## Economic Analysis for Proposed Aquatic Life and Aquatic

- D ependent
Wildlife Criteria for
Selenium in the San Francisco Bay and Delta, California

Contract # EP

- C

- 13

- 03

Final June, 2016

Prepared for:
U nited S tates 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, LLCCONTENTS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. i 

### Contents

Contents

................................ ................................ ................................ ................................ .... i

Exhibit List

................................ ................................ ................................ ............................. iii

Acronym List

................................ ................................ ................................ .......................... iv

Executive Summary

................................ ................................ ................................ ............... vi
Background and Proposed Revised Criteria

................................ ................................ vi
Implementation

................................ ................................ ................................ ............ vi
Estimated Compliance Costs

................................ ................................ ...................... vii

1. Introduction

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

1.1 Background

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

1.2 Purpose and Scope of the Analysis

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

1.3 Organization of Report

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

2. Base line for the Analysis

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

2.1 Water Quality Criteria and Implementation Procedures

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

2.2 Water Quality in the Bay and Delta

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

2.3 Sources of Selenium to the Bay and Delta

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

2.3.1 Sediment and Soil

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

2.3.2 Agriculture

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

2.3.3 Municipal and Industrial Dischargers

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

2.3.4 Urban Storm Water

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

2.3.5 Atmospheric Deposition

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

3. Proposed Revised Criteria

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

4. Method for Estimating Potential Cost s: Point Sources

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

4.1 Identification of Potentially Affected Point Source Dischargers

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

4.2 Reasonable Potential Analysis

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

4.3 Projecting Effluent Limitations

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

4.4 Compliance Scenarios and Costs

................................ ................................ ........ 28

4.4.1 Potential Compliance Scenarios

................................ ............................. 28

4.4.2 Summary of Facility Control Costs

................................ ........................ 35

5. Methods for Identifying Potential Co sts: Nonpoint Sources

................................ . 38CONTENTS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. ii 6. Summary of Results, Uncertainties, and Quality Assurance

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

6.1 Point Sources

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

6.2 Nonpoint Sources

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

6.3 Sensitivity Analysis, Sources of Uncertainty, and Quality Assurance

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

7. References

................................ ................................ ................................ ................... 43

Appendix A

– Facility Analyses

................................ ................................ ............................ 45

A.1 City of Burlingame and North Bayside Systems Unit

................................ ........ 45

A.2 City of Livermore and EBDA

................................ ................................ ............. 47

A.3 City of Millbrae and North Bayside Systems Unit

................................ ............. 49

A.4 City of San Mateo/Foster City Estero

................................ ................................ . 50

A.5 Dublin San Ramon Services District

................................ ................................ .. 52

A.6 East Bay Dischargers Authorit y, Joint Outfall

................................ ................... 53

A.7 East Bay Municipal Utility District, Wet Weather Facilities

............................. 55

A.8 East Bay Regional Park District, Haywar d Marsh

................................ .............. 56

A.9 Palo Alto Regional Water Quality Control Plant

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

A.10 Cities of San Jose and Santa Clara

................................ ................................ ...... 60

A.11 South Bayside System Authority, Wastewater Treatment Plant

........................ 62

A.12 Cities of South San Francisco, San Bruno, and the North Bayside Systems
Unit

................................ ................................ ................................ ..................... 63

A.13 San Francisco Southeast Plant

................................ ................................ ............ 65

A.14 City of Sunnyvale

................................ ................................ ............................... 67

A.1 5 Bottling Group, LLC

................................ ................................ ........................... 69

A.16 San Francisco International Airport

................................ ................................ .... 70

Appendix B

- Potential Compliance Costs, 7% Discount Rate

................................ .......... 73CONTENTS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. iii 

### Exhibit List

Exhibit 2

- 1. Baseline Bay

- Delta Aquatic Life Water Quality Criteria for Selenium 1

............................ 6
Exhibit 2

- 2. San Francisco Bay and Delta Segments Listed as Impaired f or Selenium 1

....................... 8
Exhibit 2

- 3. Selenium Observations in Soils draining to South and Lower San Francisco Bay (Anderson 1998)

................................ ................................ ................................ .............................. 9
Exhibit 2

- 4. NPDES Permitted Dischargers to the San Francisco Bay and Del ta

............................... 11
Exhibit 2

- 5. Locations of NPDES Permittees Discharging to the San Francisco Bay and Delta

......... 14
Exhibit 3

- 1. Proposed Selenium Water Quality Criteria for the San Francisco Bay and Delta .........18

Ex hibit 4

- 1. Summary of Potentially Affected Point Source Dischargers

................................ ........... 20
Exhibit 4

- 2. Locations of Potentially Affected Point Source Dischargers

................................ ........... 21
Exhibit 4

- 3. Summary of Selenium Reasonable Potent ial Analysis

................................ ..................... 22
Exhibit 4

- 4. Summary of Selenium Effluent Limitations

................................ ................................ ..... 26
Exhibit 4

- 5. Summary of Process Optimization Study

................................ ................................ ......... 30
Exhibit 4

- 6. Summary of Potential End

- o f

- Pipe Treatment Technologies

................................ ........... 32
Exhibit 4

- 7. Summary of Potential End

- of

- Pipe Treatment Technologies

................................ ........... 33
Exhibit 4

- 8. Summary of Potential End

- of

- Pipe Treatment Unit Cost Curves 1

................................ ... 34
Exhibit 4

- 9. Estimated Unit Costs of Compliance Mechanisms (2015$)

................................ ............. 35
Exhibit 4

- 10. Treatment and Estimated Cost Increment for Affected Facilities 1

................................ . 36
Exhibit 6

- 1. End

- of

- Pipe Trea tment Costs Sensitivity Analysis

................................ .......................... 41
Exhibit 6

- 2. Uncertainties in Analysis of Costs

................................ ................................ ................... 42
Exhibit A

- 1. Summary of Selenium Effluent Data: City of Burlingame WWTP

............................... 46

Exh ibit A

- 2. Summary of Selenium Effluent Data: City of Livermore Water Reclamation Plant

..... 47
Exhibit A

- 3. Summary of Selenium Effluent Data: City of Millbrae and North Bayside Systems Unit

................................ ................................ ................................ ................................ ....................... 49
Exhib it A

- 4. Summary of Selenium Effluent Data: City of San Mateo WWTP

................................ . 51
Exhibit A

- 5. Summary of Selenium Effluent Data: Dublin San Ramon Services District WWTP

.... 52
Exhibit A

- 6. Summary of Selenium Effluent Data: East Bay Dischargers Authority Common Outfall

................................ ................................ ................................ ................................ ....................... 54
Exhibit A

- 7. Summary of Selenium Effluent Data: East Bay Regional Park District

......................... 57
Exhibit A

- 8. Summary of Selenium Effluent Data: Palo Alto Regional Water Quality Control Plant

................................ ................................ ................................ ................................ ....................... 59
Exhibit A

- 9. Summary of Selenium Effluent Data: San Jose/Santa Clara Water Pollution Control
Plant

................................ ................................ ................................ ................................ ............... 61
Exhibit A

- 10. Summary of Selenium Effluen t Data: South Bayside System Authority WWTP

........ 62
Exhibit A

- 11. Summary of Selenium Effluent Data: South San Francisco/San Bruno Water Quality
Control Plant

................................ ................................ ................................ ................................ .. 64
Exhibit A

- 12. Summary of Selenium Eff luent Data: San Francisco Southeast Plant

......................... 66
Exhibit A

- 13. Summary of Selenium Effluent Data: Sunnyvale Water Pollution Control Plant

........ 68
Exhibit A

- 14. Summary of Selenium Effluent Data: Bottling Group, Hayward Plant

....................... 69
Exhibit A

- 15. Summary of Selenium Effluent Data: San Francisco International Airports, Mel Leong
Treatment Plants

................................ ................................ ................................ ............................ 71
Exhibit B

- 1. Treatment and Estimated Cost Increment f or Affected Facilities, 7% Discount Rate

..... 74
Exhibit B

- 2: End

- of

- Pipe Treatment Costs Sensitivity Analysis, 7% Discount Rate

.......................... 76ACRONYM LIST

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. iv 

### Acronym List

AM E L Average Monthly Effluent L imit

Basin Plan R egional Water Quality Control Board Water Quality Control Plan

BAT Best Available Technology Economically A chievable

BCT Best Conventional Pollutant Control Technology

BMP Best M anagement P ractices

CCMP Comprehensive Conservation and Manageme nt Plan

CIWQS California Integrated Water Quality System

CTR California Toxics Rule

CVRWQCB Central Valley Regional Water Quality Control Board

CWA Clean Water Act

DNQ Detected, but N ot Q uan t ified

DW Dry

- Weight B asis

ECA Effluent Concent ration Allowance

EPA United States Environmental Protection Agency

gpd g allons per day

LTA Long

- T erm A verage discharge condition

MDEL Maximum D aily Effluent L imitation

MEC Maximum E ffluent C oncentration

MEP Maximum Extent P racticable

μg/L m icro grams per l iter

μg/g m icrograms per gram

mgd m illion gallons per day

MS4 Municipal S eparate Storm S ewer S ystems

North Bay North San Francisco Bay ( i.e., Central San Francisco Bay, San Pablo Bay,

Carqui nez Strait, Suisun Bay , and the western part of the Delta within the SFRWQCB )

NPDES National Pollutant Discharge Elimination System

NTR National Toxics Rule

OAL Office of Administrative LawACRONYM LIST

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. v O&M Operations and M aintenance

ppt p arts per thousand

POTW Publicly Ow ned T reatment W orks

QL Quantitation L evel

Regional Water Board Regional Water Quality Control Board

RO Reverse O smosis

RPA Reasonable P otential A nalysis

SFRWQCB San Francisco Bay Regional Water Quality Control Board

SIP State Implementation Po licy ( Policy for Implementation of Toxics

Standards for Inland Surface Waters, Enclosed Bays, and Estuaries of California )

South Bay South San Francisco Bay , Lower San Francisco Bay, and marine or

estuarine tributary waters draining thereto

SWPPP Storm W ater P ollution P revention P lan

SWRCB State Water Resources Control Board

TMDL Total Maximum Daily L oad

USGS United States Geological Survey

WQBELs Water Q uality

- B ased E ffluent L imitations

WQS Water Q uality S tandards

WWF Wet W eather F aciliti es

WWTP Wastewater T reatment P lantEXECUTIVE SUMMARY

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. vi 

### Executive Summary

The United States Environmental Protection Agency (EPA) is proposing to update the selenium criteria applicable to marine and estuarine waters of the San Francisco Bay and Delta, to ensure that the c riteria are protective of aquatic life and aquatic

- dependent wildlife in the Bay and Delta. This report provides estimates of the potential incremental compliance actions and costs that may be associated with the proposed regulation.

Background and P ropose d Revised Criteria

The proposed s elenium criteria are intended to be protective of aquatic life and aquatic

dependent wildlife, including federally listed threatened and endangered species in the San Francisco Bay and Delta. The currently applicable aquati c life water quality criteria for selenium in the San Francisco Bay and Delta were promulgated as part of the National
Toxics Rule (NTR) in 1992 . The criteria are based on EPA’s 1987 national aquatic life

selenium freshwater criteria recommendations.

The p roposed selenium criteria include an allowable fish tissue whole body or muscle value, a clam (prey) tissue value, a water column particulate concentration

, a water column
dissolved concentration , and a water column dissolved intermittent concentration

. EP A used the whole body fish tissue criterion and a p rotective bird

- egg tissue value, along with site

specific hydrologic data, to model the bioaccumulation of selenium through the estuary’s ecosystem using the United States Geological Survey ( USGS ) E cosyste m

- Scale Selenium
Model. EPA used the results of the modeling to determine the protective clam (prey) tissue criterion and the water column particulate and dissolved criteria. The allowable selenium
chronic water column dissolved criterion , which serves as the basis for the cost estimates in this document, is 0.2 micrograms per liter ( μ g/L).

Implementation

Although the proposed rule does not establish any requirements directly applicable to regulated entities or other sources of pollution, state implementat ion 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 f or 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.

This Economic Analysis follows the State of California’s establis hed procedures in the State
Water Resources Control Board’s Policy for Implementation of Toxics Standards for Inland Surface Waters, Enclosed Bays, and Estuaries of California , and may result in a conservative evaluation for some point sources. However, th e Regional Water Quality Control Boards have substantial discretion to apply other implementing permitting procedures that are consistent with the Policy’s requirements, and may elect to follow different methods to

determine whether effluent limits are nec essary and/or the value of the effluent limitations.EXECUTIVE SUMMARY

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. vii These alternative methods may result in fewer facilities requiring action and/or less stringent permit limitations.

Estimated Compliance Cost s

EPA identified 1 6 point source facilities that potentially could be affected by the rule out of a total population of 5 1 facilities that discharge to waters subject to the criteria. The remaining facilities are covered by Total Maximum Daily Loads ( TMDL s). These TMDLs were developed using stringent translations of narrative criteria, and EPA does not anticipate that facilities affected by the m will be affected by the revised criteria in the proposed rule. Of the

16 potentially affected facilities, 1 4 are classified as major dischargers, and two are minor discharger s. Minor facilities are typically those that discharge less than one million gallons per day (mgd) and do not discharge to xics in toxic amounts. EPA did not evaluate general permits (e.g., for stormwater discharges) for which permit conditions typically fo cus on best management practices (BMPs) rather than pollutant

- specific limits derived from numeric water quality criteria.

Unlike point sources, California typically does not require nonpoint sources and municipal point source stormwater dischargers to ac hieve numeric water quality

- based effluent limitations. The regulatory baseline for evaluating the potential impact of the proposed rule includes some requirements for nonpoint sources and stormwater dischargers to implement
BMPs and wasteload allocations as part of currently adopted TMDL s, including already developed and adopted TMDLs for selenium in the Lower San Joaquin River watershed and the North San Francisco Bay. EPA assumes that the proposed rule will not result in the need
for additional control a ction by nonpoint sources.

For the potentially affected point source facilities, EPA evaluated existing baseline conditions and conditions under the proposed rule to project the likelihood that control

measures might be required as a consequence of the rul e. Analysis of the available data for the affected facilities indicates that there are likely to be exceedances of projected effluent limits for selenium. 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. For the population of potentially affected point source facilities, EPA

estimates total incremental compliance cost of approximately $ 16 million per year.INTRODUCTION

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 1 

### 1. Introduction

The EPA is proposing to update the selenium criteria applicable to marine and estuarine waters of the San Francisco Bay and Delta, to ensure that the criteria are pro tective of aquatic life and aquatic

- dependent wildlife in the Bay and Delta

. This report provides estimates of the potential incremental compliance actions and costs that may be associated with the 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 t o “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 f or 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

, which 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 wa ter 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 referred to as “states and authorized tribes”) designate the uses of waters under their jurisdiction, they must establish water quality criteria that protect those designated uses. E PA’s regulation at §131.11(a)(1) provides 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 p olicies 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 s ection 303(c)(4)(B)

authoriz es the Administrator to determine, even in the absence of a state submission, that a new or revised standard is needed to meet CWA requirements.

Under CWA section 304(a), EPA periodically publishes national criteria recommendations
for states and authorize d tribes to consider when adopting water quality criteria for particularINTRODUCTION

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 2 pollutants. In establishing numeric criteria, states may adopt criteria based on EPA’s CWA section 304(a) criteria, modified 304(a) criteria to reflect site

- specific conditions, or ot her scientifically defensible methods.

EPA has developed n ational criteria recommend ations for ambient waters as water column concentrations that reflect the toxicity of the pollutant to aquatic biota. Authorities can readily implement w ater column concen trations to control and limit discharges. However, for pollutants like selenium that accumulate in aquatic biota through diet and where toxicity is exhibited through dietary exposure, tissue concentrations can better represent levels of toxicity, particula rly for higher order species if the pollutant bioaccumulates through the food

chain. Because tissue concentrations may be difficult to implement directly, it is useful to
translate tissue concentrations to water column values that reflect the bioaccumulati on, i.e., a water column concentration that is related to the tissue concentration of the predator species of concern that is accumulating the selenium. EPA recently published a revised national recommended criterion for selenium (USEPA, 201 6 ). The criteri on has several elements

, including fish tissue values (egg

- ovary, whole body

, and muscle) and water column values in
dissolved selenium concentrations that reflect the allowable tissue concentrations in lentic and lotic water body systems.

The currently applicable aquatic life water quality criteria for selenium in the San Francisco Bay and Delta are those that EPA promulgated as part of the National Toxics Rule ( NTR ; 57 FR 60848, December 22, 1992; codified at 40 CFR 131.36). The aquatic life chronic cri teri on value is 5.0 μg/L ( total recoverable). The NTR criteria are based on EPA’s 1987 national aquatic life selenium freshwater criteria recommendations, 1 and are represented in terms of
water column concentrations.

The revised proposed selenium criteri a for the San Francisco Bay and Delta include an allowable fish tissue whole body or muscle value, a clam (prey) tissue value, a water column particulate concentration

, a water column dissolved concentration and a water column
dissolved intermittent concen tration . EPA used the whole body fish tissue criterion and a protective bird

- egg tissue value, along with site

- specific hydrologic data, to model the bioaccumulation of selenium through the estuary’s ecosystem using the USGS Ecosystem

Scale Selenium Model. EPA used the results of the modeling to determine the protective clam (prey) tissue criterion and the water column particulate and dissolved criteria. The
allowable selenium chronic water column dissolved criterion is 0.2 μ g/L. This value serves

as the ba sis for estimated costs because it is expected to be the primary basis for implementing the criteria.

For determining total recoverable effluent limits in permits, EPA is proposing a translator ( the ratio of dissolved to total recoverable metal) of 1 becau se both the dissolved and particulate forms of selenium may be bioavailable for uptake into the food web in the

1 Ambient Water Quality Criteria for Selenium

- 1987, EPA

- 440/5

- 87

- 008

.INTRODUCTION

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 3 estuary

. Th e proposed criteria are applicable to the waters of the San Francisco Bay and

Delta that are either marine or estuarine waters , i.e., water s that have a salinity of greater than 1 part per thousand (ppt) 95% or more o f the time . These waters are located within the jurisdictions of the San Francisco Bay Regional Water Quality Control Board (SFRWQCB) and the Central Valley Regional Water Quality Control Board (CVRWQCB) of the State of
California.

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 t hat p ublicly owned wastewater treatment works (POTWs) and industrial point source dischargers may incur as a result of EPA’s proposed selenium criteria for the Bay and Delta

. 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 NPDES permit conditions for point source dischargers to incorporate revised water quality

- based effluent limits (WQBELs ), based on the proposed dissolved wa ter column selenium criterion.

Existing TMDLs in the Lower San Joaquin River watershed and in the North San Francisco Bay (North Bay) i.e., Central S an Francisco Bay, San Pablo Bay, Carquinez Strait, Suisun Bay and the western part of the Delta within the SFRWQCB, already address selenium discharges from nonpoint sources, and EPA assumes that no additional incremental controls in the Delta and North Bay are necessary for nonpoint sources based on the proposed
selenium criteria because of the stringency of t he existing TMDL water quality targets

. The South San Francisco Bay is scheduled for TMDL development by 2019, and as a result there may be incremental controls and costs associated with load allocations for nonpoint sources in the South Bay if necessary to attain standards. However, the data and information needed to evaluate potential control needs for nonpoint sources are very limited , and thus considered outside the scope of this analysis . Sources of selenium in the South Bay appear to originate from n aturally occurring selenium in soils.

The TMDL for the North Bay also addresses selenium discharges from point sources, and
EPA assumes that no additional incremental controls in the North Bay for point sources are

necessary based on the proposed seleniu m criteria. The TMDL analysi s u ses fish tissue targets based on EPA’s proposed revised national recommended criterion (USEPA, 2015)

, including a whole body fish tissue target consistent with the proposed whole body fish tissue
criterion for the Bay and Del ta. The TMDL an a lysis translates the whole body fish tissue target into a dissolved water column value of 0.5 μg/L . The analysis indicates that because
ambient conditions are below 0.5 μg/ L , dischargers may continue to discharge at curr ent
levels. Because current conditions in the water body are at or below 0.2 μg/ L, it follows that the TMDL analysi s would not need to be revised if a water column target of 0.2 μ g/L

, consistent with the proposed dissolved water column criterion, is used.INTRODUCTION

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 4 1.3 Organization of Repor t

This remainder of this report is organized as follows:

Section 2: Baseline for the Analysis describes the current applicable selenium criteria and
California State Water Resource s Control Board (SWRCB) procedures for implementing the criteria in NPDES pe rmits, sources of selenium to the Bay and Delta , and ongoing efforts to

reduce and eliminate them

.
Section 3: P roposed Revised Criteria ou tlines the proposed changes to existing selenium

criteria

. Section 4: Method for Estimating Potential Costs: Point So urces 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 compliance costs associated with baseline and revised criteria for nonpoint sources.

Section 6: Summary of Results, Uncertainties , and Quality Assurance summarizes cost estimate results for point and nonpoint sources, and discusses th e uncertainties associated
with the estimates.

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

Appendi ces provide data and information on individual point sources analyzed as part of this
report , as well as results using alternative d iscount assumptions

.BASELINE FOR THE ANALYSIS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 5 

### 2. Baseline for the Analysis

This section describes the applicable baseline for evaluating the incremental costs associated
with the revised selenium criteria , including current water quality criteria and associated implementation proc edures , potential sources of selenium to the Bay and Delta , the current level of impairment , and listing procedures

.

2.1 Water Quality Criteria and Implementation Procedures

In California, each Regional Water Quality Control Board (Regional Water Board) adopt s a Water Quality Control Plan (hereinafter Basin Plan) that designates beneficial (designated) uses, establishes water quality objectives (criteria) , and contains implementation programs and policies to achieve those objectives for all waters addressed thr ough the plan. Th e proposed criteri a for selenium are applicable to the waters of the San Francisco Bay and
Delta which are located within the jurisdictions of the SFRWQCB and the CVRWQCB . The Basin Plans applicable in these areas include:

 Water Quality Co ntrol Plan for the San Francisco Bay Basin (applicable to all parts of San Francisco Bay and the western part of the Delta, including South San Francisco Bay,

Lower San Francisco Bay, Central San Francisco Bay, San Pablo Bay, Carquinez Strait, Suisun Bay, and the western portion of the Sacramento

- San Joaquin Delta within the SFRWQCB )

 Water Quality Control Plan for the Sacramento and San Joaquin River Basins (applicable to eastern portions of the Delta, which includes most of the Delta and the
confluences of the Sacramento and the San Joaquin Rivers)

In addition, t he SWRCB has adopted water quality control plans and policies to protect the water quality and to control the water resources that affect the beneficial uses of the Bay and Delta Estuary. The Water Quality Control Plan for the San Francisco Bay/Sacramento

- San Joaquin Delta Estuary supplements the other Basin Plans that cover the Bay and Delta and establishes a comprehensive set of existing beneficial uses for all parts of the Bay and Delta. Existing beneficial uses in the Water Quality Control Plan for the San Francisco Bay/Sacramento

- San Joaquin Delta Estuary for the protection of aquatic life and aquatic

dependent wildlife include:

 Warm Freshwater Habitat (WARM)

– Uses of water that support warm wa ter ecosystems including, but not limited to, preservation of aquatic habitats, vegetation, fish, or wildlife, including invertebrates.

 Cold Freshwater Habitat (COLD)

– Uses of water that support cold water ecosystems including, but not limited to, preserv ation or enhancements of aquatic habitats, vegetation, fish, or wildlife, including invertebrates.

 Estuarine Habitat (EST)

– Uses of water that support estuarine ecosystems, including, but not limited to, preservation or enhancement of estuarine habitats, vegetation, fish,BASELINE FOR THE ANALYSIS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 6 shellfish, or wildlife (e.g., estuarine mammals, waterfowl, shorebirds), and the propagation, sustenance, and migration of estuarine organisms.

 Fish Migration (MIGR)

– Uses of water that support habitats necessary for migration,

acclimat ization between fresh water and salt water, and protection of aquatic organisms that are temporary inhabitants of waters within the region.

 Preservation of Rare and Endangered Species (RARE)

– Uses of waters that support habitats necessary for the survival and successful maintenance of plant or animal species established under state and/or federal law as rare, threatened, or endangered.

 Fish Spawning (SPWN)

– Uses of water that support high quality aquatic habitats suitable for reproduction and early develo pment of fish.

 Wildlife Habitat (WILD)

– Uses of waters that support wildlife habitats, including, but not limited to, the preservation and enhancement of vegetation and prey species used by wildlife, such as waterfowl.

EPA promulgated the NTR on December 22, 1992

. The NTR included several aquatic life and/or human health priority toxic pollutant criteria for various waterbodies in California, including aquatic life criteria for selenium in the San Francisco Bay and Delta . On May 18, 2000, EPA promulgated t he California Toxics Rule ( CTR ) . The CTR promulgated additional priority toxic pollutant criteria for California and referenced the previously promulgated NTR criteria that were applicable in the S tate. Although the CTR included criteria for selenium, the criteria were only promulgated for areas of California other than the Bay

- Delta

. Exhibit 2

- 1 shows the applicable baseline (i.e., current) criteria for selenium in the San Francisco Bay and Delta that were promulga ted in the NTR

.

Exhibit 2

- 1 . Baseline Bay

- Delta Aquatic Life Water Quality Criteria for Selenium 1
Chronic Aquatic Life (4

- day average;  g/L) Acute Aquatic Life (1

- hour average;  g/L)

5 20

 g/L = microgra ms per liter

1

. E xpressed as total recoverable selenium.

On March 2, 2000, the SWRCB adopted the Policy for Implementation of Toxics Standards for Inland Surface Waters, Enclosed Bays, and Estuaries of California ( hereinafter referred

to as the State Imp lementation Policy

, or SIP). The SIP became effective on April 28, 2000, and is used to implement priority pollutant criteria and objectives, including those promulgated for California in the NTR and CTR . The S WRCB adopted amendments to the SIP on February 24, 2005, that became effective on July 13, 2005. The SIP establishes implementation provisions for addressing priority pollutant criteria and objectives in NPDES permits for point sources

. These implementation provisions include

, in part, specific proced ures for assessing the reasonable potential of point source discharges to cause orBASELINE FOR THE ANALYSIS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 7 contribute to exceedances of applicable water quality criteria and objectives , and

– in those instances where there is reasonable potential

– specific procedures for establi shing WQBELs

.

2.2 Water Quality in the Bay and Delta

CWA Section 305(b) requires the State to report biennially to EPA on the condition of the surface water bodies throughout the State. Under Section 303(d) of the CWA, the S WRCB and Regional Water Boards asses s water quality monitoring data for California’s surface
waters every two years to determine if pollutants are at levels that exceed applicable WQS

. Water bodies and pollutants that exceed protective WQS are placed on the State’s 303(d) l ist.
Placement on the 303(d) list of a water body that exceeds applicable WQS for a pollutant

indicates a TMDL may be necessary

. EPA has issued guidance to s tates about integrating the two reports . For California, this combined report is called the California 303(d)/305(b) Integrated Report. In accordance with

EPA Integrated Report guidance, the SWRCB classifies ea ch assessed water segment into
one of five non

- overlapping categories based on whether the beneficial use s are support ed in the water segment.

 Category 5

– Avail able data and/or information indicate that at least one beneficial use is not being supported or is threatened, and a TMDL is needed.

 Category 4

– Available data and/or information indicate that at least one beneficial use is not being supported or is thr eatened, but a TMDL is not needed.

o Category 4 A

– A TMDL is already established.

o Category 4B

– Other required control measures are expected to result in attainment of an applicable water quality standard in a reasonable period of time.

o Category 4C

– A water that is impacted by non

- pollutant related cause(s). (e.g., aquatic life use is not supported due to hydrologic alteration or habitat alteration).

 Category 3

– There is insufficient available data and/or information to make a ny beneficial use support dete rmination

.

 Category 2

– D ata and/or information are available for some but not all beneficial uses, and where available, indicate that the beneficial use s are supported

.

 Category 1

– All beneficial uses are supported, no use is threatened

. In California, t he 303(d) l ist is made up of three of the Integrated Report categories, 5, 4A, and 4B. These categories contain water segments that are not meeting WQS or are not expected to meet WQS

. According to California's 2012 Water Quality Integrated Report (SWRCB

, 2012) , the San Francisco Bay and Delta were identified as impaired by selenium and listed as Category 5 requiring a TMDL. Exhibit 2

- 2 l ists the specific segments included on the 303(d) list for

selenium.BASELINE FOR THE ANALYSIS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 8 Exhibit 2

- 2

. San Francisco Bay and Delta Segments Listed as Impaired for Selenium 1

Waterbody Name/Segment Expected TMDL Completion Date Potential

Sources Impairment Description

Sacramento San Joaquin
Delta 2010 2

Sou rce Unknown Affected use is one branch of

the food chain; most sensitive indicator is hatchability in nesting diving birds, significant
contributions from oil refineries (control program in place) and agriculture (carried downstream by rivers); exotic spe cies may
have made food chain more susceptible to accumulation of selenium; health consumption advisory in effect for scaup and scoter (diving ducks). San Francisco Bay, Central 2010 2

San Francisco Bay, South 2019

San Pablo Bay 2010 2

Suisan Bay 2 010 2

Carquinez Strait 2010 2

Central Basin 2019

Oakland Inner Harbor 2019

1. Source: California's 2012 Water Quality Integrated Report (SWRCB, 2012).

O n July 24, 2015, the SFRWQCB proposed a TMDL for the North San Francisco Bay . The

TMDL covers a small portion of the Sacramento/San Joaquin Delta (within the San Francisco Bay region), Suisun Bay, Carquinez Strait, San Pablo Bay, and Central Bay. On November 18, 2015, the SFRWQCB adopted a Basin Plan amendment that included the

TMDL and an impleme ntation plan ( Resolution No. R2

- 2015

- 0048 ; Amending the Water Quality Control Plan for the San Francisco Bay Basin to Establish a Total Maximum Daily Load and Implementation Plan for Selenium in North San Francisco Bay ; hereinafter, the North Bay TMDL ). On March 15, 2016, the SWRCB approved the Basin Plan amendment. The Basin Plan amendment will become effective for CWA purposes upon approval by the State’s Office of Administrative Law (OAL), and EPA.

The SFRWQCB has initiate d information collection for th e development of a TMDL for the South San Francisco Bay. As this TMDL is in its earliest stages, it is not available for EPA to consider as part of the baseline or any other part of this analysis.

S elenium occurs naturally along portions of the west side o f the L ower San Joaquin River

basin

, and as a result of agricultural land use practices, subsurface agricultural drainage discharges from this area are a major source of selenium. T he CVRWQCB addressed the selenium through the adoption of a series of selen ium TMDL s in the lower basin, including

one for selenium in the Lower San Joaquin River. The TMDL is implemented through: 1) prohibitions of discharge of agricultural subsurface drainage water adopted in the Basin
Plan A mendment for the Control of Subsurfa ce Drainage Discharges (State Water Board
Resolution 96

- 078) ; and 2) load allocations in Waste Discharge R equirements.BASELINE FOR THE ANALYSIS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 9 2.3 Sources of Selenium to the Bay and Delta

According to the North Bay and Lower San Joaquin River selenium TMDLs, selenium in the

San Franc isco Bay and Delta mainly originates from natural sources. Although selenium can be released into surface waters through natural biological and geological processes, anthropogenic ( e.g., refinery and agricultural ) activities are also responsible for the di spersal of selenium in the estuary.

2.3.1 Sediment and Soil
Selenium is a naturally occurring element found in marine sediments of the Coast Ranges. Natural sources of selenium include sedimentary rocks, seleniferous soils, and selenium

- rich mineral deposits. Ac cording to the North Bay TMDL ( SFRWQCB

, 2015 ):

“ Average concentrations of selenium found in sediments and soils usually range from 0.01 to 0.02 mg/kg with most seleniferous soils containing less than 2 mg/kg (USDHHS 2003, Chapter 6). However, Cretaceous an d Tertiary marine and sedimentary deposits underlying and surrounding basins such as San Joaquin Valley, and those found in western states are enriched in selenium. Presser (1994) identified seleniferous deposits in the Coast Ranges of California and the C entral Valley with concentrations of selenium reaching 45 mg/kg and median values exceeding 6.5 mg/kg. ”

Further, s oils data representing the South San Francisco Bay reported in a literature review conducted by Anderson (1998) for the City of San Jose Envi ronmental Services Department

included evidence that naturally occurring selenium is found at relatively high levels in bedrock units, soils, and groundwater (see Exh ibit 2

- 3 ) . The author notes that, at the time of publication, no studies on processes controlling selenium transport into the South San
Francisco Bay and Lower San Francisco Bay had been conducted. However, based on the presence of marine shale bedrock units which are similar to those which release sele nium in the San Joaquin River Valley and on mercury sulfide ores which have been associated with selenium release in other regions, Anderson indicates that selenium migration from bedrock and other deposits to soils and surface water are a possibility.

Exh ibit 2

- 3 . Selenium Observations in Soils draining to South and Lower San Francisco Bay (Anderson 1998)

Location Observation (ppm Se) Study 1

Guadalupe River Vicinity Three samples with detected values (8 pp m, 2 ppm, 2 ppm) and an unspecified number of samples at <1 ppm Kleinfelder, Inc., 1995

Gilroy 0.7 Boerngen and Shacklette, 1981

Palo Alto 0.4 Boerngen and Shacklette, 1981

Mountain View 0.4 Scott, 1995

U.S. Geometric Mean 0.26 Shacklette and Boerngen, 1984

San Mateo County 0.1 Boerngen and Shacklette, 1981BASELINE FOR THE ANALYSIS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 10 Exh ibit 2

- 3 . Selenium Observations in Soils draining to South and Lower San Francisco Bay (Anderson 1998)

Location Observation (ppm Se) Study 1

ppm = parts per million 1. As cited in Anderson (1998).

2.3.2 Agriculture

D ry conditions in the Central Valley make irrigation necessary for nearly all commercially

grown crops

. Irrigation of the soils derived from seleniferous soils and selenium

- rich mineral deposits leaches selenium into surface return flows

, subsurface drainage , and groundwater

. According to the T MDL for Selenium in the Lower San Joaquin River (CVRWQCB 2001):

“ Subsurface drainage is produced when farmers drain the shallow groundwater from the root zone to protect their crops. This subsurface agricultural drainage water is high in naturally occurring salts and selenium. Soils and shallow groundwater with the highest concentrations of selenium in the SJR Basin are located in a 97,000

- acre area that has alternately been called the Drainage Study Area, Drainage Problem Area, and most recently, the Drainage Project Area (DPA). ”

Further, according to the North Bay TMDL (SFRWQCB 2015):

“ Enri chment of selenium in soils and groundwater commonly occurs in arid and semi

arid irrigated areas where application of irrigation water accelerates weathering processes and mobilizes naturally elevated levels of selenium in the soil profile. To reduce effe cts of salinization of agricultural lands in these areas, such as the southern Central Valley, large volumes of water are used to flush the excess salt and selenium that accumulates in the root zone (Seiler et al. 2003). Drainage of excess irrigation water through the system of drains and canals is then necessary to prevent waterlogging of the soils. These drains, however, provide a conduit to carry seleniferous groundwater to surface water bodies and wildlife areas as it was well documented in the case of disposal of agricultural drainage water into the Kesterson Wildlife Rufuge. This agricultural drainwater is eventually conveyed to the San Joaquin River, which delivers large selenium loads into the Delta and North Bay. Reported selenium concentrations det ected in irrigation drainage are very high and vary between 75 and 1400  g/L (Amweg el al. 2003). The arid climate amplifies evaporation

- related enrichment that takes place in lakes and wetlands resulting in selenium concentrations potentially reaching tox ic
levels. ”

The North Bay TMDL, in its discussion of nonpoint sources of selenium to the North Bay and Delta, concluded that “... the Central Valley selenium TMDLs and restoration of agricultural lands to tidal systems are likely to contribute to continued re duction in selenium loading to the North Bay ...”BASELINE FOR THE ANALYSIS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 11 2.3.3 Municipal and Industrial Dischargers
The proposed selenium criteria are applicable to marine and estuarine waters of San Francisco Bay and Delta. Marine and e stuarine waters are those in which the salinity is greater than 1 ppt 95% of the time. For purposes of this analysis, this includes the waters of San Francisco Bay and the Sacramento

- San Joaquin River Delta. Consistent with EPA’s November 3, 2015 memorandum regarding “Salinity from Ocean Influence on the S an Joaquin River”, waters of the Lower San Joaquin River upstream of Vernalis are not considered estuarine and discharges to these waters will not be considered applicable to this analysis. Based on these geographical boundaries, and data contained in the California Integrated Water Quality System (CIWQS), Exhibit 2

- 4 lists the major and minor NPDES permittees that discharge to San Francisco Bay and Delta.

Exhibit 2

- 4 . NPDES Permitted Dischargers to the San Francisco Bay and Delta
NPDES Permit Number Permittee Receiving Water Discharge Category Facility Type

CA0005550 Valero, Benicia Refinery Suisun Bay Major Industrial

CA0037958 Novato Sanitary District San Pablo Bay Major POTW

CA0004961 Tesoro, Golden Eagle

Refinery Suisun Bay Major Industrial

CA0037851 Las Gallinas Valley Sanitary

District Miller Creek Major POTW

CA0037702 East Bay Municipal Utility

District Central San Fran Bay Major POTW

CA0038024 Fairfield

- Suisun Sewer

District Boynton Slough Major POTW

CA0110116 US Navy, Treasure Island Central San Fran Bay Major POTW

CA0038440 East Bay Municipal Utility

District, Wet Weather Richmond Inner Harbor (central San Fran Bay) Minor POTW

CA0037621 City Of Sunn yvale Moffett Channel Major POTW

CA0037842 San Jose/Santa Clara Artesian Slough Major POTW

CA0038547 Delta Diablo New York Slough Major POTW

CA0037834 Palo Alto South San Fran Bay Major POTW

CA0038091 Benicia Carquinez Strait Major POTW

CA0037800 Sono ma Valley County

Sanitation District Schell Slough Major POTW

CA0038130 South San Francisco

- San

Bruno Lower San Fran Bay Major POTW

CA0037532 Millbrae Lower San Fran Bay Major POTWBASELINE FOR THE ANALYSIS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 12 Exhibit 2

- 4 . NPDES Permitted Dischargers to the San Francisco Bay and Delta
NPDES Permit Number Permittee Receiving Water Discharge Category Facility Type

CA0037885 Crockett Community

Services District, Port Costa Carquinez Str ait Minor POTW

CA0030058 Bottling Group Old Alameda Creek Minor Industrial

CA0037664 San Francisco, Southeast

Plant Lower San Fran Bay Major POTW

CA0037753 Marin County Sanitary

District #5, Tiburon Raccoon Strait in
Central San Fran Bay Minor POTW

CA0 038539 West County Agency Central San Fran Bay Major POTW

CA0037788 Burlingame Lower San Fran Bay Major POTW

CA0038318 San Francisco International

Airport, Sanitary Plant Lower San Fran Bay Major Industrial

CA0037541 San Mateo Lower San Fran Bay Major P OTW

CA0037711 Sewerage Agency Of

Southern Marin Raccoon Strait in
Central San Fran Bay Major POTW

CA0005240 C&H Sugar Company Carquinez Strait Major Industrial

CA0038067 Sausalito

- Marin City

Sanitary District Central San Fran Bay Major POTW

CA0038369 S ilicon Valley Clean Water Lower San Fran Bay Major POTW

CA0037796 Pinole San Pablo Bay Major POTW

CA0005789 Shell Oil, Martinez Refinery Carquinez Strait Major Industrial

CA0038628 Central Marin Sanitation

Agency Central San Fran Bay Major POTW

CA00378 26 Rodeo Sanitary District San Pablo Bay Major POTW

CA0037699 Vallejo Sanitation & Flood

Control District Carquinez Strait Major POTW

CA0037648 Central Contra Costa

Sanitary District Suisun Bay Major POTW

CA0038008 Livermore Lower San Fran Bay Major POT W

CA0037613 Dublin San Ramon &

Livermore

- Amador Valley Lower San Fran Bay Major POTW

CA0037869 East Bay Dischargers

Authority, Joint Outfall Lower San Fran Bay Major POTWBASELINE FOR THE ANALYSIS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 13 Exhibit 2

- 4 . NPDES Permitted Dischargers to the San Francisco Bay and Delta
NPDES Permit Number Permittee Receiving Water Discharge Category Facility Type

CA0038636 East Bay Regional Park

District, Hayward Marsh Hayward Marsh Major POTW

CA0005134 Chevron, Richmond Refinery San Pablo Bay Major Industrial

CA0005002 USS

- Posco New York Slough Major Industrial

CA0038768 American Canyon North Slough Major POTW

CA0030201 Napa Salt Pond Restoration Napa Slough Minor Industrial

CA0005053 Phil lips 66, San Francisco

Refinery, Rodeo San Pablo Bay Major Industrial

CA0037427 Marin County Sanitary

District #5, Paradise Cove Central San Fran Bay Minor POTW

CA0037575 Napa Sanitation District Napa River Major POTW

CA0037810 Petaluma Petaluma River M ajor POTW

CA0037770 Mt. View Sanitary District Peyton Slough Major POTW

CA0030198 Exploratorium San Fran Bay
Central Basin Minor Industrial

CA0029904 Crockett Cogeneration Carquinez Strait Minor Industrial

CA0006165 ECOSERVICES (Formerly

SOLVAY [Former ly RHODIA]) Carquinez Strait Major Industrial

CA0004880 GenOn Pittsburg Power

Plant Suisun Bay Major IndustrialBASELINE FOR THE ANALYSIS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 14 Exhibit 2

- 5 . Locations of NPDES Permittees Discharging to the San Francisco Bay and Delta

As shown in Exhibit 2

- 5 , there are no point sources that discharge into the portion of the Delta that would be subject to the proposed selenium criteria. Further, according to the TMDL for the Lower San Joaquin Ri ver ( CVRWQCB

, 2001), there are no municipal or

industrial sources of selenium.

The North Bay TMDL (SFRWQCB

, 2015) states that petroleum refineries are the largest source of selenium in the North Bay among point sources. However, efforts by the petroleum

r efineries in the “... 1990s and the change in speciation in effluent from more bioavailable selenite to less bioavailable dissolved selenium forms dominated by selen a te have significantly lessened the impact of the refineries’ discharge on water quality .” The refore the wasteload allocations for the petroleum refineries require them to discharge no more than their current loadings to the North Bay. Other municipal and industrial point sources are notBASELINE FOR THE ANALYSIS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 15 considered to be a significant source of selenium, and the wa steload allocations for the remaining point sources (other industrial facilities and POTWs) in the North Bay were also established at no more than their current selenium loadings

.
As shown in Exhibit 2

- 4

, 14 POTWs and two industrial dischargers are the only point sources discharging into the Lower San Francisco Bay, South San Francisco Bay, and marine or estuarine tributary waters draining thereto (South Bay )

.

2.3.4 Urban Storm W ater
Stormwater discharges are generated by precipitation and runoff from land, pavements, building rooftops, and other surfaces. Storm water from municipal and industrial areas may contribute toxic pollutants to surface waters. California regulates stormwater discharges from municipal separate s torm sewer systems (MS4s) through individual and general permits

. Under Phase I, NPDES stormwater permits for medium (serving between 100,000 and 250,000 people) and large (serving 250,000 people) municipalities have been issued by the Regional Water Board s . In several instances, NPDES permits are issued to a group of co

permittees encompassing an entire metropolitan area (e.g., counties)

. In 2003 the SWRCB issued a General Permit for the Discharge of Storm Water from Small MS4s (Water Quality Order No. 20 03

- 0005

- DWQ) to provide permit coverage for Phase II smaller municipalities (population less than 100,000), including non

- traditional small MS4s (e.g., military bases, public campuses). The Phase II Small MS4 General Permit covers Phase

II Permittees state

- wide. The Phase II General Permit (Order No. 2013

- 001 DWQ) was reissued in February 2013 by the SWRCB.

In the San Francisco Bay area, t he SFRWQCB originally issued county

- wide individual

NPDES permits to all Phase I MS4s. In 2009 , the SFRWQCB reissued all the county

- wide municipal stormwater permits as one Municipal Regional Stormwater NPDES Permit to regulate stormwater discharges from municipalities and local agencies in Alameda, Contra Costa, San Mateo, and Santa Clara counties, and the cities of Fairfi eld, Suisun City, and Vallejo. On November 18, 2015, the Municipal Regional Stormwater NPDES Permit was reissued by the SFRWQCB

.

The CVRWQCB is currently working with Phase I and II permittee s to develop a Region

wide MS4 p ermit (Region

- wide Permit) that could address bo th Phase I and II MS4

p ermittees within the Central Valley regio n. Currently, each Phase I MS4 p ermittee is covered under an individual permit issued by the CVRWQCB

. Phase II MS4 p ermittees are currently covered under the SWRCB Phase II Gen eral Order

. The single Region

- wide MS4

p ermit would promote greater watershed/drainage shed coordination and water quality measure protections, and promote greater program implementation efficiencies.

The Phase I MS4 permits require the discharger to devel op and implement a Storm w ater Management Plan/Program with the goal of reducing the discharge of pollutants to the maximum extent practicable (MEP). MEP is the performance standard specified in SectionBASELINE FOR THE ANALYSIS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 16 402(p) of the CWA . The management programs specify wha t BMPs will be used to address certain program areas. The program areas include public education and outreach; illicit discharge detection and elimination; construction and post

- construction; and good housekeeping for municipal operations. In general, medi um and large municipalities are required to conduct monitoring.

The SWRCB also regulates the stormwater discharges from industrial and construction sites. In April 2014, the SWRCB adopted the General Permit for Storm w ater Discharges

Associated with Industr ial Activities (Order 2014

- 0057

- DWQ). The Industrial General Permit regulates stormwater discharges associated with several broad categories of industrial
activities , and requires the implementation of Best Available Technology Economically Achievable (BAT ) and Best Conventional Pollutant Control Technology (BCT) to achieve performance standards. The Industrial General Permit also requires permittees to develop a Storm w ater Pollution Prevention Plan (SWPPP) and monitoring plan. The SWPPP must identify the s ite

- specific sources of pollutants and describe the measures at the facility applied to reduce stormwater pollution.

In September 2009, the SWRCB adopted the General Permit for Discharges of Storm Water Associated with Construction Activity Construction Ge neral Permit (Order 2009

- 0009

- DWQ; as amended by Orders 2010

- 0014

- DWQ and 2012

- 006

- DWQ). Dischargers whose projects disturb one or more acres of soil or whose projects disturb less than one acre but are part of a larger common plan of development that in t otal disturbs one or more acres, are required to obtain coverage under the Construction General Permit . Construction activity subject to this permit includes clearing, grading and disturbances to the ground such as stockpiling, or excavation. The Construct ion General Permit requires the development and implementation of a SWPPP , including BMPs the discharger will use to protect stormwater runoff and the placement of those BMPs. Additionally, the SWPPP must contain a visual monitoring program , and a chemical monitoring program for "non

- visible" pollutants to be implemente d if there is a failure of BMPs

.

2.3.5 Atmospheric Deposition
According to the North Bay TMDL (SFRWQCB 2015), atmospheric deposition (both wet and dry) is considered a very minor selenium source.PROPOSED REVISED CRITERIA

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 17 

### 3. P roposed Revised Criteria

The proposed selenium criteria are intended to be protective of aquatic life and aquatic

dependent wildlife, including federally listed threatened and endangered species in the San Francisco Bay and Delta.

The USGS Ecosystem

- Sc ale Selenium Model integrates two general categories of variables: those attributable to species (i.e., general food webs, representative species, critical life stages, diet mixes for representative species, trophic transfer factors, and effect
concentrati ons), and those related to the aquatic environment (i.e., partitioning coefficient, hydrologic water year type/condition, and flow season).

EPA used t he Ecosystem

- Scale Selenium Model to model two critical food webs present in the estuary, a clam

- based web and an insect

- based web, to determine protective dissolved, particulate and prey

- tissue selenium values. Endpoints included estimated selenium tissue
effect concentration values for several important species (or surrogate species) known to be living in th e estuary modeled through the species’ food web.

The results of EPA’s modeling form the basis for the proposed criteria shown in Exhibit 3

- 1

. All criteria are chronic values; the values reflect protective levels of selenium through dietary exposure, which reflects a long term or chronic exposure.PROPOSED REVISED CRITERIA

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 18 Exhibit 3

- 1 . Proposed Selenium Water Quality Criteria for the San Francisco Bay and
Delta

Media Type Tissue Water Column 1

Criteria Dissolved Par ticulate

Fish
Whole Body

or Muscle Clam Chronic Intermittent Exposure 2 Chronic

Magnitude 8.5 μg/g dw

whole body

or 11.3 μg/g dw

muscle 15 μg/g dw 0.2 μg/L WQC int =

0

. 2 μg / L

− C bkgrnd ( 1

− f int )

f int 1 μg/g dw

Duration Instantaneous

measurement Instantaneous

measurement 30 days Number of days/month with an
elevated concentration 30 days

Frequency Not to be

exceeded Not to be

exceeded Not more

than once

in three

years Not more than once in three years Not more
than once in three years

dw = dry

- weight basis
μg/g = micrograms per gram
μg/L = micrograms per liter

1 Dissolved and particulate water column values are based on tot al selenium (includes all oxidation states, i.e., selenite, selenate, organic selenium and any other forms) in water.

2 C bkgrnd is the average background selenium concentration in μg/L. f int is the fraction of any 30

- day period during which elevated sel enium concentrations occur. f int is assigned a value ≥0.033 (corresponding to one day).
Note 1: Salt and estuarine waters are define here as those in which the salinity is greater than 1 part per
thousand 95% or more of the time.

Note 2: When these criter ia are used to derive water

- quality based effluent limitations for point sources, a
translator of 1 must be used to convert dissolved selenium criteria values into total recoverable selenium values.POINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 19 

### 4. Method for Estimating Potential Costs: Point Sourc es

This section describes the method for estimating the potential costs to point sources associated with compliance with the revised selenium criteri a

. Compliance costs for municipal and industrial point sources may result from changes to NPDES permit

requ irements and associated effluent limitations

.
EPA estimated costs to all potentially affected municipal and industrial dischargers under the proposed criteri a . This section describes the identification of potentially affected major and minor dischargers, r easonable potential analysis (RPA) , identification of limits under the revised criteria and comparison to existing criteria, and estimation of costs to meet revised
criteria. Unless otherwise noted, EPA estimated costs in 2015 dollars, and where necessary, EPA updated cost estimates using the Engineering New Record construction cost index.

4.1 Identification of Potentially Affected Point Source Dischargers

As discussed in Section 3 , the proposed selenium criteri a are applicable to marine and estuarine waters of San Francisco Bay and Delta. Of the point sources permitted to discharge to these waters (see Exhibit 2

- 4 )

, only a small share would need to implement incremental

contr ols pursuant to the proposed criteri a

. Permittees discharging to North San Francisco Bay (a majority of the facilities) are subject to the North Bay TMDL adopted by the SFRWQCB. EPA anticipates that facilities subject to the TMDL will not incur any complia nce costs due

to the proposed criteria (see Section 2 ).

EPA also evaluated permittees discharging to the Delta under the jurisdiction of the CVRWQCB for applicability under the proposed criteria. Based on a revi ew of the existing NPDES permits for permittees in this area, EPA determined that in all instances the CVRWQCB had categorized the permittees as freshwater discharges not subject to marine/estuarine criteria. Therefore, these permittees were not included i n the costing population of potentially affected point source dischargers.

Permittees discharging to San Francisco Bay who are not regulated under the North Bay TMDL (i.e., dischargers to South Bay which includes all dischargers south of the I

- 80
b ridge) will be subject to the proposed criteria and potentially subject to incremental control costs. Using salinity evaluations conducted by the SFRWQCB and reported in the permittees’ existing permits, EPA identified all permittees discharging to these waters

m eeting the salinity condition of the criteria (i.e., marine or estuarine waters). NPDES permittees discharging to marine or estuarine waters of the Bay and which are not subject to

the North Bay TMDL may be affected by the proposed criteri a , and EPA includ ed these
facilities in the cost estimates described below.

Exhibit 4

- 1 and Exhibit 4

- 2 provide a summary of the facilities that EPA identified as potentially affected by th e revised selenium criteri a . Appendix A provides additional

information on these facilities.POINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 20 Exhibit 4

- 1 . Summary of Potentially Affected Point Source Dischargers

NPDES Number Facility Name Major or Minor A verage Dry

Weather Flow (mgd) 1
Municipal Facilities

CA0037621 City of Sunnyvale Major 29.5

CA0037842 City of San Jose/Santa Clara Major 167

CA0037834 City of Palo Alto Major 39

CA0038369 South Bayside System Authority Major 29

CA0037541 City of San Mateo/Foster City Estero Major 15.7

CA0038636 East Bay Regional Park District, Hayward Marsh Major 2.6

CA0037532 City of Millbrae and North Bayside Systems Unit Major 3

CA0037788 City of Burlingame and North Bayside Systems Uni t Major 5.5

CA0038130 Cities of South San Francisco, San Bruno, and North

Bayside Systems Unit Major 13

CA0038008 City of Livermore and EBDA Major 8.5

CA0037613 Dublin San Ramon Services District, LAWMA, and

EBDA Major 20.2

CA0037869 East Bay Discharge rs Authority, Joint Outfall Major 107.8

CA0037664 San Francisco Southeast Plant Major 84.5

CA0038440 East Bay Municipal Utility District, Wet Weather Minor 158

Industrial Facilities

CA0038318 San Francisco International Airpor t Major 2.2

CA0030058 Bottling Group, LLC Minor 0.14
mgd = million gallons per day 1. Average dry weather flow from facility NDPES permit fact sheets.POINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 21 Exhibit 4

- 2 . Locations of Potentially Affected Point Source Dischargers 1

. San Francisco Southeast Plant ;
2

. City of Livermore and EBDA ; Dublin San Ramon Services District, LAWMA, and

EBDA ; East Bay Disch argers Authority, Joint Outfall;

3

. City of Millbrae and North Bayside Systems Unit ; City of Bu rlingame and North Bayside Systems Unit ; Cities of South San Francisco, San Bruno, and North Bayside Systems Unit ;
San Francisco International Airport;

4

. East Bay Municipal Utility District, Wet Weather;

5

. East Bay Regional Park District, Hayward Marsh;

6

. City of San Mateo/Foster City Estero ;

7

. South Bayside System Authority ;
8

. Bottling Group, LLC ;
9

. City of Palo Alto ;
10

. City of San Jose/Santa Clara ;
11

. City of Sunnyvale ; Note: Permittees who share an outfall pipe, or whose outfall pipes ar e located in close proximity to one another, are displayed as sharing a location.POINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 22 4.2 Reasonable Potential Analys i s

For each facility, EPA conducted a n RPA to determine whether there is reasonable potential

for the effluent to cause or contribute to an excurs ion above the water quality criteri a for
selenium

. EPA based this analysis on procedures established in the SIP for evaluating and establishing WQBELs , and on the standard practices utilized at the SFRWQ C B.

EPA conducted RPAs for each facility in the cost ing population using site

- specific effluent monitoring data collected from the CIWQS. To best represent current effluent conditions, EPA utilized all available data collected on or after September 1, 2010 (i.e., the most recent
five years of data). Typical ly, less than five years of data were available

, in which case, EPA utilized all available data for a facility. If no data w ere available in CIWQS, EPA performed the RPA using data reported in the permittee’s existing permit as of September 1, 2015.

For di schargers to the San Francisco Bay, the SFRWQCB typically evaluates ambient background selenium conditions using data collected by a regional monitoring program. Using the existing permits, EPA identified the ambient monitoring stations utilized for each

d ischarger and collected all available selenium data associated with these stations.

In conformance with the SIP, EPA compared each facility’s maximum effluent concentration (MEC) for the period of record and the maximum observed receiving water concentrati on (B) to the proposed selenium dissolved water column criteri on of 0.2 μg/L (using a translator of

1 ; see Section 4.3 ) . If the MEC exceeds the criteri on , then a limitation must be imposed.
Additionall y, if B ex ceeds the criteri on and selenium is present in the discharge in detectable amounts, then a limitation must be imposed. The SIP also allows the finding of reasonable potential when the permit writer determines that other information indicates a limitation i s warranted. As such, EPA reviewed the permittees’ existing permits to determine whether any of them have reasonable potential pursuant to this provision; however, EPA did not identify any such cases, and none of the permittees have reasonable potential un der the baseline
scenario.

Exhibit 4

- 3 summarizes the results of the RPA for all potentially affected facilities.

Exhibit 4

- 3 . Summary of Selenium Reasonable Pote ntial Analysis

NPDES Number Facility Name Max Selenium Conc. (μg/L) RP? 5

Effluent 1 Background Baseline Criteri a Revised

Criteri on Municipal Facilities

CA0037621 City of Sunnyvale 1.66 0.628 2 No Yes

CA0037842 City of San Jose/Santa Clara 0.7 0.628 2 No Yes

CA0037834 City of Palo Alto 2.6 0.628 2 No Yes

CA0038369 South Bayside System

Authority 0. 77 0.39 3 No YesPOINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 23 Exhibit 4

- 3 . Summary of Selenium Reasonable Pote ntial Analysis

NPDES Number Facility Name Max Selenium Conc. (μg/L) RP? 5

Effluent 1 Background Baseline Criteri a Revised

Criteri on

CA0037541 City of San Mateo/Foster City

Estero 0.53 6 0.39 3 No Yes

CA0038636 East Bay Regional Park

District, Hayward Marsh 0.55 7 0.39 3 No Ye s

CA0037532 City of Millbrae and North

Bayside Systems Unit 0.48 6 0.39 3 No Yes

CA0037788 City of Burlingame and North

Bayside Systems Unit 1 0.39 3 No Yes

CA0038130 Cities of South San Francisco,

San Bruno, and North Bayside Systems Unit 2.7 0.39 3 No Yes

CA0038008 City of Livermore and EBDA 1.7 0.39 3 No Yes

CA0037613 Dublin San Ramon Services

District, LAWMA, and EBDA 4.7 0.39 3 No Yes

CA0037869 East Bay Dischargers

Authority, Joint Outfall 1.2 0.39 3 No Yes

CA0037664 San Francisco Southeast

Plant 1.2 6 0.39 3 No Yes

CA0038440 East Bay Municipal Utility

District, Wet Weather None; all discharges prohibited

Industrial Facilities

CA0038318 San Francisco International

Airport 0.1719 0.39 3 No Yes

CA0030058 Bottling Group, LLC <0.2 2.5 4 No No

 g/L = microg rams per liter 1. California Integrated Water Quality Information System 2. San Francisco Regional Monitoring Program

– Monitoring Station BA30 (Dumbarton Bridge) 3. San Francisco Regional Monitoring Program

– Monitoring Station BC10 (Yerba Buena Island)

4 . Site

- specific monitoring data 5. RP = reasonable potential to cause or contribute to an exceedance of a water quality criterion 6. Detected, but Not Quantified (DNQ); i.e., selenium was detected in the sample but at levels too low to accurately quantify; the reported concentration is a best estimate as determined by the laboratory instrumentation and methodology.

7. No recent data available; effluent data for East Bay Regional Park District, Hayward Marsh, based on monitoring data reported in the 2011 NPD ES permit.POINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 24 4.3 Projecting Effluent Limitations

For the 14 facilities that have reasonable potential to cause or contribute to an exceedance above the proposed selenium criteri on , EPA calculated selenium limitations based on the procedures contained in Secti on 1.4 of the SIP and the proposed criteria . These include an accounting of available dilution

— as reported in a permittee’s existing NPDES permit

— and the variability of selenium concentrations in the permittee’s effluent discharge using the

coefficient of variation. In conformance with the SIP, the effluent selenium data must meet certain data quality standards (i.e., at least 10 observations and no more than 80 percent of the observations may be non

- detect). If these standards were not met, then a coeffici ent of variation of 0.6 was assumed in the calculation of the limits. Otherwise, EPA computed the
coefficient of variation based on the effluent monitoring data.

SIP procedures allow for the establishment of mixing zones and dilution credits under certain circumstances. EPA identified those permittees where the SFRWQ C B had established mixing zones using the existing NPDES permits. However, dilution credits may only be applied in circumstances where assimilative capacity exists in the receiving water to

inc orporate the additional pollutant loading. According to SIP procedures, assimilative capacity is considered to be insufficient when the maximum observed receiving water observation (B) exceeds the criteria of concern. In this circumstance, B exceeds the pr oposed
dissolved water column criteri on for all permittees in the costing population as shown in

Exhibit 4

- 3 . Therefore, EPA did not apply dilution credits for dischargers in the costing population.

The following d emonstrates how WQBELs based on the proposed criteri on were established
for this analysis

. The process for developing these limits is in accordance with Section 1.4 of
the SIP.

Step 1: For each constituent requiring an effluent limit, identify the applicab le water quality

criteri on or objective. For each

, determine the effluent concentration allowance (ECA) using the following steady state equation:

ECA = C + D (C

- B); when C>B, and

ECA = C; when C≤ B,

Where C = The priority pollutant criterion/obj ective, adjusted if necessary for translators. The applicable translator for selenium in this instance is 1, so no adjustment is necessary.

D = The d ilution credit, and

B = The a mbient background concentrationPOINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 25 For the p ermittees in the costing popu lation, insufficient assimilative capacity was available for dilution (i.e., C≤ B) and, therefore:

ECA = C

For selenium, the applicable proposed water quality criteria are 0.2 μg/L.

Step 2: For each ECA based on aquatic life criterion/objective, determine the long

- term average discharge condition (LTA) by multiplying the ECA by a multiplier factor. The multiplier is a statistically based factor that adjusts the ECA to account for effluent variability. The value of the multiplier varies depending on the coef ficient of variation of the data set and whether it is an acute or chronic criterion/objective. Equations to develop the multipliers in place of using values in the tables are provided in Section 1.4, Step 3 of the SIP and will not be repeated here. 2

LTA ac ute = ECA acute x Multiplier acute

LTA chronic = ECA chronic x Multiplier chronic

The coefficient of variation for the data set must be determined before the multipliers can be selected and will vary depending on the number of samples and the standard deviation of a data set. If the data set is less than 10 samples, or at least 80% of the samples in the data set are reported as non

- detect, the CV shall be set equal to 0.6.

Using the City of Sunnyvale POTW (NPDES No. CA0037621) as an example, the following
data w e re used to develop the chronic LTA based on the procedures in section 1.4 Step 3 of
the SIP:

LTA chronic = ECA chronic x Multiplier chronic = 0.2 μg/L x 0.53 = 0.11 μg/L

In this case, the acute LTA is not applicable

Step 3: Select the most limiting (lowest) of the LTA.

LTA = most limiting of LTA acute or LTA chronic Since the proposed criteria are chronic, the most limiting LTA is the LTA chronic
LTA = 0.11 μg/L

Step 4: Calculate the WQBELs by multiplying the LTA by a factor (multiplier). WQBELs are expressed as Average Monthly Effluent Limitations (AMEL) and Maximum Daily Effluent Limitations (MDEL). The multiplier is a statistically based factor that adjusts the LTA for the averaging periods and exceedance frequencies of the criteria/objectives and the
effluent limitations. The value of the multiplier varies depending on the probability basis, the coefficient of variation of the data set, the number of samples (for AMEL) and whether it is a

2 The acute ECA multipliers varied from 0.22 to 0.65, and chronic ECA multipliers varied from 0.40 to 0.80.POINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 26 monthly or daily limit. Equations to develop the multipliers are provided in Section 1.4, Step 5 of the SIP and will not be repeated here. 3

AMEL aquatic life = LTA x AMEL multiplier

MDEL aquatic life = LTA x MDEL multiplier AMEL multipliers are based on a 95th percentile occurrence probability, and the MDEL multipliers are based on the 99th percentile occurrence probability.

Using the City of Sunnyvale POTW as an example, the following data was used to develop the AMEL and MDEL for aquatic life:

AMEL aquatic life = LTA x AMEL multiplier = 0.11 μg/L x 1.55 = 0.16 μg/L

MDEL aquatic life = LTA x MDEL multiplier = 0.11 μg/L x 3.11 = 0.33 μg/L

Step 5: For the ECA based on human health, set the AMEL equal to the ECA human health

. However, there are no human health water quality criteria for selenium; therefore, effluent
limitations based on hu man health criteria could not be calculated.

Step 6: Select the lower of the AMEL and MDEL based on aquatic life and human health as the WQBELs.

Since there are no applicable human health criteria for selenium, final limitations for each facility were bas ed on the AMEL and MDEL associated with the aquatic life criteri on

.
Exhibit 4

- 4 summarizes the effluent limitations that EPA calculated for each facility based on the proposed water column criteri on and effluent va riability, according to the procedures
described in the SIP. As the AMEL is the most stringent limitation of the AMEL and MDEL

, and is the relevant limitation used in the control increment analysis, only the AMEL is reported in Exhibit 4

- 4

.
Exhibit 4

- 4 . Summary of Selenium Effluent Limitations

NPDES Number Facility Name MEC (μg/L) AMEL (μg/L) 1 Control Increment Baseline Revised Municipal Facilities

CA0037621 City of Sunnyvale 1.66

-- 0.16 Yes

CA0037842 City of San Jose/Santa Clara 0.7

-- 0.18 Yes

CA0037834 City of Palo Alto 2.6

-- 0.19 Yes

CA0038369 South Bayside System

Authority 0.77

-- 0.17 Yes

CA0037541 City of San Mateo/Foster City

Estero 0.53 2

-- 0.18 Yes

3 The MDEL multipliers varie d from 1.53 to 4.48, and the AMEL multipliers varied from 1.16 to 1.85.POINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 27 Exhibit 4

- 4 . Summary of Selenium Effluent Limitations

NPDES Number Facility Name MEC (μg/L) AMEL (μg/L) 1 Control Increment Baseline Revised

CA0038636 East Bay Regional Park

District, Hayward Marsh 0.55

-- 0.16 Yes

CA0037532 City of Millbrae and North

Bayside Systems Unit 0.48 2

-- 0.16 Yes

CA0037788 City of Burlingame and North

Bayside Systems Unit 1.0

-- 0.17 Yes

CA0038130 Cities of S outh San

Francisco, San Bruno, and North Bayside Systems Unit 2.7

-- 0.17 Yes

CA0038008 City of Livermore and EBDA 1.7

-- 0.16 Yes

CA0037613 Dublin San Ramon Services

District, LAWMA, and EBDA 4.7

-- 0.15 Yes

CA0037869 East Bay Dischargers

Authority, Jo int Outfall 1.2

-- 0.17 Yes

CA0037664 San Francisco Southeast

Plant 1.17

-- 0.16 Yes

CA0038440 East Bay Municipal Utility

District, Wet Weather --

-- -- No

Industrial Facilities

CA0038318 San Francisco International

Airport 0.17

-- 0.16 Yes

CA0030058 Bottling Group, LLC <0.2

-- -- No
AMEL = average monthly effluent limitation

MEC = maximum effluent concentration μg/L = micrograms per liter

1. T he AMEL is the most stringent (i.e., lowest in magnitude) effluent limitation and is the controlling
limitati on in the cost analysis.

2. Detected, but Not Quantified (DNQ); i.e., selenium was detected in the sample but at levels too low to accurately quantify; the reported concentration is a best estimate as determined by the laboratory
instrumentation and method ology.

Minimum levels to be used by permittees when assessing compliance with effluent limitations have been specified in Appendix 4 of the SIP. A minimum level is the lowest quantifiable concentration in a sample based on the proper application of all m ethod

- based analytical procedures and the absence of any matrix interferences. The minimum level is also sometimes referred to as the limit of quantitation or the reporting level.

The SIP requires that, when assessing a parameter with an effluent limitati on, the permittee must use an analytical method with an approved minimum level below the limitation or

— if none satisfy the previous condition

— the lowest approved minimum level. The SIP specifiesPOINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 28 six analytical

- method

- specific minimum levels for selenium

, t he lowest of which is 1 μg/L using gaseous hydride atomic absorption. Compliance with effluent limitations at concentrations below the lowest minimum level cannot be ascertained for those permittees currently discharging at detectable levels below the mini mum level (i.e., the MEC is less than

1 μg/L). For example, standard language in the Monitoring and Reporting Program section
VIII.B.5 for Order R2

- 2014

- 0024 for the City of Palo Alto (NPDES No. CA0037834) states
that “ the Discharger shall be deemed out of compliance with effluent limitations if the concentration of the priority pollutant in the monitoring sample is greater than the effluent limitation and greater than or equal to the [minimum level] .”

4.4 Compliance Scenarios and Costs

EPA calculated c omplian ce costs for all dischargers for which a selenium control increment may be needed . As discussed in Section 4.2

, 14 point source dischargers may require additional compliance actions in order to comply with the p roposed water column criteri on

. EPA developed likely compliance scenarios and associated incremental costs for each permittee. For a permittee

- by

- permittee discussion of likely compliance scenarios and associated costs, refer to Appendix A.

4.4.1 Potential Compl iance Scenarios
There are a number of potential alternatives for compliance with effluent limits for selenium, including:

 Optimizing treatment processes (e.g., adding chemicals to increase flocculation or filtration efficiency) to increase pollutant remov al efficiencies ;

 Source control (e.g., pollution prevention program, inflow and infiltration reductions, more stringent pretreatment standards) ;

 Installing end

- of

- pipe treatment technology (e.g., reverse osmosis (RO)

, or chemical precipitation) ; or

 Alterna tive compliance mechanisms (e.g., site

- specific criteria , dilution credits, TMDL, or variance).

In addition to the above compliance alternatives, the Regional Water Boards may establish compliance schedules for permittees. A compliance schedule provides a discharger with a specific period of time to plan and implement compliance alternatives. A permittee who seeks a compliance schedule must demonstrate to the satisfaction of the Regional Water Board that time is needed to implement actions, such as designin g and constructing facilities or implementing new or significantly expanded programs and securing financing, if necessary, to comply with a more stringent permit limitation specified to implement a new or revised water quality criteria

. Process Optimizati on 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.POINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 29 Process optimization usually involves process analysis and process mod ifications. 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., sedim entation, 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 monitoring throu ghout the treatment process, and a treatment performance evaluation which encompasses jar testing and an operations analysis.

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 a ctivities 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 modifi cations necessary would be determined by the process analysis study.

Process optimization costs depend on the characteristics of the wastewater being treated and existing unit process and operations. For example, a facility could alter the type or dose of a flocculent aid to increase solids removal, and thus, the removal of selenite adhered to particulates. Or, to the extent practicable, hydraulic residence times could be extended or shortened to produce more favorable treatment outcomes.

The effectiveness of process optimization largely depends on the efficiency of current operations and the types of existing unit processes within the treatment plant. For example, if a facility is already well maintained and operated, implementing process optimization may not result in sufficient incremental selenium removals because the existing treatment processes are already performing at the limits of technical feasibility. Given the available information for the sample facilities, it is generally not possible to determ ine the reductions achievable with process optimization; rather, a detailed, site

- specific study would be

necessary.
EPA developed an estimate of the cost necessary to complete a typical process optimization study. This cost estimate assumes 48 wastewater samples will be collected by a POTW operator and analyzed at an off

- site laboratory, approximately 20 jar tests will be run in order to assess the effect of varying chemical doses and reaction times, and a process engineer will synthesize the resulting in formation and develop recommendations for implementing process changes (see Exhibit 4

- 5 ). EPA developed costs based on May 2014 Bureau of Labor Statistics mean hourly wage data 4 for a California POTW operator and C alifornia

4 http://www.bls.gov/oes/current/oes_ca.htm ; retrieved November 3, 2015.POINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 30 Environmental Engineer, and publicly available pricing data for laboratory analyses

. 5 Due to
the site

- specific nature of any process optimization plan, EPA is unable to estimate costs for implementing plant operational changes.

Exhibit 4

- 5 . Summary of Process Optimization Study Activity Component No. of Units Unit Cost 1 Sub

- Total

Sampling POTW Operator 48 samples $31. 93 $1, 533

Lab Costs 48 samples $40.00 $1,920

Jar Testing POTW Operator 20 jar tests $31. 93 $ 639

Lab Costs 20 jar tests $40.00 $800

Engineering Analysis Environmental

Engineer 320 person hours $144.80 2 $46, 945

Total $5 1
, 836

1. C osts are presented in 2015 dollars.

2. M ean wage has been multiplied by 3.03 to account for overhead, administrative costs, and profit.

Source Controls The population of permittees that is likely to be subject to selenium control increments is composed of POTWs and the San Francisco International Airport wastewater treatment plant (WWTP) . Insufficient in formation is available to conclusively identify the sources of

selenium in these discharges; however, evidence suggests the source could be unusually high levels of selenium present in drinking water sources and ground water sources. A literature review by Anderson (1998) reported high levels of naturally occurring selenium present in bedrock units, soils, ground water, and municipal drinking water supplies in the South San Francisco Bay region.

If the pollutant source is traced back to drinking water sour ces and municipal service supply, it is unlikely that the control increment could be addressed through source control measures since the maximum contaminant level for selenium in these sources is 50 μg/L

. Note that the maximum contaminant level applicable to drinking water sources is substantially greater than either the existing water quality chronic criteri on (5 μg/L) or proposed criteri on (0.2 μg/L) for the protection of aquatic life and aquatic

- dependent wildlife

. Addressing contamination through source control activities would necessitate either shifting the locus of control to drinking water treatment plants, which would present regulatory challenges and likely result in equivalent control costs; or changing the source of drinking water, which might no t be technically feasible and could be cost prohibitive.

Should the source of selenium be traced to industrial activities, a pollution prevention program or other source control activities may be productively employed to control selenium.

5 http://www.wtlmd.com/wastewater

- testing

- pricing

- maryland

- md

- va

- dc

- de.php ; retrieved November 3, 2015.POINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 31 Common industria l sources of selenium include petroleum refineries, steam

- electric generating stations, metals manufacturing, coal mining, and other resource extraction and processing industries (EPA, 1983). In order to identify any industrial discharges to the POTWs, EPA reviewed the existing Fact Sheets for each of the dischargers. T he documents did not report any industrial discharges which could be contributing to selenium levels in the POTW discharges. Because available information suggests that , in these cases, indus trial sources are unlikely to be a significant source of selenium to the POTWs , EPA has assumed that source control activities are unlikely to be successfully deployed for selenium control at facilities within the costing population.

End

- of

- Pipe Treatmen t If process optimization or source control would not be sufficient for compliance with the
revised criteri on , alternative discharge options or end

- of

- pipe treatment technologies may be necessary. However, the proposed criteri on approaches the limits of an alytical capabilities and falls below California’s most stringent required quantification level (QL) for selenium (i.e., 1 μg/L). In addition, the lowest levels achievable through end

- of

- pipe treatment are highly uncertain due to the fact that dischargers in the United States have not previously been required to treat to such low levels and a demonstrable technical capability to comply with the proposed selenium criteri on is not available.

In municipal and industrial wastewaters, selenium occurs in a vari ety of chemical forms and oxidation states. The various forms of selenium vary in their amenability to removal based on the technology employed

— for instance, selenite is much more amenable to iron co

precipitation treatment than selenate. Consequently, suc cessful end

- of

- pipe treatment control depends on how selenium is speciated within a give n facility’s waste stream.

Selenite

— the reduced form of selenium

— is amenable to removal by conventional chemical treatment technologies. The effectiveness of these tech nologies can be enhanced when paired with the addition of an iron salt. The addition of iron can, under certain pH conditions, encourage the formation of precipitates which are relatively insoluble, readily removable,
and adsorb selenite to their surfaces. Chemical precipitation of selenite as part of a coagulation and filtration process is currently among EPA’s Best Available Technologies for selenium removal in water treatment plants.

Selenate, however, is largely resistant to conventional chemical precip itation techniques.
Selenate can be removed via ion exchange resins, though the effectiveness of this application is inhibited by the presence of phosphates

— a common constituent of municipal wastewaters. Alternatively, selenate can be reduced to the more r eadily removable selenite through chemical (i.e., addition of elemental iron) or biological means. Both reduction processes will be hindered by the presence of sulfates or nitrates. Data on the presence of nitrates and
sulfates are not available for most B ay area plants; however, most of these facilities are required to comply with stringent ammonia water quality criteria and, consequently, it is very likely that nitrates are present at high levels in most treatment plant effluents.POINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 32 Biological reduction of selenate is an application of biological treatment processes and has been implemented at relatively small scales at various industrial facilities around the United States over the past 10 to 20 years. Typically, this involves the construction of a biofilte r, slow sand denitrification filter, or anoxic tank. In principle, the same biological treatment processes utilized in municipal WWTPs to remove nitrates could be used to reduce selenate to selenite, rendering it amenable to removal using chemical precipit ation with iron salts. However, since nitrates are likely to be present in large quantities in the municipal wastewaters and because nitrates inhibit selenate reduction, full nitrogen removal would likely be necessary in order to encourage selenate reducti on in a POTW treatment train.

Another treatment option would be use of RO to remove all selenium species. Similar to the other technologies discussed herein, selenium treatability below the proposed criteri on has not been definitively demonstrated. However , successful control using RO is likely

, due to RO’s ability to remove nearly all ions from treated water, including selenium species. However, due to the scale of implementation that would be required, EPA assumes it is unlikely municipal WWTPs would ulti mately utilize this technology due to its prohibitive

expense.

Exhibit 4

- 6 summarizes the end

- of

- pipe treatment technologies that may be used to remove

selenium

.

Exhibit 4

- 6 . Summary of Potential End

- of

- Pipe Treatment Technologies

Technology Pollutants Removed

Chemical precipitation with iron salts Selenite remo ved
Biological r eduction Selenate transformed to selenite

Reverse osmosis All selenium species removed

For this analysis, and as documented in the facility analyses in Appendix A, EPA assumed that permittees requiring end

- of

- pipe treatment to meet selenium limitations will utilize chemical precipitation with iron salts paired with sand filtration. Given the limited treatment data testing u sing analytical methods at or below the proposed criteri on , and the uncertainty regarding the selenium speciation within the wastewaters , EPA has assumed the use of conventional treatment technologies (i.e., chemical pre cipitation and filtration) to achieve compliance. Chemical precipitation paired with filtration is a widely adopted technology which has been demonstrated to achieve low effluent concentrations ( i.e., less than 1 μg/L; EPA, 1983)

.
EPA was unable to identi fy studies which have documented treatment capabilities for any treatment technology at the levels of the proposed water column criteri on (i.e., 0.2 μg/L) or the estimated effluent limitations, as most studies utilize analytical methods with detection
leve ls well in excess of the criteri on . Therefore, EPA cannot state with certainty that the proposed treatment alternatives will result in compliance with effluent limitations in allPOINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 33 cases, as the existing literature has not heretofore utilized analytical meth ods of sufficient sensitivity to detect the pollutant at these concentrations.

However, EPA has identified data (EPA, 1983; Kapoor, et al., 2007) which document effluent treatment levels for chemical treatment methods at levels equal to or below the

minim um quantification level required under California’s adopted implementation procedures (i.e., 1 μg/L) without sand filtration. By pairing this performance with sand filtration, there is a reasonable likelihood that effluent treatment consistent with the pro posed

criteri on may be achievable.

Utilizing facility descriptions and treatment process flow diagrams enclosed in the existing permits, EPA evaluated whether each of the following unit operations were present for each facility: iron salt coagulation and f locculation, and sand filtration. If one or both of the items were not present, EPA estimated costs to install the process.

EPA developed cost curves fitted to costs developed for four model treatment trains : 1 mgd, 10 mgd, 100 mgd, and 200 mgd. Costs for each treatment train were developed as follows. For coagulation flocculation costs, costs were developed on the basis of installing a ferric sulfate feed system and chemicals, a polymer feed system and chemicals, a rapid mixer, a flocculation basin, and a tertiary clarifier. Capital costs, and operations and maintenance costs (O&M) were developed for each unit process using cost curves developed by EPA (1979). Costs for sand filters included down flow filter and media costs and were based on

cost estimates developed using CapdetWorksTM construction cost estimating software. Capital and O&M costs were escalated to 2015 dollars using the Engineering News Record

construction cost index. Using the resultant cost curves for coagulation/flocculation and for
media filtration, EPA estimated costs for each permittee.

EPA assumed the indirect costs listed in Exhibit 4

- 7 in all construction cost estimates. Cost curves are presented in Exhibit 4

- 8

.

Exhibit 4

- 7 . Summary of Potential End

- of

- Pipe Treatment Technologies

Indirect Cost Percentage of Direct Capital Costs

Mobilization 6%
Site Preparation 7%

Site Electrical 16%
Yard Piping 11%

Instrumentation and Control 8%
Legal Costs 2%
Engineering Design Fee 15%
Inspection Cost 2%
Contingency 15%

Profit 15%POINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 34 Exhibit 4

- 8 . Summary of Potential End

- of

- Pipe Treatment Unit Cost Curves 1

Treatm ent Addition Capital Costs O&M Costs

Chemical Treatment $1,922,907 + $284,871/mgd x Q $63,681 + $7,771/mgd x Q

Sand Filtration $1,661,321 + $189,620/mgd x Q $100,945 + $9,872/mgd x Q

Chemical Treatment and
Sand Filtration $3,584,229 + $474,491/mgd x Q $164,627 + $17,643/mgd x Q

Q = System flow capacity in million gallons per day (mgd).

1. Al l costs are reported in 2015 dollars. Capital costs include both direct and indirect costs.

Given the uncertainties surrounding the capability of achieving effluent compliance with conventional treatment technologies, EPA has performed a sensitivity analysis of this cost estimate. For additional details on this analysis, refer to Section 6

. Alternative Compliance Mechanisms If none of the control options discussed above would result in compliance with effluent limitations, or if the costs would be prohibitive, dischargers would likely need some form of relief from the requirements.

Site

- Specific Criteria

If disch argers 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. The Water Board 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 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 inc rease 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 California’s WQS implementation provisions, Water Boards may establish intake

cre dits for intake water taken from municipal supply, or intake water that is taken from and discharged to the same waterbody. EPA has insufficient information at this time to evaluate the sources of selenium in the permittees’ influents. In addition, it is u nclear whether selenium sources which may originat e from groundwater or domestic supply and used municipally would qualify for credits under this provision. Therefore, EPA has conservatively assumed that intake credits are unlikely to serve as a valid comp liance action for the proposed selenium criteri on

.POINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 35 Dilution Credits

Under California’s WQS implementation provisions, Water Board s may implement mixing zones and associated dilution credits in NPDES permits. As discussed above, EPA evaluated currently imp lemented mixing zones when calculating WQBELs for the facilities. Due to the lack of available assimilative capacity in the receiving waters, EPA assumed that dilution credits are an unlikely compliance approach.

4.4.2 Summary of Facility Control Costs

F or plant s discharging at levels above the QL, EPA assumed that they will pursue conventional treatment methods to comply with the projected effluent limitations. EPA based
unit costs for end

- of

- pipe treatment on cost curves previously developed by EPA (19 79 ) , unit process costs estimated using CapdetWorksTM cost estimating software, and indirect cost assumptions . EPA updated these costs to reflect local labor rates and escalated to 2015 dollars using the Engineering News Record Construction Cost Index.

Facilities o perating below the QL are discharging near the projected limitations and EPA has assumed that compliance is likely to be achievable using process optimization methods. EPA developed costs associated with process optimization special studies as described in Section

4.4.1

.
To calculate annual costs for the main analysis , EPA discounted all one

- time and capital costs over 20 years using a 3 percent discount rate . Results using a 7 percent discount rate are provided in Appendix B.

Exhibit 4

- 9 summarizes the unit costs utilized in the sample facility compliance cost analyses.

Exhibit 4

- 9 . Estimated Unit Costs of Compliance Mecha nisms ( 2015 $)
Compliance Mechanism One

- Time Cost Estimate O&M Cost Estimate
Process Optimization $ 52 ,000

--
Chemical Treatment $1,922,907 + $ 284

, 871 /mgd x Q $63,681 + $7, 771 /mgd x Q

Sand Filtration $1,661,321 + $ 189

, 620 /mgd x Q $100,945 + $9, 872 /mg d x Q

Chemical Treatment
and Sand Filtration $3,584,229 + $ 474

, 491 /mgd x Q $164,627 + $17, 643 /mgd x Q

Q = Plant capacity in m illion g allons per d ay (mgd)

.

Exhibit 4

- 10 summarizes the one

- time (capital or pro cess optimization) costs , O&M costs,
and total annual cost for each of the identified facilities likely to have a control increment under the proposed selenium criteri on

. See Appendix A for facility

- specific descriptions of
the cost estimates.POINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 36 Exhibit 4

- 10

. Treatment and Estimated Cost Increment for Affected Facilities 1

NPDES Number Facility Name Capacity (mgd) MEC

(μg/L) AMEL

(μg/L) One

- Time

Cost O&M Cost Total Annual Cost 2

Municipal Facilities

CA0037621 City of Sunnyvale 29.5 1.66 0.16 $10,327,000 $293,000 $987,000

CA0037842 City of San Jose/Santa Clara 167 0.7 0.18 $52,000

-- $3,500

CA0037834 City of Palo Alto 39 2.6 0.19 $13,033,000 $367,000 $1,243,000

CA0038369 South Bayside System Authority 29 0.77 0.17 $52,000

-- $3,500

CA0037541 City of San Mateo/Foster City Estero 15.7 0.53 3 0.18 $52,000

-- $3,500

CA0038636 East Bay Regional Park District,

Hayward Marsh 2.6 0.55 0.16 $52,000

-- $3,500

CA0037532 C ity of Millbrae and North Bayside

Systems Unit 3 0.48 3 0.16 $52,000

-- $3,500

CA0037788 City of Burlingame and North Bayside

Systems Unit 5.5 1 0.17 $6,194,000 $262,000 $678,000

CA0038130 Cities of South San Francisco, San

Bruno, and North Bayside System s Unit 13 2.7 0.17 $4,126,000 $229,000 $506,000

CA0038008 City of Livermore and EBDA 8.5 1.7 0.16 $7,617,000 $315,000 $827,000

CA0037613 Dublin San Ramon Services District,

LAWMA, and EBDA 20.2 4.7 0.15 $13,169,000 $521,000 $1,406,000

CA0037869 East Bay Dischargers Authority, Joint

Outfall 107.8 1.2 0.17 $54,734,000 $2,067,000 $5,746,000

CA0037664 San Francisco Southeast Plant 84.5 1.2 3 0.16 $43,679,000 $1,655,000 $4,591,000

CA0038440 East Bay Municipal Utility District , Wet

Weather 158

-- -- $0 $0 $0

Subtotal $ 153

, 139 ,000 $5, 709 ,000 $16,001,500

Industrial Facilities

CA0038318 San Francisco International Airport 2.2 0.1719 0.16 $ 52 ,000

-- $3,500

Subtotal $ 52 ,000

-- $3,500

Total $ 153

, 191 ,000 $5, 709 ,00 0 $16,005,000POINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 37 Exhibit 4

- 10

. Treatment and Estimated Cost Increment for Affected Facilities 1

NPDES Number Facility Name Capacity (mgd) MEC

(μg/L) AMEL

(μg/L) One

- Time

Cost O&M Cost Total Annual Cost 2
mgd = million gallons per day μg/L = micrograms per liter

1. For plants discharging at levels above the most stringent quantitation level (1 μg/L), EPA assumed that facilities will pursue conventional treatment methods to comply with the pro jected effluent limitations. Facilities operating below the quantitation level are discharging near the projected limitations and EPA has assumed that compliance is likely to be achievable using process optimization methods.
2. One

- time costs annualized ov er 20 years using a 3 percent discount rate; for costs annualized using a 7 percent discount rate, see Appendix B.
3

. Detected, but Not Quantified (DNQ); i.e., selenium was detected in the sample but at levels too low to accurately quantify; t he reported

c oncentration is a best estimate as determined by the laboratory instrumentation and methodology.NONPOINT SOURCE COSTS: METHODS

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 38 

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

Unlike point sources, California typically does not require nonpoint sources and municipal

storm water discharg ers to achieve numeric WQBELs. The regulatory baseline for evaluating the potential impact of the revised criteria includes some requirements for nonpoint sources and stormwater dischargers to implement BMPs and wasteload allocations as part of TMDLs (see Section 2 ). The CVRWQCB and SFRWQCB ha ve already developed TMDLs for

selenium in the Lower San Joaquin River and the North Bay, and EPA assumes that the proposed selenium criteria will not result i n the need for additional controls by nonpoint

sources in those areas

. The San Francisco Estuary Project, a federal

- state

- local partnership established in 1987 under the National Estuary Program, is responsible for developing and implementing a Comprehens ive Conservation and Management Plan (CCMP). According to the 2007 CCMP Update (S an F rancisco E stuary P roject 2007), and as it relates to controlling nonpoint sources of selenium to the Bay:

“The control strategy should include management practices and was te discharge requirements as necessary to limit selenium in agricultural subsurface drainage to reduce selenium loadings to the Delta and attain water quality objectives for selenium in the San Joaquin River.”

The SFRWQCB has begun developing a TMDL for se lenium for the South San Francisco Bay. It is uncertain as to the extent nonpoint sources contribute to the overall selenium loading to the South Bay, and

, as described in Section 2.3.1 , naturally

- occurring sele nium may be the primary source of selenium loadings to the South Bay. A lthough the extent of incremental controls that could be required under the potential revised criteria for selenium is
uncertain , it is expected to be insignificant.REFERENCES

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 39 

### 6. Summary of Result s, Uncertainties

, and Quality Assurance

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

Incremental costs associated with the pro posed dissolved selenium criteri on represent the costs of any additional actions or controls needed for compliance with revised WQBELs under the proposed rule , beyond the actions or controls needed to meet the existing criteria
under the baseline

. 6 For com pliance with revised WQBELs under the proposed rule , f or the

5 1 dischargers within the confines of San Francisco Bay and Delta, EPA estimates the total
annual social cost to be approximately $ 16 million across 14 facilities . Of these costs, nearly

all are attributable to municipal dischargers.

6.2 Nonpoint Sources

Potential costs for compliance with the proposed criteri on include costs to nonpoint sources (e.g., agricultural and forest operations; contamination from historic mining sites), and municipal stormwa ter sources associated with implementation of existing programs and

TMDLs. Incremental costs associated with compliance with the p roposed revised criteri a represent the costs of any actions or controls above and beyond those needed to meet baseline require ments. The CVRWQCB and SFRWQCB have already developed TMDLs for
selenium in the North Bay and in the Lower San Joaquin River which flows into the Delta in order to control the primary nonpoint sources of selenium to the Delta and northern parts of the Bay

. Therefore, as discussed in Section 5 , additional measures to control the secondary nonpoint sources of selenium are unlikely to be necessary. However, if nonpoint sources in the South San Francisco Bay are foun d to be a significant source of selenium, controls could include the development and implementation of TMDLs for th at part of the Bay.

6.3 Sensitivity Analysis , Sources of Uncertainty, and Quality Assurance

T he proposed rule does not establish any requirement s directly applicable to regulated entities or other sources of pollution . S tate implementation of the proposed rule may result in new or revised NPDES permit conditions for point source dischargers

, and incremental control requirements for nonpoint source s. For point sources, EPA has estimated facility

-

6 Since the effluent data used by E PA to determine reasonable potential, effluent limitations, and compliance actions and costs may be more recent than the effluent data used to develop the existing permits, there may be some cases where EPA’s analysis indicates some requirements and costs for a facility under the baseline scenario that are not reflected in the existing permit for the facility. Such costs would not be attributable to the proposed revised criteria, but rather would be baseline costs attributable to the existing criteria.

Howe ver, in this analysis, there are no such baseline costs, and all costs estimated by EPA represent incremental costs attributable to the proposed revised criteria.REFERENCES

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 40 specific costs to reach compliance with the proposed dissolved water column criteri on

. However, the re is substantial uncertainty associated with actual state implementation of the proposed rule.

In addition , the existing body of selenium treatment performance data was developed using analytical methods that exceed the level of the criteri on

. As with other economic analyses of proposed WQS rules, EPA assumes that facilities will deploy mechanisms to achieve t he greater of permit limit or the level of detection. This introduces a level of uncertainty into the technological achievability of the proposed selenium cr iteri on using existing technologies

. Given this, EPA has performed a supplementary sensitivity anal ysis of the end

- of

- pipe

treatment costs. If applicable analytical detection limits should come to reach a level comparable to projected effluent limits, then it is possible that costs would increase. In the case of selenium, EPA has a means to evaluate thi s contingency. As discussed in Section 4.4

, the POTW effluent selenium load is composed of multiple selenium species. Two of the most abundant are selenite and selenate. The proposed conventional end

- of

- pipe tre atment technologies are effective at removing selenite, but are less effective at removing selenate.

Limited data are available on selenium speciation within municipal WWTP s within the San Francisco Bay region. A Bay area study dating to the 1980’s (Cutter and San Diego

McGlone, 1990) indicated that post

- treatment municipal effluent was composed of 70 to 90 percent selenate with the remainder primarily composed of selenite. A similar 2011

- 2012 study (Yee, 2012) found that selenium species partitioning was v ariable from plant

- to

- plant. However, for most plants, selenate was the dominant effluent, followed by organic selenium species and selenite.

This sensitivity analysis assumes that all plants requiring end

- of

- pipe treatment will need to

install denitrifica tion filters in addition to the previously proposed coagulation/filtration units. Denitrification filters will be used to create reducing conditions which will encourage

the transformation of selenate to selenite. In order to reduce selenate, the denitrifi cation filters must first remove a large fraction of any nitrates in the wastestream

— resulting in partial nitrogen removal as a potential secondary benefit of the approach. By converting selenate to selenite, a greater fraction of the selenium load is rend ered amenable to conventional treatment and is likely to achieve a commensurate improvement in treatment performance.
EPA estimated direct costs for denitrification filters based on the capital ($0. 91 /g allons p er d ay (gpd) ) and O&M ($0. 064 /gpd) unit costs for installing a denitrification filter retrofit to a 10 mgd plant (EPA, 2008; unit costs are reported in 2015 dollars). This unit capital cost was developed with CapdetWorksTM software and represents the total installed cost (i.e., indirect

cost s are incl uded) ; however, t he reference includes neither a total, nor a component breakdown of the indirect costs used. Therefore, EPA has assumed that the indirect costs used are approximately comparable to those used in EPA’s cost analysis (see Section 4.4 )

. Using the resulting flow

- normalized unit cost, EPA extrapolated costs for the permittees on the basis of each permittee’s flow rate. Due to expected returns to scale, these unit costs areREFERENCES

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 41 likely to result in conserva tive estimates since most plants requiring end

- of

- pipe treatment have capacities greater than 10 mgd.

Exhibit 6

- 1 summarizes the results of the sensitivity analysis

.

Exhibit 6

- 1 . End

- of

- Pipe Treatment Costs Sensitivity Analysis

NPDES Number Facility Name Total Annual Cost 1

Original 2 Including

Den itrification Filter
Municipal Facilities

CA0037621 City of Sunnyvale $987,000 $4,692,000

CA0037842 City of San Jose/Santa Clara 3 $3,500 $3,500

CA0037834 City of Palo Alto $1,243,000 $6,141,000

CA0038369 South Bayside System Authority 3 $3,500 $3,500

CA0037541 City of San Mateo/Foster City Estero 3 $3,500 $3,500

CA0038636 East Bay Regional Pa rk District, Hayward

Marsh 3 $3,500 $3,500

CA0037532 City of Millbrae and North Bayside Systems

Unit 3 $3,500 $3,500

CA0037788 City of Burlingame and North Bayside

Systems Unit $678,000 $1,369,000

CA0038130 Cities of South San Francisco, San Bruno,

and No rth Bayside Systems Unit $506,000 $2,139,000

CA0038008 City of Livermore and EBDA $827,000 $1,895,000

CA0037613 Dublin San Ramon Services District,

LAWMA, and EBDA $1,406,000 $3,943,000

CA0037869 East Bay Dischargers Authority, Joint

Outfall $5,746,000 $19,285,000

CA0037664 San Francisco Southeast Plant $4,591,000 $15,204,000

CA0038440 East Bay Municipal Utility District, Wet

Weather $ 0 $0

Subtotal $16,001,500 $54,685,500

Industrial Facilities

CA0038318 San Francisco In ternational Airport 3 $3,500 $3,500

Subtotal $3,500 $3,500

Total $16,005,000 $54,689,000

1. One

- time costs annualized over 20 years using a 3 percent discount rate; for costs annualized using a 7 percent discount rate, see Appendix B. 2. For plants disch arging at levels above the most stringent quantitation level (1 μg/L), EPA assumed that facilities will pursue conventional treatment methods to comply with the projected effluent limitations. Facilities operating below the quantitation level are dischargi ng near the projected limitations and EPA has assumed that compliance is likely to be achievable using process optimization methods.

3. End

- of

- pipe treatment (including denitrification filter) is unnecessary for this facility , even considering alternative analytical detection limits

.REFERENCES

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 42 The above analysis evaluates the sensitivity of the cost estimate to assumptions regarding the dissolved selenium speciation within the influent of each plant. It shows that making a substantially more conservative assumptio n regarding selenium speciation (i.e., the selenate fraction within the influent is significant) still results in cost estimate results which are on the same order of magnitude.

Exhibit 6

- 2 summarizes additional un certainties and limitations in the analysis.

Exhibit 6

- 2 . Uncertainties in Analysis of Costs

Uncertainty/Assumption Effects on Cost Estimate Notes

Effluent limitations based on the proposed criteria

cannot be met via source
control Overestimate Assumption could result in an overestimate depending on the nature of the selenium source (i.e., selenium
can be diverted from certain waste streams), or it may result in transferring the cost of treatment from the

m unicipal dischargers t o indirect industrial dischargers.

Control increment cannot
be met via intake credits Overestimate Should additional data and information indicate intake credits are a viable regulatory pathway to meeting the
control increment for m unicipal dischargers , EPA expects costs would decrease substantially for those permittees able to qualify for credits.

Assumed no compliance
schedules will be used Overestimate Facilities subject to the proposed criteria requiring
additional treatment cou ld be provided with compliance schedules by the Regional Water Boards. A compliance schedule would provide an extended period (i.e., ten years) within which a permittee may pursue compliance without being subject to penalties
for exceedances of the limitat ion. A compliance schedule would provide permittees with additional time to research and develop more cost

- effective treatment alternatives than are currently available.
Assumed current South Bay urban stormwater controls are adequate,
consistent with the analysis contained in the North Bay TMDL Underestimate It is possible that urban non

- point sources in the South Bay are of a different character from other sources in the region (i.e., urban nonpoint sources in the North Bay) with respect to selenium, and could require
incremental control measures and a TMDL

.

In order to mitigate sources of uncertainty in the analysis, EPA conducted quality assurance

checks on the data , analyses, and results, consistent with the programmatic and project

specific quality assurance plan s. In addition, EPA used California

- based permit

- writing tool s

to ensure consistency with state permitting approaches and calculations. EPA also used
California

- specific data sources as available , and for all data entry, EPA confirmed the

acc uracy of data sources and documentation following procedures described in the quality assurance plans. These procedures include check s on all inputs and calculations , and using multiple approaches to confirm results.REFERENCES

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 43 

### 7. References

Anderson, D.W. 1998

. Natural levels of nickel, selenium, and arsenic in the southern San Francisco Bay area. Prepared for the City of San Jose, Environmental Services Department.

Bo erngen, J.G.; Shacklette, H.T. 1981

. Chemical analysis of soils and other surficial

materials of the co nterminous United States: U.S. Geological Survey Open

- File Report 81

- 197.

Cutter, G.A.; San Diego

- McGlone M.L.C. 1990

. Temporal variability of selenium fluxes in San Francisco Bay. Science of the Total Environment 97/98: 235

- 250.

Central Valley Regional Wa ter Quality Control Board (CVRWQCB) 2001

. Total Maximum Daily Load for Selenium in the Lower San Joaquin River. Retrieved November 2015 from: <http://www.waterboards.ca.gov/centralvalley/water_issues/tmdl/central_valley_projects/ind
ex.shtml>

Kapoor, A.; Ta njore, S.; Viraraghavan, T. 2007

. Removal of selenium from water and wastewater. International Journal of Environmental Studies, 49:2, 137

- 147, DOI:
10.1080/00207239508711016.

Kleinfelder, Inc. 1995

. Level II hazardous materials investigation upper Guadalu pe River flood control project: Final Report to the Santa Clara Valley Water District. Retrieved November 2015 from: <http://www.valleywater.org/programs/construction.aspx>

Scott, C.M. 1995

. Background metal concentrations in soils in northern Santa Clara County, California, in Sangines, E.M.; Anderson, D.W.; and Buising, A.V.; eds. Recent geologic studies in the San Francisco Bay area: Pacific Section, Society for Sedimentary Geology
Book 76.

Shacklette, H.T.; Boerngen, J.G. 1984

. Element concentrations in soils and other surficial materials of the conterminous United States: U.S. Geological Survey Professional Paper

1270.

San Francisco Regional Water Quality Control Board ( SFRWQCB ) 2015

. Total Maximum Daily Load: Selenium in North San Francisco Bay, Staff Report. Retrieved November 2015
from: <http://www.waterboards.ca.gov/sanfranciscobay/water_issues/programs/TMDLs/seleniumt
mdl.shtml>

State Water Resources Control Board ( SWRCB ) 2012

. 2012 Clean Water Act Section 303(d) and 305(b) Integrated Report. Retriev ed November 2015 from <http://www.waterboards.ca.gov/water_issues/programs/tmdl/integrated2012.shtml>

San Francisco Estuary Project, 2007. Comprehensive Conservation and Management PlanREFERENCES

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 44 United States Environmental Protection Agency ( USEPA ) 1979

. Estimatin g Water Treatment Costs: Volume 2 Cost Curves Applicable to 1 to 200 mgd Treatment Plants. EPA

- 600/2

- 79

- 162b.

United States Environmental Protection Agency (USEPA) 1983

. Treatability Manual: Volume 1 Treatability Data. EPA

- 600/8

- 80

- 042a.

United States Envi ronmental Protection Agency (USEPA) 2008

. Municipal Nutrient Removal Technologies Reference Document: Volume 1 & 2

- Technical Report. (EPA 832

- R

- 08

- 006).

United Stated Environmental Protection Agency (USEPA) 2015. Draft Aquatic Life Ambient Water Quality Criterion for Selenium

– Freshwater. EPA 822

- P

- 15

- 001.

United States Environmental Protection Agency (USEPA) 201 6 . Aquatic Life Ambient Water Quality Criterion for Selenium

– Freshwater. EPA XXX

- X

- 16

- XXX.

Yee, D. (2012) Technical Memorandum: Selenium Frac tionation and Speciation in Final Effluents of Selected San Francisco Bay Area Municipal Wastewater Treatment Facilities. San Francisco Estuary Institute. Retrieved November 2015 from: <http://www.sfei.org/documents/selenium

- fractionation

- and

- speciation

- fi nal

- effluents

selected

- san

- francisco

- bay

- area

- muni>APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 45 

### Appendix A

– Facility Analyses

This appendix provides detailed analyses for the 16 sample fac ilities in alphabetical order,
with municipal dischargers first followed by industrial dischargers. For each facility, under the baseline scenario (i.e. using the current criteria) and the revised criteria scenario, EPA

conducted a n RPA , identified potential compliance scenarios, and estimated the associated

costs. Since the effluent data used by EPA to determine reasonabl e potential, effluent limitations, and compliance actions and costs may be more recent than the effluent data used to develop the existing permits, there may be some cases where EPA’s analysis indicates some requirements and costs for a facility under the baseline scenario that are not reflected in the existing permit for the facility. Such costs would not be attributable to the proposed revised criteria, but rather would be baseline costs attributable to the existing criteria. Only compliance actions and c osts that would be needed above the baseline level of controls are attributable to the proposed revised criteria.

A.1 City of Burlingame and North Bayside Systems Unit

The treatment facility for the City of Burlingame and North Bayside Systems Unit (Plant;

NP DES permit No. CA0037788) is located south of the San Francisco International Airport and northeast of the City of Burlingame. The Plant provides secondary treatment of domestic and commercial wastewater for the City of Burlingame, a portion of the Town of Hillsborough, and the Burlingame Hills Sewer maintenance District, a total population of approximately 37,000. No significant industrial users discharge to the Plant. The Plant design average daily dry weather flow is 5.5 mgd and the peak wet weather capa city, based on the engineered contractual limit for the North Bayside System Unit (NBSU) forcemain, is 16 mgd . The Plant discharges to Lower San Francisco Bay.

Treatment Processes
Treatment consists of screening, grit removal, primary sedimentation, secon dary biological treatment, secondary clarification, and chlorine disinfection. Treated water undergoes dechlorination at the South San Francisco and San Bruno Water Quality Control Plant prior to discharge to Lower San Francisco Bay.

During wet weather, pr imary effluent flows in excess of 13 mgd are directed to the Facility’s 2.38 million gallon onsite temporary storage units. When the storage units reach their maximum capacity, primary effluent flows in excess of 13 mgd are blended with secondary effluent, disinfected, and discharged to the NBSU forcemain. Stored water from the temporary storage facilities is returned to the primary clarifier for full treatment after the influent flow subsides to a level protective of secondary treatment processes. The Plan t is permitted to discharge an average dry weather flow of 5 mgd

.
Effluent Data

Exhibit A

- 1 summarizes selenium effluent data for the treated wastewater between September 2011 and September 2015.APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 46 Exhibit A

- 1

. Summary of Selenium Effluent Data: City of Burlingame WWTP
No. of Observations Effluent Summary (μg/L)

Total Nondetect CV Average Standard Deviation Max

23 5 0.534 0.407 0.217 1 Source: California Integrated Water Quality Sy stem CV = Coefficient of Variation μg/L = micrograms per liter Concentrations are total recoverable form.

Receiving Water
The facility discharges to Lower San Francisco Bay. The SFRWQCB utilized the Yerba Buena Island monitoring station (station number B C 10) for purposes of background receiving water characterization. The available ambient receiving water monitoring data was collected from the Yerba Buena Island monitoring station between 1993 and 2013. The
maximum total recoverable selenium concentratio n observed during this period was 0.39 μg/L.

Baseline Scenario
The permit does not include any WQBELs based on the existing chronic aquatic life
selenium criteri on (i.e., 5 μg/L) and the existing acute aquatic life selenium criteri on (i.e., 20 μg/L). EPA p erformed an RPA based on the existing criteria to confirm that no baseline WQBELs would be needed based on the analytical approaches described in Section 4.2 . As neither the maximum effluent nor receiving water concentration exceed the existing criteria, this facility does not have reasonable potential to exceed the existing selenium criteria

. Additionally, since there are no existing selenium WQBELs for this facility, EPA assumes that there is no reasonable pote ntial under the third “trigger” which is activated when a review of other information (beyond the maximum effluent and ambient concentrations) suggests that limits are needed to protect beneficial uses. As such, EPA assumed that the facility would incur no costs under the baseline scenario.

Proposed Criteri a Scenario
EPA performed an RPA based on the proposed water column selenium criteri on (0.2 μg/L). As with the baseline scenario, EPA based the analysis on the analytical approaches described
in Section 4.2 . The MEC (i.e., 1 μg/L) exceed s the proposed criteri on and, therefore, the discharge has reasonable potential to cause or contribute to the exceedance of the proposed water quality criteri on

. WQBELs were calc ulated according to the procedures described in Section 4.3 and using the

effluent coefficient of variation described in Exhibit A

- 1 . Due to an absence of assimilative capacity (i.e., the B exceeded the proposed water column criteri on ), EPA did not consider

dilution , and instead calculated end

- of

- pipe limitations. Under the proposed criteri on , the discharger would have to meet an AMEL of 0.17 μg/L and MDEL of 0.30 μg/L.APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 47 Since the MEC is above the QL , EPA assumed that the Plant will need to pursue conventional treatment methods to comply with the projected effluent limitations (see
Section 4.4 )

. According to the existing permit , the Plant does not currently use iron salt chemical addition or media filtration unit processes. Therefore, EPA has developed a cost estimate to install a chemical treatment system and sand filters using the cost curves

describe d in Section 4.4

. Using a flow rate of 5.5 mgd, t he estimated installed capital cost for the Plant is approximately $6. 2 million and the estimated annual O&M cost is $260,000.

A.2 City of Livermore and EBDA

The WWTP for the City of Livermore and EBDA (Plant; NPDES Permit No. CA0038008) serves approximately 83,600 people from the City of Livermore. The Plant provides secondary treatment for up to 8.5 mgd . During high flow events, a side flow weir in the influent manhole structure diverts peak untreated wastewater flows to a 15 million gallon emergency holding basin. Additionally, an average of 1.3 mgd of wastewater receives tertiary treatment and is used as recycled water and sent to the Zone 1 Distribution System. The Plant has a current permi tted average dry weather design flow of 8.5 mgd , a future average dry weather design flow of 11.1 mgd , and a contractual peak wet weather design
flow of 12.4 mgd . The Plant discharges to Lower San Francisco Bay.

Treatment Processes

The 2012 Permit fact she et reports that treatment consists of screening, grit removal, pre

aeration, primary clarification with ferric chloride addition for hydrogen sulfide control in the digestion process, activated sludge, secondary clarification and disinfection using sodium hypochlorite. The tertiary treated wastewater is diverted after the secondary clarifiers and routed through in

- line granular media filtration and ultraviolet disinfection. Sludge is anaerobically digested, dewatered using belt filter presses, and trucked o ffsite.

Effluent Data

Exhibit A

- 2 summarizes selenium effluent data for the treated wastewater between March 2011 and July 2015.

Exhibit A

- 2

. Summary of Selenium Effluent Data: City of Livermore Water Reclamation Plant
No. of Observations Effluent Summary (μg/L)

Total Nondetect CV Average Standard Deviation Max

53 50 0.567 1 0.501 0.284 1.7 Source: California Integrated Water Quality System CV = Coefficient of Variation μg/L = mic rograms per liter Concentrations are total recoverable form.
1. A CV of 0.6 was used to calculate W ater Q uality

- B ased E ffluent L imitation s due to the limited number of detected observations

.APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 48 Receiving Water
The facility discharges to Lower San Francisco Bay. The S FRWQCB utilized the Yerba Buena Island monitoring station (station number BC 10) for purposes of background receiving water characterization. The available ambient receiving water monitoring data was
collected from the Yerba Buena Island monitori ng station between 1993 and 2013. The maximum total recoverable selenium concentration observed during this period was 0.39 μg/L.

Baseline Scenario
The permit does not include any WQBELs based on the existing chronic aquatic life

selenium criteri on (i.e., 5 μg/L) and the existing acute aquatic life selenium criteri on (i.e., 20 μg/L). EPA performed an RPA based on the existing criteria to confirm that no baseline WQBELs would be needed based on the analytical approaches described in Section 4.2 . As neither the maximum effluent nor receiving water concentration exceed the existing criteria, this facility does not have reasonable potential to exceed the existing selenium criteria

. Additionally, since there are no exi sting selenium WQBELs for this facility, EPA assumes that there is no reasonable potential under the third “trigger” which is activated when a review of other information (beyond the maximum effluent and ambient concentrations) suggests that limits are nee ded to protect beneficial uses. As such, EPA assumed that the facility would incur no costs under the baseline scenario.

Proposed Criteria Scenario
EPA performed an RPA based on the proposed water column selenium criteri on (0.2 μg/L).
As with the baseline scenario, EPA based the analysis on the analytical approaches described
in Section 4.2 . The MEC (i.e., 1.7 μg/L) exceed s the proposed criteri on and, therefore, the discharge has reasonable potential to cause or contribute to the exceedance of the proposed water quality criterion

.
W QBELs were calculated according to the procedures described in Section 4.3 and using the
effluent coefficient of variation described in Exhibit A

- 2 . Due to an absence of assimilative capacity (i.e., the B exceeded the proposed criteri on ), EPA did not consider dilution, and

instead calculated end

- of

- pipe limitations . Under the proposed criteri on , the discharger would
have to meet an AMEL of 0.16 μg/L and MDEL of 0.33 μg/L.

Since the MEC is above the QL, EPA assumed that the Plant will need to pursue conventional treatment methods to comply with the projected effluent limitations (see
Section 4.4 ). According to the existing permit, the Plant does not currently use iron salt chemical addition or media filtration unit processes. Therefore, EPA has developed a cost estimate to install a chemical treatment system and sand filters using the cost curves
described in Section 4.4 . Using a flow rate of 8.5 mgd, the estimated installed capital cost for the Plant is approximately $7. 6 million and the estimated annual O&M cost is $310,000.APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 49 A.3 City of Millbrae and North Bayside Systems Unit

The WWTP for the City of Millbrae and North Bayside Systems Unit (Plant; NPDES Permit No. CA0037532) provides primary and secondary treatment of wastewater for the City of
Millbrae and serves a population of about 21,500. The Plant has a permitted average dry weather design capacity of 3.0 mgd and can process up to 9.0 mgd of wastewater during wet weather. The Plant discharges to Lower San Fran cisco Bay

.

Treatment Processes
The 2013 permit fact sheet reports that treatment processes include a headworks with coarse and fine bar screens and grit removal, primary sedimentation in rectangular clarifiers, biological activated sludge treatment, secondary clarification, disinfection with sodium hypochlo rite, and final effluent skimming. Effluent is dechlorinated prior to discharge into Lower San Francisco Bay.

Effluent Data

Exhibit A

- 3 summarizes selenium effluent data for the treated wastewater between Novembe r 2011 and November 2014.

Exhibit A

- 3

. Summary of Selenium Effluent Data: City of Millbrae and North Bayside Systems Unit
No. of Observations Effluent Summary (μg/L)

Total Nondetect CV Average Standard Deviation Max

7 2 0. 316 1 0.353 0.112 0.48 2

CV = Coefficient of Variation μg/L = micrograms per liter Concentrations are total recoverable form.
1. A CV of 0.6 was used to calculate W ater Q uality

- B ased E ffluent L imitation s due to the limited number of detected observations

. 2 . T he max result was detected but not quantified ( DNQ ; i.e., selenium was detected in the sample but at levels too low to accurately quantify

— the reported concentration is a best estimate).

Receiving Water
The facility discharges to Lower San Francisco B ay. The S FRWQCB utilized the Yerba Buena Island monitoring station (station number BC 10) for purposes of background receiving water characterization. The available ambient receiving water monitoring data was
collected from the Yerba Buena Island monitorin g station between 1993 and 2013. The maximum total recoverable selenium concentration observed during this period was 0.39 μg/L.

Baseline Scenario
The permit does not include any WQBELs based on the existing chronic aquatic life
selenium criteri on (i.e., 5 μg/L) and the existing acute aquatic life selenium criteri on (i.e., 20 μg/L). EPA performed an RPA based on existing criteria to confirm that no baselineAPPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 50 WQBELs would be needed based on the analytical approaches described in Section 4.2 . As neither the maximum effluent nor receiving water concentration exceed the existing criteri a , this facility does not have reasonable potential to exceed the existing selenium criteri a

. Additionally, since there are no existing selenium WQBELs for this facility, EPA assumes that there is no reasonable potential under the third “trigger” which is activated when a review of other information (beyond the maximum effluent and ambient concentrations) suggests that limits are needed t o protect beneficial uses. As such, EPA assumed that the facility would incur no costs under the baseline scenario.

Proposed Criteria Scenario
EPA performed an RPA based on the proposed water column selenium criteri on (0.2 μg/L).
As with the baseline scen ario, EPA based the analysis on the analytical approaches described
in Section 4.2 . The MEC (i.e., 0.48 μg/L) exceed s the proposed criteri on and, therefore, the discharge has reasonable potential to cause or con tribute to the exceedance of the proposed water quality criterion.

WQBELs were calculated according to the procedures described in Section 4.3 and using the
effluent coefficient of variation described in Exhibit A

- 3 . Due to an absence of assimilative capacity (i.e., the B exceeded the proposed criter ion ), EPA did not consider dilution, and

instead calculated end

- of

- pipe limitations . Under the p roposed criteri on , the dis charger would
have to meet an AMEL of 0.16 μg/L and MDEL of 0.33 μg/L.

Since the MEC for the Plant is below the QL, EPA assumed that it is discharging near the projected limitations and that compliance is likely to be achievable using process optimization methods (see Section 4.4 ). EPA developed one

- time costs for implementing a process optimization study of $52,000.

A.4 City of San Mateo/Foster City Estero

The WWTP for the City of San Mateo/Foster City Estero Muni cipal Improvements District (Plant; NPDES Permit No. CA0037541) provides secondary and advanced secondary treatment of domestic, commercial, and industrial wastewater for the City of San Mateo, the City of Foster City, the Town of Hillsborough, and portion s of the City of Belmont and unincorporated San Mateo County. The Plant serves a population of approximately 139,000, and has an average daily dry weather design flow of 15.7 mgd and a peak wet weather design flow for secondary treatment of 40 mgd

. The Pla nt discharges to Lower San Francisco Bay.

Treatment Processes
The 2013 permit fact sheet states that treatment at the Plant consists of primary sedimentation, secondary biological treatment through aeration basins, secondary clarification, chlorine disinfe ction, and dechlorination using sodium bisulfite, as well as the option of pressure filters when necessary to comply with effluent limitations.APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 51 Effluent Data

Exhibit A

- 4 summarizes selenium effluent data for the treated wastewater between June 2011
and March 2015.

Exhibit A

- 4

. Summary of Selenium Effluent Data: City of San Mateo WWTP
No. of Observations Effluent Summary (μg/L)

Total Nondetect CV Average Standard Deviation Max

44 2 0.578 0.215 0.124 0.53 1

CV = Coefficient of Variation μg/L = micrograms per liter Concentrations are total recoverable form. 1. The max result was reported as detected but not quantified (DNQ; i.e., selenium was detected in the sample but at levels too l ow to accurately quantify

— the reported concentration is a best estimate).

Receiving Water
The facility discharges to Lower San Francisco Bay. The S FRWQCB utilized the Yerba Buena Island monitoring station (station number BC 10) for purposes of background receiving water characterization. The available ambient receiving water monitoring data was collected from the Yerba Buena Island monitoring station between 1993 and 2013. The maximum total recoverable selenium concentration observed during this period wa s 0.39 μg/L.

Baseline Scenario
The permit does not include any WQBELs based on the existing chronic aquatic life

selenium criteri on (i.e., 5 μg/L) and the existing acute aquatic life selenium criteri on (i.e.,

20 μg/L). EPA performed an RPA based on existin g criteria to confirm that no baseline WQBELs would be needed based on the analytical approaches described in Section 4.2 . As neither the maximum effluent nor receiving water concentration exceed the existing cr iteria, this facility does not have reasonable potential to exceed the existing selenium criteria

. Additionally, since there are no existing selenium WQBELs for this facility, EPA assumes that there is no reasonable potential under the third “trigger” whic h is activated when a review of other information (beyond the maximum effluent and ambient concentrations) suggests that limits are needed to protect beneficial uses. As such, EPA assumed that the facility would incur no costs under the baseline scenario.

Proposed Criteria Scenario
EPA performed an RPA based on the proposed water column selenium criteri on (0.2 μg/L). As with the baseline scenario, EPA based the analysis on the analytical approaches described

in Section 4.2 . The MEC (i.e., 0.53 μg/L) exceed s the proposed criteri on and, therefore, the discharge has reasonable potential to cause or contribute to the exceedance of the proposed water quality criterion.

WQBELs were calculated according to the procedures described in Section 4.3 and using the
effluent coefficient of variation described in Exhibit A

- 4 . Due to an absence of assimilativeAPPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 52 capacity (i.e., the B exceeded the proposed criterion ), EPA did not consider dilution, and

instead calculated end

- of

- pipe limitations . Under the proposed criteri on , the discharger would
have to meet an AMEL of 0.18 μg/L and MDEL of 0.29 μg/L.

Since the MEC for the Plant is below the QL, E PA assumed that it is discharging near the projected limitations and that compliance is likely to be achievable using process optimization methods (see Section 4.4 ). EPA developed one

- time costs for implementing a process optimization study of $52,000.

A.5 Dublin San Ramon Services District

The WWTP for the Dublin San Ramon Services District (Plant; NPDES Permit No. CA0037613) serves the City of Dublin, the city of Pleasanton, and the southern portion of the City o f San Ramon, a service area population of approximately 131,900 people. The Plant has an average dry weather flow design capacity of 17 mgd from the Dublin San Ramon Services District, plus 3.2 mgd of Zone 7 groundwater RO reject flow (i.e., a total of 20. 2 mgd) . Treated effluent is discharged to Lower San Francisco Bay.

Treatment Processes
The 2012 Permit fact sheet reports that treatment consists of screening, grit removal, primary clarification, activated sludge, secondary clarification, and disinfection using sodium hypochlorite.

Effluent Data

Exhibit A

- 5 summarizes selenium effluent data for the treated wastewater between March 2011 and July 2015.

Exhibit A

- 5

. Summary of Seleniu m Effluent Data: Dublin San Ramon Services District WWTP
No. of Observations Effluent Summary (μg/L)

Total Nondetect CV Average Standard Deviation Max

53 12 0.896 1.218 1.091 4.7

CV = Coefficient of Variation μg/L = micrograms per liter Concentrations are total recoverable form.

Receiving Water
The facility discharges to Lower San Francisco Bay. The S FRWQCB utilized the Yerba Buena Island monitoring station (station number BC 10) for purposes of background receiving water characterization. The availab le ambient receiving water monitoring data was collected from the Yerba Buena Island monitoring station between 1993 and 2013. The maximum total recoverable selenium concentration observed during this period was 0.39 μg/L.APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 53 Baseline Scenario
The permit does not include any WQBELs based on the existing chroni c aquatic life
selenium criterion (i.e., 5 μg/L) and the existing acute aquatic life selenium criteri on (i.e., 20 μg/L). EPA performed an RPA based on existing criteria to confirm that no baseline WQBELs would be needed based on the analytical approaches described in Section 4.2 . As neither the maximum effluent nor receiving water concentration exceed the existing criteria, this facility does not have reasonable potential to exceed the existing selenium criteria

. Additionally, since there are no existing selenium WQBELs for this facility, EPA assumes that there is no reasonable potential under the third “trigger” which is activated when a

review of other informat ion (beyond the maximum effluent and ambient concentrations) suggests that limits are needed to protect beneficial uses. As such, EPA assumed that the facility would incur no costs under the baseline scenario.

Proposed Criteria Scenario
EPA performed an R PA based on the proposed water column selenium criter ion (0.2 μg/L). As with the baseline scenario, EPA based the analysis on the analytical approaches described
in Section 4.2 . The MEC (i.e., 4.7 μg/L) exceed s the proposed criteri on and, therefore, the discharge has reasonable potential to cause or contribute to the e xceedance of the proposed water quality criterion

.
W QBELs were calculated according to the procedures described in Section 4.3 and using the
effluent coefficient of variation described in Exhibit A

- 5 . Due to an absence of assimilative capacity (i.e., the B exceeded the proposed criteri on ), EPA did not consider dil ution , and
instead calculated end

- of

- pipe limitations . Under the proposed criteri on , the discharger would
have to meet an AMEL of 0.1 5 μg/L and MDEL of 0. 36 μg/L.

Since the MEC is above the QL , EPA assumed that the Plant will need to pursue
conventional t reatment methods to comply with the projected effluent limitations (see
Section 4.4 ). According to the existing permit, the Plant does not currently use iron salt chemical addition or media filtration unit proce sses. Therefore, EPA has developed a cost estimate to install a chemical treatment system and sand filters using the cost curves
described in Section 4.4 . Using a flow rate of 20.2 mgd, the estimated installed c apital cost for the Plant is approximately $13 .2 million and the estimated annual O&M cost is $ 520 ,000.

A.6 East Bay Dischargers Authority , Joint Outfall

East Bay Dischargers Authority (EBDA; NPDES No. CA0037869) is a Joint Exercise of Power Agency, the member s of which separately own and operate collection and treatment facilities for domestic, commercial, and industrial wastewater. EBDA is comprised of five member agencies: City of Hayward, Oro Loma Sanitary District, Castro Valley Sanitary District, City of San Leandro, and Union Sanitary District. EBDA conveys treated wastewater from its member agencies’ three treatment facilities together with treated

wastewater from the Livermore

- Amador Valley Water Management Agency’s treatment plant, which is comprised o f treated wastewater from the City of Livermore, to aAPPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 54 dechlorination station near the San Leandro Marina (collectively, these treatment plants will be referred to as the Plants, hereinafter). The total permitted average dry weather flow to be discharged at the EBDA Common Outfall is 107.8 mgd , and the total peak daily wet weather
flow is 189.1 mgd

. EBDA discharges to Lower San Francisco Bay.

Treatment Processes
The 2012 Permit fact sheet reports that treatment consists of dechlorination of the combined

trea ted wastewater by sodium bisulfite before discharge from the common outfall to Lower San Francisco Bay. Treatment at the City of Wayward Water Pollution Control Facility consists of comminution, grit removal, primary sedimentation, flow equalization, high

- rate trickling filtration, secondary clarification, and chlorination. Treatment at the Oro Loma and Castro Valley Sanitary Districts’ treatment facility consists of screening, grit removal, primary sedimentation, activated sludge, secondary clarification, and chlorination. Treatment at the San Leandro Water Pollution Control Plant grinding, primary sedimentation, trickling filter, activated sludge, secondary clarification, and disinfection by sodium hypochlorite. Treatment at the Union Sanitary District con sists of screening, primary sedimentation, activated sludge, secondary clarification, and chlorination

Effluent Data

Exhibit A

- 6 summarizes selenium effluent data for the treated wastewater between April
2011 and July 2015.

Exhibit A

- 6

. Summary of Selenium Effluent Data: East Bay Dischargers Authority Common Outfall
No. of Observations Effluent Summary (μg/L)

Total Nondetect CV Average Standard Deviation Max

53 9 0.575 0.523 0.301 1.2

CV = Coefficient of Variation μg/L = micrograms per liter Concentrations are total recoverable form.

Receiving Water
The facility discharges to Lower San Francisco Bay. The S FRWQCB utilized the Yerba Buena Island monitoring station (station number BC 10) for purposes of background receiving water characterization. The available ambient receiving water monitoring data was collected from the Yerba Buena Island monitoring station between 1993 and 2013. The
maximum total recoverable selenium concentrati on observed during this period was 0.39 μg/L.

Baseline Scenario
The permit does not include any WQBELs based on the existing chronic aquatic life

selenium criter ion (i.e., 5 μg/L) and the existing acute aquatic life selenium criteri on (i.e., 20 μg/L). EPA performed an RPA based on existing criteria to confirm that no baselineAPPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 55 WQBELs would be needed based on the analytical approaches described in Section 4.2 . As neither the maximum effluent nor receiving water con centration exceed the existing criteria, this facility does not have reasonable potential to exceed the existing selenium criteri a

. Additionally, since there are no existing selenium WQBELs for this facility, EPA assumes that there is no reasonable potenti al under the third “trigger” which is activated when a review of other information (beyond the maximum effluent and ambient concentrations) suggests that limits are needed to protect beneficial uses. As such, EPA assumed that the facility would incur no co sts under the baseline scenario.

Proposed Criteria Scenario
EPA performed an RPA based on the proposed water column selenium criter ion (0.2 μg/L). As with the baseline scenario, EPA based the analysis on the analytical approaches described
in Section 4.2 . The MEC (i.e., 1.2 μg/L) exceed s the proposed criteri on and, therefore, the discharge has reasonable potential to cause or contribute to the exceedance of the proposed water quality criterion

.
W QBELs were calcu lated according to the procedures described in Section 4.3 and using the
effluent coefficient of variation described in Exhibit A

- 6 . Due to an absence of assimilative

c apacity (i.e., the B exceeded the proposed criteri on ), EPA did not consider dilution, and

instead calculated end

- of

- pipe limitations . Under the p roposed criter ion , the discharger would
have to meet an AMEL of 0.17 μg/L and MDEL of 0.30 μg/L.

Since the MEC is above the QL , EPA assumed that the facility will need to pursue conventional treatment methods to comply with the projected effluent limitations (see
Section 4.4 ). The Joint Outfall services a number of disch argers and the available information on their treatment processes indicated that none of the plants utilized iron salt chemical addition or media filtration. Therefore, EPA has developed a cost estimate to install a chemical treatment system and sand filte rs using the cost curves described in Section 4.4 at each of the plants. Since the cost curves are based on a linear trend of the costs for EPA’s model treatment trains, costs may be estimated using an aggregate flow rate for the Joint Outfall (i.e., cost based on an aggregate flow rate will be equal to that estimated based on individual contributing systems). Using a flow rate of 107.8 mgd, the estimated installed capital cost for the Plant s is approximately $ 54 .7 million and the estimated annual O&M cost is $2. 1 million.

A.7 East Bay Municipal Utility District, Wet Weather Facilities

East Bay Municipal Utility District, Special District No. 1 is the owner and operator of three wet weather facilities (WWF) known as t he Point Isabel WWF, the San Antonio Creek WWF, and the Oakport WWF (collectively, the Facility, NPDES Permit No. CA0038440). The WWFs are connected to an interceptor system with a hydraulic capacity of 760 mgd and
a million

- gallon wet weather storage basi n along one of the interceptors.APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 56 Treatment Processes
If influent flows at the Point Isabel WWF persist to the point of taking up the storage capacity of the units, the WWF provides treatment consisting of coarse screens, bar screens, grit chambers, and se dimentation/disinfection basins.

Treatment at the San Antonio Creek WWF consists of grit removal, fine screening, and

disinfection.

If influent flows persist to the point of taking up the storage capacity of the units, the Oakport WWF provides treatment c onsisting of coarse screens and sedimentation/disinfection basins.

Effluent Data
As of 2009, discharge from this Facility has been prohibited. This prohibition is included in the existing permit (Permit No. R2

- 2014

- 0044; NPDES Permit No. CA0038440). As su ch effluent data for the Facility is not available.

Receiving Water
All discharges from the Facility are prohibited, and as such there is no applicable receiving

water

.
Baseline Scenario
All discharges from the Facility are prohibited and, therefore, no ef fluent limitations are applicable under the baseline scenario.

Proposed Criteria Scenario
All discharges from the Facility are prohibited and, therefore, no effluent limitations are applicable under the proposed criteria, and the facility would incur no c osts.

A.8 East Bay Regional Park District, Hayward Marsh

The WWTP for the Regional Park District, Union Sanitary District, and East Bay Dischargers Authority at Hayward Marsh (Plant; NPDES Permit No. CA0038636) is a 145

- acre improved marsh system which include s three freshwater marsh basins (85 acres) and two brackish water basins (60 acres) adjacent to Lower San Francisco Bay. Approximately

2.6 mgd is diverted from the Alvarado WWTP in Union City as the freshwater source for the
Marsh. The three freshwater mar sh basins are part of the treatment process, and thus part of the treatment facility. The two brackish water basins and San Francisco Bay are the receiving waters and waters of the United States within the South San Francisco Bay Basin watershed.

The Marsh has a hydraulic capacity of 20 mgd . Hayward Marsh is operated to enhance the beneficial uses of reclaimed wastewater, to derive net environmental benefits, and as a research site to better understand development and management of a marsh using reclaimed

w astewater.APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 57 Treatment Processes
Treatment at the Plant consists of screening, primary sedimentation, activated sludge, secondary clarification, and chlorination/disinfection of final effluent. Sludge is anaerobically digested, dewatered using centrifuge pro cesses, and disposed of at an authorized disposal site. Most of the treated effluent is transported to the East Bay Dischargers pipeline where it mixes with treated effluent from other EBDA agencies and is transported to a dechlorination station near the S an Leandro Marina. This treated effluent is transported to EBDA’s deepwater outfall in Lower San Francisco Bay west of the Oakland Airport. That discharge is regulated under NPDES Permit No. CA0037869. Approximately

2.6 mgd is diverted to Hayward Marsh and is regulated under the permit in question (NPDES No. CA0038636). Secondary effluent enters a system of three freshwater marsh basins and two brackish water basins. The hydraulic capacity of the marsh system is 20 mgd . The brackish water basins discharge t he final effluent into Lower San Francisco Bay.

Effluent Data
Recent effluent data for this permittee was not available for analysis. Instead, EPA utilized
the MEC and effluent descriptive statistics reported in the discharger’s 2011 permit (Permit

No. R2

- 2011

- 0058; NPDES No. CA0037834). Exhibit A

- 7 summarizes the informati on reported in the 2011 permit.

Exhibit A

- 7

. Summary of Selenium Effluent Data: East Bay Regional Park District No. of Observations Effluent Summary (μg/L)

Total Nondetect CV Average Standard
Deviation Max

N/A N/A N/A 1 N/A N/A 0.55
N/A = Not Available
CV = Coefficient of Variation μg/L = micrograms per liter Concentrations are total recoverable form.
1. A CV of 0.6 was used to calculate W ater Q uality B ased E ffluent L imitation s due to the limited
number of detected observations.

Receiving Water
The facility discharges to Lower San Francisco Bay. The S FRWQCB utilized the Yerba Buena Island monitoring station (s tation number BC 10) for purposes of background receiving water characterization. The available ambient receiving water monitoring data was collected from the Yerba Buena Island monitoring station between 1993 and 2013. The
maximum total recoverable seleni um concentration observed during this period was 0.39 μg/L.

Baseline Scenario
The permit does not include any WQBELs based on the existing chronic aquatic life

selenium criteri on (i.e., 5 μg/L) and the existing acute aquatic life selenium criteri on (i.e., 20 μg/L). EPA performed an RPA based on existing criteria to confirm that no baselineAPPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 58 WQBELs would be needed based on the analytical approaches described in Section 4.2 . As
neither the maximum effluent nor recei ving water concentration exceed the existing criteria, this facility does not have reasonable potential to exceed the existing selenium criteri on

. Additionally, since there are no existing selenium WQBELs for this facility, EPA assumes
that there is no rea sonable potential under the third “trigger” which is activated when a review of other information (beyond the maximum effluent and ambient concentrations) suggests that limits are needed to protect beneficial uses. As such, EPA assumed that the facility wo uld incur no costs under the baseline scenario.

Proposed Criteria Scenario

EPA performed an RPA based on the proposed water column selenium criteri on (0.2 μg/L). As with the baseline scenario, EPA based the analysis on the analytical approaches described in Section 4.2

. The MEC (i.e., 0.55 μg/L) exceed s the proposed criteri on and, therefore, the discharge has reasonable potential to cause or contribute to the exceedance of the water quality criterion

.

W QBELs wer e calculated according to the procedures described in Section 4.3 and using the effluent
coefficient of variation described in Exhibit A

- 7 . Due to an absence of assimil ative capacity (i.e., the

B exceeded the proposed criteri on ), EPA did not consider dilution, and instead calculated end

- of

- pipe
limitations . Under the proposed criteri on , the discharger would have to meet an AMEL of 0.16 μg/L
and MDEL of 0.33 μg/L.

Since the MEC for the Plant is below the QL, EPA assumed that it is discharging near the projected limitations and that compliance is likely to be achievable using process optimization methods (see
Section 4.4 ). EPA d eveloped one

- time costs for implementing a process optimization study of $52,000.

A.9 Palo Alto Regional Water Quality Control Plant

The Palo Alto Regional Water Quality Control Plant and the City of Palo Alto wastewater collection system (collectively, the f acility ; NPDES Permit No. CA0037834) provides advanced secondary treatment of domestic, commercial, and industrial wastewater collected
from the cities of Los Altos, Los Altos Hills, Palo Alto, and Mountain View; the East Palo Alto Sanitary District; and t he unincorporated area of the Stanford University Campus. The service area population is approximately 220,000, and the Facility’s design flow rate is 39 mgd . Approximately 95% of the treated final effluent that is not recycled is discharged to an
unnamed channel that leads to South San Francisco Bay. The remaining 5% is discharged to Matadero Creek, which flows into Mayfield Slough and then into South San Francisco Bay at the Flood Basin tide gates.APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 59 Treatment Processes
The 2014 Permit Fact Sheet reports th at treatment processes include screening and grit removal, primary sedimentation, biological treatment, secondary clarification, filtration, and

disinfection.

Effluent Data

Exhibit A

- 8 summarizes selenium effluen t data for the treated wastewater between March
2011 and June 2015.

Exhibit A

- 8

. Summary of Selenium Effluent Data: Palo Alto Regional Water Quality Control Plant
No. of Observations Effluent Summary (μg/L)

Total Nondetect CV Average Standard Deviation Max

58 0 0.418 1.456 0.608 2.6

CV = Coefficient of Variation μg/L = micrograms per liter Concentrations are total recoverable form.

Receiving Water
The facility discharges to South San Francisco Bay. The SFRWQCB utilized t he Dumbarton Bridge monitoring station (station number BA 30) for purposes of background receiving water characterization. The available ambient receiving water monitoring data was collected from the Yerba Buena Island monitoring station between 1993 and 2 013. The maximum total recoverable selenium concentration observed during this period was 0.628 μg/L.

Baseline Scenario
The permit does not include any WQBELs based on the existing chronic aquatic life

selenium criteri on (i.e., 5 μg/L) and the existing acu te aquatic life selenium criteri on (i.e., 20 μg/L). EPA performed an RPA based on existing criteria to confirm that no baseline WQBELs would be needed based on the analytical approaches described in Section 4.2

. As neither the maximum effluent nor receiving water concentration exceed the existing criteria, this facility does not have reasonable potential to exceed the existing selenium criteri a

. Additionally, since there are no existing selenium WQBELs for this f acility, EPA assumes that there is no reasonable potential under the third “trigger” which is activated when a review of other information (beyond the maximum effluent and ambient concentrations) suggests that limits are needed to protect beneficial uses. As such, EPA assumed that the facility would incur no costs under the baseline scenario.

Proposed Criteria Scenario
EPA performed an RPA based on the proposed water column selenium cri teri on (0.2 μg/L)

. As with the baseline scenario, EPA based the analysi s on the analytical approaches described
in Section 4.2 . The MEC (i.e., 2.6 μg/L) exceed s the proposed criteri on and, therefore, theAPPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 60 discharge has reasonable potential to cause or contribute to the exceedance of the water quality criterion.

W QBELs were calculated according to the procedures described in Section 4.3 and using the
effluent coefficient of variation described in Exhibit A

- 8 8 . Due to an absence of assimilative capacity (i.e., the B exceeded the proposed criteri on ), EPA did not consider dilution, and

instead calculated end

- of

- pipe limitations . Under the p roposed criteri on , the discharger would
have to meet an AMEL of 0.19 μg/L and MDEL of 0.25 μg/L.

Since the MEC is above the QL , EPA assumed that the facility will need to pursue conventional treatment methods to comply with the projected effluent limitations (see
Section 4.4 ). According to the existing permit, the facility does not currently use iron salt chemical addition but does have a media filtration unit process. Therefore, EPA has developed a cost estimate to install a chemical treatment system using the cost curves
described in Section 4.4 . Using a flow rate of 39 mgd, the estimated installed capital cost for the Plant is approximately $13 .0 million and the estimated annual O&M cost is $ 370 ,000.

A.10 Cities of San Jose and San ta Clara

The WWTP for the Cities of San Jose and Santa Clara (Plant; NPDES Permit No. CA0037842) provides advanced

- secondary treatment of wastewater from domestic, commercial, and industrial sources. Ownership of the Plant by the City of San Jose and City of Santa Clara was established under the original Joint Powers agreement. Through a series of additional “Master Agreements for Wastewater Treatment,” five additional satellite collection systems obtained rights to a share of the treatment capacity to trea t their discharged sewage, including the City of Milpitas, Burbank Sanitation District, Cupertino Sanitation District, West Valley Sanitation District, and Santa Clara County Sanitation Districts Nos. 2 and 3. The Plant serves a population of approximately 1.4 million and has an average daily dry weather design flow of 167 mgd and a peak daily wet weather design flow
of 261 mgd

. The Plant discharges to the Artesian Slough.

Treatment Processes
The 2013 Permit Fact Sheet reports that the Plant provides treatm ent consisting of influent screening and grit removal; primary clarification; secondary treatment with an activated sludge process with two parallel aeration basin treatment trains configured and operated for biological nutrient removal (BNR); secondary cl arifiers; dual media gravity filtration; and disinfection with chlorine, ammon ia removal, and dechlorination using sulfur dioxide.

Effluent Data

Exhibit A

- 9 summarizes selenium effluent data for the treated waste water between November

2011 and November 2014.APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 61 Exhibit A

- 9

. Summary of Selenium Effluent Data: San Jose/Santa Clara Water Pollution Control Plant
No. of Observations Effluent Summary (μg/L)

Total Nondetect CV Average Standa rd Deviation Max

52 0 0.486 0.474 0.231 0.7

CV = Coefficient of Variation μg/L = micrograms per liter Concentrations are total recoverable form.

Receiving Water
The facility discharges to South San Francisco Bay. The S FRWQCB utilized the Dumbarton

Brid ge monitoring station (station number BA30) for purposes of background receiving water characterization. The available ambient receiving water monitoring data was collected from the Yerba Buena Island monitoring station between 1993 and 2013. The maximum t otal recoverable selenium concentration observed during this period was 0.628 μg/L.

Baseline Scenario
The permit does not include any WQBELs based on the existing chronic aquatic life
selenium criteri on (i.e., 5 μg/L) and the existing acute aquatic life se lenium criteri on (i.e.,

20 μg/L). EPA performed an RPA based on existing criteria to confirm that no baseline WQBELs would be needed based on the analytical approaches described in Section 4.2 . As
neither the ma ximum effluent nor receiving water concentration exceed the existing criteria, this facility does not have reasonable potential to exceed the existing selenium criteria

. Additionally, since there are no existing selenium WQBELs for this facility, EPA assum es that there is no reasonable potential under the third “trigger” which is activated when a review of other information (beyond the maximum effluent and ambient concentrations) suggests that limits are needed to protect beneficial uses. As such, EPA assum ed that the facility would incur no costs under the baseline scenario.

Proposed Criteria Scenario
EPA performed an RPA based on the proposed water column selenium criteri on (0.2 μg/L). As with the baseline scenario, EPA based the analysis on the analytica l approaches described
in Section 4.2 . The MEC (i.e., 0.7 μg/L) exceed s the proposed criteri on and, therefore, the discharge has reasonable potential to cause or contribute to the exceedance of the water quality criterion.

WQBELs were calculated according to the procedures described in Section 4.3 and using the
effluent coefficient of variation described in Exhibit A

- 9 . Due t o an absence of assimilative capacity (i.e., the B exceeded the proposed criterion ), EPA did not cons ider dilution , and

instead calculated end

- of

- pipe limitations . Under the proposed criteri on , the discharger would
have to meet an AMEL of 0.18 μg/L and MDE L of 0.26 μg/L.APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 62 Since the MEC for the Plant is below the QL, EPA assumed that it is discharging near the projected limitations and that compliance is likely to be achievable using process optimization methods (see Section 4.4 ). EPA developed one

- time costs for implementing a process optimization study of $52,000.

A.11 South Bayside System Authority, Wastewater Treatment Plant

The South Bayside System Authority WWTP (Plant; NPDES Permit No. CA0038369) provides advanc ed secondary treatment of domestic, commercial, and industrial wastewater for the cities of Belmont, San Carlos, Redwood City, and Woodside; and for the service area of the west Bay Sanitary District, which collects wastewater from the cities of Menlo Park

, Atherton, and Portola Valley, and areas of East Palo Alto, Woodside, and unincorporated San Mateo and Santa Clara counties. The service area population is approximately 199,000. The Plant has an average dry weather design flow of 29 mgd , and a peak wet w eather design flow
of 71 mgd , and discharges to Lower San Francisco Bay.

Treatment Processes
The 2012 Permit fact sheet reports treatment processes consist of primary sedimentation, secondary biological treatment through fixed film reactors and aeration ba sins, secondary clarification, mono

- or dual

- media filtration, chlorine disinfection, and dechlorination using

sodium bisulfite.

Effluent Data

Exhibit A

- 10 summarizes selenium effluent data for the treated wastew ater between January
2011 and December 2014.

Exhibit A

- 10

. Summary of Selenium Effluent Data: South Bayside System Authority WWTP
No. of Observations Effluent Summary (μg/L)

Total Nondetect CV Average Standard Deviation Max

35 1 0.591 0.317 0.187 0.77 1

CV = Coefficient of Variation μg/L = micrograms per liter Concentrations are total recoverable form.
1. The max result was detected below the method q uantification l evel and reported as an estimated concentration.

Receivi ng Water
The facility discharges to Lower San Francisco Bay. The S FRWQCB utilized the Yerba Buena Island monitoring station (station number BC 10) for purposes of background receiving water characterization. The available ambient receiving water monitoring data was collected from the Yerba Buena Island monitoring station between 1993 and 2013. The maximum total recoverable selenium concentration observed during this period was 0.39 μg/L.APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 63 Baseline Scenario
The permit does not include any WQBELs based on the existing chronic aquatic life
selenium criteri on (i.e., 5 μg/L) and the existing acute aquatic life selenium criteri on (i.e., 20 μg/L). EPA performed an RPA based on existing criteria to confirm that no baseline WQBELs would be needed based on the analytic al approaches described in Section 4.2 . As neither the maximum effluent nor receiving water concentration exceed the existing criteria, this facility does not have reasonable potential to exceed the existing sel enium criteria

. Additionally, since there are no existing selenium WQBELs for this facility, EPA assumes that there is no reasonable potential under the third “trigger” which is activated when a review of other information (beyond the maximum effluent and ambient concentrations) suggests that limits are needed to protect beneficial uses. As such, EPA assumed that the facility would incur no costs under the baseline scenario.

Proposed Criteria Scenario
EPA performed an RPA based on the proposed water column selenium criteri on (0.2 μg/L)

. As with the baseline scenario, EPA based the analysis on the analytical approaches described
in Section 4.2 . The MEC (i.e., 0.77 μg/L) exceed s the proposed criteri on and, therefor e, the discharge has reasonable potential to cause or contribute to the exceedance of the water quality criterion

.
W QBELs were calculated according to the procedures described in Section 4.3 and using the
efflue nt coefficient of variation described in Exhibit A

- 10 . Due to an absence of assimilative capacity (i.e., the B exceeded the proposed criteri on ), EPA did not cons ider dilution , and
instead calculated end

- of

- pipe li mitations . Under the p roposed criteri on , the discharger would
have to meet an AMEL of 0.17 μg/L and MDEL of 0.30 μg/L.

Since the MEC for the Plant is below the QL, EPA assumed that it is discharging near the projected limitations and that compliance is li kely to be achievable using process optimization methods (see Section 4.4 ). EPA developed one

- time costs for implementing a process optimization study of $52,000.

A.12 Cities of South San Francisco, San Bruno, and t he North Bayside Systems Unit

The WWTP for the Cities of South San Francisco, San Bruno, and the North Bayside Systems Unit (Plant; NPDES No. CA0038130) provides primary and secondary wastewater treatment. The Plant serves an approximate population of 110, 500, and has an average daily dry weather design flow of 13 mgd . The Plant discharges to Lower San Francisco Bay.

Treatment Processes
The 2014 Permit fact sheet reports that treatment consists of bar screens and two grit removal systems, and, during dry we ather, treatment with ferric chloride and polymer for flocculation and primary clarifiers for removal of grease, floating solids, and settable solids. Further treatment includes aeration basins and secondary clarifiers, disinfection with sodiumAPPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 64 hypochlorit e, blending with chlorinated effluent, and chlorine neutralization with sodium bisulfite. During wet weather, when influent flow greatly exceeds the peak secondary treatment capacity (30 mgd design capacity), primary effluent may be routed around the

aerat ion basins and secondary clarifiers and blended with secondary

- treated effluent.

Effluent Data

Exhibit A

- 11 summarizes selenium effluent data for the treated wastewater between June 2011 and July 2015.

Exhibit A

- 11

. Summary of Selenium Effluent Data: South San Francisco/San Bruno Water Quality Control Plant
No. of Observations Effluent Summary (μg/L)

Total Nondetect CV Average Standard Deviation Max

52 1 0.659 1.219 0.804 2.7

CV = Coefficient of Variation μg/L = micrograms per liter Concentrations are total recoverable form.

Receiving Water
The facility discharges to Lower San Francisco Bay. The S FRWQCB utilized the Yerba Buena Island monitoring station (station number BC 10) fo r purposes of background receiving water characterization. The available ambient receiving water monitoring data was collected from the Yerba Buena Island monitoring station between 1993 and 2013. The
maximum total recoverable selenium concentration observ ed during this period was 0.39 μg/L.

Baseline Scenario
The permit does not include any WQBELs based on the existing chronic aquatic life
selenium criteri on (i.e., 5 μg/L) and the existing acute aquatic life selenium criteri on (i.e., 20 μg/L). EPA performed an RPA based on existing criteria to confirm that no baseline WQBELs would be needed based on the analytical approaches described in Section 4.2 . As neither the maximum effluent nor receiving water concentratio n exceed the existing criteria, this facility does not have reasonable potential to exceed the existing selenium criteria

. Additionally, since there are no existing selenium WQBELs for this facility, EPA assumes that there is no reasonable potential under the third “trigger” which is activated when a review of other information (beyond the maximum effluent and ambient concentrations) suggests that limits are needed to protect beneficial uses. As such, EPA assumed that the facility would incur no costs under the baseline scenario.

Proposed Criteria Scenario
EPA performed an RPA based on the proposed water column selenium criteri on (0.2 μg/L)

. As with the baseline scenario, EPA based the analysis on the analytical approaches described
in Section 4.2 . The MEC (i.e., 2.7 μg/L) exceed s the proposed criteri on and, therefore, theAPPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 65 discharge has reasonable potential to cause or contribute to the exceedance of the water quality criterion

.
W QBELs were calculated according to the procedures described in Section 4.3 and using the
effluent coefficient of variation described in Exhibit A

- 11 . Due to an absence of assimilative capacity (i.e., th e B exceeded the proposed criteri on ), EPA did not consider dilution , and

instead calculated end

- of

- pipe limitations . Under the proposed criteri on , the discharger would
have to meet an AMEL of 0.17 μg/L and MDEL of 0.32 μg/L.

Since the MEC is above the QL

, EPA assumed that the Plant will need to pursue conventional treatment methods to comply with the projected effluent limitations (see
Section 4.4 ). According to the existing permit, the Plant does not currently use media filtration but does use iron salts addition in their treatment process. Therefore, EPA has developed a cost estimate to install a media filtration system using the cost curves described
in Section 4.4

. Using a flow rate of 13 mgd, the estimated installed capital cost for the Plant is approximately $ 4 .1 million dollars and the estimated annual O&M cost is $230,000.

A.13 San Francisco Southeast Plant

The C ity and County of San Francisco is the owner and operat or of the Southeast Water Pollution Control Plant (Southeast Plant), North Point Wet Weather Facility (North Point Facility), Bayside Wet Weather Facilities, and the wastewater collection system (collectively Facility; NPDES Permit No. CA0037664). The Faci lity serves eastern San Francisco and portions of Brisbane and Daly City, and has a service population of approximately 580,000. The Southeast Plant provides primary and secondary treatment of combined wastewater and

storm water, and has an average dry wea ther design flow capacity of 85.4 mgd and a wet weather design flow capacity of 250 mgd . The North Point Facility provides primary
treatment of combined wastewater and storm water during wet weather and has a wet weather design flow capacity (primary treat ment only) of 150 mgd . The Bayside Wet Weather Facilities provide equivalent

- to

- primary treatment during wet weather. The Facility discharges to San Francisco Bay.

Treatment Processes
During dry weather, the Southeast Plant provides secondary wastewater tr eatment. The treatment processes include a headworks with coarse and fine bar screens, and grit removal; primary sedimentation tanks; pure oxygen aeration basins; secondary clarifiers; and chlorine contact basins for chlorination using sodium hypochlorite and dechlorination using sodium bisulfite. During wet weather up to 150 mgd receives both primary and secondary treatment; the remaining flow (up to 100 mgd ) receives only primary treatment. The entire volume is disinfected prior to discharge.

The North Po int Facility discharges only during wet weather. The treatment consists of bar screens, sedimentation tanks equipped with skimmers, sodium hypochlorite injection, and dechlorination using sodium bisulfite addition.APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 66 During dry weather the Bayside Wet Weath er Facilities transport wastewater to the Southeast Plant. During wet weather, these structures transfer combined wastewater to the Southeast Plant and, if necessary, the North Point Facility. They also provide storage for more than 120 million gallons of combined wastewater. In the event that the capacities of the Southeast Plant, North Point Facility, and storage/transport structures are exceeded, the combined wastewater receives the equivalent of primary treatment consisting of settling solids with a

ser ies of baffles and weirs that also remove floatable materials prior to discharge.

Effluent Data

Exhibit A

- 12 summarizes selenium effluent data for the treated wastewater between January
2011 and December 2014.

Exhibit A

- 12

. Summary of Selenium Effluent Data: San Francisco Southeast Plant
No. of Observations Effluent Summary (μg/L)

Total Nondetect CV Average Standard Deviation Max

49 3 0.679 0.251 0.171 1.169 1

CV = Coefficient of Variation μg/L = micrograms per liter Concentrations are total recoverable form.
1. The max result was detected below the method q uantification l evel and reported as an estimated concentration.

Receiving Water
The facility discharges to Lower San Franc isco Bay. The S FRWQCB utilized the Yerba Buena Island monitoring station (station number BC 10) for purposes of background receiving water characterization. The available ambient receiving water monitoring data was
collected from the Yerba Buena Island mon itoring station between 1993 and 2013. The maximum total recoverable selenium concentration observed during this period was 0.39 μg/L.

Baseline Scenario
The permit does not include any WQBELs based on the existing chronic aquatic life
selenium criteri on (i .e., 5 μg/L) and the existing acute aquatic life selenium criteri on (i.e., 20 μg/L). EPA performed an RPA based on existing criteria to confirm that no baseline WQBELs would be needed based on the analytical approaches described in Section 4.2 . As neither the maximum effluent nor receiving water concentration exceed the existing criteria, this facility does not have reasonable potential to exceed the existing selenium criteria

. Additionally, since there are no ex isting selenium WQBELs for this facility, EPA assumes that there is no reasonable potential under the third “trigger” which is activated when a review of other information (beyond the maximum effluent and ambient concentrations) suggests that limits are ne eded to protect beneficial uses. As such, EPA assumed that the facility would incur no costs under the baseline scenario.APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 67 Proposed Criteria Scenario
EPA performed an RPA based on the proposed water column selenium criterion (0.2 μg/L)

. As with the baselin e scenario, EPA based the analysis on the analytical approaches described
in Section 4.2 . The MEC (i.e., 1.169 μg/L) exceed s the proposed criteri on and, therefore, the discharge has reasonable potential to cause or contribute to the exceedance of the water quality criterion

.
W QBELs w ere calculated according to the procedures described in Section 4.3 and using the
effluent coefficient of variation described in Exhibit A

- 12 . Due to an absence of assimilative capacity (i.e., the B exceeded the proposed criteri on ), EPA did not consider dilution, and

instead calculated end

- of

- pipe limitations . Under the p roposed criteri on , the disch arger would
have to meet an AMEL of 0.16 μg/L and MDEL of 0.33 μg/L.

Since the MEC is above the QL , EPA assumed that the Plant will need to pursue conventional treatment methods to comply with the projected effluent limitations (see
Section 4.4 ). According to the existing permit, the Plant does not currently have an iron salts addition or media filtration unit processes. Therefore, EPA has developed a cost estimate to

install chemical treatment and a media filtr ation system using the cost curves described in
Section 4.4 . Using a flow rate of 84.5 mgd, the estimated installed capital cost for the Plant is approximately $ 43.7 million and the estimated annual O&M cost is $1. 7 million.

A.14 City of Sunnyvale

The Sunnyvale Water Pollution Control Plant (Plant; NPDES Permit No. CA0037621) provides advanced

- secondary treatment of wastewater from domestic, commercial, and industrial sources from the City of Sunnyvale, Rancho Rincona da, and Moffett Field. The Plant serves a population of approximately 146,000, and has an average dry weather design flow capacity of 29.5 mgd and a peak wet weather design flow of 40 mgd . The Plant discharges to the Moffett Channel, which flows to South S an Francisco Bay via Guadalupe Slough.

Treatment Processes
The 2014 Permit fact sheet reports that treatment includes grinding and grit removal, primary sedimentation, secondary treatment through the use of oxidation ponds, fixed

- growth reactor

nitrificati on, dissolved air flotation, dual media filtration, disinfection with chlorine gas, and
dechlorination with sodium bisulfite.

Effluent Data

Exhibit A

- 13 summarizes selenium effluent data for the treated wastewate r between April 2011 and July 2015.APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 68 Exhibit A

- 13

. Summary of Selenium Effluent Data: Sunnyvale Water Pollution Control Plant
No. of Observations Effluent Summary (μg/L)

Total Nondetect CV Average Standard Deviation Max

70 60 0.629 1 0.407 0.256 1.66 2

CV = Coefficient of Variation μg/L = micrograms per liter Concentrations are total recoverable form.
1. A CV of 0.6 was used to calculate W ater Q uality

- B ased E ffluent L imitation s due to the limited number of detected observatio ns

. 2. The max result was detected below the method Q uantification L evel and reported as an estimated concentration

.

Receiving Water
The facility discharges to South San Francisco Bay. The S FRWQCB utilized the Dumbarton Bridge monitoring station (station number BA 30) for purposes of background receiving water characterization. The available ambient receiving water monitoring data was collected from the Yerba Buena Island monitoring station between 1993 and 2013. The maximum total
recoverable selenium con centration observed during this period was 0.628 μg/L.

Baseline Scenario
The permit does not include any WQBELs based on the existing chronic aquatic life

selenium criterion (i.e., 5 μg/L) and the existing acute aquatic life selenium criteri on (i.e., 20

μg /L). EPA performed an RPA based on existing criteria to confirm that no baseline WQBELs would be needed based on the analytical approaches described in Section 4.2 . As neither the maximum effluent nor receiving water concentration exceed the existing criteria, this facility does not have reasonable potential to exceed the existing selenium criteri a

. Additionally, since there are no existing selenium WQBELs for this facility, EPA assumes

that there is no reasonabl e potential under the third “trigger” which is activated when a review of other information (beyond the maximum effluent and ambient concentrations) suggests that limits are needed to protect beneficial uses. As such, EPA assumed that the facility would in cur no costs under the baseline scenario.

Proposed Criteria Scenario
EPA performed an RPA based on the proposed water column selenium criteri on (0.2 μg/L). As with the baseline scenario, EPA based the analysis on the analytical approaches described
in Sec tion 4.2 . The MEC (i.e., 1.66 μg/L) exceed s the proposed criteri on and, therefore, the discharge has reasonable potential to cause or contribute to the exceedance of the water quality criterion

. Water quality

- ba sed effluent limitations were calculated according to the procedures
described in Section 4.3 and using the effluent coefficient of variation described in Exhibit A

13

. Due to an absence of assimilative capacity (i.e., the B exceeded the proposed criteri on ), EPA did not consider dilution, and instead calculated end

- of

- pipe limitations . Under theAPPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 69 p roposed criteri on , the discharger would have to meet an AMEL of 0.16 μg/L a nd MDEL of 0.33 μg/L.

Since the MEC is above the QL , EPA assumed that the Plant will need to pursue conventional treatment methods to comply with the projected effluent limitations (see
Section 4.4 ). According to the existing permit, the Plant does not currently use iron salts addition but does have media filter in their treatment process. Therefore, EPA has developed a cost estimate to install a chemical treatment system using the cost curves described in
Secti on 4.4 . Using a flow rate of 29.5 mgd, the estimated installed capital cost for the Plant is approximately $10 .3 million and the estimated annual O&M cost is $290,000.

A.15 Bottling Group, LLC

The Bottling Group, Hay ward Plant (Plant; NPDES Permit No. CA0030058) manufactures, bottles, and distributes drinking water and soft drinks. The Pla nt uses potable water supplied by the City of Hayward, which undergoes additional treatment in the manufacturing process.

The treat ment system is capable of treating up to 900,000 gallons of supply water with an 80% recovery rate. The 20% of supply water not recovered is discharged in the RO concentrate stream. The Plant has a maximum design treatment capacity of 900,000 gallons per d ay, and a permitted average monthly discharge rate of 143,000 gallons per day. The Plant discharges RO concentrate to the Alameda County Besco Pump Station, which pumps the effluent to the Alameda County flood control and Water Conservation District Flood Channel (the tidally

- influenced downstream section of Old Alameda Creek) which flows to Lower San Francisco Bay.

Treatment Processes
The 2013 Permit fact sheet reports that treatment to filter supply water consists of anthracite and greensand filters to re move iron and manganese, 5

- micrometer cartridge

- filters, and finally RO membranes. The Plant adds chemical scale and fouling inhibitors to prevent fouling of the RO membranes and a dechlorinating agent.

Effluent Data

Exhibit A

- 14 summarizes selenium effluent data for the treated wastewater from April 9,

2015.

Exhibit A

- 14

. Summary of Selenium Effluent Data: Bottling Group, Hayward Plant
No. of Observations Effluent Summary (μg/L)

Total Nondetect CV Average Standard Deviation Max

1 1 N/A 1 <0.2 N/A <0.2

CV = Coefficient of Variation N/A = Not Available μg/L = micrograms per liter Concentrations are total recoverable form.
1. 1. A CV of 0.6 was used to calculate W ater Q uality B ased E f fluent L imitation s due to the limited number of detected observations

.APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 70 Receiving Water
The facility discharges to Alameda Creek, which flows into San Francisco Bay. The Discharger collects grab samples from Alameda Creek immediately upstream of the

disc harge location for purposes of background receiving water characterization. The available ambient receiving water monitoring data was collected from Alameda Creek on April 9, 2015. The total recoverable selenium concentration observed during this period wa s 2.5 μg/L.

Baseline Scenario
The permit does not include any WQBELs based on the existing chronic aquatic life

selenium criteri on (i.e., 5 μg/L) and the existing acute aquatic life selenium criteri on (i.e., 20 μg/L). EPA performed an RPA based on existing criteria to confirm that no baseline WQBELs would be needed based on the analytical approaches described in Section 4.2 . As neither the maximum effluent nor receiving water concentration exceed the existing cri teria, this facility does not have reasonable potential to exceed the existing selenium criteri a

. Additionally, since there are no existing selenium WQBELs for this facility, EPA assumes that there is no reasonable potential under the third “trigger” which is activated when a review of other information (beyond the maximum effluent and ambient concentrations) suggests that limits are needed to protect beneficial uses. As such, EPA assumed that the facility would incur no costs under the baseline scenario.

Proposed Criteria Scenario

E PA performed an RPA based on the proposed water column aquatic life selenium criteri on (0.2 μg/L). As with the baseline scenario, EPA based the analysis on the analytical approaches described in Section 4.2 . Selenium was not detected in the available effluent monitoring data. Additionally, since there are no existing selenium WQBELs for this facility, EPA assumes that there is no reasonable potential under the third “trigger” which is activated when a review of other information (beyond the maximum effluent and ambient concentrations) suggests that limits are needed to protect beneficial uses. As such, EPA assumed that the facility would incur no costs under the proposed criteria

.
A.16 San F rancisco International Airport

The San Francisco International Airport, Mel Leong Treatment Plants (Plants; NPDES Permit No. CA0038318) include the Industrial Plant, which treats industrial wastewater from maintenance shops and vehicle washing, and first

- f lush stormwater runoff from industrial areas; and the Sanitary Plant, which includes a collection system and treats sanitary wastewater from airplanes and airport facilities, including terminal restrooms, hangars, restaurants, and shops. In emergency situa tions, either plant may be used to store or treat flows, spills, or overflows that would normally flow to the other plant to ensure that all wastewater is adequately treated. The service population for the Plants is estimated at 10,000.
The Plants have a c ombined facility design flow of 2.2 mgd , and discharge to the Lower San Francisco Bay.APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 71 Treatment Processes
The Sanitary Plant treatment operations consist of punched plate bar screens, grit removal, flow equalization, and chlorination. Solids from the Sani tary Plant are treated by gravity belt thickening and anaerobic digestion before dewatering by belt filter presses or air drying using sludge drying beds.

Treatment from the Industrial Plant includes flocculating the combined industrial wastewater and any incoming first flush storm water, dissolved air floatation, pH adjustment (as needed), aerobic biological treatment via trickling filter, secondary clarification, and chlorination. The Plant can divert up to 0.72 mgd of the effluent from the chlorination t ank to tertiary filters. Sludge and scum are pumped to sludge beds for dewatering, and filtrate drained form the sludge is pumped back to the trickling filter for treatment.

Chlorinated wastewater from both plants is combined for dechlorination at the Sou th San Francisco Wastewater Treatment Facility

Effluent Data

Exhibit A

- 15 summarizes the available selenium effluent data for the treated wastewater
between December 2010 and October 2015.

Exhibit A

- 15

. Summary of Selenium Effluent Data: San Francisco International Airports, Mel Leong Treatment Plants
No. of Observations Effluent Summary (μg/L)

Total Nondetect CV Average Standard Deviation Max

2 0 0.168 1 0.165 0.028 0.172

CV = Co efficient of Variation μg/L = micrograms per liter Concentrations are total recoverable form.
1. A CV of 0.6 was used to calculate W ater Q uality B ased E ffluent L imitation s due to the limited number of detected observations

.

Receiving Water
The facility discharges to Lower San Francisco Bay. The S FRWQCB utilized the Yerba Buena Island monitoring station (station number BC 10) for purposes of background receiving water characterization. The available ambient receiving water monitoring data was

collected fr om the Yerba Buena Island monitoring station between 1993 and 2013. The maximum total recoverable selenium concentration observed during this period was 0.39 μg/L.

Baseline Scenario
The existing permit (Permit No. R2

- 2013

- 0011; NPDES Permit No. CA0038318) includes an

AMEL of 2.9 μg/L and a MDEL of 8.8 μg/L based on the existing chronic aquatic life

selenium criteri on (i.e., 5 μg/L) and the existing acute aquatic life selenium criteri on (i.e., 20 μg/L). EPA performed an RPA based on existing criteria using m ore recent data based on theAPPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 72 analytical approaches described in Section 4.2 . As neither the maximum effluent nor receiving water concentration exceed the existing criteria, this facility does not have
reasonable potential to exceed the existing selenium criteria . Since EPA found no reasonable potential using the most recent data and because the monitoring data demonstrated performance well below the existing WQBELs, EPA assumed that the facility would incur no

co sts under the baseline scenario.

Proposed Criteria Scenario
EPA performed an RPA based on the proposed water column selenium criteri on (0.2 μg/L). As with the baseline scenario, EPA based the analysis on the analytical approaches described
in Section 4.2 . The MEC (i.e., 0.172 μg/L) exceed s the proposed criteri on and, therefore, the discharge has reasonable potential to cause or contribute to the exceedance of the water quality criterion

.
W QBELs were calculated a ccording to the procedures described in Section 4.3 and using the
effluent coefficient of variation described in Exhibit A

- 15 . Due to an absence of assimilative capacit y (i.e., the B exceeded the proposed criterion ), EPA did not consider dilution, and

instead calculated end

- of

- pipe limitations . Under the p roposed criteria , the discharger would
have to meet an AMEL of 0.16 μg/L and MDEL of 0.33 μg/L.

Since the MEC for th e Plants is below the QL, EPA assumed that it is discharging near the projected limitations and that compliance is likely to be achievable using process optimization methods (see Section 4.4 ). EPA developed one

- time costs for implementing a process optimization study of $52,000.APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 73 

### Appendix B

- Potential Compliance Costs, 7% Discount Rate

This appendix summarizes the point source compliance costs using a 7 percent discount rate as an alternative to the main analysis, presente d in Section 4.4.2 , which uses a 3 percent
discount rate. For more details on the methodology for these analyses, see Section 4

.
Exhibit B

- 1 summarizes the one

- time (capital or process optimization) costs, O&M costs, and total annual cost for each of the identified facilities likely to have a control increment under the proposed selenium criterion. Exhibit B

- 2 summarizes the results of the sensitivity analysis (which includes additional costs for denitrification filters; as described in Section

6.3 ).APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 74 Exhibit B

- 1. Treatment and Estimated Cost Increment for Affected Facilities , 7% Discount Rate
NPDES Number Facility Name Capacity (mgd) MEC

(μg/L) AMEL

(μg/L) One

- Time

Cost O&M Cost Total Annual Cost
Municipal Facilities

CA0037621 City of Sunnyvale 29.5 1.66 0.16 $10,327,000 $293,000 $1,268,000

CA0037842 City of San Jose/Santa Clara 167 0.7 0.18 $52,000

-- $4,900

CA00378 34 City of Palo Alto 39 2.6 0.19 $13,033,000 $367,000 $1,597,000

CA0038369 South Bayside System Authority 29 0.77 0.17 $52,000

-- $4,900

CA0037541 City of San Mateo/Foster City Estero 15.7 0.53 2 0.18 $52,000

-- $4,900

CA0038636 East Bay Regional Park Di strict,

Hayward Marsh 2.6 0.55 0.16 $52,000

-- $4,900

CA0037532 City of Millbrae and North Bayside

Systems Unit 3 0.48 2 0.16 $52,000

-- $4,900

CA0037788 City of Burlingame and North Bayside

Systems Unit 5.5 1 0.17 $6,194,000 $262,000 $847,000

CA0038130 Cities of South San Francisco, San

Bruno, and North Bayside Systems Unit 13 2.7 0.17 $4,126,000 $229,000 $618,000

CA0038008 City of Livermore and EBDA 8.5 1.7 0.16 $7,617,000 $315,000 $1,034,000

CA0037613 Dublin San Ramon Services District,

LAWMA, and EB DA 20.2 4.7 0.15 $13,169,000 $521,000 $1,764,000

CA0037869 East Bay Dischargers Authority, Joint

Outfall 107.8 1.2 0.17 $54,734,000 $2,067,000 $7,234,000

CA0037664 San Francisco Southeast Plant 84.5 1.2 2 0.16 $43,679,000 $1,655,000 $5,778,000

CA0038440 East Bay Municipal Utility District, Wet

Weather 158

-- -- $0 $0 $0

Subtotal $153,139,000 $5,709,000 $20,164,000

Industrial Facilities

CA0038318 San Francisco International Airport 2.2 0.1719 0.16 $52,000

-- $4,900

Subtotal $52,000

-- $4,900

Total $15 3,191,000 $5,709,000 $20,169,000APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 75 Exhibit B

- 1. Treatment and Estimated Cost Increment for Affected Facilities , 7% Discount Rate
NPDES Number Facility Name Capacity (mgd) MEC

(μg/L) AMEL

(μg/L) One

- Time

Cost O&M Cost Total Annual Cost mgd = million gallons per day μg/L = micrograms per liter
1. One

- time costs annualized over 20 years using a 7 percent discount rate; see Section 4.4.2 for annualized results us ing a 3 percent discount

rate. 2. Detected, but Not Quantified (DNQ); i.e., selenium was detected in the sample but at levels too low to accurately quantify ; the reported concentration is a best estimate as determined by the laboratory instrumentation and methodology.APPENDIX

Abt Associ ates Cost of Compliance with Selenium Criteria in San Francisco Bay and Delta ▌ pg. 76 Exhibit B

- 2: End

- of

- Pipe Treatment Costs Sensitivity Analysis , 7% Discount Rate

NPDES Number Facility Name Total Annual Cost 1

Original 2 Including Denitrification Filter
Municipal Facilities

CA0037621 City of Sunnyvale $1,268,000 $5, 704,000
CA0037842 City of San Jose/Santa Clara 3 $4,900 $4,900

CA0037834 City of Palo Alto $1,597,000 $7,461,000

CA0038369 South Bayside System Authority 3 $4,900 $4,900

CA0037541 City of San Mateo/Foster City Estero 3 $4,900 $4,900

CA0038636 East Bay Re gional Park District,

Hayward Marsh 3 $4,900 $4,900

CA0037532 City of Millbrae and North Bayside

Systems Unit 3 $4,900 $4,900

CA0037788 City of Burlingame and North Bayside

Systems Unit $847,000 $1,674,000

CA0038130 Cities of South San Francisco, San

Brun o, and North Bayside Systems
Unit $618,000 $2,573,000

CA0038008 City of Livermore and EBDA $1,034,000 $2,312,000

CA0037613 Dublin San Ramon Services District,

LAWMA, and EBDA $1,764,000 $4,801,000

CA0037869 East Bay Dischargers Authority, Joint

Outfall $7,234,000 $23,444,000

CA0037664 San Francisco Southeast Plant $5,778,000 $18,484,000

CA0038440 East Bay Municipal Utility District, Wet

Weather $0 $0

Subtotal $20,164,000 $66,477,500

Industrial Facilities

CA0038318 San Francisco International Airport 3 $4,900 $4,900

Subtotal $4,900 $4,900

Total $20,169,000 $66,482,400 1. For plants discharging at levels above the most stringent quantitation level (1 μg/L), EPA assumed that POTWs will pursue conventional treatment methods to comply with the projected effluent limitations. POTWs operating below the quantitation level are discharging near the projected limitations and EPA has assumed that compliance is likely to be achievable using process optimization methods.
2. One

- time costs annualized over 20 years using a 7 percent discount rate; for costs annualized using a 3 percent discount rate, see Section 6.3

. 3. End

- of

- pipe treatment (including denitrification filter) is unnecessary for this facility, even
conside ring alternative analytical detection limits.