Economic Analysis 

for the Revision of 

Certain Federal

Water Quality

Criteria Applicable 

to Washington

Contract # EP-C-13-03

August 17, 2015

Prepared for:

United States Environmental 

Protection Agency

1200 Pennsylvania Ave., NW

Washington, D.C. 20460

Submitted by:

Abt Associates 

4550 Montgomery Avenue

Suite 800 North 

Bethesda, MD 20814

In Partnership with:

PG Environmental, LLC
CONTENTS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. i

Contents

Contents.................................................................................................................................... i

Exhibits................................................................................................................................... vi

Acronym List......................................................................................................................... vii

Executive Summary............................................................................................................... ix

Background and Potential Revised Criteria................................................................. ix

Point Source Compliance Costs................................................................................... ix

Nonpoint Source Controls..............................................................................................x

1. Introduction..................................................................................................................1

1.1 Background...........................................................................................................1

1.2 Purpose and Scope of the Analysis.......................................................................2

1.3 Organization of Report .........................................................................................2

2. Baseline for the Analysis .............................................................................................4

2.1 Water Quality Criteria and Implementation Procedures.......................................4

2.2 Sources of Toxic Pollutants to Surface Waters.....................................................7

2.2.1 Municipal and Industrial Dischargers.......................................................8

2.2.2 Urban Stormwater.....................................................................................8

2.2.3 Agriculture and Forestry...........................................................................9

2.2.4 Atmospheric Deposition ...........................................................................9

2.2.5 Contaminated Sediments ........................................................................10

2.3 Water Quality......................................................................................................10

3. Potential Revised Criteria .........................................................................................14

4. Method for Estimating Potential Costs: Point Sources..........................................19

4.1 Major Dischargers...............................................................................................19

4.1.1 Sample Selection.....................................................................................19

4.1.2 Reasonable Potential Analysis................................................................21

4.1.3 Projecting Effluent Limitations...............................................................22

4.1.4 Identifying Compliance Scenarios and Costs.........................................25

4.1.5 Summary of Unit Control Costs .............................................................33

4.1.6 Extrapolation to All Major Dischargers..................................................34
CONTENTS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. ii

4.2 Minor Dischargers ..............................................................................................34

5. Methods for Identifying Potential Costs: Nonpoint Sources .................................36

5.1 Identifying Exceedances.....................................................................................36

5.2 Identifying Compliance Actions and Costs........................................................38

6. Potential Compliance Costs ......................................................................................40

6.1 Point Sources ......................................................................................................40

6.2 Nonpoint Sources................................................................................................40

6.3 Uncertainties and Quality Assurance..................................................................41

7. References...................................................................................................................43

Appendix A – Facility Analyses............................................................................................46

A.1 Chambers Creek Regional Wastewater Treatment Facility................................46

A.1.1 Treatment Processes................................................................................46

A.1.2 Effluent Data...........................................................................................46

A.1.3 Receiving Water......................................................................................46

A.1.4 Baseline Scenario....................................................................................47

A.1.5 Policy Scenario .......................................................................................47

A.2 King County South WWTP and CSO System....................................................47

A.2.1 Treatment Processes................................................................................47

A.2.2 Effluent Data...........................................................................................47

A.2.3 Receiving Water......................................................................................49

A.2.4 Baseline Scenario....................................................................................49

A.2.5 Policy Scenario .......................................................................................52

A.3 King County West Point WWTP and CSO System............................................53

A.3.1 Treatment Processes................................................................................53

A.3.2 Effluent Data...........................................................................................53

A.3.3 Receiving Water......................................................................................54

A.3.4 Baseline Scenario....................................................................................55

A.3.5 Policy Scenario .......................................................................................57

A.4 Pasco Wastewater Treatment Works..................................................................58

A.4.1 Treatment Processes................................................................................58

A.4.2 Effluent Data...........................................................................................59

A.4.3 Receiving Water......................................................................................59

A.4.4 Baseline Scenario....................................................................................59
CONTENTS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. iii

A.4.5 Policy Scenario .......................................................................................61

A.5 Puyallup WWTP.................................................................................................62

A.5.1 Treatment Processes................................................................................62

A.5.2 Effluent Data...........................................................................................63

A.5.3 Receiving Water......................................................................................63

A.5.4 Baseline Scenario....................................................................................63

A.5.5 Policy Scenario .......................................................................................64

A.6 Redondo WWTP.................................................................................................64

A.6.1 Treatment Processes................................................................................64

A.6.2 Effluent Data...........................................................................................64

A.6.3 Receiving Water......................................................................................67

A.6.4 Baseline Scenario....................................................................................67

A.6.5 Policy Scenario .......................................................................................69

A.7 Salmon Creek WWTP.........................................................................................70

A.7.1 Treatment Processes................................................................................70

A.7.2 Effluent Data...........................................................................................70

A.7.3 Receiving Water......................................................................................71

A.7.4 Baseline Scenario....................................................................................72

A.7.5 Policy Scenario .......................................................................................73

A.8 BP Cherry Point Refinery ...................................................................................74

A.8.1 Treatment Processes................................................................................74

A.8.2 Effluent Data...........................................................................................75

A.8.3 Receiving Water......................................................................................77

A.8.4 Baseline Scenario....................................................................................78

A.8.5 Policy Scenario .......................................................................................79

A.9 Cosmo Specialty Fibers ......................................................................................80

A.9.1 Treatment Processes................................................................................81

A.9.2 Effluent Data...........................................................................................81

A.9.3 Receiving Water......................................................................................81

A.9.4 Baseline Scenario....................................................................................81

A.9.5 Policy Scenario .......................................................................................82

A.10 Intalco Aluminum Corporation...........................................................................82

A.10.1 Treatment Processes................................................................................82

A.10.2 Effluent Data...........................................................................................82

A.10.3 Receiving Water......................................................................................83
CONTENTS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. iv

A.10.4 Baseline Scenario....................................................................................84

A.10.5 Policy Scenario .......................................................................................85

A.11 Quincy Industrial Wastewater Treatment Facility..............................................86

A.11.1 Treatment Processes................................................................................86

A.11.2 Effluent Data...........................................................................................86

A.11.3 Receiving Water......................................................................................86

A.11.4 Baseline Scenario....................................................................................87

A.11.5 Policy Scenario .......................................................................................87

A.12 Steelscape Inc......................................................................................................87

A.12.1 Treatment Processes................................................................................87

A.12.2 Effluent Data...........................................................................................87

A.12.3 Receiving Water......................................................................................88

A.12.4 Baseline Scenario....................................................................................88

A.12.5 Policy Scenario .......................................................................................88

A.13 Sonoco Products..................................................................................................88

A.13.1 Treatment Processes................................................................................88

A.13.2 Effluent Data...........................................................................................89

A.13.3 Receiving Water......................................................................................89

A.13.4 Baseline Scenario....................................................................................89

A.13.5 Policy Scenario .......................................................................................91

A.14 Tesoro Refining and Marketing LLC - Anacortes..............................................92

A.14.1 Treatment Processes................................................................................92

A.14.2 Effluent Data...........................................................................................92

A.14.3 Receiving Water......................................................................................95

A.14.4 Baseline Scenario....................................................................................95

A.14.5 Policy Scenario .......................................................................................97

A.15 TransAlta Centralia Generating Station..............................................................98

A.15.1 Treatment Processes................................................................................98

A.15.2 Effluent Data...........................................................................................98

A.15.3 Receiving Water....................................................................................101

A.15.4 Baseline Scenario..................................................................................101

A.15.5 Policy Scenario .....................................................................................103

A.16 TransAlta Centralia Mining ..............................................................................104

A.16.1 Treatment Processes..............................................................................104

A.16.2 Effluent Data.........................................................................................104
CONTENTS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. v

A.16.3 Receiving Water....................................................................................104

A.16.4 Baseline Scenario..................................................................................105

A.16.5 Policy Scenario .....................................................................................106

A.17 U.S. Oil & Refining Corporation......................................................................107

A.17.1 Treatment Processes..............................................................................107

A.17.2 Effluent Data.........................................................................................108

A.17.3 Receiving Water....................................................................................108

A.17.4 Baseline Scenario..................................................................................109

A.17.5 Policy Scenario .....................................................................................110

A.18 References and Sources ....................................................................................111

Appendix B – Sample Facility Results and Statewide Extrapolation .............................113

B.1 Baseline Scenario Extrapolation.......................................................................113

B.2 Policy Scenario Extrapolation...........................................................................115
CONTENTS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. vi

Exhibits

Exhibit 2-1. Baseline Freshwater and Marine Water Quality Criteria for Toxic Pollutants in 

Washington1.....................................................................................................................................4

Exhibit 2-2. Number of Dischargers in Washington by Category..........................................................8

Exhibit 2-3. 2015 Proposed Category 4 and 5 Listings for Toxic Pollutants.......................................11

Exhibit 2-4. Summary of TMDLs for Toxic Pollutants in Waters in Washington1.............................12

Exhibit 3-1. Summary of Key Assumptions for Calculating Human Health Criteria ..........................15

Exhibit 3-2. Proposed Human Health Criteria (μg/L)..........................................................................15

Exhibit 4-2. Summary of Major Discharger Sample............................................................................20

Exhibit 4-3. Summary of Projected Effluent Limitations and Incremental Load Reductions under the 

Proposed Criteria ...........................................................................................................................24

Exhibit 4-4. Summary of Potential End-of-Pipe Treatment Technologies...........................................30

Exhibit 4-5. Estimated Unit Costs of Compliance Mechanisms (2014$).............................................33

Exhibit 5-1. Potential Incremental Impairments1.................................................................................37

Exhibit 6-1. Total Annual Costs by Discharger Type ..........................................................................40

Exhibit 6-2. Uncertainties in Analysis of Costs ...................................................................................41
ACRONYM LIST

Abt Associates Cost of Compliance with WQS for Washington ▌pg. vii

Acronym List

AML Average monthly effluent limit

BMP Best management practices

CWA Clean Water Act

DMR Discharge monitoring report

Ecology Washington Department of Ecology

EIM Environmental Information Management

EPA United States Environmental Protection Agency

FCR Fish consumption rate

I&I Inflow and infiltration

MDL Maximum daily effluent limit

MEC Maximum effluent concentration

MEP Maximum extent practicable

MERA Mercury Education and Reduction Act

MS4 Municipal separate storm sewer systems

NPDES National Pollutant Discharge Elimination System

NTR National Toxics Rule

P2 Pollution prevention

PARIS Permitting and Reporting Information System

POTW Publicly owned treatment works

QL Quantitation level

SMS Sediment management standards

SWMP Stormwater management program

SWPPP Stormwater pollution prevention plan

TMDL Total maximum daily load

WAC Washington Administrative Code

WLA Waste load allocation

WQBELs Water quality based effluent limitations

WQS Water quality standards
ACRONYM LIST

Abt Associates Cost of Compliance with WQS for Washington ▌pg. viii

WWTF Wastewater treatment facility
EXECUTIVE SUMMARY

Abt Associates Cost of Compliance with WQS for Washington ▌pg. ix

Executive Summary

The United States Environmental Protection Agency (EPA) is proposing to update the 

current federal human health criteria applicable to waters under jurisdiction of the State of 

Washington, to protect Washington residents from exposure to toxic pollutants. This report 

provides estimates of the potential incremental compliance actions and costs that may be 

associated with the proposed regulation.

Background and Potential Revised Criteria

EPA promulgated existing criteria for the protection of human health for waters in the State 

of Washington in 1992 as part of the National Toxics Rule (NTR) (40 Code of Federal 

Regulations 131.36). The NTR was necessary to bring all states into compliance with the 

requirements of Clean Water Act (CWA) section 303(c)(2)(B). 

EPA derived the criteria in the NTR using a fish consumption rate (FCR) of 6.5 grams per 

day (g/day) based on national surveys. The best available data now demonstrate that fish 

consumers in Washington, including tribes with treaty-protected rights, consume much more 

fish than 6.5 g/day. There are also new data and scientific information available to update the 

toxicity and exposure parameters used to calculate human health criteria. Therefore, EPA 

proposes to revise the federal human health criteria applicable to waters under jurisdiction of 

the state of Washington to take into account the best available science, including local and 

regional information, as well as applicable EPA policies, guidance, and legal requirements, to 

protect human health.

Although the proposed rule does not establish any requirements directly applicable to 

regulated entities or other sources of pollution, state implementation may result in new or 

revised National Pollutant Discharge Elimination System (NPDES) permit conditions for 

point source dischargers and additional controls on nonpoint sources of pollutant loadings. 

This analysis provides information on the potential for incremental costs to be associated 

with such incremental requirements necessary to assure attainment of state water quality 

designated uses protected by the criteria in the proposed rule.

Point Source Compliance Costs

EPA identified approximately 406 point source facilities that could ultimately be affected by

the rule. Of these potentially affected facilities, 73 are classified as major dischargers, and 

333 are minor dischargers. Minor facilities are unlikely to incur costs as a result of 

implementation of the rule. Minor facilities are typically those that discharge less than one

million gallons per day (mgd) and do not discharge toxics in toxic amounts. Although lower 

human health criteria could potentially change this characterization (effluent monitoring 

could indicate concentrations at levels of concern), EPA did not have effluent data on toxic 

pollutants to evaluate any minor dischargers for this preliminary analysis. Additionally, EPA 

also did not have data to evaluate general permits (e.g., stormwater discharges) for which
EXECUTIVE SUMMARY

Abt Associates Cost of Compliance with WQS for Washington ▌pg. x

permit conditions typically focus on best management practices rather than pollutant-specific 

limits derived from numeric water quality criteria.

Of the 73 potentially affected major dischargers, EPA evaluated a sample of 17 major 

facilities. EPA evaluated the 2 major municipal facilities with design flows greater than 100 

mgd, and the largest industrial facility, in attempt to capture potential for the largest costs. 

For the remaining major facilities, EPA evaluated a random sample of facilities to represent 

discharger type and category. For all sample facilities, EPA evaluated existing baseline 

permit conditions, reasonable potential to exceed human health criteria based on the 

proposed rule, and potential to exceed projected effluent limitations based on the last three 

years of effluent monitoring data (if available). 

Analysis of the available data for the sample of facilities indicates that there are likely to be 

exceedances of projected effluent limits for arsenic and mercury. In instances of baseline 

effluent limitations not being reflective of baseline criteria, EPA estimated baseline effluent 

limitations, compliance actions, and costs. In instances of exceedances of projected effluent 

limitations under the proposed rule, EPA determined the likely compliance scenarios and 

costs. Only compliance actions and costs that would be needed above the baseline level of 

controls are attributable to the proposed rule. 

EPA assumed that dischargers will pursue the least cost means of compliance with water 

quality based effluent limits. Incremental compliance actions attributable to the proposed rule 

may include pollution prevention, end-of-pipe treatment, and alternative compliance 

mechanisms (e.g., variances). EPA annualized capital costs, including study (e.g., variance) 

and program (e.g., pollution prevention) costs, over 20 years using a 7% discount rate to 

obtain total annual costs per facility.

1

For the random sample, EPA extrapolated the 

annualized costs based on the sampling weight for each sample facility. To obtain an 

estimate of total costs to point sources, EPA added the results for the certainty sample to the 

extrapolated random sample costs.

For the 73 major dischargers in the state, EPA estimates that the total annual cost may be 

approximately $13 million. All of these costs are attributable to industrial dischargers, 

primarily for treatment of arsenic. Overall, compliance with revised human health criteria for 

arsenic accounts for 99% of the costs, while compliance with revised human health criteria 

for mercury accounts for the remaining 1%.

Nonpoint Source Controls

Revised human health criteria could also have implications for nonpoint sources. However, it 

is difficult to model and evaluate the potential costs impacts of this rule to those sources 

because they are intermittent, variable, and occur under hydrologic or climatic conditions

 

1 EPA updated unit cost estimates that it developed previously using a 7% discount rate (see Section 4.1.4) 

and as such used the same discount rate for this analysis. Note that using a lower discount rate (e.g., 3%) 

would yield lower compliance costs.
EXECUTIVE SUMMARY

Abt Associates Cost of Compliance with WQS for Washington ▌pg. xi

associated with precipitation events. Also, data on instream and discharge levels of the 

pollutants of concern after dischargers have implemented controls to meet current water 

quality standards, total maximum daily loads for impaired waters, or other water quality 

improvement plans, are not available. Therefore, determining which sources would need an 

incremental level of control attributable to the revised human health criteria after complying 

with existing regulations and policies may not be possible.

EPA identified potential incremental exceedances of the revised human health criteria based 

on available data in the State of Washington Department of Ecology (Ecology) 

Environmental Information Management System (EIM). According to the state’s Water 

Quality Program Policy (Ecology, 2012c), Ecology generally uses the last ten years of data to 

determine impairment status of surface waters. EPA used available surface water monitoring 

data on pollutants of concern from EIM for the years 2005 to 2014. For each monitoring 

station and parameter, EPA compared the pollutant concentration to both the existing 

baseline human health criteria and the revised human health criteria. Station results that 

would indicate impairment under EPA’s proposed criteria but not under the existing baseline 

criteria may represent potential incremental impairments.2

Using the baseline criteria, monitoring data indicate potential impairment on the basis of 

human health criteria exceedances in the water column at 205 stations. Under the revised 

criteria, there are 254 exceedances, for a total of 49 potential incremental impairments (or a 

24% increase compared to the baseline).

 

2 Note that these results may not reflect the actual listed impairment status of the waterbody. EPA compared 

identified impairments to Ecology’s current draft impairment listings; however, data limitations (e.g. the 

ability to match monitoring stations to existing impairment status at the waterbody level across data sets) 

largely preclude matching of monitoring stations to specific waterbody impairments. 
INTRODUCTION

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 1

1. Introduction

The United States Environmental Protection Agency (EPA) is proposing to update the 

current federal human health criteria applicable to waters under jurisdiction of the state of 

Washington, to protect Washington residents from exposure to toxic pollutants. This report 

provides estimates of the potential incremental compliance actions and costs that may be 

associated with the proposed regulation.

1.1 Background

The Federal Water Pollution Control Act (as amended through P.L. 107–303, November 27, 

2002), also known as the Clean Water Act (CWA), sets the basic structure for regulating 

pollutant discharges into the waters of the United States. In the CWA, Congress established 

the national objective to “restore and maintain the chemical, physical, and biological integrity 

of the Nation’s waters,” and to achieve “wherever attainable, an interim goal of water quality

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

recreation in and on the water” (CWA sections 101(a) and 101(a)(2)).

The CWA establishes the basis for the current water quality standards (WQS) regulation and 

program. CWA section 303 addresses the development of state and authorized tribal WQS. 

WQS reflect the CWA national objectives for each water body. The core components of 

these standards are designated uses, water quality criteria, and antidegradation requirements. 

Designated uses establish the environmental objectives for a water body, while water quality 

criteria define the minimum conditions necessary to achieve those environmental objectives. 

The antidegradation program complements designated uses and criteria by providing a 

framework for maintaining and protecting water quality.

After states, authorized tribes, territories, and the District of Columbia (hereafter, states and 

authorized tribes) designate the uses of waters under their jurisdiction, they must establish 

water quality criteria that protect those designated uses. EPA’s regulation at §131.11(a)(1) 

provides that that such criteria “must be based on sound scientific rationale, and must contain 

sufficient parameters or constituents to protect the designated use.” States and authorized 

tribes must also adopt antidegradation policies to protect and maintain high quality waters 

and existing uses of all waters, and identify specific methods to implement those policies 

(§131.12).

The CWA also requires states and authorized tribes to hold public hearings once every three 

years for the purpose of reviewing applicable WQS and, as appropriate, modifying and 

adopting standards. The results of this triennial review must be submitted to EPA, and EPA 

must approve or disapprove any new or revised standards. CWA Section 303(c)(4)(B) 

authorizes the Administrator to determine, even in the absence of a state submission, that a 

new or revised standard is needed to meet CWA requirements.
INTRODUCTION

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 2

EPA promulgated existing criteria for the protection of human health for waters in the State 

of Washington in 1992 as part of the National Toxics Rule (NTR) (40 Code of Federal 

Regulations 131.36). The NTR was necessary to bring all states into compliance with the 

requirements of CWA section 303(c)(2)(B).

EPA derived the criteria in the NTR using a fish consumption rate (FCR) of 6.5 grams per 

day (g/day) based on national surveys. The best available data now demonstrate that fish 

consumers in Washington, including tribes with treaty-protected rights, consume much more 

fish than 6.5 g/day. There are also new data and scientific information available to update the 

toxicity and exposure parameters used to calculate human health criteria. Therefore, EPA 

proposes to revise the federal human health criteria applicable to waters under jurisdiction of 

the state of Washington to take into account the best available science, including local and 

regional information, as well as applicable EPA policies, guidance, and legal requirements, to 

protect human health.

1.2 Purpose and Scope of the Analysis

The purpose of this analysis is to identify, using available water quality and discharge data 

and information, the incremental compliance actions and costs that publicly owned 

wastewater treatment works (POTWs) and industrial point source dischargers may incur as a 

result of EPA’s proposed criteria. EPA did not consider potential costs associated with new 

or expanding facilities. Although the proposed rule does not establish any requirements 

directly applicable to regulated entities or other sources of pollution, state implementation 

may result in new or revised National Pollutant Discharge Elimination System (NPDES) 

permit conditions for point source dischargers to incorporate revised water quality based 

effluent limits (WQBELs). Due to the large number of pollutants of concern, the estimates of 

statewide compliance costs reflect the extrapolation of results for a sample of major 

dischargers.

The revised standards may also result in incremental determinations that waters exceed 

WQS. As such, Ecology may need to develop additional total maximum daily loads 

(TMDLs) for impaired waters. There may also be incremental controls and costs associated 

with load allocations for nonpoint sources under such TMDLs to attain standards. However, 

the data and information needed to evaluate potential control needs are more limited. For this 

preliminary analysis, EPA identified the potential for incremental impairment, and thus

incremental controls and costs for nonpoint sources, but did not develop statewide cost 

estimates.

1.3 Organization of Report

This remainder of this report is organized as follows:

Section 2: Baseline for the Analysis – describes the current applicable toxic criteria and 

Ecology procedures for implementing the criteria in NPDES permits, sources of toxic 
INTRODUCTION

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 3

pollutants to surface waters, water quality impairments from toxic pollutants, and ongoing 

efforts to reduce and eliminate these impairments. 

Section 3: Potential Revised Criteria – outlines the changes to existing water quality 

standards.

Section 4: Method for Estimating Potential Costs: Point Sources – describes the method 

for estimating compliance costs associated with baseline and revised criteria for point sources 

in terms of revisions to NPDES permits.

Section 5: Method for Identifying Potential Costs: Nonpoint Sources – describes the 

method for identifying potential for incremental impairment and compliance costs associated 

with baseline and revised criteria for nonpoint sources.

Section 6: Potential Compliance Costs – provides estimates of potential costs to comply

with the revised WQS, and discusses the uncertainties associated with the estimates. 

Section 7: References – provides the references used in the analysis. 

Appendices provide data and information on individual sample facilities, and analyses of 

potential impacts under the proposed rule.
BASELINE FOR THE ANALYSIS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 4

2. Baseline for the Analysis

This section describes the applicable baseline for evaluating the incremental costs associated 

with the revised WQS, including current water quality criteria and associated implementation 

procedures, potential sources of the pollutants of concern, the current level of impairment, 

and listing procedures.

2.1 Water Quality Criteria and Implementation Procedures

Exhibit 2-1 shows the applicable baseline criteria for toxic pollutants for which there are 

human health criteria. Ecology designates all surface waters for the protection of both aquatic 

life and human health.3EPA did not consider further those pollutants for which the aquatic 

life criteria are more stringent than the proposed revised human health criteria because the 

more stringent criteria coupled with the implementing procedures (e.g., allowable dilution 

factors) would always result in more stringent effluent limitations. Therefore the proposed 

rule would not lead to additional compliance costs for these pollutants.

Exhibit 2-1. Baseline Freshwater and Marine Water Quality Criteria for Toxic 

Pollutants in Washington1

Parameter

Freshwater 

Aquatic Life

(μg/L)

Marine Aquatic 

Life (μg/L) Human Health (μg/L)

Acute Chronic Acute Chronic

Water and 

Fish Fish Only

1,1,2,2-Tetrachloroethane 0.17 11

1,1,2-Trichloroethane 0.6 42

1,1-Dichloroethylene 0.057 3.2

1,2,4-Trichlorobenzene

1,2-Dichlorobenzene 2700 17000

1,2-Dichloroethane 0.38 99

1,2-Dichloropropane

1,2-Diphenylhydrazine 0.04 0.54

1,2-Trans-Dichloroethylene

1,3-Dichlorobenzene 400 2600

1,3-Dichloropropene 10 1700

1,4-Dichlorobenzene 400 2600

2,3,7,8-TCDD (Dioxin) 0.000000013 0.000000014

 

3

Section 173-201A-600 specifies that all surface waters of the state that do not have specific listings in 

Table 602 are “to be protected for the designated uses of: Salmonid spawning, rearing, and migration; 

primary contact recreation; domestic, industrial, and agricultural water supply; stock watering; wildlife 

habitat; harvesting; commerce and navigation; boating; and aesthetic values.”
BASELINE FOR THE ANALYSIS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 5

Exhibit 2-1. Baseline Freshwater and Marine Water Quality Criteria for Toxic 

Pollutants in Washington1

Parameter

Freshwater 

Aquatic Life

(μg/L)

Marine Aquatic 

Life (μg/L) Human Health (μg/L)

Acute Chronic Acute Chronic

Water and 

Fish Fish Only

2,4,6-Trichlorophenol 2.1 6.5

2,4-Dichlorophenol 93 790

2,4-Dimethylphenol

2,4-Dinitrophenol 70 14000

2,4-Dinitrotoluene 0.11 9.1

2-Chloronaphthalene

2-Chlorophenol

2-Methyl-4,6-dinitrophenol 13 765

3,3'-Dichlorobenzidine 0.04 0.077

4,4'-DDD 0.00083 0.00084

4,4'-DDE 0.00059 0.00059

4,4'-DDT 0.00059 0.00059

Acenaphthene

Acrolein 320 780

Acrylonitrile 0.059 0.66

Aldrin 0.00013 0.00014

alpha-BHC 0.0039 0.013

alpha-endosulfan 0.93 2

Anthracene 9600 110000

Antimony 14 4300

Arsenic 360 190 69 36 0.018 0.14

Asbestos27000000

Benzene 1.2 71

Benzidine 0.00012 0.00054

Benzo(a) anthracene 0.0028 0.031

Benzo(a) pyrene 0.0028 0.031

Benzo(b) fluoranthene 0.0028 0.031

Benzo(k) fluoranthene 0.0028 0.031

beta-BHC 0.014 0.046

beta-endosulfan 0.93 2

Bis(2-chloroethyl) ether 0.031 1.4

Bis(2-chloroisopropyl) ether 1400 170000

Bis(2-ethylhexyl) phthalate 1.8 5.9
BASELINE FOR THE ANALYSIS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 6

Exhibit 2-1. Baseline Freshwater and Marine Water Quality Criteria for Toxic 

Pollutants in Washington1

Parameter

Freshwater 

Aquatic Life

(μg/L)

Marine Aquatic 

Life (μg/L) Human Health (μg/L)

Acute Chronic Acute Chronic

Water and 

Fish Fish Only

Bromoform 4.3 360

Butylbenzyl phthalate

Carbon tetrachloride 0.25 4.4

Chlordane 2.4 0.0043 0.09 0.004 0.00057 0.00059

Chlorobenzene 680 21000

Chlorodibromomethane 0.41 34

Chloroform 5.7 470

Chrysene 0.0028 0.031

Copper 4.8 3.1

Cyanide 22.0 5.2 1.0 700 220000

Dibenzo(a,h) anthracene 0.0028 0.031

Dichlorobromomethane 0.27 22

Dieldrin 2.5 0.0019 0.71 0.0019 0.00014 0.00014

Diethyl phthalate 23000 120000

Dimethyl phthalate 313000 2900000

Di-n-butyl phthalate 2700 12000

Endosulfan sulfate 0.22 0.056 0.034 0.0087 0.93 2

Endrin 0.18 0.0023 0.037 0.023 0.76 0.81

Endrin aldehyde 0.76 0.81

Ethylbenzene 3100 29000

Fluoranthene 300 370

Fluorene 1300 14000

Hexachlorocyclohexane 

(gamma-BHC; lindane) 2.0 0.08 0.16 0.019 0.063

Heptachlor 0.52 0.0038 0.053 0.0036 0.00021 0.00021

Heptachlor Epoxide 0.0001 0.00011

Hexachlorobenzene 0.00075 0.00077

Hexachlorobutadiene 0.44 50

Hexachlorocyclopentadiene 240 17000

Hexachloroethane 1.9 8.9

Indeno(1,2,3-cd) pyrene 0.0028 0.031

Isophorone 8.4 600

Methyl bromide 48 4000
BASELINE FOR THE ANALYSIS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 7

Exhibit 2-1. Baseline Freshwater and Marine Water Quality Criteria for Toxic 

Pollutants in Washington1

Parameter

Freshwater 

Aquatic Life

(μg/L)

Marine Aquatic 

Life (μg/L) Human Health (μg/L)

Acute Chronic Acute Chronic

Water and 

Fish Fish Only

Methylene chloride 4.7 1600

Nickel 74.0 8.2 610 4600

Nitrobenzene 17 1900

N-Nitrosodimethylamine 0.00069 8.1

N-Nitrosodi-n-propylamine

N-Nitrosodiphenylamine 5 16

Pentachlorophenol (PCP) 13.0 7.9 0.28 8.2

Phenol 21000 4600000

Polychlorinated biphenyls 

(PCBs) 2.0 0.0014 10.0 0.03 0.00017 0.00017

Pyrene 960 11000

Selenium 20.0 5.0 290 71.0

Tetrachloroethylene 0.8 8.9

Thallium 1.7 6.3

Toluene 6800 200000

Toxaphene 0.73 0.0002 0.21 0.0002 0.00073 0.00075

Trichloroethylene 2.7 81

Vinyl chloride 2 525

Zinc 90.0 81.0

Mercury 2.1 0.012 1.8 0.025 0.14 0.15

Source: Ecology (2014a) and WAC 173-201A-240.

1. Metals criteria are in dissolved form; blanks indicate no baseline criteria.

2. Asbestos criteria are in fibers/L.

Section 173-201A-260 of the Washington Administrative Code (WAC) specifies the 

procedures for applying water quality criteria. As part of these procedures, the state addresses 

how to handle situations when natural and irreversible human conditions cause a receiving 

water to not meet applicable criteria. In those instances, Section 173-201A-260(1)(a) 

stipulates that the natural conditions constitute the water quality criteria.

2.2 Sources of Toxic Pollutants to Surface Waters

Toxic pollutants can be introduced to surface water through natural and human activities, 

including municipal and industrial effluents, stormwater discharges, agricultural runoff, 

forestry (chemical application), atmospheric deposition, and contaminated sediments.
BASELINE FOR THE ANALYSIS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 8

2.2.1 Municipal and Industrial Dischargers

Ecology’s Water Quality Permitting and Reporting Information System (PARIS) indicates 

that there are 406 major and minor NPDES permitted dischargers in Washington. Exhibit 2-2

shows the number of facilities by type (major/minor) and category (based on SIC codes

provided in PARIS and facility-specific fact sheets).

Exhibit 2-2. Number of Dischargers in Washington by Category

Category Minor Major All

Agriculture, Fishing, and Forestry 14 0 14

Mining 4 1 5

Construction 4 0 4

Food and Kindred Products 30 1 31

Lumber and Wood Products, Except Furniture 11 0 11

Paper and Allied Products 1 12 13

Chemicals and Allied Products 10 1 11

Petroleum Refining and Related Industries 4 5 9

Stone, Clay, Glass, and Concrete Products 5 0 5

Primary Metal Industries 6 4 10

Fabricated Metal Products, except Machinery and Transportation 

Equipment 1 0 1

Transportation Equipment 19 0 19

Transportation & Public Utilities (except POTWs) 19 1 20

POTW 184 48 232

Wholesale Trade 10 0 10

Retail Trade 2 0 2

Services 7 0 7

Public Administration 2 0 2

Total 333 73 406

Source: based on data from the Washington Department of Ecology Water Quality Permitting and 

Reporting Information System (PARIS) database, and supplementary data from facility fact sheets. 

Categorizations based on 2-digit SIC codes.

Ecology issues general NPDES permits for 18 different discharger categories, including

industrial (e.g. lumber and wood products, petroleum refining, metal manufacturing, and 

construction) and municipal, with over half of permitted dischargers being municipal 

POTWs. 

2.2.2 Urban Stormwater

Stormwater discharges are generated by precipitation and runoff from land, pavements, 

building rooftops, and other surfaces. Stormwater from municipal and industrial areas may

contribute pollutants (including toxic pollutants) to surface waters (for example, see Ecology, 
BASELINE FOR THE ANALYSIS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 9

2012a). Ecology regulates stormwater discharges from municipal separate storm sewer 

systems (MS4s) through general permits. The MS4 permits require the discharger to develop 

and implement a stormwater management program (SWMP), with the goal of controlling 

pollutant discharges to the maximum extent practicable (MEP). According to Ecology, an 

SWMP involves planning, public education and involvement, illicit discharge detection 

programs, and passing appropriate ordinances to reduce stormwater pollution (Ecology, 

2014b).4

Ecology has issued a Phase I permit (Ecology, 2015a), which covers 6 jurisdictions (Seattle 

and Tacoma, and unincorporated King, Pierce, Snohomish, and Clark counties), each serving 

more than 100,000 people. The Phase II general permits cover those systems serving 

municipalities with populations less than 100,000 located within Census Bureau-defined 

urbanized areas. There are two Phase II stormwater permits; one for the eastern part 

(Ecology, 2012b) of the state and one for the western part (Ecology, 2014c).

Industrial dischargers, including those engaged in manufacturing, transportation, mining, and 

steam electric power industries, scrap yards, landfills, certain sewage treatment plants, and 

hazardous waste management facilities may have stormwater requirements in their NPDES 

permits. Additionally, Ecology issues an Industrial Stormwater general permit (Ecology, 

2014d), which requires industrial stormwater dischargers to develop a Stormwater Pollution 

Prevention Plan (SWPPP) that includes best management practices (BMPs) to prevent, 

control, and treat stormwater pollution, a monitoring plan and discussion of the site controls 

that the discharger will implement to prevent stormwater pollution.

2.2.3 Agriculture and Forestry

Pesticides applied to agricultural or forestry lands can reach surface waters through irrigation 

return flow, stormwater runoff, and erosion of soils. 

The Department of Ecology works with farmers in Washington to incentivize and implement 

BMPs on agricultural land to reduce runoff of pollutants from agricultural lands.

Washington regulates forestry activities on State and private lands through the Washington 

Forest Practices Act (chapter 76.09 RCW) and the associated forest practices rules (Title 222 

WAC). The Washington Forest Practices Board (the authority empowered to enforce forest 

practices rules) designed and adopted the forest practice rules, in part, to meet the 

requirements of the CWA and State water quality standards. The rules cover a variety of 

forestry activities, including timber harvesting, thinning, road construction, fertilization, and 

chemical application.

2.2.4 Atmospheric Deposition

Atmospheric deposition may be a potential nonpoint source to surface waters through either 

direct or indirect deposition. Direct deposition occurs when pollutants are deposited directly 

 

4

SWMPs do not include numeric WQBELs.
BASELINE FOR THE ANALYSIS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 10

on surface waters from the atmosphere. Indirect deposition reflects the process by which 

metals and other pollutants such as pesticides deposited on the land surface are washed off 

during storm events and enter surface water through stormwater runoff. Atmospheric 

deposition is not directly addressed through any existing regulation, but may be indirectly 

addressed through TMDLs.

2.2.5 Contaminated Sediments

When pollutants enter a waterbody through runoff, precipitation, or other means, they can 

accumulate in sediments and contribute to poor water quality for many years (U.S. EPA, 

2012). Many waterbody sediments are contaminated by legacy pollutants including DDT, 

PCBs, and other pesticides. To address sediment contamination, Washington implemented 

the Washington State Sediment Management Standards (SMS) Chapter 173-204 WAC to 

reduce and ultimately eliminate sediment contamination in Washington waterbodies.5The 

SMS set numeric and narrative criteria for sediments, apply the standards to reduce pollutant 

discharges, and provide a decision process for the cleanup of contaminated sites. 

2.3 Water Quality

Ecology classifies all surface waters into one of five categories, based on available 

monitoring data, as follows:

 Category 1 waters are those for which sufficient monitoring data are available to 

determine that the water is below all applicable criteria (i.e., it is not impaired)

 Category 2 waters are “waters of concern,” which means that there is one observation 

exceeding the criteria or two or more observations exceeding the criteria but not within a 

3-year period

 Category 3 waters for which there are insufficient data to determine whether it is 

impaired

 Category 4 waters are impaired but Ecology is not pursuing TMDLs for them because a) 

there is an EPA-approved TMDL, b) there is a pollution control program in place, or c) it 

is impaired by a cause other than a pollutant

 Category 5 waters are impaired and a TMDL or pollution control plan is required; to be 

placed into Category 5 on the basis of water concentrations, there must be two or more 

exceedances of criteria within a 3-year period.

Waters can also be placed into Category 5 on the basis of fish tissue concentrations, if the 

mean of the three highest available resident fish tissue observations exceed the fish tissue 

criteria, which are back-calculated from surface water concentrations using bioconcentration 

factors from the NTR. 

 

5

See: http://www.ecy.wa.gov/programs/tcp/smu/sed_standards.htm. EPA has not taken a CWA action on the 

2013 revisions the SMS.
BASELINE FOR THE ANALYSIS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 11

Ecology recently conducted a public review of the latest updated Water Quality Assessment 

and 303(d) List for Washington State (the public comment period for the review ended on 

May 15, 2015). This assessment updates fresh water listings based on data collected as of the 

end of December 2010.6The integrated report identifies impaired waters and reports on the 

status of water quality statewide. Exhibit 2-3 summarizes the proposed Category 4 and 5 

listings for each of the pollutants of interest. Exhibit 2-4 summarizes existing TMDLs 

targeting or including toxic pollutants in waters in Washington.7

Exhibit 2-3. 2015 Proposed Category 4 and 5 Listings for Toxic Pollutants

Parameter Waterbodies

Lake/Marine Square 

Kilometers River Kilometers

2,3,7,8-TCDD (dioxin) 65 50 52

4,4'-DDD 31 3 97

4,4'-DDE 93 14 182

4,4'-DDT 64 4 184

Aldrin 4 2 7

alpha-BHC 10 6 7

Arsenic 12 3 18

Benzo(a) anthracene 25 11 0

Benzo(a) pyrene 23 9 0

Benzo(b) fluoranthene 28 11 0

Benzo(k) fluoranthene 23 10 0

beta-BHC 3 2 0

Bis(2-ethylhexyl) phthalate 3 1 0

Chlordane 13 5 16

Chrysene 34 14 0

Copper 19 1 32

Dibenzo(a,h) anthracene 11 3 0

Dieldrin 54 25 78

Heptachlor epoxide 2 0 7

Hexachlorobenzene 10 11 23

Indeno(1,2,3-cd) pyrene 16 5 0

Toxaphene 19 11 20

Zinc 12 0 47

Mercury 29 8 37

Source: Based on data from the Proposed Draft Assessment Database (available at: 

https://fortress.wa.gov/ecy/wats/SearchList.aspx).

 

6

See: http://www.ecy.wa.gov/programs/wq/303d/freshwtrassessmnt/index.html.

7 Additionally, there is a TMDL for sediment contamination in Bellingham Bay (see Ecology, 2001).
BASELINE FOR THE ANALYSIS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 12

Exhibit 2-4. Summary of TMDLs for Toxic Pollutants in Waters in Washington

Waterbody Parameter(s) Status and Notes Source

Stillaguamish 

Basin

Dissolved oxygen, 

fecal coliform, 

mercury, pH, 

temperature

Mercury levels exceeding aquatic life criteria 

are rare (occurring during high-flow events)

and attributable to natural background 

sources without contribution from 

anthropogenic sources; load allocation for 

total suspended solides expected to reduce 

occurrences of mercury concentrations higher 

than aquatic life criteria.

Ecology 

(2005)

Snohomish 

River Area

Dioxin Exceedances of human health criteria 

attributed to a point source discharge.

Ecology 

(1992a)

Commencement Bay

Dioxin Exceedances of human health criteria 

attributed to a point source discharge.

Ecology 

(1992b)

Deschutes 

River 

Watershed

Dissolved oxygen, 

fecal coliform, PCB, 

pH, phosphorus, 

temperature

TMDL is under development. Ecology 

(2014e)

Walla Walla

River

Watershed

Chlorinated 

pesticides, PCBs, 

fecal coliform, pH, 

dissolved oxygen, 

temperature

Exceedances of human health criteria for 

chlorinated pesticides and PCBs attributed to 

historical application of chlorinated pesticides 

to soils and crops in agricultural areas of the 

watershed.

Ecology 

(2006a)

Palouse 

River

Chlorinated 

pesticides and 

PCBs

Exceedances of human health criteria for 

chlorinated pesticides and PCBs; TMDL 

includes waste load allocations for WWTPs 

and nonpoint sources.

Ecology 

(2007a)

Yakima River 

Watershed

Toxics and 

Pesticides

Exceedances of human health and aquatic life 

criteria are attributed to historical applications.

Ecology 

(2012c; 2010)

Wanatchee 

River Area

DDT Exceedances of human health criteria are 

attributed to historical applications.

Ecology 

(2007b)

Lake Chelan DDT and PCBs Exceedances of human health criteria are 

attributed to historical applications 

Ecology 

(2006b)

Lower 

Okanogan 

River Basin

DDT and PCBs Exceedances of human health and aquatic life 

criteria are attributed to historical applications.

Ecology 

(2004a)

Lower

Similkameen 

River

Arsenic Exceedances of human health criteria for 

arsenic attributed to historic mining practices 

and natural sources.

Ecology 

(2004b)

Spokane 

River

Dissolved metals Exceedances of aquatic life criteria for 

dissolved metals attributed to point sources in 

Idaho (upstream) and Washington.

Ecology 

(1999)
BASELINE FOR THE ANALYSIS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 13

Exhibit 2-4. Summary of TMDLs for Toxic Pollutants in Waters in Washington

Waterbody Parameter(s) Status and Notes Source

Source: information from the Department of Ecology Water Quality Improvement Projects database 

(available at: http://www.ecy.wa.gov/programs/wq/tmdl/TMDLsbyWria/TMDLbyWria.html)

TMDL = total maximum daily load

WWTP = wastewater treatment plant
POTENTIAL REVISED CRITERIA

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 14

3. Potential Revised Criteria

EPA is proposing changes to several inputs in the equation for calculating human health 

criteria. The criteria are calculated as follows (EPA, 1980):

 = ( × ) × 



 + ( × )



 = 

10

1 ∗

 × 



 + ( × )



where,

AWQC = ambient water quality criterion (mg/L)

BW = human body weight (kg)

RfD = reference dose based on noncancer human health effects (mg/kg BW-day)

RSC = relative source contribution (%)

DI = drinking water intake (L/day)

FI = human fish consumption (kg fish/day)

BAF = bioaccumulation factor (L/kg fish)

q1* = cancer potency factor in (kg BW-day/mg).

The criteria from the NTR are the applicable existing AWQC for each pollutant of concern. 

EPA is proposing updated values for BW, RfD, RSC, DI, FI, BAF and q1*. These updates 

come from EPA (2014 (as available); 2002), with a FI specifically proposed for Washington. 

In 2001, EPA published a revised methylmercury criterion based on the concentration of 

methylmercury in fish tissue, calculated using the following equation (EPA, 2001a):

 =

 × ( − )

∑ 





where,

TRC = tissue residual concentration in mg methylmercury/kg fish

FIi = human fish consumption of trophic level i (kg fish/day)

RSC = relative source contribution in mg methylmercury/kg body weight-day.

Exhibit 3-1 summarizes the key assumptions that EPA made to calculate human health 

criteria.
POTENTIAL REVISED CRITERIA

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 15

Exhibit 3-1. Summary of Key Assumptions for Calculating Human Health Criteria

Variable Value

Fish consumption rate (FCR; g/day) 175

Body weight (BW; kg) 80

Drinking water intake (DWI; L/day) 2.4

Excess cancer risk level (RL) 10-6

Relative source contribution (RSC) 0.2 to 0.8

Toxicity factors basis U.S. EPA (2014)

Mercury criteria basis U.S. EPA (2001a)

Exhibit 3-2 summarizes the human health criteria for the pollutants of concern derived using 

the assumptions in Exhibit 3-1. The exhibit also shows Ecology’s quantification limits (QLs) 

which represent the minimum level to which dischargers need to measure each pollutant. 

Compared with the proposed criteria, the state’s freshwater and marine aquatic life criteria 

are more stringent for selenium, while the marine aquatic life criteria are more stringent for 

copper, nickel, and zinc (see Exhibit 2-1). Because the aquatic life criteria are more stringent, 

EPA did not analyze discharges of these pollutants in relevant areas.

Exhibit 3-2. Proposed Human Health Criteria (μg/L)

Parameter

Freshwater 

Criteria Marine Criteria

Quantification 

Limit

1,1,1-Trichloroethane 8000 20000 2.0

1,1,2,2-Tetrachloroethane 0.1 0.3 2

1,1,2-Trichloroethane 0.35 0.90 2

1,1-Dichloroethylene 300 2000 2

1,2,4-Trichlorobenzene 0.036 0.037 0.6

1,2-Dichlorobenzene 300 300 7.6

1,2-Dichloroethane 8.9 73 2

1,2-Dichloropropane 0.72 3.3 2

1,2-Diphenylhydrazine 0.01 0.02 20

1,2-Trans-Dichloroethylene 100 400 2

1,3-Dichlorobenzene 0.9 1 7.6

1,3-Dichloropropene 0.22 1.2 2

1,4-Dichlorobenzene 70 80 17.6

2,3,7,8-TCDD (Dioxin) 5.8E-10 5.9E-10 0.000005

2,4,6-Trichlorophenol 0.25 0.28 4

2,4-Dichlorophenol 4 6 1

2,4-Dimethylphenol 90 300 1

2,4-Dinitrophenol 10 40 2

2,4-Dinitrotoluene 0.039 0.18 0.4
POTENTIAL REVISED CRITERIA

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 16

Exhibit 3-2. Proposed Human Health Criteria (μg/L)

Parameter

Freshwater 

Criteria Marine Criteria

Quantification 

Limit

2-Chloronaphthalene 100 100 0.6

2-Chlorophenol 20 80 2

2-Methyl-4,6-Dinitrophenol 1 3 NR

3,3'-Dichlorobenzidine 0.012 0.015 1

3-Methyl-4-Chlorophenol 200 200 NR

4,4'-DDD 7.9E-6 7.9E-6 0.05

4,4'-DDE 8.8E-7 8.8E-7 0.05

4,4'-DDT 1.2E-6 1.2E-6 0.05

Acenaphthene 10 10 0.4

Acrolein 3 50 10

Acrylonitrile 0.058 0.85 2

Aldrin 4.1E-8 4.1E-8 0.05

alpha-BHC 4.8E-5 4.8E-5 0.05

alpha-Endosulfan 3 3 0.05

Anthracene 40 40 0.6

Antimony 2.5 37 1

Arsenic10.0045 0.0059 0.5

Asbestos27000000 NC NR

Benzene30.44 1.7 2

Benzidine 0.00013 0.0012 24

Benzo(a) Anthracene 0.00016 0.00016 0.6

Benzo(a) Pyrene 1.6E-5 1.6E-5 1

Benzo(b) Fluoranthene 0.00016 0.00016 1.6

Benzo(k) Fluoranthene 0.0016 0.0016 1.6

beta-BHC 0.0013 0.0014 0.05

beta-Endosulfan 4 4 0.05

Bis(2-Chloroethyl) Ether 0.027 0.24 1

Bis(2-Chloro-1-Methylethyl) Ether8200 400 0.6

Bis(2-Ethylhexyl) Phthalate 0.045 0.046 0.5

Bromoform 4.6 12 2

Butylbenzyl Phthalate 0.013 0.013 NR

Carbon Tetrachloride 0.2 0.5 2

Chlordane 0.000022 0.000022 0.05

Chlorobenzene 50 80 2

Chlorodibromomethane 0.60 2.2 2

Chloroform 50 200 2
POTENTIAL REVISED CRITERIA

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 17

Exhibit 3-2. Proposed Human Health Criteria (μg/L)

Parameter

Freshwater 

Criteria Marine Criteria

Quantification 

Limit

Chrysene 0.016 0.016 0.6

Copper4,51300 NC 2

Cyanide 4 50 10

Dibenzo(a,h) Anthracene 1.6E-5 1.6E-5 1.6

Dichlorobromomethane 0.73 2.8 2

Dieldrin 7.0E-8 7.0E-8 0.05

Diethyl Phthalate 80 80 7.6

Dimethyl Phthalate 200 200 6.4

Di-n-Butyl Phthalate 3 3 1

Endosulfan Sulfate 4 4 0.05

Endrin 0.002 0.002 0.05

Endrin Aldehyde 0.1 0.1 0.05

Ethylbenzene 12 13 2

Fluoranthene 2 2 0.6

Fluorene 5 5 0.6

Gamma-BHC; Lindane 0.43 0.43 NR

Heptachlor 3.4E-7 3.4E-7 0.05

Heptachlor Epoxide 2.4E-6 2.4E-6 0.05

Hexachlorobenzene 5.0E-6 5.0E-6 0.6

Hexachlorobutadiene 0.01 0.01 1

Hexachlorocyclopentadiene 0.4 0.4 1

Hexachloroethane 0.02 0.02 1

Indeno(1,2,3-cd) Pyrene 0.00016 0.00016 1

Isophorone 30 200 1

Methyl Bromide 100 1000 10

Methylene Chloride 10 100 10

Methylmercury60.033

Nickel530 39 0.5

Nitrobenzene 10 60 1

N-Nitrosodimethylamine 0.00065 0.34 4

N-Nitrosodi-n-Propylamine 0.0044 0.058 1

N-Nitrosodiphenylamine 0.62 0.69 1

Pentachlorophenol (PCP) 0.002 0.002 1

Phenol 4000 30000 4

Polychlorinated Biphenyls (PCBs)77.3E-6 7.3E-6 0.5

Pyrene 3 3 0.6
POTENTIAL REVISED CRITERIA

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 18

Exhibit 3-2. Proposed Human Health Criteria (μg/L)

Parameter

Freshwater 

Criteria Marine Criteria

Quantification 

Limit

Selenium525 95 1

Tetrachloroethylene 2.4 2.9 2

Thallium 0.048 0.054 0.36

Toluene 29 52 2

Toxaphene 6.6E-5 6.6E-5 0.5

Trichloroethylene 0.3 0.7 2

Vinyl Chloride 0.020 0.18 2

Zinc5450 580 2.5

NC = no criteria proposed

NR = not reported

1. The criteria for arsenic refer to the inorganic form of arsenic only.

2. The criterion for asbestos is expressed in fibers/L, and is the Maximum Contaminant Level Goal

(MCLG) developed under the Safe Drinking Water Act (56 FR 3526, January 30, 1991).

3. EPA’s national 304(a) recommended criteria for benzene use a CSF range of 0.015 to 0.055 

per mg/kg-day. EPA proposes to use the higher end of the CSF range (0.055 per mg/kg-day) to 

derive the proposed benzene criteria.

4. The criterion for copper is the MCLG developed under the Safe Drinking Water Act (40 CFR 

141.80, June 7, 1991).

5. The existing aquatic life criteria are more stringent than the proposed freshwater and marine 

criteria for selenium, and the proposed marine criteria for copper, nickel, and zinc. As such, EPA 

did not analyze discharges of these pollutants. 

6. The criterion for methylmercury is expressed as the fish tissue concentration of methylmercury 

(mg methylmercury/kg fish). See Water Quality Criterion for the Protection of Human Health: 

Methylmercury (EPA-823-R-01-001, January 3, 2001) for how this value is calculated using the 

criterion equation in EPA's 2000 Human Health Methodology rearranged to solve for a protective 

concentration in fish tissue rather than in water.

7. The criteria for PCBs apply to total PCBs (e.g., the sum of all congener or isomer or homolog or 

Aroclor analyses).

8. Bis(2-Chloro-1-Methylethyl) Ether was previously listed as Bis(2-Chloroisopropyl) Ether.
POINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 19

4. Method for Estimating Potential Costs: Point Sources

This section describes the method for estimating the potential costs to point sources 

associated with compliance with the revised human health criteria. Compliance costs for 

municipal and industrial point sources may result from changes to NPDES permit 

requirements and associated effluent limitations.

4.1 Major Dischargers

EPA estimated costs to major municipal and industrial dischargers under the proposed 

criteria by estimating costs to a representative sample of facilities, then extrapolating the 

results to the rest of the facilities (by category). This section describes sample selection, the 

reasonable potential analysis, identification of limits under the revised criteria and 

comparison to existing criteria, estimation of costs to meet revised criteria, and extrapolation 

to all major dischargers. Unless otherwise noted, EPA updated all cost estimates to 2014 year 

dollars using the consumer price index.

4.1.1 Sample Selection

Factors that may affect the potential magnitude of compliance costs include flow and type of 

facility. Larger flows are typically associated with the largest treatment costs, although perunit costs may decrease due to economies of scale. Industrial category may also be indicative 

of the potential to incur costs. Treatment requirements differ for municipal and industrial 

discharges, and effluent quality may be similar across categories of facilities. As shown in 

Exhibit 2-2, there are 406 total individually permitted dischargers, including 73 major 

dischargers (48 municipal POTWs and 25 industrial dischargers) and 333 minor dischargers 

(184 municipal POTWs and 149 industrial). 

To evaluate potential costs to major dischargers, EPA selected a representative sample of the 

major dischargers to evaluate potential costs in detail. First, EPA selected a certainty sample 

of the two largest municipal facilities8and the largest industrial facility; this certainty sample

attempts to ensure that the highest potential for cost is captured in the analysis. From the 

remaining major dischargers, EPA selected a random sample of dischargers across 

categories. EPA then extrapolated the results of the sample evaluation to estimate costs 

across all major dischargers by category. Exhibit 4-1 provides a summary of major 

discharger categories and the distribution of the sample across those categories. 

 

8 The two largest facilities, the King County West Point POTW and the King County South POTW, 

represent 25% of all major discharger flow and 35% of major POTW flow.
POINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 20

Exhibit 4-1. Summary of Major Dischargers by Industrial Category

Category

Universe Sample

Facilities

Design Flow 

(mgd) Facilities

Design Flow 

(mgd)

Food and Kindred Products 1 5 1 (100%) 5 (100%)

Mining 1 0 1 (100%) 0 (NA)

Paper and Allied Products 12 336 2 (17%) 24 (7%)

Chemicals, Petroleum Refining,

and Related Industries 6 27 3 (50%) 18 (67%)

Primary Metal Industries 4 27 2 (50%) 8 (28%)

POTW 48 1,019 7 (15%) 419 (41%)

Transportation & Public Utilities 

(except POTWs) 1 12 1 (100%) 12 (100%)

Total 73 1,425 17 (23%) 486 (34%)

mgd = million gallons per day

POTW = publicly owned treatment works

Exhibit 4-2 provides a summary of the sample for evaluation. Appendix A provides

additional information on these facilities.

Exhibit 4-2. Summary of Major Discharger Sample

NPDES 

Number Facility Name Category

Design Flow 

(mgd)

Certainty Sample

WA0029581 King County South WWTP POTW 144.0

WA0029181 King County West Point WWTP POTW 215.0

WA0022900 BP Cherry Point Refinery Petroleum Refining and 

Related Industries

13.0

Random Sample

WA0039624 Chambers Creek STP POTW 28.7

WA0044962 Pasco WWTP POTW 3.5

WA0037168 Puyallup STP POTW 14.0

WA0023451 Redondo WWTP POTW 5.6

WA0022772 Salmon Creek WWTP POTW 8.1

WA0037338 Transalta Centralia Mining Mining 5.0

WA0000884 Sonoco Products Company Paper and Allied Products 0.3

WA0000809 Cosmo Specialty Fibers, Inc. Paper and Allied Products 24.0

WA0001783 U.S. Oil & Refining Facility Petroleum Refining and 

Related Industries

0.6

WA0000761 Tesoro Refining & Marketing 

Company LLC

Petroleum Refining and 

Related Industries

4.3
POINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 21

Exhibit 4-2. Summary of Major Discharger Sample

NPDES 

Number Facility Name Category

Design Flow 

(mgd)

WA0021067 Quincy Industrial Food and Kindred Products 4.9

WA0040851 Steelscape, Inc. Primary Metal Industries 0.2

WA0002950 Intalco Aluminum Corp Ferndale Primary Metal Industries 7.4

WA0001546 Transalta Centralia Generation Transportation & Public 

Utilities (except POTWs)

12.1

mgd = million gallons per day

POTW = publicly owned treatment works

WWTP = wastewater treatment plant

STP = sewage treatment plant

4.1.2 Reasonable Potential Analysis

For each facility in the sample, EPA conducted a reasonable potential analysis to determine 

whether there is reasonable potential for the effluent to cause a water quality violation for 

any parameter.9For consistency with state implementation procedures (Ecology, 2015c), 

EPA utilized Ecology’s spreadsheet tool (PermitCalc) for permit writers for determining 

reasonable potential.10

For each facility and parameter, the reasonable potential analysis uses data on effluent 

concentrations, receiving water characteristics, ambient parameter concentrations, and 

dilution factors. EPA gathered these data from a variety of sources, including:

 Facility-specific permit fact sheets, available from PARIS

 Discharge Monitoring Report (DMR) data available from PARIS

 Ambient pollutant concentrations from the Environmental Information Management 

(EIM) database

 Other facility documentation such as inspection reports and permit applications, available 

from PARIS.

There were not sufficient and adequate data available for all sample facilities to perform 

reasonable potential analyses for all parameters for which human health criteria have been 

specified. EPA did not assess reasonable potential for parameters for which data were 

unavailable.11 Appendix A provides facility-specific reasonable potential results (under both

 

9

Parameters for which the revised human health criteria are more stringent than aquatic life criteria.

10 Available at: http://www.ecy.wa.gov/programs/wq/permits/guidance.html

11 Effluent data for two facilities (Chambers Creek STP and Steelscape) were not available for any of the 

pollutants for which human health criteria are proposed, so EPA did not carry the analysis further for these 

facilities.
POINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 22

the baseline and policy scenarios) and additional information on the specific data sources 

used for each facility.

4.1.3 Projecting Effluent Limitations

When EPA found reasonable potential, it calculated average monthly and maximum daily

effluent limitations based on procedures contained in the PermitCalc tool. These procedures 

specify that the permit writer first derive a waste load allocation according to the following 

equation:

WLA = D × WQC – Cb × (D – 1)

where,

WLA = waste load allocation (in units of concentration)

D = dilution factor

WQC = water quality criterion concentration (applicable human health criterion)

Cb = ambient background concentration (geometric mean).

In instances where the receiving water is impaired due to natural or irreversible 

anthropogenic conditions (i.e., Cb > WQC), EPA set the WLA equal to the WQC.12 This 

approach is consistent with EPA guidance (see EPA, 1991).

According to Chapter 7, Section 5.1 of the Washington Permit Writer’s Manual (Ecology, 

2015c), the projected average monthly effluent limitation (AML) to protect human health is 

computed by setting the AML equal to the applicable WLA:

AML = WLA (in units of concentration)

Chapter 7, Section 5.1 of the Washington Permit Writer’s Manual further states that the 

maximum daily effluent limit (MDL) is calculated by multiplying the AML by a factor 

derived on the basis of the effluent variability and the anticipated number of monitoring and 

compliance samples collected per month (which is based on EPA, 1991; Table 5-3).

In order to estimate compliance costs attributable to the proposed rule, EPA then compared 

the projected AML and MDL for each pollutant to the existing NPDES permit limitations for 

that pollutant. If the projected AML and MDL are more stringent than existing NPDES 

permit limitations, EPA estimated the costs for the control mechanisms required to ensure 

compliance with the projected AML and MDL (see Section 4.1.4). However, the NPDES 

permits for the sampled facilities do not contain any WQBELs.

 

12 It should be noted that the approach EPA used in instances when Cb > WQC differs from the approach used 

by Ecology. According to WAC 173-201A-260 (Natural conditions and other water quality criteria and 

applications), when the receiving water cannot meet applicable water quality criteria due to the natural 

conditions, the natural conditions represent the water quality criteria.
POINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 23

Based on EPA’s evaluation of the NPDES permit fact sheets for the sample facilities, it 

appears that the absence of WQBELs in the sample facility NPDES permits is due to a 

number of reasons. For example, in evaluating reasonable potential for the sample facilities, 

EPA identified instances where background pollutant concentrations exceeded applicable 

water quality criteria and no WQBELs were established based on Ecology’s use of natural 

conditions as the water quality criteria. In other instances, it was not clear based on the data 

and information provided in the fact sheet. Particularly for arsenic, EPA noted discussions in 

several permit facts sheets that describe the lack of data to quantify the extent of the natural 

background concentrations of arsenic, and a lack of regulatory mechanism to deal with the 

issue.

The lack of existing WQBELs may not accurately characterize the potential impacts

attributable to the proposed revisions to the human health criteria (i.e., compared to the NTR)

because the lack of existing WQBELs appears to be the result of implementing state-specific 

policies unrelated to EPA’s proposed rule that, should they continue to be applied in the 

context of revised criteria, would continue to result in a lack of WQBELs. However, it is also 

possible that Ecology would change these implementation policies and practices and develop 

and implement WQBELs. Therefore, a fair and reasonable approach to evaluate the potential 

upper-bound impact of EPA’s proposed rule is for EPA to evaluate reasonable potential 

based on the existing human health criteria as a baseline and determine whether a WQBEL 

would have been included in the permit were it not for the approaches and other policies used 

by Ecology. EPA’s approach reflects the most conservative approach to compliance with 40 

CFR 122.44(d)(1), which states that effluent limitations must be established when a pollutant 

is discharged “...at a level which will cause, have the reasonable potential to cause, or 

contribute to an excursion above any State water quality standard, including State narrative 

criteria for water quality.” Thus, in cases of no existing WQBELs under the baseline criteria

and current Ecology policies, EPA evaluated reasonable potential and projected baseline 

effluent limitations consistent with the approach described above. For facility-specific 

results, see Appendix A. 

In all cases, an AML would be more stringent than the corresponding MDL. Therefore, EPA 

compared the baseline AML to the projected AML to determine whether the discharger 

would be in compliance with the new effluent limitation. In the absence of a baseline effluent 

limitation (i.e., there was no reasonable potential to exceed existing human health criteria), 

EPA compared the maximum observed effluent concentration (MEC) to the projected AML 

to determine whether the discharger will be in compliance with the new effluent limitation. 

This method ensures facilities are discharging below applicable limitations. If the baseline 

AML or MEC exceeds the projected AML, compliance actions and associated costs are 

likely. A summary of these determinations is provided in Exhibit 4-3.
POINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 24

Exhibit 4-3. Summary of Projected Effluent Limitations and Incremental Load Reductions

under the Proposed Criteria

Facility Name1 QL (μg/L)

MEC or 

Baseline AML 

(μg/L)

Projected 

AML (μg/L)

Incremental 

Reduction 

(lbs/year)

Antimony

Transalta Centralia Generation 0.21 2.0 2.5 0

Arsenic

BP Cherry Point Refinery 0.5 19 0.81 720

Intalco Aluminum Corporation 0.5 11 0.46 237

King County South WWTP 0.5 0.14 0.0059 0

King County West Point WWTP 0.5 0.14 0.0059 0

Pasco WWTP 0.5 0.018 0.0045 0

Redondo WWTP 0.5 0.14 0.0059 0

Salmon Creek WWTP 0.5 0.14 0.0059 0

Sonoco Products Company 0.5 2.3 0.59 1.6

Tesoro Refining and Marketing 

Group 0.5 0.14 0.0059 0

Transalta Centralia Generation 0.5 0.018 0.0045 0

Transalta Centralia Mining 0.5 0.018 0.0045 0

US Oil & Refining 0.5 0.14 0.0059 0

Mercury

Transalta Centralia Mining 0.0005 0.0029 0.00088 0.031

BP Cherry Point Refinery 0.0005 0.0114 0.00088 0.42

Tesoro Refining and Marketing 

Group 0.0005 0.44 0.017 0.24

AML = average monthly effluent limitation

MEC = maximum effluent concentration

QL = quantitation level (as established by Ecology; see Attachment 1-I (to Form 2C) or Appendix A of 

EPA/Ecology Form 2A at http://www.ecy.wa.gov/programs/wq/permits/forms.html) 

WWTP = wastewater treatment plant

1. Includes sample facilities for which EPA found that there is reasonable potential to exceed the 

proposed criteria. Chambers Creek STP, Puyallup STP, Quincy Industrial, and Steelscape have no 

reasonable potential for any pollutants and are not included here. See Appendix A for more details.

EPA estimated the incremental pollutant loading reduction based on the difference between 

the MEC and the AML (either baseline or projected), in most circumstances, according to the 

following equation:

LR = 0.00834 × Q × (MEC – AML) × 365

where, 

LR = load reduction (lbs/year)
POINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 25

0.00834 = conversion factor [(lbs)(L)/(μg)(mg)]

Q = effluent flow rate (mgd)

MEC = maximum effluent concentration (μg/L)

AML = average monthly effluent limitation (μg/L)

When the AML was below the analytical limit of quantitation established by Ecology, EPA 

based the reduction on the difference between the MEC and the QL according to the 

following equation:

LR = 0.00834 × Q ×(MEC – QL) × 365

where, 

LR = load reduction (lbs/year)13

0.00834 = conversion factor [(lbs)(L)/(μg)(mg)]

Q = effluent flow rate (mgd)

MEC = maximum effluent concentration (μg/L)

QL = quantitation level (μg/L).

EPA calculated the incremental load reduction by subtracting the load reduction due to the 

baseline AML (i.e., the baseline scenario) from the load reduction from the projected AML 

(i.e., the policy scenario).

ILR = LRpolicy – LRbaseline 

where,

ILR = incremental load reduction (lbs/year)

LRpolicy = load reduction to meet the policy scenario (lbs/year)

LRbaseline = load reduction to meet the baseline scenario (lbs/year).

4.1.4 Identifying Compliance Scenarios and Costs

Analysis of the available data for the sample of facilities indicates that there are likely to be 

exceedances of projected effluent limits for arsenic and mercury (i.e., instances where the 

projected effluent limits under the baseline criteria are less stringent then the projected 

effluent limits based on the proposed criteria). There are a number of potential alternatives 

for compliance with effluent limits for these pollutants, including:

 Optimizing treatment processes (e.g., adding chemicals to increase flocculation or 

filtration efficiency) to increase pollutant removal efficiencies

 

13 In instances of a negative load reduction, EPA set the load reduction to zero.
POINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 26

 Source control (e.g., pollution prevention (P2) program, inflow and infiltration (I&I)

reductions, more stringent pretreatment standards)

 Installing end-of-pipe treatment technology (e.g., reverse osmosis, granular activated 

carbon, or chemical precipitation)

 Alternative compliance mechanisms (e.g., site-specific criterion, dilution credits, TMDL, 

or variance).

Dischargers will pursue the lowest cost means of compliance with effluent limitations. 

However, for the proposed human health criteria, technical feasibility is also an issue, 

particularly when projected effluent limitations are below analytical limits of quantification. 

Hence, there may be a need for alternative compliance mechanisms. For example, many 

projected effluent limitations based on the proposed arsenic human health criteria will be 

below analytical limits of quantification (i.e., dischargers will be unable to demonstrate 

compliance with the effluent limitations). 

Process Optimization

The lowest cost option is likely the adjustment of existing treatment (process optimization). 

This option would be most feasible when relatively low pollutant reductions are needed or 

monitoring data indicate that pollutant loads increase throughout the treatment process as a 

result of chemical additions or treatment techniques. 

Process optimization usually involves process analysis and process modifications. Process 

analysis is an investigation of the performance-limiting factors of the treatment process and 

is a key factor in achieving optimum treatment efficiency. Performance-limiting factors for 

common wastewater treatment processes (e.g., sedimentation, activated sludge, filtration) 

may include operator training, response to changes in wastewater quality, maintenance 

activities, automation, and process control testing. The cost of process analysis includes the 

cost of additional or continuous monitoring throughout the treatment process, and a treatment 

performance evaluation. These costs vary based on the number of treatment processes 

utilized and the magnitude of the reductions needed. 

Process modifications include activities short of adding new treatment technology units 

(conventional or unconventional) to the treatment train. For increasing pollutant removal 

efficiencies, process modifications could include adjusting coagulant doses to increase 

settling, equalizing flow if pollutant concentrations spike during wet weather events, 

increasing filter maintenance activities or backwash cycles, training operators, and installing 

automation equipment including necessary hardware and software. Several months of 

adjustments may be needed to achieve a desired level of process optimization. In practice, the 

process modifications necessary would be determined by the process analysis study.

Process optimization costs depend on the pollutant needing reductions and existing treatment 

processes and operations. For example, a facility could add a flocculent aid to secondary

treatment to increase solids removal, and thus, the removal of any pollutants that adhere to 

particulates (e.g., mercury). In addition, chemicals used in wastewater treatment could 
POINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 27

contain contaminants (e.g., chlorine contaminated with low levels of mercury), and for 

certain pollutants (e.g., mercury) the use of such chemicals could result in exceedances. 

Thus, switching chemicals or the source of chemicals could be another low cost process 

optimization control option. 

The effectiveness of process optimization largely depends on the efficiency of current 

operations, the existing treatment processes, and the fate and transport of the pollutant 

through the treatment train. For example, if a facility is already well maintained and 

operated, implementing process optimization may not result in sufficient pollutant reductions 

because the existing treatment processes are already performing at feasible limits. Also, 

because the design of most conventional treatment technologies maximizes removal of 

suspended solids, process optimization aimed at increasing those removal efficiencies may

not result in sufficient reductions for pollutants existing primarily in dissolved form. Given 

the available information for the sample facilities, it is generally not possible to determine the 

reductions achievable with process optimization; rather, a detailed, site-specific study would 

be necessary. 

Source Controls

If adjusting existing operations would not be feasible or would not be sufficient to achieve 

the necessary reductions, source controls would likely be the next most cost-effective control 

option. Source control could be used alone, or in conjunction with process optimization. The 

feasibility of source control efforts depends on the makeup of the influent and potential 

sources of the pollutant. For example, certain toxic pollutants are primarily used in industrial 

processes. Thus, for a municipal facility, a feasible source control option would be regulating 

indirect industrial dischargers through pretreatment permits. However, for pollutants in 

which the main sources are commercial and residential wastewater (e.g., mercury), a facility

would likely have to concentrate efforts on public outreach and education or a sewer use 

ordinance. Other pollutants, such as arsenic, may be present in the wastewater due to natural 

sources (e.g., groundwater), and reducing I&I or treating source water may be necessary.

Costs for source control activities depend on the pollutant and the measures or controls 

implemented. P2 programs can be a cost-effective means of reducing mercury in wastewater 

effluents. However, as contributing sources are identified and controlled, the costeffectiveness and efficacy that a P2 program would provide will diminish, and a discharger 

may need to pursue alternative compliance mechanisms (i.e., a variance) if compliance with 

permit conditions has not been achieved.

EPA estimated a range of source control actions and costs for control of arsenic that include 

industrial P2 programs, I&I reduction programs, and variances. In Washington, arsenic 

occurs naturally at high levels in state surface waters and groundwater (see 

http://www.ecy.wa.gov/programs/wq/swqs/PolicyForum5Presentations.pdf#page=31). These 

naturally occurring sources can be a significant source within municipal wastewater systems, 

as contaminated groundwater leaks into sewer systems. I&I controls may enable compliance 

with baseline and revised criteria and EPA estimated the associated costs based on unit costs 
POINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 28

used in other cost analyses conducted within the region. Note that these costs may be 

incurred independent of compliance with arsenic criteria or be partially off-set by secondary

benefits associated with I&I reduction activities (i.e., reduce flow to treatment plant, which 

reduces treatment costs, and sewer overflows).

Pollution Prevention Program

Successful P2 programs will likely include at least some of the following steps:

 Identify sources – particularly sources that contribute the greatest load to the influent

 Form a workgroup – preferably composed of representatives from government, industry, 

community, and environmental organizations that are either familiar with P2 strategies or 

familiar with the pollutant

 Define program goals – including a statement of how the municipality intends to reduce

pollutant levels in its effluent, the purpose for doing so, and a time line for completion

 Develop an approach – including selecting sectors for P2 efforts, the criteria for targeting 

efforts (e.g., size of the source loading, authority available to control the source, time 

required to produce desired results), whether efforts will be voluntary or regulatory, and 

who will execute each program effort

 Estimate program costs – develop estimates and identify entities that will bear the costs

 Implement program – starting with the most cost-effective measures and modifying 

activities and approach based on measured results

 Assess progress – including both successes and failures (i.e., lessons learned) throughout 

the duration of the program 

 Provide follow-up – necessary to ensure P2 measures continue to be implemented

 Develop a contingency plan – including a description of actions to be taken if plan efforts 

are unsuccessful.

The focus and approach of the program will be different for each community and sector 

targeted. As such, plans vary in complexity and in the resources necessary to achieve the 

goals set forth. 

The reductions in mercury achievable through P2, and thus the ability to achieve compliance 

with numeric effluent limits using P2 alone, will vary based on existing treatment processes, 

the makeup and size of the service area (e.g., number of potential mercury sources), and the 

level of P2 already being implemented in the community. For example, in 2003, the 

Washington State Legislature passed the Mercury Education and Reduction Act (MERA). 

MERA bans the sale of some mercury-containing products, requires the labeling of mercurycontaining light bulbs and lamps, and requires the removal of mercury from elementary and 

high schools. The State may fine repeat violators of MERA up to $5000 per violation.

Ecology also administers an automotive mercury switch removal program. Many

automobiles made before 2003 contain mercury switches or other mercury-containing 
POINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 29

equipment. Ecology offers auto recyclers up to $9 per mercury-containing component. 

Dentists in the State must use and maintain a dental amalgam separator.

Large municipal facilities with numerous potential mercury sources may see significant 

reductions after implementation of a measure that targets a major influent mercury source. 

However, facilities with much smaller service areas may not be able to achieve the same 

effluent reductions with P2 due to a lower percent of easily identifiable and controllable 

sources contributing to the influent mercury load. For example, sources from the residential 

sector are not as easy to identify as those from industrial and commercial sectors since these 

may originate from a wide range of products and smaller municipalities are likely to receive 

most of their inflow from the residential sector. 

There is little information available on the cost of P2 programs for individual pollutants 

because facilities typically do not account for pollutant-specific P2 costs as a budget item that 

can be verified apart from other base program costs. However, the experiences of facilities 

that have already developed P2 programs for pollutants such as mercury provide some 

information on likely program components and costs. 

Community size is likely to be a factor affecting P2 program costs. For example, it is 

unlikely that a minor facility would need the same amount of resources for program 

development and outreach efforts as a large major municipal facility because the service area 

is smaller and contains fewer households and commercial/industrial dischargers to target. 

Smaller facilities may also pool their resources together and develop a joint P2 program to 

save time and money on program development and outreach materials. 

EPA (2008)14 previously estimated that P2 program costs for mercury may be approximately

$58,000 per year for a small municipal facility (1 mgd to 5 mgd), $109,000 for a mediumsized municipal facility (≥5 mgd to 20 mgd), and to $165,000 per year for a large municipal 

facility (> 20 mgd). P2 program costs for pollutants with fewer potential sources would likely 

be lower ($25,000 to $50,000). More recent information pertaining to program costs is not 

available, but P2 programs should become less costly over time as more jurisdictions adopt 

these programs and refine best practices. EPA updated the labor rate components of these 

cost estimates to incorporate Washington-specific labor rates (Bureau of Labor Statistics

(BLS), 2014). In total, these estimates encompass costs for the following program 

components:

 Program planning and development

 Sampling and analysis of internal process waters and effluents

 Site visits and workshops

 Development of public-service announcements, advertising, and a website to promote 

awareness of program activities and goals

 

14 All historical cost estimates are converted and presented in terms of 2014 dollar values.
POINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 30

 Procurement and distribution of mercury free products (e.g., thermometers) to certain 

public and commercial sector entities. 

EPA also estimated costs to indirect dischargers to a municipal wastewater treatment plant

(WWTP) under a mercury P2 program (see Appendix A). For other pollutants, identifying 

groups of indirect dischargers likely to be contributing to the influent load at the treatment 

plant is more difficult because the pollutants are no longer actively used (e.g., legacy

pesticides), could be formed as a byproduct of numerous processes (e.g., dioxin), or there is a 

lack of information available. Thus, it is not possible to estimate pretreatment or P2 costs to 

indirect dischargers for pollutants other than mercury without specific information on the 

types of industrial dischargers in each service area.

End-of-Pipe Treatment

If process optimization or source control would not be sufficient for compliance with the 

baseline or revised criteria, alternative discharge options or end-of-pipe treatment 

technologies may be necessary. However, many of the criteria approach the limits of 

analytical capabilities (e.g., mercury) or fall below QLs (e.g., arsenic). In addition, for some

pollutants, the lowest levels achievable through end-of-pipe treatment are highly uncertain 

due to the fact that dischargers have not been required to treat to such low levels and 

performance data are not available. 

For metals such as mercury and arsenic, technologies that primarily target the dissolved 

fraction of the pollutant are most likely to achieve low effluent levels because most of the 

particulate fraction would already have been removed with existing treatment controls 

designed to remove solids (see discussion of process optimization). 

Exhibit 4-4 summarizes the end-of-pipe treatment technologies that may be used to remove 

the pollutants of concern. 

Exhibit 4-4. Summary of Potential End-of-Pipe Treatment Technologies

Technology Pollutants Removed

Granular activated carbon Mercury

Membrane filtration Arsenic, mercury

Reverse osmosis Arsenic

For this analysis, and as documented further in Appendix A (Facility Analyses), EPA 

determined that only end-of-pipe treatment for arsenic was necessary for ensuring 

compliance with projected effluent limits (i.e., there are compliance options other than 

treatment for mercury). Based on information contained in U.S. EPA 2008, EPA assumed the 

use of reverse osmosis as the treatment system for arsenic. Although less costly treatment 

options exist (e.g., membrane filtration), reverse osmosis can consistently reduce arsenic 

effluent concentrations to below analytical detection levels. EPA derived the costs for reverse 

osmosis treatment based on the costs documented in U.S. EPA, 2008.
POINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 31

Alternative Compliance Mechanisms

If none of the control options discussed above would result in compliance with baseline or 

revised effluent limitations, or if the costs of available treatment would be prohibitive, 

dischargers would likely need some form of relief from the requirements. 

Site-Specific Criteria

If dischargers suspect that the conditions in the vicinity of their discharge warrant alternative 

(i.e., site-specific) criteria values that would result in less stringent effluent limitations in 

their permit, they may work to collect data to develop site-specific criteria. Ecology may also 

develop site-specific criteria as part of a TMDL process (i.e., identifying the appropriate 

target value). EPA must review and approve site-specific criteria prior to implementation. 

Because additional data are likely required to assess the appropriateness of site-specific 

criteria at a particular location, the extent of use of this mechanism by dischargers is 

uncertain. However, consideration within the context of a TMDL is likely, and may or may

not reflect an incremental increase in effort above that associated with current TMDLs (this 

type of data collection and evaluation may already be a part of TMDL development efforts).

Intake Credits

Under 40 CFR 122.45(g), EPA allows dischargers to request that technology-based effluent 

limitations be adjusted to reflect credit for pollutants in the discharger’s intake water when 

certain conditions are met. However in terms of complying with WQBELs, the State of 

Washington does not yet have an approved intake credit policy and, therefore, does not 

provide intake credits for water quality-based effluent limitations. Therefore EPA did not 

consider intake credits as a valid compliance action for the proposed human health criteria.15

Variances

Under WAC 173-201A-420, Ecology may temporarily modify criteria for individual 

facilities, or stretches of water, through the use of a variance. Variances may be approved 

when:

(a) The modification is consistent with the requirements of federal law (currently 40 CFR 

131.10(g) and 131.10(h));

(b) The water body is assigned variances for specific criteria and all other applicable 

criteria must be met; and

(c) Reasonable progress is being made toward meeting the original criteria.

The decision to approve a variance is subject to a public and intergovernmental involvement 

process. Under the state’s current regulations, the department may issue a variance for up to 

five years, and may renew the variance after providing for another opportunity for public and 

intergovernmental involvement and review. Variances are not in effect until they have been 

 

15 Washington proposed an intake credit policy on January 12, 2015. See 

http://www.ecy.wa.gov/programs/wq/ruledev/wac173201A/1203ov.html.
POINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 32

adopted under state law and approved by EPA. Factors for allowing variances under 40 CFR 

131.10(g):

1. Naturally occurring pollutant concentrations prevent the attainment of the use.

2. Natural, ephemeral, intermittent, or low flow conditions or water levels prevent the 

attainment of the use, unless these conditions may be compensated for by the 

discharge of sufficient volume of effluent discharges to enable uses to be met without 

violating state water conservation requirements.

3. Human-caused conditions or sources of pollution prevent the attainment of the use 

and cannot be remedied or would cause more environmental damage to correct than 

to leave in place.

4. Dams, diversions, or other types of hydrologic modifications preclude the attainment 

of the use, and it is not feasible to restore the water body to its original condition or to 

operate such modification in a way which would result in the attainment of the use.

5. Physical conditions related to the natural features of the water body, such as the lack 

of a proper substrate, cover, flow, depth, pools, riffles, and unrelated to water quality

preclude attainment of aquatic life protection uses.

6. Controls more stringent than those required by CWA sections 301(b) and 306 would 

result in substantial and widespread economic and social impact.

To demonstrate that any of the first five conditions above apply as part of an application for a 

variance, dischargers would likely prepare documentation of the conditions warranting the 

variance. 

To evaluate the potential for control costs to cause substantial and widespread economic and 

social impacts (the sixth condition above), dischargers are likely to follow EPA’s (1995) 

Interim Economic Guidance for Water Quality Standards Workbook which provides 

worksheets and instructions for public and private sector entities. Following EPA (1995), 

dischargers conduct a two-step analysis, first determining whether the control costs would 

have a substantial adverse financial impact and, if so, whether that impact would cause 

widespread adverse impacts on the surrounding community.

Permitting authorities may require implementation of a P2 or source control program as part 

of the conditions for granting a variance. Thus, to be conservative (i.e., err on the side of 

overestimating costs), EPA assumed that facilities would need to implement a P2 program as 

part of a variance.

Dilution Credits

Under WAC 173-201A-410, Ecology may implement mixing zones and associated dilution 

credits in NPDES permits. Regulatory mixing zones may be established when a discharger 

has applied all known and reasonable treatment and a mixing zone analysis has been 

performed. Once approved, dilution credits can reflect no more than the level of effluent and 

ambient receiving water mixing which occurs under critical conditions. Dilution credits are 
POINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 33

used to account for the assimilative capacity of the receiving water when computing the 

waste load allocation applicable to a specific parameter and associated effluent limitations, as 

described in Section 4.1.3.

Dischargers who cannot readily comply with end-of-pipe effluent limitations based on the 

proposed human health criteria and who do not currently possess an approved regulatory 

mixing zone, may elect to pursue approval of a regulatory mixing zone as means of coming 

into compliance with the effluent limitations. 

When applying for a regulatory mixing zone, a special study is required to estimate and 

document the level of mixing which is likely to be present in the receiving water under 

applicable critical conditions. A special study of this type will typically require data 

collection and the mathematical modeling of the discharge and ambient receiving 

environment. In developing costs associated with developing a dilution special study, EPA 

estimated that approximately 320 hours would be required of an environmental engineer to 

develop and interpret the model, and an additional 50 hours by an environmental engineer at 

Ecology to review the model. EPA assumed the costs to obtain modeling software would be 

negligible, as EPA distributes software appropriate to this application (i.e., VisualPlumes) 

free of charge. Labor costs are based on median wage rates for an environmental engineer in 

the State of Washington (BLS, 2014).

4.1.5 Summary of Unit Control Costs

EPA based unit costs for P2 programs, I&I reduction, alternative compliance mechanisms, 

and end-of-pipe treatment (i.e., reverse osmosis) on estimates previously developed for 

economic analysis of WQS for the State of Oregon (U.S. EPA, 2008). EPA updated these 

costs to reflect local labor rates and escalated to 2014 dollars using appropriate cost indices.

16

EPA developed costs associated with applying for dilution credits and for process 

optimization special studies as described in Section 4.1.4. 

Exhibit 4-5 summarizes the unit costs utilized in the sample facility compliance cost

analyses.

Exhibit 4-5. Estimated Unit Costs of Compliance Mechanisms (2014$)

Compliance Mechanism

Municipals

1-5 mgd 5-20 mgd >20 mgd Industrials

Pollution prevention program ($/year) $58,000 $110,000 $165,000 $28,000

Other pollution prevention programs $60,000 $60,000 $60,000 $28,000

Dilution study $50,000 $50,000 $50,000 $50,000

End-of-pipe treatment (reverse 

osmosis)1 See note See note See note See note

 

16 EPA updated all costs to 2014$ using the consumer price index, except for pipeline rehabilitation costs; for 

these, EPA updated costs using the Engineering News Record Construction Cost Index. 
POINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 34

Exhibit 4-5. Estimated Unit Costs of Compliance Mechanisms (2014$)

Compliance Mechanism

Municipals

1-5 mgd 5-20 mgd >20 mgd Industrials

Variance $180,000 $300,000 $426,000 $180,000

Inflow and infiltration reduction ($/mile)2$69,000 $69,000 $69,000 See note

Source: EPA (2008); updated to 2014 dollars using the Engineering News Record Construction cost 

Index for inflow and infiltration pipeline rehabilitation and the average annual Consumer Price Index 

for other components. Dilution study estimate based on best professional judgement using 

assumptions identified in the text.

mgd = million gallons per day

1. EPA did not identify a need for end-of-pipe treatment costs for municipal dischargers; for industrial 

end-of-pipe treatment costs, EPA derived the following linear regression equation from the data in 

EPA (2008) to estimate costs:

y = [(1.1 x106)(x)]+(1.63x106)

where:

y = Total annual project cost ($ millions; 7% and 20 years)

x = Facility flow (mgd)

2. Inflow and infiltration reduction is applicable to municipal dischargers only.

4.1.6 Extrapolation to All Major Dischargers

To extrapolate the sample facility costs, EPA added the estimated compliance costs for the 

facilities in the certainty sample to the sum of the estimated costs for each facility in the 

random sample multiplied by the facility weight from the original sampling scheme. See 

Appendix B for details on this extrapolation.

4.2 Minor Dischargers

Minor dischargers often do not have monitoring requirements for toxic pollutants and may

not contribute significantly to instream loads even if such pollutants were present in the 

effluent from these facilities. Thus, the potential for minor facilities to incur costs as a result 

of revised human health criteria is low.

EPA reviewed data and information contained in the NPDES permit fact sheets for two 

minor industrial dischargers to evaluate potential for impact under the proposed rule [KB 

Alloys, LLC (WA0002976), and Sandvik Special Metals, LLC (WA0003701)]. The primary

pollutants of concern for which data were available are metals (e.g., aluminum, chromium, 

copper, cyanide, lead, nickel and zinc). For metals, aquatic life protection criteria are more 

stringent than the proposed human health criteria. For both facilities, due in part to the lack of 

background pollutant data (i.e., background was set equal to zero) and the dilution factors 

applied to each facility discharge, there was no reasonable potential to exceed water quality

criteria for the metals. The NPDES permits include technology-based effluent limitations for 

the metals of concern.

Effluent data were not available for all other pollutants for which human health criteria are 

being proposed. In the fact sheets for each facility, Ecology had determined that discharges 
POINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 35

from each facility are unlikely to contain chemicals regulated to protect human health.

Additional data would be needed to confirm or dispute this finding under the proposed rule.
NONPOINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 36

5. Methods for Identifying Potential Costs: Nonpoint Sources

Changes in water quality criteria could result in incremental impacts on nonpoint sources of 

pollution, such as agriculture, urban areas, and forestry, through TMDLs or other pollution 

cleanup plans. Section 2.2 discusses the nonpoint sources of pollution, and Section 2.3

summarizes the process by which Ecology categorizes waterbodies. Ambient water quality 

data can be used to determine the impact that a change in human health criteria may have on 

the attainment of the criteria and thus the potential for incremental control strategies and 

costs for nonpoint sources.

5.1 Identifying Exceedances

EPA identified potential incremental impairments based on available data in EIM. According 

to the state’s Water Quality Program Policy (Ecology, 2012d), Ecology generally uses the 

last ten years of data to determine impairment status of surface waters. EPA used available 

surface water monitoring data on pollutants of interest from EIM for the years 2005 to 

2014.17 EPA acknowledges that Ecology uses fish tissue equivalent concentrations to trigger 

waterbody impairments based on the human health criteria in their 303(d) listing 

methodology, whereas for the purposes of this analysis, EPA identified potential incremental 

impairments using water column concentrations. For each monitoring station and parameter, 

EPA compared the pollutant concentration to both the existing baseline human health criteria 

and the proposed criteria. Station results that would represent impairment under the proposed 

criteria but not under the existing baseline criteria may represent potential incremental 

impairments.18

Exhibit 5-1 shows the results of this analysis. Using the baseline criteria values, monitoring 

data indicate potential impairment on the basis of human health criteria exceedances in the 

water column at 205 stations. Using the proposed criteria, there would be exceedances in the 

 

17 EPA did not include observations resulting from sampling at known contamination sites, cleanups, 

groundwater, and outfall monitoring stations. EPA acknowledges that Ecology may use such data to 

determine impairments. Additionally, EPA eliminated observations with the following data qualifiers: U 

(analyte was not detected at or above the reported result) and UJ/UJG/UJK (analyte was not detected at or 

above the reported estimate), REJ (data are unusable for all purposes), but kept observations with the 

following qualifiers: J (analyte was positively identified, reported result is an estimate), JL (analyte was 

positively identified, value may be less than reported, B (analyte detected in sample and method blank), T 

(result is below quantitation level but above MDL), JK (analyte was positively identified, reported result is 

an estimate with unknown bias), JT (analyte was positively identified, reported result is estimate below

quantitation level but above MDL), C (not specified), and NTJ (evidence that analyte is present, estimate is

below quantitation level but above MDL). 

18 Note that these results may not reflect the actual listed impairment status of the waterbody. EPA compared 

identified impairments to Ecology’s current draft impairment listings; however, data limitations (e.g. the 

ability to match monitoring stations to existing impairment status at the waterbody level across data sets) 

largely preclude matching of monitoring stations to specific waterbody impairments.
NONPOINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 37

water column at 254 stations, for a total of 49 potential incremental exceedances (or a 24% 

increase compared to the baseline).

Exhibit 5-1. Potential Incremental Impairments1

Parameter

Number of 

Locations

Potential Impairments

Baseline2Proposed3Incremental4

1,2-Dichloropropane D

1,3-Dichloropropene D

2,3,7,8-TCDD (dioxin) D

4,4'-DDT 45 7 24 17

Acenaphthene 5 0 0 0

Anthracene 8 0 0 0

Antimony 49 0 0 0

Arsenic 178 167 167 0

Benzo(a) anthracene 16 5 7 2

Benzo(a) pyrene 10 5 7 2

Benzo(b) fluoranthene 10 6 7 1

Benzo(k) fluoranthene 15 4 5 1

Bis(2-ethylhexyl) phthalate 22 0 14 14

Butylbenzyl phthalate 6 0 2 2

Chlordane D

Chrysene 10 5 4 -1

Copper5238 0 0 0

Dibenzo(a,h) anthracene 6 2 3 1

Diethyl phthalate 6 0 0 0

Dimethyl phthalate 2 0 0 0

Di-n-butyl phthalate 19 0 0 0

Fluoranthene 11 0 0 0

Fluorene 5 0 0 0

Indeno(1,2,3-cd) pyrene 15 4 6 2

Nickel 163 0 0 0

Polychlorinated biphenyls 

(PCBs)

D

Pyrene 10 0 0 0

Thallium 6 0 0 0

Zinc5201 0 0 0

Mercury618 0 8 8
NONPOINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 38

Exhibit 5-1. Potential Incremental Impairments1

Parameter

Number of 

Locations

Potential Impairments

Baseline2Proposed3Incremental4

Source: Based on 2005 to 2014 surface water monitoring data from Washington’s Environmental 

Information Management System (EIM).

D = EIM data are available, but all observations are unusable due to the study type (contaminated 

site), waterbody type (groundwater), or result qualifiers.

1. Blanks indicate that data are not available, or that EPA did not use all observations due to study, 

location, or data quality reasons.

2. Number of stations at which monitoring data indicate two or more exceedances of the baseline 

human health criteria within 3 years.

3. Number of stations at which monitoring data indicate two or more exceedances of the proposed 

human health criteria within 3 years.

4. Represents difference in results between baseline and proposed criteria.

5. For zinc, nickel, and copper, includes only freshwaters since the aquatic life criteria are more 

stringent than proposed human health criteria for marine waters.

6. Potential to exceed the proposed fish tissue criterion based on the projected water column target.

5.2 Identifying Compliance Actions and Costs

EPA does not have data on all parameters for all waterbodies, or data on the sources of 

loadings to potentially impaired waterbodies. Additionally, Ecology is currently in the 

process of revising and updating its management plan for nonpoint source pollution (see 

Ecology, 2015b). Reductions in nonpoint source pollution loadings arising from this revised 

plan will occur in the absence of the proposed rule and represent baseline requirements. 

If the revised criteria lead to additional waters being listed on the state’s 303(d) list for 

exceedances of human health based water quality criteria, the magnitude of cost impacts to 

nonpoint sources depends on the extent to which additional practices are needed for 

compliance with the potential revisions in comparison to compliance with existing baseline 

standards. 

If nonpoint sources are the primary cause of some incremental impairments, then the revised 

criteria may result in some costs to nonpoint sources, including:

 Agricultural and forest lands – sediment and erosion controls beyond those specified 

under existing state and federal regulations and plans;

 Mining – cleanup and remediation including excavation and onsite capping of 

contaminated soils, capping of onsite solid waste mining debris, regrading of tailings to 

mitigate mass wasting and off-site migration, and abatement and mitigation of physical 

hazards; and

 Stormwater discharges – increased or additional nonstructural BMPs (e.g., institutional, 

education, or P2 practices designed to limit generation of runoff or reduce the pollutants 

load of runoff); and structural controls (e.g., engineered and constructed systems 

designed to provide water quantity or quality control). 
NONPOINT SOURCE COSTS: METHODS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 39

Control of nonpoint sources of the pollutants of concern could reduce costs to point sources. 

In the context of a TMDL, load and wasteload allocations reflecting the source of the 

pollutant could result in less stringent limits for point sources than anticipated through the 

analysis of the sample facilities as described in Section 4. 

If an additional number of TMDLs are needed under the revised criteria, there may be an 

increase in government regulatory costs. EPA (2001b) estimates that TMDL development 

costs per water body typically range from under $26,000 to over $500,00019 depending on 

the number of TMDLs, the level of complexity, and the extent to which impaired waters are 

clustered together for TMDL development.

20

 

 

19 Not updated from original dollar years (2000$).

20 EPA (2001b) anticipates that in the future, states will increasingly adopt efficient practices when 

developing TMDLs, thus potentially reducing development costs.
COMPLIANCE COSTS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 40

6. Potential Compliance Costs

This section summarizes the potential costs to point sources and nonpoint sources, and 

discusses the limitations and uncertainties associated with the analyses. 

6.1 Point Sources

Costs for compliance with baseline criteria include costs associated with compliance with 

WQBELs reflective of existing criteria. Incremental costs associated with the potential 

revised criteria represent the costs of any additional actions or controls needed for 

compliance with revised WQBELs under the proposed rule. Exhibit 6-1 provides a summary

of the potential total annual statewide costs. The low estimate represents the assumption that 

the projected control scenario will result in compliance with projected effluent limits; the 

high estimate includes the estimated cost of also obtaining a variance under the assumption 

that control actions will not result in compliance with very low limits. For the 73 major 

dischargers in the state, EPA estimates that the total annual cost may be in the range of $13 

million.

21

Exhibit 6-1. Total Annual Costs by Discharger Type

Discharger Type

Statewide Annual Costs (millions; 2014$)

Low High

Municipal $0.00 $0.00

Industrial $13.03 $13.06

Total $13.03 $13.06

Of the costs shown in Exhibit 6-1, all costs are attributable to industrial dischargers, 

primarily for treatment of arsenic. Overall, 99% of the costs are attributable to the revised 

human health criteria for arsenic while the remaining 1% are attributable to the revised 

human health criteria for mercury.

6.2 Nonpoint Sources

Costs for compliance with baseline criteria include costs to nonpoint sources (e.g., 

agricultural and forest operations; contamination from historic mining sites), and municipal 

stormwater sources associated with implementation of existing programs and TMDLs. 

Incremental costs associated with compliance with the potential revised criteria represent the 

costs of any actions or controls above and beyond those needed to meet baseline 

requirements. EPA did not estimate incremental costs for nonpoint sources for this 

preliminary analysis. However, if nonpoint sources are the primary source of the pollutants 

 

21 These costs represent the proposed criteria scenario only. EPA estimated costs to come into compliance 

with baseline criteria to be in the range of $46.4 million to $47.1 million. For a description of sample 

facility-specific baseline and proposed criteria scenario costs, see Appendix A.
COMPLIANCE COSTS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 41

of concern, control of nonpoint sources could result in less stringent limitations and lower 

costs than estimated for point sources. For situations in which controls beyond those required 

under the baseline are necessary, controls could include the development and implementation 

of TMDLs. 

6.3 Uncertainties and Quality Assurance

As noted previously, the proposed rule does not establish any requirements directly

applicable to regulated entities or other sources of pollution. State implementation of the 

proposed rule may result in new or revised NPDES permit conditions for point source 

dischargers, and incremental control requirements for nonpoint sources. For point sources,

EPA has estimated these impacts as the difference between compliance with the existing 

human health criteria and compliance with the proposed human health criteria. However, 

there is substantial uncertainty associated with actual state implementation of the proposed 

rule. 

The proposed rule establishes human health criteria applicable to the waters in the state and

as such there could be a need for additional controls on nonpoint sources of pollutant

loadings to attain WQS. EPA estimated potential incremental impairments using readily

available ambient water quality data. However, data are limited to identify specific 

incremental control actions and costs that may be required of nonpoint sources.

Exhibit 6-2 summarizes additional uncertainties and limitations in the analysis.

Exhibit 6-2. Uncertainties in Analysis of Costs

Uncertainty/Assumption

Effect on Cost 

Estimate Notes

Sample facility costs are 

representative of all facilities in 

state (by category)

Uncertain

Could result in an overestimate or 

underestimate of statewide costs if sample 

facilities are higher or lower than average 

costs. Does not account for new/expanding

facilities.

Baseline controls Uncertain

EPA did not conduct extensive site-specific 

review of facility plans and information for 

addressing baseline water quality issues; 

thus, facility analyses could under- or 

overstate baseline and incremental actions 

and costs.

Means of addressing incremental 

impairments Overestimate

Under a TMDL, load and wasteload 

allocations may result in less stringent 

requirements for point sources if nonpoint 

sources are the cause of impairments.

Zero compliance costs for two 

sample facilities for which effluent 

data are not available

Underestimate

If these facilities do need to take actions to 

comply with the revised requirements, the 

total cost of compliance would be greater 

than that estimated here.
COMPLIANCE COSTS

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 42

Exhibit 6-2. Uncertainties in Analysis of Costs

Uncertainty/Assumption

Effect on Cost 

Estimate Notes

Total arsenic and dissolved 

arsenic monitoring data represent 

only the inorganic fraction of 

arsenic

Overestimate

Effluent and ambient monitoring data 

available for the analysis are in terms of total 

and dissolved arsenic; if some fraction of 

arsenic measured is in the organic form then 

this may result in an overestimate of costs 

since the proposed criterion is in terms of the 

inorganic form, which is more toxic than other 

forms.

 

EPA conducted quality assurance checks on the data, analyses, and results, consistent with 

the programmatic and project-specific quality assurance plans. In addition, the Agency used 

Ecology’s permit-writing tool, ensuring consistency with state permitting approaches and 

calculations. EPA also used Washington-specific data sources as available, and for all data 

entry, EPA confirmed the accuracy of data sources and documentation following procedures 

described in the quality assurance plans. These procedures include checks on all inputs and 

calculations, and using multiple approaches to confirm results.
REFERENCES

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 43

7. References

Bureau of Labor Statistics, United States Department of Labor. 2014. May 2014 State 

Occupational Employment and Wage Estimates: Washington. (available at: 

http://www.bls.gov/oes/current/oes_wa.htm)

Department of Ecology, State of Washington (Ecology). 2015a. Phase I Municipal 

Stormwater Permit. National Pollutant Discharge Elimination System and State Waste 

Discharge General Permit for Discharges from Large and Medium Municipal Separate Storm 

Sewer Systems. Modification Date: January 16, 2015.

Department of Ecology, State of Washington (Ecology). 2015b. Washington’s Water Quality

Management Plan to Control Nonpoint Sources of Pollution: Draft. Publication No. 15-10-

015.

Department of Ecology, State of Washington (Ecology). 2015c. Water Quality Program 

Permit Writer’s Manual. Publication Number 92-109.

Department of Ecology, State of Washington (Ecology). 2014a. Draft -- Washington Human 

Health Criteria Review Documents. Revised 8/8/2014.

Department of Ecology, State of Washington (Ecology). 2014b. Frequently Asked Questions, 

Water Quality Program: Municipal Stormwater Permits.

Department of Ecology, State of Washington (Ecology). 2014c. Western Washington Phase 

II Municipal Stormwater Permit. National Pollutant Discharge Elimination System and State 

Waste Discharge General Permit for Discharges from Small Municipal Separate Storm 

Sewers in Western Washington. Modification Date: January 16, 2014.

Department of Ecology, State of Washington (Ecology). 2014d. Industrial Stormwater 

General Permit. A National Pollutant Discharge Elimination System (NPDES) and State 

Waste Discharge General Permit for Stormwater Discharges Associated with Industrial 

Activities. Issuance Date: December 3, 2014.

Department of Ecology, State of Washington (Ecology). 2014e. Water Quality Improvement 

Project Deschutes River Watershed Area: Multi-Parameter. Available at: 

http://www.ecy.wa.gov/programs/wq/tmdl/deschutes/index.html (accessed 4/7/2015).

Department of Ecology, State of Washington (Ecology). 2012a. 2012 Stormwater 

Management Manual for Western Washington. Amended in December 2014. Publication 

Number 14-10-055. 

Department of Ecology, State of Washington (Ecology). 2012b. Eastern Washington Phase II 

Municipal Stormwater Permit. National Pollutant Discharge Elimination System and State 

Waste Discharge General Permit for Discharges from Small Municipal Separate Storm 

Sewers in Eastern Washington. Issuance Date: August 1, 2012.
REFERENCES

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 44

Department of Ecology, State of Washington (Ecology). 2012c. Water Quality Improvement 

Project, Yakima Watershed Area: Toxics. Available at: 

http://www.ecy.wa.gov/programs/wq/tmdl/yakima_wq/YakToxicsTMDL.html (accessed 

4/7/2015).

Department of Ecology, State of Washington (Ecology). 2012d. Water Quality Program 

Policy: Assessment of Water Quality for the Clean Water Act Section 303(d) and 305(b) 

Integrated Report. Chapter 1: WQP Policy 1-11.

Department of Ecology, State of Washington (Ecology). 2010. Yakima River Pesticides and 

PCBs Total Maximum Daily Load. Volume 1: Water Quality Study Findings. Publication 

No. 10-03-018. 

Department of Ecology, State of Washington (Ecology). 2007a. Palouse River Chlorinated 

Pesticides and PCBs Total Maximum Daily Load: Water Quality Improvement Report and 

Implementation Plan. Publication No. 07-03-018.

Department of Ecology, State of Washington (Ecology). 2007b. Mission Creek Watershed 

DDT Total Maximum Daily Load: Water Quality Improvement Report. Publication No. 07-

10-046.

Department of Ecology, State of Washington (Ecology). 2006a. Walla Walla River 

Chlorinated Pesticides and PCBs Total Maximum Daily Load (Water Cleanup Plan): 

Submittal Report. Publication No. 05-10-079.

Department of Ecology, State of Washington (Ecology). 2006b. Lake Chelan Watershed 

DDT and PCB Total Maximum Daily Load: Water Quality Improvement Report. Publication 

No. 06-10-022.

Department of Ecology, State of Washington (Ecology). 2005. Lower Okanogan River Basin 

DDT and PCBs Total Maximum Daily Load: Submittal Report. Publication No. 04-10-043.

Department of Ecology, State of Washington (Ecology). 2004a. Stillaguamish River 

Watershed Fecal Coliform, Dissolved Oxygen, pH, Mercury, and Arsenic Total Maximum 

Daily Load (Water Cleanup Plan): Submittal Report. Publication No. 05-10-044.

Department of Ecology, State of Washington (Ecology). 2004b. Lower Similkameen River 

Arsenic Total Maximum Daily Load: Submittal Report for Joint Issuance. Publication 

Number 03-10-074.

Department of Ecology, State of Washington (Ecology). 2001. Inner Bellingham Bay

Contaminated Sediments Total Maximum Daily Load: Submittal Report. Publication 

Number 99-58-WQ.

Department of Ecology, State of Washington (Ecology). 1999. Spokane River Dissolved 

Metals Total Maximum Daily Load: Submittal Report. Publication Number 99-49-WQ.

Department of Ecology, State of Washington (Ecology). 1992a. Total Maximum Daily Load. 

TMDL Number: 07-001.
REFERENCES

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 45

Department of Ecology, State of Washington (Ecology). 1992b. Total Maximum Daily Load. 

TMDL Number: 10-001.

United States Environmental Protection Agency (U.S. EPA). 2014. Toxicity and 

Bioaccumulation Factors Used in the Draft 2014 Updated Ambient Water Quality Criteria for 

the Protection of Human Health. (available from: 

http://water.epa.gov/scitech/swguidance/standards/criteria/current/hhdraft.cfm)

United States Environmental Protection Agency (U.S. EPA). 2012. Water: Contaminated 

Sediments. Basic Information. (available from: 

http://water.epa.gov/polwaste/sediments/cs/aboutcs.cfm)

United States Environmental Protection Agency (U.S. EPA). 2008. Cost of Compliance with 

Water Quality Criteria for Toxic Pollutants for Oregon Waters. Prepared by Science 

Applications International Corporation.

United States Environmental Protection Agency (U.S. EPA). 2002. National Recommended 

Water Quality Criteria: 2002. Human Health Criteria Calculation Matrix. EPA 822-R-02-

012. November.

United States Environmental Protection Agency (U.S. EPA). 2001a. Water Quality 

Criterion for the Protection of Human Health: Methylmercury. EPA-823-R-01-001. 

January.

United States Environmental Protection Agency (U.S. EPA). 2001b. The National Costs of 

the Total Maximum Daily Load Program (Draft Report). EPA 841-D-01-003. August.

United States Environmental Protection Agency (U.S. EPA). 1995. Interim Economic 

Guidance for Water Quality Standards Workbook. EPA 823-B-95-002. March.

United States Environmental Protection Agency (U.S. EPA). 1991. Technical Support 

Document for Water Quality-Based Toxics Control. EPA/505/2-90-001.

United States Environmental Protection Agency (U.S. EPA). 1980. Guidelines and 

Methodology Used in the Preparation of Health Effect Assessment Chapters of the Consent 

Decree Water Criteria Documents. Federal Register 45: 79347, Appendix 3.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 46

Appendix A – Facility Analyses

This appendix provides detailed analyses for the sample facilities in alphabetical order by

municipal dischargers first followed by industrial dischargers.

A.1 Chambers Creek Regional Wastewater Treatment Facility

The Chambers Creek Regional Wastewater Treatment Facility (WWTF; NPDES permit

WA0039624) provides wastewater treatment to 65,000 households and 2,000 businesses in 

DuPont, Lakewood, Tacoma, University Place, Steilacoom, and other unincorporated areas. 

The facility also treats wastewater from five industrial users, including the Boeing 

Corporation Skin and Spar fabrication facility, the Land Recovery Incorporated Hidden 

Valley Landfill, James Hardie Building Products, and Fredrickson Power.22 The facility

discharges a maximum monthly flow of 14 to 20 mgd (dry weather flow and maximum 

monthly flow, respectively) to Puget Sound Gordon Point Area.

A.1.1 Treatment Processes

The 2008 permit fact sheet indicates that the current treatment consists of screening 

equipment and primary sedimentation; secondary treatment includes bioselectors, secondary

clarifiers and ultraviolet disinfection.

A.1.2 Effluent Data 

No recent effluent monitoring data for the WWTF were available for any of the pollutants for 

which human health criteria are being proposed. 

A.1.3 Receiving Water

The facility discharges to Puget Sound Gordon Point Area, which is a Class AA 

extraordinary receiving water. According to the 2008 permit fact sheet, Commencement Bay

(monitoring station BRW-COMMENCEBAY) is the nearest monitoring station with 

available water column data. Exhibit A-1 summarizes the available ambient receiving water 

concentrations for the station based on data from Ecology’s Environmental Information 

Management System between 2008 and 2009. 

Exhibit A-1. Ambient Receiving Water Concentrations: Commencement Bay

Pollutant Water Column Concentration (μg/L)

Maximum Average

Copper 1.3 0.837

Zinc 2.91 1.515

Source: Washington State Department of Ecology Environmental Information Management System, 

2008 to 2009 data for station BRW-COMMENCEBAY.

 

22 The 2008 Fact Sheet does not identify the fifth industrial discharger.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 47

A.1.4 Baseline Scenario

The permit does not include any WQBELs based on the existing human health criteria for the 

pollutants of concern. The necessary data to confirm the reasonable potential analysis under 

the baseline scenario were not available. 

A.1.5 Policy Scenario

EPA did not have the necessary data to perform the reasonable potential analysis under the 

policy scenario. Thus, it could not determine reasonable potential or calculate permit limits 

and costs.

A.2 King County South WWTP and CSO System

The King County Department of Natural Resources and Parks (Wastewater Treatment 

Division) operates the King County South WWTP (NPDES permit WA0029581), which 

serves 25 jurisdictions and utility districts, including Seattle, across 152 square miles. The 

majority of flow to the treatment facility is from separated sanitary systems, with 

approximately 4% coming from a combined system in Seattle. Average WWTP flow is 76 

mgd.

A.2.1 Treatment Processes

The 2009 permit fact sheet reports that primary treatment consists of screening and settling 

followed by primary clarification. Secondary treatment is an activated sludge process and 

includes aeration and secondary clarification. After disinfection (using sodium hypochlorite), 

effluent is discharged to Puget Sound.

A.2.2 Effluent Data 

Exhibit A-2 summarizes the last three years of effluent data for the treated wastewater for the 

pollutants of concern for which data are available, based on Ecology’s priority pollutant 

monitoring data and reasonable potential analysis (Appendices C and H in the 2009 permit 

fact sheet). 

Exhibit A-2. Summary of Effluent Data: King County South WWTP1

Pollutant

Observations

QL (μg/L)

Summary of Detected Values (μg/L)2

Total Nondetect Median Average

95th 

Percentile Max

1,1,2,2-Tetrachloroethane 23 23 1

1,1,2-Trichloroethane 23 23 1

1,2,4-Trichlorobenzene 24 24 0.57-0.71

1,2-Trans-dichloroethylene 23 23 1

2,4-Dimethylphenol 24 24 0.94 – 1.2

2,4-Dinitrophenol 24 24 1.9 – 2.4

2-Chlorophenol 24 24 1.9 – 2.4

Acenaphthene 24 24 0.57-0.71
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 48

Exhibit A-2. Summary of Effluent Data: King County South WWTP1

Pollutant

Observations

QL (μg/L)

Summary of Detected Values (μg/L)2

Total Nondetect Median Average

95th 

Percentile Max

Acrolein 23 23 5

Acrylonitrile 23 23 5

Antimony 32 0.5 0.25 <0.51 0.514 0.67

Arsenic 34 0.5 1.26 1.516 1.60

Benzene 23 23 1

Benzidine 24 24 23-28

Benzo(a) anthracene 24 24 0.57-0.71

Bromoform 23 23 1

Carbon tetrachloride 23 23 1

Chloroform 23 1.32 1.3 <1.32 2.034 2.18

Copper 32 0.4 16.5 31.34 42.4

Cyanide 33 0.005 .0025 <0.008 0.019 0.028

Dichlorobromomethane 23 23 1

Ethylbenzene 23 23 1

Fluoranthene 24 24 0.57-0.71

Fluorene 24 24 0.57-0.71

Hexachlorocyclopentadiene 24 24 0.94-1.2

Hexachloroethane 24 24 0.94-1.2

Indeno(1,2,3-cd) Pyrene 24 24 0.94-1.2

Isophorone 24 24 0.94-1.2

Methyl bromide 23 23 5

Methylene chloride 23 5 2.5 <4.74 2.5 7

Nickel 33 0.3 2.90 2.99 4.004 4.45

Nitrobenzene 24 24 0.94-1.2

N-Nitrosodimethylamine 24 24 3.8-4.7

N-Nitrosodi-n-propylamine 24 24 0.94-1.2

N-Nitrosodiphenylamine 24 24 0.94-1.2

Pentachlorophenol (PCP) 24 24 0.94-1.2

Phenol 24 24 3.9

Pyrene 24 24 0.57-0.71

Selenium 33 33 1.5

Tetrachloroethylene 23 23 1

Thallium 33 33 0.04-0.2
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 49

Exhibit A-2. Summary of Effluent Data: King County South WWTP1

Pollutant

Observations

QL (μg/L)

Summary of Detected Values (μg/L)2

Total Nondetect Median Average

95th 

Percentile Max

Toluene 23 4 2 <1.45 3.41 3.86

Trichloroethylene 23 23 1

Vinyl Chloride 23 23 1

Zinc 33 0.5 29 49.34 68

Mercury 33 0.05 0.025 <0.05 0.052 0.058

Source: 2009 permit fact sheet (Appendix C and H).

QL = quantitation level

1. Blanks indicate unreported data.

2. Metal concentrations are total recoverable form.

A.2.3 Receiving Water

The facility discharges to Puget Sound, which Ecology has designated as an extraordinary

marine water. Exhibit A-3 summarizes the available ambient receiving water concentrations 

based on 2011 to 2012 data from Ecology’s Environmental Information Management System 

(monitoring station LSNT01, identified in the permit fact sheet as the most appropriate 

monitoring station for ambient data). 

Exhibit A-3. Ambient Receiving Water Concentrations (2011 to 2012): Puget Sound

Pollutant

Water Column Concentration (μg/L)1

Minimum Median Geometric 

Mean

90th 

Percentile Maximum

Antimony 0.143 0.158 0.158 0.172 0.173

Arsenic 1.22 1.4 1.364 1.45 1.46

Copper 0.231 0.287 0.296 0.355 0.387

Cyanide nd nd nd nd nd

Mercury nd nd nd nd nd

Nickel 0.39 0.4115 0.410904577 0.4275 0.43

Zinc 0.27 0.395 0.428224144 0.605 0.707

Source: based on data from Ecology’s Environmental Information Management System, monitoring 

station LSNT01.

nd=nondetect

1. Metal concentrations are dissolved.

A.2.4 Baseline Scenario

The permit does not include any WQBELs based on the existing human health criteria for the 

pollutants of concern. In this case, EPA performed a reasonable potential analysis for each 

pollutant based on the baseline (i.e., existing) human health criteria to confirm whether a 
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 50

WQBEL would have been included in the NPDES permit.23 In cases of reasonable potential, 

EPA calculated a WQBEL using the existing human health criteria and evaluated compliance 

with this baseline WQBEL. 

Exhibit A-4 summarizes the reasonable potential analysis under the policy scenario. Based 

on effluent concentrations in Exhibit A-2 and available ambient data in Exhibit A-3, there is 

reasonable potential to exceed the baseline human health criteria for arsenic.

Exhibit A-4. Human Health Reasonable Potential Analysis for King County South 

WWTP – Baseline Scenario1

Parameter Effluent Conc. 

(total; μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 1.26 1.364 1.364 0.14

1. See effluent concentrations in Exhibit A-2 (reasonable potential analysis uses the maximum or 95th

percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean) and available ambient concentrations in Exhibit A-3. 

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 428.

3. Consumption of organisms only.

Exhibit A-5 summarizes the calculated permit limits for arsenic under the baseline scenario. 

Exhibit A-5. Human Health Based Effluent Limitations for King County South WWTP –

Baseline Scenario

Parameter Average Monthly Effluent Limit 

(total; ug/L)1

Maximum Daily Effluent Limit 

(total; ug/L)1

Arsenic 0.14 0.16

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Under the baseline scenario, the discharger would have to meet an average monthly effluent 

limit (AML) of 0.14 μg/L and a maximum daily effluent limitation (MDL) of 0.16 μg/L. 

Since the average effluent concentration is 1.26 μg/L and the maximum effluent 

concentration is 1.6 μg/L, which are greater than the projected baseline permit limitations, 

the discharger will need to reduce arsenic in its effluent to ensure that permit limitations are 

consistently met.

Arsenic and arsenic-containing chemicals are not used in wastewater treatment. However, the 

facility has a large industrial base and regulates 65 industrial users of which 27 are 

significant industrial users and 19 are categorical industrial users (i.e., users subject to EPA’s 

 

23 Based on 40 CFR 122.44(d)(1), were it not for the approaches and other policies used by Ecology. 40 CFR 

122.44(d)(1) requires that effluent limitations must be established when a pollutant is discharged “...at a 

level which will cause, have the reasonable potential to cause, or contribute to an excursion above any State 

water quality standard, including State narrative criteria for water quality.”
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 51

national pretreatment standards), including 32 in the electroplating and metal finishing 

categories. Thus, a source control program that targets or imposes more stringent limits on 

the most likely indirect industrial dischargers of arsenic to the plant could reduce arsenic 

concentrations to the necessary levels. Costs for such a program would depend on the 

number of arsenic sources and the measures that could be implemented at those sources to 

reduce arsenic. However, without more detailed information on these industrial users and

King County’s pretreatment program (e.g., flows and arsenic concentrations for each 

industrial user, local limits for arsenic, ordinances, etc.), it is not possible to estimate 

pretreatment or P2 costs to indirect dischargers. 

Other potential sources of arsenic to the treatment plant are water and groundwater 

infiltration. Details on the drinking water sources for the municipalities served by King 

County South, including whether these sources are surface water or groundwater and levels 

of arsenic in these sources, were not evaluated. The drinking water maximum contaminant 

level is 10 μg/L, which is higher than current wastewater effluent concentrations and human 

health criteria. EPA did not attempt to determine with any certainty whether drinking water is 

contributing to high arsenic levels in the wastewater effluent. However, if the facility 

determines that drinking water is the source of high arsenic values in the wastewater, it is 

likely that the facility would pursue a variance.

The fact sheet for the facility’s 2009 permit indicates that King County created a Regional 

Infiltration and Inflow (I&I) Control Program in 1999 as part of the Regional Wastewater 

Services Plan (RWSP) to explore the feasibility of a regional I&I control program to reduce 

the amount of peak wet weather flow entering the County's wastewater conveyance. In 

response to the RWSP I&I Control Program policies, County staff, working in a consensusbased approach with the local sewer agencies, conducted a comprehensive 6-year, $41 

million, I&I control study. The study began in 2000 and culminated with the County

Executive’s recommendation for a regional I&I control program. 

The study included: defining levels of I&I for each local agency tributary to the regional 

system through an extensive flow monitoring and modeling program; constructing 10 pilot 

projects in 12 local agency jurisdictions to demonstrate the effectiveness of collection system 

rehabilitation projects and to test various technologies and gain cost information; developing 

model standards, procedures, policies, and guidelines for use by local agencies to reduce I&I 

in their systems; performing a cost-benefit analysis to determine the cost-effectiveness of I&I 

reduction; developing a long-term regional I&I control plan; working with the local sewer 

agencies to conduct an I&I reduction feasibility analysis; and performing several I&I 

reduction projects. 

As the focus of these studies and analyses were on reduction of peak flows to minimize 

combined sewer overflows, it is uncertain whether this I&I reduction program and these 

modifications to the collection system would address arsenic levels (there are a number of 

modifications that can correct I&I issues that would not necessarily reduce arsenic 

concentrations). If groundwater infiltration is causing the high arsenic effluent levels, the 
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 52

facility may have to implement modifications to the existing I&I reduction program for 

compliance with the baseline scenario criteria.

Due to the fact that ambient receiving water concentrations exceed the baseline human health 

criteria, the discharger may pursue obtaining a water quality standards variance. The onetime cost associated with pursuing a variance is estimated to be $426,000, with minimal costs 

associated with renewal. If the arsenic effluent levels are the result of infiltration of arseniccontaminated groundwater, total costs could be $10,600,000 for a comprehensive I&I 

reduction program that includes source identification and pipe rehabilitation for a system 

with 145 miles24 of sewer pipes (approximately $1,000,000 per year annualized at 7% over 

20 years). Note that if groundwater infiltration is not the only source of arsenic to the 

treatment plant, an I&I reduction program alone may not be sufficient for compliance and the 

discharger would not likely undertake such a program for compliance with toxic criteria 

alone.

A.2.5 Policy Scenario

Exhibit A-6 summarizes the reasonable potential analysis under the policy scenario. Based 

on effluent concentrations in Exhibit A-2 and available ambient data in Exhibit A-3, there is 

reasonable potential to exceed the proposed human health criteria for arsenic.

Exhibit A-6. Human Health Reasonable Potential Analysis for King County South 

WWTP – Policy Scenario1

Parameter

Baseline 

Average Monthly 

Effluent Limit 

(total; μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 0.14 1.364 1.364 0.0059

1. See effluent concentrations in Exhibit A-2 (reasonable potential analysis uses the maximum or 95th

percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean) and available ambient concentrations in Exhibit A-3.

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 428.

3. Consumption of organisms only.

Exhibit A-7 summarizes the calculated permit limits for arsenic under the policy scenario. 

 

24 Estimated based on information from the King County Long Term Control Plan, which indicated “over 350 

miles” of service lines in the basin, pro-rated for each plants sub-basin based on the plant’s share of the 

total flow capacity (41% for King County South).
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 53

Exhibit A-7. Human Health Based Effluent Limitations for King County South WWTP –

Policy Scenario

Parameter Average Monthly Effluent Limit 

(total; ug/L)1

Maximum Daily Effluent Limit 

(total; ug/L)1

Arsenic 0.0059 0.0069

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Under the policy scenario, the discharger would have to meet an AML of 0.0059 μg/L and a 

MDL of 0.0069 μg/L. Under the baseline scenario, the projected effluent limitations are 

below the analytical quantitation level (QL) and EPA estimated that the discharger would 

incur costs for I&I control as well as pursuit of a variance in order to ensure compliance with 

effluent limitations below the QL. Since the projected effluent limitations under the policy

scenario are also below the QL, no additional compliance strategy would be required under 

the policy scenario (i.e., the discharger would not pursue a second variance).

A.3 King County West Point WWTP and CSO System

King County provides wholesale wastewater treatment services to 17 cities, 16 local sewer 

utilities, and one Indian tribe. The King County West Point WWTP and Combined Sewer 

Overflow (CSO) System (NPDES permit WA0029181) provides coverage for King County’s 

West Point WWTP, four CSO treatment facilities (Alki, Carkeek, Elliott West, and 

Henderson/MLK), and 38 CSO outfalls. The WWTP discharges to the Puget Sound, and the 

CSO treatment plants discharge to the Puget Sound, Elliot Bay, and Duwamish Waterway. 

Average annual WWTP flow is 95 mgd.

A.3.1 Treatment Processes

The 2014 permit fact sheet for the facility indicates that the West Point WWTP treats 

domestic, commercial, and industrial wastewater and CSO stormwater from the greater 

Seattle area using a high rate oxygenated activated sludge biological treatment process with 

chlorine disinfection before discharging the treated effluent to central Puget Sound. The Alki, 

Carkeek, Denny/Elliott West, and Henderson/MLK CSO treatment plants have primary

treatment with disinfection.

A.3.2 Effluent Data 

Exhibit A-8 summarizes effluent monitoring data for the WWTP from the permit fact sheet, 

which reports detected concentrations only for the pollutants of concern. 

Exhibit A-8. Summary of Effluent Data (2009-2013): King County West Point WWTP

Pollutant Number of 

Observations

Effluent Concentration (μg/L)1

Minimum Median 95th Percentile Maximum 

1,4-Dichlorobenzene 9 1.0 10.2 10.2

2,4-Dichlorophenol 9 0.12 0.96 0.96

2,4-Dimethylphenol 9 0.24 0.48 0.48
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 54

Exhibit A-8. Summary of Effluent Data (2009-2013): King County West Point WWTP

Pollutant Number of 

Observations

Effluent Concentration (μg/L)1

Minimum Median 95th Percentile Maximum 

Antimony 15 0.30 0.44 0.63

Arsenic 15 0.27 2.196 2.28

Bis(2-ethylhexyl) 

phthalate 9 0.41 7.332 10.20

Chloroform 9 1.00 5.68 5.68

Copper 15 0.40 16.3 16.3

Cyanide 15 5.0 6.0

Diethyl phthalate 9 0.120 0.85 0.85

Mercury 21 0.002 0.005 0.0155 0.016

Methylene chloride 9 5.0 5.3 5.3

Nickel 23 0.1 2.81 5.999 6.5

Phenol 9 40 0.95 90

Pyrene 9 0.071 0.29 0.290

Selenium 15 0.50 0.5 0.74 1.30

Thallium 15 0.040 0.050 0.130

Toluene 9 1.0 1.1 1.1

Zinc 23 10.7 50.78 54.2

Source: Summarized data from 2014 Fact Sheet, Table 15 and Appendix F.

1. Metal concentrations are total recoverable form.

A.3.3 Receiving Water

Exhibit A-9 summarizes the available ambient receiving water concentrations based on data 

from the 2014 Fact Sheet for the permit and King County Department of Natural Resources 

(2013). 

Exhibit A-9. Ambient Receiving Water Concentrations: Puget Sound

Pollutant

Water Column Concentration (μg/L)1

Minimum Median Mean

90th

Percentile Maximum

Arsenic 1.15 1.33 1.29 1.36 1.43

Copper 0.234 0.308 0.322 0.41 0.617

Mercury nd nd nd nd nd

Nickel 0.387 0.407 0.408 0.437 0.443

Zinc 0.170 0.417 0.438 0.685 0.694
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 55

Exhibit A-9. Ambient Receiving Water Concentrations: Puget Sound

Pollutant

Water Column Concentration (μg/L)1

Minimum Median Mean

90th

Percentile Maximum

nd = nondetect

Source: King County Department of Natural Resources (2013; Table 3-2) and 2014 Fact Sheet (for 

90th percentile values only); based on 12 samples (9 with detectable concentrations of total mercury).

1. Metal concentrations are dissolved.

A.3.4 Baseline Scenario

The permit does not include any WQBELs based on the existing human health criteria for the 

pollutants of concern. In this case, EPA performed a reasonable potential analysis for each 

pollutant based on the baseline (i.e., existing) human health criteria to confirm whether a 

WQBEL would have been included in the NPDES permit.25 In cases of reasonable potential, 

EPA calculated a WQBEL using the existing human health criteria and evaluated compliance 

with this baseline WQBEL. 

Exhibit A-10 summarizes the reasonable potential analysis under the baseline scenario. 

Based on effluent concentrations in Exhibit A-8 and available ambient data in Exhibit A-9, 

there is reasonable potential to exceed the baseline human health arsenic criterion.

Exhibit A-10. Human Health Reasonable Potential Analysis for King County West 

Point WWTP – Baseline Scenario1

Parameter Effluent Conc. 

(total; μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 0.27 1.33 1.33 0.14

1. See effluent concentrations in Exhibit A-8 (reasonable potential analysis uses the maximum or 95th

percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean) and available ambient concentrations in Exhibit A-9. 

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 324.

3. Consumption of organisms only.

Exhibit A-11 summarizes the calculated permit limits for arsenic under the baseline scenario. 

 

25 Based on 40 CFR 122.44(d)(1), were it not for the approaches and other policies used by Ecology. 40 CFR 

122.44(d)(1) requires that effluent limitations must be established when a pollutant is discharged “...at a 

level which will cause, have the reasonable potential to cause, or contribute to an excursion above any State 

water quality standard, including State narrative criteria for water quality.”
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 56

Exhibit A-11. Human Health Based Effluent Limitations for King County West Point 

WWTP – Baseline Scenario

Parameter Average Monthly Effluent Limit 

(total; ug/L)1

Maximum Daily Effluent Limit 

(total; ug/L)1

Arsenic 0.14 0.28

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Under the baseline scenario, the discharger would have to meet an AM) of 0.14 μg/L and a 

MDL of 0.28 μg/L. Since the average effluent concentration is not listed in the fact sheet and 

the maximum effluent concentration is 2.28 μg/L, which is greater than the projected 

baseline permit limitations, the discharger will need to reduce arsenic in its effluent to ensure 

that permit limitations are consistently met.

Arsenic and arsenic-containing chemicals are not used in wastewater treatment. However, 

the facility has a large industrial base and regulates 48 industrial users of which 27 are 

significant industrial users and 39 are categorical industrial users (i.e., users subject to EPA’s 

national pretreatment standards), including 16 in the electroplating and metal finishing 

categories. West Point receives an estimated daily flow of 9.6 MGD from these industrial 

users. Thus, a source control program that targets or imposes more stringent limits on the 

most likely indirect industrial dischargers of arsenic to the plant could reduce arsenic 

concentrations to the necessary levels. Costs for such a program would depend on the 

number of arsenic sources and the measures that could be implemented at those sources to 

reduce arsenic. However, without more detailed information on these industrial users and 

King County’s pretreatment program (e.g., flows and arsenic concentrations for each 

industrial user, local limits for arsenic, ordinances), it is not possible to estimate pretreatment 

or P2 costs to indirect dischargers. 

Other potential sources of arsenic to the treatment plant are drinking water and groundwater 

infiltration. Details on the drinking water sources for the municipalities served by West 

Point, including whether these sources are surface water or groundwater and levels of arsenic 

in these sources, were not evaluated. The drinking water maximum contaminant level is 10 

μg/L, which is higher than current wastewater effluent concentrations and human health 

criteria. EPA did not attempt to determine with any certainty whether drinking water is 

contributing to high arsenic levels in the wastewater effluent. However, if the facility 

determines that drinking water is the source of high arsenic values in the wastewater, it is 

likely that the facility would pursue a variance.

The fact sheet for the facility’s 2014 permit indicates that King County created a Regional 

I&I Control Program in 1999 as part of the Regional Wastewater Services Plan (RWSP) to 

explore the feasibility of a regional I&I control program to reduce the amount of peak wet 

weather flow entering the County's wastewater conveyance. In response to the RWSP I&I

Control Program policies, County staff, working in a consensus-based approach with the 

local sewer agencies, conducted a comprehensive 6-year, $41 million, I&I control study. The 
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 57

study began in 2000 and culminated with the County Executive’s recommendation for a 

regional I&I control program. 

The study included: defining levels of I&I for each local agency tributary to the regional 

system through an extensive flow monitoring and modeling program; constructing 10 pilot 

projects in 12 local agency jurisdictions to demonstrate the effectiveness of collection system 

rehabilitation projects and to test various technologies and gain cost information; developing

model standards, procedures, policies, and guidelines for use by local agencies to reduce I&I 

in their systems; performing a cost-benefit analysis to determine the cost-effectiveness of I&I 

reduction; developing a long-term regional I&I control plan; working with the local sewer 

agencies to conduct an I&I reduction feasibility analysis; and performing several I&I 

reduction projects. 

As the focus of these studies and analyses were on reduction of peak flows to minimize 

combined sewer overflows, it is uncertain whether this I&I reduction program and these 

modifications to the collection system would address arsenic levels (there are a number of 

modifications that can correct I&I issues that would not necessarily reduce arsenic 

concentrations). If groundwater infiltration is causing the high arsenic effluent levels, the 

facility may have to implement modifications to the existing I&I reduction program for 

compliance with the baseline scenario criteria.

Due to the fact that ambient receiving water concentrations exceed the baseline human health 

criteria, the discharger may pursue obtaining a water quality standards variance. The onetime cost associated with pursuing a variance is estimated to be $426,000, with minimal costs 

associated with renewal. If the arsenic effluent levels are the result of infiltration of arseniccontaminated groundwater, total costs could be $11,650,000 for a comprehensive I&I 

reduction program that includes source identification and pipe rehabilitation for a system 

with 165 miles26 of sewer pipes (approximately $1,100,000 per year annualized at 7% over 

20 years). Note that if groundwater infiltration is not the only source of arsenic to the 

treatment plant, an I&I reduction program alone may not be sufficient for compliance and the 

discharger would not likely undertake such a program for compliance with toxic criteria 

alone.

A.3.5 Policy Scenario

Exhibit A-12 summarizes the reasonable potential analysis under the policy scenario. Based 

on effluent concentrations in Exhibit A-8 and available ambient data in Exhibit A-9, there is 

reasonable potential to exceed the proposed human health criteria for arsenic.

 

26 Estimated based on information from the King County LTCP, which indicated “over 350 miles” of service 

lines in the basin, pro-rated for each plants’ sub-basin based on the plant’s share of the total flow capacity 

(47% for King County West Point).
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 58

Exhibit A-12. Human Health Reasonable Potential Analysis for King County West 

Point WWTP – Policy Scenario1

Parameter

Baseline 

Average Monthly 

Effluent Limit

(total; μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 0.14 1.33 1.33 0.0059

1. See effluent concentrations in Exhibit A-8 (reasonable potential analysis uses the maximum or 95th

percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean) and available ambient concentrations in Exhibit A-9. 

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 324.

3. Consumption of organisms only.

Exhibit A-13 summarizes the calculated permit limits for arsenic under the policy scenario. 

Exhibit A-13. Human Health Based Effluent Limitations for King County West Point 

WWTP – Policy Scenario

Parameter Average Monthly Effluent Limit 

(total; ug/L)1

Maximum Daily Effluent Limit 

(total; ug/L)1

Arsenic 0.0059 0.012

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Under the policy scenario, the discharger would have to meet an AML of 0.0059 μg/L and a 

MDL of 0.012 μg/L. Under the baseline scenario, where the projected effluent limitations are 

below the analytical QL, EPA estimated that the discharger would incur costs for I&I control 

as well as pursuit of a variance in order to ensure compliance with effluent limitations below 

the QL. Since the projected effluent limitations under the policy scenario are also below the 

QL, no additional compliance strategy would be required under the policy scenario (i.e., the 

discharger would not pursue a second variance).

A.4 Pasco Wastewater Treatment Works

The Pasco Wastewater Treatment Works (NPDES permit WA0044962) provides wastewater 

treatment to 43,500 people in the City of Pasco and two permitted industrial users (Easterday

Farms Produce Company and A1 Quality Services, a truck washing facility). The Wastewater 

Treatment Works discharges an annual average flow of 4.5 mgd to the Lake Wallula reach of 

the Columbia River.

A.4.1 Treatment Processes

The 2014 permit limits evaluation indicates that treatment processes include headworks with 

traveling screens, grit removal, primary clarifiers, a trickling filter, an intermediate clarifier, 

aeration basins, and secondary clarifiers followed by disinfection.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 59

A.4.2 Effluent Data 

Exhibit A-14 summarizes available effluent monitoring data for the Wastewater Treatment 

Works from 2012 through 2014. 

Exhibit A-14. Summary of Effluent Data (2012-2014): Pasco Wastewater Treatment 

Works

Pollutant Number of 

Observations

Effluent Concentration (μg/L)1

Median Average 95th Percentile Maximum

Arsenic 3 1.0 1.5 2.35 2.5

Chloroform 6 1.65 1.94

Copper 15 40.7 42.013 53.57 54.9

Cyanide 15 10 10 10 10

Mercury 27 0.0004 0.012

Methylene chloride 2 0.72 0.76

Phenol 2 0.77 0.87

Selenium 3 3 5.3 9.21 9.9

Zinc 3 42.1 54.167 74.68 78.3

Source: Discharge monitoring reports for 2012 through 2014 (for arsenic, copper, cyanide, selenium, 

and zinc), a 2014 permit application (for chloroform and mercury), and a 2014 permit limit evaluation 

(for methylene chloride and phenol).

1. Metal concentrations are in total recoverable form.

A.4.3 Receiving Water

Exhibit A-15 summarizes the available ambient receiving water concentrations based on data 

from Ecology’s Environmental Information Management System between 2004 and 2014. 

Exhibit A-15. Ambient Receiving Water Concentrations: Columbia River

Pollutant Water Column Concentration (μg/L)

90th Percentile Average

Arsenic 0.77 0.6175

Copper 1.1 0.677

Mercury 0.002 0.002

Nickel 0.71 0.6183

Zinc 6.2 3.77

Source: Washington State Department of Ecology Environmental Information Management System, 

2004 to 2014 data for station 36A070.

A.4.4 Baseline Scenario

The permit does not include any WQBELs based on the existing human health criteria for the 

pollutants of concern. In this case, EPA performed a reasonable potential analysis for each 
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 60

pollutant based on the baseline (i.e., existing) human health criteria to confirm whether a 

WQBEL would have been included in the NPDES permit.27 In cases of reasonable potential, 

EPA calculated a WQBEL using the existing human health criteria and evaluated compliance 

with this baseline WQBEL. 

Exhibit A-16 summarizes the reasonable potential analysis under the baseline scenario. 

Based on effluent concentrations in Exhibit A-14 and available ambient data in Exhibit A-15, 

there is reasonable potential to exceed the baseline human health arsenic criterion. 

Exhibit A-16. Human Health Reasonable Potential Analysis for Pasco Wastewater 

Treatment Works – Baseline Scenario1

Parameter Effluent 

Conc. (μg/L)

Ambient Conc. 

(μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 2.35 0.6175 0.6178 0.018

1. See effluent concentrations in Exhibit A-14 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

median) and available ambient concentrations in Exhibit A-15. 

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 8477 for carcinogens and 3077 for non-carcinogens.

3. Consumption of water and organisms.

Exhibit A-17 summarizes the calculated permit limits for arsenic under the baseline scenario. 

Exhibit A-17. Human Health Based Effluent Limitations for Pasco Wastewater 

Treatment Works– Baseline Scenario

Parameter Average Monthly Effluent Limit 

(total; ug/L)1

Maximum Daily Effluent Limit 

(total; ug/L)1

Arsenic 0.018 0.036

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Under the baseline scenario, the discharger would have to meet an AML of 0.018 μg/L and a 

MDL of 0.036 μg/L. Since the average effluent concentration is 1.5 μg/L and the maximum 

effluent concentration is 2.5 μg/L, which are greater than the projected baseline permit 

limitations, the discharger will need to reduce arsenic in its effluent to ensure that permit 

limitations are consistently met.

Arsenic and arsenic-containing chemicals are not used in wastewater treatment and the 

facility has only two permitted industrial users, one of which is a produce company. If the 

produce is treated with arsenic-containing pesticides, then any wash water from the 

 

27 Based on 40 CFR 122.44(d)(1), were it not for the approaches and other policies used by Ecology. 40 CFR 

122.44(d)(1) requires that effluent limitations must be established when a pollutant is discharged “...at a 

level which will cause, have the reasonable potential to cause, or contribute to an excursion above any State 

water quality standard, including State narrative criteria for water quality.”
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 61

packaging operations could contribute to the high effluent arsenic levels. Thus, a source 

control program that targets the most likely indirect industrial dischargers of arsenic to the 

plant could reduce arsenic concentrations to the necessary levels. Costs for such a program 

would depend on the number of arsenic sources and the measures that could be implemented 

at those sources to reduce arsenic. Without specific information on the types of industrial 

dischargers that may need controls, it is not possible to estimate pretreatment or P2 costs to 

indirect dischargers. 

Other potential sources of arsenic to the treatment plant include drinking water and 

groundwater infiltration. Details on the drinking water source(s) for the City of Pasco, 

including whether these sources are surface water or groundwater and levels of arsenic in 

these sources, were not evaluated. The drinking water maximum contaminant level is 10 

μg/L, which is higher than current wastewater effluent concentrations and human health 

criteria. EPA did not attempt to determine with any certainty whether drinking water is 

contributing to high arsenic levels in the wastewater effluent. However, if the facility 

determines that drinking water is the source of high arsenic values in the wastewater, it is 

likely that the facility would pursue a variance.

The wastewater treatment plant exceeded 85% of the design maximum month in October, 

November and December 2008, likely due to infiltration. The City has been working on 

relining old sewer lines to prevent I&I. It is uncertain whether this I&I reduction program 

would address arsenic levels (there are a number of modifications that can correct I&I issues 

that would not necessarily reduce arsenic concentrations). If groundwater infiltration is 

causing the high arsenic effluent levels, the facility may have to implement modifications to 

the existing I&I reduction program for compliance with the baseline scenario criteria.

Due to the fact that ambient receiving water concentrations exceed the baseline human health 

criteria, the discharger may pursue obtaining a water quality standards variance. The onetime cost associated with pursuing a variance is estimated to be $180,000, with minimal costs 

associated with renewal. If the arsenic effluent levels are the result of infiltration of arseniccontaminated groundwater, total costs could be $16,200,000 for a comprehensive I&I 

reduction program that includes source identification and pipe rehabilitation for a system 

with 307 miles of sewer pipes (approximately $1,530,000 per year annualized at 7% over 20 

years). Note that if groundwater infiltration is not the only source of arsenic to the treatment 

plant, an I&I reduction program alone may not be sufficient for compliance and the 

discharger would not likely undertake such a program for compliance with toxic criteria 

alone. 

A.4.5 Policy Scenario

Exhibit A-18 summarizes the reasonable potential analysis under the policy scenario. Based 

on effluent concentrations in Exhibit A-14 and available ambient data in Exhibit A-15, there 

is reasonable potential to exceed the proposed human health criteria for arsenic.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 62

Exhibit A-18. Human Health Reasonable Potential Analysis for Pasco Wastewater 

Treatment Works – Policy Scenario1

Parameter

Baseline 

Average 

Monthly 

Effluent Limit

(μg/L)

Ambient Conc. 

(μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3 (μg/L)

Arsenic 0.018 0.6175 0.6178 0.0045

1. See effluent concentrations in Exhibit A-14 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

median) and available ambient concentrations in Exhibit A-15. 

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 8477 for carcinogens and 3077 for non-carcinogens.

3. Consumption of water and organisms.

Exhibit A-19 summarizes the calculated permit limits for arsenic under the policy scenario. 

Exhibit A-19. Human Health Based Effluent Limitations for Pasco Wastewater 

Treatment Works – Policy Scenario

Parameter Average Monthly Effluent Limit 

(total; ug/L)1

Maximum Daily Effluent Limit 

(total; ug/L)1

Arsenic 0.0045 0.0091

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Under the policy scenario, the discharger would have to meet an AML of 0.0045 μg/L and a 

MDL of 0.0091 μg/L. Under the baseline scenario, where the projected effluent limitations 

are below the analytical QL, EPA estimated that the discharger would incur costs for I&I 

control as well as pursuit of a variance in order to ensure compliance with effluent limitations 

below the QL. Since the projected effluent limitations under the policy scenario are also 

below the QL, no additional compliance strategy would be required under the policy scenario 

(i.e., the discharger would not pursue a second variance).

A.5 Puyallup WWTP

The City of Puyallup owns and operates a municipal WWTP (NPDES permit WA0037168)

that provides primary and secondary treatment. The WWTP discharges an annual average 

flow of 4.07 mgd to the Puyallup River within the Puyallup Reservation. The EPA has 

authority to issue permits for the facility based on the Puyallup Tribe’s WQS, pursuant to a 

memorandum of understanding among the EPA, the Puyallup Tribe, and Ecology. 

A.5.1 Treatment Processes

The 2014 fact sheet for the permit states that the facility uses preliminary treatment 

consisting of fine screening for solids removal, and primary treatment includes clarification, 

sludge/grit centrifugal separation, and grit disposal. Secondary treatment consists of activated 

sludge, secondary clarification, and ultraviolet light disinfection.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 63

A.5.2 Effluent Data 

Exhibit A-20 summarizes available effluent monitoring data for the WWTP from 2012 

through 2014. 

Exhibit A-20. Summary of Effluent Data (2012-2014): Puyallup WWTP

Pollutant Number of 

Observations

Effluent Concentration (μg/L)1

Median Average 95th Percentile Maximum

Copper 15 5.60 5.39 6.34 6.90

Mercury 15 0.00180 0.00183 0.00279 0.00300

Zinc 15 33.90 33.83 43.93 44.70

Source: Discharge monitoring reports for 2012 through 2014. 

1. Metal concentrations are in total recoverable form.

A.5.3 Receiving Water

Exhibit A-21 summarizes the available ambient receiving water concentrations based on data 

from Ecology’s Environmental Information Management System from 2009. 

Exhibit A-21. Ambient Receiving Water Concentrations: Puyallup River

Pollutant Water Column Concentration (μg/L)

90th Percentile Average

Arsenic 0.90 0.62

Di(2-ethylhexyl) phthalate 0.07 0.07

Copper 11.60 3.36

Zinc 12.66 5.28

Source: Washington State Department of Ecology Environmental Information Management System, 

2009 data for station PSTLA-RIV05.

A.5.4 Baseline Scenario

The permit does not include any WQBELs based on the existing human health criteria for the 

pollutants of concern. In this case, EPA performed a reasonable potential analysis for each 

pollutant based on the baseline (i.e., existing) human health criteria to confirm whether a 

WQBEL would have been included in the NPDES permit.28 In cases of reasonable potential,

EPA calculated a WQBEL using the existing human health criteria and evaluated compliance 

with this baseline WQBEL.

 

28 Based on 40 CFR 122.44(d)(1), were it not for the approaches and other policies used by Ecology. 40 CFR 

122.44(d)(1) requires that effluent limitations must be established when a pollutant is discharged “...at a 

level which will cause, have the reasonable potential to cause, or contribute to an excursion above any State 

water quality standard, including State narrative criteria for water quality.”
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 64

Based on effluent concentrations in Exhibit A-20 and available ambient data in Exhibit A-21, 

there is no reasonable potential to exceed the proposed human health criteria for pollutants 

for which effluent data are available (copper, mercury, and zinc). Thus, there are no permit 

limits or costs associated with the baseline scenario.29

A.5.5 Policy Scenario

Based on effluent concentrations in Exhibit A-20 and available ambient data in Exhibit A-21, 

there is no reasonable potential to exceed the proposed human health criteria for pollutants 

for which effluent data are available (copper, mercury, and zinc). Thus, there are no permit 

limits or costs associated with the policy scenario.

A.6 Redondo WWTP

The Lakehaven Utility District owns and operates the Redondo WWTP (NPDES permit 

WA0023451) which serves residential and commercial customers. The WWTP discharges an 

annual average flow of 2.8 mgd30 to Puget Sound – Poverty Bay.

A.6.1 Treatment Processes

The 2013 fact sheet for the permit (Washington Department of Ecology, 2013a) indicates that 

the facility employs primary and secondary treatment consisting of screening, grit removal 

and comminution, primary clarification, biological treatment using plastic media trickling 

filters, secondary clarification, and ultraviolet disinfection (p. 8).

A.6.2 Effluent Data 

Exhibit A-22 summarizes available effluent monitoring data for the WWTP from 2009 

through 2012. 

Exhibit A-22. Summary of Effluent Data (2009-2012): Redondo WWTP

Pollutant Number of Observations Detected Value (μg/L)1

Total Nondetect QL (μg/L) Maximum Average

1,1,2,2-Tetrachloroethane 3 3 1

1,1,2-Trichloroethane 3 3 1

1,1-Dichloroethylene 3 3 1

1,2,4-Trichlorobenzene 3 3 0.29

1,2-Dichloropropane 3 3 1

1,2-Diphenylhydrazine 3 3 0.95

1,2-Trans-dichloroethylene 3 3 1

 

29 For all pollutants except arsenic, the aquatic life criteria are more stringent than human health criteria (as 

noted in the 2014 fact sheet, p. 31). The facility has water quality-based limits for copper; the average 

monthly limit is 8.5 μg/L and the maximum daily limit is 13.7 μg/L.

30 Based on average flow between 2008 and 2012, from the 2013 fact sheet for the permit, Appendix D.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 65

Exhibit A-22. Summary of Effluent Data (2009-2012): Redondo WWTP

Pollutant Number of Observations Detected Value (μg/L)1

Total Nondetect QL (μg/L) Maximum Average

1,3-Dichlorobenzene 3 3 1

1,4-Dichlorobenzene 3 3 1

2,4,6-Trichlorophenol 3 3 1.9

2,4-Dichlorophenol 3 3 0.4

2,4-Dinitrotoluene 3 3 0.16

2-Chloronaphthalene 3 3 0.24

2-Chlorophenol 3 3 1

3,3'-Dichlorobenzidine 3 3 0.48

4,4'-DDD 3 3 0.024

4,4'-DDE 3 3 0.024

4,4'-DDT 3 3 0.024

Acenaphthene 3 3 0.029

Acrolein 3 3 5

Acrylonitrile 3 3 5

Aldrin 3 3 0.024

alpha-BHC 3 3 0.024

alpha-endosulfan 3 3 0.024

Anthracene 3 3 0.29

Antimony 3 3 0.3

Arsenic 5 2.39 1.61

Benzene 3 3 1

Benzidine 3 3 11

Benzo(a) anthracene 3 3 0.29

Benzo(a) pyrene 3 3 0.48

beta-BHC 3 3 0.024

beta-endosulfan 3 3 0.024

Bis(2-chloroethyl) ether 3 3 0.29

Bis(2-Ccloroisopropyl) ether 3 3 0.29

Bis(2-ethylhexyl) phthalate 3 3.69 2.88

Bromoform 3 3 1

Butylbenzyl Phthalate 3 2 0.29 0.76 0.39

Carbon Tetrachloride 3 3 1

Chlorobenzene 3 3 1

Chlorodibromomethane 3 3 1
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 66

Exhibit A-22. Summary of Effluent Data (2009-2012): Redondo WWTP

Pollutant Number of Observations Detected Value (μg/L)1

Total Nondetect QL (μg/L) Maximum Average

Chloroform 3 3 1

Chrysene 3 3 0.29

Copper 5 68.7 42.1

Cyanide 3 3 5

Dichlorobromomethane 3 3 1

Dieldrin 3 3 0.024

Diethyl Phthalate 3 3 0.48

Dimethyl Phthalate 3 3 0.19

Di-n-Butyl Phthalate 3 3 0.48

Endosulfan Sulfate 3 3 0.024

Endrin 3 3 0.024

Endrin Aldehyde 3 3 0.024

Ethylbenzene 3 3 1

Fluoranthene 3 3 0.29

Fluorene 3 3 0.29

Heptachlor 3 3 0.024

Heptachlor epoxide 3 3 0.024

Hexachlorobenzene 3 3 0.29

Hexachlorobutadiene 3 3 0.48

Hexachlorocyclopentadiene 3 3 0.48

Hexachloroethane 3 3 0.48

Indeno(1,2,3-cd) pyrene 3 3 0.48

Isophorone 3 3 0.48

Mercury 5 0.0851 0.0341

Methyl Bromide 3 3 5

Nickel 5 2.05 1.60

Nitrobenzene 3 3 0.48

N-Nitrosodi-n-propylamine 3 3 0.48

N-Nitrosodiphenylamine 3 3 0.48

Pentachlorophenol (PCP) 3 3 0.48

Phenol 3 3 1.9

Pyrene 3 3 0.29

Selenium 5 0.51 0.50

Tetrachloroethylene 3 3 1
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 67

Exhibit A-22. Summary of Effluent Data (2009-2012): Redondo WWTP

Pollutant Number of Observations Detected Value (μg/L)1

Total Nondetect QL (μg/L) Maximum Average

Toluene 3 3 0.38

Thallium 3 3 0.04

Toxaphene 3 3 1

Trichloroethylene 3 3 1

Vinyl chloride 3 3 1

Zinc 3 57.4 51.0

Source: 2013 Fact Sheet, Appendix D.

QL = quantitation level

1. Metal concentrations are in total recoverable form.

A.6.3 Receiving Water

Exhibit A-23 summarizes the available ambient receiving water concentrations in Puget 

Sound based on data from Ecology’s Environmental Information Management System from 

2011 to 2013. 

Exhibit A-23. Ambient Receiving Water Concentrations (2011 to 2013): Puget Sound

Pollutant Water Column Concentration (μg/L)1

90th Percentile Average

Antimony 0.172 0.158625

Arsenic 1.45 1.36625

Copper 0.3545 0.299

Cyanide nd nd

Mercury nd nd

Nickel 0.4275 0.411125

Zinc 0.662 0.604167

nd=nondetect

Source: Environmental Information Management System data (NPDES receiving water 

characterization study).

1. Metal concentrations are dissolved form.

A.6.4 Baseline Scenario

The permit does not include any WQBELs based on the existing human health criteria for the 

pollutants of concern. In this case, EPA performed a reasonable potential analysis for each 

pollutant based on the baseline (i.e., existing) human health criteria to confirm whether a 
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 68

WQBEL would have been included in the NPDES permit.31 In cases of reasonable potential, 

EPA calculated a WQBEL using the existing human health criteria and evaluated compliance 

with this baseline WQBEL.

Exhibit A-24 summarizes the reasonable potential analysis under the baseline scenario. 

Based on effluent concentrations in Exhibit A-22 and available ambient data in Exhibit A-23, 

there is reasonable potential to exceed the baseline human health criterion for arsenic. 

Exhibit A-24. Human Health Reasonable Potential Analysis for Redondo WWTP –

Baseline Scenario1

Parameter Effluent Conc. 

(total; μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 2.39 1.3663 1.371 0.14

1. See effluent concentrations in Exhibit A-22 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean) and available ambient concentrations in Exhibit A-23. 

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 182.

3. Consumption of organisms only.

Exhibit A-25 summarizes the calculated permit limits for arsenic under the baseline scenario. 

Exhibit A-25. Human Health Based Effluent Limitations for Redondo WWTP – Baseline 

Scenario

Parameter Average Monthly Effluent Limit 

(total; ug/L)1

Maximum Daily Effluent Limit 

(total; ug/L)1

Arsenic 0.14 0.28

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Under the baseline scenario, the discharger would have to meet an AML of 0.14 μg/L and a 

MDL of 0.28 μg/L. Since the average effluent concentration is 1.61 μg/L and the maximum 

effluent concentration is 2.39 μg/L, which are greater than the projected baseline permit 

limitations, the discharger will need to reduce arsenic in its effluent to ensure that permit 

limitations are consistently met.

Arsenic and arsenic-containing chemicals are not used in wastewater treatment and the 

facility does not have any significant or categorical industrial users. However, drinking water 

and groundwater infiltration are two potential sources of arsenic to the treatment plant. 

 

31 Based on 40 CFR 122.44(d)(1), were it not for the approaches and other policies used by Ecology. 40 CFR 

122.44(d)(1) requires that effluent limitations must be established when a pollutant is discharged “...at a 

level which will cause, have the reasonable potential to cause, or contribute to an excursion above any State 

water quality standard, including State narrative criteria for water quality.”
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 69

Details on the drinking water sources for the communities served by the Redondo WWTP, 

including whether these sources are surface water or groundwater and levels of arsenic in 

these sources, were not evaluated. The drinking water maximum contaminant level is 10 

μg/L, which is higher than current wastewater effluent concentrations and human health 

criteria. EPA did not attempt to determine with any certainty whether drinking water is 

contributing to high arsenic levels in the wastewater effluent. However, if the facility 

determines that drinking water is the source of high arsenic values in the wastewater, it is 

likely that the facility would pursue a variance.

The fact sheet for the facility’s 2013 permit indicates that the District completed a 

comprehensive wastewater system plan in 1999. A collection system analysis found that I&I 

is a significant problem at this plant, and it recommended various I&I and flow reduction 

programs. The District incorporated an I&I rehab program focusing on the Redondo basin 

areas. It is uncertain whether this I&I reduction program and these modifications to the 

collection system would address arsenic levels (there are a number of modifications that can 

correct I&I issues that would not necessarily reduce arsenic concentrations). If groundwater 

infiltration is causing the high arsenic effluent levels, the facility may have to modify or 

expand the existing I&I reduction program for compliance with the baseline scenario criteria.

Due to the fact that ambient receiving water concentrations exceed the baseline human health 

criteria, the discharger may pursue obtaining a water quality standards variance. The onetime cost associated with pursuing a variance is estimated to be $180,000, with minimal costs 

associated with renewal. If the arsenic effluent levels are the result of infiltration of arseniccontaminated groundwater, total costs could be $6,020,000 for a comprehensive I&I 

reduction program that includes source identification and pipe rehabilitation for a system 

with 114 miles of sewer pipes (approximately $568,000 per year annualized at 7% over 20 

years). Note that if groundwater infiltration is not the only source of arsenic to the treatment 

plant, an I&I reduction program alone may not be sufficient for compliance and the 

discharger would not likely undertake such a program for compliance with toxic criteria 

alone.

A.6.5 Policy Scenario

Exhibit A-26 summarizes the reasonable potential analysis under the policy scenario. Based 

on effluent concentrations in Exhibit A-22 and available ambient data in Exhibit A-23, there 

is reasonable potential to exceed the proposed human health criterion for arsenic. 

Exhibit A-26. Human Health Reasonable Potential Analysis for Redondo WWTP –

Policy Scenario1

Parameter

Baseline 

Average Monthly 

Effluent Limit

(total; μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 0.14 1.3663 1.371 0.0059
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 70

Exhibit A-26. Human Health Reasonable Potential Analysis for Redondo WWTP –

Policy Scenario1

Parameter

Baseline 

Average Monthly 

Effluent Limit

(total; μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

1. See effluent concentrations in Exhibit A-22 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean) and available ambient concentrations in Exhibit A-23. 

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 182.

3. Consumption of organisms only.

Exhibit A-27 summarizes the calculated permit limits for arsenic under the policy scenario. 

Exhibit A-27. Human Health Based Effluent Limitations for Redondo WWTP – Policy 

Scenario

Parameter Average Monthly Effluent Limit 

(total; ug/L)1

Maximum Daily Effluent Limit 

(total; ug/L)1

Arsenic 0.0059 0.012

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Under the policy scenario, the discharger would have to meet an AML of 0.0059 μg/L and a 

MDL of 0.012 μg/L. Under the baseline scenario, where the projected effluent limitations are 

below the analytical QL, EPA estimated that the discharger would incur costs for I&I control 

as well as pursuit of a variance in order to ensure compliance with effluent limitations below 

the QL. Since the projected effluent limitations under the policy scenario are also below the 

QL, no additional compliance strategy would be required under the policy scenario (i.e., the 

discharger would not pursue a second variance).

A.7 Salmon Creek WWTP

The Salmon Creek WWTP (NPDES permit WA0022772), operated by the Southwest 

Suburban Sewer District (District), serves households and some commercial customers in 

King County. The facility does not serve any industrial customers. It has an average wet 

weather flow of 3.6 mgd.

A.7.1 Treatment Processes

According to a 2009 inspection report, treatment at the facility includes screening, grit 

removal, primary clarification, biological treatment, secondary clarification, and chlorine 

disinfection.

A.7.2 Effluent Data 

Exhibit A-28 summarizes available effluent monitoring data for the WWTP from 2010 

through 2012. 
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 71

Exhibit A-28. Summary of Effluent Data (2010-2012): Salmon Creek WWTP

Pollutant Number of 

Observations

Effluent Concentration (μg/L)1

Maximum Average

Antimony 3 0.55 0.45

Arsenic 3 2.37 1.76

Bis(2-ethylhexyl) phthalate 3 1.5

Copper 3 11.6 8.62

Nickel 3 2.3 1.87

Selenium 3 1.4 1.14

Thallium 3 0.017 0.017

Toluene 3 1.1 1.1

Zinc 3 44.2 37.7

Mercury 3 0.0074 0.0064

Source: 2012 priority pollutant monitoring report; bis(2-ethylhexyl) phthalate data are from 2013 fact 

sheet addendum.

1. Metal concentrations are in total recoverable form.

A.7.3 Receiving Water

The facility discharges to Puget Sound, which is designated as a Class AA receiving water in 

the vicinity of the outfall. Exhibit A-29 summarizes the available ambient receiving water 

concentrations in Puget Sound based on data from Ecology’s Environmental Information 

Management System from 2011 to 2013. 

Exhibit A-29. Ambient Receiving Water Concentrations (2011 to 2013): Puget Sound 

Pollutant Water Column Concentration (μg/L)1

90th Percentile Average

Antimony 0.172 0.158625

Arsenic 1.45 1.36625

Copper 0.3545 0.299

Cyanide nd nd

Mercury nd nd

Nickel 0.4275 0.411125

Zinc 0.662 0.604167

nd=nondetect

Source: Environmental Information Management System data (NPDES receiving water 

characterization study).

1. Metal concentrations are dissolved form.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 72

A.7.4 Baseline Scenario

The permit does not include any WQBELs based on the existing human health criteria for the 

pollutants of concern. In this case, EPA performed a reasonable potential analysis for each 

pollutant based on the baseline (i.e., existing) human health criteria to confirm whether a 

WQBEL would have been included in the NPDES permit.32 In cases of reasonable potential, 

EPA calculated a WQBEL using the existing human health criteria and evaluated compliance 

with this baseline WQBEL. 

Exhibit A-30 summarizes the reasonable potential analysis under the baseline scenario. 

Based on effluent concentrations in Exhibit A-28 and available ambient data in Exhibit A-29, 

there is reasonable potential to exceed the baseline human health arsenic criterion. 

Exhibit A-30. Human Health Reasonable Potential Analysis for Salmon Creek WWTP –

Baseline Scenario1

Parameter Effluent Conc. 

(total; μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 2.37 1.3663 1.368 0.14

1. See effluent concentrations in Exhibit A-28 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean) and available ambient concentrations in Exhibit A-29. 

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 1025.

3. Consumption of organisms only.

Exhibit A-31 summarizes the calculated permit limits for arsenic under the baseline scenario. 

Exhibit A-31. Human Health Based Effluent Limitations for Salmon Creek WWTP –

Baseline Scenario

Parameter Average Monthly Effluent Limit 

(total; ug/L)1

Maximum Daily Effluent Limit 

(total; ug/L)1

Arsenic 0.14 0.28

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Under the baseline scenario, the discharger would have to meet an AML of 0.14 μg/L and a 

MDL of 0.28 μg/L. Since the average effluent concentration is 1.76 μg/L and the maximum 

effluent concentration is 2.37 μg/L, which are greater than the projected baseline permit 

limitations, the discharger will need to reduce arsenic in its effluent to ensure that permit 

limitations are consistently met.

 

32 Based on 40 CFR 122.44(d)(1), were it not for the approaches and other policies used by Ecology. 40 CFR 

122.44(d)(1) requires that effluent limitations must be established when a pollutant is discharged “...at a 

level which will cause, have the reasonable potential to cause, or contribute to an excursion above any State 

water quality standard, including State narrative criteria for water quality.”
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 73

Arsenic and arsenic-containing chemicals are not used in wastewater treatment and the 

facility does not have any significant or categorical industrial users. However, drinking water 

and groundwater infiltration are two potential sources of arsenic to the treatment plant.

Details on the drinking water sources for the communities served by the Salmon Creek 

WWTP, including whether these sources are surface water or groundwater and levels of 

arsenic in these sources, were not evaluated. The drinking water maximum contaminant level 

is 10 μg/L, which is higher than current wastewater effluent concentrations and human health 

criteria. EPA did not attempt to determine with any certainty whether drinking water is 

contributing to high arsenic levels in the wastewater effluent. However, if the facility 

determines that drinking water is the source of high arsenic values in the wastewater, it is 

likely that the facility would pursue a variance.

The fact sheet for the facility’s 2003 permit indicates that the District had performed an 

evaluation of I&I attributed to direct storm runoff and that I&I flow for the Salmon Creek 

basin was 48%. The District obtained funds for a major rehabilitation program for the 

Salmon Creek basin and identified a list of collection system rehabilitation projects in its 

Comprehensive Sewer Plan to address I&I. It is uncertain whether this I&I reduction 

program and these modifications to the collection system would address arsenic levels (there 

are a number of modifications that can correct I&I issues that would not necessarily reduce 

arsenic concentrations). If groundwater infiltration is causing the high arsenic effluent levels, 

the facility may have to modify or expand its existing I&I reduction program for compliance 

with the baseline scenario limitations.

Due to the fact that ambient receiving water concentrations exceed the baseline human health 

criteria, the discharger may also pursue obtaining a water quality standards variance. The 

one-time cost associated with pursuing a variance is estimated to be $180,000, with minimal 

costs associated with renewal. If the arsenic effluent levels are the result of infiltration of 

arsenic-contaminated groundwater, total costs could be $6,810,000 for a comprehensive I&I 

reduction program that includes source identification and pipe rehabilitation for a system 

with 129 miles of sewer pipes (approximately $643,000 per year annualized at 7% over 20 

years). Note that if groundwater infiltration is not the only source of arsenic to the treatment 

plant, an I&I reduction program alone may not be sufficient for compliance and the 

discharger would not likely undertake such a program for compliance with toxic criteria 

alone.

A.7.5 Policy Scenario

Exhibit A-32 summarizes the reasonable potential analysis under the policy scenario. Based 

on effluent concentrations in Exhibit A-30 and available ambient data in Exhibit A-31, there 

is reasonable potential to exceed the proposed human health arsenic criterion. 
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 74

Exhibit A-32. Human Health Reasonable Potential Analysis for Salmon Creek WWTP –

Policy Scenario1

Parameter

Baseline 

Average Monthly 

Effluent Limit

(total; μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 0.14 1.3663 1.368 0.0059

1. See effluent concentrations in Exhibit A-28 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean) and available ambient concentrations in Exhibit A-29. 

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 1025.

3. Consumption of organisms only.

Exhibit A-33 summarizes the calculated permit limits for arsenic under the policy scenario. 

Exhibit A-33. Human Health Based Effluent Limitations for Salmon Creek WWTP –

Policy Scenario

Parameter Average Monthly Effluent Limit 

(total; ug/L)1

Maximum Daily Effluent Limit 

(total; ug/L)1

Arsenic 0.0059 0.012

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Under the policy scenario, the discharger would have to meet an AML of 0.0059 μg/L and a 

MDL of 0.012 μg/L. Under the baseline scenario, where the projected effluent limitations are 

below the analytical QL, EPA estimated that the discharger would incur costs for I&I control 

as well as pursuit of a variance in order to ensure compliance with effluent limitations below 

the QL. Since the projected effluent limitations under the policy scenario are also below the 

QL, no additional compliance strategy would be required under the policy scenario (i.e., the 

discharger would not pursue a second variance).

A.8 BP Cherry Point Refinery

The BP Cherry Point Refinery (NPDES permit number WA0022900) encompasses 740 acres 

in a rural area of Whatcom County. The facility’s wastewater treatment plant treats process 

water, ballast water from tankers, tank water draws, and stormwater that falls in process areas 

of the site. The permit also authorizes treatment of wastewater from the Praxair, Inc. 

Ferndale facility and a proposed cogeneration facility. The facility discharges treated effluent 

into the Strait of Georgia. The facility’s average flow is 3.87 million gallons per day (mgd).

A.8.1 Treatment Processes

The 2012 NPDES permit for the facility lists current treatment processes as four parallel 

oil/water separators, two induced gas floatation units, an equalization tank, a complete mix 

activated sludge unit, a secondary clarifier, and two clarification ponds.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 75

A.8.2 Effluent Data 

Exhibit A-34 summarizes the last three years of effluent data for the treated wastewater for 

the pollutants of concern for which data are available. 

Exhibit A-34. Summary of Effluent Data (2012-2014): BP Cherry Point Refinery, Outfall

Parameter

Number of Observations Summary of Detected Values (μg/L)

Total Nondetect QL 

(μg/L) Maximum Geometric Mean

Minimum

1,1,2,2-Tetrachloroethane 1 1 0.4

1,1,2-Trichloroethane 1 1 0.4

1,1-Dichloroethylene 1 1 0.4

1,2,4-Trichlorobenzene 1 1 0.4

1,2-Dichlorobenzene 1 1 0.4

1,2-Dichloroethane 1 1 0.4

1,2-Dichloropropane 1 1 0.4

1,2-Diphenylhydrazine 1 1 0.4

1,2-Trans-Dichloroethylene 1 1 0.4

1,3-Dichlorobenzene 1 1 0.4

1,3-Dichloropropene 1 1 0.4

1,4-Dichlorobenzene 1 1 0.4

2,3,7,8-TCDD (Dioxin) 1 1 0.0005

2,4,6-Trichlorophenol 1 1 1

2,4-Dichlorophenol 1 1 1

2,4-Dimethylphenol 1 1 1

2,4-Dinitrophenol 1 1 1

2,4-Dinitrotoluene 1 1 0.4

2-Chloronaphthalene 1 1 0.4

2-Chlorophenol 1 1 1

Acenaphthene 1 1 0.1

Acrolein 1 1 2

Acrylonitrile 1 1 2

Anthracene 1 1 0.1

Antimony 1 1 1

Arsenic (total) 1 46 46 46

Benzene 1 1 0.4

Benzidine 1 1 10

Benzo(a) Anthracene 1 1 0.1

Benzo(a) Pyrene 1 1 0.1
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 76

Exhibit A-34. Summary of Effluent Data (2012-2014): BP Cherry Point Refinery, Outfall

Parameter

Number of Observations Summary of Detected Values (μg/L)

Total Nondetect QL 

(μg/L) Maximum Geometric Mean

Minimum

Benzo(b) Fluoranthene 1 1 0.1

Benzo(k) Fluoranthene 1 1 0.1

Bis(2-Chloroethyl) Ether 1 1 0.4

Bis(2-Chloroisopropyl) 

Ether 1 1 0.4

Bis(2-Ethylhexyl) Phthalate 1 1 0.4

Bromoform 1 1 0.4

Butylbenzyl Phthalate 1 1 0.4

Carbon Tetrachloride 1 1 0.4

Chlorobenzene 1 1 0.4

Chloroform 1 1 0.4

Chrysene 1 1 0.1

Copper (total) 1 10 10 10

Cyanide 1 5

Dibenzo(a,h) Anthracene 1 1

Dichlorobromomethane 1 0.4

Diethyl Phthalate 1 0.4

Dimethyl Phthalate 1 0.4

Di-n-Butyl Phthalate 1 0.4

Ethylbenzene 1 0.4

Fluoranthene 1 0.1

Fluorene 1 0.1

Hexachlorobenzene 1 1 0.4

Hexachlorobutadiene 1 1 0.4

Hexachlorocyclopentadiene 1 1 0.4

Hexachloroethane 1 1 0.4

Indeno(1,2,3-cd) Pyrene 1 1 0.1

Isophorone 1 1 0.4

Methyl Bromide 1 1 0.4

Methylene Chloride 1 1 0.4

Nickel (total) 1 42 42 42

Nitrobenzene 1 1 0.4

N-Nitrosodimethylamine 1 1 0.4
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 77

Exhibit A-34. Summary of Effluent Data (2012-2014): BP Cherry Point Refinery, Outfall

Parameter

Number of Observations Summary of Detected Values (μg/L)

Total Nondetect QL 

(μg/L) Maximum Geometric Mean

Minimum

N-Nitrosodi-n-Propylamine 1 1 0.4

N-Nitrosodiphenylamine 1 1 0.4

Pentachlorophenol (PCP) 1 1 1

Phenol 1 1 1

Pyrene 1 1 0.1

Selenium (total) 1 83 83 83

Tetrachloroethylene 1 1 0.4

Thallium (total) 1 0.5 0.5 0.5

Toluene 1 1 0.4

Trichloroethylene 1 1 0.4

Vinyl Chloride 1 1 0.4

Zinc (total) 1 55 55 55

Mercury (total) 1 0.0114 0.0114 0.0114

Source: Based on discharge monitoring reports submitted to Washington Department of Ecology, 2012 

to 2014.

QL = Quantification limit

A.8.3 Receiving Water

The Strait of Georgia has been categorized by Ecology as extraordinary marine receiving 

water with characteristic uses including fish, shellfish, clam, oyster, and mussel rearing, 

spawning, migration, and harvesting; wildlife habitat, primary contact recreation, sport 

fishing, commerce and navigation, boating, and aesthetic enjoyment. The Strait is also part of 

the Cherry Point Aquatic Reserve. The BP Cherry Point facility’s NPDES permit contains 

requirements pursuant to the Cherry Point Reserve Plan. Further, the Strait of Georgia is on 

the 303(d) list for benzo[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene, and chrysene 

concentrations in tissue (mussels) approximately 15 miles from the facility. 

Exhibit A-35 summarizes the available ambient receiving water concentrations based on data 

from 1999 and 2005. 

Exhibit A-35. Ambient Receiving Water Concentrations: Strait of Georgia

Parameter Geometric Mean Concentration (dissolved; μg/L)

Copper 0.673

Mercury 0.001

Zinc 3.9

Source: reported in 2012 Fact Sheet for BP Cherry Point NPDES permit (Appendix I) from Ecology’s 

reasonable potential analysis.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 78

A.8.4 Baseline Scenario

The permit does not include any WQBELs based on the existing human health criteria for the 

pollutants of concern. In this case, EPA performed a reasonable potential analysis for each 

pollutant based on the baseline (i.e., existing) human health criteria to confirm whether a 

WQBEL would have been included in the NPDES permit.33 In cases of reasonable potential, 

EPA calculated a WQBEL using the existing human health criteria and evaluated compliance 

with this baseline WQBEL. 

Exhibit A-36 summarizes the reasonable potential analysis under the baseline scenario. 

Based on effluent concentrations in Exhibit A-34 and available ambient data in Exhibit A-35, 

there is reasonable potential to exceed human health criteria for arsenic

Exhibit A-36. Human Health Reasonable Potential Analysis for BP Cherry Point1–

Baseline Scenario

Parameter Effluent Conc. 

(total; μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 46 NR 0.842 0.14

NR = not reported

1. See effluent concentrations in Exhibit A-34 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean) and available ambient concentrations in Exhibit A-35. 

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 136.

3. Consumption of organisms only.

Exhibit A-37 summarizes the calculated permit limits for arsenic under the baseline scenario. 

Exhibit A-37. Human Health Based Effluent Limitations for BP Cherry Point – Baseline 

Scenario

Parameter Average Monthly Effluent Limit 

(total; μg/L)1

Maximum Daily Effluent Limit 

(total; μg/L)1

Arsenic 19 38

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Under the baseline scenario, the discharger would have to meet an AML of 19 μg/L and a 

MDL of 38 μg/L. Arsenic was observed in the effluent at of 46 μg/L. Since the effluent 

monitoring data exceeds the applicable effluent limitations under the baseline scenario, the 

discharger will need to control arsenic in its effluent to ensure that permit limits are 

 

33 Based on 40 CFR 122.44(d)(1), were it not for the approaches and other policies used by Ecology. 40 CFR 

122.44(d)(1) requires that effluent limitations must be established when a pollutant is discharged “...at a 

level which will cause, have the reasonable potential to cause, or contribute to an excursion above any State 

water quality standard, including State narrative criteria for water quality.”
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 79

consistently met. It is possible that more recent or future monitoring data could provide 

evidence that the facility is in compliance with the projected effluent limits and no costs 

would be incurred for compliance. However, additional data could provide further evidence 

of non-compliance. Based on the available information, EPA assumes the discharger will 

need to reduce discharge concentrations for compliance with the baseline scenario.

End-of-pipe treatment technologies capable of controlling arsenic include options such as 

chemical precipitation, microfiltration, and reverse osmosis. Given the limited nature of the 

information available regarding the internal process operations at the facility, EPA has 

assumed the use of reverse osmosis for arsenic control. Reverse osmosis is capable of 

reliably controlling arsenic at levels below the limit of quantitation. Further, EPA has 

assumed that treatment of the entire plant flow will be necessary. This is a conservative 

assumption as it is possible that a detailed study of the facility’s internal process operations 

would result in a more targeted treatment strategy—for instance, if only a single internal 

process flow was the source of the contamination, then only the contaminated stream would 

require treatment. EPA estimated a reverse osmosis treatment cost for a 3.87 mgd flow at 

$7,054,000 per year assuming an interest rate of 7 percent over 20 years.

A.8.5 Policy Scenario

Exhibit A-38 summarizes the RP analysis under the policy scenario. Based on effluent 

concentrations in Exhibit A-34 and available ambient data in Exhibit A-35, there is 

reasonable potential to exceed human health criteria for arsenic and mercury. However, 

ambient concentrations for mercury exceed the criteria.

Exhibit A-38. Human Health Reasonable Potential Analysis for BP Cherry Point1–

Policy Scenario

Parameter

Baseline 

Average Monthly 

Effluent Limit or 

Conc. (total; 

μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 19 NR 0.842 0.0059

Mercury 0.0114 0.001 0.0012 0.00088

NR = not reported

1. See effluent concentrations in Exhibit A-34 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean) and available ambient concentrations in Exhibit A-35. 

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 136.

3. Consumption of organisms only.

Exhibit A-39 summarizes the calculated permit limits for arsenic under the policy scenario. 
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 80

Exhibit A-39. Human Health Based Effluent Limitations for BP Cherry Point – Policy 

Scenario

Parameter Average Monthly Effluent Limit 

(total; μg/L)1

Maximum Daily Effluent Limit 

(total; μg/L)1

Arsenic 0.81 1.6

Mercury 0.00088 0.0018

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Arsenic

Under the policy scenario, the discharger would have to meet an AML of 0.81 μg/L and a 

MDL of 1.6μg/L. Under the baseline scenario, EPA estimated that the discharger would 

incur costs for end-of-pipe treatment using reverse osmosis which would likely result in an 

effluent quality performance at or near the limit of quantitation. However, if the facility has 

not yet achieved a level of performance which would result in immediate compliance with 

effluent limitations under the policy scenario, EPA has included costs associated with a P2

program which is likely to result in compliance. 

Mercury

Under the policy scenario, the discharger would have to meet an AML of 0.00088 μg/L and a 

MDL of 0.0018 μg/L. The maximum effluent concentration is 0.0029 μg/L and the average 

effluent concentration is 0.0019 μg/L. Based on the available data, the discharger will likely

need to reduce mercury in its effluent to ensure that permit limits are consistently met. 

Because there are no proven end-of-pipe treatment technologies that can achieve low 

mercury levels (e.g., <10 ng/L) on a consistent basis, the facility would likely implement a 

P2 program for compliance with the projected effluent limits. Annual P2 program costs for 

this industrial facility are estimated to be approximately $28,000. To ensure compliance in 

case a P2 program would not be sufficient to meet the projected effluent limitations, EPA 

assumed that the facility would incur costs for a variance.

A.9 Cosmo Specialty Fibers

Cosmo Specialty Fibers (NPDES permit WA0000809) operates a paper mill that produces 

dissolving pulp of the acetate, viscose, and ether grades with a permitted capacity of 550 tons 

per day. Average flow is approximately 24 mgd,34 and the facility discharges to Grays 

Harbor and Chehalis River.

 

34 Based on discharge monitoring reports between 2012 and 2014; average monthly flow for Outfall 1 

(discharging to Grays Harbor) is 18 mgd and average monthly flow for Outfall 2 (discharging to Chehalis 

River) is 6 mgd.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 81

A.9.1 Treatment Processes

Primary treatment consists of an ash clarifier, a disco strainer, a Brinkley screen, and a sweet 

sewer settling basin. Secondary treatment consists of four aeration lagoons, two clarifiers, 

and disinfection. Wastewater is routed to a system of storage ponds and then discharged 

through Outfall 1. Stormwater, truck wash overflow, and filter plant backwash are discharged 

through Outfall 2.

A.9.2 Effluent Data 

Exhibit A-40 summarizes 2012 to 2014 effluent monitoring data for the facility discharge 

monitoring reports for Outfall 1. Data are not available for Outfall 2. 

Exhibit A-40. Summary of Effluent Data (2012-2014): Cosmo Specialty Fibers, 

Outfall 1

Pollutant Number of Observations Detected Values (μg/L)

Total Nondetects 95th Percentile Median

2,3,7,8-TCDD (dioxin) 14 13 0.000002 nd1

2,4,6-Tricholorophenol 32 32

Chloroform 32 1 28.85 19.1

Pentachlorophenol 

(PCP) 32 32

Source: Discharge monitoring reports, 2012 to 2014

nd = nondetect

1. Discharge monitoring report data notes various detection limits for dioxin, between 1 μg/L and 9.3 

μg/L.

A.9.3 Receiving Water

The facility discharges to Grays Harbor (via Outfall 1), a Class B marine water, and Chehalis 

River (via Outfall 2), a Class A fresh water. Ambient data for these waters are not available.

A.9.4 Baseline Scenario

The NPDES permit for facility does not have WQBELs based on human health criteria for 

the pollutants of concern. In this case, EPA performed a reasonable potential analysis for 

each pollutant based on the baseline (i.e., existing) human health criteria to confirm whether 

a WQBEL would have been included in the NPDES permit.

35 Based on the effluent 

concentrations in Exhibit A-40, there is no reasonable potential to exceed criteria for the 

pollutants of concern. Therefore, there are no costs associated with achieving compliance 

with the baseline scenario.

 

35 Based on 40 CFR 122.44(d)(1), were it not for the approaches and other policies used by Ecology. 40 CFR 

122.44(d)(1) requires that effluent limitations must be established when a pollutant is discharged “...at a 

level which will cause, have the reasonable potential to cause, or contribute to an excursion above any State 

water quality standard, including State narrative criteria for water quality.”
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 82

A.9.5 Policy Scenario

Based on the effluent concentrations in Exhibit A-40, there is no reasonable potential to 

exceed criteria for the pollutants of concern. Therefore, there are no costs associated with 

achieving compliance with the policy scenario.

A.10 Intalco Aluminum Corporation

Intalco Aluminum Corporation operates multiple wastewater treatment plants that combine 

and discharge to the Strait of Georgia. The facility produces primary aluminum metal from 

alumina ore using the Hall-Heroult reduction process. Wastewater associated with the 

industrial process includes contact and non-contact cooling water for metal casting and anode 

production, and wastewater generated from wet air pollution control systems. Additionally,

the facility generates domestic wastewater, wastewater from steam cleaning operating 

systems, and some stormwater. Average flow is 3 mgd.

A.10.1 Treatment Processes

The 2014 permit fact sheet for the facility (p. 10) states that the facility treats wastewater 

from the casting process and from the wet scrubbers using primary treatment consisting of an 

800 gallon receiving tank, a polymer addition system, two clarifiers, two filter feed pumps, a mud 

recycle tank, a vacuum pump, a vacuum filter drum, a recycle tank, a caustic addition system, 

and three recycle pumps. Secondary treatment includes an equalization tank and two treatment 

trains consisting of reaction tanks and flocculation tanks that feed into a clarifier. 

Anode cooling water, which is contaminated with coke and pitch containing benzo(a)pyrene, 

is treated using a baffled settling chamber (fact sheet, p. 11).

Domestic sanitary wastewater treatment consists of inlet vault, lagoon system, outlet weir 

box, and ultraviolet disinfection (fact sheet, p. 11).

A.10.2 Effluent Data 

Exhibit A-41 summarizes 2010 to 2013 effluent monitoring data for the facility from the 

permit fact sheet. 

Exhibit A-41. Summary of Effluent Data (2010 to 2013): Intalco Aluminum Facility

Pollutant Number of 

Observations Maximum (μg/L) Average (μg/L)

Acenaphthene 5 0.6 0.25

Anthracene 5 0.5 0.04

Antimony 9 17 3.6

Arsenic 5 50 27.4

Benzo(a) Anthracene 5 1.6 0.53

Benzo(a) Pyrene 5 1.9 0.75

Benzo(k) Fluoranthene 5 0.9 0.32

Copper 6 5.2 4.0
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 83

Exhibit A-41. Summary of Effluent Data (2010 to 2013): Intalco Aluminum Facility

Pollutant Number of 

Observations Maximum (μg/L) Average (μg/L)

Cyanide 2 0.7

Fluoranthene 5 3.3 1.09

Fluorene 5 0.2 0.07

Indeno(1,2,3-cd) Pyrene 5 1.6 0.37

Mercury 6 0.00354 0.0025

Methylene Chloride 2 0.59 0.3

Nickel 9 90 37

Phenol 2 25

Polychlorinated Biphenyls 

(PCBs)1 36 nd nd

Pyrene 5 2.8 0.92

Selenium 5 12 3

Thallium 5 1 0.17

Zinc 5 62 53

nd = nondetect

Source: 2014 Fact Sheet, Appendix E and Table 3.

1. Data for PCBs from Ecology’s discharge monitoring reports; 36 observations below detection limits.

A.10.3 Receiving Water

Exhibit A-42 summarizes the available ambient receiving water concentrations based on data 

from the 2014 fact sheet for the permit. 

Exhibit A-42. Ambient Receiving Water Concentrations: Strait of Georgia

Pollutant Water Column Concentration (μg/L)

90th Percentile Average

Chrysene 0.47 NR

Copper (dissolved) NR 0.47

Indeno(1,2,3-cd) 

Pyrene

0.012 NR

Mercury (dissolved) NR 0.00065

Selenium 0.57 NR

Zinc (dissolved) NR 0.57

Source: 2014 fact sheet for the permit; 90th percentile values are from Appendix E (reasonable 

potential analysis); average values based on Table 2 (from 10 samples collected upstream from 

Intalco discharges in July and September 1999).

NR = not reported
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 84

A.10.4 Baseline Scenario

The facility does not have WQBELs based on human health criteria for the pollutants of 

concern.36 In this case, EPA performed a reasonable potential analysis for each pollutant 

based on the baseline (i.e., existing) human health criteria to confirm whether a WQBEL 

would have been included in the NPDES permit.37 In cases of reasonable potential, EPA 

calculated a WQBEL using the existing human health criteria and evaluated compliance with 

this baseline WQBEL. 

Exhibit A-43 summarizes the reasonable potential analysis under the baseline scenario. 

Based on effluent concentrations in Exhibit A-41 and available ambient data in Exhibit A-42, 

there is reasonable potential to exceed the baseline human health criteria for arsenic. 

Exhibit A-43. Human Health Reasonable Potential Analysis for Intalco Aluminum1–

Baseline Scenario

Parameter Effluent 

Conc. (μg/L)

Ambient Conc. 

(μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 50.0 NR 0.6063 0.14

1. See effluent concentrations in Exhibit A-41 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean) and available ambient concentrations in Exhibit A-42. 

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 77 for carcinogens and 105 for non-carcinogens.

3. Consumption of organisms only.

Exhibit A-44 summarizes the calculated permit limits for arsenic under the baseline scenario. 

Exhibit A-44. Human Health Based Effluent Limitations for Intalco Aluminum –

Baseline Scenario

Parameter Average Monthly Effluent Limit 

(total; μg/L)1

Maximum Daily Effluent Limit 

(total; μg/L)1

Arsenic 11 22

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Arsenic

Under the baseline scenario, the discharger would have to meet an AML of 11 μg/L and a 

MDL of 22 μg/L. Arsenic was observed in the effluent at a concentration of 50 μg/L. Since 

the effluent monitoring data exceed the applicable effluent limitations under the baseline 

scenario, the discharger will need to control arsenic in its effluent to ensure that permit limits 

 

36 There are technology-based limits for benzo(a)pyrene, antimony, and nickel.

37 Based on 40 CFR 122.44(d)(1), were it not for the approaches and other policies used by Ecology. 40 CFR 

122.44(d)(1) requires that effluent limitations must be established when a pollutant is discharged “...at a 

level which will cause, have the reasonable potential to cause, or contribute to an excursion above any State 

water quality standard, including State narrative criteria for water quality.”
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 85

are consistently met. It is possible that more recent or future monitoring data could provide 

evidence that the facility is in compliance with the projected effluent limits and no costs 

would be incurred for compliance. However, additional data could provide further evidence 

of noncompliance. Based on the available information, EPA assumes the discharger will need 

to reduce discharge concentrations for compliance with the baseline scenario.

End-of-pipe treatment technologies capable of controlling arsenic include options such as 

chemical precipitation, microfiltration, and reverse osmosis. Given the limited nature of the 

information available regarding the internal process operations at the facility, EPA has 

assumed the use of reverse osmosis for arsenic control. Reverse osmosis is capable of 

reliably controlling arsenic at levels below the limit of quantitation. Further, EPA has 

assumed that treatment of the entire plant flow will be necessary. This is a conservative 

assumption as it is possible that a detailed study of the facility’s internal process operations 

would result in a more targeted treatment strategy—for instance, if only a single internal 

process flow was the source of the contamination, then only the contaminated stream would 

require treatment. EPA estimated a reverse osmosis treatment cost for a 3.0 mgd flow at 

$5,907,000 per year assuming an interest rate of 7 percent over 20 years.

A.10.5 Policy Scenario

Based on effluent concentrations in Exhibit A-41 and available ambient data in Exhibit A-42, 

there is reasonable potential to exceed human health criteria for the pollutants shown in 

Exhibit A-45.

Exhibit A-45. Human Health Reasonable Potential Analysis for Intalco Aluminum1–

Policy Scenario

Parameter

Baseline 

Average 

Monthly 

Effluent Limit

(μg/L)

Ambient Conc. 

(μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 11.0 NR 0.6063 0.0059

1. See effluent concentrations in Exhibit A-41 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean) and available ambient concentrations in Exhibit A-42. 

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 77 for carcinogens and 105 for non-carcinogens.

3. Consumption of organisms only.

Exhibit A-46 summarizes the calculated permit limits for arsenic under the policy scenario. 

Exhibit A-46. Human Health Based Effluent Limitations for Intalco Aluminum – Policy 

Scenario

Parameter Average Monthly Effluent Limit 

(total; μg/L)1

Maximum Daily Effluent Limit 

(total; μg/L)1

Arsenic 0.46 0.92

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 86

Under the policy scenario, the discharger would have to meet an AML of 0.46 μg/L and a 

MDL of 0.92 μg/L. Under the baseline scenario, EPA assumed that end-of-pipe treatment 

(i.e., reverse osmosis) would be necessary to meet effluent limitations. Since reverse osmosis 

is capable of treating the effluent to levels below the QL on a regular basis and further 

treatment below the QL is infeasible, EPA estimated that the discharger would incur costs for 

a P2 program to assist in ensuring compliance.

A.11 Quincy Industrial Wastewater Treatment Facility

The City of Quincy owns an industrial wastewater treatment facility (NPDES permit number 

WA0021067) that treats process wastewater from a potato and vegetable processor (ConAgra 

Foods and Quincy Foods, respectively). The facility discharges to a U.S. Bureau of 

Reclamation wasteway.

38

.Ecology has developed a proposed NPDES permit which contains 

requirements to develop a special study and reapplication to direct the discharge to a new 

location. The average flow is 1.5 mgd.

A.11.1 Treatment Processes

The fact sheet for the 2012 NPDES permit for the facility lists primary and secondary

treatment processes consisting of primary settling, anaerobic digestion, sequencing batch 

reactors, disinfection, summer season cooling, and re-aeration. 

A.11.2 Effluent Data 

Effluent monitoring data for the pollutants of interest are not available for this facility. 

Ecology has determined that the discharge is not likely to contain any pollutants addressed by 

the proposed human health criteria.

A.11.3 Receiving Water

Quincy Industrial discharges treated process wastewater to the U.S. Bureau of Reclamation 

wasteway DW237. The wasteway joins with other wasteways and eventually discharges to 

Potholes Reservoir. The entire water system is part of the federal Columbia Basin Irrigation 

Project.

According to the 2012 fact sheet for the NPDES permit (p. 25), Potholes Reservoir, 

downstream of the discharge point, is impaired for dieldrin, 2,3,7,8-TCDD, 4-4-DDE, and 

PCB. Another downstream waterbody, Frenchman Hills Waterway, is impaired for 

temperature and pH. Ecology finds that the travel distance from the facility’s discharge to 

these impairments is large and the influence of the discharge is negligible.

 

38 A wasteway drain is a manmade part of an irrigation project that receives excess water from irrigated lands 

and field underdrain systems. This wasteway system is part of the Columbia Basin Irrigation Project that 

brings water from the Columbia River to 500,000 acres in central Washington (2012 fact sheet, page 12).
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 87

A.11.4 Baseline Scenario

The NPDES permit for the facility does not have WQBELs based on human health criteria 

for the pollutants of concern. Due to the lack of available monitoring data, EPA could not 

evaluate reasonable potential and compliance costs for the facility under the baseline

scenario.

A.11.5 Policy Scenario

Due to the lack of available monitoring data, EPA could not determine reasonable potential 

and estimate compliance costs under the policy scenario.

A.12 Steelscape Inc.

Steelscape, Inc., located in Kalama, Washington, is an industrial facility (NPDES permit 

WA0040851) for the cold rolling and coating of steel strip. The facility is composed of four 

primary production lines: Pickle Line, Cold Rolling Mill, Metallic (zinc) Coating Line, and 

Coil Paint Line. 

A.12.1 Treatment Processes

The facility has two distinct wastewater treatment systems: one for treating “oily waste” from 

all process waters that are potentially contaminated with oil or grease, and the other for 

treating “metal waste.” Domestic waste is treated by the Port of Kalama Municipal 

Wastewater Treatment System.

The oil waste system treats wastewater from the Cold Roll Mill, Metallic Coating, and Coil 

Paint lines, using collection and blending, oil water separation, holding systems, and feeding 

systems for hydrochloric acid, de-emulsifier, coagulant, and polymer.

The metal waste system treats waste streams from the Pickle line, Metallic Coating line, Coil 

Paint line, and other auxiliary waste water from the facility (e.g., demineralizer regenerant 

waste, cooling tower blowdowns, and clear effluent from the oily waste system). The metal 

wastewater is chemically reduced, neutralized, oxidized, coagulated, precipitated, clarified, 

filtered, and dewatered (2010 fact sheet for the permit, p. 7).

A.12.2 Effluent Data 

Exhibit A-47 summarizes available effluent monitoring data for the facility for 2012 through 

2014. Concentration-based effluent monitoring data were not available for the reasonable 

potential analysis.

Exhibit A-47. Summary of Effluent Data (2012 to 2014): Steelscape Inc.

Pollutant Number of 

Observations

Quantified Values

Maximum Average Units

Arsenic (total) 32 7 1.34 kg/day

Copper (total) 32 0.004 0.0011 kg/day

Cyanide 32 0.004 0.00032 kg/day

Nickel (total) 32 0.005 0.0016 kg/day
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 88

Exhibit A-47. Summary of Effluent Data (2012 to 2014): Steelscape Inc.

Pollutant Number of 

Observations

Quantified Values

Zinc (total) 32 0.024 0.0019 kg/day

Source: Based on discharge monitoring reports submitted to Ecology.

A.12.3 Receiving Water

The facility discharges to the Columbia River through a submerged outfall that is shared with 

the Port of Kalama Municipal Wastewater Treatment Plant.

Exhibit A-48 summarizes the available ambient receiving water concentrations. 

Exhibit A-48. Ambient Receiving Water Concentrations: Columbia River

Pollutant Water Column Concentration (μg/L)

90th Percentile Geometric Mean

Arsenic (dissolved) 1.53 0.879

Copper (dissolved) 1.29 0.741

Nickel (dissolved) 0.842 0.4839

Zinc (dissolved) 2.76 1.5862

Source: 2010 Fact Sheet (Table 23).

A.12.4 Baseline Scenario

The NPDES permit for the facility does not have WQBELs based on human health criteria 

for the pollutants of concern. Due to the lack of available concentration-based effluent 

monitoring data, EPA could not evaluate reasonable potential and compliance costs for the 

facility under the baseline scenario.

A.12.5 Policy Scenario

Due to the lack of available concentration-based effluent monitoring data, EPA could not 

determine reasonable potential and estimate compliance costs under the policy scenario.

A.13 Sonoco Products

Sonoco Products (NPDES permit WA0000884) is a recycled paperboard manufacturing 

facility in Sumner Washington, producing an average of 138 tons of paperboard per day from 

recycled materials (based on data between 2007 and 2012). The facility discharges to the 

White River. Average flow is 0.14 mgd.

A.13.1 Treatment Processes

The 2013 permit fact sheet indicates that the current treatment consists of primary

clarification, activated sludge aeration, and secondary clarification. 
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 89

A.13.2 Effluent Data 

The fact sheet for the 2013 NPDES permit states that the effluent contains some heavy

metals. Exhibit A-49 summarizes available effluent monitoring data for the facility from the 

2013 permit fact sheet and a 2014 inspection report from Ecology. 

Exhibit A-49. Summary of Effluent Data (2012-2014): Sonoco Products

Pollutant Number of Observations Concentration (total recoverable; μg/L)

Antimony 1 1.18

Arsenic 1 2.16

Copper1 12 5.56 -28.6

Mercury 1 0.007

Nickel 1 3.04

Selenium22 0.82 - 10

Thallium 1 nondetect

Zinc32 28.6 - 40

Source: 2013 fact sheet for the permit and 2014 inspection report.

1. The 2013 fact sheet reports a maximum copper concentration of 28.6 out of 12 samples; the 2014 

inspection report has 5.56 ug/L. 

2. The 2013 fact sheet reports a concentration of 10 ug/L for selenium; the 2014 inspection report has 

0.82 ug/L.

3. The 2013 fact sheet reports a concentration of 40 ug/L for zinc; the 2014 inspection report has 28.6 

ug/L.

A.13.3 Receiving Water

The facility discharges to the White River, which has designated uses of salmonid spawning, 

rearing and migration, habitat, and primary contact recreation. Exhibit A-50 summarizes the 

available ambient receiving water concentrations based on data reported in the 2013 permit 

fact sheet.

Exhibit A-50. Ambient Receiving Water Concentrations: White River

Pollutant Water Column Concentration (total recoverable; μg/L)

Copper 1.94

Zinc 1.91

Source: 2013 fact sheet for the permit (Table 2); average of 8 samples.

A.13.4 Baseline Scenario

The NPDES permit for facility does not have WQBELs based on human health criteria for 

the pollutants of concern.39 In this case, EPA performed a reasonable potential analysis for 

 

39 The facility has discharge limitations for selenium and copper; however, these limitations are based on 

aquatic life rather than human health. All organic toxics have technology-based limitations of nondetect.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 90

each pollutant based on the baseline (i.e., existing) human health criteria to confirm whether 

a WQBEL would have been included in the NPDES permit. 40 In cases of reasonable 

potential, EPA calculated a WQBEL using the existing human health criteria and evaluated 

compliance with this baseline WQBEL.

Exhibit A-51 summarizes the reasonable potential analysis under the baseline scenario. 

Based on effluent concentrations in Exhibit A-49 and available ambient data in Exhibit A-50, 

there is reasonable potential to exceed the human health arsenic criterion.

Exhibit A-51. Human Health Reasonable Potential Analysis for Sonoco Products1–

Baseline Scenario

Parameter Effluent Conc. 

(total; μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 2.16 NR 0.0414 0.0045

NR = not reported

1. See effluent concentrations in Exhibit A-49 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean) and available ambient concentrations in Exhibit A-50. 

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 130.

3. Consumption of water and organisms.

Exhibit A-52 summarizes the calculated permit limits for arsenic under the baseline scenario.

Exhibit A-52. Human Health Based Effluent Limitations for Sonoco Products –

Baseline Scenario

Parameter Average Monthly Effluent Limit 

(total; μg/L)1

Maximum Daily Effluent Limit (total; 

μg/L)1

Arsenic 2.3 4.7

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Under the baseline scenario, the discharger would have to meet an AML of 2.3 μg/L and a 

MDL of 4.7 μg/L. Effluent arsenic was observed at an average concentration of 2.16 μg/L. 

Since the effluent monitoring data are less than the effluent limitations under the baseline 

scenario, EPA anticipates that immediate compliance with effluent limitations under the 

baseline scenario will be feasible, and that no compliance activities are necessary.

 

40 Based on 40 CFR 122.44(d)(1), were it not for the approaches and other policies used by Ecology. 40 CFR 

122.44(d)(1) requires that effluent limitations must be established when a pollutant is discharged “...at a 

level which will cause, have the reasonable potential to cause, or contribute to an excursion above any State 

water quality standard, including State narrative criteria for water quality.”
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 91

A.13.5 Policy Scenario

Exhibit A-53 summarizes the reasonable potential analysis under the policy scenario. Based 

on effluent concentrations in Exhibit A-49 and available ambient data in Exhibit A-50, there 

is reasonable potential to exceed the human health arsenic criterion.

Exhibit A-53. Human Health Reasonable Potential Analysis for Sonoco Products1–

Policy Scenario

Parameter Effluent Conc. 

(total; μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 2.16 NR 0.0414 0.0045

NR = not reported

1. See effluent concentrations in Exhibit A-49 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean) and available ambient concentrations in Exhibit A-50. 

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 130.

3. Consumption of water and organisms.

Exhibit A-54 summarizes the calculated permit limits for arsenic under the policy scenario.

Exhibit A-54. Human Health Based Effluent Limitations for Sonoco Products – Policy 

Scenario

Parameter Average Monthly Effluent Limit 

(total; μg/L)1

Maximum Daily Effluent Limit (total; 

μg/L)1

Arsenic 0.59 1.2

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Under the policy scenario, the discharger would have to meet an AML of 0.59 μg/L and a 

MDL of 1.2 μg/L. Effluent arsenic was observed at an average concentration of 2.16 μg/L. 

Since this value exceeds the applicable effluent limitations under the policy scenario, the 

discharger will need to control arsenic in its effluent to ensure that permit limits are 

consistently met. It is possible that more recent or future monitoring data could provide 

evidence that the facility is in compliance with the projected effluent limits and no costs 

would be incurred for compliance. However, additional data could provide further evidence 

of non-compliance. Based on the available information, EPA assumes the discharger will 

need to reduce discharge concentrations for compliance with the policy scenario.

End-of-pipe treatment technologies capable of controlling arsenic include options such as 

chemical precipitation, microfiltration, and reverse osmosis. Given the limited nature of the 

information available regarding the internal process operations at the facility, EPA has 

assumed the use of reverse osmosis for arsenic control. Reverse osmosis is capable of 

reliably controlling arsenic at levels below the limit of quantitation. Further, EPA has 

assumed that treatment of the entire plant flow will be necessary. This is a conservative 

assumption as it is possible that a detailed study of the facility’s internal process operations 
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 92

would result in a more targeted treatment strategy—for instance, if only a single internal 

process flow was the source of the contamination, then only the contaminated stream would 

require treatment. EPA estimated a reverse osmosis treatment cost for a 0.14 mgd flow at 

$2,136,000 per year assuming an interest rate of 7 percent over 20 years.

A.14 Tesoro Refining and Marketing LLC - Anacortes

Tesoro Refining and Marketing LLC operates a wastewater treatment plant (NPDES permit 

WA0000761) that discharges to Fidalgo Bay in northwestern Washington. The refinery

processes crude oil from Alaska’s Northern Slope, Canada, and the Bakken Shale Reserves 

of Montana and North Dakota. The wastewater treatment plant treats process water, sanitary

wastewater, stormwater, and ballast water. The permit also authorizes the treatment of 

wastewater from an onsite crude railcar offloading facility. Average flow is 2.8 mgd.

During extremely heavy rainfall events, Tesoro may also discharge water from a retention 

pond that would consist almost entirely of stormwater, but may contain small amounts of oily

wastewater. Tesoro has increased the volume of the retention pond and no discharges have 

occurred since December 1996.

A.14.1 Treatment Processes

The 2013 draft fact sheet for the permit states that the facility uses primary and secondary

treatment for process wastewater and contaminated stormwater. This system consists of API

oil/water separators, primary clarifiers, activated sludge units, secondary clarifiers, and 

holding ponds. Sanitary wastewater is treated with a septic tank and a neutralization pit.

A.14.2 Effluent Data

Exhibit A-55 summarizes the effluent data for the treated wastewater for the pollutants of 

concern for which data are available, based on Ecology’s reasonable potential analysis 

(Appendix H in the 2013 draft permit fact sheet). 

Exhibit A-55. Summary of Effluent Data: Tesoro Refinery, Outfall 1

Pollutant

Number of 

Observations Quantification 

Limit (μg/L)

Summary of Detected 

Values (μg/L)1

Total Nondetect Maximum Average

1,1-Dichloroethylene 4 4 0.2

1,2-Dichlorobenzene 1 1 2

1,2-Dichloroethane 4 4 0.1

1,2-Dichloropropane 4 4 0.4

1,2-Diphenylhydrazine 4 4 0.5

1,3-Dichlorobenzene 1 1 2

1,4-Dichlorobenzene 1 1 2

2,4-Dichlorophenol 4 4 1

2,4-Dimethylphenol 1 1 2
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 93

Exhibit A-55. Summary of Effluent Data: Tesoro Refinery, Outfall 1

Pollutant

Number of 

Observations Quantification 

Limit (μg/L)

Summary of Detected 

Values (μg/L)1

Total Nondetect Maximum Average

2,4-Dinitrophenol 4 4 1

2,4-Dinitrotoluene 4 4 0.1

2-Chloronaphthalene 1 1 2

3,3'-Dichlorobenzidine 1 1 2

Anthracene 1 1 2

Antimony 2 1.4

Arsenic 1 5.33 5.33

Benzene 4 44.9

Benzidine 1 1 2

Benzo(a) anthracene 1 1 2

Benzo(a) pyrene 1 1 2

Benzo(b) Ffuoranthene 1 1 2

Benzo(k) fluoranthene 1 1 2

Bis(2-chloroethyl) ether 1 1 2

Bis(2-ethylhexyl) phthalate 1 1 1

Bromoform 4 0.6

Butylbenzyl phthalate 1 1 2

Carbon tetrachloride 4 4 0.4

Chlordane 4 4 0.1

Chlorobenzene 4 4 0.4

Chlorodibromomethane 4 1.9

Chloroform 4 13.7

Chrysene 4 4 2

Copper 4 7 5.01

Cyanide 4 15 7.0

Dibenzo(a,h) anthracene 1 1 2

Dichlorobromomethane 1 2.4

Diethyl phthalate 4 4

Dimethyl phthalate 1 1 2

Di-n-butyl phthalate 4 4 0.5

Endosulfan sulfate 4 4 0.1

Endrin 4 4 0.1

Endrin aldehyde 4 4 0.1
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 94

Exhibit A-55. Summary of Effluent Data: Tesoro Refinery, Outfall 1

Pollutant

Number of 

Observations Quantification 

Limit (μg/L)

Summary of Detected 

Values (μg/L)1

Total Nondetect Maximum Average

Ethylbenzene 4 4 0.4

Fluoranthene 4 4 0.5

Fluorene 4 4 0.5

Hexachlorobutadiene 4 4 0.5

Hexachlorocyclopentadiene 4 4 0.5

Hexachloroethane 4 4 0.5

Indeno(1,2,3-cd) pyrene 1 1 0.1

Isophorone 4 4 0.5

Mercury235 0.44 0.069

Methyl bromide 4 4 0.4

Methylene chloride 4 0.6

Nickel 4 7 5.33

Nitrobenzene 4 4 0.5

N-Nitrosodimethylamine 1 1 0.2

N-Nitrosodi-n-propylamine 1 1 0.2

N-Nitrosodiphenylamine 1 1 0.2

Pentachlorophenol (PCP) 4 4 0.5

Phenol 52 2 0.009

Pyrene 4 0.8

Selenium 4 21

Tetrachloroethylene 4 4 0.6

Thallium 4 4 1

Toluene 4 8.2

Toxaphene 4 4 0.5

Trichloroethylene 4 4 0.4

Vinyl chloride 4 4 0.4

Zinc 4 66 66

Source: 2013 draft permit fact sheet (Appendix H and Table 2); based on the 2010 permit application 

and annual priority pollutant scans (years not specified).

1. Metal concentrations are total recoverable.

2. Data for mercury is from 2012 to 2014 discharge monitoring reports.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 95

A.14.3 Receiving Water

Tesoro discharges to Fidalgo Bay, which Ecology has designated as an extraordinary marine 

receiving water. Exhibit A-56 summarizes the available ambient receiving water 

concentrations based on data in the permit fact sheet for 1998 through 2005.

Exhibit A-56. Ambient Receiving Water Concentrations: Fidalgo Bay1

Pollutant Geometric Mean Concentration (μg/L) Concentration at 90th Percentile 

Temperature (μg/L)

Arsenic 1.15 NR

Copper 0.512 0.673

Nickel 0.522 NR

Selenium 0.0713 NR

Zinc 1.26 3.9

Mercury 0.0007 0.001

Source: 2013 Draft Fact Sheet Table 3 and Appendix H (reasonable potential analysis).

NR = not reported

1. Metal concentrations are dissolved.

A.14.4 Baseline Scenario

The permit does not include any WQBELs based on the existing human health criteria for the 

pollutants of concern. In this case, EPA performed a reasonable potential analysis for each 

pollutant based on the baseline (i.e., existing) human health criteria to confirm whether a 

WQBEL would have been included in the NPDES permit.41 In cases of reasonable potential, 

EPA calculated a WQBEL using the existing human health criteria and evaluated compliance 

with this baseline WQBEL. 

Exhibit A-57 summarizes the reasonable potential analysis under the baseline scenario.

Based on effluent concentrations in Exhibit A-55 and available ambient data in Exhibit A-56, 

there is reasonable potential to exceed the baseline human health arsenic criterion.

Exhibit A-57. Human Health Reasonable Potential Analysis for Tesoro Facility1–

Baseline Scenario

Parameter Effluent Conc. 

(total; μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health

Criterion3(μg/L)

Arsenic 5.33 1.15 13.3 0.14

 

41 Based on 40 CFR 122.44(d)(1), were it not for the approaches and other policies used by Ecology. 40 CFR 

122.44(d)(1) requires that effluent limitations must be established when a pollutant is discharged “...at a 

level which will cause, have the reasonable potential to cause, or contribute to an excursion above any State 

water quality standard, including State narrative criteria for water quality.”
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 96

Exhibit A-57. Human Health Reasonable Potential Analysis for Tesoro Facility1–

Baseline Scenario

Parameter Effluent Conc. 

(total; μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health

Criterion3(μg/L)

1. See effluent concentrations in Exhibit A-55 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean) and available ambient concentrations in Exhibit A-56. 

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using end-of-pipe 

limitations.

3. Consumption of organisms only.

Exhibit A-58 summarizes the calculated permit limits for arsenic and mercury under the

baseline scenario.

Exhibit A-58. Human Health Based Effluent Limitations for Tesoro Facility – Baseline 

Scenario

Parameter Average Monthly Effluent Limit 

(total; μg/L)1

Maximum Daily Effluent Limit 

(total; μg/L)1

Arsenic 0.14 0.28

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Under the baseline scenario, the discharger would have to meet an AML of 0.14 μg/L and a 

MDL of 0.28 μg/L. According to the draft 2013 Fact Sheet for the facility, arsenic was 

observed in the effluent with a long-term average concentration of 5.3 μg/L. Since this value 

exceeds the applicable effluent limitations under the baseline scenario, the discharger will 

need to control arsenic in its effluent to ensure that permit limits are consistently met. It is 

possible that more recent or future monitoring data could provide evidence that the facility is 

in compliance with the projected effluent limits and no costs would be incurred for 

compliance. However, additional data could provide further evidence of non-compliance. 

Based on the available information, EPA assumes the discharger will need to reduce 

discharge concentrations for compliance with the baseline scenario.

Crude petroleum is an important source of metals at petroleum refining and processing 

facilities, including arsenic. Metals found in crude petroleum, and their concentrations, 

depend on the origin of the crude oil. Other sources include arsenic contaminated process 

equipment and other manufacturing inputs (i.e., spent catalyst). A P2 program that identifies 

likely sources of arsenic in the facility’s waste stream can provide adequate levels of control 

through updated source control and P2 best management practices. Costs for designing and 

implementing a P2 program for arsenic is estimated to be $28,000 per year. However, if the 

facility determines that source water derived from ground water, surface waters, or drinking 

water is the source of high arsenic values in the wastewater, or if it is determined that control 

of arsenic in the discharge is infeasible (e.g., due to the economic impacts of controlling the 

pollutant) it is likely that the facility would pursue a variance.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 97

Due to the fact that ambient receiving water concentrations exceed the proposed human 

health criteria, the discharger may pursue obtaining a water quality standards variance. The 

one-time cost associated with pursuing a variance is estimated to be $180,000, with minimal 

costs associated with renewal. 

A.14.5 Policy Scenario

Exhibit A-59 summarizes the reasonable potential analysis under the policy scenario. Based 

on effluent concentrations in Exhibit A-55 and available ambient data in Exhibit A-56, there 

is reasonable potential to exceed the human health arsenic and mercury criteria.

Exhibit A-59. Human Health Reasonable Potential Analysis for Tesoro Facility1–

Policy Scenario

Parameter

Baseline Average 

Monthly Effluent 

Limit or Conc. (total; 

μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 0.14 1.15 13.3 0.0059

Mercury 0.44 0.0007 0.069 0.017

1. See effluent concentrations in Exhibit A-55 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean) and available ambient concentrations in Exhibit A-56. 

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 93 for arsenic and 91 for mercury.

3. Consumption of organisms only.

Exhibit A-60 summarizes the calculated permit limits for arsenic and mercury under the policy 

scenario.

Exhibit A-60. Human Health Based Effluent Limitations for Tesoro Facility – Policy

Scenario

Parameter Average Monthly Effluent Limit 

(total; ug/L)1

Maximum Daily Effluent Limit 

(total; ug/L)1

Arsenic 0.0059 0.012

Mercury 0.017 0.042

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Arsenic

Under the policy scenario, the discharger would have to meet an AML of 0.0059 μg/L and a 

MDL of 0.12 μg/L. Under the policy scenario, where the projected effluent limitations are 

below the analytical QL, EPA estimated that the discharger would incur costs for P2 as well 

as pursuit of a variance in order to ensure compliance with effluent limitations below the QL. 

Since the projected effluent limitations under the policy scenario are also below the QL, no 

additional compliance strategy would be required under the policy scenario (i.e., the 

discharger would not pursue a second variance).
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 98

Mercury

Under the policy scenario, the discharger would have to meet an AML of 0.017 μg/L and a 

MDL of 0.042 μg/L. The average effluent concentration is 0.069 μg/L and the maximum 

effluent concentration is 0.44 μg/L. The average ambient mercury concentration is 0.0007 

μg/L. Based on the available data, the discharger will likely need to reduce mercury in its 

effluent to ensure that permit limits are consistently met. Fidalgo Bay is not listed on the 

State’s 303(d) list for mercury.

Because there are no proven end-of-pipe treatment technologies that can achieve low 

mercury levels (e.g., <10 ng/L) on a consistent basis, the facility would likely implement a 

P2 program for compliance with the projected effluent limits. Annual P2 program costs for 

this industrial facility are estimated to be approximately $28,000.

A.15 TransAlta Centralia Generating Station

The TransAlta Centralia Generating Station (NPDES permit WA0001546) is a coal-fired 

power plant with two 702.5 Megawatt turbine units as well as a 250 Megawatt natural gas 

power plant on the same site. The facility generates process wastewater, stormwater runoff, 

and sanitary effluent, as well as sanitary effluent from the adjacent TransAlta Centralia 

Mining facility. Average flow for the facility is 3.57 mgd.

A.15.1 Treatment Processes

The fact sheet for the facility’s 2010 NPDES permit lists current treatment processes as an oil 

skimmer pond and two effluent detention ponds. Sanitary effluent from the facility, 

TransAlta Centralia Mining, and the Big Hanaford Project is treated using an activated 

sludge process.

A.15.2 Effluent Data 

Exhibit A-61 summarizes the results of a 2008 priority pollutant scan, from the 2010 fact 

sheet for the permit (Appendix C). 

Exhibit A-61. Summary of Effluent Data (2008): Transalta Centralia Generation, Outfall 1

Pollutant Number of Observations Quantitation 

Level (μg/L)

Detected Value 

(μg/L)1

Total Nondetect

1,1,2,2-Tetrachloroethane 1 1 1

1,1,2-Trichloroethane 1 1 1

1,1-Dichloroethylene 1 1 1

1,2,4-Trichlorobenzene 1 1 2.5

1,2-Dichlorobenzene 1 1 2.5

1,2-Dichloroethane 1 1 1

1,2-Dichloropropane 1 1 1

1,3-Dichlorobenzene 1 1 2.5

1,4-Dichlorobenzene 1 1 2.5
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 99

Exhibit A-61. Summary of Effluent Data (2008): Transalta Centralia Generation, Outfall 1

Pollutant Number of Observations Quantitation 

Level (μg/L)

Detected Value 

(μg/L)1

Total Nondetect

2,4,6-Trichlorophenol 1 1 2.5

2,4-Dichlorophenol 1 1 2.5

2,4-Dinitrophenol 1 1 10

2,4-Dinitrotoluene 1 1 2.5

2-Chloronaphthalene 1 1 2.5

2-Chlorophenol 1 1 2.5

3,3'-Dichlorobenzidine 1 1 20

4,4'-DDD 1 1 0.01

4,4'-DDE 1 1 0.01

4,4'-DDT 1 1 0.01

Acenaphthene 1 1 1

Acrolein 1 1 10

Acrylonitrile 1 1 10

Aldrin 1 1 0.01

alpha-BHC 1 1 0.01

Anthracene 1 1 1

Antimony 1 0.21 2

Arsenic 1 0.24 5

Benzene 1 1 1

Benzidine 1 1 20

Benzo(a) anthracene 1 1 1

Benzo(a) pyrene 1 1 1

Benzo(k) fluoranthene 1 1 1

beta-BHC 1 1 0.01

Bis(2-chloroethyl) ether 1 1 2.5

Bis(2-chloroisopropyl) ether 1 1 2.5

Bis(2-ethylhexyl) phthalate 1 1 2.5

Bromoform 1 1 1

Butylbenzyl phthalate 1 1 2.5

Carbon tetrachloride 1 1 1

Chlorobenzene 1 1 1

Chlorodibromomethane 1 1 1

Chloroform 1 1 1

Chrysene 1 1 1
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 100

Exhibit A-61. Summary of Effluent Data (2008): Transalta Centralia Generation, Outfall 1

Pollutant Number of Observations Quantitation 

Level (μg/L)

Detected Value 

(μg/L)1

Total Nondetect

Copper 1 0.18 2

Dibenzo(a,h) anthracene 1 1 1

Dichlorobromomethane 1 1 1

Dieldrin 1 1 0.01

Diethyl phthalate 1 1 2.5

Dimethyl phthalate 1 1 2.5

Di-n-butyl phthalate 1 1 2.5

Endosulfan sulfate 1 1 0.01

Endrin 1 1 0.01

Endrin aldehyde 1 1 0.01

Ethylbenzene 1 1 1

Fluoranthene 1 1 1

Fluorene 1 1 1

Heptachlor 1 1 0.01

Heptachlor epoxide 1 1 0.01

Hexachlorobenzene 1 1 2.5

Hexachlorobutadiene 1 1 2.5

Hexachlorocyclohexane 

(gamma-BHC; lindane) 1 1 0.01

Hexachlorocyclopentadiene 1 1 2.5

Hexachloroethane 1 1 2.5

Indeno(1,2,3-cd) pyrene 1 1 1

Isophorone 1 1 2.5

Methyl bromide 1 1 1

Methylene chloride 1 1 1

Nickel 1 0.14 1

Nitrobenzene 1 1 2.5

N-Nitrosodi-n-propylamine 1 1 2.5

Pentachlorophenol (PCP) 1 1 10

Phenol 1 1 2.5

Polychlorinated biphenyls 

(PCBs) 1 1 0.1

Pyrene 1 1 1

Selenium21 0.39 3
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 101

Exhibit A-61. Summary of Effluent Data (2008): Transalta Centralia Generation, Outfall 1

Pollutant Number of Observations Quantitation 

Level (μg/L)

Detected Value 

(μg/L)1

Total Nondetect

Tetrachloroethylene 1 1 1

Thallium 1 1 0.28

Toluene 1 1 1

Toxaphene 1 1 1

Trichloroethylene 1 1 1

Vinyl chloride 1 1 1

Zinc 1 0.33 1

Source: 2010 Fact Sheet, Appendix C.

1. Metal concentrations are total recoverable.

2. Appendix C, Table 2 lists the selenium detected value as 3 ug/L; however Ecology used a maximum 

value of 80 ug/L in the reasonable potential analysis (Appendix C Table 3).

A.15.3 Receiving Water

The facility discharges to Hanaford Creek. Ambient water quality data are not available for 

this receiving water.

A.15.4 Baseline Scenario

The NPDES permit for facility does not have WQBELs based on human health criteria for 

the pollutants of concern.42 In this case, EPA performed a reasonable potential analysis for 

each pollutant based on the baseline (i.e., existing) human health criteria to confirm whether 

a WQBEL would have been included in the NPDES permit.43 In cases of reasonable 

potential, EPA calculated a WQBEL using the existing human health criteria and evaluated 

compliance with this baseline WQBEL.

Exhibit A-62 summarizes the reasonable potential analysis under the baseline scenario. 

Based on effluent concentrations in Exhibit A-61, there is reasonable potential to exceed 

human health criteria for arsenic.

 

42 The facility has discharge limitations for selenium and copper; however, these limitations are based on 

aquatic life rather than human health criteria. All organic toxics have technology-based limitations of 

nondetect.

43 Based on 40 CFR 122.44(d)(1), were it not for the approaches and other policies used by Ecology. 40 CFR 

122.44(d)(1) requires that effluent limitations must be established when a pollutant is discharged “...at a 

level which will cause, have the reasonable potential to cause, or contribute to an excursion above any State 

water quality standard, including State narrative criteria for water quality.”
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 102

Exhibit A-62. Human Health Reasonable Potential Analysis for Transalta Centralia 

Generation1– Baseline Scenario

Parameter Effluent Conc. 

(total; μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 5.0 NR 12.448 0.018

NR = not reported

1. See effluent concentrations in Exhibit A-61 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean).

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 1.

3. Consumption of water and organisms.

Exhibit A-63 summarizes the calculated permit limits for arsenic under the baseline scenario. 

Exhibit A-63. Human Health Based Effluent Limitations for Transalta Centralia 

Generation – Baseline Scenario

Parameter Average Monthly Effluent Limit (total; 

μg/L)1

Maximum Daily Effluent Limit (total; 

μg/L)1

Arsenic 0.018 0.036

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Under the baseline scenario, the discharger would have to meet an AML of 0.018 μg/L and a 

MDL of 0.036 μg/L. Arsenic was observed in the effluent at of 5 μg/L. No ambient data are

available and Hanaford Creek near the discharge is not listed on the State’s 303(d) list as 

impaired for arsenic. Since the effluent monitoring data exceeds the applicable effluent 

limitations under the baseline scenario, the discharger will need to control arsenic in its 

effluent to ensure that permit limits are consistently met. It is possible that more recent or 

future monitoring data could provide evidence that the facility is in compliance with the 

projected effluent limits and no costs would be incurred for compliance. However, additional 

data could provide further evidence of non-compliance. Based on the available information, 

EPA assumes the discharger will need to reduce discharge concentrations for compliance 

with the baseline scenario.

A P2 program is a possible pathway to achieve compliance with effluent limitations for 

arsenic. A P2 program that identifies likely sources of arsenic in the facility’s waste stream 

can provide adequate levels of control through updated source control and P2 best 

management practices. Costs for designing and implementing a P2 program for arsenic is 

estimated to be $28,000 per year. However, if the facility determines that source water 

derived from ground water, surface waters, or drinking water is the source of high arsenic 

values in the wastewater, or if it is determined that control of arsenic in the discharge is 

infeasible (e.g., due to the economic impacts of controlling the pollutant) it is likely that the 

facility would pursue a variance.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 103

Due to the fact that ambient receiving water concentrations exceed the proposed human 

health criteria, the discharger may pursue obtaining a water quality standards variance. The 

one-time cost associated with pursuing a variance is estimated to be $180,000, with minimal 

costs associated with renewal.

A.15.5 Policy Scenario

Exhibit A-64 summarizes the reasonable potential analysis under the policy scenario. Based 

on effluent concentrations in Exhibit A-61, there is reasonable potential to exceed human 

health criteria for antimony, arsenic, and selenium.

Exhibit A-64. Human Health Reasonable Potential Analysis for Transalta Centralia 

Generation1– Policy Scenario

Parameter

Baseline Average 

Monthly Effluent Limit or 

Conc. (total; μg/L)

Ambient Conc. 

(dissolved; 

μg/L)

Conc. at Edge of 

Mixing Zone2

(μg/L)

Human Health 

Criterion3

(μg/L)

Antimony 2.0 NR 4.98 2.49

Arsenic 0.018 NR 12.448 0.0045

Selenium 80.0 NR 199.16 24.69

NR = not reported

1. See effluent concentrations in Exhibit A-61 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean).

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 1.

3. Consumption of water and organisms.

Exhibit A-65 summarizes the calculated permit limits for antimony and arsenic under the 

policy scenario. For this analysis, EPA did not consider limitations for selenium further since 

under the policy scenario the discharger would face more stringent limitations established on 

the basis of aquatic life criteria.

Exhibit A-65. Human Health Based Effluent Limitations for Transalta Centralia 

Generation – Policy Scenario

Parameter Average Monthly Effluent Limit (total; 

ug/L)1

Maximum Daily Effluent Limit (total; 

ug/L)1

Antimony 2.5 5.0

Arsenic 0.0045 0.0091

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Antimony

Under the policy scenario, the discharger would have to meet an AML of 2.5 μg/L and a 

MDL of 5.0 μg/L. Based on the available effluent data, the facility will be capable of 

immediate compliance with antimony effluent limitations under the policy scenario. 
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 104

Therefore, EPA estimates there will be no compliance cost associated with effluent 

limitations. 

Arsenic

Under the policy scenario, the discharger would have to meet an AML of 0.0045 μg/L and a 

MDL of 0.0091 μg/L. Under the baseline scenario, where the projected effluent limitations 

are below the analytical QL, EPA estimated that the discharger would incur costs for P2 as 

well as pursuit of a variance in order to ensure compliance with effluent limitations below the 

QL. Since the projected effluent limitations under the policy scenario are also below the QL, 

no additional compliance strategy would be required under the policy scenario (i.e., the

discharger would not pursue a second variance).

A.16 TransAlta Centralia Mining

TransAlta Centralia Mining (NPDES permit number WA0037338) mines and processes 

approximately 6 million tons of coal annually for use at the adjacent TransAlta Centralia 

Generating Station. The mine discharges stormwater overflow to Big Hanaford Creek and its 

tributaries. Average monthly flow is approximately 8 cubic feet per second (or 5 mgd).44

A.16.1 Treatment Processes

The 2011 NPDES permit fact sheet for the facility lists current treatment processes as 

sedimentation ponds, which are built as excavation progresses and abandoned as reclamation 

progresses. Discharges from the facility consist of stormwater overflows. Sanitary effluent 

from the facility is treated by the TransAlta Centralia Generating Station.

A.16.2 Effluent Data 

Exhibit A-66 summarizes 2014 and 2015 effluent monitoring data for the mine. 

Exhibit A-66. Summary of Effluent Data (2014 to 2015): Transalta Centralia Mining, 

Outfall1

Pollutant Number of 

Observations

Water Column Concentrations (total recoverable; μg/L)

Median Average 95th Percentile Maximum

Arsenic 12 2.8 3.567 22.275 12.1

Mercury 3 0.00195 0.001907 0 0.00294

Source: discharge monitoring data submitted to Ecology.

A.16.3 Receiving Water

The facility discharges to Big Hanaford Creek and several tributaries, which are designated 

as “Class A” receiving waters. Ambient water quality data are not available for this receiving 

water.

 

44 Based on 2012 to 2014 discharge monitoring reports submitted to Ecology.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 105

A.16.4 Baseline Scenario

The permit does not include any water quality-based effluent limitations (WQBELs) based 

on the existing human health criteria for the pollutants of concern. In this case, EPA 

performed a reasonable potential analysis for each pollutant based on the baseline (i.e., 

existing) human health criteria to confirm whether a WQBEL would have been included in 

the NPDES permit.45 In cases of reasonable potential, EPA calculated a WQBEL using the 

existing human health criteria and evaluated compliance with this baseline WQBEL. 

Exhibit A-67 summarizes the reasonable potential analysis under the baseline scenario. 

Based on effluent concentrations in Exhibit A-66, there is reasonable potential to exceed the 

baseline human health arsenic criterion.

Exhibit A-67. Human Health Reasonable Potential Analysis for Transalta Centralia 

Mining1– Baseline Scenario

Parameter

Effluent 

Conc. (total; 

μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of Mixing 

Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 2.8 NR 2.8 0.018

NR = not reported

1. See effluent concentrations in Exhibit A-66 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

median).

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 1.

3. Consumption of water and organisms.

Exhibit A-68 summarizes the calculated permit limits for arsenic under the baseline scenario. 

Exhibit A-68. Human Health Based Effluent Limitations for Transalta Centralia Mining

– Baseline Scenario

Parameter Average Monthly Effluent Limit (total; 

ug/L)1

Maximum Daily Effluent Limit (total; 

ug/L)1

Arsenic 0.018 0.060

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Under the baseline scenario, the discharger would have to meet an AML of 0.018 μg/L and a 

MDL of 0.060 μg/L. Arsenic was observed in the effluent at of 2.8 μg/L. No ambient data 

are available and Hanaford Creek near the discharge is not listed on the State’s 303(d) list as 

impaired for arsenic. Since the effluent monitoring data exceeds the applicable effluent 

 

45 Based on 40 CFR 122.44(d)(1), were it not for the approaches and other policies used by Ecology. 40 CFR 

122.44(d)(1) requires that effluent limitations must be established when a pollutant is discharged “...at a 

level which will cause, have the reasonable potential to cause, or contribute to an excursion above any State 

water quality standard, including State narrative criteria for water quality.”
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 106

limitations under the baseline scenario, the discharger will need to control arsenic in its 

effluent to ensure that permit limits are consistently met. It is possible that more recent or 

future monitoring data could provide evidence that the facility is in compliance with the 

projected effluent limits and no costs would be incurred for compliance. However, additional 

data could provide further evidence of non-compliance. Based on the available information, 

EPA assumes the discharger will need to reduce discharge concentrations for compliance 

with the baseline scenario.

A P2 program is a possible pathway to achieve compliance with effluent limitations for 

arsenic. A P2 program that identifies likely sources of arsenic in the facility’s waste stream 

can provide adequate levels of control through updated source control and P2 best 

management practices. Costs for designing and implementing a P2 program for arsenic is 

estimated to be $28,000 per year. However, if the facility determines that source water 

derived from ground water, surface waters, or drinking water is the source of high arsenic 

values in the wastewater, or if it is determined that control of arsenic in the discharge is 

infeasible (e.g., due to the economic impacts of controlling the pollutant) it is likely that the 

facility would pursue a variance.

Due to the fact that ambient receiving water concentrations exceed the proposed human 

health criteria, the discharger may pursue obtaining a water quality standards variance. The 

one-time cost associated with pursuing a variance is estimated to be $180,000, with minimal 

costs associated with renewal.

A.16.5 Policy Scenario

Exhibit A-69 summarizes the reasonable potential analysis under the policy scenario. Based 

on effluent concentrations in Exhibit A-66, there is reasonable potential to exceed human 

health criteria for arsenic and mercury.

Exhibit A-69. Human Health Reasonable Potential Analysis for Transalta Centralia 

Mining1– Policy Scenario

Parameter

Baseline Average 

Monthly Effluent Limit

or Conc. (total; μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2

(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 0.018 NR 2.8 0.0045

Mercury 0.0029 NR 0.0035 0.00088

NR = not reported

1. See effluent concentrations in Exhibit A-66 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

median).

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 1.

3. Consumption of water and organisms.

Exhibit A-70 summarizes the calculated permit limits for arsenic and mercury under the policy 

scenario.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 107

Exhibit A-70. Human Health Based Effluent Limitations for Transalta Centralia Mining

– Policy Scenario

Parameter Average Monthly Effluent Limit (total; 

μg/L)1

Maximum Daily Effluent Limit (total; 

μg/L)1

Arsenic 0.0045 0.015

Mercury 0.00088 0.0018

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Arsenic

Under the policy scenario, the discharger would have to meet an AML of 0.0045 μg/L and a 

MDL of 0.015 μg/L. Under the baseline scenario, where the projected effluent limitations are 

below the analytical QL, EPA estimated that the discharger would incur costs for P2 as well 

as pursuit of a variance in order to ensure compliance with effluent limitations below the QL. 

Since the projected effluent limitations under the policy scenario are also below the QL, no 

additional compliance strategy would be required under the policy scenario (i.e., the 

discharger would not pursue a second variance).

Mercury

Under the policy scenario, the discharger would have to meet an AML of 0.00088 μg/L and a 

MDL of 0.0018 μg/L. The maximum effluent concentration is 0.0029 μg/L and the average 

effluent concentration is 0.0019 μg/L. Based on the available data, the discharger will likely

need to reduce mercury in its effluent to ensure that permit limits are consistently met. 

Because there are no proven end-of-pipe treatment technologies that can achieve low 

mercury levels (e.g., <10 ng/L) on a consistent basis, the facility would likely implement a 

P2 program for compliance with the projected effluent limits. Annual P2 program costs for 

this industrial facility are estimated to be approximately $28,000. To ensure compliance in 

case a P2 program would not be sufficient to meet the projected effluent limitations, it is 

assumed that the facility would incur costs for a variance.

A.17 U.S. Oil & Refining Corporation

U.S. Oil and Refining Corporation (NPDES permit WA0001783) in Tacoma consists of an 

oil refinery, tank farm, and marine terminal. The facility encompasses 122 acres and has a 

daily throughput of 36,000 barrels per day (based on output between 2002 and 2006). The 

refinery separates crude oil into component parts and blends them into petroleum products 

including gasoline, jet fuel, diesel fuel, marine fuel, gas oils, and asphalts. The average 

wastewater flow for the maximum month is 0.62 mgd.

A.17.1 Treatment Processes

The 2008 permit fact sheet for the facility indicates that the facility employs primary and 

secondary treatment for process wastewater and contaminated stormwater before discharging 

to a City of Tacoma storm drain. Primary treatment includes an oil/water separator and an 

induced air flotation unit, and secondary treatment is an activated sludge biological unit and a 
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 108

clarifier. Sanitary waste from the facility is collected separately and treated by the City of 

Tacoma’s municipal wastewater treatment plant.

A.17.2 Effluent Data 

Exhibit A-71 summarizes effluent monitoring data for the facility from a 2014 monitoring 

report, which reports detected concentrations only for the pollutants of concern.46 According 

to the 2008 NPDES permit fact sheet, monitoring data for organic toxics are not reported 

because all samples were below detection limits.

Exhibit A-71. Summary of Effluent Data (2013-2014): US Oil & Refining Facility1

Pollutant Number of 

Observations Average (μg/L) Maximum (μg/L)

Antimony 2 0.47 0.54

Arsenic 2 6.5 8.6

Copper 2 0.58 0.6

Mercury 2 0.00245 0.0028

Nickel 2 1.295 1.4

Phenols 2 nd nd

Selenium 2 3.08 3.56

Thallium 2 nd 0.02

Zinc 2 3.7 5.7

nd = nondetect

Source: 2014 Inspection Report (Table 1 and Table 2); includes one sample taken by Washington 

Department of Ecology (2014) and one sample submitted by the facility (2013).

1. Metal concentrations are in total recoverable. 

A.17.3 Receiving Water

USOR discharges to the Lincoln Avenue Ditch, where it flows to the Blair Waterway which 

is a tidal inlet to Commencement Bay. The Blair Waterway is a Class B marine waterbody, 

with uses including industrial uses; fish migration; shellfish spawning, rearing and 

harvesting; wildlife habitat; secondary contact recreation; sport fishing; boating and aesthetic 

enjoyment; commerce; and navigation. 

Exhibit A-72 summarizes the available ambient receiving water concentrations from the 

2008 permit fact sheet. 

 

46 The NPDES permit requires an annual priority pollutant scan; however, these data are not available in 

Ecology’s discharge monitoring report (DMR) online tool nor EPA’s ICIS-NPDES database.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 109

Exhibit A-72. Ambient Receiving Water Concentrations: Blair Waterway

Pollutant Water Column Concentration (μg/L)

Arsenic (unfiltered) 1.3

Copper (dissolved) 0.81

Mercury (total recoverable) 0.0023

Zinc (dissolved) 3.7

Source: 2008 permit fact sheet (p. 21).

A.17.4 Baseline Scenario

The permit does not include any WQBELs based on the existing human health criteria for the 

pollutants of concern. In this case, EPA performed a reasonable potential analysis for each 

pollutant based on the baseline (i.e., existing) human health criteria to confirm whether a 

WQBEL would have been included in the NPDES permit.47 In cases of reasonable potential, 

EPA calculated a WQBEL using the existing human health criteria and evaluated compliance 

with this baseline WQBEL. 

Exhibit A-73 summarizes the reasonable potential analysis under the baseline scenario. 

Based on effluent concentrations in Exhibit A-71 and available ambient data in Exhibit A-72, 

there is reasonable potential to exceed the baseline human health arsenic criterion. 

Exhibit A-73. Human Health Reasonable Potential Analysis for U.S. Oil & Refining 

Facility1– Baseline Scenario

Parameter Effluent Conc. 

(total; μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 8.6 1.3 1.466 0.14

1. See effluent concentrations in Exhibit A-71 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean) and available ambient concentrations in Exhibit A-72. 

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 1025.

3. Consumption of organisms only.

Exhibit A-74 summarizes the calculated permit limits for arsenic under the baseline scenario. 

 

47 Based on 40 CFR 122.44(d)(1), were it not for the approaches and other policies used by Ecology. 40 CFR 

122.44(d)(1) requires that effluent limitations must be established when a pollutant is discharged “...at a 

level which will cause, have the reasonable potential to cause, or contribute to an excursion above any State 

water quality standard, including State narrative criteria for water quality.”
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 110

Exhibit A-74. Human Health Based Effluent Limitations for U.S. Oil & Refining Facility

– Baseline Scenario

Parameter Average Monthly Effluent Limit 

(total; μg/L)1

Maximum Daily Effluent Limit 

(total; μg/L)1

Arsenic 0.14 0.28

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Under the baseline scenario, the discharger would have to meet an AML of 0.14 μg/L and a 

MDL of 0.28 μg/L. Arsenic was observed in the effluent at a concentration of 8.6 μg/L and 

in the ambient receiving water at a concentration of 1.3 μg/L. Blair Waterway near the 

discharge is not listed on the State’s 303(d) list as impaired for arsenic, though ambient data 

used in the reasonable potential analysis does exceed criteria. Since the effluent monitoring 

data exceeds the applicable effluent limitations under the baseline scenario, the discharger 

will need to control arsenic in its effluent to ensure that permit limits are consistently met. It 

is possible that more recent or future monitoring data could provide evidence that the facility

is in compliance with the projected effluent limits and no costs would be incurred for 

compliance. However, additional data could provide further evidence of non-compliance. 

Based on the available information, EPA assumes the discharger will need to reduce 

discharge concentrations for compliance with the baseline scenario.

A P2 program is a possible pathway to achieve compliance with effluent limitations for 

arsenic. A P2 program that identifies likely sources of arsenic in the facility’s waste stream 

can provide adequate levels of control through updated source control and P2 best 

management practices. Costs for designing and implementing a P2 program for arsenic is 

estimated to be $28,000 per year. However, if the facility determines that source water 

derived from ground water, surface waters, or drinking water is the source of high arsenic 

values in the wastewater, or if it is determined that control of arsenic in the discharge is 

infeasible (e.g., due to the economic impacts of controlling the pollutant) it is likely that the 

facility would pursue a variance.

Due to the fact that ambient receiving water concentrations exceed the proposed human 

health criteria, the discharger may pursue obtaining a water quality standards variance. The 

one-time cost associated with pursuing a variance is estimated to be $180,000, with minimal 

costs associated with renewal.

A.17.5 Policy Scenario

Exhibit A-75 summarizes the reasonable potential analysis under the policy scenario. Based 

on effluent concentrations in Exhibit A-71 and available ambient data in Exhibit A-72, there 

is reasonable potential to exceed human health criteria for arsenic.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 111

Exhibit A-75. Human Health Reasonable Potential Analysis for US Oil & Refining 

Facility1– Policy Scenario

Parameter

Baseline Average 

Monthly Effluent 

Limit (total; μg/L)

Ambient Conc. 

(dissolved; μg/L)

Conc. at Edge of 

Mixing Zone2(μg/L)

Human Health 

Criterion3(μg/L)

Arsenic 0.14 1.3 1.466 0.0059

NA = not available

1. See effluent concentrations in Exhibit A-71 (reasonable potential analysis uses the maximum or 

95th percentile concentration if the number of observations is less than 10, and otherwise uses the 

geometric mean) and available ambient concentrations in Exhibit A-72. 

2. Based on Washington Department of Ecology’s Permit writer spreadsheet tool using a dilution 

factor of 71.

3. Consumption of organisms only.

Exhibit A-76 summarizes effluent limitations for arsenic applicable to the facility under the policy 

scenario. 

Exhibit A-76. Human Health Based Effluent Limitations for US Oil & Refining Facility –

Policy Scenario

Parameter Average Monthly Effluent Limit 

(total; ug/L)1

Maximum Daily Effluent Limit 

(total; ug/L)1

Arsenic 0.0059 0.012

1. Based on Washington Department of Ecology’s Permit writer spreadsheet tool.

Under the policy scenario, the discharger would have to meet an AML of 0.0059 μg/L and a 

MDL of 0.012 μg/L. Under the baseline scenario, where the projected effluent limitations are 

below the analytical QL, EPA estimated that the discharger would incur costs for P2 as well 

as pursuit of a variance in order to ensure compliance with effluent limitations below the QL. 

Since the projected effluent limitations under the policy scenario are also below the QL, no 

additional compliance strategy would be required under the policy scenario (i.e., the 

discharger would not pursue a second variance).

A.18 References and Sources

City of Pasco. 2014. NPDES Permit Application Form 2A.

Fairfield-Suisun Sewer District (SD). 2003. 2003 NPDES Permit Renewal Infeasibility

Analyses. June 17. Online at http://www.swrcb.ca.gov/rwqcb2/Agenda/08-20-03/08-20-03-

5ainfeasibilityrev.doc.

King County Department of Natural Resources. 2013. Receiving Water Characterization 

Study: King County NPDES Monitoring Program. Final Report prepared for the King 

County Department of Natural Resources and Parks and the Washington State Department of 

Ecology.
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 112

King County Department of Natural Resources and Parks. 2012. 2012 King County Longterm Combined Sewer Overflow Control Plan Amendment.

Washington Department of Ecology. 2014. Fact Sheet for NPDES Permit WA0029181: West 

Point Wastewater Treatment Plant (WWTP) and Combined Sewer Overflow (CSO) System.

Washington Department of Ecology. 2013. Fact Sheet for NPDES Permit No.WA0023451, 

Lakehaven Utility District Redondo Wastewater Treatment Plant.

Washington Department of Ecology. 2013. Addendum to the Fact Sheet for National 

Pollutant Discharge Elimination System (NPDES) Permit No. WA0022772, March 1, 2013.

Washington Department of Ecology. 2009. Fact Sheet for NPDES Permit WA0029581: King 

County South Wastewater Treatment Plant (WWTP).

Washington Department of Ecology. 2008. Fact Sheet for NPDES Permit No. WA0044962 

City of Pasco Wastewater Treatment Works.

Washington Department of Ecology. 2003. Fact Sheet for NPDES Permit WA0022772, 

Southwest Suburban Sewer District Salmon Creek Wastewater Treatment Plant.

U.S. Environmental Protection Agency (EPA). 2014. Fact Sheet: The U.S. Environmental 

Protection Agency (EPA) Proposes to Reissue a National Pollutant Discharge Elimination 

System (NPDES) Permit to Discharge Pollutants Pursuant to the Provisions of the Clean 

Water Act (CWA) to: City of Puyallup Wastewater Treatment Plant, 1602 18th St NW, 

Puyallup, WA 98371.

U.S. Environmental Protection Agency (EPA). 2014. Response to Comments: City of 

Puyallup Wastewater Treatment Plant, NPDES Permit WA0037168, September 23, 2014.

U.S. Environmental Protection Agency (EPA). 2004. Technical Support Document for the 

2004 Effluent Guidelines Program Plan for the Petroleum Refining Category. EPA-821-R04-014
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 113

Appendix B – Sample Facility Results and Statewide Extrapolation

This appendix provides a summary of the sample facility results (facility-specific details are 

provided in Appendix A), and shows the extrapolation of statewide costs for the baseline 

scenario and the policy scenario.

EPA annualized capital costs, including study (e.g., dilution, variance) and program (e.g., 

pollution prevention) costs over 20 years using a 7% discount rate to obtain total annual costs 

per facility, then calculated a minimum and maximum annual cost for each facility in the 

sample. 

B.1 Baseline Scenario Extrapolation

Exhibit B-1 summarizes the estimated annual compliance costs for the sample facilities under 

the baseline scenario.

Exhibit B-1. Potential Total Annual Compliance Costs for Sample Facilities, Baseline 

Scenario

Facility Name Permit 

Number Category

Total Costs (2014$)1

Low High

Certainty Sample

King County West 

Point WWTP WA0029181 POTW $1,100,000 $1,140,211

King County South 

WWTP WA0029581 POTW $1,000,000 $1,040,211

BP Cherry Point 

Refinery WA0022900 Chemicals, petroleum, and related industries $7,053,698 $7,053,698

Random Sample

Chambers Creek 

STP WA0039624 POTW $0 $0

Puyallup STP WA0037168 POTW $0 $0

Salmon Creek 

WWTP WA0022772 POTW $643,000 $659,991

Redondo WWTP WA0023451 POTW $568,000 $584,991

Pasco WWTP WA0044962 POTW $1,530,000 $1,546,991

Tesoro Refining & 

Marketing Company 

LLC

WA0000761 Chemicals, petroleum, 

and related industries $28,000 $44,991

U.S. Oil & Refining 

Facility WA0001783 Chemicals, petroleum, and related industries $28,000 $44,991

Quincy Industrial WA0021067 Food and kindred 

products $0 $0
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 114

Exhibit B-1. Potential Total Annual Compliance Costs for Sample Facilities, Baseline 

Scenario

Facility Name Permit 

Number Category

Total Costs (2014$)1

Low High

Transalta Centralia 

Mining WA0037338 Mining $28,000 $44,991

Cosmo Specialty 

Fibers, Inc. WA0000809 Paper and allied products $0 $0

Sonoco Products 

Company WA0000884 Paper and allied products $0 $0

Intalco Aluminum 

Corp Ferndale WA0002950 Primary metal industries $5,906,642 $5,906,642

Steelscape, Inc. WA0040851 Primary metal industries $0 $0

Transalta Centralia 

Generation WA0001546 Transportation & public utilities (except POTWs) $28,000 $44,991

1. Annual costs plus one-time costs annualized over 20 years using a 7% discount rate.

Exhibit B-2 shows the extrapolation of the sample results to estimate statewide costs for 

major dischargers under the baseline scenario. For each category of facilities, EPA calculated 

a per-facility cost based on the sample, and applied that cost to all other facilities in that 

category statewide.

Exhibit B-2. Sample and Total Annual Compliance Costs (millions; 2014$) by 

Discharger Category, Baseline Scenario

Category

Major Dischargers Sample Costs Total Costs

Sample Statewide Low High Low High

Certainty

Municipal 2 2 $2.10 $2.18 $2.10 $2.18

Chemicals, Petroleum, and 

Related Industries 1 1 $7.05 $7.05 $7.05 $7.05

Random

Municipal 5 46 $2.74 $2.79 $25.22 $25.69

Mining 1 1 $0.03 $0.04 $0.03 $0.04

Food and Kindred 

Products 1 1 $0.00 $0.00 $0.00 $0.00

Paper and Allied Products 2 12 $0.00 $0.00 $0.00 $0.00

Chemicals, Petroleum, and 

Related Industries 2 5 $0.06 $0.09 $0.14 $0.22

Primary Metal Industries 2 4 $5.91 $5.91 $11.81 $11.81
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 115

Exhibit B-2. Sample and Total Annual Compliance Costs (millions; 2014$) by 

Discharger Category, Baseline Scenario

Category

Major Dischargers Sample Costs Total Costs

Sample Statewide Low High Low High

Transportation & Public 

Utilities (except POTWs) 1 1 $0.03 $0.04 $0.03 $0.04

Total

All Dischargers 17 73 $17.91 $18.11 $46.38 $47.05

1. Annual costs plus one-time costs annualized over 20 years using a 7% discount rate.

B.2 Policy Scenario Extrapolation

Exhibit B-3 summarizes the annual compliance costs for the sample facilities under the 

policy scenario.

Exhibit B-3. Potential Total Annual Compliance Costs for Sample Facilities, Policy

Scenario 

Facility Name Permit 

Number Category

Total Costs (2014$)1

Low High

Certainty Sample

King County West Point 

WWTP WA0029181 POTW $0 $0

King County South 

WWTP WA0029581 POTW $0 $0

BP Cherry Point 

Refinery WA0022900 Chemicals, petroleum, and related industries $56,000 $72,991

Random Sample

Chambers Creek STP WA0039624 POTW $0 $0

Puyallup STP WA0037168 POTW $0 $0

Salmon Creek WWTP WA0022772 POTW $0 $0

Redondo WWTP WA0023451 POTW $0 $0

Pasco WWTP WA0044962 POTW $0 $0

Tesoro Refining & 

Marketing Company LLC WA0000761 Chemicals, petroleum, and related industries $28,000 $28,000

U.S. Oil & Refining 

Facility WA0001783 Chemicals, petroleum, and related industries $0 $0

Quincy Industrial WA0021067 Food and kindred products $0 $0

Transalta Centralia 

Mining WA0037338 Mining $28,000 $44,991

Cosmo Specialty Fibers, 

Inc. WA0000809 Paper and allied products $0 $0
APPENDIX

Abt Associates Cost of Compliance with WQS for Washington ▌pg. 116

Exhibit B-3. Potential Total Annual Compliance Costs for Sample Facilities, Policy

Scenario 

Facility Name Permit 

Number Category

Total Costs (2014$)1

Low High

Sonoco Products 

Company WA0000884 Paper and allied products $2,135,858 $2,135,858

Intalco Aluminum Corp 

Ferndale WA0002950 Primary metal industries $28,000 $28,000

Steelscape, Inc. WA0040851 Primary metal industries $0 $0

Transalta Centralia 

Generation WA0001546 Transportation & public utilities (except POTWs) $0 $0

1. Annual costs plus one-time costs annualized over 20 years using a 7% discount rate.

Exhibit B-4 shows the extrapolation of the sample results to estimate statewide costs for 

major dischargers. For each category of facilities, EPA calculated a per-facility cost based on 

the sample, then applied that cost to all other facilities in that category statewide.

Exhibit B-4. Sample and Total Annual Compliance Costs (millions; 2014$) by 

Discharger Category, Policy Scenario

Category

Major Dischargers Sample Costs Total Costs

Sample Statewide Low High Low High

Certainty

Municipal 2 2 $0.00 $0.00 $0.00 $0.00

Chemicals, Petroleum, and 

Related Industries 1 1 $0.06 $0.07 $0.06 $0.07

Random

Municipal 5 46 $0.00 $0.00 $0.00 $0.00

Mining 1 1 $0.03 $0.04 $0.03 $0.04

Food and Kindred 

Products 1 1 $0.00 $0.00 $0.00 $0.00

Paper and Allied Products 2 12 $2.14 $2.14 $12.82 $12.82

Chemicals, Petroleum, and 

Related Industries 2 5 $0.03 $0.03 $0.07 $0.07

Primary Metal Industries 2 4 $0.03 $0.03 $0.06 $0.06

Transportation & Public 

Utilities (except POTWs) 1 1 $0.00 $0.00 $0.00 $0.00

Total

All Dischargers 17 73 $2.28 $2.31 $13.03 $13.06

1. Annual costs plus one-time costs annualized over 20 years using a 7% discount rate.