# Section 14.0 Ecological Benchmarks

1 

# For this analysis, CSCLs refer to constituent concentr ations (e.g., mg/kg soil) in environmental media that are presumed to cause de minimis e ffects on ecological receptors. Benchmar ks, in mg/kg/d, provide protective ingestion doses that are estimated to cause de minimis effects to mammalian and avian receptors.



# 14-1 

# 14.0 Ecological Benchmarks

The Ecological Risk Module was created to generate risk estimates for receptor taxa of concern. The risk quotient method was used to identify the potential for adverse effects to terrestrial and freshwater receptors. The risk quotient compares, by ratio, the modeled media concentrations to an estimated protective level for receptors of concern in the respective exposure media (i.e., water, soil, sediment, prey items). When the ratio exceeds 1, there is a potential for adverse effects to that receptor; when the ratio is less than 1, minimal risk to the receptor is indicated. The specific methods used to calculate the protective level (i.e., benchmarks and chemical stressor concentration limits [CSCLs]) varied with the receptor taxa. 1 

# Protective CSCLs were derived (in ppm) for specific communities and populations in direct contact with contaminated media (i.e., terrestrial plants, soil biota, sediment biota, fish/aquatic invertebrates, herpetofauna). Protective be nchmark doses (mg/kg/d) were developed for mammals and birds based on exposure through the food web by ingestion of contaminated food items. A complete review of how modeled media exposure concentrations were generated is provided in the documentation of the ecological exposure module. This section describes in detail how the benchmarks and CSCLs used in the risk quotient were derived.



# 14.1 Parameters

The key database developed in support of the ecological risk module was the benchmark/CSCL database. The parameters used to calculate ecological risk in the module are listed in Table 14-1. As the table indicates, all the parameters generated in the benchmark/CSCL database are chemical-specific properties.



# 14.2 Data Sources

In developing the chemical-specific benchmark/CSCL database, the major source of ecotoxicity data was the primary literature. Secondary sources of data included documents and databases developed by the U.S. Environmental Protection Agency, other government agencies (e.g., the National Oceanographic and Atmospheri c Administration [NOAA]), and other research facilities (e.g., Oak Ridge National Laboratories [ORNL] ). Given that changes were made to the priority constituent list after initial literature searches were completed, secondary review sources were the only references reviewed for some of the chemicals. The status of the literature

# Section 14.0 Ecological Benchmarks



# 14-2 Steps in Identifying Ecotoxicological Data

Step 1: Review Existing Synopses



# # Develop understanding of behavior of constituents and generally recognized adverse

effects.



# # Summarize available data and identify primary studies for further analysis.



# # Delineate key parameters that would mitigate (or enhance) the toxicity of constituents.

Step 2: Search Toxicological Databases



# # Compile quantitative data on effects.



# # Fill data gaps identified from review of

synopses.



# # Identify critical endpoints for benchmark development.

Step 3: Conduct Online Literature Search



# # Focus on critical endpoints and fill in data gaps.



# # Identify recent studies and data not available in synopses or toxicological databases.



# # Provide supporting information for benchmark
development



# . Table 14-1. Parameters Included in the Benchmark/CSCL Database

Parameter Description Parameter Code

Ecological benchmark for representative receptors that receive ingested

doses ChemEBRec

CSCL for water based on total concentrations ChemCSCLWaterTotRec

CSCL for water based on dissolved concentrations ChemCSCLWaterDissRec

CSCL for sediment ChemCSCLSedimentRec

CSCL for soil ChemCSCLSoilRec



# searches for each constituent is presented in Table 14-2. Secondary review sources helped identify the most current literature available for benchmark and CSCL development; unfortunately, sufficient time was not available to complete more thorough literature searches for many of the constituents.

To provide a context for how data searches were initiated to develop the benchmark/CSCL database, the general steps taken in primary literature searches are outlined here. The key steps to the literature review process consisted of (1) reviewing existing synopses, (2) searching toxicological databases, and (3) conducting comprehensive online literature searches (see text box). A more detailed description of each step is provided in subsequent sections. This framework is not meant to be all-inclusive; rather, it provides key approaches and examples of data sources that have been shown to be highly productive in characterizing ecotoxicological effects.

14.2.1 Review Existing Synopses

In this step, major reviews of ecotoxicological effects are investigated. This step ensures that no obvious sources of effects data are missed and provides a road map for what information might be available.

Documents such as U.S. Fish and Wildlife

# Section 14.0 Ecological Benchmarks



# 14-3 Table 14-2. Status of Literature Review Process for Chemicals of Concern

Primary Literature Review Completed Secondary Source Review Completed

Methoxychlor Pentachlorophenol (PCP) 2,3,7,8-Tetrachlorodibenzo- p -dioxin

Arsenic Mercury

Lead

Silver

Zinc

Cadmium Beryllium Bis-(2-ethylhexyl) phthalate Benzo[a]pyrene Antimony

Thallium

Chromium

Barium

Nickel

Selenium

Vanadium Chromium, total

Chromium III

Chromium VI Benzene Toluene (methyl benzene) Ethylene dibromide (1,2-dibromoethane)

Thiram Methylene chloride (dichloromethane) 1,1,1-Trichloroethane Vinyl chloride (chloroethylene) Trichloroethylene

Chlorobenzene Hexachloro-1,3-butadiene 2,4-Dichlorophenoxyacetic acid (2,4-D)

Phenol Methyl ethyl ketone Methyl methacrylate Dibenz[a,h]anthracene

Carbon disulfide

Acetonitrile Pyridine

Nitrobenzene

Aniline Tetrachloroethylene Chloroform (trichloromethane) Acrylonitrile (2-propenenitrile)

Service (FWS) synoptic reviews, EPA water quality criteria documents, and Agency for Toxic Substances and Disease Registry (ATSDR) toxi cological profiles provide a broad overview of the fate and toxicological effects of constituen ts. These reviews provide a necessary foundation to delineate environmental characteristics that mitigate (or enhance) toxicity. Further, these reviews offer a first look at whether the available data suggest that the constituent is likely to be of ecological concern.

14.2.2 Search Toxicological Databases

Two distinct steps were made in searching toxicological databases. First, databases related to animal health effects, commonly used in conjunction with human health risk assessments, were searched to identify effects data for mammals and birds. Second, ecologically related databases were searched to evaluate the toxicity data available for other receptors (e.g., terrestrial plants, algae, fish/aquatic invertebrates). Expanded descriptions of these steps and

databases follow:

# Section 14.0 Ecological Benchmarks



# 14-4 

# # Step 1 —The Hazardous Substance Database (HSDB) and the Registry of Toxic Effects of Chemical Substances (RTECS) were reviewed for toxicological

information of constituents on animals. These databases were selected because (1) they included a wide variety of toxicity data, (2) they were readily available, and (3) they provided a rapid (if incomplete) picture of the chemical toxicology. Results from searching these databases also were useful in identifying primary references for the development of stressor-response profiles and benchmarks for mammals and birds. These databases are limited, however, because toxicological data are presented only for mammals (including humans) and birds and because narrative text is generally insufficient to interpret the study data. Nevertheless, these data were enormously important in defining the range of effect levels and critical endpoints (e.g., teratogenicity) necessary for the stressor-response profile.



# # Step 2 —EPA’s ECOTOX database has become an essential reference for benchmark development because (1) it is the largest database of ecological effects data currently available, (2) it includes primary literature citations, and (3) it is readily available.

Three databases were available within ECOTOX covering different groups of ecological receptors: (1) TERRETOX for terrestrial wildlife and soil biota, (2) PHYTOTOX for effects on terrestrial plant species, and (3) the Aquatic Information Retrieval (AQUIRE) system for effects on aquatic biota (fish, invertebrates, and aquatic plants). The drawback to using ECOTOX is that its databases are only updated periodically. AQUIRE is updated annually. TERRETOX and PHYTOTOX offer a thorough search of data up to 1991; however, updates from 1991 to the present only partially represent the primary literature. The ecological effects information culled from ECOTOX was used to fill data gaps and to refine the bibliographic and keyword search for specific receptors in the next step. If sufficient data were not identified in ECOTOX (e.g., toxicity is only characterized for a few species), a more broad-based strategy was adopted for the online literature search.

14.2.3 Conduct Online Literature Search

Commercial online databases such as Dissertation Abstracts include extensive bibliographic databases that can provide add itional information not found in ECOTOX or other similar databases. The general strategy for searching online bibliographic databases is summarized in Steps 1and 2 as follows:

Step 1 —The bibliographic database search began with Toxline ® 

# /Medline ® 

# because they are relatively low-cost databases that specialize in toxicological citations. Research Triangle Institute (RTI) has used these databases frequently with a high degree of success.

Step 2 —Based on the results of the primary search in Toxline ® 

# /Medline ® 

# , it was sometimes necessary to reconsider the search strategy and submit a new search or to search more costly databases (e.g., royalty databases). Depending on the data gaps for specific ecological receptors (e.g., no data on birds), a more appropriate database was searched. For example, if we

# Section 14.0 Ecological Benchmarks



# 14-5 needed data on avian effects, we would select a database such as Biological Abstracts rather than a database limited to aquatic effects (i.e., Water Resources). For data-poor constituents, more general environmental databases such as Environline ® 

# or Pollution Abstracts were searched.

Following primary literature searches, appropriate studies were identified for benchmark and CSCL derivation. A summary of the key documents and databases consulted to develop benchmarks and CSCLs is provided in Table 14-3. The actual primary references that were specifically identified to derive benchmark doses for mammals and birds are provided in Table 14-4. For constituents added after primary literature searches were completed, only Steps 1 and 2 were completed (see text box). For these chemicals, the searches were limited to the effects data outlined in the sources presented in Table 14-3. The benchmarks and CSCLs for

the newer constituents should be considered preliminary until further primary literature reviews

are conducted.



# 14.3 Methodology

14.3.1 Benchmark/CSCL Database

14.3.1.1 Database Compilation

. The methods used to derive each of the benchmarks and CSCLs were different across receptor taxa. Because of these differences, the methods used to develop benchmarks and CSCLs are reviewed separately for each receptor taxon. The discussion of the methods used in developing th e benchmark/CSCL database is organized around the specific module parameters listed in Table 14-1. Because parameters are media-specific, some parameters cover more than one receptor category. For instance, total water CSCLs are generated for herpetofauna, the freshwater community, and algae/aquatic plants. In these cases, receptor-specific methods are discussed as subsections.

14.3.1.1.1 Ecological Benchmarks for Representative Receptors (ChemEBRec)

. Ecological benchmarks (EBs), derived in un its of dose (mg/kg/d), were developed for representative taxa of mammals and birds. The EBs were appropriate for upper-trophic-level consumers because the primary exposure route occurs through ingestion of contaminated prey items. Because the degree of exposure to mammals and birds is dependent on the foraging range, uptake rates, and percentage of the diet that is contaminated, in constructing the example 3MRA data set ecological exposure modeling system, these life history factors were used to develop an estimated dose for representative mammals and birds exposed to constituents. The risk estimate was derived by comparing exposure doses to the benchmark dose to assess whether the benchmark dose had been exceeded. An exceedance indicates the potential for adverse

effects.

The overall approach used to establish these benchmarks is similar to the methods applied to derive reference doses (RfDs) for humans, as described in the Integrated Risk Information System (IRIS) (U.S. EPA, 1993c). The method adopted for the representative national data set uses a hierarchy for the selection of ecotoxicity data and extrapolates from a test species to the species of interest (in this cas e, wildlife). There are fundamental differences between the goals of noncancer risk assessments for humans and ecological receptors. For example, risk assessments

# Section 14.0 Ecological Benchmarks



# 14-6 Table 14-3. Key Sources of Information Consulted in the Development of

Benchmarks and CSCLs

Source Contents

Mammals and Birds

U.S. EPA (Environmental Protection Agency). 1995b. Great Lakes Water Quality Initiative Criteria Documents for the Protection of Wildlife. Office of

Water. This document provides wildlife criteria in surface water for exposures to DDT, 2,3,7,8-(TCDD), mercury, and polychlorinated biphenyls (PCBs).

Sample, B.E., D.M. Opresko, and G.W. Suter, II.

1996. Toxicological Benchmarks for Wildlife: 1996

Revision. This compendium reference reviews ecotoxicity data derived from the primary literature of various constituents to species of mammals and birds.

U.S. EPA (Environmental Protection Agency). 1999a. Ecotoxicological Database System. Office of Research and Development, U.S. Environmental Protection Agency. The terrestrial animal toxicity database (TERRETOX) contains more than 33,000 toxicity tests on terrestrial wildlife for more than 1,200 chemicals and 253 species.

U.S. FWS (Fish and Wildlife Service). Various years.

Contaminant Hazard Reviews . U.S. Department of the Interior (e.g., Eisler, 1989). These profiles review chemical-specific toxicity to various ecological receptors. These compendia also expand discussions to assess issues of bioaccumulation

and biochemical effects.

Plant Community

Efroymson, R.A., M.E. Will, G.W. Suter, II, and A.C.

Wooten. 1997. Toxicological Benchmarks for Screening Contaminants of Potential Concern for Effects on Terrestrial Plants: 1997 Revision

. This document provides ecotoxicity effects data for terrestrial plants exposed in soil and solution media. Approximately 45 constituents have proposed soil

criteria.

U.S. EPA (Environmental Protection Agency). 1999a. Ecotoxicological Database System. Office of Research and Development, U.S. Environmental Protection Agency. The terrestrial plant toxicity (PHYTOTOX) database contains more than 49,000 toxicity tests on terrestrial plants for more than 1,600 organic and inorganic chemicals and 900 species.

Freshwater Community

U.S. EPA (Environmental Protection Agency). 1999a. Ecotoxicological Database System. Office of Research and Development, U.S. Environmental Protection Agency. The aquatic biota toxicity database (AQUIRE) contains more than 145,000 toxicity tests for more than 5,900 organic and inorganic chemicals and 2,900 aquatic species.

U.S. EPA (Environmental Protection Agency). Various years. Ambient Water Quality Criteria

. Office of Water, Washington, DC. (Example U.S. EPA, 1989). These chemical-specific documents provide the ecotoxicity data and derivation methodologies used to develop the National Ambient Water Quality Criteria (NAWQC).

(continued)

# Table 14-3. (continued) Section 14.0 Ecological Benchmarks

Source Contents



# 14-7 Freshwater Community (continued)

U.S. EPA (Environmental Protection Agency). 1995a. Great Lakes Water Quality Initiative Criteria Documents for the Protection of Aquatic Life in

Ambient Water . Office of Water.

U.S. EPA (Environmental Protection Agency). 1996a. 1995 Updates. Water Quality Criteria Documents for the Protection of Aquatic Life in Ambient Water . EPA 820B96-001. Office of Water, Washington, DC. For a limited number of constituents, the Great Lakes Water Quality Initiative (GLWQI) has proposed surface water criteria for aquatic biota using analogous methods as implemented in the derivation of the NAWQC.

Suter, II, G.W., and C. Tsao. 1996. Toxicological Benchmarks for Screening Potential Contaminants of Concern for Effects on Aquatic Biota : 1996 Revision

. This compendium reference provides acute and chronic water quality criteria for freshwater species, including algae.

Algae and Aquatic Plants

Suter II, G.W. and C. Tsao. 1996. Toxicological Benchmarks for Screening Potential Contaminants of Concern for Effects on Aquatic Biota : 1996 Revision

. This compendium reference provides acute and chronic water quality criteria for freshwater species, including algae.

U.S. EPA (Environmental Protection Agency). 1999a. Ecotoxicology Database System. Environmental Research Laboratory, Office of Research and Development. The AQUIRE database contains more than 145,000 toxicity tests for more than 5,900 organic and inorganic chemicals and 2,900 aquatic species.

Soil Community

Efroymson, R.A., M.E. W ill, and G.W. Suter, II.

1997. Toxicological Benchmarks for Contaminants of Potential Concern for Effects on Soil and Litter Invertebrates and Heterotrophic Process: 1997

Revision . Oak Ridge National Laboratory. This document provides effects data for soil biota (i.e., microbial processes and earthworms). Approximately 35 constituents have proposed soil criteria, and some

field studies are included.

CCME (Canadian Council of Ministers of the Environment). 1997. Recommended Canadian Soil Quality Guidelines

. The criteria developed by the CCME are concentrations above which effects are likely to be

observed.

Sediment Community

U.S. EPA (Environmental Protection Agency). 1993a. Technical Basis for Deriving Sediment Quality Criteria for Nonionic Organic Contaminants for the Protection of Benthic Organisms by Using Equilibrium Partitioning

. This document supplies toxicological criteria (sediment quality criteria [SQC]) for nonionic hydrophobic organic chemicals using final chronic values (FCVs) and secondary chronic values (SCVs) developed for

surface water. The criteria are estimated based on the assumption that the partitioning of the constituent between sediment organic carbon and pore water is at equilibrium.

(continued)

# Table 14-3. (continued) Section 14.0 Ecological Benchmarks

Source Contents



# 14-8

Sediment Community (continued)

Long, E.R., and L.G. Morgan. 1991. The Potential for Biological Effects of Sediment-Sorbed

Contaminants Tested in the National Status and Trends Program . National Oceanic and Atmospheric Administration (NOAA) Technical Memorandum. Field-measured sediment concentrations are correlated with impacts to sediment biota in estuarine environments. Measures of abundance, mortality, and species composition are the primary toxicity endpoints.

Jones, D.S., G.W. Suter, II, and R.N. Hull. 1997. Toxicological Benchmarks for Screening Contaminantsof Potential Concern for Effects on SedimentAssociated Biota: 1997 Revision. Oak Ridge National Laboratory. This document proposes sediment criteria for both organic and inorganic constituents using both field and estimation methodologies.

Long, E.R., D.D. MacDonald, S.L. Smith, and F.D. Calder. 1995. Incidence of adverse biological effects with ranges of chemical concentrations in marine and

estuarine sediments. Environmental Management 19(1):81-97. This paper contains an updated version of the NOAA approach (Long and Morgan, 1991) in which additional data were added to the data set. The range of sediment concentrations that may result in adverse impacts to benthic-dwelling invertebrates are indicated.

MacDonald, D.D. 1994. Approach to the Assessment of Sediment Quality in Florida Coastal Waters . Vol. 1. Florida Department of Environmental Protection (FDEP), Tallahassee, FL. This approach applies statistical derivation methods to determine sediment criteria using NOAA data. The resulting criteria are more conservative than NOAA

values.

Herpetofauna

Power, T., K.L. Clark, A. Harfenist, and D.B. Peakall.

1989. A Review and Evaluation of the Amphibian Toxicological Literature. Technical Report Series No. 61, Canadian Wildlife Service. This reference was developed by Environment Canada to review the ecotoxicity literature so that risks to amphibian populations could be evaluated.

U.S. EPA (Environmental Protection Agency). 1996b. Amphibian Toxicity Data for Water Quality Criteria

Chemicals . EPA/600/R-96/124. National Health and Environmental Effects Research Laboratory, Corvallis,

OR. This reference was developed by EPA to evaluate the primary literature available on amphibians in an effort to include more amphibian data into the development of NAWQC under the data requirement for species in phylum Chordata.

Devillers, J., and J.M. Exbrayat (eds). 1992. Ecotoxicity of Chemicals to Amphibians . Philadelphia,

PA: Gordon and Breach Science. This text provides test study summarizes for amphibians reporting endpoints related to reproduction

and survival.

# Section 14.0 Ecological Benchmarks



# 14-9 Table 14-4. Primary Literature Used in Mammalian and Avian Benchmark Derivation a



# Constituent Mammalian Reference Avian Reference

Antimony Rossi et al., 1987 ID

Arsenic Byron et al., 1967 Stanley et al., 1994

Barium ID Johnson et al., 1960

Benzene Sample et al., 1996 ID

Benzo(a)pyrene MacKenzie and Angevine, 1981 ID

Bis(2-ethylhexyl) phthalate Shiota and Nishimura, 1982 ID

Cadmium Sutou et al., 1980 White and Finley, 1978

Chloroform Sample et al., 1996 ID

Chromium III (insoluble salts) Sample et al., 1996 ID

Chromium VI Zahid et al., 1990 ID

Lead Krasovskii et al., 1979 Edens and Garlich, 1983

Mercury Wobeser et al., 1976a, 1976b Heinz, 1974, 1975, 1979

Methyl ethyl ketone Sample et al., 1996 ID

Nickel Ambrose et al., 1976 Sample et al., 1996

Pentachlorophenol Welsh et al., 1987 Prescott et al., 1982

Selenium Rosenfeld and Beath, 1954 Heinz and Hoffman, 1987

TCDD, 2,3,7,8- Murray et al., 1979 Nosek et al., 1992

Thallium Sample et al., 1996 ID

Toluene Sample et al., 1996 ID

Trichloroethylene Sample et al., 1996 ID

Trichloroethane, 1,1,1- Sample et al., 1996 ID

Vanadium Domingo et al., 1986 Romoser et al., 1961

Vinyl chloride Sample et al., 1996 ID

Zinc Schlicker and Cox, 1968 Sample et al., 1996

ID=Insufficient data identified for benchmark derivation.

a 

# Chemicals not listed had insufficient data to develop mammalian or avian benchmarks.

# Section 14.0 Ecological Benchmarks



# 14-10 conducted for humans seek to protect the individual, while ecological risk assessments seek to protect populations or communities of important species (U.S. EPA, 1992a). Consequently, benchmark studies for mammals and birds were selected using a few key guidelines. These guidelines represent the minimum requirements for a study to be of sufficient rigor for

benchmark derivation.



# # Measurement Endpoints— Studies containing measurement endpoints reported as

either a no-observed-adverse-effect level (NOAEL) or a lowest-observedadverse-effect level (LOAEL) in units of daily dose were preferred. From these results, the geometric mean between the NOAEL and the LOAEL (i.e., maximum acceptable toxicant concentration [MATC]) was calculated. The MATC was the preferred benchmark for representative mammalian and avian species.



# # Toxicity Endpoints —Because population viability in mammals and birds was selected as the assessment endpoint, the benchmarks were developed from toxicity endpoints of reproductive or developmental success or, if unavailable, other effects that could conceivably impair population dynamics.



# # Methods —No specific test methodologies were required in studies used for benchmark derivation. Standard laboratory practices (e.g., control dose groups), however, were required. Field data may not be appropriate to develop a daily dose exposure.



# # Receptor Requirements —Ecotoxicity data for wildlife species were preferred (e.g., mallards or mink); however, because of the paucity of studies exposing wildlife species, rats and mice were typically the surrogate species exposed in

benchmark studies.



# # Durations —Studies were selected that reflected chronic or subchronic exposure durations extending over a large percentage of the test species’ lifetime, over multiple generations, or over a particularly sensitive life stage of a species.



# # Exposure Routes —Studies indicating oral exposure (e.g., dietary, gavage) were preferred to studies using other exposure routes (e.g., intraperitoneal injection). Mammals and birds in the field are typically more highly exposed through ingestion of contaminated prey than th rough inhalation or direct contact, although there are exceptions (e.g., burrowing animals).



# # Dosing Scheme —Dose-response curves characterized by at least three data points were selected over studies exposing animals to one dose level. This helped identify both a NOAEL and a LOAEL for MATC calculations.

In addition to the primary literature, several review sources of ecotoxicity data were identified containing study data of sufficient quality to meet data requirements (Table 14-3). Several benchmark studies, however, were selected from Sample et al. (1996), a compendium of study values reporting NOAELs and LOAELS for chronic and subchronic durations measuring reproductive and developmental endpoints.

# Section 14.0 Ecological Benchmarks



# 14-11 Mammalian and avian benchmarks represent population-inference benchmarks. By developing benchmarks from NOAELs and LOAELs in mammals and birds, benchmarks were estimated to provide protection from ingested doses that may inhibit the reproductive capacities of these populations. The ability of the population to sustain itself (within normal biological variation) was inferred from individual effects su ch as fecundity. This inference, however, has yet to be validated from field or microcosm studies on exposed populations. Without validation, it is likely that some benchmarks are overprot ective and others are underprotective of wildlife populations. Although this method does not conf irm protection of populations, by protecting individuals from adverse effects to reproductive and developmental endpoints, some level of protection is provided to populations.

Once the benchmark study was identified, a scaled benchmark was calculated for representative receptors of mammals. This method used an allometric scaling equation based on body weight to extrapolate test species doses to estimate wildlife species doses. For mammals, a scaling factor of 3/4 was used (Equation 14-1) . This is the default methodology EPA proposes for carcinogenicity assessments and reportable quantity documents for adjusting animal data toan equivalent human dose (U.S. EPA, 1992b). For birds, recent research suggests that the crossspecies scaling equation used for mammals is not appropriate for avian species (Mineau et al., 1996). Using a database that characterized acute toxicity of pesticides to avian receptors of various body weights, Mineau et al. (1996) concluded that applying mammalian scaling equations may not sufficiently predict protective doses for avian species. Benchmarks scaled for small-bodied avian species using the mammalian equation generated scaled doses that were not protective enough for small birds. Mineau et al. (1996) suggested a scaling factor of 1 provided a better dose estimate for birds. Therefore, a scaling factor of 1 was applied for avian receptors (Equation 14-2).

(14-1)

(14-2)

where

EB

w 

# = scaled ecological benchmark for species w (mg/kg/d)

MATC
t 

# = maximum acceptable toxicant concentration (mg/kg/d)

bw
t 

# = body weight of the surrogate test species (kg)

bw

w 

# = body weight of the representative wildlife species (kg).

Body weights for ecological receptors were identified from two primary sources: the Wildlife Exposure Factors Handbook (U.S. EPA, 1993b) and Sample et al. (1997). Body weights for wildlife species not covered in these sources were identified through primary

# Section 14.0 Ecological Benchmarks

2 

# Herpetofauna includes species of amphibians and reptile s. Insufficient ecotoxicity data were identified to derive CSCLs for reptiles. Therefore, c ontinued discussions only review amphibians.



# 14-12 Data Requirements for FCV Calculation



# # The family Salmonidae in the class Osteichthyes,



# # One other family (preferably a commercially or recreationally important warmwater species) in the class Osteichthyes (e.g., bluegill, channel catfish),



# # A third family in the phylum Chordata (e.g., fish, amphibian),



# # A planktonic crustacean (e.g., a cladoceran, copepod),



# # A benthic crustacean (e.g., ostracod, isopod, amphipod),



# # An insect (e.g., mayfly, dragonfly, damselfly, stonefly, midge),



# # A family in a phylum other than Arthropoda or Chordata (e.g., Rotifera, Annelida, Mollusca),

and



# # A family in any order of insect or any phylum not already presented. 

# literature sources. (See the exposure factors database documentation section for an expanded discussion of receptor body weights.) Applying these decision criteria and methods resulted in the selection of benchmark studies and derivation of benchmark doses presented in Appendix 14A, Tables 14A-1 and 14A-2, for mammals and birds, respectively. The final scaled benchmarks for representative species are presented in Appendix 14A, Table 14A-10.

14.3.1.1.2 Total Surface Water CSCLs (ChemCSCLWaterTotRec ). The CSCLs developed for surface water based on total concentrations of the constituent covered the following receptor taxa: freshwater community (i.e., fish and aquatic invertebrates), algae/aquatic plants, and herpetofauna. 2 

# The methods used to derive CSCLs are reviewed here for each receptor taxon. The CSCL developed for the freshwater community was derived to reflect both total and dissolved water concentrations (see Section 14.3.1.1.3 for a discussion of the methods used to derive dissolved CSCLs). The resulting CSCLs developed for these taxa are presented in Appendix 14A in Table 14A-3 (total freshwater community), Table 14A-5 (algae and aquatic plants), and Table 14A-6 (amphibians).

Freshwater Community

The freshwater community CSCL was developed to protect species of fish and aquatic invertebrates. The CSCL does not extend to protect species of mammals and birds that may forage in freshwater ecosystems. The methods adopted to develop freshwater community CSCLs are consistent with those supported across EPA offices. The CSCLs were derived using methodologies founded through the development of the National Ambient Water Quality Criteria (NAWQC). These methods require the compilation of appropriate acute and chronic ecotoxicity data reporting effects to survival, growth, and reproduction in aquatic biota for specific members of the freshwater community. The NAWQC method uses a list of ecotoxicity data requirements for eight taxonomic families that represent typical freshwater species (see accompanying text box). Whether a final chronic value (FCV) or a secondary chronic value (SCV) is calculated depends on how well the eight taxonomic families are represented by the data.

# Section 14.0 Ecological Benchmarks



# 14-13 For populations of the freshwater community (e.g., fish, aquatic invertebrates), the FCV developed for the NAWQC or the criterion conti nuous concentration (CCC) developed for the Great Lakes Water Quality Initiative (GLWQI) was the preferred CSCL to use for this analysis (U.S. EPA, 1995a, 1996a). If neither a CCC nor an FCV was available, an SCV was calculated using Tier II methods developed through the GLWQI (Stephan et al., 1985; Suter and Tsao, 1996).

A brief overview of the derivation methodology is provided here; however, note that this description is a simplification of the actual methods and does not address many of the nuances of study selection and data interpretation. For a complete review of calculation methods, refer to Stephan et al. (1985).



# # FCV and CCC —An FCV and a CCC are calculated in one of two ways. If acceptable chronic toxicity data are available on at least one species representing each of the eight different data requirements, the FCV is essentially the concentration corresponding to a cumulative probability of 0.05 for the appropriate species. If the chronic toxicity data do not meet the eight family requirements, the FCV is calculated by (1) calculating a final acute value (FAV) that meets the eight species requirements, (2) estimating an acute-to-chronic ratio (ACR) as the ratio of at least three comparable (e.g., same-species) acute and chronic toxicity studies, (3) dividing the FAV by 2, and (4) dividing the result of the Step 3 value by the ACR.



# # SCV —An SCV is calculated using analogous methods as those applied in calculating the FCV. The Tier II methods, however, (1) require chronic data on at least one of the eight species requirements, (2) use a secondary acute value (SAV) in place of the FAV, and (3) are derived based on a statistical analysis of NAWQC data conducted by Host et al. ( 1991). Host et al. (1991) developed adjustment factors (AFs) depending on the number of taxonomic families represented in the database. The Tier II methodology was designed to generate SCVs that are below FCVs (for a complete data set) with a 95 percent confidence

limit.

Algae and Aquatic Plants

For algae and aquatic plants, toxicological benchmarks were identified in the open literature or from data compiled in Toxicological Benchmarks for Screening Potential Contaminants of Concern for Effects on Aquatic Biota: 1996 Revision (Suter and Tsao, 1996). For most contaminants, studies were not availabl e for aquatic vascular plants, but lowest-effects concentrations were identified for algae. The criteria for algae and aquatic plants were based on a lowest-observed-effect concentration (LOEC) for vascular aquatic plants or an effective concentration (EC

xx 

# ) for a species of freshwater algae, frequently a species of green algae (e.g., Selenastrum capricornutum ). Because of the lack of data in this receptor group and the differences between vascular aquatic plants and algae sensitivity, usually the lowest value of those identified was used. In instances where only a median effective carcentration (EC 50 

# ) was identified to characterize effects to algae growth and survival, a safety factor of 5 was applied to generate an estimated low effects concentration.

# Section 14.0 Ecological Benchmarks



# 14-14 Amphibians

Amphibians appear to be highly sensitive to a number of toxicants during the developmental stages of their life cycle (e.g., trace metals). Amphibians are essential parts of a number of food webs (particularly wetlands) and are likely to provide a fairly sensitive indicator for chemical stressors relevant to higher leve ls of biological organization. Though amphibians are a significant ecological receptor, ecotoxicity data characterizing the chronic dose-response relationship for chemicals of concern are limited. After a review of several compendia presenting amphibian ecotoxicity data (e.g., De villers and Exbrayat, 1992; Power et al., 1989; U.S. EPA, 1996b) as well as primary literature sources, no suitable subchronic or chronic studies were identified that reported effects to reproductive or developmental endpoints in amphibian species. Therefore, a CSCL based on chronic endpoints and exposure durations was not derived. Instead, the CSCL was developed from a geometric mean of acute (i.e., LC 50 

# , lethal water concentration resulting in 50 percent mortality) amphibian ecotoxicity data. A few general guidelines were followed in selecting analogous acute studies for developing the CSCL:



# # Test duration was usually less than 15 d.



# # Toxicity endpoints included mortality (LC 50 

# )



# # Exposure occurred during early life stages (i.e., embryo, larvae, and tadpole).

Because the criteria are based on acute data (i.e., lethality), the severity of the potential adverse effects that this criteria indicates is significant. Incorporating the amphibian data into the NAWQC within the data requirement categories is currently under consideration. Because amphibian species are more likely to breed in standing waters such as wetlands, ponds, or temporary puddles, the appropriateness of combining protection of amphibian receptors with the freshwater community CSCL is unclear.

14.3.1.1.3 Dissolved Surface Water CSCLs (ChemCSCLWaterDissRec ). Conversion

factors were available for several of the metal constituents to convert total metal concentrations in the water column to total dissolved concentrations (U.S. EPA, 1999b). Although the total concentrations supplied by the NAWQC and GLWQI are still deemed scientifically defensible by EPA, the Agency recommends the use of dissolved metal concentrations when they are available (Prothro, 1993).

Methods are currently only available to develop dissolved CSCLs for metals in the freshwater community. Dissolved CSCLs were derived from total water CSCLs using a conversion factor. The conversion factors appli cable to chronic criterion in freshwater are presented in Table 14-5. The conversion factor s were developed by EPA using a series of filtration experiments that measured the difference between filtered and unfiltered concentrations of metals in surface waters. Dissolved CSCLs were derived by multiplying the total CSCL by the conversion factor (Equation 14-3).

(14-3)

where

# Section 14.0 Ecological Benchmarks



# 14-15 Metal CSCL total 

# = either an FCV or an SCV in freshwater

Conversion Factor = the fraction of dissolved metal.

The final CSCLs generated for the freshwater community based on the total dissolved constituent concentrations are provided in Table 14A-4 of Appendix 14A.

Table 14-5. Conversion Factors for Dissolved Metal a



# Constituent Conversion Factor

Arsenic 1.00

Cadmium 2 

# 1.1017-[(ln hardness)(0.04184)]

Chromium III 0.860

Chromium VI 0.960

Lead b 

# 1.4620-[(ln hardness)(0.14571)]

Mercury 0.850

Zinc 0.986

aConversion factor for chronic CSCLs in freshwater.

b 

# Dependent on the water hardness (assumed to be 100 mg CaCO 3 

# /L for this analysis).



# 14.3.1.1.4 Sediment CSCL (ChemCSCLSedimentRec ). Two methods were applied in developing the CSCL for the benthic community (e.g., worms, amphipods). The first and preferred method used measured sediment concentrations that resulted in minimal effects to the composition and abundance of the sediment community. The sediment criteria were derivedfrom the upper limit of the range of sediment contaminant concentrations dominated by noeffects data to survival, species diversity, and abundance endpoints. Measurements to derive the

CSCLs were taken at the national scale and refl ected a variety of sediment types and benthic community species. The second CSCL derivation method used the equilibrium partitioning (EqP) relationship between sediments and surface waters to predict a protective concentration for the benthic community. This method was used only for nonionic organic constituents. For the benthic community, the approach used to establish CSCLs was based on a complete assessment of several sources proposing protective sediment CSCLs (Table 14-3). A discussion of each method (i.e., measured and estimated CSCLs) is provided. The resulting benthic CSCLs are presented in Appendix 14A, Table 14A-7.

Measured Sediment CSCLs

The primary sources of measured sediment CSCLs are the National Oceanic and Atmospheric Administration (NOAA) and the Flor ida Department of Environmental Protection (FDEP) sediment documents. NOAA annually co llects and analyzes sediment samples from sites located in coastal marine and estuarine environments throughout the United States as part of

# Section 14.0 Ecological Benchmarks



# 14-16 the National Status and Trends (NS&T) Progr am. Data collected by NOAA include measured sediment concentrations and the corresponding measures of toxicity in resident species such as amphipods, arthropods, and bivalves on a variety of community-based endpoints (e.g., abundance, mortality, species composition, and species richness). These data are used by NOAA to estimate the 10th percentile effects concentration (ER-L) and a median effects concentration (ER-M) for adverse effects in the sediment community. These values are not NOAA standards; rather, they are used to rank sites based on the potential for adverse ecological effects. In contrast, the FDEP sediment criteria were developed from the ER-L and ER-M data to approximate a probable effects level (PEL, estimated from ER-M data) and a threshold effects level (TEL, estimated from ER-L data). PELs and TELs correspond to the statistically derived upper limit of contaminated sediment concentrations that demonstrate probable effects and no effects to the benthic community, respectively. Generally, FDEP values are more conservative than NOAA values. Even though these criteria were developed for a marine community, researchers have demonstrated that marine TELs have good correlation with no-effects levels found for freshwater systems (Smith et al., 1996). In order of preference, TELs were adopted as CSCLs if available; if not, ER-L values were used. The FDEP criteria were chosen above the NOAA criteria for the following reasons:



# # The same database was used for both the NOAA criteria and the FDEP criteria development.



# # In most cases, the FDEP criteria were more conservative than the NOAA criteria because a larger portion of the low-effects data was used in benchmark development.



# # The marine TELs developed by the FDEP were found to be analogous to TELs observed in freshwater organisms (Smith et al., 1996).

Estimated Sediment CSCLs

When measured effects data were not available for organic constituents using the TEL or ER-L approach, the value was derived using the EqP approach to estimate the sediment CSCL (U.S. EPA, 1993a). The surface water FCV or SCV was used to generate a sediment CSCL using the partitioning relationships among surface water, pore water, and organic carbon in sediment. This method assumes that the equilibrium partitioning between the sediment and the water column is a function of the organic carbon. Equations 14-4 and 14-5 were used to calculate the sediment CSCL depending on whether an FCV or an SCV was available. In calculating sediment CSCL for nonionic chemicals, the fraction organic carbon (f

oc 

# ) was assumed to be 1 percent total organic carbon and K

oc 

# s (organic carbon partitioning coefficients) were adopted as reported in Jones et al. ( 1997). However, because sediment CSCLs were derived for organic constituents based on site-specific f

oc 

# , the CSCLs in Table 14A-7 were recalculated within the 3MRA modeling system on a site-specific basis.

(14-4)

# Section 14.0 Ecological Benchmarks



# 14-17 (14-5)

14.3.1.1.5 Soil CSCLs (ChemCSCLSoilRec ). Soil CSCLs were derived for the terrestrial plant community and the soil community. Each of the specific methods, including the rationale and the derivation methods, is outlined in the following sections. The results of the soil CSCL development are presented in Table 14A-8 (terrestrial plant community) and Table 14A-9 (soil community) of Appendix 14A.

Terrestrial Plants

For the terrestrial plant community, toxicological benchmarks were identified from a summary document prepared at the Oak Ridge National Laboratory (ORNL): Toxicological Benchmarks for Screening Potential Contaminant s of Concern for Effects on Terrestrial Plants:

1997 Revision (Efroymson, Will, Suter, and Wooten, 1997). The measurement endpoints were generally limited to growth and yield parameters for the following reasons:



# # They are the most common class of responses reported in phytotoxicity studies and, therefore, allow for criterion calculations for a large number of constituents.



# # They are ecologically significant responses, both in terms of plant populations and, by extension, the ability of producers to support higher trophic levels.

As presented in Efroymson, Will, Suter, and Wooten (1997), criteria for phytotoxicity were selected by rank ordering the LOEC values and then approximating the 10th percentile. If there were 10 or fewer values for a chemical, the lowest LOEC was used. If there were more than 10 values, the 10th percentile LOEC was used.

Soil Community

Two methods were used in deriving soil community CSCLs: a community-based CSCL

and an earthworm/microbial CSCL.

Community-Based CSCL —The first, and preferred, method was based on a communitylevel approach similar to that applied in deriving the NAWQC. This method developed a CSCL based on NOECs to reproductive and development endpoints in a number of key functional taxa in the soil community. The CSCL was designed to protect the structure and function of the soil community and its critical role in the overall nutrient processing that occurs in the terrestrial

food web. A detailed discussion of the decision criteria and calculations used to develop a community-based CSCL are provided in the following section “Methodology to Develop Community-Based CSCLs.” Review of the primary literature only supplied sufficient data to develop a community-based soil CSCL for the constituents of lead and cadmium.

Two key uncertainties were noted in the development of community-based CSCLs. First, the ecotoxicity data used in the method are based on NOECs. The CSCLs developed using the earthworm/microbial method for the soil community were based on low-effects levels. Because these CSCLs are based on no-effects soil concentrations, some added conservatism was

# Section 14.0 Ecological Benchmarks



# 14-18 generated in the soil community CSCLs for lead and cadmium. Second, the species taxa groups designed to represent key compartments in the soil community did not include microbes. This introduces some uncertainty in the soil CSCL because microflora make up approximately 80 to 90 percent of the biomass in soil and microflora ar e responsible for the majority of the biological activity in soil (e.g., N mineralization).

Earthworm and Microbial CSCLs —The second method used to derive soil CSCLs required the identification of LOECs for earthworms and microbial endpoints. However, because a single species alone cannot predict the potential toxicological impacts to the soil community, the community-based method was preferred over using an earthworm or microbial

CSCL.

Earthworms have been recognized to play important roles in promoting soil fertility, releasing nutrients, and providing aeration and aggr egation of soil, as well as being an important food source for higher trophic level organisms. In addition, their constant contact with soil media and permeable epidermis makes them more susceptible to contaminant exposures. Likewise, microbial communities play a key functional role in soil fertility, decomposition processes, and nutrient cycling, providing nutrients in available forms to plants. Microbial CSCLs were only used when they indicated a significantly higher sensitivity to a particular constituent than the corresponding earthworm toxicity data. This was the case only for nickel

and zinc.

The earthworm and microbial CSCLs were developed using the ER-L approach, which was also applied to develop terrestrial plant CSCLs. When more than 10 studies were identified reporting LOECs, then the 10th percentile of the values was derived as the CSCL. When less than 10 values were identified, however, the lowest LOEC was selected as the CSCL. When sufficient LOEC data were identified, this method was used to develop soil CSCLs for all constituents except lead and cadmium.

Methodology to Develop Community-Based CSCLs –The process of developing community-based soil CSCLs may be divided into three basic components: (1) selection of representative soil species, (2) collection of toxicological data on soil species, and (3) calculation of a CSCL for the soil community. Each of these steps is detailed in the following sections.

Selection of Representative Soil Species

— Two important assumptions were made in developing the approach to select representative soil species. First, species using resources in a similar way (e.g., similar diet) should receive similar exposures (i.e., guild theory). Second, taxonomically related soil invertebrates tend to have similar toxicological sensitivity to chemicals (Neuhauser et al., 1986). Soil communities are made up of numerous groups of species performing one or more functions for the community. Thus, the set of representative species was designed to reflect the breadth a nd variety of taxonomic and structural/functional groups. Five metrics were identified to serve as a practical guide in the selection of appropriate soil species. Figure 14-1 illustrates the generalized soil community that is reflected in these

metrics.

Five metrics were used to select representative soil species, as follows:

# Section 14.0 Ecological Benchmarks



# 14-19 1. Organism size –classified into three groups: microfauna (<0.15 mm; e.g., Protozoa, Nematoda), mesofauna (0.16 to 10 mm; e.g., Enchytraeidae, Acari), and macrofauna (>10 mm; i.e., larger invertebrates). This convenient, albeit somewhat arbitrary, classification was useful in considering the interactions between soil species and their habitat.

2. Distribution in soil horizon –divided into three layers: deep mineral, shallow organic, and soil litter. Exposures to soil contaminants are presumed to occur for organisms at any horizon. The top two horizons, however, tend to receive higher exposures to persistent and relatively immobile contaminants (such as some metals).

3. Abundance –the number of individuals present in a typical habitat. Caution must be implemented in using this criterion because abundant species are not always the most ecologically significant. For example, nematodes and annelids both contribute equally to the flux of CO 2 

# , yet nematodes outnumber annelids more than 100 to 1 (Reiche, 1977).

4. Energy metabolism –the relative importance of a species to the overall community can be based on the contribution of energy that species provides (Curry, 1994). Increasingly, energy budgets are being viewed as useful tools in assessing ecological significance.

5. Function in community –feeding preferences of different organisms largely define their role in the trophic structure (see Figure 14-1), shaping the dynamics of the soil community. The selection of species should adequately represent different functional roles within the trophic structure. To ensure a balanced representation of a generalized soil community, organisms were classified into four functional categories (Brown, 1978):

# Section 14.0 Ecological Benchmarks



# 14-20 Figure 14-1. Simplified trophic structure of a generalized soil community.



# # Microphytic–organisms that feed on fungal spores, hyphae, lichens, and bacteria (e.g., ants, fungus gnats, nematodes, and Protozoa)



# # Saprophytic–organisms that feed on dead or decaying organic matter (e.g., earthworms, Acari, and Collembola)



# # Phytophagous–organisms that feed on living plant material including plant stems, leaves, roots, or woody parts (e.g., mollusks, symphylids, termites, and insect larvae)



# # Carnivorous–organisms that are true predators (e.g., carabids, mites, and spiders).

Collection of Toxicological Data on Soil Species —Guidelines were established to collect data on NOECs for representative species in the soil community. The toxicological data included studies on a variety of relevant physiologi cal and process-based endpoints (e.g., cocoon production, maintenance of reproductive processes). Assumed routes of exposure were direct contact and ingestion. Toxicological representa tion of each of the following species groups was the goal of data collection efforts.

# Section 14.0 Ecological Benchmarks



# 14-21 (14-6) Group 1 –one species from the phylum Nematoda. Nematodes are the most abundant organisms in the soil and provide the third largest amount of biomass. In addition, they represent the only microfauna evaluated.

Group 2 –one species of soil mite (Acarina) from one of the following suborders: Cryptostigmata, Prostigmata, Mesostigmata, or Metastigmata. Soil mites are important as decomposers, predators, and plant eaters. Mites provide the largest amount of CO 2 

# flux among these groups.

Group 3 –one insect from the order Collembola. Springtails were selected because they are saprophytic and the second most abundant invertebrates in the soil. Their high abundance also results in moderately high biomass.

Groups 4 and 5 –two annelids from the orders Plesiopora or Opisthopora (families Enchytraeidea and Lumbricidae preferred). The Oligochaeta represent some of the largest soil organisms and, as subterranean animals, are important saprophytic feeders. Members of Opisthopora are the largest contributors to soil fauna biomass.

Groups 6 and 7 –two additional species of arthropods selected from one of the following taxonomic groups: Diptera, Coleoptara, Isopoda , Chilopoda, and Diplopoda. Arthropods play a variety of critical roles in the soil community and rank high in terms of all five metrics.

Group 8 –a species of mollusk from the order Stylommatophora. Although the majority of mollusks are marine organisms, they represent surface decomposers in the trophic structure that are not duplicated by the other organisms in the representative set.

Calculation of CSCL for the Soil Community

— The statistical approach adopted consisted of two steps: (1) fitting the NOEC data on repr esentative species of soil biota to a lognormal distribution and (2) extrapolating to a criterion ba sed on the mean and standard deviation of the toxicity data set. Key assumptions were that NOEC data are distributed lognormally and the 95 percent level of protection is ecologically signi ficant. The approach to calculating CSCLs for the soil community was based on efforts by Dutch scientists (the RIVM methodology) to develop hazardous concentrations (HCs) at specifi ed levels of protection (primarily 95 percent) at both a 95th percentile and a 50th percentile level of confidence (Aldenberg & Slob, 1993; Sloof, 1992; VanStraalen & Denneman, 1989). For the soil community CSCL, the 50th percentile level of confidence was selected because the 95th percentile appeared to be overly conservative for a no-effects approach. Equation 14-6 was used to calculate soil community

CSCLs.

where

HC 5% 

# = soil concentration protecting 95 percent of the soil species

# Section 14.0 Ecological Benchmarks



# 14-22 x m 

# = sample mean of the log NOEC data

k l 

# = extrapolation constant for calculating the one-sided leftmost confidence limit for a 95 percent protection level

s
m 

# = sample standard deviation of the log NOEC data.

Note that only one value for k l 

# is calculated for the 50th and 95th percentile confidence limits, respectively, for each sample size (m). Consequently, it is assumed that there is just one extrapolation constant with the required confidence property for each species sample size and extrapolation factors may be determined through Monte Carlo simulation by generating random sample averages and deviations for the standard logistic distribution and adjusting for a specified confidence level (i.e., 50th or 95th).

14.3.1.2 Database Processing

. Minimal manual processing of the benchmark/CSCL database was conducted. Most of the CSCL and benchmark values generated were manuallyentered into the data table. The parameters for the benchmark/CSCL database were onedimensional chemical properties that were dimensioned on the variable Num Receptor in the Ecological Risk Module.

Processing of the benchmark/CSCL database was conducted for the scaling of mammalian and avian benchmarks and the derivation of module-generated, site-based CSCLs (e.g., hardness dependent upon water quality criteria). Data processing was conducted on the mammalian benchmarks, which were scaled by body weight to extrapolate from surrogate laboratory species to representative wildlife species (see Section 14.3.1). In addition, some of the criteria were generated on a site-specific basis using parameters of water hardness (mg

CaCO 3 

# /L) and f

oc 

# in sediment. In cases where CSCLs were developed on a site-specific basis, CSCLs reported in the database may not reflect the value used in calculate hazard quotient (HQ)

calculations.

14.3.1.3 Assumptions and Uncertainties

. In this section, the key assumptions and uncertainties associated with the application and development of the ecological benchmark and CSCL database are reviewed. The discussion of assumptions and uncertainties is constructed around three key issues: (1) the relationship between assessment endpoints and measures of effect, (2) the quality of the ecotoxicological data, and (3) the extrapolation methods used to derive receptor-specific benchmarks and CSCLs from the ecotoxicity data.

14.3.1.3.1 Relationship Between Assessment Endpoints and Measures of Effect

. In developing ecological benchmarks and CSCLs for the representative national data set, it is crucial to establish the relationship between the assessment endpoints (i.e., the ecological values to be protected) and the measures of effect (i.e., the ecotoxicity data used to support benchmarks and CSCLs). Because the 3MRA modeling system is predictive, there is no mechanism to verify that assessment endpoints are, in fact, protected by the measures of effect selected to support benchmark/CSCL development. Consequently, there is uncertainty in applying the benchmarks/CSCLs to evaluate risks to the assessment endpoints chosen for the example data set. These uncertainties are discussed below along with key assumptions that are implicit in developing benchmarks and CSCLs (e.g., 95 per cent protection level for aquatic biota).

# Section 14.0 Ecological Benchmarks



# 14-23 Mammals and Birds



# # Assessment Endpoint : maintain viable mammalian and avian wildlife populations. The attribute to be protected was the reproductive and developmental success of representative species.



# # Measure of Effect : a de minimis threshold for developmental and reproductive toxicity in mammalian and avian wildlife species. The threshold was calculated as the geometric mean of the NOAEL and LOAEL, frequently referred to as the maximum acceptable toxicant concentration (MATC). Implicit in this calculation is the assumption that the toxicological sensitivity is lognormal.

An important source of uncertainty is the benchmark calculation of the MATC. Based on numerous discussions among the technical staff at OSW, this threshold value was determined to be appropriate given the assessment endpoints for a national assessment. The rationale for this determination is based on two assertions: (1) the MATC is above a no effects level and, therefore, is associated with some finite level of risk (i.e., the regulations would not be based on no effects), and (2) the MATC is conservative in that it does not allow for the level of effect associated with a low effects level (often estim ated at roughly 20 percent of the population). In making the assumption that a threshold for effects on individual organisms can be used to predict the potential risks to populations, we accept considerable uncertainty regarding the “true” effects on wildlife populations that can only be addre ssed through simulations with population-level models. These models are designed to address various elements of population dynamics, such as predator prey interactions, carrying capacity of the habitat, immigration and emigration, and initial population size (to name but a few attribut es of population-level models). Nevertheless, because the MATC is assumed to be below the level of effect distinguishable from natural population variability, it is assumed that the benchmark provides a reasonably conservative level of protection to wildlife populations.

A second important source of uncertainty is in the selection of study endpoints, in essence, how well an MATC based on reproductive/developmental effects translates into maintenance of wildlife populations. Although th e selection of reproductive and developmental effects is consistent with current EPA guidance on ecological risk assessment, it is not possible to demonstrate with certainty that these are the critical endpoints of concern. For example, neurological effects that impact behavior may occur at a threshold value below the MATC. Depending upon the nature and severity of the effect (e.g., inability to avoid predators), a constituent may affect enough organisms that relatively few reach reproductive maturity. As a result, the overall impacts on the wildlife population may be greater than those inferred from endpoints on reproductive fitness and developmental effects. The implications for receptors with relatively large home ranges (e.g., wolves) are difficult to interpret. For these receptors, the study area may impact only a single reproducing pair of animals and the endpoint of interest may be crucial in determining: (1) whether adverse effects occur and (2) what the ecological significance of those effects might be.

# Section 14.0 Ecological Benchmarks



# 14-24 CSCLs for the Freshwater and Soil Communities



# # Assessment Endpoint : maintain sustainable community structure and function

. The attributes to be protected were growth, survival, and reproductive success of species that represent key functional roles in the community.



# # Measure of Effect : concentration in soil or surface water, respectively, based on ecotoxicity studies on endpoints that include lethality, fecundity, growth, and

survival . The CSCLs for the freshwater and soil communities were typically derived at a 95 percent protection level us ing both no effects and low effects data, as appropriate. When available, the Ambient Water Quality Criteria for chronic

effects were chosen as the freshwater CSCLs.

The CSCLs derived for the soil and freshwater organisms are intended to ensure protection of critical structures and functions of the respective communities. However, the

CSCLs are not true community-level measures of effect in that they do not consider the complex interactions among community members. Consequently, there is uncertainty inherent in inferring risk estimates for the community from a statistical interpretation of data on individual organisms.

In addition, there has been some criticism of the method used to develop the communitybased soil CSCL because it does not incorporate microbial populations as a taxa category. There is some question about the endpoint and level of effect that would result in an ecologically significant no- or low-adverse effects to microorganisms (e.g., LOEC, EC 25 

# , or EC 50 

# for nitrification). There is no doubt that microbial communities are critical to the continued functioning of soil communities, and work is ongoing to consider how to appropriately include this receptor group in the species requirements. Their absence in the current method generates some uncertainty that the measure of effect provides protection to this key receptor.

Ecotoxicity data on earthworms were used to derive CSCLs for the soil community if no other suitable data were identified (i.e., if the data set were limited exclusively to earthworms). However, earthworms represent only one element of a healthy soil community and there is large uncertainty in applying these data to evaluate risks to the entire community. Earthworms play an important role in the soil community (e.g., soil fertility, nutrient release, aeration, food source for predators) and, because ecotoxicity data are relatively abundant, are valuable as indicator species.

Benthic Community



# # Assessment Endpoint : maintain sustainable community structure and function

. The attributes of the benthic community to be protected included the growth, survival, and reproductive success of benthic biota.



# # Measure of Effect : concentration in sediment based on ecotoxicity studies on endpoints that include lethality, fecundity, growth, and survival . The CSCLs for the sediment community were typically derived at a 95 percent protection level using both no effects and low effects data, as appropriate. As with the freshwater

# Section 14.0 Ecological Benchmarks



# 14-25 CSCLs, the Ambient Water Quality Criteria for chronic effects were used to support the sediment CSCLs. In addition, field data on the toxicity of metals to sediment communities in saltwater were also used to develop sediment CSCLs and include a number of “true” community-level effects (e.g., abundance of sediment biota).

The CSCLs for metals were derived from fi eld studies conducted in marine ecosystems. These data were based on effects to marine biota and reflect the surface water chemistry and equilibria characteristic of marine systems. It is implicitly assumed that: (1) the relative sensitivity of species in saltwater sediments is similar to those in freshwater sediments, and (2) the behavior of metals (e.g., bioavailability) in the marine environment is not significantly

different from the freshwater environment. However, comparisons made between freshwater and marine CSCLs developed using analogous met hods indicate that there is not a significant difference between the effects seen across these systems at low exposure levels (Smith et al., 1996). The methods used to collect field data do not fully support a definitive cause-effect relationship because they do not account for other stressors that may impact the sediment community (i.e., temperature, predation). Th e CSCLs for non-ionizing organic constituents were developed based on EPA guidelines for sediment community criteria.

Terrestrial Plant Community



# # Assessment Endpoint : maintain structure and function of terrestrial plant
community . The attributes to be protected included growth and survival of terrestrial plants.



# # Measure of Effect : soil concentrations related to growth, yield, seedling emergence germination endpoints . The low effects data on phytotoxicity were rank ordered and the plant CSCL was estimated as the 10 th 

# percentile value.

The endpoints for plants were limited to low effects concentrations for growth and yield parameters such as seed germination, seedling emergence, and vegetative vigor. It is unclear, however, if the selected measure of effect actua lly represents a biologically significant effect to populations of wild plants since terrestrial plant communities are quite robust and can shift to more tolerant plant species, and still maintain an adequate prey base for herbivores. There is added uncertainty because most of the ecotoxicity data identified were based on studies using agricultural varieties of plants. Further, other e ffects, such as RNA synthesis or respiration, may be more sensitive indicators of potentially significant risks to plants. Substantial uncertainty will be associated with evaluating risks to the plant community until studies are available to determine: (1) the most sensitive, biologically significant endpoint for plants (e.g., seed germination, early growth), and (2) the effects level at which the effect should be considered significant in terms of plant population growth and survival.

Algae/Aquatic Plants



# # Assessment Endpoint : maintain primary producers in freshwater systems, including both algal and vascular aquatic plant communities . The attribute to be protected for this taxa was the growth and biomass.

# Section 14.0 Ecological Benchmarks



# 14-26 

# # Measure of Effect : surface water concentrations related to gross measures of “health” (e.g., biomass) for the algal community and a variety of endpoints for aquatic plants (e.g., number of fronds, root number, plant number, root length). For algae, the EC 20 

# was selected as an adequate threshold for adverse effects and, because of the paucity of data, the lowest LOEC for endpoints of interest was chosen for vascular aquatic plants.

Algae and aquatic plants not only provide a food source for aquatic biota, but also provide needed structure and habitat for many aquatic species. Because the assessment endpoint includes the functional contribution of primary aquatic producers to aquatic ecosystems, there is uncertainty in applying low effects concentrations to this receptor group to protect its value to the ecosystem as a whole. Nevertheless, the design of the 3MRA modeling system goes well beyond screening and, therefore, use of no effects data was considered inappropriate.

Data availability on algae far exceeded the data identified for vascular aquatic plants. As a result, the CSCL for aquatic producers generally reflects ecotoxicity studies on algae. Because little is known about the relative sensitivity between algae and aquatic plants, representing this receptor group with algal data introduces additional uncertainty in the risk estimates for freshwater systems. There are significant diffe rences in uptake, transport, and biochemical processes between algae and aquatic plants and, therefore, uncertainty in determining how well the measures of effect act to maintain communities of primary producers in aquatic systems.

Amphibians



# # Assessment Endpoint : maintain viable amphibian populations. The attribute to be protected was the survival and developmental success of these receptors.



# # Measure of Effect : The measure of effect selected to meet the assessment endpoint was the acute LC 50 

# s for lethality and survival and developmental effects resulting from early lifestage exposures.

As indicated by the assessment endpoint, this surface water CSCL was designed to protect amphibian species.

There is additional uncertainty that the measure of effect used for herpetofauna adequately represents a level of protection suitable to the assessment. The CSCL represents a relatively severe effect that includes lethality to 50 percent of the population; this level of effect far exceeds other CSCLs developed for the representative national data set and should be considered as nonconservative. Therefore, there is substantial uncertainty in applying this measure of effect given the goal of maintaining vi able herp populations. Acute data were used to develop this CSCL because so few chronic data were available. There potentially could be dramatic impacts to other more sensitive endpoints such as reproduction at these surface water CSCLs and, moreover, herpetofauna appear to be under considerable stress from other, as yet unidentified, factors.

The CSCLs for herpetofauna cannot be categorized as protective given nature and magnitude of potential effects. Additional analysis of the risk results for this receptor group may

# Section 14.0 Ecological Benchmarks



# 14-27 be warranted for exit criteria associated with herpetofauna HQs close to the target value of 1. The uncertainty associated with the protection of this species needs special attention when the risk results are interpreted.

14.3.1.3.2 Data Quality Issues. In addition to uncertainties associated with the application of benchmarks/CSCLs, there are uncertainties inherent in the development of benchmarks/CSCLs (e.g., extrapolating from dose-response data; interspecies scaling of benchmarks). The quality and quantity of data used to develop the benchmarks and CSCLs varies greatly across the receptor groups. Thus, there are uncertainties inherent in deriving benchmarks and CSCLs using such a wide range of ecotoxicological data. The key data quality

issues are reviewed here.

No-Effects Concentrations Used When Low-Effects Data Were Unavailable

For some of the receptor taxa, only a no-effects concentration was identified through

literature searches. In cases where no-effects data were available but sufficient low-effects data were not, the no-effects level was used. As a result, some benchmarks are more conservative than others. This was the case for the soil community CSCLs calculated for lead and cadmium.

Statistically Based Soil Community CSCLs

The community-based soil CSCL was developed to assess the potential effects to multiple trophic elements and various key taxa. This method was applied only for a limited number of metals in the analysis; however, there are several unresolved issues in the application

of this method.



# # A variety of endpoints were aggregated to derive a geometric mean for the NOEC data for each of the eight representative soil species data requirements. The geometric mean of multiple values representing several measurement endpoints has statistical meaning but not well-defi ned biological significance. The loss of the true stressor-response relationship in this approach makes interpreting the ecological significance of CSCL exceedances difficult.



# # The issue of bioavailability is particularly important in assessing the impacts to the soil community, particularly for metals that exist in multiple ionic forms in the environment. The toxicity and mobility of a metal can be highly influenced by the local environmental chemistry of the soil matrix. Characterizing the bioavailability of metals in different environmental conditions is crucial in establishing CSCLs that are useful across different soil matrices. Bioavailability was not accounted for in this methodology.



# # Although soil invertebrates may be classified according to ecological function (e.g., trophic level, feeding habits), few studies were identified that supported the assumption that taxonomically related soil invertebrates have toxicologically similar responses to chemical stressors (e.g., Neuhauser et al., 1986). In addition, many species of soil invertebrates were excluded that occur only in specialized microenvironments such as dung piles, carrion, and rotting wood (i.e., niche

# Section 14.0 Ecological Benchmarks



# 14-28 organisms). As a result, species were selected to represent a range of trophic levels and functions in the community (rather than selecting the "most sensitive" species). This community-based approach assumes that, if key components in the soil community are protected, community structure and function will not be adversely affected. However, this approach has not been validated in field or mesocosm studies. The development of a more generalized soil comunity reduced the resolution of the potential impacts to this community.

Statistical versus Biological Endpoints

There is some uncertainty associated with using the MATC as a benchmark because it is

derived from statistically relevant endpoints rather than biologically relevant endpoints. Because the NOAELs and LOAELs are generated using hypothesis-testing statistics, the quantification of these effects levels depends on the size, design, and variability of an experiment (e.g., range-finding test or definitive test). B ecause the MATC is a geometric mean of two statistically derived toxicity endpoints, uncertainty is generated by establishing this value as a “protective” benchmark. In some cases, low-effects and no-effects concentrations derived using hypothesis testing result in chronic benchmarks for aquatic organisms (e.g., MATCs) that result in greater than 50 percent mortality (Stephan et al., 1985). For example, the MATC has been shown to correspond to fairly high levels of effect. Data from 176 tests on 93 chemicals with 18 species indicated that average reductions in reproductive endpoints at the MATC were 20 percent for parental survival, 42 percent for fecundity, and 35 percent for an integrative weight/egg parameter (Suter et al., 1987). The uncertainty associated with the biological

relevance and conservatism of these doses needs to be considered in the characterization of the

risk results.

Research and Analysis of Data Supporting Benchmarks and CSCLs

A complete and exhaustive primary literature search has been completed for almost half of the constituents considered in this analysis. For other constituents, secondary sources have been consulted to identify appropriate benchmarks and CSCLs. The different levels of data review and analysis were the result of changes made to the list of constituents after primary literature searches were completed. Rather than conducting primary literature searches for the newly added constituents, compendia were used to identify preliminary benchmarks and CSCLs to support the risk estimates. The limited literature review given to these chemicals, listed in Table 14-2, magnifies the uncertainties in developing benchmarks and CSCLs.

14.3.1.3.3 Extrapolation

Uncertainty Factors Applied

Additional uncertainty was introduced into the analysis through developing the measures of effect by applying uncertainty factors to convert LOAELs for mammalian and avian benchmarks to NOAELs. When only LOAELs were available, the LOAEL was divided by 10 to estimate the NOAEL. This is not an uncommon procedure when only a low-effects concentration is available; however, EPA has recently assessed the accuracy of uncertainty factors and reported that, in many cases, the difference can be less than 10. Applying a factor of

# Section 14.0 Ecological Benchmarks



# 14-29 10 may create added conservatism in the MATCs generated for mammals and birds (Abt Associates, Inc., 1995). For algae and aquatic plants, a similar uncertainty factor of 5 was applied to convert EC 50 

# data to estimate a low-effects concentration.

Allometric Scaling

For mammals, differences in interspecies uncertainty were indirectly addressed through the use of the species-scaling equation. This method is used by EPA in carcinogenicity assessments when extrapolating from rats to humans. Wildlife toxicologists commonly scale dose to body weight without incorporating the exponential factor. There is continued disagreement among experts whether the application of scaling factors is appropriate in ecological risk because this method may not account for physiological/biochemical differences in species sensitivity. Applying this method to species demonstrating different sensitivities across chemical classes introduces some uncertainty in the analysis. Allometric scaling was not applied to avian receptors because a recent study indicated that scaling benchmark doses for birds may not be protective of small-bodied avian receptors (Mineau et al., 1996).

Laboratory-to-Field Extrapolation

The toxicological benchmarks for ecological receptors were developed assuming that effects that are observed in laboratory test species are applicable to wildlife species under similar field conditions. As a result, there were no labor atory-to-field extrapolation factors applied to account for the additional stress that may be encountered under field conditions (e.g., cold or drought). Van Straalen and Denneman (1989) a nd Stephan et al. (1985) examined arguments both for and against a laboratory-to-field extrapol ation factor and concluded that laboratory-tofield extrapolation factors were not necessary; i. e., criteria derived with laboratory data should protect soil fauna in the field. However, other authors have suggested that laboratory species tend to be more homogeneous and have narrower tolerance distributions than their field counterparts, and that the distribution of the ta rget population of species is likely to have a different shape and scale relative to the laboratory species (Smith and Cairns, 1993; Suter et al., 1983). As a result, the distribution of the endpoint will be narrower for the laboratory species. In addition, Smith and Cairns (1993) point out that local adaptation to conditions may make an individual species more or less tolerant to a chemical stressor.



# 14.4 Quality Assurance/Quality Control

14.4.1 Technical QA/QC

Each value in the benchmark/CSCL database has undergone some level of technical QA. Constituents that were included in the proposed representative national data set have undergone extensive review and have been periodically updated to reflect new findings. Additional constituents included after the primary literature review was completed have been technically reviewed for appropriateness. Technical QA effo rts went into reviewing the decision criteria used in benchmark and CSCL development to ensure that the implementation of the methods produced appropriate values.

# Section 14.0 Ecological Benchmarks



# 14-30 14.4.2 Data Entry QA/QC

Data entry was performed primarily by hard-copy data entry. Data were checked by different ecological staff members by reviewing data input from the original and secondary

sources. Identified errors were reviewed and corrected. The calculations used in allometric scaling were manually checked for confirmation that equations in the spreadsheet were coded properly.

14.4.3 Data Formatting QA/QC

Manual QA/QC checks were conducted to identify errors that may have occurred during data formatting efforts. Approximately 10 percent of the values were checked to ensure formatting for the modeling system did not change or shift values.



# 14.5 References

Abt Associates, Inc. 1995. Review and Analysis of Toxicity Data to Support the Development of Uncertainty Factors for Use in Estimating Risks of Contaminant Stressors to Wildlife. Review Draft. Prepared for Office of Water, U.S. Environmental Protection Agency. Washington, DC.

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# 14-31 Denneman, C. A. J., and N. M. van Straalen. 1991. The toxicity of lead and copper in reproduction tests using the oribatid mite Platynothrus peltifer

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# 14-32 Johnson, D., A.L. Mehring, and H.W. Titus. 1960. Tolerance of chickens for barium. Proc. Soc. Exp. Biol. Med. 104:436-438.

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# 14-33 Neuhauser, E.F., P.R. Durkin, M.R. Malecki, and M. Anatra. 1986. Comparative toxicity of ten organic chemicals to four earthworm species. Comp. Biochem. Physiol . 83C(1):197-200.

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Russell, L. K., J. I. DeHaven, and R. P. Botts. 1981. Toxic effects of cadmium on the garden snail (Helix aspersa). Bull. Environm. Conam. Toxicol., 26:634-640.

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# 14-34 Shiota, K., and H. Nishimura. 1982. Teratogeni city of di(2-ethylhexyl) phthalate (DEHP) and

di- n -butyl phthalate (DBP) in mice. Environ. Health Perspect. 45:65-70.

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# 14-35 U.S. EPA (Environmental Protection Agency). 1989. Ambient Water Quality Criteria Document: Addendum for Antimony (Draft Report [Final]). Cincinnati, OH.

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# Appendix 14A Ecological Benchmarks



# 14-37 

# Appendix 14A

Ecological Benchmarks

Table 14A-1. Mammalian Benchmark Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-39

Table 14A-2. Avian Benchmark Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-45 Table 14A-3. Freshwater Community CSLs Based on Total Water Concentrations . . . . 14-49 Table 14A-4. Freshwater Community CSCLs Based on Total Dissolved Water

Concentrations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-56 Table 14A-5. Aquatic Plants and Algae CSCLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-59 Table 14A-6. Amphibian CSCLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-64 Table 14A-7. Benthic Community CSCLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-69

Table 14A-8. Terrestrial Plant CSCLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-76 Table 14A-9. Soil Community CSCLs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14-81 Table 14A-10. Scaled Benchmark Doses for Ecological Receptors . . . . . . . . . . . . . . . . . . 14-87

# Appendix 14A Ecological Benchmarks



# 14-38 This page intentionally left blank

# 14-39 Appendix 14A Ecological BenchmarksTable 14A-1. Mammalian Benchmark StudiesCAS Number Constituent NameBenchmarkDose(mg/kg-d)TestSpeciesEndpoint/Duration Notes SourceOrganics75-05-8 Acetonitrile ID --- --- No studies evaluating reproductiveendpoints were identified.---107-13-1 Acrylonitrile ID --- --- No studies evaluating reproductiveendpoints were identified.---62-53-3 Aniline ID --- --- No studies evaluating reproductiveendpoints were identified.---71-43-2 Benzene 83.4 Mouse Reproduction/6 to 12 d ofgestationBenchmark dose was the MATCcalculated from a NOAEL of 26.36mg/kg-d and a LOAEL of 263.6mg/kg-d.Sample et al., 199675-15-0 Carbon disulfide ID --- --- No studies evaluating reproductiveendpoints were identified.---108-90-7 Chlorobenzene ID --- --- No studies evaluating reproductiveendpoints were identified.---67-66-3 Chloroform 24.8 Rat Reproduction/13 weeks sub-chronicBenchmark dose was the MATCcalculated from a NOAEL of 15mg/kg-d and a LOAEL of 41mg/kg-d.Sample et al., 199694-75-7 2,4-Dichlorophenoxyacetic acid(2,4-D)ID --- --- No studies evaluating reproductiveendpoints were identified.---106-93-4 Ethylene dibromide ID --- --- No studies evaluating reproductiveendpoints were identified.---(continued)

# 14-40 Appendix 14A Ecological BenchmarksCAS Number Constituent NameBenchmarkDose(mg/kg-d)TestSpeciesEndpoint/Duration Notes SourceTable 14A-1. (continued)87-68-3 Hexachloro-1,3-butadiene ID --- --- No studies evaluating reproductiveendpoints were identified.---72-43-5 Methoxychlor 141 Rat Reproduction/6 to 15 dgestationBenchmark dose was the MATCcalculated from a NOAEL of 100mg/kg-d and a LOAEL of 200mg/kg-d.Khera et al., 197878-93-3 Methyl ethyl ketone 2,845 Rat Reproduction/2 generationsBenchmark dose was the MATCcalculated from a NOAEL of 1,771mg/kg-d and a LOAEL of 4,571mg/kg-d.Sample et al., 199680-62-6 Methyl methacrylate ID --- --- No studies evaluating reproductiveendpoints were identified.---75-09-2 Methylene chloride ID --- --- No studies evaluating reproductiveendpoints were identified.---98-95-3 Nitrobenzene ID --- --- No studies evaluating reproductiveendpoints were identified.---108-95-2 Phenol ID --- --- No studies evaluating reproductiveendpoints were identified.---110-86-1 Pyridine ID --- --- No studies evaluating reproductiveendpoints were identified.---127-18-4 Tetrachloroethylene ID --- --- No studies evaluating reproductiveendpoints were identified.---137-26-8 Thiram ID --- --- No studies evaluating reproductiveendpoints were identified.---(continued)

# 14-41 Appendix 14A Ecological BenchmarksCAS Number Constituent NameBenchmarkDose(mg/kg-d)TestSpeciesEndpoint/Duration Notes SourceTable 14A-1. (continued)108-88-3 Toluene 82.2 Mouse Reproduction/6 to 12 d ofgestationBenchmark dose was the MATCcalculated from a NOAEL of 26mg/kg-d and a LOAEL of 260mg/kg-d.Sample et al., 199671-55-6 1,1,1-Trichloroethane 1,000 Mouse Reproduction/2 generationsBenchmark dose was the NOAELof 1,000 mg/kg-d. No LOAEL wasidentified.Sample et al., 199679-01-6 Trichloroethylene 2.2 Mouse Hepatictoxicity/6weeksBenchmark dose was the MATCcalculated from a NOAEL of 0.7mg/kg-d and a LOAEL of 7mg/kg-d.Sample et al., 199675-01-4 Vinyl chloride 0.54 Rat Longevity/144weeksBenchmark dose was the MATCcalculated from a NOAEL of 0.17mg/kg-d and a LOAEL of 1.7mg/kg-d.Sample et al., 1996Metals7440-36-0 Antimony 0.45 Rat Reproduction/60 dBenchmark dose was the MATCcalculated from a NOAEL of 0.143mg/kg-d LOAEL of 1.431mg/kg-d.Rossi et al., 19877440-38-2 Arsenic 6.54 Rat Growth anddevelopment/2 yrBenchmark dose was the MATCcalculated from a NOAEL of 4.6mg/kg-d and a LOAEL of 9.3mg/kg-d.Byron et al., 19677440-39-3 Barium ID --- --- No studies evaluating reproductiveendpoints were identified.---(continued)

# 14-42 Appendix 14A Ecological BenchmarksCAS Number Constituent NameBenchmarkDose(mg/kg-d)TestSpeciesEndpoint/Duration Notes SourceTable 14A-1. (continued)7440-41-7 Beryllium ID --- --- No studies evaluating reproductiveendpoints were identified.---7440-43-9 Cadmium 3.16 Rat Reproduction/6 weeksthroughgestationBenchmark dose was the MATCcalculated from a NOAEL of 1mg/kg-d and a LOAEL of 10mg/kg-d.Sutou et al., 19807440-47-3 Chromium ID --- --- No studies evaluating reproductiveendpoints were identified.---16065-83-1 Chromium III (insoluble salts) 2737 Rat Reproduction/2 yrBenchmark dose was the NOAELof 2,737 mg/kg-d. No LOAEL wasidentified.Sample et al., 199618540-29-9 Chromium VI 10.4 Mouse Growth/1 yr Benchmark dose was the MATCcalculated from a NOAEL of 3.3mg/kg-d and a LOAEL of 33mg/kg-d.Zahid et al., 19907439-92-1 Lead 0.016 Rat Reproduction Benchmark dose was the MATCcalculated from a NOAEL of 0.005mg/kg-d and a LOAEL of 0.05mg/kg-d.Krasovskii et al.,19797440-02-0 Nickel 75.7 Rat Reproduction/3 yrsBenchmark dose was the MATCcalculated from a NOAEL of 53.5mg/kg-d and a LOAEL of 107mg/kg-d.Ambrose et al., 19767782-49-2 Selenium 0.26 Rat Reproduction/78 dBenchmark dose was the MATCcalculated from a NOAEL of 0.20mg/kg-d and a LOAEL of 0.34mg/kg-d.Rosenfeld and Beath,1954(continued)

# 14-43 Appendix 14A Ecological BenchmarksCAS Number Constituent NameBenchmarkDose(mg/kg-d)TestSpeciesEndpoint/Duration Notes SourceTable 14A-1. (continued)7440-22-4 Silver ID --- --- No studies evaluating reproductiveendpoints were identified.---7446-18-6 Thallium 0.023 Rat Reproduction./60 dBenchmark dose was the MATCcalculated from a NOAEL of0.0074 mg/kg-d and a LOAEL of0.074 mg/kg-d.Sample et al., 19967440-62-2 Vanadium 1.6 Rat Reproduction/60 dBenchmark dose was the MATCcalculated from a NOAEL of 0.5mg/kg-d and a LOAEL of 5mg/kg-d.Domingo et al., 19867440-66-6 Zinc 290 Rat Reproduction/1 to 16 d ofgestationBenchmark dose was the MATCcalculated from a NOAEL of 200mg/kg-d and a LOAEL of 410mg/kg-d.Schlicker and Cox,1968Special117-81-7 Bis(2-ethylhexyl) phthalate 115 Mouse Reproduction/throughgestationBenchmark dose was the MATCcalculated from a NOAEL of 70mg/kg-d and a LOAEL of 190mg/kg-d.Shiota andNishimura, 198250-32-8 Benzo(a)pyrene 3.2 Mouse Reproduction/7 to 16 d ofgestationBenchmark dose was the MATCcalculated from a NOAEL of 1mg/kg-d and a LOAEL of 10mg/kg-d.MacKenzie andAngevine, 198153-70-3 Dibenz(a,h)anthracene ID --- --- No studies evaluating reproductiveendpoints were identified.---(continued)

# 14-44 Appendix 14A Ecological BenchmarksCAS Number Constituent NameBenchmarkDose(mg/kg-d)TestSpeciesEndpoint/Duration Notes SourceTable 14A-1. (continued)87-86-5 Pentachlorophenol 7.2 Rat Reproduction/181 dBenchmark dose was the MATCcalculated from a NOAEL of 4mg/kg-d and a LOAEL of 13mg/kg-d.Welsh et al., 1987Mercury and Dioxin7439-97-6m Methyl mercury 0.099 Mink Reproduction/ Benchmark dose was the MATCcalculated from a NOAEL of 0.055mg/kg-d and a LOAEL of 0.18mg/kg-d.U.S. EPA, 19977439-97-6e Mercury (elemental) ID --- --- No studies evaluating reproductiveendpoints were identified.---7439-97-6 Mercury (divalent) 1 Mink Reproduction/6 monthsBenchmark dose was the NOAELof 1 mg/kg-d. No LOAEL wasidentified.Sample et al., 19961746-01-6 2,3,7,8-Tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD)0.0000032 Rat Reproduction/3 generationsBenchmark dose was the MATCcalculated from a NOAEL of0.000001 mg/kg-d and a LOAELof 0.00001 mg/kg-d.Murray et al., 1979ID = Insufficient data.LOAEL = Lowest-observed-adverse-effects level.--- = Not applicable because insufficient data were identified.MATC = Maximum acceptable toxicant concentration.NOAEL = No-observed-adverse-effects level.

# 14-45 Appendix 14A Ecological BenchmarksTable 14A-2. Avian Benchmark StudiesCAS Number Constituent NameBenchmarkDose(mg/kg-d)TestSpeciesEndpoint/Duration Notes SourceOrganicsAll Organics ID --- --- No studies evaluating reproductiveendpoints were identified.---Metals7440-36-0 Antimony ID --- --- No studies evaluating reproductiveendpoints were identified.---7440-38-2 Arsenic 0.011 Mallard Reproduction/128 dBenchmark dose was the MATCcalculated from a NOAEL of 0.0057mg/kg-d and a LOAEL of 0.023mg/kg-d.Stanley et al., 19947440-39-3 Barium 30 Chicken Reproduction/3 weeksBenchmark dose was the MATCcalculated from a NOAEL of 21mg/kg-d and a LOAEL of42 mg/kg-d.Johnson et al., 19607440-41-7 Beryllium ID --- ---No studies evaluating reproductiveendpoints were identified.---7440-43-9 Cadmium 4.4 Mallard Reproduction/90 dBenchmark dose was the MATCcalculated from a NOAEL of 1.4mg/kg-d and a LOAEL of14 mg/kg-d.White and Finley,1978(continued)

# 14-46 Appendix 14A Ecological BenchmarksCAS Number Constituent NameBenchmarkDose(mg/kg-d)TestSpeciesEndpoint/Duration Notes SourceTable 14A-2. (continued)7440-47-3 Chromium ID --- --- No studies evaluating reproductiveendpoints were identified.---16065-83-1 Chromium III (insolublesalts)2.2 Duck Reproduction/10 monthsBenchmark dose was the MATCcalculated from a NOAEL of 1mg/kg-d and a LOAEL of5 mg/kg-d.Sample et al., 199618540-29-9 Chromium VI ID --- --- No studies evaluating reproductiveendpoints were identified.---7439-92-1 Lead 0.066 Quail Reproduction/4 weeksBenchmark dose was the MATCcalculated from a NOAEL of 0.021mg/kg-d and a LOAEL of0.21 mg/kg-d.Edens and Garlich,19837440-02-0 Nickel 91 Mallard Growth andbehavior/90 dBenchmark dose was the MATCcalculated from a NOAEL of 77.4mg/kg-d and a LOAEL of 07mg/kg-d.Sample et al., 19967782-49-2 Selenium 0.71 Mallard Reproduction/4 weeksBenchmark dose was the MATCcalculated from a NOAEL of 0.05mg/kg-d and a LOAEL of1.0 mg/kg-d.Heinz andHoffman,19877440-22-4 Silver ID --- --- No studies evaluating reproductiveendpoints were identified.---7446-18-6 Thallium ID --- --- No studies evaluating reproductiveendpoints were identified.—(continued)

# 14-47 Appendix 14A Ecological BenchmarksCAS Number Constituent NameBenchmarkDose(mg/kg-d)TestSpeciesEndpoint/Duration Notes SourceTable 14A-2. (continued)7440-62-2 Vanadium 1.8 Chicken Growth atsensitive lifestage/30 dBenchmark dose was the MATCcalculated from a NOAEL of 1.5mg/kg-d and a LOAEL of2.2 mg/kg-d.Romoser et al., 19617440-66-6 Zinc 32 Hen Reproduction/44 weeksBenchmark dose was the MATCcalculated from a NOAEL of 11mg/kg-d and a LOAEL of94 mg/kg-d.Sample et al. 1996Special117-81-7 Bis(2-ethylhexyl)phthalate1.1 RingeddoveReproduction/90 dBenchmark dose was the NOAEL of1.1 mg/kg-d. No LOAEL valueswere identified.Sample et al., 199650-32-8 Benzo(a)pyrene ID --- --- No studies evaluating reproductiveendpoints were identified.---53-70-3 Dibenz(a,h)anthracene ID --- --- No studies evaluating reproductiveendpoints were identified.---87-86-5 Pentachlorophenol 62 Chicks Growth atsensitive lifestage/8 weeksBenchmark dose was the MATCcalculated from a NOAEL of 44mg/kg-d and a LOAEL of88 mg/kg-d.Prescott et al., 1982(continued)

# 14-48 Appendix 14A Ecological BenchmarksCAS Number Constituent NameBenchmarkDose(mg/kg-d)TestSpeciesEndpoint/Duration Notes SourceTable 14A-2. (continued)Mercury and Dioxin7439-97-6m Methyl mercury 0.025 Mallard Reproduction/3 generationsBenchmark dose was the MATCcalculated from a NOAEL of 0.0078mg/kg-d and a LOAEL of 0.078mg/kg-d.Heinz 1974, 1975,1979;U.S. EPA, 19977439-97-6e Mercury (elemental) ID --- --- No studies evaluating reproductiveendpoints were identified.---7439-97-6 Mercury (divalent) 0.64 JapanesequailReproduction/1 yrBenchmark dose was the MATCcalculated from a NOAEL of 0.45mg/kg-d and a LOAEL of0.9 mg/kg-d.Sample et al., 19961746-01-6 2,3,7,8-Tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD)0.0000443 Pheasant Reproduction/10 weeksBenchmark dose was the MATCcalculated from a NOAEL of0.000014 mg/kg-d and a LOAEL of0.00014 mg/kg-d.Nosek et al., 1992ID = Insufficient data.LOAEL = Lowest-observed-adverse-effects level.MATC = Maximum acceptable toxicant concentration.NOAEL = No-observed-adverse-effects level.--- = Not applicable because insufficient data were identified.

# 14-49 Appendix 14A Ecological BenchmarksTable 14A-3. Freshwater Community CSLs Based on Total Water ConcentrationsCAS Number Constituent NameCSCL(Total)(mg/L) Method Notes SourceOrganics75-05-8 Acetonitrile ID --- Insufficient ecotoxicity data were available todevelop a water quality criteria.---107-13-1 Acrylonitrile ID --- Insufficient ecotoxicity data were available todevelop a water quality criteria.---62-53-3 Aniline ID --- Insufficient ecotoxicity data were available todevelop a water quality criteria.---71-43-2 Benzene 0.13 SCV Value was calculated using the Tier II methodologyfrom 29 data points representing 6 of the 8 speciesrequirements.Stephan et al., 1985;Suter and Tsao, 199675-15-0 Carbon disulfide 0.00092 SCV Value was calculated using the Tier II methodologyfrom one data point representing two of the eightspecies requirements.Stephan et al., 1985;Suter and Tsao, 1996108-90-7 Chlorobenzene 0.064 SCV Value was calculated using the Tier II methodologyfrom 12 data points representing 4 of the 8 speciesrequirements.Stephan et al., 1985;Suter and Tsao, 199667-66-3 Chloroform 0.028 SCV Value was calculated using the Tier II methodologyfrom 15 data points representing 3 of the 8 speciesrequirements.Stephan et al., 1985;Suter and Tsao, 199694-75-7 2,4-Dichlorophenoxyacetic acid(2,4-D)ID --- Insufficient ecotoxicity data were available todevelop a water quality criteria.---(continued)

# 14-50 Appendix 14A Ecological BenchmarksCAS Number Constituent NameCSCL(Total)(mg/L) Method Notes SourceTable 14A-3. (continued)106-93-4 Ethylene dibromide ID --- Insufficient ecotoxicity data were available todevelop a water quality criteria.---87-68-3 Hexachloro-1,3-butadiene ID --- Insufficient ecotoxicity data were available todevelop a water quality criteria.---72-43-5 Methoxychlor 0.000019 SCV Value was adopted from OSWER calculated usingthe Tier II methodology.Suter and Tsao, 199678-93-3 Methyl ethyl ketone ID --- Insufficient ecotoxicity data were available todevelop a water quality criteria.---80-62-6 Methyl methacrylate ID --- Insufficient ecotoxicity data were available todevelop a water quality criteria.---75-09-2 Methylene chloride 2.2 SCV Value was calculated using the Tier II methodologyfrom five data points representing three of the eightspecies requirements.Stephan et al., 1985;Suter and Tsao, 199698-95-3 Nitrobenzene ID --- Insufficient ecotoxicity data were available todevelop a water quality criteria.---108-95-2 Phenol 0.11 FCV Value was calculated as the chronic NAWQCmeeting all of the data and species requirements.U.S. EPA, 1999110-86-1 Pyridine ID --- Insufficient ecotoxicity data were available todevelop a water quality criteria.---127-18-4 Tetrachloroethylene 0.098 SCV Value was calculated using the Tier II methodologyfrom nine data points representing four of the eightspecies requirements.Stephan et al., 1985;Suter and Tsao, 1996(continued)

# 14-51 Appendix 14A Ecological BenchmarksCAS Number Constituent NameCSCL(Total)(mg/L) Method Notes SourceTable 14A-3. (continued)137-26-8 Thiram ID --- Insufficient ecotoxicity data were available todevelop a water quality criteria.---108-88-3 Toluene 0.0098 SCV Value was calculated using the Tier II methodologyfrom seven data points representing two of the eightspecies requirements.Stephan et al., 1985;Suter and Tsao, 199671-55-6 1,1,1-Trichloroethane 0.011 SCV Value was calculated using the Tier II methodologyfrom two data points representing two of the eightspecies requirements.Stephan et al., 1985;Suter and Tsao, 199679-01-6 Trichloroethylene 0.047 SCV Value was calculated using the Tier II methodologyfrom five data points representing two of the eightspecies requirements.Stephan et al., 1985;Suter and Tsao, 199675-01-4 Vinyl chloride ID --- Insufficient ecotoxicity data were available todevelop a water quality criteria.---Metals7440-36-0 Antimony 0.03 Draft FCV Value is a draft FCV and met all data requirementsfor calculating NAWQC.U.S. EPA, 19887440-38-2 Arsenic 0.15 CCC NAWQC value was updated through the GLWQIincorporating newly identified toxicity data forfreshwater biota.U.S. EPA, 1996a7440-39-3 Barium 0.004 SCV Value was calculated using the Tier II methodologyfrom 12 data points representing 4 of the 8 speciesrequirements.Stephan et al., 1985;Suter and Tsao, 1996(continued)

# 14-52 Appendix 14A Ecological BenchmarksCAS Number Constituent NameCSCL(Total)(mg/L) Method Notes SourceTable 14A-3. (continued)7440-41-7 Beryllium 0.00066 SCV Value was calculated using the Tier II methodologyfrom 27 data points representing 6 of the 8 speciesrequirements.Stephan et al., 1985;Suter and Tsao, 19967440-43-9 Cadmium 0.0025 CCC NAWQC value was updated through the GLWQIincorporating newly identified toxicity data forfreshwater biota. This criteria is dependent on waterhardness and was calculated using the followingequation, assuming a water hardness of 100 mgCaCO3/L:CCC = e0.7852(ln hardness) - 2.715U.S. EPA, 1996a7440-47-3 Chromium ID --- Insufficient ecotoxicity data were available todevelop a water quality criteria.---16065-83-1 Chromium III (insoluble salts) 0.086 CCC NAWQC value was updated through the GLWQIincorporating newly identified toxicity data forfreshwater biota. This criteria is dependent on waterhardness and was calculated using the followingequation, assuming a water hardness of 100 mgCaCO3/L:CCC = e0.819(ln hardness) + 0.6848U.S. EPA, 1996a18540-29-9 Chromium VI 0.011 CCC NAWQC value was updated through the GLWQIincorporating newly identified toxicity data forfreshwater biota.U.S. EPA, 1996a7439-92-1 Lead 0.0032 FCV Value is an FCV and met all data requirements forcalculating NAWQC.U.S. EPA, 1985(continued)

# 14-53 Appendix 14A Ecological BenchmarksCAS Number Constituent NameCSCL(Total)(mg/L) Method Notes SourceTable 14A-3. (continued)7440-02-0 Nickel 0.052 CCC NAWQC value was updated through the GLWQIincorporating newly identified toxicity data forfreshwater biota. This criteria is dependent on waterhardness and was calculated using the followingequation, assuming a water hardness of 100 mgCaCO3/L:CCC = e0.846(ln hardness) + 0.0584U.S. EPA, 1996a7782-49-2 Selenium 0.005 CCC NAWQC value was updated through the GLWQIincorporating newly identified toxicity data forfreshwater biota, including some field studies.U.S. EPA, 1996a7440-22-4 Silver 0.00036 SCV Value derived from the NAWQC FAV for silver. Suter and Tsao, 19967446-18-6 Thallium 0.012 SCV Value was calculated using the Tier II methodologyfrom 10 data points representing 3 of the 8 speciesrequirements.Stephan et al., 1985;Suter and Tsao, 19967440-62-2 Vanadium 0.02 SCV Value was calculated using the Tier II methodologyfrom 25 data points representing 4 of the 8 speciesrequirements.Stephan et al., 1985;Suter and Tsao, 19967440-66-6 Zinc 0.12 CCC NAWQC value was updated through the GLWQIincorporating newly identified toxicity data forfreshwater biota. This criteria is dependent on waterhardness and was calculated using the followingequation, assuming a water hardness of100 mg CaCO3/L:CCC = e0.8473(ln hardness) + 0.884U.S. EPA, 1996a(continued)

# 14-54 Appendix 14A Ecological BenchmarksCAS Number Constituent NameCSCL(Total)(mg/L) Method Notes SourceTable 14A-3. (continued)Special117-81-7 Bis(2-ethylhexyl) phthalate 0.003 SCV Valuewas calculated using the Tier II methodologyfrom 15 data points representing 5 of the eightspecies requirements.Stephan et al., 1985;Suter and Tsao, 199650-32-8 Benzo(a)pyrene 0.000014 SCV Value was calculated using the Tier II methodologyfrom one data point representing one of the eightspecies requirements.Stephan et al., 1985;Suter and Tsao, 199653-70-3 Dibenz(a,h)anthracene ID --- Insufficient ecotoxicity data were available todevelop a water quality criteria.---87-86-5 Pentachlorophenol 0.0055 CCC NAWQC value was updated through the GLWQIincorporating newly identified toxicity data forfreshwater biota. This criteria is dependent on pHand was calculated using the following equation,assuming a pH of 6.8:CCC = e1.005(pH) - 5.134 0.884U.S. EPA, 1996aMercury and Dioxin7439-97-6m Methyl mercury 0.0000028 SCV Value was calculated using the Tier II methodologyfrom four data points representing one of the eightspecies requirements.Stephan et al., 1985;Suter and Tsao, 19967439-97-6e Mercury (elemental) ID --- Insufficient ecotoxicity data were available todevelop a water quality criteria.---(continued)

# 14-55 Appendix 14A Ecological BenchmarksCAS Number Constituent NameCSCL(Total)(mg/L) Method Notes SourceTable 14A-3. (continued)7439-97-6 Mercury (divalent) 0.00091 CCC NAWQC value was updated through the GLWQIincorporating newly identified toxicity data forfreshwater biota.U.S. EPA, 1996a1746-01-6 TCDD 2,3,7,8- ID --- Insufficient ecotoxicity data were available todevelop a water quality criteria.---CSCL = Chemical stressor concentration limit.CCC = Criterion continuous concentration.FCV = Final chronic value.GLWQI = Great lakeswater quality initiative.ID = Insufficient data.NAWQC = National ambient water quality criteria.SCV = Secondary chronic value.--- = Not applicable because insufficient data identified.

# 14-56 Appendix 14A Ecological BenchmarksTable 14A-4. Freshwater Community CSCLs Based on Total Dissolved Water ConcentrationsCAS Number Constituent Name1CSCL(Total)2(mg/L)ConversionFactor3CSCL(Dissolved)(mg/L) Notes SourceMetals7440-36-0 Antimony 0.03 ID ID Insufficient data were available to derive adissolved surface water concentration.U.S. EPA, 19887440-38-2 Arsenic 0.15 1.00 0.15 EPA’s Office of Water supports the use ofdissolved criteria over the total criteriabecause dissolved criteria reflect thebioavailable fraction of the metal.U.S. EPA, 1996a;19997440-39-3 Barium 0.004 ID ID Insufficient data were available to derive adissolved surface water concentration.Stephan et al., 1985;Suter and Tsao, 19967440-41-7 Beryllium 0.00066 ID ID Insufficient data were available to derive adissolved surface water concentration.Stephan et al., 1985;Suter and Tsao, 19967440-43-9 Cadmium 0.0025 0.909 0.0023 Conversion factor was derived as a hardness,dependent criterion assuming 100 mgCaCO3/L using the following equation:CF =1.101672-[(ln hardness)(0.041838)]U.S. EPA, 1996a; 19997440-47-3 Chromium ID ID ID Insufficient data were available to derive adissolved surface water concentration.---16065-83-1 Chromium III(insoluble salts)0.086 0.860 0.074 EPA’s Office of Water supports the use ofdissolved criteria over the total criteriabecause dissolved criteria reflect thebioavailable fraction of the metal.U.S. EPA, 1996a, 1999(continued)

# 14-57 Appendix 14A Ecological BenchmarksCAS Number Constituent Name1CSCL(Total)2(mg/L)ConversionFactor3CSCL(Dissolved)(mg/L) Notes SourceTable 14A-4. (continued)18540-29-9 Chromium VI 0.011 0.962 0.011 EPA’s Office of Water supports the use ofdissolved criteria over the total criteriabecause dissolved criteria reflect thebioavailable fraction of the metal.U.S. EPA, 1996a, 19997439-92-1 Lead 0.0032 0.791 0.0025 Conversion factor was derived as a hardness-dependent criterion, assuming 100 mgCaCO3/L using the following equation:CF =1.46203-[(ln hardness)(0.145712)]U.S. EPA, 1985, 19997440-02-0 Nickel 0.052 0.997 0.052 EPA’s Office of Water supports the use ofdissolved criteria over the total criteriabecause dissolved criteria reflect thebioavailable fraction of the metal.U.S. EPA, 1996a, 19997782-49-2 Selenium 0.005 ID ID Insufficient data were available to derive adissolved surface water concentration.U.S. EPA, 19997440-22-4 Silver 0.00036 ID ID Insufficient data were available to derive adissolved surface water concentration.Suter and Tsao, 19967446-18-6 Thallium 0.012 ID ID Insufficient data were available to derive adissolved surface water concentration.Stephan et al., 1985;Suter and Tsao, 19967440-62-2 Vanadium 0.02 ID ID Insufficient data were available to derive adissolved surface water concentration.Stephan et al., 1985;Suter and Tsao, 1996(continued)

# 14-58 Appendix 14A Ecological BenchmarksCAS Number Constituent Name1CSCL(Total)2(mg/L)ConversionFactor3CSCL(Dissolved)(mg/L) Notes SourceTable 14A-4. (continued)7440-66-6 Zinc 0.12 0.986 0.12 EPA’s Office of Water supports the use ofdissolved criteria over the total criteriabecause dissolved criteria reflect thebioavailable fraction of the metal.U.S. EPA, 1996a, 19991Dissolved CSCLs are currently available to estimate concentrations of metals in surface waters; therefore, constituents categorized as special, organicconstitutents, and mercury and dioxin compounds are not included in this table.2Values were derived as indicated in Table 10.3Conversion factors were developed to estimate the fraction of thetotal concentration that was dissolved in the water column.The conversion factorsdeveloped by EPA for converting freshwater chronic criteria were adopted.ID = Insufficient data.CSCL = Chemical stressor concentration limit.— = Not applicable because insufficient data were indentified.

# 14-59 Appendix 14A Ecological BenchmarksTable 14A-5. Aquatic Plants and Algae CSCLsCAS Number Constituent NameCSCL(mg/L) Methodology Notes SourceOrganics75-05-8 Acetonitrile ID --- Insufficient data were available to develop anaquatic plant CSCL.---107-13-1 Acrylonitrile ID --- Insufficient data were available to develop anaquatic plant CSCL.---62-53-3 Aniline ID --- Insufficient data were available to develop anaquatic plant CSCL.---71-43-2 Benzene 530 Lowest chronicvalue EC50Based on a 48-h EC50test by exposingChlorellavulgaris.Suter and Tsao, 199675-15-0 Carbon disulfide ID --- Insufficient data were available to develop anaquatic plant CSCL.---108-90-7 Chlorobenzene 220 Lowest chronicvalue EC50Based on a 96-h EC50test for cell number, byexposingSelenastrum capricornutum.Suter and Tsao, 199667-66-3 Chloroform ID --- Insufficient data were available to develop anaquatic plant CSCL.---94-75-7 2,4-Dichlorophenoxyacetic acid(2,4-D)ID --- Insufficient data were available to develop anaquatic plant CSCL.---106-93-4 Ethylene dibromide ID --- Insufficient data were available to develop anaquatic plant CSCL.---87-68-3 Hexachloro-1,3-butadiene ID --- Insufficient data were available to develop anaquatic plant CSCL.—(continued)

# 14-60 Appendix 14A Ecological BenchmarksCAS Number Constituent NameCSCL(mg/L) Methodology Notes SourceTable 14A-5. (continued)72-43-5 Methoxychlor ID --- Insufficient data were available to develop anaquatic plant CSCL.---78-93-3 Methyl ethyl ketone ID --- Insufficient data were available to develop anaquatic plant CSCL.---80-62-6 Methyl methacrylate ID --- Insufficient data were available to develop anaquatic plant CSCL.SSC---75-09-2 Methylene chloride ID --- Insufficient data were available to develop anaquatic plant CSCL.---98-95-3 Nitrobenzene ID --- Insufficient data were available to develop anaquatic plant CSCL.---108-95-2 Phenol 20 Lowest chronicvalue EC50Based on a value that exhibited 60 percentreduction in cell numbers and 12percent growthinhibition by exposingSelenastrumcapricornutum.Suter and Tsao, 1996110-86-1 Pyridine ID --- Insufficient data were available to develop anaquatic plant CSCL.---127-18-4 Tetrachloroethylene ID --- Insufficient data were available to develop anaquatic plant CSCL.---137-26-8 Thiram ID --- Insufficient data were available to develop anaquatic plant CSCL.---108-88-3 Toluene 250 Lowest chronicvalue EC50Based on an unspecified 10-d test by exposingChlorella vulgaris.Suter and Tsao, 1996(continued)

# 14-61 Appendix 14A Ecological BenchmarksCAS Number Constituent NameCSCL(mg/L) Methodology Notes SourceTable 14A-5. (continued)71-55-6 1,1,1-Trichloroethane 669 Lowest chronicvalue EC50Based on a value that exhibited 60 percentreduction in cell numbers and 12percent growthinhibition by exposingSelenastrumcapricornutum.Suter and Tsao, 199679-01-6 Trichloroethylene ID --- Insufficient data were available to develop anaquatic plant CSCL.---75-01-4 Vinyl chloride ID --- Insufficient data were available to develop anaquatic plant CSCL.---Metals7440-36-0 Antimony 0.61 Lowest chronicvalue EC50Based on a 4-d EC50for chlorophyll A inhibitionby exposingSelenastrum capricornutum.Suter and Tsao, 19967440-38-2 Arsenic 0.048 Lowest chronicvalue EC50Based on a 14-d EC50test by exposingScendesmusobliquus.Suter and Tsao, 19967440-39-3 Barium ID --- Insufficient data were available to develop anaquatic plant CSCL.7440-41-7 Beryllium 100 Lowest chronicvalue EC50Based on a 10 to 20percent reduction inautotrophic growth rates by exposingChlorellavannieli.Suter and Tsao, 19967440-43-9 Cadmium 0.002 Lowest chronicvalue EC50Based on the population growth rate by exposingAsterionella formosa.Suter and Tsao, 19967440-47-3 Chromium ID --- Insufficient data were available to develop anaquatic plant CSCL.(continued)

# 14-62 Appendix 14A Ecological BenchmarksCAS Number Constituent NameCSCL(mg/L) Methodology Notes SourceTable 14A-5. (continued)16065-83-1 Chromium III (insoluble salts) 0.4 Lowest chronicvalue EC50Based on a 4-d chronic test in which there was a50percent inhibition of growth, by exposingSelenastrum capricornutum.Suter and Tsao, 199618540-29-9 Chromium VI 0.002 Lowest chronicvalue EC50Based on a value that showed incipient inhibitionof growth by exposingMicrocystis aeruginosa.Suter and Tsao, 19967439-92-1 Lead 0.5 Lowest chronicvalue EC50Based on value based on 53percent, 35percent,and 52percent growth inhibition by exposingChlorella vulgaris,Scenedesmus quadricauda,andSelenastrum capricornutum.Suter and Tsao, 19967440-02-0 Nickel 0.005 Lowest chronicvalue EC50Based on a value that showed incipient inhibitionof growth by exposingMicrocystis aeruginosa.Suter and Tsao, 19967782-49-2 Selenium 0.1 Lowest chronicvalue EC50Based on 14-d chronic toxicity tests by exposingScenedesmus obliquus.Suter and Tsao, 19967440-22-4 Silver 0.03 Lowest chronicvalue EC50Based on growth inhibition by exposingChlorellavulgaris.Suter and Tsao, 19967446-18-6 Thallium 0.1 Lowest chronicvalue EC50Based on a 4-d EC50which reduced the plant’s cellnumbers by exposingSelenastrum capricornutum.Suter and Tsao, 19967440-62-2 Vanadium ID --- Insufficient data were available to develop anaquatic plant CSCL.7440-66-6 Zinc 0.03 Lowest chronicvalue EC50Based on 7-d tests that showed incipient inhibitionof growth by exposingSelenastrumcapricornutum.Suter and Tsao, 1996(continued)

# 14-63 Appendix 14A Ecological BenchmarksCAS Number Constituent NameCSCL(mg/L) Methodology Notes SourceTable 14A-5. (continued)Special117-81-7 Bis(2-ethylhexyl) phthalate ID --- Insufficient data were available to develop anaquatic plant CSCL.---50-32-8 Benzo(a)pyrene ID --- Insufficient data were available to develop anaquatic plant CSCL.---53-70-3 Dibenz(a,h)anthracene ID --- Insufficient data were available to develop anaquatic plant CSCL.---87-86-5 Pentachlorophenol ID --- Insufficient data were available to develop anaquatic plant CSCL.---Mercury and Dioxin7439-97-6m Methyl mercury ID --- Insufficient data were available to develop anaquatic plant CSCL.---7439-97-6e Mercury (elemental) ID --- Insufficient data were available to develop anaquatic plant CSCL.---7439-97-6 Mercury (divalent) 0.005 Lowest chronicvalue EC50Based on an 8-d test that showed incipientinhibition of growth by exposingMicrocystisaeruginosa.Suter and Tsao, 19961746-01-6 TCDD 2,3,7,8- ID --- Insufficient data were available to develop anaquatic plant CSCL.---CSCL = Chemical stressor concentration limit.EC50= Effective concentration for 50% of the organisms.ID = Insufficient data.--- = Not applicable because insufficient data were identified.

# 14-64 Appendix 14A Ecological BenchmarksTable 14A-6. Amphibian CSCLsCAS Number Constituent NameCSCL(mg/L) Methodology Notes SourceOrganics75-05-8 Acetonitrile ID --- Insufficient data were available to develop anamphibian CSCL.---107-13-1 Acrylonitrile ID --- Insufficient data were available to develop anamphibian CSCL.---62-53-3 Aniline 370 Geomean ofacute valuesThe geomean of LC50values was based on 7 valuesranging from 95 to 940 mg/L.U.S. EPA, 1996b71-43-2 Benzene 34 Geomean ofacute valuesThe geomean of LC50values was based on 4 valuesranging from 3.7 to 370 mg/L.U.S. EPA, 1996b75-15-0 Carbon disulfide ID --- Insufficient data were available to develop anamphibian CSCL.---108-90-7 Chlorobenzene ID --- Insufficient data were available to develop anamphibian CSCL.---67-66-3 Chloroform 11 Geomean ofacute valuesThe geomean of LC50values was based on 7 valuesranging from 2.7 to 68 mg/L.U.S. EPA, 1996b94-75-7 2,4-Dichlorophenoxyacetic acid(2,4-D)ID --- Insufficient data were available to develop anamphibian CSCL.---106-93-4 Ethylene dibromide ID --- Insufficient data were available to develop anamphibian CSCL.---87-68-3 Hexachloro-1,3-butadiene ID --- Insufficient data were available to develop anamphibian CSCL.---(continued)

# 14-65 Appendix 14A Ecological BenchmarksCAS Number Constituent NameCSCL(mg/L) Methodology Notes SourceTable 14A-6. (continued)72-43-5 Methoxychlor 0.29 Geomean ofacute valuesThe geomean of LC50values was based on 4 valuesranging from 0.10 to 0.33 mg/L.U.S. EPA, 1996b78-93-3 Methyl ethyl ketone ID --- Insufficient data were available to develop anamphibian CSCL.---80-62-6 Methyl methacrylate ID --- Insufficient data were available to develop anamphibian CSCL.---75-09-2 Methylene chloride ID --- Insufficient data were available to develop anamphibian CSCL.---98-95-3 Nitrobenzene 0.64 Geomean ofacute valuesThe geomean of LC50values was based on one value. U.S. EPA, 1996b108-95-2 Phenol 1.3 Geomean ofacute valuesThe geomean of LC50values was based on 9 valuesranging from 0.04 to 51 mg/L.U.S. EPA, 1996b110-86-1 Pyridine ID --- Insufficient data were available to develop anamphibian CSCL.---127-18-4 Tetrachloroethylene ID --- Insufficient data were available to develop anamphibian CSCL.---137-26-8 Thiram ID --- Insufficient data were available to develop anamphibian CSCL.---108-88-3 Toluene 0.58 Geomean ofacute valuesThe geomean of LC50values was based on twovalues, 0.39 and 0.85 mg/L.U.S. EPA, 1996b71-55-6 1,1,-Trichloroethane ID --- Insufficient data were available to develop anamphibian CSCL.---(continued)

# 14-66 Appendix 14A Ecological BenchmarksCAS Number Constituent NameCSCL(mg/L) Methodology Notes SourceTable 14A-6. (continued)79-01-6 Trichloroethylene 89 Geomean ofacute valuesThe geomean of LC50values was based on six valuesranging from 34 to 443 mg/L.U.S. EPA, 1996b75-01-4 Vinyl chloride ID --- Insufficient data were available to develop anamphibian CSCL.---Metals7440-36-0 Antimony 0.3 Geomean ofaacute valuesThe geomean of LC50values was based on one value. U.S. EPA, 1996b7440-38-2 Arsenic 4.3 Geomean ofacute valuesThe geomean of LC50values was based on six valuesranging from 0.040 to 71 mg/L.U.S. EPA, 1996b7440-39-3 Barium ID --- Insufficient data were available to develop anamphibian CSCL.---7440-41-7 Beryllium 11 Geomean ofacute valuesThe geomean of LC50values was based on 8 valuesranging from 3.2 to 32 mg/L.U.S. EPA, 1996b7440-43-9 Cadmium 2.2 Geomean ofacute valuesThe geomean of LC50values was based on 28 valuesranging from 0.04 to 20 mg/L.Power et al., 1989;U.S. EPA, 1996b7440-47-3 Chromium 12 Geomean ofacute valuesThe geomean of LC50values was based on 10 valuesranging from 0.03 to 100 mg/L.Power et al., 1989;U.S. EPA, 1996b16065-83-1 Chromium III (insoluble salts) ID --- Insufficient data were available to develop anamphibian CSCL.---18540-29-9 Chromium VI ID --- Insufficient data were available to develop anamphibian CSCL.---(continued)

# 14-67 Appendix 14A Ecological BenchmarksCAS Number Constituent NameCSCL(mg/L) Methodology Notes SourceTable 14A-6. (continued)7439-92-1 Lead 2.1 Geomean ofacute valuesThe geomean of LC50values was based on 6 valuesranging from 0.04 to 105 mg/L.U.S. EPA, 1996b7440-02-0 Nickel 2.2 Geomean ofacute valuesThe geomean of LC50values was based on 11 valuesranging from 0.05 to 53 mg/L.Power et al., 1989;U.S. EPA, 1996b7782-49-2 Selenium 1.8 Geomean ofacute valuesThe geomean of LC50values was based on 13 valuesranging from 0.09 to 11 mg/L.U.S. EPA, 1996b7440-22-4 Silver 0.03 Geomean ofacute valuesThe geomean of LC50values was based on 7 valueshaving ranging from 0.004 to 26 mg/L.Power et al., 1989;U.S. EPA, 1996b7446-18-6 Thallium 0.11 Geomean ofacute valuesThe geomean of LC50values was based on one value. U.S. EPA, 1996b7440-62-2 Vanadium ID --- Insufficient data were available to develop anamphibian CSCL.---7440-66-6 Zinc 10 Geomean ofacute valuesThe geomean of LC50values was based on 25 valuesranging from 0.01 to 47 mg/L.Power et al., 1989;U.S. EPA, 1996bSpecial117-81-7 Bis(2-ethylhexyl) phthalate ID --- Insufficient data were available to develop anamphibian CSCL.---50-32-8 Benzo(a)pyrene ID --- Insufficient data were available to develop anamphibian CSCL.---(continued)

# 14-68 Appendix 14A Ecological BenchmarksCAS Number Constituent NameCSCL(mg/L) Methodology Notes SourceTable 14A-6. (continued)53-70-3 Dibenz(a,h)anthracene ID --- Insufficient data were available to develop anamphibian CSCL.---87-86-5 Pentachlorophenol 0.070 Geomean ofacute valuesThe geomean of LC50values was based on 10 valuesranging from 0.0003 to 0.35 mg/L.Power et al., 1989;U.S. EPA, 1996bMercury and Dioxin7439-97-6m Methyl mercury 0.06 Geomean ofacute valuesThe geomean of LC50values was based on 67 valuesranging from 0.001 to 108 mg/L.Power et al., 1989;U.S. EPA, 1996b7439-97-6e Mercury (elemental) ID --- Insufficient data were available to develop anamphibian CSCL.---7439-97-6 Mercury (divalent) 0.06 Geomean ofacute valuesThe geomean of LC50values was based on 2 valuesranging from 0.056 to 0.060 mg/L.---1746-01-6 TCDD 2,3,7,8- ID --- Insufficient data were available to develop anamphibian CSCL.---CSCL = Chemical stressor concentration limit.ID = Insufficient data.LC50= Lethal concentration for 50% of the organisms.--- = Not applicable because insufficient data were identified.

# 14-69 Appendix 14A Ecological BenchmarksTable 14A-7. Benthic Community CSCLsCAS Number ConstituentCSCL(mg/kgsedimentDW) Methodology Notes SourceOrganics75-05-8 Acetonitrile ID --- No water quality criteria have been developed;therefore, the EqP approach could not be applied toestimate a benthic community CSCL.---107-13-1 Acrylonitrile ID --- No water quality criteria have been developed;therefore, the EqP approach could not be applied toestimate a benthic community CSCL.---62-53-3 Aniline ID --- No water quality criteria have been developed;therefore, the EqP approach could not be applied toestimate a benthic community CSCL.---71-43-2 Benzene 0.16 EqP Based on the SCV of 0.13 mg/L calculated by Suterand Tsao (1996), assuming 1percent total organiccarbon and log Kocequal to 2.09.Jones et al., 1997;U.S. EPA, 1993a75-15-0 Carbon disulfide 0.00085 EqP Based on the SCV of 0.00092 mg/L calculated bySuter and Tsao (1996), assuming 1 percent totalorganic carbon and log Kocequal to 1.97.Jones et al., 1997;U.S. EPA, 1993a108-90-7 Chlorobenzene 0.41 EqP Based on the SCV of 0.064 mg/L calculated by Suterand Tsao (1996), assuming 1 percent total organiccarbon and log Kocequal to 2.81.Jones et al., 1997;U.S. EPA, 1993a67-66-3 Chloroform 0.022 EqP Based on the SCV of 0.028 mg/L calculated by Suterand Tsao (1996), assuming 1percent total organiccarbon and log Kocequal to 1.89.Jones et al., 1997;U.S. EPA, 1993a(continued)

# 14-70 Appendix 14A Ecological BenchmarksCAS Number ConstituentCSCL(mg/kgsedimentDW) Methodology Notes SourceTable 14A-7. (continued)94-75-7 2,4-Dichlorophenoxyacetic acid(2,4-D)ID --- No water quality criteria have been developed;therefore, the EqP approach could not be applied toestimate a benthic community CSCL.---106-93-4 Ethylene dibromide ID --- No water quality criteria have been developed;therefore, the EqP approach could not be applied toestimate a benthic community CSCL.87-68-3 Hexachloro-1,3-butadiene ID --- No water quality criteria have been developed;therefore, the EqP approach could not be applied toestimate a benthic community CSCL.---72-43-5 Methoxychlor 0.019 EqP Based on the SCV of 0.000019 mg/L calculated bySuter and Tsao (1996), assuming 1percent totalorganic carbon and log Kocequal to 4.99.Jones et al., 1997;U.S. EPA, 1993a78-93-3 Methyl ethyl ketone ID --- No water quality criteria have been developed;therefore, the EqP approach could not be applied toestimate a benthic community CSCL.---80-62-6 Methyl methacrylate ID --- No water quality criteria have been developed;therefore, the EqP approach could not be applied toestimate a benthic community CSCL.---75-09-2 Methylene chloride 0.37 EqP Based on the SCV of 2.2 mg/L calculated by Suterand Tsao (1996), assuming 1percent total organiccarbon and log Kocequal to 1.23.Jones et al., 1997;U.S. EPA, 1993a98-95-3 Nitrobenzene ID --- No water quality criteria have been developed;therefore, the EqP approach could not be applied toestimate a benthic community CSCL.—(continued)

# 14-71 Appendix 14A Ecological BenchmarksCAS Number ConstituentCSCL(mg/kgsedimentDW) Methodology Notes SourceTable 14A-7. (continued)108-95-2 Phenol 0.031 EqP Based on the FCV of 0.11 mg/L calculated by Suterand Tsao (1996), assuming 1 percent total organiccarbon and log Kocequal to 1.46.Jones et al., 1997;U.S. EPA, 1993a110-86-1 Pyridine ID --- No water quality criteria have been developed;therefore, the EqP approach could not be applied toestimate a benthic community CSCL.---127-18-4 Tetrachloroethylene ID --- No water quality criteria have been developed;therefore, the EqP approach could not be applied toestimate a benthic community CSCL.---137-26-8 Thiram ID --- No water quality criteria have been developed;therefore, the EqP approach could not be applied toestimate a benthic community CSCL.---108-88-3 Toluene 0.05 EqP Based on the SCV of 0.0098 mg/L calculated bySuter and Tsao (1996), assuming 1 percent totalorganic carbon and log Kocequal to 2.70.Jones et al., 1997;U.S. EPA, 1993a71-55-6 1,1,1-Trichloroethane 0.03 EqP Based on the SCV of 0.011 mg/L calculated by Suterand Tsao (1996), assuming 1 percent total organiccarbon and log Kocequal to 2.44.Jones et al., 1997;U.S. EPA, 1993a79-01-6 Trichloroethylene 0.22 EqP Based on the SCV of 0.047 mg/L calculated by Suterand Tsao (1996), assuming 1 percent total organiccarbon and log Kocequal to 2.66.Jones et al., 1997;U.S. EPA, 1993a75-01-4 Vinyl chloride ID --- No water quality criteria have been developed;therefore, the EqP approach could not be applied toestimate a benthic community CSCL.—(continued)

# 14-72 Appendix 14A Ecological BenchmarksCAS Number ConstituentCSCL(mg/kgsedimentDW) Methodology Notes SourceTable 14A-7. (continued)Metals7440-36-0 Antimony 2 ER-L Estimated from a distribution of 13 effectsconcentrations measured in field sediments.Endpoints were associated with decreasedabundance and species diversity as well as shifts incommunity structure.Long andMorgan, 19917440-38-2 Arsenic 7.2 TEL Estimated from a distribution of 295 sedimentconcentrations associated with no- and low-effectsconcentrations to endpoints of lethality, abundance,diversity, and benthic community structure.MacDonald, 19947440-39-3 Barium ID --- Insufficient data were available to develop a benthiccommunity CSCL.---7440-41-7 Beryllium ID --- Insufficient data were available to develop a benthiccommunity CSCL.---7440-43-9 Cadmium 0.68 TEL Estimated from a distribution of 433 sedimentconcentrations associated with no- and low-effectsconcentrations to endpoints of lethality, abundance,diversity, and benthic community structure.MacDonald, 19947440-47-3 Chromium 52 TEL Estimated from a distribution of 354 sedimentconcentrations associated with no- and low-effectsconcentrations to endpoints of lethality, abundance,diversity, and benthic community structure.MacDonald, 1994(continued)

# 14-73 Appendix 14A Ecological BenchmarksCAS Number ConstituentCSCL(mg/kgsedimentDW) Methodology Notes SourceTable 14A-7. (continued)16065-83-1 Chromium III ID --- Insufficient data were available to develop a benthiccommunity CSCL.---18540-29-9 Chromium VI ID --- Insufficient data were available to develop a benthiccommunity CSCL.---7439-92-1 Lead 30 TEL Estimated from a distribution of 402 sedimentconcentrations associated with no- and low-effectsconcentrations to endpoints of lethality, abundance,diversity, and benthic community structure.MacDonald, 19947440-02-0 Nickel 16 TEL Estimated from a distribution of 355 sedimentconcentrations associated with no- and low-effectsconcentrations to endpoints of lethality, abundance,diversity, and benthic community structure.MacDonald, 19947782-49-2 Selenium ID --- Insufficient data were available to develop a benthiccommunity CSCL.---7440-22-4 Silver 0.73 TEL Estimated from a distribution of 190 sedimentconcentrations associated with no- and low-effectsconcentrations to endpoints of lethality, abundance,diversity, and benthic community structure.MacDonald, 19947446-18-6 Thallium ID --- Insufficient data were available to develop a benthiccommunity CSCL.---7440-62-2 Vanadium ID --- Insufficient data were available to develop a benthiccommunity CSCL.---(continued)

# 14-74 Appendix 14A Ecological BenchmarksCAS Number ConstituentCSCL(mg/kgsedimentDW) Methodology Notes SourceTable 14A-7. (continued)7440-66-6 Zinc 120 TEL Estimated from a distribution of 411 sedimentconcentrations associated with no- and low-effectsconcentrations to endpoints of lethality, abundance,diversity, and benthic community structure.MacDonald, 1994Special117-81-7 Bis(2-ethylhexyl) phthalate 0.18 TEL Estimated from a distribution of 131 sedimentconcentrations associated with no- and low-effectsconcentrations to endpoints of lethality, abundance,diversity, and benthic community structure.MacDonald, 199450-32-8 Benzo(a)pyrene 0.089 TEL Estimated from a distribution of 259 sedimentconcentrations associated with no- and low-effectsconcentrations to endpoints of lethality, abundance,diversity, and benthic community structure.MacDonald, 199453-70-3 Dibenz(a,h)anthracene 0.0062 TEL Estimated from a distribution of 246 sedimentconcentrations associated with no- and low-effectsconcentrations to endpoints of lethality, abundance,diversity, and benthic community structureMacDonald, 199487-86-5 Pentachlorophenol ID --- Insufficient data were available to develop a benthiccommunity CSCL.---Mercury and Dioxin7439-97-6m Methyl mercury ID --- Insufficient data were available to develop a benthiccommunity CSCL.(continued)

# 14-75 Appendix 14A Ecological BenchmarksCAS Number ConstituentCSCL(mg/kgsedimentDW) Methodology Notes SourceTable 14A-7. (continued)7439-97-6e Mercury (elemental) ID --- Insufficient data were available to develop a benthiccommunity CSCL.---7439-97-6 Mercury (divalent) 0.13 TEL Estimated from a distribution of 331 sedimentconcentrations associated with no- and low-effectsconcentrations to endpoints of lethality, abundance,diversity, and benthic community structure.MacDonald, 19941746-01-6 TCDD 2,3,7,8- ID --- Insufficient datawere available to develop a benthiccommunity CSCL.---ID = Insufficient data.CSCL = Chemical stressor concentration limit.FCV = Final chronic value.SCV = Secondary chronic value.ER-L = Effects range low- The value was the 10th percentile fromthe ranked distribution of sediment effects concentrations.EqP = Equilibrium partitioning. The value is the product of the following calculation.--- = Not applicable because insufficient data identified.Benthic Community CSCL = Surface Well Water CSCL x This is calculation foc) x KocTEL = Threshold effects level - The value calculated from the following equation, where EDS-L is the 15thhpercentile of theeffects data set and NEDS-M is the 50th percentile of the no-effects data set:

# 14-76 Appendix 14A Ecological BenchmarksTable 14A-8. Terrestrial Plant CSCLsCAS Number ConstituentCSCL(mg/kg soilDW) Methodology Notes SourceOrganics75-05-8 Acetonitrile ID --- Insufficient data were available to develop aterrestrial plant CSCL.---107-13-1 Acrylonitrile ID --- Insufficient data were available to develop aterrestrial plant CSCL.---62-53-3 Aniline ID --- Insufficient data were available to develop aterrestrial plant CSCL.---71-43-2 Benzene ID --- Insufficient data were available to develop aterrestrial plant CSCL.---75-15-0 Carbon disulfide ID --- Insufficient data were available to develop aterrestrial plant CSCL.---108-90-7 Chlorobenzene ID --- Insufficient data were available to develop aterrestrial plant CSCL.---67-66-3 Chloroform ID --- Insufficient data were available to develop aterrestrial plant CSCL.---94-75-7 2,4-Dichlorophenoxyacetic acid(2,4-D)ID --- Insufficient data were available to develop aterrestrial plant CSCL.---106-93-4 Ethylene dibromide ID --- Insufficient data were available to develop aterrestrial plant CSCL.---87-68-3 Hexachloro-1,3-butadiene ID --- Insufficient data were available to develop aterrestrial plant CSCL.—(continued)

# 14-77 Appendix 14A Ecological BenchmarksCAS Number ConstituentCSCL(mg/kg soilDW) Methodology Notes SourceTable 14A-8. (continued)72-43-5 Methoxychlor ID --- Insufficient data were available to develop aterrestrial plant CSCL.---78-93-3 Methyl ethyl ketone ID --- Insufficient data were available to develop aterrestrial plant CSCL.---80-62-6 Methyl methacrylate ID --- Insufficient data were available to develop aterrestrial plant CSCL.---75-09-2 Methylene chloride ID --- Insufficient data were available to develop aterrestrial plant CSCL.---98-95-3 Nitrobenzene ID --- Insufficient data were available to develop aterrestrial plant CSCL.---108-95-2 Phenol 70 Lowest LOEC Derived from the lowest of two toxicityvalues (range: 79 to 170 mg/kg soil) basedon effects to plant weight.Efroymson, Will, Suter,and Wooten, 1997110-86-1 Pyridine ID --- Insufficient data were available to develop aterrestrial plant CSCL.---127-18-4 Tetrachloroethylene ID --- Insufficient data were available to develop aterrestrial plant CSCL.---137-26-8 Thiram ID --- Insufficient data were available to develop aterrestrial plant CSCL.---108-88-3 Toluene ID --- Insufficient data were available to develop aterrestrial plant CSCL.---71-55-6 1,1,1-Trichloroethane ID --- Insufficient data were available to develop aterrestrial plant CSCL.—(continued)

# 14-78 Appendix 14A Ecological BenchmarksCAS Number ConstituentCSCL(mg/kg soilDW) Methodology Notes SourceTable 14A-8. (continued)79-01-6 Trichloroethylene ID --- Insufficient data were available to develop aterrestrial plant CSCL.---75-01-4 Vinyl chloride ID --- Insufficient data were available to develop aterrestrial plant CSCL.---Metals7440-36-0 Antimony 5 Lowest LOEC Value was the only LOEC identified basedon phytotoxic effects.Efroymson, Will, Suterand Wooten, 19977440-38-2 Arsenic 10 ER-L Derived as the 10th percentile of 15 toxicityvalues (range: 2 to 1,000 mg/kg soil) basedon effects to plant weight and yield.Efroymson, Will, Suterand Wooten, 19977440-39-3 Barium 500 Lowest LOEC Derived from the lowest of two toxicityvalues (range: 500 to 2,000 mg/kg soil)based on effects to plant weight.Efroymson, Will, Suterand Wooten, 19977440-41-7 Beryllium 10 Lowest LOEC Derived from the lowest of three toxicityvalues (range: 10 to 25 mg/kg soil) based oneffects to plant weight and survival.Efroymson, Will, Suterand Wooten, 19977440-43-9 Cadmium 4 ER-L Derived as the10th percentile of 74 toxicityvalues (range: 1 to 300 mg/kg soil) based oneffects to plant weight, yield, andgermination success.Efroymson, Will, Suterand Wooten, 19977440-47-3 Chromium ID --- Insufficient data were available to develop aterrestrial plant CSCL.—(continued)

# 14-79 Appendix 14A Ecological BenchmarksCAS Number ConstituentCSCL(mg/kg soilDW) Methodology Notes SourceTable 14A-8. (continued)16065-83-1 Chromium III ID --- Insufficient data were available to develop aterrestrial plant CSCL.---18540-29-9 Chromium VI 1 Lowest LOEC Derived from the lowest of seven toxicityvalues (range: 1.8 to 31 mg/kg soil) based oneffects to plant weight.Efroymson, Will, Suterand Wooten, 19977439-92-1 Lead 50 ER-L Derived as the 10th percentile of 17 toxicityvalues (range: 50 to 5,000 mg/kg soil) basedon effects to plant weight and transpiration.Efroymson, Will, Suter,and Wooten, 19977440-02-0 Nickel 30 ER-L Derived as the 10th percentile of 14 toxicityvalues (range: 25 to 290 mg/kg soil) basedon effects to plant weight.Efroymson, Will, Suter,and Wooten, 19977782-49-2 Selenium 1 ER-L Derived as the 10th of 14 toxicity values(range: 1 to 4 mg/kg soil) based on effects toplant weight.Efroymson, Will, Suter,and Wooten, 19977440-22-4 Silver 2 Lowest LOEC Value was the only LOEC identified basedon phytotoxic effects.Efroymson, Will, Suter,and Wooten, 19977446-18-6 Thallium 1 Lowest LOEC Value was the only LOEC identified basedon phytotoxic effects.Efroymson, Will, Suter,and Wooten, 19977440-62-2 Vanadium 2 Lowest LOEC Derived from the lowest of two toxicityvalues (range: 2.5 to 50 mg/kg soil) based onphytotoxic effects.Efroymson, Will, Suter,and Wooten, 19977440-66-6 Zinc 50 ER-L Derived as the 10th percentile of 14 toxicityvalues (range: 25 to 400 mg/kg soil) basedon effects to plant weight, growth, and yield.Efroymson, Will, Suter,and Wooten, 1997(continued)

# 14-80 Appendix 14A Ecological BenchmarksCAS Number ConstituentCSCL(mg/kg soilDW) Methodology Notes SourceTable 14A-8. (continued)Special117-81-7 Bis(2-ethylhexyl) phthalate ID --- Insufficient data were available to develop aterrestrial plant CSCL.---50-32-8 Benzo(a)pyrene ID --- Insufficient data were available to develop aterrestrial plant CSCL.---53-70-3 Dibenz(a,h)anthracene ID --- In sufficient data were available to develop aterrestrial plant CSCL.---87-86-5 Pentachlorophenol 3 Lowest LOEC Derived from the lowest of four toxicityvalues (range: 8 to 20 mg/kg soil) based oneffects to plant weight.Efroymson, Will, Suter,and Wooten, 1997Mercury and Dioxin7439-97-6m Methyl mercury ID --- Insufficient data were available to develop aterrestrial plant CSCL.7439-97-6e Mercury (elemental) ID --- Insufficient data were available to develop aterrestrial plant CSCL.---7439-97-6 Mercury (divalent) 0.3 Lowest LOEC Derived from the lowest of two toxicityvalues (range: 0.3 to 64 mg/kg soil) based oneffects to seedling height and phytotoxicity.Efroymson, Will, Suter,and Wooten, 19971746-01-6 TCDD 2,3,7,8- ID --- Insufficient data were available to develop aterrestrial plant CSCL.---CSCL = Chemical stressor concentration limit.ER-L = Effects range low—The value was the 10th percentile from the ranked distribution of soil effects concentrations.ID = Insufficient data.LOEC = Lowest observed effect concentration.--- = Not applicable because insufficient data were identified.

# 14-81 Appendix 14A Ecological BenchmarksTable 14A-9. Soil Community CSCLsCAS Number ConstituentCSCL(mg/kgsoil DW) Methodology Notes SourceOrganics75-05-8 Acetonitrile ID --- Insufficient data were available to develop asoil community CSCL.---107-13-1 Acrylonitrile ID --- Insufficient data were available to develop asoil community CSCL.---62-53-3 Aniline ID --- Insufficient data were available to develop asoil community CSCL.---71-43-2 Benzene ID --- Insufficient data were available to develop asoil community CSCL.---75-15-0 Carbon disulfide ID --- Insufficient data were available to develop asoil community CSCL.---108-90-7 Chlorobenzene 40 Lowest LC50Value is based on the lowest of four valuesassessing lethality to populations ofearthworms. The lowest LC50of 240 wasused, applying an uncertainty factor of 5.Efroymson, Will, andSuter, 199767-66-3 Chloroform ID --- Insufficient data were available to develop asoil community CSCL.---94-75-7 2,4-Dichlorophenoxyacetic acid(2,4-D)ID --- Insufficient data were available to develop asoil community CSCL.---106-93-4 Ethylene dibromide ID --- Insufficient data were available to develop asoil community CSCL.---87-68-3 Hexachloro-1,3-butadiene ID --- Insufficient data were available to develop asoil community CSCL.---(continued)

# 14-82 Appendix 14A Ecological BenchmarksCAS Number ConstituentCSCL(mg/kgsoil DW) Methodology Notes SourceTable 14A-9. (continued)72-43-5 Methoxychlor ID --- Insufficient data were available to develop asoil community CSCL.---78-93-3 Methyl ethyl ketone ID --- Insufficient data were available to develop asoil community CSCL.---80-62-6 Methyl methacrylate ID --- Insufficient data were available to develop asoil community CSCL.---75-09-2 Methylene chloride ID --- Insufficient data were available to develop asoil community CSCL.---98-95-3 Nitrobenzene 40 Lowest LC50Value is based on the lowest of four valuesassessing lethality to populations ofearthworms. The lowest LC50of 226 wasused, applying an uncertainty factor of 5.Efroymson, Will, andSuter, 1997108-95-2 Phenol 30 Lowest LC50Value is based on the lowest of five valuesassessing lethality to populations ofearthworms. The lowest LC50of 188 wasused, applying an uncertainty factor of 5.Efroymson, Will, andSuter, 1997110-86-1 Pyridine ID --- Insufficient data were available to develop asoil community CSCL.---127-18-4 Tetrachloroethylene ID --- Insufficient data were available to develop asoil community CSCL.---137-26-8 Thiram ID --- Insufficient data were available to develop asoil community CSCL.---108-88-3 Toluene ID --- Insufficient data were available to develop asoil community CSCL.---71-55-6 1,1,1-Trichloroethane ID --- Insufficient data were available to develop asoil community CSCL.---

# 14-83 Appendix 14A Ecological BenchmarksCAS Number ConstituentCSCL(mg/kgsoil DW) Methodology Notes SourceTable 14A-9. (continued)79-01-6 Trichloroethylene ID --- Insufficient data were available to develop asoil community CSCL.---75-01-4 Vinyl chloride ID --- Insufficient data were available to develop asoil community CSCL.---Metals7440-36-0 Antimony ID --- Insufficient data were available to develop asoil community CSCL.---7440-38-2 Arsenic 60 Lowest LOEC Value was the only LOEC identified basedon reproductive endpoints in earthworms.Efroymson, Will, andSuter, 19977440-39-3 Barium ID --- Insufficient data were available to develop asoil community CSCL.---7440-41-7 Beryllium ID --- Insufficient data were available to develop asoil community CSCL.—7440-43-9 Cadmium 1 Community-based CSCLBased on NOEC data for eight differenttaxonomic groups represented in the soilcommunity. Concentrations ranged from 1to 19 mg/kg soil based on toxicity endpointsof reproduction, growth, and development.vanStraalen &Denneman, 1989;Aldenberg & Slob,1993; Sloof, 1992;Haight et al., 1982;vanStraalen et al.,1989; van de Meent etal., 1990; Russell et al.,1981; Malecki et al.,1982(continued)

# 14-84 Appendix 14A Ecological BenchmarksCAS Number ConstituentCSCL(mg/kgsoil DW) Methodology Notes SourceTable 14A-9. (continued)7440-47-3 Chromium 66 Geometric mean The ecotoxicity data indicate that soilconcentrations indicating effects to survivalare below soil concentrations indicatingreproductive effects in earthworms. Ageometric mean of LOEC data from bothreproductive and survival endpoints wasused to remain consistent with theassessment endpoints of the analysis..Efroymson, Will, andSuter, 199716065-83-1 Chromium III 66 Geometric mean Hexavalent chromium is reduced to Cr3+under normal soil pH and redox conditions(Katz and Salem, 1994); hence, a greaterportion of chromium in the soil is found asCr3+; therefore, the same benchmark used fortotal chromium is appropriate for Cr3+.Efroymson, Will, andSuter, 199718540-29-9 Chromium VI 0.4 Lowest LOEC Value was the only LOEC identified basedon reproductive endpoints in earthworms.---7439-92-1 Lead 28 Community-based CSCLBased on NOEC data for six differenttaxonomic groups represented in the soilcommunity. Concentrations ranged from 23to 1,100 mg/kg soil based on toxicityendpoints of reproduction, growth, and litterbreakdown.vanStraalen &Denneman, 1989;Aldenberg & Slob,1993; Sloof, 1992;Denneman & vanStraalen, 1991; van deMeent et al., 1990;Bengtsson et al., 1986,Marigomez et al., 1986(continued)

# 14-85 Appendix 14A Ecological BenchmarksCAS Number ConstituentCSCL(mg/kgsoil DW) Methodology Notes SourceTable 14A-9. (continued)7440-02-0 Nickel 90 ER-L Derived as the 10th percentile of 56 toxicityvalues (range: 50 to 8,100 mg/kg soil) basedon effects microbial growth and productivityendpoints. Microbial endpoints appearedmore sensitive than earthworms.Efroymson, Will, andSuter, 19977782-49-2 Selenium 70 Lowest LOEC Value was the only LOEC identified basedon reproductive endpoints in earthworms.Efroymson, Will, andSuter, 19977440-22-4 Silver ID --- Insufficient data were available to develop asoil community CSCL.---7446-18-6 Thallium ID --- Insufficient data were available to develop asoil community CSCL.---7440-62-2 Vanadium ID --- Insufficient data were available to develop asoil community CSCL.---7440-66-6 Zinc 100 ER-L Derived as the 10th percentile of 46 toxicityvalues (range: 50 to 9,700 mg/kg soil) basedon effects microbial growth and productivityendpoints. Microbial endpoints appearedmore sensitive than earthworms.Efroymson, Will, andSuter, 1997Special117-81-7 Bis(2-ethylhexyl) phthalate ID --- Insufficient data were available to develop asoil community CSCL.---50-32-8 Benzo(a)pyrene ID --- Insufficient data were available to develop asoil community CSCL.---53-70-3 Dibenz(a,h)anthracene ID --- Insufficient data were available to develop asoil community CSCL.---(continued)

# 14-86 Appendix 14A Ecological BenchmarksCAS Number ConstituentCSCL(mg/kgsoil DW) Methodology Notes SourceTable 14A-9. (continued)87-86-5 Pentachlorophenol 6 ER-L Derived asthe 10th percentile of 21 toxicityvalues (range: 16 to 2,300 mg/kg soil) basedon effects earthworm mortality andreproductive success.Efroymson, Will, andSuter, 1997Mercury and Dioxin7439-97-6m Methyl mercury ID --- Insufficient data were available to develop asoil community CSCL.7439-97-6e Mercury (elemental) ID --- Insufficient data were available to develop asoil community CSCL.---7439-97-6 Mercury (divalent) 0.1 Lowest LOEC Derived from the lowest of two toxicityvalues (range: 0.5 to 12.5 mg/kg soil) basedon effects to earthworm survival andreproduction.Efroymson, Will, andSuter, 19971746-01-6 TCDD 2,3,7,8- ID --- Insufficient data were available to develop asoil community CSCL.---ID = Insufficient data.LOEC = Lowest observed effects concentration.CSCL = Chemical stressor concentration limit.ER-L = Effects range low— The value was the 10thpercentile from the ranked distribution of soil effects concentrations.NOEC = No observed effects concentration.--- = Not applicable because insufficient data were identified.

# 14-87 Appendix 14A Ecological BenchmarksTable 14A-10. Scaled Benchmark Doses for Ecological ReceptorsCAS Number Chemical NameChemicalTypeAlligatorSnappingTurtleAmericanKestrelAmericanRobinAmericanWoodcockBaldEagle BeaverBeltedKingfisherBlackBearBlack-TailedJackrabbit BullfrogBurrowingOwl75-05-8 Acetonitrile O ID ID ID ID ID ID ID ID ID ID ID107-13-1 Acrylonitrile O ID ID ID ID ID ID ID ID ID ID ID62-53-3 Aniline O ID ID ID ID ID ID ID ID ID 370 ID7440-36-0 Antimony M ID ID ID ID ID 0.15 ID 0.11 0.26 0.3 ID7440-38-2 Arsenic M ID 0.011 0.011 0.011 0.011 2.5 0.011 1.6 4.3 4.3 0.0117440-39-3 Barium M ID 30 30 30 30 ID 30 ID ID ID 3071-43-2 Benzene O ID ID ID ID ID 17 ID 12 28 34 ID50-32-8 Benzo(a)pyrene S ID ID ID ID ID 0.67 ID 0.41 1.1 ID ID7440-41-7 Beryllium M ID ID ID ID ID ID ID ID ID 11 ID117-81-7 Bis(2-ethylhexyl) phthalate S ID 1.1 1.1 1.1 1.1 23 1.1 16 38 ID 1.17440-43-9 Cadmium M ID 4.4 4.4 4.4 4.4 1.2 4.4 0.77 2.1 1.9 4.475-15-0 Carbon disulfide O ID ID ID ID ID ID ID ID ID ID ID108-90-7 Chlorobenzene O ID ID ID ID ID ID ID ID ID ID ID67-66-3 Chloroform O ID ID ID ID ID 9.1 ID 5.7 15 15 ID7440-47-3 Chromium M ID ID ID ID ID ID ID ID ID 8.8 ID16065-83-1 Chromium III (insoluble salts) M ID 2.2 2.2 2.2 2.2 1,000 2.2 570 1,700 ID 2.218540-29-9 Chromium VI M ID ID ID ID ID 1.9 ID 1.2 3.3 ID ID53-70-3 Dibenz(a,h)anthracene S ID ID ID ID ID ID ID ID ID ID ID94-75-7 2,4-Dichlorophenoxyaceticacid (2,4-D)O ID ID ID ID ID ID ID ID ID ID ID106-93-4 Ethylene dibromide O ID ID ID ID ID ID ID ID ID ID ID87-68-3 Hexachloro-1,3-butadiene O ID ID ID ID ID ID ID ID ID ID ID7439-92-1 Lead M ID 0.066 0.066 0.066 0.066 0.0062 0.066 0.0036 0.011 2.1 0.066(continued)

# 14-88 Appendix 14A Ecological BenchmarksCAS Number Chemical NameChemicalTypeAlligatorSnappingTurtleAmericanKestrelAmericanRobinAmericanWoodcockBaldEagle BeaverBeltedKingfisherBlackBearBlack-TailedJackrabbit BullfrogBurrowingOwlTable 14A-10. (continued)7439-97-6 Mercury (divalent) Hg ID 0.64 0.64 0.64 0.64 0.48 0.64 0.34 0.8 2.1 0.647439976e Mercury (elemental) Hg ID ID ID ID ID ID ID ID ID ID ID72-43-5 Methoxychlor O ID ID ID ID ID 44 ID 31 74 0.19 ID78-93-3 Methyl ethyl ketone O ID ID ID ID ID 1000 ID 650 1800 ID ID7439976m Methyl mercury Hg ID 0.025 0.025 0.025 0.025 0.045 0.025 0.032 0.075 ID 0.02580-62-6 Methyl methacrylate O ID ID ID ID ID ID ID ID ID ID ID75-09-2 Methylene chloride O ID ID ID ID ID ID ID ID ID ID ID7440-02-0 Nickel M ID 91 91 91 91 22 91 14 38 2.2 9198-95-3 Nitrobenzene O ID ID ID ID ID ID ID ID ID 0.64 ID87-86-5 Pentachlorophenol O ID 62 62 62 62 2.6 62 1.6 4.4 0.013 62108-95-2 Phenol O ID ID ID ID ID ID ID ID ID 1.3 ID110-86-1 Pyridine O ID ID ID ID ID ID ID ID ID ID ID7782-49-2 Selenium M ID 0.71 0.71 0.71 0.71 0.094 0.71 0.066 0.16 1.6 0.717440-22-4 Silver M ID ID ID ID ID ID ID ID ID 0.03 ID1746-01-6 2,3,7,8-Tetrachlorodibenzo-p-dioxinD ID 4.4E-05 4.4E-05 4.4E-05 4.4E-05 6.5E-07 4.4E-05 4.0E-07 1.1E-06 ID 4.4E-05127-18-4 Tetrachloroethylene O ID ID ID ID ID ID ID ID ID ID ID7446-18-6 Thallium S ID ID ID ID ID 0.0087 ID 0.005 0.015 0.11 ID137-26-8 Thiram O ID ID ID ID ID ID ID ID ID ID ID108-88-3 Toluene O ID ID ID ID ID 16 ID 10 27 0.58 ID71-55-6 1,1,1-Trichloroethane O ID ID ID ID ID 210 ID 130 350 ID ID79-01-6 Trichloroethylene O ID ID ID ID ID 0.44 ID 0.27 0.74 89 ID7440-62-2 Vanadium M ID 1.8 1.8 1.8 1.8 0.54 1.8 0.38 0.9 ID 1.875-01-4 Vinyl chloride O ID ID ID ID ID 0.2 ID 0.12 0.33 ID ID7440-66-6 Zinc M ID 32 32 32 32 88 32 62 150 6.5 32(continued)

# 14-89 Appendix 14A Ecological BenchmarksTable 14A-10. (continued)CAS Number Chemical NameCanadaGooseCeruleanWarblerCooper'sHawk CoyoteDeerMouseEastern BoxTurtleEasternCottontailEasternNewtFlatwoodsSalamanderGopherFrogGreat BasinPocket MouseGreat BlueHeron75-05-8 Acetonitrile ID ID ID ID ID ID ID ID ID ID ID ID107-13-1 Acrylonitrile ID ID ID ID ID ID ID ID ID ID ID ID62-53-3 Aniline ID ID ID ID ID ID ID 370 370 370 ID ID7440-36-0 Antimony ID ID ID 0.18 0.84 ID 0.3 0.3 0.3 0.3 0.89 ID7440-38-2 Arsenic 0.011 0.011 0.011 2.8 14 ID 5.1 4.3 4.3 4.3 15 0.0117440-39-3 Barium 30 30 30 ID ID ID ID ID ID ID ID 3071-43-2 Benzene ID ID ID 19 91 ID 33 34 34 34 97 ID50-32-8 Benzo(a)pyrene ID ID ID 0.73 3.7 ID 1.3 ID ID ID 3.8 ID7440-41-7 Beryllium ID ID ID ID ID ID ID 11 11 11 ID ID117-81-7 Bis(2-ethylhexyl) phthalate 1.1 1.1 1.1 26 130 ID 46 ID ID ID 130 1.17440-43-9 Cadmium 4.4 4.4 4.4 1.4 7 ID 2.5 1.9 1.9 1.9 7.1 4.475-15-0 Carbon disulfide ID ID ID ID ID ID ID ID ID ID ID ID108-90-7 Chlorobenzene ID ID ID ID ID ID ID ID ID ID ID ID67-66-3 Chloroform ID ID ID 10 51 ID 18 15 15 15 52 ID7440-47-3 Chromium ID ID ID ID ID ID ID 8.8 8.8 8.8 ID ID16065-83-1 Chromium III (insoluble salts) 2.2 2.2 2.2 1,100 5,600 ID 2,000 ID ID ID 5,700 2.218540-29-9 Chromium VI ID ID ID 2.1 11 ID 3.9 ID ID ID 11 ID53-70-3 Dibenz(a,h)anthracene ID ID ID ID ID ID ID ID ID ID ID ID94-75-7 2,4-Dichlorophenoxyaceticacid (2,4-D)ID ID ID ID ID ID ID ID ID ID ID ID106-93-4 Ethylene dibromide ID ID ID ID ID ID ID ID ID ID ID ID(continued)

# 14-90 Appendix 14A Ecological BenchmarksCAS Number Chemical NameCanadaGooseCeruleanWarblerCooper'sHawk CoyoteDeerMouseEastern BoxTurtleEasternCottontailEasternNewtFlatwoodsSalamanderGopherFrogGreat BasinPocket MouseGreat BlueHeronTable 14A-10. (continued)87-68-3 Hexachloro-1,3-butadiene ID ID ID ID ID ID ID ID ID ID ID ID7439-92-1 Lead 0.066 0.066 0.066 0.0069 0.035 ID 0.013 2.1 2.1 2.1 0.035 0.0667439-97-6 Mercury (divalent) 0.64 0.64 0.64 0.55 2.6 ID 0.95 2.1 2.1 2.1 2.8 0.647439976e Mercury (elemental) ID ID ID ID ID ID ID ID ID ID ID ID72-43-5 Methoxychlor ID ID ID 51 240 ID 88 0.19 0.19 0.19 260 ID78-93-3 Methyl ethyl ketone ID ID ID 1100 5800 ID 2100 ID ID ID 6000 ID7439976m Methyl mercury 0.025 0.025 0.025 0.051 0.25 ID 0.089 ID ID ID 0.26 0.02580-62-6 Methyl methacrylate ID ID ID ID ID ID ID ID ID ID ID ID75-09-2 Methylene chloride ID ID ID ID ID ID ID ID ID ID ID ID7440-02-0 Nickel 91 91 91 25 130 ID 45 2.2 2.2 2.2 130 9198-95-3 Nitrobenzene ID ID ID ID ID ID ID 0.64 0.64 0.64 ID ID87-86-5 Pentachlorophenol 62 62 62 2.9 15 ID 5.2 0.013 0.013 0.013 15 62108-95-2 Phenol ID ID ID ID ID ID ID 1.3 1.3 1.3 ID ID110-86-1 Pyridine ID ID ID ID ID ID ID ID ID ID ID ID7782-49-2 Selenium 0.71 0.71 0.71 0.11 0.51 ID 0.19 1.6 1.6 1.6 0.55 0.717440-22-4 Silver ID ID ID ID ID ID ID 0.03 0.03 0.03 ID ID1746-01-6 2,3,7,8-Tetrachlorodibenzo-p-dioxin4.4E-05 4.4E-05 4.4E-05 7.1E-07 3.6E-06 ID 1.3E-06 ID ID ID 3.7E-06 4.4E-05127-18-4 Tetrachloroethylene ID ID ID ID ID ID ID ID ID ID ID ID7446-18-6 Thallium ID ID ID 0.0095 0.049 ID 0.018 0.11 0.11 0.11 0.049 ID137-26-8 Thiram ID ID ID ID ID ID ID ID ID ID ID ID(continued)

# 14-91 Appendix 14A Ecological BenchmarksCAS Number Chemical NameCanadaGooseCeruleanWarblerCooper'sHawk CoyoteDeerMouseEastern BoxTurtleEasternCottontailEasternNewtFlatwoodsSalamanderGopherFrogGreat BasinPocket MouseGreat BlueHeronTable 14A-10. (continued)108-88-3 Toluene ID ID ID 18 91 ID 33 0.58 0.58 0.58 94 ID71-55-6 1,1,1-Trichloroethane ID ID ID 230 1200 ID 410 ID ID ID 1200 ID79-01-6 Trichloroethylene ID ID ID 0.48 2.5 ID 0.88 89 89 89 2.5 ID7440-62-2 Vanadium 1.8 1.8 1.8 0.61 2.9 ID 1.1 ID ID ID 3.1 1.875-01-4 Vinyl chloride ID ID ID 0.22 1.1 ID 0.39 ID ID ID 1.1 ID7440-66-6 Zinc 32 32 32 100 480 ID 180 6.5 6.5 6.5 510 32

# 14-92 Appendix 14A Ecological BenchmarksTable 14A-10. (continued)CAS Number Chemical NameGreenFrogGreenHeronHerringGull Kit FoxLeastWeaselLesserScaupLittleBrownBatLoggerheadShrikeLong-TailedWeaselMallardDuckMarshWrenMeadowVole75-05-8 Acetonitrile ID ID ID ID ID ID ID ID ID ID ID ID107-13-1 Acrylonitrile ID ID ID ID ID ID ID ID ID ID ID ID62-53-3 Aniline 370 ID ID ID ID ID ID ID ID ID ID ID7440-36-0 Antimony 0.3 ID ID 0.27 0.73 ID 1.1 ID 0.55 ID ID 0.737440-38-2 Arsenic 4.3 0.011 0.011 4.6 12 0.011 17 0.011 8.1 0.011 0.011 147440-39-3 Barium ID 30 30 ID ID 30 ID 30 ID 30 30 ID71-43-2 Benzene 34 ID ID 30 79 ID 120 ID 59 ID ID 7850-32-8 Benzo(a)pyrene ID ID ID 1.2 3.1 ID 4.6 ID 2.1 ID ID 3.77440-41-7 Beryllium 11 ID ID ID ID ID ID ID ID ID ID ID117-81-7 Bis(2-ethylhexyl) phthalate ID 1.1 1.1 41 110 1.1 160 1.1 82 1.1 1.1 1107440-43-9 Cadmium 1.9 4.4 4.4 2.2 5.8 4.4 8.5 4.4 4 4.4 4.4 6.975-15-0 Carbon disulfide ID ID ID ID ID ID ID ID ID ID ID ID108-90-7 Chlorobenzene ID ID ID ID ID ID ID ID ID ID ID ID67-66-3 Chloroform 15 ID ID 16 42 ID 62 ID 29 ID ID 507440-47-3 Chromium 8.8 ID ID ID ID ID ID ID ID ID ID ID16065-83-1 Chromium III (insoluble salts) ID 2.2 2.2 1,800 4,600 2.2 7,500 2.2 3,000 2.2 2.2 4,60018540-29-9 Chromium VI ID ID ID 3.5 9 ID 13 ID 6.2 ID ID 1153-70-3 Dibenz(a,h)anthracene ID ID ID ID ID ID ID ID ID ID ID ID94-75-7 2,4-Dichlorophenoxyaceticacid (2,4-D)ID ID ID ID ID ID ID ID ID ID ID ID106-93-4 Ethylene dibromide ID ID ID ID ID ID ID ID ID ID ID ID(continued)

# 14-93 Appendix 14A Ecological BenchmarksCAS Number Chemical NameGreenFrogGreenHeronHerringGull Kit FoxLeastWeaselLesserScaupLittleBrownBatLoggerheadShrikeLong-TailedWeaselMallardDuckMarshWrenMeadowVoleTable 14A-10. (continued)87-68-3 Hexachloro-1,3-butadiene ID ID ID ID ID ID ID ID ID ID ID ID7439-92-1 Lead 2.1 0.066 0.066 0.011 0.028 0.066 0.046 0.066 0.018 0.066 0.066 0.0297439-97-6 Mercury (divalent) 2.1 0.64 0.64 0.85 2.3 0.64 3.4 0.64 1.7 0.64 0.64 2.37439976e Mercury (elemental) ID ID ID ID ID ID ID ID ID ID ID ID72-43-5 Methoxychlor 0.19 ID ID 79 210 ID 310 ID 160 ID ID 21078-93-3 Methyl ethyl ketone ID ID ID 1,900 4,900 ID 7,100 ID 3,300 ID ID 5,8007439976m Methyl mercury ID 0.025 0.025 0.08 0.22 0.025 0.32 0.025 0.16 0.025 0.025 0.2180-62-6 Methyl methacrylate ID ID ID ID ID ID ID ID ID ID ID ID75-09-2 Methylene chloride ID ID ID ID ID ID ID ID ID ID ID ID7440-02-0 Nickel 2.2 91 91 41 100 91 150 91 71 91 91 12098-95-3 Nitrobenzene 0.64 ID ID ID ID ID ID ID ID ID ID ID87-86-5 Pentachlorophenol 0.013 62 62 4.7 12 62 18 62 8.3 62 62 14108-95-2 Phenol 1.3 ID ID ID ID ID ID ID ID ID ID ID110-86-1 Pyridine ID ID ID ID ID ID ID ID ID ID ID ID7782-49-2 Selenium 1.6 0.71 0.71 0.17 0.45 0.71 0.66 0.71 0.33 0.71 0.71 0.447440-22-4 Silver 0.03 ID ID ID ID ID ID ID ID ID ID ID1746-01-6 2,3,7,8-Tetrachlorodibenzo-p-dioxinID 4.4E-05 4.4E-05 1.2E-06 3.0E-06 4.4E-05 4.4E-06 4.4E-05 2.1E-06 4.4E-05 4.4E-05 3.6E-06127-18-4 Tetrachloroethylene ID ID ID ID ID ID ID ID ID ID ID ID7446-18-6 Thallium 0.11 ID ID 0.015 0.039 ID 0.064 ID 0.026 ID ID 0.04137-26-8 Thiram ID ID ID ID ID ID ID ID ID ID ID ID(continued)

# 14-94 Appendix 14A Ecological BenchmarksCAS Number Chemical NameGreenFrogGreenHeronHerringGull Kit FoxLeastWeaselLesserScaupLittleBrownBatLoggerheadShrikeLong-TailedWeaselMallardDuckMarshWrenMeadowVoleTable 14A-10. (continued)108-88-3 Toluene 0.58 ID ID 30 76 ID 110 ID 52 ID ID 9071-55-6 1,1,1-Trichloroethane ID ID ID 370 960 ID 1,400 ID 660 ID ID 1,10079-01-6 Trichloroethylene 89 ID ID 0.8 2 ID 3 ID 1.4 ID ID 2.47440-62-2 Vanadium ID 1.8 1.8 0.96 2.6 1.8 3.8 1.8 1.9 1.8 1.8 2.575-01-4 Vinyl chloride ID ID ID 0.36 0.92 ID 1.4 ID 0.63 ID ID 1.17440-66-6 Zinc 6.5 32 32 160 420 32 620 32 310 32 32 420

# 14-95 Appendix 14A Ecological BenchmarksTable 14A-10. (continued)CAS Number Chemical Name Mink Mule Deer MuskratNorthernBobwhiteNorthernWater Snake OspreyPaintedTurtle Pine Vole Prairie Vole Raccoon Racer Red Fox75-05-8 Acetonitrile ID ID ID ID ID ID ID ID ID ID ID ID107-13-1 Acrylonitrile ID ID ID ID ID ID ID ID ID ID ID ID62-53-3 Aniline ID ID ID ID ID ID ID ID ID ID ID ID7440-36-0 Antimony 0.35 0.12 0.34 ID ID ID ID 0.8 0.75 0.21 ID 0.237440-38-2 Arsenic 5.3 1.8 5.5 0.011 ID 0.011 ID 13 12 3.4 ID 3.67440-39-3 Barium ID ID ID 30 ID 30 ID ID ID ID ID ID71-43-2 Benzene 38 13 36 ID ID ID ID 86 81 23 ID 2450-32-8 Benzo(a)pyrene 1.4 0.47 1.4 ID ID ID ID 3.5 3.1 0.9 ID 0.967440-41-7 Beryllium ID ID ID ID ID ID ID ID ID ID ID ID117-81-7 Bis(2-ethylhexyl) phthalate 53 17 50 1.1 ID 1.1 ID 120 110 32 ID 347440-43-9 Cadmium 2.6 0.88 2.7 4.4 ID 4.4 ID 6.5 5.8 1.7 ID 1.875-15-0 Carbon disulfide ID ID ID ID ID ID ID ID ID ID ID ID108-90-7 Chlorobenzene ID ID ID ID ID ID ID ID ID ID ID ID67-66-3 Chloroform 19 6.5 20 ID ID ID ID 48 42 12 ID 137440-47-3 Chromium ID ID ID ID ID ID ID ID ID ID ID ID16065-83-1 Chromium III (insoluble salts) 2,000 680 2,200 2.2 ID 2.2 ID 5,300 5,000 1,300 ID 1,40018540-29-9 Chromium VI 4.1 1.4 4.2 ID ID ID ID 10 9 2.6 ID 2.853-70-3 Dibenz(a,h)anthracene ID ID ID ID ID ID ID ID ID ID ID ID94-75-7 2,4-Dichlorophenoxyaceticacid (2,4-D)ID ID ID ID ID ID ID ID ID ID ID ID106-93-4 Ethylene dibromide ID ID ID ID ID ID ID ID ID ID ID ID(continued)

# 14-96 Appendix 14A Ecological BenchmarksCAS Number Chemical Name Mink Mule Deer MuskratNorthernBobwhiteNorthernWater Snake OspreyPaintedTurtle Pine Vole Prairie Vole Raccoon Racer Red FoxTable 14A-10. (continued)87-68-3 Hexachloro-1,3-butadiene ID ID ID ID ID ID ID ID ID ID ID ID7439-92-1 Lead 0.012 0.0042 0.013 0.066 ID 0.066 ID 0.033 0.031 0.0083 ID 0.00877439-97-6 Mercury (divalent) 1.1 0.36 1 0.64 ID 0.64 ID 2.5 2.3 0.66 ID 0.717439976e Mercury (elemental) ID ID ID ID ID ID ID ID ID ID ID ID72-43-5 Methoxychlor 100 34 97 ID ID ID ID 230 220 61 ID 6678-93-3 Methyl ethyl ketone 2,200 740 2,300 ID ID ID ID 5,500 4,800 1,400 ID 1,5007439976m Methyl mercury 0.1 0.034 0.098 0.025 ID 0.025 ID 0.23 0.22 0.062 ID 0.06680-62-6 Methyl methacrylate ID ID ID ID ID ID ID ID ID ID ID ID75-09-2 Methylene chloride ID ID ID ID ID ID ID ID ID ID ID ID7440-02-0 Nickel 47 16 49 91 ID 91 ID 120 100 30 ID 3298-95-3 Nitrobenzene ID ID ID ID ID ID ID ID ID ID ID ID87-86-5 Pentachlorophenol 5.5 1.9 5.7 62 ID 62 ID 14 12 3.5 ID 3.7108-95-2 Phenol ID ID ID ID ID ID ID ID ID ID ID ID110-86-1 Pyridine ID ID ID ID ID ID ID ID ID ID ID ID7782-49-2 Selenium 0.22 0.071 0.21 0.71 ID 0.71 ID 0.49 0.46 0.13 ID 0.147440-22-4 Silver ID ID ID ID ID ID ID ID ID ID ID ID1746-01-6 2,3,7,8-Tetrachlorodibenzo-p-dioxin1.4E-06 4.6E-07 1.4E-06 4.4E-05 ID 4.4E-05 ID 3.4E-06 3.0E-06 8.8E-07 ID 9.3E-07127-18-4 Tetrachloroethylene ID ID ID ID ID ID ID ID ID ID ID ID7446-18-6 Thallium 0.017 0.0059 0.019 ID ID ID ID 0.046 0.043 0.012 ID 0.012137-26-8 Thiram ID ID ID ID ID ID ID ID ID ID ID ID(continued)

# 14-97 Appendix 14A Ecological BenchmarksCAS Number Chemical Name Mink Mule Deer MuskratNorthernBobwhiteNorthernWater Snake OspreyPaintedTurtle Pine Vole Prairie Vole Raccoon Racer Red FoxTable 14A-10. (continued)108-88-3 Toluene 34 12 35 ID ID ID ID 86 76 22 ID 2371-55-6 1,1,1-Trichloroethane 430 150 450 ID ID ID ID 1,100 960 280 ID 30079-01-6 Trichloroethylene 0.92 0.31 0.95 ID ID ID ID 2.3 2 0.6 ID 0.637440-62-2 Vanadium 1.2 0.41 1.2 1.8 ID 1.8 ID 2.8 2.6 0.74 ID 0.875-01-4 Vinyl chloride 0.41 0.14 0.43 ID ID ID ID 1 0.92 0.27 ID 0.287440-66-6 Zinc 200 67 190 32 ID 32 ID 460 430 120 ID 130

# 14-98 Appendix 14A Ecological BenchmarksTable 14A-10. (continued)CAS Number Chemical NameRed-TailedHawk River OtterShort-TailedShrewShort-TailedWeaselSnappingTurtleSouthernHognoseSnakeSpottedSandpiper Tree SwallowWesternMeadowlarkWhite-TailedDeer75-05-8 Acetonitrile ID ID ID ID ID ID ID ID ID ID107-13-1 Acrylonitrile ID ID ID ID ID ID ID ID ID ID62-53-3 Aniline ID ID ID ID ID ID ID ID ID ID7440-36-0 Antimony ID 0.2 0.89 0.59 ID ID ID ID ID 0.127440-38-2 Arsenic 0.011 3.1 15 7.9 ID ID 0.011 0.011 0.011 1.87440-39-3 Barium 30 ID ID ID ID ID 30 30 30 ID71-43-2 Benzene ID 21 96 63 ID ID ID ID ID 1350-32-8 Benzo(a)pyrene ID 0.81 4 2.1 ID ID ID ID ID 0.487440-41-7 Beryllium ID ID ID ID ID ID ID ID ID ID117-81-7 Bis(2-ethylhexyl) phthalate 1.1 29 130 88 ID ID 1.1 1.1 1.1 197440-43-9 Cadmium 4.4 1.5 7.4 3.9 ID ID 4.4 4.4 4.4 0.975-15-0 Carbon disulfide ID ID ID ID ID ID ID ID ID ID108-90-7 Chlorobenzene ID ID ID ID ID ID ID ID ID ID67-66-3 Chloroform ID 11 55 28 ID ID ID ID ID 6.67440-47-3 Chromium ID ID ID ID ID ID ID ID ID ID16065-83-1 Chromium III (insoluble salts) 2.2 1200 5800 2800 ID ID 2.2 2.2 2.2 68018540-29-9 Chromium VI ID 2.4 12 6.1 ID ID ID ID ID 1.453-70-3 Dibenz(a,h)anthracene ID ID ID ID ID ID ID ID ID ID94-75-7 2,4-Dichlorophenoxyaceticacid (2,4-D)ID ID ID ID ID ID ID ID ID ID106-93-4 Ethylene dibromide ID ID ID ID ID ID ID ID ID ID(continued)

# 14-99 Appendix 14A Ecological BenchmarksCAS Number Chemical NameRed-TailedHawk River OtterShort-TailedShrewShort-TailedWeaselSnappingTurtleSouthernHognoseSnakeSpottedSandpiper Tree SwallowWesternMeadowlarkWhite-TailedDeerTable 14A-10. (continued)87-68-3 Hexachloro-1,3-butadiene ID ID ID ID ID ID ID ID ID ID7439-92-1 Lead 0.066 0.0076 0.036 0.017 ID ID 0.066 0.066 0.066 0.00427439-97-6 Mercury (divalent) 0.64 0.61 2.8 1.8 ID ID 0.64 0.64 0.64 0.397439976e Mercury (elemental) ID ID ID ID ID ID ID ID ID ID72-43-5 Methoxychlor ID 57 260 170 ID ID ID ID ID 3678-93-3 Methyl ethyl ketone ID 1,300 6,300 3,300 ID ID ID ID ID 7607439976m Methyl mercury 0.025 0.057 0.26 0.17 ID ID 0.025 0.025 0.025 0.03680-62-6 Methyl methacrylate ID ID ID ID ID ID ID ID ID ID75-09-2 Methylene chloride ID ID ID ID ID ID ID ID ID ID7440-02-0 Nickel 91 27 130 70 ID ID 91 91 91 1698-95-3 Nitrobenzene ID ID ID ID ID ID ID ID ID ID87-86-5 Pentachlorophenol 62 3.2 16 8.2 ID ID 62 62 62 1.9108-95-2 Phenol ID ID ID ID ID ID ID ID ID ID110-86-1 Pyridine ID ID ID ID ID ID ID ID ID ID7782-49-2 Selenium 0.71 0.12 0.54 0.36 ID ID 0.71 0.71 0.71 0.0767440-22-4 Silver ID ID ID ID ID ID ID ID ID ID1746-01-6 2,3,7,8-Tetrachlorodibenzo-p-dioxin4.4E-05 7.9E-07 3.9E-06 2.0E-06 ID ID 4.4E-05 4.4E-05 4.4E-05 4.7E-07127-18-4 Tetrachloroethylene ID ID ID ID ID ID ID ID ID ID7446-18-6 Thallium ID 0.011 0.05 0.024 ID ID ID ID ID 0.0058137-26-8 Thiram ID ID ID ID ID ID ID ID ID ID(continued)

# 14-100 Appendix 14A Ecological BenchmarksCAS Number Chemical NameRed-TailedHawk River OtterShort-TailedShrewShort-TailedWeaselSnappingTurtleSouthernHognoseSnakeSpottedSandpiper Tree SwallowWesternMeadowlarkWhite-TailedDeerTable 14A-10. (continued)108-88-3Toluene ID 20 98 51 ID ID ID ID ID 1271-55-6 1,1,1-Trichloroethane ID 250 1,200 650 ID ID ID ID ID 15079-01-6 Trichloroethylene ID 0.54 2.6 1.4 ID ID ID ID ID 0.327440-62-2 Vanadium 1.8 0.69 3.1 2.1 ID ID 1.8 1.8 1.8 0.4475-01-4 Vinyl chloride ID 0.24 1.2 0.62 ID ID ID ID ID 0.147440-66-6 Zinc 32 110 510 340 ID ID 32 32 32 71ID = Insufficient data.O = Organic constituent.M = Metal.S = Special.Hg = Mercury.