ANALYSIS OF THE POTENTIAL BENEFITS
RELATED TO IMPLEMENTATION OF THE
CALIFORNIA TOXICS RULE
U.S. Environmental Protection Agency
Office of Policy, Planning and Evaluation
Office of Sustainable Ecosystems and Communities
401 M. Street SW
Washington, D.C. 20460
and
U.S. Environmental Protection Agency
Region IX
75 Hawthorne Street
San Francisco, CA 94105
June 1997
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ACKNOWLEDGMENTS
This report was prepared under the direction of Christine Ruf, U.S. EPA, Office of Policy,
Planning and Evaluation, Office of Sustainable Ecosystems and Communities, Washington, D.C.,
and Diane Frankel, U.S. EPA, Region IX. Industrial Economics, Incorporated performed much of
the analysis and technical evaluation presented in this document. Many thanks go to the insights and
encouragement offered by EPA staff during all phases of the report. In particular we wish to thank
Brad Crowder for contributing his ornithological wisdom, Gary Wolinsky and Molly Whitworth for
their advice on endangered species, Phil Woods for knowing (and sharing) everything there is to
know about water quality criteria and standards, Keith Sappington for providing quantitative
ecological analyses, Erik Beck and Gary Sheth for their contributions to Chapter 7, Matthew
Mitchell for specific comment and review of previous drafts, Cheryl Henley for preparing many of
the maps presented here, and Lisa A. Harris for her work on Chapter 6. Finally we would like
specifically to thank the following staff at Industrial Economics for their assistance, technical
support, and analysis provided during the entire project: Bob Black, Mark Curry, Brian Morrison,
Matt Schwartz, Eric Ruder, and Andy Schwarz.
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TABLE OF CONTENTS
EXECUTIVE SUMMARY CHAPTER 1
Introduction 1-1
Methodologies 1-2
Results 1-9
CHARACTERIZATION OF BASELINE WATER QUALITY ............ CHAPTER 2
Introduction 2-1
Data and Methodology 2-5
Statewide Assessment of Toxic Water Pollution 2-9
Regional Assessment of Toxics Impairment 2-15
Conclusions 2-20
References 2-22
ANGLER HEALTH RISK ASSESSMENT CHAPTER 3
Introduction 3-1
Methodology For Estimating Recreational Angler Risk 3-14
Freshwater Anglers 3-19
San Francisco Bay Anglers 3-30
Uncertainties ; 3-42
Environmental Justice 3-45
Potential Health Benefits to Recreational Anglers Associated With
Implementation of the California Toxics Rule 3-48
Conclusions: Baseline Risks and Post-CTR Benefits to Recreational Anglers 3-55
References 3-62
ECONOMIC BENEFITS CHAPTER 4
Introduction 4-1
Methodology 4-3
Recreational Fishing Benefits Associated With
Meeting Water Quality Criteria 4-8
Non-Use Values 4-21
Human Health Benefits 4-24
Other Benefits Not Quantified 4-25
References 4-30
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TABLE OF CONTENTS
(continued)
ECOLOGICAL BENEFITS CHAPTERS
Introduction 5-1
Methodology 5-8
Ecological Effects of Toxic Pollutants and Affected Resources 5-11
Toxic Pollutants and Threatened and Endangered Species 5-42
Illustrative Ecological Risk Analysis:
The Species Sensitivity Distribution Approach 5-52
Population, Cpmmunity, and Ecosystem Impacts 5-53
Toxic Reductions and Potential Ecological Benefits of the California Toxics Rule .. 5-66
Limitations 5-68
References 5-70
CASE STUDIES OFECOLOGICAL BENEFITS CHAPTER6
Introduction 6-1
San Francisco Bay 6-1
Salton Sea 6-35
References ' 6-44
APPORTIONING BENEFITS TO POINT SOURCES CHAPTER 7
Introduction 7-1
Determination of Point Source Contributions to Toxics Loadings 7-3
Apportionment of Economic Benefits 7-19
Apportionment of Recreational Angler Health Benefits 7-24
Apportionment of Ecological Benefits 7-33
Uncertainties and Limitations 7-37
References 7-42
APPENDICES:
A: 1994 Assessment of California Water Quality, by Region, for Toxics
B: California Fish Tissue Contaminant Data Bases
C: Fish Consumption Rates
D: Supplemental Information for the Angler Risk Assessment
E: Ecology and Ecological Effects
F: Loadings Data Used in Apportionment Analysis
G: Comparison of Possible Point Source Industrial PCB Discharges in California
and the Great Lakes Region by SIC Code
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EXECUTIVE SUMMARY CHAPTER 1
INTRODUCTION
California is one of the most biologically diverse areas in the world. Within its 160,000 square
miles of land, and hundreds of thousands of acres and miles of water resources, California harbors
more unique plants and animals than any other state in the nation. The diversity of climates,
landscapes, and habitats, and all the barriers to migrations such as mountains and deserts, have led
over thousands of years to the evolution of a large number of unique species and varieties of plants
and animals, many of which are found only in California. Many of these species exist in or are
dependant upon aquatic resources during all or a part of their lives, and consequently may be
adversely affected by toxic discharges to surface waters.
Clean Water Act (CWA) Section 303 requires states to adopt water quality criteria for certain
toxic pollutants, and authorizes EPA to promulgate such criteria for states that fail to meet the
requirements of the Act. A recent court decision has invalidated the Section 303 toxic pollutant
criteria adopted by the State of California. As a result, EPA is drafting a proposed federal rule to
define allowable levels of toxic pollutants for inland waters and enclosed bays and estuaries within
California. The criteria EPA intends to promulgate include those for which guidance values under
CWA Section 304(a) have been issued and which were not already promulgated for California in the
National Toxics Rule (40 CFR Part 131 et seq.). The criteria are included as Attachment 1 to this
chapter.
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The toxic pollutant criteria proposed for California inland freshwater bodies and enclosed bays
and estuaries are designed to protect both human health and aquatic/wildlife species, and are expected
to yield significant ecological and human health benefits when implemented by the State. In addition,
reducing toxics to achieve the criteria is expected to result in increased economic benefits associated
with both direct and passive human use of estuarine and freshwater resources. While time and
resource constraints did not permit detailed analysis of all such benefits for the entire State, our
analysis includes a comprehensive qualitative discussion of the rule's potential benefits. In addition,
we have developed some quantitative evaluations of a subset of benefits, some of which have been
monetized.
METHODOLOGIES
Baseline Water Quality Conditions
We estimated baseline water quality conditions for fresh and estuarine waters throughout the
State by evaluating California's Water Quality Assessment (WQA) database, developed and
maintained by the State Water Resources Control Boards. The WQA is a compilation of data from
the State's nine regional Water Quality Control Boards and is organized by region and by waterbody
type. It contains a range of information on surface water pollution, including the pollutants that
adversely affect water quality in bodies of water that have been evaluated, the sources of pollution,
the beneficial uses impaired, and an overall rating of water quality.1 The State relies on the WQA to
develop the biennial water quality report required by §305(b) of the Clean Water Act. We used the
1994 WQA data to evaluate baseline water quality conditions in each of California's nine water
regions as well as to evaluate water quality conditions in selected water bodies such as San Francisco
Bay, the Bay Delta, the Sacramento River, and the Salton Sea.2 A summary of the baseline conditions
by region is presented in Exhibit 1-1.
1 Currently, not all of California waters are assessed. Approximately 90 percent of all streams
and rivers, 23 percent of lakes and reservoirs, and 46 percent of wetlands in the State have not been
evaluated for water quality impacts.
2 Water Quality Assessment, State Water Resources Control Board, 1994. Due to the need
for assessment lead time, it was not possible to use updated 1996 information.
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Exhibit 1-1
SUMMARY OF CALIFORNIA REGIONAL
WATER QUALITY ASSESSMENTS
Region
Areal Extent of Toxics
Impairment
Pollutants of
Concern
Primary Pollutant
Sources
Key Waterbodies
Affected
Natural Resources and
Beneficial Uses Affected
Region 1: North
Coast Region
55% of bays (16,500 acres); minor
impairment of other water bodies
Metals, pesticides
Mix of point sources
(municipal and industrial
effluent) and nonpoint
sources (agriculture and
urban runoff)
Arcata Bay, Humboldt Bay
Recreation, municipal supply, wildlife habitat (e.g.,
salmon); fish spawning and/or migration; rare and
endangered species
Region 2: San
Francisco Bay
Large areas impaired by toxics,
including 70% of bays (200,000 acres);
60% of wetlands (57,000 acres); 39%
of rivers (244 miles)
Metals, trace elements,
priority organics
Urban runoff and other
nonpoint sources affect
largest areas; some
impairment from municipal
and industrial point sources
San Francisco Bay (Lower,
Central, South), Suisun
Marsh
Recreation, commercial fishing; wildlife habitat, fish
migration and/or spawning; rare and endangered
species; elevated concentrations of toxics in shellfish,
fish, and waterfowl; fish consumption advisories for
several waterbodies, including San Francisco Bay,
Lake Herman, Guadalupe Reservoir, and others;
waterfowl consumption advisory.
Region 3: Central
Coast Region
47% of lakes (11,700 acres); 36% of
estuaries (1,700 acres); minor
impairment of rivers and bays
Metals, pesticides
Agriculture, mining,
unspecified nonpoint
sources
Morro Bay, Carpinteria
Marsh, Elkhorn Slough
Recreation, wildlife habitat; fish consumption
advisory for Nacimiento River; fish migration and/or
spawning; rare and endangered species
Region 4: Los
Angeles Basin
Over 90% of bays and estuaries
impaired (16,000 acres); minor
impairment of rivers and lakes
Pesticides, priority
organics, trace
elements
Mix of point sources
(municipal treatment,
"other" point sources) and
nonpoint sources
(agriculture, hydrological
modification, and urban
runoff)
Mugu Lagoon
San Gabriel River (lower),
Los Angeles River (upper)
Recreation, commercial shellfishing, navigation,
wildlife habitat; fish migration and/or spawning; rare
and endangered species; fish consumption advisories
for Lake Nacimiento and Los Angeles Harbor
Region 5: Central
Valley Region
Large areas impaired by toxics,
including 100% of estuaries (48,000
acres); 23% of lakes (120,000 acres);
21% of rivers (1,200 miles)
Metals, trace elements
Agriculture, mining; smaller
areas affected by municipal
treatment, urban runoff,
storm sewers, and other
nonpoint sources
Delta Waterways, Clear
Lake, American River,
Feather River, Sacramento
River, Grasslands Marshes,
Shasta Lake
Municipal supply, agriculture, recreation, wildlife
habitat; fish migration and/or spawning; rare and
endangered species; fish consumption advisories for
Clear Lake, Lake Berryessa, and Grasslands Area;
waterfowl consumption advisory for Grasslands Area
Region 6:
Lahontan Region
34% of saline lakes (66,000 acres);
19% of lakes (36,000 acres; 13% of
rivers (372 miles)
Metals, trace elements,
priority organics
Naturally occurring levels
of metal sand trace
elements; lesser areas
affected by agriculture, land
development, and mining
Eagle Lake, Owens River,
Truckee River, Honey Lake
Recreation, municipal supply (exported); fish
migration and/or spawning; rare and endangered
species
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Exhibit 1-1
SUMMARY OF CALIFORNIA REGIONAL
WATER QUALITY ASSESSMENTS
Region
Region 7:
Colorado River
Basin
Region 8: Santa
Ana River Basin
Region 9: San
Diego Basin
Areal Extent of Toxics
Impairment
60% of rivers ( 1 ,400 miles) impaired;
220,000 acres of saline lake (Salton
Sea) .
Over 90% of bays and estuaries
impaired (4,000 acres); 27% of lakes
(4,000 acres)
14% of estuaries; minor impairment of
other waterbodies
Pollutants of
Concern
Pesticides, trace
elements
Metals, pesticides
Metals, pesticides,
priority organics, trace
elements
Primary Pollutant
Sources
Agriculture
Primarily nonpoint sources
including agriculture, urban
runoff, and land
development
Estuaries affected by land
disposal; other waterbodies
affected by diverse mix of
point and nonpoint sources
Key Waterbodies
Affected
Salton Sea
Upper Newport Bay
San Diego Bay, Tijuana
River Estuary
Natural Resources and
Beneficial Uses Affected
Recreation, wildlife habitat; rare and endangered
species; fish consumption advisory for Salton Sea
Recreation, municipal supply, wildlife habitat, fish
spawning and/or migration
Recreation, commercial fishing and shellfishing,
wildlife habitat, fish spawning and/or migration, rare
and endangered species
Source: EPA analysis of 1994 California Water Quality Assessment data base; State of California data on fish and waterfowl consumption advisories. Some key waterbodies impaired by toxics may have
changed since the 1994 analysis, but more recent data were not used in the preparation of this report due to time constraints.
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It is important to note that information on the extent to which California surface waters
currently meet the proposed toxic water quality criteria is incomplete. Water quality conditions in
many State waters have not been fully assessed, and assessments of waters that have been evaluated
often do not contain monitoring data that is extensive or detailed enough to determine whether the
waterbody meets all of the proposed criteria. According to water quality experts from U.S. EPA and
the State of California, extrapolating information from the WQA to all waters in the State may create
a bias towards overestimating the extent of toxics contamination Statewide. Key assumptions
include: assuming that the percentage of toxics impairment found in assessed waters is the same as
the percentage of toxic impairment of waters throughout the State; assuming that waters rated as
medium impaired waters (those which partially support their uses) were counted together with those
rated as poor impaired waters (those which do not support their uses); and that waters listed as
impaired in one data base, and associated with toxics in a second data base, were considered waters
impaired by toxics.
Although the consensus of the U.S. EPA and State experts is that the above assumptions may
create a bias toward overestimating toxics contamination Statewide, these experts also believe that
certain other assumptions used in the analysis may create a bias in underestimating the extent of
toxics contamination. For example, the assumption that the type and scope of all toxics of concern
in all State waters appear in the WQA data base may underestimate the extent of toxics impairment
because of the infrequency of ambient monitoring throughout the State, or because of the difficulty
of detecting the ambient concentrations of certain toxic pollutants when their water quality criteria
fall below the minimum detection limit. Consequently, because of all of the uncertainties associated
with the WQA data base, State of California and U.S. EPA experts advise against an attempt to
quantitatively estimate the magnitude of the bias in either direction.
Human Health
The bioaccumulation of toxic pollutants in aquatic life and water-dependant wildlife can pose
a significant health risk to those who eat fish and waterfowl. This is particularly true for recreational
or subsistence anglers, who tend to consume greater quantities offish than the average person and
may catch fish from areas that are highly contaminated. A benefit of the proposed rule is a reduction
in the concentration of pollutants in fish and waterfowl tissue, with a resulting decrease in risk to
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recreational/subsistence anglers and waterfowl hunters. We quantified health benefits for recreational
anglers by comparing risks from the consumption of fish under baseline conditions to those that
would prevail post-rule.
The calculation of baseline risk (excess cancers and/or non-carcinogenic health effects) was
developed using current contaminant levels in fish tissue samples collected from San Francisco Bay
and freshwater sport fisheries throughout California. The potential health benefits of the rule have
been developed by estimating the potential baseline health risks to anglers consuming contaminated
fish, and then comparing these to health risks predicted to occur post-rule, assuming waters meet the
CTR criteria based on a cancer risk level of 1 x 10"6 for the general population. Since the State of
California has the flexibility to choose criteria based on less stringent cancer risk levels, we also
evaluate the potential health benefits to anglers based on a risk level of 1 x 10~5.
We did not estimate health benefits for subsistence anglers or family members of recreational
anglers who might consume contaminated fish. We also were not able to quantify the health benefits
associated with consumption of contaminated waterfowl. Finally, we may have underestimated some
of the angler human health benefits associated with meeting the CTR criteria because we have not
considered the health risks associated with consuming commercially caught fish.
Economic Benefits
From an economic perspective, implementation of water quality programs to achieve the
proposed criteria will reduce toxics contamination of aquatic resources in California and will result
in avoided costs of illness (cancer and noncancer), and increased protection and restoration of
currently affected natural resources that provide valuable services to the 31 million inhabitants of
California. These resources support recreational uses such as fishing, wildlife viewing, hiking,
hunting, and swimming. These resources also support commercial fishing, serve as sources of
drinking water, and provide process and cooling water to industry.
In addition to use values, the total value of an aquatic system also includes values that
individuals hold for the resource unrelated to their current use of goods and services provided by the
resource. Individuals may value the existence of the aquatic system or the availability of the goods
and services provided by the system, even if they do not use the goods and services themselves.
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Non-use values may also stem from the desire to preserve the resource for future generations
(bequest value) or from a philanthropic sense of environmental responsibility. Reducing toxic
contamination to meet the toxic water quality criteria is expected to increase these non-use values.
Economists define the primary economic benefits provided by a natural resource as the sum
of individuals' willingness to pay for the services the resource provides, net of any costs associated
with enjoying those services. Many natural resource services, however, are not traded in the
marketplace and therefore, willingness to pay information cannot be directly obtained from observed
behavior. Instead, economists have developed a variety of techniques to value natural resource
services, or to estimate the economic benefits of improvements in environmental quality. These
methods attempt to determine individuals' willingness to pay for natural resource services directly,
through survey research, or indirectly, through the examination of behavior in related markets. They
include such techniques as contingent valuation; analysis of added or avoided costs caused by changes
in environmental quality; and revealed preference methods, such as travel cost analysis and hedonic
property value studies.
While each of these methods was potentially applicable to the California benefits assessment,
available resources did not support original research. In lieu of such analysis, we have estimated
baseline and post-rule economic benefits using a benefits transfer approach: the application of
benefits estimates, contingent valuation studies, functions, data, and/or models developed in other
areas to estimate benefits in a similar but alternative context. Specifically, we use the benefit transfer
method to value improvements in recreational fishing as well as to estimate non-use values. The
benefit transfer method is similar to the approach used by EPA in the Regulatory Impact Analysis for
the Agency's Great Lakes Water Quality Guidance, which establishes numeric criteria for toxic
pollutants similar to those proposed for California, as well as numerous other economic benefit
analyses. In this assessment, where accurate or complete data are not available for each of the water
resources evaluated, we have applied as set of reasonable assumptions to obtain lower and upper
bound estimates that represent a realistic range of potential benefits likely to occur, rather than
developing a single point estimate of benefits.
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Ecosystem Benefits
A great proportion of the toxic pollutants addressed in this rule pose relatively high morbidity
and mortality risks to both aquatic and aquatic-dependant organisms. Time and data constraints
precluded performing site, regional and state-wide quantitative ecological risk assessment for each
constituent and water resource covered by todays rule. We therefore evaluated a range of qualitative
and quantitative indicators of ecosystem benefits that are likely to accrue from reducing toxic
contamination to surface waters and sediments to meet water quality criteria. We utilized data on
selected constituent-specific adverse ecological effects at the individual, population, and community
level (e.g., decreased direct mortality, reduced breeding success, decreased productivity) that are
likely to be occurring in California, as well as site and area-specific data on adverse species impacts.
We discuss in somewhat greater detail the ecological benefits expected to accrue in San Francisco
Bay and The Salton Sea. In addition, we quantify the areal extent of waters that are likely to
experience improvements in ecological quality. These areas include waters that support fish spawning
and migration; State and Federal rare, threatened and/or endangered species; and terrestrial and
aquatic wildlife. We also estimated the potential hazard for piscivorous wildlife consuming mercury-
contaminated fish in selected areas in California based on fish tissue data from throughout the State.
Finally, we present and apply one approach for assessing changes in ecological risk associated with
potential reductions of copper in parts of the Sacramento River. We do not value or monetize these
ecosystem benefits because of the inherent complexity and uncertainty associated with most of the
valuation methods.
Apportionment to Point Sources
The benefits estimates in this report represent the total benefits expected to occur once water
quality control programs have been fully implemented by California and water quality criteria have
been achieved for toxic pollutants. However, the cost analysis for the CTR focused on point sources
typically subject to numeric water-quality based NPDES permits. Consequently, EPA did not
calculate costs for any program for which it does not have numeric water quality-based effluent limits
in effect. Although EPA has focused on calculating costs to NPDES permitted facilities, EPA
believes that a comprehensive watershed approach that addresses all significant sources of pollutants
will often present more cost-effective approaches. Because EPA is developing estimates of costs
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associated with implementation of the proposed water quality criteria, it is important to estimate the
benefits specifically associated with reducing toxic discharges from point sources. This will allow a
more consistent comparison of costs and benefits.
To apportion benefits to point sources, we first use available data to estimate the percent of
all toxics loadings coming from point sources. We then adjust this figure by the percentage reduction
in point source loadings expected to occur when the toxics criteria are fully implemented by the state
(based on the cost analysis for the proposed rule). Finally, we use this information to scale the health,
economic, and ecological benefits developed in earlier chapters.
Throughout the apportionment analysis, we define point sources to include NPDES permitted
sources — publicly owned treatment works (POTWs), industrial dischargers, and active/inactive
mines.3 Although stormwater discharges are regulated as a point source, they are not included as a
point source category in this analysis because they are not explicitly addressed in the available data
and because they are typically not subject to numeric water quality-based effluent limits. Although
data sources vary, "other" sources generally include urban runoff, runoff from forestry and
agriculture, rangeland runoff, and atmospheric deposition.
RESULTS
Human Health Benefits
We estimate that human health risks associated with anglers eating contaminated sport fish
may be reduced substantially if health risk target levels associated with proposed water quality criteria
in California fisheries are achieved. These benefits would accrue to the estimated 125,000
3 While mines are considered to be a point source subject to NPDES under the Clean Water
Act, not all mines in California have been permitted. Loadings reductions for mines (both active and
inactive) with major NPDES permits have been estimated, and are used in this analysis, although they
do not represent the entire universe of mines in the State. Consequently, some of the benefits
described here may not occur in the same time frame as benefits associated with other point sources
evaluated (POTWs and industrial dischargers).
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anglers fishing in San Francisco Bay and 2.2 million freshwater anglers. Similar population benefits
may accrue for an additional 500,000 to 600,000 saltwater anglers in other California estuaries, but
specific risk estimates for these anglers were not calculated.
Summary of Potential Cancer Health Benefits to Anglers
Our analysis of human health risks based on a risk level of 1 x 10"6 for the general population
supports the following conclusions:
• Cancer risks for freshwater anglers would be reduced by 91 percent.
• The population cancer risk for freshwater anglers would decrease from
between 5 and 11 cases per year to approximately one case per year.
• Freshwater anglers would have a post-rule individual excess lifetime cancer
risk ranging from 1.4 x 10"5 to 3.3 x 10"5 for typical fish consumption.
• Cancer risks for San Francisco Bay anglers would be reduced by 91 percent.
• The population cancer risk for Bay area anglers would decrease from the
baseline of one or fewer cases per year to zero cases per year.
• San Francisco Bay anglers would have a post-rule individual excess lifetime
cancer risk ranging from 1.7 x 10"5 to 3.8 x 10"5 for typical fish consumption.
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Summary of Potential Noncancer Health Benefits
Our analysis of human health non-cancer risks for the general population supports the
following conclusions:
•. Noncancer risks for freshwater anglers would be reduced by 67 percent.
• The hazard index for freshwater anglers would decrease from the baseline of
2.3 to 5.4 to less than 0.8 to 1.8 for typical fish consumption.
• Mercury would have the highest post-rule hazard quotient for an individual
freshwater contaminant — 0.6 to 1.4 for typical consumption.
• Non-cancer risks for San Francisco Bay anglers would be reduced by 76
percent.
• The hazard index for Bay area anglers would decrease from the baseline of 3.5
to 8.2 to less than 0.9 to 2.0 for typical fish consumption.
• Mercury would have the highest post-rule hazard quotient for an individual
San Francisco Bay contaminant ~ 0.8 to 1.7 for typical consumption.
Uncertainties
The analysis of angler health risks involves a series of assumptions that are generally designed
to characterize typical recreational anglers. To the extent that anglers differ from this
characterization, the analysis may over- or underestimate risk. Some of the areas of potential
uncertainty include consumption rates, mixing of species in an individual's diet, and assigning
concentration values to contaminants in samples in which they were below detection. We addressed
these issues by developing ranges of potential exposure values. In the case of consumption rates,
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we present results based on reasonable bounds for typical consumption and for 90th percentile
consumption. With respect to species mixing and nondetected values, we have conducted sensitivity
analyses to characterize the magnitude of these uncertainties.
Other uncertainties, especially those affecting subpopulations, could not be fully characterized
within this analysis. These include ethnic and income effects on consumption rates, fish preparation
methods, and risks to family members. We reviewed our standard assumptions against information
provided in the relevant literature on angler subpopulations to determine the potential effects each
of these uncertainties has on the analysis.
Finally, we may have underestimated some of the angler human health benefits associated with
meeting CTR criteria because we have not considered the health risks associated with consuming
commercially caught fish. California has commercial fisheries in water bodies covered by this rule,
and it is likely that achievement of the CTR criteria will result in some reduced toxic contamination
of commercial fisheries. However, because of difficulties in estimating the number of exposed
individuals as well as difficulties in linking toxic contamination solely to California sources, we were
not able to estimate the baseline health risks and benefits associated with meeting CTR criteria.
Economic Benefits
The economic benefits associated with meeting toxic water quality criteria are significant, and
include multiple use and non-use components. Exhibit 1-2 summarizes these results. Key findings
include the following:
• Monetized benefits associated with achieving toxic water quality criteria
established by the CTR are estimated for recreational fishing, human health
cancer effects, and passive use values only. These benefits are significant,
ranging from a low of $62 million per year to an upper bound of
approximately $600 million per year.
• Recreational fishing benefits are valued at between $35 and $196 million per
year. Related non-use benefits are estimated to be $17 to $294 million.
Finally, avoided cancer deaths are valued at between $10 and $110 million per
year.
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EXHIBIT 1-2
SUMMARY OF POTENTIAL ANNUAL BENEFITS ASSOCIATED WITH ACHIEVING
WATER QUALITY STANDARDS ESTABLISHED BY THE CALIFORNIA TOXICS RULE
Benefit Category
Total Benefits
(Millions $1996X1X2)
Point Source Benefits
(Millions $1996X1X2X3)
USE VALUES
Improved Recreational Fishing
Improved Recreational Hunting
Improved Water Enhanced Recreation
Improved Commercial Fisheries
Drinking Water and Sludge Treatment Savings
Improved Property Values
Avoided Cost of endangered species management and associated
land use restrictions
Human Health (4)
Reduced cancer risk - anglers
Reduced non-cancer risk - anglers
Reduced health risk to some subsistence anglers
$35- $196
$ - Not Estimated
$- Not Estimated
$ - Not Estimated
$- Not Estimated
$ - Not Estimated
$- Not Estimated
$10 -$110;
91% reduction in individual excess
lifetime risk
67% - 76% reduction in non-cancer
risk; $- Not Estimated
S- Not Estimated
$2 - $26
$ - Not Estimated
$ - Not Estimated
$- Not Estimated
$- Not Estimated
$- Not Estimated
$ - Not Estimated
$- Not Estimated
reduction in individual excess
lifetime risk
reduction in non-cancer risk;
$- Not Estimated
$- Not Estimated
NON-USE
Bequest and Existence Values
Ecological
Reduced morbidity/mortality to aquatic and terrestrial wildlife;
Improved integrity of aquatic and aquatic-dependent ecosystems
Improved conditions in habitat supporting fish
spawning/migration
Improved conditions in habitat supporting threatened and
endangered species
TOTAL
$17 -$294
- 815,000 acres of bays, harbors,
estuaries, lakes, and wetlands
- 4,000 miles of rivers
-227,000 acres of bays, harbors
and estuaries
-102,000 acres of lakes
- 1 1,000 acres of saline lakes
- 1,000 miles of rivers
- 180,000 acres of bays, harbors
and estuaries
- 230,000 acres saline lakes
- 1,900 miles of rivers
$62 - $600 + $ Benefits Not
Estimated
$l-$39
- 20,000 acres of bays, harbors,
estuaries, lakes and wetlands
- 133 miles of rivers
- 14,000 acres of bays, harbors
and estuaries
- 5,000 acres of lakes
- 53 miles of rivers
- 10,000 acres of bays,
harbors, and estuaries
- 1,700 acres of lakes
- 100 miles of rivers
S3 - $65 +$ Benefits Not
Estimated
(1) Dollars converted to first quarter 1996 using Gross Domestic Product implicit price deflator.
(2) $ - Not Estimated = Dollar benefits expected to accrue, but not yet monetized.
(3) Point Sources are defined as POTWs and industrial NPDES dischargers.
(4) Health risks estimated for 80 percent of California anglers.
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• A number of other economic benefits are expected to accrue when water
quality criteria are met. However, we have not quantified or monetized these
comprehensively. They include: increased value for commercial fishing;
drinking water treatment, sludge treatment, and dredged material management
cost savings; increased property values; increased value and participation in
recreational hunting and other near-stream activities; avoided cost of illness
associated with consumption of commercially caught seafood; and avoided
costs of endangered species management.
These findings are subject to some uncertainty given the limited availability of Statewide data
and the overall benefits transfer methodology approach used. First, we assume that the condition of
asessed waters in California is representative of conditions in all assessed resources. If conditions are
considerably worse or better in these unassessed waters, then benefits estimates are likely to be higher
or lower than those presented here. , Currently, EPA and State water quality experts agree that
because of all of the uncertainties in the WQA data base (both in underestimating and overestimating
waters that are adversely affected by toxics) it is not possible to quantitatively or qualitatively
estimate the magnitude of the bias in either direction. Second, estimation of the increased value of
current angling and increased participation in recreational angling assumes that anglers have not
substituted away from contaminated waters. It is likely that some anglers are substituting away from
contaminated waters, causing some of the angler benefits to be overstated. Alternatively, fishing
effort may be disproportionately concentrated on impaired waters because of the proximity of the
waters to population centers, resulting in an understatement of angling benefits. Because we have
not done a waterbody-by-waterbody evaluation of substitute fishing areas and angler substitution
behavior, we cannot estimate the direction or degree of bias of our estimates.
Third, the approach used here assumes that reductions in toxic loadings and the resulting
benefits are linearly related. This may not be true under certain circumstances, although the direction
of the bias introduced is unclear. Fourth, the monetized estimate of benefits omits several categories
of benefits that are expected to accrue, resulting in a potentially significant underestimation of total
economic benefits. Finally, the persistence and toxicity of the pollutants covered by the criteria have
important implications for all parts of the benefits analysis. Because some of these compounds (e.g.
dioxins, mercury) may persist in various waters, sediment, and animal tissue for years after toxic
discharges have been reduced, a portion of the benefits described here may not be realized
immediately.
1-14
-------
JUNE 1997
Ecological
The ecological benefits associated with achieving the criteria in all California waters are
significant. Large areas of water resources in every region of the state currently are adversely
affected by toxics. Reducing toxic loadings to meet criteria will lead to healthier and more stable
organisms, ecological populations, and ecological communities. Exhibit 1-3 summarizes these overall
benefits. Specific findings of the ecological benefits analysis include the following:
• Toxics driving ecological benefits include copper, silver, zinc, cadmium,
chromium, PCBs, selenium, mercury, and estrogenic pesticides (e.g.,
endosulfan). These latter four contaminants can bioaccumulate, and pose an
additional threat to fish and wildlife throughout the State.
• Reducing loadings of contaminants to meet criteria levels may contribute to
improved stability, resilience and overall integrity of organisms, populations,
and communities living in or dependant on more than 800,000 acres of
assessed bays, estuaries, lakes, and wetlands and more than 4,000 miles of
rivers that are now currently affected.
• Reduced toxic loadings are expected to contribute to improved conditions for
fish spawning and/or migration in more than 227,000 acres of bays, harbors,-
and estuaries; 102,000 acres of lakes; 1,000 miles of rivers and streams; and
11,000 acres of saline lakes.
1-15
-------
EXHIBIT 1-3
ECOLOGICAL BENEFITS OF THE CALIFORNIA TOXICS RULE
'
Toxic of Concern
Arsenic
Cadmium
Chromium
PI! and VI)
Copper
Lead
Mercury
Nickel
Selenium
Silver
Zinc
Dioxins
Endosulfan and
Other Estrogenic
Pesticides (1)
Selected Documentation in
California Waters, Sediments and/or Biota
Endangered species, mussels, fish, sediments, water
Endangered species, mussel, fish, bird, seal, waterfowl
sediments, water
Striped bass, mussel, clam, fish, sediments, water
Endangered species, striped Bass, mussel, clam, fish,
bird, seal, sediments, water
Endangered species, mussel, fish, bird, seal, sediments,
water
Endangered species, striped bass, mussel, fish, bird,
seal, (piscivorous wildlife) sediments, water
Striped bass, mussel, fish, bird, seal, sediments, water
Endangered species, mussel, clam, fish, bird, seal,
waterfowl, (piscivorous animals) sediments, water
Endangered species, mussel, clam, fish, striped bass,
bird, sediments, water
Endangered species, striped bass, mussel, fish, bird,
sediments, water
Endangered species, wildlife, fish, piscivorous
animals, waterfowl
Endangered species, fish, striped bass, birds,
waterfowl, water, sediments
Potential Beneficial Effects to Individual
Organisms When Toxic Reduced to Meet
Water Quality Criteria
Improved growth and survival; Improved
reproduction; Improved physiology; Increased
resistance to infection; Reduced mutagenic,
teratogenic, carcinogenic effects.
Improved.growth and survival; Improved
reproduction; Reduced mutagenic, teratogenic,
carcinogenic effects.
Improved growth and survival; Improved
reproduction; Reduced mutagenic, teratogenic,
carcinogenic effects.
Improved growth and survival; Improved
reproduction
Improved metabolism.
Improved growth and survival; Improved
reproduction; Improved development; Improved
metabolism;
Improved growth and survival; Improved
reproduction; Improved development; Improved
metabolism
Improved growth and survival; Improved
reproduction; Improved development; Improved
behavior; Reduced mutagenic, teratogenic,
carcinogenic effects.
Improved growth and survival; Improved
reproduction; Reduced carcinogenic effects.
Improved growth and survival; Improved
reproduction; Improved behavior; Improved
physiology
Improved growth and survival; Improved
reproduction; Improved physiology
Improved growth and survival; Improved physiology
Improved reproduction.
-------
Toxic of Concern
Selected Documentation in
California Waters, Sediments and/or Biota
Potential Beneficial Effects to Individual
Organisms When Toxic Reduced to Meet
Water Quality Criteria
Polycyclic
Aromatic
Hydrocarbons
(PAHs)
Mussel, fish, sediments, water
Improved growth and survival; Improved
reproduction; Improved immunity; Reduced
mutagenic, teratogenic and carcinogenic effects.
Polychlorinated
Biphenyls
(PCBs)
Endangered species, starry flounder, black-crowned
night heron, mussel, seal, waterfowl, striped bass,
piscivorous wildlife, sediments, water
Improved growth and survival; Improved
reproduction; Improved behavior; Improved
immunity; Reduced mutagenic, teratogenic,
carcinogenic effects.
(1) Estrogenic pesticides are those that are associated with the disruption of normal endocrine and reproductive functions.
Estrogenic pesticides include banned pesticides like DDT and toxaphene, as well as currently-used pesticides, such as Endosulfan.
Sources: Brown, 1996; California Environmental Protection Agency, State Water Resources Control Board, 1994; Department of
Fish and Game, State of California, 1991; Fry, 1996; Harvey, et al., 1992; Herbold, et al., 1992; Kopec and Harvey, 1995; Larry
Walker Associates, 1992; Ohlendorf and Fleming, 1988; Pease, 1995; Schwarzback, et al., 1996; Setzler-Hamilton, etal., 1988;
Smith and Flegal, 1993; Solomon et al., 1996; Thompson, 1996; U.S. EPA, 1985a; U.S. EPA, 1992; U.S. Fish and Wildlife Service,
I997.U.S.G.S., 1990;U.S.G.S., 1993
Population
Increased Health
Improved Genetic
Diversity
Improved
Recruitment
Increased
Abundance
Community
Improved Species
Diversity and
Composition
Enhanced
Population Stability
Maintain species
assemblages
Improved food web
supply and diversity
Increased and.
improved
productivity
Ecosystem
Improved System
Stability
Increased
Community
Resilience
Improved
Community
Diversity
Improved
niodiversily
Ecosystem: A functional system consisting of the living biotic
community and the physical environment, comprised of all living
organisms, their remains, and the minerals, chemicals and resources
on which they depend for their survival and reproduction.
Community: An assemblage of populations living in a prescribed
area or physical habitat that have a functional and compositional
unity; may be relatively independent or dependent on neighboring •
assemblages.
Population: A group of organisms of the same species, generally
occupying a contiguous area, and capable of interbreeding.
-------
JUNE 1997
• Statewide, threatened and endangered species may be at risk from toxics in
approximately 180,000 acres of bays, harbors and estuaries, 1,900 river miles,
and 230,000 acres of saline lakes. Reducing toxic contaminants to criteria
levels is expected to help contribute to improved conditions for the successful
recovery of threatened and endangered species including species such as the
Delta smelt, Desert pupfish, California brown pelican, Bald eagle, California
clapper rail, California tiger salamander, and western snowy plover.
• Mercury concentrations in California fish are estimated to reach levels that
may be hazardous to piscivorous wildlife.4 Adverse effects on wildlife are
also occurring as a result of exposure to selenium.
• The aquatic and terrestrial wildlife of the San Francisco Bay watershed and
the Central Valley are expected show the greatest improvement relative to
other regions because of the extent of current toxic loadings and the diversity
and richness of species, populations, and communities potentially affected by
toxics.
• Reduced concentrations of both selenium and pesticides in the waters that
feed the Salton Sea are expected to contribute to the restoration and
maintenance of some populations of wildlife, including threatened and
endangered species. However, current selenium criteria may not be stringent
enough to adequately protect some aquatic-dependent wildlife species.
• Reducing copper discharges to the Sacramento River to meet water quality
criteria would result in substantial protection for 90 percent or more of the
organisms and communities that are currently adversely affected.
• Because all components of the ecosystem are linked, we expect that reducing
toxic discharges will contribute to reduced morbidity/mortality of individual
organisms, may help to contribute to the increased stability, resilience and
overall integrity of numerous ecosystems throughout the State, and may
contribute to restoring and maintaining California's rich biodiversity.
4 Piscivorous wildlife are birds, fish, mammals, and other animals that eat fish.
1-17
-------
JUNE 1997
Apportioning Benefits to Point Sources
To apportion the benefits of implementing the California Toxics Rule criteria to point source
dischargers, we reviewed regional loadings studies to determine how point sources contribute to total
loadings of priority toxic pollutants throughout the State. Then we apportioned economic benefits
to point sources using point source contribution estimates averaged across the key pollutants
controlled. We then quantitatively discussed apportionment of recreational angler health benefits to
point sources, and examined key pollutants and analytical obstacles that preclude a strict quantitative
apportionment of risks from cancer and noncancer. Finally, we apportioned ecological benefits based
on qualitative and quantitative ecological assessments. Our conclusions are as follows:
• Point sources such as POTWs, industrial dischargers, and mines are significant
contributors of total toxic pollutants discharged to California surface waters,
although other sources (e.g., urban runoff, agricultural runoff) tend to be
more significant.
• Point sources are responsible for a large share of toxics loadings to California
bays. For bays other than San Francisco Bay, we estimate that point sources
account for between 42 and 64 percent of toxics loadings. Point sources
account for between five and 30 percent of toxics loadings to freshwater, and
between four and 11 percent of loadings to San Francisco Bay.
• We estimate that control of toxics discharged from point sources will yield
between $3 million and $65 million per year in economic benefits (recreational
fishing and non-use values), with a midpoint estimate of about $34 million per
year.
1-18
-------
JUNE 1997
Apportioning health risks to point sources is difficult because a number of the
most significant pollutants occur in concentrations below detection limits; this
precludes tracing the pollutants to point sources and other sources. However,
examination of effluent data and literature, as well as discussions with
knowledgeable regulatory staff, suggests that a number of health risk drivers
- PCBs, dioxin, pesticides, and mercury ~ are discharged, at least in part, by
point sources. Despite this finding, representative calculations suggest that
the potential health risk reductions associated with control of point sources
are likely to be limited unless additional effluent reductions are achieved.
Point source discharge reductions are likely to yield a number of ecological
benefits as well. First, reduced loadings will reduce morbidity/mortality of
aquatic and some terrestrial wildlife and improve the integrity of ecosystems
in at least 20,000 acres of assessed bays, estuaries, lakes, and wetlands as well
as 100 miles of miles of rivers that are now currently impaired. Reduced point
source loadings may also improve conditions for fish spawning and/or
migration in about 14,000 acres of bays, harbors, and estuaries; 5,000 acres
of lakes; and 50 miles of rivers and streams. Finally, reductions in point
source contributions of toxics are expected to improve habitat supporting
threatened and endangered species in about 10,000 acres of bays, harbors and
estuaries; 1,700 acres of lakes; and 100 river miles.
Improved water quality resulting from point source controls implemented to
meet the CTR criteria, and the associated improvements in survival, growth,
and reproductive capacity of aquatic and aquatic-dependent organisms, will
contribute to the increased stability, resilience, and overall health of numerous
ecosystems throughout California, and may contribute to protecting,
restoring, and maintaining California's rich biodiversity.
These findings are subject to some uncertainty given the limited availability of Statewide data
and the overall limitations of the apportionment approach used. First, the extent and diversity of
surface water resources and the great number and variety of dischargers make it difficult to draw
general conclusions regarding the relative influence of point sources and nonpoint sources discharging
to California waters. While available data provide enough information to estimate broad ranges of
benefits associated with reducing toxic discharges from point sources throughout the state, the
1-19
-------
JUNE 1997
circumstances at a specific waterbody may differ from these general estimates. Second, the
apportionment approach used here assumes that reductions in toxic loadings and the resulting benefits
are linearly related. This may not be true undercertain circumstances, although the direction of the
bias introduced is unclear.
1-20
-------
JUNE 1997
Attachment 1:
CRITERIA FOR PRIORITY TOXIC POLLUTANTS
IN THE STATE OF CALIFORNIA
-------
PART 131 - WATER QUALITY STANDARDS
SUBPART D - [Amended]
1. Section 131.38 is added to subpart D to read as follows:
§131.38 Establishment of Numeric Criteria for Priority Toxic
Pollutants for the State of California.
(a) Scope. This section is a, general promulgation of criteria for
priority toxic pollutants in the State of California for inland
surface waters and enclosed bays and estuaries. This section also
contains a compliance schedule provision.
(b)(1) Criteria for Priority Toxic Pollutants in the State of
California.
-------
Coi
1.
2.
3.
4.
5a
5b
6.
7.
8.
9.
10
A
mpound
Antimony
Arsenic
Beryllium
Cadmium
. Chromium
(III)
. Chromium
(VI)
Copper
Lead
Mercury
Nickel
. Selenium
B C D
FRESHWATER SALTWATER HUMAN HEALTH
CAS CMC d CCC d CMC d CCC d For Consumption of:
Number (ug/L) (ug/L) (ug/L) (ug/L) Water & Organisms Organisms Only
Bl B2 Cl C2 . (ug/L) (ug/L)
Dl D2
7440360 14 a,s 4300 a,t
7440382 340 i,m,w 150 i,m,w 69 i,m 36 i,m
7440417 n n
7440439 4.3 e,i,m, 2.2 e,i,m, 42 i,m 9.3 i,m n n
w/x w
16065831 550 e,i,m, 180 e,i,m, n n
o o
18540299 16 i,m,w 11 i,m,w 1100 i,m 50 i,m n n
7440508 13 e,i,m, 9.0 e,i,m, 4.8 i,m 3.1 i,m 1300
w,x w
7439921 65 e,i,m 2.5 e,i,m 210 i,m 8.1 i,m n n
7439976 1.4 i,m,w 0.77 i,m,w 1.8 i,m 0.94 i,m 0.050 a 0.051 a
7440020 470 e,i,m, 52 e,i,m, 74 i,m 8.2 i,m 610 a 4600 a
w w
7782492 p 5.0 q 290 i,m 71 i,m n n
11. Silver
12. Thallium
13. Zinc
7440224 3.4 e,i,m
7440280
1.9 i,m
1.7 a,s
7440666 120 e,i,m, 120 e,i,m, 90 i,m 81 i,m
w,x w
6.3 a,t
14. Cyanide 57125 22 o
5.2 o
1 r
1 r
700 a
220,000 a,j
-------
A
Compound
B
FRESHWATER
CAS CMC d CCC d
Number (ug/L) (ug/L)
Bl B2
SALTWATER
CMC d CCC d
(ug/L) (ug/L)
Cl C2
HUMAN HEALTH
•For Consumption- of:
Water & Organisms Organisms Only
(ug/L) (ug/L)
Dl D2
15. Asbestos 1332214
16. 2,3,7,8 Tetrachloro-dibenzo-p-dioxin (TCDD or Dioxin)
1746016
17. Acrolein 107028
18.
7,000,000 fibers/L k, s
0.000000013 c 0.000000014 c
320 8 780 t
19.
20.
21.
22.
23.
24.
25.
Acrylonitrile
107131
Benzene 71432
Bromoform 75252
0.059 a,c,s
1.2 a,c
4.3 a,c
0.66 a,c,t
71 a,c
360 a,c
Carbon Tetrachlorid*
56235
Chlorobenzene .
108907
Chlorodibromomethane
124481
Chloroethane
75003
2-Chloroethylvinyl
Ether 110758
0.25 a,c,a
680 a, B
0.41 a,c
4.4 a,c,t
21,000 a,j,t
34 a,c
26. Chloroform 67663
27. Dichlorobromomethane
75274
5.7 a,c
0.56 a,c
470 a,c
46 a,c
28. 1,1-Dichloroethane 75343
-------
A
Compound
FRESHWATER
CAS CMC d CCC d
Number (ug/L) (ug/L)
Bl B2
SALTWATER
CMC d CCC d
(ug/L) (ug/L)
Cl C2
HUMAN HEALTH
For Consumption of:
Water & Organisms Organisms Only
(ug/L) (ug/L)
Dl D2
29. 1,2-Dichloroethane
107062
30. I/1-Dichloroethylene
75354
31. 1/2-Dichloropropane
78875
32. 1,3-Dichloropropylene
542756
33. Ethylbenzene
100414
0.38 a,c,s
0.057 a,c,s
0.52 a
10 a, s
3,100 a,s
99 a,c,t
3.2 a,c,t
39 a
1,700 a,t
29,000 a,t
4,000 a
34. Methyl Bromide
74839
35. Methyl Chloride
74873
36. Methylene Chloride
75092
37. 1,1,2,2-Tetrachloroethane
79345
38. Tetrachloroethylene
127184
48 a
4.7 a,c
0.17 a,c,s
0.8 c,s
6,800 a
700 a
1,600 a,c
11 a,c,t
8.85 c,t
200,000 a
140,000 a
39. Toluene 108883
40. 1,2-Trans-Dichloroethylene
156605
-------
A
Compound
FRESHWATER
CAS CMC d CCC d
Number (ug/L) (ug/L)
Bl B2
SALTWATER
CMC d CCC d
(ug/L) (ug/L)
Cl C2
HUMAN HEALTH
For Consumption of:
Water & Organisms Organisms Only
(ug/L) (ug/L)
Dl D2
41. 1,1,1-Trichloroethane
71556
42. 1,1,2-Trichloroethane
79005
43. Trichloroethylene
79016
44. Vinyl Chloride
75014
45. 2-Chlorophenol
95578
0.60 a,c,s
2.7 c,s
2 c,s
120 a
42 a,c,t
81 c,t
525 c,t
400 a
46. 2,4-Dichlorophenol
120832
47. 2,4-Dimethylphenol
105679
48. 2-Methyl- 4,6-Dinitrophenol
534521
49. 2,4-Dinitrophenol
51285
50. 2-Nitrophenol
88755
93 a,s
540 a
13.4 s
70 a,s
790 a,t
2,300 a
765 t
14,000 a,t
51. 4-Nitrophenol
100027
52. 3-Methyl 4-Chlorophenol
59507
-------
A
Compound
B
FRESHWATER
CAS CMC d CCC d
Number (ug/L) (ug/L)
Bl B2
SALTWATER
CMC d CCC d
(ug/L) (ug/L)
Cl C2
HUMAN HEALTH
For Consumption of:
Water & Organisms Organisms Only
(ug/L) (ug/L)
Dl D2
53. Pentachlorophenol
87865
54. Phenol 108952
55. 2,4,6-Trichlorophenol
88062
56. Acenaphthene
83329
57. Acenaphthylene
208968
19 f,w 15 £,w
13
7.9
0.28 a,c
21,000 a
2.1 a,c
1,200 a
8.2 a,c,j
4,600,000 a,j,t
6.5 a,c
2,700 a
58. Anthracene
120127
59. Benzidine 92875
6 0. Benzo(a)Anthracene
56553
61. Benzo(a)Pyrene
50328
62. Benzo(b)Fluoranthene
205992
9,600 a
0.00012 a,c,s
0.0044 a,c
0.0044 a,c
0.0044 a,c
110,000 a
0.00054 a,c,t
0.049 a,c
0.049 a,c
0.049 a,c
63. Benzo(ghi)Perylene
191242
6 4. Benzo(k)Fluoranthene
207089
0.0044 a,c
0.049 a,c
-------
A
Compound
FRESHWATER
CAS CMC d CCC d
Number (ug/L) (ug/L)
Bl B2
SALTWATER
CMC d CCC d
(ug/L) (ug/L)
Cl C2
HUMAN HEALTH
For Consumption of:
Water & Organisms Organisms Only
(ug/L) (ug/L)
Dl D2
65. Bis(2-Chloroethoxy)Methane
111911
66. Bis(2-Chloroethyl)Ether
111444
67. Bis(2-Chloroisopropyl)Ether
108601
68. Bis(2-Ethylhexyl)Phthalate
117817
69. 4-Bromophenyl Phenyl Ether
101553
0.031 a,c,s
1,400 a
1.8 a,c,s
1.4 a,c,t
170,000 a,t
5.9 a,c,t
70. Butylbenzyl Phthalata
85687
71. 2-Chloronaphthalene
91587
72. 4-Chlorophenyl Phenyl Ether
7005723
73. Chzysene 218019
74. Dibenz o(a,h)Anthracene
53703
3000 a
1,700 a
0.0044 a,c
0.0044 a,c
5200 a
4,300 a
0.049 a,c
0.049 a,c
75. 1,2 Dichlorobenzene
95501
76. 1,3 Dichlorobenzene 541731
2,700 a
400
17,000 a
2,600
-------
A
Compound
FRESHWATER
CAS CMC d CCC d
Number (ug/L) (ug/L)
Bl B2
SALTWATER
CMC d CCC d
(ug/L) (ug/L)
Cl C2
HUMAN HEALTH
For Consumption of:
Water & Organisms Organisms Only
(ug/L) (ug/L)
Dl D2
77. 1,4 Dichlorobenzene
106467
78. 3,3 Dichlorobenzidine
91941
79. Diethyl Phthalate
84662
80. Dimethyl Phthalate
131113
81. Di-n-Butyl Phthalate
84742
400
0.04 a,c,s
23,000 a,s
313,000 s
2,700 a,s
0.11 c,s
2,600
0.077 a,c,t
120,000 a,t
2,900,000 t
12,000 a,t
9.1 c,t
82. 2,4-Dinitrotoluene
121142
83. 2,6-Dinitrotoluene
606202
84. Di-n-Octyl Phthalate
117840
85. 1,2-Diphenylhydrazine
122667
86. Fluoranthene
206440
0.040 a,c,s
300 a
1,300 a
0.00075 a,c
0.54 a,c,t
370 a
14,000 a
0.00077 a,c
87. Fluorene 86737
88. Hexachlorobenzene
118741
-------
A
Compound
B
FRESHWATER
CAS CMC d CCC d
Number '(ug/L) (ug/L)
Bl B2
SALTWATER
CMC d CCC d
(ug/L) (ug/L)
Cl C2
HUMAN HEALTH
for Consumption of:
Water & Organisms Organisms Only
(ug/L) (ug/L)
Dl D2
89. Hexachlorobutadiene
87683
90. Hexachlorocyclopentadiene
77474
91. Hexachloroethane
67721
92. Indenod,2,3-cd)Pyrene
193395
93. Isophorone
78591
0.44 a,c,s
240 a,s
1.9 a,c,s
0.0044 a,c
8.4 c,s
50 a,c,t
17,000 a,j,t
8.9 a,c,t
0.049 a,c
600 c,t
94. Naphthalene
91203
95. Nitrobenzene
98953
96. N-Nitrosodimethylamine
62759
97. N-Nitrosodi-n-Propylamine
621647
98. N-Nitrosodiphenylamine
86306
17 a, s
0.00069 a,c,s
0.005 a
5.0 a,c,s
1,900 a,J,t
8.1 a,c,t
1.4 a
16 a,c,t
99. Phenanthrene
85018
100. Pyrene 129000
960 a
11,000 a
-------
1
Compc
101.
102.
103.
104.
105.
106.
107.
108.
109.
110.
111.
112.
V B C :
FRESHWATER SALTWATER HUMAN
jund CAS CMC d CCC d CMC d CCC d For Consum
Number (ug/L) (ug/L) (ug/L) (ug/L) Water & Organism
Bl B2 Cl C2 (ug/L)
Dl
1, 2, 4-Trichlorobenzene
120821
Aldrin 309002 3 g 1.3 g 0.00013 a,c
alpha-BHC
319846 0.0039 a,c
beta-BHC 319857 . 0.014 a,c
gamma-BBC
58899 0.95 g,w 0.16 g 0.019 c
delta-BHC
319868
Chlordane
57749 2.4 g 0.0043 g 0.09 g 0.004 g 0.00057 a,c
4, 4 '-DDT 50293 1.1 g 0.001 g 0.13 g 0.001 g 0.00059 a,c
4, 4 '-DDE 72559 0.00059 a,c
4,4'-DDD 72548 0.00083 a,c
Dieldrin 60571 0.24 g,w 0.056 g,w 0.71 g 0.0019 g 0.00014 a,c
alpha-Endosulfan
D
HEALTH
ption of:
s Organisms Only
(ug/L)
D2
0.00014 a,c
0.013 a,c
0.046 a,c
0.063 c
0.00059 a,c
0.00059 a,c
0.00059 a,c
0.00084 a,c
0.00014 a,c
959988 0.22 g 0.056 g
113. beta-Endosulfan
33213659 0.22 g 0.056 g
114. Endosulfan Sulfate
1031078
0.034 g 0.0087 g 110 a
0.034 g 0.0087 g 110 a
110
240 a
240 a
240 a
-------
A
Compound
FRESHWATER
CAS CMC d CCC d
Number (ug/L) (ug/It)
Bl B2
SALTWATER
CMC d CCC d
(ug/L) (ug/L)
Cl C2
HUMAN HEALTH
For Consumption of:
Water & Organisms Organisms Only
(ug/L) (ug/L)
Dl D2
115. Endrin 72208 0.086 g,w 0.036 g,w 0.037 g 0.0023 g 0.76 a
116. Endrin Aldehyde
7421934
0.76 a
117. Heptachlor
76448 0.52 g 0.0038 g 0.053 g 0.0036 g 0.00021 a,c
118. Heptachlor Epoxide 0.52 g 0.0038 g 0.053 g 0.0036 g 0.00010 a,c
1024573
119.- 125. Polychlorinated biphenyls
(PCBs) 0.014 g,u
0.03 g,u 0.00017 v
0.0002 0.00073 a,c
0.81 a,j
0.81 a,j
0.00021 a,c
0.00011 a,c
0.00017 v
0.00075 a,c
126. Toxaphene 8001352 0.73 0.0002
0.21
TOTAL NUMBER OF
CRITERIA (h):
24
28
23
27
99
97
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FOOTNOTES:
a. These criteria have been revised to reflect the Agency ql* or RfD, as
contained in the Integrated Risk Information System (IRIS) as of October 1, 1996.
The fish tissue bioconcentration factor (BCF) from the 1980 documents was
retained in each case.
b. This letter is not used as a footnote.
c. These criteria are based on carcinogenicity of 10 (-6) risk.
d. The Criteria Maximum Concentration (CMC) equals the highest
concentration of a pollutant to which aquatic life can be exposed for a short
period of time without deleterious effects. Criteria Continuous Concentration
(CCC) equals the highest concentration of a pollutant to which aquatic life can
be exposed for an extended period of time (4 days) without deleterious effects.
ug/1 equals micrograms per liter.
e. These freshwater aquatic life criteria for metals are expressed as a
function of total hardness (mg/1) in the water body. The equations are provided
in matrix at §131.38(b) (2). Values displayed above in the matrix correspond to
a total hardness of 100 mg/1.
f. These freshwater aquatic life criteria for pentachlorophenol are
expressed as a function of pH, and are calculated as follows: Values displayed
above in the matrix correspond to a pH of 7.8. CMC «= exp(1.005(pH) - 4.830).
CCC - exp(1.005(pH) - 5.290).
g. These aquatic life criteria for these compounds were issued in 1980
utilizing the 1980 Guidelines for criteria development. The acute values shown
are final acute values (FAV) which by the 1980 Guidelines are instantaneous
values as contrasted with a CMC which is a short-term average.
h. These totals simply sum the criteria in each column. For aquatic life,
there are 30 priority toxic pollutants with some type of freshwater or saltwater,
acute or chronic criteria. For human health, there are 100 priority toxic
pollutants with either "water + organism" or "organism only" criteria. Note that
these totals count chromium as one pollutant even though EPA has developed
criteria based on two valence states. In the matrix, EPA has assigned numbers
5a and 5b to the criteria for chromium to reflect the fact that this list of 126
priority pollutants includes only a single listing for chromium.
i. Criteria for these metals are expressed as a function of the water-
effect ratio, HER, as defined in 40 CFR 131.38(c). CMC - column Bl or Cl value
x WER; CCC - column B2 or C2 value x WER.
j. No criteria for protection of human health from consumption of aquatic
organisms (excluding water) was presented in the 1980 criteria document or in the
1986 Quality Criteria for Water. Nevertheless, sufficient information was
presented in the 1980 document to allow a calculation of a criterion, even though
the results of such a calculation were not shown in the document.
k. This criterion for asbestos is the MCL (56 FR 3526, January 30, 1991).
1. This letter is not used as a footnote.
m. These freshwater and saltwater criteria for metals are expressed in
terms of the dissolved fraction of the metal in the water column. Criterion
values were calculated by using EPA's Clean Water Act 304(a) guidance values
(described in the total recoverable fraction) and then applying the conversion
factors in 40 CFR Part 131, Stay of Federal Water Quality Criteria for Metals;
Water Quality Standards; States' Compliance - Revision of Metals Criteria; Final
Rules, 60 FR 22228 (May 4, 1995).
n. EPA is not promulgating human health criteria for these contaminants.
However, permit authorities should address these contaminants in NPDES permit
actions using the State's existing narrative criteria for toxics.
o. These criteria were promulgated for specific waters in California in
the National Toxics Rule ("NTR"), codified at 40 CFR 131.36, 57 FR 60848-60923,
December 22, 1992, as amended by 60 FR 22228, May 4, 1995. The specific waters
to which the NTR criteria apply include: Waters of the State defined as bays or
estuaries and waters of the State defined as inland, i.e., all surface waters of
-------
the State not ocean waters. These waters specifically include the San Francisco
Bay upstream to and including Suisun Bay and the Sacramento-San Joaquin Delta.
Note: This rule does not supersede the NTR, as amended, for this criterion.
p. The CMC - l/[(fl/CMCl)+ (f2/CMC2)] where fl and f2 are the fractions
of total selenium that are treated as selenite and selenate respectively/ and
fl + f2 = 1. CMC1 and CMC2 are the CHCs for selenite and selenate, respectively,
or 185.9 ug/1 and 12.83 ug/1, respectively. This criterion is proposed in the
total recoverable form. A criterion of 20 ug/1 was promulgated for specific
waters in California in the NTR, as amended, and was promulgated in the total
recoverable form. The specific waters to which the NTR criterion applies include:
Waters of the San Francisco Bay upstream to and including Suisun Bay and the
Sacramento-San Joaquin Delta; and waters of Salt Slough, Mud Slough (north) and
the San Joaquin River, Sack Dam to the mouth of the Merced River. Note: This
rule does not supersede the NTR, as amended, for this criterion. The criterion
in today's rule applies to additional waters of the United States in the State
of California by this rulemaking. Note also: The State of California adopted.
and EPA approved a site specific criterion for the San Joaquin River, mouth of
Merced to Vernalis; therefore, this proposed criterion does not apply to these
waters.
q. This criterion is proposed in the total recoverable form. This
criterion was promulgated for specific waters in California in the NTR, as
amended, and was promulgated in the total recoverable form. The specific waters
to which the NTR criterion applies include: Waters of the San Francisco Bay
upstream to and including Suisun Bay and the Sacramento-San Joaquin Delta; and
waters of Salt Slough, Mud Slough (north) and the San Joaquin River, Sack Dam to
Vernalis. Note: This rule does not supersede the NTR, as amended, for this
criterion. This criterion applies to additional waters of the United States in
the State of California by this rulemaking. Note also: The State of California
adopted and EPA approved a site-specific criterion. for the Grassland Water
District, San Luis National Wildlife Refuge, and the Los Banos State Wildlife
Refuge; therefore, this proposed criterion does not apply to these waters.
r. These criteria were promulgated for specific waters in California in
the NTR, as amended. The specific waters to which the NTR criteria apply
include: Waters of the State defined as bays or estuaries including the San
Francisco Bay upstream to and including Suisun Bay and the Sacramento-San Joaquin
Delta. Note: This rule does not supersede the NTR, as amended, for these
criteria.
s. These criteria were promulgated for specific waters in California in
the NTR, as amended. The specific waters to which the NTR criteria apply
include: Waters of the Sacramento-San Joaquin Delta and waters of the State
defined as inland (i.e., all surface waters of the State not bays or estuaries
or ocean) that include a MUN use designation. Note: This rule does not
supersede the NTR, as amended, for these criteria.
t. These criteria were promulgated for specific waters in California in
the NTR, as amended. The specific waters to which the NTR criteria apply include:
Waters of the State defined as bays and estuaries including San Francisco Bay
upstream to and including Suisun Bay and the Sacramento-San Joaquin Delta; and
waters of the State defined as inland (i.e., all surface waters of the State not
bays or estuaries or ocean) without a MUN use designation. Note: This rule
does not supersede the NTR, as amended, for these criteria.
u. PCBs are a class of chemicals which include aroclors 1242, 1254,
1221, 1232, 1248, 1260, and 1016, CAS numbers 53469219, 11097691, 11104282,
11141165, 12672296, 11096825, and 12674112, respectively. The aquatic life
criteria apply to this set of PCBs.
v. This criterion applies to total PCBs or congener or isomer analyses.
w. This criterion has been recalculated pursuant to the 1995 Updates:
Water Quality Criteria Documents for the Protection of Aquatic Life in Ambient
Water, Office of Water, EPA-820-B-96-001, September 1996. See also Great Lakes
-------
Water Quality Initiative Criteria Documents for the Protection of Aquatic Life
in Ambient Water, Office of Water, EPA-80-B-95-004, March 1995.
x. The State of California has adopted and EPA has approved site
specific criteria for the Sacramento River (and tributaries) above Hamilton City;
therefore, these proposed criteria do not apply to these waters.
General Notes:
1. This chart lists all of EPA's priority toxic pollutants whether or not
criteria guidance are available. Blank spaces indicate the absence of criteria
guidance. Because of variations in chemical nomenclature systems, this listing
of toxic pollutants does not duplicate the listing in Appendix A of 40 CFR Part
423. EPA has added the Chemical Abstracts Service (CAS) registry numbers, which
provide a unique identification for each chemical.
2. The. following chemicals have organoleptic-based criteria
recommendations that are not included on this chart (for reasons which are
discussed in the preamble): zinc, 3-methyl-4-chlorophenol.
3. For purposes of this rulemaking, freshwater criteria and saltwater
criteria apply as specified in 40 CFR 131.38(c)(3).
-------
(2) Factors for Calculating Metals Criteria
CMC = WER x (Acute Conversion Factor) x (exp{mA[In (hardness)] +bA})
CCC = WER x (Chronic Conversion Factor) x (exp{n^[In (hardness)] +bc))
Final CMC and CCC values should be rounded to two significant figures.
Metal Conversion Factor
(CF)
acute
Antimony
Arsenic
Beryllium
Cadmium (b)
Chromium (III)
Chromium (VI)
Copper
Lead (b)
Mercury
Nickel
Selenium
Silver
Thallium
Zinc •
for freshwater
criteria
(d)
1.000
(d)
0.944
0.316
0.982
0.960
0.791
0.85
0.998
(c)
0.85
(d)
0.978
CF for
freshwater
chronic
criteria
(d)
1.000
(d)
0.909
0.860
0.962
0.960
0.791
0.85
0.997
(c)
(d)
(d)
0.986
CF for .
saltwater
acute
criteria
(d)
1.000
(d)
0.994
(d)
0.993
0.83
0.951
0.85
0.990
0.998
0.85
(d)
0.946
CF (a) for
saltwater
chronic
criteria
(d)
1.000
(d)
0.994
(d)
0.993
0.83
0.951
0.85
0.990
0.998
(d)
(d)
0.946
NOTE: The term "Conversion Factor" represents the recommended conversion factor
for converting a metal criterion expressed as the total recoverable fraction in
the water column to a criterion expressed as the dissolved fraction in the water
column. See 'Office of Water Policy and Technical Guidance on Interpretation and
Implementation of Aquatic Life Metals Criteria', October 1, 1993, by Martha G.
Prothro, Acting Assistant Administrator for Water; and 40 CFR Part 131, Stay of
Federal Water Quality Criteria for Metals; Water Quality Standards; Establishment
of Numeric Criteria for Priority Toxic Pollutants; States' Compliance - Revision
of Metals Criteria; Final Rules, 60 FR 22228, May 4, 1995.
(a) Conversion Factors for chronic marine criteria are not currently available.
Conversion Factors for acute marine criteria have been used for both acute and
chronic marine criteria.
(b) Conversion Factors for these pollutants are hardness dependent. CFs are
based on a hardness of 100 mg/1 as calcium carbonate (CaC03) . Other hardness can
be used; CFs should be recalculated using the following equations:
Cadmium: Acute: CF = 1.136672 - [(In {hardness})(0.041838)]
Chronic: CF = 1.101672 - [(In {hardness})(0.041838)]
Lead: Acute and Chronic: CF = 1.46203 - [(In {hardness})(0.145712)]
(c) Bioaccumulative compound and inappropriate .to adjust to percent dissolved.
(d) EPA has not published an aquatic life criterion value.
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Metal • mA bA m- bc
Cadmium
Copper
Chromium (III)
Lead
Nickel
Silver
Zinc
1.128
0.9422
0.8190
1.273
0.8460
1.72
0.8473
-3.6867
-1.700
3.688
-1.460
2.255
-6.52
0.884
0.7852
0.8545
0.8190
1.273
0.8460
0.8473
-2.715
-1.702
1.561
-4.705
0.0584
0.884
NOTE: The term "exp" represents the base e exponential function.
(c) Applicability. • (1) The criteria in paragraph (b) of this
section apply to the State's designated uses cited in paragraph (d)
of this section and apply concurrently with any criteria adopted by
the State, except when State regulations contain criteria which are
more stringent for a particular parameter and use, or except as
provided in footnotes p, q, and x in paragraph (b) of this section.
(2) The criteria established in this section are subject to
the State's general rules of applicability in the same way and to
the same extent as are other Federally-adopted and State-adopted
numeric toxics criteria when applied to the same use
classifications including mixing zones, and low flow values below
which numeric standards can be exceeded in flowing fresh waters.
(i) For all waters with mixing zone regulations or
implementation procedures, the criteria apply at the appropriate
locations within-or at the boundary of the mixing zones; otherwise
the criteria apply throughout the water body including at the point
of discharge into the water body.
(ii) The State shall not use a low flow value below which
numeric standards can be exceeded that is less stringent than the
following for water suitable for the establishment of low flow
return frequencies (i.e., streams and rivers):
Aquatic Life: Acute Criteria (CMC): IQlOorlBB
Chronic Criteria (CCC): 7 Q 10 or 4 B 3
Human Health: Non-carcinogens: 30 Q 5
Carcinogens: Harmonic Mean Flow
Where: CMC (Criteria Maximum Concentration) is the water quality
criteria to protect against acute effects in aquatic life and is
the highest instream concentration of a priority toxic pollutant
consisting of a short-term average not to be exceeded more than
once every three years on the average;
CCC (Continuous Criteria Concentration) is the water quality
criteria to protect against chronic effects in aquatic life and is
the highest in stream concentration of a priority toxic pollutant
consisting of a 4-day average not to be exceeded more than once
-------
every three years on the average;
1 Q 10 is the lowest one day flow with an average recurrence
frequency of once in 10 years determined hydrologically;
1 B 3 is biologically based and indicates an allowable
exceedence of once every 3 years. It is determined by EPA's
computerized method (DFLOW model);
7 Q 10 is the lowest average 7 consecutive day low flow with
an average recurrence frequency of once in 10 years determined
hydrologically;
4 B 3 is biologically based and indicates an allowable
exceedence for 4 consecutive days once every 3 years. It is
determined by EPA's computerized method (DFLOW model);
30 Q 5 is the lowest average 30 consecutive day flow with an
average recurrence frequency of once in 5 years determined
hydrologically; and the harmonic mean .flow is a long term mean flow
value calculated by dividing the number of daily flows analyzed by
the sum of the reciprocals of those daily flows.
(iii) If the State does not have such a low flow value
below which numeric standards do not apply, then the criteria
included in paragraph (d) or this section herein apply at all
flows.
(3) The aquatic life criteria in the matrix in paragraph (b)
of this section apply as follows:
(i) For waters in which the salinity is equal to or less
than 1 part per thousand' 95% or more of the time, the applicable
criteria are the freshwater criteria in Column B;
(ii) For waters in which the salinity is equal to or
greater than 10 parts per thousand 95% or more of the time, the
applicable criteria are the saltwater criteria in Column C except
for selenium in the San Francisco Bay estuary where the applicable
criteria are the freshwater criteria in Column B (refer to
footnotes p and q in section (b)(1) above); and
(iii) For waters in which the salinity is between 1 and
10 parts per thousand as defined in paragraphs (c)(3)(I) and (ii)
of this section, the applicable criteria are the more stringent of
the freshwater or saltwater criteria. However, the Regional
Administrator may approve the use of the alternative freshwater or
saltwater criteria if scientifically defensible information and
data demonstrate that on a site-specific basis the biology of the
water body is dominated by freshwater aquatic life and that
freshwater criteria are more appropriate; or conversely, the
biology of the water body is dominated by saltwater aquatic life
and that saltwater criteria are more appropriate.
(4) Application of metals criteria. (i) For purposes of
calculating freshwater aquatic life criteria for metals from the
equations in paragraph (b)(2) of this section, for waters with a
hardness of 400 mg/1 or less as calcium carbonate, the actual
ambient hardness of the surface water shall be used in those
-------
equations. For waters with a hardness of over 400 mg/1 as calcium
carbonate, a hardness of 400 mg/1 as calcium carbonate shall be
used with a default Water-Effect Ratio (WER) of 1, or the. actual
hardness of the ambient surface water shall be used with a WER.
The same provisions apply for calculating the metals criteria for
the comparisons provided for in paragraph (c)(3)(iii) of this
section.
(ii) The hardness values used shall be consistent with
the design discharge conditions established in paragraph (c)(2) of
this section for flows and mixing zones.
(iii) The criteria for metals (compounds #1 - #13 in
paragraph (b) of this section) are expressed as dissolved except
where otherwise noted. For purposes of calculating aquatic life
criteria for metals from the equations in footnote i in the
criteria matrix in paragraph (b) (!) of this section and the
equations in paragraph (b) (2) of this section, the water effect
ratio is generally computed as a specific pollutant's acute or
chronic toxicity value measured in water from the site covered by
the standard, divided by the respective acute or chronic toxicity
value in laboratory dilution water. To .use a water effect ratio
other than the default of-1, the WER must be determined as set
forth in Interim Guidance on Determination and Use of Water Effect
Ratios, U.S. EPA Office of Water, EPA-823-B-94-001, February 1994,
or alternatively, other scientifically defensible methods adopted
by the State as part of its water quality standards program and
approved by EPA. For calculation of criteria using site-specific
values for both the hardness and the water effect ratio, the
hardness used in the equations in paragraph (b)(2) of this section
must be determined as required in paragraph (c) (4) (ii) of this
section. Water hardness must be calculated from the measured
calcium and magnesium ions present, and the ratio of calcium to
magnesium should be approximately the same in standard laboratory
toxicity testing water as in the site water.
(d)(1) Except as specified in paragraph (d)(3), below, all waters
assigned any aquatic life or human health use classifications in
the Water Quality Control Plans for the various Basins of the State
("Basin Plans"), as amended, adopted by the California State Water
Resources Control Board ("SWRCB"), except for ocean waters covered
by the Water Quality Control Plan for Ocean Waters of California
("Ocean Plan") adopted by the SWRCB with resolution Number 90-27 on
March 22, 1990, are subject to the criteria in paragraph (d)(2) of
this section, without exception. These criteria apply to waters
contained in the Basin Plans. More particularly, these criteria
apply to waters in the Basin Plan chapters specifying water quality
objectives (the State equivalent of federal water quality criteria)
for the toxic pollutants identified in paragraph (d) (2) of this
section. Although the State has adopted several use designations
-------
for each of these waters, for purposes of this action, the specific
standards to be applied in paragraph (d)(2) of this section are
based' on the presence in all waters of some aquatic life
designation and the presence or absence of the MUN use designation
(municipal and domestic supply). (See Basin Plans for more
detailed use definitions.)
(2) The following criteria from the matrix in paragraph (b)(1)
of this section apply to the water and use classifications defined
in paragraph (d)(1) of the section and identified below:
Water and use classification
All inland waters of the United States
or enclosed bays and estuaries that
are waters of the United States that
include a MUN use designation
All inland waters of the United States
or enclosed bays and estuaries that
are waters of the United States that
do not include a MUN use designation
Applicable Criteria
These waters are assigned
the criteria in:
Columns Bl and B2 - all
pollutants
Columns Cl and C2 - all
pollutants
Column Dl - all pollutants
These waters are assigned
the criteria in:
Columns Bl and B2 - all
pollutants
Columns Cl and C2 - all
pollutants
Column D2 - all pollutants
(3) Nothing in this section is intended to supersede specific
criteria, including specific criteria for the San Francisco Bay
estuary, promulgated for California in the National Toxics Rule, 40
CFR 131.36, 57 FR 60848-60923, December 22, 1992, as amended by 60
FR 22228, May 4, 1995.
(4) The human health criteria shall be applied at the State-
adopted 10 (-6) risk level.
(5) Nothing in this section applies to waters located in
Indian Country.
(e) Schedules of Compliance: (1) It is presumed that new and
existing point source dischargers will promptly comply with any new
or more restrictive water quality-based effluent limitations
("WQBELs") based on the water quality criteria set forth in this
section.
(2) When a permit issued on or after the effective date of
this regulation to a new discharger contains a WQBEL based on water
quality criteria set forth in the section, the permittee shall
comply with such WQBEL upon the commencement of the discharge. A
new discharger is defined as any building, structure, facility, or-
-------
installation from which there is or may be a "discharge of
pollutants" (as defined in 40 CFR 122.2) to the State of
California's inland surface waters or enclosed bays and estuaries,
the construction of which commenced after the effective date of
this regulation.
(3) Where an existing discharger reasonably believes that it
will be infeasible to promptly comply with a hew or more
restrictive WQBEL based on the water quality criteria set forth in
this section, the discharger may request approval from the permit
issuing authority for a schedule of compliance.
(4) A compliance schedule shall require compliance with
WQBELs based on water quality criteria set forth in this section as
soon . as possible, taking into account the dischargers technical
ability to achieve compliance with such WQBEL.
(5) If the schedule of compliance exceeds one year from the
date of permit issuance, reissuance or modification, the schedule
shall . set forth interim requirements and dates for their
achievement. The dates of completion between each requirement may
not exceed one year. If the time necessary for completion of any
requirement is more than one year and is not readily divisible into
stages for completion, the permit shall require, at a minimum,
specified dates for annual submission of progress reports on the
status of interim requirements.
(6) In no event shall the permit issuing authority approve a
schedule of compliance for a point source discharge which exceeds
five years from the date of permit issuance, reissuance, or
modification, whichever is sooner. Where shorter schedules of
compliance are prescribed or schedules of compliance are prohibited
by law, those provisions shall govern.
(7) If a schedule of compliance exceeds the term of a permit,
interim permit limits effective during the permit shall be included
in the permit and addressed in the permit' s fact sheet or statement
of basis. The administrative record for the permit shall reflect
final permit limits and final compliance dates. Final compliance
dates for final permit limits, which do not occur during the term
of the permit, must occur within five years from the date of
issuance, reissuance or modification of the permit which initiates
the compliance schedule. Where shorter schedules of compliance are
prescribed or schedules of compliance are prohibited by law, those
provisions shall govern.
(8) No compliance schedule established in accordance with
paragraphs (e)(3)-(7) of this section shall allow more than ten
years from the effective date of this rule to achieve compliance
with any WQBEL based on the criteria set forth in this section.
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JUNE 1997
CHARACTERIZATION OF
BASELINE WATER QUALITY CHAPTER!
INTRODUCTION
To characterize the potential benefits associated with achieving EPA's proposed numeric
criteria for priority pollutants, we begin by describing current water quality conditions in California.
Information on the extent to which State waters currently meet the proposed criteria is incomplete.
Water quality conditions in many State waters have not yet been fully assessed, and assessments of
waters that have been evaluated often do not contain monitoring data that is extensive or detailed
enough to determine whether the waterbody meets all of the proposed criteria. Nonetheless, there
are numerous sources of information on current water quality conditions in California, many of
which attempt to characterize the nature and extent of toxics pollution. We rely on these sources to
describe current water quality conditions in California's inland waters, enclosed bays, and estuaries.
Our analysis indicates that toxic pollutants impair many of California's surface water
resources.1 Exhibit 2-1 summarizes the water quality assessment for the entire state.
• Toxic pollutants adversely affect large areas of surface water in California.
. Available data suggest that over 800,000 acres of bays, estuaries, lakes, and
wetlands are affected by toxics, as are over 3,700 miles of rivers. Most
notably, over two-thirds of the assessed area of both bays and saline lakes are
thought to be affected by toxics.
1 We define "impaired" waters as those that are rated by the State of California as medium
or poor water quality for at least one toxic water quality pollutant or groups of pollutants. See text
below for a more detailed discussion.
2-1
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JUNE 1997
Exhibit 2-1
SUMMARY OF CALIFORNIA REGIONAL
WATER QUALITY ASSESSMENTS
Region
Region 1 : North
Coast Region
Region 2: San
Francisco Bay
Region 3 : Central
Coast Region
Region 4: Los
Angeles Basin
Region 5: Central
Valley Region
Region 6:
Lahontan Region
Region 7:
Colorado River
Basin
Areal Extent of Toxics
Impairment
55% of bays (16,500 acres); minor
impairment of other waterbodies
Large areas impaired by toxics,
including 70% of bays (200,000 acres);
60% of wetlands (57,000 acres); 39%
of rivers (244 miles)
47% of lakes (1 1,7.00 acres); 36% of
estuaries (1,700 acres); minor
impairment of rivers and bays
Over 90% of bays and estuaries
impaired (16,000 acres); minor
impairment of rivers and lakes
Large areas impaired by toxics,
including 100% of estuaries (48,000
acres); 23% of lakes (120,000 acres);
21% of rivers (1,200 miles)
34% of saline lakes (66,000 acres);
19% of lakes (36,000 acres; 13% of
rivers (372 miles)
60% of rivers (1,400 miles) impaired;
220,000 acres of saline lake (Salton
Sea)
Pollutants of
Concern
Metals, pesticides
Metals, trace elements,
priority organics
Metals, pesticides
Pesticides, priority
organics, trace
elements
Metals, trace elements
Metals, trace elements,
priority organics
Pesticides, trace
elements
Primary Pollutant Sources
Mix of point sources
(municipal and industrial
effluent) and nonpoint
sources (agriculture and
urban runoff)
Urban runoff and other
nonpoint sources affect
largest areas; some
impairment from municipal
and industrial point sources
Agriculture, mining,
unspecified nonpoint
sources
Mix of point sources
(municipal treatment,
"other" point sources) and
nonpoint sources
(agriculture, hydrological
modification, and urban
runoff)
Agriculture, mining; smaller
areas affected by municipal
treatment, urban runoff,
storm sewers, and other
nonpoint sources ,
Naturally occurring levels
of metals and trace
elements; lesser areas
affected by agriculture, land
development, and mining
Agriculture
Key Waterbodies
Affected
Arcata Bay, Humboldt Bay
San Francisco Bay (Lower,
Central, South), Suisun
Marsh
Morro Bay, Carpinteria
Marsh, Elkhorn Slough
Mugu Lagoon
San Gabriel River (lower),
Los Angeles River (upper)
Delta Waterways, Clear
Lake, American River,
Feather River, Sacramento
River, Grasslands Marshes,
Shasta Lake
Eagle Lake, Owens River,
Truckee River, Honey Lake
Salton Sea
Natural Resources and
Beneficial Uses Affected
Recreation, municipal supply, wildlife habitat (e.g.,
salmon); fish spawning and/or migration; rare and
endangered species
Recreation, commercial fishing; wildlife habitat, fish
migration and/or spawning; rare and endangered
species; elevated concentrations of toxics in shellfish,
fish, and waterfowl; fish consumption advisories for
several waterbodies, including San Francisco Bay,
Lake Herman, Guadalupe Reservoir, and others;
waterfowl consumption advisory.
Recreation, wildlife habitat; fish consumption
advisory for Nacimiento River; fish migration and/or
spawning; rare and endangered species
Recreation, commercial shellfishing, navigation,
wildlife habitat; fish migration and/or spawning; rare
and endangered species; fish consumption advisories
for Lake Nacimiento and Los Angeles Harbor
Municipal supply, agriculture, recreation, wildlife
habitat; fish migration and/or spawning; rare and
endangered species; fish consumption advisories for
Clear Lake, Lake Berryessa, and Grasslands Area;
waterfowl consumption advisory for Grasslands Area
Recreation, municipal supply (exported); fish
migration and/or spawning; rare and endangered
species
Recreation, wildlife habitat; rare and endangered
species; fish consumption advisory for Salton Sea
2-2
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Exhibit 2-1
SUMMARY OF CALIFORNIA REGIONAL
WATER QUALITY ASSESSMENTS
Region
Region 8: Santa
Ana River Basin
Region 9: San
Diego Basin
Areal Extent of Toxics
Impairment
Over 90% of bays and estuaries
impaired (4,000 acres); 27% of lakes
(4,000 acres)
14% of estuaries; minor impairment of
other waterbodies
Pollutants of
Concern
Metals, pesticides
Metals, pesticides,
priority organics, trace
elements
Primary Pollutant Sources
Primarily nonpoint sources
including agriculture, urban
runoff, and land
development
Estuaries affected by land
disposal; other waterbodies
affected by diverse mix of
point and nonpoint sources
Key Waterbodies
Affected
Upper Newport Bay
San Diego Bay, Tijuana
River Estuary
Natural Resources and
Beneficial Uses Affected
Recreation, municipal supply, wildlife habitat, fish
spawning and/or migration
Recreation, commercial fishing and shellfishing, •
wildlife habitat, fish spawning and/or migration, rare
and endangered species
Source: EPA analysis of 1994 California Water Quality Assessment data base; State of California data on fish and waterfowl consumption advisories. Some key waterbodies impaired by toxics may have
changed since the 1994 analysis, but more recent data were not used in the preparation of this report due to time constraints.
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JUNE 1997
• Both point and nonpoint sources play a role in contributing to toxic pollution.
Agriculture, primarily agricultural drainage, is the most frequently cited
pollution source that impairs rivers and is also frequently cited as a
contributor to the impairment of lakes and reservoirs. Urban runoff and
"other" nonpoint sources (e.g., deposition, spills) are most frequently cited
as factors contributing to water quality problems in toxics-impaired bays.
Mining is the most frequently cited point source, particularly for lakes and
reservoirs, while toxics discharged by municipal wastewater treatment plants
contribute to the impairment of a variety of waterbody types, particularly
estuaries and wetlands.
• Inorganic pollutants such as metals and trace elements are the most
significant categories of toxic pollutants affecting waters statewide.
Pesticides are also associated with large areas of impairment.
• Based on the areal extent of contamination and the uses of affected
waterbodies, San Francisco Bay and the Central Valley appear to be the areas
most influenced by toxic contamination. In addition, toxics adversely affect
a high percentage of river and saline lake area in the Colorado River Basin.
While these areas constitute those most extensively affected by toxics, waters
in all regions show some degree of toxics impairment.
• Review of regional basin reports suggests that numerous affected waterbodies
currently or formerly supported recreational activity, and several are used for
commercial fishing or municipal water supplies. In addition, nearly all of the
affected waters serve as wildlife habitat, including habitat for threatened and
endangered species.
The following discussion summarizes available information on the nature and extent of toxic
pollution in waters subject to the proposed water quality criteria. It begins by describing the data
and analytic methods employed to characterize current water quality. It then presents the results of
the analysis, describing the share of State waters impaired by toxics, the specific pollutants that
contribute to impairment of water quality, and the sources of these pollutants. The discussion also
summarizes a more detailed assessment of water quality conditions in each of the State's nine Water
Quality Control Board regions. Appendix A presents the full detailed, regional assessment.
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JUNE 1997
DATA AND METHODOLOGY
Our primary source of information on surface water quality in California is the State's Water
Quality Assessment (WQA) database, developed and maintained by the State Water Resources
Control Board (SWRCB). The WQA is a compilation of data from the State's nine regional Water
Quality Control Boards and is organized by region and by waterbody type. It contains a range of
information on surface water pollution, including the pollutants that adversely affect water quality
in bodies of water that have been evaluated, the sources of pollution, the beneficial uses impaired,
and an overall rating of water quality. The State relies on the WQA to develop the biennial water
quality report required by §305(b) of the Clean Water Act. The WQA was last updated in 1994.2
The WQA is comprised of three major files: FACTSHT, SITEDATA, and POLLUTANT.
We relied on two of these files, POLLUTANT and SITEDATA, to characterize the extent to which
toxic pollutants adversely affect California's surface water resources. Both POLLUTANT and
SITEDATA report State evaluations of individual waterbodies or waterbody segments, each
stressing different aspects of the assessment. POLLUTANT presents information on the region in
which the waterbody is located, the size (acres or miles) of the waterbody or waterbody segment,
the types of pollutants affecting the waterbody, and the sources of those pollutants. SITEDATA
classifies waterbodies by type, identifies the beneficial uses of each waterbody, and indicates the
number of stream miles or acres to which the State has assigned water quality ratings of "good,"
"medium," "poor," or "unknown." As described below, we rely on information from both files to
identify California waters adversely affected by the toxic pollutants of interest.
Relevant Pollutants
The WQA includes data on a range of pollutants, including conventional pollutants and non-
conventional pollutants that are not addressed by the proposed rule. To identify waters impaired by
the pollutants of interest (toxic pollutants as defined by section 307(a) of the CWA), we cross-
referenced the pollutants cited in the WQA with those for which EPA proposes to establish criteria.
Exhibit 2-2 presents the resulting list of pollutants, along with the pollutant group to which they
belong (e.g., metals), as identified in the WQA. In analyzing the WQA to identify waters impaired
by the toxic pollutants of interest, we employ the subset of pollutants and pollutant groups listed in
the exhibit.
2 Water Quality Assessment; State Water Resources Control Board, California Environmental
Protection Agency, December 1994, p. i.
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JUNE 1997
Exhibit 2-2
WQA POLLUTANTS INCLUDED
IN THE BASELINE ASSESSMENT
OF CRITERIA POLLUTANT IMPACTS
Specific
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Silver
Unspecified. Metals
Zinc
Arsenic
Beryllium
Selenium
Unspecified Trace Element
Unspecified Toxic
2,4-D
Aldrin
Alpha-HCH
Beta-HCH
Chlordane
DDT
Dieldrin
Endosulfan
Endosulfan I
Endrin
Group A
HCB
HCH (Total)
Heptachlor
Heptachlor E
Herbicide
Lindane
PCP
Toxaphene
Unspecified Pesticide
PAH
PCB's
TCE
Unspecified. Priority Organic
Group
Metal
Metal
Metal
Metal
Metal
Metal
Metal
Metal
Metal
Trace Element
Trace Element
Trace Element
Trace Element
Misc. Toxic
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide
Pesticide •
Priority Organic
Priority Organic
Priority Organic
Priority Organic
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JUNE 1997
Exhibit 2-2 includes a number of pesticides listed by brand name, as they appear in the
WQA. In determining whether to include such pesticides in our analysis, we used the Registry of
Toxic Effects of Chemical Substances to identify their ingredients. Brand name pesticides are
included in the analysis only if their ingredients include compounds addressed by the proposed rule.
Exhibit 2-2 also includes several broad categories of pollutants listed in the WQA (e.g.,
Group A pesticides, or unspecified metals, toxics, pesticides, priority organics, or trace elements).
We include these categories in our analysis because they are likely to encompass one or more of the
specific pollutants addressed by the proposed rule. Similarly, we include in the analysis waters that
the WQA indicates are impaired by a relevant pollutant group ~ i.e., metals, pesticides, priority
organics, or trace elements - when no specific pollutant is listed. Since these categories or groups
may include pollutants other than those addressed by the proposed rule, this approach may overstate
the impact of the pollutants of interest; available data are insufficient to estimate the magnitude of
this potential effect. The approach is preferable, however, to excluding these categories or groups
from the analysis, since to do so would clearly understate current impacts.
Finally, there are several specific constituents for certain waterbodies in California that are
not included in the proposed rulemaking because EPA promulgated criteria for these pollutants in
a prior rulemaking (December 22, 1992 National Toxics Rule [40 CFR Part 131.36]). A detailed
summary of these constituents and waterbodies is presented in Chapter 1 along with a table of the
proposed water quality criteria. In describing the baseline conditions for waters in California, we
were not able to adjust the summary of water quality assessments to reflect this prior criteria
promulgation because the WQA data base did not include constituent-specific statistics. For
example, the National Toxics rule promulgated an aquatic life criterion for selenium for San
Francisco Bay. However, selenium is not specifically listed in the WQA, and is included only under
the "trace element" grouping. Consequently, we were not able to adjust downward ("net out") the
San Francisco Bay acreage affected by selenium in our summary tables. We do, however, attempt
to adjust for earlier promulgations in the assessment of ecological, human health, and economic
benefits, as described in later chapters.
Identifying Impaired Waters
To identify the extent to which California waters are adversely affected by the toxic
pollutants of interest, we employ data from both the SITED ATA and POLLUTANT files. The
definition of "impaired" that we employ is based on the water quality ratings assigned by the WQA.
As noted above, SITED ATA classifies the quality of assessed waters as good, medium, poor, or
unknown. The State defines the first three ratings as follows:
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JUNE 1997
Good quality waters support and enhance designated beneficial uses.
Medium quality waters support designated beneficial uses with occasional
degradation and include waters suspected to be "poor" where available data
are inadequate to allow a definitive conclusion.
Poor waters are those that cannot reasonably be expected to support
designated beneficial uses.3
For the purposes of this analysis, we define impaired waters as those rated "medium" or "poor." We
focus solely on the State's inland waters, enclosed bays, and estuaries, excluding from the analysis
the State's ocean waters, which are unaffected by the proposed rule.
To arrive at an estimate of the waterbody area impaired specifically by toxics (rather than
conventional pollutants), we first look at the POLLUTANT table. Since this table contains
pollutant-specific information for each waterbody, we link this table to the list of toxics regulated
under the proposed rule. We delete any waterbody that does not possess at least one of the toxics
listed in Exhibit 2-2 from the POLLUTANT data table.
Using the abridged POLLUTANT data table, which now contains only those waterbodies
having toxics regulated under the proposed rule, we identify the impaired waterbody area by looking
at the table's "Segment Size" field. This area is preferable to the area listed in SITED ATA because
it is specifically linked with the toxic pollutant(s), whereas the SITED ATA area cannot be linked
to specific pollutants.
In some cases, however, the POLLUTANT file is incomplete; indicating that a water segment
is affected by toxics, but failing to note the areal extent of toxics impairment (i.e., the "Segment
Size" field is either blank or contains a zero value). In these cases, we rely on information in the
SITED ATA table to identify the areal extent of potential toxics impacts. Since the SITED ATA
figures indicate the areal extent of impairment without reference to the pollutant(s) that cause(s) the
impairment, this approach may overstate the extent to which the pollutants of concern adversely
affect State waters. The extent of any such overstatement, however, is unknown.4
3 Water Quality Assessment; State Water Resources Control Board, California Environmental
Protection Agency, December 1994.
4 For a more detailed description of.the methodology used in analyzing the WQA data, see:
memorandum prepared for Christine Ruf, OPPE, prepared by Matt Schwartz and Bob Black,
Industrial Economics, Incorporated, "Analysis of the 1994 California Water Quality Assessment
Database," May 21,1997.
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JUNE 1997
Limitations of the Analysis
According to water quality experts from U.S. EPA and the State of California, some of the
assumptions used in the analysis may have created a bias towards overestimating the extent of toxics
contamination when this information was extrapolated to all waters in the State. These include
assuming that the percentage of toxics impairment found in assessed waters was the same as the
percentage of toxic impairment of waters throughout the State; that waters rated as medium impaired
waters (those which partially support their uses) were counted together with those rated as poor
impaired waters (those which do not support their uses); and that waters listed as impaired in one
data base, and associated with toxics in a second data base, were considered waters unpaired by
toxics.
Although the consensus of the U.S. EPA and State experts was that the above assumptions
may have created a bias toward overestimating toxics contamination Statewide, they also stated that
certain other assumptions used in the analysis may underestimate the extent of toxics contamination.
For example, the assumption that the type and scope of all toxics of concern in all State waters
appear in the WQA data base may underestimate the extent of toxics impairment because of the
infrequency of ambient monitoring throughout the State, or because of the difficulty of detecting the
ambient concentrations of certain toxic pollutants when their water quality criteria fall below the
minimum detection limit. Consequently, because of all of the uncertainties associated with the
WQA data base, State of California and U.S. EPA experts advised against an attempt to
quantitatively estimate the magnitude of the bias in either direction.
In addition to the limitations noted above, it is important to note that the waters we identify
as impaired by the pollutants of interest may also be impaired by other pollutants; bringing these
waters into compliance with the proposed criteria will not necessarily ensure compliance with all
applicable water quality standards or ensure full support of all designated uses. Moreover, the WQA
data and water quality ratings are based largely on the subjective evaluation of State experts, rather
than extensive ambient water quality monitoring. The subjective nature of this information
contributes to further uncertainty in the characterization of baseline water quality.
STATEWIDE ASSESSMENT OF TOXIC WATER POLLUTION
The data and analysis described above provide a general profile of the degree to which the
toxic pollutants addressed by EPA's proposed criteria adversely affect water quality in California's
inland waters, enclosed bays, and estuaries. The following discussion outlines the results of the
analysis, including:
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JUNE 1997
the areal extent of toxic contamination;
the primary sources of toxic contaminants; and
the principal categories of toxic pollutants that impair surface waters.
Areal Extent of Contamination
Exhibit 2-3 summarizes the estimated extent of toxic contamination in California waters,
based on analysis of the WQA data. The analysis indicates that the pollutants of interest impair over
800,000 acres of bays, estuaries, lakes, and wetlands, and over 3,700 miles of the State's rivers and
streams.
Exhibit 2-3
TOXICS-IMPAIRED WATERS AS A PERCENTAGE OF ASSESSED WATERS
Waterbody Type
Inland Bays
Estuaries
Lakes & Reservoirs
Rivers & Streams
Saline Lakes
Wetlands
Area Impaired
229,774 acres
55,738 acres
175,552 acres
3,737 miles
286, 182 acres
66,680 acres
Area Assessed
348,223 acres
11 9,683 acres
910,795 acres
19,994 miles
4 16,4 16 acres
244,050 acres
Percent of Assessed Area
Impaired by Toxics
66%
47%
19%
19%
69%
27%
Source: EPA analysis of 1 994 State of California WQA data.
To place these estimates in context, Exhibit 2-3 compares the figures given above to the share
of surface water resources for which the WQA provides water quality assessments. As the exhibit
indicates, relatively high percentages of assessed waters are impaired by toxics. In particular,
approximately two-thirds of assessed bay and saline lake areas suffer toxics impairment.5 Forty-
seven percent of the estuarine waters that the State has evaluated are impaired by toxics, as are 27
percent of assessed wetlands. In addition, approximately 19 percent of lake and reservoir acreage
and 19 percent of assessed stream and river miles are toxics-impaired.
5 For some categories, the figures reported in Exhibit 2-3 are driven by conditions in a single
large waterbody that accounts for most of the category's total assessed area. For example, most of
the saline lake acreage impaired by toxics is attributable to the Salton Sea in southeast California,
where 286,000 acres are affected.
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JUNE 1997
Whether these figures are representative of conditions in unassessed waters is unknown.
Although the WQA provides water quality assessments for only nine percent of California's total
stream and river miles, and approximately 50 percent of wetlands, about 77 percent of State total
lake and reservoir acreage has been assessed. Further, water quality analysts in EPA believe that
nearly all bays/estuaries and saline lakes in the State have been well characterized, monitored, or
otherwise evaluated for toxic contamination. As discussed earlier, based on recommendations from
EPA and State of California water quality experts, we have not attempted to systematically adjust
upwards or downwards the estimates given in Exhibit 2-3 to characterize the degree of impairment
of all California waters.
Categories of Toxic Pollutants
Exhibit 2-4 summarizes the frequency with which the WQA cites major categories of toxic
pollutants as contributors to water quality impairment. For each waterbody type, the exhibit
indicates the total area impaired by each pollutant category and the percentage of the total impaired
area with which the pollutant group is associated. Because a waterbody can be affected by more than
one pollutant, the percentages do not add to 100.
Exhibit 2-4 suggests that inorganic pollutants such as metals and trace elements are the most
common causes of water quality impairment by toxic pollutants statewide. The exhibit indicates that
with the exception of saline lakes, metals are a major cause of impairment for all waterbody types.
Metals contribute to the impairment of more than 90 percent of bay and esruarine areas adversely
affected by toxics, are cited as a factor in 87 percent of toxics-impaired lakes, reservoirs, and
wetlands, and contribute to impairment of 37 percent of the river and stream miles identified as
toxics-impaired. Trace elements, particularly selenium, also affect a large share of impaired waters.6
This is especially true for saline lakes, where all impaired waters are influenced by trace elements.
Trace elements also contribute greatly to impairment of bays, rivers, and streams.
6 An aquatic life criterion for selenium is already in effect for certain waterbodies in the state,
such as the Bay-Delta. However, current selenium criteria may not be stringent enough to
adequately protect some aquatic-dependent wildlife species.
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JUNE 1997
Exhibit 2-4
EXTENT OF IMPAIRMENT BY POLLUTANT TYPE
Bays (acres)
Estuaries (acres)
Lakes and
Reservoirs
(acres)
Rivers and
Streams (miles)
Saline Lakes
(acres)
Wetlands (acres)
Total
Area
Impaired
229,774
55,738
175,552
3,737
286,182
66,680
Metals
218,334
51,223
152,563
1,344
0
57,870
Share of
Total
Toxics-
Impaired
Area
95%
92%
87%
36%
0%
87%
Pesticides
135,385
52,480
507
2,392
0
588
Share of
Total
Toxics-
Impaired
Area
59%
94%
0%
64%
0%
1%
Priority
Organics
13,110
362
50
61
0
160
Share of
Total
Toxics-
Impaired
Area
6%
1%
0%
2%
0%
0%
Trace
Elements
118,501
2,749
28,527
2,049
286,182
8,274
Share of
Total Toxics-
Impaired
Area
52%
5%
16%
55%
100%
12%
Toxics
67,874
48,294
6,441
762
0
400
Share of
Total
Toxics-
Impaired
Area
30%
87%
4%
20%
0%
1%
Source: EPA analysis of California WQA data.
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JUNE 1997
Although less commonly cited than metals or trace elements, pesticides also contribute
significantly to toxic pollution in California waters. As Exhibit 2-4 shows, the WQA lists pesticides.
as a concern for 94 percent of toxics-impaired estuarine waters, hi addition, pesticides are identified
as the leading cause of impairment in toxics-impaired rivers and streams (64 percent of impaired
stream miles), and contribute to the pollution of 59 percent of the toxics-impaired waters in inland
bays.
I
In comparison to the other pollutant categories, priority organic pollutants play a relatively
minor role. The WQA lists priority organics as a causal factor for only six percent of toxics-
impaired bay waters, two percent of toxics-impaired river and stream miles, and less than one
percent of other toxics-impaired waters.
Toxic Pollutant Sources
The WQA identifies 11 pollution source categories, including agriculture,
hydrological/habitat modification, industrial point sources, land development, land disposal, mining,
municipal point sources, storm sewers, "other" point sources, urban runoff, and "other" nonpoint
sources (air deposition, cross-border pollution, spills, and natural sources). Each of these sources
contributes to water quality problems in State waters that are impaired by toxic pollutants. Exhibit
2-5 summarizes the available data on these sources, indicating, for each waterbody type, the total
area of toxic impairment for which the WQA lists the source. The exhibit also indicates the
percentage of the total toxics-impaired area that is associated with each source. Because a waterbody
can be affected by more than one source, the percentages do not add to 100.
The WQA data indicate that both point and nonpoint sources contribute significantly to toxic
pollution, although the importance of different sources varies considerably across waterbody
categories. For example, "other" nonpoint sources are cited most frequently as contributors to
pollution in toxics-impaired bays, followed by urban runoff and municipal point source discharges.7
In contrast, the WQA identifies a wide range of sources - including agriculture, hydrological/habitat
modification, mining, municipal point sources, urban runoff, and "other" point and nonpoint sources
— as frequent contributors to the pollution of toxics-impaired estuaries. Mining, "other" nonpoint
sources, and land development are the leading sources of pollution in toxics-impaired lakes and
reservoirs. For toxics-impaired rivers and streams, agriculture is the most frequently listed pollution
source, followed by "other" nonpoint sources, mining, and urban runoff.
7 The WQA frequently lacks information on pollution sources for enclosed bays. This
accounts in part for the relatively low percentages of toxics-impaired bay areas that are associated
with specific sources.
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JUNE 1997
Exhibit 2-5
MAJOR SOURCES OF TOXIC POLLUTANTS IN CALIFORNIA WATERBODIES
Agriculture
Hydro/Habitat
Modification
Industrial
Land Development
Land Disposal
Mining
Municipal
Other Nonpoint
Sources
Other Point
Sources
Storm Sewers .
Urban Runoff
Bays
(acres)
17,860
2,100
16,805
0
0
474
27,201
83,149
12,910
165
44,152
Share of Total
Toxics-Impaired
Area
8%
<1%
7%
0%
0%
<1%
12%
36%
6%
<1%
19%
Estuaries
(acres)
51,883
48,150
238
1,182
1,261
48,000
48,003
52,731
0
1,457
50.880
Share of Total
Toxics-Impaired
Area
93%
86%
<1%
2%
2%
86%
86%
95%
0%
3%
91%
Lakes &
Reservoirs
(acres)
2,410
0
295
26,500
0
106,748
0
64,350
0
0
7,995
Share of Total
Toxics-Impaired
Area
1%
0%
<1%
15%
0%
61%
0%
37%
0%
0%
5%
Rivers &
Streams
(miles)
2,260
40
273
106
19
930
276
987
4
185
537
Share of Total
Toxics-Impaired
Area
60%
1%
7%
3%
1%
25%
7%
26%
<1%
5%
14%
Saline
Lakes
(acres)
286,182
0
0
10,855
0
0
0
230,855
0
0
0
Share of Total
Toxics-Impaired
Area
100%
0%
0%
4%
0%
0%
0%
81%
0%
0%
0%
Wetlands
(acres)
9,211
0
0
500
400
2
57,000
58,204
0
235
58,203
Share of Total
Toxics-Impaired
Area
14%
0%
0%
1%
1%
0%
85%
87%
0%
<1%
87% •
Source: EPA analysis of California 1994 WQA data.
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JUNE 1997
In contrast to the data on other categories, the source data on toxics-impaired saline lakes and
wetlands primarily reflect conditions in each category's largest waterbody. The saline lake category
is dominated by the Salton Sea (220,000 acres), which is affected by agriculture in the Imperial
Valley as well as by other nonpoint sources. Likewise, the wetlands category is dominated by the
San Francisco Bay region's Suisun Marsh (48,000 acres), which is affected by municipal point
source discharges as well as by urban runoff and other nonpoint sources.
REGIONAL ASSESSMENT OF TOXICS IMPAIRMENT
To provide a more thorough assessment of toxic pollution in California waters, we have
developed detailed profiles of water quality conditions in each of the State's nine water quality
regions (see Figure 2-1 for the regions' locations). Appendix A presents these regional profiles,
including an overview of regional hydrology, a discussion of the nature and extent of toxic pollution
in each region, and a description of toxic pollutant impacts on major bays, estuaries, lakes, rivers and
wetlands. The following discussion identifies the sources consulted in developing these regional
assessments, then briefly summarizes the analysis, focusing on the regions and major waterbodies
most affected by toxic pollutants.
Information Sources
In addition to analysis of the WQA, the regional assessment relies on a number of additional
sources to describe current water quality conditions in California, including regional basin reports,
the State's CWA § 305(b) and § 303(d) reports, and the California Bay Protection and Toxic Cleanup
Program. These sources are described briefly below.
• Basin Reports; In accordance with § 303(c) of the Clean Water Act,
California's nine Water Quality Control Boards each periodically issue basin
reports documenting water quality objectives for each region. The basin
reports provide information on regional hydrology and describe the beneficial
uses of the region's waterbodies. They also provide information on regional
water quality issues.
'2-15
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Figure 2-1
LEGEND
Regional Water Quality Control Board
1 North Coast
2 San Francisco Bay
3 Central Coast
4 Los Angeles
5 Central Valley
6 Lahontan
7 Colorado River
8 Santa Ana
9 San Diego
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JUNE 1997
• California §305(fr> Report: As required by CWA §305(b), California's
biennial Report on Water Quality summarizes water quality conditions
throughout the State. The report also provides anecdotal information on
waterbodies in which toxic pollutants are a major concern, and highlights
selected efforts to improve toxic pollution control.8
• California §303(cn Report: In accordance with CWA §303(d), the
California Report on Impaired Surface Waters lists waters that do not support
designated beneficial uses or meet water quality objectives. The report also
indicates regional priorities for future efforts to improve water quality,
ranking each impaired waterbody on a scale of 1 (highest) to 5 (lowest) based
on: (1) the degree of impairment; and (2) the intrinsic value of the waterbody
as a function of beneficial uses potentially associated with the waters.9
• California's Bay Protection and Toxic Cleanup Program (BPTCP) is a
state-run effort to identify enclosed bays and estuaries most affected by toxic
pollution and provide for their cleanup. This effort lists toxic "hot spots" and
"potential hot spots". Hot spots are defined as areas exhibiting significant
toxicity, high levels of bioaccumulation, and impairment of ecologic
beneficial uses, while potential hot spots display elevated toxic
concentrations in water or sediment, but lack sufficient data to designate as
a known hot spot.10
Summary of Findings
Exhibit 2-1 (presented above) summarizes the findings of the State's regional water quality
assessment. The exhibit provides the following information for each region:
• Areal Extent of Toxics Impairment: Identifies, by waterbody type, the
percent of assessed area adversely affected by toxics, as indicated by analysis
of WQA data.
8 Draft: California 305(b) Report on Water Quality; State Water Resources Control Board,
October 1994.
9 In instances where regional staff could not agree on a waterbody ranking, no ranking is
provided.
10 Bay Protection and Toxic Cleanup Program: Staff Report, State Water Resources Control
Board, State of California, November, 1993, p. 8.
2-17
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JUNE 1997
Primary Sources: Identifies the major sources of toxic pollutants in the
region, as indicated by analysis of WQA data.
Key Waterbodies Impaired: Identifies significant waterbodies affected by
toxics, based on a cross-tabulation of WQA data with California's § 303(d)
list. The waterbodies listed are those rated highest on the § 303(d) priorities
list (i.e., those assigned a priority rating of 1 or 2).
Natural Resources and Beneficial Uses: Identifies the ecological services
and human uses associated with toxics-impaired waters. This information is
based on the beneficial use tables included in the regional basin plans,
supplemented with information from the WQA database.11
The regional assessment suggests that impairment of water quality by toxics is particularly
significant in Region 2 (San Francisco Bay). According to the analysis of WQA data, San Francisco
Bay alone accounts for approximately 85 percent of the total inland bay area affected by toxics. In
addition, the WQA analysis indicates that approximately 60 percent of assessed wetlands in Region
2 ~ a sizeable portion of the State total - is affected by toxics, as is a significant share of the
Region's rivers.12 The WQA data on the sources of toxic pollutants in Region 2 are limited;
however, the available data suggest that urban runoff and nonpoint sources are the principal toxics
sources. Point sources are less prominent, with municipal treatment plants affecting the Suisun
Marsh wetlands and mining contributing to impairment of some lakes and rivers. Other information
sources support the WQA analysis. For example, research on San Francisco Bay compiled by EPA
state and local agencies suggests that non-urban runoff is a major source of several toxics, including
arsenic, cadmium, chromium, copper, lead, mercury, and zinc. Urban runoff contributes significant
shares of lead and PCBs. Trace element loadings can be^traced to irrigation return flows and other
nonpoint sources in the Central Valley, transported to San Francisco Bay via the San Joaquin
River.13
11 The beneficial uses drawn from the basin reports are based on the best judgment of regional
Water Quality Control Board staff. In most cases, the beneficial use is ongoing. Available data do
not. clearly indicate whether certain uses have been precluded by toxic pollution.
12 Suisun Marsh accounts for all of the impaired wetland acreage.
13 State of the Estuary: San Francisco Estuary Project, U.S. EPA and the Association of Bay
Area Governments, June 1992, p. 172.
2-18
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JUNE 1997
Toxics also affect a high percentage of assessed waters in the State's largest region, Region
5 (Central Valley). All of the estuarine waters assessed in the Region (48,000 acres) are adversely
affected by toxics, as are approximately 23 percent of assessed lakes (120,000 acres) and 21 percent
of assessed rivers (1,200 miles).14 Agriculture and mining are the most significant sources of toxic
pollutants in the Central Valley. The WQA data suggest that agriculture affects large portions of
estuaries, rivers, and wetlands, while mining discharges affect estuaries, lakes, and rivers.
Unspecified nonpoint sources, municipal wastewater treatment plants, storm sewers, and urban
runoff also add to toxic impairment.
California's § 303(d) list indicates that many of the Central Valley waterbodies affected by
toxics are high priorities for State action because of the degree of pollution and/or the beneficial uses
associated with the waterbody. These include the Delta Waterways, Clear Lake, the lower sections
of the American and Feather Rivers, and sections of the Sacramento River. Metals, pesticides, and
unspecified toxics combine to affect these waterbodies. Shasta Lake and the Grasslands Marshes,
which are also high priority waters, are affected by metals and trace elements, respectively.
A number of other State water quality regions also suffer high degrees of toxics pollution.
For example, toxic pollutants associated with agricultural activity in Region 7 — the Colorado River
Basin in southeast California - impair a significant percentage of the Region's river and saline lake
areas. Trace element contamination in the Salton Sea accounts for the majority of impaired saline
lake acreage in California. Similarly, over 1,400 river miles in Region 7 are affected by pesticides
and trace elements from agricultural activity; this accounts for about 40 percent of all impaired river
miles statewide.
The beneficial uses associated with toxics-impaired waterbodies are diverse and suggest that
toxic pollution affects critical areas. As shown in Exhibit 2-1, every region contains toxics-impaired
waters that are intended to support both contact (e.g., swimming, fishing) and non-contact (e.g.,
boating) recreational activities. As just one indicator of impairment, toxics pollution has led to fish
consumption advisories in several areas. Likewise, all the regions include toxics-impaired waters
that function as wildlife habitat. In many cases, the affected area supports an endangered species
or has been afforded "wild and scenic" status. As one example, both the Klamath (Region 1) and
Sacramento (Region 5) Rivers support endangered salmon species.
14 The Delta Waterways account for all of the impaired estuarine area.
2-19
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JUNE 1997
A variety of other beneficial uses are associated with California's toxics-impaired waters.
For example, commercial fishing and shellfishing are common in San Francisco Bay and other bay
areas. In addition, waterbodies serving as municipal water supplies in several regions are affected
by toxics.15 Most notably, several affected waters in Region 6 supply large municipalities in
California and Nevada, including Los Angeles.
CONCLUSIONS
Analysis of California's Water Quality Assessment database and a variety of other sources
supports the following conclusions:
• Toxic pollutants adversely affect large areas of surface water in California.
Available data suggest that over 800,000 acres of bays, estuaries, lakes, and
wetlands are affected by toxics, as are over 3,700 miles of rivers. Most
notably, over two-thirds of the assessed area of both bays and saline lakes are
thought to be affected by toxics.
• Both point and nonpoint sources play a role in contributing to toxic pollution.
Agriculture, primarily agricultural drainage, is the most frequently cited
source of pollutants that impair rivers and is also frequently cited as a
contributor to the impairment of lakes and reservoirs. Urban runoff and
"other" nonpoint sources (e.g., deposition, spills) are most frequently cited
as contributing factors to water quality problems hi toxics-impaired bays.
Mining is the most frequently cited point source, particularly for lakes and
reservoirs, while toxics discharged by municipal wastewater treatment plants
contribute to the impairment of a variety of waterbody types, particularly
estuaries and wetlands.
• Inorganic pollutants such as metals and trace elements are the most
significant categories of toxic pollutants affecting waters statewide.
Pesticides are also associated with large areas of impairment.
15 Because the available data are not specific, it is possible that the portion of a waterbody
from which municipal supplies are drawn may be different from the toxics-affected portion.
2-20
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JUNE 1997
• Based on the areal extent of contamination and the uses of affected
waterbodies, San Francisco Bay and the Central Valley appear to be the areas
most influenced by toxic contamination. In addition, toxics impair a high
percentage of river and saline lake area in the Colorado River Basin. While
these areas constitute those most extensively affected by toxics, waters in all
regions show some degree of toxics impairment.
• Improving the quality of many of the waters impaired by toxics is a high
priority for the State. Review of regional basin reports suggests that
numerous affected waterbodies currently or formerly supported recreational
activity, and several are used for commercial fishing or municipal water
supplies. In addition, nearly all of the affected waters serve as wildlife
habitat, including habitat for threatened and endangered species.
2-21
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JUNE 1997
REFERENCES
State Water Resources Control Board, Water Quality Assessment, California Environmental
Protection Agency, December 1994.
State Water Resources Control Board, California 305(b) Report on Water Quality (Draft), California
Environmental Protection Agency, October 1994.
State Water Resources Control Board, Bay Protection and Toxic Cleanup Program (Staff Report),
California Environmental Protection Agency, November 1993.
U.S. EPA, "Analysis of the 1994 California Water Quality Assessment Database," memorandum to
Christine Ruf, OPPE, prepared by Matt Schwartz and Bob Black, Industrial Economics,
Incorporated, May 21,1997.
U.S. EPA, State of the Estuary, San Francisco Estuary Project, Association of Bay Area
Governments, June 1992.
2-22
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JUNE 1997
ANGLER HEALTH RISK ASSESSMENT CHAPTER 3
INTRODUCTION
This chapter characterizes the health risks faced by recreational anglers in California as a
result of the consumption of fish contaminated by toxics. The chapter also evaluates the angler
health benefits associated with meeting the water quality criteria established by the California Toxics
Rule (CTR). The analysis begins by estimating health risks under current, or baseline, conditions,
evaluating both the carcinogenic and noncarcinogenic (systemic) risks from consumption of fish
caught by recreational or subsistence anglers. The analysis then estimates potential reductions in
angler health risks by comparing baseline health risks to the proposed criteria's target health risk
levels.
It is important to note that we may underestimate some of the angler human health benefits
associated with meeting CTR criteria because we have not considered the health risks associated
with consuming commercially caught fish. California has commercial fisheries in water bodies
covered by this rule, and it is likely that reduced toxics contamination of California waters to meet
the CTR criteria will result in some reduced toxic contamination of commercial fisheries. However,
because of difficulties in estimating the number of exposed individuals as well as difficulties in
linking toxic contamination solely to California sources, we were not able to estimate the baseline
health risks and benefits associated with meeting the CTR.
3-1
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JUNE 1997
The California Toxics Rule addresses both inland freshwater bodies and enclosed bays and
estuaries. This analysis considers two populations of anglers in California who utilize these
resources - inland freshwater anglers and San Francisco Bay anglers. The first group includes all
freshwater anglers throughout the state. The second group, San Francisco Bay anglers, is presented
as a case study of the baseline health risks for anglers fishing in enclosed bays and estuaries. San
Francisco Bay represents one of the most significant non-commercial fisheries among the bays and
estuaries covered by the rule. In addition, the Bay has been adversely affected by toxic pollution,
as evidenced by the current health advisory warning against consumption of San Francisco Bay sport
fish, including striped bass and shark. Despite the issuance of the warning in December 1994, the
Bay remains a popular area for anglers.
The potential for health risks from consumption offish contaminated with toxics is illustrated
by the health advisories that have been issued in California warning anglers against consuming fish
caught in specific inland waters, bays, and estuaries. Currently, there are 12 fish consumption health
advisories in the state: nine in inland waterbodies and three in enclosed bays and estuaries. Exhibit
3-1 provides details for each of these advisories. Inland waterbodies with advisories include rivers,
lakes and the Salton Sea. Enclosed bays and estuaries with advisories include San Francisco Bay
and Los Angeles/Long Beach Harbor. The advisories in these areas range from avoiding
consumption of all species to limiting consumption of specific species. Fish contaminants that are
responsible for these advisories include DDT, chlordane, dioxin, mercury, PCBs and selenium.
The baseline assessment of angler health risks has been developed based on current
contaminant levels in fish tissue samples collected from San Francisco Bay and freshwater sport
fisheries throughout California. The potential health benefits of the rule have been developed by
estimating the potential baseline health risks to anglers consuming contaminated fish, and then
comparing these to health risks predicted to occur post-rule, assuming waters meet the CTR criteria
based on a cancer risk level of 1 x 10'6 for the general population. Since the State of California has
the flexibility to choose criteria based on less stringent cancer risk levels, we evaluate the potential
health benefits to anglers based on a risk level of 1 x 10~5 for the general population. To more fully
evaluate the health benefits of the rule, it would be necessary to estimate the resulting reductions in
toxics loadings to surface water and the impact of these reductions on contaminant levels in fish
tissue. However, due to the complex interactions between toxics loadings to surface water, toxics
in other media (e.g., sediment), and fish tissue contaminant levels, such an analysis is beyond the
scope of this effort.
3-2
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JUNE 1997
Exhibit 3-1
FISH CONSUMPTION HEALTH ADVISORIES IN CALIFORNIA
Waterbody/Location
Number of Samples
in Study Database1
Advisory for General Population
Avoid
Consumption
Limit
Consumption3
Advisory for Sensitive Populations1
Avoid
Consumption
Limit
Consumption1
Contaminants of
Concern
New River
12
All species
All species
Pesticides
Biological contaminants
Clear Lake
(Lake County)
1 Ib. per month
- Largemouth bass over 13"
- Channel catfish over 24"
- Crappie over 12"
2 Ibs. per month
- Largemouth bass under 13"
3 Ibs. per month
- Channel catfish under 24"
- Crappie under 12"
- White catfish
6 Ibs. per month
- Brown bullhead
- Sacramento blackfish
10 Ibs. per month
- Hitch
All species
Mercury
Lake Nacimiento
(San Luis Obispo
County)
4 meals per month
- Largemouth bass
Largemouth bass
Mercury
Lake Herman
(Solano county)
1 Ib. per month
- Largemouth bass
Catfish
Mercury
3-3
-------
Exhibit 3-1
FISH CONSUMPTION HEALTH ADVISORIES IN CALIFORNIA
||||||||||U||||M
Waterbody/Location
Lake Berryessa
(Napa County)
Guadalupe Reservoir
Calero Reservoir .
Alamaden Reservoir
Guadalupe River
Guadalupe Creek
Alamital Creek
Plus associated ponds
along these rivers and
creeks
(Santa Clara County)
Harbor Park Lake
(Los Angeles County)
Grassland Area
Kesterson National
Wildlife Refuge
(Merced County)
Number of Samples
in Study Database1
0
0
0
0
0
0
0
0
0
0
MBMI^^MMM^Bi^MBMiaiaiiaiBaaBSaiSBalSISliaBMMi
Advisory for General Population
Avoid
Consumption
All fish
Goldfish
Carp
Catfish
Limit
Consumption3
1 Ib. per month
- Largemouth bass over 15"
- Smallmouth bass
2 Ibs. oer month
- Largemouth bass under 15"
- White catfish
3 Ibs. oer month
- Channel catfish
10 Ibs. per month
- Rainbow trout
Max. of 4 oz. everv two weeks
All fish
Advisory for Sensitive Populations*
Avoid
Consumption
All fish
All fish
Goldfish
Carp
All fish
Limit
Consumption3
^HI^^BO^
Contaminants of
Concern
Mercury
Mercury
DDT
Chlordane <
Selenium
3-4
-------
Exhibit 3-1
FISH CONSUMPTION HEALTH ADVISORIES IN CALIFORNIA
^^^^™
Waterbody/Location
Salton Sea
SBBaB^^^^^^^BBB
^^^~
Number of Samples
in Study .Database1
0
=^^^^_^^___
^^^^^^^^^^••HMMH^HB^^^
Advisory for General Population
Avoid
Consumption
^^^^^Bas^s
Limit
Consumption3
Max, of 4 oz. every two weeks
- Croaker .
-Sargo
- Tilapia
- Orangemouth Corvina
^ -^ __-—
^^^^^^^~
Advisory for Sensitive Populations2
Avoid
Consumption
All fish
— —^g. — ^^^^^
Limit
Consumption1
^HOI^^^^^H
Contaminants of
Concern
Selenium
San Francisco Bay
Belmont Pier/Pier J
(Los Angeles Harbor)
Los Angeles/Long
Beach Harbors
(esp. Cabrillo Pier)
64
0
0
Striped Bass over
35"
White Croaker
Max, of 2 meals per month
- All sport fish
Max, of 2 meals per month
- Surfperches
Max, of 2 meals per month
- Queenfish
- Surfperches
- Black Croaker
Striped Bass over
27"
Shark over 24"
Max, of 1 meal per
month
All sport fish
Mercury
PCBs
Dioxins
Pesticides
DDT, PCBs
DDT, PCBs
Notes:
1 Number of samples in the freshwater or San Francisco Bay fish tissue databases developed for this study that were collected from these waterbodies.
2 California EPA defines sensitive populations as women who are pregnant, who may become pregnant, or who are breast-feeding, and children
under six years of age.
3 California EPA defines a meal as six to eight ounces (170 grams to 227 grams) offish for a 154 pound (70 kilogram) individual. Meal size should be adjusted according to body
weight (roughly one ounce offish per 20 pounds of body weight).
4 In addition to these advisories, California EPA has issued consumption warnings for the following ocean sites in Southern California that are not included within the scope of the
California Toxics Rule: Newport Pier, Redondo Pier, Malibu Pier, Short Bank, Malibu/Point Dume, Point Vicente, Palos Verdes-Northwest, White's Point, Los Angeles/Long
Beach Breakwater (ocean side), and Horseshoe Kelp. Detailed information on these advisories is available in the California Sport Fishing Regulations Handbook.
3-5
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JUNE 1997
Exhibit 3-1 (continued)
CALIFORNIA FRESHWATER AND INLAND BAYS AND ESTUARIES
FISH CONSUMPTION HEALTH ADVISORIES
IKesterson National Wildlife Refuge I
IGuadalupe Reservior/River/Creek and other Sanla Clara Co. Lakes!
(1) Los Angeles Harbor/Long Beach Harbor
(2) Belmonl Pier/Pier J
3-6
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JUNE 1997
Summary of Findings
There are potentially significant cancer and noncancer health baseline risks associated with
consumption offish containing toxic pollutants for both freshwater and San Francisco Bay anglers.
The cancer and noncancer health risks for these two populations of anglers are summarized in
Exhibits 3-2 and 3-3, respectively. Risk levels for freshwater anglers are slightly lower than those
for San Francisco Bay anglers, with freshwater angler cancer risks and noncancer risks being roughly
1.2 to 1.5 times less than those for San Francisco Bay anglers.
Summary of Potential Baseline Cancer Risks to Anglers
• mdividual excess lifetime cancer risks from fish consumption for freshwater
anglers range from 1.5 x 10"4 to 3.5 x 10~* for typical angler consumption (i.e.,
21.4to49.6g/day).1
• Upper-bound consumption (i.e., 90th percentile fish consumption of 107.1
g/day) for freshwater anglers results in an individual excess lifetime cancer
risk of 7.6 xlO-4.
• California's freshwater angling population may incur between 5 and 11 cases
of cancer each year (based on typical consumption rates and a population of
approximately 2.2 million freshwater anglers).
• Current individual excess lifetime cancer risks for typical San Francisco Bay
anglers range from 1.8 x 10^ to 4.3 x 104.
• Upper-bound consumption for San Francisco Bay anglers results in an
individual excess lifetime cancer risk of 9.2 x 10~*.
• San Francisco Bay's angling population may incur less than one to one case
of cancer each year, or a total of 23 to 53 cases over 70 years (based on
typical consumption and a Bay area angler population of approximately
125,000 individuals).
1 See the section on Risk Assessment and Appendix D for a complete description of the
methodology for evaluating cancer health effects.
3-7
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JUNE 1997
The San Francisco Bay case study provides quantitative health risk estimates
for 125,000 recreational anglers fishing in the Bay area. The CTR, however,
also governs water quality in California's other saltwater inland bays and
estuaries. The case study does not include baseline risk estimates for the
500,000 to 600,000 saltwater anglers that fish outside of San Francisco Bay.
These potential baseline cancer risks are dominated by four contaminants. Polychlorinated
biphenyls (PCBs) account for nearly 40 percent of the freshwater angler cancer risk. Toxaphene
accounts for approximately 20 percent of the risk, while DDT and dieldrin each make up 16 percent
of the risk. Two contaminants dominate the San Francisco Bay angler cancer risks. PCBs account
for roughly 50 percent of the cancer risk, followed by dioxin contributing 40 percent.
Exhibit 3-2
POTENTIAL BASELINE CANCER RISKS FOR
FRESHWATER AND SAN FRANCISCO BAY ANGLERS
Freshwater Anglers
San Francisco Bay Anglers
Individual Excess Lifetime Cancer Risk
Typical
Consumption1
1. 5 xlO"1- 3.5x10-"
1.8x10-" -4.3x10-"
90th Percentile
Consumption2
7.6 xlO"4
9.2 x 10"4
Annual
Population Risk
(excess cases per year)3
5-11
<1-1
1 Typical fish consumption for recreational anglers in California ranges from 2 1 .4 to 49.6 grams/day.
2 90th percentile consumption rate of 107. 1 grams/day.
3 Based on typical consumption (2 1 .4 - 49.6 grams/day).
Summary of Potential Baseline Noncancer Risks to Anglers
• The hazard index for freshwater anglers with typical fish consumption (i.e.,
21.4 to 49.6 grams per day) ranges from 2.4 to 5.5.2
2 A hazard index greater than 1 indicates the potential for adverse noncancer health effects.
See the section on Risk Assessment and Appendix D for a complete description of the methodology
for evaluating noncancer health effects.
3-8
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JUNE 1997
• The hazard index for freshwater anglers with 90th percentile fish
consumption (i.e., 107.1 grams per day) is 11.9.
• The hazard index for San Francisco Bay anglers with typical fish
consumption ranges from 3.6 to 8.4.
• The hazard index for San Francisco Bay anglers with 90th percentile fish
consumption is 18.1.
Like cancer risks, baseline noncancer risks are dominated by a small number of
contaminants. Again, PCBs account for approximately 60 percent of the noncancer risks for
freshwater anglers. The hazard quotient for PCBs ranges from 1.4 to 3.3 for typical consumption
and 7.0 at the 90th percentile consumption level. Mercury is the only other freshwater contaminant
with a hazard quotient greater than 1.0 at the typical 21.4 to 49.6 g/day fish consumption level.
Mercury, which has been cited as a contaminant of concern in six of the 12 fish consumption health
advisories in California, has a hazard quotient of 0.6 to 1.4 for typical consumption. At the 90th
percentile consumption rate, mercury's hazard quotient is 3.1.
PCBs also account for the majority of baseline noncancer risk for San Francisco Bay anglers
— 62 percent. The hazard quotient for PCBs ranges from 2.3 to 5.2 for typical consumption,
increasing to 11.3 at the 90th percentile fish consumption level. Mercury has a hazard quotient of
0.75 to 1.74 for typical consumption, accounting for 21 percent of the risk. At 90th percentile
consumption, mercury's hazard quotient is 3.8. Dioxin has a hazard quotient of 0.51 to 1.17 at
typical consumption levels and accounts for 14 percent of the risk. At 90th percentile consumption,
dioxin's hazard quotient is 2.5.
Exhibit 3-3
POTENTIAL BASELINE NONCANCER RISKS FOR
FRESHWATER AND SAN FRANCISCO BAY ANGLERS
Freshwater Anglers
San Francisco Bay Anglers
Hazard Index
Typical Consumption1
2.4 - 5.5
3.6 - 8.4
90th Percentile Consumption1
11.9
18.1
1 Typical fish consumption for recreational anglers in California ranges from 2 1 .4 to 49.6 grams/day.
2 90th percentile consumption rate of 1 07. 1 grams/day.
3-9
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JUNE 1997
Potential Benefits of the CTR
An analysis of the CTR's potential health benefits suggests that baseline risks may be reduced
substantially if the rule is fully implemented and achieves the target health risk levels associated with
the proposed water quality criteria. If the CTR achieves its goals, these reductions would result in
a post-rule cancer risk of 1 x 10"6 for the general population. Alternatively, since the State of
California has the flexibility to choose criteria based on less stringent cancer risk levels, we have also
estimated potential benefits associated with a post-rule cancer risk of 1 x 10~5 for the general
population. The potential benefits associated with reductions in cancer and noncancer risks that
could accrue as a result of the CTR's implementation are summarized in Exhibits 3-4 and 3-5,
respectively.
Summary of Potential Cancer Health Benefits to Anglers
• At criteria based on a 1 x 10"6 risk level for the general population, cancer
risks for freshwater anglers would be reduced by 91 percent. If criteria were
based on a risk level of 1 x 10~5, cancer risks for freshwater anglers would be
reduced by 37 percent.
• At criteria based on a 1 x 10'6 risk level, the population cancer risk for
freshwater anglers would decrease from between 5 and 11 cases per year to
approximately one case per year. If criteria were based on a risk level of 1
x 10'5, the number of cancer cases would be reduced to between three and
seven cases per year.
• At criteria based on a 1 x 10"6 risk level, freshwater anglers would have a
post-rule individual excess lifetime cancer risk ranging from 1.4 x 10'5 to 3.3
x 10"5 for typical fish consumption. If criteria were based on a risk level of
1 x 10'5, individual excess lifetime cancer risks would range from 9.4 x 10'5
102.2x10-".
• At criteria based on a 1 x 10"6 risk level, cancer risks for San Francisco Bay
anglers would be reduced by 91 percent. If criteria were based on a risk level
of 1 x 10'5, cancer risks for Bay area anglers would be reduced by 55 percent.
3-10
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JUNE 1997
At criteria based on a 1 x 10'6 risk level, the population cancer risk for Bay
area anglers would decrease from the baseline of one or fewer cases per year
to zero cases per year. If criteria were based on a risk level of 1 x 10'5, the
number of cancer cases would be reduced to between zero and less than one
case per year.
At criteria based on a risk level of 1 x 10"6, San Francisco Bay anglers would
have a post-rule individual excess lifetime cancer risk ranging from 1.7 x 10~5
to 3.8 x 10'5 for typical fish consumption. If criteria were based on a risk
level of 1 x 10'5, individual excess lifetime cancer risks would range from 8.3
x 1O5 to 1.9x10^.
Exhibit 3-4
POTENTIAL CANCER HEALTH BENEFITS TO RECREATIONAL
ANGLERS ASSOCIATED WITH IMPLEMENTATION OF THE CTR1
Freshwater
San Francisco
Bay
Baseline
Individual
Excess Lifetime
Cancer Risk
1.5x10^-3.5x10^
1.8xlO-"-4.2xlO-4
Post-Rule
Achieve Post-Rule Criteria
Based on a Risk Level of 1 x 10"*
for the General Population
Individual
Excess Lifetime
Cancer Risk
1.4xlO-5-3.3xlO-5
1.7xlO-5-3.8xlO-5
Percent
Reduction
91%
91%
Achieve Post-Rule Criteria
Based on a Risk Level of 1 x 10s
for the General Population
Individual
Excess Lifetime
Cancer Risk
9.4xlO'5- 2.2x10-"
S-SxlO-'-l^xlO-4
Percent
Reduction
37%
55%
1 Baseline cancer risks represent 98 percent of the total estimated risk for freshwater anglers and 99
percent of the risk for San Francisco Bay Anglers. All estimates are based on typical consumption
(2 1 .4 - 49.6 grams per day).
3-11
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JUNE 1997
Summary of Potential Noncancer Health Benefits
• At criteria based on a 1 x 10"6 risk.level for the general population, noncancer
risks for freshwater anglers would be reduced by 67 percent. If criteria were
based on a risk level of 1 x 10'5, noncancer risks for freshwater anglers would
be reduced by 25 percent.
• At criteria based on a 1 x 10^ risk level for the general population, the hazard
index for freshwater anglers would decrease from the baseline of 2.3 to 5.4
to less than 0.8 to 1.8 for typical fish consumption. If criteria were based on
a risk level of 1 x 10~5, the hazard index would range from 1.7 to 4.0.
• At criteria based on a 1 x 10"6 risk level for the general population, mercury
would have the highest post-rule hazard quotient for an individual freshwater
contaminant - 0.6 to 1.4 for typical consumption. If criteria were based on
a risk level of 1 x 10"5, PCBs would have a HQ of 0.8 to 1.9 while mercury's
HQ would range from 0.6 to 1.4. All other freshwater contaminants would
have hazard quotients of less than one under both post-rule scenarios.
• At criteria based on a 1 x 10~6 risk level for the general population, noncancer
risks for San Francisco Bay anglers would be reduced by 76 percent. If
criteria were based on a risk level of 1 x 10~5, noncancer risks for Bay area
anglers would be reduced by 49 percent.
• At criteria based on a 1 x 10"6 risk level for the general population, the hazard
index for Bay area anglers would decrease from the baseline of 3.5 to 8.2 to
less than 0.9 to 2.0 for typical fish consumption. If criteria were based on a
risk level of 1 x 10'5, the hazard index would range from 1.8 to 4.2.
• At criteria based on a 1 x 10"6 risk level for the general population, mercury
would have the highest post-rule hazard quotient for an individual San
Francisco Bay contaminant — 0.8 to 1.7 for typical consumption. If criteria
were based on a risk level of 1 x 10'5, PCBs would have a HQ of 0.8 to 1.9
while mercury's HQ would range from 0.8 to 1.7. All other Bay area
contaminants would have hazard quotients of less than one under both post-
rule scenarios.
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JUNE 1997
Exhibit 3-5
POTENTIAL NONCANCER HEALTH BENEFITS TO RECREATIONAL
ANGLERS ASSOCIATED WITH IMPLEMENTATION OF THE CTR1
Freshwater
San Francisco
Bay
\
Baseline
Individual
Hazard Index
2.31-5.39
3.52-8.18
Post-Rule
Achieve Post-Rule Criteria
Based on a Risk Level of 1 x 10"*
for the General Population
Individual
Hazard Index
0.76-1.77
0.85-1.98
Percent
Reduction
67%
76%
Achieve Post-Rule Criteria
Based on a Risk Level of 1 x 10'5
for the General Population
Individual
Hazard Index
1.73-4.00
1.79-4.16
Percent
Reduction
25%
49%
1 Baseline cancer risks represent 98 percent of the total estimated risk for freshwater anglers and 99
percent of the risk for San Francisco Bay Anglers. All estimates are based on typical consumption
(21.4 - 49.6 grams per day).
Uncertainties
The analysis of angler health risks involves a series of assumptions that are generally
designed to characterize typical recreational anglers. To the extent that anglers differ from this
characterization, the analysis may over- or underestimate risk. Some of the areas of potential
uncertainty include consumption rates, mixing of species in an individual's diet, and assigning
concentration values to contaminants in samples in which they were not detected. We addressed
these assumptions by developing ranges of potential exposure values. In the case of consumption
rates, we present results based on reasonable bounds for typical consumption and for 90th percentile
consumption. With respect to species mixing and nondetected values, we have conducted sensitivity
analyses to characterize the magnitude of these uncertainties. These analyses are presented
throughout the chapter.
Other uncertainties, especially those affecting subpopulations, could not be fully
characterized within this analysis. These include ethnic and income effects on consumption rates,
fish preparation methods, and risks to family members. We reviewed our standard assumptions
against information provided in the relevant literature on angler subpopulations to determine the
potential effects each of these uncertainties has on the analysis. Additional information for each of
these areas and the results of our literature review are summarized at the end of this chapter.
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JUNE 1997
Finally, we may have underestimated some of the angler human health benefits associated
with meeting CTR criteria because we have not considered the health risks associated with
consuming commercially caught fish. California has commercial fisheries in water bodies covered
by this rule, and it is likely that reduced toxics contamination of California waters to meet the CTR
criteria will result in some reduced toxic contamination of commercial fisheries. However, because
of difficulties in estimating the number of exposed individuals as well as difficulties in Unking toxic
contamination solely to California sources, we were not able to estimate the baseline health risks and
benefits associated with meeting the CTR.
Organization of Chapter
The remaining sections of this chapter provide detailed information on our health risk
analysis. First, we describe the general method used to estimate the baseline health risks for both
freshwater and San Francisco Bay anglers. In the second and third sections, we describe the specific
analyses of the health risks for each of these populations. These sections include discussions of data
sources, exposure assumptions, and uncertainties in the health risk estimates for these two
populations. The fourth section addresses environmental justice concerns related to the exposure
of California anglers to toxic contaminants in fish tissue. The fifth section describes some of the
general uncertainties in assessing health risks to anglers that are relevant to both the freshwater and
San Francisco Bay analyses. The sixth section describes potential reductions in angler health risks
associated with meeting the water quality criteria established by the California Toxics Rule. The
final section summarizes our findings.
METHODOLOGY FOR ESTIMATING
RECREATIONAL ANGLER RISK
This section describes our general approach to estimating the potential health risks to anglers
in California from consuming the fish they catch in freshwater and in San Francisco Bay. We have
estimated both the cancer and noncancer health risks associated with exposure to contaminants
limited to the California Toxics Rule. Specific descriptions of the methods and assumptions used
to assess the risks for freshwater and San Francisco Bay anglers are provided in the following
sections of this chapter. The general steps in estimating these risks are:
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JUNE 1997
Determining arithmetic mean contaminant levels in fish tissue that is
consumed by anglers;
Assessing potential angler exposure to these contaminants; and
Calculating the potential risks associated with exposure.
Fish Tissue Contaminant Levels
The first step in analyzing potential angler health risks was to obtain fish tissue contaminant
data. Detailed descriptions of the fish tissue databases selected for this assessment are presented in
Appendix B. Each of the databases selected for this analysis meet the following general criteria:
• They contain data on recently collected samples that reflect current
contaminant levels — the freshwater fish tissue data were collected between
1988 and 1993; San Francisco Bay fish tissue data were collected in May and
June 1994;
• They pro vide data on the concentration of contaminants found in fish fillets,
which are the most commonly eaten portion offish;
• They provide data on fish species that are commonly caught and consumed
by anglers in California.
For both the freshwater and San Francisco Bay analyses, we calculated the mean
concentration of contaminants in fish tissue solely for those contaminants that will be addressed by
the California Toxics Rule. All contaminants that are not addressed by this rule, including those
already regulated under the National Toxics Rule for the specific locations considered in this
analysis, have been excluded from our estimates of angler health risks.3
3 Under the National Toxics Rule (57 FR 60848-60923), EPA promulgated water quality
criteria for selected pollutants in certain waters within the State of California. For example, the rule
establishes a criterion for selenium in the waters of the San Joaquin River (between Sack Dam and
Vernalis), Salt Slough and Mud Slough. In calculating freshwater angler health risks associated with
selenium concentrations in fish tissue, we excluded any samples collected in these waterbodies.
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JUNE 1997
We calculate arithmetic mean contaminant concentrations for individual species of fish
represented in the freshwater and San Francisco Bay databases. In calculating these values, we
follow the standard EPA practice of using one-half of the method detection limit (MDL) for samples
in which contaminants were reported as not detected.4 However, in cases where a contaminant is
not detected in any sample within the database, we conclude that the contaminant is not present. We
employ sensitivity analysis to determine the impact of this assumption on our findings.
Exposure Assessment
The next step in calculating potential health risks for anglers is to determine their exposure
to individual contaminants found in fish tissue. Exposure can be calculated from the fish tissue
contaminant concentration and the fish consumption rate. The general equation for calculating
average daily dose on a body weight basis is shown below.
. Fish Tissue Fish Consumption
Contaminant Concentration x Rate
(mglkg) (kg/day)
Body Weight (kg)
= Dose (mg/kg-day)
Since this is a health risk assessment for anglers, the consumption rate should reflect the
habits of this population, rather those of the general population. As a group, anglers tend to consume
larger quantities offish than the general population. EPA guidance on evaluating risks associated
with fish consumption reports that the general population consumes an average of 6.5 g/day of fish.
Numerous studies evaluate consumption among anglers, and all estimate substantially higher
consumption rates for anglers compared to the general population. EPA offers default values, but
recommends using local consumption data whenever they are available.5
4 USEPA, Guidance for Assessing Chemical Contaminant Data for Use in Fish Advisories:
Volume 1, Fish Sampling and Analysis, Office of Water, EPA 823-R-93-002, August 1993.
5 USEPA, Guidance for Assessing Chemical Contaminant Data for Use in Fish Advisories,
Volume 1: Fish Sampling and Analysis, Office of Water, EPA 823-R-93-002, August 1993.
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A 1994 survey offish consumption patterns among anglers in Santa Monica Bay provides
recent estimates of consumption rates for California anglers.6 The results of this study, conducted
by the Santa Monica Bay Restoration project, are based on interviews with 554 anglers fishing from
beaches, piers, private boats, party boats, and charter boats to determine the level and nature of sport-
caught fish consumption. Although these estimates were developed by interviewing only consuming
anglers, EPA applied them to total anglers because they are supported by fish consumption rates for
all anglers reported in other studies.7 In addition, representatives of the California EPA's Office of
Environmental Health Hazard Assessment (OEHHA) consider the Santa Monica study applicable
to anglers throughout the state.8
We use the Santa Monica Bay study for three estimates of fish consumption rates among
California anglers. We assume that a "typical" California angler consumes between 21.4 and 49.6
grams offish per day. This range is bounded by the median (21.4 g/day) and the mean (49.6 g/day)
from the Santa Monica Bay study. This range covers the entire central portion of the study's fish
consumption distribution, so we assume that the vast majority of California anglers consume fish
within these rates. We present all estimates of potential individual and population risks (cancer and
noncancer) based on this range.
We also provide individual risk estimates for anglers at the high end of the fish consumption
distribution. Based on the Santa Monica Bay study, we use the 90th percentile consumption rate of
107.1 g/day to represent these high consumption anglers. The 90th percentile value may also be
representative of subgroups of anglers, such as those relying on their fish catch for subsistence, or
those from a specific ethnic group, whose diets contain substantially more fish than other anglers'.
Appendix C compares each of the study's consumption rates to those reported in other representative
studies.
Another issue in calculating exposure to fish tissue contaminants is the,species composition
of angler fish diets. Angler fishing and consumption habits can vary. Some anglers catch and
consume a mix of species. To calculate exposures for these anglers, it is necessary to develop a
6 Santa Monica Bay Restoration Project, Santa Monica Bay Seafood Consumption Study,
prepared by Southern California Coastal Water Research Project and MBC Applied
Environmental Sciences, June 1994.
7 See Appendix C for a summary of these other sport-fish consumption studies.
8 Dr. Gerald Pollack, Office of Environmental Health Hazard Assessment, California EPA,
personal communication, August 1995.
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JUNE 1997
species-weighted contaminant concentration that reflects the relative contribution of different species
to their diet. Other anglers target their efforts toward catching a single species. For these anglers,
we would expect their preferred species to account for virtually all of their fish consumption.
Therefore, exposures for these anglers can be calculated from mean contaminant concentrations for
individual preferred species. Accordingly, we have estimated angler exposure to fish tissue
contaminants based on both mixed species and single species diets. The specific approaches for
deriving the average contaminant concentrations for the mixed species diets are described separately
for each angler group.
Risk Assessment
The final step in this analysis is to calculate the potential cancer and noncancer risks from
the estimated exposures to contaminants in fish tissue. The approach to calculating risk is briefly
described below. A more detailed description of the risk assessment approach, including limitations
and uncertainties, is presented in Appendix D.
Risk assessors express cancer effects in terms of individual excess lifetime cancer risk
(ILCR). The ILCR is calculated for each contaminant by multiplying the dose by the cancer slope
factor (CSF), which is the slope of the cancer dose-response curve. The risks for the individual
contaminants are then summed to produce the total ILCR. In promulgating water quality criteria,
EPA generally considers a ILCR of 1 x 10~6 (i.e., each individual faces a 1 in 1,000,000 chance of
contracting cancer over a lifetime) sufficient to protect the general population.
Multiplying the ILCR by the total population exposed and dividing by the typical life span
of 70 years produces an estimate of the population cancer risk, expressed as the annual number of
cancer cases. The calculation of individual and population cancer risks are summarized in the
following equations.
Dose (mglkg-day) x CSF (mglkg-day)'1 = ILCR
TTf* D i .- P Annual Population
ILCR x Population Size _ „. ,
= Cancer Risk
70 years (cases per year)
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JUNE 1997
Noncancer health effects are assumed to be additive and are assessed by means of a hazard
index (HI). The HI is the sum of hazard quotients (HQs) for individual contaminants and is
described in Appendix D. As shown in the equations below, the HQ is calculated by dividing the
dose by the reference dose (RfD), where the RfD represents the dose below which no adverse health
effects are expected over a lifetime exposure. Thus, an HI of 1.0 implies that contaminant exposures
exceed the established threshold of toxicity, indicating the potential for adverse health effects.
Dose (mg/kg-day) _
" — flL/
RfD (mg/kg-day)
2J HQ (for individual contaminants) = HI
In the following two sections, we describe how these methods were applied in assessing
health risks for freshwater and San Francisco Bay anglers. We also present the results of the analysis
for these two angler populations.
FRESHWATER ANGLERS
This section describes the specific methods and assumptions used to estimate the potential
health risks associated with exposure to contaminants present in freshwater fish tissue. In addition,
we discuss the results of this analysis and the primary uncertainties in the health risk estimate for
freshwater anglers.
Fish Tissue Contaminant Levels
Freshwater fish tissue contaminant levels were obtained from California's Toxic Substances
Monitoring Program (TSMP). This program monitors the occurrence of toxic pollutants in
California's waters through sampling and analysis of fish tissue. The TSMP includes freshwater
tissue samples collected throughout the state. For purposes of this analysis, we selected all of the
available data collected from 1988 to 1993. This included over 360 samples of 32 different
freshwater fish species. We combined these 32 individual species into five broad groups: trout, bass,
catfish, panfish and other. We review the TSMP, including waterbodies sampled, in Appendix B.
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JUNE 1997
The TSMP data provide broad coverage of freshwater resources within the state of California.
Fish tissue samples collected from locations within each of the nine State Water Control Board
Regions were used in this analysis. Exhibit 3-6 shows how the 224 sampling locations for metals
and 170 sampling locations for organics were distributed across these regions. Despite this wide
representation of freshwater bodies, the database may not provide a representative sample of the
impact of water quality in California on fish tissue contaminant concentrations. This occurs because
fish tissue sampling under this program generally has been targeted to waterbodies with known or
suspected water quality impairments. Thus, the data in the TSMP may tend to overstate contaminant
levels in freshwater fish in California.
A review of the TSMP sampling stations included within this analysis indicates that the
program's potential bias may not be significant. First, across the entire state, approximately 53
percent of the waterbodies (encompassing 51 percent of the fish tissue samples) included in the
freshwater analysis are currently expected to meet applicable water quality criteria. Second, each
of the California Water Quality Control Board regions samples impaired waterbodies at different
rates. Regions 4, 6, and 8, for example, collect between 75 and 95 percent of their samples from
impaired waterbodies. The six remaining regions collect between eight and 38 percent of their
samples from impaired sources. Analysis of sample size by region, however, indicates that regions
with a large number of samples from impaired waters are not likely to exert a disproportionate
impact on average tissue concentrations because the number of samples collected in these regions
is generally equal to or less than the number of samples collected in other regions.
Exhibit 3-6
DISTRIBUTION OF FISH TISSUE SAMPLING LOCATIONS
ACROSS CALIFORNIA STATE WATER QUALITY CONTROL BOARD REGIONS
Region
Region 1
Region 2
Region 3
Region 4
Region 5
Region 6
Region 7
Region 8
Region 9
Total
Number of Sampling Locations
Metals
19
16
25
27
44
41
21
6
25
224
Organics
15
11
18
27
27
16
22
9
25
170
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JUNE 1997
Similarly, comparison of TSMP sampling locations to areas where California's OEHHA has
issued health advisories warning against fish consumption shows that less than three percent of the
samples (12 out of more than 360 samples) used in this analysis were collected from locations where
advisories had been issued. These results also suggest that any bias toward higher fish tissue
contaminant levels introduced by this targeted sampling effort may be limited.
The TSMP database contains concentration data for 15 different contaminants covered by
the California Toxics Rule, including both metals and organic compounds. Of these, eight are
classified by EPA as carcinogens and 13 (including six of the eight carcinogens) are associated with
noncarcinogenic effects. Exhibit 3-7 lists the cancer slope factor (CSF), weight of evidence for
carcinogenicity, reference dose (RfD), and specific target organs for each of these contaminants.
These toxicity values were used in calculating the health risks associated with freshwater angler fish
consumption.
For this analysis, we applied a CSF of 2.0 mg/kg-day for polychlorinated biphenyls (PCBs)
based on EPA's revised October 1,1996 guidance for assessment of carcinogenic human health risks
associated with PCB exposure. EPA's revised guidance recommends a tiered approach that uses
PCB CSFs ranging from 0.04 to 2.0 mg/kg-day depending on the characteristics of the exposure
pathway and congener composition of the PCB mixture. EPA notes that bioaccumulated congeners
ingested through the food chain (e.g., consumption of recreationally caught fish) tend to exhibit the
highest chlorine content and persistence. Therefore, EPA recommends using the highest PCB CSF
of 2.0 mg/kg-day for food chain exposure pathways where environmental processes tend to increase
risk.9
It is also important to note that the TSMP does not analyze fish tissue samples for dioxin and
furan. In 1992, however, EPA's National Study of Chemical Residues in Fish identified dioxins and
furans in fish tissues collected from several freshwater locations in California.10 While the EPA
study targeted most sampling sites based on their high potential for dioxin and furan contamination,
these results indicate the potential for dioxin health risks may exist throughout California's
freshwaters. Therefore, to the extent that dioxin and furans exist in California's freshwater fish
tissues, this assessment may understate angler health risks and benefits.
9 USEPA, National Center for Environmental Assessment, Office of Research and
Development. PCBs: Cancer Dose-Response Assessment and Application to Environmental
Mixtures, EPA/600/P-96/001F, September 1996.
10 USEPA. National Study of Chemical Residues in Fish, Volumes I and II. Office of
Science and Technology, EPA 823-R-92-008a,b, September 1992.
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Exposure Assumptions
Consumption Rate
As previously discussed, potential health risks were estimated for "typical" California anglers
and high consumption individuals. For typical anglers, we assumed a consumption rate range of
21.4 to 49.6 g/day. We characterized high end consumption as the 90th percentile of the population,
or 107.1 g/day. Population risks (for cancer effects only) were calculated using the typical angler
consumption range to reflect average consumption across the entire population.
To estimate potential exposure to fish tissue contaminants it is necessary to derive
appropriate measures of mean contaminant levels that reflect the relative proportion of individual
species in anglers' diets. As shown in Exhibit 3-8, species-weighted contaminant concentrations
were developed from estimates of fishing activity and keep rates by species." Estimates of the
fishing activity for California freshwater anglers, expressed as the number of fishing days per year
that anglers attempt to catch a certain species, were obtained from the U.S. Fish and Wildlife
Service's (FWS) 1991 National Survey of Fishing, Hunting, and Wildlife-Associated Recreation,
California. Trout account for the largest percentage of fishing days followed by bass and catfish.
Panfish and other species account for the smallest percentage of the fishing days. Keep rates were
obtained from data collected by the California Department of Fish and Game (CDFG) through its
Sacramento River Sport Fish Catch Inventory Project.12 Based on four years of angler survey data
on the Sacramento, American, Feather, and Yuba Rivers, keep rates are highest for panfish and
catfish, roughly 90 percent and 80 percent, respectively. Keep rates for bass and trout were
significantly lower, at 20 percent to 25 percent. For purposes of this analysis, we assumed that keep
rates for these two species, as well as for "other" species, were all 25 percent.13
When fishing activity by species is adjusted according to keep rate, catfish become the largest
contributor to anglers' .diets, accounting for nearly 35 percent. The contribution of trout to anglers'
diets is 28 percent. Bass and panfish contribute roughly equal proportions of the diet (16 percent and
18 percent, respectively). Other species represent less than five percent of the diet.
11 Ideally, the contribution of each species to anglers' diets would be calculated by
multiplying fishing activity (number of days) by catch rates and keep rates. We were unable
to obtain estimates of state-wide catch rates by species. In lieu of this information, we assumed that
catch rates do not vary across species.
12 California Department of Fish and Game Inland Fisheries Division, Sacramento River
System Sport Fish Catch Inventory, Final Performance Report, June 30,1995.
13 Dennis Lee, California Department of Fish and Game, personal communication, August
1995.
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Exhibit 3-7
TOXICITY VALUES FOR CONTAMINANTS IN FRESHWATER FISH TISSUE
Contaminant
Copper
Mercury
Nickel
Selenium
Zinc
Chlordane
DDT
Dieldrin
Endosulfan
Endrin
HCH-alpha
HCH-gamma
Hexachlorobenzene
PCBs"
Toxaphene
CSF1
(mg/kg-day)
NA
NA
NA
NA
NA
1.3
0.34
16.0
NA
NA
6.3
1.3
1.6
2.0
1.1
Cancer Weight2 of
Evidence
D
C
NA .
D
D
B2
B2
B2
NA
D
B2
B2-C
B2
B2
B2
RFD3
(mg/kg-day)
3.7 xlO-2
l.OxlO-1
2.0 xlO'2
5.0 xlO'3
3.0x10-'
6.0 xlO'5
5.0x10"
5.0 xlO-5
6.0x10°
3.0 xlO"
NA
3.0 x 10"
8.0x10"
2.0 xlO'5
NA
Target Organ
Castro-intestinal tract
Central nervous system (CNS)
Decreased body and organ weight
Selenosis (liver, blood, CNS)
Blood
Liver
Liver
Liver
Kidney, CNS, circulatory system, increased body weight
Liver, CNS
NA
Liver, kidney .
Liver
Immune system, reproductive system, liver, skin
NA
Source: Toxicity values obtained from USEPA's Integrated Risk Information System (4th Quarter, 1 996), except for the copper and the HCH-gamma CSFs, which were
obtained from USEPA's Health Effects Assessment Summary Table, 1 994.
1 Cancer Slope Factor.
2 See Appendix D for definitions of weight of evidence.
3 Reference Dose.
* PCBs are calculated as the sum of Aroclors 1248, 1254, and 1260; individual PCB congener concentrations were not available in the TSMP database. The RfD for
PCBs is based on Aroclor 1254.
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JUNE 1997
Exhibit 3-8
SPECIES WEIGHTS FOR FRESHWATER FISH CONSUMPTION
Species
Trout
Bass
Catfish
Panfish
Other
Total
Annual Fishing Activity1
(number of days)
10,641
6,164
4,098
1,866
1,315
24,084
Keep Rate2
25%
25%
80%
90%
25%
Keep Rate
Weighted Days
2,660
1,541
3,278
1,679
329
9,487
Consumption3
Weighting Factors
28.0%
16.2%
34.6%
17.7%
3.5%
100%
1 Fishing Activity obtained from National Survey of Fishing. Hunting, and Wildlife-Associated Recreation,
California, 1991, IJSFWS.
2 Keep rate estimated from Sacramento River Sport Fish Catch Inventory Project, Final Performance Report, CDFG,
1995.
3 Calculated by dividing the Keep Rate Weighted Days for each species by the Total Keep Rate Weighted Days.
Angler Population
We estimated a population of 2,244,371 full-time equivalent freshwater anglers in
California.14 We calculated this freshwater angler population based on data reported by the U.S. Fish
and Wildlife Service (F&WS) in the 7997 National Survey of Fishing, Hunting, and Wildlife-
Associated Recreation and license sales reported by the California Department of Fish and Game.
According to the F&WS survey, there are approximately 3,607,500 resident anglers in
California. Of these, 2,499,600 are adult resident anglers and 1,107,900 are resident anglers between
the ages of six and 15. These anglers split their fishing activity between fresh and saltwater. The
F&WS study reports that approximately 60.8 percent of California's adult anglers fish exclusively
in freshwater, 19.5 percent fish exclusively in saltwater, and 19.7 percent split their activity between
14 To calculate the number of full-time equivalent freshwater anglers in California we add
the number of anglers who fish exclusively in freshwater to one-half the number of anglers who fish
in both freshwater and saltwater.
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JUNE 1997
fresh and saltwater.15 We have assumed that anglers who have mixed fishing activity split their
effort equally between fresh and saltwater. Based on these proportions and the total angler
population, we estimate that there are 1,058,801 saltwater anglers and 2,548,699 freshwater anglers
in California.
We further adjust the freshwater angler population downward to reflect the infrequent anglers
included in the results of the F&WS study. We remove these anglers from the population risk
estimate because they are unlikely to satisfy the exposure criteria used to calculate individual health
risks (e.g., consumption of 21.4 to 49.6 grams offish per day for a lifetime). The F&WS study,
however, does not provide detailed information on fishing frequency. Accordingly, we net out
infrequent angler activity using data on the number of one-day fishing licenses sold in California in
1991. Specifically, based on 1991 one-day license sales, we reduce the freshwater angler population
by an additional 304,328 to reflect the infrequent anglers included in the F&WS estimate. This
estimate includes several assumptions. First, since one-day licenses entitle anglers to fish in both
fresh and saltwater, we assume the same proportions identified above to adjust the license data to
freshwater equivalents. Further, these license data only reflect adult angling activity since anglers
ages six to 15 are not required to obtain a license to fish in California. As a result, we assume that
the proportion of one^day anglers with ages six to 15 is identical to the proportion of one-day
licenses purchased by adult freshwater anglers.
Potential Angler Health Risks
Our estimates of potential cancer risks associated with exposure to all eight carcinogenic
contaminants at concentrations currently found in freshwater fish are presented in Exhibit 3-9. The
total ILCR for typical anglers consuming a mixed species diet ranges from 1.5 x 10"4 to 3.5 x 10"4.
At the 90th percentile consumption level, a mixed species diet results in an ILCR of 7.6 x 10"4. The
population cancer risk ranges from 5 to 11 cases per year. These risks are dominated by four
contaminants. PCBs account for 37 percent of the cancer risk, ranging from 5.6 x 10'5 to 1.3 x 10"4
under the typical consumption scenario. Toxaphene risk ranges from 3.2 x 10"5 to 7.5 x 10"5 under
typical consumption, and accounts for 21 percent of the cancer risk. DDT and Dieldrin each account
for 16 percent of the cancer risk.
15 The F&WS study does not provide comparable percentages for children (i.e., anglers aged
six to 15). For the purposes of calculating the total exposed population, we assume that children
divide their fishing activity among waterbody types in the same proportions as adult anglers.
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JUNE 1997
Exhibit 3-9
POTENTIAL BASELINE CANCER RISK FOR RECREATIONAL
ANGLERS CONSUMING FRESHWATER FISH IN CALIFORNIA
Contaminant
PCBs
Toxaphene
DDT
Dieldrin
Chlordane
HCH-alpha
Hexachlorobenzene
HCH-gamma
Total
Individual Excess Lifetime Cancer Risk
Typical
Consumption
(21.4 - 49.6 g/day)
5.6 xlO'5- 1.3x10^
3.2 x lO'5 - 7.5 x lO'5
2.5 x 10-5 - 5.8 x 10-3
2.4 x lO'5 - 5.6 x lO'5
UxlO-5-2.5xlO-5
2.0 x 10"6 - 4.6 x 10-6
l.OxlO"6- 2.4x10-*
4.6xlO-7-l.lxlO-6
1.5 x 10"1 - 3.5 x 1C"4
90th Percentile
Consumption
(107.1 g/day)
2.8 x 10-"
1.6x10-"
1.3 x 10-4
1.2 xlO"4
5.3 x lO'5
1.0 xlO-5
5.1 x 10-*
2.3 x 10-*
7.6 xlO"4
Population
Cancer Risk1
(excess cases per year)
2-4
1-2
1
1-2
1-2
<1-1
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JUNE 1997
Exhibit 3-10
POTENTIAL BASELINE NONCANCER RISK FOR RECREATIONAL
ANGLERS CONSUMING FRESHWATER FISH IN CALIFORNIA
Contaminant
PCBs
Mercury
DDT
Chlordane
Dieldrin
Selenium
Endrin
Endosulfan
Zinc
Copper
HCH-gamma
Nickel
Hexachlorobenzene
Hazard Index
Hazard Quotient
Typical
Consumption
(21.4- 49.6 g/day)
1.40-3.30
0.62-1.44
0.15-0.34
0.14-0.31
0.03 - 0.07
0.02 - 0.06
0.01 - 0.02
<0.01 - 0.01
O.01-0.01
<0.01-<0.01
<0.01-<0.01
<0.01-<0.01
<0.01-<0.01
2.38 - 5.52
90th Percentile
Consumption
(107.1 g/day)
7.02
3.12
0.74
0.68
0.15
0.12
0.04
0.02
0.02
0.01
0.01
0.01
<0.01
11.92
Relative
Contribution
58.9 %
26.1 %
6.2 %
5.7 %
1.3%
1.0%
0.3 %
0.2 %
0.2 %
0.1 %
<0.1 %
<0.1 %
<0.1 %
100 %
To determine whether anglers who catch and consume a single species are not subject to
disproportionate risks, we also calculated health risk based on mean contaminant concentrations for
each of the five freshwater species groups. The species-specific health risks are shown in Exhibit
3-11. Cancer risks for single species diets vary by no more than a factor of 2.4 from the risk
associated with a mixed species diet. A fish diet consisting entirely of "other" species produces the
highest cancer risk. Based on typical consumption, the risk associated with a diet of "other" species
ranges from 3.6 x lO^to 8.3 x 10"*, approximately two times higher than the species-weighted risk.
Panfish pose the lowest risk, ranging from 9.1 x 10"5 to 2.1 x 10"4 at typical consumption rates, about
1.6 times less than the species-weighted risk.
3-27
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JUNE 1997
Similarly, noncancer risks for single species diets differ from the risk associated with a mixed
species diet by similar proportions. "Other" species pose the highest risk with an HI ranging from
4.0 to 9.3 for typical anglers, again approximately two times greater than the species-weighted HI
of 2.4 to 5.5. Trout pose the lowest noncancer risk, an HI of 1.8 to 4.3, only 1.3 times less than the
species-weighted HI.
Exhibit 3-11
POTENTIAL BASELINE HEALTH RISKS ASSOCIATED WITH
CONSUMPTION OF DIFFERENT FRESHWATER SPECIES IN CALIFORNIA
Species
Other
Catfish
Bass
Trout
Panfish
Species- Weighted
Value
Individual Excess Lifetime Cancer Risk
Typical
Consumption
(21.4 - 49.6 g/day)
3.6 x ID"4 - 8.3 x 10-4
2.3 x 10-" - 5.4 x 10^
1.0xlO-"-2.3xlO-4
9.2 xlO'5- 2.1 xKT1
9. IxlO'5- 2.1x10-"
1.5 xlO"4- 3.5x10-"
90th Percentile
Consumption
(107.1 g/day)
l.SxlO'3
1.2xlO'3
5.0 x 10-"
4.6 x 10-"
4.6 x lO"4
7.6x10^ .
Noncancer Risk (Hazard Index)
Typical
Consumption
(21.4 -49.6 g/day)
4.0 - 9.3
. 2.8-6.4
2.6 - 5.9
1.8-4.3
2.0 - 4.6
2.4 - 5.5
90th Percentile
Consumption
(107.1 g/day)
20.1
13.9
12.8
9.2
10.0
11.9
Uncertainties
The methodology used to estimate baseline health risks for freshwater anglers includes a
series of assumptions that introduce uncertainty into the results of this analysis. Some of these
assumptions apply to the analyses of both freshwater and San Francisco Bay anglers, while others
are specific to the freshwater angler analysis. The impacts of uncertainties related to two key
assumptions in the freshwater angler analysis are described below. These uncertainties arise from
the following elements of the freshwater angler analysis:
• Deriving species weights that reflect the relative contribution of individual
species to the freshwater angler fish diet; and
3-28
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JUNE 1997
Assigning concentration values to contaminants for samples in which they
were not detected above the MDL.
Additional uncertainties that are relevant to both the freshwater and San Francisco Bay angler
analysis will be discussed in a later section of this chapter.
Species Weights
The relative contribution of individual species to freshwater anglers' fish diets is based on
several assumptions. First, by using the keep rates from the Sacramento River Inventory Project,
we have assumed that keep rates for species are consistent across all freshwater fisheries in
California. Second, in lieu of having estimates of species-specific catch rates, we assumed that catch
rates were uniform across all species. Despite these uncertainties, the assumptions used to develop
species weights are unlikely to significantly over- or underestimate freshwater angler health risks,
because the difference between the species-weighted risk and the risk for each individual species is
relatively small. Based on the maximum and minimum risks for each species, any change in the
relative contribution of individual species to the total fish diet could increase the species-weighted
cancer risk by no more than a factor of 2.4, or decrease it by no more than a factor of 1.6. Cancer
risk would be greater than 1 x 10'5 in all cases. Noncancer risks could increase by no more than a
factor of 1.7 or decrease by a maximum factor of 1.3. In all cases, the noncancer hazard index would
remain above 1.0.
Contaminants Not Detected Above MDLs
In calculating the average fish tissue concentrations used to estimate health risks for
freshwater anglers, we assume that all contaminants not detected in specific fish tissue samples
above Method Detection Limits (MDLs) are present at concentrations equal to one-half of the MDL.
As discussed above, this is a standard but somewhat conservative approach. A nondetect value
means that a contaminant is not present above the MDL, but does not mean that it may not be present
at some concentration below this level. Therefore, a sample in which a contaminant is not detected
either does not contain the contaminant, or contains the contaminant at a concentration less than the
detection limit. We conducted a sensitivity analysis to evaluate the impact of this assumption by
estimating potential freshwater angler health risks under the alternative assumptions that these
contaminants were not present in the fish tissue, and that they were present in concentrations equal
to the detection limit.
3-29
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JUNE 1997
Increasing the value used for nondetected contaminants from one-half the MDL to the MDL
increases the species-weighted cancer risk by approximately 53 percent.16 At typical consumption
rates, the cancer risk never falls below 7.1 x 10'5. The impact on cancer risks for consumption of
individual species ranges from 95 percent for panfish to 19 percent for "other" species (see Appendix
B). Risks for consuming catfish and "other" species always remain greater than 1 x 10"4, and risks
associated with bass consumption remain greater than 1 x 10'5. Only the risks for consumption of
trout and panfish fall into the 1 x 10'6 range when nondetects are set equal to zero.
Changing the value used for contaminants that were not detected above MDLs has a similar
impact on estimated noncancer risks. The species-weighted HI changes by approximately 50
percent, resulting in a minimum HI of 1.2 and a maximum HI of 8.3 for typical consumption. At
90th percentile consumption, the HI ranges from a minimum of 5.9 to a maximum of 18.0. On a
species-specific basis, the minimum His for trout and panfish fall below 1.0, while minimum His
for bass, catfish, and "other" species remain greater than 1.0.
SAN FRANCISCO BAY ANGLERS
The second component of our analysis of health risks associated with exposure to fish tissue
contaminants is a case study of San Francisco Bay anglers. The enclosed bays and estuaries that are
addressed in the California Toxics Rule support diverse non-commercial fisheries that vary with
respect to fishing activity, species composition, and contaminant levels. There is no one database
or set of assumptions that can be applied across all of the anglers who fish in these waterbodies.
Therefore, the impact of the rule on health risks for saltwater anglers must be considered on a site-
specific basis. This case study provides a general indication of the potential risks faced by all
anglers fishing in enclosed bays and estuaries. However, the case study only provides quantitative
health risk estimates for the 125,000 recreational anglers fishing in San Francisco Bay; risks to the
remaining 500,000 to 600,000 bay and estuary anglers throughout California are not calculated.17
16 A corresponding 53 percent decrease in the species-weighted cancer risk occurs when the
value used for nondetected contaminants decreases from one-half the MDL to 0.
17 The estimate of 500,000 to 600,000 non-San Francisco Bay anglers is based on 3.6 million
bay and estuary angler-days outside of San Francisco Bay and an average of 6.2 days per angler (see
Chapter 4).
3-30
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JUNE 1997
We selected San Francisco Bay for this case study because it represents one of the most
significant non-commercial fisheries among the bays and estuaries covered by the rule. In addition,
the Bay has been adversely affected by toxic water pollution, as evidenced by a health advisory
issued in 1994 recommending against consumption of Bay sportfish more than twice a month. The
advisory also recommends that adults should not eat any striped bass over 35 inches in length; and
that sensitive populations (i.e., children under six years old and women who are pregnant, may
become pregnant, or are breast feeding) should not eat more than one meal of sportfish per month
and should not eat any large shark (over 24 inches) or large striped bass (over 27 inches).
While this advisory has been widely publicized, and pamphlets outlining these recommended
restrictions are distributed with fishing licenses, extensive non-commercial fishing continues in the
Bay. This case study estimates the potential individual and population risks faced by anglers
consuming their catch, given the current level of toxics contamination in San Francisco Bay fish
tissue.
Fish Tissue Contaminant Levels
San Francisco Bay fish tissue contaminant levels were obtained from the San Francisco
Regional Water Quality Control Board's 1994 study. Contaminant Levels in Fish Tissue from San
Francisco Bay. This study includes fish tissue samples from 16 stations throughout the Bay. As
shown in Exhibit 3-12, these sampling locations were selected to provide broad geographic coverage
of the Bay. In addition, they were selected to include commonly fished shorelines and piers, areas
of known contamination, and areas thought to be relatively contaminant free. Fish samples were
collected at all of these areas in May and June 1994. Therefore, this database represents a snapshot
offish tissue contaminant levels throughout the Bay. Appendix B provides additional detail on the
study's sampling design and protocol.
Our health risk analysis is based on fish tissue data for four species collected in the San
Francisco Bay study: white croaker, striped bass, perch (shiner, walleye and white surf perch), and
shark (brown smoothhound and leopard shark). A small number of halibut and sturgeon were also
collected as part of this study; however, there were too few samples of these species to incorporate
them into this analysis. In addition, jacksmelt was a targeted species in the San Francisco Bay study.
Despite efforts to collect samples of this species, the investigators were unable to collect sufficient
tissue samples to conduct chemical analyses.
3-31
-------
Exhibit 3-12
SAN FRANCISCO BAY FISH SAMPLING LOCATIONS
I Oakland Middle Harbor |
| San Francisco Pier #7
[Oakland Inner Harbor!
Fremont Forebayl
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JUNE 1997
The San Francisco Bay database contains concentration data for 19 contaminants covered
by the California Toxics Rule, including both metals and organic compounds. Of these, 11 are
classified by EPA as carcinogens and 17 are associated with noncarcinogenic effects. Exhibit 3-13
lists the weight of evidence for carcinogenicity, CSF, RfD, and specific target organs for each of
these contaminants. These toxicity values were used in calculating the angler health risks associated
with San Francisco Bay fish consumption.
For this analysis, we applied a CSF of 2.0 mg/kg-day for polychlorinated biphenyls (PCBs)
based on EPA's revised October 1,1996 guidance for assessment of carcinogenic human health risks
associated with PCB exposure. EPA's revised guidance recommends a tiered approach that uses
PCB CSFs ranging from 0.04 to 2.0 mg/kg-day depending on the characteristics of the exposure
pathway and congener composition of the PCB mixture. EPA notes that bioaccumulated congeners
ingested through the food chain (e.g., consumption of recreationally caught fish) tend to exhibit the
highest chlorine content and persistence. Therefore, EPA recommends using the highest PCB CSF
of 2.0 mg/kg-day for food chain exposure pathways where environmental processes tend to increase
risk.18
The San Francisco Bay case study also follows EPA's recommendation to sum concentrations
of individual PCB congeners (as opposed to Aroclor equivalents) in calculating Total PCBs.19 The
guidance further recommends that concentrations of PCB congeners exhibiting dioxin-like toxicity
(often referred to as coplanar PCBs) be removed from PCB exposure estimates and added into
estimates of 2,3,7,8-TCDD exposure using the Toxic Equivalence (TEQ) approach. This analysis,
however, currently includes dioxin-like PCBs within the calculation of Total PCBs. This is done
because the health risk analysis does not express 2,3,7,8-TCDD using the TEQ approach. Future
revisions of this analysis will use the TEQ approach. As a result, the dioxin-like PCBs will be
removed from the estimate of Total PCBs and added instead to the total concentration for 2,3,7,8-
TCDD using Toxic Equivalent Factors (TEFs). TEFs will also be used to incorporate additional
dioxin and furan congeners into the TEQ calculation of 2,3,7,8-TCDD. This will reduce the
potential risks associated with PCBs while increasing risks associated with 2,3,7,8-TCDD.
18 USEPA, National Center for Environmental Assessment, Office of Research and
Development. PCBs: Cancer Dose-Response Assessment and Application to Environmental
Mixtures, EPA/600/P-96/001F, September 1996.
19 It was not possible to follow this convention in the freshwater analysis because the TSMP
only measures PCBs as Aroclor equivalents. In the absence of congener concentrations, we relied
on the Aroclor measurements in the calculation of Total PCBs in freshwater fish tissues.
3-33
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JUNE 1997
Exhibit 3-13
TOXICITY VALUES FOR CONTAMINANTS IN SAN FRANCISCO BAY FISH TISSUE
Contaminant
Cadmium
Copper
Mercury
Silver
Zinc
Chlordane
DDT5
Dioxin
Dieldrin
HCH-alpha
HCH-beta
HCH-gamma
Heptachlor
Heptachlor Epoxide
Hexachlorobenzene
Fluoranthene
Fluorene
PCBs6
Pyrene
CSF1
(mg/kg-day)-1
NA
NA
NA
NA
NA
1.3
0.34
1.50 xlO5
16.0
6.3
1.8
1.3
4.5
9.1
1.6
NA
NA
2.0
NA
Cancer Weight1
of Evidence
D4
D
C
D
D
B2
B2
B2
B2
B2
C
B2-C
B2
B2
B2
D
D
B2
D
RfD3
(mg/kg-day)
l.OxlO-3
3.7 xlO'2
l.OxlO-1
5.0 xlO'3
3.0 x 10-'
6.0 x 10'5
5.0x10"
l.OxlO-9
5.0 xlO'5
NA
NA
3.0 x 10"
5.0x10"
1.3 xlO'5
8.0x10"
4.0 x lO'2
4.0 xlO'2
2.0 xlO'5
3.0 xlO'2
Target Organ
Kidney
Gastro intestinal tract
Central nervous system
Skin
Blood
Liver
Liver
Reproductive system
Liver
NA
NA
Liver, kidney
Liver
Liver
Liver
Liver, kidney, blood
Blood
Immune system, reproductive
system, liver, skin
Kidney
Source: Toxicity values obtained from USEPA's Integrated Risk Information System (4th Quarter, 1996) except for the
copper and dioxin RfDs and the dioxin and HCH-gamma CSFs. Copper RfD and dioxin and HCH-gamma CSF
values obtained from USEPA's Health Effects Assessment Summary Table, 1994. Dioxin RfD obtained from
Toxicological Profile for 2,3, 7,8-Tetrachlorodibenzo-p-Diaxin, Agency for Toxic Substances and Disease Registry,
1989.
1 Cancer Slope Factor
2 See Appendix D for definitions of weight of evidence.
3 Reference Dose
4 Classification for oral exposure only.
5 Toxicity values for DDT are based on 4,4'-DDT.
6 PCBs is calculated as the sum of the available congeners. The RfD for PCBs is based on Aroclor 1254.
3-34
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JUNE 1997
Exposure Assumptions
Consumption Rate
The same fish consumption levels used to estimate exposure for freshwater anglers have been
applied to Bay anglers. Specifically, individual risks were estimated based on typical consumption
rates of 21.4 to 49.6 g/day. We calculated risks to individuals consuming larger amounts of fish
using the 90th percentile consumption rate of 107.1 g/day. Population risks (for cancer effects only)
were calculated using the typical fish consumption range, reflecting average consumption across the
entire population.
As in the freshwater angler analysis, we estimated angler exposure in two ways. The first
was based on the average contaminant concentrations for individual species to reflect the exposures
of anglers who catch and consume a single species. The second was based on species-weighted
average contaminant concentrations, reflecting the exposure of anglers who catch and consume a
variety of species.
As shown in Exhibit 3-14, species-weighted contaminant concentrations were based on catch
rates in San Francisco Bay reported by the National Marine Fisheries Service (NMFS).20 White
croaker is the most frequently caught species, representing 43 percent of the catch. It is followed
by surf perch, striped bass and shark at 35 percent, 14 percent and eight percent of the catch,
respectively.21 Keep rates for these species were not available. Therefore, we use catch rates alone
to develop overall species weights. As a result, we assume that anglers keep and eat fish in the same
proportions that the recreational catch occurs. Any difference in keep rates across species would
alter the species weights. The potential impact of this uncertainty is explored later in this section.
20 National Marine Fisheries Service, National Marine Recreational Fishery Statistics Survey,
Pacific Coast, 1987-1989 and 1993.
21 Jacksmelt were the second most frequently caught fish species in San Francisco Bay;
however, we have excluded this species from this analysis due to a lack of contaminant data.
3-35 '
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JUNE 1997
Exhibit 3-14
SPECIES WEIGHTS FOR SAN FRANCISCO BAY FISH CONSUMPTION
Species1 '
White croaker
Surf perch2
Striped bass
Shark3
Total
Number of Fish Caught
532
432
171
99
1,234
Percent of Catch
43.1 %
35.0 %
13.9 %
8.0 %
100 %
Source: National Marine Fisheries Service Marine Recreational Fishing Statistics
Survey, Pacific Coast, 1987-1989 and 1993.
1 Jacksmelt was the second most frequently caught species (435 fish). This
species was excluded from calculations of species weights because no tissue
contaminant data were available.
2 Includes shiner, walleye, pile, black and rubberlip surf perch.
3 . Includes brown, smoothhound, and leopard shark.
Angler Population
In estimating the angler population for this case study, we focused on people living in the
eight counties in the immediate San Francisco Bay area. These counties include Alameda, Contra
Costa, Marin, San Francisco, San Mateo, Santa Clara, Solano and Sonoma. Statistics reported in a
survey of fishing activity in Central and Northern California conducted by NMFS support this
approach.22 Coastal county residents account for more than 95 percent of saltwater fishing activity
in seven counties that abut San Francisco Bay for which the survey reported fishing participation by
area of residence.23
22 National Marine Fisheries Service, Results of the Bay Area Sportfish Economic Study,
NOAA-TM-NMFS-SWFC-78, August 1987.
23 The survey included fishing in San Francisco Bay and in the Pacific Ocean in all of the
counties surrounding the Bay, except for Santa Clara. The percentage of fishing activity attributable
to coastal county residents was assumed to be equal for both bay and ocean fishing.
3-36
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JUNE 1997
According to NMFS' survey, there are approximately 332,000 saltwater anglers living in the
eight counties that abut San Francisco Bay. Fishing activity among these anglers is split in two
ways. First, San Francisco Bay anglers may fish exclusively in the Bay or the ocean, while others
may fish in both areas. Second, these anglers may limit their fishing activity to saltwater, or they
may fish in both salt and freshwater. These variations in fishing habits among San Francisco Bay
anglers have implications for estimating the individual and population exposure levels to fish tissue
contaminants. At the individual level, anglers fishing exclusively in the Bay will have higher
exposures to any contaminants present in Bay fish than anglers who spend a portion of their time
fishing either in the ocean or freshwater. For purposes of this analysis, we have focused on the
individual risks for anglers who limit their fishing activity to the Bay.
To estimate population exposure levels, though, it is important to consider the impact of
differing fishing habits on the average exposure across the population of anglers. As noted earlier,
the average exposure level is particularly relevant when estimating the population cancer risk.
Therefore it is necessary to adjust the angler population to reflect this range of fishing habits.
NMFS1 survey of Central and Northern California fishing activity provides a means of estimating
the proportion of saltwater fishing activity that occurs in the Bay. Roughly 50 percent of the
saltwater fishing trips over a geographic area that includes the Pacific Coast from north of Stimson
Beach to south of Davenport, as well as the Bay itself, occur in the Bay. This estimate incorporates
fishing activity by all modes, including beach, pier, private boat, and party/charter boat.
The F&WS 1991 National Survey of Fishing, Hunting and Wildlife-Associated Recreation
provides a means of estimating the proportion of anglers who fish exclusively in saltwater.
According to this survey, 50 percent of the saltwater anglers in California fish exclusively in
saltwater, while the remaining saltwater anglers split their fishing activity between salt and
freshwater. In the absence of data on the relative level of effort devoted to fresh and saltwater
fishing among these anglers, we have assumed that activity is evenly split between these two types
of fishing.
Combining the information from these two surveys, we adjusted the Bay angler population
to reflect the number of full-time equivalent anglers. Starting with the original estimate of 332,000
Bay anglers, we reduce the figure by half to account for saltwater fishing activity outside of the Bay.
This number is then further reduced by 25 percent to reflect that 50 percent of the Bay anglers split
their fishing activity evenly between fresh and saltwater. Thus, the full-time equivalent estimate of
Bay anglers is approximately 125,000.
3-37
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JUNE 1997
Potential Angler Health Risks
Potential cancer risks associated with exposure to all 11 carcinogenic contaminants at
concentrations currently found in San Francisco Bay fish are presented in Exhibit 3-15. The total
incremental excess lifetime cancer risk (ILCR) for typical anglers consuming a mixed species diet
ranges from 1.8 x 10~* to 4.3 x 10"4. For anglers consuming a mixed species fish diet at the 90th
percentile consumption levels, the ILCR is 9.2 x 10"4. Based on typical consumption rates and an
angler population of approximately 125,000, we expect these contaminants to result in less than one
to one case of cancer per year; over 70 years, we expect between 23 and 53 excess cases of cancer.
These risks are dominated by PCBs and dioxin, which contribute roughly 49 and 41 percent of the
cancer risk, respectively. PCBs have an ILCR ranging from 9.0 x 10'5 to 2.1 x 10"4 for typical
consumption. Dioxin has an ILCR ranging from 7.6 x 10'5 to 1.8 x 10"4 under typical consumption.
Exhibit 3-15
POTENTIAL BASELINE CANCER RISK FOR RECREATIONAL
ANGLERS CONSUMING SAN FRANCISCO BAY FISH
Contaminant
PCBs
Dioxin
Dieldrin
DDT
Chlordane
HCH-alpha
Heptachlor Epoxide
HCH-beta
Heptachlor
HCH-gamma
Hexachlorobenzene
Total
Individual Excess Lifetime Cancer Risk
Typical
Consumption
(21.4 - 49.6 g/day)
9.0xlO'5-2.1xlO-4
7.6xlO'5-1.8xlO-4
7.8xlO-«-1.8xlO-5
4.9xlO-*-l.lxlO-5
3.9 xlO-6- 9.1x10-*
4.8xlO'7-l.lxlO-«
3.8xlO'7-8.8xlO-7
1.7xlO-7-3.9xlO-7
1.6xlO-7-3.6xlO-7
9.2xlO-"-2.1xlO-7
8.1xlO-8-1.9xlO-7
1.8xlO-4-4.3xlO-«
90th Percentile
Consumption
(107.1 g/day)
4.5 xKr4
3.8 xKr4
3.9x1 a5
2.4 x ia>
2.0 x l(r»
2.4 x \0*
.1.9 xlO*
8.5 x 10 7
7.7 x 10-7
4.6x107
4.1 x Ifr7
9.2 x 10-1
Population
Cancer Risk1
(excess cases.
per year)
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JUNE 1997
Noncancer risks for Bay anglers are summarized in Exhibit 3-16. At the typical consumption
rate, HI values range from 3.6 to 8.4. At the 90th percentile consumption rate, the HI is 18.1. PCBs
dominate these risks, accounting for 62 percent of the HI. The HQ for PCBs ranges from 2.3 to 5.2
for typical anglers; the HQ increases to 11.3 at the 90th percentile level. Mercury accounts for
approximately 21 percent of the noncancer risk. At typical consumption rates, mercury's HQ ranges
from 0.8 to 1.7; at 90th percentile consumption, mercury's HQ is 3.8. Dioxin, which accounts for
14 percent of the HI, is the only other contaminant that has an HQ as high as 1.0; dioxin's HQ ranges
from 0.51 to 1.17 at typical consumption rates. These results suggest that PCBs, mercury, and
dioxin are the contaminants with the greatest potential to cause adverse health effects for Bay
anglers. The specific noncancer effects associated with all of these contaminants are listed above
in Exhibit 3-13 and described in Appendix D.
Exhibit 3-16
POTENTIAL BASELINE NONCANCER RISK FOR RECREATIONAL
ANGLERS CONSUMING SAN FRANCISCO BAY FISH
Contaminant
PCBs
Mercury
Dioxin
Chlordane
DDT
Dieldrin
Zinc
Heptachlor Epoxide
Copper
Cadmium
HCH-gamma
Silver
Heptachlor
Hexachlorobenzene
Fluoranthene
Pyrene
Fluorene
Hazard Index
Hazard Quotient
Typical Consumption
(21.4. 49.6 g/day)
2.26 - 5.24
0.75-1.74
0.51-1.17
0.05-0.12
0.03 - 0.07
0.01 - 0.02
0.01-0.02
<0.01 - 0.01
<0.01 - 0.01
<0.01-<0.01
<0.01 - <0.01
<0.01 - <0.01
<0.01 - <0.01
<0.01-<0.01
<0.01 - <0.01
<0.01-<0.01
<0.01-<0.01
3.62-8.39
90th Percentile Consumption
(107.1 g/day)
11.31
3.77
2.54
0.25
0.14
0.05
0.04
0.02
0.01
<0.01
<0.01
<0.01
<0.01
<0.01
<0.01
<0.01
<0.01
18.13
Relative
Contribution
62.4 %
20.8 %
14.0%
1.4%
0.8 %
0.3 %
0.2 %
0.1%
0.1 %
<0. %
<0. %
<0. %
<0. %
<0. %
<0. %
<0. %
<0. %
100 %
3-39
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JUNE 1997
To ensure that anglers who catch and consume a single species are not subject to higher risk
levels than those consuming mixed species diets, we estimated health risks based on mean
contaminant concentrations for each of the four San Francisco Bay species groups. As shown in
Exhibit 3-17, a fish diet consisting of white croaker poses the highest cancer risk. Based on typical
consumption patterns, the excess risk associated with a diet of white croaker ranges from 2.9 x 10"4
to 6.7 x 10"4, approximately 1.6 times higher than the species-weighted risk. Shark pose the lowest
risk with an DLCR ranging from 3.7 x 10'5 to 8.6 x 10'5. Although this is approximately five times
less than the species-weighted risk, shark still pose risk at the 1 x 10'5 level.
Exhibit 3-17
POTENTIAL BASELINE HEALTH RISKS ASSOCIATED WITH
CONSUMPTION OF DIFFERENT SAN FRANCISCO BAY SPECIES
Species
White croaker
Striped bass
Surf perch
Shark
Species- Weighted Value
Individual Excess Lifetime Cancer Risk
Typical
Consumption
(21.4 - 49.6 g/day)
2.9 x lO"4 - 6.7 x 10-4
i.exio^-s.vxio-4
1.2 xlO"4- 2.8 xKT1
3.7xlO-5-8.6xlO-5
1. 8x10-" -4.3x10-"
90th
Percentile
Consumption
(107.1 g/day)
1.4xlO-3
8.0 x 10*
6.0 x W4
1.9 xlO-"
9.2 x 10"4
Noncancer Risk (Hazard Index)
Typical
Consumption
(21.4 -49.6 g/day)
5.1-11.8
3.0-7.0
2.3 - 5.4
2.7 - 6.3
3.6 - 8.4
90th
Percentile
Consumption
(107.1 g/day)
25.5
15.1
11.6
13.6
18.1
Noncancer risks for single species also are comparable to the risk associated with a mixed
species diet. White croaker produce the highest HI of 5.1 to 11.8 at the typical consumption level,
1.4 times higher than the species-weighted HI. Surf perch pose the lowest noncancer risk, an HI of
2.3 to 5.4, only about 1.6 times less than the species-weighted HI. Note that each individual species
poses substantial noncancer health risks, as all species have His greater than 2.0 at the low end of
the typical consumption range.
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JUNE 1997
Uncertainties
The methodology used to estimate health risks for Bay anglers includes a series of
assumptions that are a source of uncertainty in the results of this analysis. Some of these
assumptions apply to the analyses of both freshwater and Bay anglers, while others are specific to
the Bay angler analysis. The uncertainties related to assumptions made in the following two
elements of the Bay angler analysis are described below:
• Deriving species weights that reflect the relative contribution of individual
species to the Bay angler fish diet; and
• Assigning concentration values to contaminants for samples in which they were not
detected above the MDL.
Additional uncertainties that are relevant to both the freshwater and Bay angler analyses are
discussed in a later section of this chapter.
Species Weights
The relative contribution of individual species to Bay anglers' diets is based on catch rates
from NMFS fishing surveys conducted in San Francisco Bay from 1987 to 1989 and in 1993. By
relying on catch rates to develop species weights, we assume that keep rates are comparable across
the four species in our analysis: shark, striped bass, surf perch, and white croaker. Given that there
is relatively little variation in the health risks associated with contaminant levels in these different
species, any change in the species weights due to differences in keep rates would have little impact
on the health risk estimates. Based on the range of risk estimates across the four species presented
in Exhibit 3-17, any change in the species weights could increase or decrease the species-weighted
risk by a factor of roughly 1.4 to 4.9. In all cases, potential health risks remain significant.
An additional source of uncertainty in the species weights for Bay anglers' diets is the
exclusion of jacksmelt from the analysis. According to the NMFS fishing surveys, jacksmelt is the
second most frequently caught fish in the Bay. However, we could not evaluate the potential risk
associated with consuming jacksmelt because no fish tissue contaminant data were available for this
species. The relatively small degree, of variation in risks associated with consuming the four species
that were included in the analysis suggests that the lack of contaminant data on jacksmelt is unlikely
to significantly over- or underestimate Bay angler risks.
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Contaminants Not Detected Above MDLs
As noted previously, in calculating the average fish tissue concentrations used to estimate
health risks for anglers, we assume that all contaminants not detected in specific fish tissue samples
above MDLs are present at concentrations equal to one-half of the MDL. To test the impact of this
assumption on the analysis of Bay angler health risks, we estimated Bay angler health risks under
two alternative assumptions. First, we set the concentration of nondetected contaminants in these
fish tissue samples to zero. Second, we set nondetect concentrations equal to the MDL.
The results of these analyses show that changing the concentration assigned to nondetected
values from one-half the MDL to either zero or the MDL has little effect on the estimated risks for
anglers. Cancer risk levels change by approximately 16 percent under the alternative assumptions
and do not fall below 1 x 10"4. Noncancer risks change by no more than six percent and the hazard
index remains above 3.0. The low variation across alternate MDL assumptions mainly results from
the stringency of the detection limits applied in the San Francisco Bay study and the corresponding
high frequency of detection.
UNCERTAINTIES
As noted above, the methodology used to estimate health risks for freshwater and San
Francisco Bay anglers includes a series of assumptions that are a source of uncertainty in the results
of this analysis. We have discussed many of these assumptions and their potential impacts on either
the freshwater or Bay angler results in previous sections of this chapter. In this section, we focus
on additional uncertainties that affect both of these analyses.
Risks to Family Members
This analysis focuses solely on risks associated with anglers' consumption of fish containing
toxic contaminants. It does not address the potential risks that anglers' families may face by sharing
in consumption of their catch. A study of San Francisco Bay anglers fishing from public piers
suggests that the impact of this assumption on the estimated health risks associated with Bay area
fishing could be significant. Approximately 45 percent of the anglers surveyed shared some portion
3-42
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JUNE 1997
of their catch with family members.24 Although quantitative estimates are not available, anglers that
share their catch are likely to keep more fish than anglers who do not share their catch. As a result,
each family member could be exposed at typical consumption rates (adjusted for age and body
weight). Therefore, we may understate the size of the population exposed to toxic contaminants in
non-commercially caught fish, as well as the resulting population risk.25 In addition, family
members with increased exposure on a body weight basis or increased sensitivity to exposure, such
as young children or women who are pregnant or breast feeding, may face higher risks than those
estimated for anglers.
Cooking
Freshwater and Bay angler risk estimates were based on tissue contaminant levels measured
in raw fish fillets. The data reported for raw tissue may overstate angler exposure due to reductions
in contaminant levels during cooking. Studies have shown that virtually all methods of cooking fish
can lead to reductions in contaminant levels. In its study of marine fish contamination in Southern
California, OEHHA noted that PCB and DDT concentrations decrease by 20 percent to 80 percent
after cooking.26 A recently published study of cooking-related reductions in dioxin concentrations
in Great Lakes fish suggests that many cooking methods produce significant reductions in dioxin
24 See Save San Francisco Bay Association's, Eating Seafood from San Francisco Bay: a
Report on Fishing and Consumption Patterns, and a Review of Government Monitoring and
Assessment of Health Risk from Contaminants in the Bay, Draft, April 1995. No comparable data
were available for freshwater anglers; however, it is likely that a proportion of these anglers also
share their catch with family members.
25 The fish consumption values used to assess individual and population angler health risks
are estimates of consumption by only the anglers. No consumption by family members is reflected
in these values. Any consumption of an angler's catch by family members would represent
consumption of additional fish over and above the values used for angler consumption in this
analysis.
26 California OEHHA, A Study of Chemical Contamination of Marine Fish from Southern
California II: Comprehensive Study, 1991.
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JUNE 1997
concentrations. Baking, charbroiling, pan frying and deep fat flying all resulted in dioxin reductions
of roughly 50 percent. Reductions of PCB and pesticide levels after cooking averaged roughly 33
percent.27
Although cooking-related reductions in contaminant levels can range from 20 percent to 80
percent, this uncertainty does not significantly alter estimated angler health risks. First, potential
reductions are highly variable across contaminants and cooking methods. Second, even if we
assume the maximum possible reduction of 80 percent for all contaminants, potential individual risks
for anglers generally remain high. Under this scenario, cancer risks for freshwater and San Francisco
Bay anglers remain approximately 3.0 x 10'5 to 8.0 x 10'5 in the typical consumption range. The
noncancer hazard indices for typical consumption rates remain approximately 0.5 to 1.1 for
freshwater anglers and 0.7 to 1.7 for San Francisco Bay anglers.
Arsenic
EPA classifies inorganic forms of arsenic (e.g., arsenite and pentavalent arsenic) as human
carcinogens through oral exposure. In almost all cases, however, arsenic in edible fish tissues is
present as arsenic-containing organic compounds.28 These organic forms of arsenic are much less
toxic than the inorganic forms and generally are not considered a threat to human health.29 Both the
San Francisco Bay study and the TSMP measured arsenic in fish tissues. In the San Francisco Bay
study, arsenic was detected in all of the composites at a mean concentration of 1.1 parts per million.
Shark had the highest mean concentration of any Bay area species at 3.2 parts per million. The,
TSMP measured arsenic in approximately one-half of the composites tested for the compound at a
mean concentration of 0.9 parts per million.
27 Zabik, M.E and M.J. Zabik. "Tetrachlorodibenzo-p-dioxin Residue Reduction by
Cooking/Processing of Fish Fillets Harvested from the Great Lakes," Bulletin of Environmental
Contamination and Toxicology. V.55,1995, pp. 264-269.
28 National Academy of Sciences, Seafood Safety. Committee on Evaluation of the Safety
of Fishing Products, National Academy Press, Washington D.C., 1991.
29 USEPA, Guidance for Assessing Chemical Contaminant Data for Use in Fish Advisories:
Volume J, Fish Sampling and Analysis, Office of Water, EPA 823-R-93-002, August 1993.
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JUNE 1997
Tissue samples from the San Francisco Bay study were dominated by the organic forms of
arsenic (organoarsenical and arsenobetaine); the TSMP does not provide information on the form
of arsenic measured in its fish tissues. Similarly, neither study attempted to calculate organic to
inorganic arsenic ratios. Therefore, since the available evidence indicates that organic arsenic
dominates California fish tissues, we do not calculate potential cancer or noncancer health risks
associated with arsenic exposure. However, to the extent that small amounts of inorganic forms of
arsenic are present in edible fish tissues, the analysis will understate potential angler health risks.
ENVIRONMENTAL JUSTICE
Executive Order 12898 requires all federal agencies to identify and address as appropriate
the potential impact of proposed regulations on minority and low-income populations within the
community. In keeping with this Executive Order we have examined the potential for minority and
low-income anglers to face greater health risks from exposure to current levels of toxics in fish
tissue. The potential for minority and low-income anglers to face higher risk levels arises from
differences in their fish consumption patterns relative to the overall population of anglers, including
differences in the amount offish consumed and in fish preparation methods.
Fish Consumption Rates
According to the results of the Santa Monica Bay study, differences in consumption rates
between the general California angler population and minority and low-income anglers are generally
small; neither the typical nor the 90th percentile consumption rates selected for this analysis
significantly understate potential risks for these anglers. There was little difference in the median
consumption rates reported across White, Hispanic, Black and Asian anglers. Values ranged from
16.1 g/day to 24.1 g/day, very close to the 21.4 g/day median value used in this analysis. There was
more variation in the 90th percentile consumption rates across ethnic groups. These high level
consumption rates were lowest for Hispanic and Black anglers, 64.3 g/day and 85.7 g/day,
respectively. Rates for White and Asian anglers were considerably higher, at 112.5 g/day and 115.7
g/day, respectively. These higher rates, however, are only slightly higher or lower than the 90th
percentile value of 107.1 g/day used in this analysis.
Results reported for anglers of "other" ethnic descent do suggest the potential for higher
consumption rates for some California ethnic groups. Values reported for the 14 Middle Eastern,
Samoan and Cambodian anglers included in this ethnic category were 85.7 g/day and 173.6 g/day
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JUNE 1997
at the median and 90th percentile levels, respectively. Although these rates are four and 1.6 times
higher than those used in this analysis, the small sample of anglers on which they are based makes
it difficult to evaluate the representativeness of these consumption rates.
The Santa Monica Bay study also reported only minor differences in fish consumption rates
across income levels. The median consumption rate for the lowest income anglers in this study (less
than $5,000) was 32.1 g/day; while the consumption rate for all anglers with incomes above $5,000
was 21.4 g/day. The 90th percentile consumption rates for different income levels range from 64.3
g/day to 128.6 g/day, with high income anglers having the highest rate. Thus, neither the typical nor
the 90th percentile consumption rates used in this analysis significantly understate consumption rates
for low-income anglers.
In a 1988 study, Lance et al. surveyed low income mothers enrolled in Los Angeles County's
Women, Infants, and Children program to evaluate fresh fish consumption and breast milk
contaminants.30 Out of the 45 participants in the breast milk study, 35 ate fresh fish obtained from
local markets or recreational/subsistence angling. More than fourteen percent of the fish eaters
obtained fish directly from a family member or local angler. Study participants ate an average of
4.2 fish meals per month. Other mothers that were not eligible or refused to participate in the breast
milk study ate approximately 4.8 fish meals per month.
Using a fish fillet model, Lance et al. found that half of the fish eaters in the study ate
approximately 150 grams offish per meal, while the other half ate more than 150 grams per meal.
Therefore, assuming 4.2 meals per month and 150 grams per meal, these low-income mothers ate
approximately 21 grams offish per day. Since these are both lower bounds, the consumption rates
used in this study do not appear to significantly over- or under-estimate fish consumption for low-
income anglers.
Contrary to the Santa Monica Bay study and Lance et al. income findings, EPA has reported
higher consumption rates for low-income, minority and subsistence anglers in other studies. In the
Regulatory Impact Analysis of the Final Great Lakes Water Quality Guidance, EPA cites a 1993
study of Michigan anglers by West that reports a consumption rate of 43.1 g/day for low-income
30 Lance, L., Papanek, P., Ward, C., and Peterson, J. Breast Milk Contaminants and Fresh
Fish Consumption in Southern California: Results of a Pilot Survey. DRAFT. Prepared by the
Department of Health Services, County of Los Angeles, 1988.
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minority anglers.31 In its draft report to Congress on mercury, EPA cites median and 90th percentile
consumption rates for subsistence anglers of 30 g/day and 170 g/day, respectively.32 A comparison
of these rates to those used in this analysis suggests that we may understate risks for low-income,
minority, and subsistence anglers by a factor of 1.4 at the median level and a factor of 1.6 at the 90th
percentile level.
Currently, EPA's Region 9 office is designing a study in conjunction with local community
networks to provide more accurate estimates of fish consumption rates in California's Asian and
subsistence fishing populations.33 The study, which will be finalized sometime in 1998, will provide
complete fishing activity profiles for many of California's ethnic populations. At that time, we will
be able to provide quantitative determinations about whether members of specific ethnic groups face
disproportionate health risks as a result of consuming local fish and shellfish.
Fish Preparation Methods
Differences in preparation and cooking techniques represent another way in which risks could
vary across subgroups of the general population. Many of the toxic contaminants evaluated in this
analysis (including PCBs, which represent the most significant source of human health risk)
accumulate in fatty tissue and internal organs of fish. Therefore, anglers who consume whole fish
or untrimmed fillets (i.e., including the skin) face higher risks than those consuming only trimmed
fillets. For example, trimming the fat and skin may remove approximately 45 percent of the PCBs
in a standard fillet.34
31 USEPA, Regulatory Impact Analysis of the Final Great Lakes Water Quality Guidance,
Final Report, Office of Science and Technology, March 1995.
32 USEPA, Mercury Study Report to Congress, Volume VI: Characterization of Human Health and
Wildlife Risks from anthropogenic Mercury Emissions in the United States, Draft, Office of Air Quality
Planning and Standards and Office of Research and Development, December 12,1994.
33 Arthur Den (USEPA) and Audry Chiang (Asian Pacific Environmental Network), personal
communication, October 7,1996.
34 Voiland, MP ,DL Gall, DJ Lisk, and DB MacNeill, "Effectiveness of Recommended Fat-
Trimming Procedures on the Reduction of PCB and Mirex Levels in Brown Trout from Lake
Ontario," Journal of Great Lakes Research, volume 17, number 4, pages 454-460,1991.
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eat fish whole, but gutted, including nearly 50 percent of Asians and 44 percent of Hispanics. The
freshwater angler analysis understates risks for these anglers because freshwater fish tissue
contaminant data are based on chemical analysis of fillets without skin. The San Francisco Bay angler
risk estimates, however, do not significantly understate risks for these anglers because
Bay fish tissue samples were prepared for chemical analysis according to the most frequent means of
consumption (i.e., white croaker and surf perch fillets were analyzed with skin, and shark and striped
bass were analyzed without skin).
POTENTIAL HEALTH BENEFITS TO RECREATIONAL
ANGLERS ASSOCIATED WITH IMPLEMENTATION OF
THE CALIFORNIA TOXICS RULE
Reducing loadings of toxic chemicals to California's waters to meet the ambient water quality
criteria prescribed by the California Toxics Rule has the potential to result in corresponding
reductions in fish tissue contaminant levels. The magnitude of these reductions, however, depends
on implementation of the rule and complex interactions among future pollutant loadings, historic
contamination (including sediment contamination), site-specific ecological and geologic
characteristics, and chemical absorption and bioaccumulation in fish tissues. Based on the potential
post-rule contaminant reductions in water and fish tissues, we estimated the potential human health
benefits associated with achieving criteria under the CTR.
Because of the uncertainty in determining post-rule conditions, we estimate potential benefits
under two scenarios.
Scenario 1: The first benefit scenario assumes the water quality criteria in the
proposed rule (which for human health criteria for carcinogens are based on a 1 x 10"6
risk level for the general population) are attained. While the criteria would apply to
all waters specified in the rule, the Clean Water Act provides regulatory authority only
for point sources (nonpoint source controls are either voluntary or come from state
law). Where there are nonpoint sources contributing discharges, point source
controls may only reduce a portion of the overall discharges to the waterbody. Thus,
this approach yields an upper bound of the rule's human health benefits. (See Chapter
7 for the apportionment of health benefits associated with point source controls).
Scenario 2: The second benefit scenario assumes the water quality criteria in the
proposed rule are attained using a 1 x 10~5 risk level for the general population. This
approach yields a lower bound of the rule's human health benefits.
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Cancer Risk Benefits to Recreational Anglers
Calculation of Post-Rule Fish Tissue Contaminant Concentrations
We calculated the potential risk reductions associated with implementation of the California
Toxics Rule by comparing baseline health risks with estimated post-rule risks. For the purposes of
this analysis, post-rule conditions are defined as the fish tissue concentrations associated with a human
health criteria based on the 1 x 10"6 and 1 x 1(T5 risk levels. We calculate the post-rule fish tissue
levels and resulting health risks based on the same exposure assumptions and risk analysis equations
used to calculate potential baseline risks.
The analysis of freshwater and San Francisco Bay health benefits focuses on six contaminants
representing 98 percent or more of the quantified/monetized risk for freshwater and San Francisco
Bay anglers. To calculate post-rule fish tissue concentrations, we first identified the most stringent
criteria for each compound (i.e., the chronic aquatic life criteria or the human health criteria). For
five of the contaminants (chlordane, DDT, dieldrin, dioxin, and PCBs), the rule's proposed human
health criteria for consumption of aquatic organisms are the most stringent.
The CTR's target risk level of 1 x 10"6 is based on a 6.5 gram per day consumption rate for
the general population. As a result, the CTR protects the general population at the rule's target risk
level. Scenario 1 recognizes that recreational and subsistence anglers consume fish at higher rates
than the general population. Therefore, we substitute the consumption estimates used in this analysis
into the exposure equations. This results in estimated post-rule fish tissue concentrations that are
higher than those derived using 6.5 grams per day consumption. We then use the cancer slope factors
for each contaminant to estimate post-rule risks. Since these estimates are based on consumption of
21.4 to 49.6 grams per day, the resulting estimates of post-rule individual risks for these contaminants
range from 3.3 x KT6 to 7.6 x 10"6.
We follow the same procedure to calculate post-rule fish tissue concentrations and risks under
Scenario 2. Under this scenario, however, we calculated post-rule risks associated with human health
criteria based on a target risk level of 1 x 10~5. Again, we derived the post-rule fish tissue
concentrations and estimates of health risks based on the higher consumption rates used in the
3-49
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JUNE 1997
baseline analysis. Under Scenario 2, the calculated risk levels for chlordane, DDT, and dieldrin
would be higher than baseline risks; as a result, there is no change in risk as a result of the rule's
implementation. For PCBs and dioxin, the individual post-rule cancer risk for criteria based on the
1 x 10'5 risk level for the general population ranges from 3.3 x 10'5 to 7.6 x 10'6.
We applied a modified approach to determine the post-rule cancer risks associated with
toxaphene. The aquatic life criterion for toxaphene is nearly four times more stringent than the
human health criterion. Thus, the post-rule individual risk levels for this contaminant range from
8.8 x 10'7 to 2.0 x 10'6 for the typical fish consumption rate.
Freshwater Cancer Benefits to Recreational Anglers
The potential health benefits associated with full implementation of the CTR's proposed
water quality criteria are presented in Exhibit 3-18. Assuming criteria based on a risk level of 1 x
10'6 for the general population, potential cancer risks for freshwater anglers decrease by 91 percent
when the water quality criteria established by the CTR are met. Baseline population cancer risks
resulted in 5 to 11 cancer cases per year among freshwater anglers; once implemented, the rule has
the potential to reduce this to between zero and one case per year. Baseline individual excess
lifetime cancer risks range between 1.5 x 10"4 and 3.5 x 10"4 for typical anglers. Post-rule risks for
individual contaminants range from 70 to 97 percent below baseline estimates. The largest
reductions are associated with toxaphene (97 percent) and PCBs (94 percent).
Under Scenario 2, criteria based on a risk level of 1 x 10'5 for the general population, the total
potential reduction in cancer risks is 37 percent. The resulting number of annual cancer cases is
between three and seven for typical consumption. Baseline risks for chlordane, DDT, and dieldrin
already meet the 1 x 10'5 risk level, and consequently have no post-rule benefits. Post-rule risks for
toxaphene and PCBs, however, are 97 and 41 percent lower than baseline, respectively.
San Francisco Bay Cancer Benefits to Recreational Anglers
The results of the San Francisco Bay benefits analysis for carcinogenic effects are presented
in Exhibit 3-19. Assuming criteria based on a protection standard of 1 x 10'6 for the general
population, cancer risks for these anglers decrease by 91 percent post-rule. Baseline population
cancer risks resulted in less than one to one cancer case per year among San Francisco Bay anglers
(approximately 23 to 53 cases for the population over 70 years). Achieving the CTR's water quality
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Exhibit 3-18
POTENTIAL FRESHWATER CANCER HEALTH BENEFITS TO RECREATIONAL ANGLERS UNDER THE CALIFORNIA TOXICS RULE:
ESTIMATED POST-RULE FRESHWATER ANGLER RISKS AND PERCENT REDUCTION RELATIVE TO BASELINE1
Contaminant
Chlordane2
DDT2
Dieldrin2
PCBs2
Toxaphene3
Total
Baseline
Individual Excess
Lifetime Cancer Risk
(21.4 - 49.6 g/day)
l.lxlO-5-2.5xlO-5
2.5xlO-5-5.8xlO-5
2.4 xlO'3- 5.6 xlO5
5.6 xlO-3- 1.3x10-"
3.2xlO-s-7.5xlO-5
1.5 xKT1- 3.5 x NT1
Population
Cancer Risk
(excess cases
per year)
<1-1
1-2
1-2
2-4
1-2
5-11
Post-rule
Achieve Post-rule Criteria Based on Risk Level of
1 x 10^ for the General Population
Individual Excess
Lifetime Cancer Risk
(21.4 - 49.6 g/day)
3.3x10-* -7.6x10"*
3.3x10"* -7.6x10^
3.3 xlO-6- 7.6x10"*
3.3x10-*- 7.6x10^
8.8 xlO'7- 2.0x10-*
1.4xlO-5-3JxlO-5
Population
Cancer Risk
(excess cases
per year)
-------
JUNE 1997
Exhibit 3-19
POTENTIAL SAN FRANCISCO BAY CANCER HEALTH BENEFITS TO RECREATIONAL ANGLERS UNDER THE CALIFORNIA TOXICS RULE:
ESTIMATED POST-RULE SAN FRANCISCO BAY ANGLER RISKS AND PERCENT REDUCTION RELATIVE TO BASELINE1
Contaminant
Chlordane2
DDT2
Dieldrin2
Dioxin2
PCBs5
Total
Baseline
Individual Excess
Lifetime Cancer Risk
(21.4-49.6g/day)
3.9x10* -9. 1x10*
4.9 x 10* -I.I x 10'
7.8x10* -1.8x10'
7.6 x 10s -1.8x10^
9.0xlO'-2.1xlOJt
1.8x10^-4.2x10^
Population
Cancer Risk
(excess cases
per year)
0
0
0
-------
JUNE 1997
criteria has the potential to reduce this to zero cases per year. Post-rule individual excess lifetime
cancer risks range between 1.7 x 10'5 and 3.8 x 10"5 for typical Bay area anglers. Post-rule risks for
individual contaminants are 16 to 96 percent below baseline estimates. The largest reductions (96
percent) are associated with PCBs and dioxin.
Under Scenario 2, criteria based on a risk level of 1 x 10~5, the total reduction in cancer risks
is 55 percent. The resulting number of annual excess cancer cases is between zero and one for
typical consumption. Baseline risks for chlordane, DDT, and dieldrin are not significantly reduced
and consequently have no post-rule benefits. Post-rule risks for dioxin and PCBs, however, are 58
and 64 percent lower than baseline, respectively.
Noncancer Risk Benefits to Recreational Anglers
Calculation of Post-Rule Fish Tissue Contaminant Concentrations
In estimating the potential health benefits from reduced noncancer risk, we focused on the
contaminants that represent 97 percent of the risk for freshwater and San Francisco Bay anglers.
Post-rule noncancer risks for these' contaminants are based on the rule's human health standard for
consumption of aquatic organisms. Under Scenario 1, we assume post-rule water quality meets these
criteria, based on a risk level of 1 x 10'6 individual excess lifetime cancer risk for the general
population. Under Scenario 2, we assume a risk level of 1 x 10'5 for the general population. To
estimate post-rule noncancer risks for these contaminants, we back-calculated fish tissue
contaminant levels from these target risk levels and applied the same methodology as was used to
estimate baseline noncancer risks. For mercury, which is a noncarcinogen, we back-calculated the
post-rule fish tissue concentrations from the noncancer risk target goal (HQ=1.0).
Freshwater Noncancer Benefits to Recreational Anglers
The results of the freshwater benefits analysis for noncancer effects are presented in Exhibit
3-20. Assuming criteria based on a risk level for the general population of 1 x 10~6, noncancer risks
for freshwater anglers decrease by 67 percent post-rule. The baseline hazard index ranges from 2.3
to 5.4 for freshwater anglers; once fully implemented, the rule has the potential to reduce this to 0.8
to 1.8. Hazard quotients for typical anglers for chlordane and DDT are less than one in both baseline
and post-rule conditions, although the rule reduces the HQs for both contaminants by 70 and 87
percent, respectively. PCBs fall from the 1.4 to 3.3 baseline HQ to 0.1 to 0.2 after the rule, a
reduction of 94 percent. Baseline risks for mercury are not significantly reduced under this rule, and
therefore have no post-rule benefits.
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Exhibit 3-20
POTENTIAL FRESHWATER NONCANCER HEALTH BENEFITS
TO RECREATIONAL ANGLERS UNDER THE CALIFORNIA TOXICS RULE:
ESTIMATED POST-RULE FRESHWATER ANGLER RISKS AND PERCENT REDUCTION RELATIVE TO BASELINE1
Contaminant.
Chlordane2
DDT2
Mercury3
PCBs2
Hazard Index
Baseline
Individual Risk
Hazard Quotient
(21.4- 49.6 g/day)
0.14-0.31
0.15-0.34
0.62-1.44
1.40 - 3.30
2.31 -539
Post-rule
Achieve Post-rule Criteria
Based on Risk Level of 1 x 10"*
for the General Population
Individual Risk
Hazard Quotient
(21.4 - 49.6 g/day)
0.04-0.01
0.02 - 0.04
0.62-1.44
0.08-0.19
0.76 - 1.77
Percent
Reduction
70%
87%
0%
94%
67%
Achieve Post-rule Criteria
Based on Risk Level of 1 x 10 s
for the General Population
Individual Risk
Hazard Quotient
(21.4 - 49.6 g/day)
0.14-0.31
0.15-0.34
0.62-1.44
0.82-1.91
1.73 - 4.00
Percent
Reduction
0%
0%
0%
41%
25%
1 Noncancer risks associated with the contaminants listed in this exhibit represent 97 percent of the total estimated cancer risk for freshwater
anglers.
2 Post-rule estimated angler noncancer risk based on the human health criterion (consumption of aquatic organisms only) cancer risk targets
adjusted to reflect the fish consumption rates used in this analysis.
3 Post-rule estimated angler noncancer risk based on the human health criterion (consumption of aquatic organisms only) noncancer risk target of
Hazard Quotient = 1 .0.
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JUNE 1997
Under Scenario 2, protection to 1 x 10'5, the total reduction in noncancer risks is 25 percent,
for a post-rule hazard index of 1.7 to 4.0 for typical anglers. Baseline risks for chlordane, DDT, and
mercury already meet the 1 x 10~5 risk level, and consequently have no post-rule benefits. Post-rule
risks for PCBs, however, are 41 percent lower than baseline, and have a post-rule HQ of 0.8 to 1.9
for typical anglers.
San Francisco Bay Noncancer Benefits to Recreational Anglers
The results of the San Francisco Bay benefits analysis for noncancer effects are presented
in Exhibit 3-21. Assuming criteria based on a risk level of 1 x 10~6 for the general population,
noncancer risks for Bay area anglers decrease by 76 percent due to the rule. The baseline hazard
index ranges from 3.5 to 8.2 for Bay area anglers; once fully implemented, the rule has the potential
to reduce this to 0.9 to 2.0. Hazard quotients for dioxin and PCBs each fall by 96 percent. Post-rule
HQs for both compounds are less than one. Baseline risks for mercury already meet the rule's goal,
and therefore have no post-rule benefits.
Under Scenario 2, criteria based on a risk level for the general population of 1 x 10"5, the total
reduction in noncancer risks in San Francisco Bay is 49 percent, resulting in a post-rule hazard index
of 1.8 to 4.2 for typical anglers. Post-rule risks for dioxin and PCBs decrease by 57 and 64 percent,
respectively. The post-rule HQ for dioxin is less than one, while the post-rule HQ for PCBs remains
greater than 1.0 within the typical consumption range. Baseline risks for mercury already meet the
rule's goal, and therefore have no post-rule benefits.
CONCLUSIONS: BASELINE RISKS AND POST-CTR
BENEFITS TO RECREATIONAL ANGLERS
Our analysis shows that the potential baseline health risks associated with consumption of
fish containing toxic pollutants for both freshwater and San Francisco Bay anglers are significant.
Individual risk levels for freshwater anglers are slightly lower than those for San Francisco Bay
anglers. Due to the larger population of freshwater anglers, however, the population risks for this
group are roughly 15 times larger than those for Bay anglers. An analysis of post-CTR benefits
suggests that there may be substantial reductions in recreational angler health risks. These baseline
risks and CTR-associated benefits are summarized below.
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JUNE 1997
Exhibit 3-21
POTENTIAL SAN FRANCISCO BAY NONCANCER HEALTH BENEFITS
TO RECREATIONAL ANGLERS UNDER THE CALIFORNIA TOXICS RULE:
ESTIMATED POST-RULE SAN FRANCISCO BAY ANGLER RISKS AND PERCENT REDUCTION RELATIVE TO BASELINE1
Contaminant
Dioxin2
Mercury3
PCBs2
Hazard Indei
Baseline
Individual Risk
Hazard Quotient
(21.4 - 49.6 g/day)
0.51-1.17
0.75-1.74
2.26 - 5.24
3.52 - 8.18
Post-rule
Achieve Post-rule Criteria
Based on Risk Level of 1 x 10^
for the General Population
Individual Risk
Hazard Quotient
(21.4 -49.6 g/day)
0.02 - 0.05
0.75 - 1.74
0.08 - 0.19
0.85-1.98
Percent
Reduction
96%
0%
96%
76%
Achieve Post-rule Criteria
Based on Risk Level of 1 x 10s
for the General Population
Individual Risk
Hazard Quotient
(21.4 - 49.6 g/day)
0.22-0.51
0.75 - 1.74
0.82 - 1.91
1.79 - 4.16
Percent
Reduction
57%
0%
64%
49%
1 Noncancer risks associated with the contaminants listed in this exhibit represent 97 percent of the total estimated cancer risk for San Francisco
Bay anglers.
2 Post-rule estimated angler noncancer risk based on the human health criterion (consumption of aquatic organisms only) cancer risk targets
adjusted to reflect the fish consumption rates used in this analysis.
3 Post-rule estimated angler noncancer risk based on the human health criterion (consumption of aquatic organisms only) noncancer risk target of
Hazard Quotient = 1.0.
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JUNE 1997
Summary of Potential Baseline Cancer
Risks to Recreational Anglers
• Individual excess lifetime cancer risks from fish consumption for freshwater
anglers range from 1.5 x 10"* to 3.5 x lO4 for typical angler consumption (i.e.,
21.4to49.6g/day).
• Upper-bound consumption (i.e., 90th percentile fish consumption of 107.1
g/day) for freshwater anglers results in an individual excess lifetime cancer
risk of 7.6 xlO-4.
• California's freshwater angling population will incur between 5 and 11 cases
of cancer each year (based on typical consumption rates and a population of
approximately 2.2 million freshwater anglers).
• Individual excess lifetime cancer risks for typical San Francisco Bay anglers
range from 1.8 x 10"4 to 4.3 x 10"4.
• Upper-bound consumption for San Francisco Bay anglers results in an
individual excess lifetime cancer risk of 9.2 x 10"4.
• San Francisco Bay's angling population may incur less than one to one case
of cancer each year, or a total of 23 to 53 cases over 70 years (based on
typical consumption and a Bay area angler population of approximately
125,000 individuals).
• The San Francisco Bay case study provides quantitative health risk estimates
for 125,000 recreational anglers fishing in the Bay area. The CTR, however,
also governs water quality in California's other inland bays and estuaries.
The case study does not include risk estimates for the 500,000 to 600,000 bay
and estuary anglers that fish outside of San Francisco Bay.
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JUNE 1997
These baseline cancer risks are dominated by a small number of contaminants. PCBs and
toxaphene account for nearly 58 percent of the baseline freshwater angler cancer risk. DDT,
dieldrin, and chlordane account for an additional 40 percent of the risk. In San Francisco Bay, PCBs
and dioxin dominate angler cancer risks. PGBs account for nearly 50 percent of the baseline cancer
risk while dioxin contributes an additional 40 percent.
Summary of Potential Baseline Noncancer
Risks to Recreational Anglers
• The hazard index for freshwater anglers with typical fish consumption (i.e.,
21.4 to 49.6 grams per day) ranges from 2.4 to 5.5.
• The hazard index for freshwater anglers with 90th percentile fish
consumption (i.e., 107.1 grams per day) is 11.9.
• The hazard index for San Francisco Bay anglers with typical fish
consumption ranges from 3.6 to 8.4.
• The hazard index for San Francisco Bay anglers with 90th percentile fish
consumption is 18.1.
Like cancer risks, baseline noncancer risks are dominated by a relatively small number of
contaminants. Again, PCBs with an HQ of 1.4 to 3.3 at typical consumption, account for the
majority of baseline noncancer risks for freshwater anglers (60 percent). Mercury contributes an
additional 26 percent of the baseline noncancer risk with an HQ of 0.6 to 1.4 under typical
consumption. These are the only freshwater contaminants with hazard quotients greater than 1.0
within the typical or 90th percentile fish consumption scenarios.
PCBs also account for the majority of baseline noncancer risk for San Francisco Bay anglers
~ 62 percent. Mercury and dioxin are the only other contaminants with a hazard quotient as high
as 1.0 for typical or 90th percentile Bay area anglers. Mercury's baseline hazard quotient ranges
from 0.8 to 1.7 at the typical consumption rate, increasing to 3.8 at 90th percentile consumption.
Dioxin has a baseline HQ ranging from 0.5 to 1.2 for typical consumption, and increases to 2.5 at
90th percentile consumption.
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The freshwater and San Francisco Bay baseline angler risk estimates are subject to
uncertainties associated with the series of assumptions included in the methodology for this analysis.
For example:
• Relying on contaminant concentrations measured in raw fish tissue to
estimate exposure overstates risks;
• Not considering fish consumption by anglers' families understates baseline
population risks for anglers and individual risks for sensitive subgroups; and
• Assuming that contaminants not detected above the MDL are present at one-
half of the MDL may either under- or overstate risks.
• Not estimating health risks associated with consuming contaminated
commercial fish underestimates baseline risks.
Overall, we found that these and other uncertainties do not alter our finding that both
freshwater and Bay anglers face potentially significant health risks from consumption of fish
contaminated with toxics.
In addition, we have explored the environmental justice implications of angler health risks.
We have examined whether differences in fish consumption patterns, including fish consumption
rates and preparation methods, create the potential for certain ethnic or income subgroups of the
angler population to face disproportionate health risks. According to the primary study we used to
derive fish consumption rates, ethnic and income groups in California do not differ substantially in
their fish consumption rates. Furthermore, the typical and 90th percentile consumption rates used
in our analysis are applicable to virtually the entire angler population.
Data on food preparation methods from this same study suggest that some individuals may
face additional risks due to the consumption of whole fish, including the intestines. Moreover, risks
for roughly 50 percent of these individuals may be underestimated because they prepare and eat fish
with the skin, while the freshwater tissue samples were analyzed without skin. This is not the case
for Bay angler risk estimates, since Bay fish tissue samples were prepared according to the most
frequent means of consumption for each species.
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Potential Benefits of the CTR
An analysis of the potential health benefits associated with achieving the water quality
criteria established by the California Toxics Rule suggests that once the rule is fully implemented,
substantial reductions in angler health risks may occur.
• We estimated that post-rule cancer risks, under criteria based on a risk level
of 1 x 10"6 for the general population, for freshwater and San Francisco Bay
anglers could be as much as 91 percent lower than baseline levels.
• The estimated population risk for freshwater anglers decreases from between
5 and 11 cases per year to one or fewer cases per year.
• Assuming post-rule water quality meets the rule's proposed criteria based on
a risk level of 1 x 10~6 for the general population, the individual excess
lifetime cancer risks for anglers consuming fish at typical rates would range
froml.4xlO-5to3.3xlO-5.
• For San Francisco Bay anglers, population cancer risk is estimated to
decrease from the baseline of one or fewer cases per year (23 to' 53 cases over
70 years) to zero cases per year as a result of the rule.
• Assuming the rule is implemented and achieves ambient water quality criteria
based on a risk level of 1 x 10'6 for the general population, post-rule
individual excess lifetime cancer risks for these typical Bay area anglers
could range from 1.7 x 10'5 to 3.8 x 10'5.
• Noncancer risks for California anglers may decrease by as much as 67
percent for typical freshwater anglers and 76 percent for typical San
Francisco Bay anglers. The HI for freshwater anglers is estimated to decrease
from the current range of 2.4 to 5.5 to the potential post-rule level of 0.8 to
1.8. These results suggest that if the rule achieves ambient water quality
criteria, it could effectively eliminate noncancer risks associated with PCBs,
chlordane, and DDT.
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For San Francisco Bay anglers, the HI is estimated to decrease from the 3.6
to 8.4 baseline range to the post-rule range of 0.9 to 2.0 at the typical
consumption level. The results suggest that if the rule achieves ambient
water quality goals, typical San Francisco Bay anglers are unlikely to face a
risk of adverse noncancer health effects from dioxin or PCBs.
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REFERENCES
California EPA, State Water Resources Control Board, Toxic Substances Monitoring
Program, Data Reports, June 1991 (91-1WQ), May 1992 (92-1WQ), January 1993
(90-1WQ), and June 1993 (93-1WQ).
California Department of Fish and Game Inland Fisheries Division, Sacramento River
System Sport Fish Catch Inventory, Final Performance Report, June 30,1995.
California OEHHA, A Study of Chemical Contamination of Marine Fish from Southern
California Volume II: Comprehensive Study, 1991.
Lance, L., Papanek, P., Ward, C., and Peterson, J, Breast Milk Contaminants and Fresh
Fish Consumption in Southern California: Results of a Pilot Survey. DRAFT.
Prepared by the Department of Health Services, County of Los Angeles, 1988.
National Academy of Sciences, Seafood Safety. Committee on Evaluation of the Safety of
Fishing Products, National Academy Press, Washington D.C., 1991.
National Marine Fisheries Service, National Marine Recreational Fishery Statistics Survey,
Pacific Coast, 1987-1989 and 1993.
National Marine Fisheries Service, Results of the Bay Area Sportfish Economic Study,
NOAA-TM-NMFS-SWFC-78, August 1987.
San Francisco Regional Water Quality Control Board, Contaminant Levels in Fish Tissue
from San Francisco Bay, 'Final Draft Report, December 1994.
Santa Monica Bay Restoration Project, Santa Monica Bay Seafood Consumption Study,
prepared by Southern California Coastal Water Research Project and MBC Applied
Environmental Sciences, June 1994.
Save San Francisco Bay Association's, Eating Seafood from San Francisco Bay: a Report
on Fishing and Consumption Patterns, and a Review of Government Monitoring and
Assessment of Health Risk from Contaminants in the Bay, Draft, April 1995.
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JUNE 1997
REFERENCES
(continued)
USEPA, National Center for Environmental Assessment, Office of Research and
Development. PCBs: Cancer Dose-Response Assessment and Application to
Environmental Mixtures, EPA/600/P-96/001F, September 1996.
USEPA, Regulatory Impact Analysis of the Final Great Lakes Water Quality Guidance,
Final Report, Office of Science and Technology, March 1995.
USEPA, Mercury Study Report to Congress, Volume VI: Characterization of Human Health
and Wildlife Risks from Anthropogenic Mercury Emissions in the United States,
Draft, Office of Air Quality Planning and Standards and Office of Research and
Development, December 12, 1994.
USEPA, Guidance for Assessing Chemical Contaminant Data for Use in Fish Advisories:
Volume J, Fish Sampling and Analysis, Office of Water, EPA 823-R-93-002, August
1993.
USEPA, National Study of Chemical Residues in Fish, Volumes I and II. Office of Science
and Technology, EPA 823-R-92-008a,b, September 1992.
US Fish and Wildlife Service, 1991 National Survey of Fishing, Hunting, and Wildlife-
Associated Recreation, California, July 1993.
Voiland, MP, DL Gall, DJ Lisk, and DB MacNeill, "Effectiveness of Recommended Fat-
Trimming Procedures on the Reduction of PCB and Mirex Levels in Brown Trout
from Lake Ontario," Journal of Great Lakes Research, volume 17, number 4, pages
454-460, 1991.
Zabik, M.E and M.J. Zabik."Tetrachlorodibenzo-p-dioxin Residue Reduction by
Cooking/Processing of Fish Fillets Harvested from the Great Lakes," Bulletin of
Environmental Contamination and Toxicology. V.55, 1995, pp. 264-269.
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JUNE 1997
ECONOMIC BENEFITS CHAPTER 4
INTRODUCTION
This chapter describes and estimates a variety of potential economic benefits associated with
meeting water criteria established by the California Toxics Rule (CTR). Exhibit 4-1 summarizes
these potential benefits. Because of data, time, and budgetary constraints, we have valued only use
benefits associated wjth recreational fishing and related non-use benefits. In addition, we have
monetized some of the health benefits presented in Chapter 3. Key results of our evaluation include:
• Monetized benefits associated with achieving toxic water quality criteria
established by the CTR are estimated for recreational fishing, human health
cancer effects, and passive use values only. These benefits are significant,
ranging from a low of $62 million per year to an upper bound of
approximately $600 million per year.
• Recreational fishing benefits are valued at between $35 and $196 million per
year. Related non-use benefits are estimated to be $17 to $294 million.
Finally, avoided cancer deaths are valued at between $10 and $110 million
per year.
• A number of other economic benefits are expected to accrue when water
quality criteria are met. However, we have not quantified or monetized these
comprehensively. They include: increased value for commercial fishing;
drinking water treatment, sludge treatment, and dredged material
management cost savings; increased property values; increased value and
participation in recreational hunting and other near-stream activities; avoided
cost of illness associated with consumption of commercially caught seafood;
and avoided costs of endangered species management.
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JUNE 1997
Exhibit 4-1
SUMMARY OF POTENTIAL ANNUAL ECONOMIC BENEFITS
ASSOCIATED WITH ACHIEVING WATER QUALITY STANDARDS
ESTABLISHED BY THE CALIFORNIA TOXICS RULE
Benefit Category
USE VALUES
Improved Recreational Fishing
Improved Recreational Hunting
Water Enhanced Recreation
Improved Commercial Fisheries
Drinking Water Treatment Savings
Sludge Treatment Savings
Property Values
Avoided cost of endangered species management and
associated land use restrictions
Human Health (3)
Reduced cancer risk - anglers
Reduced non-cancer risk —anglers
Reduced health risk to some subsistence anglers
NON-USE
Bequest and Existence Values
Ecological
Reduced morbidity/mortality to aquatic and
terrestrial wildlife; improved integrity of aquatic
and aquatic-dependent ecosystems
Improved conditions in habitat supporting fish
spawning/migration
Improved conditions in habitat supporting
threatened and endangered species
TOTAL
Lower Bound Estimate
(Millions S1996X1)(2)
$35
$ - Not Estimated
$ - Not Estimated
$- Not Estimated .
$- Not Estimated
$ - Not Estimated
$ - Not Estimated
$ - Not Estimated
S10
67% reduction in Hazard
Index; $ - Not Estimated
$ - Not Estimated
$17
- 81 5,000 acre* of bay*, harbors,
estuancs. lakes, and wetlands
-4,000 mile* of riven
• 1 75,000 acres of bays/harbors
- 52,000 acre* of estuaries
-102.000 acres of lakes
- 1 1 ,000 acre* of saline lakes
- 1,000 rates of nven
-180,000 acres of bays,
harbor* and ei tuanes
- 230.000 acres salme lakes
- 1,900 river mi let
$42 + $ BcMflti Mt
Estimated
Upper Bound
Estimate
(Millions $1996')
$196
$ - Not Estimated
$ - Not Estimated
$- Not Estimated
$ - Not Estimated
$ - Not Estimated
$ - Not Estimated
$ - Not Estimated
$110
76% reduction in Hazard Index;
$- Not Estimated
$ - Not Estimated
$294
- 815,000 acres of bays, harbors,
estuaries, lakes, and wetlands
- 4,000 miles of rivers
- 175,000 acres of bays/harbors
- 52,000 acres of estuaries
- 102,000 acres of lakes
- 1 1 ,000 acres of saline lakes
- 1 ,000 miles of rivers
- 180,000 acres of bays, harbors
and estuaries
- 230,000 acres saline lakes
-1,900 river miles
MOO + $ Benefits not
Estimated
(1 ) Dollars converted to first quarter 1 996 using Gross Domestic Product implicit price deflator.
(2) $ — Not Estimated = Dollar benefits expected to accrue, but not yet monetized.
(3) Health risks estimated for 80 percent of California anglers.
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JUNE 1997
Thus, total benefits associated with achieving the water quality criteria
established by the CTR are expected to exceed the total of the monetized
benefits ($62 million to $600 million per year).
It is important to note that these benefits will not accrue until California fully attains the
water quality standards through various programs to reduce point and non-point source toxic
discharges.
The remainder of this chapter describes these benefits in more detail. The chapter is
organized as follows:
• First, we briefly summarize the methodology that we have used in estimating
the quantitative benefits associated with the rule.
• Second, we evaluate the recreational use value benefits that may be realized
when toxic water quality criteria are achieved. Specifically, we examine
benefits associated with an improved recreational fishing experience and
increased recreational fishing participation.
• Third we estimate the non-use benefits associated with meeting toxic water
quality criteria.
• Next we monetize the health benefits to anglers described in Chapter 3.
• Finally, we briefly discuss a number of benefits that may be significant, but
which cannot be readily quantified or monetized for this benefits assessment.
METHODOLOGY
From an economic perspective, reducing toxic discharges to achieve water quality standards
established by the CTR will contribute to increased protection and restoration of currently impaired
bays, estuaries, lakes, streams, rivers, and wetlands that produce a stream of services to the 31
million inhabitants of California. These aquatic systems support commercial fishing and
recreational uses such as fishing, wildlife viewing, hiking, hunting, and swimming. Further they
serve as sources of drinking water and provide process and cooling water to industry. In addition,
if the resources are not currently used, they may be used in the future; preserving the right to exercise
future options to visit and use the resource has intrinsic value. Finally, California's aquatic systems
provide benefits to society entirely separate from their use. These "non-use" services include an
existence value derived from simply knowing the resource exists in a preserved state; and a bequest
4-3
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JUNE 1997
value derived from knowing that the resource will continue to exist for the benefit of future
generations. Exhibit 4-2 presents a summary of these and other potential benefit categories that
typically are associated with improvements in aquatic systems.
Exhibit 4-2
POTENTIAL BENEFITS OF WATER QUALITY IMPROVEMENTS
Use Benefits
Iii-Stream
Near Stream
Option Value
Diversionary
Aesthetic
Bequest
Existence
Ecological
• Commercial fisheries, shellfisheries, and aquaculture; navigation
• Recreation (fishing, boating, swimming, etc.)
• Subsistence fishing
• Human health risk reductions
• Water-enhanced non-contact recreation (picnicking, photography, jogging,
camping, etc.)
• Nonconsumptive use (e.g., wildlife observation)
• Premium for uncertain future demand
• Premium for uncertain future supply
• Industry/commercial (process and cooling waters)
• Agriculture/irrigation
• Municipal drinking water (treatment cost savings and/or human health risk
reductions)
• Residing, working, traveling and/or owning property near water, etc.
Non-Use Benefits
• Intergenerational equity
Stewardship/preservation
Vicarious consumption
Reduced mortality/morbidity for aquatic and terrestrial wildlife
Improved reproductive success for aquatic and terrestrial wildlife
Increased diversity of aquatic and terrestrial wildlife
Improved conditions for successful recovery of threatened and endangered
species
• Improved integrity of aquatic and aquatic-dependent ecosystems
Source: U.S. EPA
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JUNE 1997
Economists quantify and value improvements in water quality by estimating overall changes
in consumer and producer surplus associated with that resource. Consumer surplus is the
individual's willingness to pay for the services the resource provides (now and into the future), net
of any costs associated with enjoying those services. For example, if a birder pays $10 in gas,
entrance fees, equipment, etc. to drive to a wildlife area to view birds, and she would be willing to
pay up to $40 to visit the site, then the birder is receiving $30 in consumer surplus as a result of the
trip.1
Estimating the consumer surplus that is associated with water quality improvements involves
several steps, as summarized in Figure 4-1. As shown, the first step requires evaluating how
reducing discharges will lead to changes in physical, chemical and/or biological indicators of aquatic
system water quality and water-dependant resources. A key challenge in this step is to adequately
measure or predict the relationship between changes in the aquatic system parameter (e.g., reduced
contamination by toxic pollutants) and the appropriate biological or physical receptor of the induced
change.
The second step requires evaluating the range of uses and activities that will be affected by
improvements in water quality, the scope and magnitude of which will vary by site and by water
quality parameter (see Exhibit 4-2). Evaluating how these uses will change requires developing
accurate estimates of baseline environmental conditions and anticipating future levels of activity that
may occur as a result of specific post-rule water quality improvements. The final step requires
quantifying and, to the extent possible, monetizing the changes in human use and activity estimated
in the previous step.
Evaluating the specific economic benefits attributable to meeting water quality criteria is
theoretically straightforward but in reality is often difficult to do at both the site-specific and regional
level because of limited or non-existent scientific, economic, and/or social data. In this assessment,
where accurate or complete data are not available for each of the water resources evaluated, we have
applied a set of reasonable assumptions to obtain lower and upper bound estimates that represent a
realistic range of potential benefits likely to occur, rather than developing a single point estimate of
benefits.
1 In a similar fashion, producer surplus represents the difference between the cost of
producing a good/service and the price of that good/service.
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JUNE, 1997
Figure 4-1
STEPS IN WATER QUALITY BENEFITS ANALYSIS
1. EPA Promulgation of Regulation
2. Changes in Production Processes and/or Treatment
3. Reductions in Pollutant Discharges
4. Changes in Ambient Water Quality
(Pollutant Concentrations & Aquatic Habitat)
5. Change in Aquatic Ecosystem
(e.g., Increased Fish Populations & Diversity & Reduced
Bioaccumulation)
6. Change in Level of Demand & Value of Fishery
(e.g., Recreational & Other Benefit Categories)
7. Potential Change in Health Risk
(e.g., From Consumption of Fish Caught)
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JUNE 1997
In this analysis we estimated baseline water resource conditions for the entire State using data
from California's Water Quality Assessment (WQA) database.2 Benefits were then calculated
assuming that water quality programs will be implemented to reduce point and non-point discharges,
thereby achieving the water quality criteria specified in the CTR.
In evaluating the value of the improvement in water quality, we measure the net willingness
to pay for these services under baseline conditions relative to conditions when toxic criteria are
achieved statewide. Because many natural resource services are not traded in the marketplace,
willingness to pay information cannot be directly obtained from observed behavior. Consequently,
we can apply a variety of techniques to value natural resource services, or to estimate the economic
benefits of improvements in environmental quality. These methods attempt to determine individuals'
willingness to pay for natural resource services directly, through survey research, or indirectly,
through the examination of behavior in related markets. They include such techniques as contingent
valuation; analysis of added or avoided costs caused by changes in environmental quality; and
revealed preference methods, such as travel cost analysis and hedonic property value studies.3
While each of these methods is potentially applicable to the California benefits assessment,
budget limitations did not support implementation of these analyses. In lieu of such analysis, we
have estimated baseline and post-rule economic benefits using a benefits transfer approach: the
application of benefits estimates, contingent valuation studies, functions, data, and/or models
developed in other areas to estimate benefits in a similar but alternative context. When possible
we have adjusted the functions, data and/or models used to reflect California-specific characteristics.
When applying dollar values from studies performed prior to 1996, we adjust to $1996 (first quarter)
using the GDP deflator.4 Finally, we present benefit estimates in terms of annual, rather than
annualized values because of the difficulty in predicting a stream of benefits expected to occur in
the future, and uncertainty about the timing associated with achieving the water quality criteria.
2 The WQA is a compilation of data from California's nine regional Water Quality Control
Boards and is organized by region and by waterbody type. It contains a range of information on
surface water pollution, including the pollutants that adversely affect water quality in bodies of water
that have been evaluated, the sources of pollution, the beneficial uses impaired, and an overall rating
of water quality. See Chapter 2 for a more detailed description.
3 For a comprehensive summary of approaches available to measure market and non-market
benefits, see U.S. EPA, Ecological Benefits Assessment Framework, draft, prepared for EPA Social
Sciences Discussion Group, EPA Science and Policy Council, 1996.
4 Gross Domestic Product Implicit Price Deflator, U.S. Department of Commerce, Bureau
of Economic Analysis.
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It is important to point out the limitations of this standard economic approach to estimating
the full range of environmental benefits expected to accrue when water quality standards and criteria
are met.5 First, the true value of natural resources probably is often underestimated by humans.
Since natural goods and services are provided free of charge, their ecological value (and potential
value) is probably not fully appreciated. Further, because ecosystem functional services are
complex, incompletely understood, and difficult to quantify, the values of these services have
generally been ignored in valuation exercises.6 Third, people value money differently, so that
aggregate prices fail to account for the different values people place on the evaluation unit itself.
Fourth, different social groups, interest groups, and individuals value resources differently, but
"damages" represent aggregate losses without accounting for distributional changes in resource use.
For these reasons, we believe that the benefits associated with achieving the water quality criteria
established by the CTR cannot be fully monetized, and when benefits are monetized, they often are
underestimated. Other specific methods, assumptions, and limitations are described in greater detail
in the sections that follow.
The benefit assessment methods used in this chapter are similar to the approach used by
EPA in the Regulatory Impact Assessment of Proposed Effluent Limitation Guidelines and
Standards for the Metal Products and Machinery Industry (Phase I) and the Regulatory Impact
Analysis for the Agency's Great Lakes Water Quality Guidance, which establishes numeric criteria
for toxic pollutants similar to those proposed for California.7
RECREATIONAL FISHING BENEFITS ASSOCIATED
WITH MEETING WATER QUALITY CRITERIA
As described in Chapters 5 and 6 of this report, reducing toxic contamination to meet water
quality criteria established under the CTR may increase the diversity, stability, and overall health
of aquatic ecosystems throughout California, leading to overall improvement in recreational and
5 For a more detailed discussion of the limited ability of traditional economic analyses to
capture ecological benefits, see U.S. EPA; A Brief Overview of Natural Resource Valuation Issues
and Methodologies, 1994.
6 For a more detailed discussion, see and Costanza, Robert, et al., "The Value of the World's
Ecosystem Services and Natural Capital," Nature, May 15,1997.
7 See RIA of Proposed Effluent Limitation Guidelines and Standards for the Metal
Products and Machinery Industry (Phase I), U.S. EPA, 1995; and Regulatory Impact Analysis of
the Proposed Great Lakes Water Quality Guidance, Final Report, U.S. EPA, 1995.
4-8
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JUNE 1997
commercial fisheries.8 In addition, decreasing toxics to California waters also may result in reduced
toxics contamination of recreational and commercial fish tissue, thereby reducing public concern
about the adverse health effects of consuming contaminated fish.
To evaluate the economic effect of these improvements, we examine two components of
recreational fishing benefits: (1) the value of improving the recreational experience of current
participants; and (2) the value of increased participation in the activity. The basic microeconomic
theory behind these components is reflected in Figure 4-2. Demand for a given recreational activity
increases because reduced toxic contamination of aquatic systems makes the activity more attractive.
This change in consumer preferences is shown by movement of the demand curve from D] to D2.
The area ABCD shows the change in consumer surplus for participants already engaged in the
recreational activity. Area ADE shows the increase in consumer surplus that results when new
participants engage in the recreational activity, or when current participants increase activity beyond
the current level.
This section discusses our approach for valuing these two components for recreational fishing
in California. Generally, we employ a benefits transfer methodology that incorporates estimates
from previous studies to value changes in recreational activity in California. Although this analysis
is applied at the statewide level, and therefore does not address the numerous site-specific
considerations that will affect fishing behavior at each discrete local area, the results are intended
to provide a rough approximation of the potential range of Statewide benefits associated with
meeting water quality criteria established under the CTR.
Value of Improved Fishing Experience
As described in this report, waters throughout California are affected by toxic pollutants such
as metals, selenium, pesticides, mercury, and priority ofganics. Reductions in toxics loadings are
expected to contribute to improved conditions for fish spawning and/or migration in more than
223,000 acres of bays/harbors and estuaries, 102,000 acres of lakes, 1,000 miles of rivers and
streams, and 11,000 acres of saline lakes.9 Further, toxic contamination is responsible for 12 fish
consumption advisories currently in place throughout the State in waters covered by the CTR,
including advisories for selenium, mercury, dioxin, DDT, chlordane, and PCBs (see Chapter 3). In
addition, California EPA has issued consumption warnings for 10 ocean sites in California that are
not included in the CTR as enclosed bays or estuaries.10
8 See Setzler-Hamilton, Eileen, et al., "Striped Bass Populations in Chesapeake and San
Francisco Bays: Two Environmentally Impacted Estuaries," Marine Pollution Bulletin, Vol. 19, No.
9, pp. 466-477.
9 See chapter 5 for a more detailed description of these benefits.
10 Fish consumption warnings for sites not covered by the CTR include Newport Pier,
Redondo Pier, Malibu Pier, Short Bank, Malibu/Pint Dume, Point Vicente, Palow Verdes-Northwest,
White's Point, Los Angeles Harbor/Long Beach Breakwater (ocean side) and Horseshoe Kelp.
4-9
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JUNE, 1997
Figure 4-2
COMPONENTS OF VALUE IN
RECREATIONAL BENEFITS ESTIMATES
$ Benefits
Increase in consumer surplus associated with improved
experience of those already participating
Increase in consumer surplus associated with
increased recreational activity
Recreational
Activity
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JUNE 1997
Knowledge of the degree of toxic contamination in waterbodies throughout the State, plus
awareness offish consumption advisories in specific sites, may affect how anglers appreciate their
fishing experience. Consequently, reducing toxics in California waters to meet water quality criteria
established by the CTR may result in an overall increase in the value that anglers place on fishing.
EPA found little available research on the incremental value to California anglers of reducing
toxic contamination of surface waters applicable to the CTR.11 However, the potential significance
of how anglers value a fishery relatively free of toxics is illustrated by a 1992 study of the Wisconsin
Great Lakes open water sport fishery.12 In this study, Lyke estimated the current value of sport
fishing on the Wisconsin Great Lakes, and the potential benefits of a "contaminant free" fishery. In
a survey, Lyke posed questions that elicited willingness to pay for a fishery "completely free of
pollutants that may threaten human health."13 The findings indicate that these values range between
11.1 and 31.3 percent of the value of the fishery under current conditions.
EPA transferred the Lyke results by first estimating the number of fishing days in California
that occur in toxic-impaired waters, distinguishing between waterbody type (e.g., river, lake, estuary,
etc.). Then, we multiplied the number of fishing days by an average consumer surplus for the
different modes of fishing to obtain a baseline value of the fishery under current conditions. EPA
then multiplied these numbers by 11 percent to 31 percent (from Lyke) to obtain the value of a
"contaminant-free" fishery. These steps are described below and are summarized in Exhibit 4-3
below.14
11 One study, which estimates California residents' willingness-to-pay to protect aquatic and
aquatic-dependant wildlife from adverse effects of selenium in the Central Valley, could not be
applied to this analysis because of data limitations (see Loomis et al, in Dinar, 1991).
12 Lyke, A.J. "Discrete Choice Models to Value Changes in Environmental Quality: A Great
Lakes Case Study", dissertation submitted to the Graduate School of the University of Wisconsin-
Madison, 1993.
1? Lyke, 1993. Note that the wording "contaminant free" was used in the Lyke survey
instrument. We assume that respondents interpret "contaminant free" as meaning a fishery free of
pollutants in concentrations that would threaten human health, not complete elimination of toxic
pollutants. Note also that the area of Lake Michigan addressed in the Lyke study has been the focus
of several fishing advisories. As we discuss below, there are uncertainties associated with using the
results of this study to estimate benefits for California waters that may be less impaired.
14 Several other EPA water quality benefits studies have taken this approach. See Regulatory
Impact Analysis of the Proposed Great Lakes Water Quality Guidance, Final Report, U.S. EPA
Office of Water, 1995; and Regulatory Impact Assessment of Proposed Effluent Limitation
Guidelines and Standards for the Metal Products and Machinery Industry (Phase I), U.S. EPA,
1995.
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JUNE 1997
Estimating Toxic-Impaired Fishing Days
To apply Lyke's willingness to pay values, we must first estimate the amount of fishing
activity that occurs on California waters affected by toxics. Estimates of total fishing days are taken
from the Fish and Wildlife Service's 1991 National Survey of Fishing, Hunting, and Wildlife-
Associated Recreation, and are divided by waterbody type.15 The survey does not report saltwater
fishing days by waterbody type. Therefore, we have developed an estimate of saltwater days that
assumes that half are associated with bays, 30 percent with estuaries, and 10 percent with saline
lakes, with the remaining 10 percent representing open sea fishing on waters not addressed by the
toxics criteria.16 We further subdivide the estimate of fishing days in bays into San Francisco Bay
and other California bays. We estimate the number of San Francisco Bay fishing days by
multiplying the estimated number of San Francisco Bay anglers (125,000 anglers, taken from the
fish consumption risk estimates previously described in Chapter 3) by the average number of days
per angler (6.2).17 The estimate of fishing days for other bays (1,974,350) is therefore the total
number of bay days net of the estimated number of days in San Francisco Bay (775,000). Note that
many of the fishing advisories in California have been issued since 1991, the year of the fishing
activity data. Because advisories may discourage fishing activity, it is possible that current fishing
activity is less than estimated. However, this factor may be offset by the growth in the California
population, which would tend to increase the number of fishing days.
We then estimate the total number of toxics-affected fishing days. We scale the total number
of fishing days for each waterbody type by the statewide estimate of surface water impaired by toxic
pollutants.18 This estimate is based on our analysis of California's Water Quality Assessment data,
as discussed in detail in Chapter 2 of this report. For example, the WQA data indicate that for all
15 U.S. Fish and Wildlife Service, National Survey of Fishing, Hunting, and Wildlife-
Associated Recreation — California, July 1993.
16 The distribution of saltwater fishing days to different waterbody types is based on best
professional judgment. If open sea fishing and coastal fishing not associated with enclosed bays and
estuaries represents greater than 10 percent of all fishing activity, we may overstate benefits.
17 Average days per angler taken from the Bay Area Sport Fish Economic Survey, as reported
in Huppert, Daniel D., "Measuring the Value of Fish to Anglers: Application to Central California
Anadramous Species," Marine Resource Economics, Vol. 6, pp. 89-107,1989.
18 As mentioned above, we define "impaired" waters as those that have been assessed and are
rated by the State of California as medium or poor water quality for at least one toxic water quality
pollutant or group of pollutants.
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JUNE 1997
Exhibit 4-3
RECREATIONAL FISHING: POTENTIAL ANNUAL BENEFITS OF IMPROVED EXPERIENCE
($1996)
FRESHWATER FISHING
Lakes and Reservoirs
Ponds
Rivers and Streams
SUBTOTAL:
SALTWATER FISHING
Bays
- San Francisco Bay
— Other California Bays
Estuaries
Saline Lakes
SUBTOTAL:
TOTAL
Statewide
Fishing Days
Per Year
9,678,800
1,534,100
6,002,900
17,215,800
775,000 *
1,974,350 *
1,649,610 *
549,870 *
4,948,830
22,164,630
Percent of
Assessed
Waters
Toxics-
Impaired**
19%
19%
19%
69%
51%
47%
69%
Statewide Toxics-
Affected
Fishing Days
1,838,972
291,479
1,140,551
534,750
1,006,919
775,317
379,410
Day Value
Lower
Bound
$25
$25
$25
$50
$50
$50
$50
Upper
Bound
$35
$35
$35
$100
$100
$100
$100
Total Value
Lower
Bound
$45,974,300
$7,286,975
$28,513,775
$81,775,050
$26,737,500
$50,345,925
$38,765,835
$18,970,515
$134,819,77
$216,594,82
Upper
Bound
$64,364,020
$10,201,765
$39,919,285
$114,485,07
$53,475,000
$100,691,85
$77,531,670
$37,941,030
$269,639,55
$384,124,62
Lower Bound
Increase in
Willingness-
to-Pay
$5,057,173
$801,567
$3,136,515
$8,995,256
$2,941,125
$5,538,052
$4,264,242
$2,086,757
$14,830,175
$23,825,431
Upper Bound
Increase in
Willingness-
to-Pay
$19,952,846
$3,162,547
$12,374,978
$35,490,372
$16,577,250
$31,214,474
$24,034,818
$11,761,719
$83,588,261
$119,078,632
* Based on a total of 5,498,700 total saltwater fishing days. Assumes 50 percent in bays (e.g., pier fishing) 30 percent on estuaries, and 10 percent on saline lakes.
Remainder is open sea fishing not addressed by the rule. Estimated fishing days for San Francisco Bay based upon estimated number of anglers from health risk
analysis (125,000) multiplied by the average days per angler (6.2) from Huppert, 1989.
** EPA defines "impaired" waters as those assessed and rated by the State of California as medium or poor quality for at least one toxic pollutant or group of
pollutants.
Sources: U.S. Fish & Wildlife Service, 1991 Survey of Fishing, Hunting, and Wildlife- Associated Recreation.
EPA analysis of 1994 California Water Quality Assessment data base (see Chapter 2).
Lyke, 1993
Studies in Exhibit 4-4
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JUNE 1997
lakes and reservoirs, toxics affect 19 percent of all waters assessed. Therefore, we multiply the total
lakes and reservoirs fishing days of 9,678,800 by 0.19 to obtain a statewide number of toxics-
affected fishing days of 1.84 million.
Baseline Fishery Value .
To estimate the value of toxics-affected fishing days, we multiply days by the applicable
estimate of consumer surplus per fishing day. To best reflect the value of different types of fishing
in California, we searched the literature for relevant studies. Exhibit 4-4 summarizes the result of
this search. As shown, several freshwater studies for California waters suggest a value per day in
the range of $25 to $35.l9 This range is consistent with that found by Walsh, et al. in a review of
studies for freshwater fishing nationwide.20 Therefore, we use the $25 to $35 range in estimating
the value of freshwater fishing.
Exhibit 4-4
ESTIMATES OF CONSUMER SURPLUS PER FISHING DAY
($1996)
Freshwater
Saltwater
Study
Roach, 1996
Hay, 1988
Loomis and
Cooper, 1990
Walsh, 1988
NOAA, 1986
Huppert, 1989
Walsh, 1988
Location/Species
American, Feather, Sacramento, and Yuba
Rivers
California bass anglers
Trout in Feather River
Average of national studies
Marine fishing in Southern California
San Francisco Bay, salmon and striped bass
Average of national studies
Consumer
Surplus Estimate
$15.24 to $36.89; Preferred
model specification yields
$31.17-$36.37 estimate
$31.17
$26.69
$30.85 to $40.08
Charter: $29.74 to $66.24
Private: $82.46 to $100.02
Shore/Pier: $44.23 to $84.01
$70.88 to $357.36
$94.89
19 Roach (1996) applied a number of different model specifications to the same data. While
lower values were obtained, the preferred model specifications yielded an estimate in the $30 to $35
range.
20 Walsh, Richard G., Donn M. Johnson, and John R. McKean, Review of Outdoor
Recreation Economic Demand Studies with Nonmarket Benefit Estimates, 1968-1988, December,
1988.
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JUNE 1997
Estimates of consumer surplus per day of saltwater fishing vary more widely, depending
upon the mode of fishing (charter boat, private boat, or shore fishing) and the species sought. Most
of the results fall in the range of $50 to $100.21 This range is consistent with the average value ($95
per day) reported by Walsh et al. for saltwater fishing. Therefore we use the range of $50 to $100
in estimating saltwater fishing value.
, We can then develop a baseline value of recreational fishing on toxic-affected waters by
multiplying the toxic-affected fishing days times the unit day value. For example, for lakes and
reservoirs, 1.84 million toxic-affected fishing days times $25 to $35 day yields a total value of $46
to $64 million per year.
Potential Benefits
Using the baseline value of recreational fishing on toxics-affected waters, we can estimate
the value of the improved experience associated with fishing these waters when toxic contamination
is reduced to achieve water quality standards. As shown in Exhibit 4-3, for all waterbody types,
application of Lyke's willingness to pay range (11 to 31 percent) yields a benefit estimate of between
$9 and $35 million for freshwater and $15 and $84 million for saltwater. Overall, we estimate that
the value of the improved fishing experience associated with meeting the toxic water quality criteria
would be between $24 and $119 million per year.
Value of Increased Participation
In addition to decreasing the value of existing angling days, toxic pollution may also
discourage participation in recreational fishing. Anglers may refrain from fishing because of concern
that fish consumption is unsafe. In addition, since toxic contamination of surface waters occurs
throughout the State, negative perceptions of water quality may exist Statewide, thereby reducing
anglers' interest in fishing, regardless of concern that fish consumption is unsafe. A Statewide
decrease in the level of toxics contamination on all waterbodies may improve perceptions of water
quality, and thus have the benefit of restoring lost participation.
21 While certain model specifications used by Huppert yielded high estimates (e.g., $344 per
trip), these values represent outliers and apply specifically to two highly sought species (striped bass
and chinook salmon) and therefore may not be broadly representative of saltwater fishing.
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JUNE 1997
Estimating Increased Participation
We can value increased angling participation associated with achieving CTR water quality
criteria by using the parameters discussed above for both baseline fishing days and mean consumer
surplus per fishing day. We begin with the number of fishing days associated with toxics-impaired
waters and the value of those fishing days. As discussed above, these parameters are derived from
statewide participation figures and are scaled according the overall areal extent of toxics
contamination as derived from the WQA database.
We then assume a range for the increase in participation that would result when toxic
contaminants in California waters are reduced to meet the proposed criteria. The degree to which
fishing days are reduced depends on two key factors. First, anglers must be aware of the
contamination. While studies have shown that anglers are attentive to formal warnings and
advisories (see below), they may be less attuned to lower-level toxics contamination in areas with
no formal advisories. Second, the availability of substitute fishing areas plays a major role in how
anglers respond to contamination. Specifically, if contamination affects a relatively limited area
where substitutes are available, anglers will not reduce fishing effort, but will simply choose a new
location.22 The availability of substitutes will vary greatly depending upon geographic location and
the economic status of the affected anglers. For example, poorer urban anglers fishing from piers
in San Francisco Bay may be less able to simply change fishing location given the lack of equivalent
substitutes and the practical constraints associated with traveling out of the city.
i
Most available studies focus on how toxics contamination affects fish consumption behavior
rather than fishing effort. These studies are noteworthy because they provide a clear indication that
angler behavior can be influenced by perceptions of toxic contamination, a key element in estimating
reduced fishing days. For example, one study found that about half of the anglers who were aware
offish consumption warnings in Santa Monica Bay altered their consumption habits in some way.23
This included nine percent of the anglers who stopped consuming fish altogether, although the study
is unclear whether the elimination of fish consumption is associated with reduced fishing. Other
behavior changes include reductions in the amount offish consumed and changes in preparation and
cooking methods.24
22 This new location may require more extensive travel which in itself can reduce the
consumer surplus the angler enjoys.
23 Santa Monica Bay Seafood Consumption Study — September 1991 to August 1992,
prepared for Santa Monica Bay Restoration Project, prepared by MBC Applied Environmental
Sciences, August 1993.
24 Other studies show similar results. These include Udd, Edward and Joseph Fridgen,
Anglers'Perceptions of Toxic Chemicals in Rivers and Sport Fish, paper presented at the National
Wilderness Research Conference, "July 1985; and Connelly, Nancy A., Barbara Knuth, and John
Vena, New York State Angler Cohort Study: Health Advisory Knowledge and Related Attitudes and
Behavior, With a Focus on Lake Ontario, September 1993.
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JUNE 1997
Only a limited number of studies specifically consider the reduction in fishing days in a
specific area due to water quality degradation. For example, a survey of New York State anglers
found that of those who were aware of fishing advisories, 17 percent took fewer fishing trips.25 In
another study of lake recreation in Wisconsin, Caulkins, et al. estimated that the number of
recreationalists using the site would increase by between 12 and 16 percent in response to general
improvements in water quality.26 Another study of acid rain contamination in New York's
Adirondack region estimated recreational fishing losses associated with acidic deposition.27 This
study estimated a five percent decrease in angler days.
In addition, other EPA studies have used angler response to fishing advisories to justify a 20
percent reduction in fishing days in response to toxic pollution. For example, EPA's Regulatory
Impact Analysis for the Metal Products and Machinery rule reduced the recreational fishing
population by 20 percent in estimating benefits.28 This assumption was based on studies conducted
by Silverman (1990), West et al. (1989), and Connelly et al. (1993).
Toxic water contamination hi California ranges in nature, from extensive pollution that
results in fishing advisories hi estuaries, rivers, and lakes, to more limited pollution that may likely
go unknown or unheeded by many anglers. While all of the studies reviewed above indicate that
anglers change behavior significantly in the face of extensive contamination, it is less clear what the
effect of more limited toxic contamination would be. Therefore, in light of this uncertainty, we
apply a range of estimates to derive the increase in fishing days that might occur if the CTR criteria
are met. In the upper bound, we use 20 percent, a figure consistent with evidence from fishing
advisory studies. This upper bound is applicable because many key fishing areas located near large
population centers currently have fishing advisories in effect, including San Francisco Bay,
25 Connelly, Nancy A., Tommy Brown, and Barbara Knuth, New York Statewide Angler
Survey, 1988,p. 111.
26 Caulkins, Peter P., Richard Bishop, Nicolas Bouwes, "The Travel Cost Model for Lake
Recreation: A Comparison of Two Methods for Incorporating Site Quality and Substitution Effects,"
American Journal of Agricultural Economics, May, 1986.
27 Mullen, John K. and Fredric Menz, "The Effect of Acidification Damages on the
Economic Value of the Adirondack Fishery to New York Anglers," American Journal of
Agricultural Economics, February, 1985.
*
28 U.S. EPA, Office of Science and Technology, Regulatory Impact Assessment of Proposed
Effluent Guidelines and Standards for the Metal Products and Machinery Industry (Phase I), April,
1995.
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JUNE 1997
Los Angeles/Long Beach Harbor, and the area around the Kesterson National Wildlife Refuge. In
the lower bound, we use five percent, a figure intended to reflect the increase in participation that
Would occur on waters with minor to moderate toxics contamination.
Potential Benefits
Exhibit 4-5 presents estimates of the value of potential increased angling participation. As
shown, we multiply the number of toxics-affected fishing days by the value of these days (estimated
in the previous section and shown in Exhibit 4-3) to derive the total value of toxics-affected fishing
days. We then multiply this value by five percent and 20 percent to estimate the value of the
expected increase in angling participation attributable to meeting the CTR criteria. As the exhibit
shows, we estimate a lower bound annual benefit of $ 11 million and an upper bound benefit of $77
million. When these values associated with increased participation are added to the benefits of
improved experience, we estimate a range of $35 million to $196 million of total use-value benefits
associated with recreational fishing.
Uncertainties
There are several limitations and uncertainties associated with this analysis of potential
recreational fishing benefits. First, as with any benefits transfer, we assume that the willingness to
pay to fish in cleaner waters (expressed by respondents in the Lyke survey) is representative of the
range of values that California anglers would place on a "contaminant free" fishery. Currently, we
have no information to indicate that California behavior would be significantly different than that
reported by Lyke for the Midwest. However, the Lyke study addressed an impaired area of Lake
Michigan where several fishing advisories had been issued. In contrast, many of the California
waters classified as impaired may be less contaminated than the waters in the Lyke study. To the
extent that this is true, we may overstate benefits by using the Lyke willingness to pay range.
Second, we assume that reducing toxic discharges to meet toxic water quality criteria is
approximately equivalent to achieving a "contaminant free" fishery. Further, we assume that
reducing contamination to meet water quality criteria should apply to both ambient water quality
criteria for aquatic life (both chronic and acute) as well as ambient water quality criteria levels for
human health. Currently we have no information to indicate that this would not be a reasonable
assumption to make for this analysis. If this assumption is incorrect, however, then our benefit
estimates may be overstated.
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JUNE 1997
Exhibit 4-5
RECREATIONAL FISHING: POTENTIAL ANNUAL BENEFITS OF INCREASED PARTICIPATION
FRESHWATER FISHING
Lakes and Reservoirs
Ponds
Rivers and Streams
Subtotal:
SALTWATER FISHING
Bays
— San Francisco Bay
~ Other California Bays
Estuaries
Saline Lakes
Subtotal:
TOTAL
Total Value of Toxics- Affected
Fishing Days
Lower Bound
$45,974,300
$7,286,975
$28,513,775
$81,775,050
$26,737,500
$50,345,925
$38,765,835
$18,970,515
$134,819,775
$216,594,825
Upper Bound
$64,364,020
$10,201,765
$39,919,285
$114,485,070
$53,475,000
$100,691,850
$77,531,670
$37,941,030
$269,639,550
$384,124,620
Lower Bound
Percent Increase
In Participation
5%
5%
5%
5%
5%
5%
5%
Upper Bound
Percent Increase
In Participation
20%
20%
20%
20%
20%
20%
20%
Lower Bound
Benefit of
Increased
Participation
$2,298,715
$364,349
$1,425,689
$4,088,753
$1,336,875
$2,517,296
$1,938,292
$948,526
$6,740,989
$10,829,741
Upper Bound
Benefit of
Increased
Participation
$12,872,804
$2,040,353
$7,983,857
$22,897,014
$10,695,000
$20,138,370
$15,506,334
$7,588,206
$53,927,910
$76,824,924
Source: EPA analysis
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JUNE 1997
Third, by scaling according to the areal extent of toxic pollution, we implicitly assume that
anglers are somewhat evenly distributed to all surface water bodies. In fact, anglers may be free to
relocate away from water bodies affected by toxics and fish in cleaner areas. If this is the case, then
our benefit estimates could be overstated. Alternatively, fishing effort may be disproportionately
concentrated on impaired waters (including those with fish consumption advisories)'because of the
proximity of the waters to population centers (e.g., San Francisco Bay, Los Angeles Harbor, Lake
Herman, Santa Clara County Lakes, and the Grassland Area/Kesterson National Wildlife Refuge).
This would lead us to understate benefits. Because we have not done a waterbody-by-waterbody
evaluation of substitute fishing areas and angler substitution behavior, we cannot estimate the
direction or degree of bias in our estimates.
Fourth, we assume that the condition of assessed waters in California is representative of
conditions in all unassessed resources. If conditions are considerably worse or better in these
unassessed waters, then benefit estimates are likely to be higher or lower than those presented here.
As described in greater detail in Chapter 2, although the WQA provides water quality assessments
for only nine percent of California's total stream and river miles, and approximately 50 percent of
wetlands, the majority of State total lake and reservoir acreage has been assessed. Further, water
quality analysts in EPA believe that nearly all the bays/estuaries and saline lakes in the State have
been well characterized, monitored, or otherwise evaluated for toxic contamination. Although the
consensus of the U.S. EPA and State experts was that some of the assumptions used here may have
created a bias toward overestimating toxics contamination Statewide, they also stated that certain
other assumptions used in the analysis may have created a bias in underestimating the extent of
toxics contamination. For example, we assume that the type and scope of all toxics of concern in
all State waters appear in the WQA data base. However, this may underestimate the extent of toxics
impairment because of the infrequency of ambient monitoring throughout the State or because of the
difficulty of detecting the ambient concentrations of certain toxic pollutants when their water quality
criteria are below minimum detection limits. Consequently, because of all of the uncertainties
associated with the WQA data base, State of California and U.S. EPA experts advised against an
attempt to quantitatively estimate the magnitude of the bias in either direction.
Fifth, this analysis assumes that anglers are aware of toxic contamination beyond waters that
have fish consumption advisories, and that their angling behavior is affected. To the extent that
anglers are unaware of the presence of toxic pollutants, or that they are aware and don't change how
often and where they fish, their fishing experience is not diminished. If this is the case, then this
analysis may overstate the benefits associated with meeting toxics water quality criteria.
Finally, the persistence and toxicity of the pollutants covered by the criteria have important
implications for all parts of the benefits analysis. Because some of these compounds (e.g., PCBs,
dioxins, mercury) may persist in various waters, sediment, and animal tissue for years after point and
non-point source toxic discharges have been eliminated, a portion of the benefits described here may
not be realized immediately.
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JUNE 1997
In addition to use values, the total value of an aquatic system also includes values that
individuals hold for the resource unrelated to their current use of goods and services provided by the
resource. Individuals may value the existence of the aquatic system or the availability of the goods
and services provided by the system, even if they do not use the goods and services themselves.
Non-use values may also stem from the desire to preserve the resource for future generations
(bequest value) or from a philanthropic sense of environmental responsibility. Reducing toxic
contamination to meet the toxic water quality criteria is expected to increase these non-use values.
Relationship Between Use and Non-Use Values
Non-use values can be estimated roughly by considering the relationship between the use
value and non-use value of a resource. While the non-use values of a resource need not be directly
related to use value, such a comparison provides a simple rule-of-thumb for developing approximate
measures of non-use values.
Application of this approach requires two key inputs: (1) an estimate of use values; and (2)
an estimate of the typical ratio of non-use value to use value. The first input is based on the use
values derived previously for recreational fishing: from $35 million per year to $196 million per year.
To estimate the ratio of non-use to use values, we rely on a literature search performed for a
previous EPA study.29 Based on five studies of water resources, this literature search.yielded a range
of approximately 0.5 to 2.0 in the ratio of non-use values to use values. The studies are summarized
in Exhibit 4-6 below. Past EPA studies have relied on the lower end of this range (i.e., 0.5, meaning
that passive use values are equal to 50 percent of use values).30 The mathematical average of
the studies shown in Exhibit 4-6 is approximately 1.5. Therefore, we use the range of 0.5 to 1.5,
implying that passive use values are equal to between 50 and 150 percent of use values.
Potential Benefits
To estimate non-use benefits, we apply the range of non-use to use value ratios discussed
above (0.5 to 1.5) to the previously estimated range of recreational angling use values (both the value
of the improved fishing experience and the value of increased participation, roughly $35 to $196
29 U.S. EPA Office of Pollution Prevention and Toxics, Ecological Benefits Assessment Model:
Documentation Manual, May, 1997.
30 For example, see U.S. EPA Office of Water, Regulatory Impact Analysis of the Final
Great Lakes Water Quality Guidance, Final Report, March 1995.
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JUNE 1997
Exhibit 4-6
ESTIMATES OF THE RATIO OF NON-USE VALUE TO USE VALUE
FOR STUDIES OF WATER RESOURCES
Authors (Date)
Study Location
Description of Good
Valued in the Study
Ratio of
Ecological and
Passive Use Value
to Use Value
Dornbusch and Falcke (1974)
Communities along
seven U.S. water
bodies
Survey of property
owners on important of
attributes of water
quality improvement
0.75 to 2.03'
Greenley, Walsh and Young (1981)2
Denver and Fort
Collins, Colorado
Preservation and
improvement of water
quality of South Platte
River Basin
0.46 to 0.843
Walsh, Loomis and Oilman (1984)2
Colorado
Value for protection of
additional 1.2 to 10
million acres of
Colorado wilderness
0.55 to 0.97
Sutherland and Walsh (1985)2
Montana
Value of protecting
water quality at
Flathead Lake and
River
2.56
Sanders, Walsh and Loomis (1990)2
Colorado
Value of increasing
protection of Colorado
Rivers
1.88
1. Ratios vary depending on whether aesthetic value is considered as part of use or passive use value.
2. These studies used the contingent valuation method. All four studies asked respondents to first state their total value for
the good in question, and in subsequent questions asked respondents to allocate this total to recreation use, option value,
existence value and bequest value. In all cases, the wording of the question describing option value focused on the value
of potential future use (i.e., option price). For the purposes of estimating the ratio of use to non-use value, we have included
option price in use value.
3. This range reflects the results of two payment scenarios considered in the survey (increase in water bill or sales tax) and
comparisons of use value to passive use value held by users and use value to passive use values held by non-users.
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million). This approach yields an estimate of non-use benefits of between $17 million and $294
million. It is important to note that we have only monetized estimates of recreational fishing benefits
associated with meeting toxic water quality criteria, even though other use benefit values such as
recreational hunting, wildlife viewing, and commercial use are expected to be significant, but have
not been quantified or monetized for the aquatic life criteria.31 Consequently, the benefits presented
here likely understate the total non-use benefits likely to accrue when toxic discharges from all
sources are reduced to meet CTR water quality criteria.
There are several limitations involved in using this approach. First, the studies from which
these ratios were derived did not explicitly consider ecological values, but only asked respondents
about existence and bequest value. It is difficult to determine the extent to which respondents may
have incorporated ecological values into their responses, however. For example, when thinking about
existence value, individuals may consider the wildlife habitat provided by a distant harbor, but may
not explicitly consider objectives such as biodiversity. Overall, it is difficult to know the extent to
which ecological non-use values drive the responses to contingent valuation surveys. ,
Second, contingent valuation is the only method available to evaluate non-use values of a
resource. Use of this method, however, is controversial because it measures attitudes and not
behavior, and therefore is subject to the uncertainties inherent in any survey-based research; i.e., it
may over- or understate actual values, depending upon the quality of the survey instrument, the
incentives of the respondents, and other factors. As a result, significant debate exists over whether
contingent valuation can yield reliable results." NOAA has proposed guidelines for contingent
valuation studies for use in natural resource damage assessment.33 While some of the contingent
valuation studies summarized in Exhibit 4-6 meet some of the guidelines, none meet all of these
proposed guidelines. While guidelines for policy analysis studies may differ somewhat from
NOAA's guidelines for damage assessments, the cited studies did not use state-of-the-art
approaches, which may reduce the reliability of the resulting estimates.
31 For example, the U.S. Fish and Wildlife Service recommends a 2 ug/1 selenium standard
for protecting aquatic-dependent wildlife species. The economic benefits of a selenium wildlife
criterion are reviewed in U.S. EPA, Potential Benefits of a Selenium Wildlife Water Quality
Criterion in California, June 1997.
32 See Mitchell, R.C., and R.T. Carson, Using Surveys to Value Public Goods: The
Contingent Valuation Method, Washington DC, Resources for the Future, 1989.
33 U.S. Department of Commerce, National Oceanic and Atmospheric Administration, 15 CFR
Part 990, Natural Resource Damage Assessments: Proposed Rules, 59 FR 1062, 1994.
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HUMAN HEALTH BENEFITS
As previously described in Chapter 3, the bioaccumulation of toxic pollutants in aquatic life
and water-dependant wildlife can pose a significant health risk to those who eat fish and waterfowl.
This is particularly true for recreational or subsistence anglers, who tend to consume greater
quantities of wildlife than the average person and may catch fish from areas that are highly
contaminated. A potential post-rule benefit is a likely reduction in the concentration of pollutants
in fish and waterfowl tissue, with a resulting decrease in risk to recreational/subsistence anglers and
waterfowl hunters.
We quantified health benefits for recreational anglers in Chapter 3 by comparing risks from
the consumption of fish under baseline conditions to those that would prevail once California
implements water quality programs to achieve the criteria. Results of the analysis include:
• The cancer population risk for freshwater anglers throughout the State would
decrease by between 5 and 10 cases per year (5 to 11 cases under baseline
conditions to zero to one cases post-compliance). For San Francisco Bay
anglers, population risk would decrease by less than one case per year.
• Individual cancer risks for the 2.2 million California freshwater anglers and
125,000 San Francisco Bay anglers would be reduced by 91 percent.
• The non-cancer hazard index is reduced by 67 percent for freshwater anglers.
The hazard index for freshwater anglers would decrease from 2.4 to less than
0.8 at the median consumption level.
• The non-cancer hazard index for San Francisco Bay anglers is reduced by 76
percent. The hazard index would decrease from 3.6 to less than 0.9 at the
median consumption level.
• It is possible that a small subset of California anglers (Middle Eastern,
Samoan and Cambodian) are at greater risks because of higher consumption
rates. Asian and Hispanic anglers face disproportionately higher risks due to
the consumption of whole fish.
• Risks to subsistence anglers have not been estimated, but are likely to be
somewhat higher than risks to anglers because of their higher levels offish
consumption.
• We were not able to estimate cancer or non-cancer health risks associated
with consuming contaminated waterfowl.
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We estimated a monetary value of benefits to society from avoided cancer cases associated
with consuming contaminated fish, based on a methodology developed and explained in more detail
in the RIA of the Proposed Effluent Limitations Guidelines and Standards for the Metal Products
and Machinery Industry (MP&M).34 The valuation of benefits is based on estimates of society's
willingness-to-pay to avoid the risk of cancer-related premature mortality. Although it is not certain
that all cancer cases will result in death, to develop a worst case estimate for this analysis, avoided
cancer cases are valued on the basis of avoided mortality. To value mortality, we used the range of
values — approximately $2 million to $10 million per case — developed and applied in other studies
such as the RIAs for the MP&M effluent guidelines and the Great Lakes Water Quality Guidance.
To derive the benefits associated with reducing the incidence of cancer from consumption
of contaminated fish, we multiply total cancer cases (5 to 11) times the range of $2 million to $10
million per case to derive a total monetized benefit of $10 to $110 million.
We were unable to value decreased incidence of non-cancer illness. Non-cancer illnesses
include reproductive, neurological, immunological, and circulatory .problems. Little data are
available regarding both dose-response relationships for non-cancer outcomes and the monetary
value of avoiding such outcomes.35 Because we were not able to evaluate the monetized value of
decreased incidence of non-cancer disease, our economic benefit estimates likely understate the
range of total health-related economic benefits associated with this rule.
OTHER BENEFITS NOT QUANTIFIED
Reducing toxic contamination of aquatic systems to meet the proposed water quality criteria
will likely yield other benefits that we were unable to quantify or monetize. Therefore, our
quantitative estimates of benefits probably understate total benefits. These unmonetized benefit
categories are briefly summarized below.
34 U.S. EPA, April 1995.
35 Cannon, Matt, Raymond Kopp, and Alan Krupnick, Valuation of Developmental and
Reproductive Effects: A Scoping Study, October 1996.
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Drinking Water Treatment Savings
Reducing toxics discharges from all sources to meet water quality criteria may reduce the
degree of treatment needed to bring surface water sources into compliance with drinking water
standards. For instance, if supplies drawn from ambient waters are treated to remove toxic
contaminants before they are ingested, or contaminated sources are abandoned when they fail to
meet (or cannot be treated efficiently to meet) drinking water standards, then improvement of
ambient water quality to meet the criteria would reduce the cost of treatment or avoid the cost of
switching to alternative water supplies. Drinking water treatment savings might be especially large
when the criterion for a pollutant is more stringent than the maximum contaminant level (MCL)
permitted for the pollutant under the Safe Drinking Water Act. Chemicals for which the aquatic life
standard is more stringent than the human health standard for drinking water include the metals
cadmium, chromium, copper, lead, mercury, nickel, silver, and zinc. Although we have not
quantified or monetized these potential cost savings, they could be significant.
Sludge Treatment Savings
/
Reducing toxic contamination of surface waters to meet water quality criteria may generate
sludge treatment savings if toxic contaminants are reduced prior to entering publicly or privately
owned sewage treatment plants (POTWs). As a result of reducing toxic pollution in the sewage
sludge, POTWs may be able to meet more stringent limits, which, in turn, may permit less expensive
use or disposal of the sewage sludge. In the best case, sewage sludge will meet land application
pollutant concentration limits. This sewage sludge may be disposed of via land application, which
in some instances, may be substantially less costly than other use or disposal practices such as
incineration or land-filling.36 Because of time and budget constraints, we were not able to estimate
this benefit for POTWs throughout California, but we expect that sludge treatment cost savings
might be substantial if toxics are reduced via pollution prevention (e.g., prior to arriving at the
POTW).
Dredging and Navigation
Toxic contaminants discharged to surface water may settle to sediment and remain there for
decades if the pollutants are persistent (e.g., metals such as mercury, complex organics). Previous
studies have demonstrated how dredging costs increase greatly when sediment contamination is
36 For a more detailed description of this potential benefit, see Chapter 11 of the MP&M
Effluent Guideline RIA, 1995.
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JUNE 1997
present.37 Most of this increased cost is attributable to proper disposal of the contaminated sediment.
Reducing loadings of toxic pollutants to sediments to achieve water quality criteria may ultimately
reduce sediment contamination in California waters, thereby reducing dredged material management
costs.
Commercial Fishing and Shell Fishing
Commercial fishing and shell fishing are major economic activities in the State of California.
In 1991 the value of the statewide commercial fishery catch totaled approximately $134.8 million,
which was below historical levels.38 The decline in commercial fisheries values is largely
attributable to harvest declines rather than decreasing fish prices. Toxics contamination of water,
sediments and fish tissue can lead to harvest restrictions and bans, and also can adversely affect the
survival, abundance and biomass of the fisheries population, consequently reducing the economic
value of the fishery. Reducing toxics loadings to meet water quality criteria may contribute to the
overall improvement of the health and abundance offish populations, and therefore will increase the
economic value of the harvest. Further, reduced toxics loadings could result in reduced
contamination offish tissue, possibly reducing cancer and non-cancer illness incidence associated
with consumption of contaminated fish. Because of data and time limitations, we have not estimated
the economic or health implications for California fisheries of reducing toxics contamination to meet
water quality criteria. However, we believe such benefits could be significant.
Avoided Cost of Endangered Species Management and Associated Land Use Restrictions
The avoided costs of managing State and Federal Threatened and Endangered species and
the costs associated with attendant land use restrictions are a potential benefit of the toxics rule.
California has the greatest number of T&E species of any state (see Chapter 5 for a more detailed
discussion of T&E species). Currently, USFWS spends several million dollars per year in California
managing T&E species, including preparing species-specific listings, recovery plans, etc. These
listings and recovery plans describe species-specific management actions that are necessary to avoid
37 National Oceanic and Atmospheric Administration, Summary of Potential Economic
Damages to the Resources of Lavaca Bay and Matagorda Bay Texas as Result of Mercury
Contamination, May 1991.
38 U.S. EPA, Regulatory Impact Assessment of the Final Water Quality Standards for the San
Francisco Bay/Delta and Critical Habitat Requirements for the Delta Smelt, Region 9, (December), 1994.
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species extinction. For instance, exposure to toxic water contaminants39 has been identified as one
of several factors together with habitat destruction, to be considered in the recovery of the Federal
Endangered California Clapper Rail, which occurs only in South San Francisco and Suisun Bay.
Some of the management plans may lead to establishment of numerous new and complex
requirements on land use. For instance, listing of a species associated with a river, stream or estuary
may severely restrict water management, adjacent agricultural activities, or development of the
species' habitat. Reducing toxics to meet the proposed water quality criteria may enhance and
contribute to the overall recovery of certain listed species, may help to prevent future listings of
certain species, and may result in significant avoided costs associated with T&E management plans.
Property Value Impacts
Knowledge of toxics contamination may lead to reductions in the value of properties
surrounding surface water bodies.40 The results of a 1988 property value study in San Francisco Bay
suggest that this benefit could exist for the large population centers surrounding toxics-impaired bays
(e.g., San Francisco, Los Angeles, Santa Monica).41 The San Francisco study concluded that the
marginal implicit price of proximity to water for residential property was significantly greater in
areas of San Francisco Bay where the condition of the water was better. The marginal implicit price
of this difference in water condition was estimated to be approximately $41,000 (1985$) in absolute
terms, or approximately 11 percent of the value of a waterfront property in relative terms.
Because the study did not estimate the individual contribution that the different water quality
constituents (e.g. toxics, oxygen, floatables, odor) made to overall water quality in the areas
evaluated, it is not possible to estimate what percentage of the 11 percent property value increase
was due to'toxic pollutants covered by this rule. The results of this study indicate however, that
increased property values could be significant statewide if loadings of toxic constituents from all
sources were reduced to meet proposed water quality criteria.
39 Clapper Rail eggs have been found to harbor elevated levels of mercury, selenium, and
other contaminants.
40 Mendelsohn, Robert, Daniel Hellerstein, Michael Huguenin, Robert Unsworth, and
Richard Brazee, "Measuring Hazardous Waste Damages with Panel Models," Journal of
Environmental Economics and Management, Vol. 22, No. 3,1992.
41 D. Kirshner and Deborah Moore, "The Effect of San Francisco Bay Water Quality on
Adjacent Property Values," Journal of Environmental Management (1989) 27:263-274.8.
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Ecological Benefits
Achievement of the water quality criteria established by the CTR may enhance a variety of
ecological services provided by aquatic systems. While it is beyond the scope of this study to
monetize these services, it is important to note that society may place significant value on them.
Relevant ecological benefits that may accrue include reduced mortality/morbidity to aquatic and
terrestrial wildlife, improved habitat supporting fish spawning and migration, improved habitat
supporting threatened and endangered species, and avoidance of the cost of endangered species
management and associated land use restrictions. We characterize several of these benefits more
fully in Chapter 5 of this report.
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JUNE 1997
REFERENCES
Caulkins, Peter P., Richard Bishop, Nicolas Bouwes, "The Travel Cost Model for Lake Recreation:
A Comparison of Two Methods for Incorporating Site Quality and Substitution Effects,"
American Journal of Agricultural Economics, May, 1986.
Connelly, Nancy A., Barbara Knuth, and John Vena, New York State Angler Cohort Study: Health
Advisory Knowledge and Related Attitudes and Behavior, With a Focus on Lake Ontario,
September 1993.
Connelly, Nancy A., Tommy Brown, and Barbara Knuth, New York Statewide Angler Survey, 1988.
Costanza, Robert, et al., "The Value of the World's Ecosystem Services and Natural Capital,"
Nature, May 15,1997.
Daily, Gretchen, editor, Nature's Services: Societal Dependence on Natural Ecosystems, Island
Press, 1997.
Hay, Michael J., Analysis of the 1985 National Survey of Fishing, Hunting, and Wildlife-Associated
Recreation, U.S. Department of the Interior Report 85-1, Net Economic Values for Deer, Elk,
and Waterfowl Hunting and Bass Fishing, 1988.
Huppert, Daniel D., "Measuring the Value of Fish to Anglers: Application to Central California
Anadramous Species," Marine Resource Economics, VoL 6, pp. 89-107,1989.
Kirshner, D., and Deborah Moore, "The Effects of San Francisco Bay Water Quality on Adjacent
Property Values," Journal of Environmental Management (1989) 27:263-274.8.
Loomis, John and Joseph Cooper, "Economic Benefits of Instream Flow to Fisheries: A Case Study
of California's Feather River," Rivers, January, 1990, pp. 23-30.
Lyke, "Discrete Choice Models to Value Changes in Environmental Quality: A Great Lakes Case
Study," Dissertation submitted to the Graduate School of the University of Wisconsin-
Madison, 1993.
MBC Applied Environmental Sciences, Santa Monica Bay Seafood Consumption Study —
September 1991 to August 1992, prepared for Santa Monica Bay Restoration Project, August
1993.
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REFERENCES
(continued)
Mendelsohn, Robert, Daniel Hellerstein, Michael Huguenin, Robert Unsworth, and Richard Brazee,
"Measuring Hazardous Waste Damages with Panel Models," Journal of Environmental
Economics and Management, Vol. 22, No. 3,1992.
Mitchell, R.C., and R.T. Carson, Using Surveys to Value Public Goods: The Contingent Valuation
Method, Washington DC, Resources for the Future, 1989.
Mullen, John K. and Fredric Menz, "The Effect of Acidification Damages on the Economic Value
of the Adirondack Fishery to New York Anglers," American Journal of Agricultural
Economics, February, 1985.
National Oceanic and Atmospheric Administration, Summary of Potential Economic Damages to
the Resources of Lavaca Bay and Matagorda Bay Texas as Result of Mercury
Contamination, May 1991.
Roach, Brian, Angler Benefits Along Four California Rivers: An Application of Tobit Analysis,
March 1996.
Setzler-Hamilton, Eileen, et al., "Striped Bass Populations in Chesapeake and San Francisco Bays:
Two Environmentally Impacted Estuaries," Marine Pollution Bulletin, Vol. 19, No. 9, pp.
466-477.
Silverman, W., Michigan's Sport Fish Consumption Advisory: A Study in Risk Communication,
thesis submitted in partial fulfillment of the requirements for the degree of Master of Science
(Natural Resources) at the University of Michigan, May 1990.
U.S. Department of Commerce, National Oceanic and Atmospheric Administration, 15 CFR, Part
990, Natural Resource Damage Assessments: Proposed Rules, 59 FR 1062,1994.
U.S. EPA, Ecological Benefits Assessment Framework, draft, prepared for EPA Social Sciences
Discussion Group, EPA Science and Policy Council, 1996.
U.S. EPA, Office of Science and Technology, Regulatory Impact Assessment of Proposed Effluent
Guidelines and Standards for the Metal Products and Machinery Industry (Phase I), April,
1995.
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REFERENCES
(continued)
U.S. EPA, Office of Pollution Prevention and Toxics, Ecological Benefits Assessment Model:
Documentation Manual, May, 1997.
U.S. EPA, A Brief Overview of Natural Resource Valuation Issues and Methodologies, Office of
Policy, Planning and Evaluation, 1994.
U.S. EPA Office of Water, Regulatory Impact Analysis of the Proposed Great Lakes Water Quality
Guidance, Final Report, March 1995.
U.S. EPA, Regulatory Impact Assessment of the Final Water Quality Standards for the San
Francisco Bay/Delta and Critical Habitat Requirements for the Delta Smelt, Region 9,
(December), 1994.
U.S. Fish and Wildlife Service, National Survey of Fishing, Hunting, and Wildlife-Associated
Recreation — California, July 1993.
Udd, Edward and Joseph Fridgen, Anglers' Perceptions of Toxic Chemicals in Rivers and Sport
Fish, paper presented at the National Wilderness Research Conference, July 1985.
Walsh, Richard G., Donn M. Johnson, and John R. McKean, Review of Outdoor Recreation
Economic Demand Studies with Nonmarket Benefit Estimates, 1968-1988, December, 1988.
West, P., et al., Michigan Sport Anglers Fish Consumption Survey: A Report to the Michigan Toxic
Substances Control Commission, University of Michigan School of Natural Resources,
Technical Report # 1, May 1989.
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ECOLOGICAL BENEFITS CHAPTER 5
INTRODUCTION
California is one of the most biologically diverse areas in the world. Within its 160,000 square
miles of land, and hundreds of thousands of acres and miles of water resources, California harbors
more unique plants and animals than any other state in the nation. The diversity of climates,
landscapes, and habitats, and all the barriers to migrations such as mountains and deserts, have led
over thousands of years to the evolution of a large number of unique species and varieties of plants
and animals, many of which are found only in California.1 For example, there are 46 species of
amphibians, 96 species of reptiles, 563 species of birds, 190 species of mammals, 8,000 species of
plants and 30,000 species of insects recorded in the State. The 63 types of freshwater fish are unique
in that a high percent of them are found only in California.2 Many of these species exist in or are
dependent upon aquatic ecosystems during all or a part of their lives, and consequently may be
adversely affected by toxic discharges to surface waters.
The purpose of this chapter is to describe the potential ecological benefits expected to occur
when toxic pollutant discharges are reduced to meet the water quality criteria proposed in the
California Toxics Rule (CTR). As described in the previous chapter on economic benefits, the
standard approaches used to evaluate environmental and ecological benefits are entirely
anthropocentric. Improving the survival, growth, productivity, and reproductive capacity of aquatic
and terrestrial organisms, populations and communities has worth above and beyond the direct
1 Steinhart, 1994.
2Moyle, 1994.
5-1
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JUNE 1997
consumptive use of selected species for recreation, commercial, and other purposes. Economic
valuation methods become more and more difficult to use to evaluate ecological benefits as the
ecosystem services in question become more complex, large-scale, interconnected, and subtle. The
complexity of ecosystems, our limited ability to predict ecosystem-level responses to toxics, and
difficulties in assessing causal linkages between the current levels of toxics in California waters and
associated ecological impacts makes the determination of ecological and economic benefits very
difficult. Furthermore, economic valuations cannot entirely capture the full range of benefits
associated with protecting and/or restoring the function, structure, and composition of ecosystems.
The goal of this chapter (and Chapter 6) therefore, is to characterize the range of ecological effects
and impacts associated with specific toxic pollutants discharged to California's aquatic ecosystems,
and to describe some of the organism, population, and community benefits that are expected to be
associated with reducing these discharges to meet water quality criteria, independent of their direct
monetary value to humans!
Key Findings
The ecological benefits expected to accrue when toxic contaminants are reduced to levels that
meet chronic and acute criteria in all California waters are significant. As shown in Exhibit 5-1,
large areas of ecological resources in every region of the state currently experience impairment of
water quality (and by extension, the resources they support) by such toxics as metals, selenium,
pesticides, and priority organics (see Figure 5-1 for the location of the nine regions cited). Reducing
loadings of these contaminants to meet criteria levels is expected to lead to healthier and more stable
organisms, populations, and communities in ecosystems that exist in or are dependant on more than
800,000 acres of assessed bays, estuaries, lakes, and wetlands and more than 3,700 miles of rivers
that are now currently impaired by toxic pollutants. Other specific ecological benefits expected to
result from implementation of this rule include the following:
• Reductions in toxics loadings are expected to contribute to improved
conditions for fish spawning and/or migration in more than 223,000 acres of
bays/harbors and estuaries, 102,000 acres of lakes, 1,000 miles of rivers and
streams, and 11,000 acres of saline lakes.
• Potential bioaccumulatives of concern that currently threaten fish and wildlife
throughout the State include selenium, mercury, PCBs, dioxins, and
chlorinated pesticides. Mercury concentrations in California fish are
estimated to reach levels that may be hazardous to piscivorous wildlife.3
Adverse effects on wildlife are also occurring as a result of exposure to
selenium. Populations that may widely benefit from reduced concentrations
,3 Piscivorous wildlife are birds, fish, and mammals that eat fish.
5-2
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JUNE 1997
Exhibit 5-1
SUMMARY OF BASELINE CALIFORNIA REGIONAL
WATER QUALITY ASSESSMENTS
Region
Areal Extent of Toxics
Impairment
Pollutants of
Concern
Primary Pollutant
Sources
Key Waterbodies
Impaired
Ecological Resources Potentially Affected
Region 1:
North Coast
Region
55% of bays (16,500 acres); minor
impairment of other waterbodies
Metals, pesticides
Mix of point sources
(municipal and industrial
effluent) and nonpoint
sources (agriculture and
urban runoff)
Arcata Bay, Humboldt
Bay
Wildlife habitat; fish spawning and migration;
rare and endangered species
Region 2: San
Francisco Bay
Large areas impaired by toxics,
including 70% of bays (200,000
acres);60% of wetlands (57,000
acres); 39% of rivers (244 miles);
172,000 acres impaired supporting
fish spawning/migration and rare
and endangered species
Metals, trace
elements, priority
organics
Urban runoff and other
nonpoint sources affect
largest areas; some
impairment from
municipal and industrial
point sources
San Francisco Bay
(Lower, Central, South),
Suisun Marsh
Wildlife habitat; fish spawning and migration;
rare and endangered species; waterfowl;
piscivorous wildlife in San Francisco Bay, Lake
Herman, Guadalupe Reservoir, and others
species
Region 3:
Central Coast
Region
47% of lakes (11,700 acres);36%
of estuaries (1,700 acres); minor
impairment of rivers and bays
Metals, pesticides
Agriculture, mining,
unspecified nonpoint
Morro Bay, Carpinteria
Marsh, Elkhom Slough
sources
Wildlife habitat; fish migration and spawning;
rare and endangered species; piscivorous
wildlife in Nacimiento River
Region 4: Los
Angeles Basin
Over 90% of bays and estuaries
impaired (16,000 acres); minor
impairment of rivers and lakes
Pesticides, priority
organics, trace
elements
Mix of point sources
(municipal treatment,
"other" point sources)
and nonpoint sources
(agriculture,
hydrological
modification, and urban
runoff)
Mugu Lagoon,
San Gabriel River (lower),
Los Angeles River
(upper)
Wildlife habitat; fish migration and spawning;
rare and endangered species; piscivorous
wildlife in Lake Nacimiento and Los Angeles
Harbor
5-3
-------
Exhibit 5-1
SUMMARY OF BASELINE CALIFORNIA REGIONAL
WATER QUALITY ASSESSMENTS
Region
Areal Extent of Toxics
Impairment
Pollutants of
Concern
Primary Pollutant
Sources
Key Waterbodies
Impaired
Ecological Resources Potentially Affected
Region 5:
Central Valley
Region
Large areas impaired by toxics,
including 100% of estuaries
(48,000 acres); 23% of lakes
(120,000 acres); 21% of rivers
(1,200 miles); 48,000 acres of
Delta waterways impaired for fish
spawning/migration and rare and
endangered species
Metals, trace
elements
Agriculture, mining;
smaller areas affected by
municipal treatment,
urban runoff, storm
sewers, and other
nonpoint sources
Delta Waterways, Clear
Lake, American River,
Feather River, Sacramento
River, Grasslands .
Marshes, Shasta Lake
Wildlife habitat; fish spawning and migration;
rare and endangered species; piscivorous
wildlife in Clear Lake, Lake Berryessa, and
Grasslands Area; waterfowl in Grasslands Area
Region 6:
Lahontan
Region
34% of saline lakes (66,000 acres);
19% of lakes (36,000 acres); 13%
of rivers (372 miles)
Metals, trace
elements, priority
organics
Naturally occurring
levels of metals and trace
elements; lesser areas
affected by agriculture,
land development, and
mining
Eagle Lake, Owens River,
Truckee River, Honey
Lake
Wildlife habitat; fish spawning and migration;
rare and endangered species
Region 7:
Colorado
River Basin
60% of rivers (1,400 miles)
impaired; 220,000 acres of saline
lake (Salton Sea) supporting rare
and endangered species and
wildlife
Pesticides, trace
elements
Agriculture
Salton Sea
Wildlife habitat; rare and endangered species.
piscivorous wildlife and waterfowl in Salton Sea
Region 8:
Santa Ana
River Basin
Over 90% of bays and estuaries
impaired (4,000 acres); 27% of
lakes (4,000 acres)
Metals, pesticides
Primarily nonpoint
sources including
agriculture, urban runoff,
and land development
Upper Newport Bay
Wildlife habitat; fish spawning and migration;
rare and endangered species
5-4
-------
Exhibit 5-1
SUMMARY OF BASELINE CALIFORNIA REGIONAL
WATER QUALITY ASSESSMENTS
Region
Areal Extent of Toxics
Impairment
Pollutants of
Concern
Primary Pollutant
Sources
Key Waterbodies
Impaired
Ecological Resources. Potentially Affected
Region 9: San
Diego Basin
14% of estuaries; minor
impairment of other waterbodies;
239 acres San Diego Ray impaired
supporting fish
spawning/migration and rare and
endangered species
Metals, pesticides.
priority organics.
trace elements
F.stuanes affected by
land disposal: other
waterbodies affected by
diverse mix of point and
nonpoint sources
San Diego Bay, Tijuana
River Estuary
Wildlife habitat; fish spawning and migration;
rare and endangered species
Source: EPA analysis of 1994 California Water Quality Assessment data base; State of California data on fish and waterfowl consumption advisories. Impaired waters are defined as
those that have been assessed and rated by the State of California as medium or poor water quality for at least one toxic water quality pollutant or groups of pollutants.
Some key waterbodies impaired by toxics may have changed since 1994. However, more recent data were not used because of time constraints.
5-5
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Figure 5-1
LEGEND
Regional Water Quality Control Board
1 North Coast.
2 San Francisco Bay
3 Central Coast
4 Los Angeles
5 Central Valley
6 Lahontan
7 Colorado River
8 Santa Ana
9 San Diego
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JUNE 1997
include estuarine and freshwater fish and piscivorous animals, although the proposed criteria may
not be stringent enough to provide benefits to all wildlife species currently at risk throughout the
State.
• Reducing toxic contaminants to meet water quality criteria may contribute to improved
conditions for the successful recovery of Federal and State threatened and endangered (T&E)
species, including the Delta smelt, Desert pupfish, California brown pelican, Bald eagle,
California clapper rail, California tiger salamander and western snowy plover. Statewide,
T&E species may be at risk from toxics in approximately 180,000 acres of bays, harbors and
estuaries, 2,000 river miles, and 230,000 acres of saline lakes.
• The greatest reductions in the likelihood of adverse toxics-related impacts on aquatic and
terrestrial wildlife may accrue for the San Francisco Bay Watershed and the Central Valley.
These areas have the greatest amount of toxic loadings and the greatest diversity and richness
of species, populations, and communities.
• Reducing copper discharges to the Sacramento River to meet water quality criteria would
result in substantial protection for 90 percent or more of the .organisms and communities that
are currently adversely affected.
• Reduced concentrations of both selenium and pesticides in the waters that feed the Salton
Sea are expected to contribute to improved conditions for the restoration and maintenance
of currently declining populations of wildlife, including threatened and endangered species.
These include the California brown pelican, peregrine falcon, bald eagle, Yuma clapper rail,
and desert pupfish.4
• All components of the ecosystem are inextricably linked. Therefore, we expect that the
improved water quality and likely associated improvements in survival, growth, and
reproductive capacity of aquatic and aquatic-dependant organisms resulting from reduced
exposure to toxics will help to contribute to the increased stability, resilience and overall
health of numerous ecosystems throughout California, and may contribute to protecting,
restoring and maintaining California's rich biodiversity.
4 However, current selenium criteria may not be stringent enough to adequately protect some
aquatic-dependant wildlife species. The U.S. Fish and Wildlife Service is recommending a selenium
criterion of 2 ug/liter to protect some of these aquatic-dependant wildlife.
5-7
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JUNE 1997
Organization of the Chapter
This chapter's first section briefly describes the methodology used to characterize the
ecological benefits associated with the California Toxics rule. We then describe the potential
impacts of selected toxic pollutants of concern on exposed species, populations, and communities
throughout the State. We next discuss the potential impact of toxics on waters of special concern,
including waters that the State has designated for the support of important ecological functions, and
waters that support threatened and endangered species. Finally, the chapter presents a method for
examining the proposed rule's potential beneficial impacts on biological communities, presenting
an illustration based on ambient water quality data from the Sacramento River. To provide
additional detail on the potential ecological benefits of the proposed rule, we present case studies
illustrating these benefits for two areas: the San Francisco Bay Estuary and the Salton Sea. These
case studies are presented in Chapter 6.
METHODOLOGY
A great proportion of the toxic compounds addressed in this rule pose morbidity and
mortality risks to both aquatic and aquatic-dependant organisms at relatively low environmental
concentrations. In order to more completely describe ecosystem benefits, it is necessary to consider
not just toxic impacts to individual organisms, but their adverse effect on the structure and function
of all components of the ecosystem. This includes population and community effects, and the
complex food and energy relationships that inextricably link them all. It is also important to
consider the cumulative impact of various toxics on aquatic ecosystems, and the influence of other
types of stressors (e.g., habitat destruction) on the function and structure of these ecosystems.
As shown in Figure 5-2, discharges of pollutants can affect individuals, populations and
communities either directly or indirectly. Toxic discharges can impair not only individual health,
behavior and survival, but they can also disrupt the vital interactions and flow of energy between
individuals and the other components of the food web, potentially leading to an adverse change in
population and community structure and function. Further, in the same way that energy flows from
primary producers (e.g., phytoplankton) to primary consumers (e.g., zooplankton and mussels),
secondary consumers (e.g., fish larvae and invertebrates), tertiary consumers (e.g., fish and crabs)
and to higher trophic level consumers (e.g., carnivorous fish, aquatic birds and seals), certain toxic
contaminants can also be transferred and biomagnify to toxic levels as they move through and up
the foodweb. Consequently, pollutants that enter rivers, lakes, estuaries and other waterbodies can
bioaccumulate to very high levels in biotic tissues and can adversely impair organisms and animals
that consume them, even though the pollutants occur in relatively low and non-toxic concentrations
in water.
5-8
-------
Figure 5-2
Simplified Diagram of the Flow of Contaminants Through Aquatic Food Web
Input
\\
'. \
Jt
Aquatic bird
Volatilization or
aerosol ization
Colloidal
coagulation
Solution in water
Uptake by
phytoplankton
Herbivorous
fis
Adsorption onto clay
or organic matter
f Carnivorous
fish
Sedimentation
Absorption by \
Adsorption by
sediments
Release as
organic compound
following bacterial
transformation
Sedimentation
Source: Westman, 1985
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JUNE 1997
To capture all the ecosystem benefits associated with reduced toxic discharges to California
waters, we would have to evaluate all of these interactive processes (including those associated with
non-chemical stressors), in addition to individual organism effects. Appendix E describes the
fundamental concepts in greater detail and provides a brief summary of the steps involved in a
complete ecological risk assessment.
Because state-wide data on ecosystem impacts that can be solely attributed to toxics are
limited, it was not possible to perform a comprehensive ecological risk assessment for ecosystems
throughout the State. Further, a number of factors precluded us from performing numerous site or
region-specific evaluations of the ecological risks posed by each constituent at each water resource
covered by the CTR. These factors include the number and complexity of toxics being discharged
to California waters, the variety of exposure pathways to aquatic and terrestrial wildlife and
limitations in assessing strict causal linkages between toxics exposure and impacts. We therefore
evaluated the range of qualitative and quantitative indicators and other relative measures of
ecosystem benefits that are likely to accrue from reducing toxic contamination to surface waters and
sediments to meet CTR water quality criteria.
We primarily utilize data on selected constituent-specific adverse ecological effects at the
individual, population, and community level (e.g., direct mortality, reduced breeding success, and
decreased productivity) that are likely to occur in California. Where possible, we also discuss higher
trophic level impacts. We discuss in somewhat greater detail the ecological benefits expected to
accrue in San Francisco Bay and the Salton Sea (presented separately, in Chapter 6). In addition,
we quantified the areal extent of water quality improvements that may lead to improved fish
spawning and migration. State and Federal rare, threatened and/or endangered species, and terrestrial
and aquatic wildlife. We also estimated the potential hazard for piscivorous wildlife consuming
mercury-contaminated fish in selected areas in California based on fish tissue data from throughout
the State. Finally, we present and apply one approach for assessing changes in ecological risks
associated with potential reductions of copper in parts of the Sacramento River.
As described in Chapter 2, we have characterized baseline water quality conditions for fresh
and estuarine waters throughout the State by evaluating the State's Water Quality Assessment
(WQA) database, developed and maintained by the State Water Resources Control. Boards.5 The
WQA is a compilation of data from the State's nine regional Water Quality Control Boards and is
organized by region and by waterbody type. It contains a range of information on surface water
pollution, including the pollutants that adversely affect water quality in bodies of water that have
5 California Water Quality Assessment, 1994.
5-10
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JUNE 1997
been evaluated, the sources of pollution, the beneficial uses that are expected to experience some
degree of impairment, and an overall rating of water quality.6 The State relies on the WQA to
develop the biennial water quality report required by Section 305(b) of the Clean Water Act. The
WQA was last updated in 1994. In addition, we used site-specific studies to evaluate water quality,
water sediment, and biotic conditions in selected water bodies such as San Francisco Bay, the Bay
Delta, Sacramento River, and the Salton Sea.
ECOLOGICAL EFFECTS OF TOXIC
POLLUTANTS AND AFFECTED RESOURCES
Occurrence of Toxics-Related Impairments
Based on analyses of state WQA data and other sources, it is clear that toxic pollutants
covered by the proposed rule have a significant potential to affect many of California's surface water
resources.7 Exhibit 5-1 (see above) summarizes for the nine major regions in California the areal
extent of toxics impairment, the pollutants of concern, the primary pollutant sources, key
waterbodies impaired, and the ecological resources potentially affected. Major impacts include the
following:
• Available data suggest that over 800,000 acres of assessed bays, estuaries,
lakes, and wetlands are affected by one or more toxic pollutants, as are over
3,700 miles of rivers. Most notably, over two-thirds of the assessed area of
both bays and saline lakes are adversely affected by toxics.
• Inorganic pollutants such as metals and trace elements (particularly selenium)
are the most significant categories of toxic pollutants affecting the water
quality in assessed waters statewide. Pesticides are also associated with large
areas of water quality impairment.
6 Currently, not all of California waters are assessed. Approximately 90 percent of all streams
and rivers, 23 percent of lakes and reservoirs, and 46 percent of wetlands in the State have not been
evaluated for water quality impacts.
7 We define "impaired" waters as those that have been assessed and are rated by the State of
California as medium or poor water quality for at least one toxic water quality pollutant or group of
pollutants. See chapter 2 and Appendix A for a more detailed description of California water
quality.
5-11
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JUNE 1997
Trace elements (especially selenium) are responsible for water quality
impairment in 52 percent of all assessed Bays, 55 percent of assessed rivers
and streams assessed, and 16 percent of all assessed lakes and reservoirs. In
addition, they affect water quality in all saline lakes in the State:
Based on the areal extent of contamination and the uses of affected
waterbodies, San Francisco Bay and the Central Valley appear to be the areas
most influenced by toxic contamination. In addition, toxics are responsible
for impaired water quality in a high percentage of river and saline lake areas
in the Colorado River Basin. While these areas constitute those most
extensively affected by toxics, waters in all regions show some degree of
toxics impairment.
Both point and nonpoint sources play a role in contributing to toxic pollution.
Agriculture, primarily agricultural drainage, is the most frequently cited
source of pollutants that impair rivers and is also frequently cited as a
contributor to the impairment of lakes and reservoirs. Urban runoff and
"other" nonpoint sources (e.g., deposition and spills) are most frequently
cited as contributing factors to water quality problems in toxics-impaired
bays. Mining is the most frequently cited point source, particularly for lakes
and reservoirs, while toxics discharged by municipal wastewater treatment
plants contribute to the impairment of a variety of waterbody types,
particularly estuaries and wetlands.
Currently, there are 12 fish consumption health advisories in waters covered
by the CTR (nine inland waterbodies and three enclosed bays and estuaries)
due to high levels of contamination in fish tissue from mercury, PCBs,
chlordane, dioxin, DDT, pesticides, and selenium.8 (Figure 5-3 shows the
location of these advisories and Exhibit 3-1 in Chapter 3 identifies
contaminants of concern in the 12 locations.) Some of these tissue
contaminants are also hazardous to fish and piscivorous species as well.
8 While the existence offish consumption advisories for the protection of human health does not
directly translate into risks to piscivorous wildlife, it does demonstrate that these pollutants
accumulate to harmful levels for at least one top consumer (humans) and implies the possibility that
other top consumers (piscivorous wildlife such as seals, birds, etc.) may also be at risk.
5-12
-------
Figure 5-3
CALIFORNIA FRESHWATER AND INLAND BAYS AND ESTUARIES
FISH CONSUMPTION HEALTH ADVISORIES
ISan Francisco Bay I
IKesterson National Wildlife Refuge!
IGuadalupe Reservior/River/Creek and other Santa Clara Co. Lakes!
ILake Nacimientol
|HarborParkLake|
(1) Los Angeles Harbor/Long Beach Harbor
(2) Belmont Pier/Pier J
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JUNE 1997
In addition there are four health warnings for consuming waterfowl taken
from Grasslands area, Suisun Bay, San Pablo Bay, and San Francisco Bay
based on elevated selenium levels in duck, greater and lesser scaup, and
scoters. In addition to presenting a risk to human health, exposure to
excessive concentrations of selenium poses a threat to the health and survival
of waterfowl.
Occurrence of Toxics-Related Impairment of Ecological Beneficial Uses
\
Of particular importance in characterizing the potential ecological benefits of the California
Toxics Rule is the extent to which California waters affected by toxics are designated to support
important ecological uses. As one indicator of these impacts, Exhibit 5-2 lists all waters that (1) are
identified as impaired in California's Section 303(d) report; (2) are at least partially impaired by
toxics, according to the State's Water Quality Assessment (WQA) database; and (3) have associated
with them one of the following current or potential beneficial uses, as indicated in the WQA:
• WILD: the support of terrestrial ecosystems, including but not limited to, the
preservation and enhancement of terrestrial habitats, vegetation, wildlife, or
wildlife water and food sources;
• MIGR: the support of habitats necessary for migration, spawning, or other
temporary activities by aquatic organisms, such as anadromous fish; and
• RARE: the support of habitats necessary, at least in part, for the survival and
successful maintenance of plant or animal species established under State or
Federal law as rare, threatened, or endangered.
For each listed waterbody, the exhibit identifies the region in which it is located; the
waterbody type (i.e., bay, estuary, wetland, river, or freshwater/saline lake); the priority assigned in
California's Section 303(d) report for future efforts to improve water quality; the areal extent of
impairment (in miles for rivers and streams and in acres for all other waterbodies); the toxic
pollutants associated with the impairment; and the applicable designated use(s).9 The designation
"NA" indicates that data on beneficial uses for some waterbodies are not available.10
9 As noted in Chapter 2, California's §303(d) report ranks impaired waterbodies for potential
future action on a scale of 1 (highest) to 5 (lowest). The §303(d) priority assigned to a waterbody
reflects the degree of impairment and the intrinsic value of the waterbody as a function of its current
and potential beneficial uses.
10 The exhibit includes waterbodies for which WQA data are not available on any of the three
beneficial use categories.
5-14
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JUNE 1997
Exhibit 5-2
ECOLOGICAL BENEFICIAL USES ASSOCIATED WITH PRIORITY WATERBODIES IMPAIRED BY TOXIC POLLUTANTS
Region
1
1
1
1
1
1
2
2
2
2
2
2
2
2
2
2
2
2
2
2
3
3
3
3
3
3
3
3
3
3
3
3
TypV
E
E
R
R
R
R
B
B
B
B
L
L
L
R
R
R
R
R
R
W
B
B
B
E
E
E
E
L
R
R
W
W
Wfvtsfbooy tteniv
ESTERO AMERICANO
ESTERO DC SAN ANTONIO
KLAMATH RIVER
MAD RIVER
SHASTA RIVER
VAN DUZEN RIVER
SAN FRANCISCO BAY. CENTRAL
SAN FRANCISCO BAY. LOWER
SAN FRANCISCO BAY, SOUTH
TOMALES BAY
CALERO RESERVOIR
GUADALUPE RES
HERMAN LAKE
ALAMEOA CREEK
ALAMITOS CREEK
GUADALUPE RIVER
NAPA RIVER
PETALUMA RIVER
WALKER CREEK
SUISUN MARSH
MONTEREY HARBOR
MORRO BAY
MOSS LANDING HARBOR
CARPINTERIA MARSH
ELKHORN SLOUGH
GOLETA SLOUGH/ESTUARY
WATSONVILLE SLOUGH
NACIMIENTO RESERVOIR
SALINAS RIVER
SAN LORENZO RIVER
ESPINOSA SLOUGH
MORO COJO SLOUGH
J0*d)
Prtortty
t
i
i
2
3
2
1
1
1
3
• 4
4
5
4
4
4
3
3
4
1
4
2
4
2
2
3
4
3
3
3
4
5
Am of
170
»5
1
3
2
2
67.700
79,900
24,500
400
350
BO
110
27
14
30
55
25
25
57,000
74
100
40
80
1,000
200
300
5,370
50
20
160
100_
Po««t»iH Types
MM**
•Mats
Menu
Ptstlclde*
Pesticides
Pesticides
Metals
Metals
Metals
Metals
Metals
Metals
Metals
Metals
Metals
Metals
Metals
Metals
Metals
Metals
Metals
Metals
Pesticides
Priority
Pesticides
Metals
Pesticides
Metals
Pesticides
Trace
Pesticides
Pesticides
Pesticides
Trace Elements
Pesticides
Pesticides
Trace Elements
Trace Elements
Trace Elements
Trace Elements
Pesticides
Unspec. Toxics
Unspec. Toxics
Metals
Priority Organic*
Pesticides
Priority Organlcs
Trace Elements
Unspec. Toxics
Trace Elements
Unspec. Toxics
Trace Elements
Supports
Wildlife
X
X
X
X
X
X
X
X
X
X
X
X
NA
X
X
X
X
NA
X
X
X
X
X
X
X
X
X
X
x
Supports Fish
Spawn, and/or Mlgr.
X
X
X
X
X
X
X
X
X
X
X
X
X
X
NA
X
X
X
X
NA
X
X
X
X
X
X
Jf
Supports Rare or
Endangered Species
X
X
X
X
X
X
X
X
X
NA
X
X
X
NA
X
X
X
X
X
X
X
X
X
X
x
5-15
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Exhibit 5-2
ECOLOGICAL BENEFICIAL USES ASSOCIATED WITH PRIORITY WATERBODIES IMPAIRED BY TOXIC POLLUTANTS
Region
3
3
4
4
4
4
4
4
4
4
4
4
4
4
4
4
5
5
5
5
5
S
5
5
5
S
5
5
S
5
5
5
Type'
W
W
E
E
E
B
E
R
R
L
R
B
R
R
R
B
E
L
L
L
L
L
L
L
L
R
R
R
R
R
R
R
Watertaody Name
SALINAS RIVER REFUGE LAGOON (SOUTH)
TEMBLADERO SLOUGH
MUGU LAGOON
BALLONA WETLANDS
COLORADO LAGOON
LONG BEACH HARBOR (INNER)
LOS ANGELES RIVER (TIDAL PRISM)
VENTURA RIVER (LOWER)
CALLEGUAS CREEK
'HARBOR LAKE
LOS ANGELES RIVER (UPPER)
MARINA DEL REY HARBOR
REVOLON SLOUGH
SAN GABRIEL RIVER; FIRESTONE BLVD - ESTUARY
SAN GABRIEL RIVER (TIDAL PRISM)
PORT HUENEME
DELTA WATERWAYS
BEACH LAKE
BERRYESSA LAKE
CLEAR LAKE
DAVIS CREEK RESERVOIR
KESW1CK RESERVOIR
MARSH CREEK RESERVOIR
SHASTA LAKE
WHISKEYTOWN RESERVOIR
AMERICAN RIVER, LOWER
FEATHER RIVER, LOWER
KINGS RIVER. LOWER
LITTLE BACKBONE CREEK
LITTLE GRIZZLY CREEK
MERCED RIVER, LOWER
MOKELUMNE RIVFR 1 OWFR
303(d)
Priority
4
3
2
3
3
3
3
3
4
4
4
4
4 '
4
4
5
1
S
3
1
5
4
5 .
2
3
1
1
4
S
5
4
4
Area of
Impairment1
50
75
1,500
150
13
840
1,260
6
11
50
25
354
9
18
3
121
48,000
295
20,700
43,000
290
450
375
20
3,251
23
60
30
1
10
60
28
Pollutant Types
Pesticides
Pesticides
Pesticides '
Metals
Metals
Pesticides
Metals
Metals
Pesticides
Pesticides
Priority
Metals
Pesticides
Metals
Metals
Metals
Metals
Metals
Metals
Metals
Metals
Metals
Metals
Metals
Unspec.
Metals
Metals
Metals
Metals
Metals
Pesticides
Metal*
Trace Elements
Pesticides
Priority Organlcs
Priority Organlcs
Priority Organlcs
Trace Elements
Pesticides
Priority Organlcs
Priority Organlcs
Pesticides
Pesticides
Pesticides
Pesticides
Pesticides
Unspec. Toxics
Trace Elements
Metals
Pesticides
Pesticides
Unspec. Toxics *
Unspec. Toxics
Unspec. Toxics
Trace Elements
Supports
Wildlife
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
NA
X
X
X
NA
NA
X
X
X
X
NA
NA
NA
X
X
Supports Fish
Spawn, and/or Mlgr.
X
X
X
X
X
X
X
NA
X
X
X
NA
NA
X
X
X
X
NA
NA
NA
X
x
Supports Rare or
Endangered Species
X
X
X
X
X
X
X
X
X
X
NA
NA
NA .
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
5-16
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Exhibit 5-2
ECOLOGICAL BENEFICIAL USES ASSOCIATED WITH PRIORITY WATERBODIES IMPAIRED BY TOXIC POLLUTANTS
Region
5
5
5
5
5
5
5
5
5
5
6
6
6
6
6
6
6
6
6
6
6
6
6
6
7
7
7
7
7
7
8
8
Type'
R
R
R
R
R
R
R
W
W
W
L
L
L
L
R
R
R
R
R
R
R
R
S
S
R
R
R
R
R
S
B
B
Waterbody Name
MUD SLOUGH
SACRAMENTO RIVER, SHASTA DAM TO RED BLUFF
SACRAMENTO RIVER, RED BLUFF TO DELTA
SACRAMENTO SLOUGH
SALT SLOUGH
STANISLAUS RIVER. LOWER
TUOLUMNE RIVER, LOWER
GRASSLANDS MARSHES
MORMON CHANNEL
MORMON SLOUGH
EAGLE LAKE (2)
FALLEN LEAF LAKE
LAKE TAHOE
TOPAZ LAKE
BRYANT CREEK
CARSON RIVER, E FK
CARSON RIVER, W FK
EAST WALKER RIVER
OWENS RIVER
SUSAN RIVER
TRUCKEE RIVER
WEST WALKER RIVER
ALKALI LAKE, LOWER
HONEY LAKE
ALAMO RIVER
COACHELLA VALLEY STORM CHANNEL
IMPERIAL VALLEY DRAINS
NEW RIVER (R7)
PALO VERDE OUTFALL DRAIN
SALTON SEA
UPPER NEWPORT BAY ECOLOGICAL RESERVE
ANAHEIM BAY
303(d)
Priority
4
1
1
5
4
3
4
2
5
S
2
3
1
4
S
3
4
3
2
4
2
3
3
2
4
S
5
5
5
1
2
3
Area of
Impairment1
16
SO
185
1
15
48
32
8,224
1
1
25,000
1,410
160
2,300
10
46
6
8
120
7
106
1
10,855
55,327
52
20
1,305
60
16
220,000
1,500
180
Pollutant Types
Pesticides
Metals
Metals
Metals
Pesticides
Pesticides
Pesticides
Trace
Pesticides
Pesticides
Metals
Trace
Metals
Trace
Metals
Trace
Trace
Metals
Trace
Metals
Trace
Trace
Trace
Trace
Pesticides
Pesticides
Pesticides
Trace
Pesticides
Trace
Pesticides
Pestlelrfo*
Unspec. Toxics
Unspec. Toxics
Unspec. Toxics
Unspec. Toxics
Trace Elements
Unspec. Toxics
Unspec. Toxics
Metals
Metals
Pesticides
Trace Elements
Metals
Priority Organic*
Trace Elements
Priority Organlcs
Metals
Trace Elements
Trace Elements
Pesticides
Trace Elements
Metals
Trace Elements
Pesticides
Unspec. Toxics
Metals
Supports
Wildlife
NA
X
X
NA
NA
X
X
NA
NA
NA
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Supports Fish
Spawn, and/or Mlgr.
NA
X
X
NA
NA
X
X
NA
NA
NA
X
X
X
X
X
X
X
X
X
X
X
X
NA
NA
NA
NA
NA
NA
X
x
Supports Rare or
Endangered Species
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
X
X
X
X
X
X
X
X
X
X
X
X
X
X
5-17
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Exhibit 5-2
ECOLOGICAL BENEFICIAL USES ASSOCIATED WITH PRIORITY WATERBODIES IMPAIRED BY TOXIC POLLUTANTS
Region
8
8
a
8
9
9
9
9
9
9
9
Type1
L
B
L
R
B
B
B
B
E
R
R
Waterbody Name
BIG BEAR LAKE
NEWPORT BAY, LOWER
LAKE ELSINORE
SANTA ANA RIVER, REACHES 3 AND 4
CENTRAL MISSION BAY
OCEANSIDE HARBOR
SAN DIEGO BAY, NORTH
SAN DIEGO BAY, SOUTH
TIJUANA RIVER ESTUARY '
ARROYO TRABUCO
TIJUANA RIVER
303
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JUNE 1997
Exhibit 5-3 summarizes the data by region, and Exhibit 5-4 summarizes the data for the entire
State. These exhibits indicate the areal extent of waters that are impaired by toxics and are
designated for support of wildlife habitat, fish spawning and migration, and rare or endangered
species. As the exhibit shows, toxic pollutants are of concern in a large number of waters designated
for the support of terrestrial and aquatic wildlife. In addition, water quality in 175,000 acres of
bays/harbors, 52,000 acres of estuaries, 102,000 acres of lakes, 1,000 miles of rivers and streams,
and 11,000 acres of saline lakes that support fish spawning and/or migration is toxics-impaired.
Toxics contribute to the impairment of approximately 176,000 acres of bays or harbors, 2,000 river
miles, and 230,000 acres of saline lakes designated for the support of rare, threatened, or endangered
species.
Based on this statewide information, it is clear that toxic contaminants addressed by the rule
are ubiquitous throughout the state, and that aquatic and terrestrial life is exposed to a range of toxic
pollutants that may adversely affect their health and survival.
In interpreting the figures presented in these exhibits, it is important to note that some regions
do not report all three categories of use in their water quality assessments. This is the case, for
example, with Region 5, where available WQA data do not include an assessment of whether
specific waters support rare, threatened, or endangered species. As a result, the analysis likely
understates the extent to which toxics-impaired waters support habitats important for the survival
of these species.
Exposure Pathways
Pollutants entering California waters may ultimately end up in aquatic and aquatic-dependant
animals and plants through either direct or indirect pathways of exposure. Direct pathways of
exposure occur when biota come in direct contact, either singularly or in combination, with toxics
in the water column, sediments, or diet. For example, benthic filter feeds (e.g., oysters, clams,
various crustaceans) can ingest pollutants when they pump contaminated water over their gills.
Snails and worms can ingest pollutants that have adhered to sediment particles as they graze on
organic matter in sediments." Indirect pathways of exposure occur when ecological resources (e.g.,
spawning beds, prey sources) have been reduced or otherwise altered by toxics. Toxics may also
bioaccumulatc in organisms, making them available to terrestrial predators (e.g., fish-eating wildlife)
dependant on the aquatic food web of the contaminated system. Predators such as seals, fish, ducks,
and waterbirds that eat these organisms are then exposed to the pollutants in their prey tissue. The
extent to which organisms are adversely affected depends on the pathway and duration of exposure
as well as the concentration and type of toxics present in the pathway.
11 U.S. EPA, 1992.
5-19
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JUNE 1997
Exhibit 5-3
BENEFICIAL USES OF PRIORITY AQUATIC RESOURCES THAT ARE
IMPAIRED, AT LEAST IN PART, BY TOXIC POLLUTANTS
Supports Fish Spawning
and/or Migration
Region
1
1
2
2
2
3
3
3
3
4
4
5
5
5
6
6
6
8
9
9
Type*
E
R
B
L
R
E
L
R
W
E
R
E
L
R
L
R
S
B
B
E
/
Area of
Impairment
625
8
172,500
540
162
1,380
5,370
70
225
1,650
9
48,000
67,261
486
28,870
294
10,855
2,380
245
1
Supports Wildlife
Region
1
1
2
2
2
3
3
'3
3
1 3
4
4
4
4
5
5
5
6
6
6
7
7
8
8
8
9
9
9
Type*
E
R
B
L
R
B
E
L
R
W
B
E
L
R
E
L
R
L
R
S
R
S
B
L
R
B
E
R
Area of
Impairment
625
8
172,500
110
162
140
1,580
5,370
70
385
475
1,663
50
72
48,000
67,261
486
28,870
304
66,182
1,453
220,000
2,380
5,570
30
245
1
6
Supports Rare or
Endangered Species
Region
1
1
2
2
3
3
3
3
3
4
4
4
4
6
6
6
' 7 ,
7
8
8
8
9
9
9
5
Type*
E
R
B
R
B
E
L
R
W
B
E
L
R
L
R
S
R
S
B
L
R
B
E
R
N/A
Area of
Impairment
625
6
172,500
105
214
1,580
5,370
70
225
840
2,910
50
20
25,000
166
10,855
1,453
220,000
2,380
2,970
30
245
1
6
N/A
*B = Bays/Harbors E = Estuaries L = Lakes R = Rivers & Streams S = Saline Lakes W= Wetlands
Rivers & streams are measured in miles, all others in acres.
5-20
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JUNE 1997
Exhibit 5-4
ECOLOGICAL BENEFICIAL USES OF PRIORITY AQUATIC RESOURCES THAT ARE IMPAIRED,
AT LEAST IN PART, BY TOXIC POLLUTANTS
Ecological
Beneficial Use of
Impaired Area
Supports rare or endangered
species
Supports wildlife
Supports fish spawning and/or
migration
Bays/Harbors
(Acres)
San Francisco Bay: 172,500
Other Inland Bays: 3,679
San Francisco Bay: 172,500
Other Inland Bays: 3,240
San Francisco Bay: 172,500
Other Inland Bays: 2,625
Estuaries
(Acres)
5,116
51,869
51,656
Lakes
(Acres)
33,390
107,231
102,041
Rivers and
Streams
(Miles)
1,856
2,591
1,029
Saline Lakes
(Acres)
230,855
286,182
10,855
Wetlands
(Acres)
225
385
225
Source: WQA, 1994.
5-21
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JUNE 1997
Selected Pollutants of Concern and Their Ecological Effects
The California Toxics Rule proposes freshwater and saltwater water quality criteria for 120
priority pollutants, including metals, pesticides, other organics, and trace elements (see Attachment
1 at the end of Chapter 1 of this report for a complete list of CTR constituents and their proposed
numeric criteria).12 As mentioned earlier, because of time and data constraints, we were not able to
perform site-specific, regional, or state-wide quantitative ecological risk analyses for each of the 120
priority pollutants covered by the CTR. Instead, the following discussion presents an overview of
information on a subset of pollutants that may pose particularly significant risks to organisms
throughout California's aquatic ecosystems and provides more detailed information on the ecological
effects of a few selected pollutants.
Biological organisms are effective receptors for toxics in aquatic systems through the uptake,
accumulation, and eventual biological disposition of contaminants. Uptake of toxics results from
various exposure pathways via contaminated diet, water, and/or sediment. Consequently, biota
exposed to contaminants found in California's aquatic ecosystems can experience adverse acute
and/or chronic effects at the sub-cellular, cellular, and organism level. Acute effects include any
toxic effect produced within a short period of time, generally 96 hours or less. Although the effect
most frequently considered is mortality, the end result of an acute impact could be any harmful
biological effect.
In contrast, a chronic effect is any toxic effect on an organism that results after exposure of
relatively long duration (often the majority of the organism's life span). The end results of a chronic
effect can be death, although the usual effects are sub-lethal such as impaired growth, reduced
reproduction, developmental effects, etc. Exhibit 5-5 summarizes the major categories of adverse
biotic effects that individual organisms will experience when exposed to sufficiently high levels of
selected contaminants. The 14 chemicals shown here represent contaminants that are highly toxic
to aquatic and aquatic-dependant organisms at relatively low levels, are highly persistent and/or
bioaccumulative, have been detected or have been predicted to occur at sufficient levels to cause
toxic effects in California waters, sediments and/or biota, and generally have been identified by
Federal, State and local sources as being of concern in waters throughout the State.
12 There are several specific constituents for certain waterbodies in California that are not
included in the proposed rulemaking because EPA/State promulgated criteria for these pollutants in
prior rulemakings. The Preamble provides a summary of these constituents by waterbody.
5-22
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JUNE 1997
Exhibit 5-5
TOXICS OF CONCERN IN CALIFORNIA AND
THEIR ADVERSE ECOLOGICAL EFFECTS
Toxic of Concern
Arsenic
Cadmium
Chromium
(HI and VI)
Copper
Lead
Mercury
Nickel
Selenium
Silver
Zinc
Dioxins
Endosulfan and Other
Estrogenic Pesticides
(1)
Selected Documentation in
California Waters, Sediments and/or Biota
Endangered species, mussels, fish, sediments, water
Endangered species, mussel, fish, bird, seal, waterfowl sediments,
water
Striped bass, mussel, clam, fish, sediments, water
Endangered species, striped Bass, mussel, clam, fish, bird, seal,
sediments, water
Endangered species, mussel, fish, bird, seal, sediments, water
Endangered species, striped bass, mussel, fish, bird, seal, (piscivorous
wildlife) sediments, water
Striped bass, mussel, fish, bird, seal, sediments, water
Endangered species, mussel, clam, fish, bird, seal, waterfowl,
(piscivorous animals) sediments, water
Endangered species, mussel, clam, fish, striped bass, bird, sediments,
water
Endangered species, striped bass, mussel, fish, bird, sediments, water
Endangered species, wildlife, fish, piscivorous animals, waterfowl
Endangered species, fish, striped bass, birds, waterfowl, water,
sediments
Potential Advene Effects to Individual Organisms
Reduced growth and survival
Impaired reproduction
Impaired physiology
Decreased resistance to infection
Mutagenic
Teratogenic
Carcinogenic
Reduced growth and survival
Impaired reproduction
Possible mutagen
Teratogenic
Carcinogenic
Reduced growth and survival
Impaired reproduction
Mutagenic
Teratogenic
Carcinogenic
Reduced growth and survival
Impaired reproduction
Impaired metabolism
Reduced growth and survival
Impaired reproduction
Impaired development
Impaired metabolism
Reduced growth and survival
Impaired reproduction
Impaired development
Impaired metabolism
Reduced growth and survival
Reduced reproduction
Impaired development
Impaired behavior
Mutagenic
Teratogenic
Carcinogenic
Reduced growth and survival
Reduced reproduction
Carcinogenic
Reduced growth and survival
Reduced reproduction
Impaired behavior
Impaired physiology
Reduced growth and survival
Reduced reproduction
Impaired physiology
Reduced growth and survival
Impaired physiology
Teratogenic to amphibians
Reduced reproduction
5-23
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JUNE 1997
Exhibit 5-5
TOXICS OF CONCERN IN CALIFORNIA AND
THEIR ADVERSE ECOLOGICAL EFFECTS
Toxic of Concern
Selected Documentation In
California Waters, Sediments and/or Biota
Potential Advene Effect* to Individual Organisms
Polycyclic Aromatic
Hydrocarbons (PAHs)
Mussel, fish, sediments, water
Reduced growth and survival
Impaired reproduction
Compromised immunity
Mutagenic
Teratogenic
Carcinogenic
Polychlorinated
Biphcnyls
(PCBs)
Endangered species, starry flounder, black-crowned night heron,
mussel, seal, waterfowl, striped bass, piscivorous wildlife, sediments,
water
Reduced growth and survival
Reduced reproduction
Impaired behavior
Compromised immunity
Mutagenic
Teratogenic
Carcinogenic
(1) Estrogenic pesticides are those that are associated with the disruption of normal endocrine and reproductive functions. Estrogenio pesticides include banned
pesticides like DDT and toxapheite, as well as currently-used pesticides, such as Endosulfan.
Sources: Brown, 1996; California Environmental Protection Agency, State Water Resources Control Board, 1994; Department of Fish and Game, State of California,
1991; Fry, 1996; Harvey, el •!.. 1992; Hcrbold, et a!., 1992; Kopec and Harvey, 1995; Larry Walker Associates, 1992; Ohlendorf and Fleming, 1988; Pease, 1995;
Schwartzback, et al., 19%; Settler-Hamilton, et al.. 1988; Smith and Flegal, 1993; Solomon et al., 1996; Thompson, 1996; U.S. EPA, 1985a; U.S. EPA, 1992; U.S.
Fish and Wildlife Service. 1997; U.S.O.S.. 1990; U.S.G.S.. 1993
5-24
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JUNE 1997
As shown, exposure to these pollutants at levels exceeding the proposed criteria will result
in adverse effects that can change or alter the structural or functional ability of the organism to
survive, reproduce, and/or flourish. Toxics present in California's aquatic systems can affect cellular
metabolism and physiology and can reduce normal growth and development in organisms. Other
adverse impacts from exposure to toxics include impaired ability for organisms to fight chronic and
acute diseases, altered physiology and behavior, impaired reproductive health and behavior, and if
concentrations are high enough, death. Exposure to certain toxics present in California's aquatic
systems, including aromatic hydrocarbons and heavy metals, can also increase an organism's rate
of genetic mutations. Increased rates of genetic mutations can reduce the fitness of individuals and
populations, especially in contaminated areas providing breeding or spawning habitat, because there
would be greater risk to embryonic life stages undergoing rapid development. Any one of these
adverse effects can ultimately affect the survival, reproductive success, and overall health of a
population which hi turn may alter community structure, function, and overall integrity.
It is important to emphasize the bioconcentration, bioaccumulation, and biomagnification
of toxic pollutants through the food web. Bioconcentration is the net accumulation of a substance
by an aquatic organism as a result of direct uptake from water (through gill membranes or other
external body surfaces). For example, phytoplankton and other plants can absorb metals from
surrounding water and can often retain these metals and concentrate them to very high levels (e.g.,
some organisms can concentrate cadmium to levels 250,000 times its concentration in ambient
water). Bioaccumulation refers to the net uptake from all environmental sources, including food and
water. For instance, in the process of collecting essential nutrients, phytoplankton can accumulate
certain chemicals which bioaccumulate in their tissues and become concentrated at levels that are
much higher than in the surrounding water. When small fish and zooplankton consume these
contaminated phytoplankton in vast quantities, chemicals accumulated by the phytoplankton may
be further concentrated in their bodies. These concentrations then biomagnify — that is they increase
in concentration ~ as they move through the food web. When top fish-eating predators (e.g.,
chinook salmon, gulls, herons, bald eagles, mink, otter, and seals) eat the contaminated fish, they
may accumulate concentrations of a toxic chemical several orders of magnitude higher than
concentrations originally present in ambient waters. These extremely high tissue residues of
contaminants can cause adverse effects such as impaired reproduction, altered behavior,
developmental deformities, or death.
Ten of the 14 constituents shown in Exhibit 5-5 are metals, which are acutely and chronically
toxic at relatively low levels, are highly persistent and, in some instances, can bioconcentrate and
bioaccumulate to extremely high levels. The other four contaminants shown are organics or groups
of organics that are extremely toxic and can bioconcentrate and bioaccumulate readily. Because
5-25
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JUNE 1997
these complex organic pollutants remain stored in fat, are difficult to excrete, and have extremely
high bioaccumulation rates, they can easily move through the food web resulting in very high
concentrations in and adverse impacts to higher trophic level organisms. The organics shown here —
dioxin, endosulfan, PAHs and PGBs - are highly toxic in very small concentrations (e.g., parts per
billion) and are extremely persistent. For instance, PCBs, which are more persistent than DDT, can
bioaccumulate and biomagnify to levels up to one million times those in the water.
Specific Pollutant Effects
Toxic pollutants discharged into California's water resources can have a wide range of
adverse impacts on organisms, ranging from subtle physiological changes to overt changes in
reproductive success or survival. A pollutant's direct impact on a particular organism is a function
of the organism's inherent sensitivity to the pollutant and the extent to which the organism is exposed
(i.e., magnitude, duration, and frequency of exposure). It is known that the sensitivity of various
aquatic species can vary widely depending on the pollutant. For instance, certain types offish (e.g.,
chinook salmon, and rainbow trout) are considered to be extremely sensitive to low concentrations
of silver .while other fish species (e.g., bluegill) are not. Some toxics may disproportionately affect
certain components of the food web at low concentrations while others can adversely affect
species/genera in various levels of the food web at ambient concentrations. For example, the
pesticide atrazine tends to be most toxic to phytoplankton and aquatic plants compared to other
groups of organisms (fish, zooplankton, benthic invertebrates).13 This is not surprising given that
it is an herbicide and was developed for a specific mode of action (inhibition of photosynthesis).
Other contaminants exhibit effects at multiple levels of the food web at relatively narrow
concentration ranges.
Figure 5-4 illustrates how species can vary in their sensitivity to a pollutant.14 As shown,
each data point on the horizontal axis represents a given toxicological effect concentration for an
individual species (here it is the LC50 which is the concentration that is lethal to 50 percent of the test
population). As one can see, the acute sensitivity of aquatic animals to cadmium (as measured by
the acute LC50) varies from 1.6 ug/1 (for the brown trout) to 8,300 ug/L (for the goldfish, not
labeled). The corresponding values on the vertical axis represent the cumulative rank order
(expressed as a cumulative percentage) of the number of tested species that would be affected at least
at a 50 percent lethal level. Thus, as the concentration increases, a greater proportion of aquatic
species would be adversely affected.
13 Solomon et al, 1996, Figure 17
14 U.S. EPA, 1985a.
5-26
-------
Figure 5-4. Acute Sensitivity Distribution of Freshwater Species Exposed to Cadmium
100%,
> 80%
0)
1" 60%
H
ib
0
I 40%
i
0 20%
0%
1
-
8
channel catfish •
N. Squawfish S^
American eel
\
£• ^\mayfly
' m A ,
^•r \snail
salmon Z? — —__ isopod
/ Daphnia m
trout / A w
• ^^
\vorm
10 100 1,000 10,000
Species Acute Value (LC50 in ug/L)
• Fish
® Zooplankton
A Benthic Invertebrates
Source: Species Mean Acute Values from EPA Aquatic Criteria Document (U.S. EPA, 1985a)
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JUNE 1997
As shown in this figure, trout are more sensitive to cadmium than are certain species of
zooplankton, while other species such as mayfly and snail are more sensitive than eels or channel
catfish. Similarly, the vertical axis shows that about 45 percent of the community of tested species
would be adversely affected at or below the LC50 for American eel, while just 2 percent of the
aquatic species tested would be affected at the LC50 corresponding to trout (or, alternatively, 98
percent of the tested species are less sensitive to cadmium compared to trout). EPA typically sets
aquatic life criteria at a concentration that corresponds to the fifth percentile of species effect
concentration, therefore theoretically protecting 95 percent of aquatic species. In this instance, the
California cadmium criteria of 4.3 ug/liter would provide protection for most species indicated,
except for some species of trout.
Exhibit 5-6 presents more detailed information on the specific adverse effects of five of the
14 pollutants across species and populations. As shown, all five of these pollutants can cause
adverse impacts to all types of organisms, from reducing productivity and reproduction in
zooplankton (copper), to adversely affecting reproduction in birds (estrogenic pesticides, mercury,
and selenium), to impairing behavior in fish (mercury and copper). Additional information on the
ecological effects of particular pollutants is provided, below.
Mercury
Mercury is among the more toxic of all heavy metals and is of great concern in both
freshwater and estuarine waters in California. Mercury can bioaccumulate to concentrations nearly
100,000 times greater than concentrations in ambient waters.15 The biological effects of mercury
are extensive and widespread and adversely affect all trophic levels, from aquatic plants and
invertebrates to fish, birds, and mammals. Impacts include behavioral abnormalities (inability to
capture food, erratic behavior, hyperactivity, and impaired maternal-young response), impaired
immune response, blindness, inhibited growth and development, decreased reproductive success and
death. Mercury may cause mutagenic, teratogenic, or carcinogenic effects to aquatic organisms.
15 U.S. EPA, 1992.
5-28
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Exhibit 5-6
ECOLOGICAL EFFECTS FROM SELECTED CHEMICALS
Organlim
Population
Examples of Documented or Predicted
Adverse Impacts in Selected Areas of
California
Copper
Inhibited growth, enzyme activity; reduced
survival, fry growth, productivity,
reproduction, and blood osmoregularity;
significant change in blood chemistry;
decreased biomass; depressed olfactory
response and feeding; asynchronous
spawning; deformity; death.
Local disappearance of species; reduced
species abundance (benthos).
Some waterfowl in San Francisco
Bay/Delta; Aquatic species in some parts of
Sacramento River. Reduced abundance,
diversity and health of benthos in San'
Francisco Bay; impaired spawning
invertebrates SF Bay;
Mercury
Abnormal mitotic activity; neurological
effects; muscular atrophy; impaired growth
and developmentincreased rate of
respiration, reduced cardiovascular function,
damage to internal organs; weight loss;
spinal cord damage; impaired immune
response; behavioral abnormalities; adverse
reproductive effects and behaviors; loss of
equilibrium; sluggishness; inability to
capture food; abnormal motor coordination;
hyperactivity; reduced predatory success
and muscular coordination; impaired
coordination, response rate and speed of
response of young to maternal calls; death.
Reduced breeding success (fish and
birds); population declines (fish and
birds); high susceptibility to infection and
infestations of parasites (birds).
Some piscivorous wildlife, including birds
and mammals throughout the State;
California clapper rail; populations of
salmon, steel head, and other trout species
in upper tributaries" of Sacramento River;
some threatened and endangered (T&E)
species.
Selenium
reduced larvae growth; inhibited growth;
pathological changes in gill tissue;
degeneration and dysfunction of internal
organs; swelling; chromosomal aberrations;
teratogenic effects intestinal lesions;
reproductive impairment; asynchronous
spawning; decreased hatching rates; high
rate of deformed bird embryos; reproductive
failure; growth retardation; behavioral
modifications; death
Reduced abundance of birds and fish;
reduced reproductive success (birds);
some population declines (birds).
San Francisco Bay/Delta waterfowl,
bivalves and fish; impaired spawning
invertebrates SF Bay; Salton Sea avian
wildlife; some aquatic-dependant wildlife
in Central Valley; some T&E species.
-------
Exhibit 5-6
ECOLOGICAL EFFECTS FROM SELECTED CHEMICALS
Organism
Population
Examples of Documented or Predicted
Adverse Impacts in Selected Areas of
California
Endosulfan,
DDT and
Other
Estrogenic
Pesticides
reproductive impairment; reduced fertility;
eggshell thinning; decreased hatching rate;
behavioral modifications; reduced breeding
success; reduced growth; death
Local disappearance of avian species;
some population declines.
Fish kills (bass.shad) throughout the State;
some fish populations throughout the State;
California Brown Pelican; some avian and
fish populations in San Francisco Bay/Delta.
Some T&E species.
Silver
inhibited copper synthesis; phytotoxicity;
metal-induced stress in benthos; inhibited
growth; increased mortality; induced
selenium-vitamin E deficiency symptoms;
enlarged heart; edema; CNS effects; kidney
congestion; degenerative aspects in liver and
kidney; decreased biomass production;
coma; death.
population loss; species loss
Reduced benthos diversity and health, and
decline of some fisheries in San Francisco
Bay; some waterfowl in San Francisco
Bay/Delta; decline of some diving birds in
SFBay dependant on bivalves.
CNS = Central Nervous System; Estrogenic pesticides are those that are associated with the disruption of normal endocrine and reproductive
functions. Estrogenic pesticides include banned pesticides like DDT and toxaphene, as well as currently-used pesticides, such as endosulfan.
Sources: USEPA, December 19^-1. Smith and Flegal 1993; EPA Ambient Water Quality Criteria for Silver, Copper, Mercury, Selenium; Luoma
and Phillips, 1988; Sanders and Cibik, 1988; USFWS, May 1993; Lemley, 1992; Pease, 1995; Schwarzbach, 1996; Ohlendorf and Fleming, 1988;
Larry Walker Associates, 1993; Skorupa, 1993; Fry, 1996; Thompson, 1996; Luoma and Cloem, 1982; Brown, 1996; Setzler-Hamilton, 1988;
USGS 1990; USGS 1993; USEPA June 1991; USFWS, May 1992.
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JUNE 1997
Mercury is a pollutant of particular concern in San Francisco Bay and in rivers and lakes
throughout the state. For example, mercury is considered the primary pollutant of concern in the San
Francisco Bay for one endangered species of bird (California clapper rail). Recent studies indicate
that mean sediment concentrations of methyl-mercury (the more toxic form of mercury) in the bay
approach calculated toxicological thresholds of about 3 ng/g.16 Maximum methyl-mercury
concentrations in sediments of the North Bay (12.5 ng/g) and the South Bay (25 ng/g) exceed the
toxicological thresholds by a factor of five and 10, respectively, and approach levels believed to be
associated with more severe effects. Furthermore, mercury concentrations in Clapper Rail eggs were
reported to be the most contaminated in the San Francisco Bay estuary. In addition, mercury has
been identified as a likely contaminant of concern for waterfowl and other avian species in the San
Francisco Bay/Delta based on a hazard evaluation of reported concentrations of mercury in bird
tissues or eggs (see Exhibit 5-10 and discussion in the latter part of this chapter).17
Mercury concentrations in California fish may also reach levels that are hazardous to
piscivorous wildlife (see Exhibit 5-7). This exhibit shows a cumulative frequency distribution of
total mercury concentrations found in various species offish in California rivers and streams. These
data are taken from the California Environmental Protection Agency's Toxic Substance Monitoring
Database.18 Since mercury residues in fish have been shown to correlate with fish size, the data
shown here are for sizes commonly consumed by piscivorous wildlife (less than 30 cm in length).
Also shown in Exhibit 5-4 are toxicological threshold concentrations determined for methyl-mercury
in the diet of avian and mammalian species. Since the vast majority (i.e., >95 percent) of total
mercury in fish occurs in the methylated form, comparisons between total mercury in fish to
toxicological thresholds for methyl-mercury are appropriate.
The data presented in Exhibit 5-7 indicate that while the majority of mercury concentrations
in fish fall below the avian and mammalian toxicological thresholds, mercury in some samples of
fish may be hazardous to piscivorous wildlife. Specifically, mercury concentrations exceed the avian
toxicological threshold in about six percent of the samples and the mammalian toxicological
threshold in about two percent of the samples.
16 Schwarzbach et al., USFWS, 1996.
17 Ohlendorf and Fleming, 1988.
18Rasmussen, 1994.
5-35
-------
Exhibit 5-7. Mercury Residues Reported in California Fresh Water Fish
In Relation to Dietary Hazards to Wildlife
100%
80%
ro--
0)
g" 60
ro
Q>
I 40%
3
20
'0-
6% > 0.5 ppm
2%>l.lppm
n=265
0.5 ppm avion reproductive
LOAEL
1.1 ppm mammalian
NOAEL
H 1 1—I I I I
0.1 1
Hg Fish Tissue Cone, (mg/kg w.w.)
10
Source: Fish fillet mercury data from CA Toxics Substance Monitoring Program Database
(Rasmussen 1994). Data from fish < 30 cm in length.
Avian dietary Lowest Observed Adverse Effect Level (LOAEL) from 3-generation study of
mallard by Heinz (1979).
Mammalian dietary No Observed Adverse Effect Level (NOAEL) from 93-day methylmercury
study of mink by Wobeser et al. (1976).
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JUNE 1997
Mercury discharges to the Sacramento River can be particularly damaging. For example,
mine drainage from Iron Mountain Mine contains high concentrations of mercury (along with other
toxics) and has disrupted migration behavior and lowered reproduction rates in populations of
salmon, steel head, and other trout species that spawn in the upper tributaries of the Sacramento
River.19 Sources of mercury include both industrial and municipal point sources as well as runoff
from inactive mines.
Selenium
Selenium is much more acutely and chronically toxic at low concentrations in fresh water
systems than in marine systems. Freshwater fish are particularly sensitive to ambient concentrations
of selenium. Potential adverse effects include impaired reproduction (including sterilization of
adults and larval mortality) and impaired physiology, deformities, and reduced growth. Current
selenium criteria may not be stringent enough to adequately protect some aquatic-dependant wildlife
species. Since many chemicals are not highly bioaccumulative, this practice is generally acceptable.
However, in a few instances, chemicals are highly bioaccumulative and toxic to life in higher trophic
levels within the surrounding ecosystem.20
Selenium, like other chemicals such as PCBs, mercury, and chlorinated pesticides, has also
been shown to bioaccumulate and biomagnify to levels that can adversely affect wildlife at
environmentally realistic concentrations. For instance, some studies have shown that, depending on
the form, selenium can bioaccumulate 200,000 times by zooplankton when water concentrations of
selenium are in the parts per billion.21 Typical bioconcentration factors for selenium range between
500 and 35,000.
As a trace element, selenium is an essential part of wildlife diets. In larger quantities,
however, selenium is toxic. It is important to note that there is a very narrow tolerance between
beneficial and toxic doses. Generally, selenium concentrations that are ten times higher than normal
19
Larry Walker Associates, March 1993.
20 U.S. Fish and Wildlife Service recommends a criterion of 2 ug/1 to fully protect aquatic and
aquatic-dependant wildlife. '
21Lemley, 1992.
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JUNE 1997
background concentrations are sufficient to cause adverse biological effects.22 Adverse effects to
birds exposed to selenium through the food web include reduced survival, inhibited reproduction,
reduced growth, behavioral modifications, gross deformities, immuno-suppression, and death. In
addition, selenium contamination poses carcinogenic, mutagenic and teratogenic risks. Elevated
concentrations of selenium may also drastically alter wildlife and fish community structure by
excluding sensitive species and allowing proliferation of less desirable species.
Major human sources of selenium in California include agricultural drainage and point
sources such as industrial dischargers (e.g., oil refineries). Elevated levels of selenium are estimated
to impair numerous aquatic ecosystems throughout the state, although many wetlands, rivers and
streams have yet to be evaluated. Based on California WQA data, we estimate that of all the waters
that have been assessed, nearly 119,000 acres of bays, 3,000 acres of estuaries, 29,000,acres of lakes,
2,000 miles of rivers and streams, 286,000 acres of saline lakes and 9,000 acres of wetlands are
contaminated with selenium at levels that may adversely affect both aquatic life and water-dependant
wildlife. San Francisco Bay, the Central Valley, and the Colorado River Basin are areas particularly
afTected by selenium contamination. Selenium has been identified as a contaminant of concern for
waterfowl in the San Francisco Bay/Delta based on a hazard evaluation of reported concentrations
of selenium in bird tissues or eggs (see Exhibit 5-10 and discussion in the latter part of this
chapter)." Additional research has shown that food web bioaccumulation of selenium in bivalves
and fish in Suisan Bay (which is part of San Francisco Bay) is currently at levels which cause
embryo malformation and reproductive failure in birds which are continuously exposed.24
The impact of selenium contamination drew national attention at Kesterson National Wildlife
Refuge in California when selenium was identified as the cause of the disappearance offish, the
decrease in aquatic bird hatching rates, and the extremely high (64 percent) rate of deformed and
dead bird embryos. Currently, the San Francisco Bay/Delta has a 5 ug/1 criteria level in effect. In
addition, several California Water Boards have promulgated a more stringent 2 ug/1 criteria to protect
22 Skorupa, 1993.
23 Ohlendorf and Fleming, 1988.
24 Michael Fry, "Organic Contaminants and Selenium: Implications for Waterfowl in the Bay,"
in 3rd Biennial State of the Estuary Conference, October 1996.
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fish and wildlife from bioaccumulation of selenium. A more thorough discussion of selenium wildlife
impacts is presented in the Salton Sea Case Study in Chapter 6 and in a separate document assessing
the potential economic benefits of a selenium wildlife criterion in California.25
Copper and Silver
Copper and silver are two metals that are extremely toxic in relatively low concentrations and
have been identified as contaminants of concern throughout the State. Copper can bioaccumulate
in shellfish up to 30,000 times the concentration in the water while silver can bioaccumulate in
shellfish/fish up to 3,000 times its ambient levels. In freshwater and saltwater, zooplankton and fish
are particularly sensitive to low concentrations of copper and silver. Adverse chronic impacts to fish
from these two chemicals include impaired reproductive impacts (premature hatching and reduced
survival) and reduced growth. Impacts to invertebrates include impaired growth and delayed
spawning. Asynchronous spawning is potentially deleterious to any organism that depends on
external fertilization, which is typical of most bottom-dwelling invertebrates.26
Silver has been identified as a contaminant of concern throughout San Francisco Bay.27
Metal-induced stress among benthos in the south Bay has been specifically associated with elevated
silver concentrations in sediments.28 It has been proposed that elevated silver concentrations may
have limited primary productivity, reduced species diversity of benthos, and contributed to the
decline of fisheries throughout the estuary.29 Recent research in San Francisco Bay indicates that
increasing concentrations of copper, silver and other metals in North Bay waters are correlated with
25 See U. S. EPA, 1997 Potential Benefits of a Selenium Criterion to Protect Wildlife in
California.
26 Janet Tompson, et al., "Response of Potamocorbula amurensis to Riverine Inputs and
Pollutants in Suisan Bay," in 3rd Biennial State of the Estuary Colnference, October 1996.
27 Based on a comparison of silver concentrations measured in mussels from San Francisco Bay
and mussels located in 63 other locations in North American estuaries and the northeast Pacific
coastal waters, silver contamination of benthic organisms in the southern part of San Francisco Bay
may be greater than or equal to that of any other estuary in North America (see Smith and flegal,
1993).
28 Luoma and Phillips, 1988.
29 Luoma and Cloern, 1982.
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decreased condition index of bivalves, a measure of organism health.30 Not only does this suggest
that current ambient concentrations of copper and silver may be adversely affecting the growth of
individual invertebrates in this estuary, but that these physiological effects might ultimately reduce
the abundance or survival rate of bivalve populations. A reduction in these bivalve populations
could potentially lead to changes in the availability of food for bottom-feeding fish and diving birds.
In addition, the abundance of healthy clam populations is hypothesized to be crucial for controlling
potentially problematic algae growth in parts of San Francisco Bay.31
Both copper and silver have been identified as potential contaminants of concern for
waterfowl in the San Francisco Bay/Delta based on a hazard evaluation of reported concentrations
of copper or silver in bird tissues or eggs32 (see Exhibit 5-10 and discussion in the latter part of this
chapter). In addition, both chronic and acute impacts associated with discharges of copper and silver
from mines are a problem throughout California, particularly in the Sacramento River (see
discussion in the latter part of this chapter).
Endosulfan. DDT and Other Organochlorine Pesticides: Estrogenic Pesticides
Observed levels of organochlorine pesticide contamination in California waters are
associated with the disruption of normal endocrine and reproductive functions, and in some areas
have caused severe impacts on entire populations offish and birds.33 Many of the organochlorine
and organotin pesticides act in a manner that mimics the natural sex hormones of organisms.
Estrogenic pesticides include banned pesticides like DDT and toxaphene, as well as currently-used
pesticides, such as endosulfan.
The endocrine and reproductive disruptions associated with exposures to estrogenic
pesticides in California are believed to account, in part, for observed declines in fish populations.
In addition, bird species at the top of the food chain, such as the California brown pelican (a Federal
30 Cynthia Brown, "Effects of Chronic Metal Contamination in Suisun Bay on Resident
Populations of Bivalves," in 3rd Biennial State of the Estuary Conference, October 1996, (p. 17).
31 Brown, 1996.
32 Ohlendorf and Fleming, 1988.
33 This section is based on data and information presented in Pease, 1995.
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endangered species) are threatened by relatively high levels of pesticide residues in their tissues.34
Other bird species such as gulls have been adversely affected by DDT's capacity to mimic estrogen.
Populations of western gulls in southern California, for example, decreased markedly in the 1970s
because of reproductive damage caused by bioaccumulate DDT in their diet.35 It is important to note
that although DDT was banned in the United States in 1962 and in Mexico in 1983, DDT continued
to be released because it was present as a manufacturing impurity in dicofol, an acaricide used on
cotton, one of the major crops in California. DDT and other banned chemicals are highly persistent,
and consequently can continue to adversely affect organisms for decades following their ban. The
entire aquatic food chain — from aquatic plants to zooplankton, up to higher trophic levels of aquatic-
based wildlife — has been contaminated with these chemicals because of their high persistence and
high bioaccumulative capacity.
One currently used pesticide, endosulfan, shares many of the hazardous characteristics of the
largely banned group of organochlorine pesticides. Endosulfan tends to persist in the environment
and can bioconcentrate in animal tissues. It can inhibit growth and productivity of aquatic plants and
adversely impair reproduction in invertebrates. Endosulfan has been implicated in more fish kills
in California than any other pesticide and is one of the most frequently detected pesticides in State
monitoring programs. Because of its persistence, acute toxicity, and high bioconcentration factor,
endosulfan received the highest hazard rating from the National Oceanic and Atmospheric
Administration of 35 pesticides currently in use in the U.S.36
Pesticides such as these have been identified as likely contaminants of concern for avian
species such as the snowy egret and black-crowned night heron in the San Francisco Bay/Delta based
on a hazard evaluation of reported concentrations of DDE and other organochlorines in bird tissues
or eggs (see Exhibit 5-10 and discussion in the latter part of this chapter).37 In addition, field studies
34 Department of Fish and Game, State of California, 1991. "Annual Report on the Status of
California State Listed Threatened and Endangered Animals and Plants."
35Fryetal, 1987.
36 NO AA, 1992.
37 Ohiendorf and Fleming, 1988.
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in the San Francisco Bay Delta area suggest that one of the factors contributing to the decline of
striped bass populations is increased toxic pollutant burdens of chlorinated hydrocarbon residues,
including DDT and other estrogen-mimicking pesticides, which have adversely affected both egg
production and egg and larval survival.38
TOXIC POLLUTANTS AND THREATENED AND ENDANGERED SPECIES
California is one of the most biologically diverse areas in the world. Within its 160,000 square
miles of land, and hundreds of thousands of acres and miles of estuaries, wetlands, rivers, streams and
lakes, California harbors more unique plants and animals than any other state in the nation. The
diversity of climates, landscapes, and habitats, and all the barriers to migrations such as mountains
and deserts, have led over thousands of years to the evolution of a large number of isolated species
and varieties of animals, many of which are found only in California.39 For example, there are 46
species of amphibians, 96 species of reptiles, 563 species of birds, 190 species of mammals, 8,000
species of plants and 30,000 species of insects recorded in the State. The 63 types of freshwater fish
are unique in that a high percentage of them are endemic to the state, that is they are found nowhere
else.40
Unfortunately, California's biota diversity is threatened. On average, over 20 percent of the
naturally occurring species of amphibians, reptiles, birds, and mammals are classified as endangered,
threatened or of "special concern" by State and Federal Agencies. Sixty-three percent of California's
fish species and subspecies are extinct, endangered or declining (Moyle and Williams, 1990).41
California has more threatened and endangered species than any other state in the country. Many of
these species exist in or are dependant upon aquatic resources during all or part of their lives, and
consequently may be adversely affected by toxic discharges to surface waters.
38 Eileen Setzler-Hamilton, et al., 1988 "Striped Bass Populations in Chesapeake and San
Francisco Bays Two Environmentally Impacted Estuaries," Marine Pollution Bulletin, Volume 19,
No. 9. p. 466-477
39Steinhart. 1994
40 Moyle, 1994.
41 Moyle, P.B and J.E. Williams, 1990. "Biodiversity loss in the temperate zone: decline of the
native fish fauna of California." Conservation Biology 4:475-484.
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In an evaluation of threats to imperiled freshwater fauna in the United States (including
California) experts concluded that toxic pollutants remain a serious threat for nearly 25 percent of
all species evaluated.42 Previous studies reported that the most important threats generally fall within
the categories of habitat destruction and fragmentation (73% of extinctions), followed by introduced
species (68%) and chemical pollution (38%). Threats to aquatic species seldom act alone; less than
seven percent of federally listed fishes have a single overriding threat to their survival, whereas more
than 40 percent had five or more major threats.43
California defines a species as endangered if it is:
• a native species or subspecies;
• a bird, mammal, fish, amphibian, reptile, mollusca, crustacean, insect or other
animal, or a plant in serious danger of becoming extinct throughout all, or a
significant portion of its range; and
• affected by loss of habitat, change in habitat (including degradation by
pollutants) over exploitation, predatiori, competition, or disease.
A threatened species is one that is likely to become endangered in the foreseeable future in the
absence of special protection provided by the Act.44 Federal definitions of the terms "endangered"
and "threatened" are essentially the same as the state definitions.
Many factors determine the vulnerability of a species and any single or multiple set of
environmental stressors can contribute to a species' decline or extinction.45 Some are inherent
properties of the organism or species, and impart vulnerability whether the stressor is natural or
42 Species evaluated included fishes, crayfishes, dragonflies and damselflies, mussels, and
amphibians. See Richter, et al., 1997, in press, Threats to Imperiled Freshwater Fauna for more
detailed discussion of these results.
43 Wilcove, J.E., and M.J. Bean, editors, 1994: The Big Kill. Environmental Defense Fund,
Washington, DC.
44 California Fish and Game Code, Sec. 2067.
45 For a more detailed discussion of factors, see Elliott Norse, Threats to Biological Diversity in
the United States, September 1990.
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JUNE 1997
properties of the organism or species, and impart vulnerability whether the stressor is natural or
anthropogenic. Others result largely from the nature of anthropogenic stresses. Vulnerability factors
include small effective population size (e.g., number of breeding males and females), species with
a narrow geographic distribution, those with large area requirements, and those "amphibious"
species requiring more than one type of habitat. Species requiring a particular type of habitat or
food, and species intolerant of disturbance are at greater risk. Species of large organism size are
vulnerable despite the advantages of large size because many natural and anthropogenic stresses
(e.g., hunting) select against large organisms. Similarly, organisms with slow reproductive rates are
more vulnerable to increases in mortality.
The major anthropogenic factors most affecting the survival of declining and/or threatened
and endangered (T&E) species include intentional taking (e.g., hunting, trapping, fishing, and
collecting), physical alteration of habitat (e.g., conversion of wetlands to agricultural or urban land),
fragmentation of habitat, introduction of alien species, climate change, air pollution, and water
pollution. Although physical alteration is by far the major factor contributing to the
decline/extinction of a species, discharges of toxic pollutants, particularly pesticides, and other
chemicals that bioaccumulate and move up the food web, can also represent a serious threat.46
Currently there are 151 Federally listed species in California: 122 Endangered species (68
of which are plants) and 29 Threatened species (eight of which are plants).47 Exhibit 5-8 presents
a list of these species. Pursuant to Section 7(a) of the Endangered Species Act (ESA), EPA is
consulting with the U.S. Fish and Wildlife Service (FWS) and the U.S. National Marine Fisheries
Service concerning this rulemakSng. As part of this consultation, EPA has developed an Effect
Determination Matrix to evaluate the effects of some identified issues and chemicals that FWS
indicated might be of concern. These include: bioaccumulation (e.g., pesticides, mercury, and
selenium); the use of dissolved metals standards; and synergistic, additive, or antagonistic effects
of combinations of proposed criteria (e.g., mercury, arsenic, lead, cadmium, copper, and zinc). In
addition, FWS has identified several contaminants that might be adversely affecting T&E species.
These include: mercury, lead, zinc, cadmium, copper, selenium, pentachlorophenol, acrolein,
chlorine, and boron.
Currently, EPA is informally consulting with FWS on these issues. Based on current
information, however, it appears that threatened and endangered species throughout ;the State may
be exposed to adverse levels of toxics, and that reducing these discharges to meet water quality
criteria may be a factor contributing to the future recovery of these species. Species of particular
46 Norse, 1990.
47 Draft Endangered Species Effect Determination Matrix, U.S. EPA Region 9, prepared for
California Toxics Rule Endangered Species Act Consultation, 1995.
5-44
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Exhibit 5-8
CALIFORNIA TOXICS RULE ENDANGERED SPECIES ACT CONSULTATION
EFFECT DETERMINATION
STATUS COMMON NAME
FISH
E Bonytail chub
E Colorado squawfish
T Delta smelt
E Desert pupfish
T Lahontan cutthroat trout
T Little Kern golden trout
E Lost River sucker
E Modoc sucker
E Mohavetulchub
E Owens pupfish
E Owens tui chub
T Palute cutthroat trout
E Razorback sucker
PT Sacramento spfittail
E • Shortnose sucker
E Tidewater goby
E Unarmored threesplne stickleback
E Winter-run chlnook'salmon
AMPHIBIANS
PE Arroyo southwestern toad
PE California red-legged frog
E Desert slender salamander
E Santa Cruz long-toed salamander
REPTILES
PE Alameda whipsnake
E Blunt-nosed leopard lizard
T Coachella Valley fringe-toed lizard
E Desert tortoise
PT Rat-tailed homed lizard
T Giant garter snake
SCIENTIFIC NAME
Gfla elegans
Ptychocheilus luclus
Hypomesus transpacificus
Cyprinodon macularius
Oncorhynchus clarid henshawi
Oncorhynchus myWss white!
Dettlstes luxatus
Catostomus mfcrops
Glla bteolor mohavensls
Cyprinodon radiosus
Glla bicolor snyderi
Onchorynchus clarid selenlris
Xyrauchen texanus
Pogontehthys macrotepidotus
Chasmistes brevfrostris
Eucyclogobius newberryl
Gasterosteus aculeatus wllllamsoni
Oncorhynchus tshawytscha *
Bufo mlcroscaphus caDfomlcus
Rana aurora draytonil
Batrachoseps aridus
Ambystoma macrodactylum croceum
Masticophis teteralis euryxanthus
Gambelia (=Crotaphytus) sllus
Uma inomata
Gopherus (=Xcrobates) agasslz!)
Phrynosoma mealltl
Thamnophis gigas
-------
T Island night lizard
E San Francisco garter snake
BIRDS
T Aleutian Canada goose
E American peregrine falcon
E Bald eagle
E California brown pelican
E California clapper rail
E California condor
E California least tern
T Coastal California gnatcatcher \
T Inyo brown townee
E Least Belts vireo
E Light-footed clapper rail
T Marbled murretet
T ' Northern spotted owl
T San Ctemente sage sparrow
E Short-tailed albatross
PE Southwestern willow flycatcher
T Western snowy plover (coastal population)
E Yuma clapper rail
MAMMALS
E Amargosa vole
E Fresno kangaroo rat
E Giant kangaroo rat
E Morro Bay kangaroo .rat
E Pacific little pocket mouse
E Point Arena mountain beaver
E Salt marsh harvest mouse
E San Joaquin kit fox
T Southern sea otter
E Stephen's kangaroo rat
E Tipton kangaroo rat
INVERTEBRATES
T Bay checkerspot butterfly
.PE Behren's silverspot butterfly
E California freshwater shrimp
PE Calliope silverspot butterfly
Xantusia (=Wauberina) riverslana
Thamnophis sirtalis tetrataenia
Branta canadensis (eucopareia
Falco peregrfnus anattim
Hallaeetus leucocephalus
Pelecanus occidental californicus
Rallus longirostris obsoletus
Gymnogyps califomianus
Sterna antiflarum (=albifrons) browni
Polioptila callfornica californfca
Pipllo fuscus eremophilus
Woe belli! pusillus
Rallus longirostris levipe
Brachyramphus marmoratus
Strix occidentalis caurina'
Amphlspiza belli clementeae
Diomedea albatrus
Empidonax traillil extlmus
Charadrius alexandrinus nivosus
Rallus longirostris yumanesis
Microtus californicus scirpensis
Olpodomys nitratoides exilis
Dipodomys ingens
Dipodomys heermanni morroensis
Perognathus tongimembrls pacificus
Aplodontia rufa nigra
Reithrodontomys ravfventris
Vulpes macrotis mutica
Enhydra lutris nereis
Oipodomys Stephens!
Olpodomys nitratoides nitratoides
Euphydryas editha bayensis
Speyeria zerene behrensii
Syncaris pacifica
Speyeria callippe callippe
CALIFORNIA TOXICS RULE ENDANGERED SPECIES ACT CONSULTATION
EFFECT DETERMINATION
-------
E Conservancy fairy shrimp
E Delhi Sands flower-loving fly
T Defta green ground beefo
E El Segundo MM butterfly
T Ksm prtmrosa gphins moth
PE Lagura Mountains sMpp»
E lange's metalmark butterfly
E Longnom fairy shrimp
E Lotls blue butterfly
E Mission blue butterfly
E Mono shoulderband snafl
PE Mount Hermon June beetle
E Myrtles's silverspot butterfly
E Palos Verdes blue butterfly
PE Qulno checkerspot butterfly
E Riverside fairy shrimp
E San Bruno elfin butterfly
PE San Diego fairy shrimp
PE Santa Cruz rain beetle
E Shasta crayfish
E Smith's blue butterfly
T Valley elderberry tonghom beetle
T Vernal pool fairy shrimp
E Vernal pool tadpole shrimp
PE Zayante band-winged grasshopper
PLANTS
E Amargosa nttrewort
E Antioch Dunes evening-primrose
T Ash Meadows gumplant
E Baker's stickyseed
E Bakersfield cactus
£ Beach fayia
E Ben Lomond spinefiower
E Ben Lomond wallflower
PT Big-leaved crown beard
PE Braunton's milk-vetch
E Burke's goldfiefete
E Butte County meadowfoam
Branchinecta conservatte
Rhaphtomidas terminatus abdomlnaia
Etaphru* vWdta
Euphftrtra (-ShfmiaaaldM) tattaUn tfyn
EuproMrpinm tuttrpe
Pyrgu» runts togunac
ApodemJa mormo langH
BrancrUnecta tengtontenra
Lycaeldea argyrognoiiion totte
Icarida tearteWes messtenenste
Helminthoglypta wafkeriana
Polyphytla barbata
Speyerla zerene myrtleae
Glaucopsyche lygadamus palosverdesensis
Euphydryas editha qulno
Streptocepahlus woottoni
Incisalla rnossD bayensto
Branchinecta sandtegoensis .
Pleocoma conjungens conjungens
Paclfastacus fortls
Euphflotes (=Shijimlaeoldes) enoptes smith!
Desmocsrus cafifomlcus olmorphus
Branchinecta lynchi
Lepldurus packardl
Trimerotropis Infantilis
Nirophila mohavensls
Oenothera dettoides ssp. howefli
Grindelia fraxino-pratensis
Blennosperma baked
Opuntia treleasei (= O. basilaris var. treteaseO
Layiacamosa
Chorizanthe pungens var. hartweglana
Erysimum tetetlfofium
Verbesina dlssrta
Astragalus brauntonfl
Lasthenia burkei
Umnanthes Roccosa ssp. caflfomtea
CALIFORNIA TOXICS RULE ENDANGERED SPECIES ACT CONSULTATION
EFFECT DETERMINATION
-------
E California Orcutt grass
E California jewefflower
PE California sea-blite
PT Carpentaria
PE Chinese camp brodiaea
E Chorro Creek bog thistle
E Clover lupine
PE Coachefla Valley milk-vetch
PT Colusa Grass
PT . Conejo dudleya
PE Contra Costa goWfields
E Contra Costa wallflower
E Coyote eeanotnus
E Cushenbury buckwheat
E Cushenbury milk-vetch
E Cushenbury oxytheca
PE Cuyamaca Lake downingia
PT Del Mar Mesa sand aster
PE Del Mar manzantta
PE El Dorado bedstraw
PT Enclnltls baccharls
E Eureka Valley evening-primrose
E Eureka dune grass
PE Few flowered navarretia
PE Fish Slough milk-vetch
PT Fleshy owTs-clover
E Fountain thistle
E Cambers watercress
PE Greene's tuctorla
PE Hairy Orcutt grass
PE Hartweg's golden sunburst
PE Hoover's spurge
T Hoover's wooly-star
E HowelFs spineflower
PE Indian Knob mountainbalm
PE Kelso Creek monkey flower
E . Kem mallow
PE Lake County stonecrop
Orcuttia California
Caulanthus califomicus
Suaeda callfomica
Carpenteria californlca
Brodiaea paltlda
Cirsium fontinale var. obtepoense
Lupinus tldestromil
Astragalus lentlginosus var. coachellae
Neostapfla colusana
Dudleya abramsll ssp. parva
Lasthemfa conjugens
Erysimum capftatum ssp. angustatum
Ceanothus ferrisae
Eriogonum ovalifolium var. vineum
Astragalus albens
Oxytheca parish!) var. goodmanlana
Downlngia con var. brevier
Corethrogyne fllaginifolla var. Rnifolia
Arctostaphyka glandulosa ssp. crasslfofia
Galium caDfomicum ssp. sierrae
Baccharfs vanessae
Oenothera avfta ssp. eurekensls
Swatlenia alexandrae
Navarretia leucocehala ssp. pauciftera
Astragalus lentiglnosus var. pisclnensls
Castilleja campestris ssp. succutenta
Cirsium fontinale var. fontinale
Rorippa gambellii
Tuctoria greenei
Orcuttia pilosa
Pseudobahia bahiifolla
Chamaesyce hooveri
Eriastrum hooveri
Chorizanthe noweflii
Ericdictyon altissumum
Mimubus snevocleii
Eremalche kernesis
Parvisedum leiocarpum
CALIFORNIA TOXICS RULE ENDANGERED SPECIES ACT CONSULTATION
EFFECT DETERMINATION
-------
PE Lane Mountain milk-vetch
E Large-flowered fiddleneck
PT Layne's butterweed
E Loch Lomond coyote-thistle
PE Lyon'3 pentachaeta
PE Many dowered navarretia
PT Marcescent dudleya .
PT Marin dwarf-flax
PE Mariposa pussypaws
PE Maripose lupine
E Marsh sandwort
E McDonald's rock-cress
E Menzies' wallflower
PE Metcalf Canyon jewelflower
E Monterey gilia
T ' Monterey spineflower
E Morro manzanita
PE Munz*s onton
PE Orcutfs splneflower .
E Otay mesa mint
E Palmate-bracketed birrfs-beak
T Parish's daisy
PT Parish's meadowfoam
E Pedate checker-mallow
PE Peirson's milk-vetch
E Penndrs birrfs-beak
PE Pine Hill ceanothus
PE Pine Hill flannelbush
E Ptemo clarkia
PT Piute Muntains navarretia
E Presidio (-Raven's) manzanita
E Presidio clarWa
PT Rawhide Hill onion
PT Red Hills vervain
E Robust spineflower
PE Sacramento Orcutt grass
E Salt marsh bird's beak
T San Bentto evening-primrose
Astragalus jaegertanus
AmsincMa grandiflora
Senecto layneae
Eryngium constancei
Pentachaeta lyonli
Navarretia knicocephala sp. plieantna
Dudleya cymosa ssp. marcenscens
Herperolinon congestum
Calyptridium pulchellum
Lupinus citrtnum var. deflexus
Arenaria paludicola
Arabls macdonaldiana
Erysimum menziesii
Streptanthus albidus sp. albidus
Gilia tenuiflora ssp. arenaria
Chorizanthe pungens var. pungens
Arctostaphylos morroensb
Allium munzil
Chorizanthe orcuttlana
Pogogyne nudiuscula
Cordylanthus palmatus '
Erigeron parish)!
Umnathes gracilis ssp. parishH
Sidalcea pedata
Astragalus magdalenae var. peirsortfl
Cordylanthus tenius ssp. capillaris
Ceanothus roderickii
Fremontodendron califomicum ssp. decumbens
Clarkia speciosa var. Immaculata
Navarretia setitoba
Arctostaphylos hooker! (=pungens) ssp. ravenii
Clarkia franciscana
Allium tuolumnense
Verbena califomica
Chorizanthe robusta
Orcuttia viscida
Cordylanthus maritimus ssp. maritimus
Camissonia benitensis
CALIFORNIA TOXICS RULE ENDANGERED SPECIES ACT CONSULTATION
EFFECT DETERMINATION
-------
E San Bernardino Mountfans Nadderpod
PT San Bruno manzanfta
E San Clements Island Indian paintbrush
E San Clemente Island broom
E San Clemente Island bush-mallow
E San Clemente Island larkspur
E San Diego button-celery
E San Oiego mesa mint
•
PE San Francisco lessingia
PE San Jacinto Valley crownscale
PE San Joaquin Valley Orcutt grass
PE San Joaquin adobe sunburst
E San Joaquin wooly threads
E San Mateo thommint
PE . San Mateo woody sunflower
E Santa Ana River wooly-star
E Santa Barbara Island live-forever
PE Santa Clara Valley dudleya
E Santa Cruz cypress
PT Santa Monica Mountains dudleya
E Sebastopol meadowfoam
PT Shiny milk-vetch
PE Short-leaved dudleya
PT Slender Orcutt grass
E Slender-horned splneflower
E Slender-petaled mustard
PT Sodaville milk-vetch
E Solano grass
E Sonoma spineflower
PT Spreading navarretia
T Spring-loving certtaury
PT Springvflle clarkia
PE Stebbin's Morning-glory
PT Thread-leaved brodiaea
PE Tiburon jewelftower
E Tiburon mariposa lily
E Tiburon paintbrush
PE Triple-ribbed milk-vetch
lesquereRa Wngfl ssp. bemardtna
San Bruno Mountain manranita
Castffleja grisea
Lotus dendroMeus ssp. trasMae
Malaconthamnus dementinus
Delphinium variegatum ssp. Wnklense
Eryngium aristulatum var. parishD
Pogogyne abramsil
Lessingia germanorum
Atriplex coronata var. notatior CRITICAL HABITAT ALSO
Orcuttla inaeqalls
Pseudobahia peirsonii
Lembertia congdonii
Acantftomlntha duttonil -A. obovata ssp. d.)
Erfophyllum latllobum
Eriastrum densifollum ssp. sanctorum
Dudleya trasMae
Dudleya setchellii
Cupressus abramslana
Dudleya cymosa ssp. ovatffofla
Limnanthes vinculans
Astragalus lentlginosus var. micans
Dudleya blochmaniae ssp. brevifofla
Orcuttla tenufs
Dodecahama (=Centrostegia) teptoceras
Thelypodium stenopetalum
Astragalus lentlginosus var. sesquimetralis
Tuctoria (-Orcuttla) mucronata
Chorizanthe valida
Navarretia foHalis
Centaurium namophilum
Clarkia springvellensis
Calystegia stebbinsil
Brodiaea filifolia
Streptanthus niger
Calochortus tiburonensis
Castilleja affinis ssp. neglecta (=C. neglecta)
Astragalus trlcarinatus
CALIFORNIA TOXICS RULE ENDANGERED SPECIES ACT CONSULTATION
EFFECT DETERMINATION
-------
E Truckee barberry
PT Verity's dudtoya
T Water howeflla
E Western dry
PE White-rayed pentachaeta
Berberis («Mahonla) sonnH
Oudleya verity)
HowelDa aquatilis
Ulium occWentato
Pentachaeta bellWlftora
Listed and Proposed Species Administered by the Fish and Wildlife Service
Endangered Species • 122 (plants • 68)
Threatened Species • 29 (plants • 8)
Total Number Listed Species • 151 (ptanb) • 78)
Total Number of Proposed Species • 71 (plants • 56)
•Administered by the National Marine Fisheries Service
CALIFORNIA TOXICS RULE ENDANGERED SPECIES ACT CONSULTATION
EFFECT DETERMINATION
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JUNE 1997
concern are higher trophic level predators at the top of the food chain. The Delta smelt, Delta
pupfish, Sail Joaquin kit fox, California brown pelican, Bald eagle, and California clapper rail
include some of the species that have been listed. Although we do not have a map to illustrate the
location of endangered species at risk throughout the State, Figure 5-5 shows the location of natural
areas in California where a great many T&E species are observed either permanently or seasonally.48
Reducing discharges of toxic pollutants to aquatic ecosystems throughout the State,
particularly chemicals that are highly persistent, bioconcentrate readily, and are highly
bioaccumulative, may contribute to the improved conditions for the successful recovery of many
Federal and State threatened and endangered species, and may significantly contribute to increased
biodiversity in many areas of the State. It is important to note, however, that some current criteria
(e.g., selenium and mercury) may not be stringent enough to adequately protect some aquatic-
dependant wildlife species.
ILLUSTRATIVE ECOLOGICAL RISK ANALYSIS:
THE SPECIES SENSITIVITY DISTRIBUTION APPROACH
Given the complexity of ecological interactions and the range of adverse impacts of all the
pollutants covered by the CTR, it was outside the scope of this report to estimate precisely the degree
to which achieving the water quality criteria would improve species, populations, and communities
of organisms currently affected by toxic pollution. This section discusses one approach, which relies
on comparing pollutant exposure information to species sensitivity distributions, for characterizing
the link between reduced pollutant concentrations and the likelihood of reduced harmful exposures.
Recently, various aquatic ecological risk assessments have relied upon comparisons of
exposure data to the entire distribution of species sensitivity (e.g., Figure 5-4) for characterizing
ecological risk.49 Such approaches offer advantages because they can help describe the likelihood
(probability) that certain types of impacts would occur and some indication of the severity of direct
4)1 Source: California Dept. Fish and Game, Natural Heritage Division, 1995. Significant natural
areas are identified using biological criteria only, and may occur on public or private land. They
include: areas supporting extremely rare species or natural communities; areas supporting
associations or concentrations of rare species or communities; areas exhibiting representative
examples of common or rare communities; and areas of high species-richness or habitat-richness.
49 USEPA, April 1995; Solomon et al., 1996.
5-52
-------
Figure 5-5
Significant Natural Areas
in California
\
-------
JUNE 1997
impacts based on the proportion of species likely to be affected at a given exposure concentration.
As shown in Figure 5-4, different species of aquatic organisms differ widely in their sensitivity to
a given pollutant (in this case, acute exposures to cadmium). Such species sensitivity distributions
form the basis of EPA water quality criteria. To develop the distributions, the sensitivities of aquatic
species to a contaminant are ranked in ascending order according to a common metric (in this case,
the acute LC50). Next, the cumulative frequency of each observation is determined based on its rank
order and the total number of observations. The cumulative frequency or probability for each species
sensitivity is then converted into a z-score assigned from the standard normal distribution. The z-
scores (standard normal deviates) and corresponding contaminant concentrations (log scale) are
regressed to derive the cumulative species sensitivity distribution. Interested readers are referred to
the U.S. EPA, April 1995 and Solomon, et al., 1996 for a comprehensive discussion of the analytical
process and assumptions underlying this methodology.
With some modification, species sensitivity distributions can be applied to analyze the
potential benefits of the California Toxics Rule. The broad scope of the rule — both with respect
to the pollutants addressed and the ecological resources affected — makes a comprehensive
application of this approach impractical. For illustrative purposes, however, we apply the approach
using data on copper concentrations in the Sacramento River and several of its acid mine impaired
tributaries (Figure 5-6). Shown in Figure 5-6 is the cumulative distribution of acute sensitivity of
aquatic species to copper. The observed acute sensitivity range for copper is from 9 ug/L for one
species of the zooplankton, Daphnia. to 10,240 ug/L for one species of stonefly. As shown, the
range of concentrations reported for several sites severely affected by copper-contaminated acid
mine drainage (2,000 ug/L to 15,000 ug/L) exceeds the LC50 values for 90 percent or more of the
tested species. For less adversely affected sites along the Sacramento River, the maximum
concentration reported (18 ug/L) exceeds the LC50 value for about six percent of the tested species.
Notably, the proposed copper criterion (9 ug/L) equals or exceeds the LC50 value for less than two
percent of the tested species. Thus, reductions in copper discharges to meet the proposed criterion
would afford substantial protection (e.g., up to 90 percent or more for the affected sites) to a range
of aquatic species.
POPULATION, COMMUNITY AND ECOSYSTEM IMPACTS
Ecosystems are complex and dynamic functional systems that consist of all the living biotic
communities and their physical environment, made up of all living organisms, their remains, and the
minerals, chemical and resources on which they depend for their survival and reproduction. For the
most part, we have focused on describing the impacts to individuals from toxics covered by the CTR
5-53
-------
Figure 5-6. Selected Copper Concentrations Measured in the Sacramento River
Basin Site Compared to Acute Sensitivity Distribution of Aquatic Species
100%
>
u
c
0>
3
U"
£
u.
0)
+3
J5
3
E
3
O
98% 4-
84%
50%
16%
2%
0%
.'
x*
yr
I ,
f Max. of
S selected
4 Sacramento
^ River Sites
/ (2)
>
•<
•
•
•
Copper-
impaired
streams
*— *
*•
1
AWQC (9.0 ug/L)
100 1,000 10,000 100,000
Species Acute Value (ug/L)
Notes:
(1) Concentration ranges from 2.000 to 15,000 ug/l measured at Spring Creek, Town Cr., W. Squaw Cr., Clear Lk., &
Spring Cr. Dam (as cited by Larry Walker Associates, 1992).
(2) Concentrations up to 18 ug/L measured in selected sites of Sacramento River, including Shasta & Keswick Dam,
Colusa, Freeport & Hood sites (as cited by Larry Walker Associates, 1992).
Each data point denotes a Species Mean Acute Value (i.e., cone, killing 50% of individuals) for various aquatic
species, Source: U.S. EPA, 1985b.
-------
JUNE 1997
because data are most readily available for these types of effects. To describe all of the potential
ecological benefits associated with toxics-reductions to California waters, however, we need to
describe impacts that might be occurring at the population and community level.50
The effects of toxics on ecosystem structure and function above the organism level are
complex, because of the diversity of species assemblages and the variety of trophic interactions
between populations in aquatic food webs. Exhibit 5-9 summarizes the measures of ecosystem
integrity and "health" that can be affected by toxics, to the detriment of the individual, the
population, the community, and the ecosystem. Several authors have predicted the specific adverse
effects of toxic stress at the ecosystem level.51 These impacts to the structural components of
ecosystems include reduced size and life-span of organisms; shortened or altered food chains;
decreased species diversity and increased dominance of selected species; reduced number of native
species; changes in standing crop biomass; and changes in predator/prey relationships. Under toxic
stress, sensitive individuals and species can be reduced and/or eliminated and may not return until
stress is removed (and assuming a species source is available for recolonization). Surviving species
may exhibit broad tolerance, rapid reproduction, or resistance to the toxicant.
Toxic effects become ecologically significant for populations when they affect the survival,
productivity, or function of a significant number of individuals such that population size is reduced,
population structure is altered, or total function is impaired.52 Population size can be reduced when
toxic stressors reduce mating success or egg production; reduce survival of offspring or
reproductive-age adults; increase susceptibility to predation,, parasitism, and disease; affect
recruitment through altered immigration or emigration rates; or reduce development or maturation
rates. Population structure can be altered when stressors have different effects on one age group or
development stage, reduce development or maturation rates, or differentially affect one sex. The
resulting changes in species/population composition and number may lead to alterations in
community function, the shortening of food chains, or a reversal of normal successional trends.53
50 A population is a group of organisms of the same species generally occupying a contiguous
area and capable of interbreeding. A community is an assemblage of populations living in a
prescribed area or physical habitat that have a functional and compositional unity. A community
may be relatively independent or dependant on neighboring assemblages.
51 See Odum, 1985; Rapport et al, 1985; Schindler, 1987; Schaeffer, 1988; Caims, 1992;
Rapport,1995;
52 Cockerham and Shane, 1994.
53 Caims, et al, 1992.
5-55
-------
JUNE 1997
EXHIBIT 5-9
POTENTIAL EFFECTS OF TOXIC STRESS ON AQUATIC ECOSYSTEMS
Organism Impacts
Disease
Mutation
Reproduction
Physiology
Growth
Acclimation
Individual behavior
Survival
Population Impacts
Intraspecific behavior:
territoriahty, dominance
Reproduction: mortality,
survivorship, fecundity
Physiology
Adaption
Disease frequency
Population survival
System Level Impacts:
Community/Ecosystem
Decomposition
Gross/net'primary production
Relative energy flow to grazing and
decomposer food chains
Recovery
Resiliency/Stability
Resistance
Species diversity
Species abundance
Food web diversity
Community composition
Source: Cairns, 1982; Odum, 1985; Schindler, 1987; Schaeffer, 1988; Cockerham et al, 1994.
5-56
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JUNE 1997
Adverse impacts to ecosystem function from biotic exposure to both acute and chronic toxics
can include changes in important processes such as primary production, nutrient cycling, or
community respiration; changes in relative energy flow to grazing and decomposer food chains; and
changes in mechanisms of, and capacity for, dampening undesirable oscillations.54 Ultimately, toxic
stress has the potential for reducing the overall stability and diversity of aquatic ecosystems.55
It is difficult to measure comprehensively the toxic-induced ecological effects at the
population and community level because of the complexity and diversity of species assemblages and
their interactions in the food chain. Further, changes in ecological interactions that might be
indicative of toxic stress may be difficult to identify relative to natural variability or other
confounding environmental impacts (e.g., habitat loss). One such study that is illustrative of the
potential impact of toxics on trophic relationships within an ecosystem, and offers some insight into
the potential adverse effects of contaminants transferred through the ecosystem, is a study of
phytoplankton in the Chesapeake Bay.56 The study showed that phytoplankton assemblages
exhibited rapid, large shifts in species composition and succession of dominant species in response
to low-level metal contamination. This resulted in dramatically altered phytoplankton communities
and affected succession of dominant species, suggesting a potential to significantly affect higher
trophic levels which feed on the phytoplankton (e.g. zooplankton, fish). In addition, the arsenic-
induced changes in species composition and species succession, and the associated shift in carbon
transfer within the estuary, was predicted to contribute to the problem of oxygen depletion in bottom
waters of the Bay. Consequently, the chronic loading of arsenic was thought to have potentially
serious implications for the estuary as a whole.
Summary of California Population Effects
Few studies have evaluated or predicted the adverse effects of chronic level loadings of
pollutants to the different trophic levels in California ecosystems. Because structural effects (e.g.,
loss of sensitive species) are easier to measure than functional endpoints (e.g., community
respiration), and because functional endpoints may be somewhat less sensitive to toxic effects than
structural properties in certain ecosystems with functional redundancy (where several species may
perform similar functions), there are more data and research available on the adverse toxic impacts
54 Schaeffer et al, 1988.
55 D.J. Rapport, et al, 1985.
56 Sanders and Cibik, 1988,
5-57
-------
JUNE 1997
to species diversity, size distribution, and population declines.57 The majority of toxics-associated
trophic level effects that we have been able to document for California have also been at the
population level, and include reduced recruitment, increase in disease, and changes in abundance.
Reducing loadings of toxic contaminants to California waters to meet water quality criteria may
significantly contribute to the eventual recovery of selected populations, and improve the overall
health and stability of aquatic ecosystems. Some specific examples are described below.
Exhibit 5-10 presents a summary of a hazard evaluation for waterfowl and other avian species
from selected pollutants found to be contaminating bird tissues or eggs in populations in San
Francisco Bay and the Delta. The exhibit shows that mercury, selenium, DDE, and PCBs are
occurring in concentrations in some samples that are equal to or greater than those associated with
adverse effects. Wildlife species potentially affected include Greater scaup, Lesser scaup, Surf
scoter, and Black-crowned night heron. Other contaminants such as silver, cadmium, copper, zinc,
DDE, PCBs, and other organochlorines are occurring in elevated concentrations to warrant some
concern. Species potentially affected include Greater scaup, Lesser scaup, Surf scooter, Black-
crowned night heron, Caspian tern, and Forster's tern.
Raptor populations (e.g., peregrine falcons and bald eagles) in California have increased from
historic lows that were caused by a variety of stresses, including DDT and other pesticides.
Populations of the California brown pelican, California clapper rail, and California gull have
similarly increased. Despite this recovery, however, populations of these birds generally remain
below historic levels, which may be partly a result of the continuing impacts from bioaccumulate
toxics.
Migratory shorebird populations are extremely vulnerable to environmental stresses, in part,
because they concentrate on a relatively small number of traditional stopover sites on their long
journeys to and from their northern and southern feeding grounds (Figure 5-7 illustrates the
migratory routes of these shorebirds). Shorebird populations have been declining throughout
California (e.g., San Francisco Bay, Monterey Bay, and Newport Bay). Destruction of habitat,
combined with toxic pollutant stresses (e.g., PCBs and pesticides) and other stresses are believed to
be contributing to the decline of these bird populations.
57 Unfortunately, testing focused on single species cannot predict numerous effects that would
be expected at the community and ecosystem level. For example, single species toxicity tests can
underestimate ecological effects when pollutants bioaccumulate or when a pollutant eliminates key
species or adversely affects species performing key ecosystem functions. (Cairns, et al., 1992).
5-58
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JUNE 1997
Exhibit 5-10
HAZARD EVALUATION OF ENVIRONMENTAL CONTAMINANTS IN BIRD TISSUES
OR EGGS FROM SAN FRANCISCO BAY DELTA*
(From Ohlendorf and Fleming, 1988)
Species
Waterfowl
Mallard
Northern pintail
Northern shoveler
Canvasback
Greater scaup
Lesser scaup
Surf scoter
Trace Elements
Ag
Cd
Cr
Cu
Hg
Ni
Organochlorines References**
Pb Se Zn DDE PCBs Others
ND
ND
ND
ND
+
ND
+
ND
ND
ND
ND
+
ND
+
ND
ND
ND
ND
-
ND
-
ND
ND
ND
ND
+
ND
+
ND
ND
ND
ND
-
ND
-H-
ND
ND
ND
ND
-
ND
-
ND - ND ND ND ND 1
ND ND ND - - - 2
ND - ND ND ND ND 3
ND + ND ND ND ND 3
- - - ND ND ND gJJ
ND -H- ND ND ND ND 1,3
++ + ND ND ND 1,3,4,5,6,7,9
Other species
Double-crested
cormorant
American bittern
Snowy egret
Block-crowned
night heron
American coot
Black-necked Milt
American avocet
Willct
Caspian tern
f-oiMcr's tern
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND.
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND'
?
+
ND
ND
ND
ND
7
7
ND
ND
ND
ND
ND
ND
' ND
ND
ND
ND
ND ? ND ND ND ND 1,10
ND - ND ND ND ND 3
ND ND ND + + + 11,12
ND ND ND ++ -H- + 11,13,14
ND - ND ND ND ND 1,3,15,16
ND - ND ND ND ND 1,15,16,17
ND - ND ND ND ND 1,15,17'
ND - ND ND ND ND 1
ND ND ND + + + 11
ND ND ND + + + 11
'Listed as follows, based upon field or laboratory determinations with these or other avian species:
"•*+" ° reported concentrations in some samples are equal to or greater than those associated with adverse effects;
"+" = reported concentrations are elevated to warrant some concern although effect levels are not well known,
"•" = reported concentrations are not elevated in comparison with other areas or are below the known effect level;
*"•" Q relative status unknown (because comparative or effect levels are not known);
"ND" ° no data available
••References I - White ei. at. (1987), 2 = Ohlendorf and Miller (1984), 3 = White el. al. (1988),
4 o Mem? (I97Q), 5 = Vermeer and Peakall (1979), 6 = Di Giulio and Scanlon (1984), 7 = Ohlendorf el. al.
(198(>c and in press c). 8 = Gochfeld and Burger (1987), 9 = Heinz el. al. (1987), 10 = King and Cromartie (1986),
11 ° Ohlendorf rt at (in press a); 12 = Ohlendorf el. al. (1979), 13 = Ohlendorf el. al. (1978), 14 = Hoffman el. al.
(1986). 15 = Ohlendorf ei. al. (1987), 16 = Presser and Ohlendorf (1987), 17 = White and Cromartie (1985).
5-59
-------
Figure 5-7
Shorebird Migration Patters of the Western Hemisphere
DELIA
Northward
Migration
NAaONAUS
• HEMISPHERIC:
>500jOOO ShoraUrdi
or 30H of th* Population
• INTERNATIONAL:
>100jOOO Shore birds
or 15H of the Population
• REGIONAL:
>20,000 Shonbirds
or 5% of A» Population
rczco
OPPOUHI
lACOAOOPDZI
Southward
Migration
FDECO
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JUNE 1997
Colonial wading birds are in significant decrease nationwide and declines are most serious
in California and Florida, where there has been almost total collapse of a wading bird population that
once numbered in the hundreds of thousands.58 In California, these include birds such as black-
crowned night herons and egrets. Although habitat loss due to wetland conversion represents the
key stressor, pesticide pollutants and contaminants associated with irrigation return flows (e.g.,
selenium, arsenic, mercury, etc.) have had significant local impacts.59
Waterfowl populations in California may also be at risk from selenium and pollutants that
move through the food web and contaminate food sources. As described in Chapter 6, population
declines of waterfowl in the Salton Sea may be caused, in part, by exposure to selenium and
pesticides.60 Migrating waterfowl populations that use California estuarine areas as staging areas
along the Pacific Flyway, have also been declining.61 Contaminants thought to be adversely
affecting migratory waterfowl include cadmium, selenium, and mercury. Migratory birds wintering
in the Imperial Valley, where they bioaccumulate DDT, suffer reproductive problems in their
northern breeding grounds, suggesting potential population impacts.62
Disease is a major cause of declining populations of waterfowl wintering in the Delta, San
Francisco Bay, and throughout the State.63 The effects of disease are compounded as populations
concentrate in increasingly small habitat areas. Overcrowding, poor habitat and water quality, and
adverse weather may contribute to the spread of diseases such as avian cholera and botulism. For
instance, the San Francisco Bay/Delta are two of the four areas in the State considered to be focal
points of avian cholera. Expansion in the range of cholera outbreaks during the last 40 years is
thought to be a result of interactions among the disease, habitat deterioration, and increasing
pollution from chlorinated pesticides.64
58 Ogden, 1987.
59 Norse, 1990.
60 Pease, 1995.
61 U.S. EPA, 1992.
62 Pease, 1995.
63 U.S. EPA, 1992.
64 McLandress, 1983.
5-61
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JUNE 1997
Finally, other recent studies suggest that adverse population impacts occurring in California
could be attributable, in part, to toxic pollutants. Toxic water quality is a contributing factor in the
decline of winter-run chinook salmon populations that utilize the Sacramento River.65 It has been
proposed that elevated silver concentrations may have limited primary productivity, reduced species
diversity of benthos, and contributed to the decline of fisheries throughout the San Francisco Bay
Delta estuary.M Other field studies in this estuary/delta suggest that one of the factors contributing
to the decline of striped bass populations is increased toxic pollutant burdens of chlorinated
hydrocarbon residues, including DDT and other estrogen-mimicking pesticides, which have
adversely affected both egg production and egg and larval survival.67
Additional research has shown that food web bioaccumulation of selenium in bivalves and
fish in Suisan Bay (which is part of San Francisco Bay) is currently at levels which cause embryo
malformation and reproductive failure in birds which are continuously exposed.68 This recent data
indicates an increasing reproductive risk to waterfowl populations (e.g. scaup and scoters) wintering
in San Francisco Bay. Resident harbor seal populations in the Bay may also be adversely affected
by PCB contamination, which has been measured in seal tissue at levels associated with immune
suppression and reduced reproductive capacity.
Potential Biodiversity Effects
California's aquatic ecosystems include trophic webs of phytoplankton, invertebrates, fish,
birds, mammals and other organisms that are all intricately connected to each other by the complex
flow of matter and energy. Reducing toxic discharges and exposures that result in increased health
and stability of individuals and species will also help to contribute to improving and maintaining the
health and survival of other species, populations, and communities throughout the food web. This
65 Department of Fish and Game, State of California, 1991.
66 Luoma and Cloern, 1982.
"Eileen Setzler-Hamilton, et al, 1988.
68Michael Fry, 1996.
5-62
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JUNE 1997
benefit - improving and maintaining biodiversity69 in the ecosystem ~ is significant because the
resilience and stability of most ecosystems (the rapid recovery from any kind of natural or man-made
disturbance) is based, in part, on the presence of many stable and healthy species and populations.70
Data and time constraints have prevented us from performing an in-depth evaluation of the
biodiversity benefits that might bl associated with reducing toxic discharges in California to meet
water quality criteria. It is possible, however, to use information derived from a national assessment
of impacts affecting biodiversity to make some general conclusions about biodiversity benefits in
California associated with reducing toxics to meet water quality criteria.
As described earlier, many factors determine the vulnerability of species, and any single or
multiple set of environmental stressors can contribute to a species decline or extinction.71 Some are
inherent properties of the organism or species, and impart vulnerability whether the stressor be
natural or anthropogenic. Others result largely from the nature of anthropogenic stresses. The major
anthropogenic factors affecting the survival of declining and/or threatened and endangered (T&E)
species include intentional taking (e.g., hunting, trapping, fishing, and collecting), physical alteration
of habitat (e.g., conversion of wetlands to agricultural or urban land), fragmentation of habitat,
introduction of alien species, climate change, air pollution, and water pollution. Although physical
alteration is by far the major factor contributing to the decline/extinction of a species, discharges of
toxic pollutants, particularly pesticides, and other chemicals that bioaccumulate and move up the
food web, also represent a serious threat.72
Exhibit 5-11 presents a summary and ranking of factors affecting biological diversity in
freshwater and marine systems throughout the United States. As shown, pesticides and discharges
from industrial facilities (defined primarily as toxic pollutants) can represent very serious threats.
In freshwater systems, pesticides and toxics from industrial sources can represent a very serious
threat to insects in streams; fish, mollusca and algae/submerged aquatic vegetation (SAV) in rivers;
and fish, insects and algae/SAV in lakes/wetlands. They can also pose substantial impacts to fish,
69 Biodiversity refers to the variety of life forms, the ecological roles they play, and the genetic
diversity they contain (see Angermeir, et al., 1994).
70Odum. 1993.
71 For a more detailed discussion of factors, see Elliott Norse, Threats to Biological Diversity in
the United States, September 1990.
72 Norse, 1990.
5-63
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EXHIBIT 5-11 Overview off Threats to Biological Diversity
in the Contiguous 48 States
O Minor impact
Substantial impact
Very serious threat
Lack of or conflicting Information
'Air
WMIM pollutants
CO
uv-a
Climatic
NudMr
*»•!••
FRESHWATER
Stream
Amphibians
Intact*
0
o
Producers
o
0?
o
o
o
o
o
Rlvar
Birds
£
©
0
o
o
o
o
Raptllas
O
0
o
O
o
0
o
o
AmpMMans
0
0
0
0
o
o
o
o
0
o
Fishes
o
0
o
o
o
o
o
o
Molluscs
0
o
o ?
o
o
0
o
o
0
Insects
o
0?
0
o
0
o
o
o
Emerg Plants
o
o
©
0
o
o
Algas/SAV
0
0 ?
o
o
O
o
o
o
Lake/Wetland
Birds
6
o
©
0
O
o
0
O
0
o
o
Amphibians
O
o
0?
0 ?
0
0
o
o
o
O
o
Fishes
O
o
0
o
Molluscs
O
o
0
o
0
o
o
O
o
Insects
o
o
0 ?
0
o
0
o
o
0
O
o
Emerg Veg
0
o
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0?
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0
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Source; None. 1990.
0
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-------
EXHIBIT 5-11
Overview of Threats to Biological Diversity
In The Contiguous 48 Stales
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7 Lack of or conflicting Information
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-------
JUNE 1997
birds, amphibians, mollusca and other biota in all freshwater systems. Finally, pesticides are also
suspected of adversely affecting the diversity of a large number of other categories of biota (e.g.,
amphibians, mollusca, and emerging vegetation) although data are quite limited on these effects.
Impacts in marine systems are less pronounced, although still substantial. Industrial discharges can
result in substantial impacts to nearly all biota in estuarine and nearshore areas. The effects of
pesticides on these systems are much less known other than representing a potentially substantial
impact to birds in estuarine areas.
The information presented here suggests that toxic discharges in California could potentially
represent a serious threat or substantial impact to biodiversity in freshwater systems and may present
a substantial threat to biodiversity in marine ecosystems. It is important to note that as the
magnitude and scope of these threats continue to increase, and as new threats continually appear,
interactions between stressors will become more important. While currently not well studied or
understood, interactions between two or more stressors could produce cumulative effects which are
far more destructive than the individual threat alone. This suggests that although toxic-related
threats to biodiversity often are not as serious as other factors (e.g., physical habitat alteration) they
must be considered and addressed to ensure adequate protection of biodiversity.73
TOXIC REDUCTIONS AND POTENTIAL ECOLOGICAL
BENEFITS OF THE CALIFORNIA TOXICS RULE
When the State of California implements the NPDES permit program, as well as other non-
regulatory programs and activities, to achieve water quality standards, it is anticipated that ambient
water quality will improve through reductions in the concentrations of toxics in California's aquatic
systems. California's aquatic ecosystems include food webs of phytoplankton, invertebrates, fish,
birds, mammals, and other organisms that interact with each other through a complex flow of matter
and energy. Because, of this linkage, toxic reductions in ambient waters that result in increased
survival, growth, and reproductive fitness of individuals and populations should contribute to the
health of other ecosystem components, including other species, populations, and communities.
Toxic reductions are anticipated for a variety of metals, pesticides, aromatics, trace elements,
and chlorinated organic contaminants. Exposure of biota to these pollutants at levels exceeding the
resulting water quality standard based on the proposed criteria may result in adverse ecological
effects that will change or alter the structural or functional ability of the organism to survive, grow,
"Norse, 1990.
5-66
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JUNE 1997
and reproduce. Adverse effects of many toxics include increased susceptibility to disease, reduced
growth and development, altered physiology and behavior, impaired reproductive health and
behavior, and if concentrations are high enough, death. Any one of these adverse effects can
ultimately affect the survival, reproductive success, and overall health of a population, which may
affect ecosystem health.
Because all components of ecosystems are linked to each other, improved survival, growth,
productivity, and reproductive capacity of aquatic and terrestrial organisms should translate to
improved ecosystem stability, resilience, and overall health. Specific improvements in ecosystem
health following toxics reductions will depend on the interaction of a variety of factors, including:
the timing, duration, and magnitude of baseline toxics exposure; the rate of toxics reduction
attributable to achieving CTR-based water quality standards; the species assemblages present; the
trophic structure of the system; the reproductive capacity and growth rate of susceptible and tolerant
populations, and the availability of colonizing organisms.
Site-specific benefits for the entire State could not be quantified comprehensively because
of the complexity, scale, and uncertainties of the interaction of the multitude of ecological systems
and toxics to be affected by the proposed rule. However, ecological benefits from the proposed rule
may be substantial because of the extensive variety, proportion, and geographic area of the affected
aquatic systems, the diversity and uniqueness of California ecological resources, and the large
number of toxics to be regulated under the CTR.
EPA concludes that the potential ecologic benefits associated with reducing toxics to meet
CTR water quality criteria include:
• Reductions in toxics loadings are expected to contribute to improved
conditions for fish spawning and/or migration in more than 223,000 acres of
bays/harbors and estuaries, 102,000 acres of lakes, 1,000 miles of rivers and
streams, and 11,000 acres of saline lakes.
• Potential bioaccumulatives of concern that currently threaten fish and wildlife
throughout the State include selenium, mercury, PCBs, dioxins, and
chlorinated pesticides. Mercury concentrations in California fish are
estimated to reach levels that may be hazardous to piscivorous wildlife.
Adverse effects on wildlife are also occurring as a result of exposure to
selenium. Populations that may widely benefit from reduced concentrations
include estuarine and freshwater fish and piscivorous animals, although
current criteria may not be stringent enough to adequately protect some
aquatic-dependant wildlife species.
\
5-67
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JUNE 1997
• Reducing toxic contaminants to meet water quality criteria is expected to help
contribute to improved conditions for the successful recovery of Federal and
State threatened and endangered (T&E) species including species such as the
Delta smelt, Desert pupfish, California brown pelican, Bald eagle, California
clapper rail, California tiger salamander and western snowy plover.
Statewide, T&E species may be at risk from toxics in approximately 180,000
acres of bays, harbors and estuaries, 2,000 river miles, and 230,000 acres of
saline lakes.
• The greatest reductions in the likelihood of adverse toxics-related impacts on
aquatic and terrestrial wildlife will accrue for the San Francisco Bay
Watershed and the Central Valley. These areas have the greatest amount of
toxic loadings and the greatest diversity and richness of species, populations,
and communities.
• Reducing copper discharges to the Sacramento River to meet water quality
criteria is likely to result in substantial protection for 90 percent or more of
the organisms and communities that are currently adversely affected.
• Reduced concentrations of both selenium and pesticides in the waters that
feed the Salton Sea are expected to contribute to improved conditions for the
restoration and maintenance of currently declining populations of wildlife,
including threatened and endangered species. These include the California
brown pelican, peregrine falcon, bald eagle, Yuma clapper rail, and desert
pupfish.
• All components of the ecosystem are linked to each other. Therefore, we
expect that the improved water quality and likely associated improvements
in survival, growth, and reproductive capacity of aquatic and terrestrial
organisms resulting from reduced exposure to toxics will help to contribute
to the increased stability, resilience and overall health of numerous
ecosystems throughout California, and may contribute to protecting, restoring
and maintaining California's rich biodiversity.
LIMITATIONS
The characterization of ecological benefits presented in this chapter is based on
evaluation of indicators of specific effects, rather than detailed modeling and/or direct
measurement of the proposed rule's impact on species, populations, and communities.
5-68
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JUNE 1997
Because such modeling and measurement was beyond the scope of this effort, we cannot
draw comprehensive conclusions about the proposed rule's effect on ail the ecological
benefits that may occur. The benefits described and presented here are only illustrative of
the potential benefits of reducing toxics loadings to California's waters. The total benefits
to organisms, populations, communities and ecosystems throughout the State are likely to
be far greater than those benefits briefly described here and in Chapter 6.
Second, the proposed rule establishes criteria only for concentrations of pollutants
in the water column, and for the most part does not directly address problems associated
either with contaminated sediments or contaminants that have already entered the food web.
The persistence of certain toxic pollutants in sediment and the tendency for many of the most
persistent pollutants to bioaccumulate suggests that some of the benefits associated with
decreased toxic loadings may not be realized immediately.
Third, there has been relatively little scientific research to date on chronic toxic
effects to organisms as compared to acute effects. Data are extremely limited or not
available on chronic effects for many species, particularly for organisms at lower trophic
levels (e.g., phytoplankton and zooplankton). Consequently, some chronic aquatic life
criteria have been established based on as few as five species data sets. In addition, aquatic
life criteria are established to protect only 95 percent of the species. It is possible that the
remaining five percent of the most sensitive species could be keystone species or species
providing functions critical to the survival and health of other organisms and populations,
and thus may not be fully protected. Finally, aquatic life criteria do not take into account
potential synergistic effects of pollutants. As a result, there is considerable uncertainty
concerning the type and range of ecological benefits likely to accrue from reducing chronic
concentrations of toxics. Benefits could either be greater or less than those described here.
Finally, most assessment techniques and data collection efforts used to evaluate toxic
impacts to ecosystems typically assess only isolated components of the ecosystem (usually
organisms) rather than the interactions among ecosystem components. Species interactions
among and between trophic levels are not considered in establishing water quality criteria,
and have not been analyzed in detail in this report. In general, data are sparse on specific
impacts to populations and communities from all toxic pollutants. Further, when population
impacts are evaluated, they usually only describe impacts to higher trophic level consumers
(e.g., birds and mammals). Consequently, the complete range of ecosystem benefits
associated with meeting the proposed water quality criteria are not fully understood, and are
probably understated in this analysis.
5-69
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JUNE 1997
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*
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REFERENCES FOR EXHIBIT 5-10
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selenium. Environ. Toxicol. Chem. 6: 423-433.
Hoffinan, D.J., Rattner, B.A., Bunck, C.M., Krynitsky, A., Ohlendorf, H.M., and Lowe R.W. 1986.
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Ohlendorf, H.M., Marois, K.C., Lowe, R.W., Harvey, I.E., and Kelly, P.R. Environmental
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Presser, T.S., and Ohlendorf, H.M. 1987. Biogeochemical cycling of selenium in the San Joaquin
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Fish and Game, Sacramento.
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CASE STUDIES OF ECOLOGICAL BENEFITS CHAPTER 6
INTRODUCTION
This chapter provides a more detailed description of the range of ecological benefits expected
to occur when toxic pollutant discharges are reduced to meet the proposed water quality criteria for
the State of California. The chapter presents case studies of two areas: the San Francisco Bay
Estuary and the Salton Sea.
Because of time and data constraints, it was not possible to perform a comprehensive
assessment of the benefits of the California Toxics Rule for these two areas. As an alternative, we
have evaluated a range of qualitative and quantitative indicators and other relative measures of
potential ecosystem benefits. We rely primarily upon selected constituent-specific data for these two
sites, using these data to identify potential benefits at the individual, population, and community
level (e.g., decreased mortality rates, enhanced breeding success, increased productivity); where
possible, we also discuss higher trophic level impacts. The limitations of this approach are similar
to those described in Chapter 5.
SAN FRANCISCO BAY
The San Francisco Bay Estuary is the largest estuary on the west coast of the Americas. It
is a highly productive and valuable ecosystem supporting a diversity of plants and animals. It is also
an important economic and recreational resource that is heavily affected by the activities of the
nearly 12 million people who live in the Bay area. An estimated 5,000 to 40,000 tons of over 60
different toxic pollutants enter the Bay daily from more than 50 sewage treatment plants, more than
6-1
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JUNE 1997
65 industrial facilities, and a range of nonpoint sources.1 The introduction of these pollutants into
the ecosystem poses a range of risks. This case study describes these risks and discusses the
potential ecological benefits of reducing toxic pollution inputs to the San Francisco Bay Estuary.
The case study's key findings include the following:
• Toxic contaminants such as mercury, selenium, PCBs, pesticides, cadmium,
and copper have been observed in San Francisco Bay waters, sediments and
organisms at hazardous levels. Scientific data indicate that animals
chronically exposed to these pollutants can experience numerous adverse
effects.
• Reductions in chronic exposures to toxic pollutants are expected to improve
the reproduction, growth, general health, and survival of Estuary biota. In
particular, many species that migrate through the Bay - including chinook
salmon, striped bass, and waterfowl - may benefit from improved breeding
habitat.
• Reductions in cumulative toxic loadings to sediments reduce the possibility
of resuspension of toxics in the water column. Filter-feeding animals such
as clams and other mollusks, which take in suspended solids when feeding,
are among those most likely to benefit from such reductions.
• Reduced toxic inputs to the Bay could improve habitat and enhance lower
trophic-level food supplies, with the potential for contributing to improved
conditions necessary for the recovery of threatened and endangered species
like the California clapper rail, California brown pelican, and American
peregrine falcon.
• Improved water quality conditions in the Bay may also reduce the
bioaccumulation of toxic pollutants in upper trophic levels. It has been found
that upper level predators in the San Francisco Bay Estuary acquire pollutants
of concern through food-web transfer. Predator species that most likely
would benefit from better control of toxics include predatory fish and
piscivorus birds, as well as harbor seals and other piscivorus mammals.
1 This discussion is based upon information provided in two documents: San Francisco
Estuary Project, 1992 State of the Estuary, U.S. EPA and the Association of Bay Area Governments;
and California Regional Water Quality Control Board, Water Quality Control Plan, San Francisco
Bay Basin, Region 2,1986.
6-2-
-------
JUNE 1997
• Because all components of the ecosystem are linked, the improved survival,
growth, productivity, and reproductive capacity of aquatic and terrestrial
organisms resulting from reduced exposure to toxics should contribute to the
increased stability, resilience and overall health of the Bay, and help to
maintain and improve the rich biodiversity of the Estuary.
The remainder of this chapter discusses the geographic setting of the San Francisco Bay
Estuary, its biological resources, the extent to which these resources have been affected by toxic
pollutants, and the potential benefits of reducing concentrations of toxic pollutants in the Bay.
Geographic Setting
California's Region 2, the San Francisco Bay Region, extends over approximately 1,620
square miles of the state's central coast. Figure 6-1 shows the location of major water bodies in this
region. As the figure shows, the region is dominated by the San Francisco Bay Estuary, a complex
of several interconnected water bodies that includes Suisun Bay, Carquinez Strait, San Pablo Bay,
Central Bay, and South Bay. Together these bays cover approximately 470 square miles, or about
30 percent of the area of Region 2, and represent the largest coastal embayment on the Pacific coast
of the United States. Additional detail on the waters that comprise the San Francisco Bay Estuary
is provided below.
• Suisun Bay is an important nursery ground for several fish species. As the
site of an entrapment zone, where high densities of food are brought in from
tidal and freshwater flows, Suisun Bay supports large numbers of
zooplankton, juvenile fish, and small fish species.2 In addition, the Bay is
bordered by Suisun Marsh, the largest brackish marsh in the United States,
covering approximately 57,000 acres.
• Carquinez Strait is a deep, narrow, 12-mile channel that connects Suisun Bay
and San Pablo Bay. It averages 29 feet in depth and is characterized by
strong currents. It also serves as a U.S. Army Corps of Engineers' dredged
material disposal site. The Strait's strong currents often carry dredge spoils
into other areas of the Estuary.
• San Pablo Bay is a large and open bay that averages nine feet in depth. It has
extensive shallows, salt ponds, and a significant riverine freshwater inflow
causing euryhaline conditions (i.e., a wide range in salinity). Few marine fish
2 Herbold, 1992.
6-3
-------
Figure 6-1
MAP OF SAN FRANCISCO BAY ESTUARY AND DELTA
JUNE 1997
or*
6-4
-------
JUNE 1997
inhabit this embayment because of the variations in salinity, but the bay
provides an important passage for migratory fish and a nursery area for
Dungeness crabs. In addition, many migratory waterfowl, shorebirds, and
other birds utilize the habitat the Bay provides. Like Carquinez Strait, San
Pablo Bay is also a major dredge spoil site.3
Central Bay stretches between San Pablo Bay and the Oakland-San Francisco
Bay Bridge. It includes the deepest waters in San Francisco Bay, averaging
35 feet in depth, and is directly affected by marine currents that flow through
the Golden Gate.
South Bay includes the remainder of San Francisco Bay south of the
Oakland-San Francisco Bay Bridge. It is comprised of extensive shallow
areas, salt evaporation ponds, marshes, and mudflats, particularly at its
southern tip.4 The southernmost portion of South Bay, referred to in this
report as the extreme South Bay, has a fairly constant salinity and is
essentially a shallow tidal lagoon with a long residence time, particularly
during periods of low flow.5 During dry periods it receives most of its
freshwater inputs from sewage treatment discharges.6 The extreme South
Bay is also characterized by daytime high tides that promote high organic
productivity and rapid benthic organism growth. This growth is important
in providing food sources for higher organisms in the Estuarine food chain.7
A number of rivers and more than 175 streams drain to the Bay. Among the more significant are the
Sacramento and San Joaquin Rivers of the Delta, the Napa River to the north, and the Guadalupe
River and Alameda Creek to the south. In total, the San Francisco Bay Estuary drains more than 40
percent of California's land area.
3Herbold, 1992.
4Herbold, 1992.
5 U.S. EPA, 1992. State of the Estuary: A Report on the Conditions and Problems in the San
Francisco Bay/Sacramento - San Joaquin Delta Estuary, Region 9 (June).
6 Luoma and Phillips, 1988.
7 Herbold, 1992.
6-5
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JUNE 1997
Biological Resources
An estuary is defined as a partially enclosed body of water that interfaces a fresh water source
with tidal ocean water. This transition zone between salt and freshwater results in a variety of
diverse habitats that support a plethora of biological resources, and creates one of the richest and
most productive types of ecosystems. The San Francisco Bay Estuary has been designated a
National Priority Estuary under Section 320 of the Federal Clean Water Act, a designation based in
part upon its ecological importance. The Bay supports approximately 120 fish species, 380 species
of wildlife (including 255 species of birds, 14 species of amphibians, 30 species of reptiles, and 81
species of mammals), more than 200 species of zooplankton, hundreds of species of phytoplankton,
countless numbers of benthic organisms, and a wide variety of plant life.8
Exhibit 6-1 presents a partial list of biota found in different areas of the Bay, reflecting the
diversity of the ecosystem. For example, the Bay is a major haul-out and pupping area for harbor
seals (see Figure 6-2).9 In addition, the area is a stopover for approximately half of the migrating
shorebirds and waterfowl that travel the Pacific Flyway, with the San Francisco National Wildlife
Refuge, located along South Bay, offering particularly important migratory bird habitat.10 More than
a million waterfowl (see Figure 6-3) utilize the Bay as a staging and wintering area on their
migration routes. The Bay is also an important shorebird staging area (see Figure 6-4), and has been
designated as having hemispheric importance for this purpose by the Western Hemisphere Shorebird
Reserve Network, a recognition given to only three other sites on the western shores of the Americas
(see Figure 6-5).u Resident and migratory bird species common to the Bay area include avocets,
stilts, plovers, sandpipers, phalaropes, grebes, pelicans, cormorants, herons, egrets, gulls,
canvasbacks, greater scaup, lesser scaup, and surf scoter.12
8 USEPA, 1992.
9 Kopec et al., 1994. Harbor seals utilize estuarine sand and mudflats for birthing and
rearing pups. These areas are isolated and undisturbed and provide abundant food sources.
However, these environments also expose the seals to highly polluted areas associated with coastal
urban activities.
10 USEPA, 1992. The Pacific Flyway is a major bird migratory route that extends from
Alaska and Canada south along the U.S. west coast into Mexico. It covers approximately 25 percent
of the continental United States and provides passage for countless waterfowl and shorebirds.
11 USEPA, 1992. The Western Hemisphere Shorebird Reserve Network is a collaborative
effort formed by the World Wildlife Fund, the International Association of Fish & Wildlife
Agencies, and the Academy of Natural Sciences of Philadelphia that coordinates agencies,
conservation groups and other organizations in efforts to protect migratory shorebirds. Sites
declared to be of hemispheric importance host at least 500,000 shorebirds annually or 30 percent of
a species' flyway population.
12 USEPA, 1992.
6-6
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JUNE 1997
Exhibit 6-1
REPRESENTATIVE SPECIES FOUND IN SAN FRANCISCO BAY REGION
Bay
Suisun
San Pablo
Central
South
Entire San
Francisco Bay
Constituents of
Concern
Nickel
Selenium
Chromium sources
Pesticides
Metals .
Selenium
PCBs
Silver
Selenium
Chromium
Copper
Nickel
Silver
Zinc
Selenium
Mercury
Cadmium
Arsenic
PCBs
Trace elements
DDT
Mercury
Dieldrin
Dioxin
Furans
Species
Delta Smelt
Longfin Smelt
Striped Bass
Yellowfin Goby
Opossum Shrimp
Zooplankton
Juvenile/small fish
Sacramento Splittail
Waterfowl
Peregrine Falcon
Striped Bass
Starry Flounder
Longfin Smelt
Yellowfin Goby
Migratory Birds
Dungeness Crab
American Avocet
Chinook Salmon
American Shad
Pacific Herring
Harbor Seal
Loons
Peregrine Falcon
Northern Anchovy
Bay Goby
Bat Rays
Walleye Surfperch
Harbor Seal
Brown
Smoothhound
Eared Grebe
Surf Scoter
Homed Grebe
Diving Ducks
Dabbling Ducks
Asian Clam
Dabbling Ducks
Geese
Tundra Swan
Cranes
White Sturgeon
Tule Perch
Mussel
Suisun Shrew
Scaup
Scoter
Cahvasback
Ruddy Duck
Northern Shoveler
Harbor Seal
CA Brown Pelican
Suisun Shrew
English Sole
Northern Anchovy
Pacific Pompano
CA Brown Pelican
Starry Flounder
White Croaker
SurfPerch
White Croaker
CA Clapper Rail
Salt Marsh Harvest
Mouse
Clams
American Avocet
Topsmelt
Snowy Egret
Shorebirds
Snowy Plover
Habitat
Nursery for young
of year fish
Entrapment Zone
marshes
Open water
Tidal salt marshes
Brackish marshes
Shallows
Large freshwater
inflow
Open water
Intertidal mudflats
Rocky shore
Tidal salt marshes
Brackish marshes
Deepwater
High velocity water
flow
Open water
Rocky shore
Tidal marsh
Salt ponds
Tidal marshes
Freshwater inflow
Intertidal mudflat
Sources: Herbold et al., 1992; Harvey et al., 1992; Moore, 1995; Kopec and Harvey, 1995; Ohlendorf
and Fleming, 1988; State WQA database.
6-7
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JUNE 1997
Figure 6-2
HARBOR SEAL CAPTURE, HAUL-OUT SITES, AND FEEDING AREAS
IN THE SAN FRANCISCO BAY AREA
San Pablo Bay
Pacific
Ocean
'.. Newark Slou&h
HalfMooa
t.Bay
Corterew Slougji'
Greco Uari
Haul-out She
Haul-out and Captara Site
Harbcr seal fe«diit««a« (1 - 7)
NoAtto^J^'/^?
AlvisoSlough
6-8
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JUNE 1997
Figure 6-3
AVERAGE RELATIVE COMPOSITION OF WATERFOWL SPECIES IN THE
SAN FRANCISCO BAY ESTUARY 1987-1990
NORTH BAY SALT PONDS (127.)
E CANVASBACK (22.4%)
H RUOOY DUCK (I9.6X)
F SCAUP (19.2%)
K OTHER QAB8UN6 OUCXS (18.7%)
0 NORTHERN SHOVELER (10.4%)
y AMERICAN COOT (10.4%)
NORTH BAY (30%)
F SCAUP (74.1%)
G SCOTER (18.1%)
J OTHER DUCKS (4 J%)
E CANVASBACK (3.3%)
SUISUN BAY (7%)
SCAUP (47.0%)
CANVAS8ACK (29.9%)
SCOTER (IS.0%)
OTHER DUCKS (7.6%)
SOUTH BAY (12%)
F SCAUP (69.8%)
G SCOTER (30.1%)
J OTHER DUCKS (4.1%)
CENTRAL BAY (16%)
SCOTER (58.7%)
SCAUP (38.8%)
OTHER DUCKS (4.5 *)
SOUTH BAY SALT PONDS (23%)
D NORTHERN SHOVELER (48.4%)
H RUOOY DUCK (19.8%)
L OTHER DIVING DUCKS (10.6%)
K OTHER DABBLING DUCKS (9.5*)
J OTHER DUCKS (7.7%)
C AMERICAN WIGEON (6.2%)
6-9
-------
JUNE 1997
Figure 6-4
Shorebird L'se of San Francisco Bay
= 10.000 individuals
6-10
-------
JUNE 1997
Figure 6-5
SHOREBIRD MIGRATION PATTERNS OF THE WESTERN HEMISPHERE
COFFER
MLXA
Northward
Migration
UABT«1IA«
NAdONALZS
• HEMISPHERIC:
>500,QOO ShoreUrds
or 30H of the Population
• INTERNATIONAL:
> 100,000 Shorebtrds
or 15% of the Population
• REGIONAL:
>20,000 Shorebirdfl
or 5% of the Population
OPFEKAHI
FUZCO
FUZCO
6-11
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JUNE 1997
In addition to providing important habitat for birds and mammals, the San Francisco Bay
Estuary supports a broad range offish species and a large sport fishery, with striped bass, sturgeon,
American shad, white catfish, and starry flounder among the sport fish most popular with
recreational anglers. The region was also once the site of a rich and diverse commercial fishery,
including sardine, herring, smelt, sole, salmon, flatfish, white sturgeon, flounder, anchovy, steelhead
trout, crustaceans, and mollusks. Today, the only fish commercially harvested directly from the Bay
are Pacific herring, Northern anchovy, and Bay shrimp; however, many commercially important fish
species continue to rely upon the estuary as a nursery ground, spawning area, migration route, and
feeding area. For example, two-thirds of California's migratory salmon, which are highly valued as
both a sport and commercial species, pass through the Bay on their journey to and from upstream
spawning grounds. In addition, more than 100 non-sport or non-commercial fish species inhabit the
Bay.
Of additional note in profiling the biota of the San Francisco Bay Estuary are the relatively
large number of rare, threatened, or endangered species that inhabit the region. As shown in Exhibit
6-2, members of several federally listed endangered animal species - including piscivorus birds like
the Bald eagle, California brown pelican, or American peregrine falcon, shorebirds like the
California clapper rail and California least tern, mammals like the Salt marsh harvest mouse, and fish
like the Delta smelt - rely directly or indirectly upon the habitat the Estuary provides.13 Figure 6-6
further illustrates this point, identifying locations at which state or federally listed threatened or
endangered species have been sighted. As the exhibit and map suggest, there is significant potential
for the quality of the Bay's waters to affect area populations of threatened or endangered species.
Nature of Toxics Impairment
The water resources of Region 2 are among the most heavily affected by toxic pollution in
the state of California. As described in Chapter 2, over two-thirds of the region's bays, 60 percent
of its wetland areas, and 39 percent of its rivers and streams are affected by toxics.14 According to
California's 303(d) list, a number of the water bodies adversely affected by toxics in Region 2 are
of significant priority for the state.15 Exhibit 6-3 presents information on these water bodies, which
include all major sections of San Francisco Bay and the Suisun Marsh wetlands, as well as several
of the rivers that discharge to the Bay. California's Bay Protection and Toxic Cleanup Program
(BPTCP) provides further data on key water bodies affected by toxic pollutants. The known toxic
13USEPA. 1994.
14 As elsewhere in this report, we classify as affected by toxics those waters that have been
assessed and rated by the State of California as of medium or poor water quality due, in whole or in
part, to contamination by toxic pollutants.
15 California Report on Impaired Surface Waters, Clean Water Act Section 303(d), May 1994.
6-12
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JUNE 1997
Exhibit 6-2
SPECIES OF CONCERN IN THE SAN FRANCISCO BAY ESTUARY REGION
Species
Greater sandhill crane
^3ald eagle
California Brown Pelican
Aleutian Canada goose
American peregrine falcon
Black rail
California clapper rail
Western snowy plover
California least tern
Alameda song sparrow
San Pablo song sparrow
Suisun song sparrow
Salt marsh harvest mouse
Salt marsh wandering shrew
Suisun ornate shrew
Delta Smelt
Winter-run chinook salmon
Longfm smelt
Spring-run chinook salmon
Sacramento splittail
Green sturgeon
Status
ST
FE.SE
FE.SE
FT.SE
FE.SE
ST, FC1
FE, SE
FC2, SSC
FE,SE
FC2, SSC
FC2, SSC
FC2, SSC
FE.SE
FC1.SSC
FC1.SSC
FE
FE
Species of concern
Species of concern
Species of concern
Species of concern
Location
Delta
northern and eastern periphery of estuary
Central and San Pablo Bays
Suisun Marsh
South and North Bays, Suisun Marsh, Delta
North Bay, Suisun Marsh
South and North Bays, Suisun Marsh
entire bay (nesting in South Bay only)
South and North Bays, Suisun Marsh
South Bay
San Pablo
Suisun Bay
South and North Bays, Suisun Marsh
South Bay
Grizzly Island
Suisun Bay, Delta
South and North Bays, Suisun Marsh, Delta
San Pablo, Suisun, South and Central Bays,
Delta
Central, San Pablo, Suisun Bays, Delta
Suisun Marsh
San Pablo, Suisun Bays
Habitat
brackish/freshwater, seasonal
marshes
open water, brackish & freshwater
marshes
open water, salt ponds
seasonal marshes, fanned wetlands,
grasslands
salt, brackish & freshwater marshes
salt marshes
salt marshes
salt ponds
salt ponds, sandy bayshore
salt marshes
salt marshes
salt marshes
salt marshes
salt marshes
salt marshes
Suisun Bay - river channels, open
water and shoals
open waters to Delta
brackish water
open water, up to and through
Delta
salt marshes
open water, brackish water
FE = federal endangered FC = federal candidate for listing
FT = federal threatened Call = Taxa for which the USFWS has sufficient biological
SE = state endangered information to support a proposal to list as endangered or
ST = state threatened threatened.
SSC = species of state concern Cat 2 = Taxa for which existing information may warrant listing,
but for which substantial information to support a
proposed rule is lacking.
Sources: USEPA. 1994. Regulatory Impact Assessment of the Final Water Quality Standards for the San Francisco Bay/Delta and Critical Habitat
Requirements for the Delta Smelt. December 15, 1994. San Francisco, CA. With technical assistance from Jones & Stokes Associates, Inc.
Sacramento, CA (JSA 94-130).
San Francisco Estuary Project. 1992. State of the Estuary. San Francisco, CA.
Herbold, B., A.D. Jassby, and P.B. Moyle. 1992. Status and Trends Report on Aquatic Resources in the San Francisco Estuary. San
Francisco Estuary Project. Oakland, CA.
6-13
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JUNE 1997
Figure 6-6
SAN FRANCISCO BAY
AND
DELTA AREA
Endangered Species, Land Ownership, and Land Use
Produced By
LKC
USEPA Region 9 GIS Center
November 28, 1995
Endangered
• and
Threatened
Species
Sitings
L/l Agricultural I I Privately
a Owned
Transportation,
Communications, Space
and Utilities
Land Use
Industrial
I I Uiban
State Lands
Federal Lands
County, City,
Regional
Military Bases
10
15 MILES
0 5 10 15 KILOMETERS
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JUNE 1997
Exhibit 6-3
PRINCIPAL WATERBODIES IMPAIRED BY TOXIC
POLLUTION IN SAN FRANCISCO BAY BASIN (REGION 2)
Waterbody
San Francisco Bay, Central
San Francisco Bay, Lower
San Francisco Bay, South
Suisun Bay
Tomales Bay
Calero Reservoir
Guadalupe Reservoir
Herman Lake
Alameda Creek
Alamitos Creek
Guadalupe River
Napa River
Petaluma River
Walker Creek
Suisun Marsh
Pollutants
Metals, selenium1
Metals
Metals, trace elements'
Metals, arsenic
Mercury
Mercury, arsenic, trace
elements
Nickel, trace elements
Mercury
Trace elements
Mercury, trace elements
Pesticides, other toxics
Metals
Metals
Mercury
Metals
303(d) Priority
1
1
1
n/a
3
4
4
5
4
4
4
3
3
4
.1
Area Affected
67,700 acres
79,900 acres
24,500 acres
25,000 acres
400 acres
350 acres
80 acres
110 acres
27 miles
14 miles
30 miles
55 miles
25 miles
25 miles
57,000 acres
Sources: 303(d) list; WQA Data Base
1 A water quality criterion of 5 /ug/1 is currently in effect for the San Francisco Bay/Delta; a more
stringent criterion of 2 /ug/1, designed to protect some species of aquatic-dependent wildlife, has been
implemented in portions of the Delta's Grasslands region.
6-15
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JUNE 1997
hot spots identified by this effort include Suisun Bay proper as well as several wetlands and smaller
bays (Peyton Slough, Boynton Slough, Chadbourne Slough, and Honker Bay); Miller Creek (feeding
the Central Bay); Castro Cove and Richmond Harbor (off of the Lower Bay); Oakland Inner Harbor;
Hunters Point; Redwood Creek; Dumbarton Bridge; and the area south of Dumbarton Bridge
(extreme South Bay).16
The information presented in Exhibit 6-3 includes data on the toxic pollutants responsible
for impairing water quality in Region 2. The exhibit indicates that metals are the most common
source of impairment, although selenium, arsenic, trace elements and pesticides are also problematic.
Exhibit 6-4 expands upon this list, identifying specific pollutants of concern, the nature of the risks
they pose to exposed organisms, and researchers' current understanding of these pollutants' impacts
in San Francisco Bay. The pollutants of concern identified in Exhibit 6-4 include arsenic, cadmium,
chromium, copper, lead, mercury, nickel, selenium, zinc, and PCBs. In addition, recent studies have
found elevated concentrations of dieldrin, DDT, chlordane, dioxins and furans in the tissues offish
from the Bay.17
The sources that contribute to toxic pollution in San Francisco Bay are varied. Exhibit 6-5
summarizes estimated loadings of key toxic pollutants by point sources and other sources, including
upstream sources (i.e., loadings to rivers whose waters flow to the Bay) and urban or non-urban
runoff. As the exhibit indicates, upstream and nonpoint sources account for the majority of loadings
for a number of toxics, including arsenic, cadmium, chromium, copper, lead, mercury, and zinc. In
contrast, point sources discharge slightly more than half of the total quantity of chlorinated
hydrocarbons that enter the Bay, and also account for a significant share of mercury loadings.
Figures 6-7 and 6-8 note the location of the largest of these sources, as indicated by daily mean
discharge volumes during the mid-1980s. As the figures illustrate, major municipal sources are
distributed throughout the Bay region, with several of the largest treatment works discharging to
South Bay; in contrast, major industrial dischargers - including a number of oil refineries, chemical
plants, and a large steel mill - are clustered in the northern reaches of the Bay.18
In addition to the dimensions of the toxics problem described above, it is important to note
that conservative toxic pollutants have accumulated in the sediments of the Bay. For example,
sediments in Grizzly Bay have been found to contain high concentrations of arsenic, chromium,
copper, nickel, and zinc, while sediments in South Bay contain the region's highest concentrations
of mercury, silver, and lead.19 Both by direct contact or accumulation through ingestion, estuarine
16 State Water Resources Control Board, 1993.
17 SFBRWQCB. 1995.
18USEPA, 1992.
19 San Francisco Estuary Institute. 1993.
6-16
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JUNE 1997
Exhibit 6-4
SAN FRANCISCO BAY TOXICS OF CONCERN AND THEIR EFFECTS ON ORGANISMS
Toxic
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Selenium
Effects on Organisms
Carcinogenic/mutagenic. Toxicity dependent on chemical
form. Acutely toxic to most marine organisms.
Carcinogenic/mutagenic/teratogenic. Highly toxic in
aquatic environments. Bioaccumulates up to 250,000
times concentration in water. Of exceptional toxicity to
mammals, including humans.
Carcinogenic/mutagenic/teratogenic. Strongly
accumulates in sediments and biota. Detrimental effects
in biota at levels in water of 10 ppb. Accumulates highly
in sediments.
Chronically toxic to marine organisms at concentrations in
water of .01-10.0 ppm. Acutely toxic at concentrations in
water greater than .01 ppm. Bioaccumulates in shellfish
up to 30,000 times concentration in water. Highly
bioavailable in the estuary.
Carcinogenic/teratogenic. Chronically toxic to marine
organisms at concentrations in water of 0. 1 ppm.
Bioaccumulates readily. Highly toxic to mammals.
Teratogenic. Most toxic of all trace elements. Effects
occur at low parts per billion level. Wide range of acute
and chronic toxicities to aquatic biota. Chronic toxicity to
marine organisms occurs at concentrations in water of 1
ppb. Bioaccumulates in some aquatic biota at levels
100,000 times that in water.
Carcinogenic/mutagenic. Chronically toxic in water at
levels greater than 0. 1 ppm. Acutely toxic at
concentrations above 1 .0 ppm.
Teratogenic. Toxicity depends greatly on chemical form.
Toxic effects occur at concentrations of 10 ppb in
freshwater, 1 ppm dry mass in sediments, and 0.3 ppm wet
weight in shellfish.
Effects Specific to San Francisco Bay
Effect on estuary biota unknown. Probably a pollutant of
less concern.
A pollutant of greatest concern. Ubiquitous in Bay.
Levels in biota warrant health concern and further
investigation.
Poorly characterized in estuary. Large industrial source in
Suisun Bay area. Elevated levels cause for concern and
further investigation.
A pollutant of greatest concern. Elevated levels in water,
sediment, and biota cause for further investigation.
Given moderate toxicity and relatively even distribution, a
problem only at specific sites.
Possibly a pollutant of greatest concern. Given effect and
high concentrations in biota, further investigation
warranted.
Poorly characterized in estuary. Enrichment in sediments
and biota is localized.
A pollutant of greatest concern. Effects on biota,
especially those higher in food web, and levels in water
and biota warrant further investigation.
References
SFEP 1992; SFEI 1993; CH2M
1991b
Herboldl 992; Flegal 1991;
Ohlendorf 1988; Kopec 1994;
Harvey 1992; SFEP 1992; Luoma
and Phillips 1988; SFEI 1993;
CH2M 1991b
Herbold 1992; Harvey 1992; SFEP
1992;CH2M1991b
Herbold 1992; Flegal 1991; Kopec
1994; Harvey 1992; SFEP 1992;
Luoma and Phillips 1988; SFEI
1993; CH2M 199 la; Ohlendorf
1988
Kopec 1994; Harvey 1992; SFEP
1992
Flegal 1991; Ohiendorf 1988;
Kopec 1994; Harvey 1992; SFEP
1992; Luoma and Phillips 1988;
SFEI1993;CH2M1991a
Kopec 1994; SFEP 1992; Flegal
1991; SFEI 1993; CH2M 1991a
Harvey 1992
6-17
-------
Exhibit 6-4
SAN FRANCISCO BAY TOXICS OF CONCERN AND THEIR EFFECTS ON ORGANISMS
(continued)
Toxic
Zinc
PCB
Effects on Organisms
Moderately toxic. Chronically toxic to marine organisms
at concentrations in water of about 0.05 ppm. Acute
toxicity to marine and freshwater animals occurs at
concentrations in water above 0. 1 ppm. Bioaccumulates
in shellfish to levels 100,000 times that of water.
Carcinogenic. More persistent than DDT. Effects occur
at extremely low concentrations. Bioaccumulates at levels
up to one million times that in water. May affect
reproduction in birds and mammals.
Effects Specific to sn Francisco Bay
Toxicity and concentrations in sediment and biota indicate
minor concern.
Elevated levels in sediments and tissue are cause for
concern. Increasing levels in black-crowned night heron
linked to decreasing embryo weights and thin eggshells.
References
Harvey 1992; SFEP 1992; SFEI
1993; Flegal 1991; Ohlendorf 1988
Ohlendorf 1988; Kopec 1994;
Harvey 1992
6-18
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JUNE 1997
Exhibit 6-5
SOURCES OF TOXIC POLLUTANT LOADINGS TO SAN FRANCISCO BAY
Pollutant
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Zinc
Chlorinated Hydrocarbons
Point Sources
Raw
Loadings
(tons)
18.14
12.70
32.66
55.34
41.73
4.38
143.34
0.57
Percent of
Total
11.43%
15.56%
2.57%
5.51%
7.36%
44.79%
5.18%
51.45%
Other Sources
Raw
Loadings
(tons)
140.62
68.95
1,236.51
948.92
525.27
5.40
2,623.61
0.53
Percent of Total
88.57%
84.44%
97.43%
94.49%
92.64%
55.21%
94.82%
48.55%
Notes: Point sources are defined as POTWs, industrial effluents, and power plant emissions.
Other sources are defined as urban runoff, cropland runoff, forestland runoff, rangeland
runoff, and upstream sources.
Source: NOAA, The National Coastal Pollutant Discharge Inventory; Estimates for San Francisco
Bay, Data Summary, Ocean Assessments Division, National Oceanic and Atmospheric
Administration, June 1988.
6-19
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JUNE 1997
Figure 6-7
Municipal Dischargers and Mean Discharge Volumes to the
Bay/Delta Estuary, 1984-1986
Eight Largett Discharger*
(Discharge. Million GaHom/Dty)
1. Sacramento RWTPfT34)
2. StocKton STP (29)
3. Central Contra Costa SO (39)
4. East Bay MUD (87)
5. San Francisco Southeast (74)
8. East Bay Dischargers Authority (68)
7. Palo Alto WTP (28)
8. San Jose/Santa Clara WTP (118)
Nott:
D
V(
From dzQ in
DiscturyuuptoKMGDannpnstnttdtiydots.
**., 1987
6-20
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JUNE 1997
Figure 6-8
Industrial Facilities and Mean Discharge Volumes (Million Gallons/Day)
to the Bay/Delta Estuary, 1984-1986
LLJ Refintrfts
1. Tosco
2. Exxon
3. Shell Oil
4. Union Oil
5. Pacific Refining
8. Chevron USA (a)
Q) Othir Industrin
1. McCormick and Baxter
2. Libbey-Owens-Ford
3. USSPosco
4. Dow Chemical
5. General Chemical
6. Stauffer Chemical
7. C&H Sugar
8. Mare Island Shipyard
9. Chevron Chemical
10. Stauffer Chemical
11. San Francisco Int'l Airport
12. New United Motors
MGO
4.4
2.2
4.3
2.5
0.2
16.7
MGO
0.2
0.2
20.0
0.4
1.1
0.1
1.0
0.5
0.2
0.1
4.0
0.9
(a) Rows from Chevron USA deems*! substantially
after 1986. Average flow in 1990 was 7 M6D
(b) Discharges of less than 0.1 MGO an not shown.
• Names listed an those used (luring the
period of study.
• Sow tart^ discharging great* than 0.1 U6D
did not monitor toxic poUutants.
From data in Gunther et */.. 1387
6-21
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JUNE 1997
organisms may be adversely affected by contaminants in sediments or contaminant fluxes from
sediments to the water column.20 This problem is exacerbated in San Francisco Bay by the need for
frequent dredging to maintain navigational access for recreational, commercial, and military vessels.
In order for shipping channels to remain operative, an average of 8 million cubic yards of material
must be'dredged from the Bay annually. This process can lead to the re-exposure of toxic
contaminants contained in buried sediments, transport of contaminated dredged material from the
Bay's designated spoil disposal sites to other areas, and resuspension of contaminants in the water
column, thereby increasing the bioavailability of toxic pollutants throughout the Bay.21
Impacts of Toxic Pollutants on Biota
Figure 6-9 illustrates the potential transport and fate of toxic pollutants introduced to an
estuarine system like San Francisco Bay. The transport of a particular pollutant can be complex and
difficult to predict, dependent as it is upon the pollutant's physical and chemical characteristics, as
well as environmental parameters such as salinity, temperature, and direction and the direction and
strength of local currents. Added to this complexity is the interaction among the estuarine organisms
that comprise the food web. As illustrated in Figure 6-10, lower trophic level organisms that take
in contaminants can become a toxic source for their predator counterparts. Successive
bioaccumulation of toxics can occur through upper trophic levels by the consumption of
contaminated prey, with the potential for impacts beyond estuary boundaries when migratory species
travel from one area to another. Moreover, impacts on any one species may have implications for
others, due to the complex interactions among species within an ecosystem. These interconnections
must be considered to characterize fully the potential impact of toxic pollutants on the ecological
resources of San Francisco Bay.
Unfortunately, the dynamic interactions among the various components of San Francisco
Bay's ecosystem are far from folly characterized. Therefore, our assessment of the effects of toxic
pollutants on the Bay's biota is largely anecdotal, focusing on the known or potential impacts of
particular pollutants on individual species. Nonetheless, the available data indicate a number of
actual or potential adverse impacts on Bay area biota due to exposure to toxic pollutants. For
example:
• Exhibit 6-6 presents a hazard evaluation for waterfowl and other avian
species that inhabit the Bay area, based on the concentrations of selected
contaminants found in the tissues or eggs of local bird populations. The
exhibit shows that mercury, selenium, DDE, and PCBs occur in
20Flegal,etal., 1994.
21USEPA, 1992.
6-22
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JUNE 1997
Figure 6-9
TRANSPORT AND FATES OF POLLUTANTS IN A TYPICAL ESTUARY
— •*• Dissolved Contaminants
> Particle-bound Contaminants
Contaminants
Eggs
Municipal
and
Industrial
Discharge
HaroorSatts.
Other Marnmus ami Biros
Ptiotodegraditlon Evaporation
A A
Soluoli Contaminants
Insolubla Contaminants
PartleH-Boand
Contaminants
Blotranstonnatloa Bioieaimulitlon
6-23
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JUNE 1997
Figure 6-10
FOOD WEB OF A TYPICAL ESTUARY OPEN WATER HABITAT
I_CGCND-
CONSUME*
SECONOMT CONSUMER
TCNTUNt CONSUME*
OUTSIDE OF NANITAT
6-24
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JUNE 1997
Exhibit 6-6
HAZARD EVALUATION OF ENVIRONMENTAL CONTAMINANTS IN BIRD TISSUES
OR EGGS FROM SAN FRANCISCO BAY DELTA*
(From Ohlendorf and Fleming, 1988)
Species
Waterfowl
Mallard
Northern pintail
Northern shoveler
Canvasback
Greater scaup
Lesser scaup
Surf scoter
Trace Elements
Ag
Cd
Cr
Cu
Hg
Ni
Pb Se Zn
Organochlorines
DDE PCBs Others
ND
ND
ND
ND
+
ND
+
ND
ND
ND
ND
*
ND
+
ND
ND
ND
ND
-
ND
-
ND
ND
ND
ND
+
ND
+
ND
ND
ND
ND
•H-
ND
•H-
ND
ND
ND
ND
-
ND
-
ND - ND
ND ND ND
ND - ND
ND + ND
- ~ +
ND ++ ND
•H- • +
ND ND ND
.
ND ND ND
ND ND ND
ND ND ND
ND ND ND
ND ND ND
References**
1
2
3
3
1,3,4,5,
6,7,8,9
1,3
1,3,4,5,6,7,9
Other species
Double-crested
cormorant
American bittern
Snowy egret
Black-crowned
night heron
American coot
Black-necked stilt
American avocet
Willet
Caspian tern
Forster's tern
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
7
+
ND
ND
ND
ND
7
7
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND ? ND
ND - ND
ND ND ND
ND . ND ND
ND - ND
ND - ND
ND - ND
ND - ND
ND ND ND
ND ND ND
ND ND ND
ND ND ND
+
-H- ++ +
ND ND ND
ND ND ND
ND ND ND
ND ND ND
+ + '
+ + +
1,10
3
11,12
11,13,14
1,3,15,16
1,15,16,17
1,15,17
1
11
11
'Listed as follows, based upon field or laboratory determinations with these or other avian species:
"++" = reported concentrations in some samples are equal to or greater than those associated with adverse effects;
"+" = reported concentrations are elevated to warrant some concern although effect levels are not well known;
"-" = reported concentrations are not elevated in comparison with other areas or are below the known effect level;
"?" = relative status unknown (because comparative or effect levels are not known);
"ND" = no data available.
"References: 1 = White el al. (1987); 2 = Ohlendorf and Miller (1984); 3 = White el al. (1988);
4 = Heinz (1979); 5 = Vermeer and Peakall (1979); 6 = Di Giulio and Scanlon (1984); 7 = Ohlend9rf el al.
(1986c and in press ); 8 = Gochfeld and Burger (1987); 9 = Heinz et al. (1987); 10 = King and Cromartie (1986);
11 = Ohlendorf et al. (in press); 12 = Ohlendorf et al. (1979); 13 = Ohlendorf el al. (1978); 14 = Hoffman el al
(1986); 15 = Ohlendorf et al. (1987); 16 = Presser and Ohlendorf (1987); 17 = White and Cromartie (1985).
6-25
-------
JUNE 1997
concentrations that in some cases equal or exceed those associated with
adverse effects. Contaminants such as silver, cadmium, copper, zinc, and
organochlorines other than PCBs or DDE are also found in concentrations
that may warrant concern. The species at risk include Greater scaup, Lesser
scaup, Surf scoter, Black-crowned night heron, Caspian tern, and Forster's
tem. In particular, evidence of reduced embryo weights in black-crowned
night herons has been linked with PCB concentrations, and DDE
concentrations in 1982-1984 were high enough to cause reproductive
impairment.22
There is evidence that declines in the Bay's stock of striped bass, oysters, and
Dungeness crab (Cancer magister), as well as declines in both the winter and
spring runs of chinook salmon, may be attributable in part to the deleterious
effects of toxic pollutants.23 For example, striped bass suffered a summer
die-off in 1985 in the Carquinez Strait and Sacramento-San Joaquin estuary,
possibly from liver dysfunction caused by exposure to hydrocarbons,
chlorinated hydrocarbons, and heavy metals.24
Available data suggest that reduced reproductive success and MFO25 activity
in starry flounder are related to PCB contamination.26 PCBs are also
suspected as the cause of liver abnormalities in starry flounder and a high
incidence of liver lesions in white croaker from Central Bay.27
Elevated concentrations of nickel, which is highly toxic to fish, invertebrates,
and zooplankton, have been found in mussels in Carquinez Strait. In
addition, high concentrations of chromium and silver have been detected in
shellfish from Central Bay.28
22 Aquatic Habitat Institute. ,1991.
23Affl,p. 134.
24 Pereira et al., 1994.
25 Mixed-function oxidase (MFO) activity measures the enzymatic response of fish to
exposure to organic contaminants.
26Long,etal. 1988.
"USEPA, 1992.
28USEPA, 1992.
6-26
-------
JUNE 1997
• High concentrations of silver in South Bay are of concern because of silver's
extreme toxicity to some organisms, including marine invertebrates and
microorganisms. Elevated levels of silver may limit primary ecosystem
productivity and reduce benthos species diversity, ultimately fostering the
decline of fisheries throughout the estuary.29
• The U.S. Fish and Wildlife Service has found that concentrations of selenium
in the tissues of certain birds and fish from the San Francisco Bay region -
including the federally endangered California clapper rail, diving ducks, and
white sturgeon - exceed the levels associated with potential adverse effects.30
The San Pablo Bay and South Bay populations of the California clapper rail
are particularly at risk from exposure to selenium.31
• Bay area populations of the California clapper rail may also be adversely
affected by mercury. Recent studies indicate that mean sediment
concentrations of methyl-mercury (the more toxic form of mercury) in the
Bay approach calculated lexicological thresholds of about three ng/g.
Maximum methyl-mercury concentrations in sediments of the North Bay
(12.5 ng/g) and the South Bay (25 ng/g) exceed the lexicological thresholds
by a factor of five and ten, respectively, and approach levels believed to be
associated with more severe effects.32
• Fish consumption advisories are in effect throughout the Bay for mercury,
PCBs, dioxins, and pesticides, and a waterfowl consumption advisory is in
effect for selenium. While the existence of human health consumption
advisories does not confirm risks to other species, it does demonstrate that
these pollutants accumulate to harmful levels for at least one top consumer
(humans) and implies the possibility that other top consumers (e.g.,
piscivorus wildlife) may also be at risk.
29 Smith and Flegal, 1993.
30 USFWS has found that ambient concentrations of selenium of 5 /^g/1 can result in the
bioaccumulation of selenium in some species to adverse levels. Jennifer Fowler-Propst, USFWS,
draft letter indicating USFWS intent to testify for the Water Quality Standards for Interstate and
Intrastate Streams in New Mexico, September 27,1993.
31 Ohlendorf and Fleming, 1988. Selenium enriched areas near point source outfalls have
also been detected by bioaccumulation of the trace element in shellfish from Suisun, San Pablo, and
South Bays.
32 Schwarzbach et al., USFWS, 1996.
6-27
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JUNE 1997
Figure 6-11 provides a summary of Bay area sites exhibiting elevated concentrations of toxic
pollutants in sediments or biota. As the figure illustrates, the areas of concern are numerous and
widespread. Exhibit 6-7 provides additional information, summarizing expert observations
regarding the adverse effects of toxic pollutants in San Francisco Bay.
Trophic Level and Food Web Impacts
Beyond the immediate impacts noted above, continued exceedence of the proposed water
quality criteria could adversely alter food webs. Such impacts might include a change in primary
production levels that provides less favorable prey species for upper trophic levels, and a resulting
change in community composition that could culminate in an unhealthy, less diverse, less resilient
ecosystem. A parallel example is illustrated in a report by Sanders and Cibik that looked at
phytoplankton communities in Chesapeake Bay, which comprise the foundation of the estuarine food
web. The study shows that chronic loadings of arsenic and silver have modified the competition
between species, resulting in a change in species composition that has created the potential to affect
preferred food organisms for resident zooplankton. "Dominant zooplankton... in the Chesapeake
Bay exhibited dramatically decreased survival and fecundity when fed an arsenic-altered
phytoplankton assemblage."33
Studies of highly contaminated areas of San Francisco Bay have revealed metal-induced
stress among the benthos. Adverse effects are most evident in the South Bay, where silver and
copper concentrations in sediments and benthic organisms are highest.34 Although ambient toxic
levels are not comprehensively and consistently measured, currently available data suggest the
potential for negative impacts on San Francisco Bay's biota from chronic exposure to metals.
Improved control of toxics could potentially reduce these exposures and relieve metal-induced
stresses on important biotic communities.
Available information also suggests that toxic pollutants may adversely affect zooplankton
populations in Suisun Bay, where the entrapment zone concentrates food particles and creates an
integral feature of the food web, supporting early stages of valued fish species such as striped bass.35
If toxics are present in such key areas, species assemblages may be altered and result in an inferior
or unacceptable food source for consumers such as fish, waterfowl, and shorebirds. Such is the case
33 Sanders and Cibik, 1988.
34 Luoma and Phillips, 1988.
35 Alpine and Cloem, 1992.
6-28
-------
JUNE 1997
Figure 6-11
Bay Area Sites Exhibiting Elevated Pollutant Concentrations in Sediments or Biota
N
1
Mare island
Strait
Suisun Bay
San Pablo Bay
Reyon
'•;;^T::-'Slough
„ ... _, _.. Martinez
Selby Slag Pile Manna
Cove
tiitnmond
Point Isabel
: Liquid Gold/Hoffman Marsh.
Treasure
mpsrte Is
Berkeley Marina
Emeryville Marina
- Oakland Inner Harbor/Oakland Estuary
EBMUO Outfall
Outer Harbor
San Leandro Bay
San Francisco Marinas
WarmwaterCove
Air Station^
Hunters Point
Candlestick Cove/Brisbafle Lagoon
Oyster
Coyote Point Marina
Palo Alto Outfatt
Pittsburg Marina
Antiocn ttcm Club
Concord Naval
Weapons Station
irk Slough &
Plumcner:Cwek
i -v»v- •
Creek
^Gwoilupe •Slough
0 2 4 6 810
0 4 8 12 *
6-29
-------
JUNE 1997
Exhibit6-7
ANECDOTAL EXPERT OBSERVATIONS REGARDING TOXICS IN THE BAY
Flegal et aL, 1991
South Bay silver and copper concentrations of sediments and benthos highest in the Bay.
Smith and Flegal, 1993
High levels of silver contamination are of concern in South Bay since it is extremely toxic to some
organisms. Metal-induced stress is found among benthos in regions of the estuary with high
sediment concentrations.
Sanders and Cibik, 1988
Persistent introduction of low-level toxic concentrations may cause, "more subtle, sublethal pressure
to the estuarine ecosystem, perhaps altering community structure."
"The phytoplankton assemblages incorporated significant quantities of silver, in proportion to the
level of silver dosing."
"...chronic loading of arsenic can have serious implications to the estuary as a whole."
"...natural competition between species can be modified by the presence of the low-level
contaminant."
Ohlendorf and Fleming,
1988
"Mercury and cadmium concentrations in surf scoters collected in 1985...were high enough to have
potential effects."
Luoma and Phillips, 1988
"Silver is strongly accumulated by invertebrates in estuaries..." .
"Concentrations of Cu in bivalves at several localities in South Bay and in the northern reach are as
high as any reported..."
Metal stress indicated in levels of biological organization in Palo Alto include:
sub-cellular (M. balthica intracellular protein distribution of Cu and Ag); whole organism (M.
balthica); population (M. balthica); absence of other species - whole organism bioassay; community
ecology (M. balthica and A. abdita).
"Stress [from metal exposure] in benthic communities is evident in extremely contaminated
localities."
Herbold et al., 1992
"Industrial pollutants and urban runoff, particularly organic chemicals, heavy metals, and thermal
pollution, are now the main concerns in the Bay."
Kopec et al., 1994
The environmental health of the bay is threatened by potential consequences of accumulation of
toxic pollutants, "...knowledge of the biological fate and effects of toxic pollutants is inadequate for
establishing discharge levels that ensure a healthy estuarine ecosystem."
Bennet et al., 1995
"...because estuaries are typically near urban and agricultural centers, cause-and-effect relationships
in food webs can be obfuscated by anthropogenic interventions, including...pollution."
Harvey et al., 1992
"Environmental contaminants known to be present at concentrations that could threaten wildlife
populations in San Francisco Bay Estuary include cadmium, copper, mercury, selenium, and silver."
"Contaminants may adversely affect wildlife if they reduce the food base or otherwise disrupt the
habitat required for the survival of wildlife."
"The San Francisco Bay Estuary is a critical wintering area for diving ducks, including scaup, scoter,
and canvasbacks. These and other diving ducks feed on benthic organisms, especially mussels and
clams, which have been shown to contain high concentrations of... heavy metals..."
Copper and zinc concentrations in scoters were higher in the South Bay.'
"Contaminants have been shown to adversely affect reproduction in many species of wildlife,
especially birds."
Harbor seals in the Bay have been found to have elevated PCB and DDE concentrations
6-30
-------
JUNE 1997
Exhibit 6-7
ANECDOTAL EXPERT OBSERVATIONS REGARDING TOXICS IN THE BAY
(continued)
SFEP 1992
"Pollutants that enter the estuary can concentrate at high levels in animal tissues, even though they
occur at low concentrations in the water and sediments."
"Bioassays of estuary water, sediments, municipal and industrial effluent, urban runoff, and
nonurban runoff have elicited toxic effects in many test organisms."
"...concentrations of chemicals in parts of the estuary are known to equal or exceed those
concentrations known to be associated with toxicity in numerous studies."
"...sediments from several [sites evaluated] have elicited toxic responses including development
abnormalities and high mortality in amphipods, mussels, and oysters."
Davis etal., 1991.
"There is concern that many toxic pollutants being discharged into the Estuary are affecting the
health of aquatic life and wildlife, therefore reducing the viability of biological communities."
"...there may be additional effects, particularly effects resulting from many pollutants acting
together."
6-31
-------
JUNE 1997
with the Delta smelt, an endangered species, which subsists on a restricted diet of zooplankton
(copepoda).36 This suggests that the striped bass and other economically valuable fish in the Bay
may also be affected through food chain impacts.
In addition to the impacts noted above, higher trophic level organisms in San Francisco Bay
show signs of stress-related impacts from their food web connection with prey species. For example,
harbor seals are tertiary predators that, as previously indicated, use San Francisco Bay as an
important pupping and feeding area. They are at risk from- their diet of fish, crustaceans,
invertebrates, and other available prey, which pass on toxic residues in their tissues. It is believed
that a reduction or change in prey species may decrease reproduction and survival of the seals;
moreover, increased concentrations of toxic pollutants in prey species could accumulate in harbor
seals, causing reproductive and physiological problems.37 This possibility is supported by a recent
study of harbor seals from San Francisco Bay, which found PCB residues, mercury, lead, selenium,
copper, and cadmium in seal tissue samples.38 Of particular concern is the potential for serious
adverse impacts due to chronic exposure to cadmium.39 An additional concern is exposure to
lipophilic contaminants, like PCBs, which accumulate in the blubber that seals use as an energy
reserve during breeding periods.40
Impacts on Migratory Species
As previously noted, a significant proportion of the Pacific Flyway's waterfowl and shorebird
population winters in the San Francisco Bay region. The San Francisco Bay contaminants that pose
the greatest risk to migratory waterfowl are cadmium, selenium and mercury, while PCBs and DDE
are of greatest concern in shorebirds and black-crowned night-herons.41 The impact of toxics on
these migratory species may ultimately have far-reaching negative impacts for other ecosystems.
An example of this is provided by migratory birds that overwinter in California's Imperial Valley,
where they are exposed to DDT; bioaccumulation of this compound causes the birds to suffer
reproductive problems in their northern breeding grounds, and may ultimately affect not only these
migratory species but also their predators in northern regions.42
36Herboldetal., 1992.
37 Kopec etal., 1994.
38 Kopec et.al., 1994.
39 Kopec and Harvey, 1995.
^USEPA, 1993.
41 Ohlendorf and Fleming, 1988.
42 Pease, 1995.
6-32.
-------
JUNE 1997
Similarly, many migratory species of fish travel through the San Francisco Bay Estuary's
waters to spawn, feed, and live out various stages of their life cycles. For example, Chinook salmon,
and American shad spawn in fresh water tributaries of the Bay, but live adult lives in the ocean.
Longfin smelt and striped bass (see Figure 6-12) spawn in tributary streams and live in Bay or ocean
waters, while Pacific herring both spawn and live their adult lives in the Bay. In contrast, English
sole and starry flounder spawn outside the Bay, but migrate to the Bay during other stages of their
life cycle.43 Reduction of toxics in the Bay's waters would provide more favorable habitat that could
promote higher reproductive success for these migratory fish. It would also reduce potential risks
to which predators of these migratory species might otherwise be exposed.
Summary of Potential Ecological Benefits
Reducing toxic loadings to San Francisco Bay to meet the proposed water quality criteria is
likely to reduce the cumulative stresses on individual organisms and populations, and to improve
habitat conditions and organism health. This may in turn improve organisms' and populations'
chances for success. In considering the benefits of the proposed water quality criteria, however, it
is important to go beyond the potential impacts on individuals and populations. The ecosystem
involves complex species assemblages that may suffer from chronic effects that do not manifest in
typical measured assessment endpoints like reproduction or mortality. Often, species, populations,
and communities exposed to chronic and cumulative impacts, such as those from low level toxic
exposure, show very subtle signs of stress after long-term exposure. Sometimes synergistic effects
from multiple stressors cause even greater adverse impacts than those predicted by looking at a
single cause.
In summary, the likely ecological benefits of meeting the proposed water quality criteria for
San Francisco Bay include but are not necessarily limited to the following:
• Reductions in chronic exposures to toxic pollutants should improve the
reproduction, growth, general health, and survival of Estuary biota. In
particular, many species that migrate through the Bay - including chinook
salmon, striped bass, and waterfowl - may benefit from improved breeding
habitat.
• Reductions in cumulative toxic loadings to sediments will reduce the
possibility of resuspension of toxics in the water column. Filter-feeding
animals such as clams and other mollusks, which take in suspended solids
when feeding, are among those most likely to benefit from such reductions.
43Herboldetal., 1992.
6-33
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JUNE 1997
Figure 6-12
SPAWNING AREAS AND SPAWNING MIGRATION OF STRIPED BASS
IN THE SAN FRANCISCO BAY DELTA ESTUARY
SPAWNING
GROUNDS
SPAWNING
GROUNDS
30'
1230
6-34
-------
JUNE 1997
Reduced toxic inputs to the Bay could improve habitat and enhance lower
trophic-level food supplies, with the potential for contributing to improved
conditions necessary for the recovery of threatened and endangered species
like the California clapper rail, California brown pelican, and American
peregrine falcon.
Improved water quality conditions hi the Bay may reduce the
bioaccumulation of toxic pollutants in upper trophic levels. Predator species
that most likely would benefit from better control of toxics include predatory
fish and piscivorus birds, as well as harbor seals and other piscivorus
mammals.
Because all components of the ecosystem are linked, the improved survival,
growth, productivity, and reproductive capacity of aquatic and terrestrial
organisms resulting from reduced exposure to toxics should contribute to the
increased stability, resilience and overall health of the Bay, and help to
maintain and improve the rich biodiversity of the Estuary.
SALTONSEA
Background
The Salton Sea, California's largest inland waterbody (approximately 220,000 acres) is a
saline lake located hi the southeastern desert portion of California (see Figures 6-13 and 6-14 for
maps of the area). The Sea was formed when a diversion set up to distribute water from the
Colorado River to the Imperial Valley failed, flooding the low-lying area. The Sea is fed primarily
by the New and Alamo Rivers and the Coachella Valley Storm Water Channel, each of which carry
large volumes of agricultural runoff and irrigation drainage water. The Salton Sea also receives
drainage water from the Mexican' Valley in Mexico. The total flow of water entering the Sea, which
has no outlet, is approximately 1 million acre-feet per year.
According to the Water Quality Control Plan for the Colorado River Basin Region, the
designated beneficial uses of the Salton Sea include the support of warmwater and wildlife habitat.
The Sea supports a large number of artificially introduced sport fish, including orangemouth corvina,
gulf croaker, sargo, and tilapia. In addition, both the Salton Sea National Wildlife Refuge and
California's Imperial Wildlife Management Area are located in and around the Salton Sea. The
National Refuge encompasses 45,000 acres and hosts more than 90,000 migratory waterfowl each
6-35
-------
Figure 6-13
JUNE 1997
-------
Figure 6-14
SALTON SEA
JUNE 1997
Imperial Wildlife
Management Area
-------
JUNE 1997
year, supporting the most diverse bird populations of any national wildlife refuge in the State.44 The
Refuge also provides essential habitat to nesting birds, including the great blue heron, cattle egret,
great egret, and snowy egret. The surrounding desert is home to other birds, including piscivorus
raptors, as well as to rodents, coyotes, foxes, and assorted reptiles.
As Figure 6-15 shows, several rare, threatened, or endangered species inhabit the Salton Sea
area. According to the Natural Diversity Database maintained by the State, species of concern that
have been identified within the confines of the Sea (or a 100 meter area surrounding it) include at
least two federally-listed endangered species: the desert pupfish, which is the only fish species
indigenous to the area; and the Yuma clapper rail. According to a 1993 U.S. Geological Survey
(USGS) report, about one-third of the world's population of Yuma clapper rails inhabit wetlands near
the Salton Sea. Other federally-listed endangered species found in the area include the peregrine
falcon and bald eagle. In addition, as many as 5,000 brown pelicans, another federally-listed
endangered species, occasionally spend their summers on the Salton Sea.45
Nature of Toxics Impairment
California's WQA database indicates that elevated loadings of trace elements, including
selenium, impair water quality in the Salton Sea, Other potential toxics problems in the Salton Sea
area include elevated concentrations of pesticides in the Alamo River, New River, and Coachella
Valley Storm Channel, and slightly elevated concentrations of chromium and cadmium in irrigation
drainwater. Elevated concentrations of mercury have also been detected in the Salton Sea area.46
*
The United States Geological Survey has conducted many studies on the quality of the water
column and sediments in the Salton Sea. Sampled concentrations of selenium, the key trace element
of concern, are shown in Figure 6-16. The exhibit compares these concentrations to EPA's proposed
water quality criteria of 5 micrograms per liter for chronic exposure for the protection of aquatic
organisms. As the exhibit indicates, 10 of the 12 samples exceed the chronic water quality criterion
and six exceed higher levels associated with more acute effects, with the highest reported
concentrations associated with tile drain outfalls. 'Other pollutants of concern identified in sediment
studies include DDT metabolites (DDE and DDD), which have been detected in Alamo and New
River sediments, and other organochlorine pesticides, including chlordane and toxaphene.47
'"U.S. Geological Survey, 1990.
"• U.S. Geological Survey, 1993.
46 U.S. Geological Survey, 1993.
47U..S. Geological Survey, 1990.
6-38
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Figure 6-15
Salton Sea
Natural Diversity Database
Occurrences
within 100 m buffer of shoreline
5 Kilometers
o
iil NDDB Occurrence
f~n Salton Sea 100m buffer
/\y Salton Sea shoreline
NDDB Species Occurrence --Common Name
ACTIVE DESERT DUNES
BLACK CROWNED NIGHT HERON
BLACK SKIMMER
BLACK-TAILED GNATCATCHER
CRISSAL THRASHER
DESERT PUPFISH
GREAT BLUE HERON
GREAT EGRET
GULL BILLED TERN
LE CONTES THRASHER
SNOWY EGRET
STABILIZED AND PARTIALLY STABILIZED DESERT DUNES
YELLOW BREASTED CHAT
YELLOW WARBLER
YUMA CLAPPER RAIL
Count \
1
1
2
1
1
43
1.
1
4
1
1
1
2
1
5
Map produced by
California Rivers Assessment
Data provided by Natural
Heritage Division, CA DFG
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JUNE 1997
Figure 6-16
CONCENTRATIONS OF SELENIUM IN WATER SAMPLES
FROM THE SALTON SEA AREA, 1986
SITES
New River at outlet
Trifolium Drain 1
Alamo River at outlet
Salton Sea composite
Tile drain 1
Tile drain 2
Tile drain 3
Tile drain 4
Tile drain 5
Tile drain 6
Tile drain 7
Tile drain 8
Median concentration
25th quartile
75th quartile
19
WtWm*
50 100 150 200 250 . 300
SELENIUM CONCENTRATION, IN MICROGRAMS PER LITER
350
Source: Adapted from Reconnaissance Investigation of Water Quality, Bottom Sediment, and Biota
Associated with Irrigation Drainage in the Salton Sea Area, California, 1986-1987, U.S. Geological
Survey, Water Resources Investigations Report 89-4102,1990, p. 29.
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JUNE 1997
Effects on Biota
Selenium is the contaminant of greatest concern in the Salton Sea area. Once it enters the
sediments of the Salton Sea, selenium is taken up by sediment feeding organisms and enters the food
web, where it bioaccumulates and biomagnifies to toxic levels. The increased concentration of
selenium in plant and animal material can then pose substantial risks to the health and survival of
fish and piscivorus birds. Exhibit 6-8 summarizes several of the adverse effects that selenium can
have on fish and wildlife at concentrations observed in the Salton Sea. Adverse impacts include
reduced survival, inhibited reproduction, reduced growth, behavioral modifications, gross
deformities, immuno-suppression, and death.
Exhibit 6-8
SUBLETHAL EFFECTS TO FISH AND WILDLIFE RESOURCES FROM
IRRIGATION DRAINWATER CONSTITUENTS
(Primarily Selenium)
Category
Reproduction
Growth/Physical
Internal Structure
Behavior
Physiology
Biochemistry
Observed Effect
Reduced fertility
Increased mutagenesis and teratogenesis
Reduced egg production (number/size/rate)
Eggshell thinning
Reduced hatching success
Reduced oogenesis/spermatogenesis
Reduced length, weight, and height; gross deformities
Altered organs (heart, liver, bones)
Altered cells (chromosomes)
Intestinal lesions
Abnormal mating, nesting
Altered migration
Reduced predator avoidance
Reduced bodily maintenance (feeding, bathing)
Altered osmoregulation
Altered immune response
Altered concentrations/ratios of: acetocholinase,
adenosine triphosphatase, glutathione peroxidase, and
other enzymes
Source: An Overview of Irrigation Drainwater Techniques, Impacts on Fish and Wildlife Resources, and
Management Options, U.S. Fish and Wildlife Service, May 1992.
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JUNE 1997
Excessive levels of selenium found in some fish in the Salton Sea area are believed to be
responsible for observed declines in fish populations. Evidence has shown a significant decrease
in the reproductive capacity of two forage fish, bairdiella and sargo. In addition, deformities such
as retarded cephalic development have been observed in some fish; the selenium concentration in
the species may be at least partially responsible for the observed deformities.48
Selenium's impact on birds in the Salton Sea area has been even more pronounced. A 1993
U.S. Fish and Wildlife Service assessment identifies 92 avian species in the area that may suffer
adverse effects from exposure to elevated concentrations of pollutants originating from irrigation
drainage. In particular, the levels of dietary selenium faced by northern shovelers, black-necked
stilts, and eared grebes are high enough to pose a risk of embryotoxicity. Moreover, concentrations
of selenium in the liver of double-breasted cormorants in the area averaged approximately 25
micrograms per gram of body weight from 1986 through 1990, with a maximum detected
concentration of 42 micrograms per gram. These levels approach or exceed the 30 micrograms per
gram threshold for risk of reproductive impairment. Consistent with these conditions, the number
of active double-crested cormorant nests observed in the Salton Sea area declined from 63 in 1987
to zero in 1991.49
California's Toxic Substances Monitoring Program has also identified high concentrations
of pesticides as a potential ecological threat in the Salton Sea area. For example, the area has the
State's highest detection rate for endosulfan - double the State average ~ indicating the likelihood
that aquatic organisms are chronically exposed to elevated concentrations of this pesticide. The
bioaccumulation of this compound has resulted in the detection of concentrations as high as 2,050
parts per billion in fish samples collected near the Salton Sea National Wildlife Refuge.50 Such high
concentrations of endosulfan pose reproductive and other risks to piscivorus birds.
Exhibit 6-9 summarizes the findings of a USGS analysis of the impact of toxics on avian
species in the Salton Sea area. As the exhibit indicates, current exposure to selenium poses a threat
to 83 percent of both resident and migratory bird species; it also poses a risk to three of four
Federally endangered species. Similarly, exposure to DDE, a metabolite of DDT, poses a risk to 81
percent of the area's resident bird species and 62 percent of its migratory species, including three of
the area's four Federally endangered bird species. These figures suggest significant potential for
ecological harm associated with exposure to the toxic substances to be regulated under the proposed
water quality criteria.
48 U.S. Geological Survey, 1993.
49 U.S. Geological Survey, 1993.
50 Pease, 1995.
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JUNE 1997
Exhibit 6-9
NUMBER OF BIRD SPECIES IN THE SALTON SEA AREA
ACTUALLY OR POTENTIALLY INJURED BY EXPOSURE TO
SELENIUM OR DDE*
Category
Total Species
Selenium
DDE*
Resident
42
35 (83%)
34 (81%)
Migratory
82
68 (83%)
51 (62%)
Federally endangered
4 (100%)
Source: Detailed Study of Water Quality, Bottom Sediment, and Biota Associated with Irrigation
Drainage in the Salton Sea Area, California, 1988-1990. U.S. Geological Survey, 1993.
* DDE is a metabolite of DDT.
Potential Ecological Benefits
As described above, selenium and pesticides have accumulated in the sediment and biota
of the Salton Sea area in concentrations that have deleterious impacts on fish and wildlife
populations. This affected population includes the brown pelican, peregrine falcon, bald eagle,
Yuma clapper rail, and desert pupfish, all of which are listed by the U.S. Fish and Wildlife Service
as endangered species.
Reducing concentrations of selenium and pesticides to meet aquatic criteria levels is likely
to contribute to the improved health, survival, and reproduction offish and birds in the Salton Sea.
The proposed selenium criteria may not yield full benefits for some aquatic-dependent wildlife
species and populations.51 Moreover, reducing current loadings of these pollutants is unlikely to
yield immediate benefits, due to the already elevated concentration of the pollutants in the sediments
and food web. Over time, however, reduced concentrations of toxic contaminants to the Sea should
contribute to the maintenance and restoration of healthy populations of wildlife and could
significantly contribute to the recovery of certain endangered species.
51 The U.S. Fish and Wildlife Service has recommended a selenium criterion of 2 /^g/liter to
protect some aquatic-dependent wildlife.
6-43
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REFERENCES
Alpine, A. E. and J. E. Cloem. 1992. "Trophic Interactions and Direct Physical Effects Control
Phytoplankton Biomass and Production in an Estuary," in Limnology and Oceanography
37(5): 946-955.
Aquatic Habitat Institute. 1991. San Francisco Estuary Project: Status and Trends Report on
Pollutants in the San Francisco Estuary. Final Draft. Richmond, CA, (March).
Bennet, et al. 1995. "Larval Striped Bass Condition in a Drought-Stricken Estuary: Evaluating
Pelagic Food-Web Limitation," in Ecological Applications, Vol. 5, No. 3.
California Regional Water Quality Control Board. 1986. Water Quality Control Plan, San
Francisco Bay Basin Region (2), (December).
California Report on Impaired Surface Waters, Prepared as Required in Clean Water Act Section
303(d), May 1994.
Casarett & Doull's Toxicology: The Basic Science of Toxics. 3rd Edition. New York. Macmillan.
1986.
CH2M Hill. 1991. Results of Ambient Toxicity Characterization Testing in the Vicinity of the San
Jose/Santa Clara Water Pollution Control Plant, prepared by Larry Walker Associates and
Kinetic Laboratories, Inc., for the City of San Jose, (July).
CH2M, 1991. Bioaccumulation Monitoring of Trace Elements in South San Francisco Bay Using
Transplanted Marine Mussels (Mytilus califomianus,), prepared by Larry Walker Associates
and Kinetic Laboratories, Inc., for the City of San Jose, (July).
Flegal, A. R. et al. 1991. "Dissolved Trace Element Cycles in the San Francisco'Bay Estuary," in
Marine Chemistry 36(1991):329-363.
Flegal, A. R. et al. 1994. San Francisco Estuary Pilot Regional Monitoring Program: Sediment
Studies. Final Report, Prepared for the San Francisco Bay Regional Water Quality Control
Board, State Water Resources Control Board. San Francisco, CA.
Harvey, T.E., KJ. Miller, R.L. Hothem, M.J. Rauzon, G.W. Page and R.A. Keck. 1992. Status and
Trends Report on Wildlife of the San Francisco Estuary, prepared by the U.S. Fish &
Wildlife Service for the San Francisco Estuary Project, U.S. Environmental Protection
Agency. San Francisco, CA.
6-44
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REFERENCES
Harvey, J.T., and M.L. Torok. 1994. "Movements, Dive Behaviors, and Food Habits of Harbor
Seals (Phoca vitulina Richardsi) in San Francisco Bay, California," Toxic Pollutants, Health
Indices, and Population Dynamics of Harbor Seals in San Francisco Bay, 1982-1992, A
Final Report By A.D. Kopec and J.T. Harvey, (October).
Herbold, B., A. D. Jassby, and P. B. Moyle. 1992. Status and Trends Report on Aquatic Resources
in the San Francisco Estuary, prepared by the San Francisco Estuary Project. Oakland, CA.
Karras, G. 1992. "Clean Safe Jobs: the Benefits of Toxic Pollution Prevention and Industrial
Efficiency to the Communities of South San Francisco Bay," a preliminary report prepared
for Citizens for a Better Environment. San Francisco, CA. 25 pp.
Kirshner, D. and D. Moore. 1988. "The Effect of San Francisco Bay Water Quality on Adjacent
Property Values," Journal of Environmental Management 27(1989):263-274.
Kockelman, W.J., TJ. Conomos and A.E. Leviton. 1982. San Francisco Bay: Use and Protection,
Sixty-first Annual Meeting of the Pacific Division/American Association for the
Advancement of Science. San Francisco, CA. 310pp.
Kopec, A. D., J. T. Harvey, and M. L. Torok. 1994. Toxic Pollutants, Health Indices, and
Population Dynamics of Harbor Seals in San Francisco Bay, a preliminary report submitted
to the San Francisco Estuary Project. Moss Landing Marine Laboratories. Moss Landing,
CA.
Long, E.R., D. MacDonald, B.B. Matta, K. VanNess, M. Buchman, and H. Harris. 1988. Status and
Trends in Concentrations of Contaminants and Measures of Biological Stress in San
Francisco Bay, NOAA Technical Memorandum NOSOMA41. Seattle, WA, (May).
Luoma, S. N. and D. J. H. Phillips. 1988. "Distribution, Variability, and Impacts of Trace Elements
in San Francisco Bay," Marine Pollution Bulletin 19(9):413-425.
Moore, S. 1995. "Moseley Tract Salt Marsh Restoration Proposal: Mitigation Credit
Recommendation for San Jose/Santa Clara Water Pollution Control Plant," Staff Report,
California Regional Water Quality Control Board, San Francisco Bay Region, San Francisco,
CA, (August).
Ohlendorf, H.M and W.J. Fleming. 1988. "Birds and Environmental Contaminants in San Francisco
and Chesapeake Bays," Marine Pollution Bulletin 19(9):487-495.
Pease, William, Pesticide Impacts on California Ecosystems, 1995 (Draft) California Policy
Seminar, Berkeley, California.
6-45
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REFERENCES
Pereira, W.E., F.D. Hostettler, J.R. Cashman, and R.S. Nishioka. 1994. "Occurrence and
Distribution of Organochlorine Compounds in Sediment and Livers of Striped Bass (Morone
saxatilis) from the San Francisco Bay-Delta Estuary," Marine Pollution Bulletin. Vol. 28,
No. 7.
Pianka,E.R. 1983. Evolutionary Ecology. Third Edition. Harper & Row, Publishers, Inc. New
York, NY. 416pp.
Rickleffs, R. E. 1982. Ecology. Second edition. Chiron Press, Inc. New York, NY. 966pp.
San Francisco Estuary Institute. 1993. Annual Report: San Francisco Estuary Regional Monitoring
Program for Trace Substances. San Francisco, CA.
San Francisco Estuary Project. December 1990. "San Francisco Estuary Project Fact Sheet," San
Francisco, CA.
San Francisco Bay Regional Water Quality Control Board. 1995. Contaminant Levels in Fish
Tissue from San Francisco Bay: Final Report, (June).
Sanders, J. G. and S. J. Cibik. 1988. "Response of Chesapeake Bay Phytoplankton Communities
to Low Levels of Toxic Substances," Marine Pollution Bulletin 19(9):439-444.
Setzler-Hamilton, E.M., J.A. Whipple, and B. Macfarlane. 1988. "Striped Bass Populations in
Chesapeake and San Francisco Bays: Two Environmentally Impacted Estuaries," Marine
Pollution Bulletin, Vol. 19, No. 9.
Skorupa, J. 1991. Testimony of Dr. Joseph Skorupa regarding selenium risk thresholds, with
special reference to San Francisco Bay. Presented before the California RWQCB, San
Francisco Bay Region, January 16,1991.
Smith, G. J. and A. R. Flegal. 1993. "Silver in San Francisco Bay Estuarine Waters," Estuaries
16(3A):547-558.
State of California. 1995. California Hunting Regulations for Resident and Migratory Game Birds.
State Water Resources Control Board. 1993. Bay Protection and Toxic Cleanup Program: Staff"
Report, California Regional Water Quality Control Board, San Francisco Bay Region,
(November).
6-46
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REFERENCES
U.S. Department of Commerce. 1987. San Francisco Bay: Issues, Resources, Status and
Management, National Oceanic and Atmospheric Administration, NOAA Estuarine
Programs Office, (October).
USEPA. 1992. State of the Estuary: A Report on the Conditions and Problems in the San
Francisco Bay/Sacramento-San Joaquin Delta Estuary, Region 9 (June).
USEPA. 1993. Wildlife Exposure Factors Handbook. Washington, DC.
USEPA. 1994. Regulatory Impact Assessment of the Final Water Quality Standards for the San
Francisco Bay/Delta and Critical Habitat Requirements for the Delta Smelt. December 15,
1994. San Francisco, CA. With technical assistance from Jones & Stokes Associates, Inc.
Sacramento, CA (JSA 94-130).
USFWS. 1993. Draft letter of USFWS intent to testify for the Water Quality Standards for
Interstate and Intrastate Streams in New Mexico, September 27, 1993. Jennifer Fowler-
Propst, author.
U.S. Fish and Wildlife Service, 1992. Status and Trends Report on Wildlife of the San Francisco
Estuary, January.
Western Hemisphere Shorebird Reserve Network, 1996. WWW Homepage.
Http://www.quickweb.com/wetnet/imagemap.html.
6-47
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REFERENCES FOR CHAPTER 6 FIGURES
Figure 6-1: U.S. EPA, 1992.
Figure 6-2: Kopec, 1994.
Figure 6-3: USFWS, 1992.
Figure 6-4: U.S. EPA, 1992.
Figure 6-5: Western Hemisphere Shorebird Reserve Network, 1996.
Figure 6-6: U.S. EPA Region IX, GIS Center, 1995.
Figure 6-7: U.S. EPA, 1992.
Figure 6-8: U.S. EPA, 1992.
Figure 6-9: U.S. EPA, 1992.
* •
Figure 6-10: U.S. EPA, 1992.
Figure 6-11: U.S. EPA, 1992.
Figure 6-12: Setzler-Hamilton, 1988.
Figure 6-13: U.S. EPA Region IX, GIS Center, 1995.
Figure 6-14: U.S. EPA Region IX, GIS Center, 1995.
Figure 6-15: U.S. EPA Region IX, GIS Center, 1995.
6-48
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REFERENCES FOR EXHIBIT 6-6
Di Giulio, R.T. and Scanlon, P.P. 1984. Heavy metals in tissues of waterfowl from the Chesapeake Bay,
USA. Environ. Pollut. (Ser. A) 35: 29-48.
Heinz, G.H. 1979. Methylmercury: reproductive and behavioral effects on three generations of mallard
ducks. J. Wildl Manage. 43: 394-401.
Heinz, G.H., Hoffman, D.J., Krynitsky, A.J., and Weller, D.M.G. 1987. Reproduction in mallards fed
selenium. Environ. Toxicol. Chem. 6: 423-433.
Hoffman, D.J., Rattner, B.A., Bunck, C.M., Krynitsky, A., Ohlendorf, H.M., and Lowe R.W. 1986.
Association between PCBs and lower embryonic weight in black-crowned night heron in San
Francisco Bay. J. Toxicol. Environ. Health. 19: 383-391. ~
Gochfeld, M. and Burger, J. 1987. Heavy metal concentrations in the liver of three duck species: influence
of species and sex. Environ. Pollut. 45: 1-15.
King, K.A., and Cromartie, E. 1986. Mercury, cadmium, lead, and selenium in three waterbird species
nesting in Galveston Bay, Texas, USA. Colonial Waterbirds. 9: 90-94.
Ohlendorf, H.M., Custer, T.W., Lowe, R.W., Rigney, M., and Cromartie, E. (In press a) Organochlorines
and mercury in eggs of coastal terns and herons in California, USA. Colonial Waterbirds.
Ohlendorf, H.M., Hothem, R.L., Aldrich, T.W., and Krynitsky, A.J. 1987. Selenium contamination of the
Grasslands, a major California waterfowl area. Sci. Total Environ. 66: 169-183.
Ohlendorf, H.M., Klaas, E.E., and Kaiser, T.E. 1978. Environmental pollutants and eggshell thinning in the
black-crowned night heron. In Wading Birds (A. Spnmt, IV, J.C. Ogden, and S. Winckler, eds.), pp.
63-82. National Audubon Society Research Report No. 7.
Ohlendorf, H.M., Klaas, E.E., and Kaiser, T.E. 1979. Environmental pollutants and eggshell thickness:
anhingas and wading birds in the eastern United States. Special Scientific Report — Wildlife No.
216. U.S. Fish and Wildlife Service.
Ohlendorf, H.M., Lowe, R.W., Kelly, P.R., and Harvey, T.E. 1986c. Selenium and heavy metals in San
Francisco Bay diving ducks. J. Wildl. Manage. 50: 64-71.
Ohlendorf, H.M., Marois, K.C., Lowe, R.W., Harvey, T.E., and Kelly, P.R. Environmental contaminants
and diving ducks in San Francisco Bay. Symposium' on selenium and agricultural drainage
implications for the environment (Selenium IV) Berkeley, California.
Ohlendorf, H.M. and Miller, M.R. 1984. Organochlorine contaminants in California Waterfowl. J. Wildl.
Manage. 48: 867-877.
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Ohlendorf and Fleming, 1988. Hazard Evaluation of Environmental Contaminants in Bird Tissues
or Eggs from San Francisco Bay Delta.
Presser, T.S., and Ohlendorf, H.M. 1987. Biogeochemical cycling of selenium in the San Joaquin
Valley of California. Environ. Manage. 11: 805-821.
Vermeer, K.; and Peakall, D.B. 1979. Trace metals in seaducks of the Fraser River Delta intertidal
area, British Columbia. Mar. Pollut. Bull. 10: 189-193.
White, D.H and Cromartie, E. 1985. Bird use and heavy metal accumulation in waterbirds at dredge
disposal impoundments, Corpus Christi, Texas. Bull. Environ. Contain. Toxicol. 34:295-300.
White, D.H., Hofmann, P.S., Hammond, D., and Baumgarten, S. 1988. Selenium Verification Study,
1986-87: A Report to the State Water Resources Control Board. California Department of
Fish and Game, Sacramento.
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JUNE 1997
APPORTIONING BENEFITS TO POINT SOURCES CHAPTER 7
INTRODUCTION
The benefits estimates presented in previous chapters represent the total benefits expected
to occur once water quality control programs have been fully implemented by California and water
quality criteria have been achieved for toxic pollutants. Because EPA is developing estimates of
costs associated with implementation of the proposed water quality criteria, it is important to
estimate the benefits specifically associated with reducing toxic discharges from point sources. This
will allow a more consistent comparison of costs and benefits.
This chapter draws on available data to apportion benefits to point and nonpoint sources. Our
general approach consists of first using available data to estimate the percent of all toxics loadings
coming from point sources. We then adjust this figure by the percentage reduction in point source
loadings expected to occur when the toxics criteria are fully implemented by the state. Finally, we
use this information to scale the human health, economic, and ecological benefits developed in
earlier chapters.
Throughout this chapter, we define point sources to include NPDES permitted sources —
publicly owned treatment works (POTWs), industrial dischargers, and active/inactive mines.1
Although stormwater discharges are regulated as a point source, they are not included as a point
source category in this analysis because they are not explicitly addressed in the available data and
1 While mines are considered to be a point source subject to NPDES under the Clean Water
Act, not all mines in California have been permitted. Loadings reductions for mines (both active and
inactive) with major NPDES permits have been estimated, and are used in this analysis, although
they do not represent the entire universe of mines in the State. Consequently, some of the benefits
estimated in this chapter may not occur in the same time frame as benefits associated with other
point sources evaluated here (POTWs and industrial dischargers).
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JUNE 1997
because they are typically not subject to numeric water quality-based effluent limits. Although data
sources vary, "other" sources generally include urban runoff, runoff from forestry and agriculture,
rangeland runoff, and atmospheric deposition.
This chapter first reviews regional loadings studies to determine how point sources contribute
to total loadings of priority toxic pollutants. Second, we apportion economic benefits to point
sources using point source contribution estimates averaged across the key pollutants. Next, we
qualitatively discuss apportionment of recreational angler health benefits to point sources, examining
key pollutants and discussing analytic obstacles that preclude a strict quantitative apportionment of
cancer cases and noncancer risks. Finally, we apportion ecological benefits based on estimates
developed in Chapter 5.
Summary of Findings
Our research supports the following conclusions:
• Point sources such as POTWs, industrial dischargers, and mines are
significant contributors of total toxic pollutants discharged to California
surface waters, although other sources (e.g., urban runoff, agricultural runoff)
tend to be more significant.
• Point sources are responsible for a large share of toxics loadings to California
bays. For bays other than San Francisco Bay, we estimate that point sources
account for between 42 and 64 percent of toxics loadings. Point sources
account for between five and 30 percent of toxics loadings to freshwater, and
between four and 11 percent of loadings to San Francisco Bay.
• We estimate that control of toxics discharged from point sources will yield
between $3 million and $65 million per year in economic benefits
(recreational fishing and non-use values), with a midpoint best estimate of
about $34 million per year.
• Apportioning health risks to point sources is difficult because a number of the
most significant pollutants occur in concentrations below detection limits;
this precludes tracing the pollutants to point sources and other sources.
However, examination of effluent data and literature, as well as discussions
with knowledgeable regulatory staff, suggests that a number of health risk
drivers — PCBs, dioxin, pesticides, and mercury — are discharged, at least in
part, by point sources. Despite this finding, representative calculations
suggest that the potential health risk reductions associated with control of
•point sources are likely to be limited unless significant effluent reductions are
achieved.
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JUNE 1997
Point source discharge reductions are likely to yield a number of ecological
benefits as well. First, reduced loadings will reduce morbidity/mortality of
aquatic and some terrestrial wildlife and improve the integrity of ecosystems
in at least 20,000 acres of assessed bays, estuaries, lakes, and wetlands as
well as 100 miles of miles of rivers that are now currently impaired. Reduced
point source loadings may also improve conditions for fish spawning and/or
migration in at least 14,000 acres of bays, harbors, and estuaries; 5,000 acres
of lakes; and 50 miles of rivers and streams. Finally, reductions in point
source contributions of toxics are expected to improve habitat supporting
threatened and endangered species in at least 10,000 acres of bays, harbors
and estuaries; 1,700 acres of lakes; and 100 river miles.
These findings are subject to some uncertainty given the limited availability of Statewide
data and the overall limitations of the apportionment approach used. First, the extent and diversity
of surface water resources and the great number and variety of dischargers make it difficult to draw
general conclusions regarding the relative influence of point sources and nonpoint sources
discharging to California waters. While available data provide enough information to estimate broad
ranges of benefits associated with reducing toxic discharges from point sources throughout the state,
the circumstances at a specific waterbody may differ from these general estimates. Second, the
apportionment approach used here assumes that reductions in toxic loadings and the resulting
benefits are linearly related. As discussed later in this chapter, this may not be true under certain
circumstances, although the direction of the bias introduced is unclear.
DETERMINATION OF POINT SOURCE
CONTRIBUTIONS TO TOXICS LOADINGS
To apportion the benefits of implementing the toxics criteria to point source dischargers, we
first need to estimate the portion of key pollutants that are discharged by point and nonpoint sources.
Because California waters are extensive and diverse, it is difficult to make state-wide generalizations
about the relative toxic discharge contribution of point sources to all water bodies in the state.
Therefore, the sections below discuss three categories of waterbodies: San Francisco Bay, other
enclosed bays and estuaries, and freshwater. We chose these three categories because of likely
similarities in the profile of discharge sources and because of the need to match the categories for
which benefits (e.g., health risks, economic benefits) were estimated.
We performed a literature search to identify studies that address the relative magnitude of
point and other discharges of toxics to the three water categories. Available information was limited
in two key ways. First, we located many studies of specific discharge categories (e.g., industrial
sources) that affect particular waterbodies; however, few of these studies compare the relative
contribution from all sources (point and other). Second, the size and diversity of water resources in
California precluded performing a comprehensive study of point source contributions across the
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JUNE 1997
state. Instead, all of the studies and data located apply to site-specific waterbodies or segments of
waterbodies. Except in the case of San Francisco Bay, this requires that we generalize from studies
of one waterbody to other similar waterbodies in California.2
San Francisco Bay
The sections below review the data sources used to estimate point and other source loadings
of toxic pollutants to San Francisco Bay, the results of the data analysis, and uncertainties and
limitations of the analysis.
2 In addition to the studies discussed in this chapter, we also reviewed the following
documents, but found no information relevant to the apportionment analysis: Association of Bay
Area Governments, State of the Estuary: A Report on Conditions and Problems in the San
Francisco Bay.'Sacramcnto-San Joaquin Delta Estuary, San Francisco Estuary Project, June 1992;
Association of Bay Area Governments, Comprehensive Conservation and Management Plan, San
Francisco Estuary Project. June 1994; California Environmental Protection Agency, Mass Emission
Reduction Strategy for Selenium, Staff Report, Basin Planning and Protection Unit, October 12,
1992; Cross, J.. el al.. Annual Report 1990-91 and 1991-92, Southern California Coastal Water
Research Project, November 1992; Davis, J., et al., "Priority Pollutant Loads from Effluent
Discharges to the San Francisco Estuary," Water Environment Research, Vol. 64, No. 2,
March/April 1992; Flceal. A. Russell, et al., "Comparable Levels of Trace Metal Contamination in
Two Semi-Enclosed Embayments: San Diego Bay and South San Francisco Bay," Environmental
Science ami Technology, Vol. 27, No. 9, 1993; Los Angeles County Public Works, Report of
Stormwatcr Monitoring: Winter of 1994-95, Environmental Programs Division, March 1996;
Southern California Association of Governments, The State of Santa Monica Bay, Part Two:
Assessment of the Management Framework, Santa Monica Bay Project, November 1988; State
Water Resources Control Board, 7994 Section 305(b) Water Quality Report for the State of
California, October 1994; State Water Resources Control Board, Status of the Bay Protection and
Toxic Cleanup Program, Staff Report, State of California, November 1993; U.S. EPA, Los Angeles
River Loadings of Trace Metals and Synthetic Organics, Office of Research and Development,
Report No. 600'X-91/030, April 1991; WE&T Staff, "California Water Boards Address Impaired
Rivers," Water Environment and Technology, Vol. 7, No. 5, May 1995; Wranic, A.D., et al.,
"Pollutant Loadings Generated by Nonpoint Sources in the Santa Monica Bay Drainage Basin: A
Case Study," Water Resources Management, No. 8, 1994.
7-4
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JUNE 1997
Data Sources
Two studies serve as the foundation for the San Francisco Bay toxics apportionment:
• Davis et al., Status and Trends Report on Pollutants in the San Francisco
Estuary (1991)3; and
, • National Oceanic and Atmospheric Administration (NOAA), National
Coastal Pollutant Discharge Inventory (1988).4
Below, we discuss the loadings estimation methodology used in the two studies and the resulting
characterization of relative point source and other source contributions to overall toxic loadings.
Davis Study
The Status and Trends Report on Pollutants in the San Francisco Estuary uses existing data
to establish an upper and lower bound range for several toxic contaminants originating from both
point and nonpoint sources. Davis et al. estimate that 5,000 to 40,000 metric tons of at least 65
different pollutants are released annually into the San Francisco Estuary. These pollutants include
trace elements such as arsenic, lead, and mercury, and organic compounds such as pesticides.
Davis used effluent monitoring data from the National Pollutant Discharge Elimination
System (NPDES) to estimate municipal (POTW) and industrial loadings. These data were gathered
from 1984 through 1987. Other (nonpoint) sources of pollution, as defined by Davis et al., consist
of urban runoff, nonurban runoff, riverine inputs, atmospheric deposition, dredged material, and oil
spills. A study by Gunther et al. (1987) provided the range estimates for urban runoff.5 This study
used data on precipitation, land use, runoff coefficients and pollutant concentrations originally
gathered by NOAA and the National Urban Runoff Program (1983 data) to calculate loadings.
3 Davis, J.A., et al., Status and Trends Report on Pollutants in the San Francisco Estuary,
prepared by the San Francisco Bay-Delta Aquatic Habitat Institute for the San Francisco Estuary
Project, U.S. EPA, March 1991.
4 NOAA, The National Coastal Pollutant Discharge Inventory: Estimates for San Francisco
Bay. Data Summary, Ocean Assessments Division, National Oceanic and Atmospheric
Administration, June 1988.
5 Gunther, A. J., et al., An Assessment of the Loading of Toxic Contaminants, to the San
Francisco Bay-Delta, prepared by the Aquatic Habitat Institute, 1987.
7-5
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JUNE 1997
Nonurban runoff originates from agricultural, range, and forest lands. Davis used a NOAA
model that factors in sediment loss from nonurban lands and average trace metal concentrations in
soil to estimate runoff loadings to the Bay. Since NOAA chose a high precipitation year (1982) as
its modeling year, these estimates became the high ends of the ranges. To calculate the low ends of
the ranges, Davis et al. divided the high end figures by 11.5, a factor which accounts for values that
one might expect in a lower precipitation year.
Davis considers all pollutants transported past the city of Sacramento by the Sacramento
River and past the city of Vernalis by the San Joaquin River as riverine inputs to the Delta. Loadings
estimates for the San Joaquin River came from water quality data collected by the U.S. Geological
Survey under the San Joaquin Valley Drainage Program (SJVDP). Under the SJVDP at Vernalis,
scientists collected samples twice per month from June 1985 to March 1987. A study conducted by
the California Department of Water Resources in 1987-88 on selenium cycling serves as the only
source of information on loadings from the Sacramento River.
Given the lack of site-specific data for the San Francisco Bay area, Gunther et al. (1987)
applied deposition data measured in other parts of the U.S. when calculating their range of load
estimates. Davis incorporates these data.
Finally, in calculating total pollutant loads to the Estuary, Davis examined the possible
quantities that dredging activities might contribute. They believed that dredging could redistribute
buried pollutants to the extent that these pollutants would then become bioavailable to estuarine
biota. Gunther et al. (1987) estimated the pollutant loads derived from dredging activities in the
Estuary. Other studies suggest that these estimates may be highly conservative.
NOAA Study
The Strategic Assessment Branch of NOAA developed the National Coastal Pollutant
Discharge Inventory (NCPDI) to estimate pollutant loadings for all point, nonpoint, and riverine
sources located in coastal counties throughout the U.S. NOAA estimates that approximately 22,000
metric tons of toxic substances are released annually into the San Francisco Estuary. As with the
study by Davis, these substances include a variety of trace elements and synthetic compounds.
NOAA's point source estimates reflect discharges in a 1985 base year; the estimates for nonpoint
sources reflect discharges in a 1982 base year.
Similar to Davis, NOAA used effluent monitoring data from the National Pollutant Discharge
Elimination System (NPDES) to estimate municipal and industrial loadings in the base year 1985.
Other sources of pollution, as defined by NOAA, consist of urban runoff, nonurban runoff,
and riverine inputs. NOAA used four data sources to obtain its urban runoff estimates. First, NOAA
examined the 1980 Census of Population for definitions of urban areas and estimates of total county
and city urban land area and population. Second, the U.S. EPA Office of Water furnished the 1982
Needs Survey, a biennial survey of all POTW wastewater and stormwater conveyance and treatment.
7-6
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JUNE 1997
Third, NOAA's National Climatic Data Center provided detailed weather station records and
precipitation data for estimating runoff. Fourth, the U.S. Geological Survey's Land Use Data
Analysis system supplied information on urban land use activities. Combining these values with
runoff coefficients and pollutant concentrations yielded the final urban runoff estimates.
To estimate the contribution of nonurban runoff to loadings, NOAA examined those areas
deemed most likely to contribute significantly to loadings. These areas fall into one of four
categories: areas where farming, silviculture or other activities have exposed bare soil to wind, rain,
and surface runoff; areas where soil is most credible; areas where large amounts of chemical
fertilizers and pesticides have been applied to the land surface; and areas where sufficient runoff
exists to transport these pollutants. To compute the pollutant loadings, NOAA collected data on the
topography, soils, climate, land uses and management practices of all the areas studied. NOAA
obtained the majority of its data from three sources: the U.S. Geological Survey's Land Use Data
Analysis system, the U.S. Department of Agriculture's 1982 National Resource Inventory, and a
study by Shacklette and Boerngen (1984). In tabulating the specific pollutant loadings to the
Estuary, NOAA multiplied the quantity of eroded sediment by the soil pollutant concentration.
Riverine inputs to the Estuary originate primarily from the Sacramento and San Joaquin
Rivers. To estimate the share of pollutant loadings stemming from upstream sources, NOAA
obtained water quality data from the U.S. Geological Survey (USGS) National Stream Quality
Accounting Network (NASQAN). NOAA used the raw USGS data in a simulation model to
estimate loadings to San Francisco Bay.
Results for San Francisco Bay
We use the NOAA and Davis data to estimate relative loadings of toxics from point and other
sources discharging to San Francisco Bay. Exhibit 7-1 summarizes these estimates. Each entry in
the table shows the percentage of all loadings estimated to be from point sources. For example,
NOAA estimates that five percent of the zinc discharged to San Francisco Bay originates from point
sources, while Davis estimates that the point source percentage for zinc falls between four and 19
percent.6
In general, the exhibit shows that point sources contribute a smaller share of toxic loadings
than other sources. This is best summarized by developing an average percent contribution across
the pollutants for which data are available. A straight average of the point source contribution
percentages would be misleading because some pollutants are more toxic than others. For example,
a small quantity of mercury discharged to the Bay has much greater human health, ecological, and
economic implications than the same quantity of copper. A straight average would not recognize
6 Appendix F of this document provides the detailed loadings data from the NOAA and Davis
studies, as well as other data to be review later in this chapter.
7-7
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JUNE 1997
Exhibit 7-1
POINT SOURCE CONTRIBUTIONS TO SAN FRANCISCO BAY
Pollutant
Zinc
Copper
Nickel
Lead
Chromium
Arsenic
Cadmium
Selenium
Mercury (3)
Chlorinated Hydrocarbon
Pesticides
Toxic-Weighted Average
NOAA (1)
5%
6%
N/A
7%
3%
11%
16%
N/A
45%
51%
7% - 11%*
Davisetal.(l)
Lower Bound
4%
4%
26%
2%
1%
4%
30%
28%
26%
N/A
2%
Upper Bound
19%
12%
28%
8%
6%
6%
65%
28%
52%
N/A
7%
(1) NOAA, The National Coastal Pollutant Discharge Inventory: Estimates for San Francisco Bay, Data Summary,
Ocean Assessments Division, National Oceanic and Atmospheric Administration, June 1988. NOAA assessed the
following point sources: POTWs, industrial effluents, and power plant emissions. NOAA assessed the following
other sources: urban runoff, cropland runoff, forestland runoff, rangeland runoff, and upstream sources.
(2) Davis, J.A., et al., Status and Trends Report on Pollutants in the San Francisco Estuary, prepared by the San
Francisco Bay-Delta Aquatic Habitat Institute for the San Francisco Estuary Project, U.S. EPA, March 1991 . Davis
et al. assessed the following point sources: municipal effluents and industrial effluents. Davis et al. assessed the
following other sources: upstream sources, urban runoff, nonurban runoff, atmospheric deposition, dredged material,
and oil spills.
(3) The NOAA data show large mercury loadings associated with riverine inputs to the Bay. We classified 46.34
percent of these riverine loadings as point sources given that upstream mines are the likely original source of the
mercury. The 46.34 percent figure is based on the average point source contribution for several metals discharged
to the Sacramento River (see Exhibit 7-4).
* Lower bound of range based on median toxic weight for pesticides (100); upper bound of range based on mean
weight for pesticides (5,300).
7-8
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JUNE 1997
this difference and potentially would allow high-quantity/low-consequence pollutants to drive our
assessment of point source contributions. Therefore, we develop a toxicity-weighted average based
on the toxicity weights used in the cost analysis.7 Toxic weight factors were derived for toxic
pollutants primarily from EPA's chronic freshwater aquatic life criteria and toxicity values.
However, EPA human health criteria also were used in cases where a human health criterion had
been established for the consumption offish. Generally, toxic weights were derived by EPA through
standardizing these criteria using copper as the standard pollutant (the original EPA criterion for
copper, 5.6 ug/L, was used as the water quality criterion and the standardization factor).
Toxic weights for pollutants were taken from the Assessment of Compliance Costs Resulting
from Implementation of the Final Great Lakes Water Quality Guidance (March 13,1995). The toxic
weights used in the Great Lakes analysis represent toxic weights calculated by EPA's Office of
Science and Technology (OST) in 1988 using pollutant criteria that have been used in various EPA
regulatory efforts.8
The process of developing a toxicity-weighted average is illustrated in Exhibit 7-2, using the
NOAA data. We follow three steps: (1) we weight each "raw" loadings estimate from the NOAA
and Davis data by the relevant weighting factor shown in Exhibit 7-2; (2) we sum the weighted loads
to arrive at a total toxic loadings estimate for point and other sources; and (3) we estimate the
proportion of all loadings (point and other) that come from point sources.
In the case of chlorinated hydrocarbon pesticides, we need to estimate a weight for the entire
class of pollutants." The relevant weights range from a low of 0.35 for 2,4,6 trichlorophenol to a
high of 57,000 for dieldrin. 'Because of this range we use two weights in a sensitivity analysis: a
weight of 100 representing the median of the distribution, and a weight of 5,300 representing the
mean of the distribution.
7 SAIC. Analysis of Potential Costs Related to the Implementation of the California Toxics
Rule, Final Draft, prepared for the U.S. Environmental Protection Agency, May 1997.
8 National water quality criteria have changed over the years, resulting in corresponding
changes in toxic weights. Also, because California point sources discharge to both freshwater and
saltwater bodies of water, two different sets of toxic weights would need to be covered. To maintain
a general level of consistency between the CTR and previous rules, this study used previously
calculated toxic weights.
9 NOAA's estimate for chlorinated hydrocarbon pesticides includes fifteen different
pesticides, such as DDT and dieldrin.
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JUNE 1997
Exhibit 7-2
DERIVATION OF TOXIC-WEIGHTED LOADINGS
Pollutant
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Zinc
Chlorinated
Hydrocarbon
Pesticides
Toxicity
Weight
• .4
5.2
35.5
0.47
1.8-
500
0.051
100
Point Sources
Raw
Loadings
(tons)
18.14
12.70
32.66
55.34
41.73
4.38
143.34
0.57
Sum of Weighted Loadings
Toxic-
Weighted
Loadings
72.58
66.04
1,159.39
26.01
.75.12
2,190.00
7.31
56.52
3,652.97
Percent of
Total
11%
16%
3%
6%
7%
45%
5%
51%
7%
Other Sources
Raw
Loadings
(tons)
140.62
68.95
1,236.51
948.92
525.27
5.40
2,623.61
0.53
N/A
Toxic-
Weighted
Loadings
562.46
358.52
43,895.94
445.99
945.48
2,700.00
133.80
53.34
49,095.55
Percent of
Total
89%
84%
97%
94%
93%
' 55%
95%
49%
93%
Total From All Sources
Total
Loadings
635.04
424.57
45,055.34
472.00
1,020.59
4,890.00
141.11
109.86
52,748.51
Percent of
Total
100%
100%
100%
100%
100%
100%
100%
100%
100%
Notes:
1) Toxic weights obtained from: SAIC, Analysis of Potential Costs Related to the Implementation of the California Toxics Rule, prepared for the U.S.
Environmental Protection Agency, May 1997.
2) Point sources are defined as POTWs, industrial effluents, and power plant emissions. Other sources are defined as urban runoff, cropland runoff, forestland
runoff, rangeland runoff, and upstream sources.
Source: NOAA, The National Coastal Pollutant Discharge Inventory: Estimates for San Francisco Bay, Data Summary, Ocean Assessments Division, National
Oceanic and Atmospheric Administration, June 1988.
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JUNE 1997
Exhibit 7-1 lists the resulting toxicity-weighted loadings estimates. As shown, the toxicity-
weighted estimate of point source contributions ranges from about 2 percent (the lower bound of the
Davis data) to 11 percent (based on the NOAA data). The weighted average for the Davis data is
remarkably low relative to the percentages for individual pollutants. This is the result of the large
share of weighted loadings accounted for by chromium* a pollutant for which point sources
contribute only a small portion of total loadings.
Uncertainties and Limitations
Our analysis using the NOAA and Davis data to estimate point source contributions of toxics
is subject to several uncertainties and limitations:
First, detection limits in the sampling data used in the NOAA and Davis
studies required simplifying assumptions. When pollutants were below
detect limits, Davis calculated the lower end of each discharge range by
counting values below detection limits as zero, and calculated the upper end
of each range by assuming that below-detect values indicated a concentration
equal to the detection limit. NOAA did the same, but assumed that
concentrations were equal to one-tenth the detection limit.10 It is difficult to
determine the direction or magnitude of the bias introduced by these
assumptions.
Second, the NOAA and Davis data do not include specific estimates for many
sources, both point and nonpoint. Most notably, the estimates do not include
point source mine drainage, a significant source of toxic metals. In addition,
the NOAA data do not include atmospheric deposition or dredging. Again,
it is difficult to determine the direction of the bias introduced by these
limitations, although the variety of other (nonpoint) sources absent in the
analysis may tend to overstate the importance of point sources.
While both studies include riverine inputs as a nonpoint source, discharges
to these rivers may have originated as point or nonpoint sources. Again, it
is difficult to characterize the degree or direction of the bias without further
study.
, 10 No detect values for PCBs were especially problematic in the Davis data. PCBs were
detected in only 0.15%, or one in 677 samples. We therefore chose not to use these data in our
apportionment analysis.
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JUNE 1997
The data from both studies are based on discharges from the early and mid-
1980s, and therefore may not be entirely representative of current conditions
in San Francisco Bay.
It is uncertain whether toxics discharged upstream of the Delta actually reach
the Bay, or are, instead, bound up in sediments for long periods of time. It
is unclear how the NOAA and Davis studies deal with toxics fate and
transport. If fully conservative fate and transport assumptions were made,
this would tend to overstate the amount of toxics which actually reach the
Bay.
In addition, the Davis study has several specific shortcomings. Most notably, despite the fact
that the Sacramento River contributes 80 percent of the freshwater inflow to the Estuary, and
probably carries numerous toxic pollutants, Davis did not include estimates for the River. Because
much of the impairment of the Sacramento is attributable to mines, this omission likely leads us to
understate point source contributions." Also, in estimating urban runoff, Davis did not have local
runoff pollutant concentrations; as an alternative, the study uses national averages from the National
Urban Runoff Program (1983 data). Finally, as stated earlier, Gunther and Davis used atmospheric
deposition rates from other parts of the country to estimate loads to the Estuary. Use of these rates
from the rest of the country would tend to overestimate loadings from this source as there are few
sources of airborne toxics upwind from the Bay area. If values from the upper mid-west were used,
the overestimate could be large.12
Other Bays and Estuaries
Data Sources
To estimate the contribution of point source loadings of toxics to bays other than San
Francisco Bay, we use the same set of NOAA data (the National Coastal Pollutant Discharge
Inventory) used for San Francisco Bay. NOAA data are available for five "other" bays: San Diego,
Humboldt, Monterey, Santa Monica, and San Pedro.13
1' Mine drainage contributes significantly to the impairment of the Sacramento River,
especially for copper, zinc, and cadmium. See California Regional Water Quality Control Board,
Central Valley Region, Inactive Mine Drainage in the Sacramento Valley, California, 1992.
12 Personal communication with Dave Smith, U.S. EPA, Region IX, San Francisco,
California, February 20,1996.
13 Note that Only two of these bays — San Diego and Humboldt — are enclosed bays that are
therefore covered by the rule. We assume that the data for the non-enclosed bays generally will be
applicable to enclosed bays.
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JUNE 1997
Results for Other Bays and Estuaries
Exhibit 7-3 summarizes the relative contribution of point sources to "other" California bays.
In general, the toxicity-weighted average contribution of toxic loadings stemming from point sources
ranges greatly, from 23 percent (for Monterey Bay) to 93 percent (for Santa Monica Bay). A pattern
clearly evident in the data is the difference between urban and non-urban bays. In general, urban
bays tend to have a greater portion of their toxics loadings originating from point sources than do
less urbanized bays. Urban area discharges typically come from point sources such as POTWs,
storm water discharges, electric power plants, and industrial facilities. San Diego, Santa Monica,
and San Pedro Bays (the latter two being near Los Angeles) can be treated as representative of other
urban bays covered by the CTR (including Mission Bay, Upper and Lower Newport Bay, and Los
Angeles-Long Beach Harbor). As shown, the three bays for which we have data all have average
point source contributions of about 90 percent.
Non-urban bays are less populated and have different dischargers than urban bays. A larger
portion of their toxic loadings originate from nonpoint sources such as farming and forestry runoff.
For example, the largest town surrounding Humboldt Bay is Eureka, which contains fewer than
100,000 inhabitants. Most of the land surrounding Humboldt Bay is designated as national forest
or wilderness area. For these reasons, Humboldt and Monterey Bay can be treated as representative
of the non-urban bays covered by the rule (Bodega Harbor, Morro Bay, Drake's Estero, Tomales
Bay, and Carmel Bay). As shown, the two bays for which we have data have average point source
contributions of between 23 and 33 percent.
Uncertainties and Limitations
Above, we noted limitations that apply to the NOAA data on San Francisco Bay; these
limitations are also applicable to the data for other bays. In addition, it is noteworthy that the
estimated point source contributions for San Francisco Bay are much lower than for the other urban
bays. The reason for this discrepancy is not readily apparent. Most likely, the contrast is attributable
to the hydrologic difference between San Francisco Bay and the other bays. San Francisco Bay is
a major estuarine system and represents the drainage basin for a massive geographic area comprising
urban, agricultural, and other land uses. In addition, the area is fed by two major rivers (the San
Joaquin and the Sacramento) that contribute significantly to loadings. In contrast, the other bays are
much smaller waterbodies that in many cases do not represent major drainage basins and are fed by
smaller or even seasonal rivers. Overall, this will enhance the relative importance of point sources.
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JUNE 1997
Exhibit 7-3
CONTRIBUTION OF POINT SOURCES TO OTHER CALIFORNIA BAYS
Pollutant
Arsenic
Cadmium
Chromium
Copper
Lead
Mercury
Zinc
Chlorinated
Hydrocarbon
Pesticides
Toxic-
Weighted
Average
Non-Urban Bays (1)
Monterey Bay
57%
84%
15%
16%
30%
76%
24%
N/A
23%
Humboldt Bay
33%
40%
35%
17%
19%
9%
27%
N/A
33%
Urban Bays (2)
San Diego Bay
88%
100%
95%
87%
41%
90%
81%
93%
91% - 92%*
Santa Monica
Bay
90%
100%
88%
89%
67%
88%
78%
99%
-
88% - 93%*
San Pedro Bay
87%
100%
88%
79%
. 27%
81%
71%
94%
83% - 89%*
(1) NOAA, The National Coastal Pollutant Discharge Inventory, Summary of Pollutant Discharges in West Coast
Study Area by Extuarine Watershed, circa 1982/1984; obtained on disk from Mr. Percy Pacheco, Office of Ocean
Resources Conservation and Assessment. NOAA assessed the following point sources: POTWs, industrial effluents,
and power plant emissions. NOAA assessed the following other sources: urban runoff, cropland runoff, forestland
runoff, rangeland runoff, irrigation return flows, and upstream sources.
(2) NOAA, The National Coastal Pollutant Discharge Inventory: Estimates for Santa Monica Bay, San Pedro Bay,
and San Diego Bay. Data Summary, Ocean Assessments Division, National Oceanic and Atmospheric
Administration, July 1988.
Notes:
* Lower bound of range based on median toxic weight for pesticides (100); upper bound of range based on mean
weight for pesticides ( 5,300).
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JUNE 1997
Freshwater
Developing general conclusions on the relative loadings contributions of point and nonpoint
sources discharging toxics to freshwater is difficult. California has a diverse interior landscape and
numerous sources of toxic pollutants, including farming, mining, and forestry, as well as residential,
industrial, and commercial establishments. As a result, available data show significant variability
in overall point source contributions of toxics depending upon the specific location. For example,
discharges from mines, which are regulated as point sources, are significant to the Sacramento River,
while other pollution sources associated with agricultural drainage dominate toxics loadings to the
San Joaquin River. This diversity makes it difficult to generalize about the role of point sources in
overall discharges of toxics to freshwater. Ideally, we would characterize the benefits of toxics
control and the sources of toxics loadings for each major freshwater resource and apportion the
benefits based on the distribution of loadings by source. Such an analysis, however, is beyond the
scope of this analysis.
Other uncertainties include the fact that data are not available for assessing point and
nonpoint contributions of toxics. While such inter-source data are available for key coastal
waterbodies, little information exists for California freshwater generally, or even for specific bodies
of freshwater.
Because of these difficulties, we rely on a limited set of data to develop a relatively broad
range of point source contributions to freshwater. First, we consider loadings data on two major
rivers in California. Second, we rely on other information from our analysis of the Water Quality
Assessment data base.
Loadings Data
The Central Valley Regional Water Quality Control Board (CVRWQCB) assembled data on
the principal sources discharging several metals to the Sacramento and the San Joaquin Rivers.14
The sources analyzed included the following:
14 Central Valley Regional Water Quality Control Board, Mass Emission Strategy Load
Estimates, internal staff report, no date. Most of the data in this report are based on California
Regional Water Quality Control Board, Central Valley Region, A Mass Loading Assessment of
Major Point and Nonpoint Sources Discharging to Surface Waters in the Central Valley, California,
1985, Draft Staff Report, October, 1988.
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JUNE 1997
Urban runoff calculated for 19 major cities in the Central Valley region;
Agricultural drainage based on monitoring data collected by the Regional and
State water quality boards in the mid 1980s (for the Sacramento River) and
modeled loadings (for the San Joaquin River);
Mining drainage based on monitoring data for 34 mining sites in the
Sacramento River valley and one mine in the San Joaquin River valley;
Industrial and municipal point sources based on effluent concentration data
from the Sacramento County sewage treatment plant and flow data for the
individual NPDES-permitted dischargers.15
The CVRWQCB report points to a number of uncertainties and shortcomings in the data
reported. First, the urban runoff estimates used probably understate total runoff discharges given
that only a subset of cities in the Central Valley region were incorporated and "below detect"
pollutant concentration values were counted as zero. Second, mining drainage estimates for the San
Joaquin River include only one mine for which samples were taken at only one point in time.
Finally, use of effluent concentration data from the Sacramento County POTW may not be
representative of effluent from other facilities, although the direction of the bias is unclear.
Because land use around the Sacramento and San Joaquin Rivers is diverse, the percentage
contribution of toxic pollution from point sources varies greatly. Exhibit 7-4 shows the percentage
of loadings attributable to point sources on each river. For all pollutants, point source contributions
for the Sacramento River are greater than those for the San Joaquin. This is explained by the strong
influence of point source mine discharges on the Sacramento.16 Using a toxicity-weighted average
across all five pollutants indicates that about 46 percent of loadings to the Sacramento River are
associated with point sources, while only three percent of loadings to the San Joaquin River are
associated with point sources.
15 Facility-specific loadings were not used because: (a) monitoring was performed for only
a subset of pollutants, and (b) much of this sampling used high detection limits.
16 As noted earlier, mines are regulated as point sources. However, NPDES permits have
not been issued for all mines. Therefore, all toxic discharges may not be reduced immediately under
the point source controls assumed in the CTR cost analysis.
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JUNE 1997
Exhibit 7-4
POINT SOURCE CONTRIBUTIONS TO FRESHWATER RIVERS
Pollutant
Arsenic
Cadmium
Copper
Lead
Zinc
Toxic-Weighted
Average
Sacramento River
22%
82%
72%
6%
73%
46%
San Joaquin River
3%
6%
3%
3%
7%
3%
(1) Central Valley Regional Water Quality Control Board, Mass Emission Strategy -
Load Estimates, no date. The CVRWQCB assessed two point sources, inactive mine
drainage and NPDES discharges. The CVRWQCB assessed two other sources, urban
runoff and agricultural drainage.
If we assume that the Sacramento River data are representative of mining areas, and that the
San Joaquin data are representative of areas not heavily influenced by mines, we can develop a
weighted average of the available data. This average weights the point source contribution in mining
areas (46 percent across all pollutants) by the percentage of California freshwater influenced by
mining, and the point source contribution in non-mining areas (3.4 percent) by the percentage of
waters not influenced by mines. This calculation can be implemented using data from our analysis
of California's Water Quality Assessment data base. Data compiled for Exhibit 2-5 of Chapter 2
indicate that 61 percent of lake acreage and 25 percent of river miles are adversely influenced by
mining. Using this information, we can calculate the following:
Lakes: (0.61 * 0.46) + (0.39 * 0.034) = 0.29, i.e., 29 percent of loadings to
lakes are attributable to point sources;
Rivers: (0.25 * 0.46) + (0.75 * 0.034) = 0.14, i.e., 14 percent of loadings to
rivers are attributable to point sources.
Water Quality Assessment Data
To develop a point source contribution range for freshwater, the above loadings information
should be considered in the context of other available information. Most notably, the Water Quality
Assessment database analysis from Chapter 2 provides useful information about sources of toxics
to California freshwaters. Exhibit 7-5 summarizes data reported earlier in Chapter 2. The table
7-17
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JUNE 1997
shows the various sources associated with toxics-impaired freshwater. Two key factors impede our
ability to draw precise conclusions from these data. First, a given waterbody can be affected by
more than one source type (e.g., a lake acre can be influenced by both mining and urban runoff).
Second, the WQA data do not report actual loadings, only the association between a waterbody and
a particular source category; i.e., mining and urban runoff may both affect a waterbody, but one may
be much more important than the other.
Exhibit 7-5
MAJOR SOURCES OF TOXIC POLLUTANTS IN CALIFORNIA FRESHWATER RESOURCES
ndustrial
Mining
Municipal
Other Point Sources
Agriculture
iydro/Habitat Modification
^and Development
.and Disposal
Other Nonpoint Sources
Storm Sewers
Jrban Runoff
Lakes &
Reservoirs
(acres)
295
106,748
0
0
2,410
0
26,500
0
64,350
0
7,995
Share of Total
Toxics-Impaired
Area
<1%
61%
0%
0%
1%
0%
15%
0%
37%
0%
5%
Rivers &
Streams (miles)
273
930
276
4
2,260
40
106
19
987
185
537
Share of Total Toxics-
Impaired Area
7%
25%
7%
<1%
60%
1%
3%
1%
26%
5%
14%
Source: EPA analysis of California 1994 WQA data.
Despite these drawbacks, the data clearly show that point sources play a significant role in
toxics loadings to freshwater. Most notably, mines affect 61 percent of impaired lakes and 25
percent'of impaired rivers. Likewise, industrial and municipal point sources adversely affect a
significant share of impaired rivers. Contributions from other sources, however, are still equally
important for lakes (e.g., other nonpoint sources and urban runoff) and possibly more important than
point sources for rivers, where about 60 percent of all impaired river miles are associated with
agricultural runoff. Taken together, this information suggests that point sources, especially mines,
are important contributors of toxics loadings to freshwater, but other sources dominate. This finding
is generally consistent with the loadings data presented above.
7-18
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JUNE 1997
Summary of Point Source Contributions to Freshwater Loadings
We can merge the available information to establish a range of point source contributions to
freshwater loadings. For the lower bound, we assume that point sources contribute at least five
percent of toxics loadings, based on the CVRWQCB data for the San Joaquin River. For the upper
bound, we assume that point sources account for 30 percent of toxics loadings, based on the lake-
weighted average of the CVRWQCB data. We use this range — five to 30 percent ~ to apportion
economic benefits below.
APPORTIONMENT OF ECONOMIC BENEFITS
The analysis of point source contributions to total toxics loadings can be used to estimate the
portion of economic benefits (see Chapter 4) attributable to controls at point sources. However, the
apportionment of economic benefits cannot be developed on a pollutant-specific basis. It is difficult
to estimate pollutant-specific effects on aquatic life and translate them into economic measures (such
as recreational fishing benefit or non-use benefits). Therefore, we develop an apportionment
analysis that uses average point source contributions and loadings reductions across regulated
pollutants. In general, we follow three steps:
First, we sum the use and non-use benefits for three waterbody categories:
(1) San Francisco Bay, (2) other bays and estuaries, and (3) freshwater and
saline lakes.17
Next, we multiply the economic benefit estimate for each waterbody category
by the relevant point source contribution range. The range used represents
an average across the pollutants for which data are available. In effect, this
provides a rough estimate of the benefits that would be realized if all point
source discharges were reduced to meet water quality standards.
Finally, we multiply by the percentage reduction in point source discharges
as estimated in the cost analysis performed for this rule.18 Specifically, we
use the average loadings reduction across the 50 pollutants addressed in the
cost analysis. We develop the toxic-weighted average load reduction by
dividing the sum of the toxic-weighted loadings reductions by the sum of the
17 The latter category includes freshwater rivers and lakes as well as saline lakes; we include
saline lakes in this category because the profile of point and nonpoint discharges is likely to have
more in common with freshwater lakes than with bays and estuaries.
18 SAIC, Analysis of Potential Costs Related to the Implementation of the California Toxics
Rule, prepared for the U.S. EPA, May 1997.
7-19
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JUNE 1997
toxic-weighted baseline loadings. We develop this estimate for both the
upper and lower bound control scenarios from the cost analysis. Exhibit 7-6
presents the reductions for individual pollutants and the estimated average
reduction — 27 percent in the lower bound and 31 percent in the upper bound.
This approach can be summarized with the following equation:
Economic Percent of Toxics Percent Reduction Benefits From
Benefit * Discharged by * Of Total Toxics = Controls Implemented
Estimate Point Sources Discharges At by Point Sources
Point Sources19
Exhibit 7-7 shows how we combine these pieces of information to estimate the total
economic benefits attributable to point source control. As shown, we estimate that control of toxics
discharged from point sources will yield between $3 million and $65 million per year in economic
benefits. The method and results differ somewhat for each waterbody category. Below, we discuss
each category in more detail.
San Francisco Bay
To estimate the benefits attributable to point source control in San Francisco Bay, we use the
toxic-weighted average of the point source contributions for individual pollutants (see Exhibit 7-1).
For a lower bound, we use the mid-point of the estimates derived from the Davis data — 4 percent
(the mid-point of 1.5 percent and 7.09 percent, the unrounded Davis results). As an uppef bound,
we use the higher estimates from the NOAA study —11 percent.
We then multiply by the range in point source reduction of toxic loadings (27 to 31 percent)
to estimate the total benefits attributable to point source control. As shown, the range is very broad,
reflecting the uncertainty inherent in the estimates. Specifically, we estimate that point source
controls in San Francisco Bay will yield between $69,000 and $2 million per year in recreational
fishing benefits and non-use benefits.
19 Calculating the gross change in water quality attributable to point source controls requires
two pieces of information: (1) the percent of toxics discharged by point sources; and (2) the percent
reduction of total toxics discharges at point sources. The first piece of information only identifies
the portion of water quality changes attributable to point source discharges versus nonpoint source
discharges. To calculate the gross change, an estimate of the reduction in toxics achieved through
point source controls is also needed.
7-20
-------
Exhibit 7-6
BASELINE TOXIC-WEIGHTED LOADINGS AND LOAD REDUCTIONS
Pollutant
Arsenic (As)
Cadmium (Cd)
Chromium VI (Cr-VI)
Copper (Cu)
Lead (Pb)
Mercury (Hg)
Nickel (Ni)
Selenium (Se)
Silver (Ag)
Zinc (Zn)
1,2 Dichlorobenzene
1,3 Dichlorobenzene
1,4 Dichlorobenzene
1 ,4-Dichlorobenzene
2,4,6 Trichlorophenol
4,4'-DDD
4,4'-DDT
Aldrin
alpha-BHC
alpha-Endosulfan
Benzene
beta-BHC
Bromoform
Butylbenzyl-pthalate
Chlordane
Chlorobenzene
Chlorodibromomethane
Chloroform
delta-BHC
Dichlorobromomethane
Dichloromethane
Dieldrin
Endosulfan
Endrin
Fluoranthene
Fluorene
gamma-BHC
Heptachlor
Heptachlor epoxide
Hexachlorobenzene
Toxicity
Weight
4.00
5.20
35.50
0.47
1.80
500.00
0.04
1.10
47.00
0.05
0.01
1.00
1.00
1.00
0.35
760.00
6,500.00
50.00
100.00
100.00
0.02
100.00
1.00
1.00
2,300.00
0.00
1.00
0.00
1.00
1.00'
0.00
57,000.00
100.00
98.00
0.92
0.70
70.00
4,100.00
1.00
720.00
Lindane gamma-BHC \ 70.00
Methylene chloride
PCBs
Pentachlorophenol
Phenol
TCDD equivalents
.Tetrachloroethene
Toluene
Toxaphene
Total
Toxic-Weighted Average
0.00
7,490.00
0.50
0.03
420,000,000.00
0.07
0.01
29,000.00
High
Baseline
Loadings
2,635,683
280,642
4,936,864
258,616
644,423
2,390,662
81,083
54,473
12,098,544
132,997
518,483
5,647,941
172,888
0
384
8,804
114,842
118,039
195,477
3,883
1,329
12,544
22,188
0
1,174
0
55,576
3,436
0
74,218
0
50,838
221
1,436
205,844
0
32,823
4,364
0
117,285
0
1,078
4,974
6,527
0
6,533
0
2,688,007
2,823
33,587,944.8
Reductions
0
0
682,996
47,103
257,842
1,699,029
24,578
7,980
6,176,143
14,127
22,631
0
0
0
0
6,867
72,287
116,066
135,466
1,071
0
0
2,829
0
0
0
9,084
58
0
282
0
0
41
186
830
0
4,249
0
0
110,933
0
3
0
738
0
0
0
895,635
0
10,289,055.8
Percent
Reduction
0.0%
0.0%
13.8%
18.2%
40.0%
71.1%
30.3%
14.6%
51.0%
10.6%
4.4%
0.0%
0.0%
0.0%
78.0%
62.9%
98.3%
69.3%
27.6%
0.0%
0.0%
12.8%
0.0%
16.3%
1.7%
0.4%
0.0%
18.3%
12.9%
0.4%
12.9%
0.0%
0.0%
94.6%
0.3%
0.0%
11.3%
0.0%
33.3%
0.0%
30.63%
Low
Baseline
Loadings
307,983
75,867
2,171,424
217,637
127,664
1,661,481
11,883
5,913
2,041,181
65,905
0
0
596
0
0
8,804
104,576
118,026
191,932
0
200
0
20,005
0
0
0
55,427
480
0
79,468
0
0
0
836
0
L_ 0
25,884
2,584
0
0
0
4
0
0
0
0
Reductions
0
0
399,958
8,034
0
1,092,898
0
0
214,546
0
0
0
0
0
0
0
0
115,533
135,369
0
0
0
0
0
0
0
8,202
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Percent
Reduction
0%
0%
18%
4%
0%
66%
0%
0%
11%
0%
0%
0%
0%
98%
71%
0%
0%
15%
0%
0%
0%
|
0%
0%
t
0%)
o|
0
0
0
01 0
0
0
7,295,760.3
0
0
1,974,540.2
1
1
27.06%
Source: Science Applications International Corporation and Jones and Stokes Associates, Incorporated, Analysis of Potential Costs Related to
the Implementation of the Proposed California Water Quality Toxics Rule, prepared for the U.S. Environmental Protection Agency, November
1996
-------
JUNE 1997
Exhibit 7-7
APPORTIONING USE AND NON-USE BENEFITS TO CONTROL OF POINT SOURCES
San Francisco Bay
Other Bays and
Estuaries
Rivers and Lakes*
TOTAL
Baseline Recreational
Fishing
Lower
$4,278,000
$14,257,882
$16,119,290
$34,655,172
Upper
$27,272,250
$90,893,995
$77,737,311
$195,903,556
Baseline
Non-Use Benefits
Lower
$2,139,000
$7,128,941
$8,059,645
$17,327,586
Upper
$40,908,375
$136,340,993
$116,605,967
$293,855,334
Point Source
Contribution
Lower
4%
42%
5%
Upper
11%
64%
30%
Point Source
Reduction
Lower
27%
27%
27%
Upper
31%
31%
31%
Potential Benefits
Attributable to
Implementing Point
Source Controls
Lower
$69,304
$2,425,266
$326,416
$2,820,985
Upper
$2,324,959
$45,083,422
$18,073,925
$65,482,306
Potential Benefits Attributable
to Control of Other Sources
Lower
$6,347,696
$18,961,557
$23,852,520
$49,161,773
Upper
$65,855,666
$182,151,566
$176,269,353
$424,276,585
* Includes saline lakes.
Sources: EPA analysis
Economic benefits analysis (see Chapter 4) .
7-22
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JUNE 1997
Other Bays and Estuaries
To estimate the economic benefits associated with point source control in bays and estuaries
other than San Francisco Bay, we first need to refine our estimate of point source contributions to
total toxics discharges. As shown earlier in Exhibit 7-3, available data suggest that urban bays are
influenced more heavily by point sources than are non-urban bays. While point sources account for
about 67 percent of toxics loadings to urban bays, they represent about 28 percent of toxic-weighted
loadings to non-urban bays.20 We developed two methods to obtain a combined measure of point
source contributions to other bays. First, we develop an estimate scaling by population living around
urban versus non-urban bays:
Population Near Urban Bays Population Near Non-Urban Bays
* 67% + * 28%
Population Near All Bays Population Near All Bays
This calculation implicitly assumes that the benefits we are apportioning to point sources
(recreational fishing and non-use benefits) are proportional to the population living in different areas.
For example, it assumes that more fishing occurs in urban bays than non-urban bays. While
exceptions may exist, this generally will be true..
To estimate the population near urban and non-urban bays, we first identified the relevant
set of enclosed bays covered by the rule. Urban bays include San Diego Bay, Mission Bay, Upper
and Lower Newport Bay, and Los Angeles-Long Beach Harbor. Non-urban bays include Humboldt
Bay, Bodega Harbor, Morro Bay, Drake's Estero, Tomales Bay, and Carmel Bay.21 We obtained the
total population living within 10 miles of each bay by aggregating census tract-level data (1990
Census) using geographic information system software. This method yields an estimate of
approximately 3.1 million people living near urban bays and 275,000 people living near non-urban
bays.
20 The average urban bay figure represents the mean of the average point source contributions
for the three "other" urban bays for which data were available, as well as San Francisco Bay. We
added San Francisco Bay to this average because it is an urban bay for which available data suggest
a lower point source contribution, offsetting the uncertainty associated with the NOAA data for the
three other urban bays. The non-urban bay figure is simply the mean of the toxic-weighted average
for Monterey and Humboldt Bay. In all cases, we use the median weight (100) for chlorinated
pesticides in calculating the average across the different bays.
21 The set of enclosed bays is taken from Water Resources Control Board, State of California,
California Enclosed Bays and Estuaries Plan, April 1991.
7-23
-------
JUNE 1997
Using the population-weighted approach, we estimate a weighted average point source
contribution of about 64 percent for all bays other than San Francisco Bay.22
We can also scale urban and non-urban bays by their area rather than by the population living
around them. Using information from the Water Quality Assessment data base, we compiled data
on the total acreage of each of the urban and non-urban bays covered by the rule. Scaling by area
yields an estimate of 42 percent of toxics loadings associated with point sources. We use this figure
as the lower bound in developing the apportionment estimate.
t
Combining the range in estimated point source contributions (42 to 64 percent) with the
range in point source control (27 to 31 percent) yields an estimate of $2 million to $45 million per
year of economic benefits realized through control of point source discharges to other bays. These
represent the majority of benefits to be realized through point source control, relative to the San
Francisco Bay and freshwater estimates.
Freshwater
The benefits associated with control of point sources discharging to freshwater can be
estimated by multiplying the baseline benefits by the point source contribution range estimated
earlier in this chapter ~ 5 to 30 percent. We then multiply by the point source reduction range (27
to 31 percent) to determine the benefits attributable to implementing point source control to meet
the proposed water quality standards. As shown, this benefit ranges from a low of $300,000 to a
high of $18 million.
APPORTIONMENT OF RECREATIONAL
ANGLER HEALTH BENEFITS
EPA's health benefits assessment (presented in detail in Chapter 3) indicates that PCBs,
dioxin, pesticides, and mercury account for the greatest share of cancer and noncancer risks to
recreational anglers. A series of fish consumption health advisories in California waters
demonstrates the potential risk posed by these four contaminants. For example, areas of Los Angeles
Harbor (e.g., Belmont Pier and Cabrillo Pier) have fish consumption advisories for PCBs and
pesticides, while San Francisco Bay has advisories posted for PCBs, pesticides, dioxin, and mercury.
Additionally, regulators have issued consumption advisories for several ocean sites in southern
California that are not included in the California Toxics Rule (e.g., Newport Pier, Redondo Pier,
Malibu Pier, and Short Bank).
22 [(3,100,000/3,379,000) * 67%] + [(275,000/3,379,000) * 28%] = 64 %
7-24
-------
JUNE 1997
To derive apportioned angler health benefit estimates associated with reducing PCB, dioxin,
mercury, and pesticide contaminant levels to meet water quality criteria, we examined existing
literature and contacted experts to explore the extent to which these contaminants may be coming
from point sources. Below, we discuss the results of our research. While the level of uncertainty
in the available data precludes a quantitative estimate of risk reduction associated with point source
control, we use the findings to roughly illustrate potential cancer and noncancer benefits.
Discussion of Information
PCBs
Production of PCBs, which began in 1929, was banned in the U.S. in 1979 because of
concerns about toxicity, biomagnification, and environmental persistence. EPA estimates that more
than 50 percent of all PCBs ever produced can be found in currently operating electrical transformers
and capacitors. Point source PCB discharges can occur during the maintenance and disposal of
electrical equipment, the overheating of transformers containing PCBs, leaks from industrial
systems, and PCB waste disposal.23
Detection limits that are higher than effluent concentrations and water quality criteria pose
the greatest obstacle to obtaining concrete data on point source discharges of PCBs. Limitations
associated with current analytical techniques often prohibit the detection of PCBs in municipal and
industrial effluent, even though these sources are suspected of discharging PCBs at concentrations
greater than zero. In other words, since current analytical techniques can only measure water column
concentrations that exceed the minimum detection limit (MDL) and water quality criteria fall below
this level (i.e., 0 < water quality criteria < MDL), point source discharges that exceed water quality
criteria may go unnoticed. EPA estimates a MDL of 0.065 micrograms per liter for most PCB
compounds.
Point source discharges that exist, but can not be quantified using current analytical
techniques, can be thought of as "hidden loads". EPA examined "hidden" PCB loadings from point
sources as part of the Great Lakes Water Quality Guidance (1993).24 Specifically, the report
concluded that measured and "hidden" current point source loadings contributed between 0.02 and
1.28 percent of the concentration of PCBs in fish fillets. This evidence suggests that even if
monitoring data do not explicitly link PCBs and point sources, discharges may still be significant.
23 U.S. EPA, Issues Related to the Cost-Effectiveness of Reducing PCB Inputs to the Great
Lakes from Point Sources, March 8, 1995.
24 U.S. EPA, March 1995.
7-25
-------
JUNE 1997
To further explore the question of whether point sources could be contributing to PCB
discharges in California waters, EPA contacted informed personnel from the State Water Resources
Control Board and various Regional Water Quality Control Boards, and other knowledgeable
sources.25 Most of those contacted had minimal knowledge of specific reports or data that directly
link point sources to PCBs in California surface waters. Some staff members provided anecdotal
information and suggested alternative leads for EPA to explore. These leads yielded three pieces
of evidence indicating that a portion of PCB loadings may come from point sources.
First, EPA consulted a Superfund database for sites affected by PCBs.
Effluent from groundwater treatment at these sites may be discharged under
a point source permit or to a point source permitted facility (e.g., local
POTW). Some of the sites obtained from the database search include:
Westinghouse Electric (Sunnyvale Plant), MGM Brakes (Cloverdale), and
Lorentz Barrel & Drum (San Jose).
Second, Permit Compliance System (PCS) data from 1990 to 1994 revealed
that some POTWs observed PCB concentrations above detection limits, but
below permit limits.
Finally, upon review of the same PCS data, EPA discovered that some
facilities without PCB limits had detected PCBs during routine monitoring.
Some of the detected levels were significantly above the proposed water
quality criterion and the MDL (i.e., greater than 0.065 micrograms per liter).
EPA also analyzed economic census data (1992) and PCS data for industries in the Great
Lakes region reporting PCB discharges to see if any of these industries exist in California. For
example, six nonmetallic mineral mining operations located in the Great Lakes region reported PCB
discharges. Assuming that mining operations in the Great Lakes region and California use similar
practices for mineral extraction, a portion of the 219 nonmetallic mining operations in California
also may discharge PCBs. To test this claim, EPA examined PCS data for industries in California
reporting PCB discharges. The results of this analysis indicate that of the 219 nonmetallic mining
operations in California suspected of discharging PCBs, three reported actual discharges. Overall,
many industries found to discharge PCBs to the Great Lakes are also present in California; these
include lumber, furniture, printing, publishing, and chemical production. Appendix G provides a
complete list that compares industries reporting PCB discharges in the Great Lakes region and the
existence and number of similar industries in California.
25 U.S. EPA, "PCB Data Search for California Toxics Rule (CTR)," memorandum from Erik
Beck to California Toxics Rule File, October 17,1996.
7-26
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JUNE 1997
Finally, an EPA research initiative, the National Study of Chemical Residues in Fish,
revealed potential point sources of PCBs and dioxin in California.26 EPA established the study to
determine the prevalence of selected bioaccumulative pollutants in fish. Scientists collected tissue
samples of 119 different fish species from sampling sites across the U.S. thought to be influenced
by a variety of point and nonpoint sources. This included tissue data taken from 26 sampling sites
in California. More than half of the fish samples collected in California contained detectable levels
of PCBs. Qualitative examination of site conditions determined that a portion of the contamination
originated from point sources. Note that the qualitative examination of site conditions and the fish
tissue analysis were conducted independently, thus we can not isolate the exact source of a particular
pollutant. We list the 26 sampling sites and their associated contamination sources in Exhibit 7-8.
Dioxin
Similar to PCBs, dioxin is difficult to trace to point sources because of concentration levels
that fall below detection limits. To obtain information on point source discharges of dioxin, EPA
contacted a diverse group of knowledgeable personnel from the State Water Resources Control
Board, Regional Water Quality Control Boards, and environmental non-profit organizations.27
Initial information gathered indicate that EPA Region IX currently has limited knowledge
of dioxin discharges from current NPDES permitted paper or pulp mills. In addition, EPA Region
IX has no evidence that any NPDES permitted POTWs were in violation of their dioxin discharge
limits. As for industrial sources, a review of PCS data indicated that no facilities reported recent
dioxin violations. Various conversations and data searches yielded a list of 45 facilities suspected
of discharging dioxin to surface water currently or historically. Only two facilities on this list
detected dioxin and had no discharge permit. However, no dioxin detection has occurred at either
site since 1993. Once again, however, this lack of specific quantitative data may be attributable to
dioxin concentration levels that fall below detection limits.
Subsequent investigations by EPA, however, did yield some information linking dioxin to
point sources. Data from the Region 2 Water Quality Control Board indicate that several facilities
around San Francisco Bay have recorded above-detect levels of dioxin in effluent. Additionally,
stormwater data collected around San Francisco Bay indicate that dioxin congeners exist
ubiquitously in area discharges.28 The report concludes that if dioxin is measured in TEQs, all but
two samples exceed the 0.013 pg/L level.
26 U.S. EPA, National Study of Chemical Residues in Fish, Volumes I-II, Office of Science
and Technology, September 1992.
27 U.S. EPA, "Summary of Dioxin Data Search for California Toxics Rule (CTR) and
Summary of Significant Findings," memorandum from Gary Sheth to California Toxics Rule File,
October 18, 1996.
28 California Regional Water Quality Control Board, Survey of Storm Water Runoff for
Dioxins in the San Francisco Bay Area, February 1997.
7-27
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JUNE 1997
rihlMt 74
POSSIBLE KB AND DIOXIN DISCHARKF MM RCFS AT SFI.F.CTF.D CALIFORNIA SAMPLE SITES
Episode
n
3282
3288
3285
3273
3286
3271
3272
3275
3276
3289
3451
3354
Waterbody
Alamo River
Blanco
Drain
Colorado
Lagoon
Elk Creek
Harbor Park
Lake
Hayfork
Creek
Lauritzen
Canal
Mad River
Mad River
Slough
Moss
Landing
Dam
Mouth of
Malibu
Creek
New
Mormon
Slough
Location
Calipatria
Salinas
Long
Beach
Crescent
City
Harbor
City
Hayfork
Richmond
Arcata
Arcata
Moss
Landing
Malibu
Stockton
P*4nt S««rm
Paper/Pulp
Mill Using
Chlorine
Paper/Pulp
Mill Not
Using
Chlorine
Refinery
Superfund
Site
X
X
Other
Industrial
Discharge
X
X
X
X
X
X
X
POTW
X
Wood
Preserving
Activity
X
X
Nonpoint Sources
Urban
Runoff
X
X
X
Agricultural
Runoff
X
X
X
Pollutant
Detected
PCBs
/
/
/
/
/
/
/
/
/ '
Dioxin
/
/
/
/
/
/
/
/
V
S
S
7-28
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JUNE 1997
Exhibit 7-8
POSSIBLE PCB AND DIOXIN DISCHARGE SOURCES AT SELECTED CALIFORNIA SAMPLE SITES
Episode
#
3283
3355
3290
3274
3357
3267
3270
3287
2748
3281
Waterbody
New River
Old
Mormon
Slough
Port of
Stockton
Rowdy
Creek
Sacramento
Delta
Sacramento
River
Sacramento
River
San Gabriel
River
Santa Clara
River
Santa Clara
River
Location
Westmore-
land
Stockton
Stockton
Smith
River
Antioch
Anderson
Red Bluff
Long
Beach
Santa
Paula
Santa
Paula
Point Sources
Paper/Pulp
Mill Using
Chlorine
X
X
Paper/Pulp
Mill Not
Using
Chlorine
X
X
Refinery
Superfund
Site
X
X
Other
Industrial
Discharge
X
X
X
X
POTW
Wood
Preserving
Activity
X
Nonpoint Sources
Urban
Runoff
X
Agricultural
Runoff
X
X
X
Pollutant
Detected
PCBs
/
/
/
/
/
/
/
/
/
Dioxin
/
S
S
S
S
S
S
S
/
7-29
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JUNE 1997
Exhibit 7-8
POSSIBLE PCB AND DIOXIN DISCHARGE SOURCES AT SELECTED CALIFORNIA SAMPLE SITES
Episode
#
3264
3450
3269
3278
Waterbody
Santa
Monica Bay
Short Bank
Stanislaus
River
Upper Eel
River
Location
Los
Angeles
Los
Angeles
Ripon
Potter
Valley
Point Sources
Paper/Pulp
Mill Using
Chlorine
Paper/Pulp
Mill Not
Using
Chlorine
Refinery
X
Superfund
Site
Other
Industrial
Discharge
X
X
POTW
X
X
Wood
Preserving
Activity
X
Nonpoint Sources
Urban
Runoff
X
Agricultural
Runoff
Pollutant
Detected
PCBs
/
Dioxin
/
/
/
/
Source: U.S. EPA, National Study of Chemical Residues in Fish, Volumes I-II, Office of Science and Technology, September 1992.
7-30
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JUNE 1997
In addition, a study developed for EPA found that sludge samples taken from 175 POTWs
across the U.S. all contained detectable levels of at least one dioxin congener.29 The presence of
dioxin in sludges suggests that small amounts of dioxin may be present in effluent, although these
discharges may occur at concentrations below detection. Other studies trace the dioxin found in
household wastewater and POTW sludge to fabric dyes.30 These studies suggest that clothing
containing dioxin-contaminated dyes, when washed in household washing machines, may be a
potential source of dioxins to POTWS serving primarily residential populations. The authors also
hypothesized an additional source of dioxins to POTWs via the use of pentachlorphenol (PCP) to
preserve cotton, particularly when it is randomly strewn on bales of cotton as a preservative during
sea transport.31
Finally, the EPA national fish tissue study mentioned for PCBs (see above) also examined
dioxin contamination. Specifically, more than half of the fish samples collected contained detectable
levels of dioxin that could negatively affect human health. A qualitative evaluation of discharges
in the area suggests that point sources may be a significant contributor (see Exhibit 7-8).
Mercury
Mercury poses significant noncancer risk to recreational anglers in California. As reviewed
in Chapter 3, mercury hazard quotients greater than 1 are possible under typical consumption
assumptions for both freshwater and San Francisco Bay anglers. While data are sparse, it is likely
that a significant share of mercury originates from point sources. The Davis and NOAA data for San
Francisco Bay suggest that point sources may contribute between 26 and 52 percent of mercury
loadings.32 In addition, mine drainage to freshwater such as the Sacramento River is a major source
of mercury loadings, although data are not available to assess the specific magnitude of this
contribution.
29Rubin, A. and White, C., Work conducted for the U.S. EPA, Office of Science and
Technology, Health and Ecological Criteria Division,-Sludge Risk Assessment Branch, December
21,1992.
30 Hoistman and McLachlan in U.S. EPA, Estimating Exposure to Dioxin-Like Compounds,
Vol. Ill, June 1988, (EPA/600/6-88/005Ca,b,c).
31 While PCP for nonwood uses has been banned in the U.S. since 1987, it is still used in other
countries, especially for the purpose of preserving cotton during sea transport.
32 Davis, J.A., et al., Status and Trends Report on Pollutants in the San Francisco Estuary,
prepared by the San Francisco Bay-Delta Aquatic Habitat Institute for the San Francisco Estuary
Project, U.S. EPA, March 1991.
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JUNE 1997
Pesticides
Our analysis in Chapter 3 also demonstrates that pesticides pose significant risks — both.
cancer and noncancer - to recreational anglers. Overall, pesticides account for 63 percent of total
cancer cases in freshwater and 51 percent of total cancer cases for San Francisco Bay. In addition,
pesticides contribute significantly to the overall hazard index for noncancer risks.
The NOAA data suggest that point sources account for about half of the pesticide discharges
to San Francisco Bay. Data for inland waters are not readily available. Many pesticide loadings
originate from household waste disposal, accidental industrial releases, and the expansion of cities
into land formerly used for farming. In the case of DDT, whose production is banned in the U.S.,
potential sources include historic sludge residuals in sewers, the chemical breakdown of currently
manufactured pesticides, and possible illegal importation from outside the U.S.33 This complex
"cycling" of pesticides in the environment makes it difficult to accurately divide pesticide releases
between point and nonpoint sources.
Illustrative Calculation of Benefits
Attributable to Point Source Control
While none of the data sources mentioned above definitively estimates the relative point
source contribution of PCBs, dioxin, pesticides, or mercury, they collectively support the argument
that at least a portion of these pollutants may be discharged by point sources. Point source controls
potentially could lead to reductions in both cancer and noncancer health risks. To estimate potential
benefits in terms of averted cancer cases, we perform the following calculation:
Point Source Point Source Cancer Cases Cancer Cases
Contribution • Reduction * Per Year = Averted
(Percent) (Percent)
For illustrative purposes, we assume that point sources contribute a relatively small
percentage (five percent) of the total toxic loadings of PCBs and dioxin to surface waters in
California. We base this assumption on the limited knowledge of the sources of these constituents,
as discussed above. Further, we assume that when the proposed water quality criteria are fully
implemented by the Slate through the NPDES point source discharge program, a small (five percent)
point source load reduction will occur. We can take this calculation one step further by multiplying
the number of cancer cases averted by the statistical value of a human life ($2 to $10 million).
33 Personal Communications with Phil Woods and Terry Oda, U.S. EPA, Region IX, San
Francisco, California, December 1996.
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JUNE 1997
Potential cancer health benefits for point source controls of PCBs are presented in Exhibit
7-9. The results of our analysis indicate that if implementation of the proposed rule leads to a five
percent loadings reduction of PCBs discharged from point sources to freshwater, then we can expect
an upper bound benefit of $100,000 per year.
We can use essentially the same calculation to estimate the reduction in the hazard quotient
for noncancer risks. As shown in Exhibit 7-10, the potential reduction in noncancer risks is minor
for most pollutants. For example, if the proposed rule leads to a five percent loadings reduction for
PCBs discharged from point sources along San Francisco Bay, then we can expect an upper bound
noncancer hazard quotient reduction of 0.008.
As shown in Exhibit 7-10, there is a potential reduction in the hazard quotient for freshwater
mercury. For the point source contribution figure, we use the toxics-weighted average (46 percent)
of several metals discharged to the Sacramento River (the CVRWQCB data from Exhibit 7-4). For
the discharge reduction percent, we use the upper bound figure from the cost analysis (71 percent).
Under these assumptions, the upper bound hazard quotient would be reduced from 1.44 to 0.97.
Conclusions
Overall, the inability to detect small but potentially harmful concentrations of PCBs and
dioxin limits our ability to definitively link these pollutants to point source dischargers.
Nonetheless, some evidence exists to suggest that point sources contribute to overall releases of these
pollutants. However, even if we assume that point sources are responsible for five percent of
discharges and will reduce these discharges by five percent, the cancer and noncancer benefits are
limited. For example, monetized cancer reduction benefits for PCBs might approach $100,000 per
year in the upper bound based on simple illustrative calculations.
For mercury and pesticides, the link to point sources is somewhat more established. This is
especially true in the case of mercury, for which mines are associated with a large share of
discharges. Preliminary estimates suggest that the noncancer hazard quotient for mercury could be
reduced from hazardous levels (HQ > 1) to non-hazardous levels (HQ < 1) if the predicted point
source mercury reductions presented in the costing analysis are achieved.
APPORTIONMENT OF ECOLOGICAL BENEFITS
The analysis of point source contributions to total toxics loadings can be used to approximate
very generally the portion of ecological benefits attributable to point source controls. Because
California waters and the ecosystems they support are extensive and diverse, it is difficult to make
7-33
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JUNE 1997
Exhibit 7-9
POTENTIAL CANCER RISK BENEFITS ASSOCIATED WITH POINT SOURCE CONTROLS ACHIEVED
THROUGH IMPLEMENTATION OF THE CALIFORNIA TOXICS RULE
Pollutant
PCBs
(Freshwater)
Point Source
Contribution
5%
Point Source
Reduction
5%
Population
Cancer Risk
(excess cases
per year)
Lower
2
Upper
4
Number of Excess
Cancer Cases Averted
Lower
0.005
Upper
0.01
Statistical Value of a
Human Life
Lower
$2M
Upper
$10M
Annual Benefits
Attributable to Point
Source Control
Lower
$10,000
Upper
$100,000
7-34
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JUNE 1997
Exhibit 7-10
POTENTIAL NONCANCER RISK BENEFITS ASSOCIATED WITH POINT SOURCE
CONTROLS ACHIEVED THROUGH IMPLEMENTATION OF THE CALIFORNIA TOXICS RULE
Pollutant
PCBs
(Freshwater)
PCBs
(San Francisco)
Dioxih
(San Francisco)
Mercury
(Freshwater)
Point Source
Contribution
5%
5%
5%
46%'
Point Source
Reduction
5%
5%
5%
71%2
Hazard Quotient from Typical Consumption
(21.4 - 49.6 g/day)
Lower Bound
1.40
2.26
0.51
0.62
Upper Bound
3.30
5.24
1.17
1.44
Reduction in Hazard Quotient from .
Point Source Control
Lower Bound
0.004
0.006
0.001
0.204
Upper Bound
0.008
0.013
0.003
0.474
Notes: 1) The 46.34 percent figure can be found in Exhibit 7-4. This figure represents the toxic-weighted average point source contribution to freshwater for
several metals other than mercury; mercury data are not available.
2) The 71.1 percent figure can be found in Exhibit 7-6 and reflects the upper bound point source reduction estimate.
7-35
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JUNE 1997
state-wide generalizations about the relative toxic discharge contribution of point and nonpoint
sources to all water bodies in the State. Consequently, we apply information developed for San
Francisco Bay, other enclosed bays and estuaries, and freshwater (as described earlier in this chapter)
to apportion ecological benefits for the entire State. Like the economic assessment, it is not possible
to allocate ecological benefits on a pollutant-specific basis because of data, methodological, and time
constraints. Therefore, we develop a very rough, quantitative apportionment analysis that uses
average point source contributions and loadings reductions across all pollutants, similar to that
described in the previous economic apportionment section.
First, we use the quantitative measure of miles of rivers, or acres of lakes, bays, harbors,
estuaries, and wetlands that may be adversely affected by toxics and whose beneficial use includes
waters supporting rare or endangered species; supporting wildlife; or supporting fish spawning
and/or migration. Exhibit 7-11 summarizes the total baseline toxics-affected acreage for California
waters, disaggregated by type of waterbody and beneficial use, based on information described and
presented in Chapter 5.
Next, we multiply this area estimate by a relevant point source contribution range. This
provides a very rough estimate of the benefits that would be realized if all point source discharges
of pollutants were reduced to meet CTR criteria. The point source contributions we apply are
developed from information presented earlier in this chapter. For rivers and streams and lakes and
reservoirs, we use the same range of five to 30 percent used in the economic analysis. For San
Francisco Bay, we have applied a slightly higher single estimate of point source contribution (15
percent) consistent with the upper range of the NOAA and Davis studies of San Francisco Bay. We
do so because silver is not included as a constituent in these latter studies, although other studies
have demonstrated that silver in San Francisco Bay is primarily attributable to industrial wastewater
discharges.34 Further, silver is more toxic to aquatic life than all the other metals except for mercury,
and has the highest baseline loadings and one of the highest upper bound percent reductions (51
percent) of any of the other constituents considered in the NOAA/Davis data (see Exhibit 7-6). For
these reasons, we assume that the point source contribution to San Francisco Bay is slightly higher
than that developed for the economic analysis. It is possible that the point source contribution in
some parts of the Bay could be even higher than 15 percent, although data and time limitations
precluded a more detailed assessment and conclusion.
For point source contributions of other inland bays, and wetlands, we have applied the range
of 87 to 91 percent reported in NOAA for Urban Bays, and for estuaries we have applied the 23 to
33 percent reported for non-urban bays (see Exhibit 7-3). We have not adjusted these estimates by
population figures (as we did in the economic application) because the ecological benefits are not
34 Smith, Geoffrey, and A. Russell Flegal, "Silver in San Francisco Bay Estuarine Waters,"
Estuaries, Vol. 16, No. 3A, September 1993, pp. 547-558.
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JUNE 1997
dependant on any population measure of activity. For saline lakes, the point source contribution of
toxics is estimated to be zero given the generally accepted dominance of agricultural runoff
influencing the Salton Sea.
Finally, we multiply by the average percentage reduction in point source loadings as
estimated in the cost analysis and used in both the economic and human health apportionment to
derive an estimate of ecological benefits attributable to expected point source controls.
The results of this screening analysis are shown in Exhibit 7-11. Average point source
benefits range from a low of zero percent improvement in saline lakes, to a potential 25 percent
improvement in other inland bays. Approximately 20,000 acres of bays, harbors, estuaries, lakes,
and wetlands and nearly 150 miles of rivers may experience improved conditions as a result of point
source controls. These areas support wildlife, rare or endangered species, or fish spawning and/or
migration.
UNCERTAINTIES AND LIMITATIONS
As discussed throughout the chapter, the apportionment methodology has a number of
uncertainties and limitations. Exhibit 7-12 summarizes these uncertainties and highlights several
that are likely to be of greatest significance.
Most importantly, the estimates presented here do not make direct causal links between point
source controls and the stated benefits (e.g., improved recreational fishing, reduced health risk).
Instead, the method is based on an accounting of recent loadings to various waterbodies and assumes
that benefits accrue in proportion to these loadings (i.e., reducing loadings will reduce the damages
linearly). A number of factors may preclude this outcome. For example, fish tissue concentrations
may be the result of toxics in sediments that move through the food chain to fish and humans.
Reduction of point source loadings to meet water quality standards may do little in the near term to
reduce the effects of this kind of historical pollution. Similarly, recovery of a stressed ecosystem
or species may be subject to a threshold effect. For instance, reduction of toxics loadings by 20
percent may have no effect if a particularly sensitive species requires complete elimination of a given
contaminant. Conversely, a small reduction in loadings may be all that is need for a full recovery
of a species or ecosystem.
7-37
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JUNE 1997
EihibltT-ll
APPORTIONING ECOLOGICAL BENEFITS TO CONTROL OF POINT SOURCES
Area
San Francisco
Bay (Acres)
Other Inland
Bays (Acres)
Estuaries
(Acres)
Lakes &
Reservoirs
(Acres)
Saline
Lakes
(Acres)
Rivers &
Streams
(Miles)
Wetlands
(Acres)
Total Baseline Waters AfTected
Supporting:
(a) Rare or Endangered Species
(b) Wildlife
(c) Fish spawning and/or Migration (1)
(a) 1 72,500
(b) 172,500
(c) 172,500
(a) 3,679
(b) 3,240
(c) 2,625
(a) 5,1 16
(b) 5 1,869
(c) 5 1,656
(a) 33,390
(b) 107,231
(c) 102,241
(a)230,855
(b) 286, 182
(c) 10,855
(a) 1,856
(b) 2,591
(c) 1,029
(a) 225
(b)385
(c)225
Point
Source
Contribution
(2)
15%
87-91%
23 - 33%
5 - 30%
0%
5 - 30%
23 - 33%
Point
Source
Reduction
(3)
27-31%
27-31%
27-31%
27-31%
27-31%
27-31%
27-31%
Average
Point source
Benefits
5%
25%
8%
5%
0%
5%
8%
Potential Benefits
Attributable to Control
of Point Sources
Waters Supporting:
(a) Rare or Endangered Species
(b) Wildlife
(c) Fish spawning and/or
Migration
(a) 8,625
(b) 8,625
(c) 8,625
(a) 920
(b)810
(c) 656
(a) 420 .
(b) 4,253
(c) 4,236
(a) 1,720
(b) 5,522
(c) 5,255
(a)0
(b)0
(c)0
(a) 96
(b) 133
(e)53
(a) 18
(b)32
(c)18
Potential Benefits
Attributable to Control
of Nonpoint Sources
Waters Supporting:
(a) Rare or Endangered Species
(b) Wildlife
(c) Fish spawning and/or
Migration
(a) 163,875
(b) 163,875
(c) 163,875
(a) 2,759
(b) 2,430
(c) 1,969
(a) 4,696
(b) 47,616
(c) 47,420
(a) 31,670
(b) 101,709
(c) 96,986
(a) 230,855
(b) 286,182
(c) 10,855
(a) 1,760
(b) 2,458
(c) 976
(a) 207
(b) 353
(c) 207
(1) Source: Exhibit 5-4, based on WQA data base.
(2) Source: Exhibits 7-1, 7-2, 7-3, 7-4, 7-5, and 7-6.
(3) Source: Exhibit 7-6.
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JUNE 1997
Exhibit 7-12
UNCERTAINTIES AND LIMITATIONS IN THE APPORTIONMENT ANALYSIS
Description of Uncertainty
Assume direct proportionality between economic/health benefits and point source
controls.
Generalize from limited loadings data for a small set of water bodies to the extensive
system of salt and freshwater in California.
Uncertainties associated with the 1994 California Water Quality Assessment data base
to characterize the quality of California surface waters.
Analysis based on a limited set of pollutants. Little information on pesticides, PCBs,
dioxin, and certain metals (e.g., silver).
Detection limits for some key pollutants (e.g., PCBs and dioxin) too high to estimate
reliably the relative contribution of point and other sources.
Assume reduced loadings of toxics from point source discharges from active, inactive,
and abandoned mines occurs in the same time frame as other point source controls.
Data for San Francisco Bay do not include many sources, such as mine drainage.
NOAA lacks several nonpoint sources.
While riverine inputs are classified as a nonpoint source, discharges to these rivers may
have originated from either point or nonpoint sources.
Relative
Significance
High
High
High
High
High
High
Medium
Medium
Nature and Direction of Bias in Point
Source
Control Benefit Estimates
Overstate
Estimates
•
/
/
Understate
Estimates
/
/
/
Not Clear
/
/
/
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JUNE 1997
Exhibit 7-12
UNCERTAINTIES AND LIMITATIONS IN THE APPORTIONMENT ANALYSIS
Description of Uncertainty
Davis did not include loadings estimates for the Sacramento River.
Point source contributions for San Francisco Bay are much lower than for the other
urban bays.
CVRWQCB data for freshwater consider urban runoff at only a limited subset of cities.
CVRWQCB data for San Joaquin River include only one mine.
NOAA and Davis data are based on discharges from the early and mid-1980s.
Davis used national runoff pollutant concentrations to estimate loadings from urban
runoff.
Davis' atmospheric deposition estimates are based on deposition rates from other parts
of the country.
CVRWQCB data use effluent concentrations from only one POTW.
Relative
Significance
Medium
Medium
Medium
Medium
Low
Low
Low
Low
Nature and Direction of Bias in Point
Source
Control Benefit Estimates
Overstate
Estimates
/
/
Understate
Estimates
/
Not Clear
s
/
/
/
/
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JUNE 1997
A second key limitation already mentioned above is the need to generalize from very limited
loadings data to all waters in California. Except in the case of San Francisco Bay, we assume that
large, complex waterbodies have a discharge profile like the example for which we have data; for
example, we assume that other rivers are similar to the Sacramento and San Joaquin for which we
have data. Unique local conditions make it likely that certain areas and waterbodies will be poorly
represented by the available data. While a more detailed analysis of point source and other
discharges in key waterbodies would be desirable, such an analysis is beyond the scope of this effort.
Third, we analyze a relatively limited set of pollutants. Available data focus primarily on
several metals. While these are important pollutants from the standpoint of ecological risk, they may
not fully represent benefits and the likely impact of point source controls. Silver provides a good
illustration of this uncertainty. Studies have demonstrated that silver in San Francisco Bay is
primarily attributable to industrial wastewater discharges.35 In addition, silver has a high toxicity
weight (47), suggesting that it would strongly influence the calculation of average point source
contributions for San Francisco Bay. Nonetheless, complete data on discharges of silver from point
and nonpoint sources were not available. In this case, the likely result is that we understate point
source contributions. For other pollutants missing from the analysis, nonpoint sources may dominate
and lead us to overstate point source contributions.
Fourth, while mines are considered to be a point source subject to NPDES under the Clean
Water Act, not all mines in California have been permitted. Loadings reductions for mines (both
active and inactive) with major NPDES permits have been estimated, and are used in this analysis,
although they do not represent the entire universe of mines in the State. Consequently, some of the.
benefits estimated in this chapter, particularly those based on the control of mercury, may not occur
in the same time frame as benefits associated with other point sources evaluated here (POTWs and
industrial dischargers). The likely result is an overstatement of some of the benefits associated with
point sources, although it is not possible to evaluate the magnitude of the bias.
Finally, one key reason for analyzing a relatively limited set of pollutants is the problem of
detection limits. Pollutants such as dioxin and PCBs play a significant role in the health risk
analysis; however, apportionment of these benefits is impeded by the inability to detect certain
pollutants, even in concentrations exceeding the criteria. When pollutants cannot be detected, it
becomes impossible to characterize the relative importance of point sources and other sources.
35 Smith, Geoffrey, and A. Russell Flegal, "Silver in San Francisco Bay Estuarine Waters,"
Estuaries, Vol. 16, No. 3A, September 1993, pp. 547-558.
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REFERENCES
Beck, E., U.S. EPA, "PCB Data Search for California Toxics Rule (CTR)," memorandum to
California Toxics Rule File, October 17,1996
California Regional Water Quality Control Board, San Francisco Bay Region, Survey of Storm
Water Runoff for Dioxins in the San Francisco Bay Area, February 1997.
California Regional Water Quality Control Board, Central Valley Region, Inactive Mine Drainage
in the Sacramento Valley, California, 1992.
California Regional Water Quality Control Board, Central Valley Region, A Mass Loading
Assessment of Major Point and Nonpoint Sources Discharging to Surface Waters in the
Central Valley, California, 1985, Draft Staff Report, October, 1988.
«
Central Valley Regional Water Quality Control Board, Mass Emission Strategy Load Estimates,
internal staff report, no date.
Davis, J.A., et al.. Status and Trends Report on Pollutants in the San Francisco Estuary, prepared
by the San Francisco Bay-Delta Aquatic Habitat Institute for the San Francisco Estuary
Project, U.S. EPA, March 1991.
Gunther, A.J., et al.. An Assessment of the Loading of Toxic Contaminants to the San Francisco Bay-
Delta, prepared by the Aquatic Habitat Institute, 1987.
NOAA, The National Coastal Pollutant Discharge Inventory: Estimates for San Francisco Bay,
Data Summary, Ocean Assessments Division, National Oceanic and Atmospheric
Administration, June 1988.
Rubin, A. and White, C, Work conducted for the U.S. EPA, Office of Science and Technology,
Health and Ecological Criteria Division, Sludge Risk Assessment Branch, December 21,
1992.
SAIC, Assessment of Compliance Costs Resulting from Implementation of the Final Great Lakes
Water Quality Guidance, prepared for the U.S. Environmental Protection Agency, March 13,
1995.
SAIC, Analysis of Potential Costs Related to the Implementation of the California Toxics Rule, Final
Draft, prepared for the U.S. Environmental Protection Agency, May 1997.
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Sheth, G., U.S. EPA, "Summary of Dioxin Data Search for California Toxics Rule (CTR) and
Summary of Significant Findings," memorandum to California Toxics Rule File,
October 18,1996.
Smith, Geoffrey, and A. Russell Flegal, "Silver in San Francisco Bay Estuarine Waters," Estuaries,
Vol. 16, No. 3A, September 1993, pp. 547-558.
U.S. EPA, Estimating Exposure to Dioxin-Like Compounds, Volume HI, June 1988, (EPA/600/6-
88/005 Ca,b,c).
U.S. EPA, Issues Related to the Cost-Effectiveness of Reducing PCB Inputs to the Great Lakes from
Point Sources, March 8,1995.
U.S. EPA, National Study of Chemical Residues in Fish, Volumes I-II, Office of Science and
Technology, September 1992.
Water Resources Control Board, State of California, California Enclosed Bays and Estuaries Plan,
April 1991.
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