the technical and 

economic feasibility evaluations. 

BPJ Permitting Tools and References 

Permit writers can develop BPJ limits using one of two different methods. A 

permit writer can either transfer numerical limitations from an existing source such as 

from a similar NPDES permit or an existing ELG, or derive new numerical limitations. 

Numerous tools and references for BPJ permit writing exist. As one gains experience 

drafting BPJ permits, it is common practice to rely on some references more than 

others. Exhibit 5-5 lists references and provides some examples for selected BPJ 

data sources that have proven useful to permit writers over the years. 

Most of the tools and references listed in Exhibit 5-5 can be used to derive new 

BPJ-based permit limits. They provide information related to the expected 

performance of wastewater treatment systems. For example, the Treatability Manual 

and associated data base provides treatability information for over 1,400 pollutants. 

Information collected for use in developing effluent guidelines and standards can also 

provide treatability data for a significant number of pollutants and for a variety of types 

of industrial wastewaters. The Technical Support Document for Water Quality-Based 

Toxics ControP provides extensive information and guidance related to the statistical 

considerations when establishing effluent limits. 

Since best management practices (BMPs) can also be used by permit writers 

as the basis for effluent limits, the Guidance Manual for Developing Best Management 

Practices’ can be used by permit writers to identify potentially applicable BMPs that 

could be used for the facility to be permitted. In addition, Storm Water Management 

4USEPA (1980). Treatability Manual, Volumes I - V. EPA-600/8-80-042a-e. Office of Research 

and Development. 

‘USEPA (1991). Technical Support Document for Water Quality-Based Toxics Control. EPA505/2-90-001. Office of Water Enforcement and Permits. 

%SEPA (1993). Guidance Manual for Developing Best Management Practices. (BMPs). EPA833-B-93-004. Off ice of Water. 

QEM NPDES Permit Writers’ Manual - 71 
Chatier 5 Technology-Based Effluent Urn&s 

EXHIBIT S-S 

BP J Permitting Tools 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

Abstracts of Industrial NPDES Permits 

Treatability Manual and Data Base 

NPDES Best Management Practices Guidance Document 

Guidance Manual for Developing Best Management Practices (BMPs). EPA 833-B-93-004. 

(USEPA, 1993) Office of Water and Storm Water Management for Industrial Activities: 

Developing Pollution Prevention Plans and Best Management Practices. EPA 832-R-92-006. 

(USEPA, 1992) Office of Water. 

Technical Support Document for the Development of Water Quality-based Permit Toxic Control 

Workbook for Determining Economic Achievability for NPDES Permits 

National Environmental Investigation Center reports on specific facilities 

Toxicity reduction evaluations for selected industries 

Industry experts within EPA Headquarters, Regions, and States 

Effluent guidelines development information 

CWA Section 308 questionnaires 

- Screening and verification data 

Development documents 

- Contractor’s reports 

- Proposed regulations 

Project Officers 

Permit Compliance System data 

Permit/compliance file information 

- Previous NPDES application forms 

- Discharge Monitoring Reports 

- Compliance Inspection reports 

Other media permit files (e.g., Resource Conservation and Recovery Act (RCRA) permit 

applications and Spill Prevention Countermeasure and Control (SPCC) plans) 

Literature (e.g., technical journals and books). 

for Industrial Activities: Developing Pollution Prevention Plans and Best Management 

Practices’ can be used by permit writers responsible for establishing BPJ permit limits 

for storm water discharges. 

‘USEPA (1992). Storm Water Management for Industrial Activities: Developing Pollution 

Prevention Plans and Best Management Practices. EPA 832-R-92-006. Office of Water. 

72 - 88# NPDES Permit Writers’ Manual 
Chapter 5 Technology-Based Effluent Limits 

To assist permit writers in identifying other NPDES permits from which 

technology-based effluent limits can be transferred, EPA has developed the NPDES 

Industrial Permit Abstracts*. The abstracts are a compilation of NPDES permits 

issued by authorized State agencies and EPA Regional offices to a variety of nonmunicipal dischargers. The abstracts assist permit writers by providing rapid access 

to permit information in a standardized, cross-referenced and easy-to-read format. 

As previously discussed, permit writers must consider the costs to comply when 

establishing BPJ permit limits for toxic and nonconventional pollutants. To assist 

permit writers in determining whether the estimated costs are reasonable for the 

facility to be permitted, a draft document, Workbook for Determining Economic 

Achievability for National Pollutant Discharge Elimination System Pem?itsg, has been 

developed. This guidance document provides a step-by-step procedure for permit 

writers to determine the economic achievability of BPJ effluent limits. 

BP J Statistical Considerations 

The quality of the effluent from a treatment facility will normally vary over time. 

If BOD, data for a typical treatment plant are plotted against time, the day-to-day 

variations of effluent concentrations can be seen. Some of this behavior can be 

described by constructing a frequency-concentration plot. From this plot, one can see 

that for most of the time, BOD, concentrations are near some average value. Any 

treatment system can be described using the mean concentration of the parameter of 

interest (i.e., the long-term average) and the variance (or coefficient of variation) and 

by assuming a particular statistical distribution (usually lognormal). 

Permit limits are generally set at the upper bounds of acceptable performance. 

As required at 40 CFR $122.45(d), two expressions of permit limits are required-an 

average monthly limit and a maximum daily limit. The use of average and maximum 

limits can vary depending on the effluent guidelines and water quality criteria that are 

consulted. Instantaneous maximums, daily averages and daily maximums, weekly 

averages, and monthly averages are all commonly used limitation expressions. 

‘USEPA (1993). NPDES lndusfrial Permit Absfracfs 7993. EPA-833/B-93-005. Office of Water. 

‘USEPA (1982). Workbook for Determining Economic Achievability for National Pollutant Discharge 

Eliminafion System Permits (DRAFT). Permits Division Prepared by Putnam, Wayes & Bartlett, Inc. 

&EM NPDES Permit Writers’ Manual - 73 
Chapter 5 Technology-Based Effluent Limits 

Generally, the definitions are consistent with those set forth in the Glossary of this 

manual. 

If permit limits are set too lenient relative to the long-term average, a discharger 

not complying with expected performance will not exceed the limits. If permit limits 

are set too stringently, a discharger that is complying with expected performance may 

frequently exceed the limits. It is important to note that statistical variability is already 

built in with respect to the ELGs, and the permit writer may not perform a separate 

evaluation in those cases where a permit limitation is derived from a guideline. 

When developing a BPJ limit, permit writers can use an approach consistent 

with EPA’s ELG statistical approach. Specifically, the daily maximum limitation can be 

calculated by multiplying the long-term average by a daily variability factor. The 

monthly maximum limitation can be calculated similarly except that the variability factor 

corresponds to the distribution of monthly averages instead of daily concentration 

measurements. 

The daily variability factor is a statistical entity defined as the ratio of the 

estimated 99th percentile of a distribution of daily values divided by the mean of the 

distribution. Similarly, the monthly variability factor is typically defined as the 

estimated 95th percentile of the distribution of 4-day averages divided by the mean of 

the monthly averages. 

A modified delta-lognormal distribution can be fit to concentration data. 

Variability factors can then be computed for a facility distribution. The modified deltalognormal distribution models the data as a mixture of non-detect observations and 

measured values. This distribution is often selected because the data for most 

analytes consists of a mixture of measured values and non-detects. The modified 

delta-lognormal distribution assumes that all non-detects have a value equal to the 

detection limit and that the detected values folJow a lognormal distribution. 

For more details on EPA’s use of statistical methods for developing ELGs, refer 

to Development Document for Effluent Limitations Guidelines and Standards for the 

74 - 8Ef% NPDES Permit Writers’ Manual 
Chapter 5 Technology-Based Effluent Limits 

Organic Chemicals, Plastics and Synthetic Fibers Point Source Category” or 

Technical Support Document for Water Quality-Based Toxics Control”. 

5.2 Application of Technology-Based Effluent Limitations for 

Municipal Dischargers 

The largest category of dischargers requiring individual NPDES permits is 

municipal POTWs. Similar to its approach for controlling the discharges from 

industrial sources, the 1972 CWA required POTWs to meet performance-based 

requirements based on available wastewater treatment technology. Section 301 of the 

CWA established a required performance level, referred to as “secondary treatment,” 

that all POTWs were required to meet by July 1, 1977. 

More specifically, Section 301(b)(l)(B) of the CWA requires that EPA develop 

secondary treatment standards for POTWs as defined in Section 304(d)(l) of the Act. 

Based on this statutory requirement, EPA developed secondary treatment regulations 

which are specified in 40 CFR Part 133. These technology-based regulations apply to 

all municipal wastewater treatment plants and identify the minimum level of effluent 

quality attainable by secondary treatment in terms of BOD,, TSS, and pH. The 

regulations provide for special considerations regarding combined sewers, industrial 

wastes, waste stabilization ponds, and less concentrated influent wastewater for 

combined and separate sewers. Pursuant to Section 304(d)(4) of the CWA, the 

regulations also define “treatment equivalent to secondary treatment” and the 

alternative standards that apply to facilities meeting this definition. 

5.2.1 Secondary Treatment 

An important aspect of municipal wastewater is that it is amenable to biological 

treatment. The biological treatment component of a municipal treatment plant is 

termed secondary treatment and is usually preceded by simple settling (primary 

treatment). In response to the CWA requirements, EPA evaluated performance data 

“USEPA (1987). Development Document for Efiluenl Limitations Guidelines and Sfandards for the 

Organic Chemicals, Plastics, and Synthetic Fibers Point Source Category. Vol I and Vol II. EPA 440/i87/009. Office of Water, Industrial Technology Division. 

“USEPA (1991). Technical Support Document for Wafer Quality-Based Toxics Control. EPA505/2-90-001. Office of Water Enforcement and Permits. 

8Ep# NPDES Permit Writers’ Manual - 75 
Chapter 5 Technology-Based Effluent Llmits 

for POTWs practicing secondary treatment and established performance standards 

based on its evaluation. Secondary treatment standards, therefore, are defined by the 

limitations provided in Exhibit 5-6. 

Parameter 

5-Day BOD 

TSS 

PH 

Removal 

EXHIBIT 5-6 

Secondary Treatment Standards 

30-Day Average 7-Day Average 

30 mgll 45 mgfl 

30 mg/l 45 mgil 

6 - 9 S.U. (instantaneous) - 

85% BOD, and TSS - 

According to 40 CFR $122.45(f), permit writers must apply these secondary 

treatment standards as mass-based limits using the design flow of the plant. Permit 

writers may also apply concentration-based effluent limitations for both 30-day and 

-/-day average limitations. 

Example: 

A POTW with a design flow rate of 2.0 mgd would have permit limits based on secondary treatment 

standards as follows: 

Mass-Based Limit = Design Flow x Concentration-Based Limit x Conversion Factor 

BOD 

(30-day average) 2.0 mgd x 30mg/l x 8.34 (Ib)(l)/(mg)(gal) = 500 lb/da 

(7-day average) 2.0 mgd x 45mg/l x 8.34 (Ib)(l)/(mg)(gal) = 737niz& 

TSS 

(30-day average) 2.0 mgd x 30mg/l x 8.34 (Ib)(l)/(mg)(gal) = 500 lb/da 

(7-day average) 2.0 mgd x 45mg/l x 8.34-$b)(l)/(mg)(gal) = d 

PH 

(instantaneous) 6-9 

Removal 

(30-day average) 85% BOD, and TSS removal 

Where nitrification is occurring in a treatment process, BOD, may not provide a 

reliable measure of the oxygen demand of the effluent. This is because nitrifying 

bacteria use a large amount of oxygen to consume unoxidized nitrogen and ammonia76 - QEfY4 NPDES Permit Writers’ Manual 
Chapter 5 Technology-Based Eff bent Llmits 

nitrogen and convert these to oxidized nitrate. In these instances, basing permit limits 

on carbonaceous BOD, (CBOD,) instead of BOD, eliminates the impact of nitrification 

on effluent limits. EPA, therefore, allows for the use of CBOD, limits to minimize false 

indications of poor facility performance as a result of nitrogenous pollutants. Allowed 

under 40 CFR 9133.102(a)(4), the permit writer does have the discretion to set 

effluent Jimits for CBOD, in lieu of a BOD, limit. EPA has studied the use of a CBOD, 

limit and has concluded that a 25 mg/l 30-day average and 40 mg/l 7-day average are 

effectively equivalent to the (30/45) BOD, limits. 

Chemical oxygen demand (COD) and total organic carbon (TOC) laboratory 

tests can provide an accurate measure of the organic content of wastewater in a 

shorter time frame than a BOD, test (i.e., several hours versus 5 days). Pursuant to 

40 CFR 5133.104(b), the permit writer may substitute COD or TOC monitoring for 

BOD, when a long-term BOD:COD or BOD:TOC correlation has been demonstrated. 

Municipal wastewater treatment facilities are required to meet secondary 

treatment standards with few exceptions. The exceptions, identified at 40 CFR 

s133.103, include: 

. Treatment works that receive flows from combined sewers during wet 

weather can qualify for alternative monthly percent removal limits during wet 

weather events. 

. Treatment works that receive wastes from industrial categories that have 

ELGs for BOD, and TSS less stringent than the secondary treatment 

requirements in 40 CFR Part 133, can qualify to have their BOD, and TSS 

limits adjusted upwards provided that: (1) the permitted discharge is less 

than would be permitted under the corresponding ELGs for direct 

discharges, and (2) the flow or loading of such pollutants introduced by the 

industrial category exceeds ten percent of the design flow or loading of the 

POTW. 

. Treatment works that use waste stabilization ponds as the principal process 

for secondary treatment and whose operation and maintenance data 

indicate that the TSS values specified in the equivalent-to-secondary 

regulations (discussed in Section 5.2.2) cannot be achieved, can qualify to 

have their minimum TSS levels adjusted upwards. 

. Treatment works that receive less concentrated wastes from separate 

sewer systems can qualify to have their percent removal limit reduced or 

receive a mass loading limit provided that: (1) the facility can consistently 

meet its permit effluent concentration limits but cannot meet its percent 

&a# NPDES Permit Writers’ Manual - 77 
Chapter 5 Technology-Based Eff bent Llmits 

removal limits because of less concentrated effluent water, (2) the facility 

would have been required to meet significantly more stringent limitations 

than would otherwise be required by the concentration-based standards, 

and (3) the less concentrated effluent is not the result of excessive 

infiltration/inflow (l/l). 

[Note: The determination of excessive l/l is based on (1) the “excessive l/l” 

definition in 40 CFR §352005(b)(16) as the quantities of l/l which can be 

economically eliminated from a sewer system as determined in a costeffectiveness analysis that compares the costs for correcting the l/l 

conditions to the total costs for transportation and treatment of the l/l and 

(2) l/l is not excessive if the total flow (i.e., wastewater plus l/l) to the 

POTW is less than 275 gallons per capita per day.] 

. Treatment works receiving less concentrated wastes from combined sewers 

during dry weather can qualify to have their percent removal limit reduced 

or receive a mass loading limit provided that: (1) the facility can 

consistently meet its permit effluent concentration limits, but cannot meet its 

percent removal limits because of less concentrated effluent water, (2) the 

facility would have been required to meet significantly more stringent 

limitations than would otherwise be required by the concentration-based 

standards, and (3) the less concentrated influent wastewater does not result 

from either excessive infiltration or clear water industrial discharges during 

dry weather periods. If the less concentrated influent is the result of clear 

water industrial discharges, the treatment works must control such 

discharges pursuant to 40 CFR Part 403. 

[Note: The determination of excessive infiltration is based on (1) the 

“excessive infiltration” definition in 40 CFR §352005(b)(28) as the quantity 

of flow which is less than 120 gallons per capita per day (domestic flow and 

infiltration) or the quantity of infiltration which cannot be economically and 

effectively eliminated from a sewer system as determined in a cost 

effectiveness analysis and (2) the criterion that either 40 gallons per capita 

per day or 1,500 gallons per inch diameter per mile of sewer may be used 

as the threshold value for that portion of the dry weather base flow 

attributed to infiltration.] 

The NPDES regulations also provide for a waiver from secondary treatment 

requirements for discharges into marine waters. In these instances, the POTW must 

file a modification request for a marine discharge in accordance with the requirements 

of 40 CFR Part 125, Subpart G. More detail on marine variance requests is provided 

in Section 10.1.3. 

78 - 8EFR NPDES Permit Writers’ Manual 
Chapter 5 Technology-Based Eff bent Llmits 

5.2.2 Equivalent-to-Secondary Treatment Definition 

Following publication of the secondary treatment regulations, legislative history 

indicates that Congress was concerned that EPA had not “sanctioned” the use of 

certain biological treatment techniques that were effective in achieving significant 

reductions in BOD, and SS for secondary treatment. Therefore, to prevent 

unnecessary construction of costly new facilities, Congress included language in the 

1981 amendment to the Construction Grants statutes [Section 23 of Pub. L. 97-1471 

that required EPA to provide allowances for alternative biological treatment 

technologies, such as a trickling filter or waste stabilization pond. In response to this 

requirement, definition of secondary treatment was modified on September 20, 1984, 

and June 3, 1985, and published in the revised secondary treatment regulations 

contained in 40 CFR $133.105. These regulations allow alternative limits for facilities 

using trickling filters and waste stabilization ponds that meet the requirements for 

“equivalent to secondary treatment.” Several important concepts form the basis for 

this revision of the regulations: 

l Certain classes of biological treatment facilities that are capable of 

achieving significant reductions in BOD, and TSS, but cannot consistently 

achieve secondary treatment, should be defined as separate and distinct 

from secondary treatment facilities. 

l These facilities (equivalent-to-secondary) are cheaper and easier to operate 

and, therefore, are utilized by smaller communities. The provisions 

established by EPA should provide for continued use of these technologies 

where possible. 

. The technology-based effluent limitation approach used to establish 

secondary treatment should be retained for equivalent-to-secondary 

treatment limits. 

l Water quality must not be adversely affected by the application of 

equivalent-to-secondary treatment. 

l Costly treatment plant upgrading or replacement should be avoided where 

equivalent facilities are operating sufficiently (e.g., achieving their original 

design performance levels). 

. Regulations should address variations in facility performance due to 

geographic, climatic, or seasonal conditions. 

In recognition of the above factors, the revisions to include a definition for 

equivalent-to-secondary treatment entail a change in the traditional definition of 

secondary treatment for some POTWs. The capability and performance of an 

&EfW NPDES Permit Writers’ Manual - 79 
Chapter 5 Technology-Based Effluent Urnits 

individual plant is assessed, and limits are selected from a range of possible values. 

Although this process has been used for industrial facilities, the concept has generally 

not been applied to municipal permits (with the exception of interim permit limits). 

To be eligible for equivalent-to-secondary limitations, a POTW must meet all of 

the following criteria: 

. The principal treatment process must be either a trickling filter or waste 

stabilization pond (e.g., the largest percentage of BOD, and TSS removal is 

provided by the trickling filter or waste stabilization pond system). 

l The effluent quality consistently achieved, despite proper operations and 

maintenance, is in excess of 30 mg/l BOD, and TSS. 

. Water quality is not adversely affected by the discharge. 

. The treatment works as a whole provides significant biological treatment 

such that a minimum 65 percent reduction of BOD, is consistently attained 

(30-day average). 

A treatment works that is operating beyond its design hydraulic or organic 

loading limit is not considered an eligible facility. If overloading or structural failure is 

causing poor performance, the SOlUtiOn to the prObl8m is conSttUCtiOn, not effluent 

limitations adjustment. There are several important implications of the equivalent-tosecondary treatment regulation as it applies to specific municipal permitting issues. 

These issues are discussed beiow. 

New Facility Limitations 

As specified in 40 CFR 3133.1 OS(f), the permitting authority must set more 

stringent limits for new facilities if an analysis of new plant performance shows that 

more stringent limits than the maximum equiv$ent-to-secondary limits (45/45) can be 

met. Recently, a wide range of designs (e.g., solids contact channels, covers) have 

been used on trickling filters to improve their performance. This situation creates a 

performance dichotomy between old trickling filters and current state-of-the-art plants. 

The regulations recognize this disparity and encourage States to establish separate 

limits for new trickling filters based on current design practices in the State. Where 

possible, an analysis of similar plants is the preferred method for establishing permit 

limits where in-state data on new trickling filters are not available. Where no 

80 - 8EY4 NPDES Permit Writers’ Manual 
Chapter 5 Technology-Based Eff bent Urnits 

performance data are available for determining new plant capability, literature values 

may be used. 

Calculation of Permit Limits for Equivalent-to-Secondary Facilities 

In most cases, the permit limits for equivalent-to-secondary facilities will be 

selected from the 30 to 45 mg/l BOD, and TSS monthly average, and 45 to 65 mg/l 

BOD, and TSS weekly average range established by the regulation. Obviously, not all 

permits will be set at the 45 mg/l monthly average and 65 mg/l Weekly average top of 

the range. The selection should be based on current performance data for the last 

two years of operation, at a minimum. 

Where the plant performance data contain erroneous values because of plant 

upsets, or other situations not associated with poor operation or maintenance, an 

adjustment to the permit limit calculation may be made. The data for the month in 

question may be adjusted by dropping the erroneous daily value and recalculating the 

monthly average based on the remaining daily values. Another alternative is to 

analyze monthly average values for a period greater than two years and drop the 

monthly averages that are erroneous because of explained upset situations. 

Discharge Monitoring Report (DMR) data should be used for calculations whenever 

possible., The DMRs must support the permit writer’s decision for an equivalent to 

secondary facility. It should be noted that the burden of proof for performance data 

and demonstration of proper operation and maintenance is the responsibility of the 

municipality. 

A trickling filter or lagoon will often be combined with another biological process 

(i.e., activated sludge process) in one treatment plant. In this case, if the trickling filter 

or lagoon qualifies for equivalent-to-secondary limits, the permit limits for the treatment 

plant can be derived by averaging the equivalent-to-secondary and conventional 

secondary treatment limits. To accomplish this, a flow-weighted average of the two 

effluent concentration limits should be calculated and applied as the outfall limitation 

for the permit. An alternative to this approach is the use of internal waste stream 

limitations as authorized by 40 CFR 5122.45(h) for each biological process effluent 

line. The permit writer should encourage the continued use of existing trickling filters 

and lagoons, where appropriate, through the application of appropriate equivalent-tosecondary limits. However, the permit writer must be sure that these facilities are 

&EFYA NPDES Permit Writers’ Manual - 81 
Chapter 5 Technology-Based Effluent Urnits 

capable of meeting the proposed effluent limits without causing water quality impacts 

before the permit limits can be adjusted. if one cannot determine this, equivalent-tosecondary limits cannot be used in the permit. 

Alternative State Requirements (ASRs) 

The Alternative State Requirement (ASR) provision contained in 40 CFR 

§133.105(d) of the regulation allows States the flexibility to set permit limits above the 

maximum levels of 45 mg/l monthly average and 65 mg/l w88kly average BOD, and 

TSS from lagoons meeting certain requirements. Where lagoon suspended solids 

requirements are already above 45 mg/l in accordance with 40 CFR §133.103(c), an 

ASR by the State is not necessary, unless higher limits are desired. To establish an 

ASR, the State must do two things: 

. Identify a group of equivalent facilities that warrant different limits in 

exceedance of the equivalent-to-secondary values contained in 40 CFR 

Part 133 

. Justify the higher permit limitations for these facilities. 

The group of facilities can be selected because of climatic or geographic 

location, the type of technology used, or any other supportable criteria. The analysis 

of plant data for the group must be statistically sound and should follow the methods 

presented in EPA’s Technical Support Document for Water Quality-Based Toxics 

Control.” The ASR must be approved by the EPA Region before permits can be 

written using the ASR values. The public notice of a proposed ASR is the 

responsibility of the State. EPA has published approved ASRs in 49 FR 37005, 

September 20, 1984. Exhibit 5-7 is a summary of the ASRs for 8aCh State. 

Carbonaceous BOD Limits 

EPA recognizes that the carbonaceous BOD (CBOD) test can provide accurate 

information on treatment plant performance in many cases. However, the use of 

CBOD in permits should be focused on facilities with known or suspected nitrification 

“USEPA (1991). Technical Support Document for Water Quality-Based Toxics Control. EPA50512-90-001. Office of Water Enforcement and Permits. 

82 - BEPA NPDES Permit Writers’ Manual 
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problems such as underloaded facilities and new facilities with long detention times. 

These conditions favor nitrifying bacteria and can lead to erroneous BOD, test results. 

The equivalent-to-secondary treatment regulations In 40 CFR §133.105(e) allow 

optional use of a CBOD limit and test procedure in municipal permits as a substitute 

for the standard BOD,. This substitution is at the discretion of the permitting authority. 

To establish a CBOD limit for an equivalent-to-secondary treatment facility, the 

permitting authority must have data to show that nitrifying bacteria in the treatment 

plant are causing the BOD, test results to be significantly impacted. Extensive 

BODJCBOD comparisons should not be necessary because the actual CBOD limit will 

be established by (1) determining the BOD, limit that can be met through proper 

operation and maintenance, and (2) if the BOD, limit is between 30 and 45 mg/l, 

setting the CBOD limit 5 units lower (e.g., between 25 and 40 mg/l). 

The EPA-approved test procedures In 40 CFR Part 136 now contain a CBOD 

(nitrogen inhibited) test procedure. The CBOD test can be specified for any municipal 

permit. However, the BODJCBOD relationship (5 mg/l difference) may not apply 

outside the 30 to 45 mg/l BOD, range. If CBOD limits will be used for equivalent-tosecondary permits above 45 mg/l (BOD,), a BOD&BOD relationship should be 

established during the ASR process. Where parallel BODJCBOD test data are 

available, they must be submitted to the EPA Regional office with the proposed ASRs 

for approval. For permit limits below 30 mg/l BOD, the corresponding CBOD limit 

should be developed during an aavanced treatment review or from the wasteload 

allocation. The use of CBOD in the permit is not a substitute for nitrogen or ammonia 

limits if in-stream nitrification or ammonia toxicity is creating a problem. 

8B4 NPDES Permit Writers’ Manual - 83 
Chapter 5 Technology-Based Effluent Limita 

EXHIBIT 5-7 

State-Specific ASRs 

84 - XfM NPDES Permit Writers’ Manual 
Chapter 5 Technology-Based Eff bent Urnits 

EXHIBIT 5-7 

State-Specific ASRs (continued) 

Alternate TSS Limit 

Location 

Nebraska 80 

North Carolina 90 

North Dakota 

North and East of Missouri River 60 

South and West of Missouri River 100 

Nevada 

New Hampshire 

90 

45 

New Jersey None 

New Mexico 90 

New York 70 

Ohio 65 

Oklahoma ! 90 I 

Oregon 

East of Cascade Mountains 

West of Cascade Mountains 

Pennsylvania 

Puerto Rico 

Rhode Island 

South Carolina 

South I-w&~ 

Tennessee 

Texas 

Utah 

Vermont 

Virginia 

East of Blue Ridge Mountains 

West of Blue Ridge Mountains 

East slope counties: Loudoun, Fauquier, 

Rappahannock, Madison, Green, Albemarle, 

Nelson, Amherst, Bedford, Franklin, Patrick. 

Virgin Islands 

Washington 

West Virginia 

Wisconsin 

Wyoming 

Trust Territories and N. Marianas 

Source: 49 FR 37005: 9/20/84 

85 

SO 

None 

None 

45 

90 

120 

100 

90 

None 

55 

60 

78 

Case-by-base application of 60/78 limits. 

None 

75 

80 

80 

loo 

None 

&EM NPDES Permit Writers’ Manual - 85 
Chapter 6 

Water Quality-Based Effluent 

Limits 

Permit writers must consider the impact of every proposed surface water 

discharge on the quality of the receiving water. Water quality goals for a water body 

are defined by State water quality standards. A permit writer may find, by analyzing 

the effect of a discharge on the receiving water, that technology-based permit limits 

are not sufficiently stringent to meet these water quality standards. In such cases, the 

CWA and EPA regulations require development of more stringent, water quality-based 

effluent limits (WQBEL) designed to ensure that water quality standards are met. In 

order to develop effective WQBELs, permit writers must be familiar with State water 

quality standards methods for predicting water quality impacts from discharges, and 

procedures for establishing WQBELs. This chapter provides basic information on 

these subjects. For more detailed information on water quality-based permitting, refer 

to the Technical Support Document for Water Quaky-Based Toxics Control (TSD),13 

or equivalent State or regional procedures. 

13USEPA (1991). Technical Support Document for Water Quality-Based Toxics Control. EPA505/2-90-001. Office of Water Enforcement and Permits. 

EPA NPDES Permit Writers’ Manual - 87 
Chapter 6 Water Quality-Based Effluent Limits 

6.1 Overview of Water Quality Standards 

WQBELs involve a site-specific evaluation of the discharge and its effect on the 

receiving water. A WQBEL is designed to protect the quality of the receiving water by 

ensuring that State water quality standards are met. To understand how to develop 

WQBELs, the permit writer must understand State water quality standards and the 

water quality goals they define. 

Section 303(c) of the CWA requires every State to develop water quality 

standards applicable to all water bodies or segments of water bodies that lie within the 

State. Once standards are developed, EPA must approve or disapprove them. Water 

quality standards should (1) include provisions for restoring and maintaining the 

chemical, physical, and biological integrity of State waters, (2) provide, wherever 

attainable, water quality for the protection and propagation of fish, shellfish, and 

wildlife and recreation in and on the water (“fishable/swimmable”), and (3) consider the 

use and value of State waters for public water supplies, propagation of fish and 

wildlife, recreation, agriculture and industrial purposes, and navigation. Currently, 

States are required to review their water quality standards at least once every three 

years and revise them as necessary. When writing a permit, the permit writer must 

use the most current State water quality standards. For more information regarding 

procedures for developing water quality standards, refer to EPA’s Water Quality 

Standards Regulation at 40 CFR Part 131 and the Water Quality Standards 

Handbook: Second Edition.14 

Under §510 of the CWA, States may develop water quality standards more 

stringent than required by the Water Quality Standards Regulation. Also, EPA reviews 

and approves or disapproves State-adopted water quality standards. EPA’s review is 

to ensure that the State water quality standards meet the requirements of the CWA 

and the Water Quality Standards Regulation. EPA may promulgate a new or revised 

standard for a State where necessary to meet the requirements of the CWA. 

14USEPA (1994). Water Quality Standards Handbook: Second Edition. EPA 823-B-94-005a. 

Office of Water. 

88 - EPA NPDES Permit Writers’ Manual 
Chapter 6 Water Quality-Based Effluent limits 

61.1 Components of Water Quality Standards 

Water quality standards are composed of three parts: 

. Use classifications 

. Numeric and/or narrative water quality criteria 

. Antidegradation policy. 

Each of these three components is described below. 

Use Classification 

The first part of a State’s water quality standard is a classification system for 

water bodies based on the expected beneficial uses of those water bodies. The CWA 

describes various uses of waters that are considered desirable and should be 

protected. These uses include public water supply, recreation, and propagation of fish 

and wildlife. The States are free to designate more specific uses (e.g., cold water 

aquatic life, agricultural), or to designate uses not mentioned in the CWA, with the 

exception of waste transport and assimilation which is not an acceptable designated 

use (see 40 CFR 5131.10(a)). Designated uses should support the “fishable/ 

swimmable” goal of Section 101 (a)(2) of the CWA where such uses are attainable. A 

State must perform a use attainability analysis under 40 CFR $131.10(j) where it: (1) 

does not designate a “fishable/swimmable” use for a water; (2) wishes to remove a 

“fishable/swimmable” designated use; or (3) wishes to adopt subcategories of a 

designated “fishable/swimmable” use that would require less stringent criteria. The 

use attainability analysis is a structured scientific assessment of the factors affecting 

the attainment of a use. The analysis may include physical, chemical, biological, and 

economic factors as described in 40 CFR 9131.10(g). 

Water Quality Criteria 

The second part of a State’s water quality standard is the water quality criteria 

deemed necessary to support the designated uses of each water body. Section 

303(a-c) of the CWA requires States to adopt criteria sufficient to protect designated 

uses for State waters. These criteria may be numeric or narrative. The CWA requires 

States to adopt numeric criteria for certain toxic pollutants where they are necessary 

to protect designated uses. EPA’s Water Quality Standards Regulation encourages 

8ElY4 NPDES Permit Writers’ Manual - 89 
Chapter 6 Water Quality-Based Effluent Urn&s 

States to adopt both numeric and narrative water quality criteria. See Section 6.1.2, 

Establishing Water Quality Criteria, of this manual for additional information on the 

development of numeric and narrative criteria. 

Antidegradation Policy 

The third part of a State’s water quality standard is the State’s antidegradation 

policy. Each State is required to adopt an antidegradation policy consistent with 

EPA’s antidegradation regulations (40 CFR 9131.12) and to identify the methods it will 

use for implementing the policy. Antidegradation policies provide three tiers of 

protection from degradation of water quality: 

l Tier l-Protects existing uses and provides the absolute floor of water 

quality for all waters of the United States. Existing instream water uses are 

those uses that were attained on or after November 28, 1975, the date of 

EPA’s first Water Quality Standards Regulation, or uses for which existing 

water quality is suitable unless prevented by physical problems such as 

substrate or flow. 

l Tier 2-Protects the level of water quality necessary to support propagation 

of fish, shellfish, and wildlife and recreation in and on the water in waters 

that are currently of higher quality than required to support these uses. 

Before water quality in Tier 2 waters can be lowered, there must be an 

antidegradation review consisting of: (1) a finding that it is necessary to 

accommodate important economical or social development in the area 

where the waters are located; (2) full satisfaction of all intergovernmental 

coordination and public participation provisions; and (3) assurance that the 

highest statutory and regulatory requirements for point sources and best 

management practices for nonpoint sources are achieved. Furthermore, 

water quality may not be lowered to less than the level necessary to fully 

protect the “fishable/swimmable” uses and other existing uses. 

l Tier 3-Protects the quality of outstanding national resources, such as 

waters of national and State parks and wildlife refuges and waters of 

exceptional recreational or ecological significance. There may be no new 

or increased discharges to these waters and no new or increased 

discharges to tributaries of these waters that would result in lower water 

quality (with the exception of some limited activities that result in temporary 

and short-term changes in water quality). 

90 - 8Ep# NPDES Permit Writers’ Manual 
Chapter 6 Water Quality-Based Effluent limits 

Additional information on water quality standards is available in the Water Quality 

Standards Handbook: Second Edifion.‘5 

6.1.2 Establishing Water Quality Criteria 

Water quality criteria set ambient levels of individual pollutants or parameters, 

or describe conditions of a water body that, if met, will generally protect the 

designated use of the water. Water quality criteria are developed to protect aquatic 

life and human health, and, in some cases, wildlife from the deleterious effects of 

pollutants. Section 304(a) of the CWA directs EPA to publish water quality criteria 

guidance to assist States in developing water quality standards. EPA criteria or 

guidance consists of three components: 

l Magnitude-The level of pollutant (or pollutant parameter), generally 

expressed as a concentration, that is allowable. 

0 Duration-The period of time (averaging period) over which the instream 

concentration is averaged for comparison with criteria concentrations. 

l Frequency-l-low often criteria can be exceeded. 

EPA’s efforts on criteria development have been focused on the 65 pollutants 

listed in Section 307(a) of the CWA. Some of the 65 pollutants on the list are actually 

families or classes of organic compounds consisting of many individual chemicals. 

EPA translated this list into a new list of 129 priority toxic pollutants. Subsequently, 

two volatile chemicals and one water unstable chemical were removed from the list so 

that the present list contains 126 priority toxic pollutants. Criteria for the priority toxic 

pollutants that EPA has developed to date are contained in individual criteria 

documents and summarized in a document entitled Qualify Criteria for Water 7986,16 

more commonly referred to as the Gold Book. 

“USEPA (1994). Water QuaMy Sfandards Handbook: Second Edition. EPA 823-B-94-005a. Office of 

Water. 

“%lSEPA (1986). Quality Criteria for Water, 1986. EPA-440/5-86-001. Office of Water Regulations 

and Standards. 

88R4 NPDES Permit Writers’ Manual - 91 
Chapter 6 Water Quality-Based Effluent lfmltr 

Numeric Criteria 

Numeric water quality criteria are values expressed as levels, constituent 

concentrations, toxicity units (see discussion of whole effluent toxicity below), or 

numbers deemed necessary to protect designated uses. These criteria often form the 

basis for NPDES WQBELs. They also can be useful in assessing and managing 

nonpoint sources. In 1987, Congress increased the emphasis of the CWA on numeric 

criteria for toxic pollutants by enacting Section 303(c)(2)(B) of the act. This section 

requires States to adopt numeric criteria for the 126 priority toxic pollutants for which 

EPA has developed criteria guidance and where the discharge or presence of the 

pollutant could reasonably be expected to interfere with the designated uses of a 

water body. States may establish numeric criteria using EPA criteria guidance, 

modified to reflect site specific conditions, or other scientifically defensible methods. 

EPA criteria for the protection of aquatic fife address both short-term (acute) 

and long-term (chronic) effects on both freshwater and saltwater species. The 

following example shows the current EPA criteria for cadmium. 

Example: 

Aquatic Life 

The procedures described in the GuideMines for Deriving NUm8IiCsi National Water Quality Criten’a for the 

Protection of Aquatic Organisms and Their Uses indicate that, except possibly where a locally important 

species is very sensitive, freshwater aquatic organisms and their uses should not be affected unacceptably 

if the 4-da2 average concentration (in ug/L) of cadmium does not exceed the numerical value given by 

e10.78~1nm neu\~3.4 I more than once every 3 years on the average and if the one-hour average 

concentration (in ug/L) does not exceed the numerical value given by e(’ ‘za[‘n’hardneu~~3~sa) more than once 

every 3 years on the average. For example, at hardnesses of 50, 100, and 200 mg/L as CaCO, the 4-day 

average concentrations of cadmium are 0.66, 1 .l , and 2.0 ug/L, respectively, and the l-hour average 

concentrations are 1.8, 3.9 and 8.6 ~$1. If brook trout, brown trout, and striped bass are as sensitive as 

some data indicate, they might not be protected by this criterion. 

Human health criteria are designed to protect people from exposure resulting 

from consumption of water and fish or other aquatic life (e.g., mussels, crayfish). The 

following example contains EPA’s human health criteria for CadMiUM. 

92 - 8Ep# NPDES Permit Writers’ Manual 
Chapter 6 Water Quality-Basxf Effluent Umfts 

Example: 

Human Health 

The ambient water quality criterion for cadmium is recommended to be identical to the existing drinking 

water standard which is 10 ug/L. Analysis of the toxic effects data resulted in a calculated level which is 

protective of human health against the ingestion of contaminated water and contaminated aquatic 

organisms. The calculated value is comparable to the present standard. For this reason a selective 

criterion based on exposure solely from consumption of 6.5 grams of aquatic organisms was not derived. 

Narrative Criteria 

All States have adopted narrative criteria to supplement numeric criteria for 

toxicants. Narrative criteria are statements that describe the desired water quality 

goal. Examples of narrative criteria are provided below. Narrative criteria can be the 

basis for limiting specific pollutants where the State has no numeric criteria for those 

pollutants or they can be used to limit toxicity where the toxicity cannot be traced to a 

specific pollutant. EPA’s Water Quality Standards Regulation requires States to 

develop implementation procedures for narrative criteria that address all mechanisms 

to be used by the State to ensure that narrative criteria are attained. 

Example: 

Narrative criteria can be statements, requiring that discharges be “free from toxics in toxic amounts” or 

“free of objectionable color, odor, taste, and turbidity.” 

6.1.3 Future Directions for Water Quality Standards 

The water quality standards program is constantly evolving. New scientific, 

regulatory, and policy developments affect the nature of the program. For example, 

three new areas where criteria are being developed include biological, sediment, and 

wildlife criteria. 

0 Biological Criteria-EPA is developing numerical values or narrative 

expressions that describe the reference biological integrity of aquatic 

communities inhabiting unimpaired waters of a designated aquatic life use. 

The biological communities in these waters represent the best attainable 

condition for the organisms. According to EPA policy, States should 

develop and implement biological criteria in their water quality standards. 

l Sediment Criteria-Sediment contamination can result from the deposition 

of toxicants over long periods of time and is also responsible for water 

Qe# NPDES Permit Writers’ Manual - 93 
Chapter 6 Water Quality-Based Effluent lfmfts 

quality impacts when these toxicants are released back into the water 

column. EPA has proposed sediment criteria for five organic chemicals 

(phenanthrene, fluoranthene, dieldrin, acenaphthene, and endrin) 

(59 FR 2652; l/18/94). EPA also is developing sediment criteria for metals, 

and has begun development of implementation guidance for sediment 

criteria. 

0 Wildlife Criteria-EPA is undertaking an initiative to develop numeric 

wildlife criteria to establish ambient concentrations of certain chemicals to 

protect mammals and birds from adverse impacts due to consumption of 

food and/or water containing those chemicals. 

6.2 Approaches to Implementing Water Quality Standards 

The control of toxic discharges to waters of the United States in an important 

objective of the CWA. To effectively accomplish this objective, EPA recommends an 

integrated approach to implementing water quality standards and developing WQBELs. 

This integrated approach includes three elements: a chemical-specific approach, a 

whole effluent toxicity (WET) approach, and a biological criteria or bioassessment 

approach. Each of the three approaches is briefly described below. Exhibit 6-1 

summarizes the capabilities and limitations of each approach. 

6.2.1 Chemical-Specific Approach 

The chemical-specific approach uses the chemical-specific criteria for protection 

of aquatic life, human health, and wildlife adopted into a State’s water quality 

standards. The criteria are used as the basis to analyze an effluent, decide which 

chemicals need controls, and derive permit limits that will control those chemicals to 

the extent necessary to achieve water quality standards in the receiving water. 

Chemical-specific WQBELs in NPDES permits involve a site-specific evaluation of the 

discharge and its effect upon the receiving water. This approach allows for the control 

of individual chemicals before a water quality impact has occurred or to assist in 

returning water quality to a level that will meet designated uses. 

6.2.2 Whole EMuent Toxicity (WET) Approach 

WET, the second approach to water quality-based toxics control, protects the 

receiving water quality from the aggregate toxic effect of a mixture of pollutants in the 

effluent. WET tests measure the degree of response of exposed aquatic test 

organisms to an effluent The WET approach is useful for complex effluents where it 

94 - 8EW NPDES Permit Writers’ Manual 
Chapter 6 Water Quality-Based Effluent limits 

EXHIBIT 6-l 

Components of an Integrated Approach to 

Water Quality-Based Toxics Control 

Cmtrol Approach Capabuities Limitations 

chemical-Specific - Human health protection - Does not consider all toxics 

- Complete toxicology present 

- Straightforward treatabiiity - Bioavailability not measured 

- Fate understood - Interactions of mixtures (e.g., 

- Less expensive testing if additivity) unaccounted for 

only a few toxicants are - Complete testing can be expensive 

present - Direct biological impairment not 

- Prevents impacts measured 

Whole effluent - Aggregate toxicity - No direct human health protection 

:oxicity - Unknown toxicants - Incomplete toxicology (few 

addressed species may be tested) 

- Bioavailability measured - No direct treatment 

- Accurate toxicology - No persistency or sediment 

- Prevents impacts coverage 

- Conditions in ambient may be 

different 

- Incomplete knowledge of 

causative toxicant 

Bioassessments - Measures actual receiving - Critical flow effects not always 

water effects assessed 

- Historical trend analysis - Difficult to interpret impacts 

- Assesses quality above - Cause of impact not identified 

standards - No differentiation of sources 

- Total effect of all sources, 

including unknown sources 

- Impact has already occurred 

- No direct human health protection 

may be infeasible to identify and regulate all toxic pollutants in the discharge or where 

chemical-specific pollutant limits are set, but synergistic effects are suspected to be 

problematic. The WET approach allows the permit writer to be protective of the 

narrative “no toxics in toxic amounts” criterion that is applicable to all waters of the 

United States and implement numeric criteria for toxicity (see the discussion below on 

acute and chronic toxicity). 

There are two types of WET tests: acute and chronic. An acute toxicity test is 

usually conducted over a short time period (e.g., 48 hours) and the endpoint 

measured is mortality. The endpoint for an acute test is often expressed as an LC50 

BEPA NPDES Permit Writers’ Manual - 95 
Chapter 6 Water Quality-Based Effluent Limits 

(i.e., the concentration of effluent that is lethal to 50 percent of the exposed test 

organisms). A chronic toxicity test is usually conducted over a longer period of time 

(e.g., 7 days) and the endpoint measured is mortality and sublethal effects, such as 

changes in reproduction and growth. The endpoint is often expressed as the no 

observed effect concentration (NOEC), the lowest observed effect concentration 

(LOEC), or the inhibition concentration (IC). The NOEC is the highest concentration of 

effluent at which no adverse effects are observed on the aquatic test organisms. The 

LOEC is the lowest concentration of effluent that causes observable adverse effects in 

exposed test organisms. The IC is an estimate of the effluent concentration that 

would cause a given percent reduction in a biological measurement of the test 

organisms. 

To express criteria, facilitate modeling, and express permit limits, EPA 

recommends that toxicity be expressed in terms of “toxic units.” A toxic unit (TU) is 

merely the inverse of the sample fraction. Toxicity, expressed as percent sample, is 

divided into 100 to obtain toxic units. 

Example: 

If a chronic test result is a NOEC of 25 percent effluent, that result can be expressed as 100/25 or 4.0 

chronic toxic units (4.0 TUc); 

If an acute test result is a LC,, of 60 percent, that result can also be expressed as 100/60 or 1.7 acute 

toxic units (1.7 TUa). 

It is important to distinguish acute toxic units (TUa) from chronic toxic units 

(TUc). The difference between TUa and TUc can be likened to the difference 

between miles and kilometers. Thus, to compare a TUa and a TUc, a conversion 

factor called an acute-to-chronic ratio (ACR), must be developed. The ACR is a 

conversion factor that changes TUa into equivalent TUc. If data are insufficient to 

calculate an ACR (i.e., less than 10 sets of WET data), EPA recommends a default 

value of ACR=lO. Where sufficient data are available, the ACR should be calculated 

as the mean of the individual ACRs for each pair of acute and chronic WET test data. 

The following examples show: (1) how the ACR converts TUa into TUc; (2) how to 

calculate an ACR from existing data; and (3) how the ACR allows permit writers to 

compare TUa and TUc. 

96 - 8ER9 NPDES Permit Writers’ Manual 
Chapter 6 Water Quality-Based Effluent Llmk 

Acute to Chronic Ratio Formulas: 

. By definition: 

. Thus: 

. Substituting: 

Example 1: 

ACR = 

Acute Endpoint = L&O 

Chronic Endpoint NOEC 

TUa = 100 

Go 

TUG = & 

LC, = E NOEC = z 

ACR = L% - = (1OOflUa) _ TUc 

NOEC (1 OOjTUc) TUa 

Given: LC,, = 28% 

NOEC = 10% 

Example 2: 

ACR - 

LC, 28% =2a -=- . 

NOEC 10% 

Given: TUc = 10.0 

TUa = 3.6 

Example: 

Toxicity data from POlW Discharge Monitoring Reports (C. dubia): 

LCSO NOEC 

(% Effluent) % Effluent) 

62 10 

18 10 

68 25 

61 10 

63 25 

70 25 

17 5 

35 10 

35 10 

35 25 

47 10 

Mean z T; 

l Calculated value. 

Acute to Chronic Ratio’ 

(ACR) 

6.2 

1.8 

2.7 

6.1 

2.5 

2.8 

3.4 

3.5 

3.5 

1.4 

4.7 

G 

88# NPDES Permit Writers’ Manual - 97 
Chapter 6 Water QualitylBaatd Effluent Llmfts 

Example: 

Where: Wasteload Allocation (WLA) = toxicity level in discharge that will meet 

state water quality criteria (calculated 

value) 

Acute WLA = 1.5 TUa 

Chronic WLA = 4.9 TUc 

Because TUc and TUa are in different units, we can use the ACR to convert TUa to TUc 

assuming an ACR = 10 (default value). 

TUa x ACR = TUa,c 

[where “TUa,c” = acute toxicity eXpreSSed in chronic 

toxicity units] 

1.5TUax 10 = 15 TUa,c 

4.9 TUc < 15 TUa,c: therefore the chronic WLA (4.9 TUc) is more stringent than 

the acute WLA (1.5 TUa); thus 4.9 TUc is used to develop the permit limit. 

The ACR allows us to directly compare the chronic WLA of 4.9 TUc with the acute WLA of 1.5 TUa. 

Using the ACR of 10, we can express 1.5 TUa in chronic toxicity units as 15 TUa,c. We see that 4.9 TUc 

is less than 15 TUa,c, (the acute WIA 8Xpr8SSed in chronic toxicity units}. The more stringent value 

should be used for developing permit limits. Thus, the appropriate requirement that would meet both 

acute and chronic criteria for toxicity is 4.9 TUc. 

6.2.3 Biological Criteria or Biological Assessment Approach 

The biological criteria or biological assessment approach is the third approach 

to water quality-based toxics control. This approach is used to assess the overall 

biological integrity of an aquatic community. Biological criteria, or “biocriteria,” are 

numerical values or narrative statements that describe the reference biological integrity 

of aquatic communities inhabiting waters of a given designated aquatic life use. When 

incorporated into State water quality standards, biological criteria and aquatic life use 

designations serve as direct, legal endpoints for determining aquatic life use 

attainment. Once biocriteria are developed, the biological condition of a water body 

may be assessed through a biological assessment, or “bioassessment.” A 

bioassessment is an evaluation of the biological condition of a water-body using 

biological surveys and other direct measurements of resident biota in surface waters. 

A biological survey, or “biosurvey,” consists of collecting, processing, and analyzing 

representative portions of a resident aquatic community to determine the community 

structure and function. The results of biosurveys may be compared to the reference 

water body to determine if the biocriteria for the designated use of the water body are 

96 - 8ER9 NPDES Permit Writers’ Manual 
Chapter 6 Water Quality-Bad Effluent Limits 

being met. EPA issued guidance on this approach in Nological Criteria: National 

Program Guidance for Surface Waters.” 

To be fully protective of water quality, EPA developed the concept of 

“independent application” to characterize the relationship of the three approaches to 

implementing water quality standards. Independent application says that the results of 

one approach should not be used to contradict or overrule the results of the others. 

Independent application recognizes that each approach has unique as well as 

overlapping attributes, sensitivities, and program applications; thus, no single approach 

for detecting impact should be considered uniformly superior to any other approach. 

For example, the inability to detect receiving water impacts using a biosurvey alone is 

insufficient evidence to waive or relax a permit limit established using either the 

chemical-specific or WET method. 

6.3 Determining ‘the Need for WQBELs 

Once the applicable designated uses and water quality criteria for a water body 

are determined, the permit writer must ensure that dischargers do not cause 

exceedences of these criteria. If, after technology-based limits are applied, the permit 

writer projects that a point source discharger may exceed an applicable criterion, a 

WQBEL must be imposed. EPA regulations at 40 CFR $122.44(d) require that all 

effluents be characterized by the permitting authority to determine the need for 

WQBELs in the permit. 

6.3.1 Defining “Reasonable Potential” to Exceed Applicable Criteria 

In deciding whether or not WQBELs are needed to protect water quality, a 

permit writer must determine whether the discharge causes, has the reasonable 

potential to cause, or contributes to an excursion of numeric or narrative water quality 

criteria. EPA’s regulation at 40 CFR 5122.44(d)(l) establishes the basis for 

determining if there is an excursion of the numeric or narrative water quality criteria. 

At a minimum, the permit writer must make this determination at each permit 

reissuance and must develop WQBELs as necessary to control the discharge of 

pollutants. 

“USEPA (1990). Biological Criteria: National Program Guidance for Surface Waters. EPA-4401 

5-91-004. Office of Science and Technology. 

8EfY4 NPDES Permit Writers’ Manual - 99 
Chapter 6 Water Quality-Bad Effluent Limits 

Reasonable Potential and Numeric Criteria 

When conducting an effluent characterization to determine if WQBELs are 

needed based on chemical-specific numeric criteria in the water quality standards, the 

permit writer projects the receiving water concentration of pollutants contained in the 

effluent once that effluent enters the receiving water. If the projected concentration 

exceeds the applicable numeric water quality criterion for a specific pollutant, there is 

reasonable potential that the discharge may cause or contribute to an excursion above 

the applicable water quality standards and the permit writer must develop a WQBEL. 

If a State has numeric criteria for WET, the permit writer projects the toxicity 

once the effluent enters the receiving water. The permit writer then compares the 

toxicity of the receiving water to the applicable State water quality criteria. If the 

projected toxicity exceeds the applicable numeric water quality criterion for WET, there 

is reasonable potential that the discharge may cause or contribute to an excursion 

above the applicable water quality standards and the permit writer must develop a 

WQBEL for WET. 

Reasonable Potential and Narrative Criteria 

If the permit writer determines that a discharge causes, has the reasonable 

potential to cause, or contributes to an in-stream excursion above a narrative 

criterion, the permit must contain effluent limits for WET unless the permit writer 

demonstrates that chemical-specific limits for the effluent are sufficient to attain and 

maintain applicable numeric narrative water quality criteria. 

The permit writer must investigate effluents for the presence of specific 

chemicals for which the State has not adopted numeric criteria, but which may be 

contributing to an excursion above a narrative criterion. In such cases, permit writers 

must establish limits using one of three options: (1) use EPA’s national criteria, (2) 

develop their own criteria, or (3) control the pollutant through the use of an indicator. 

100 - BEfM NPDES Permit Writers’ Manual 
Chapter 6 Water Quality-8ased Effluent Llmtts 

General Considerations 

When determining whether WQBELs are needed in a permit, the permit writer 

is required to consider, at a minimum: (1) existing controls on point and nonpoint 

sources of pollution; (2) the variability of the pollutant or pollutant parameter in the 

effluent; (3) the sensitivity of the species to toxicity testing; and (4) where appropriate, 

the dilution of the effluent in the receiving water (40 CFR §122.44(d)(ii)). The permit 

writer also must consider whether technology-based limits are sufficient to maintain 

State water quality standards. Finally, the permit writer should consider other 

available data and information pertaining to the discharger (e.g., compliance history, 

in-stream survey data, dilution, data from similar facilities) in addition to effluent 

monitoring data to assist in making an informed reasonable potential determination. 

6.3.2 Determining Reasonable Potential With Effluent Monitoring Data 

When characterizing an effluent for the need for a WQBEL, the permit writer 

should use any available effluent monitoring data as well as other information 

pertaining to the discharge (e.g., type of industry, compliance history, stream surveys) 

as the basis for a decision. The permit writer may already have effluent data available 

from previous monitoring, or he or she may decide to require the permittee to 

generate effluent monitoring data prior to permit issuance or as a condition of the 

issued permit. EPA recommends monitoring data be generated prior to permit limit 

development for the following reasons: (1) the presence or absence of a pollutant can 

be more clearly established or refuted; and (2) effluent variability can be more clearly 

defined. Data collection should begin far enough in advance of permit development to 

allow sufficient time for conducting toxicity tests and chemical analyses. 

The permit writer can use the available effluent data and a water quality model 

to perform a reasonable potential analysis. The mass balance equation, presented in 

Exhibit 6-2, is a simple water quality model that can be used for this analysis. The 

permit writer would use the maximum observed effluent concentration, or a statistically 

projected worst-case value, to calculate a projected in-stream concentration, under 

critical stream conditions. The permit writer would then compare the projected 

receiving water concentration to the applicable water quality criteria to determine 

whether a water quality-based effluent limit is needed. 

8EM NPDES Permit Writers’ Manual - 101 
Chapter 6 Water Quality-8ased Effluent Llmtts 

EXHIBIT 6-2 

Basic Mass Balance Water Quality Equation 

Q&d + QsC, = Q&, 

Qd = waste discharge flow in million gallons per day (mgd) or cubic feet per second 

(cfs) 

Cd = pollutant concentration in waste discharge in milligrams per liter (mg/l) 

Q, = background stream flow in mgd or cfs above point of discharge 

C, = background in-stream pollutant concentration in mg/l 

Q, = resultant in-stream flow, after discharge in mgd or cfs 

C, = resultant in-stream pollutant concentration in mg/l in the stream reach (after 

complete mixing occurs) 

All toxic effects testing and exposure assessment parameters, for both effluent 

toxicity and individual chemicals, have some degree of uncertainty associated with 

them. The more limited the amount of data, the larger the uncertainty. To better 

characterize the effects of effluent variability and reduce uncertainty in the process of 

deciding whether to require an effluent limit EPA has developed a statistical approach 

to determining reasonable potential. This approach is described in detail in Chapter 3 

of the Technical Support Document for Water Quality-Based Toxics Control” 

(hereafter referred to as the “TSD”). The statistical approach combines knowledge of 

effluent variability with the uncertainty due to a limited number of data to project an 

estimated maximum concentration for the effluent. This projected maximum 

concentration, after considering dilution, can then be compared to an appropriate 

water quality criterion to determine the need for an effluent limit. 

Example: 

Q, = Available dilution from upstream river flow = 1.2 cfs 

Q, = Discharge flow = 0.31 cfs 

c, = Upstream river concentration = 0.8 mg/l 

c, = Statistically projected maximum discharge concentration = 2.0 mg/l 

C, = Receiving water concentration 

Water Quality Criterion = 1.0 mg/l 

c = Qd Cd + Qs cs = (0.31 cfs) (2.0mg/l) + (1.2cfs) (OJmg/l) 

r Qr (1.2cfs) + (0.31 cfs) 

Discussion: 

C, = 1.05 mg/l 

Since the downstream concentration (C,) exceeds the water quality criterion, there is a 

reasonable potential for water quality standards to be exceeded. 

‘*USEPA (1991). Technical Support Document for Water Quality-Based Toxics Control. EPA505/2-90-001. Office of Water Enforcement and Permits. 

102 - &EM NPDES Permit Writers’ Manual 
Chapter 6 Water Quality-8aatd Effluent Llmtts 

Example: 

c, = Receiving water (downstream) concentration 

(in toxic units) 

C, = Receiving water background 

concentration = 0 TU 

Qs = Receiving water flow = 23.6 cfs (for acute 

protection) 

70.9 cfs (the 7QlO for 

chronic protection) 

= Discharge flow 

2 = Discharge TUa 

= 7.06 cfs 

= 2.49 TUa 

TUc = 6.25 TUc 

Q, = Downstream flow = Q, + Q, 

Water quality criterion for 

acute protection = 0.3 TUa 

Water quality criterion for 

chronic protection = 1.0 TUc 

C, = (2m49) v*06) + (‘1 (23*6) = 6.57 TUa for acute toxicity 

(7.06 + 23.6) 

c = (6.25) (7.06) + (0) (70.9) 

r (7.06 + 70.9) 

= 0.57 TUc for chronic toxicity 

Discussion: Since the downstream concentration (C,) exceeds the water quality criterion for acute 

toxicity (0.3 TUa), there is reasonable potential for water quality standards for toxicity to 

be exceeded. 

6.3.3 Determining Reasonable Potential Without Effluent Monitoring Data 

If the permit writer so chooses, or if the circumstances dictate, he or she may 

decide to develop and impose a WQBEL without facility-specific effluent monitoring 

data. WQBELs can be set for a single parameter or WET based on the available 

dilution and the water quality criterion or State standard in the absence of faciiityspecific effluent monitoring data. In justifying a limit, the more information the permit 

writer can acquire to support the limit, the better will be the regulatory authority’s 

position in defending the limit, if necessary. Types of information that the permit writer 

may find useful include: type of industry or POTW, existing data on toxic pollutants, 

history of compliance problems and toxic impact, and type of receiving water and 

designated use. The permit writer must provide adequate justification for the limit in 

the permit development rationale or in the permit fact sheet. The permit writer may 

86% NPDES Permit Writers’ Manual - 103 
Chapter 6 Water QualiCy-&wed Effluent Llmfts 

well find that he or she would benefit from the collection of effluent monitoring data 

prior to establishing the limit. The TSD” provides guidance on collecting monitoring 

data for establishing WQBELs. 

If the permit writer, after evaluating all available information on the effluent, in 

the absence of effluent monitoring data, is not able to decide whether the discharge 

causes, has the reasonable potential to cause, or contributes to an excursion above a 

numeric or narrative criterion for WET or for individual toxicants, the permit writer 

should require WET or chemical-specific testing to gather further data. In such cases, 

the permit writer can require the monitoring prior to permit issuance, if sufficient time 

exists, or may require the testing as a condition of the issued (or reissued) permit. 

The permit writer could then include a clause in the permit that would allow the 

permitting authority to reopen the permit and impose an effluent limit if the effluent 

testing establishes that there is reasonable potential that the discharge will cause or 

contribute to an excursion above a water quality criterion. 

6.4 Exposure Assessment and Wasteload Allocation 

Before calculating a WQBEL, the permit writer must first determine the point 

source’s wasteload allocation (WLA). The WLA is the fraction of a total maximum 

daity load (TMDL) for the water body that is assigned to the point source. This section 

discusses the concepts of the TMDL and WLA, describes methods for assessing 

exposure to pollutants in the receiving water, and explains how WLAs for a point 

source are calculated. 

6.4.1 Total Maximum Daily Loads 

A TMDL is a determination of the amount of a pollutant, or property of a 

pollutant, from point, nonpoint, and natural background sources, including a margin of 

safety, that may be discharged to a water quality-limited water body. Any loading 

above this capacity risks violating water quality standards. TMDLs can be expressed 

in terms of chemical mass per unit of time, by toxicity, or by other appropriate 

measures. Exhibit 6-3 provides a graphic illustration of allocations under a TMDL. 

“USEPA (1991). Technical Supper? Document for Water Quality-Based Toxics Control. EPA505/2-90-001. Office of Water Enforcement and Permits. 

104 - &Et# NPDES Permit Writers’ Manual 
Chapter 6 Water Quality-8aatd Effluent Llmtts 

EXHIBIT 6-3 

Components of a TMDL 

Wasteload allocations (WLAs) 

are assigned to each point 

source discharge 

Load allocations (LAS) are 

assigned to nonpoint sources 

WLAs and LAS are 

established so that predicted 

receiving water 

concentrations do not exceed 

water quality criteria 

Section 303(d) of the CWA established the TMDL process to provide for more 

stringent water quality-based controls when technology-based controls are inadequate 

to achieve State water quality standards, These statutory requirements were codified 

at 40 CFR 5130.7. When implemented accordingly, the TMDL process can broaden 

the opportunity for public comment, expedite water quality-based NPDES permitting, 

and lead to technically sound and legally defensible decisions for attaining and 

maintaining water quality standards. Also, the TMDL process provides a mechanism 

for integrating point and nonpoint pollutant sources into one evaluation. 

Based on the TMDL, point source WLAs and nonpoint source load allocations 

(LAS) are established so that predicted receiving water concentrations do not exceed 

water quality criteria. TMDLs, WLAs, and LAS are established at levels necessary to 

attain and maintain the applicable narrative and numerical water quality standards, 

with seasonal variations and a margin of safety that account for any lack of knowledge 

concerning the relationship between point source and nonpoint source loadings and 

water quality. 

In some cases, the waterbody segment under consideration may contain only 

one point source discharger, In this situation, States typically develop a simple TMDL 

86% NPDES Permit Writers’ Manual - 105 
Chapter 6 Water QurlRy-Bamd Effluant Lfmik 

that considers the point source and background contributions of a pollutant from other 

sources. For other waterbody segments, a TMDL may not be available at the time the 

permit must be issued, or a TMDL may not be required at all. In such cases, 

permitting authorities have historically developed a single WLA for a point source 

discharging to the waterbody segment. Both simple TMDLs and single WLAs 

commonly rely on mass balance and simplified water quality models which assume 

steady-state, or constant conditions for variables such as background pollutant 

concentrations and stream flow. EPA has encouraged States to develop TMDLs for 

more difficult water quality problems involving multiple point and nonpoint source 

pollutant loads. These types of TMDLs require complex water quality models capable 

of simulating rainfall events and analyzing cumulative chemical fate and transport. 

Simple, steady-state modeling and more complex, dynamic modeling are discussed in 

greater detail in Section 6.4.3 below. 

EPA is supporting innovative approaches linked to developing and implementing 

TMDLs, such as watershed-based trading. Trading means that pollution sources can 

sell or barter their ability to reduce pollution with other sources that are unable to 

reduce their pollutant loads as economically. TMDLs provide a basis for successful 

trading because they can be adapted to incorporate trades, and because the data and 

analyses generated in TMDLs allow water quality managers to better understand and 

predict the effects of proposed trades. The success of trading will rely on reasonable 

assurance that a TMDL will be implemented. 

Further guidance related to establishing TMDLs can be found in Chapter 4 of 

EPA’s TSD2* and in the Guidance fur Water Quality-Based Decisions: The TMDL 

Process.2’ 

6.4.2 Calculating Wasteload Allocations 

Before calculating a WQBEL, the permit writer must first know the WLA for the 

point source involved. As discussed above, the WLA is the fraction of a receiving 

?JSEPA (1991). Technical Support Document for Water Quality-Based Toxics Conlrol. EPA505/2-90-001. Office of Water Enforcement and Permits. 

2’USEPA 1991, Guidance for Water Quality-Based Decisions: The TMDL Process. EPA-440/4-91-0001. 

Office of Water. 

106 - 8ER9 NPDES Permit Writers’ Manual 
Chapter 6 Water QurMty-Bamd Effluant Lhnfts 

water’s TMDL that is allocated to one of its existing or future point sources of pollution. 

The appropriate WLA is determined through an exposure assessment. Water quality 

models are the primary tools utilized by regulatory agencies in conducting an exposure 

assessment to determine a WLA. Models establish a quantitative relationship 

between a waste’s load and its impact on water quality. Modeling is usually 

conducted by a specialized work group within the regulatory agency; however, it is 

important that the permit writer understand this process. The permit writer will use the 

end result of the model, a WLA, to derive a WQBEL. 

6.4.3 Selecting a Water Quality Model 

Determining which model is appropriate for a given discharge and receiving 

water is based upon whether or not there is rapid and complete mixing of the effluent 

with the receiving water. If the receiving water does not have rapid and complete 

mixing, a mixing zone assessment is recommended, If there is rapid and complete 

mixing near the discharge point-, a complete mix assessment involving fate and 

transport models is recommended. 

Mixing Zone Assessment 

In incompletely mixed discharge receiving water situations, mixing zone 

modeling is appropriate. Mixing zones are areas where an effluent undergoes initial 

dilution and are extended to cover secondary mixing in the ambient water body. A 

mixing zone is an allocated impact zone in the receiving water where acute and 

chronic water quaiity criteria can be exceeded as long as toxic conditions are 

prevented and the designated use of the water is not impaired as a result of the 

mixing zone. 

The CWA allows mixing zones at the discretion of the State. Individual State 

policy determines whether or not a mixing zone is allowed. EPA recommends that 

States make a definitive statement in their water quality standards on whether or not 

mixing zones are allowed and how they will be defined. EPA provides guidance on 

when to require a mixing zone and how to determine the boundaries and size of a 

mixing zone. 

0Ei# NPDES Permit Writers’ Manual - 107 
Chapter 6 Water QurMty-Bamd Effluant Lhnfts 

In general, there are two stages of mixing: discharge-induced and ambient 

induced. The first stage is controlled by discharge jet momentum and buoyancy of the 

effluent. This stage generally covers most of the mixing zone allowed by State water 

quality standards. Beyond the point of discharge-induced mixing, mixing is controlled 

by ambient turbulence. Both discharge-induced mixing and ambient-induced mixing 

models are available for mixing zone analyses. The Water Quality Sfandards 

Hand.booti2 and Chapter 4 of the TSD23 provide further guidance on mixing zones 

and how to conduct a mixing zone analysis. 

Complete Mix Assessment 

If the distance from the outfall to complete mixing is insignificant, then mixing 

zone modeling is not necessary. For completely mixed discharge receiving water 

situations, there are two major types of fate and transport water quality models: 

steady-state and dynamic. Model selection depends on the characteristics of the 

receiving water, the availability of effluent data, and the level of sophistication desired. 

The minimum data required for model input include receiving water flow, effluent flow, 

effluent concentrations, and background pollutant concentrations. 

a. Steady-State Modeling 

A steady-state model requires single, constant inputs for effluent flow, effluent 

concentration, background receiving water concentration, receiving water flow, 

and meteorological conditions (e.g., temperature). If only a few pollutant or 

effluent toxicity measurements are available or if a daily receiving water flow 

record is not available, steady-state assessments should be used. Steady-state 

models calculate WLAs at critical conditions that are usually combinations of 

worst-case assumptions of receiving water flow, effluent pollutant 

concentrations, and environmental effects. For example, a steady-state model 

for ammonia considers the maximum effluent discharge to occur on the day of 

the lowest river flow, highest upstream concentration, highest pH, and highest 

temperature. WLAs and permit limits derived from a steady-state model will be 

“USEPA (1994). Wafer Quality Standards Handbook: Second Edition. EPA 823-B-94-005a. 

Office of Water. 

23USEPA (1991). Technical Support Document for Water Quality-Based Toxics Control. EPA505/2-90-001. Office of Water Enforcement and Permits. 

108 - BB# NPDES Permit Writers’ Manual 
Chapter 6 Water CkuMty-Bamd Effiuent Urn&s 

protective of water quality standards at the critical conditions and for all 

environmental conditions less than critical. 

Steady-state modeling involves the application of a mass balance equation that 

allows the analyst to equate the mass of pollutants upstream of a given point 

(generally at a pollutant discharge, tributary stream or lateral inflow) to the mass 

of pollutants downstream after complete mixing. The basic formula for the 

mass balance model was presented as Exhibit 6-2. This model assumes that 

pollutants are conservative and additive, and considers only dilution as a 

mitigating factor affecting the pollutant concentration in-stream. The formula 

can be modified to account for factors such as degradation or sorption of the 

pollutant (in addition to dilution) where appropriate and feasible. A number of 

steady-state toxicant fate and transport models that consider factors affecting 

in-stream potlutant concentrations other than dilution are available and are 

discussed in Chapter 4 of the TSD24. 

The simple mass balance equation can be rearranged as follows to determine 

the downstream effect of a particular discharge concentration: 

Q,C, + QC, = c&C, 

c = Q,C,+QsCs 

r 

Qr 

The equation can be further rearranged to determine the WLA necessary to 

achieve a given in-stream concentration (CJ, such as a water quality criterion: 

Example: 

Assume a stream has a critical design Row of 1.2 cfs and a background zinc concentration of 0.80 mgIl. 

The State water quality criterion for zinc is 1 .O mg/l or less. The WIA for a discharge of zinc with a fiow 

of 200,000 gpd is (Note: 200,000 gpd = 0.3t cfs]: 

I C, = [(1.0)(0.31+1.2)-(0.8)(1.2))/0.31 = (1.51-0.96)/0.31 = 0.55/0.31 = 1.77 m@ I 

“USEPA (1991). Technical Support Document for Water Quality43ased Toxics Control. EPA505/2-90-001. Office of Water Enforcement and Permits. 

08# NPDES Permlt Writers’ Manual - 109 
Chapter 6 Water ChWty-&md Effiuent LMts 

Most States have adopted both acute and chronic numeric criteria for at least 

some pollutants. As such, steady-state WLA models should be used to 

calculate the allowable effluent load that will meet criteria at the appropriate 

design up-stream flow for those criteria. Each State specifies the appropriate 

design up-stream flow at which its water quality criteria should be applied. EPA 

recommends a design upstream flow for acute aquatic life criteria at the 1 QlO 

(l-day low flow over a lo-year period) and for chronic aquatic life criteria at the 

7QlO (7-day low flow over a lo-year period). EPA also recommends that the 

receiving water harmonic mean flow be used as the design upstream flow for 

human health protection. 

Once a permit writer has a WLA for each applicable criterion, those WLAs must 

be translated into long term average effluent concentrations and, subsequently, 

maximum daily and average monthly permit limits. This process is discussed in 

Section 6.5 - Permit Limit Derivation. Calculating WLAs and the associated 

long-term average effluent concentrations for each applicable criteria and using 

the most stringent long-term average effluent concentration to calculate permit 

limits will ensure that the permit limits are protective of all applicable criteria. 

b. Dynamic Modeling 

If adequate receiving water flow and effluent concentration data are available to 

estimate frequency distributions of effluent concentrations, one of the dynamic 

modeling techniques could be used to develop WLAs. In general, dynamic 

models account for the daily variations of and relationships between flow, 

effluent, and environmental conditions, and therefore, directly determine the 

actual probability that a water quality standard will be exceeded. The three 

dynamic modeling techniques recommended by EPA include: continuous 

simulation, Monte Carlo simulation, and tognormal probability modeling. 

l Continuous simulation is a fate and transport modeling technique that 

uses time series input data to predict receiving water quality concentrations 

in the same chronological order as that of the input variables. 

. Monte Carlo simulation is a modeling technique that involves random 

selection of sets of input data for use in repetitive model runs in order to 

predict the probability distributions of receiving water quality concentrations. 

l Lognormal probabilistic dilution is a modeling technique that calculates 

the probability distribution of receiving water quality concentrations from the 

lognormal probability distributions of the input variables. 

110 - 8B4 NPDES Permit Wrlters’ Manual 
Chapter 6 Water Puaiity-Bd Effiuant Lh#s 

These methods calculate a probability distribution for receiving water 

concentrations rather than a single, worst-case concentration based on critical 

conditions. Thus, they determine the entire effluent concentration frequency 

distribution required to produce the desired frequency of criteria compliance. 

Chapter 4 of the TSD25 describes steady-state and dynamic models in detail 

and includes specific model recommendations for toxicity and individual toxic 

pollutants for each type of receiving water-rivers, lakes, and estuaries. In 

addition, EPA has issued detailed guidelines on the use of fate and transport 

models of individual toxicants. Specific references for these models may be 

found in the Watershed Tools Directory - A Collection of Watershed Tools, 

available through the Assessment and Watershed Protection Division of the 

Office of Wetlands, Oceans and Watersheds [available through the internet at 

http://www.epa.gov]. These manuals describe in detail the transport and 

transformation processes involved in water quality modeling. 

6.5 Permit Limit Derivation 

WLAs are the outputs of water quality models, and the requirements of a WLA 

must be translated into a permit limit. The goal of the permit writer is to derive permit 

limits that are enforceable, adequately account for effluent variability, consider 

available receiving water dilution, protect against acute and chronic impacts, account 

for compliance monitoring sampling frequency, and assure attainment of the WLA and 

water quality standards. To accomplish these objectives, EPA recommends that 

permitting authorities use the statistical permit limit derivation procedure discussed in 

Chapter 5 of the TSDz6 with outputs from either steady-state or dynamic water quality 

models. EPA believes this procedure will result in the most defensible, enforceable, 

and protective WQBELs for both specific chemicals and WET. 

25USEPA (1991). Technical Support Document for Water Qualify-Based Toxics Control. EPA505/2-90-001. Office of Water Enforcement and Permits. 

*‘jibid. 

8ER9 NPDES Permit Writers’ Manual - 111 
Chapter 6 Water PuaUty-Boweb Effiuant Llm#s 

6.51 Expression of Permit Limits 

The NPDES regulations at 40 CFR 5122.45(d) require that all permit limits be 

expressed, unless impracticable, as both average monthly limits (AMLs) and maximum 

daily limits (MDLs) for all discharges other than POTWs, and as average weekly limits 

(AWLS) and AMLs for POTWs. The MDL is the highest allowable discharge measured 

during a calendar day or 24-hour period representing a calendar day. The AML is the 

highest allowable value for the average of daily discharges obtained over a calendar 

month. The AWL is the highest allowable value for the average of daily discharges 

obtained over a calendar week. 

Technical Note 

In lieu of an AWL for POTWs, EPA recommends establishing an MDL (or a maximum test result for 

chronic toxicity) for toxic pollutants and pollutant parameters in water quality permitting. This is 

appropriate for at least two reasons. First, the basis for the 7-day average for POTWs derives from the 

secondary treatment requirements. This basis is not related to the need for assuring achievement of 

water quality standards. Second, a 7-day average, which could comprise up to seven or more daily 

samples, could average out peak toxic concentrations and therefore the discharge’s potential for causing 

acute toxic effects would be missed. A MDL, which is measured by a grab sample, would be 

toxicologically protective of potential acute toxicity impacts. 

The objective is to establish permit limits that result in the effluent meeting the 

WLA under normal operating conditions virtually all the time. It is not possible to 

guarantee, through permit limits, that a WLA will never be exceeded. It is possible, 

however, using the recommended permit limit derivation procedures to account for 

extreme values and establish low probabilities of exceedance of the WLA in 

conformance with the duration and frequency requirements of the water quality 

standards. 

Since effluents are variable, and permit limits are developed based on a low 

probability of exceedance, permit limits should take effluent variability into 

consideration and ensure that the requisite loading from the WLA is not exceeded 

under normal conditions. In effect, the limits must force treatment plant performance 

levels that, after considering acceptable effluent variability, will only have a low 

statistical probability of exceeding the WLA and will achieve the desired loadings. 

6.52 Limits Derived from Steady-State Model Outputs 

A permit limit derived from a steady-state model output depends on the type of 

WLA. WLAs based on protecting aquatic life will have two results: acute and chronic 

112 - 8ER9 NPDES Permit Writers’ Manual 
Chapter 6 Water Puaiity-Bd Effiuant Lh#s 

requirements because State water quality standards generally provide both acute and 

chronic protection for aquatic life. In contrast, WLAs based on protecting human 

health will have only a chronic requirement. In either case, these WLA outputs need 

to be translated into maximum daily limits and average monthly limits. The acute and 

chronic WLA can be achieved for either specific chemicals or WET by using the 

following methodology to derive permit limits: 

. Calculate a treatment performance level (frequency distribution described 

by a long-term average or LTA and a coefficient of variation or CV) that will 

allow the effluent td meet the WLA requirements modeled (there will be a 

calculation for the acute WLA requirement and a calculation for the chronic 

WLA requirement) 

. For WET only, convert the acute WLA into an equivalent chronic WLA by 

multiplying the acute WLA by an acute-to-chronic ratjo (ACR) 

(e.g., 2.0 TUa x 10 = 20 TUc where ACR = TUc/TUa = 10) 

. Derive permit limits directly from whichever performance level is more 

protective. 

EPA has developed tables (see Tables 5-l and 5-2 in Chapter 5 of the TSD2’) 

that permit writers can use to quickly determine the values necessary to translate a 

WLA into a permit limit. In addition, some permit authorities have developed their own 

computer programs to compute WQBELs from the appropriate inputs. 

Some State water quality criteria and the corresponding WLAs are reported as 

a single value from which to define an acceptable level of effluent quality. An example 

of such a requirement is “copper concentration must not exceed 0.75 milligrams per 

liter (mg/l) in stream.” Steady state analyses assume that the effluent is constant and 

that the WLA value will never be exceeded. This assumption presents a problem in 

deriving permit limits because permit limits need to consider effluent variability. Where 

there is on\y one water quality criterion and only one WLA, permit limits can be 

developed using the following procedure: 

l Consider the single WLA to be the chronic WLA 

*‘USEPA (1991). Technical Support Document for Water Quality-Based Toxics Control. EPA505/2-90-001. Office of Water Enforcement and Permits. 

8ER4 NPDES Permit Writers’ Manual - 113 
Chaptar 6 Water Puaiity-Bd Effiuant Lh#s 

l Calculate a treatment performance level (an LTA and CV) that will allow the 

effluent to meet the WLA requirement modeled 

. Derive maximum daily and average monthly permit limits based on the 

calculated LTA and CV. 

6.5.3 Limits Derived from Dynamic Model Outputs 

The least ambiguous and most exact way that a WLA for specific chemicals or 

whole effluent toxicity can be specified is through the use of dynamic modeling from 

which the wasteload allocation is expressed as a required effluent performance in 

terms of the LTA and CV of the daily values. When a WLA is expressed as such, 

there is no confusion about assumptions used and the translation to permit limits. A 

permit writer can readily design permit limits to achieve the WLA objectives. Once the 

WLA and corresponding LTA and CV are determined, the permit limit derivation 

procedure found in Chapter 5 of the TSD28 may be used to develop effluent limits 

both for specific chemicals and for whole effluent toxicity. 

6.5.4 Special Considerations Permits Protecting Human Health 

Developing permit limits for pollutants affecting human health is somewhat 

different from setting limits for other pollutants because the exposure period is 

generally longer than one month, and can be up to 70 years, and the average 

exposure rather than the maximum exposure is usually of concern. Because 

compliance with permit limits is normally determined on a daily or monthly basis, it is 

necessary to set human health permit limits that meet a given WLA for every month. 

If the procedures for aquatic life protection were used for developing permit limits for 

human health pollutants, both the MDL and AML would exceed the WLA necessary to 

meet the required criteria concentrations. In addition, the statistical derivation 

procedure is not applicable to exposure periods over 30 days. Therefore, the 

recommended approach for setting WQBELs for human health protection is to set the 

average monthly limit equal to the WLA and calculate the maximum daily limit based 

on effluent variability and the number of samples per month using the statistical 

procedures described in Chapter 5 of the TSD2’. 

?JSEPA (1991). Technical Support Document for Water Quality-Based Toxics Control. EPA505/2-90-001. Off ice of Water Enforcement and Permits. 

“ibid. 

114 - liiB3I NPDES Permit Writers’ Manual 
Chapter 7 

Monitoring and Reporting 

Conditions 

Having developed the effluent limits for a municipal or industrial discharger, the 

permit writer’s next step is to establish monitoring and reporting requirements. 

Requiring the permittee to routinely self-monitor its discharge and to report the 

analytical results of such monitoring provides the permitting authority with the 

information necessary to evaluate discharge characteristics and compliance status. 

Periodic monitoring and reporting also serve to remind the permittee of its compliance 

responsibilities and provides feedback regarding the performance of the treatment 

facility(s) operated by the permittee. Permit writers should be aware of and concerned 

with the potential problems that may occur in a self-monitoring program such as 

improper sample collection procedures, poor analytical techniques, and poor or 

improper report preparation and documentation. To prevent or minimize these 

problems, the permit writer should clearly detail monitoring and reporting requirements 

in the permit. 

EPA NPDES Permit Writers’ Manual - 115 
Monitoring and Reporting Conditions Chapter 7 

The monitoring and reporting conditions section of a NPDES individual permit 

should contain specific requirements for the following items: 

• Sampling location 

• Sample collection method 

• Monitoring frequencies 

• Analytical methods 

• Reporting and recordkeeping requirements. 

Several factors should be considered in determining the specific requirements 

to be imposed. Basic factors that may affect sampling location, sampling method, and 

sampling frequency are: 

• Applicability of “effluent limitations guidelines” (ELG) 

• Effluent and process variability 

• Effect of flow and/or pollutant, load on the receiving water 

• Characteristics of pollutants discharged 

• Permittee compliance history. 

These factors must be carefully considered by the permit writer, as any error could 

lead to inaccurate compliance determination, misapplication of national ELGs, and/or 

misapplication of State water quality standards. 

The following sections provide an overview of the considerations involved in 

determining appropriate monitoring, reporting, and recordkeeping requirements, and 

describe how to properly incorporate the requirements in a NPDES permit. 

7.1 Establishing Monitoring Conditions 

The NPDES Program is structured such that facilities that discharge pollutants 

in waters of the United States are required to periodically evaluate compliance with the 

effluent limitations established in their permit and provide the results to the permitting 

authority. In addition, NPDES permits can require the permittee to monitor for 

additional parameters or processes not directly linked to the effluent discharge such as 

storm water, combined sewer overflows, municipal sludge, and/or treatment plant 

influent. This section describes the regulatory requirements and authorities for 

116 - EPA NPDES Permit Writers’ Manual 
Monitoring and Reportlng Conditions Chapter 7 

monitoring conditions, and describes how these conditions can be incorporated in 

NPDES permits. 

The regulations requiring the establishment of monitoring and reporting 

conditions in NPDES permits are found in 40 CFR $122.44(i) and 40 CFR 5122.48. 

Section 122.44(i) requires permittees to monitor pollutant mass (or other applicable 

unit of measure), effluent volume, provide other measurements (as appropriate), and 

to utilize the test methods established at 40 CFR 9136. Section 122.41(i) also 

establishes that NPDES permittees (with certain specific exceptions) must monitor for 

all limited pollutants and report data at least once per year. 

EPA regulations at 40 CFR 5122.48 state that all permits must specify requirements concerning the proper use, maintenance, and installation of monitoring equipment or methods (including biological monitoring methods when appropriate). All 

permits must also specify the required monitoring including the type, intervals, and 

frequency sufficient to yield data that are representative of the activity. The following 

sections focus on ensuring that permit monitoring conditions properly address these 

regulatory requirements. 

7.1.1 Monitoring Location 

The NPDES regulations do not specify the exact location to be used for 

monitoring. The permit writer is responsible for determining the most appropriate 

monitoring location and explicitly specifying this in the permit. Ultimately, the 

permittee is responsible for providing a safe and accessible sampling point that is 

representative of the discharge (40 CFR 3122.41(j)(l)). 

Specifying the appropriate monitoring location in a NPDES permit is critical to 

producing valid compliance data. Important factors to consider in selecting a 

monitoring location include: 

. The wastewater flow should be measurable 

. The location should be easily and safeiy accessible 

l The sample must be representative of the effluent during the time period 

that is monitored. 

4bER9 NPDES Permit Writers’ Manual - 117 
Monktorlng and Reporting Conditions Chapter 7 

Technical Note 

When establishing monitoring locations for determining NPDES permit compliance, permit writers must 

select locations that are representative of the expected wastewater discharge. Locations should be 

established where the wastewater is well mixed, such as near a parshall flume or at a location in a sewer 

with hydraulic 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. 

The most logical monitoring point for an effluent is just prior to discharge to the 

receiving water. This is particularly true for ensuring compliance with water qualitybased effluent limits (WQBELs). However, there are instances when the permit writer 

may need to specify alternate monitoring locations in a permit. 

One typical instance that necessitates establishing an alternative monitoring 

location occurs when a facility combines a variety of process and non-process 

wastewaters prior to discharge through a common outfall structure. Under certain 

circumstances, when a variety of wastewaters are combined, requiring monitoring only 

at the final combined outfall may not be appropriate. To address this situation, 40 

CFR 5122.45(h) allows permit writers to establish monitoring locations at internal 

outfalls. Examples of situations that may require designation of internal monitoring 

locations include: 

l To ensure compliance with effluent limitations guidelines and 

standards (at non-municipal facilities)-When non-process wastewaters 

dilute process wastewaters regulated under effluent guidelines, monitoring 

the combined discharge may not accurately depict whether the facility is 

complying with the effluent guidelines. Under these circumstances, the 

permit writer may consider requiring monitoring for compliance with 

technology-based effluent limits (based on application of effluent guidelines) 

before the process wastewater is combined with the other wastewaters. 

l To ensure compliance with secondary treatment standards (for 

POTWs only)-Certain POTWs include treatment processes that are 

ancillary to the secondary treatment process that may impact their ability to 

monitor for compliance with secondary treatment standards. Under these 

circumstances, the permit writer may consider requiring monitoring for 

compliance with secondary treatment standards just after the secondary 

treatment process (e.g., require monitoring of effluent just after secondary 

clarification) before any additional treatment processes. 

l To allow detection of a pollutant-Instances may arise where the 

combination of process and non-process wastewaters result in dilution of a 

pollutant of concern that will not be detectable using approved analytical 

118 - 06% NPDES Permit Writers’ Manual 
Monitoring and Reporting Conditions Chapter 7 

methods. Establishing monitoring for the pollutant at an internal location 

will enable characterization of the pollutant prior to dilution with other 

wastewaters. 

When establishing internal monitoring points, permit writers need to consider 

the location of wastewater treatment units within the facility. This is particularly true 

when establishing internal monitoring locations for determining compliance with 

technology-based effluent limits. A facility will most likely not be able to comply with 

technology-based effluent limits if the permit writer establishes the monitoring location 

prior to the wastewater treatment unit. 

Permit writers may also need to require monitoring of influent to the wastewater 

treatment units for certain facilities. lnfluent monitoring must be required for POTWs 

to ensure compliance with the 85 percent removal condition of the secondary 

treatment standards. lnfluent monitoring at non-POTWs may also be desired to 

determine influent characteristics, and if additional information related to the 

performance of the wastewater treatment unit is needed. 

Exhibit 7-1 provides examples of how to specify sampling locations in a permit 

either by narrative or diagram. 

7.1.2 Monitoring Frequency 

The frequency for monitoring pollutants should be determined on a case-bycase basis, and decisions for setting the frequency should be set forth in the fact 

sheet. Some States have their own recommended sampling guidelines that can help 

a permit writer determine an appropriate sampling frequency. The intent is to 

establish a frequency of monitoring that will detect most events of noncompliance 

without requiring needless or burdensome monitoring. 

To establish a monitoring frequency, the permit writer should estimate the 

variability of the concentration of the parameter by reviewing effluent data for the 

facility (e.g., from DMRs) or in the absence of actual data, information from similar 

dischargers. A highly variable discharge should require more frequent monitoring than 

a discharge that is relatively consistent over time (particularly in terms of flow and 

8Ep# NPDES Permit Writers’ Manual - 119 
Monltorlng and Reportlng Conditions Chapter 7 

EXHIBIT 7-1 

Examples of Specifying Sampling Locations in Permits 

NARRATIVE: 

Part I. SELF-MONITORING REQUIREMENTS 

A. Sample Locations 

I. Discharge from the Chemistry-Fine Arts Building shall be sampled at outfall 001 

2. Discharge from the Duane Physics Building shall be sampled at outfall 002 

3. Discharge from the Research Lab No. 1 shall be sampled at outfall 003 

DIAGRAM: 

Part I. EFFLUENT LIMITATIONS AND MONITORING REQUIREMENTS 

A. Sample Locations 

Outfall Description 

001 Discharge Pipe- Discharge of wastewater generated by all regulated metal finishing 

processes at the facility. Samples shall be collected at the point indicated on the attached 

diagram. 

Parshall Flume 

’ 3 

L 

Receiving 

A 

-I 

Stream 

Outfall 001 

*Sample Point 

IWe 

Final pH 

Adjustment 

Tank 

pollutant concentration). In addition to the estimated variability, other factors that 

should be considered when establishing appropriate monitoring frequencies include: 

0 Design capacity of treatment facility-As an example, at equivalent 

average flow rates, a large lagoon system that is not susceptible to 

bypasses requires less frequent monitoring than an overloaded treatment 

facility that experiences fluctuating flow rates due to infiltration or large 

batch discharges from an industrial user system. The lagoon should have a 

relatively low variability compared to the facility receiving batch discharges. 

120 - 88# NPDES Permit Writers’ Manual 
Monltorlng and Reportlng C~nbtions Chapter 7 

l Type of treatment method used-The type of wastewater treatment used 

by the facility will determine the need for process control monitoring and 

effluent monitoring. An industrial facility with biological treatment would 

have similar monitoring frequencies to a secondary treatment plant with the 

same units used for wastewater treatment. If the treatment method is 

appropriate and achieving high pollutant removals on a consistent basis, the 

need for monitoring may be less than a plant with little treatment or 

insufficient treatment. 

a Post compliance record/history-The monitoring frequency may be 

adjusted to reflect the compliance history of the facility. A facility with 

problems achieving compliance generally should be required to perform 

additional monitoring to characterize the source or cause of the problems or 

to detect noncompliance. 

0 Cost of monitoring relative to discharger’s capabilities-The permit 

writer should not require excessive monitoring unless it is necessary to 

provide sufficient information about the discharge (analytical costs are 

addressed in Section 7.1.5). 

0 Frequency of the discharge--If wastewater is discharged in batches on 

an infrequent basis, the monitoring frequency should be different from a 

continuously discharged, highly concentrated wastewater, or a wastewater 

containing a pollutant that is found infrequently and at very low 

concentrations. The production schedule of the facility (e.g., seasonal, 

daily), the plant washdown schedule, and other similar factors should be 

considered. 

0 Number of monthly samples used in developing permit limit-The 

monitoring frequency should reflect the number of monthly samples used in 

developing the permit limits, and/or the monitoring frequencies used to 

develop any applicable effluent guidelines. 

0 Tiered Limits-Where the permit writer has included “tiered” limits in an 

NPDES permit, consideration should be given to varying the monitoring 

frequency requirements to correspond to the applicable tiers. For example, 

if a facility has seasonal discharge limits, it may be appropriate to increase 

the monitoring frequency during the higher production season, and reduce 

the frequency during the off-season. 

An alternative method that can be used by permit writers to establish monitoring 

frequencies is the quantitative approach described in the Technical Support Documenf 

for Water Quality-Based Toxics Control (TSD)30. In short, the TSD3’ approach 

30USEPA (1991). Technical Support Document for Water Quality-Based Toxics Control. EPA505/Z-90-001. Office of Water Enforcement and Permits. 

3’ibid. 

8ER4 NPDES Permit Writers’ Manual - 121 
Monltwlng and Reporting Cmiiions Chapter 7 

requires calculating the long-term average pollutant concentration (accounting for the 

expected variability of the discharge) and comparing it to the permit limit to determine 

the likelihood of noncompliance. The closer the long-term average is to the permit 

limit, the more frequent the monitoring that should be required. Obviously, this 

quantitative approach requires a reasonable data set from which to calculate the longterm average. Permit writers should refer to the TSD3* for more information 

regarding this approach. 

A permit writer may also establish a tiered monitoring schedule that reduces or 

increases monitoring frequency during a permit cycle. Tiered monitoring, which 

reduces monitoring over time, may be useful for discharges where the initial sampling 

shows compliance with effluent limits. If problems are found during the initial 

sampling, more frequent sampling and more comprehensive monitoring can be 

applied. This step-wise approach could lead to lower monitoring costs for permittees 

while still providing an adequate degree of protection of water quality. 

Regulatory Update 

In response to President Clinton’s Regulatory Reinvention initiative, which established the goal of 

reducing monitoring and reporting burden by 25%, EPA issued interim Guidance for Performance-Based 

Reductions of NPDES Permit Monitoring frequencies on April 19, 1996 (EPA-833-B-96-001 ). Under this 

guidance, NPDES reporting and monitoring requirements are reduced based on a demonstration of 

excellent historical performance. Facilities can demonstrate this historical performance by meeting a set 

of compliance and enforcement criteria and by demonstrating their ability to consistently discharge 

pollutants below the levels necessary to meet their existing NPDES permit limits. Reductions are 

determined parameter-by-parameter, based on the existing monitoring frequency and the percentage 

below the limit that parameter is being discharged at. The reductions are incorporated into the permit at 

the time of permit reissuance. To remain eligible for these reductions, permittees are expected to 

maintain parameter performance levels and good compliance and enforcement history that were used as 

the basis for granting the reductions. 

7.1.3 Sample Collection Methods 

In addition to establishing the frequency of monitoring, the permit writer must 

specify the type of sample that must be collected. The two basic sample collection 

methods include “grab” and “composite.” 

The analytical methods specified in 40 CFR Part 136 are required for all 

monitoring performed under the NPDES Program, unless the permit specifically 

?JSEPA (1991). Technical Support Document for Water Quality-Based Toxics Control. EPA50542-90-001. Office of Water Enforcement and Permits. 

122 - 8ER9 NPDES Permit Writers’ Manual 
Monltorlng and Repmthg Cmbtions Chapter 7 

requires alternate methods. For many analytical procedures, the sample collection 

method (grab or composite) is not specified in 40 CFR Part 136, thus it should be 

specified in the discharge permit. 40 CFR Part 136 specifies that grab samples must 

be collected for pH, temperature, dissolved oxygen, chlorine, purgeable organics, 

sulfides, oil and grease, coliform bacteria and cyanide. The reason grab samples 

must be.taken for these parameters is that they evaluate characteristics that may 

change during the time necessary for compositing. 

A “grab” sample is a single sample collected at a particular time and place that 

represents the composition of the wastestream only at that time and place. When the 

quality and flow of the wastestream being sampled is not likely to change over time, a 

grab sample is appropriate. Grab samples should be used when: 

. The wastewater characteristics are relatively constant. 

l The parameters to be analyzed are likely to change with storage such as 

temperature, residual chlorine, soluble sulfide, cyanides, phenols, 

microbiological parameters and pH. 

l The parameters to be analyzed are likely to be affected by the cornpositing 

process such as oil and grease and volatiles. 

. Information on variability over a short time period is desired. 

l Composite sampling is impractical or the cornpositing process is liable to 

introduce artifacts of sampling. 

l 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. Each 

batch dumping event should be sampled. 

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 

automatic sampling device collects relatively small amounts of a sampled 

wastestream, with the interval between sampling either time or flow proportioned. 

Unlike the automatic composite sampler, the sequential 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 

am NPDES Permit Writers’ Manual - 123 
Monltorlng and Repmthg CmGtions Chapter 7 

composite sampler which combines aliquots in a common bottle. This type of 

sampling is effective for determining variations in effluent characteristics over short 

periods of time. 

A “composite” sample is a collection of individual samples obtained at regular 

intervals, usually based upon time or flow volume. A composite sample is desirable 

when the material being sampled varies significantly over time either as a result of 

flow or quality changes. There are two general types of composites and the permit 

writer should clearly express which type is required in the permit: 

l Time composite samples collect a fixed volume at equal time intervals and 

are acceptable when flow variability is not excessive. Automatically timed 

cornposited 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 time intervals when flow variability is not excessive. 

. Flow-proportional cornpositing is usually preferred when effluent flow 

volume varies appreciably over time. The equipment and instrumentation 

for flow-proportional cornpositing have more downtime due to maintenance 

problems. 

When manually cornpositing 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. 

There are numerous cases where composites are inappropriate. Samples for 

some parameters should not be cornposited (pH, residual chlorine, temperature, 

cyanides, volatile organics, microbiological tests, oil and grease, total phenols). They 

are also not recommended for sampling batch or intermittent processes. Grab 

samples are needed in these cases to determine fluctuations in effluent quality. 

For whole effluent toxicity (WET), composite samples are used unless it is 

known that the effluent is most toxic at a particular time. Some toxic chemicals are 

short-lived, degrade rapidly, and will not be present in the most toxic form after lengthy 

cornpositing even with refrigeration or other forms of preservation. Grab samples 

should be required for bioassays to be taken under those circumstances. 

124 - 8ER9 NPDES Permit Writers’ Manual 
Monltorlng and Reporting Cmdiions Chapter 7 

If a sampling protocol is not specified in the regulations, the duration of the 

cornpositing 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 hours. 

Eight types of composite samples and the advantages and disadvantages of 

each are shown in Exhibit 7-2. As shown in Exhibit 7-2, samples may be cornposited 

by time or flow and a representative sample will be assured. However, where both 

flow and pollutant concentration fluctuate dramatically, a flow-proportioned composite 

sample should be taken because a greater quantity of pollutant will be discharged 

during these periods. As an alternative, time-proportioned samples may be taken with 

flow records used for weighing the significance of various samples. 

Continuous monitoring is another option for a limited number of parameters 

such as flow, total organic carbon (TOC), temperature, pH, conductivity, fluoride and 

dissolved oxygen. Reliability, accuracy and cost of continuous monitoring 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 variable effluent. The environmental significance of the variation of any of these 

parameters in the effluent should be compared to the cost of continuous monitoring. 

Technical Note 

When establishing continuous monitoring requirements, the permit writer should be aware that the 

NPDES regulations concerning pH limits allow for a periid of excursion when the effluent is being 

continuously monitored (40 CFR 5401 .17). 

7.1.4 Analyticai Methods 

The permit writer must specify the analytical methods to be used for monitoring. 

These are usually indicated as 40 CFR Part 136 in the standard conditions of the 

permit [40 CFR @122.41(j)(4) and 122.44(i)]. In particular, analytical methods for 

industrial and municipal wastewater pollutants must be conducted in accordance with 

8EFM NPDES Permit Writers’ Manual - 125 
Monltorlng and Fleporthg Conditions Chapter 7 

EXHIBIT 7-2 

Compositing Methods 

Method I Advantages I Disadvantages I Comments 

rime Composite 

1 Constant sample Minimal instrumentation May lack representativeness, Widely used in both 

volume, constant time and manual effort; requires especially for highly variable automatic samplers 

interval between no flow measurement flows and manual handling 

samples 

Flow-Proportional Composite 

B Constant sample Minimal manual effort Requires accurate flow Widely used in 

volume, time interval measurement reading automatic as well as 

between samples equipment; manual manual sampling 

proportional to stream compositing from flowchart 

flow 

B Constant time interval Minimal instrumentation Manual cornpositing from Used in automatic 

between samples. flowchart in absence of prior samplers and widely 

sample volume information on the ratio of used as manual 

proportional to total minimum to maximum flow; method 

stream flow at time of chance of collecting too small 

sampling or too large individual discrete 

samples for a given composite 

volume 

m Constant time interval Minimal instrumentation Manual compositing from flow Not widely used in 

between samples, chart in absence of prior automatic samplers 

sample volume information on the ratio of but may be done 

proportional to total minimum to maximum flow; manually 

stream flow since last chance of collecting either too 

sample small or too large individual 

discrete samples for a given 

composite volume 

Sequential Composite 

l Series of short period Useful if fluctuations occur Requires manual compositing Commonly used; 

composites, constant and time history is desired of aliquots based on flow however, manual 

time intervals between compositing is labor 

samples intensive 

l Series of short period Useful if fluctuations occur Requires flow totalizer; Manual compositing 

composites. aliquots and time history is desired requires manual compositing is labor intensive 

taken at constant of aliquots based on flow 

discharge increments 

Continuous Composite 

l Constant sample volume Minimal manual effort, 

requires no flow 

measurement 

Requires large sample Practical but not 

capacity; may lack widely used 

representativeness for highly 

variable flows 

l Sample volume 

proportional to stream 

flow 

Minimal manual effort, 

most representative 

especially for highly 

variable flows 

Requires accurate flow Not widely used 

measurement equipment, large 

sample volume, variable 

pumping capacity, and power 

126 - 8ER9 NPDES Permit Writers’ Manual 
Monltorlng and Fleportlng CmdSons Charrter 7 

the methods specified pursuant to 40 CFR Part 136, which references one or more of 

the following: 

. Test methods in Appendix A of 40 CFR Part l3633 

. Standard Methods for the Examination of Water and Wastewater, 18th 

Edition 34 

. Methods for the Chemical Analysis of Water and Wasfewafer35 

. Test Methods: Methods for Organic Chemical Analysis of Municipal and 

Industrial Wasfewater.36 

The analytical methods contained in 40 CFR Part 136 are test methods 

designed only for priority and conventional pollutants, and some nonconventional 

pollutants. In the absence of analytical methods for other parameters, the permit 

writer must still specify the analytical methods to be used. An excellent source of 

analytical method information is the Environmental Monitoring Methods index (EMMI). 

The EMMI is an official EPA database linking 50 EPA regulatory lists, 2,600 

substances and 926 analytical methods on EMMI. EMMI data correlate EPA’s 

regulated substances with their associated analytical methods, published detection 

limits, and regulatory limits. For more information, call NTIS at (703) 321-8547 for 

system requirements. 

7.1.5 Other Considerations in Establishing Monitoring Requirements 

The regulations do not specifically require a permit writer to evaluate costs 

when establishing monitoring conditions in a permit. However, as a practical matter, 

the permit writer should consider the cost of sampling that he/she imposes on the 

permittee. The sample frequency and analyses impact the analytical cost. The 

estimated 1994-1995 costs for analytical procedures are shown in Exhibit 7-3. 

33Guidelines Establishing Test Procedures for the Analysis of Pollutants Under the Clean Water Act 

(40 CfR Part 736). (Use most current version) 

%American Public Health Association, American Water Works Association, and Water Pollution 

Control Federation (1992). Standard Methods for the Examination of Water and Wastewater, 18th Ed. 

%SEPA (1979). Methods for the Chemical Analysis of Wafer and Wastewater. EPA-600/ 

4-79-020. Environmental Monitoring and Support Laboratory. 

%SEPA (1982). Test Methods: Methods for Organic Chemical Analysis of Municipal and 

industrial Wastewater. EPA-600/4-82-057. 

643% NPDES Permit Writers’ Manual - 127 
Mcfnttorlng and Reporting Conditions Chapter 7 

EXHIBIT 7-3 

Estimated Costs for Common Analytical Procedures’ 

Gasoline (Benzene, Toluene, Xylene) 

Purgeable Halocarbons (EPA Method 601) 

Acrolein and Acrylonitrile (EPA Method 603) 

Purgeables {EPA Method 624) 

Phenols (EPA Method 604) 

Organochlorine Pesticides and PCBs (EPA Method 608) 

Polynuclear Aromatic Hydrocarbons (EPA Method 6 10) 

Dioxin (2, 3, 7, 8-TCDD (EPA Method 613)) 

Base/Neutrals and Acids (EPA Method 625) 

Priority poIlution scan2 

Acute WET 

Chronic WET 

1 Based on 1994-I 995 costs. 

$100 

$113 

$133 

$25 1 4 

$160 

$157 

$175 

$400 

$434 

$2,000 

$750 

$1,500 

2 Includes 13 metals, cyanide, dioxin, volatiles (purgeables), base/neutral and acids, pesticides and PCBs, and 

asbestos. 

128 - 8694 NPDES Permit Writers’ Manual 
Monitoring and Flepotthtg Conditions Chapter 7 

If simple or inexpensive indicator parameters (e.g., BOD, acts as an indicator for the 

priority pollutants in the Wood and Gum Chemicals category) or alternate parameters 

will produce data representative of the pollutant present in the discharge, then the 

indicators or surrogate pollutants or parameters should be considered. Complex and 

expensive sampling requirements may not be appropriate if the permit writer cannot 

justify the need for such analyses. 

7.1.6 Establishing Monitoring Conditions for Unique Discharges 

There are a variety of discharges that are regulated under the NPDES permit 

program that are different than traditional wastewater discharges. A permit writer 

needs to account for these unique discharges in establishing monitoring requirements. 

This section discusses several of these unique discharges including storm water, 

combined sewer and sanitary sewer overflows, WET, and municipal sludge. 

Storm Water Monitoring Considerations 

Monitoring requirements vary according to the type of permit regulating the 

storm water discharge and the activity. Storm water discharges may be regulated by 

State programs, provided the State is authorized to administer the NPDES Storm 

Water Program, or EPA Regions. At the Federal level, several permitting options are 

available; depending on the type of activity, industrial facilities may seek coverage 

under an individual permit, the Baseline Industrial General Permit, or the Multi-sector 

General Permit. In addition, construction activities that disturb 5 or more acres of land 

are regulated under the Baseline Construction General Permit. Municipalities serving 

over 100,000 people are also regulated, but on an individual permit basis. Each of 

these permitting mechanisms establishes different monitoring programs. Several 

States have used the Federal permits as models for their permit conditions. 

Specific monitoring conditions for the Federal general permits are detailed in the 

following documents: 

. “Final NPDES General Permits for Storm Water Discharges Associated 

With industrial Activity,” Federal Register, September 9, 1992. (Baseline 

Industrial General Permit). 

&El% NPDES Permit Writers’ Manual - 129 
Monttorlng and Fleportlng Ceons Chapter 7 

. “Final NPDES General Permits for Storm Water Discharges from 

Construction Sites,” Federal Register, September 9, 1992. (Baseline 

Construction General Permit). 

. “Final NPDES Storm Water Multi-Sector General Permit for fndustrial 

Activities,” Federal Register, September 9, 1992. (Multi-Sector General 

Permit). 

Monitoring Combined Sewer Overflows and Sanitary Sewer Overflows 

EPA’s CSO Control Policy (59 FR 18688) requires monitoring to characterize 

the combined sewer system, assist in developing the Long-Term Control Plan (LTCP), 

and illustrate compliance with permit requirements. Monitoring as part of the nine 

minimum controls (NMC) is done to develop an initial system characterization and 

includes analyzing existing data on precipitation events, on the combined sewer 

system and CSOs, on water quality, and conducting field inspections. As part of the 

LTCP, a permittee is required to develop a more complete characterization of the 

sewer system through monitoring and modeling. Finally, to illustrate compliance with 

the permit requirements, the permittee is required to conduct a post-construction 

compliance monitoring program. Specific monitoring requirements of this postconstruction compliance monitoring program will be unique to each permittee’s LTCP 

and should be established as specific monitoring conditions in the individual NPDES 

permit. These monitoring conditions should require monitoring of a representative 

number of CSOs for a representative number of wet weather events for certain key 

parameters along with ambient water quality monitoring to ascertain attainment with 

water quality standards. EPA is currently preparing eight guidance manuals on 

various aspects of the CSO Control Policy, including one on monitoring, Combined 

Sewer Overflows: Guidance for Monitoring and Modeling (draft).37 

A facility’s permit may also contain monitoring requirements for sanitary sewer 

overflows (SSOs). These would be developed on a case-by-case basis. 

37USEPA (1995). Combined Sewer Overflows-Guidance for Monitoring and Modeling. (DRAFT). 

EPA-832/R-95-005. 

130 - &EM NPDES Permit Writers’ Manual 
Monftorlng and Flqmthg Conditions Chapter 7 

Whole Effluent Toxicity Monitoring 

The use of whole effluent toxicity (WET) testing to evaluate the toxicity in a 

receiving stream was discussed in Chapter 6. The biomonitoring test procedures were 

promulgated in 40 CFR Part 136 on October 16, 1995 (60 FR 53529). WET 

monitoring conditions included in permits should specify the particular biomonitoring 

test to be used, the test species, required test endpoint, and QA/QC procedures. EPA 

has published recommended toxicity test protocols in four manuals: 

. Methods for Measuring the Acute Toxicity of Effluents and Receiving 

Waters to Freshwater and Marine Organisms.38 

l Short-Term Methods for Estimating the Chronic Toxicity of Effluents and 

Receiving Waters to Marine and Estuarine Organisms3’ 

. Short-Term Methods for Estimating the Chronic Toxicity of Effluents and 

Receiving Waters to Freshwater Organisms.40 

. NPDES Compliance Monitoring Inspector Training: Biomonitoring.4’ 

Samples for WET may be composite or grab samples. Twenty-four hour 

composite samples are suggested except when (1) the effluent is expected to be 

more toxic at a certain time of day; (2) toxicity may be diluted during cornpositing; and 

(3) the size of the sample needed exceeds the composite sampler volume (e.g., 5 

gallons). 

WET tests are relatively expensive (see Exhibit 7-3 on costs). Therefore the 

test frequency should be related to the probability of any discharger having whole 

?JSEPA (1991). Methods for Measuring the Acute Toxicify of Effluents and Receiving Waters fo 

freshwater and Marine Organisms 

%SEPA (1991). Short-Term Methods for Estimating the Chronic Toxicity of Effluents and 

Receiving Waters to Matine and Estuarine Organisms, EPA-600/4-91-003. Environmental Monitoring 

and Support Laboratory. 

“USEPA (1991). Short-Term Methods for Estimating fhe Chronic Toxicity of Effluents and 

Receiving Waters to freshwater Organisms, Third Edition. EPA-600/4-91-002. Environmental 

Monitoring and Support Laboratory. 

41USEPA (1990). NPDES Compliance Monitoring inspector Training: Biomonitoring. Office of 

Water. 

88F# NPDES Permit Writers’ Manual - 131 
Manitorlng and Reporting Cm&Sons Chapter T 

effluent toxicity. Samples should be evenly spaced throughout the year so that 

seasonal variability can be ascertained. 

Municipal Sludge Monitoring 

The purpose of monitoring municipal sludge is to ensure safe use or disposal. 

The 40 CFR Part 503 sludge regulations require monitoring of sewage sludge that is 

applied to land, placed on a surface disposal site, or incinerated. The frequency of 

monitoring is based on the annual amount of sludge that is used or disposed by these 

methods. POTWs that provide the sewage sludge to another party for further 

treatment (such as composting) must provide that party with the information necessary 

to comply with 40 CFR Part 503. Sewage sludge disposed of in a municipal solid 

waste landfill unit must meet the requirements in 40 CFR Part 258, which is the 

criteria for municipal solid waste landfills. 

Exhibit 7-4 shows the minimum monitoring requirements for sewage sludge 

prior to use and disposal established in 40 CFR Part 503. More frequent monitoring 

for any of the required or recommended parameters is appropriate when the POTW: 

. lnfluent load of toxics or organic solids is highly variable 

. Has a significant industrial load 

. Has a history of process upsets due to toxics, or of adverse environmental 

impacts due to sludge use or disposat activities. 

The sampling and analysis methods specified in 40 CFR $503.8 should be 

followed for monitoring the required parameters. In the absence of any specific 

methods in 40 CFR Part 503, guidance on appropriate methods is contained in 

Part 503 Implementation Guidance,42 Control of Pathogens and Vector Attraction in 

Sewage SIudge,43 and PO7W Sludge Sampling and Analysis Guidance 

Documen t.44 

“USEPA (1995). Part 50.3 Implementation Guidance. EPA 833-R-95-001. Office of Water. 

‘?JSEPA (1992). Control of Pathogens and Vector Attraction in Sewage Sludge. EPA-625/R-92- 

013. Office of Research and Development. 

“USEPA (1989). POW Sludge Sampling and Analysis Guidance Document. Office of Water, 

Permits Division. 

132 - 8ER9 NPDES Permit Writers’ Manual 
Manitorlng and Reporthg Conditions Chapter 7 

EXHIBIT 7-4 

Minimum Requirements for Sewage Sludge Monitoring, 

Based on Method of Sludge Use or Disposal 

Method 

Land 

Application 

Co-disposal 

in Municipal 

Solid Waste 

Landfill 

Surface 

Disposal: 

Lined Sites 

with leuchate 

collection and 

Unlined Sites 

Incineration 

Monitoring Requirements Frequency 

(I) Sludge weight and $4: total 

solids 

Metals: As, Cd, Cu, Pb, 

Hg, MO, Ni, Se, and Zn 

Pathogen Reduction 

Vector Attraction Reduction 

(I) Sludge weight and c/c total 

solids 

( 1) 0< illld < 290*, annually 

290~ and < I ,SOO, 

quarterly 

1 SOO< and < 15,000. 

bimonthly 

15,000 = or <. monthly 

(2) Passes Paint-Filter Liquid 

Test 

(3) Suitability of sludge used as 

cover 

(I), (2), (3). and (4) 

Monitoring requirements or 

frequency not specified by 40 

CFR Part 503. Determined by 

local health authority or 

landfill owner/operator 

(4) Characterize in accordance 

with hazardous waste rules 

(I) Sludge weight and ‘3 total 

solids 

(I) Based on sludge quantity 

(as above) 

Pathogen Reduction 

Vector Attraction Reduction 

Metals: As, Cr, Ni (Unlined 

Sites Only) 

(2) Continuously 

(2) Methane gas 

( 1) Sludge weight and o/c total 

solids 

(I) Based on sludge quantity 

(as above) 

Metals: As. Cd, Crl Pb, and 

h‘i 

(2) Be and Hg (Nat. Emissions 

Standards) 

(2) As required by subparts C 

and E of 40 CFR Part 61 

as may be specified by 

permitting authority (local 

air authority) (3) THC or CO, 0,. moisture, 

combustion temperatures (3) Continuously 

(4) Air pollution control device (4) Daily 

operating parameters cCi Cation 

40 CFR 

Part 503. I 6 

10 CFR 

Part 258.28 

10 CFR 

Part 503.26 

40 CFR 

Part 503.46 

Notes: 1. Monitoring frequencies rcquircd under 40 CFR Part 503 may he reduced after 2 years of monitoring 

hut in no case shall he less than once per year. 

2. A successful land application program may necessitate sampling for other constituents of concern 

(such as nitrogen) in determining appropriate ngronomk rates. This will be detcmlined by the 

permit writer. 

*Dry weight of sludge in metric tons per year. 

&El% NPDES Permit Writers’ Manual - 133 
Chapter 7 Monitoring and Reporting Conditions 

7.2 Reporting and Recordkeeping Requirements 

The NPDES regulations at 40 CFR ~~122.41(1)(4)(j) and (I) require the 

permittee to keep records and periodically report on monitoring activities. Discharge 

Monitoring Reports (DMRs) (see form in Exhibit 7-5) must be used by permittees to 

report self-monitoring data. Data reported include both data required by the permit 

and any additional data the permittee has collected consistent with permit 

requirements. All facilities are required to submit reports (on discharges and sludge 

use or disposal) at least annually per 40 CFR $122,44(i)(2). POTWs with 

pretreatment programs are required to submit a pretreatment report at least annually 

per Section 403.12(i). However, the NPDES regulation states that monitoring 

frequency and reporting should be dependent on the nature and effect of the 

discharge/sludge use or disposal. Thus, the permit writer can require more frequent 

than annual reporting. 

Records must be kept by the permittee for at least 3 years and this time may 

be extended by the Director upon request. An exception is for sewage sludge records 

which must be kept 5 years or longer if required by 40 CFR Part 503. The permit 

writer should designate where records should be located. Monitoring records include: 

. Date, place, time 

. Name of sampler 

. Date of analysis 

. Name of analyst 

. Analytical methods used 

. Analytical results. 

According to 40 CFR 5122.41(j), monitoring records must be representative of 

the discharge. Records which must be retained include continuous strip chart recordings, calibration data, copies of all reports for the permit, and copies of all data used 

to compile reports and applications. Sludge regulations under 40 CFR §§ 503.17, 

503.27, and 503.47 establish recordkeeping requirements that vary depending on the 

use and disposal method for the sludge. The same recordkeeping requirements 

should be applied to other sludge monitoring parameters not regulated by the 40 CFR 

Part 503 rule. 

134 - iiEfM NPDES Permit Writers’ Manual 
EXHIBIT 7-5. 

Discharge Monitoring Report (DMR) 

,~t”“,,,tt *,YI,AwIILss,h.t-c *.rrDurHa,Y,..,D(~“1)*it‘LIYln*IK)*S”~rlYIN~~~.,, ,r,r, ALldLyljl ~,do~~n OISCHAROE mowlo(u11o MPoa’ Il*(RI “AME ,l ld, ,,7 I”, 

..--- ---- --- _-- --- --- 

____ ADDRESS ---------- . . ---- - 

_____ -_---_ _--- ----- \GGizq F] 

8ER4 NPDES Permit Wrlters’ Manual - 135 
Chapter 8 

Special Conditions 

Special conditions in NPDES permits are designed to provide an additional 

measure of control (beyond numeric effluent limits) for the reduction of discharges of 

pollutants to waters of the United States. They are not included in the effluent 

limitations section of a permit because they do not contain specific numeric limits. 

The purpose of special conditions is to encourage the permittee to undertake activities 

designed to reduce the overall quantity of pollutants being discharged, or to reduce 

the potential for discharges of pollutants. 

There are many different reasons to incorporate special conditions into a permit 

including the following: 

• To address unique situations, such as facilities discharging pollutants for 

which data are absent or limited such that derivation of technology- or water 

quality-based effluent limits (WQBELs) is difficult or impossible 

• To incorporate preventative requirements, such as requirements to install 

process control alarms, containment structures, good housekeeping 

practices, etc. 

• To address foreseeable changes to discharges, such as planned changes 

to process, products, or raw materials that may affect discharge 

characteristics 

l To incorporate compliance schedules to provide the time necessary to 

comply with permit conditions 

EPA NPDES Permit Writers’ Manual - 137 
Special Conditions Chapter 8 

• To incorporate other NPDES Programmatic requirements (e.g., 

pretreatment, municipal sewage sludge) 

• To impose additional monitoring activities that provide the permit writer data 

to evaluate the need for changes in permit limitations 

• To increase or decrease monitoring requirements, depending on the 

monitoring results or certain changes in processes or products, etc. 

• To impose requirements to conduct special studies such as ambient stream 

surveys, toxicity reduction evaluations (TREs), bioaccumulation studies, 

sediment studies, mixing or mixing zone studies, pollutant reduction 

evaluations, or other such information gathering studies. 

Section 8.1 of this chapter addresses the general types of special conditions for 

both municipal and non-municipal facilities. Special conditions for storm water 

discharges associated with industrial activity are explained in Section 8.2. Finally, 

special conditions unique to POTW/municipal permits are addressed in Section 8.3. 

8.1 General Types of Special Conditions 

This section discusses several general types of special conditions that could be 

used in any NPDES permit (i.e., municipal or non-municipal). The special conditions 

include: 

• Special studies/additional monitoring 

• Best Management Practices (BMPs) 

• Pollution prevention 

• Compliance schedules. 

8.1.1 Special Studies and Additional Monitoring 

Special studies and additional monitoring requirements imposed beyond those 

required under the effluent limits section of the permit are useful for collecting data 

that was not available to the permit writer for consideration during permit development. 

Special studies and additional monitoring requirements are generally used to 

supplement numeric effluent limits or support future permit development activities. 

138 - EPA NPDES Permit Writers’ Manual 
Special CondMons Chapter 8 

Examples of the types of special studies that could be required in a NPDES permit 

include: 

0 Treatability studies-Applicable when treatability information is lacking for 

a pollutant or pollutants that would prohibit a permit writer from developing 

defensible technology-based effluent limits. Treatability studies can also be 

required when the permit writer suspects that a facility may not be able to 

comply with an effluent limit. 

l Toxicity identification evaluation/Toxicity reduction evaluation 

(TImRE)-Required for facilities for which wastewater discharges are 

found to be toxic as a result of a whole effluent toxicity (WET) test. The 

purpose of these evaluations is to identify and control the sources of toxicity 

in an effluent. Further guidance related to EPA recommended TIE/TRE 

procedures and requirements can be found in the following guidance 

manuals: 

- Toxicity Reduction Evabation Protocol for Municipal Wastewater 

Treatment Plants.45 

- Generalized Methodology for Conducting Industrial Toxicity Reduction 

Evaluations (TREs).~~ 

- Methods for Aquatic Toxicity identification Evaluations: Phase 1 Toxicity 

Characterization Procedures. Second Edition.47 

- Sediment Toxicity identification Evaluations: Phase I (Characterization), 

Phase II (Identification), Phase 111 (Confirmation) Modifications of 

Effluent Procedures.48 

- Toxicity identification Evaluations: Characterization of Chronically Toxic 

Effluents, Phase L4’ 

45USEPA (1989). Toxicity Reducfion Evaluation Protocol for Municipal Wastewater Treatment 

Plants. EPA-600/4-89-OOlA. Water Engineering Research Laboratory, Cincinnati, Ohio. 

46USEPA (1989). Generalized Methodology for Conducting industrial Toxicity Reduction Evaluations 

(TRES). EPA-600/2-88-070. Water Engineering Research Laboratory, Cincinnati, Ohio. 

47USEPA (1991). Methods for Aquatic Toxicity ldentificafion Evaluations: Phase I Toxicity 

Characterization Procedures. Second Edition. EPA-600/6-91-003. Environmental Research 

Laboratory, Duluth, Minnesota. 

48USEPA (1991). Sediment Toxicity identification Evaluations: Phase I (Characterization), Phase II 

(Id&tification), Phase 111 (Confirmation) Modifications of Effluent Procedures. EPA-600/6-91-007. 

Environmental Research Laboratory, Duluth, Minnesota. 

4gUSEPA (1992). Toxicity ldenfificafion Evaluations: Characterization of Chronically Toxic Effluents, 

Phase 1. EPA-600/6-91-005F. Environmental Research Laboratory, Duluth, Minnesota. 

86% NPDES Permit Writers’ Manual - 139 
Special Conditions Chapter 8 

- Methods for Aquatic Toxicity Identification Evaluations: Phase !I 

Toxicity Identification Procedures for Samples Exhibiting Acute and 

Chronic Toxicity.5o 

- Methods for Aquatic Toxicity Identification Evaluations: Phase III 

Confirmation Procedures for Samples Exhibiting Acute and Chronic 

Toxicity. 5 ’ 

l Mixing or mixing zone studies -Used to assist in determining the 

allowable ambient mixing that can be applied when developing WQBELs. 

. Sediment monitoring-Used if a permit writer suspects that pollutants 

contained in wastewater discharges accumulate in the sediments of the 

receiving water. 

. Bioconcentration studies-These biological monitoring studies are used 

to determine whether pollutants contained in wastewater discharges 

bioaccumulate in aquatic organisms (e.g., fish, invertebrates). These types 

of studies are usually recommended when WQBELs for pollutants that 

bioaccumulate are established below analytical detection levels. Additional 

guidance related to evaluating the bioaccumulation potential of a pollutant 

can be found in the EPA Great Lakes Water Quality Initiative Technical 

Support Document for the Procedure to Determine Bioaccumulation 

Factors.52 

When establishing special conditions, permit writers must ensure that any 

particular requirements related to the study (e.g., special sampling or analytical 

procedures) are specified in the permit condition. In addition, permit writers must 

establish a reasonable schedule for completion and submission of the study or 

monitoring program. If the anticipated schedule is longer than 6 months to 1 year, 

then it is recommended that the permit writer require that the facility provide an interim 

progress report. 

“USEPA (1993). Methods for Aquatic Toxicity ldentificaiion Evaluations: Phase I/ Toxicity 

Identification Procedures for Samples Exhibiting Acute and Chronic Toxicity, EPA-600/R-92-080. 

Environmental Research Laboratory, Duluth, Minnesota. 

5’USEPA (1993). Methods for Aquatic Toxicity Identification Evaluations: Phase 111 Confirmation 

Procedures for Samples Exhibiting Acute and Chronic Toxicity EPA-600/R-92-081. Environmental 

Research Laboratory, Duluth, Minnesota. 

“USEPA (1995). Great Lakes Water Quality Initiative Technical Support Document for the 

Procedure to Determine Bioaccumufation Factors. EPA-820/B-95-005. Office of Science and 

Technology. 

140 - 8ER9 NPDES Permit Writers’ Manual 
Special Conditions Chapter 8 

8.1.2 Best Management Practices (BMPs) 

In general, BMPs are measures to prevent or mitigate water pollution from 

sources ancillary to the industrial manufacturing or treatment process. The NPDES 

regulations, at 40 CFR $122.2, define the term “best management practices” and 

provide the following measures as examples of BMPs: 

l Schedules of activities 

l Prohibitions of practices 

. Maintenance procedures 

. Treatment requirements 

l Operating procedures and practices to control 

- Plant site runoff 

- Spillage or leaks 

- Sludge or waste disposal 

- Drainage from raw material storage areas. 

The NPDES regulations at 40 CFR $122.44(k) acknowledge that BMPs shall be 

included as permit conditions (when applicable) where they are authorized under 

Section 304(e) of the CWA; when numeric effluent limitations are infeasible; or when 

they are necessary to achieve limitations or carry out the purpose and intent of the 

CWA. Examples of when numeric effluent limitations are infeasible include: 

. Regulating a pollutant for which limited treatability or aquatic impact 

information are available to allow development of technology-based or 

water quality-based effluent limits 

. Regulating releases when the types of pollutants vary greatly over time. 

Other circumstances when BMPs should be imposed as permit conditions include: 

l When chemical analyses are inappropriate or impossible 

. When a history of leaks and spills exist or when housekeeping is sloppy 

. When a complex facility lacks toxic pollutant data 

l When other discharge control options are prohibitively expensive. 

Permit writers may include BMPs in pennits in two basic ways: require the 

development of a general BMP plan, and/or require site-, process-, or pollutant- 

&EM NPDES Permit Writers’ Manual - 141 
Special Conditions Chapter 8 

specific BMPs. How BMPs are included as a permit condition, depends on the type of 

permit being developed. In the case of an individual permit, where a permit writer is 

developing permit conditions for a particular facility and has the opportunity to review 

the circumstances of the facility, the development of site- or pollutant-specific BMPs 

may be appropriate. On the other hand, including site- or pollutant-specific BMPs as 

conditions in a general permit may not be appropriate since they are highly dependent 

on the circumstances of individual facilities. As a result, discharges covered under a 

general permit may be required to develop a general BMP plan that allows the 

permittee to determine appropriate BMPs based on the circumstances of their 

particular facility. 

The Guidance Manual for Developing Best Management Practices (BMP@ 

describes the activities and materials at an industrial or municipal facility which are 

best addressed by BMP plans. The manual also describes how BMPs work and gives 

examples of the types of BMPs that can be used. 

If a permit writer uses a general permit requirement for a BMP plan, it is the 

responsibility of the facility to plan, develop and implement, and reevaluate the 

success/shortfalls of its own plan. Usually, a BMP committee (group of individuals 

within the plant organization) is responsible for developing the BMP plan and assisting 

the plant management in implementing and updating the BMP plan. However, plant 

management, not the committee, has overall responsibility and accountability for the 

quality of the BMP plan. 

EPA has identified several recommended components for effective BMP plans. 

The minimum suggested components of a general BMP plan are presented below: 

l General Requirements 

- Name and location of facility 

- Statement of BMP policy and objective 

- Review by plant manager 

l Specific Requirements 

- BMP committee 

53USEPA (1993). Guidance Manual for Developing Best Management Practices (BMPs). EPA 

833-B-93-004. Office of Water. 

142 - 88# NPDES Permit Writers’ Manual 
Special Conditions Chapter 8 

- Risk identification and assessment 

- Reporting of BMP incidents 

- Materials compatibility 

- Good housekeeping 

- Preventive maintenance 

- Inspections and records 

- Security 

- Employee training. 

Each of these components are discussed in more detail in the Guidance 

Manual for Developing Best Management Practices (BMPs) .54 

Site-, process-, and pollutant-specific BMPs are designed to address conditions 

particular to a site, process, or pollutant. The need for specific BMPs at a facility often 

will be discovered in conjunction with other permit-related activities, such as 

compliance inspections. Poor housekeeping or a history of spills, for example, 

indicate a need for specific BMPs to supplement the quantitative effluent limits for 

specific pollutants in the permit. 

To select a specific BMP, the permit writer must: 

. Review the industry profiles to determine the industrial processes that apply 

. Evaluate whether the BMP would help to achieve the environmental 

objectives of the industry 

. Use industry- or municipal-specific examples from other permits, pollution 

prevention sources, existing permits for similar processes, or EPA guidance 

documents. 

BMP plans can be submitted for review by the regulatory agency but are 

usually kept onsite and made available to the permitting authority upon request. The 

normal compliance schedule is to require preparation of the BMP plan within 6 

months, and implementation of the plan within 12 months of permit issuance. 

Specific BMPs have been developed for storm water discharges and combined 

sewer overflows (CSOs) and are discussed in Sections 8.2 and 8.3, respectively. 

54USEPA (1993). Guidance Manual for Developing Best Management Practices (BMPs). EPA 

833-B-93-004. Off ice of Water. 

86% NPDES Permit Writers’ Manual - 143 
Special Conditions Chapter 8 

Example: 

The following is example language for requiring development and implementation of a BMP Plan in 

an NPDES permit. The language should be crafted and changed as necessary to meet the individual 

facility’s needs and State/EPA goals for the facility. The text which is ‘*redlined** (i.e., text between 

asterisks) needs special permit-specific consideration. 

1. Implementation. 

If a BMP Plan does not exist: 

The permittee, shall develop and implement a Best Management Practices (BMP) Plan which 

achieves the objectives and the specific requirements listed below. A copy of the Plan shall be 

submitted to EPA ‘*and/or State agency.** The Plan shall be implemented as soon as possible but 

no later than twelve months from the effective date of the permit. 

If a BMP Plan already exists: 

The permittee shall during the term of this permit operate the facility in accordance with the BMP 

Plan **(cite existing Plan)** or in accordance with subsequent amendments to the Plan. The 

permittee shall also amend this Plan, to incorporate practices to achieve the objectives and specific 

requirements listed below, and a copy shall be submitted to EPA **and/or State agency’* The 

amended Plan shall be implemented as soon as possible but not later than six months from the 

effective date of the permit. 

2. Purpose. Through implementation of the BMP Plan the permittee shalt prevent or minimize the 

generation and the potential for the release of pollutants from the facility to the waters of the United 

States through normal operations and ancillary activities. 

3. Obiectives. The permittee shall develop and amend the BMP Plan consistent with the following 

objectives for the control of pollutants. 

a. The number and quantity of pollutants ana the toxicity of effluent generated, discharged or 

potentially discharged at the facility shall be minimized by the permittee to the extent feasible by 

managing each influent waste stream in the most appropriate manner. 

b. Under the BMP Plan, and any Standard Operating Procedures (SOPS) included in the Plan, the 

permittee shall ensure proper operation and maintenance of the treatment facility. 

c. The permittee shall establish specific objectives for the control of pollutants by conducting the 

following evaluations. 

(1) Each facility component or system shall be examined for its waste minimization opportunities 

and its potential for causing a release of significant amounts of pollutants to waters of the 

United States due to equipment failure, improper operation, and natural phenomena such as 

rain or snowfall, etc. The examination shall include all normal operations and ancillary 

activities including material storage areas, plant site runoff, in-plant transfer, process and 

material handling areas, loading or unloading operations, spillage or leaks, sludge and waste 

disposal, or drainage from raw material storage. **note that only the area from the previous 

list which apply to a facility should be included” 

(2) Where experience indicates a reasonable potential for equipment failure (e.g., a tank 

overflow or leakage), natural condition (e.g., precipitation), or other circumstances to result in 

significant amounts of pollutants reaching surface waters, the program should include a 

prediction of the direction, rate of flow and total quantity of pollutants which could be 

discharged from the facility as a result of each condition or circumstance. 

144 - 8EF# NPDES Permit Writers’ Manual 
Special Conditions Chapter 8 

Example (continued): 

4. Reuuirements. The BMP Plan shall be consistent with the objectives in Part 3 above and the general 

guidance contained in the publication entitled Guidance Mama/ for Developing Best Management 

Practices (BMPs) (USEPA, 1993) or any subsequent revisions to the guidance document. The BMP 

Plan shall: 

a. Be documented in narrative form, shall include any necessary plot plans, drawings or maps, and 

shall be developed in accordance with good engineering practices. The BMP Plan shall be 

organized and written with the following structure: 

(1) Name and location of the facility. 

(2) Statement of BMP policy. 

(3) Structure, functions, and procedures of the BMP Committee. 

(4) Specific management practices and standard operating procedures to achieve the above 

objectives, including, but not limited to, the following: 

(a) modification of equipment, facilities, technology, processes, and procedures, 

(b) reformulation or redesign of products, 

(c) substitution of materials, and 

(d) improvement in management, inventory control, materials handling or general 

operational phases of the facility. 

(5) Risk identification and assessment. 

(6) Reporting of BMP incidents. 

(7) Materials compatibility. 

(8) Good housekeeping. 

(9) Preventative maintenance. 

(10) Inspections and records. 

(11) Security. 

(12) Employee training. 

b. Include the following provisions concerning BMP Plan review: 

(1) Be reviewed by plant engineering staff and the plant manager. 

(2) Be reviewed and endorsed by the permittee’s BMP Committee. 

(3) Include a statement that the above reviews have been completed and that the BMP Plan 

fulfills the requirements set forth in this permit. The statement shall be certified by the dated 

signatures of each BMP Committee member. 

c. Establish specific best management practices to meet the objectives identified in Part 3 of this 

section, addressing each component or system capable of generating or causing a release of 

significant amounts of pollutants, and identifying specific preventative or remedial measures to be 

implemented. 

&EPA NPDES Permit Writers’ Manual - 145 
Special Condblons Chapter 8 

Example (continued): 

d. Establish specific best management practices or other measures which ensure that the following 

specific requirements are met: 

(1) Ensure proper management of solid and hazardous waste in accordance with regulations 

promulgated under the Resource Conservation and Recovery Act (RCRA). Management 

practices required under RCRA regulations shall be referenced in the BMP Plan. 

(2) Reflect requirements for Spill Prevention, Control, and Countermeasure (SPCC) plans under 

Section 311 of the Act and 40 CFR Part 112 and may incorporate any part of such plans 

into the BMP Plan by reference. 

(3) Reflect requirements for storm water control under Section 402(p) of the Act and the 

regulations at 40 CFR 122.26 and 122.44, and otherwise eliminate to the extent practicable, 

contamination of storm water runoff. 

(4), etc. 

*‘Section 4.d. needs to be tailored to each facility by the permit writer. Processes or areas of the 

facility with housekeeping problems, noncompliance, spills/leaks, or other problems which could be 

remedied through a BMP should be addressed here. If a solution to the problem is known (e.g., 

more frequent inspections, preventive maintenance, etc.) this remedy should also be included as a 

part of the BMP Plan requirements. To gather ideas for such requirements, the permit writer may 

want to contact the permittee. compliance personnel, facility inspectors, operations office personnel, 

State agency counterparts. The permit writer may also want to check requirements in other permits 

and BMP Plans for similar facilities.” 

5. Documentation. The permittee shall maintain a copy of the BMP Plan at the facility and shall make 

the plan available to EPA “and/or State agency** upon request. All offices of the permittee which 

are required to maintain a copy of the NPDES permit shall also maintain a copy of the BMP Plan. 

6. BMP Plan Modification. The permit-tee shall amend the BMP Plan whenever there is a change in the 

facility or in the operation of the facility which materially increases the generation of pollutants or their 

release or potential release to the receiving waters. The permittee shall also amend the Plan, as 

appropriate, when plant operations covered by the BMP Plan change. Any such changes to the BMP 

Plan shall be consistent with the objectives and specific requirements listed above. All changes in 

the BMP Plan shall be reported to EPA “and/or State agency** in writing. 

7. Modification for Ineffectiveness. At any time, if the BMP Plan proves to be ineffective in achieving 

the general objective of preventing and minimizing the generation of pollutants and their release and 

potential release to the receiving waters and/or the specific requirements above, the permit and/or 

the BMP Plan shall be subject to modification to incorporate revised BMP requirements. 

8.1.3 Pollution Prevention 

Pollution prevention has been shown to reduce costs as well as pollution risks 

through source reduction and recycling/reuse techniques. Under Section 6602(b) of 

the Pollution Prevention Act of 1990, Congress established a national policy for a 

hierarchy of environmental management: 

. Pollution should be prevented or reduced at the source, whenever feasible. 

. Pollution that cannot be prevented should be recycled in an environmentally 

safe manner, whenever feasible. 

146 - 8E)# NPDES Permit Writers’ Manual 
Speclal Conditions Chapter 8 

. Pollution that cannot be prevented or recycled should be treated in an 

environmentally safe manner, whenever feasible. 

. Disposal or other release into the environment should be employed only as 

a last resort and should be conducted in an environmentally safe manner. 

The Pollution Prevention Act emphasizes that pollution prevention means 

source reduction and defines source reduction as any practice that: 

. Reduces the amount of any hazardous substance, pollutant, or contaminant 

entering any waste stream or otherwise released into the environment 

(including fugitive emissions) prior to recycling, treatment, or disposal 

l Reduces the threats to public health and the environment associated with 

the release of hazardous substances, pollutants, or contaminants 

. Increases the efficiency of using raw materials, energy, water, or other 

resources, or protects natural resources by conservation. 

The environmental management hierarchy-prevention, recycling, treatment, 

and disposal-should be viewed as establishing a set of preferences, rather than an 

absolute judgment that prevention is always the most desirable option. The hierarchy 

is applied to many different circumstances that require good judgment. Prevention 

includes what is commbnly called in-process recycling. Recycling conducted in an 

environmentally sound manner shares many of the advantages of prevention (e.g., 

energy and resource conservation and reduction of the need for end-of-pipe treatment 

or waste containment). 

Within the NPDES Program, BMPs are inherently pollution prevention practices. 

Traditionally, BMPs have focused on good housekeeping measures and good 

management techniques that attempt to avoid contact between pollutants and water 

media as a result of leaks, spills, and improper waste disposal. However, based on 

the authority granted under the regulations, BMPs may include the universe of 

pollution prevention, which encompasses production modifications, operational 

changes, materials substitution, materials and water conservation, and other such 

measures. 

88# NPDES Permit Writers’ Manual - 147 
Speclal Conditions Chatier 8 

8.1.4 Compliance Schedules 

The NPDES regulations at 40 CFR 5122.47 allow permit writers to include 

schedules of compliance to allow permittees additional time to achieve compliance 

with the CWA and applicable regulations. Schedules developed under this provision 

must require compliance by the permittee as soon as possible, but may not extend the 

date for final compliance beyond compliance dates established by the Act. Examples 

of situations where compliance schedules may be appropriate include: 

. Pretreatment program development 

. Sludge use and disposal program development and/or implementation 

. New/revised effluent guidelines application 

. New/revised water quality standards application 

. BMP plan development and/or implementation 

. Storm water, CSO and/or SSO control program development and/or 

implementation. 

While compliance schedules may be appropriate for implementation of certain 

NPDES Program requirements, they are not appropriate for requirements where 

statutory deadlines have passed. In particular, compliance schedules are not 

appropriate under the following scenarios: 

1. Compliance with Technoloov-Based Effluent Limits 

Compliance schedules are not allowed at this time because statutory deadlines 

have passed for BPT, BAT, and BCT levels of treatment. 

. July 1, 1977 for BPT 

. March 31, 1989 for BAT and BCT. 

This applies to both existing and new dischargers. It should be noted, however, 

that 40 CFR $122.29(d)(4) allows a new source or new discharger up to 90 

days to “start-up” its pollution control equipment and achieve compliance with 

its permit conditions (i.e., provides for up to a go-day period to achieve 

compliance). 

2. Compliance with Water Qualitv-Based Effluent Limits 

The determination of whether a compliance schedule to meet water qualitybased permit limits is permissible depends on when the applicable State water 

148 - 8ER9 NPDES Permit Writers’ Manual 
Speclal Conditions Char&w 8 

quality standards were initially promulgated. Because States were required to 

have water quality standards promulgated by July 1, 1977, and because 

facilities were supposed to have had the opportunity to comply with the 

standards, compliance schedules are not allowed if the State water quality 

standards were promulgated before July 1, 1977. 

If a State promulgates a water quality standards after July 1, 1977, and if the 

State water quality regulations allow for a compliance schedule to comply with 

the standards, then a compliance schedule could be granted in accordance with 

40 CFR 47. 

If a State promulgates a water quality standards after July 1, 1977, and the 

State water quality regulations do not allow for a compliance schedule to 

comply with the standards, then a compliance schedule may not be granted. 

[See: Star-Kist Caribe, Inc., NPDES Appeal No. 88-51 

In situations where the permittee will be unable to meet permit conditions, and 

where a compliance schedule pursuant to 40 CFR s122.47 is not permitted, the 

practical alternative is to initiate an Administrative Order under Section 309 of the 

CWA (containing a schedule of compliance) concurrent with permit issuance. 

8.2 Permit Conditions Addressing Storm Water Discharges 

Associated With Industrial Activities 

As previously discussed in Chapter 2, all storm water discharges associated 

with industrial activity that discharge storm water through a separate municipal storm 

sewer system (MS4) or discharge directly to waters of the United States are required 

to obtain NPDES permit coverage. Following the promulgation of the November 16, 

1990, storm water application regulations, EPA and NPDES authorized States were 

faced with providing permit coverage for storm water discharges from over 100,000 

industrial facilities. Due to the nature of the discharge (i.e., storm water) and the large 

number of facilities requiring permit coverage, EPA and most NPDES authorized 

States chose to use general permits as a mechanism to provide permit coverage for 

facilities requiring permit coverage for their storm water discharges. 

Unlike discharges of process wastewater where numerical effluent limitations 

(technology-based and/or water quality-based) are typically used to control the 

discharge of pollutants from industrial facilities, the primary permit condition used to 

0EM NPDES Permit Writers’ Manual - 149 
Special Condltlons Chapter 8 

address discharges of pollutants in a facilities storm water is a pollution prevention 

plan. The development and implementation of a site-specific storm water pollution 

prevention plan is considered to be the most important requirement of the EPA and 

State issued storm water general permits. Site-specific storm water pollution 

prevention plans allow permittees to develop and implement “best management 

practices”, whether structural or non-structural, that are best suited for controlling 

storm water discharges from their industrial facility. 

Each industrial facility covered under an EPA issued storm water general permit 

must develop a pollution prevention plan, tailored to the site specific conditions, and 

designed with the goal to control the amount of pollutants in storm water discharges 

from the site. The special conditions component of EPA’s storm water general permits 

identify the requirements that each facility must include in their storm water pollution 

prevention plan, including: 

. A description of potential potlutant sources at the facility, including: 

- A map of the facility indicating the drainage areas of the site and the 

industrial activities which occur in each drainage area 

- An inventory of materials that may be exposed to storm water 

. 

- A description of the likely sources of pollutants from the site and a 

prediction of the pollutants which are likely to be present in the storm 

water 

- The history of spills and leaks of toxic and hazardous materials over the 

last three years 

The measures and controls that will be implemented to prevent or minimize 

pollution of storm water, including: 

Good housekeeping or upkeep of industrial areas exposed to storm 

water 

Preventative maintenance of storm water controls and other facility 

equipment 

Spill prevention and response procedures 

Testing of outfalls to ensure that there are no illicit discharges 

Employee training on pollution prevention measure and controls, and 

record keeping. 

A permit writer’s best source of information for developing appropriate special 

conditions for storm water controls are perhaps other storm water general permits. 

Using existing general permits as the basis for special conditions is encouraged since 

150 - 8EiY4 NPDES Permit Writers’ Manual 
Special Condltlons Chatier 8 

this will reduce duplication of efforts. A listing of all general permits (storm water and 

non-storm water) issued by EPA as well as authorized States, which can be used as a 

permit writing resource, can be found in the EPA Point Source tnformation Provision 

Exchange System (PIPES) accessible through EPA’s World Wide Web home page 

[http:/www.epa.gov]. In addition, EPA has developed the following guidance 

documents to help permit writers identify components of storm water pollution 

prevention plans as well as to assist permittees in developing plans: 

. Storm Water Management for Industrial Activities: Developing Pollution 

Prevention Plans and Best Management Pracfices.55 

l Storm Water Management for Construction Activities: Developing Pollution 

Prevention Plans and Best Management Practices.56 

8.3 Special Conditions for Municipal Facilities 

This section explains several common special conditions that are applicable 

only to municipal facilities. These conditions reflect requirements for POTWs to 

implement and enforce local pretreatment programs for their industrial users; sludge 

disposal requirements; CSO requirements; SSO requirements; and MS4 requirements. 

8.3.1 The National Pretreatment Program 

Section 402(b)(8) of the CWA requires that POTWs receiving pollutants from 

significant industrial sources subject to section 307(b) standards establish a POTW 

pretreatment program to ensure compliance with these standards. The implementing 

regulations at 40 CFR 403.8(a) state, “any POTW (or combination of POlWs operated 

by the same authority) with a total design flow greater than 5 million gallons per day 

(mgd) and receiving from industrial users pollutants which pass through or interfere 

with the operation of the POTW or are otherwise subject to pretreatment standards will 

be required to establish a POTW pretreatment program unless the NPDES State 

exercises its option to assume local responsibilities as provided in 403.1 O(e).” EPA or 

a NPDES State with an approved pretreatment program may require POTWs with 

55USEPA (1992). Storm Water Management for hcfustrial Activities: Developing Pollution 

Prevention Plans and Best Managemenf Practices. EPA 832-R-92-006. Office of Water. 

56USEPA (1992). Storm Water Management for Construction Activities: Developing Pollution 

Prevention Plans and Best Management Pracfices. EPA 832-R-92-005. 

&EPA NPDES Permit Writers’ Manual - 151 
Specjal Conditions Chapter 8 

design flows of 5 mgd or less to develop a POTW pretreatment program if 

circumstances warrant (40 CFR 403.8(a)). The requirement to develop a pretreatment 

program only appfies to POTWs or States using the option under 403.10(e), this is 

primarily due to the fact that the pretreatment regulations at 40 CFR 403 only apply to 

POTWs and industrial users of POTWs, and the State or EPA offices that issue 

permits to the POTWs. 

Since 1978, approximately 1,500 POTWs have been required to develop and 

implement pretreatment programs as special conditions of NPDES permits. The 

pretreatment program was developed to control industrial discharges to POTWs and to 

meet three objectives at the POTWs: (I) to prevent pass through, (2) to prevent 

interference, including interference with its use or disposal of municipal sludge, (3) to 

improve opportunities to recycle and reclaim municipal and industrial wastewater and 

sludges. 

As authorized by the pretreatment regulations at 40 CFR 403,8(c),(d) and (e) 

and the NPDES regulations at 40 CFR 122.44(j)(2), the requirements to develop and 

implement a POTW pretreatment program are placed as enforceable conditions in the 

POTW’s NPDES permit. 

Pretreatment Program development and Program Implementation are done as 

two separate steps, Through the NPDES permit the POTW is required to develop a 

Pretreatment Program. The POTW is required to submit an approvable program that 

meets the requirements in 40 CFR 403.9(b), specifically, these requirements are the 

provisions of a program as laid out in 40 CFR 403.8(f). 40 CFR 403.8(f) requires the 

POTW to have certain legal authority (usually a municipal ordinance or set of 

regulations) and procedures to fully and effectively exercise and implement the legal 

authority and procedures. The POTW must submit a program detailing the legal 

authority to: 

1. Deny or condition new or increased contributions of pollutants, or changes 

in nature of pollutants, to the POTW by industrial users; 

2. Require compliance with applicable pretreatment standards and 

requirements by industrial users; 

152 - 8ER9 NPDES Permit Writers’ Manual 
Special Condltlons Chapter 8 

3. Control through permit, order, or similar means the contribution to the 

POTW by each industrial user to ensure compliance with applicable 

pretreatment standards and requirements. These control mechanisms must 

have certain conditions as laid out in 403.8(f)(l)(iii) and be enforceable; 

4. Require the development of compliance schedules where necessary by 

each industrial user for the installation of technology required to meet 

applicable pretreatment standards and requirements, and submission of all 

notices and self-monitoring reports to assess and ensure compliance; 

5. Carry out all inspection, surveillance, and monitoring procedures necessary 

to determine compliance with applicable pretreatment standards and 

requirements independent of information submitted by the industrial user 

(this will include authority to enter the premises of the industrial user); 

6. Obtain remedies for noncompliance (e.g., injunctive relief, penalties); 

7. Comply with confidentiality requirements. 

Further at a minimum, the POTW must have procedures to: 

1. Identify and locate all possible industrial users which might be subject to the 

POTW pretreatment program; 

2. Identify the character and volume of pollutants contributed to the POTW by 

the industrial users; 

3. Notify industrial users of applicable pretreatment standards and applicable 

requirements under section 204(b) and 405 of the Clean Water Act and 

subtitles C and D of RCRA; 

4. Receive and analyze self monitoring reports; 

5. Conduct sampling, inspections and other surveillance activities to determine 

compliance with applicable pretreatment standards and requirements 

independent of information supplied by the industrial user; 

6. Investigate instances of noncompliance; and 

7. Comply with public participation, including public notice annually of industrial 

users determined to be in significant noncompliance during the previous 12- 

month period. 

8ElY4 NPDES Permit Writers’ Manual - 153 
Special Conditions Chapter 8 

Also, as part of the POTW pretreatment program, POTWs must have adequate 

resources and funding to implement the program, evaluate the need for local limits 

and develop them if the need exists, and develop an enforcement response plan. 

The permit requires the POTW to submit the program documentation which 

details the authority and procedures to be implemented along with other information 

about the program as laid out in 40 CFR 403.9. The permit will allow the POTW up to 

one year from the time the permitting authority determines the need for a pretreatment 

program exists to develop and submit a program for approval. Once the permitting 

authority reviews and approves the program, the program is then incorporated into the 

permit in order to make the requirement to implement the program an enforceable part 

of the permit. 

The incorporation of the requirement to develop a pretreatment is generally 

done at the time of reissuance of the permit. However, the requirement may also be 

incorporated through a modification of the permit if cause exists. Cause exists if I’... 

the addition of pollutants into POTW by an industrial user or combination of industrial 

users presents a substantial hazard to the functioning of the treatment works, quality 

of the receiving waters, human health, or the environment,” (40 CFR 403.8(e)(l)). 

A permit modification to require the development of a pretreatment program is 

considered a major modification and must follow the procedures in 40 CFR 122.62. 

The incorporation of an approved program into the permit, thereby making the 

implementation of the program an enforceable part of the permit, is considered a 

minor modification to the permit and must follow the procedures in 40 CFR 122.63(g). 

During the life of the permit it may be necessary for the POTW to modify its approved 

pretreatment program (changes to local limits, changes to the ordinance, etc.). These 

changes may be brought about by the POTW’s desire to change the way the program 

operates, or they may be the result of changes that are necessary to address 

deficiencies in the program found during inspections or audits done by the permitting 

authority. Whatever the reason for the modification, these modifications to the 

approved program require review and approval by the permitting authority (Approval 

Authority) when the modifications are considered substantial, per 40 CFR 403.18. All 

approved substantial program modifications to the POTW’s approved pretreatment 

program require minor modifications to the permit. 

154 - 8EfYI NPDES Permit Writers’ Manual 
Special Condltlons Chapter 8 

Regulatory Update 

As of December 1996, there are two proposed regulations that may impact the permitting requirements 

for POlWs with pretreatment programs. First is the regulation that defines a substantial pretreatment 

program modification. EPA is reconsidering the definition of what is a substantial modification. EPA has 

proposed to shorten the list and thereby reduce the need for minor permit modifications. Second, EPA 

has proposed a new regulation for POTWs to apply for NPDES permits. The current regulations require 

POTWs to submit an evaluation of the need for local limits with their NPDES permit application. The 

proposed regulation would require the evaluation to be submitted after the permit has been reissued. 

Therefore the permit will need to have language included that implements this requirement. 

Most of the POTWs who need pretreatment program requirements in their 

permits currently have them in place. EPA Regions and approved States have 

developed standard pretreatment development or implementation conditions (with 

minor modifications made to tailor the conditions to the specific permittee) that are 

placed in all pretreatment POTW NPDES permits in that Region or State. The permit 

writer can obtain examples of these NPDES pretreatment conditions from the EPA or 

State pretreatment coordinators. The permit writer may need to update or modify 

pretreatment implementation language or initiate corrective action related to the 

pretreatment program. 

A NPDES State or an EPA Region will often designate a pretreatment 

coordinator to serve as the pretreatment expert to review the annual report from 

the POTW and recommend any action to be taken. The State or EPA Regional 

pretreatment coordinator is a key resource on pretreatment issues, particularly at the 

time of NPDES permit reissuance. EPA has prepared a number of guidance manuals 

for POTWs on how to implement their local pretreatment programs. 

Pretreatment program information and monitoring data obtained through the 

POTW’s pretreatment program may be useful to the permit writer in identifying 

possible modifications to the pretreatment program’s local limits or procedures, or the 

need for water quality-based controls. Although there is currently no requirement for 

chemical-specific toxics effluent monitoring to be submitted with the permit application, 

most pretreatment POTWs have performed toxics monitoring of their influent, effluent, 

and sludge. The permit writer should obtain such data with the aid of the pretreatment 

coordinator. These data can be used to determine the need for water quality-based 

limits. 

&EPA NPDES Permit Writers’ Manual - 155 
Special Conditions Chapter 8 

8.3.2 Municipal Sewage Sludge 

Section 405(d) of the CWA requires that EPA regulate the use and disposal of 

sewage sludge to protect public health and the environment from any reasonably 

anticipated adverse effects of these practices. In the CWA, Congress directs EPA to 

develop technical standards for municipal sludge use and disposal options. These 

standards are set out in 40 CFR Part 503. Congress also enacted strict deadlines for 

compliance with these standards. Within 1 year of promulgation of the standards, 

compliance was required unless construction of new pollution control facilities was 

necessary, in which case compliance was required within 2 years. 

EPA promulgated the 40 CFR Part 503 Standards for the Use or Disposal of 

Sewage Sludge on February 19, 1993 (58 FR 9248) with amendments on February 

19, 1994 (59 FR 9095) and October 25, 1995 (60 FR 54764). These regulations 

address four sludge use and disposal practices: land application, surface disposal, 

incineration, and disposal in a municipal solid waste landfill. The standards for each 

end use and disposal method consist of general requirements, numeric pollutant 

limits, operational standards, and management practices, as well as monitoring, 

recordkeeping, and reporting requirements. Unlike technology standards based on 

the ability of treatment technologies to reduce the level of pollutants, EPA’s sewage 

sludge standards are based on health and environmental risks. 

40 CFR Part 503 imposes requirements on four groups: 

. Persons who prepare sewage sludge or material derived from sewage 

sludge 

. Land appliers of sewage sludge 

l Owners/operators of sewage sludge surface disposal sites 

l Owners/operators of sewage sludge incinerators. 

The regulation is largely self-implementing. This means that anyone engaged 

in activities covered by the regulation must comply with the appropriate requirements 

on or before the compliance deadlines. A person who violates 40 CFR Part 503 

requirements is subject to administrative, civil, and/or criminal enforcement actions. 

156 - 88ER9 NPDES Permit Writers’ Manual 
Special Conditions Chapter 8 

Section 405(f) of the CWA requires the inclusion of sewage sludge use or 

disposal requirements in any NPDES permit issued to a Treatment Works Treating 

Domestic Sewage (TWTDS) and authorizes the issuance of sewage sludge permits 

to non-discharging TWTDS. To provide a mechanism for this inclusion, EPA 

promulgated revisions to the NPDES permit regulations at 40 CFR Parts 122 and 124 

on May 2, 1989 (54 FR 18716). These revisions expanded EPA’s authority to include 

sewage sludge use and disposal standards in NPDES permits and to issue NPDES 

permits to treatment works that do not have an effluent discharge to waters of the 

United States, but are involved in sewage sludge use or disposal as preparers, 

appliers, or owners/operators. TWTDS includes all sewage sludge generators and 

facilities that change the quality of sewage sludge such as blenders. 

EPA recognizes that implementation of 40 CFR Part 503 requirements is a 

source of confusion for permit writers and permittees who may already have NPDES 

permits with sewage sludge special conditions. The end result is that both NPDES 

sludge permit conditions and 40 CFR Part 503 requirements apply. EPA expects that 

over time, all NPDES sludge requirements will be revised to include the 40 CFR Part 

503 requirements. To reduce confusion, EPA has provided several guidance 

documents to explain the requirements of 40 CFR Part 503. 

. Part 503 Implementation Guidance.57 

. Land Application of Sewage Sludge-A Guide for Land Appliers on the 

Recordkeeping and Reporting Requirements of the Federal Standards for 

the Use and Disposal of Sewage Sludge Management in 40 CFR Part 

503? 

. Surface Disposal of Sewage Sludge-A Guide for Owners/Operators of 

Surface Disposal Facilities on the Monitoring, Recordkeeping, and 

Reporting Requirements of the Federal Standards for the Use and Disposal 

of Sewage Sludge in 40 CFR Part 503.5g 

5’USEPA (1995). Part 503 lmplementafion Guidance. EPA 833-R-95-001. Office of Water. 

‘*USEPA (1994). Land Application of Sewage Sludge-A Guide for Land Appliers on the 

Recordkeeping and Reporting Requirements of the Federal Standards for the Use and Disposal of 

Sewage Sludge Management in 40 CFR Part 503. EPA-831/B-93-002c. Office of Water. 

5gUSEPA (1994). Surface Disposal of Sewage Sludge-A Guide for Owner/Operators of Surface 

Disposal Facilities on the Monitoring, Record Keeping, and Reporting Requirements of the Federal 

Standards for the Use and Disposal of Sewage Sludge in 40 CFR Part 503. EPA-831/B-93-002b. 

Office of Water. 

GHY4 NPDES Permit Writers’ Manual - 157 
Speclal Condltlons Chapter 8 

. Preparing Sewage Sludge for Land Application or Surface Disposal-A 

Guide for Preparers of Sewage Sludge on the Monitoring, Record Keeping, 

and Reporting Requirements of the Federal Standards for the Use or 

Disposal of Sewage Sludge in 40 CFR Part 503.60 

. Domestic Septage Regulatory Guidance, A Guide to the EPA 503 Rule.” 

. Control of Pathogens and Vector Attraction in Sewage Sludge.62 

The permit writer should refer to the Part 503 Implementation Guidance63 and 

EPA Region and State guidelines or policies for instructions on how to implement the 

applicable 40 CFR Part 503 standards into the permit. The permit writer will need to 

determine the type of sludge use or disposal practice(s) used by the permittee and 

apply the appropriate 40 CFR Part 503 standards. In general, conditions will need to 

be established to address: 

. Pollutant concentrations or loading rates 

. Operational standards (such as pathogen and vector attraction reduction 

requirements for land application and surface disposal and total 

hydrocarbons (THC) concentrations for incinerators) 

. Management practices (e.g., siting restrictions, design requirements, 

operating practices) 

. Monitoring requirements (e.g., pollutants to be monitored, sampling 

locations, frequency, and sample collection and analytical methods) 

. Recordkeeping requirements 

l Reporting requirements (e.g., contents of reports and frequency or due 

dates for submission of reports) 

l General requirements (e.g., specific notification requirements prior to land 

application, submission of closure and post closure plan for surface 

disposal sites). 

‘%SEPA (1993). Preparing Sewage Sludge for Land Application or Surface Disposal--A Guide for 

Preparers of Sewage Sludge on the Monitoring, Recordkeeping, and Repotfing Requirements of the 

Federal Standards for the Use or Disposal of Sewage Sludge in 40 CFR Part 503. EPA831/B-93-002a. Office of Water. 

“USEPA (1993). Domestic Septage Regulatory GuidanceA Guide to the EPA 503 Rule. EPA832/B-92-005. Office of Water. 

“USEPA (1992). Con&V of Pathogens and Vector Attraction in Sewage Sludge. EfA-625/R-92- 

013. Off ice of Research and Development. 

‘?JSEPA (1995). fart 503 implementation Guidance. EPA 833-R-95-001. Office of Water. 

158 - 8EF# NPDES Permit Writers’ Manual 
Special Condtilons Chapter 8 

In addition to any specific applicable 40 CFR Part 503 standards, three 

boilerplate conditions must be written in the NPDES permit: (1) language requiring the 

POTW/TWTDS to comply with all existing requirements for sludge use and disposal, 

including the 40 CFR Part 503 standards, (2) a reopener clause, which authorizes 

reopening a permit to include technical standards if the technical standards are more 

stringent or more comprehensive than the conditions in the permit, and (3) a 

notification provision requiring the permittee to give notice to the permitting authority 

when a significant change in the sludge use or disposal practice occurs (or is 

planned). 

If permit conditions based on existing regulations are insufficient to protect 

public health and the environment from adverse effects that may occur from toxic 

pollutants in sewage sludge, permit conditions should be developed on a case-by-case 

basis using BPJ to fulfill the statutory requirement. EPA’s Part 503 Implementation 

Guidance(j4 contains information to assist permit writers in developing pollutant limits 

and management practice requirements on a case-by-case basis to protect public 

health and the environment from adverse effects that may occur from toxic pollutants 

in sewage sludge. 

8.3.3 Combined Sewer Overflows (CSOs) 

Combined sewer systems are designed to collect both sanitary and industrial 

wastewater and storm water runoff. During dry weather, combined sewers carry 

sanitary wastes and industrial discharges to a treatment plant. In periods of heavy 

rainfall, however, the combined storm water runoff and untreated sanitary sewage, 

including industrial wastewater, can overflow and discharge this untreated wastewater 

directly to a water body. These overflows are called combined sewer overflows 

(CSOS). 

On April 19, 1994, EPA published a CSO Control Policy in the Federal Register 

(59 FR 18688) which represents a comprehensive national strategy to ensure that 

municipalities, permitting authorities, water quality standards authorities, and the public 

engage in a comprehensive and coordinated planning effort to achieve cost effective 

CSO controls that ultimately meet appropriate health and environmental objectives. 

%SEPA (1995). Part 503 implementation Guidance. EPA 833-R-95-001. Office of Water. 

8EFY4 NPDES Permit Writers’ Manual - 159 
Special Condtilons Chapter 8 

CSOs are point source discharges subject to both the technology-based 

requirements of the CWA and to applicable State water quality standards. Under the 

CWA, CSOs must comply with the BAT for nonconventional and toxic pollutants and 

BCT for conventional pollutants. However, there are no promulgated BAT/BCT 

effluent guidelines and limitations for CSOs. As a result, permit writers must use BPJ 

in developing technology-based permit requirements for controlling CSOs. In addition, 

permit conditions must achieve compliance with applicable water quality standards. 

The 1994 CSO Control Policy contains the recommended approach for 

developing and issuing NPDES permits to control CSOs. In addition, EPA has 

developed the following guidance documents to help permit writers and permittees 

implement the CSO Control Policy: 

l Combined Sewer Ovetflo ws-Guidance for Long- Term Control Plan.65 

. Combined Sewer Overflows-Guidance for Nine Minimum Controls.66 

l Combined Sewer Overflows-Guidance for Screening and Ranking.=? 

l Combined Sewer Overflows-Guidance for Monitoring and Modeling.=’ 

l Combined Sewer Overflows-Guidance for Financial Capability Assessment 

and Schedule Uevelopment.69 

. Combined Sewer Overflows-Guidance for Funding Options.70 

l Combined Sewer Overflows-Guidance for Permit Writers.” 

?JSEPA (1995). Combined Sewer Overflows-Guidance for Long-Term Control Plan. EPA832/B-95-002. 

?JSEPA (1995). Combined Sewer Overflows-Guidance for Nine Minimum Controls. EPA832/B-95-003. 

“USEPA (1995). Combined Sewer Overflows-Guidance for Screening and Ranking. EPA-832/B95-004. 

68USEPA (1995). Combined Sewer Overflows-Guidance for Monitoring and Modeling. (DRAFT). 

EPA-832/B-95-005. 

“gUSEPA (1995). Combined Sewer Overflows-Guidance for Financial Capability Assessment and 

Schedule Development (DRAFT). EPA-832/B-95-006. 

“USEPA (1995). Combined Sewer Overflows-Guidance for Funding Options. EPA-832/B-95-007. 

“USEPA (1995). Combined Sewer Overflows-Guidance for Permit Writers. EPA-832/B-95-008. 

160 - 8ER9 NPDES Permit Writers’ Manual 
Speclal Ccmditlons Chapter 8 

Combined Sewer Overflows-Guidance for Permit Writers contains guidance, 

and example permit language that the permit writer can use. Because the control of 

CSCs typically requires substantial long-term planning, construction, financing and 

continuous reassessment, the implementation of CSO controls will probably occur over 

several permit cycles. The Combined Sewer Overflows-Guidance for Permit Writers 

explains a phased permitting approach to CSOs. Exhibit 8-1 depicts this phased 

permitting approach and the types of permitting conditions that should be developed 

for each phase. Depending on the particular permittee’s situation, a permit may 

contain both Phase I and Phase II elements. The initial permit conditions for CSOs, 

called Phase I permit requirements, should address: 

. Implementation of technology-based CSO controls as soon as possible but 

no later than January 1, 1997. The policy describes nine CSO control 

measures that may be considered minimum BAT/BCT, based on the permit 

writer’s BPJ. Exhibit 8-2 shows the nine minimum controls (NMC). 

. Development of a CSO Long-Term Control Plan (LTCP) generally within 2 

years of permit issuance. The policy describes the minimum elements 

which the LTCP should address. Exhibit 8-3 shows those minimum 

elements. 

The second round of NPDES permits to control CSOs, called Phase II, will 

contain specific permit conditions addressing continued implementation of the NMC 

and implementation of the selected long-term CSO control measures identified in the 

LTCP. The permit writer will need to review the permittee’s LTCP and consult with 

other staff involved in the CSO control process and the permittee to determine the 

appropriate permit conditions. Water quality-based controls will be expressed as 

narrative requirements and performance standards for the combined sewer system. 

Finally, post Phase II permit conditions would address continued implementation of the 

NMC, long-term CSO controls, and post-construction compliance monitoring. There 

may also be numeric water quality-based effluent limits when sufficient data exists to 

support their development. 

88# NPDES Permit Writers’ Manual - 161 
EXHIBIT 8-l 

Categories of CSO Permitting Conditions 

Tie (yrs) 0 . . . . . . . . . . . . . . . . . . . . 5 . . . . . . . . . . . . . . . . 10 . . . . . . . . . . . . > 

NPDES Permit 

A. Technology-Based 

B. Water Quality-Based 

C. Monitoring 

Phase I Phase II Post Phase II 

l NMC, at a minimum l NMC, at a minimum l NMC, at a minimum 

l Narrative l Narrative + perfonnance- l Narrative + performancebased standards based standards + 

numeric water qualitybased effluent limits (as 

appropriate) 

l Characterization, . Monitoring to evaluate l Post-construction 

monitoring, and modeling water quality impacts compliance monitoring 

of css . Monitoring to determine 

effectiveness of CSO 

controls. 

D. Reporting l Documentation of NMC 

implementation 

l Interim LTCP 

deliverables. 

l Implementation of CSO . Report results of postcontrols (both NMC and construction compliance 

long-term controls) monitoring 

E. Special Conditions l Prohibition of dry 

weather overflows 

(DWO) 

l Development of LTCP. 

l Prohibition of DWO 

l Implementation of LTCP 

l Reopener clause for water 

quality standards 

violations 

l Prohibition of DWO 

. Reopener clause for 

water quality standards 

violations. 

l Sensitive area 

reassessment. 

162 - 8ER9 NPDES Permit Writers’ Manual 
Speclal Coftdtlons Chaptw 8 

EXHIBIT 8-2 

Nine Minimum CSO Controls 

1. Proper operation and regular maintenance programs for the sewer system and the CSOs 

2. Maximum use of the collection system for storage 

3. Review and modification of pretreatment requirements to ensure that CSO impacts are 

minimized 

4. Maximization of flow to the POTW for treatment 

5. Prohibition of CSOs during dry weather 

6. Control of solid and floatable materials in CSOs 

7. Establishment of pollution prevention programs 

8. Public notification to ensure that the public receives adequate notification of CSO 

occurrences and CSO impacts 

9. Monitoring to effectively characterize CSO impacts and the efficacy of CSO controls. 

EXHIBIT 8-3 

Elements of the Long-Term CSO Control Plan 

1. Characterization, monitoring, and modeling of the combined sewer system 

2. Public participation 

3. Consideration of sensitive areas 

4. Evaluation of alternatives 

5. Cost/performance considerations 

6. Operational plan 

7. Maximizing treatment at the existing POTW treatment plant 

8. Implementation schedule 

9. Post-construction compliance monitoring program. 

In developing permit requirements to meet technology-based requirements and 

applicable State water quality standards, the permit writer in conjunction with staff 

involved in water quality standards and the permittee, should identify the appropriate 

site-specific considerations that will determine the CSO conditions to be established in 

the permit. EPA believes that the following information will be particularly relevant in 

developing the appropriate conditions: 

&BY4 NPDES Permit Writers’ Manual - 163 
Speclal Conditions Chapter 8 

l CSO Discharge 

- Flow, frequency, and duration of the CSO discharge 

- Available effluent characterization data on the CSO discharge 

- Available information and data on the impacts of the CSO discharge(s) 

(e.g., 305(b) reports, ambient survey data, fish kills, 304(l) lists of 

impaired waters) 

- Compliance history of the CSO owner, including performance and 

reliability of any existing CSO controls 

- Current NPDES permit and NPDES permit application 

- Facility planning information from the permittee which addresses CSOs 

. Technologies 

Performance data (either from the manufacturer or from other 

applications) for various CSO technologies that may be employed, 

including equipment efficiency and reliability 

Cost information associated with both the installation, operation and 

maintenance of CSO technologies 

Reference materials on various types of CSO technologies (e.g., Water 

Environment Federation Manual of Practice, American Society of 

Chemical Engineers publications). 

8.3.4 Sanitary Sewer Overflows 

(RESERVED) 

8.3.5 Municipal Separate Storm Sewer Systems (MS4) 

The November 16, 1990 (55 FL? 47990) storm water application regulations 

established requirements for a two-part permit application that allows local 

governments to assist in defining priority pollutant sources within the municipality and 

to develop and implement appropriate controls for such discharges to MS4. Part II of 

the application required municipal applicants to propose municipal storm water 

management programs to control pollutants to the “maximum extent practicable” 

(MEP) and to effectively prohibit non-storm water discharges to the municipal system. 

Municipal storm water management programs are a combination of source controls 

and management practices that address targeted sources within the boundaries of the 

municipal system. For example, a municipality that expects significant new 

development may focus more on proposing requirements for new development and 

construction. On the other hand, a municipality that does not expect significant new 

development may focus more on municipal activities that affect storm water quality 

164 - 86R9 NPDES Permit Writers’ Manual 
Speclal Crmditlons Chap&w 8 

such as: maintenance of leaking sanitary sewers, road de-icing and maintenance, 

operation of municipal landfills, flood control efforts, and control of industrial 

contributions of storm water. 

As with any NPDES permit, MS4 pen-nits must assure compliance with 

applicable technology-based requirements (in this case, the MEP) as well as 

applicable water quality standards. However, unlike POTWs where technology-based 

requirements are defined by secondary treatment standards, and most industrial 

sources that have promulgated ELGs, there are no promulgated technology-based 

standards that define MEP. Therefore, permit writers must rely on application 

requirements specified in the regulations and the applicants proposed management 

program when developing appropriate permit conditions. EPA has developed the 

following guidance document to assist permit writers as well as permittees to 

implement the Municipal Storm Water Program: 

. Guidance Manual for the Preparation of Part 2 of the NPDES Permit 

Applications For Discharge From Municipal Separate Storm Sewer 

Sysfems.‘* 

“USEPA (1992). Guidance Manual for the Preparation of Part 2 of the NPDES Permit Application 

for Discharges from Municipal Separate Storm Sewer Systems. EPA-833/B-92-002. Office of Water. 

8EH4 NPDES Permit Writers’ Manual - 165 
Chapter 9 

Standard Conditions of 

NPDES Permits 

This chapter describes standard conditions, sometimes called “boilerplate” 

conditions, that consist of pre-established conditions that must be incorporated into 

every permit. The standard conditions set out in 40 CFR §§122.41 and 122.42 play 

an important supporting role to the numeric permit limits because these conditions 

delineate the legal, administrative, and procedural requirements of the permit. 

Standard conditions may be inserted verbatim from the regulations or incorporated into 

the permit by specific reference to the regulations. Standard conditions cover various 

topics, including definitions, testing procedures, records retention, notification 

requirements, penalties for noncompliance, and permittee responsibilities. 

The use of standard conditions helps ensure uniformity and consistency of all 

NPDES permits issued by authorized States or EPA Regional offices. The permit 

writer needs to be aware of the contents of the standard conditions because it may 

often be necessary to explain portions of these conditions to a permittee. The permit 

writer should also keep abreast of any changes in EPA’s standard conditions set out in 

40 CFR §122.41 as statutes or regulations are revised periodically. 

EPA NPDES Permit Writers’ Manual - 167 
Standard Conditions of NPDES Permits Chapter 9 

9.1 Types of Standard Conditions 

A brief discussion of each of EPA’s standard conditions for NPDES permits 

follows: 

• 

• 

• 

• 

Duty to Comply [40 CFR §122.41(a)] - The permittee must comply with all 

conditions of the permit. Noncompliance is a violation of the CWA and is 

grounds for injunctive relief, substantial monetary penalties, incarceration, 

changes or terminations to the permit, or denial of permit renewal. 

Duty to Reapply [40 CFR §122.41(b)] - If a permittee, after the expiration 

of its permit, desires to continue its activities, it must reapply for and obtain 

a new permit. 

Need to Halt or Reduce Activity not a Defense [40 CFR §122.41(c)] - 

The permittee may not use as a defense the reasoning that compliance 

could only be achieved by halting or reducing the permitted activity. 

Duty to Mitigate [40 CFR §122.41(d)] - The permittee is required to take 

all reasonable steps to 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. 

Proper Operation and Maintenance [40 CFR §122.41(e)] - The permittee 

must properly operate and maintain all equipment and treatment systems 

used by the permittee for compliance with the terms of the permit. The 

permittee must provide appropriate laboratory controls and quality 

assurance procedures. Backup systems are required when needed to 

ensure compliance. However, each main line unit treatment process must 

be operated as a minimum. 

• 

• 

• 

• 

• 

Permit Actions [40 CFR §122.41(f)] - The permit may be modified, 

revoked, reissued, or terminated for cause. The filing of a request by the 

permittee for a modification, revocation, reissuance, termination, or 

notification of planned changes or anticipated noncompliance does not halt 

any permit condition, 

Property Rights [40 CFR §122.41(g)] - The permit does not convey any 

property rights of any sort, or any exclusive privilege. 

Duty to Provide Information [40 CFR §122.41(h)] - The permittee must 

transmit any information needed to determine compliance with the permit or 

to modify the permit. 

Inspection and Entry [40 CFR §122.41(i)] - The permittee must, upon 

presentation of valid credentials by the Director or his representative, allow 

entry into the premises where the regulated activity and/or records are 

present. The Director must have access to and be able to make copies of 

any required records, inspect facilities, practices, operations, and 

equipment, and sample or monitor at reasonable times. 

168 - EPA NPDES Permit Writers’ Manual 
Standard Conditions of NPDES Permits Chtptw 9 

. 

l 

Monitoring and Records [40 CFR §122.4l(j)]-Samples must be 

representative of the monitored activity. Records must be retained for 3 

years (5 years for sludge activities) subject to extension by the Director. 

Monitoring records must identify the sampling dates and personnel, the 

sample location and time, and the analytical techniques used and 

corresponding results. Wastewater and sludge measurements must be 

conducted in accordance with 40 CFR Parts 136 or 503 or other specified 

procedures. Falsification of results is a violation. 

Signatory and Certification Requirements [40 CFR 5122.41 (k)]- 

Applications, reports, or information submitted to the Director must be 

signed and certified. Knowingly making false statements, representations, 

or certifications is subject to penalties. 

Planned Changes [40 CFR gl22.41(1)(1)]-Notice must be given to the 

Director as soon as possible of any planned physical alterations and/or 

additions to the facility. Thisnotice is required if the facility changes to 

meet the criteria for a new source or the nature and concentration of 

pollutants are affected. 

Anticipated Noncompliance [40 CFR §122.41(i)(P)]-The permittee must 

give advance notice of any conditions that may result in noncompliance. 

Permit Transfers [40 CFR §122.41(1)(3)]-The permit is not transferable 

except after written notice to the Director. The Director may require 

modification or revocation and reissuance, as necessary. 

Monitoring Reports 140 CFR §122.41(1)(4)]-Reports must be submitted 

on a DMR or on a Director-specified form for sludge use/disposal practices. 

In addition, more frequent monitoring must be reported. Calculations 

requiring averaging must use an arithmetic mean, except for fecal coliform. 

Monitoring results must be reported at the frequency specified in the permit. 

Compliance Schedules [40 CFR §122.41(1)(5)]-Reports required by a 

compliance schedule in the permit must be submitted within 14 days of the 

due date. 

Twenty-Four Hour Reporting [40 CFR §122.4l(i)(b)]-The permittee must 

report any noncompliance that may endanger human health or the 

environment within 24 hours after becoming aware of the circumstance. 

Within 5 days, the permittee must provide a written submission containing 

the information outlined in 40 CFR §122.41(1)(6)(ii) unless the requirement 

is waived by the permitting authority. 

Other Noncompliance [40 CFR 5122.41 (i)(7)]-The permittee must report 

all instances of noncompliance not reported under other specific reporting 

requirements at the time monitoring reports are submitted. 

Other information [40 CFR §122.41(1)(8)]-Where the permittee becomes 

aware that it failed to submit any relevant facts in its application, or 

submitted incorrect information in its application or other reports, it must 

promptly submit such information. 

8Bi# NPDES Permtt Writers’ Manual - 169 
Standard Conditions of NPDES Permits Chap&r 9 

a Bypass [40 CFR 9122.41 (m)]-Intentional diversions of untreated waste 

streams from any portion of a treatment facility are prohibited unless (I) the 

bypass does not cause effluent to exceed limits, and (2) the bypass was 

unavoidable to prevent loss of life, personal injury, or severe property 

damage, and there was no feasible alternatives, and the proper notification 

was submitted. 

l Upset 140 CFR §122.4l(n)+An upset can be used as an affirmative 

defense in actions brought to the permittee for noncompliance. The 

permittee (who has the burden of proof) must have operational logs or other 

evidence that shows (1) when the upset occurred and its causes, (2) that 

the facility was being operated properly, (3) proper notification was made, 

and (4) remedial measures were taken. 

9.2 Other Standard Conditions 

In addition to standard conditions specified in 40 CFR s122.41, 40 CFR 

$122.42 sets forth additional conditions applicable to specified categories of NPDES 

permits. These conditions include: 

. Existing manufacturing, commercial, mining, and silvicultural dischargers 

must notify EPA as soon as they know or have reason to believe that the 

discharge has or will exceed notification levels set forth in 

40 CFR 5122.42(a). 

. POTWs must provide adequate notice to EPA for new introduction of 

pollutants into the POTW, for substantial changes in the volume or 

character of pollutants, and related information specified in 

40 CFR $122.42(b). 

0 Large, medium or EPA-designated municipal separate storm sewer systems 

must submit an annual report addressing the status, and changes to, the 

storm water management program, water quality data and other information 

specified in 40 CFR 5122.42(c). 

170 - 88# NPDES Permit Writers’ Manual 
Chapter 10 

Variances to Permit 

Requirements and Other 

Regulatory Considerations 

To address unique permitting situations, the CWA and NPDES regulations allow 

permit writers to grant variances under certain prescribed conditions. These variances 

may apply to either technology-based or water quality-based regulatory requirements. 

The variances available under the NPDES Program are described below. 

The NPDES Program has also established certain requirements to ensure that 

NPDES permits address the statutory and regulatory requirements of other 

environmental programs. The permit writer should be aware of these other programs 

in developing permit conditions, and work with the regulatory agencies that oversee 

these programs. Section 10.3 describes these considerations. 

10.1 Variances to Technology-Based Permit Requirements 

In addition to specifying national goals for water pollution control, the CWA 

provides a mechanism for modification of the technology-based requirements of the 

CWA for exceptional cases. These modifications are called variances. Very specific 

data requirements must be met by an applicant before a variance may be granted. As 

EPA NPDES Permit Writers’ Manual - 171 
Chapter 10 

Variances to Permit Requirements and 

Other Regulatory Considerations 

the term implies, a variance is the unusual situation, and the permit writer should not 

expect to routinely receive variance requests. Nevertheless, the permit writer should 

be aware of the major types of variances and the basic requirements for each, 

because the permit writer will most likely be the person to conduct the initial reviews of 

such requests before submitting them for review to the State Director (if applicable), 

the EPA Regional office, and EPA Headquarters. The permit writer should consult 40 

CFR §124.62 for the procedures for decisions on the various types of variances. 

With one exception (fundamentally different factors variance), a variance 

request must be submitted before the close of the public comment period of the 

permit. The following paragraphs discuss variances and the factors that should be 

considered in a technical review of the variance request. 

10.1.1 Economic Variances 

Section 301(c) of the CWA provides for a variance for nonconventional 

pollutants from BAT-based effluent limitations due to economic factors. Note that 

there are no implementing regulations for §301(c); rather, variance requests must be 

made and reviewed based on the statutory language in CWA §301(c). The variance 

may also apply to non-guideline limits in accordance with 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 periods may apply, as specified in 40 CFR §122.21(m)(2). The 

application must show that the modified requirements: 

• Represent the maximum use of technology within the economic capability of 

the owner or operator; and 

• Will result in further progress toward the no discharge goal. 

The methodologies for determining economic capability for utilities is different 

than that used for other industries. Utilities should perform two financial calculations. 

Generally, EPA will only grant a variance if both tests indicate that the pollution control 

equipment is not economically achievable and the applicant can demonstrate 

“reasonable further progress.” Other industry categories must calculate three financial 

tests to determine if they are eligible on economic grounds for a 301(c) variance. 

172 - EPA NPDES Permit Writers’ Manual 
Variances to Permit Requirements and 

Other Regulatory Considerations Chapter 10 

Guidance for conducting these financial tests is available from EPA’s Office of 

Wastewater Management. Generally, EPA will only grant a variance if all three tests 

indicate that the required pollution control is not economically achievable and the 

appiicant makes the requisite demonstration about “reasonable further progress.” 

With respect to the second requirement for a 301(c) modification (reasonable 

further progress toward the no-discharge goal), the applicant must, at a minimum, 

demonstrate compliance with all applicable BPT limitations and pertinent water quality 

standards. In addition, the proposed alternative must provide for a reasonable degree 

of improvement in the applicant’s discharge. 

10.1.2 Variances Based on Localized Environmental Factors 

Section 301(g) of the CWA provides for a variance for certain nonconventional 

pollutants from BAT effluent guidelines due to localized environmental factors. These 

pollutants include ammonia, chlorine, color, iron, and total phenols. The discharger 

must file a variance application that meets the following requirements: 

. The modified requirements must result in compliance with BPT and water 

quality standards of the receiving stream. 

. No additional treatment will be required of other point or nonpoint source 

dischargers as a result of the variance approval. 

. The modified requirements will not interfere with attainment or maintenance 

of water quality to protect public water supplies, or with protection and 

propagation of a balanced population of shellfish, fish, and wildfowl, and will 

allow recreational activities in and on the water. Also, the modified 

requirements will not result in quantities of pollutants that may reasonably 

be anticipated to pose an unacceptable risk to human health or the 

environment, cause acute or chronic toxicity, or promote synergistic 

properties. 

The permit writer should review the request to ensure that it complies with each 

of the requirements for this type of variance. This variance request involves a great 

deal of water quality assessment, including aquatic toxicity, mixing zone and dilution 

model analysis, and possible site-specific criterion development. In addition, many 

complex human health effects must be assessed, including carcinogenicity, 

teratogenicity, mutagenicity, bioaccumulation, and synergistic propensities. All permit 

&ERR NPDES Permit Writers’ Manual - 173 
Chapter 10 

Variances to Permit Requirements and 

Other Regulatory Considerations 

writers should use the EPA draft 301(g) technical guidance manual to assess a 

completed variance request. Typical industries that have applied for 301(g) variances 

include Iron and Steel Manufacturing, Steam Electric Power Generating, Inorganic 

Chemicals Manufacturing, Nonferrous Metals Manufacturing, Aluminum Forming, and 

Pesticides Manufacturing facilities. 

10.1.3 Marine Discharge Variances 

Section 301 (h) of the CWA provides for variances from secondary treatment 

standards for POTVVs that discharge into marine waters if the modified requirements 

do not interfere with the attainment or maintenance of water quality. EPA has 

promulgated specific regulations pertaining to CWA $301(h) that are provided in 40 

CFR Part 125, Subpart G. 

All 301(h) modified permits must contain the following specific permit conditions: 

. Effluent limitations and mass loadings that will assure compliance with 40 

CFR Part 125, Subpart G 

. Compliance schedules for pretreatment program development, a 

nonindustrial toxics control program, and control of combined sewer 

overflows 

0 Monitoring program requirements that include biomonitoring, water quality, 

and effluent monitoring 

. Reporting requirements that include the results of the monitoring programs. 

Also, no new or substantially increased discharges from the point source of the 

affected pollutant can be released above that volume of discharge specified in the 

permit. 

EPA has developed several guidance manuals related to 301(h) variances, 

including the Revised Section 301(h) Technical Support Document.73 

‘?JSEPA (1982). Revised Section 301(h) Technical Support Document. EPA-430/9-82-011. Office 

of Water. 

174 - 88# NPDES Permit Writers’ Manual 
Vartames to Permit Requirements and 

Other Regulatory Considerations Chapter 10 

10.1.4 Fundamentally Different Factors Variances 

Section 301 (n) of the CWA provides for variances based upon fundamentally 

different factors (FDF) for BAT and BCT pollutants while 40 CFR Part 125, Subpart D 

provides the regulatory authority for BPT variances. FDF variances for direct 

dischargers are available from effluent limitations guidelines for toxic, conventional, 

and nonconventional pollutants if the individual facility is found to be fundamentally 

different from the factors considered in establishing the effluent guidelines. There is 

no FDF variance allowed from NSPS. The FDF variance for BPT must be filed by the 

close of the public comment period under 40 CFR g124.10. The FDF variance for 

BAT or BCT must be requested by the discharger within 180 days of the guideline 

promulgation. Where a FDF variance request is approved, calculated alternative limits 

cannot be any less stringent than justified by the fundamental difference and cannot 

cause violations of water quality standards. 

Factors needed to justify a BPT FDF variance must be related to a discharger’s 

facilities, equipment, processes, and compliance cost that are different from those 

considered in the development of the guidelines. Factors for BAT and BCT variance 

requests are similar except that cost cannot be considered. Additional factors that 

cannot be considered for any FDF variance request include the feasibility of installing 

the necessary treatment within the given time frame, a claim that the limits cannot be 

achieved with the given technology (unless supported with data), the discharger’s 

ability to pay, or the impact on local receiving water quality. The review or proposal of 

an FDF variance is completed on a case-by-case basis. The burden of proof lies with 

the entity requesting the variance. 

10.1.5 Thermal Discharge Variances 

Section 316(a) of the CWA provides for variances from effluent limitations for 

the thermal component of a discharge. Regulations for submitting and reviewing 

thermal discharge variance requests are promulgated at 40 CFR Part 125, Subpart I-l. 

Less stringent alternative thermal effluent limits may be included in permits if the 

discharger demonstrates that such effluent limits are more stringent than necessary to 

assure the protection and propagation of a balanced, indigenous community of 

shellfish, fish and wildlife in and on the body of water into which the discharge is 

06% NPDES Permit Writers’ Manual - 175 
Chapter 10 

Variances to Permit Requirements and 

Other Regulatory Considerations 

made, taking into account the cumulative impact of its thermal discharge together with 

all other significant impacts on the species affected. 

10.1.6 Net Credits 

In some cases, solely as a result of the level of pollutants in the intake water, 

facilities are faced with situations in which technology-based limits are difficult or 

impossible to meet with BAT/BCT technology. Under certain circumstances, the 

NPDES regulations allow credit for pollutants in intake water. The following 

requirements have been established in 40 CFR 5122.45(g) for establishing net 

limitations: 

l Credit for generic pollutants, such as BOD, or TSS, are only authorized 

where the constituents resulting in the effluent BOD, and the TSS are 

similar between the intake water and the discharge. 

l Credit is only authorized up to the extent necessary to meet the applicable 

limitation or standard, with a maximum value equal to the inffuent 

concentration. 

. Intake water must be taken from the same body of water into which the 

discharge is made. 

l Net credits do not apply to the discharge of raw water clarifier sludge 

generated during the treatment of intake water. 

Permit writers are authorized to grant net credits for the quantity of pollutants in 

the intake water where the applicable effluent guidelines specify that the guidelines are 

to be applied on a net basis or where the pollution control technology would, if 

properly installed and operated, meet applicable effluent guidelines limitations and 

standards in the absence of the pollutants in the intake waters, 

10.2 Variances to Water Quality-Based Permit Requirements 

Several types of variances exist that may change the fundamental basis of 

water quality-based effluent limitations, specifically: 

l Site-specific water quality criteria modification, 

. Designated use reclassification, and 

. Water quality standard variance. 

Each of these variances are described below. 

176 - 8Ep# NPDES Permit Writers’ Manual 
Variances to Permit Requirements and 

Other Regulatory Considerations Chapter 10 

10.2.1 Site-Specific Water Quality Criteria Modification 

Section 304(a) of the CWA recommends procedures for States to develop 

water quality criteria. The State does have the option of modifying water quality 

criteria on a site-specific basis. Setting site-specific criteria may be appropriate where 

background water quality parameters, such as pH, hardness, temperature, and color 

appear to differ significantly from the laboratory water used to develop the CWA 

5304(a) criteria; or the types of local aquatic organisms differ significantly from those 

actually tested in developing the CWA $304(a) criteria. Modifications change water 

quality criteria permanently, while maintaining the existing designated uses. 

10.2.2 Designated Use Reclassification 

Once a use has been designated for a particular water body or segment, the 

water body or water body segment cannot be reclassified for a different use except 

under specific conditions. To remove a designated use, as specified in Section 

101 {a)(2) of the CWA, the State must perform a use attainability analysis pursuant to 

40 CFR 5131 .l O(j). The Water Quality Standards Handbook: Second E~Iition’~ 

discusses use attainability analyses in greater detail. Redassifying a water body 

causes a permanent change in the water quality standard for that water body. 

10.2.3 Water Quality Standard Variance 

Water quality standard variances require similar substantive and procedural 

requirements as removing a designated use, but unlike use removal, variances are 

both discharger and pollutant specific, are time-limited, and do not forego the currently 

designated use of a water body. A variance is appropriate where the State believes 

that the standard can be ultimately attained. By maintaining the standard rather than 

changing it, the State will assure that further progress is made in improving the water 

quality and attaining the standard. State-adopted variances have been approved by 

EPA where, among other things, the State demonstrates, consistent with 40 CFR Part 

131, that meeting the standard is unattainable based on one or more of the grounds 

outlined in 40 CFR §131.1O(g). The variance is granted for a specified period of time 

“USEPA (1994). Wafer Quality Standards Handbook: Second Edition. EPA 823-B-94-005a. 

Office of Water. 

68# NPDES Permit Writers Manual - 177 
Chapter 10 

VarIanees to Permit Requirements and 

Other Regutatoty Consickratlons 

and rejustified at least every 3 years as reasonable progress is made toward meeting 

the standards. 

Modifications of or variances to water quality standards have several effects on 

permit limits. Specifically, these variances change the fundamental basis of water 

quality-based effluent limits, potentially impacting the reasonable potential 

determination and possibly resulting in more or less stringent limitations. It is the 

permit writer’s responsibility to ensure that the variance is properly reflected in the 

NPDES permit. 

10.3 Additional Programmatic Considerations and 

Requirements 

This section addresses additional programmatic requirements that must be 

considered during permit development. These requirements include anti-backsliding 

and compliance with other Federal laws. 

10.3.1 Anti-Backsliding 

In general, the term “anti-backsliding” refers to a statutory provision that 

prohibits the renewal, reissuance, or modification of an existing NPDES permit that 

contains effluents limits, permit conditions, or standards that are less stringent than 

those established in the previous permit. There are, however, exceptions to the 

prohibition-determining the applicability and circumstances of the exceptions requires 

a familiarity with both the statutory and regulatory language that addresses the issue 

of “anti-backsliding.” 

Section 402(o) of the Clean Water Act establishes express statutory language 

prohibiting the backsliding of effluent limitations. Section 402(o)+ consists of three main 

parts. First, section 402(o)(l) prohibits (subject to exceptions in sections 303(d)(4) 

and/or 402(o)(2)) the relaxation of effluent limitations for two situations: 

(1) When a permittee seeks to revise a technology-based effluent limitation 

based on best professionat judgment to reflect a subsequently 

promulgated effluent guideline which is less stringent, and 

178 - 8e# NPDES Permit Writers’ Manual 
Variances to Permit Requirements and 

Other Regulatory Considerations Chapter 10 

(2) When a permittee seeks relaxation of an effluent limitation which is 

based upon a State treatment standard or water quality standard. 

Second, Section 402(o)(2) outlines specific exceptions to the general 

prohibition against establishment of less stringent effluent limitations. Codified in the 

NPDES regulations at 40 CFR 122.44(l), Section 402(o)(2) provided that the 

establishment of less stringent limits may be allowed where: 

(1) There have been material and substantial alternations or additions to 

the permitted facility which justify this relaxation. 

(2) New information (other than revised regulations, guidance, or test 

methods) is available that was not available at the time of permit 

issuance which would have justified a less stringent effluent limitation. 

(3) Technical mistakes or mistaken interpretations of the law were made in 

issuing the permit under Section 402(a)(l)(b). 

(4 Good cause exists due to events beyond the permittee’s control (e.g., 

acts of God) and for which there is no reasonably available remedy. 

(5) The permit has been modified under 40 CFR $122.62, or a variance 

has been granted. 

(6) The permittee has installed and properly operated and maintained 

required treatment facilities but still has been unable to meet the permit 

limitations (relaxation may only be allowed to the treatment levels 

actually achieved). 

Although the statute identified six exceptions where effluent limitations may be 

relaxed, the language specifically stated that exceptions 3 and 5 (as listed above) do 

not apply to water quality-based effluent IimitatioIs. Thus, exceptions 3 and 5 would 

only apply to technology-based effluent limitations derived using best professional 

judgment. 

Third, Section 402(o)(3) prohibits the relaxation of effluent limitations in all 

cases if a revised effluent limitation would result in a violation of applicable effluent 

limitation guidelines or water quality standards, including antidegradation requirements. 

Thus, even if any of the backsliding exceptions outlined in either the statute or 

8EfM NPDES Permit Writers’ Manual - 179 
Variances to Permit Requirements and 

Other Regulatory Considerations Chapter 10 

regulations are applicable and met, Section 402(o)(3) acts as a floor and restricts the 

extent to which effluent limitations may be relaxed. This requirement affirms existing 

provisions of the CWA that require permit limits, standards, and conditions to ensure 

compliance with applicable technology-based limits and water quality standards. 

EPA’s current regulations which address the issue of anti-backsliding reflect the 

prohibition imposed by Section 402(o) for the first situation; revision of existing BPJbased permit limitations to reflect subsequently issued effluent guidelines (40 CFR 

122.44(l)(2)). However, the regulations have not been revised to reflect the prohibition 

of backsliding for the second situation: relaxation of effluent limitations established on 

the basis of Sections 301(b)(l)(C) or 303(d) or (3). EPA believes the water quality 

provisions must be implemented based upon interpretation of the CWA in the 

meantime. As such, the remainder of the discussion on anti-backsliding provisions will 

focus on clarifying the intent of the statute as it relates to relaxation of water qualitybased effluent limitations. In addition, Exhibit 10-l provides a graphical interpretation 

of the backsliding provisions as they related to the relaxation of WQBELs. 

EPA has consistently interpreted Section 402(o)(l) of the CWA to allow 

relaxation of water quality-based effluent limitations (WQBELs) if either the 

requirements of Section 402(o)(2) or section 303(d)(4) are met. These two provisions 

constitute independent exceptions to the prohibition against relaxation of permit limits. 

If either is met, relaxation is permissible. 

Section 303(d)(4) has two parts: paragraph (A) which applies to “nonattainment waters” and paragraph (B) which applies to “attainment waters.” 

. 

. 

Non-attainment water-Section 303(d)(4)(A) allows establishment of less 

stringent WQBEL when the receiving water has been identified as not 

meeting applicable water quality standards (i.e., a “nonattainment water”), if 

the permittee meets two conditions. First, the existing WQBEL must have 

been based on a total maximum daily load (TMDL) or other wasteload 

allocation (WLA) established under Section 303. Second, relaxation of a 

WQBEL is only allowed if attainment of water quality standards must be 

ensured. 

Attainment water-Section 303(d)(4)(8) applies to waters where the water 

quality equals or exceeds levels necessary to protect the designated use, or 

to otherwise meet applicable water quality standards (i.e., an “attainment 

180 - &EPA NPDES Permit Writers’ Manual 
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EXHIBIT 10-l 

Anti-Backsliding Rules Relating to Water Quality-Based Effluent Limitations 

I Is effluent limit based on a State water qu; ality standard? 3 

See existing regulations 

40 C.F.R. 122.44(l) 

t 

Yes 

f 

No 

Yes 

+ 

I Is attainment of water I 

Revision r not 

Allowed 

quality standards assured? 

(including antidegradation?) 

&, &iz-, 

BEPA NPDES Permit Writers’ Manual - 181 
Chapter 10 

VarIanees to Permit Requirements and 

Other Regutatoty Consickratlons 

water”). Under Section 303(d)(4)(B), WQBELs may only be relaxed where 

the action is consistent with State’s anti-degradation policy. 

As previously mentioned, Section 402(o)(2) outlines specific exceptions to the 

general prohibition against backsliding from WQBELs. These exceptions are 

independent of the Section 303(d)(4) exception discussed above and are also 

applicable to the backsliding of BPJ limits to reflect subsequently promulgated less 

stringent guidelines. 

Finally, all other types of backsliding [for example, backsliding from effluent 

guideline-derived limits, from new source performance standards, from existing BPJ 

limits to new BPJ limits, or from water quality-related standards or conditions (except 

for effluent limitations)] remain unaffected by the 1987 WQA amendments and EPA’s 

existing regulations at 40 CFR 122.44(l)(l) will continue to govern them. This is 

because Section 402(o) only prohibits the backsliding of “effluent limits,” not other 

standards or conditions such as monitoring frequency or changes in species or 

protocol for whole effluent toxicity (WET) testing. The relaxation of all other types of 

standards or conditions contained in a permit are, however, subject to EPA’s existing 

backsliding regulations at 40 CFR 122.41(l)(l). Under these regulations, a permittee 

must meet a cause for modification in order to allow relaxation. 

182 - 8B# NPDES Permit Writers’ Manual 
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Scenario: 

Example 1 

. A POTW seeks to relax its WQBEL for pollutant X. 

. Current permit limitation is based on the TMDL and WLA for the POTW developed in accordance 

with 40 CFR 130.7. 

. The POTW is in compliance with its existing limitation and the applicable water quality standards for 

pollutant X is attained. 

. The POTW has developed new models with new river flow information, which indicate that the water 

quality standards for pollutant X would be maintained with a relaxed permit limitation. 

. May the effluent limitation for pollutant X be relaxed? 

Answer: 

Possibly. Under the interpretation discussed above, WQBELs may be relaxed where one of the 

exceptions in $402(o)(l) or 40 CFR 122.44(l)(2) are met. In this case, although new information is being 

relied on to request the modification, 9402(o)(2) will not justify the request unless the State reduces the 

pollutant loadings from other point sources or non-point sources of pollution. This is because, as 

discussed above, paragraph 3402(o)(2) restricts the use of new information to cases where there is a 

decrease in the amount of pollutants being discharged. 

The $402(o)(l) exceptions, on the other hand, may justify the request. In this case, the paragraph (o)(l) 

exception that is relevant is the reference to $303(d)(4)(8). It provides that for receiving waters that 

where water quality standards are attained, permit limitations based on a TMDliWLA or other permit 

standard may be relaxed only if a State’s antidegradation policy are met. 

Scenario: 

Example 2 

’ 

The State has established a technology-based treatment standard for fecal coliform pursuant to 

$301 (W(l NC). 

. The State later relaxes this standard. 

. A POlW, which has been in violation of this limit, requests a revision of its permit limit for fecal 

coliform to reflect the new standard. 

. Water quality standards for fecal coliform are not being attained. 

. Models show that attainment of water quality standards will be assured if the POTW complies with a 

revised, relaxed permit limitation for fecal coliform. 

. There was no TMDL or WLA performed because the standard was a State technology-based 

standard. 

. May the permit limitation be relaxed? 

Answer: 

No. Under §402(0)(1), the applicable provision is §303(d)(4)(A). This subsection does not authorize 

backsliding in this case because it only applies to permit limitations based on a TMDUWLA. Here, the 

limitation in question is based on a type of State treatment standard. 

Furthermore, if the permit sought to apply the §402(0)(2) exceptions, the new information provision would 

not allow the revision. New information does not include “revised regulations.” 

iiEFY4 NPDES Permit Writers’ Manual - 183 
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VarIanees to Permit Requirements and 

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Scenario: 

Example 3 

. The State has a narrative water quality criterion of “no toxics in toxic amounts.” 

. On the basis of WET testing data or other information, the State finds reasonable potential to exceed 

the narrative water quality criterion and imposes a WET limitation under 40 CFR 122.44(d)(l)(v). 

. The permittee determines that pollutant Z is the cause of the WET in its discharge. 

. The permittee can demonstrate through sufficient data (including WET testing data) that an effluent 

limitation for pollutant Z will assure compliance with the narrative water quality standards as well as the 

State’s numeric criteria for pollutant Z as required by 40 CFR 12244(d)(l)(v). 

. May the State modify the permit to delete the WET limitation and to add the limitation for pollutant Z? 

Answer: 

5303(d)(4) may justify this action. The applicable provision of $303(d)(4) is 5303(d)(4)(8) because the 

narrative water quality standards is currently attained. (The permittee is currently complying with the 

existing WET limitation to attain and maintain the State’s narrative water quality standards.) Under 

3303(d)(4)(8), the permittee may backslide so long as antidegradation requirements will be met, and the 

relaxed limitation will not cause a violation of any effluent limitations guidelines and water quality standards 

applicable to the discharge. In this case, this appears likely because the discharger can demonstrate that 

the new limitation for pollutant Z will assure compliance with applicable narrative as well as numeric water 

quality standards. 

Scenario: 

Example 4 

. An industrial permittee seeks to revise its WQBEL of 1000 mg/L for TSS to 6000 mg/L, its actual 

discharge level. 

. The current permit limitation is based upon a TMDL and WLA for the permittee, which were developed 

in accordance with 40 CFR 130.7. 

. The water quality standards for TSS are not being attained. 

. A permit limit of 6000 mgR is consistent with applicable effluent guidelines. 

. New modeling infom-ration shows that the water quality standards for TSS will be attained with a permit 

limitation of 4000 mg/L. 

. May the permit limitation be revised from 1000 mg/L to 6000 mg/L? 

Answer: 

No. However, the permit limitation could be relaxed to 4000 mg/L under either 9402(o)(l) or the $402(o)(2) 

exceptions. 

The water quality standards for TSS is not currently being attained. Therefore, under 9lO2(0)(1), the 

applicable exception is 3303(d)(4)(A). In this case, the permitting authority may allow backsliding to 4000 

mg/L because the existing effluent limitation is based upon a TMDlJWLA and the data shows that 

attainment of the water quality standards is assured with a permit limitation of 4000 mg/L (but not with a 

limitation of 6000 mg/L). 

Alternatively, under 5402(o)(2), new information can be relied on to relax permit limitations where there is a 

reduction in pollutant loadings and, pursuant to 3402(o)(3), where water quality standards are complied 

with. Again, water quality standards are being met in this case, and there also will be a reduction in actual 

pollutant loadings since the new proposed permit level of 4000 mg/L will represent a real reduction 

compared with the actual discharge levels of 6000 mg/L. 

184 - &B# NPDES Permit Writers’ Manual 
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Other Regulatory Considerations Chapter 10 

10.3.2 Considerations for Other Federal Laws 

This section addresses several Federal laws that impact NPDES permitting. It 

is noteworthy that the requirements imposed under several of these statutes (e.g., the 

NHPA, ESA, FWCA, and NEPA, discussed below), only apply to Federal or federally 

supported actions (e.g., EPA issuance of permits). Under these particular statutes, 

purely State actions are not regulated. However, many States may have enacted 

State legislation that is modeled on Federal law and, therefore, it is prudent to review 

State law in these areas prior to preparing a NPDES permit. 

National Historic Preservation Act Amendments of 1992 

The National Historic Preservation Act (NHPA) establishes Federal programs to 

preserve the historical and cultural foundations of the nation. Regulations under 

Section 106 of this Act require any Federal agency, in consultation with the Advisory 

Council on Historic Preservation, to take into account the effect of proposed Federal or 

Federally assisted undertakings on architectural, archeological, historic, or cultural 

resources listed, or eligible for listing, on the National Register of Historic Places. This 

has been interpreted (see EPA Memorandum dated March 15, 1994, from Steven A. 

Herman, Assistant Administrator to Carol Browner, Administrator, entitled “EPA Policy 

Decision of a Strategy For, and Interim Compliance with the National Historic 

Preservation Act Amendments”) to mean that consultations must be made for direct 

EPA actions and for individual State actions that EPA funds under its programs. 

However, for State actions not directly funded by EPA under EPA-authorized 

programs, consultation would occur on a voluntary basis. 

To date, guidance for the permit writer in considering the NHPA requirements is 

not available. In general, the permit writer must ensure that the proposed discharge to 

be authorized under the NPDES permit will not have an adverse effect on a site listed, 

or eligible for listing, on the National Register of Historic Places. The permit writer 

may want to require that the permittee show that sufficient research has been 

conducted to identify whether a site on the Register is located within the area. 

Sufficient research should include review of the National Register and information 

gathering from local governments, Indian tribes, public and private organizations, and 

the State Historic Preservation Officer (36 CFR Part 880). An evaluation of potential 

effects should be documented. Written documentation of the evaluation should be 

&EPA NPDES Permit Writers’ Manual - 185 
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VarIanees to Permit Requirements and 

Other Regutatoty Consickratlons 

submitted to the State Historic Preservation Office and included in the permit file and 

fact sheet. 

Endangered Species Act of 1973 

The goal of the Endangered Species Act (ESA) of 1973 is to provide protection 

and support in the conservation and recovery of threatened and endangered species 

and the ecosystem on which they depend. Section 7 of the ESA requires Federal 

agencies to ensure that any action authorized, funded, or carried out by a Federal 

agency not jeopardize the continued existence of a listed or candidate species or 

result in the destruction or adverse modification of its habitat. Since the issuance of 

NPDES permits by EPA is a Federal action, consideration of a permitted discharge 

and its effect on any threatened and/or endangered species is appropriate. Section 9 

of the ESA prohibits the “taking” of any listed endangered and/or threatened species. 

The ESA regulations require that consultation with the National Marine Fisheries 

Service (NMFS) and/or the Fish and Wildlife Service (FWS), as appropriate, occur 

when the Federal activity is one which may effect an endangered and/or threatened 

species or habitat. Effect is defined as both detrimental and beneficial. Consultations 

may be either informal or formal. An informal consultation determines if an action is, 

or is not, likely to adversely effect the species. A formal consultation is required if the 

findings show that there is a likelihood for adverse impacts and evaluates if the 

proposed action is likely to jeopardize the continued existence of the species. It is 

EPA’s responsibility to ensure that consultation occurs, however, a non-Federal 

representative may be designated for the informal consultation (i.e., the permittee). 

To date, EPA has not yet entered into a national agreement with NMFS or FWS 

on the scope of consultation requirements for NPDES permits. Until then, EPA permit 

writers should review the ESA consultation regulations (50 CFR 5402) and coordinate 

with the Region’s ESA coordinator (if such a position has been established in a 

particular Region) and the FWS/NMFS office(s) located nearest the site. In evaluating 

the effects of a discharge upon endangered or threatened species, the study should 

identify the listed and candidate species and their habitats which occur in the area of 

the discharge. This information can be obtained from discussions with local FWS/ 

NMFS biologists. The proposed permit limits can then be compared to any existing 

186 - iiER9 NPDES Permit Writers’ Manual 
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Other Regulatory Considerations Chapter 10 

toxicological data and/or impacts data available for the species. Cumulative, 

combined, and independent effects should be evaluated. Additional species-specific 

information can be obtained through discussions with the local wildlife and aquatic 

biologists who are experts on a particular species (e.g., EPA, FWYNMFS, State 

Conservation, universities). 

It is EPA’s position that permits issued under State law are not subject to ESA 

consultation because they are.not Federal Actions. However, State NPDES Programs 

should have some process in place to consider potential effects on endangered and 

threatened species and their habitat if they are known to occur in the area of the 

discharge to ensure those discharges do not result in takes of listed species. 

Biological Evaluations (informal) or Biological Assessments (formal) should be 

submitted to the FWS/NMFS for review and approval. This documentation and any 

decisions from the FWS/NMFS would become part of the permit documentation. 

Wild and Scenic Rivers Act 

The 1968 Wild and Scenic Rivers Act protected selected rivers from 

construction of dams and excessive commercial development. It declared that ‘the 

established national policy of dam and other construction at appropriate section of the 

rivers of the United States needs to be complemented by a policy that would preserve 

other selected rivers or section thereof in their free-flowing condition” [Section (l)(b)]. 

The Act defines three classes of protected river (wild river; scenic river; recreational 

river) and spells out in considerable detail the management restrictions to be 

established for these rivers. A corridor of land on each side of a protected river is 

also protected. The corridor is to average no more than 320 acres per linear mile of 

river through the protected stretch. The rights of landowners within this corridor are 

maintained, subject to restrictions on the type of development allowed. Rivers are 

“studied” and may be protected for up to three years during the study period during 

which a river has the status of a protected river. 

Ml34 NPDES Permit Writers’ Manual - 187 
Chapter 10 

VarIanees to Permit Requirements and 

Other Requlatoty Consickratlons 

Coastal Zone Management Act 

The 1972 Coastal Zone Management Act (CZMA) and amendments require and 

encourage the coastal states of the United States to adopt and enforce land-use plans 

for the lands and water adjacent to their coasts. “Coastal states,” according to the 

Act, include those adjacent to the Atlantic, Pacific or Arctic oceans, the Gulf of Mexico, 

or one or more of the Great Lakes. These States are required to adopt coastal 

management plans which designate boundaries, identify areas of particular concern, 

and establish an inventory of permitted uses and an enforcement mechanism. Beach 

access, emergency planning and erosion control also must be addressed in the plans. 

EPA and other Federal agencies must coordinate their activities on coastal lands with 

State CZMA plans. 

Fish and Wildlife Coordination Act 

The Fish and Wildlife Coordination Act (FWCA) of 1934 requires mitigation for 

the loss of wildlife habitat due to the construction of Federal water resources projects. 

It requires designers of Federal dams, reservoirs, and irrigation works to include the 

costs and benefits to fish and wildlife when determining the benefit/cost ratio of a 

project. It requires EPA and other Federal agencies to consult with State and Federal 

wildlife and fisheries agencies in order to minimize the impacts of the activity on fish 

and wildlife. The Act specifically calls for ongoing studies by the United States 

Department of the Interior on the effects of waterborne sewage and industrial wastes 

on fish and wildlife. 

National Environmental Policy Act 

The 1967 National Environmental Policy Act established a Federal framework 

for policy decisions regarding Federal actions that will have a significant effect on the 

environment. “Federal” actions generally include projects undertaken by the Federal 

government, as well as non-Federal actions eligible for Federal assistance and nonFederal actions that require Federal permits or approvals. Thus, NEPA requirements 

apply to NPDES permits issued by EPA to new sources in non-delegated States. The 

Act’s most important provision is Section 102(2)(c), requiring Federal agencies such 

as EPA to file an Environmental Impact Statement (EIS) on all “proposals for 

legislation and other major Federal actions significantly affecting the quality of the 

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human environment.” The definition of what constitutes such actions is an ongoing 

discussion. The Act establishes a framework for cooperation between the United 

States government at all levels, and other countries on environmental matters. It also 

established the Council on Environmental Quality. 

&EM NPDES Permit Writers’ Manual - 189 
Chapter 11 

Administrative Process 

Previous discussions in this manual focused on the process of developing 

NPDES permit conditions and effluent limits. This chapter describes the administrative 

process that is associated with the issuance of a NPDES permit. Exhibit 11-1 

provides a flow diagram of the NPDES permit administrative process. In general, the 

administrative process includes: 

• Documenting all permit decisions 

• Coordinating EPA and State review of the draft permit 

• Providing public notice, conducting hearings (if appropriate), and responding 

to comments 

• Defending the permit and modifying it (if necessary) after issuance. 

Note that Exhibit 11-1 provides the general framework for both EPA and State NPDES 

permit administration. State requirements need not be identical to Federal regulatory 

requirements, provided they are as stringent. Therefore, some delegated States may 

have slightly different processes for developing and issuing NPDES permits. In 

addition, the evidentiary hearing and appeal process presented depicts EPA 

procedure. State procedures for NPDES permit hearings and appeals may vary 

according to State law. 

EPA NPDES Permit Writers’ Manual - 191 
Chapter 11 Administrative Process 

EXHIBIT 11-1 

NPDES Permitting Administrative Process 

192 - EPA NPDES Permit Writers’ Manual 
Administrative Process Chapter It 

11.1 Documentation For Development of the Draft Permit 

When the permit is issued, the fact sheet and supporting documentation 

(administrative record) are the primary support for defending the permit in 

administrative appeals and evidentiary hearings. The process of documenting the 

permit requires the permit writer to be organized and logical throughout the permit 

development process. Some of the content of the fact sheet and administrative record 

is directed by Federal and State regulation and the rest is dictated by good project 

management. Permit writers should recognize the importance of: 

. Ensuring development of a thorough permit in a logical fashion 

. Meeting legal requirements for preparation of an administrative record, fact 

sheet, and statement of basis 

. Helping to substantiate permit decisions and provide a sound basis in case 

challenges are made to the derivation of permit terms, conditions, and 

limitations 

. Establishing a permanent record of the basis of the permit for use in future 

permit actions. 

The following sections describe the requirements pertaining to the development 

of permit documentation, particularly the administrative record and the fact sheet. 

11.1.1 Administrative Record 

The administrative record is the foundation for issuing permits. If EPA is the 

issuer, the contents of the administrative record are prescribed by regulation (see 40 

CFR ss124.9 and 124.18). All supporting materials must be made available to the 

public, whether a State, Territory, Tribe or EPA issues the permit. The importance of 

maintaining the permit records in a neat, orderly, complete, and retrievable form 

cannot be over emphasized. The record allows personnel from the permitting agency 

to reconstruct the justification for a given permit. It also must be made available to the 

public at any time and may be examined during the public comment period and any 

subsequent public hearing. 

The administrative record for a draft permit consists, at a minimum, of certain 

specific documents as shown in Exhibit 1 l-2. Materials that are readily available in 

the permit issuing office or published material that is generally available, does not 

0Ep# NPDES Permit Writers’ Manual - 193 
Chapter It Administrative Process 

EXHIBIT 11-2 

Elements of the Draft NPDES Permit Administrative Record 

l Application and supporting data 

l Draft permit 

. Statement of basis or fact sheet 

l All items cited in the statement of basis or fact sheet, including calculations used to 

derive the permit limits 

l All other items in the supporting file 

l For new sources, any environmental assessment, the draft/final environmental impact 

statement (EIS), or other such background information, such as a Findings of No 

Significant Impact (only applies if EPA issues the permit). 

need to be physically included with the record as long as it is specifically referred to in 

the fact sheet or statement of basis. If EPA issues new source draft permits, the 

administrative record should include any EIS or environmental assessment performed 

in accordance with 40 CFR $122.29(c). 

The administrative record should include all meeting reports and 

correspondence with the applicant and correspondence with other regulatory agency 

personnel. In addition, trip reports and telephone memos should be included in the 

record. All correspondence, notes, and calculations should indicate the date and the 

name of the writer, as well as all other persons involved. Since correspondence is 

subject to public scrutiny, references or comments that do not serve an objective 

purpose should be avoided. Finally, presentation of calculations and documentation of 

decisions should be organized in such a way that they can be reconstructed and the 

logic supporting the calculation or decisions can easily be found. The administrative 

record for the final permit consists of the items in Exhibit 11-3. 

11.1.2 Fact Sheets and Statements of Basis 

A fact sheet is a document that briefly sets forth the principle facts and the 

significant factual, legal, methodological, and policy questions considered in preparing 

the draft permit. When the permit is in the draft stage, the fact sheet and supporting 

documentation serve to explain to the permittee and the general public the rationale 

and assumptions used in deriving the limits. 

194 - 8El% NPDES Permit Writers’ Manual 
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EXHIBIT 11-3 

Elements of the Administrative Records for a Final Permit 

l All elements for the draft permit administrative record (see Exhibit 1 l-2) 

l All comments received during the comment period 

l The tape or transcript of any public hearing 

l Any materials submitted at a hearing 

l Responses to comments 

l For NPDES new source permits, the draft or final EIS 

l The final permit. 

The NPDES regulations set forth in 40 CFR $124.8(a) require that every EPA 

and State-issued permit must be accompanied by a fact sheet if the permit: 

. Involves a major facility or activity 

. Incorporates a variance or requires an explanation under 40 CFR 

5124.56(b) (toxic pollutants, internal waste stream, and indicator pollutants 

and for privately owned waste treatment facilities) 

. Is a NPDES general permit 

l Is subject to widespread public interest (see 40 CFR 5124.8) 

. Is a Class 1 sludge management facility 

. Includes a sewage sludge land application plan. 

EPA permit writers are required to prepare a statement of basis for all permits 

that do not merit the detail of a fact sheet. Such statements briefly describe the 

derivation of the effluent limits and the reasons for special conditions (see 40 CFR 

5124.7). However, a prudent permit writer will develop a fact sheet for any permit that 

required complex calculations or special conditions. This will be particularly true for 

permit conditions based on BPJ. 

With a well-documented rationale for all decisions, much of the work in 

reissuing a permit in the future will be done. This will avoid any conjecture and 

guessing concerning the development of any conditions that are being carried forward 

from the expired permit to the next permit. This is also true if a modification is 

initiated during the life of the permit. A permit rationale can be as short as two to 

three pages for a relatively simple permit or as long as 20 to 100 pages for an 

8ER9 NPDES Permit Writers’ Manual - 195 
Chapter It Administrative Process 

extremely complicated permit (e.g., several discharge points, many BPJ 

determinations). The required contents of a fact sheet, as specified in 40 CFR 

ss124.8 and 124.56, include the items listed in Exhibit 11-4. 

EXHIBIT 11-4 

Required Contents of a Fact Sheet 

l A brief description of the type of facility or activity that is being regulated by the 

NPDES permit 

l The type and quantity of pollutants discharged 

l A brief summary of the basis for the draft permit conditions, including references to the 

applicable statutory or regulatory provisions 

l Name and telephone number of person to contact for additional information 

l Provisions satisfying the requirements of 40 CFR 9 124.56: 

- Explanation of derivation of effluent limitations 

- Explanation of any conditions applicable to toxic, internal waste streams, or indicator 

pollutants 

- A sketch or detailed description of the location of the discharge 

- For EPA issued permits, the requirements of any State certification 

l 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 to regulate the users under a separate 

permit 

l 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 

l If applicable, reasons why any requested variances do not appear justified 

l A description of the procedures for reaching a final decision on the draft permit, 

including: 

- The dates of the public comment period and the address 

- Procedures for requesting a hearing 

- Other procedures for public participation. 

A detailed discussion of the development of permit limits for each pollutant 

should be included in the fact sheet. For some permits, a considerable amount of 

time is spent within the permitting agency debating a permit issue that then becomes 

an assumption upon which the permit conditions are based. Documenting the 

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decision process may prevent a repeat of the debate in 5 years when the permit is up 

for reissuance. For each pollutant the following information is necessary: 

l Calculations and assumptions 

- Production 

- Flow 

. Type of limitations (i.e., effluent guideline-, water quality-, or BPJ-based) 

. Whether the effluent guidelines used were BPT, BCT, or BAT 

. The water quality standards or criteria used 

. Whether any pollutants were indicators for other pollutants 

l Citations to appropriate wasteload allocation studies, guidance documents, 

other references. 

Often, it is as important to keep a record of items that were not included in the 

draft permit, such as the following: 

. Why was BPJ or effluent guidelines used instead of water quality-based 

limitations (i.e., were the limitations checked to see that water quality 

considerations did not govern the setting of permit limits)? 

. Why was biomonitoring not included? 

. Why were pollutants that were reported as present in the permit application 

not specifically limited in the permit? 

. Why is a previously limited pollutant no longer limited in the draft permit? 

Finally, the fact sheet should address the logistics of the permit issuance 

process including the comment period begin and end dates, procedures for requesting 

a hearing, and the public involvement in the final decision. 

11.2 Items to Address Prior to Issuance of a Final Permit 

This section describes the public participation activities that must be conducted 

in the permit issuance process. These include providing public notices, collecting and 

responding to public comments, and holding public hearings as necessary. 

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11.2.1 Public Notice 

The public notice is the vehicle for informing all interested parties and members 

of the general public of the contents of a draft NPDES permit or of other significant 

actions with respect to a NPDES permit or permit application. The basic intent of this 

requirement is to ensure that all interested parties have an opportunity to comment on 

significant actions of the permitting agency with respect to a permit application or a 

permit. The exact scope, required contents, and methods for effecting public notices 

may be found in 40 CFR $124.10. 

The NPDES permit-related actions that must receive public notice are shown in 

Exhibit 11-5. 

EXHIBIT 1 l-5 

Actions That Must Receive Public Notice 

I l Tentative denial of an NPDES permit application (not necessarily applicable to State 

programs) 

l Preparation of a draft NPDES permit, including a proposal to terminate a per 

l Scheduling of a public hearing 

l Granting of an evidentiary appeal of an EPA-issued permit under 40 CFR 9 1 

l Formal appeal of permit 

l New Source Determinations (EPA only) 

mit 

24.74 

The permit writer should be primarily concerned with the first three items in 

Exhibit 11-5. It is important to note that no public notice is required when a request 

for a permit modification, revocation, reissuance, or termination is denied. 

Public notice of the various NPDES-related activities is provided by the 

following methods: 

0 For major permits, publication of a notice in daily or weekly newspaper 

within the area affected by the facility or activity. In addition, for general 

permits issued by EPA, publication in the Federal Register is required. 

1 

196 - 8EfM NPDES Permit Writers’ Manual 
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- 

. 

. 

. 

. 

. Direct mailing to various interested parties. This mailing list should include 

the following: 

- The applicant 

- Any interested parties on the mailing list 

- Any other agency that is required to issue a Resource Conservation 

and Recovery Act, Underground Injection Control, Corps of Engineers, 

or PSD permit for the same facility 

- All appropriate government authorities (e.g., United States Fish and 

Wildlife Services, National Marine Fisheries Service, neighboring 

States) 

- Users identified in the permit application of a POTW. 

A public notice must contain the information shown in Exhibit 11-6. 

EXHIBIT 11-6 

Contents of the Public Notice 

Name and address of the office processing the permit action 

Name and address of the permittee or applicant and, if different, of the facility regulated 

by the permit 

A brief description of the business conducted at the facility 

Name, address, and telephone number of a contact from whom interested persons can 

obtain additional information 

A brief description of the comment procedures required 

For EPA-issued permits, the location and availability of the administrative record 

Any additional information considered necessary. 

Public notice of the preparation of the draft permit (including a notice of intent to 

deny a permit application) must allow at least 30 days for public comment. The draft 

permit is usually submitted for public notice after it has undergone internal review by 

the regulatory agency that is issuing the permit. State/Tribal issued permits will 

typically undergo public notice after EPA has reviewed and commented on the draft 

permit. In the special case of those EPA-issued permits that require an environmental 

impact statement (EIS), public notice is not given until after a draft EIS is issued. 

11.2.2 Public Comments 

Public notice of a draft permit elicits comments from concerned individuals or 

agencies. Frequently, such comments are simply requests for additional information. 

However, some comments are of a substantive nature and suggest modifications to 

8ep# NPDES Permit Writers’ Manual - 199 
Chapter It Administrative Process 

the draft permit or indicate that the draft permit is inappropriate for various reasons, In 

such cases, those parties providing comments must submit all reasonable arguments 

and factual material in support of their positions. If the approach is technically correct 

and clearly stated in the fact sheet, it will be difficult for commenters to find fault with 

the permit. Commenters may always suggest alternatives, however. In addition, an 

interested party may also request a public hearing. 

To the extent possible, it is desirable to respond to all public comments as 

quickly as possible. In some cases it may be possible to diffuse a potentially 

controversial situation by providing further explanation of permit terms and conditions. 

It is also good public practice to inform parties who provide public comments that their 

comments have been received and are being considered. 

The permitting agency is obliged to respond to all significant comments (in 

accordance with 40 CFR 5124.17) at the time a final permit decision is reached (in the 

case of EPA-issued permits) or at the same time a final permit is actually issued (in 

the case of State-issued permits). The response should incorporate the following 

elements: 

l Changes in any of the provisions of the draft permit and the reasons for the 

changes 

. Description and response to all significant comments on the draft permit 

raised during the public comment period or during any hearing. 

In the event that any information submitted during the public comment period 

raises substantial new questions about the draft permit, one of the following actions 

may occur: 

. A new draft permit with revised fact sheet or statement of basis is prepared. 

l A final permit with necessary changes explained is issued. 

l The comment period is reopened but is limited only to new findings. 

If any of these actions are taken, a new public notice, as described earlier, must be 

given. 

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11.2.3 Public Hearing 

A public hearing may be requested in writing by any interested party. The 

request should state the nature of the issues proposed to be raised during the 

hearing. However, a request for a hearing does not automatically necessitate that a 

hearing be held. A public hearing should be held when there is a significant amount 

of interest expressed during the 30-day public comment period or when it is necessary 

to clarify the issues involved in the permit decision. 

Thus, the decision of whether or not to hold a public hearing is actually a 

judgment call. Such decisions are usually made by someone other than the permit 

writer. However, the permit writer will be responsible for ensuring that all of the 

factual information in support of the draft permit is well documented. 

Public notice of a public hearing must be given at least 30 days prior to the 

public meeting (public notice of the hearing may be given at the same time as public 

notice of the draft permit and the two notices may be combined). Scheduling a 

hearing automatically extends the comment period until at least the close of the 

hearing [40 CFR §124.12(c)]. 

The public notice of the hearing should contain the following information: 

. Brief description of the nature and purpose of the hearing, including the 

applicable rules and procedures 

. Reference to the dates of any other public notices relating to the permit 

. Date, time, and place of the hearing. 

A presiding officer is responsible for the hearing’s scheduling and orderly 

conduct. Anyone may submit written or oral comments concerning the draft permit at 

the hearing. The presiding officer should set reasonable time limits for oral 

statements. The public comment period may be extended by so stating during the 

hearing. It should be noted that a transcript or recording of the hearing must be 

available to interested persons. 

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11.2.4 State/Tribal Roles in Reviewing Draft Permit 

State/Tribal issued draft permits must be submitted to EPA for review if they 

relate to: 

. 

. 

. 

. 

. 

. 

. 

. 

Discharges into the territorial seas 

Discharges that may affect waters of a State other than the one in which 

the discharge originates 

General permits 

Discharges from a POTW with a daily average discharge exceeding 1 

million gallons per day 

Discharges of uncontaminated cooling water with a daily average discharge 

exceeding 500 million gallons per day 

Discharges from any major discharger or from any NPDES primary 

industrial category 

Discharges of from other sources with a daily average discharge exceeding 

500,000 gallons per day (however, EPA may waive review for non-process 

wastewater), and 

Class I sludge management facilities. 

Permits issued by EPA require State/Tribal review and certification under 

Section 401 of the CWA. Such certification ensures that the permit will comply with 

applicable Federal CWA standards as well as with State or Tribal water quality 

standards. This State/Tribal certification also ensures that State and Tribal initiatives 

or policies are addressed in EPA-issued NPDES permits, and functions to promote 

consistency between State- and EPA-issued permits. 

Under CWA Section 401(a)(l), EPA may not issue a permit until a certification 

is granted or waived. If EPA is preparing the draft permit, State certification is usually 

accomplished by allowing States to review and certify the application prior to draft 

permit preparation. Regulations in 40 CFR $124.53 [State Certification] and 9124.54 

[Special provisions for State certification and concurrence on applications for section 

CWA 301(h) variances] describe procedures a permit writer should follow to obtain 

State or Tribal certification. Under 40 CFR 5124.53, when a draft permit is prepared 

by EPA, but State certification has not yet been granted, EPA must send the State a 

copy of the draft permit along with a notice requesting State certification. If the State 

does not respond within 60 days, the State is deemed to have waived its right to 

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certify. If the State chooses to certify the draft permit, the State may only require 

changes to the draft permit to incorporate more stringent State laws. If the State 

requires such changes, the State must send EPA a letter justifying the changes and 

citing State regulations that support the changes. When a permit applicant requests a 

CWA Section 301 (h) variance, the State certification process is very similar to the 

process just described for permit applications and draft permits (refer to Section 40 

CFR $124.54). 

11.2.5 Schedule for Final Permit Issuance 

The final permit may be issued after the close of the public notice period and 

after State/Tribal certification has been received (for permits issued by EPA). The 

public notice period includes: 

. A 30-day period that gives notice of intent to issue or deny the permit 

. A 30-day period advertising a public hearing (if applicable) 

l Any extensions or reopening of the comment period. 

Final EPA permit decisions are effective immediately upon issuance unless 

comments request changes in the draft permit, in which case the effective date of the 

permit is 30 days after issuance (or a later date if specified in the permit). As 

discussed earlier, any comments that are received must be answered at the time of 

final permit issuance (in the case of NPDES States or Tribes) or after a final decision 

is reached (in the case of EPA). 

11.3 Administrative Actions After Final Permit Issuance 

Once the final permit has been issued, the issuing authority should integrate the 

permit limitations and any special conditions into the NPDES tracking system (i.e., the 

permit compliance system (PCS)). This will ensure that the facility’s performance will 

be tracked and the permitting agency will be alerted to the need for corrective action 

in the event of violations of permit limitations, terms, or conditions. 

After final permit issuance, interested parties have other opportunities to change 

the permit thorough permit appeals, major/minor permit modifications, permit 

termination or permit transfer. These administrative procedures are described below. 

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11.3.1 Permit Appeals 

In the process of developing a draft permit and during the public notice period, 

the permit writer should carefully consider the legitimate concerns of the permittee as 

well as the concerns of any third party who may have an interest in the permit terms 

and conditions. However, there will inevitably be situations in which a permit is issued 

in spite of the objections of the permittee or a third party. In such instances, the 

permittee or an interested party may choose to legally contest or appeal the NPDES 

permit. 

Various mechanisms are available to resolve legal challenges to NPDES 

permits. In the case of EPA-issued permits, the administrative procedure involved is 

called an evidentiary hearing. Many NPDES States and Tribes have similar 

administrative procedures designed to resolve challenges to the conditions of a permit. 

These procedures involve hearings presided over by an administrative law judge. For 

the sake of convenience, these hearings will hereafter be referred to as evidentiary 

hearings. They will naturally be known by different names in different State or Tribe 

jurisdictions. However, permit writers will, from time-to-time, be involved in permit 

appeals and will need to address the types of issues discussed below. 

Aside from preparation of the administrative record and notices, the permit 

writer may not be concerned with procedural matters relating to evidentiary hearings. 

All requests for evidentiary hearings are coordinated through the office of the EPA 

Regional Counsel or the appropriate State legal personnel. The permit writer’s first 

involvement with the hearing process will come as a result of designation of the trial 

staff and his/her role will be limited to that of a witness and technical advisor to legal 

counsel. 

A permit writer may be required to give a deposition during 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. 

To prepare for a deposition and testimony, the permit writer should be familiar 

with those laws, regulations, and policies that may affect the permit. The permit writer 

should be thoroughly familiar with the technical basis for the permit conditions. For 

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example, if the effluent limits are based on water quality requirements, the permit 

writer should thoroughly study any applicable basin plan or water quality simulation 

used to develop the effluent limits and be prepared to defend any assumptions 

inherent in the plan or simulation. If BPJ limits are based on proposed effluent 

guidelines, it will be necessary to carefully review not only the guidelines themselves 

but ail applicable data, including the development document for the specific guidelines. 

The technical defense of other BPJ requirements is much more difficult. The permit 

writer should be sure that (1) the information on which BPJ limits are based are 

unimpeachable, (2) the limits were derived from the data in a logical manner, in 

accordance with established procedures, and (3) the BPJ limits so derived are 

technically sound and meet BCT or BAT standards for economic reasonableness. 

As technical advisor to legal counsel, the permit writers most important function 

is to develop direct testimony in support of contested permit conditions. No attempt 

should be made to support technically indefensible conditions. Contested permit 

conditions that are not technically defensible and are not based on any legal 

requirement should be brought to counsel’s attention, with advice that EPA or the 

State agency withdraw those conditions. 

The second most important advisory function of the permit writer is assisting 

counsel in the development of questions for cross-examination of the opposing 

witnesses. Questions should be restricted to the subject material covered by the 

witness’ direct testimony and should be designed to elicit an affirmative or negative 

response, rather than an essay-type response. If a question must be phrased in such 

a way that the witness could attempt lengthy explanations, counsel should be 

forewarned. 

Finally, the permit writer should remember that in requesting an evidentiary 

hearing, the permittee has declared an adversary relationship with the regulatory 

agency, and the permit writer must therefore refrain from discussions about the case 

without prior consultation with legal counsel. In the role of witness and/or te ‘Inical 

advisor, the permit writer should: 

l Cultivate credibility 

. Never imply or admit weakness in his or her area of expertise 

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. Never attempt to testify about subjects outside his or her area of expertise 

. Always maintain good communication with counsel. 

Where the permitee is granted relief at the evidentiary hearing, the 

Administrative Law Judge generally will order appropriate relief. Where a request for 

an evidentiary hearing is denied, the permittee may file a notice of appeal and petition 

for review with the Environmental Appeals Board (EAB), which may or may not grant 

an evidentiary hearing based on the factual and legal issues alleged. Similarly, where 

a permittee is denied relief at an evidentiary hearing, the permittee may appeal to the 

EAB to overturn the hearing decision. Finally, under certain circumstances decisions 

of the EAB against the permittee may be appealed in Federal court. 

11.3.2 Permit Modification, Revocation, Termination, and Transfer 

After the final permit is issued, the permit may still need to be modified or 

revoked prior to the expiration date. Modifications differ from revocations and 

reissuance. In a permit modification, only the conditions subject to change are 

reconsidered while all other permit conditions remain in effect. Conversely, the entire 

permit may be reconsidered when it is revoked and reissued. A permit modification 

may be triggered in several ways. For example, a representative of the regulatory 

agency may conduct an inspection of the facility that indicated a need for the 

modification (i.e., the improper classification of an industry), or information submitted 

by the permittee may suggest the need for a change. Of course, any interested 

person may request that a permit modification be made. 

There are two classifications of modifications: major and minor. From a 

procedural standpoint, they differ primarily with respect to the public notice 

requirement. Major modifications require public notice; minor modifications do not. 

Virtually all modifications that result in less stringent conditions must be treated 

as major modifications, with provisions for public notice and comment. Generally 

speaking, a permit will not need to be modified during the term of the permit if the 

facility can fully comply with permit conditions. Conditions that would necessitate a 

major modification of a permit are described in 40 CFR 5122.62 and shown in 

Exhibit 11-7. 

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EXHIBIT 11-7 

Conditions Requiring Major Modification 

l Reopener-Conditions in the permit that required it to be reopened under certain 

circumstances. 

. Technical Mistakes-To correct technical mistakes or mistaken interpretations of law made 

in developing the permit conditions. 

. Failure to Notify-Upon failure of an approved State to notify another State whose waters 

may be affected by a discharge from the approved State. 

9 Alterations-When alterations or changes in operations occur that justify new conditions that 

are different from the existing permit. 

l New Information-When information is received that was not available at the time of permit 

issuance. 

. New Regulations- When standards or regulations on which the permit was based have been 

changed by promulgation of amended standards or regulations or by judicial decision. 

l Compliance Schedules for Innovative or Alternative Facilities-To modify the compliance 

schedule in light of the additional time that may be required to construct this type of 

facility; or when good cause for modification of a compliance schedule exists, such as an 

Act of God, strike, or flood. 

. Pretreatment-To require that an approved program be implemented or to change the 

schedule for program development. 

l Failed BPJ Compliance- When BPJ technology is installed and properly operated and 

maintained but the permittee is unable to meet its limits, the limits may be reduced to reflect 

actual removal; but in no case may they be less than the guideline limits. If BPJ operation 

and maintenance costs are totally disproportionate to the costs considered in a subsequent 

guideline, the permittee may be allowed to backslide to the guideline limits. 

l Non-Limited Pollutants-When the level of discharge of any pollutant that is not limited in 

the permit exceeds the level that can be achieved by the technology-based treatment 

requirements appropriate to the permit. 

l Variance Requests-When requests for variances, net effluent limitations, pretreatment, etc., 

are filed within the specified time but not granted until after permit issuance. 

l Adjust limits to reflect net pollutant treatment- Upon request of a permittee who qualifies 

for effluent limitations on a net basis under 40 CFR @122.45(g) and (h). 

l Insert CWA $307(a) toxic or 40 CFR Part 503 sludge use/disposal requirements. 

l Notification Levels-To establish notification levels for toxic pollutants that are not limited 

in the permit but must be reported if concentrations in the discharge exceed these levels. 

Minor modifications are generally non-substantive changes (e.g., typographical 

errors that require more stringent permit conditions). The conditions for minor 

modifications, described in 40 CFR $122.63, are shown in Exhibit 11-8. 

88# NPDES Permit Writers’ Manual - 207 
Chapter 11 Administrative Process 

EXHIBIT 11-8 

Conditions Requiring Minor Modification 

l Typographical errors must be corrected. 

l More frequent monitoring or reporting is necessary. 

l An interim compliance date in the schedule of compliance needs revision, provided the 

new date is not more than 120 days after the date specified in the permit and does not 

interfere with attainment of the final compliance date requirement. 

l Ownership has changed but no other change is necessary. 

l The construction schedule for a new source discharger needs revision. 

l A point source outfall that does not result in the discharge of pollutants from other 

outfalls must be deleted from the permit. 

l An approved local pretreatment program must be incorporated into the permit. 

11.3.3 Termination of Permits 

Situations may arise during the life of the permit that are cause for termination 

(i.e., cancellation, revocation) of the permit. Such circumstances include the following 

(see 40 CFR 5122.62(b)): 

. Noncompliance by the permittee with any condition of the permit 

0 Misrepresentation or omission of relevant facts by the permittee 

l A determination that the permitted activity endangers human health or the 

environment, either in an emergency or other situation 

l A temporary or permanent reduction or elimination of a discharge (e.g., 

plant closure). 

Once the permit is terminated, it can be placed into effect again only by the 

reissuance process, which requires a new permit application. All of the above 

situations may also be addressed through the p&nit modification process on a 

case-by-case determination. 

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11.3.4 Transfer of Permits 

Regulatory agencies will occasionally receive notification of a change in 

ownership of a facility covered by a NPDES permit. Such changes require that a 

permit be transferred by one of two provisions: 

l Transfer by Modification or Revocation-The transfer may be made 

during the process of modification, either major or minor. It may also be 

addressed by revoking and subsequently reissuing the permit. 

0 Automatic Transfer-A permit may be automatically transferred to a new 

permittee if three conditions are met: 

- The current permittee notifies the Director 30 days in advance of the 

transfer date. 

- The notice includes a written agreement between the old and new 

owner on the terms of the transfer. 

- The Director of the regulatory agency does not indicate that the subject 

permit will be modified or revoked. 

8EW NPDES Permit Writers’ Manual - 209 
Chapter 12 

Permit Compliance and 

Enforcement 

12.1 Overview 

Achieving and maintaining a high level of compliance with environmental laws 

and regulations are two of the most important goals of Federal and State 

environmental agencies. Enforcement provides a powerful incentive for NPDES 

permittees to comply. How an NPDES permit is written directly affects its 

enforceability. Each permit must be written clearly and without ambiguities so that 

compliance with the permit can be tracked effectively and the permit can be enforced 

in the event that violations occur. 

The permit writer may or may not become actively involved with the compliance 

monitoring and enforcement of the terms and conditions of the NPDES permits that he 

or she has written. The extent of the permit writer’s involvement will usually depend 

upon the organizational structure of the regulatory agency. Larger, centrally organized 

agencies will typically have specialized personnel responsible for enforcing the terms 

of NPDES permits. In other organizations, the individual who writes the permit will 

also be responsible for such enforcement activities as Discharge Monitoring Report 

(DMR) tracking, facility inspections, and enforcement recommendations. In the event 

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Chapter 12 Permit Compliance and Enforcement 

of a judicial enforcement action, the permit writer may be called upon to testify 

regarding the specific requirements of the permit or its basis. 

Regardless of the type of organizational structure within a regulatory agency, 

the permit writer should have an appreciation for the various aspects of a meaningful 

NPDES compliance enforcement program. The compliance monitoring reviews and 

inspections, and resulting data entered into the Quarterly Noncompliance Report 

database which provide the basis for evaluating compliance are addressed in the 

following section. The chapter concludes with a brief description of the enforcement 

actions available to facilitate permit compliance. 

12.2 Compliance Monitoring 

Compliance monitoring is a generic term that includes all activities undertaken 

by Federal or State regulatory agencies to ascertain a permittee’s adherence to a 

NPDES permit. Compliance monitoring data collected as part of the NPDES Program 

are used in compliance evaluation and in support of enforcement. The process 

includes receiving data, reviewing data, entering data into the Permit Compliance 

System (PCS) data base, identifying violators, and determining an appropriate 

response. 

A primary function of the compliance monitoring program is the verification of 

compliance with permit conditions, including effluent limitations and compliance 

schedules. Compliance monitoring may be described as comprising two elements: 

• Compliance Review-The review of all written reports and other material 

relating to the status of a permittee’s compliance. 

• Compliance Inspections-Field-related regulatory activities, including 

sampling, conducted to determine compliance. 

12.2.1 Compliance Review 

Compliance and enforcement personnel use two primary sources of information 

to carry out their compliance review responsibilities: 

• Permit/Compliance Files-These files include compliance schedule 

reports, compliance inspection reports, DMRs, enforcement actions, and 

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any other correspondence (e.g., summaries of telephone calls, copies of 

warning letters). Compliance personnel periodically review this information 

and use it to determine if enforcement is necessary and what level of 

enforcement is appropriate. 

l PCS-PCS is a data management system used to compile all relevant facts 

about a facility’s permit conditions, self-monitoring data, the inspections 

performed, and any enforcement actions taken. PCS is the national data 

base for the NPDES Program. As such, PCS promotes national 

consistency and uniformity in permit and compliance evaluations. To 

accomplish this goal, all required data are entered into and maintained 

regularly in PCS. 

NPDES permits must be written so that compliance data are capable of being 

tracked by PCS. There may be situations where permit limits and monitoring 

conditions are not initially compatible with PCS entry and tracking. In these cases, 

States should ensure that appropriate steps are taken by the permit writer to identify 

difficult permits to the person responsible for entering PCS codes (either in the State 

or the Region) and to mutually resolve any coding issues. To assist PCS coders in 

accurately interpreting and coding the permit into PCS and to assist enforcement 

personnel in reviewing permittee self-monitoring data and reports in a timely manner, 

permit writers should apply the compliance inspection procedures discussed in the 

next section (Section 12.2.2). 

12.2.2 Compliance Inspections 

Compliance inspections refer to all field-related regulatory activities conducted 

to determine permit compliance. Such field activities may include evaluation 

inspections (nonsampling), sampling inspections, other specialized inspections, and 

remote sensing. Certain inspections, such as-diagnostic inspections and performance 

audit inspections, aid the regulatory agency in evaluating the facility’s problems in 

addition to providing information to support enforcement action. Biomonitoring 

inspections are specifically targeted at facilities with effluent suspected or identified as 

causing toxicity problems that threaten the ecological balance of the receiving waters. 

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chapter 12 Permit Compliance and Enforcement 

Compliance inspections are undertaken for one or more of the following 

purposes: 

To establish a regulatory presence to defer violations 

To ensure that permit requirements are being met or to determine if permit 

conditions are adequate 

To check the completeness and accuracy of a permittee’s performance and 

compliance records 

To assess the adequacy of the permittee’s self-monitoring and reporting 

program 

To determine the progress or completion of corrective action 

To obtain independent compliance data on a facility’s discharge 

To evaluate the permittee’s operation and maintenance activities 

To observe the status of construction required by the permit, 

12.3 Quarterly Noncompliance Reports 

EPA Regional Offices and States that have been approved to administer the 

NPDES Program are required by regulation to report quarterly on major facilities that 

are not in compliance with the terms and conditions of their permit (i.e., effluent 

limitations meet the criteria for reportable noncompliance [RNC], schedules, and 

reporting requirements). 

The regulations in 40 CFR 123.45 established requirements for listing facility 

violations and resulting regulatory enforcement action or quarterly noncompliance 

reports (QNCRs). This regulation established reporting requirements for violations that 

meet specific, quantifiable reporting criteria, as well as for violations that are more 

difficult to quantify but are of sufficient concern to be considered reportable. The 

regulation also specifies the format that the reports must follow and the schedule for 

their submission. 

Only major facilities that meet RNC criteria must be reported on the QNCR. 

RNC consists of five general types of violations: 

l Violation of Monthly Average Effluent Limits-Data that exceeds or 

equals the limit times the Technical Review Criteria (TRC) for 2 months 

during a 6-month period, where the TRC is 1.4 for Group I pollutants and 

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1.2 for Group II pollutants (Appendix A to 40 CFR Part 123 contains a list of 

Group I and II pollutants); and data that exceeds the limit for 4 months 

during a 6-month period. 

l Interim Effluent Limits Set Forth in a Formal Enforcement Action-Any 

violation of any magnitude. 

l Schedule-Missing a compliance schedule milestone date by 90 days. 

l Reporting-Missing a report due date by 30 days. 

l Single Event-A violation of any magnitude considered to have an adverse 

effect on water quality or public health (e.g., unauthorized bypass, 

unpermitted discharge, frequent discharges of a variety of pollutants). 

A subset of instances of RNC that appear on the QNCR may be noted as 

significant noncompliance (SNC). This distinction is used solely for management 

accountability purposes as a means of tracking trends in compliance and evaluating 

relative timeliness of appropriate enforcement response toward priority violations. The 

definition of SNC is not regulatory and may change as the NPDES Program changes 

to encompass new initiatives. Generally, the designation of SNC indicates a violation 

is of sufficient magnitude and/or duration to be considered among the Agency’s 

priorities for regulatory review and/or response. The categories of SNC are: 

. Violation of enforcement action requirements (i.e., administrative effluent 

limits, key compliance schedule milestones, and key reports) 

. Violation of permit effluent limits 

. Violation of key compliance schedule milestones contained in a permit 

. Violation of key reporting requirements in a permit 

. Any unauthorized discharge or bypass considered significant by the NPDES 

Program director 

. Violations associated with water quality or health impacts. 

The Regions and NPDES States are expected to prioritize rapid enforcement 

action against all SNC violations by the time they appear on the first QNCR. Prior to 

a permittee appearing on the subsequent QNCR for the same instance of SNC, the 

permittee should either be in compliance or the administering agency should have 

initiated an appropriate formal enforcement action to achieve final compliance. If the 

facility is still considered SNC after two quarters and no formal enforcement action has 

been taken, the facility is placed on the Exceptions List. Although there are some 

legitimate justifications for facilities appearing on the Exception List, the Exceptions 

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List generally indicates facilities for which the administering agency failed to handle 

enforcement in a timely and appropriate manner. 

Regulatory Update 

In September 1995, EPA revised the definition of SNC to include violations of non-monthly average 

permit limits by major facilities. A large percentage of NPDES majors are lacking the required monthly 

average limits in their permit thus escaping detection as SNC and scrutiny for formal enforcement action. 

The new definition was effective on October 1, 1996 and is expected to result in better targeting of limited 

enforcement resources to violations posing the greatest risk to the environment and public health. 

12.4 Enforcement 

Specific enforcement actions are focused on a small subset of the total number 

of violators-violators at sites where frequent or serious violations have occurred. 

However, these actions have the effect of fostering compliance by an entire industry of 

facilities across the nation. By choosing the appropriate enforcement response to 

violations, EPA tries to achieve several goals: 

l Correction of the violation as soon as possible 

. Deterrence of future violations by the same permittee or other permittees 

. Equal treatment of the regulated community through use of a uniform 

approach to selecting enforcement responses (i.e., similar violations are 

treated similarly) 

. Punishment of serious violations 

. Effective use of enforcement resources by achieving protection of human 

health and the environment with the least amount of staff time and funds. 

Once a facility has been identified as having apparent permit violations, the 

EPA or the NPDES State or Tribal organization will review the facility’s compliance 

history. Such a review includes an assessment of the magnitude, frequency, and 

duration of violations. Significant permit violations are identified and a determination of 

the appropriate enforcement response is made. 

Section 309 of the Act authorizes the Agency to bring civil or criminal action 

against facilities which violate their NPDES permit conditions. EPA Regions and 

authorized States have specific procedures for reviewing self-monitoring and 

inspection data and for deciding what type of enforcement action is warranted. EPA 

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recommends an escalating response to continuing noncompliance. Typical types of 

enforcement actions include: 

Inspection debriefing, calling attention to deficiencies 

Telephone call 

Letter of violation 

Notice of violation 

Administrative order 

Administrative fine,of up to $125,000 per proceeding 

Civil lawsuit 

Criminal prosecution. 

Considerations when making determinations on the level of the enforcement 

response include (1) the severity of the permit violation, (2) the degree of economic 

benefit obtained through the violation, (3) previous enforcement actions taken against 

the violator, and (4) the deterrent effect of the response on similarly situated 

permittees. Equally important are considerations of fairness and equity, national 

consistency, and the integrity of the NPDES Program. 

12.5 Public Participation 

Citizens can participate in the enforcement process in a number of ways. 

Under the Freedom of Information Act, citizens have the right to request certain 

facility-specific compliance information from EPA’s PCS database. Interested citizens 

can intervene in any Federal civil action to enjoin any threatened or continuing 

violation of any program requirement or permit conditions, and to recover civil 

penalties in court. Citizens also have the opportunity to review and comment on any 

proposed consent decree to resolve a State or’ Federal civil judicial enforcement 

action. 

Section 505 of the Clean Water Act allows any citizen to commence a civil 

judicial enforcement action on his own behalf against: (1) any person (including the 

United States or any government agency) who is alleged to be in violation of an 

effluent standard or limitation or an enforcement order issued by EPA or a State, or 

(2) against EPA or the State where the regulatory authority is alleged to have failed to 

take appropriate action. Citizens may not commence suit if EPA or the State is 

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diligently prosecuting a civil or criminal action. Citizens must also give EPA, the State, 

and the alleged violator sixty days’ notice of the alleged violation prior to commencing 

a citizen suit. 

12.6 Compliance Assistance and Voluntary Compliance Policies 

On June 8, 1994, EPA established a new Office of Enforcement and 

Compliance Assurance (OECA), consolidating a number of functions formerly shared 

among different programs at EPA. One of several new offices in OECA is the Office 

of Compliance (OC). The overriding mission of the Office of Compliance is to improve 

compliance with environmental laws. To do this, OC sets national compliance 

assurance and enforcement priorities through strategic planning and targeting; collects 

and integrates compliance data; develops effective compliance monitoring programs to 

support inspections and self-reporting; builds the capacity for more effective 

compliance assistance to the regulated community; works with Regions, States, 

municipalities, citizens groups and industry, and supports enforcement activity. Three 

of the divisions in OC are organized by economic sector (SIC Code). 

As part of President Clinton’s 1995 regulatory form initiative, EPA’s Office of 

Enforcement and Compliance Assurance issued three policies to provide incentives for 

voluntary compliance. The first is “Incentives for Self-Policing: Disclosure, Correction 

and Prevention of Violations” (hereafter referred to as the “self-audit policy”), which 

was issued on December 22, 1995. This policy officers incentives in the form of 

elimination of gravity-based penalties to companies that find violations through an 

environmental audit or efforts that reflect due diligence, and promptly disclose and 

correct those violations. It also offers a 75% reduction in gravity-based penalties for 

violations that are voluntarily discovered and disclosed even if not found through an 

audit or the exercise of due diligence. The self-audit policy contains important 

safeguards to protect public health such as: excluding violations which may present 

an imminent and substantial endangerment or have resulted in serious actual harm; 

retaining the right to recover any significant economic benefit gained by the violator; 

requiring the company to remedy any environmental harm; and, excluding repeat 

violations. 

The second policy is EPA’s “Policy on Compliance Incentives for Small 

Businesses” (hereafter referred to as the “small business policy”) which became 

218 - Ml% NPDES Permit Writers’ Manual 
Permit Compliance and Enforcement chapter 12 

effective on June 10, 1996. The purpose of this policy is to promote compliance 

among small businesses by providing them with special incentives to participate in 

compliance assistance programs or to conduct environmental audits, and then to 

promptly correct violations. Under the small business policy, a “small business” is a 

person, corporation, partnership, or other entity who employs 100 or fewer individuals 

across all its facilities and operations. EPA will eliminate the entire civil penalty if a 

small business satisfies all four of the following criteria: (1) the business has made a 

good faith effort to comply as demonstrated by either receiving on-site governmental 

compliance assistance or conducting a voluntary environmental audit and promptly 

disclosing in writing all violations discovered as part of the audit; (2) in past three 

years, the business was not subject to an action for the current violation and in the 

past five years the small business has not been subject to two or more enforcement 

actions for environmental violations; (3) the business corrects the violation and 

remedies any harm associated with the violation within six months of discovery; and 

(4) the violation has not caused or does not pose actual serious harm and has not 

involved criminal conduct. 

If the small business meets all of the above criteria except that it needs a 

longer corrections period or if it has obtained a significant economic benefit from the 

violations, EPA will waive up to 100% of the gravity component of the penalty but may 

seek the full amount of any economic benefit associated with the violations. 

The third new policy is the “Policy on Flexible State Enforcement Responses to 

Small Community Violations,” which was issued on November 22, 1995 (hereinafter 

referred to as the “small community policy”). The small community policy assures 

States that they have, within appropriate limits, the flexibility to design and use multimedia compliance assistance and compliance prioritization measures as alternatives to 

traditional enforcement responses when addressing a small community’s 

environmental violations. Under the small community policy, State small community 

environmental compliance assistance programs provide (1) an adequate process to 

return a small community to environmental compliance; and (2) an opportunity to 

correct violations. States electing to provide small community environmental 

compliance assistance should establish and follow an adequate process for 

determining which communities can participate, assessing a community’s good faith 

and environmental compliance status, determining a community’s administrative, 

iiBp# NPDES Permit Writers’ Manual - 219 
chapter 12 Permit Compliance and Enforcement 

technical, and financial capacity to comply, weighting the comparative risks associated 

with competing environmental mandates, and entering into an enforceable agreement 

establishing a risk-prioritized schedule that requires compliance with all environmental 

mandates as quickly as is reasonable. 

A State can waive part or all of the noncompliance penalty if the community is 

working diligently and in good faith to achieve compliance. The small community 

policy does not apply to criminal violations. EPA also reserves the right to take 

immediate action where the community’s actions create an imminent and substantial 

endangerment to public health and the environment. 

220 - 88# NPDES Permit Writers’ Manual 
Appendix A 

Index to NPDES Regulations 
Index to NPDES Regulations Appendix A 

CLEAN WATER ACT 

40 CFR SECTION NUMBER 

301(b) 122.21(m)(1), 125 Subparts A and D 

301(h) 125 Subpart G 

301(i) 125 Subpart J 

301(k) 125 Subpart C (Reserved) 

303(c) 131 Subparts A, B,and C 

304(e) 125 Subpart K 

316(a) 124.66, 125 Subpart H 

SUBJECT A 

Administrative Procedures Act 

Permit Continuation 122.6 

Administrative Record 

Draft Permit 

Final Permit 

124.9 

124.18 

Anti-Backsliding (Reissued Permits) 

Application 

Completeness 

Existing Facilities 

State Program 

Time to Apply 

Duty to Reapply 

122.44(l), 122.62(a)(16) 

122.21(e) 

122.21(g) 

124.3 

122.21(c) 

122.21(d) 

Aquaculture 

Aquatic Animal Production Facilities 

Application 

Definition 

122.2, 125.10 

122.21(h)(2) 

122.24 

Appendix A 

Average Monthly 

Non-POTW 

POTW 

Average Weekly Limits (POTW) 

122 

122.45(d)(1) 

122.45(d)(2) 

122.45(d)(2) 

SUBJECT B 

BAT Compliance Deadline 

Best Management Practices (BMP) 

Best Professional Judgment (BPJ) 

Boilerplate Permit Conditions 

Bypass 

125.3(a)(2)(iii)(A)(v)(2) 

122.44(k), 125.100-102 

125.3 

122.41-44 

122.41(m) 

EPA NPDES Permit Writers’ Manual - Appendix A-1 
Appandlx A Index to NPDES ReguMions 

SUBJECT C 

Calculating NPDES Permit Conditions 

Case-by-Case Limitations (See BPJ also) 

Case-by-Case Permits (See BPJ also) 

Coast Guard 

Coastal Zone Management 

Comments During Public Notice 

Compliance Schedules 

Computation of Time 

Concentrated Animal Feeding Operations 

Concentrated Aquatic Animal Production 

Confidentiality of Information 

Consolidation of Permit Processing 

Continuation of Expiring Permits 

Conventional Pollutants 

SUBJECT D 

Definitions and General Requirements 

Denial of Permit 

Design Flow (POTWs) 

Dilution Prohibition 

Discharge Monitoring Report (DMR) 

Discharge of a Pollutant (definition) 

Draft Permit 

Duration of Permits 

Duty to Comply 

Duty to Mitigate 

Duty to Provide Information 

Duty to Reapply 

SUBJECT E 

Effective Date 

Endangered Species Act 

Environmental Impact Statement 

Final 

New Source 

NEPA 

Evidentiary Hearing Procedures 

Ex Parte Communication 

Exclusions 

Existing Source Definition 

Expiration Dates (Duration of Permits) 

Extension of Public Comment Period 

122.45 

12244(a), 125.3 

124.52 

122.44(p) 

12249(d) 

124.13 

122.41 (l)(5), 122.47, 

122,62(a)(13) 

7 24.20 

122.21 (h)(l), 122.23 

122.21 (h)(2), 122.24 

122.7 

124.4 

122.6 

401.16 

122.1 

122.6(b) 

122.45(b) 

122.45(f)(l)(iii) 

122.41 (l)(4)(i) 

122.2 

124.6 

122.46 

122.41 (a) 

122.41 (d) 

122.41 (h) 

122.41 (b) 

124.15 

122.49(c) 

124.61 

122.29(c), 124.10(b)(l) 

6 

124.77-91 

124.78 

122.3 

122.29(a)(3) 

122.46, 124.2 

124.12(c) 

Appendix A-2 - 8ER9 NPDES Permit Writers’ Manual 
Index to NPDES Regutations Appendix A 

SUBJECT F 

Fact Sheets 

Filter Backwash 

Fish and Wildlife Coordination Act 

Fundamentally Different Factors (FDF) 

SUBJECT G - H 

General Permits 

Public Notice 

Special Procedures 

SUBJECT I - L 

Innovative Technology (See 301 (k)) 

Inspection and Entry 

Internal Waste Streams 

Introduction of New Pollutants - POTW 

Issuance and Effective Dates 

SUBJECT M 

Mass Limitation 

Maximum Daily 

Metals 

Minor Modifications 

Modifications 

Monitoring 

Recording 

Recordkeeping 

Records 

Reports (DMRs) 

Representative 

SUBJECT N 

NPDES (Definition) 

National Environmental Policy Act 

National Historic Preservation Act 

Navigation 

Need to Halt or Reduce Activity 

Not a Defense 

Net/Gross 

New Discharger (Definition) 

New Source 

Application 

Criteria 

Definition 

124.8, 124.56 

1253(g) 

122.49(e) 

122.21(m)(l), 122.44(d)(8), 

125.30-32 

122.28 

124.10(c)(2)(i) 

124.58 

122.41 (i) 

122.45(h) 

12242(b) 

124.15, 124.20, 124.60 

122.45(f) 

12245(d)(l) 

122.45(c) 

122.63 

122.62, 124.5 

122.48 

122.48(p) 

122.41 (j)(2) 

122.41 (l)(4) 

122.41 (j)(l) 

122.2 

122.49(g) 

122.49(b) 

12244(q) 

122.41 (c) 

122.45(g) 

122.2 

122.21 (j) 

122.29 

122.2 

8ER9 NPDES Permit Writers’ Manual - Appendix A-3 
Appmdlx A Index to NPDES Regutations 

Prohibited Discharges 

Public Notice 

Non-Advisory Panel Procedures 

Non-Continuous Discharges 

Non-Compliance 

Anticipated 

Other 

Notification Levels 

SUBJECT 0 

Offshore Oil and Gas Facilities 

On-Site Construction (New Source) 

Operations and Maintenance 

SUBJECT P-Q 

pH Limits with Continuous Monitoring 

Planned Changes 

Pollutant {Definition) 

Pollutants in Intake Water (Net/Gross) 

POTW (Definition) 

Pretreatment 

Primary Industry 

Privately Owned Treatment Works 

Production-Based Limits 

Prohibitions 

Proper Operation and Maintenance 

Property Rights 

Public Hearings 

Public Notice of Permits 

Contents 

Public Hearings 

SUBJECT R 

Reapplication 

Recordkeeping 

Reopener Clause 

Reopening of Public Comment Period 

Request for Evidentiary Hearing 

Response to Comments 

Revocation and Reissuance 

SUBJECT S 

Secondary Treatment Requirements 

Secondary Treatment Variance 

Sewage Sludge 

Signatory Requirements 

122.4(i) 

124.1 O(a)(l)(vi) 

124.111-128 

122.45(e) 

122.41 (l)(2) 

122.41 (l)(7) 

122.42(a), 122.44(f) 

122.28(c) 

122.29(c)(4) 

122.41 (e) 

401.17 

122.41(l)(l) 

122.2 

122.45(g) 

122.2 

122.44(j), 403 

122 - Appendix A 

122.44(m) 

122.45(b) 

122.4 

122.41 (e) 

122.41 (g) 

124.72 

124.10 

124.10(d), 124.57 

124.10(b)(2), 124.10(d)(2) 

122.21 (d) 

22.21(p), 122.41(j)(2) 

12244(c) 

124.14 

124.74 

124.17 

122.62, 124.5 

133 

(See 301(h) of the CWA) 

122.44 (o), 503 

122.22, 122.27 

Appendix A-4 - 88# NPDES Permit Writers’ Manual 
Index to NPDES Resuhticms Appendix A 

Small Business Exemption 

State Certification 

Statement of Basis 

Statutory Deadlines 

POTW 

Non-POTW 

Statutory Variances and Extension 

Stays of Contested Permit Conditions 

Storm Water 

Application Deadline 

Group II Dischargers 

Group II Dischargers 

SUBJECT T 

Technology Based Effluent Limits 

Ten Year Protection Period 

for New Sources and Dischargers 

Termination of Permit 

Thermal Dischargers 

Toxic Pollutants 

Toxic Pollutants List 

Transfer of Permit 

Twenty Four Hour Reporting 

SUBJECT U 

Upset 

SUBJECT V 

Variances 

Non-POTWs 

POTWS 

Appeals 

Decisions 

Expedited procedures 

Procedures 

SUBJECT W,X,Y,Z 

Water Quality Standards 

Waters of the U.S. (Definition) 

122.21 (g)(8) 

124.53, 124.54, 124.55, 122.44(d)(3) 

124.7 

125.3(a)(l) 

125.3(a)(2) 

125.3(b) 

124.16, 124.60 

122.26 

122.21(c)(l) 

122.21 (f)(9) 

122.21(g)(lO) 

122.44(a) 

122.29(d) 

122.64 

(See 316(a) of the CWA) 

122.44(e) 

401.15 

122.41 (l)(3), 122.61 

122.41 (l)(6), 122.44(g) 

122.41 (n) 

122.21 (I) 

122.21(m) 

124.64 

124.62 

122.21(n) 

124.63 

122.44(d) 

122.2 

Wetlands (See “Waters of the U.S.” Definition) 

Wild and Scenic Rivers Act 122.49(a) 

8EY4 NPDES Permit Writers’ Manual - Appendix A-5 
Appendix B 

Effluent Guidelines and 

Standards 
Effluent Guidelines and Standards Appendix B 

Protection of 

Environment 

40 

PARTS 400 TO 424 

Revised as of July 1, 1995 

CONTAINING 

A CODIFICATION OF DOCUMENTS 

OF GENERAL APPLICABILITY 

AND FUTURE EFFECT 

AS OF JULY 1, 1995 

With Ancillaries 

Published by 

the Office of the Federal Register 

National Archives and Records 

Administration 

as a special edition of 

the Federal Register 

EPA NPDES Permit Writers’ Manual - Appendix B-1 
Appendix B Effluent Guidelines and Stamkuds 

Appendix B-2 - 8HY4 NPDES Permit Writers’ Manual 
Effluent Guidelines and Statwiads Appendix B 

CHAPTER I-ENVIRONMENTAL PROTECTION 

AGENCY-(Continued) 

PUrt 

2 

402 

403 

40s 

406 

407 

408 

409 

410 

411 

412 

413 

414 

416 

416 

417 

418 

419 

420 

421 

422 

4!B 

424 

SUBCHUTER N-EFFLUENT CWIDELINES AND STANDARDS 

[Reserved] 

~~*r$e~~visione . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

e 

General pretreatment regulations for existing and 

new sources of pollution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Dairy products processing point source category . . . 

Grain mills point source category . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Canned and preserved fruits and vegetables processing point source category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Canned and preserved seafood processing point 

sourcecategory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Sugar processing point source category . . . . . . . . . . . . . . . . . . 

Textile mills point source category . . . . . . . . . . . . . . . . . . . . . . . . 

Cement manufacturing point source category . . . . . . . . 

Feedlots point source category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

EleCtroplating ROillt SOllIKe category . . . . . . . . . . . . . . . . . . . . . 

Organic chemicals, plastics, and synthetic fibers . . . 

Inorganic chemicals manufacturing point source 

~ZiZZif . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Soap and detergent manufacturing point source 

category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Fertilize~r manufacturing point source category . . . . . 

Petroleum refining point source category . . . . . . . . . . . . . . 

Iron and steel manufacturing point source catww . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Nonferrous metals manufacturing point source 

category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Phosphate manufacturing point source category . . . 

Steam electric power generating point source cat 

wow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Ferroalloy manufacturing point source category . . . 

4 

4 73 

88 

ii 

347 

384 

446 

86Y4 NPDES Permit Writers’ Manual - Appendix B-3 
Appendix B Effluent Guidelines and Stamkuds 

CHAPTER I-ENVIRONMENTAL PROTECTION 

AGENCY (Continued) 

Part 

42s 

426 

z 

429 

430 

431 

432 

ifi 

z 

439 

440 

443 

446 

447 

454 

455 

iii 

469 

SUBCHAPTER N-EFFLlJENT GUIDELINES AND STANDARDS 

Leather tanning and finishing point source category .................................................................... 

Glass manufacturing point source category ........... 

Asbestos manufacturing point source category ...... 

Rubber manufacturing point source category ......... 

Timber prOdUCtS processing point source category 

Pulp, paper, and paperboard point source category 

The builders’ paper and board mills point source 

category ............................................................... 

Meat products point source category ...................... 

Metal finishing point source category .................... 

Coal mining point source category BPT, BAT, BCT 

limitations and new source performance standards ...................................................................... 

011 and gas extraction point source category ......... 

Mineral mining and processing point source category .................................................................... 

Pharmaceutical manufacturing point source category .................................................................... 

Ore mining and dressing point source category ...... 

Effluent limitations guidelines for existing sources 

and standards of performance and pretreatment 

standarti for new sources for the paving and 

roofing materials (tars and asphalt) point source 

category ............................................................... 

Paint formulating point source category ................ 

Ink formulating point source category ................... 

Gum and wood chemicals manufacturing point 

source category .................................................... 

Pesticide chemlcals ................................................. 

Explosives manufacturing point source category ... 

Carbon black manufacturing pofnt source category 

PhOtOgraphiC pint source Category ....................... 

POOC 

5 

:: 

ii 

102 

184 

E 

218 

245 

E 

311 

312 

316 

iii 

338 

Appendix B-4 - 8ER9 NPDES Permit Writers’ Manual 
Effluent Guidelines and Statwiads Appendix B 

Part 

z! 

463 

464 

465 

466 

467 

468 

469 

471 

Hospital point source category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Battery manufacturing point source category . . . . . . . . 

Plastics molding and forming point source category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Metal molding and casting point source category . . 

Coil coating point source category . . . . . . . . . . . . . . . . . . . . . . . . . 

Porcelain enameling point source category . . . . . . . . . . . . . 

Aluminum forming point source category . . . . . . . . . . . . . . 

Copper forming point source category . . . . . . . . . . . . . . . . . . . . 

Electrical and electronic components point source 

category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Nonferrous metals forming and metal powders 

point source category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

:; 

426 

435 

444 

487 

509 

516 

SUBCHAPTER O-SEWAC+E SLUDGE 

State sludge management program regulations . . . . . 641 

Standards for the use or disposal of sewage sludge 661 

SB P [RESERVEDJ 

SUBCBAPTER Q-ENERGY POLICY 

Fuel economy of motor vehicles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Fuel economy retrofit devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

6ER9 NPDES Permit Writers’ Manual - Appendix B-5 
Appendix C 

List of SIC Codes 
List of SIC Codes Appendix C 

EXECUTIVE OFFICE OF THE PRESIDENT 

OFFICE OF MANAGEMENT AND BUDGET 

STANDARD 

INDUSTRIAL 

CLASSIFICATION 

MANUAL 

1987 

EPA NPDES Permit Writers’ Manual - Appendix C-1 
Appendix C list of SIC Codes 

Part II 

Numerical List of Short Titles 

8m NPDES Permit Writers’ Manual - Appendix C-3 
Appendix C list of SIC Codes 

Numerical List of Short Titles 

The official SIC titles of the divisions and the twodigit major groups, threedigit industry groups, and fourdigit industries are those shown in Part I. For various reasons, including presentation of statistical tables, it is desirable to have a 

standard list of short SIC titles so that all agencies may use the same short titles 

for the same codes as long as the titles fit the space requirements of the publication. 

The standard short titles below have been limited to 36 spaces for fourdigit industry codes and 38 spaces for two-digit major group and thre4igit industry group 

cock. Where a twodigit major group or t-t industry group contains only a 

single fourdigit industry, the two-digit or thre4igit titles are allowed 36 rather 

than 38 spaces. If the official SIC title falls within the short title space limitation 

above, it is generally used without change. 

It is underhod, of course, that just as a title itself is not sufficient to define an 

industry, so too a short title may not appear to represent the same content as the 

official title. Content can only be defined by reference to the off’cial titles and de 

scriptions for the relevant division, major group, industry group, and industry. 

8ER9 NPDES Permlt Wrlters’ Manual - APpendlx C-5 
List of SIC Codes Appendix C 

NUMERICAL LIST OF SHORT TITLES 

A. AGRICUITURE, FORESTRY, AND FISHING 

Gnie short Tit& 

01 AGRICULTURAL PRODUCTIONCROPS 

011 Cash Grains 

0111 Wheat 

0112 Rice 

0115 Corn 

0116 Soybeans 

0119 Cash grains, net 

013 Field Cropr, Except Cash G~~IUJ 

0131 Cotton 

0132 Tobacco 

0133 Sugarcane and sugar beets 

0134 Irish potatoes 

0139 Field crepe, except caeh grain& Ned 

016 Vegetabler and Melon8 

0161 Vegetablea and melone 

017 FN~~J and Tree Nuta 

0171 Berry crop 

0172 Grapea 

0173 Tree nuta 

0174 citru fruiti 

0175 Deciduoue tree fruita 

0179 Fruita and tree nuta, net 

016 Horticultural specialticr 

0161 Ornamental nurwy productd 

0162 Food crops grown under cover 

019 General Farma. primarily Crop 

0191 General farms, primarily crop 

02 AGRICULTURAL PRODUCX‘IONLIVESTOCK 

021 Live&o&, Except Dairy and Poultry 

0211 Beef cattle feedIota 

0212 Beef cattle, except feedlota 

0213 Hoge 

0214 Sheep and goats 

0219 General livestock, net 

024 Dairy Farma 

0241 Dairy farma 

025 Poultry and Em 

0251 Broiler, fryer, and roaster chickena 

0252 Chicken w 

0253 Turkey and turkey egge 

0254 Poultry hatcheries ’ 

0259 Poultry and eggs net 

027 Animal Specialtia 

0211 Fur-hearing animals and rabbita 

0272 Ho= and other equine 

0273 Animal aquaculture 

0279 Animal specialtim llw 

tide Shari Tit& 

029 General Farme, Primarily Animal 

0291 General faruq primarily animal 

07 AGRICULTURAL SERVICES 

071 Soil Preparation Services 

0711 Soil preparation eervicea 

072 Crop Service0 

0721 Cmp planting and protectin 

0722 Crop harve8ting 

0723 Crop preparation eervicea for market 

0724 Cottonginning 

074 Veterinary Servicea 

0741 Veterinary servicea for I&stock 

0742 Veterinary eervicea, specialties 

075 Animal Services, Except VeterinuJ 

0761 Liveatock services, ext. veterinary 

0752 Animal epecidty mn-icea 

076 Farm Labor and Management Servicea 

0761 Farm labor contractore 

0762 Farm management ee.rvim 

076 Landscape and Horticultural Servicer 

0761 Landtxape counseling and pl& 

0762 Lawn and garden servicea 

0763 Ornamental ehrub and tree eervicee 

06 FORESTRY 

OS1 Timber Tmcta 

0611 Timbertracta 

063 Forest Producta 

0631 Forest products 

065 Forestry Servicu 

0661 Forekrymticea 

09 FISHING, HUNTING, AND TRAPPING 

091 Commercial Flahing 

0912 Fiu%ll 

0913 Shellfish 

0919 Ibfiadheoua marine producta 

092 fib Hateheriea and Prewrvea 

0921 Fish hafzheriea and premrvee 

097 Hunting, Trapping, Game Propyation 

0971 Hunting, trapping, game propagation 

&EM NPDES Permit Writers’ Manual - Appendix C-7 
Appemdlx C List of SIC Codes 

10 METALMINING 

101 IrMorea 

1011 Ironorell 

102 tipper Oree 

1021 copper ona 

163 LudandZincOlw 

1931 Londandrincoxw 

194 Cold urd Silver Oree 

1941 Gold ores 

1944 Silver ore0 

106 FenmalIoy Oru, Except Vuwlium 

1061 Ferroelloy oree, except vanadium 

196 Metal Mining Servicea 

1061 Metal mining mmke8 

169 Mlwell8neoue Metal Oren 

1094 Uranium-radium-vanadjum Oreo 

1999 Metal omb net 

1311 Crude petroleum and natural gae 

132 Natural Gu Liqnida 

lS2l Natural gae liquida 

136 Oil and Cu Field &Ricu 

1861 -oiJandgauweIia 

1362 Oil and gae exploration eervicae 

1369 oilandgaefieldeervias,nec 

14 NONMETALLIC IkmmBAu. EXCEPT 

12 

122 

1221 

1222 

123 

1231 

124 

l241 

COAL MINING 

Bituminoue Coal and Li6nite IUinin6 

Bituminous coal and lignite--w&x 

Bituminou coal-underground 

Antlunclte ?Aining 

Anthracitemining 

Co8i Mining Service9 

coaiminingmrvicu 

13 OIL AND GAS EXTRACTION 

131 Crude Petroleum and Natural Gu 

141 Dimension Stone 

1411 Dimension m&me 

142 Cnuhed and Broken S&me 

1422 Cnmhed and broken lime&one 

1423 Crushed and broken granite 

1429 Cruahed and broken stone, net 

144 Sand and Gravel 

1442 Coasbuction send and gravel 

1446 Induetrialrand 

145 ci8y. Ceramk, & RefrBctory bIiner8le 

1455 Kaolin and ball clay 

1459 clay and r&ted minerals, net 

147 Chemical nnd Fertlllzer Mlnemir 

1474 Potaeh, mxla, and borate minerala 

1475 Phcsphat8 rock 

1479 Chemical and fertilizer mining, net 

148 Nonmetallic Miner& &r&u 

1461 Nonmet&ic minerals services 

149 Miecellaneoue NonmetaIllc Miner& 

1499 h¶iecellaneoue nonmetallic minerals 

C. CONSTRUCTION 

cbde short Tilk 

Ishwt Title 

15 

152 

l521 

GENERAL BUILDING CONTRACI’ORS 

Buidentlal Building Conntruction 

Single-family housing comtruction 

1522 Residential construction, net 

153 Operative Buildem 

1531 Operative builders 

154 Nonruhlentlal Building Construction 

1541 Induetrial buildings and warehouem 

1542 Nonruidential COMtNCtiOn, net 

1611 Highway and street comtruction 

162 Heavy Construction, Except HIghray 

1622 Bridge, tunnel, & elevated highway 

1623 Water, ewer, and utility lima 

1629 Heavy conetruction, mc 

17 SPECIAL TRADE CONTBAcrOBS 

171 Plumbing, Heating, AirXonditionin6 

1711 Plumbing, heating, airumditioning 

172 Paintiw and Paper Huyinl[ 

1721 Painting and paper hanging 

173 Electrical Work 

1731 ElectricaI work 

SI’ANDARD INDUSTBIAL CLASSIFICATION 

B. MINING 

16 HEAVY CONSTRUCTION, EX. 

BUILDING 

161 Highr~y and Street Conrtruction 

Appendix C-8 - 8w9 NPDES Permit Writers’ Manual 
List of SIC Codes Appendix C 

NUMERICAL LIST OF SHORT TITLZS 

cods short Title 

174 Mamnry, Stonework, and Plsetering 

-1741 Masonry and other stonework 

1742 Plastering, drywall, and insulation 

1743 Terrazzo, tile, marble, moeaic work 

175 Carpentry and Floor Work 

1751 Carpentry work 

1752 Floor laying and floor work, net 

176 Roofing, Siding, and Sheet Metal Work 

cede Short Titk 

177 Concrete Work 

1771 Concrete work 

178 Water WeU Drilling 

1781 Water well drilling 

179 Misc. Special Trade Contractom 

1791 Structural &eel erection 

1793 Glaee and glazing work 

1794 Excavation work 

1795 Wrecking and demolition work 

1796 InstAling building equipment, net 

1761 Booting, siding, and sheet metal work 1799 Special trade contractore, net 

D. MANUF’ACTURING 

CGde Short Titk 

20 

201 

2011 

2013 

2015 

202 

2021 

2022 

2023 

2024 

203 

2032 

2033 

2034 

2036 

2037 

2038 

204 

2041 

2043 

2044 

2046 

2046 

2047 

2048 

206 

2061 

2052 

2053 

206 

2061 

2062 

2063 

2064 

2066 

FOOD AND KINDRED PRODUCTS 

Meat Products 

Meat packing planta 

Saueagea and other prepared meata 

Poultry slaughtering and p&g 

Dairy Producta 

Creamery butter 

Cheeee, natural and proceesed 

Dry, condensed, evaporated producta 

Ice cream and frozen deseerta 

Fluid milk 

Preserved Fruits and Vegetablea 

Canned epecialtiea 

Canned fruita and vegetables 

Dehydrated fruite, vegetablea, soup 

Picklea, naucea. and &ad dreaaingu 

Frown fruits and vegetables 

Frown specialties, net 

Grain Mill Product~~ 

Flour and other gmin mill producta 

Cereal breakfast foods 

RicemilIing 

Prepared flour mixee and doughe 

Wet corn miIling 

Dogandcatfood 

Prepared feeds, net 

Bakery Product0 

Bread, cake, and related products 

Cookies and crackem 

Frozen bakery products, except bread 

Sugar and Confectionery Froducb 

Raw cane sugar 

Cane sugar refining 

Beet sugar 

Candy & other confectionery producte 

ChocoIate and cocoa producta 

2067 

2668 

207 

2074 

2075 

2076 

2077 

2079 

208 

2082 

2083 

2084 

2085 

2086 

2087 

206 

2061 

2092 

2096 Potato chip and similar snacke 

2097 Manufactured ice 

2068 Macaroni and spaghetti 

2099 Food preparations, net 

21 TOBACCO PRODUCT!3 

211 CiglUdbS 

2111 cigarette8 

212 C&F2121 tie213 ChewingandSmoking Tobacco 

2131 Chewing and smoking tobacco 

214 Tobacco Stemming and Redrying 

2141 Tobacco stemming and redryine 

22 TEXTILE MILL PRODUCTS 

221 Broadwoven Fabric Mills, Cotton 

Short Titk 

chewing gum 

Saltedandroaetednutaaadeeeda 

Fata and Oile 

cottoIlwed oil milla 

soybean oil milla 

Vegetable oil mi&, net 

Animal and marine fata and oiIe 

Edible fate and oiIa, net 

Beverage 

Malt beverages 

Malt 

Winea, brandy, and brandy epirite 

Distilled and blended liquora 

Bottled and canned eoR drinka 

Flavoring extracta and eyrupe, net 

Misc. Food and Kindred Products 

Canned and cured fish and eeafooda 

Fnxh or frozen prepared fish 

Roasted coffee 

BEpA NPDES Permit Writers’ Manual - Appendix C-9 
Appendix C Llst of SIC coder 

STANDARD INDUSI’FUAL CLASSIFICATION 

Short Tirk 

2211 Brondwoven fabric mills, cotton 

222 Broadwoven Fabric MiL, Manmade 

2221 Broadwoven fabric mills, manmade 

223 Btiwovcn Fabric Mlllr, Wool 

2231 Sroadwoven fabric mi& wool 

224 Narrow Fabric Mills 

2241 Narrow fabric milla 

225 Knitting Milh 

2251 Women% hoeiery, except socka 

2282 Hoe&y, net 

2253 Knit out8rwear miun 

2254 Knit undeIwear miua 

2257 Weft knit fabric milIa 

2258 I&x & warp knit fabric milla 

2259 Knitting miua net 

226 Textile FinIsNng, Except Wool 

2261 l!bish& plant& cotton 

2262 Fidhing planta. manmade 

2266 Fihhing plants. net 

227 CupetmandlGum 

2273 Carpetaandnagn 

228 Yarn and Thread Yillr 

2281 Yarnappinnine mi& 

2232 Thmwingandwindingmi& 

2264 Thrwdmih 

229 MimU~eow Textile coodr 

2296 Cited fahriu, not rubbe2296 TlNcordMdfabria 

2267 Nonwovmfahriu 

2268 cordqpMdtwiw 

2269 Textilogoodm, nac 

23 APPAREL AND OTHER TEXTILE 

PlZODUCl’S 

231 Mcn'r ud Bon S&J and Coata 

2311 Men’m and boya’ m&m and coati 

232 Mca’m and Boym’ Fumkahingm 

2321 Men’r And boyd mhiru 

2322 MM’8&boydun&nrwr&nightrrsu 

2323 bfan’r and boya’ neckwear 

2325 Mdr and bon tro- and lledu 

2326 MM’B and boyd work cIotNng 

2329 Men’randboye’cl&hing,nec 

223 Women’8 and Mha’ Outerweu 

2331 Women’s & mimm’ blow & ahirta 

2336 Women’r, junim’, & ti dreacm 

2337 Women’r and miwm’ mite and coati 

2336 WomM’r and w outerweu. net 

234 Women’r and Chlldren’r Undergumentr 

2341 Woman’s and childnm’n underwuar 

2342 Brae, girdlee, and allied garmenti 

235 Hats, Cape, and Millinery 

2353 Hats, caps, and millinery 

chde Short Titk 

236 

2361 

2366 

237 

2371 

238 

2381 

2384 

24 

241 

2411 

242 

2421 

2426 

2426 

243 

2431 

2434 

2435 

2436 

2436 

244 

2441 

2448 

2449 

245 

2451 

2452 

249 

2491 

2463 

2499 

26 FuRNITuREANDFlxTuRBs 

261 Howhold FurNtum 

2511 Woodhouaehold furniture 

2512 Upholmterqi houeehold furuiture 

2614 Metal houeehold furniture 

Girla’ and Children’s Outerwear 

Girb’ & chiidren’r dreww, bloom 

Girld and childrem’r outernear. net 

Furcoodl 

hgoodr 

Mimellaneour Apparel and Accewoda 

Fabric drem and work glow 

Robeeanddreauinggowna 

Waterproof outmw4ar 

Leather and sheeplimd clothing 

Apparel belta 

Apparel and acwworim net 

MISC. Fmbriated Textile Producta 

Curtain and draperiem 

Houmw net 

Textile bago 

tl%uwM and related producte 

Pleating and etitching 

Automotive and apparel trimminga 

Schiffli machine embroideriem 

Fabricated textile producta, net 

LUMBER AND WOOD PRODUCE3 

Lonfnl 

hall 

Sawmilla and Plming MU& 

SnwmUIe and planing millr, general 

Hardwood dime&on & flooring mills 

!3pecialpKlductuwmill&nec 

Millwo~ Plywood & Smural Meah 

bfihork 

wood Ntchen CabiJlota 

Hudwood veneer and plywood 

Softwood venwr and plywood 

Structural wood member net 

Wood ConNailed wood boxw and ahook 

Woodpdetaandrkidr 

Wood conbinen, net 

Wood Buildinge and MoNk Homa 

Mobih homea 

Prefabriatedwoodbuildingm 

MlrccuMeoIu wood Producta 

wood pmmving 

RwoMtitutad wood productJ 

Wood produ* nw 

Appendix C-10 - 8Ep# NPDES Permit Writers’ Manual 
List of SIC Codes Appendix C 

NUMERICAL LIST OF SHORT TITLSS 

cbdf Short Titk 

2515 Mattreww and bedspringa 

2517 Wood TV and radio cabineta 

2519 Houeehold furniture, net 

252 Office Furniture 

2521 wood office furniture 

2522 Oflice fimiture, except wood 

253 Public Building & Related Furniture 

2531 Public building & related furniture 

254 Partitiona and Fixturea 

2541 Wood partitione and tkturea 

2542 Partitions and fixtures. except wood 

259 Mlacellaneour Furniture and Flxturee 

2591 Drapery hardware k blinda & ahad25% Furniture and fixturee, net 

26 PAPER AND ALLIED PRODUCTS 

261 Pulp Mlllr 

2611 PUlpUlilb 

262 Paper Milla 

2621 Paper miIL3 

263 Paperboard MlUn 

2631 Paperbaud mill&i 

265 Paperboard ConWnem and Boxes 

2652 Setup paperboard boxes 

2653 Corrugated and solid fiber boxes 

2655 Fiber cana, druma 8 eimihr products 

2656 Sanitary food containem 

2657 Fokling paperboard boxm 

267 MISC. Converted Paper Pruductr 

2671 Paper conted 8 Laminated, packaging 

2672 Paper coated and laminated, net 

2673 Baga: plaetia6 I aminated, & coatad 

2674 Baga: uncontd paper & multiwall 

2676 D&cut paper and bonrd 

2676 Sanitary paper producta 

2677 E?lVdOpW 

2678 Stationery producta 

2679 Convertad paper producta, net 

27 PRINTING AND PUBLISHING 

271 Newrpapem 

2711 Ne=vwm 

272 Perludl& 

2721 Periodicale 

273 Book8 

2731 Book publiahlng 

2732 Book printing 

274 Mluellaneow Publthlng 

2741 MiecelIaneoua publiehing 

276 commerc~PrlntlIlg 

2752 commercial printing* Iithoglnphic 

2754 t3mtnorclal printing, gravure 

co& Short ZWk 

2759 Commercial printing, net 

276 ManlfoId Burlnew Forma 

2761 Manifoid bueinea, forma 

277 Greeting cuds 

2771 Greeting cards 

‘278 Blankbuuka and Bookbinding 

2782 Blankboob and looeeleaf bindern 

2789 5ookblndlng and related work 

279 Prlntlng Trade Servicw 

2791 Typeestting 

27% Platemaking oervicea 

28 CHEMICALS AND ALIJRD PROD 

281 Indurtrlal Inorganic Chemlaia 

2812 Alkalies and chlorine 

2813 Imhhial gwee 

2816 Inorganic pigmentr 

2819 Industrial inorganic chemicals, net 

282 Pla&er Materida and Synthetica 

2821 PIaatica materials and maina 

2822 Synthetic rubber 

2823 Cdlulaxic manmade fibera 

2824 Organic fibers, noncA.luloeic 

283 Drulr 

2833 Medicinala and botanicala 

2834 F%anmceutical preparatione 

2835 Diagno6ticaubetanceo 

2836 Bioklgicai praducta WC. diagno6tic 

284 Soap, Cleanem. and Tollet Gaoda 

2841 Soap and other detergenta 

2842 PoIiehea and sanitation goods 

2843 Surface active agent8 

2644 Toilet preparationa 

285 Fwnta and Allied Produttr 

2851 Paints and allied producta 

2% lndustrl~ Organic ChemiaIr 

2861 Gum and wood chemicale 

2885 Cyclic crudee and intermediatee 

2869 Induetrial organic chemicaln, net 

287 Agricultuml Chemicala 

2873 Nitmgenoue ferfikem 

2874 Phwphatic fertiIizem 

2876 Fertilizem, mixing only 

2879 AgricuItuml chemicab, net 

289 MlmxUaneuw Chemkal Pruduct~ 

2891 Adhwivw and oe&nta 

2892 ExphiveN 

2893 printing ink 

2895 Carbon black 

28% Chemical preparation net 

IU( 

6HY4 NPDES Permit Writers’ Manual - Appendlx C-11 
Llst of SIC coder 

STANDARD INDUSTRIAL CLASSIFICATION 

cob She+? Titk GTde Short Titk 

29 PETROLEUM AND COAL PRODUClg 

291 Petroleum Refining 

2911 Petroleum refining 

296 bphalt Paving and Roofing Materials 

2951 Aephalt paving mixturea and blocb 

2952 Asphalt felb and coatinge 

2% Misc. Petroleum and Coal Productr 

2992 Lubricating oils and greases 

2999 Petroleum and coal products, net 

30 

301 

3011 

302 

3021 

306 

3062 

3063 

306 

3061 

3069 

368 

3081 

3082 

3083 

3084 

3086 

3086 

3087 

3083 

3089 

RUBBER AND MISC. PLASTICS 

PRODUCIg 

Tlru and Inner Tuber 

Tim and inner tubee 

Rubber and PIutica Footwear 

Rubber and plaatica footwear 

How 8 Belting 8 Gaaketa & Packing 

Rubber 6 plaatia hose 8 belting 

Gaaketa, packing and sealing devices 

Fahrlcatd Ruhher Products. NEC 

Mechanical rubber goode 

Fabricated rubber products. not 

Mlacellaneour Plaatia Producta. NEC 

Unsupported plastics film 8 eheet 

Unsupported plastics profile &apes 

Laminated plnatica plate & sheet 

PlaetiaI pipe 

Plaetica bottlee 

Plantice foam pmducte 

Cwtom compound purchased reaim~ 

Plea&a plumbing tirturee 

Plestica producte, net 

32 STONE. CLAY, AND GLASS PRODIJ~ 

321 Flat Gla~ 

3211 Fiat gb 

322 Glad and Glaxeware. Preseed or Blow,, 

3221 Glam containere 

3229 Preaed and blown gti net 

323 Producte of Purchased Glau 

3231 Producta of purchased glam 

324 Comenf HydrmuUc 

3241 Cement, hydraulic 

325 Stntcturd Clay Productr 

3251 Brick and etructural clay tile 

3253 C!emmic wall and floor tile 

3255 Chy-rim 

3259 structulnl day produ* net 

326 Pottery and Related Productr 

3261 Vitreoue plumbing fixturw 

2262 Vitreous china table 6 kitchenware 

3263 Semivitreous table & kitchenware 

3264 Porcelain electrical euppliw 

3269 Pottery producta, net 

327 Concrete, Gyprum, and Plaster Prod3271 Concrete block and brick 

3272 Concrete pro&%, net 

3273 Fteady-mixed concrete 

3274 Lime 

31 LEATHER AND LEATHER PRODUCTS 

311 Leather Tanning and Finishing 

3111 Leather tanning and ii&hing 

313 Footwear Cut Stock 

3131 Footwear cut stock 

314 Footwear, Except Rubber 

3142 House slippers 

3143 Men’8 footwear, excapt athletic 

3144 Women’8 footwear, except athletic 

3149 Footwear, excapt rubber, net 

315 Leather Glovee and Mlttenn 

3151 Leather glovw and mittma 

316 Lwmw 

3161 Luegaee 

317 Handbags and Personal Leather w 

3171 Women’r handhagn and purses 

3172 Personal leather gm net 

319 Leather Goode, NEC 

31% Leather goode. net 

3276 Gypmm pruductd 

328 Cut Stone and Stone Productr 

3281 Cut atone and stone products 

329 Misc. NonmetaUic Mineral Product 

3291 Abtive productd 

3292 Aabc&crproducta 

3296 Minerakgroundortreakd 

3296 Mineralwool 

3297 Nonclay re&actoriea 

3299 Nonmetallic mineral products, net 

33 PRIMARY METAL INDUSTRIES 

331 Blut Furnace and Basic Steel Prod3312 Blaet fumaceu and et.& milla 

3313 Electrometallurgical producta 

3315 Steel wire and related producta 

3316 Cold t&ehing of &eel ehapea 

3317 Steel pipe and tubw 

332 Iron and Steel FoundrIa 

3321 Gray and ductile iron foundries 

3322 Malleable iron foundriee 

3324 Steal inveetment foundries 

3325 Steel found&q not 

333 FWmuy Nonfermur Met& 

3331 Primary copper 

3324 Primaryahlminum 

Appendix C-12 - iiEl% NPDES Permit Writers’ Manual 
List of SIC Codes Appendix C 

NUMERICAL IJSF OF SHORT TTIZES 

cbde short Tide 

3339 Primary nonfermua metale, net 

334 Secondary Nonferrow Metals 

3341 Secondary nonfermus metals 

335 Nonferrous Rolling and Dewing 

3351 Copper rolling end drawing 

3353 Aluminum eheet, plate, and foil 

3354 Aluminum extruded products 

3355 Aluminum rolling and drawing, net 

3356 Nonferrou rolling and drawing, net 

3357 Nonferrous wiredmwing & indating 

336 Nonferrwr Found&a (Camtingm) 

3363 AluJninumdi~tingfl 

3364 Nonferrous diming ext. aluminum 

3365 Aluminum foundriee 

3366 Copper found&s 

3369 Nonferrou found&e, net 

339 Miweilaneour Primary Metal Producb 

3398 Metal heat treating 

3399 Primary metal producb, net 

34 

341 

3411 

3412 

342 

3421 

3423 

3425 

3429 

343 

3431 

3432 

3433 

344 

3441 

3442 

3443 

3444 

3446 

3448 

3449 

346 

3451 

3452 

346 

3462 

3463 

3465 

3466 

3469 

347 

3471 

WY 

FABRICATED METAL PRODUCT!3 

Metal Cane and Shipping Containem 

Metal cane 

Metal band, druma, and paila 

Cutlery, Handtoolr, and Hardware 

Cutlery 

Hand and edge tools, net 

Saw bladee end bandsawe 

Ha&ram, net 

Plumbing and Hesting, Except Electric 

Metal wnitary ware 

Plumbing tlxture fittingn and trim 

Heating equipment, except electric 

Fabricated Structural Metal Produetr 

Fabricated etructural metal 

Metal doom, wth, and trim 

Fabricated plate work (boiler shops) 

Sheet metal work 

Architectumi metal work 

Prefabricated metal buildingn 

Mlwellaneoua metal work 

Screw Machine Produetr, Bolts, Etc. 

Screw machine producta 

Flolta, nuts, rivets, and waahere 

Metal Forginga and Stunpin 

Iron and steel forginga 

Nonferrous forginge 

Automotive atampinge 

- and closuree 

Metal &*, net 

Metal Services, NEC 

Plating and polu 

Metal coating and allied eervicm 

Glde short nrlc 

348 Ordnance and Acceworiea, NEC 

3482 Small arma ammunition 

3483 Ammunition. ext. for small ~ na: 

3484 SIMUarmS 

3489 Ordnance and acceworiw. net 

349 Misc. Fabricated Metal Productr 

3491 Industrial velvee 

3492 Fluid power valves & hoee fittinga 

3493 Steel spring& except wire 

3494 Valvee and pipe fittingn, net 

3495 wire springa 

3496 Miec. fabricated wire producb 

3497 Metal foil and leaf 

3498 Fabricated pipe and fitiinga 

3499 Fabricated metal products, net 

35 

351 

3511 

3519 

352 

3523 

3524 

363 

3531 

3532 

3633 

3534 

3535 

3636 

3537 

354 

3541 

3542 

3543 

3544 

3545 

3546 

3547 

3548 

3519 

356 

3562 

3663 

3564 

3566 

xi66 

3569 

356 

3581 

3!562 

3563 

INDUSTRIAL MACHINERY AND 

EQUIPMENT 

Rnginee and Turbinea 

Turbinee and turbine generator sets 

Jnternal combustion enginee, net 

Farm and Garden Machintry 

Farm machinery and equipment 

Lnwn and garden equipment 

Construction and Related Machinery 

Construction machinery 

Mining machinery 

Oil and gae field machinery 

Elevators and moving stairwayu 

Conveyore end conveying equipment 

Hoiets. cranea, end monorti 

Industrial trucks end tractors 

Metalworking Machinery 

Machine too4 metal cutting type0 

Machine took metal forming m 

Industrial patterna 

Specialdi~too~jigs&fixtume 

Machine tool acceasoriw 

Powerdriven bandtooln 

Rolling mill machinery 

Welding apperatua 

Metalworking mad&my, net 

special Indurtry Machines 

Textile machinery 

Woodworking machinery 

Paper induetries machinery 

Printing tmdes machinery 

Food producta machinery 

Special industry machinery, net 

General Industrial Macbhmry 

Pumps and pumping equipment 

Ball and roller beaingn 

Air and gas comprewora 

8HY4 NPDES Permit Writers’ Manual - Appendix C-13 
Appemdlx C List of SIC Codes 

STANDARD INDUSTRIAL CLASSIFICATION 

cub short Title 

3564 Biowenr and fans 

3565 Packeging machinery 

3566 Speed changers, drives, and gears 

3567 Industrial fumacea and ovens 

3568 Power tranemieeion equipment, net 

3669 General industrial machinery, net 

357 Computer and Offwe Equipment 

3571 Electronic computers 

3572 Computer etarage devicen 

3575 Computer terminals 

3577 Computer peripheral equipment, net 

3578 calculating and accounting equipment 

3579 Office machines, net 

358 Refrigeration and Service Machinery 

3581 Automatic vending machinea 

3582 Commercial laundry equipment 

3585 Refrigeration and heating equipment 

3586 Meaeuring end dispeneing pumps 

3589 Service induetry machinery, net 

359 Induatriai Machinery, NEC 

2592 Carburetors, pietone, rings. valves 

3593 Fluid power cylinders Q actuators 

3594 Fluid power pumpe and motors 

3596 Scab and balances, ext. laboratory 

3599 Industrial machinery, net 

36 ELJXl’RONIC & OTHER ELECTRIC 

EQUIPMENT 

361 Electric Dirtribution Equipment 

3612 Transformers, except electronic 

3613 Switcbgeeu and nwitchboard apparatus 

362 Electrical Indurtriai Apparatus 

3621 Motors and generators 

3624 Carbon and graphite producta 

3625 Belays end industrial controle 

3629 Electrical industrial apparatus, net 

363 Hourehoid Appiiancee 

3631 Household cooking equipment 

3632 Household refrigerators end freezers 

3633 Household laundry equipment 

3634 Electric housewares and fans 

3635 Houeehold vacuum cleaners 

3639 Household appliances, net 

364 Electric Lighting and Wiring Equipment 

3641 Electric lamps 

3643 Currentcarrying wiring devices 

3644 Noncurrentarrying wiring devices 

3645 Residential lighting futures 

3646 Commercial lighting futures 

3647 Vehicular lighting equipment 

3648 Lighting equipment, net 

365 Household Audio and Video Equipment 

36Sl Household audio end video equipment 

ewe short Title 

3652 Prerecorded records and tapes 

366 cOmmunicatione Equipment 

3661 Telephone and telegraph apparatus 

3663 Radio & TV communications equipment 

3669 Communications equipment, net 

367 Electronic Components and Accessories 

3671 Electron tubee 

3672 Printed circuit boarda 

3674 Semiconductore and related devices 

3675 Electronic capacitors 

3676 Electronic resistors 

3677 Electronic wile and transformers 

3678 Electronic connectam 

3679 Electronic components, net 

369 Mien. Electrical Equipment P Suppiiea 

3691 Storage batteries 

3692 Primary batteries, dry and wet 

3694 Engine electrical equipment 

3695 Magnetic and optical recording medie 

3699 Electrical equipment & eupplies, net 

37 TRANSPORTATION EQUIPMENT 

371 Motor Vehicles and Equipment 

3711 Motor vehicles and car bodies 

3713 Truck and bus bodies 

3714 Motor vehicle parts end accessories 

3715 Truck trailers 

3716 Motor homes 

372 Aircraft and Parts 

3721 Aircraft 

3724 Aircraft engines and engine parts 

3728 Aircraft parta and equipment, net 

373 Ship and Boat Building and Repairing 

3731 Ship building and repairing 

3732 Boat building and repairing 

374 Railroad Equipment 

3743 Railroad equipment 

375 Motorcycles, Bicycles, and Parta 

3751 Motorcycles, bicycles, and parta 

376 Guided Missiles, Space Vehicles, Parta 

3761 Guided miesiies and space vehicles 

3764 Space propulsion units and parts 

3769 Space vehicle equipment, net 

379 Mieceiianeous Transportation Equipment 

3792 Travel trailers end campers 

3795 Tanks and tank components 

3799 Transportation equipment, net 

38 INSTRUMENTS AND RELATED 

PRODUCTS 

381 Search and Navigation Equipment 

3812 Search and navigation equipment 

Appendix C-14 - &EM NPDES Permit Writers’ Manual 
List of SIC Codes Appemdlx C 

NUMERICAL LIST OF SHOWT - 

382 

3821 

3822 

3823 

3824 

3825 

3829 

3827 

3829 

384 

3341 

3842 

5843 

3844 

3845 

385 

3851 

386 

3861 

387 

3873 

shod TiiL 

Meamuring and Controlling Devices 

Laboratory appnmtua and furnitare 

JInvironmentrl controla 

FWcem control inatnunenb 

Fhid meters aad counting devicem 

Imtrumenta to raeasum eiectricity 

AnalytiadiMtrumen~ 

Optical inatrumsnh and lenmm 

Meamuing & controlling devicea, net 

Medial I natnunenta and Sapplke 

Surgical and medical i&name& 

Surgical appliancea and applier 

Dental equipment and ruppiia 

X-my apparahu and tuba 

Electromedicalequipment 

0pMllahic Gooda 

w-cgoodr 

Phot@graphk Equipment and Smppltu 

Photographic equipment and ruppliee 

watcilea, CIock#. watchccws P Parta 

Watch cloc4 watchcaea & puts 

E. TRANSPORTATION 

co6 SAOH Titk 

40 RAILROAD TRANSPORTATION 

401 Raumdm 

4011 Raamad& Ulle&aul oper8tiag 

4013 switching and telrmiMl memicem 

41 

411 

4111 

4119 

412 

4121 

413 

41Sl 

414 

4141 

4142 

415 

4151 

417 

417a 

LOCALANDINTERURBAN 

PASSENGER TRANSIT 

LoaIandsubarhMTraM~ 

Laalmd NburbantmMit 

-P-wm t=nwrtdolb MC 

Tariclrhr 

Inter&y and Rnrai Blu -t&a 

IIlWCi~&lldbUhMpOdtiM 

Bru Charter Service 

Local bu chador emvice 

B~-KWIi~sxcsptloal 

Sehooi Bw 

School bw 

Bur Terminai and &mica FadMa 

Blmwmlidandearv&eAND PUBLIC UTILITIES 

code shm Title 

42 TRUCKING AMI WAREHOUSING 

421 Trucking 8 Courier Serricee, Es. Air 

4212 m trucking, without storage 

4213 Trucking, excapt iocai 

4214 Local trucking with atom@ 

4215 Courier oervicen, except by air 

422 Public Wamhourlng and Storyc 

4221 Farm product warehousing and tire@ 

4222 Refrigemted warehousing and timge 

1226 General warehoming and etorage 

4228 Special wamhouming and storage, net 

U3 Trucking Termtnai F~ciIitiea 

4231 Tbwking tarmid facilith 

43 U.S. POSTAL SERVICE 

431 U.S. Poetai Service 

4311 U.S. PoEtal Service 

44 WATER TRANSPORTATION 

441 IkepSuForelgnTmm.ofFm~t 

4412 Deep maa foreign tmna. of freight 

39 

391 

3911 

3914 

3916 

393 

3931 

394 

3942 

3944 

3949 

396 

3961 

3952 

3953 

3955 

396 

3201 

3965 

399 

3991 

3993 

3995 

3996 

3999 

Short Titk 

MISCELLANEOUS MANUFACI’URING 

INDUSTRIES 

Jewelry, Silverware, and Plated Ware 

Jewelry, precious wtai 

Silverware and plated ware 

Jewelem’ materials % lapidary work 

Murical Inatrumente 

Mu&al instrumenta 

Toy and Spoting Goode 

Dolla and stuffed toys 

Game, toys, and children’r vehici~ 

Sporting and athletic gooda, net 

Pens, Pencii~ OffIce. 8 Art Supplke 

Pens and mechanical pen& 

Leadpencilsandartgooda 

Marking devicee 

Carbon paper and inked ribbons 

Cootume Jewelry and Notiona 

costume Meti 

Fastenen buttons, needlee, & ph 

Mhcelhneoua Mulufutluu 

Brooma and brush 

Sigm and advertising qcialitiea 

Burial caakeh 

Hard aurface floor cove- net 

Manufacturing induutriw, net 

8EY4 NPDES Permit Writers’ Manual - Appendix C-15 
Appemdlx C List of SIC Codes 

STANDARD INDUSTRIAL CLASSIFICATION 

Cd Short Titk code Short Rtk 

442 

4424 

443 

.4432 

444 

4449 

448 

4481 

4482 

4489 

449 

4491 

4492 

4493 

4499 

Deep Sea Domestic Tmna. of Freight 

Deep sea domestic trans. of freight 

Freight Tmna on the Great Lakes 

Freight trans. on the Great Lakes 

Water Tmnsportation of Freight, NEC 

Water transportation of freight, net 

Water Transportation of Pmnengem 

Deep sea passenger trans.. ex. ferry 

Ferries 

4741 Rental of railroad cara 

478 Misceiisneour Tmnnportation ‘Senicea 

4783 Packing and crating 

4785 Inspection & fixed facilities 

4789 Transportation services, net 

Water passenger transportation, net 

Water Tmnqxwtation Services 

Marine cargo handling 

Towing and tugboat service 

Marinas 

Water transportation services, net 

45 TRANSPORTATION BY AIR 

451 Alr Transportation. Seheduied 

4512 Air transportation, scheduled 

4513 Air courier servicea 

452 Air Transportation. Nonscheduled 

4522 Air transportation, nonscheduled 

458 Airports. Flying Fieidr. & Servicea 

4581 Airports, flying fielda, % servicea 

48 COMMUNICATIONS 

481 Telephone Communkations 

4812 Radiotelephone communications 

4813 Telephone communicationr, ext. radio 

482 Telegraph & Other Communicationa 

4822 Telegraph 8 other communications 

483 Radio and Trievirion Broadcarting 

4832 Radio broadcasting stations 

4833 Television broadcasting stations 

484 Cable and Other Pay TV Services 

4841 Cable and other pay TV services 

489 Communkationr Smkor. NEC 

4899 Communications services, net 

49 

46 PIPELINES, EXCEPT NATURAL GAS 

461 Pipeiineu. Except Nstumi GM 

4612 Crude petroleum pipelines 

4613 Refined petroleum pipelinea 

4619 Pipelinea. net 

47 TRANSPORTATION SERVICES 

472 Panaenger Tmnrportation Arrangement 

4724 Travel agencies 

4725 Tour operators 

4729 Passenger transport arrangement. net 

473 Freighl Tmneportation Arrangement 

4731 Freight transportation arrangement 

474 Rental of Bailroad Cam 

491 

4911 

492 

4922 

4923 

4924 

492s 

493 

4931 

4932 

4939 

494 

4941 

495 

4952 

4953 

4959 

496 

4961 

497 

4971 

ELECTRIC, GAS, AND SANITARY 

SERVICES 

Electric Servicea 

Electric services 

Ga Production and Distribution 

Natural gas transmission 

Gas transmission and diatribution 

Natural gm distribution 

Gas production and/or distribution 

Combination Utility Servicer 

Electric and other aervicee combined 

Gas and other services combined 

Combination utilities, net 

Water Supply 

Water supply 

Sanit8ry Services 

Sewerage systems 

Refuse eystems 

Sanitary servicea. net 

Steam and Air-Conditioning Supply 

Steam and air-conditioning supply 

Irrigation Syrtenu 

Irrigation system8 

F. WHOLESALE TRADE 

code 

50 

561 

Short Tit& 

WHOLESALE TRADE-DURABLE 

GOODS 

Motor Vehicles, Parta. and Suppiiet 

5012 

5013 

5014 

ml, r: 

Automobiles and other motor vehicles 

Mokx vehicle rruppliea and new parts 

Tirea and tubea 

I ““1” Motor vehicle parts. ueed 

Appendix C-16 - aEM NPDES Permit Writers’ Manual 
List of SIC Codes Appendix C 

NUMERICAL LIST OF SHORT TITLEE 

code Short Titk &le ShortTitk 

502 

b921 

5023 

503 

5031 

b932 

5033 

5039 

MU 

5043 

5044 

bo4s 

6040 

6047 

bus 

Fumlture and Homefurnhhinfr 

lhmhlre 

HomeLumkr and Construction Matedah 

Lumber, plywood, and millwork 

Brick atone, 6 related materiaB 

Roofing, siding, 6 innulation 

coMtruction matEriala, IILX 

Profeuional 8 Comnterclal Equipment 

Photqraphic equipment and wppliea 

Office equipment 

Computerq peripheraln & eoftware 

Commercial equipmenk net 

Medical and hoopital equipment 

Ophthalmicgoode 

Profeeaional equipment, net 

Met& and Minerals, Except Petroleum 

Mebla m-vice centere end ofRcer 

Coal end other minerala and oree 

EkCtriUlGoob 

Electrical apparatun and equipment 

Electrical appliancee, TV 6 radioa 

Electronic parta and equipment 

Hudrue, Plumbing ik Henting Equip 

61 

511 

6111 

5112 

6113 

512 

6122 

513 

5131 

5136 

5137 

5139 

514 

5141 

6142 

6148 

5144 

5145 

6146 

5147 

6148 

6149 

615 

US3 

6154 

6159 

616 

6162 

5169 

617 

5171 

6172 

618 

6181 

5182 

519 

6191 

519% 

5193 

5194 

5198 

6199 

WHOLESALE TRADE-NONDURABLE 

GOODS 

Paper and Paper Producti 

Printing and writing paper 

&ationery and office Nppk 

Induntrial & pexnonal service paper 

Da-up, Proprietaries, and Sundrier 

Drugs, proprietaries. and sundries 

Apparel, Piece Goods. and Notiona 

Piece gooda & notions 

Men’s and hoya’ clothing 

Women% and children’r clothing 

Footwear 

Groceriu and Related Producta 

Groceriee, general line 

Packeged froz8n foode 

Dairy productr, ext. dried or canned 

Poultry and poultry producta 

Confectionery 

Fiehandaeafooda 

Meata end meet producta 

Fresh fhita and vegetahlce 

Groceriee and related producta, net 

Farm-Product Raw Materiala 

Gram and field heana 

Livestock 

Farm-product raw materials, net 

Chemkalr and Alkd Producta 

Plaetiw materiala 6 hneic shapee 

CheJmicaln 8 allied producta, net 

Petroleum and Petroleum Producta 

Petroleum bulk stationa % terminala 

Petroleum productd, net 

Beer, Wine, and Dlatilled Beveragea 

Beerandale 

Wine and &tilled beverages 

Mbc. Nondurable coodr 

Farm NpphO 

Booka, periodicale. dr newspapers 

Flowem & floristr’ supplies 

Tobacco and tobacco producta 

Paint& varnish-, end Npplim 

Nondurable m net 

b974 

6076 

607s 

b98 

b982 

5083 

6084 

soab 

b987 

5088 

609 

5091 

b992 

5093 

5094 

5099 

wnt 

Hardware 

Plumbing 6 hydronic heating supplies 

warm air heating k airuulditioning 

Refrigeration equipment and supplies 

Machinery, Equipment, snd SuppUea 

Conetruction and mining machinery 

Farm and garden machinery 

Industrial machinery and equipment 

Industrial auppliee 

Service eotahliahmeat equipment 

Tramportation equipment & ruppliMkeUaneow Durable Goada 

spa* b recreational gwde 

Toyr and ho&y 9oo& and Np&diU 

ScrapandwastemateriaL 

Jewelq 6 precio~ stonea 

Durable gao& aec 

G. RETAIL TRADE 

cob 

52 

SAwt Titlr cod SM Titk 

BUILDING MATEBULB 0 GARDEN 623 Paint, Glaxo, and Wallpaper Storea 

SUPPLIES 6231 Paint, glam, and wallpaper atoree 

521 Lumber and Other Building HaterI& 

6211 Lumber and other building matariah 

625 HardwareStoru 

6251 Hardware atorm 

526 Retail Nurseriu and Garden Storw 

8B94 NPDES Permit Writers’ Manual - Appendix C-17 
Appemdlx C List of SIC Codes 

STANDARD INDUSTRIAL -CATION 

Shad Titk 

5261 Raail numeriea md garden &ma 

527 Mobile Home Dealem 

5271 Mobile home dealen 

53 GENERAL M EXFIANDISE STORES 

531 Department Stores 

5311 Department 8tmw 

533 varietystoreo 

5331 vtietyatma 

539 MIw. GeneraI Mercbandim Storm 

5399 Misc. general merchandlae rtara 

54 FOOD STORES 

b41 Grocery Stores 

5111 Grocarystora 

S42 Meat and Flab Mukete 

b421 Meat and fish marketa 

543 Fruit and Vegetable Mark5431 Fruit and vqptahle marketa 

54.4 Candy, Nut, and cOnfLctlonory Storea 

S441 caady, nuf and confasonery otmw 

545 DairyRoductastorea 

MS1 Dairypmductartolw 

546 RetauBakertea 

S461 Retailh&xia 

519 MisceUaneo~ Food Storea 

5499 MhcelhNouafcodctome 

5s AUTOMOTIVE DEALEHS & SERVICE 

STATIONS 

bbl New and Uaad Car Dealera 

5511 Newandumulcardsalsn 

bst UudcarDealem 

b621 uaedcardeatem 

553 Auto and Home Supply Stora 

5531 Auto and home Np&dy s&rem 

554 Ga~UneSewkeStatio~ 

bb41 GaAine eerviuetdoM 

ssb BoatDeaIera 

bSb1 Bo&dmlen 

554 Rureauonal vcbick Dulen 

bb61 RecrWioMl-m 

bS7 MotorcycIeDeakm 

bb71 M~deaIem 

Sb9 Automotire Deekrm, NEC 

5599 Automotive dealem ntx 

56 APPAHEL AND AccEssoRY sTOHE8 

Wl Men’r & Hop’ clothing Stora 

6611 Men’8 & boy8’ &thing mtora 

562 Women’s tIMbh# storu 

chdi Shad litk 

5621 Women’0 clothing stora 

663 Womtn'r Auxnary & speciauy storea 

5632 Women’r accsmrJr~m~rbrc* 

SM Children’s and Inhata’ Wear Storm 

Si341 Childrw’randinfanff ueuatomm 

666 Fadly ClothIngStoru 

6661 Familyclothingetoree 

566 shoestoru 

5681 shoeatorsl 

S69 Mbe. AppueI & Auu~ry Storu 

5699 Miac.apparel&~at0m 

57 m AND HOlUEFURND3HlN~ 

STORES 

571 Fumlttm and HomdfvnbhinF Stoma 

5712 Fumituroatoru 

5715 Floor -- 

5714 Drapery and upholrtarg mtora 

5719 . . Miac.~etoru 

572 Houmbeld Apphnce 8tomo 

5722 How&old apphance ettme 

573 Itdk& Televlslon, & coapllter stww 

57151 hdio,~,&dectmaiesbrar 

5734 compltsr andaoftmre et0l-u 

5735 Record& ~tape~~ 

5736 Mueicd-tetwU 

58 EATING AND DRINIUNG PLACES 

581 EatingandDriabgpbea 

Sal2 Eatingplaau 

6813 Dhk.ingphcee 

59 MIscELLANEousRET~ 

591 DnlgStoreeMd~~ 

S91t DNgstormandprqm-Y593 Llquorstoru 

S921 uquoretorem 

593 umdM-storu 

smz ueedntedadb594 wralkncorushopp4Goodr5941 Sporthqgocdedbicgclerbop 

5942 Bookatome 

5943 stationaryetora 

6944 Jewelrymtorea 

SW Hohhy,,tq~ixu-rbop 

5946 Camera 6 photuwaphic NPPb done 

5947 Gi novelty, and muuvonir rbop 

5948 Lllggegeendlee~goodr5949 awh&de-h~~ooadr 

696 NonstoreRetdIae 

5961 cat&gandmail+der~ 

b%2 lldrrchrndtinem4chhe~~ 

Appendix C-18 - 8Ep# NPDES Permit Writers’ Manual 
List of SIC Codes Appendix C 

NUMERICAL LJSI’ OF SHORT TITLGS 

cc& Shad Titk Short l!tk 

5963 Direct selling eatabliabmenta 

598 Fuel Dealera 

5962 Fuel oil dealen 

5984 Liquefied petroleum gas dealen 

5989 Fuel dealera net 

H. FINANCE, INSURAN 

ade short ntlc clde Short Titk 

66 

601 

6611 

6619 

662 

6621 

6022 

6029 

603 

6035 

6626 

666 

6661 

6062 

608 

6081 

6982 

609 

6691 

6099 

61 NONDEPOSFFORY INSTITUTIONS 

611 FaderaI h Fed-Sponmored Credit 

6111 Federal & f~rpomored credit 

614 h8Od thdit h8thltiON 

6141 Personal credit imtitutiom 

615 Burineas Credit Inatituthu 

(lb2 shortterm bu#iNN credit 

6159 M&c. buainem credit lMtitlltioM 

616 Mortgage Bankerr and Brokera 

6162 Mortgage banken and arrapondenta 

6162 Loan brokers 

DEPOSITORY INSTITUTIONS 

ContraI Itemme DepoeUoriu 

Federal reeomebanka 

Central maem depoeitory, net 

Commercial Banka 

National commercial bankn 

state commercial banh 

c!ommerclalbank&Nc 

&Vhl~ hthltiON 

Federal wings institution 

savingn iMtltuti0~ except federal 

crdit Unionr 

Federal credit uniona 

state credit uni0M 

Foni6n Bank & Branches It Agencka 

Foreign bank 6 bran&w & agencies 

Foreign tra& & intemational bank 

FunctloN cIooe~y Related to BankIng 

Nondepoait true& facilitia 

Functi0M related to depult banking 

62 SECURITY AND COMMODITY 

BROKERS 

621 5kcurity Brokem and De&m 

6211 Security hoken and dualem 

622 Cmundity Cmtmcta Brokers, Do&n 

6221 commodity contracta brokem, cbalm 

62s secwityandcemmodityExchMgol 

599 RetaiIstorc!a,NEc 

5992 Fhrista 

5993 Tdmcco storss and otanda 

5994 New dealen and neuntandm 

5995 Optical gooda tirea 

5999 hfiacellaneoua rehil atma, net 

E, AND REAL ESTATE 

6221 Security and commodity exchanga 

628 Security and Caumodity Semicee 

6282 Invastment advice 

6289 security & ccamdlty mrvicee, net 

63 

621 

6211 

632 

6221 

6324 

655 

6221 

635 

6261 

aa6 

6261 

637 

6271 

639 

6399 

64 

641 

6411 

6s 

ii:2 

6612 

6614 

6616 

6617 

6619 

653 

6621 

654 

6641 

665 

INSURANCE cAIuuERs 

Life huurmce 

Life ineurance 

Medial Serrkc and Heatth Inmuruwe 

Amidentandhealtb inmuance 

HoqGtal and medical em-vice plana 

Fire, Marine,and CuuaIty Inmrance 

F’ire. marine, and cuuale inmuanm 

-WI-- 

suretyirlNram 

mtk InNrance 

Title insurance 

Pension, He&k, and Welfare Fun& 

Pemion, health, and welfare fun& 

In8umnceC.anlerr,NEC 

INurance -NC 

INSURANCE AGENI’S. BROXERS, It 

SERVICE 

ha- Agents, Broken, & serrice 

INuranceagMtr,broke~&lervics 

REAL ESTATE 

ReaIEatateoperatmandLueora 

Nonmmidential buildin operaton 

Apartment Mlding operaton 

DweUing operas ext. apattmenta 

Mobile home site operaton 

Raihmdproputyla8oN 

Real prom lomom net 

Red Eatate Agenta and Mamgerr 

Rsalatata~fqandwqprm 

Title Abetract OfRue 

TitIeabetMctofEwa 

s8bdlvl&rmandDevelopem 

8ER9 NPDES Permit Writers’ Manual - Appendix C-19 
Appemdlx C List of SIC Codes 

SMNDARD INDUSlWAL CLASSIFICATION 

CbdI? short luk Short Titk 

6552 Subdividers and developera, net 

ass3 Cemetery subdividers and developens 

67 

671 

6712 

6719 

672 

HOLDING AND OTHER INVESTMENT 

OFFICES 

Holding Of!‘icee 

Bank holding companiee 

Holding compauiea, net 

Inre8tment Officea 

6722 Manage.ment inveetmenf openand 

6726 Investment officeu, net 

673 Tnuta 

6732 Educational, religious, etc. trueta 

6733 TlutJt&Nc 

679 MkceUa~~ua Invuting 

6792 Oil royalty tradem 

6794 Patent owners and 1-m 

6798 Real eatata imwtment truete 

6799 lnveetom, ncnz 

I. SERVICES 

cd4 Short Titk ewe short 7-d 

70 HOTELS AND OTHJZRLOJMXNG 

PLACES 

701 Hot& and Motela 

7011 Hot& and mot& 

702 Rooming and Boudhu How 

7021 Roomin6andhaudin6houma 

703 Campa and IkcreaUonaI Vehkk Parke 

7032 Spxting and mcreational campm 

7033 Traikr parka and canpita 

704 MembenNpBaaia OrganhUon Hotek 

7641 Membernhip-baaia organization hot& 

72 

721 

7211 

7212 

7213 

7215 

7216 

7217 

7218 

7219 

722 

7221 

723 

7231 

724 

7241 

725 

7251 

726 

7261 

729 

7291 

PERSONAL SERVICES 

Laundry, Ckaning, 0 Garment Servkea 

Power laundrieq family & commercial 

Garment preaaing & cleanem’ agenta 

Linen eupply 

Coinaperated laundries and clenning 

Dryclegnine plants, e-pt rug 

carpet and upholewy cleaning 

Induetxial launderer 

Iaundry and garment mrviceq net 

Photographic Studioe, Portrait 

PhobgrapNc atudioe, portrait 

Beauty Shape 

B-J@ bP 

Barber sbope 

Barber ahope 

Shoe Rep& and Shoe&no Won 

Shoe repair and shoe&no parlon 

Funeral Semke and Crematorka 

FUN& mrviceandcrematoriu 

Mkceuaneow Permnml Senku 

Tax return preparation eeti 

73 BUSINESS SERVICES 

731 Adverti& 

7311 Ad* egenti 

7312 outdooradvertleingeenricu 

7313 Radia TV, publieher repreaentativee 

7319 Adwrti&g, net 

732 Credit I&porting and Mktion 

7322 &wtment h collection eervicee 

7323 credit reporting oervicee 

733 MaUlng, Reproduction, Steno6rapNc 

7331 Directmailadvertkingeervicu 

7334 Photocopying 6 duplicating nerviceu 

7336 Commercial photugraphy 

7336 Commercial art and graphic deign 

7338 9ecretarial&courtrepoIting 

734 Swvkm to Buildinp 

7342 Dininfecting & peet control awviom 

7349 Buildingmaintenancaaerv&a, net 

736 WK. Equipment Rent8lL Lculng 

7862 Me&al equipment rental 

7363 Heavy con&u&ion equipment rental 

7369 Equipment rental & kaslng, net 

736 Penonnel Supply ServIcea 

7361 Employment age&e8 

7363 Help NpPly oerviwe 

737 CamputerandDataFkceuh6Servicea 

7371 Computer progpmmhq aemicea 

7372 h-- 

7371 computerintegratedayetemadeaign 

7374 Data prlxmdg and preparation 

7376 Information I-et&d aerviceo 

7376 Computer facilitk management 

7377 Cbmputer rental 6 kaidng 

7378 computermainteNnce&repair 

7379 computerroktdee~nec 

738 MircdlunoIUB~&rrkcr 

7299 mpelaonal mnec 7381 Detactlvedrarmomdcarmrviceo 

Appendix C-20 - 8HY4 NPDES Permit Writers’ Manual 
List of SIC Codes Appemdlx C 

NUMRRICAL LIST OF SHORT TITLES 

code Shod Tit& 

7382 seNrityayatememrviwa 

7383 New~ayndicateo 

7384 Plloto~ kboratorlea 

7389 Bueinm eervkm, net 

7s 

751 

7513 

7514 

7615 

7519 

752 

7521 

763 

7632 

7633 

7634 

7636 

7637 

7638 

764 

7642 

7649 

76 MI8cELLANEous REPAIR SERVIC 

762 Electrtai Repair Shop 

7622 Radio and t&&ion repair 

7623 hfkigemtion eervice and repair 

7629 Ekctrical repair shop& NC 

763 Watch, Clock, and Jewelry Repair 

7631 Watch, clock andjewehy repair 

764 ReuphoWery and F’urniture Rep& 

7641 ReuphoWny and furniture repair 

769 MiacelkNoue Repair shop 

7692 Welding repeir 

7694 Armatumrewindingahope 

7699 Repair rem net 

78 MOTION PKI’URES 

781 Motion Picture Pruductiun & &r&a 

7812 Motion picture & video production 

7819 Servica allkd to motion picturea 

782 Motion Pktwe Distribution & ServIcea 

7822 Motion picture and tape diet&&ion 

7829 Motion picture distribution eervicae 

783 Motion Pkture Tbeatera 

7832 Motion picture the&em, ex driv&n 

7833 DrivGn motion picture theaten 

784 Video Tape Rental 

7841 Video tape re&al 

AUTO REPAIR, SERVICES, AND 

PARKING 

Automotive Rentals, No Drlvera 

Truck rental and leesing, no driven 

Pemenger car rental 

Pemenger car leasing 

Utility trailer rental 

Automobile Puklng 

Automobile parking 

Automotive Repair Shopr 

Top & body repair 6 paint shop 

Autoexhauetqstemrepalrohope 

Tire retreading aad repair ehopo 

Automotive glam replacement ahope 

Automotive trammbbn repair ahope 

General automotive repair shop0 

Automotive repair Bhope, net 

AutomotIve Services, Except Repair 

Canvaahea 

Automotive aeeRiasr, net 

79 

791 

7911 

792 

7922 

7929 

793 

7933 

794 

7941 

7948 

799 

7991 

7992 

7993 

7996 

7997 

7999 

86 

991 

6011 

892 

8621 

803 

8031 

864 

8941 

8642 

8643 

8649 

806 

89bl 

8662 

81 LEGAL SERVICES 

811 wsuriShort Titk 

AMIJSEMJDJT & RECREATION 

SERVICES 

Dance Stdhor, Schoola, and Halla 

Dance atudioo, echo&, end halls 

Roduccn, Orchestms, Entertainerr 

Theatrical producem and eervicsu 

Entertainers & entertainment group 

BowlinE Centerr 

Bowling centers 

conuNrclal sporta 

Sport0 cl& manegem & promotera 

Racing, including track operation 

Mkt. Amwment, Recrecrtion Servicea 

Phydall fitneae facilitk 

Public golf coumw 

Coinqeratad amusement devicea 

Amueement parka 

Membemhip eporta dr recreation cluba 

Amueement and recreation, net 

HEALTII SERVICES 

Offkea % Clink-~ of Medkal Doetorr 

OfBcea 6 clinica of medical doctor 

OfIke@ and ClInka of Dentista 

Offlceu and clinkx of dentieta 

ofncea of oateopathk Physician0 

Oflicea of cmteopathic physicians 

Off&a of Other Be&h Pmctitionvr 

Officeeandcliniceofchiropracto~ 

OfBcm and clinica of optometrL& 

Ollicee and clinica of podiatriata 

Of&m of health practitioners, net 

Nuraing and Puronal Cue FaciUtka 

Skilled nurhg care facilities 

Intmmediate care facilities 

Nursing and pemonal care, net 

HoepIt& 

General medical & rurgical hcmpitale 

Puychiatric hcepitale 

Specialty hcopitale ext. peychiatric 

Medkal and Dental Laboratories 

Medical laboratorice 

Dental khorat.oriee 

Home Health Cue Services 

Home health care eervicer 

Health and Allled Servicea, NEC 

Kidney dialpie centera 

Specialty outpatient clinim net 

Health and allied eervicee, net 

0EM NPDES Permit Writers’ Manual - Appendix C-21 
Appsndlx C List of SIC 423des 

8111 

82 EDUCATIONAL SERVICES 

821 Elementary and Secomdary fkhoob 

8211 Elemenbry and eecondary rlmola 

822 Collegea and Unirenitk 

8221 Collegea and univemiticm 

8222 Junior collegea 

823 LIbruIea 

8231 Libraria 

824 Voathal &ho& 

8243 Data prowabg achoola 

8244 Bwimmandmmtuial&mola 

8249 Vocational rho04 rmc 

a29 Schoob & Educational Sewku, NEC 

8299 Schoob & educatio~I eemicm net 

8a SOCIAL SERVICES 

8a2 Indhldual and Family Servka 

8822 Individual and family aervicea 

833 JobTmIaIngandRektaIServkea 

8531 Jobtminingandrelntulmrvka 

83s ChildDa~CueSewica 

8361 chllddayare#emicao 

8s6 Residential Care 

8361 Eeoidentiall 

a39 SOCklSUVkU,NEC 

8s99 Socialeemiceenec 

84 

841 

8412 

842 

8422 

86 MRMBERSHIP ORGANIZATION6 

891 BU#k#8- 

STANDARD INDU- -CATION 

ShvtlUk 

Legal eervicea 

MUSEUMS, BOTANIC& ZOOLOGICAL 

GARDENS 

M-MdMGti 

Muaeuma and art galkim 

Botankal and ZooktgkaI Gardena 

BatudaIradzoologicalgudam 

8611 Busincaaamcidio~ 

a62 Profeuional org8niz8tioar 

8921 Profeamional org8nizatioaa 

a63 Labor Organlxationa 

8931 Labor organimtione 

864 Clvk and Social -ona 

8941 Civic and mcial amociatioly 

a65 PditiaI OrgmtmuoIm 

9961 Politial orgmizatiolu 

866 Rellghu organbatkne 

8661 Religiouaorganimtjone 

869 MembenNp oIXd=thM. l’!Ec 

8699 Membemhip organimtio~, mc 

a7 

871 

8711 

8712 

8713 

872 

8721 

87s 

8731 

8732 

8733 

8734 

874 

8741 

8742 

874a 

8744 

8748 

88 PRIVATE HOUSEROLDS 

881 P~ImteHoweholdm 

8811 Private houwholda 

89 

899 

8999 

short ZXtk 

ENGINEERING & MANAGEIKRNF 

SERVICES 

Engineering & Arc- Servku 

EngiNeringeemicea 

Architectuml eexvica 

z3umyhgaerviwe 

Accomtirl. Auditinr. & -bE 

Accounting, auditing, & B 

Raearch and Testing &rhea 

-m5alphynkalmwuch 

Commmkl nonphysical ramrch 

Noncommerckl raearch organizationa 

Testinglabomtoria 

bnagement and Publk Rehtioea 

Mmmgcment mwicaa 

Mnnqpment coxmlting aemica 

PubucraIationaaervicee 

FaciIitkeNpp&amicee 

BusineNcoNultlng, lla 

SERVICRS, NRC 

EizE 

J. PUBLIC ADMINISTRATION 

ad8 Shd ?itk 

91 EXECUTIYE, LEGISLATIVE, AND 9121 Le&lative bodia 

GENERAL 913 Executive and Le&lathe hnbinad 

911 Executive Ofku 9121 Executiva and lagaativa cunmad 

9111 Rmcutive ofBaa B19 GenemI GomrnmefIt, NRC 

912 LegM8kive Bodies 9199 General govenunent, ant 

Appendix C-22 - 88# NPDES Permit Writers’ Manual 
NUMERICAL LIST OF SHORT TITLES 

GJde 

92 

921 

9211 

922 

9221 

9222 

922s 

9224 

9229 

93 

931 

9511 

94 

941 

9411 

943 

9431 

944 

9441 

945 

9451 

99 

short lb& 

JUSTICE, PUBLIC ORDER, AND 

SAFETY 

courtl 

COUltd 

Public Order and Safety 

Police protection 

Legal counsel and proeecution 

C4xmxtional institutions 

Fire protection 

Public order and safety, net 

FINANCE, TAXATION, % MONETARY 

POLICY 

Finance, Taxation. & Monetary Policy 

Finance, taxation, & monetary policy 

ADMINKSRATION OF HUMAN 

RESOURCES 

Admin. of Educational Prom 

Admin. of educational programa 

Admin. of Public Health Progmnu 

Admin. of public health programs 

Admin. of Social % Manpower w 

Admin. of social% manpower programa 

AdmInlrtratlon of Veterun Affairs 

Administration of veterans affain 

code 

96 

961 

9611 

9512 

953 

9521 

9652 

96 

961 

%11 

962 

9621 

953 

9621 

464 

9641 

%5 

%51 

966 

9661 

97 

971 

9711 

972 

9721 

short Titl4 

ENVIRONMENTAL QUALITY AND 

HOUSING 

Environmental Quality 

Air, water, 6% solid we& management 

Land. mineral, wildlife conemvation 

Housing and Urban Development 

Howine PW 

Urban and community development 

ADMlNISTRATION OF ECONOMIC 

PROCRAMS 

Admin. of General Economic Rgiuu 

Admin. of general economic pmgranx~ 

Regulation, Admin. of Trawportation 

Fkgulation, admin. of traneportation 

Reguhtlon, Admin. of Utilitia 

Regulation, admin. of utilitia 

Reguhtion of Agricultural Marketing 

Regulation of agricultural marketing 

Regulation Misc. Commercial Seetorn 

Regulation mhc. commercial mcbm 

Space Reearch and Technology 

Space reeearch and tachnologp 

NATIONAL SECUlU’i’Y AND INTL. 

AFFAIRS 

National Security 

National mcurity 

International Main 

International &aim 

K. NONCLASSIFIABLE ESTABLISHMENTS 

short iwe 

NONCIASSIFL’DLE 

ESTABLISHMEIVR 

ckdl short nsh 

9999 NonclamiBable e&abliehmenti 

999 Nonelaa&flable Eatablirhmenta I 

8ElY4 NPDES Permit Writers’ Manual - Appendix C-23 
Appendix D 

How to Obtain Additional 

EPA Documents 
How to Obtain Additional EPA Documents Appendix D 

HOW TO OBTAIN ADDITIONAL EPA PUBLICATIONS AND GUIDANCE 

Throughout the NPDES Permit Writers Manual, citations to supplementary guidance 

materials available from U.S. EPA are provided as footnotes. Where available, these 

documents are distributed free of charge through the EPA Office of Water Resource 

Center (WRC). The WRC distributes one free copy of each publication to each 

customer until supplies are depleted. The address and telephone number for the WRC 

are provided below (see information for the Office of Wastewater Management Catalog 

of Publications). When the WRC’s supply of documents is depleted, requestors are 

referred to either the National Technical Information Service (NTIS) or the Educational 

Resources Information Center (ERIC). Information on how to order documents from 

NTIS and ERIC is provided in the following pages. 

Another important source of information regarding EPA publications is the National 

Center for Environmental Publications and Information (NCEPI). NCEPI is a central 

repository for all EPA documents, with over 5,500 titles in paper and/or electronic 

format available for distribution. In addition to NCEPI, EPA maintains numerous 

bulletin boards and “hotlines” which provide information on specific subjects, (e.g., 

Radon or Pollution Prevention). 

In addition to the materials cited in the manual, EPA has developed numerous guidance 

and reference documents that may also support permit writers in developing NPDES 

permits. Although the list of available guidance is too voluminous to include in this 

Permit Writers’ Manual, a comprehensive list of supplementary documents is available 

through EPA. Of particular interest to NPDES permit writers, the EPA Office of 

Wastewater Management (OWM), and the Office of Science and Technology (OST) 

publish catalogs of available publications. Information on how to obtain these catalogs 

is provided below. 

1. Off ice of Wastewater Management 

Catalog of Publications 

EPA 830/B-96-001 

Copies of this catalog are available [at no cost) by writing, calling, faxing, or 

emailing: 

U.S. Environmental Protection Agency 

Office of Water Resource Center 

RC-4100 

401 M Street S.W. 

Washington, DC 20460 

(202) 260-7786 [Voice mail publication request line] 

(202) 260-0386 [Fax] 

Email: waterpubs@epamail.epa.gov 

EPA NPDES Permit Writers’ Manual - Appendix D-1 
Appendix D How to Obtain Additional EPA Documents 

2. Office of Science and Technology 

1996 Publications Catalog 

Available on-line through EPA’s Office of Water Homepage 

[http://www.epa.gov/watrhome/pubs.html] 

Or, call or write: 

US. Environmental Protection Agency 

National Center for Environmental Publications and Information (NCEPI) 

11029 Kenwood Road, Bldg. 5 

Cincinnati, OH 45242 

Fax: (513) 489-8695 

Email: OWOW-PUBS-NCEPI@epamait.epa.gov 

Introductory information describing the OWM catalogs, as well as detailed information 

on how to go about ordering EPA documents, is provided in this appendix. 

EPA’s Office of Wastewater Management also maintains an electronic bulletin board 

system (BBS) that provides immediate access to many reference materials. The Point 

Source Information Provision Exchange System (PIPES) is a free, public, BBS and 

internet site (WWW compatible) designed to facilitate the exchange of Office of Waterrelated information among EPA, States, municipalities, industry, and the public. A 

brochure describing the features of PIPES, and information on how to access the 

system, is provided in this appendix. 

Appendix D-2 - 6EFY4 NPDES Permit Writers’ Manual 
How to Obtain Additional EPA Documents Appendix D 

United States 

Environmental Pro tee tion 

Agency 

OffIce of Water 

OFFICE OF WASTEWATER MANAGEMENT 

CATALOG OF PUBLICATIONS 

April 1996 

Office of Wastewater Management 

Office of Water 

U. S. Environmental Protection egenc y 

Washington, DC 20460 

88# NPDES Permit Writers’ Manual - Appendix D-3 
Appendix D How to Obtain Additional EPA Documenb: 

HOW TO USE THIS CATALOG 

General Information 

Many publications in this catalog are distributed free of charge by the EPA’s Office of Wastewater 

Management IOWMI. The Office of Wastewater Management distributes documents through the EPA 

Office of Water Resource Center (WRCj. The WRC distributes one free copy of each publication to 

each customer until supplies are depleted. 

When OWM’r supply of u publication is depleted, requesters are referred to either the National 

Technical tnformation Service (NTIS) or the Educational Resources lnformetion Center (ERIC). These 

clearinghouses provide copies of OWM publications for e fee. 

Catalog Organization 

This catelog divides the documents into fiftwn broad subject sections: 1 I Treatment; 2) Finance; 

31 Operetion & Maintenance; 41 Storm Water/Combined Sewer Overflows; 51 Pretreatment; 

6) Siosolids; 7) Small Communities; 8) Water Guslity & Standards; 91 Permitting Issues; 10) Water 

Conservation & Efficiency; 11) Environmental Impact Statements; 12) Pollution Prevention & Control; 

13) Needs & Assessments; 141 Construction Grants; and 15) Miscellaneous. 

The Office of Wasteweter Management has assigned most documents a unique EPA number to assist 

in tracking the document. Documents without EPA numbers are tracked by tit/e. 

Entry Format 

A sample pegs from the catalog appears on the next page. Entries are explained by comments in 

italics. 

Appendix D-4 - 8e# NPDES Permit Writers’ Manual 
How to ObCain Additional EPA Documentt Appendix D 

WATER CONSERVATION & EFFICIENCY RitaC*Sirrrrollrll. 

8ER9 NPDES Permit Writers’ Manual - Appendix D-5 
Appendix D How to Obtain Additional EPA Documenb: 

You may order EPA Office of Water documents from WRC the following ways: 

1) Call the WRC voice mail request line at (2021 260-7786 and order the document by title 

and EPA number, 

21 Mail your request to: 

U.S. Environmental Protection Agency 

Office of Water Resource Center 

RC-4100 

401 M St., SW 

Washington, DC 20460 

3) Place your order via Internet: waterpubs@epamaiI.epa.gov 

4) Fax your request to WRC at (2021 260-0386. 

Please allow 3-4 weeks for delivery. 

You may order EPA documents from NCEPt the following ways: 

1) Call NCEPI at (513) 891-6561 and order documents by EPA number, 

2) Mail your request to: 

National Center for Environmental Publications & information 

11029 Kenwood Rd. 

Cincinnati, OH 45242 

31 Fax your request to NCEPl at (613) 891-6685 

Please allow 2-3 weeks for delivery. Documents may be sent by Federal Express at the requestor’s 

expense. 

Appendix D-6 - BB# NPDES Permit Writers’ Manual 
How to Obtain Additional EPA Documents Appendix D 

ORDERING DOCUMENTS FROM CERI 

You may order EPA Office of Research & Development documents from CERI the following ways: 

1) Call CERI at (513) 569-7562 and order documents by EPA number, 

2) Mail your request to: 

U.S. EPA 

Center for Environmental Research Information 

26 W. Martin Luther King Dr. 

Cincinnati, OH 45268 

3) Fax your request to CERI at (513) 569-7566. 

Please allow 3-4 weeks for delivery. Documents may be sent by Federal Express at the requestor’s 

expense. 

BEPA NPDES Permit Writers’ Manual - Appendix D-7 
OFFICE OF WASTEWATER MANAGEMENT 

PubUcadons Ordor Form 

milse print An i..hti uwdv 

Ywlmy&lqtQ?cQyafelwhwaibmIkrur#nl. masedbw34wakshftabiwy. 

ship to: . . . . . . . ..*......................................................*..... 

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

orp- . . . . . . . . . . . . . . . . . . . ..*........~.................................... 

Adhssi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

citv, sm, zip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ..*............................ 

w- pkon: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 

Please fax or mail this form to: 

U.S. Environmental Protection Agency 

Office of Water Resource Center 

RC4100 

401 M St., SW 

Washington, DC 20460 

Fax number: (202) 260-0386 
How to Obtain Additional EPA Documents Appendix D 

ORDERING DOCUMENTS FROM ERIC 

You may order documents from ERIC the following ways: 

1) Call ERIC at 1800) 276-0462 and order documents by title and ERIC number, 

2) Record your order on the ERIC order form on the following page and 

mail it to: 

Educational Resources Information Center 

1929 Kenny Road 

Columbus, Ohio 432 1 O-l 080 

3) Record your order on the ERIC order form on the following page and 

fax it to: (614) 292-0263 

Shipping md Handling 

Shipping fees range from $2.00 to 810.00 Please call ERIC or see the ERIC order form on the 

following page for more details on shipping and handling fees. 

Electronic senflces 

Many ERIC products, services, and directories are available electronically through the Internet. Tho 

ERIC staff can be contacted through e-mail lericse@osu.edul, and ERIC offers resources through 49 

Gopher server Igopher.efkse.ohio-state.edul or World Wide Web (Mosaic) server 

[http://gopher.ericse. Ohio-state.sdul . 

8EB4 NPDES Permit Writers’ Manual - Appendix D-11 
- 

Organlzatxx 

Address: 

CitylStaulZtp: 

q ERICICSMEE Federa! Tax !Da: 31-602-5906 

ERIC/CSMEE - 

EPA Order 

Fom 

Phone 

FAX 

PO # 

Item N-o. 1 Qty. 1 Abbreviated Tit& 1 Unit$ 1 kal$ I I I I 

I I I 

SWotal 

Shwlng 

Tax(Ohio Re%i~+~ts) 

To order by FAX, ~ransrtut rhlr, form with Purchase &dcr 

or credtt card wnbcr co: (614) 2924263. or 

send chls Order Form and Check. PO, or Check co: 

ERICXSMEE 

1929 KCM~ Road 

., 

Colunbus.OH 432OIO00 

l-&XI-276-0462or6W292-6717(Cohrrhs Arcad lmcrnar~l) .’ 

Total Purchase 

Order !hhtud 

s200410.00 

s10.01425.00 

SZS.014SO.W 

uo.01.vs.00 

s75.01.s1m.m 

Overs1m.m i 

SWPM 

s2m 

S3.50 

s6.m 

S8.W 

no.00 

Addlou 

It you prefer co use your VISA or MascerCard. please provdc the folknwng mfo~~~: 

Creo~c Card Number: 0 VISA 0 MH.W Card 

Cardholder’s Name: 
How to Obtain Additional EPA Documents Appendix D 

ORDERING DOCUMENTS FROM NTIS 

Telephone Orders 

Call the NTIS Sales Desk between 8:30 a.m. and 5:00 p.m., Eastern time, Monday through Friday 

at (800) 553-NTIS. TDD for the hearing impaired (703) 487-4639. 

FAX and TELEX Orders 

Record your order on the NTIS order form on the following page. Fax your order to (7031 321-8547 

or (703) 321-9038. For assistance call (703) 487-4679. International Telex - 64617. 

Mail or Emdl Orders 

Record your order on the NTIS order form on the following page. Mail your order to: 

National Technical Information Service 

U.S. Department of Commerce 

5285 Port Royal Road 

Springfield, VA 22161 

orders@ntis.fedworld.gov 

Rush Service 

Rush service is available for an additional fee by calling l-800-553-NTIS; outside the U.S. call (703) 

48774850. Rush orders are usually shipped next day by overnight courier in the U.S or by Air Mail 

outside the U.S. Do not mail rush ordsn. 

Methods of Payment 

Customers may pay for NTIS products by: 1) American Express, Mastercard, or VISA; 2) check or 

money order payable to NTIS in U.S. dollars drawn on a U.S. bank; or in U.S. dollars drawn on an 

international bank with a U.S. address on the-check; or in U.S. dollars drawn on a Canadian bank; 

(3) an NTIS Deposit Account; or (4) purchase.order - add $7.50 per order if full payment does not 

accompany order - U.S., Canada, and Mexico only. 

Handling Fee 

A $3 handling fee per total order applies to all orders except Rush Service. 

Postage 84 SFipping 

Orders are shipped First Class mail or equivalent to addresses in the U.S. For Air Mail service to 

Canada and Mexico, add $4 per printed report and $1 per microfiche copy. 

Tracing an Order 

For questions about orders, write or call the Customer Service Department at (7031 487-4660 

between 8:30 a.m. and 5:00 p.m. Eastern time. 

QEW NPDES Permit Writers’ Manual - Appendix D-15 
U.B. OEPARTWE)IT OF COMMERCE 

TECMWOLOOV ADMtNtSTRATtOW ORDER FORM m I 
us9 MCARTMEWJ OF COMMERCE 

TECWIOLOOV UmIMl~ATlON ORDER FORM heels -la-- t 

PRODUCT SELECTION SIDR 2 

FREE CATALOOS AND INFORMATION 

0 

0 

q 

q 

q 

0 

PR427 

PR-186 

PR-261 

PR-36&3 

PR-36M 

PR629 

NTlscatakgofprodlaandservices 0 

-search@Masbrcatabg 

cl 

Dirqfy of U.S. GpvemmentsoRwarr,lb 

-and- 0 

yls&x scheclule for ihe U.S.. Canada. and 

0 

PR-746 

PR-758 

PR-797 

PR-868 

PR-889 

m-936 

Gvdnmetntal DatafUes and Sahme Cakkg 

NTlSAktS@3ffWtyAbsbad-)- 

cu!wnhdaJlTent awarenabum 

Em!immntHighlii 

FedWoW-Free/kicessbfhe~c 

Mark&% of U.S. and Fomigl Government 
How to Obtain Additionrl WA Documents Appendix D 

United States Environmental Protection Agency 

Office of Wastewater Management 

September 1996 

PIPES 

Point Source Information Provision Exchange System 

The Point Source Information Provision Exchange System (PIPES) is a free, public, electronic Bulletin 

Board System (BBS) and intemet site (WWW compatible!) designed to facilitate the exchange of Office 

of Water-related information among EPA, states, municipalities, industry, and the public. 

PIPES was created by the Office of Wastewater Management (OWM) and is intended solely to further 

the mission and goals of the U.S. Environmental Protection Agency and its point source permitting 

programs. PIPES operates virtually 24 hours a day (shutting down for about 10 minutes every night 

at 3:OO a.m. EST for maintenance activities). 

PIPES allows users to: 

l Exchange public information with hundreds of environmental professionals 

l Select and download any file, or read text files online, including policy documents and guidance 

manuals 

l Send and receive E-Mail to and from PIPES and non-PIPES users NEW! 

l Search full text by keyword or multiple words; or manually search menus and file directories 

for specific files 

l View and add upcoming water-related conferences, meetings, etc. to a calendar of events NEW! 

l Download computer program utilities. 

The PIPES BBS includes numerous individual forum areas containing message centers and downloadable 

files on: 

Pretreatment Wet Weather 

Storm Water Watersheds 

NPDES Mining 

Combined Sewer Overflows Federal Advisory Committees 

Sanitary Sewer Overflows General Water Information 

Sewage Sludge BBS/WWW Utilities. 

BERA NPDES Permit Wrfters’ Manual - Appendix D-21 
Appendix D How to Obtain Additionrl WA Documen?s 

W TO CONTACT PIPES 

Modem BBS: (703) 749-9216 

NEW! WWW address: 

http://pipes.ehsg.saic.com 

telnet: pipes.ehsg.saic.com 

WHO . TO CONTACT FOR HELP. 

Technical Support: (703) 821-4697 

NEW! Sysop E-mail: brad-maguire@cpqm.saic.com 

PIPES users are strongly encouraged to download (from the Utilities directory on PIPES) and install 

“client2.exe” which provides an interface for operating PIPES in a Windows-based environment either 

through modem or the internet. Non-intemet and non-Windows users should download and install 

“riptm154.zip” which provides a graphical interface using Riptel 

For more information on PIPES, please contact: 

Tony Smith 

U.S. EPA/OWM 

401 M Street, SW 

Washington, DC 20460 

Telephone: (202) 260- 1017 

Fax: (202) 260-1156 

PIPES User ID: Tony Smith 

To use the PIPES BBS, users need a computer. a modem (the faster the better) and any necessary cables 

and telephone jacks to connect the modem to the computer and to the telephone system, and a 

communicarions software program. 

To access PIPES via the internet, users must have access to the internet (either via a dial-up service or 

a direct connection). PIPES can be accessed via the intemet through a client/server mode (e.g., telnet 

or rlogin) or WWW navigational software (e.g., Mosaic). 

The “Utilities” directory on PIPES contains several freeware communication software programs 

available for downloading that provide a user friendly interface to the PIPES BBS and are highly 

recommended. 

Appendix D-22 - 8EFVb NPDES Permit Writers’ Manual 

*U.S. COVERVME4FT PRUVIINC 0FfXE:195’8-623-08#93462 
EPA 

United States 

Environmental Protection Agency 

4203 

Washington, DC 20460 

Official Business 

Penalty for Private Use 

$300