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Ecological Risk Assessment

Freshwater Screening Benchmarks

Note: Values are expressed in terms of dissolved analyte in the water column except for those indicated with endnote 2 which are expressed in terms of total concentration.

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Notes and References

Literature Cited

^a Suter, G.W. II, and Tsao, C.L. 1996. Toxicological Benchmarks for Screening Potential Contaminants of Concern for Effects on Aquatic Biota: 1996 Revision. ES/ER/TM-96/R2.

^b CCME (Canadian Council of Ministers of the Environment). 2003. Canadian Environmental Quality Guidelines: Summary Table December 2003. Canadian Council of Ministers of the Environment, Winnipeg, Manitoba. Available at: http://www.ccme.ca/publications/ceqg_rcqe.html .

^c U.S. EPA. OSWER (Office of Solid Waste and Emergency Response). 1996. Eco Update: Ecotox thresholds. Washington, D.C. EPA 540/F-95/038. Available at: http://www.epa.gov/oswer/riskassessment/pdf/eco_updt.pdf

^d Michigan DEQ (Department of Environmental Quality). 2002. Rule 57: Water Quality Values. Available at: http://www.michigan.gov/documents/deq/wb-swas-rule57_210455_7.xls

^e NY DEC (New York State Department of Environmental Conservation), Division of Water. 1993. Technical and Operational Guidance Series (1.1.1). Ambient Water Quality Standards and Guidance Values and Groundwater Effluent Limitations. Available at: http://www.dec.ny.gov/docs/water_pdf/togs111.pdf

^f NYCRR (New York Compilation of Codes, Rules, and Regulations). 1999. Title 6, Part 706. Available at: http://www.dec.state.ny.us/website/regs/part706.html

^g Ohio EPA, Division of Surface Water. 2002. Ohio Administrative Code (OAC) 3745-1-07: Water Use Designations and Statewide Criteria.

^h TNRCC (Texas Natural Resource Conservation Commission), Toxicology and Risk Assessment Section. December 2001. Guidance for Conducting Ecological Risk Assessments at Remediation Sites in Texas. Available at: http://www.tceq.state.tx.us/comm_exec/forms_pubs/pubs/rg/rg-263_189521.pdf

ⁱ TNRCC (Texas Natural Resources Conservation Commission). 2000. Texas Surface Water Quality Standards. Texas Administrative Code (TAC), Title 30, Chapter 307. Effective August 17, 2000. Available at: http://www.tceq.state.tx.us/permitting/water_quality/wq_assessment/standards/WQ_standards_1997.html

^j U.S. EPA 1995. Final Water Quality Guidance for the Great Lakes System. 40CFR Parts 9, 122, 123, 131 and 132. March 23, 1995, 15366-15425. Available at: http://www.epa.gov/npdes/regulations/greatlakes_fedregstr.pdf

^k Van den Berg, M., Birnbaum, L., Bosveld, A.T.C., Brunstrom, B., Cook, P., Feeley, M., Giesy, J.P., Hanberg, A., Hasegawa, R., Kennedy, S.W., Kubiak, T., Larsen, J.C., Rolaf van Leeuwen, F.X., Liem, A.K.D., Nolt, C., Peterson, R.E., Poellinger, L., Safe, S., Schrenk, D., Tillitt, D., Tysklind, M., Younes, M., Waern, F., and Zacharewski, T. 1998. Toxic equivalency factors (TEFs) for PCBs, PCDDs, PCDFs for humans and wildlife. Environmental Health Perspectives. 106 (12): 775-792. Available at: http://ehp.niehs.nih.gov/members/1998/106p775-792vandenberg/vandenberg-full.html

^l U.S. EPA Region 5. 2003. Region 5 EDQL for all media. Available at: http://www.epa.gov/reg5rcra/ca/ESL.pdf.

^m U.S. EPA Region 5. 1999. Ecological Screening Levels for RCRA Appendix IX Hazardous Constituents. Draft Document.

ⁿ U.S. EPA. 2004. National Recommended Water Quality Criteria: 2004. Available at: http://www.epa.gov/waterscience/criteria/wqcriteria.html .

^oOregon DEQ (Department of Environmental Quality). 1998. Guidance for Ecological Risk Assessment: Level II Screening Benchmark Values. Updated December 2001. Oregon Dept. Env. Qual., Portland. SLV-2. Available at: http://www.deq.state.or.us/wmc/documents/eco-2slv.pdf

^p U.S. EPA. Ecoregional Nutrient Criteria. Available at: http://www.epa.gov/waterscience/criteria/nutrient/ecoregions .

^q U.S. EPA. 2000. Bioaccumulation Testing and Interpretation for the Purpose of Sediment Quality Assessment. Available at: http://www.epa.gov/waterscience/cs/biotesting/bioaccum.pdf

End Notes

¹GLWQI Tier II values (U.S. EPA OSWER 1996^c, Suter and Tsao 1996^a).

²The Canadian Water Quality Guidelines values refer to the total concentration in an unfiltered sample.

³Final Chronic Value.

⁴Value calculated using Tier I or Tier II methodology as described in NYCRR (1999^f).

⁵Data are Ohio River Basin aquatic life Tier II values from the OMZA.

⁶Values derived using LC₅₀ approach in accordance with methodology defined in TNRCC (2000ⁱ, 2001^h). Concentrations of non-persistent toxic materials shall not exceed concentrations which are chronically toxic (0.1 of acute LC₅₀ values) to the most sensitive aquatic species. Concentrations of persistent toxic materials that do not bioaccumulate shall not exceed concentrations which are chronically toxic (0.05 of LC₅₀ values) to the most sensitive aquatic species. Concentrations of toxic materials that bioaccumulate shall not exceed concentrations that are chronically toxic (0.01 of LC₅₀) to the most sensitive aquatic species.

⁷The screening value of 20 ug/L is for 2,2-Dibromo-3-nitrilopropionamide and dibromoacetonitrile combined.

⁸This value is based on the food chain and not direct toxicity.

⁹Congener- and receptor-specific dioxin equivalency.

¹⁰Value is based on an interim criterion developed according to the procedures described in U.S. EPA Region 5 (1999^m). Source data used in developing interim criteria were obtained through the Aquatic Toxicity Information Retrieval (ACQUIRE) database.

¹¹Value is the lowest test EC₂₀ for fish (Suter and Tsao 1996^a).

¹²Value is the lowest population EC₂₀ (Suter and Tsao 1996^a).

¹³Criterion Continuous Concentration (CCC) values are used rather than Criteria Maximum Concentration (CMC) values. The CMC is an estimate of the highest concentration of a material in surface water to which an aquatic community can be exposed briefly without resulting in an unacceptable effect. The CCC is an estimate of the highest concentration of a material in surface water to which an aquatic community can be exposed indefinitely without resulting in an unacceptable effect. No CCC value is available for silver, therefore the CMC value is used.

¹⁴Value is the lowest sensitive species test EC₂₀ for (Suter and Tsao 1996^a).

¹⁵See Freshwater Values for Hardness-Dependent Contaminants table if hardness does not equal 100. AWQC (2002 n) and Suter and Tsao (1996^a) values were used instead of CCME (2002^b) values if equations for variable hardness were not provided in the CCME document. The CCME values are: 0.017 ug/l cadmium, 8.9 ug/l chromium III, 1 ug/l chromium VI, 0.1 ug/l silver, and 30 ug/l zinc.

¹⁶Lowest Chronic Value for Daphnids (Suter and Tsao 1996^a).

¹⁷Applies to the sum of 1,2-, 1,3- and 1,4-dichlorobenzene.

¹⁸Wildlife value.

¹⁹LAS with side chains greater than 13 carbons only; applies to the sum of these substances. 1996^a

²⁰Applies to nitrilotriacetate (NY DEC 1993^e).

²¹Oregon Water Quality Criteria Freshwater acute criteria divided by 50, for acute to chronic conversion (Oregon DEQ 1998^o ).

²²Select a value from the criteria documents (Lakes and Reservoirs, Rivers and Streams) for the ecoregion, which corresponds to the site location.

²³Applies to the sum of 1,2,3-, 1,2,4- and 1,3,5-trichlorobenzene.

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Benchmark Selection

The screening benchmarks were selected utilizing numerous criteria. Priority was given to values based on direct toxicity over food chain modeling, as site specific food chain exposure modeling and assessment is strongly encouraged for all bioaccumulative compounds. Values under consideration were rejected if the source documents did not provide original citations and the ECOTOX database indicated no studies were available. Acute and subacute exposures and lethal endpoints were accepted if appropriate safety factors were applied. Values for individual Aroclors and PAHs which were based solely on extrapolation from another mixture or compound in the class were rejected. Preference was given to total rather than individual chemical forms for inorganics.

Hierarchy for Selection of Freshwater Benchmarks

• Preference was given to the benchmarks based on chronic exposure, non-lethal endpoint studies designed to be protective of sensitive species.
• Absent chronic exposure benchmarks, values based on acute studies for multiple species adjusted with acute to chronic ratios were selected.
• Food chain values for water from the EPA Great Lakes Water Quality Initiative were included based on the extent of benchmark evaluation process and the approval of models for DDT, mercury, 2,3,7,8-TCDD, and PCBs.
• Other food chain values were given preference over direct toxicity values only if the direct toxicity value was for a marine environment.

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Downloadable Files

• Freshwater Screening Benchmarks [EXCEL | PDF]
• Notes and References [ MS Word]
• Hardness Dependent Values [EXCEL]

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