D(vrrc^ OL^H ^ ^ BLACK & VEATCH Waste Science, Inc. .s3.»_/—-— 5 4717 Grand Avenue, Suite 500, P.O. Box 30240, Kansas City, Missouri 64112, (913) 339-2900 ' , , _j,'^ .-^/j/^ ^ _ • USEPA/ARCS V Des Moines TCE, 0U4 BVWS Project 71400 BVWS File C.3 November 22, 1994 U.S. Environmental Protection Agency 726 Minnesota Avenue Kansas City, Kansas 66101 Subject: Ecological Risk Assessment Attention: Mr. Glenn Curtis, SPFD Work Assignment Manager • Dear Mr. Curtis: Enclosed you will find a copy of our revised Ecological Risk Assessment for 0U4 of the Des Moines TCE site. Please direct any technical questions to the primary author of the report, Mr. Dane Pehrman, BVWS-Philadelphia, at (215) 928-2203. If you have other project related questions, please call me at (913) 338-6656. Very truly yours, BLACK & VEATCH Waste Science, Inc. Ct^ d.. UJIQ^ Craig A. Willis cawc:\...\ecorep.ltr Enclosure cc: Ms. Joan Dollarhide, USEPA-Cincinnati, w/enclosure Mr. Dane Pehrman, BVWS-Philadelphia, w/o enclosure 30221198 llililil Superfund
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D(vrrc^ OL^H
^
^
BLACK & VEATCH Waste Science, Inc. . s 3 . » _ / — - — 5
4717 Grand Avenue, Suite 500, P.O. Box 30240, Kansas City, Missouri 64112, (913) 339-2900 ' , , _ j , ' ^ . -^ / j /^ ^ _ •
USEPA/ARCS V Des Moines TCE, 0U4
BVWS Project 71400 BVWS File C.3
November 22, 1994
U.S. Environmental Protection Agency 726 Minnesota Avenue Kansas City, Kansas 66101
Subject: Ecological Risk Assessment
Attention: Mr. Glenn Curtis, SPFD Work Assignment Manager
•
Dear Mr. Curtis:
Enclosed you will find a copy of our revised Ecological Risk Assessment for 0U4 of the Des Moines TCE site.
Please direct any technical questions to the primary author of the report, Mr. Dane Pehrman, BVWS-Philadelphia, at (215) 928-2203. If you have other project related questions, please call me at (913) 338-6656.
Very truly yours,
BLACK & VEATCH Waste Science, Inc .
C t ^ d.. UJIQ^ Craig A. Willis
cawc:\...\ecorep.ltr Enclosure
cc: Ms. Joan Dollarhide, USEPA-Cincinnati, w/enclosure Mr. Dane Pehrman, BVWS-Philadelphia, w/o enclosure
30221198
llililil Superfund
ECOLOGICAL RISK ASSESSMENT
for the
DES MOINES TCE-0U4 SITE Des Moines, lowa
Prepared iror:
U.S. Environmental Protection Agency Region Vll - Kansas City, MO
Prepared by:
BLACK & VEATCH WASTE SCIENCE, INC. Philadelphia, PA
November 22,1994
/
•
•
•
Contents Pape N°.
1.0 Problem Formulation 1 1.1 Objectives of the BERA 1 1.2 Scope of the BERA 1 1.3 Chemicals Data Collection and Evaluation 2 1.4 Habitat Evaluation 2
Des Moines TCE Site - 0U4 Ecological Risk Assessment November 2 1 , 1994
Figures and Tables
Figures
Figure 1-1. Sample and Habitat Location Map Figure 1-2. Ecological Conceptual Site Model
Tables
Table 2-1. Aldrin and Dieldrin Exposure Point Concentrations Table 2-2. Ingestion Dose Worksheet for the Beaver Table 2-3. Ingestion Dose Worksheet for the White-Tailed Deer Table 2-4. Ingestion Dose Worksheet for the Mallard
Table 3-1. Measurement Endpoints for Target Species/Communities
Table 4-1. Quotient Indices for Wildlife Table 4-2. Quotient Indices for Benthic Macroinvertebrates
Des Moines TCE Site - 0U4 Ecological Risk Assessment November 2 1 , 1994
1.0 Problem Formulation
A semi-quantitative baseline ecological risk assessment (BERA) has been performed
for Operable Unit 4 (0U4) of the Des Moines TCE site to determine if there is any
present or potential risk to the environment from previous site activities. This evaluation
is an assessment of baseline risk which was developed by evaluating data collected during
the 0U2 RI activities and other subsequent investigations.
1.1 Objectives of the BERA This BERA evaluates the potential risks to the environment due to releases of
contaminants at the site (USEPA, 1992). The general objective of the BERA is lo
provide the information necessary to assist in the decision-making process at remedial
sites. Specific objectives of the BERA include:
• Identify and provide analysis of baseline risks (defined as risks that might exist
if no remediation or institutional controls were applied at the site);
• Provide a basis for determining the cleanup levels of chemicals that will provide
adequate protection of public health or the environment;
1.2 Scope of the BERA The goal of this BERA is to provide information on threats to the natural
environment associated with contaminants or with actions designed to remediate the site.
The BERA is also intended to reduce the inevitable uncertainty associated with
understanding the environmental effects of a site and its remediation, and to give specific
boundaries to that uncertainty. Information provided by the BERA may be used to:
• Decide if remedial action is necessary based on ecological considerations
• Evaluate the potential ecological effects of the remedial action itself
• Provide information necessary for mitigation of the threat
• Design monitoring strategies for assessing the progress and effectiveness of
remediation
• Des Moines TCE Site - 0U4 Ecological Risk Assessment November 2 1 , 1994
• 1.3 Chemicals Data Collection and Evaluation
Ecological chemicals of potential concern (ECOPCs) may often include more
individual chemicals than the human health assessment because the screening criteria for
human health do not apply to ecological receptors.
Analytical data from surface soils and sediments was used to estimate the ecological
risks at the site. The surface soil data was grouped into wetlands data and South Pond
drainage ditch data. Sediment data was only obtained for the sediments within the South
Pond. There were two sediment samples, four wetland surface soil samples, and four
drainage ditch composite surface soils used in this BERA (BVWS, 1994; Miles Corp.,
1994). The development of the ECOPCs is addressed in detail in Section 2.0 of this
BERA.
1.4 Habitat Evaluation The Habitat Evaluation was performed in February 1994 by BLACK & VEATCH
Waste Science, Inc. (BVWS) under a TES 9 contract with the U.S. Environmental
Protection Agency - Region VII (Kansas City) (BVWS, 1994).
The study area included in this Habitat Evaluation report is shown in Figure 1-1.
The study area at the Des Moines TCE site is located within a rounded triangle formed
by railroad tracks encircling an area in the southern portion of the Dico site. This
northern portion of this study area has been developed and consists of Building 4/5, dirt
roads and parking areas, and railroad tracks. The remainder of the study area is largely
undeveloped although it has been impacted by activities at and around the Dico and
DiChem facilities. Five separate types of sub-habitat were observed on the site
Office of Pesticide Programs, Washington DC. EPA/540/9-85/001.
USFWS (U.S. Fish and Wildlife Service), April 1983. Habitat Suitability Index Models:
Beaver, Department of the Interior, Washington DC.
Venman, B.C., and C. Flaga, 1985. "Development of an Acceptable Factor to Estimate
Chronic Endpoints from Acute Toxicity Data". Toxicol. Ind. Health. 1:261-269.
Des Moines TCE Site - 0U4 Ecological Risk Assessment November 2 1 , 1994 2 6
j « v
% V
South Pond Sedi mentis
Forested Wetland Soils
Legend:
Direct Ingestion
- Incidental Ingestion
Figure 1 -2 Conceptual Ecological Model Des Moines TCE - 0U4 Site
Des Moines, lowa
Table 2-1
Aldrin and Dieldrin Concentrations at
Des Moines TCE-0U4 Ecological Risk Assessment
Des Moines, lowa
Chemical Frequency of Delects Minimum Detected Concentration
Maximum Detected Concentration
Average Concentration 1
1 - •• • • Wetland Surface Soils
Pesticides/PCBs (ppm) Aldrin Dieldrin
8/11 8/11
0.002 0.015
9.4 59.0
1.48 8.65
Discharge Ditch Composite Surface Soils 1
Peslicides/PCBs (vvb) Aldrin
1 Dieldrin 3/4 4/4
8.7 640.0
53.0 7,000.0
15.4 3,085.5
South Pond Sediments
Pesticides/PCBs roob^ Aldrin Dieldrin
2/2 2/2
1,500.0 180.0
7,300.0 190.0
4,400.0 185
Notes: 1. Sediment samples used for this evaluation included SED-001, SED-002 (BVWS, 1994). 2. Surface soil samples used for this evaluation included 6, 9, 10, 11, 12, SS-3, SS-4, SS-5, SP-1-, SP-G, SP-H, SS/71-80, SS/81-90, SS-91-100, SS/101-120 (Eckenfelder, 1993; Miles, 1994).
Des Moines TCE Site - 0U4 Ecological Risk Assessment November 2 1 , 1994
^^^^^B
5 ^ § SS d ^ ^
^
Table 2-2 Ingestion Dose Worksheet for the Beaver
Des Moines TCE-0U4 Site Des Moines, lowa
Exposure Equation:
[(TCv * IR) + SIR] * CSw * FI BW * CF
Species Specific Information: Factor Area of Contamination, hectares Home Range, hectares Fraction of Diet from AOC (AOC/HR) Body Weight, Kg Ingestion Rate, g/day (BVV^O.yZ? * 0.577) Soil Ingestion Rate, g/day (BW * 2.4%) Conversion Factor, g/kg Contaminant Concentration in Wetland Soil, mg/kg Soil to Plant Transfer Coefficient, unitless Contaminant Dose, mg/kg-day
Abbreviation AOC HR Fl BW IR SIR CF CSw TCv Dose
Unit Reference 0.30 0.17 1.00 20.00 772.72 18.55 1000.00 varies varies See below
•
Contaminant Specific Information: Contaminant Aldrin Dieldrin
Species Specific Information: Factor Abbreviation Unit Wetland Soil Area of Contamination, hectares AOCw 1.00 Ditch Soil Area of Contamination, hectares AOCd 1.00 Home Range, hectares HR 183.70 Fraction of Diet from Wetland Soil (AOCw/HR) Flw 0.0054 Fraction of Diet from Ditch Soil (AOCd/HR) Fid 0.0054 Body Weight, Kg BW 45.40 Ingestion Rate, g/day IR 1600.00 Soil Ingestion Rate, g/day (BW * 1.0%) SIR 16.00 Conversion Factor, g/kg CF 1000.00 Contaminant Concentration in Wetland Soil, mg/kg CSw varies Contaminant Concentration in Ditch Soil, mg/kg CSd varies Soil to Plant Transfer Coefficient, unitless TCv varies Contaminant Dose, mg/kg-day Dose See below
Reference
Contaminant Specific Information: Contaminant Aldrin Dieldrin
CSy 1.48 8.65
CSd 0.015 3.085
TCv 0.021 0.098
Dose 6.02E-06 2.21 E-04
Table 2-4 Ingestion Dose Worksheet for the Mallard
Des Moines TCE-0U4 Site Des Moines, lowa
Exposure Equation:
[(TCv * VIR) + SIR] * CSw * FI BW*CF
Species Specific Information: Factor Area of Contamination, hectares Home Range, hectares Fraction of Diet from AOC (AOC/HR) Body Weight, Kg Ingestion Rate, g/day Percentage of Vegetation in Diet Vegetation Ingestion Rate, g/day (IR * PV) Soil Ingestion Rate, g/day (BW * 2.0%) Conversion Factor, g/kg Contaminant Concentration in Pond Sediment, mg/kg CSp Soil to Plant Transfer Coefficient, unitless Contaminant Dose, mg/kg-day
Abbreviation AOC HR Fi BW IR PV VIR SIR CF CSp TCv Dose
Unit Reference 0.40 540.00 0.0007 1.03 337.50 30.0% 101.25 6.75 1000.00 varies varies See below
•
Contaminant Specific Information: Contaminant Aidrin Dieldrin
CSp 4.40 0.19
ICy 0.021 0.098
Dose. 2.84E-05 2.24E-06
Table 3-1
Measurement Endpoints for Aquatic and Terrestrial Receptors
Des Moines TCE-0U4 Ecological Assessment
Des Moines, lowa
Chemical
Pesticides
Aldrin
Dieidrin
Aquatic
Endpoint
NOAA
ER-L
Values
NA (0.02)
0.02
Terrestrial Endpoints
Beaver
TRV
(mg/kg-day)
0.001
0.0002
Deer
TRV
(mg/kg-day)
0.001
0.2
Mallard
TRV
(mg/kg-day)
1.04
0.76
Note:
1. NA - NOAA Screening Value is not available
Des Moines TCE Site - OU4 Ecological Risk Assessment November 2 1 , 1994
•
Table 4-1
Quotient Indices for Wildlife Species
Des Moines TCE-0U4 Site
Des Moines, lowa
Species
Beaver
Deer
Mallard
Contaminant
Aldrin
Dieldrin
Aldrin
Dieldrin
Aldrin
Dieldrin
Dose
mg/kg/day
0.00257
0.0408
0.00000602
0.000211
0.0000284
0.0000224
TRV
0.001
0.002
0.001
0.2
1.04
0.76
Effects
LOAEL„, modified to NOAEL b..v„
LOAEL„, modified to NOAEL b,.,„
LOAEL„, modified to NOAEL ^„
LD50^„ modified to NOAELj,„
LD50^,„j modified to NOAEL^,.,^
LD50^,„j modified to NOAEL^,„,
Quotient
Index (Ql)
2.57
20.4
0.006
0.001
0.0000273
0.0000295
ZQI
22.97
0.007
0.0000568
Des Moines TCE Site - 0U4 Ecological Risk Assessment November 2 1 , 1994
•
Table 4-2
Quotient Indices for the Benthic Macroinvertebrate Community of South Pond
Des Moines TCE-0U4 Site
Des Moines, lowa
Spedes
Eknthic Macroinvertebrates
Contaminant
Aldrin
Dieldrin
Sediment
Concentration
(ppb)
4,400
185
NOAA
ER-L
0.02
(NA)
0.02
Effects
Increased benthic mortality,
decreased benthic abundance
Increased benthic mortality,
decreased benthic abundance
Quotient ludex
(Ql)
220,000.00
9,250.00
SQl
229,250.00
Des Moines TCE Site - OU4 Ecological Risk Assessment November 2 1 , 1994
•
UNITED STATES ENVIRONMENTAL PROTECTION AGE OFFICE OF RESEARCH AND DEVELOPMENT
Review of the Draft Ecological Risk Assessment performed on the Des Moines TCE-0U4 site (Des Moines TCE-0U4/Des Moines IA)
W^Joan S. Dollarhide.-/c:'i(.'^ (-'-'•( i ^ Director / I'
Superfund Health Risk Technical Support Center
Glenn Curtis U.S. EPA Region Vll
This memorandum responds to your request for a review of the Draft Ecological Risk Assessment performed on the Des Moines TCE-0U4 site. Please see attached review conducted by Dave Reisman(ECAO) and Chris Cubbison(ECAO). Please contact the Superfund Health Risk Technical Support Center at (513) 569-7300 with any additional questions.
\ ^ Printed on Recycled Paper
•
Attachment
The following is a summary of comments on the Ecological Risk Assessment for Operating Unit 4 of the Des Moines TCE site. The ECAO scientists who reviewed this assessment were Dave Reisman and Chris Cubbison.
This ecological risk assessment is incomplete in a number of ways and cannot be considered to be an ecological risk assessment. At best, it is a wildlife toxicity assessment. An ecological risk assessment should include discussions on population dynamics for one or more species at each trophic level from primary producers (plants) to tertiary (and higher) consumers. It would not be surprising if the ponds were not visited by raccoons feeding on fish and benthic invertebrates. Raccoons could be at greater risk than beavers (reported on in the study) because of the effect of bioconcentration in the food web.
While ecological risk assessments are fairly new, there are some basic ecological principles and draft documentation that could have been used to develop this document. In general, it would have been helpful if the authors had cited sources if standard methods were employed. The following are specific comments:
The report makes use of some new terminology and proposes new safety/uncertainty factors with little or no scientific supporting data and no justification. The Great Lakes Initiative (GLI) terminology (U.S. EPA, 1993) could temporarily fill this need until other Agency guidance is developed. Additional sources such as Glenn Suter's book on Ecological Risk Assessment provides information on some different calculations that can be used to base the risk assessment. EPA/Risk Assessment Forum case studies could also be used to formulate the structure.
It would have been helpful if there was more general background provided. How was the site being used in previous years? How did these levels of aldrin and dieldrin get into wetlands and other areas where you would not expect them? Were these caused from the flood of 1993 or was it due to poor disposal practices?
The discussion of rare or endangered species (Section 1.4.5) fails to discuss whether any were looked for. The question is: Is this habitat used by species that should be there but aren't? In other words, in similar areas, are there endangered species?
Section 1.5.1 states that no plant tissues were sampled for chemical contamination. Since the keystone species discussed in this report were all herbivores, failure to sample plants is a major omission. Estimating plant levels based upon the octanol/water partition coef. is acceptable only where you have
For internal use only. DRAFT - Do not cite or quote. -1-
•
•
supporting studies which prove its validity for each chemical or if there is some major impediment to sampling (such as a lack of standard test method).
To omit contaminated water means to omit two exposure pathways entirely-oral ingestion and dermal exposure. The report must resolve whether it can ignore these pathways because exposure or dose would be minimal. Detailed analysis of the pond was not in the report, yet the conclusion is that the most affected populations are the benthic community of that water body and those that feed on it. Furthermore, aldrin and dieldrin bioconcentrate, so aquatic life (not observed because the pond was frozen) will definitely be affected and as well as all the fish-eating animals. The report already shows the omnivorous mallard being affected by the contaminated benthic community.
There is no apparent discussion of the fate and transport of aldrin and dieldrin. These chemicals are known to undergo bioconcentration in aquatic food chains. There is no evidence that bioconcentration was considered in deriving the hazard evaluation. No fish appear to have been sampled and water concentrations of aldrin and dieldrin are lacking. Is there a risk to piscivorous wildlife (fish-eaters) such as raccoons or kingfishers?
There were no data on the decomposition products (photolysis, hydrolysis, etc.) of the chlorinated pesticides. The report only highlights these two chemicals. What is further difficult to assess is any teratogenic, mutagenic or reproductive effects from these and other chemicals present in the site. This is especially necessary given the bird population and the potential for effects.
The application of uncertainty factors (safety factors in the text) is a reasonable response to issues such as interspecies extrapolation. However, if standard methods are not used, justification should be given for the safety factor selection.
Extrapolation from an LD50 to a NOAEL using a ratio of 500 is unacceptable without a more substantive rationale. Our office studied such ratios and concluded that they were probably not scientifically defensible for protection of human health. Our analysis of ratios developed by Weil et al.(1969), McNamara (1976) and Layton et al. (1987) suggest a factor of 10,000 when estimating NOAELs from LDJQS. Lower ratios cited by the authors were based upon small samples of chemicals. Larger samples cover chemicals with more variability in toxicity and require higher ratios in order to be reasonably sure that the estimated NOAEL encompasses the actual NOAEL. Aldrin and dieldrin are reasonably well studied chemicals. A better estimate of NOAELs might be derived from the peer-reviewed literature.
Finally, little thought seems to have gone into the no-remediation option. Without the fate and transport analysis, it is not possible to predict whether aldrin and dieldrin will be permanently bound in the sediment of whether they are mobile enough
For internal use only. DRAFT - Do not cite or quote. -2-
to threaten wildlife outside the boundaries of the ponds. As stated in the study, remediation of almost any sort will destroy the ponds, at least temporarily. A decision about whether or how to remediate cannot reasonably be based upon the report reviewed here.
References
Layton, D.W. et al. 1987. Reg.Tox.and Pharm. 7:96-112.
McNamara, B.P. 1976. Concepts in Health Evaluation of Commercial and Industrial Chemicals in New Concepts in Safety Evaluation: Advances in Modern Toxicology. Vol.1, Part 1, Hemisphere Pub., Washington.
U.S. EPA. 1993. Water Quality Guidance for the Great Lakes System and Correction; Proposed Rules. 40 CFR Parts 122 et al. Federal Register, Friday, April 16, 1993, 20802-21047.
Weil, CS. et al. 1969. Tox.Appl.Pharmacol. 14:426-431.
For internal use only. DRAFT - Do not cite or quote. -3-
This memorandum r Ecological Risk Assesamer, aee attached review condut Cubblson(ECAO), Please c Center at (513) 569-7300 w,
•RU r? C»f^ f / y '
>A)
\ Draft site. Please
ll Support
Printed on Recyclea Paper
DEC- 2 -94 FRi 15; 16 ECAO-CINCINNAT I FAX NO, 513569"'4T5 P. 02
•
A t tachment
The following ie a summary of commente on the Ecological Risk Assessment for Operating Unit 4 of the Dea Moines TCE site. The ECAO scientists who reviewed this assessment v/ere Dave Reisman and Chris Cubbison.
1/ This ecological risk assessment is incomplete in a number of ways and cannot be considered to be an ecological ri$k aeeessmont. At best, it la a wildlife toxicity aeeeeerrent. A.n ecological risk aaeesament should include discussions on population dynamics for o re or more species at each trophic level from primary producers
^ (plants) to tertiary (and higher) consumers. It would not be surprising if the ponds ^ - were not visited by raccoons feeding on fish and benthic invertebrates. Raccoons
could be at greater risk than beavers (reported on in the study) because of the effect of bioconcentration in the food web.
While ecological risk assessments are fairly new, there are some basic ecological principles and draft documentation that could have been used to develop this document. In general. It would have been helpful if the authors had cited sources if standard methods were employsd. The following are specific comments:
3 , The report makes use cf some new terminology and proposes new safety/uncertainty factors with little or no scientific supporting data and no justification. The Great Lakes Initiative (GLI) terminology (U.S. EPA, 1993) could temporarily fill this need until other Agency guidance is developed. Additional sources such ae Glenn Suter's book on Ecological Risk Assessment provides information on some different calculations thet can be used to base the risk assessment. EPA/Risk Assessment Forum case studies could also be used to formulate the structure.
<j It would have been helpful if there was more general background provided. How was the site being used in previous years? How did these levels of aldrin and dieldrin get into wetlands and other areas where you would not expect them? Were these caused from the flood of 1993 or was it due to poor disposal practices?
^ The discussion of rare or endangered species (Section 1.4.5) fails to discuss whether any were looked for, The question is: Is this habitat used by species that should be there but aren't? In other words, in similar areas, are there endangered species?
^ . Section 1.5.1 states that no plant tissues were sampled for chemical contamination. Since the keystone species discussed in this report were all herbivores, failure to sample plants is a major omission. Estimating plant levels based upon the octanol/water partition coef. ie acceptable only where you have
For internal use only. DRAFT • Do not ci te or quote. -1-
supporting studies which prove its validity for each chemical or if there is some major impediment tc sampling (such as a lack of standard test method).
7, To omit contaminated water means to omit two exposure pathways entirely-oral ingestion and dermal exposure. The report must resolve whether it can Ignore these pathways because exposure or dose would be minimal. Detailed analysis of the pond was not in the report, yet the conclusion is that the most affected populations are the benthio community of that water body and those that feed on It. Furthermore, aldrin and dieldrin bioconcentrate, so aquatic life (not observed because the pond was frozen) will definitely be affected and as well as all the fish-eating animals. The report already shows the omnivorous mallard being affected by the contaminated benthic community.
0 . There is no apparent discussion of the fate and transport of aldrin and dieldrin. These chemicals are known to undergo bioconcentration in aquatic food chains. There is no evidence that bioconcentration was considered in deriving the hazard evaluation. .No fish appear to have been sampled and water concentrations of aldrin and dieldrin are lacking. Is there a risk to piscivorous wildlife (fleh-eaters) such as raccoons or kingfishers?
There were no data on the decomposition products (photolysis, hydrolysis, ' etc) of the chlorinated pesticides. The report only highlights these two chemicals.
What is further difficult to assess is any teratogenic, mutagenic or reproductive effects from these and other chemicals present in the site. This is especially necessary given the bird population and the potential for effects.
Extrapolation from an LD55 to a NOAEL using a ratio of 500 Is unacceptable without a more substantive rationale. Our office studied such ratios and concluded that they were probably not scientifically defensible for protection of human health. Our analysis of ratios developed by Well et al.(1969). IVlcNamara (1976) and Layton et al, (1987) suggest a factor of 10,000 when estimating NOAELs from LDj^s, Lower ratios cited by the authors were based upon small sampies of chemicals. Larger samples cover chemicals with more variability in toxicity and require higher ratios in order to be reasonably sure that the estimated NOAEL encompasses the actual NOAEL. Aldrin and dieldrin are reasonably well studied chemicals. A better estimate of NOAELs might be derived from the peer-reviewed literature.
Finally, little thought seems to have gone Into the no-remedlation option. Without the fate and transport analysis, It is not possible to predict whether aldrin and dieldrin will be permanently bound in the sediment of whether they are mobile enough
•
For Internal uee only. DRAFT • Do not,cite or quote. -2- >
to threaten v/ildiife outside the boundaries of the ponds. As stated in the study, remediation of almost any sort will destroy the ponds, at least temporarily. A decision about whether or how to remediate cannot reasonably be based upon the report reviewed here.
References
Layton, D.W. et al. 1987. Reg.Tox.and Pharm. 7:96-112.
McNamara, B.P, 1976. Concepts In Health Evaluation of Commercial and Industrial Chemicals In New Concepts in Safety Evaluation: Advances in Modern Toxicology. Vol.1, Part 1, Hemisphere Pub., Washington.
U.S. EPA. 1993. Water Quality Guidance for the Great Lakes System and Correction, Proposed Rules. 40 CFR Parts 122 et al. Federal Register, Friday, April 16, 1993, 20802-21047.
For internal use only. DRAFT • Do not cite or quote. -3-
•
BLACK & VEATCH Waste Science, Inc. Philadelphia Office DEC 1 3 ]994
SPFD BRAIICH MEMORANDUM REGION VII
USEPA - Region VII B&V Project 71400.032 Des Moines TCE - 0U4 B&V File PHL Revisions to WTA (formerly BERA) December 9, 1994 based on EPA Cincinnati Comments
To: Glenn Curtis
From: Dane G. Pehrman
I have completed the revisions to the Wildlife Toxicity Assessment (formerly known as the Baseline Ecological Risk Assessment) based on our discussion of comments provided by EPA - Cincinnati. I have summarized our response to each comment and point out changes to the document as follows:
Comment #1 In response to this comment, we have revised the title of the document to be a
Wildlife Toxicity Assessment. This comment is specifically related to the scope of the project and since our intent was not to prepare a full-blown EA, we are comfortable with this change. In response to the second part of this comment, raccoons were excluded from this document due to a lack of data to even estimate food-chain ingestion. This is discussed in Section 1.6.1 (p. 9) and again in 4.3.1 (p. 20).
Comment #2 No response. As we discussed this comment was a general opinion.
Comment #3 Information concerning the use and references for safety factors is provided in
Section 3.3 of the document (pp. 14 and 15). Most other referenceable points are referenced in the document. The overall structure of this document is based on EPA's Risk Assessment Forum.
Comment #4 No response. This information will be part of the overall Rl.
Comment #5 No response. We have referenced the FWS memorandum in the uncertainties
section; however, no T&E species were specifically searched for. At this point, this does not seem particularly important since the response at this site is driven by the stressor, not the receptors present (or not). Tracy Copeland at FWS indicated that they
5.0 Conclusions and Ecological Significance
The findings of the WTA will be summarized in this section. The summary will
discuss the relevance of the measurement endpoints to the developed assessment
endpoints.
5.1 Aquatic Receptor Measurement Endpoints The measurement endpoint used to assess the aquatic habitat is decreased viability
of the benthic macroinvertebrate community. The habitat evaluation indicated that there
is an aquatic habitat, South Pond, present at the site.
There is significant potential for decreased viability of the benthic community as a
result of the high concentrations of aldrin and dieldrin in the pond sediments, which
exceeded the NOAA ER-L and ER-M measurement endpoints. Aldrin, which accounts
for most of the Ql to receptors in this habitat, is not only potentially toxic to benthic
organisms through a direct exposure pathway, but as indicated by its high BCF value, has
a high potential to bioconcentrate in aquatic organisms. Therefore, other organisms that
feed upon these organisms will be exposed to pesticides via this indirect exposure
pathway.
Suggested remedial goals for aldrin and dieldrin concentrations in the pond sediments
that would be protective of the benthic community would range from 0.2 ppb to 8 ppb
for both chemicals.
5.2 Terrestrial Receptor Measurement Endpoints The measurement endpoint used to assess the terrestrial environment is decreased
viability of terrestrial wildlife species. The habitat evaluation indicated that there are
significant populations of deer on the site. Additionally, beaver is known to be present
at the shoreline of South Pond and habitat is present for waterfowl.
There was little apparent risk to the three terrestrial endpoints evaluated at the site
from aldrin and dieldrin concentrations in wetland soils and the drainage ditch. These
chemical concentrations, when evaluated to determine the daily dose for each receptor,
were below the chemical-specific TRVs.
Des Moines TCE-OU4 - Ecological Risk Assessment December 9, 1994 2 2
be important contributors of contaminant exposure and have not been evaluated in this
WTA. As a result, the risk assessment section may underestimate ecological risks.
4.3.3 Ecological Effects Assessment Uncertainty The NOAA screening values were developed using data from freshwater, estuarine,
and marine environments. Therefore, their applicability for use to evaluate potential
effects to aquatic receptors from aldrin and dieldrin in freshwater habitats must be
evaluated on a chemical-specific basis because of differences in both the toxicity of the
individual chemicals to freshwater and saltwater organisms, and the bioavailability of
contaminants in the two aquatic systems. Additionally, the lack of a NOAA ER-L
screening value for aldrin resulted in the use of the dieldrin ER-L. The toxicity and
toxicological effects of aldrin is likely to be different from dieldrin, even though they are
similar chemicals.
The development of TRVs is an essential component of the wildlife toxicity
assessment since these become the benchmark for risk determination. The use of a
laboratory rat LOAEL to develop beaver and deer TRVs does not adequately address
differences in the habits, anatomy, and physiology of these species. Additionally, the
habitat conditions are vastly different between that of a laboratory animal and that of the
wild deer and beaver. There is a larger uncertainty in the use of LDJQS to develop deer
and mallard TRVs since it is difficult to extrapolate these to an acute toxicity threshold.
An attempt to compensate for this uncertainty is made by the use of safety factors
to convert LD50S, LOAELs, and NOAELs to TRVs specific to each v/ildlife species. One
of the safety factors which is applied is recommended by the USEPA (1986c) for use in
extrapolating LDJQS to an acute toxicity threshold. The remaining safety factors have been
developed after reviewing species-specific acute and chronic toxicity data or are based on
best professional judgement.
4.4.4 Wildlife Toxicity Assessment Uncertainty The uncertainties present in the exposure assessment and ecological effects
assessment are compounded in the risk assessment, which compares the findings of the
exposure assessment to toxicity values developed in the ecological effects assessment.
There was one chemical in South Pond sediments (aldrin) that did not have a NOAA ER-
L screening value. Therefore, there was uncertainty in the development of the Ql for the
aquatic receptors being evaluated.
Des Moines TCE-OU4 - Ecological Risk Assessment Decembers, 1994 21
•
4.3.1 Endpoint Comparison Uncertainty There is uncertainty in the ecological endpoint comparison. The values used in the
ecological endpoint comparison (the NOAA ER-L screening values, and the TRVs) are
set to be protective of a majority of the potenti.il receptors. The majority of wildlife
species, populations and communities are not evaluated directly as part of this WTA.
There will be some species that will not be protected by the values because of their
increased sensitivity to the chemicals. Additionally, the toxicity of chemical mixtures is
not well understood. The toxicity information used in the wildlife toxicity assessment for
evaluating risk to ecological receptors is for individual chemicals. Chemical mixtures can
affect the receptors very differently than the individual chemicals.
Other uncertainties lie in the selection of species as surrogates for trophic feeding
groups. Due to a lack of environmentsd sample data for fish and water, it was not
possible to estimate the concentration of aldrin and dieldrin in fish. Therefore, the effects
of these chemicals on piscivores was not evaluated in this WTA. As a result, actual risks
from contamination at the site may be underestimated.
4.3.2 Exposure Assessment Uncertainty In the Exposure Assessment, a number of conservative assumptions were made. The
most significant of these conservative assumptions concerns the use of the CDI models
to evaluate decreased viability to terrestrial receptors. The most critical of the factors
used in this exposure calculations include: (1) the estimation of the soil-to-plant transfer
coefficients (TCv) of contaminants and (2) The use of average concentrations in soil at
the exposure point concentrations.
The TCv is an estimate of the relationship between soil concentrations and root
uptake and may not adequately estimate the contaminant concentrations in the edible
portion of the plant.
The use of an average concentration in the media evaluated may over estimate the
actual area of contamination Jind does not permit the location of risk-based "hot spots"
of contamination. Additionally, the exposure point concentrations are based on a very
low number of overall samples, which may not indicate conditions over the entire area
of concern. It is possible that average values may overestimate or underestimate the
ecological risks at the site from the evaluated media.
Other key exposure uncertainties are inherent in the CDI models developed since they
do not account for invertebrate ingestion, dermal adsorption, and inhalation. These may
Des Moines TCE-OU4 - Ecological Risk Assessment December 9, 1994 2 0
the TRVs derived for the mallard. As shown in Table 4-1, the quotient indices for aldrin
and dieldrin in the mallard are both below unity. These QIs would suggest little potential
risk to the mallard or waterfowl from aldrin and dieldrin in the South Pond sediments.
4.1.3 Benthic Macroinvertebrate Community Potential risk to the benthic macroinvertebrate community of South Pond was
estimated by comparing the average concentrations of sediment in South Pond to the
NOAA ER-L screening values to determine if they are exceeded. The ratios of the
maximum detected concentration to the NOAA ER-L screening values were calculated
for aldrin and dieldrin, resulting in a Ql. As shown in Table 4-2, the quotient indices for
aldrin and dieldrin in the South Pond sediments are 220,000 and 9,250, respectively.
These QIs would suggest a critically significant risk to the benthic habitat from both
aldrin and dieldrin in pond sediment.
Comparing the sediment concentrations of aldrin and dieldrin in the South Pond to
the NOAA ER-M screening value results in QIs of 550 and 23, respectively. The ER-M
screening value represents the median concentration that caused effects to tested benthic
organisms.
The effects of aldrin and dieldrin at the detected concentrations in South Pond may
have serious impacts to aquatic habitat viability. These concentrations may result in the
decrease in viability of the benthic community in the South Pond, which, in turn, would
result in loss of food sources for waterfowl, fish, and other wildlife.
4.2 Risks to Terrestrial Wildlife 4.2.1 White-Tailed Deer
Potential risk to the white-tailed deer inhabiting the uplands and wetlands adjacent
to South Pond was estimated by comparing the estimated daily dose of aldrin and dieldrin
(in wetland soils and drainage ditch soils) with the TRVs derived for the deer. As shown
in Table 4-1, the quotient indices for aldrin and dieldrin in the deer are below unity.
These QIs would suggest little risk to the deer from aldrin and dieldrin.
4.3 Uncertainty There are a number of points in the decision making process of an wildlife toxicity
assessment where there are inherent uncertainties. As a result, it is often necessary to
make certain assumptions to facilitate the preparation of the risk assessment. When data
is lacking, conservative assumptions are made to be protective of the environment.
include the Des Moines TCE-0U4 drainage ditch. The measurement endpoint, to be used
in evaluating the effects of ECOPCs on the viability of the target wildlife species, will
include Toxicity Reference Values (TRV) developed from No-Observable-Adverse-Effect-
Level (NOAELs) or Lowest-Observable-Adverse-.Effect-Levels (LOAELs) obtained from
the Integrated Risk Information System (IRIS, 1993) or other toxicological data in the
literature. Total exposure of the wildlife species of concern (white-tailed deer) to
ECOPCs in surficial soils will be determined by estimating the chronic daily intake (CDI)
dose. This CDI will be compared to the TRV to determine if the ECOPC concentrations
are protective of species viability for the wildlife species of concem.
Des Moines TCE-OU4 - Ecological Risk Assessment December 9, 1994 10
Forested Wetlands
Herbivorous Species Viability
Drainage Ditch
Herbivorous Species Viability
Loss of species and community viability is defined for the purposes of this
investigation as the loss of any species or group of species due to the direct or indirect
effects of a release of substances from the site. There is a potential for adverse effects
to terrestrial piscivores (raccoon and kingfishers); however, there is insufficient sample
data to estimate the exposure to these species.
1.6.2 Measurement Endpoints Measurement endpoints are those used in the field to approximate represent or lead
to the assessment endpoint. Because the direct measurement endpoint of habitat diversity
is incapable of being protective of the habitat until after the quantifiable degradation has
occurred, it proves an inadequate endpoint for the purposes of this study. Rather, the
most convenient expression of risk should be a probability that such an event will occur
or a simple quotient index (Ql) developed from a comparison of exposure doses or
concentrations to the toxicity information available for each chemical. This toxicity
information will be the measurement endpoint for the WTA.
1.6.2.1 Aquatic Receptor Measurement Endpoints. Aquatic habitats present include the forested wetland and South Pond. The measurement endpoint to be used in
evaluating the effects of ECOPCs on the viability of the benthic community will be the
NOAA Effects Range-Low (ER-L) screening values for aquatic sediments (USEPA,
1991). The maximum concentration of ECOPCs in sediments will be compared to the
measurement endpoint to determine if the concentrations of ECOPCs are protective of
total benthic community viability for South Pond.
The measurement endpoint, to be used in evaluating the effects of ECOPCs on the
viability of the target wildlife species, will include Toxicity Reference Values (TRV)
developed from No-Observable-Adverse-Effect-Level (NOAELs) or Lowest-Observable-
Adverse-Effect-Levels (LOAELs) obtained from the Integrated Risk Information System
(IRIS, 1993) or other toxicological data in the literature. Total exposure of the wildlife
species of concern (beaver, white-tailed deer, and the mallard) to ECOPCs in surficial
Des Moines TCE-OU4 - Ecological Risk Assessment December 9, 1994 9
o
was evidence observed on trees that the beaver feeds in this area. The beaver may
also feed on roots and tubers of emergent vegetation growing around South Pond.
1.5.1.2.2 White-tailed deer. The white-tailed deer (Odocoileus virginianus), a
herbivorous, terrestrial mammal, was used to determine the exposure of terrestrial
herbivores to contaminated sediments in the Forested Wetland. The white-tailed deer
may spend a portion of its time feeding on shrubs, grasses, and leaves in wetlands
and uplands. There was evidence of an abundant deer population observed during
the site investigation.
1.5.1.3 Drainage Ditch. The Drainage Ditch is part of the Upland Open Field habitat,
which is primarily a carnivore/grazer habitat; however, there are no known carnivorous
species present on the site. These areas, in the case of this site, are more accurately
represented by the grazer food chain. Accordingly, the white-tailed deer was selected as
wildlife species of concern subject to exposure to contaminated ditch soils. The habitat
requirements and habitat area discussed in Section 1.5.1.2.2.
1.6 Endpoints The ecological significance of the various habitats and wildlife species of concern
will be examined and appropriate goals or assessment endpoints for that value will be
determined. After determining the appropriate assessment endpoints, functional
measurement endpoints will be chosen to represent these assessment endpoints.
1.6.1 Assessment Endpoints Assessment endpoints are those describing the effects that drive decision making,
such as reduction of key populations or disruption of community structure. Assessment
endpoints for an wildlife toxicity assessment must be capable of being represented by
quantifiable measurement endpoints. They must also be protective of the value of the
various habitats of concern. With this in mind, the assessment endpoints chosen for the
Des Moines TCE-0U4 Superfund Site are:
South Pond
Omnivorous Species Viability
Macroinvertebrate Community Viability
Des Moines TCE-OU4 - Ecological Risk Assessment December 9, 1994
For vegetation, the amount of a contaminant can be estimated based on the soil or
sediment concentration and the chemical properties of each particular chemical. The
vegetation bioconcentration factor is inversely proportional to the square root of the
octanol-water coefficient for each ECOPC (Travis, 1988).
A graphical representation of the relationship between the contaminated surface soils
and sediments and the wildlife species of concem is presented in the ecological
conceptual model shown in Figure 1-2.
1.5.1.1 South Pond. The South Pond is a generally stagnant aquatic habitat represented
by both grazer and detritus food chains. The detritus food chain will be evaluated by
direct comparison of contaminant concentrations in sediments to benthic toxicity data.
The mallard, an omnivore representing the grazer food chain, will be used to model
exposure to contaminated South Pond sediments.
1.5.1.1.1 Mallard. The mallard (Anas platyrhynchos), an omnivorous bird, will be
used to determine the exposure of omnivores to contaminated sediments and
vegetation in South Pond (EPA, 1993). The mallard is commonly found in ponds,
lakes, and marshes (Bull and Farrand, 1988). The mallard feeds primarily on green
vegetation, aquatic roots and tubers, seeds, snails, and benthic invertebrates by
dabbling and filtering through soft sediments (EPA, 1993); however, only vegetation
ingestion and incidental soil ingestion were examined in this WTA. There is limited
information addressing invertebrate and insect uptake and bioaccumulation of
contaminants; therefore, an accurate determination of the contaminate dose from this
portion of the diet would not be practical.
1.5.1.2 Fores ted Wetlands. The Forested Wetland is primarily carnivore/grazer
habitat; however, there are no known carnivorous species present on the site. These areas,
in the case of this site, are more accurately represented by the grazer food chain.
Accordingly, the beaver and the white-tailed deer were selected as wildlife species of
concern subject to exposure to contaminated surface soils in the wetland.
1.5.1.2.1 Beaver. The beaver (Castor canadensis), a herbivorous, semi-aquatic
mammal, will be used to determine the exposure of herbivores to contaminated
sediments in the Forested Wetland. One beaver lodge was observed in the
southeastern portion of South Pond, in the Forested Wetland area. Additionally, there
Des Moines TCE-OU4 - Ecological Risk Assessment / December 9, 1994 7
•
1.5 Exposure Pathway and Receptor Analysis A migration pathway is defined, for the purpose of this WTA, as a route by which
a contaminant may be transported from the site to the exposure point for a particular
wildlife species or habitat of concern. An exposure route is defined, for the purposes of
this WTA, as the means by which contaminants in a specific media enter a wildlife
species of concem.
Contaminants from the Des Moines TCE site have been shown to have migrated to
the South Pond, Forested Wetlands, and the Drainage Ditch from South Pond based on
the analysis of surface soil and sediment samples (BVWS, 1994; Miles, 1994).
The exposure routes for contaminants in these habitats to representative wildlife
species may include: 1) ingestion, 2) respiration, and 3) absorption. Ingestion of
contaminants occurs when an organism ingests contaminated food, water, or other
contaminated media through direct or incidental ingestion. Respiration of contaminants
occurs when an organism absorbs contaminants through the respiratory organs such as the
skin, gills, or lungs. Contaminants are also absorbed directly through the skin, eyes, and
other mucous membranes.
Data are lacking concerning the inhalation and absorption exposure and uptake rates
for chemicals in wildlife species. Therefore, in this WTA, the exposure of wildlife to
contaminants will be solely based in the direct and incidental ingestion of contaminated
media and food by the wildlife species of concern. Since surface water samples were not
evaluated in this WTA, direct and incidental ingestion of contaminated water will not be
assessed in this WTA. As a result of these factors, the WTA will only address the direct
and incidental ingestion of contaminated sediments from each habitat, and may
underestimate the overall risks to those species of concern.
1.5.1 Exposure to Species/Habitats of Concern Based on the findings of the habitat evaluation and the environmental analytical data
available at the site, there were three habitats of concern evaluated in this WTA including
the South Pond, the Forested Wetlands, and the Drainage Ditch. The potential exposure
to actual or surrogate species indicative of the most critical trophic feeding groups was
modelled for each habitat of concern.
No samples of vegetation were analyzed, therefore, concentrations of ECOPCs in
these organisms are unknown. However, as essential points of potential ECOPC exposure
in the food chain, it becomes essential to predict the concentrations of ECOPCs in these
organisms based on the known sediment concentrations.
Des Moines TCE-OU4 - Ecological Risk Assessment j December 9, 1994 6
Pond. There were no tracks or recent signs of beaver in the study area. Beaver eat bark
and small twigs of maples and cottonwood, both species common near the beaver dam.
Songbirds were heard in the upland forests and forested wetlands within the study
area. Individual species could not be identified during the habitat evaluation. Songbirds
generally feed on insects and the seeds of herbaceous vegetation. There were no
songbirds observed or heard in the open field or emergent wetland areas, probably due
to a lack of cover.
Five to seven American crows were observed in the eastern forest areas, roosting in
the canopies of cottonwood trees. Crows eat earthworms, insects, agricultural crops, and
herbaceous seeds; although they will occasionally eat anything available. American crows
were not observed in the other habitats within the study area.
The tracks of a housecat were observed in the open field habitat, from the urban areas
to the north under the fence, and onto the Building 4/5 site. These tracks led to the
building itself, which may indicate that a family of feral cats is present at the site. Feral
cats generally feed on small rodents and birds. The presence of feral cats at the site may
be used to infer the presence of these prey animals at the site.
A flock of Canada geese were observed flying over the site. Canada geese usually
utilize pond and lake habitats, where they feed on leaves and tubers of emergent wetland
vegetation. The South Pond area may provide suitable grazing and resting habitat for
flocks of geese.
1.4.5 Rare, Threatened, and Endangered Species
Information collected during the site investigations did not indicate the presence of
any threatened or endangered species on or near the site. No threatened or endangered
species were observed during the site investigations (BVWS, 1994).
Des Moines TCE-OU4 - Ecological Risk Assessment December 9, 1994
species dominant within this area include Japanese knotweed (Polygonum cuspidalum),
blackberry (Rubus sp.), wild rose (Rosa sp), and grasses (Poacea). There was visible
evidence that this area is highly utilized by a large deer herd as a feeding, breeding, and
resting area.
The second large block of upland forest is located along the southwestern boundary
of the study area. The overstory in this upland forest was dominated by silver maple, red
maple (Acer rubrum), sugar maple (Acer saccharum), white ash, American elm, and black
cherry (Prunus serotina). The dominant shrub, sapling, and vine species include
American elm and silver maple saplings and grape. There were no herbaceous species
observed within this area.
1.4.3.2 Upland Open Field. There was one large area of upland open field located
west and south of Building 4/5 and a small strip east and south of Building 4/5. These
areas were completely void of trees, saplings, and shrubs, and contained only herbaceous
species. These species included foxtail grass (Setaria sp.), and unidentified grasses. A
dry drainage channel runs from north to south along this habitat at its eastern boundary.
1.4.4 Wildlife Usage
Wildlife observed or inferred on or near the study area included white-tailed deer
Open Field. The location of this habitat is shown in Figure 1-1.
The entire study area appears to have been impacted by the widespread flooding that
occurred during the summer months of 1993. Flood marks, suspended vegetative
material, and an oily film were observed at a uniform elevation on vegetation throughout
the study area. The height of this flood line varied from four to over ten feet, depending
on the ground elevation. This flood may have caused additional contamination from off-
site sources, shifting of contamination on the site, and loss or change of ecological
habitat.
Des Moines TCE-OU4 - Ecological Risk Assessment December 9, 1994
1.0 Problem Formulation
A semi-quantitative baseline wildlife toxicity assessment (WTA) has been performed
for the Des Moines TCE-0U4 site to determine if there is any present or potential risk
to the environment from previous site activities. This evaluation is an assessment of
baseline risk which was developed by evaluating data collected during the RI and other
previous investigations.
1.1 Objectives of the WTA This WTA evaluates the potential risks to the environment due to releases of
contaminants at the site (USEPA, 1992). The general objective of the WTA is to provide
the information necessary to assist in the decision-making process at remedial sites.
Specific objectives of the WTA include:
• Identify and provide analysis of baseline risks (defined as risks that might exist
if no remediation or institutional controls were applied at the site);
Provide a basis for determining the cleanup levels of chemicals that will provide
adequate protection of public health or the environment;
1.2 Scope of the WTA The goal of this WTA is to provide information on threats to the natural environment
associated with contaminants or with actions designed to remediate the site. The WTA
is also intended to reduce the inevitable uncertainty associated with understanding the
environmental effects of a site and its remediation, and to give specific boundaries to that
uncertainty. Information provided by the WTA may be used to:
• Decide if remedial action is necessary based on ecological considerations
Evaluate the potential ecological effects of the remedial action itself
• Provide information necessary for mitigation of the threat
• Design monitoring strategies for assessing the progress and effectiveness of
remediation
Des Moines TCE-OU4 - Ecological Risk Assessment December 9, 1994 1
Figures and Tables
Figures
Figure 1-1. Sample and Habitat Location Map Figure 1-2. Ecological Conceptual Site Model
Tables
Table 2-1. Aldrin and Dieldrin Exposure Point Concentrations Table 2-2. Ingestion Dose Worksheet for the Beaver Table 2-3. Ingestion Dose Worksheet for the White-Tailed Deer Table 2-4. Ingestion Dose Worksheet for the Mallard
Table 3-1. Measurement Endpoints for Target Species/Communities
Table 4-1. Quotient Indices for Wildlife Table 4-2. Quotient Indices for Benthic Macroinvertebrates
•
Des Moines TCE-OU4 - Ecological Risk Assessment December 9, 1994
Des Moines TCE-OU4 - Ecological Risk Assessment December 9, 1994
FINAL
WILDLIFE TOXICITY ASSESSMENT
for the
DES MOINES TCE-OU4 SITE
Des Moines, lowa
Prepared for:
U.S. Environmental Protection Agency Region Vll - Kansas City, MO
Prepared by:
BLACK & VEATCH WASTE SCIENCE, INC. Philadelphia, PA
December 9, 1994
BLACK & VEATCH Waste Science, Inc. Philadelphia Office
MEMORANDUM Page 3
USEPA - Region Vll B&V Project 71400.032 Des Moines TCE - 0U4 December 9, 1994 Revisions to WTA (formerly BERA) based on EPA Cincinnati Comments
Comment #12 We have referenced the FWS site investigation memorandum which discussed
potential remedial alternatives in Section 5.0 of the WTA. We feel this provides some more support for the discussions in this section.
Hopefully, we have sufficiently addressed all of EPA-Cincinnati's comments to your level of confidence. If you have any questions, please feel free to call me at 215/928-2203.
cc Craig Willis, BVWS-KC
BLACK & VEATCH Waste Science, Inc. Philadelphia Office
MEMORANDUM Page 2
USEPA - Region VII B&V Project 71400.032 Des Moines TCE - 0U4 December 9, 1994 Revisions to WTA (formerly BERA) based on EPA Cincinnati Comments
have no records indicating T&E on the site, but there may be better records at the local State Heritage office.
Comment #6 No response. Given the semi-quantitative nature of this WTA, we feel that the
use of the octanoiwater coefficient is sufficient to estimate plant uptake.
Comment #7 We have not discussed the inhalation exposure oral or dermal exposure to water
due to (1) a lack of water data with any "hits" for aldrin and dieldrin, (2) a lack of scientific data to quantify the dermal exposure and inhalation pathways. Additional clarifying text has been added to Section 2.3 (p. 12) to address this comment.
Comment #8 The issue of risks to piscivores was discussed and addressed in the response to
Comment #2. Bioconcentration of chemicals is generally addressed in Section 5.4 (p. 23). Fate and transport of aldrin and dieldrin will be addressed in the RJ.
Comment #9 No response. Decomposition products will be addressed in the fate and
transport discussions in the RI.
Comment #10 No response. We have used an interspecies safety factor of 5. In the report, we
have justified our rationale for this factor. The references cited in this suggest a safety factor of 10. In terms of 'order of magnitude" there is no significant difference in the conclusions by changing this value.
Comment #11 No response. We feel that the use of a NOAEL derivation factor from a LD50
of 500 is referenceable and defensible. The reference is cited in the report.
•
5.3 General Conclusions In general, the QIs for the benthic macroinvertebrate community of South Pond are
very high, based on the concentrations of aldrin and dieldrin in South Pond sediment.
There appears to be little risk posed by the chemical concentrations in the wetlands
surface soils and drainage ditch surface soils.
The ecological effects assessment indicates that the concentrations of aldrin and
dieldrin present in the South Pond sediment may cause an increase in mortality to benthic
species and decrease abundance and diversity of benthic species.
5.4 Recommendations The conclusions of this WTA seem to suggest that there may be significant ecological
risks associated with portions of this site. Thej:e risks are significant enough that remedial
activities may be required to be protective of the environment; however, remedial
activities in the wetland and South Pond would physically alter or eliminate the habitat
it is intended to remediate.
The maintenance of the status quo will continue to allow aldrin and dieldrin, which
are both bioaccumulative, to persist in the food chain and would not be protective of fish
and wildlife (FWS, 1994). Therefore, available remedial options should reduce or
eliminate the exposure threat to contaminated sediment.
One possible remedial option may include de-watering of the pond and removal of
the contaminated sediments. This option would allow the pond to become reestablished
with a benthic community and possibly enhance the surrounding habitat. However,
excavation of sediments may result in the release of chemicals into the surrounding
environment, which may be detrimental to fish and wildlife (FWS, 1994).
Another option may involve the de-watering of the pond and covering of the
sediments with clean fill. This would also allow reestablishment of the pond habitat and
would prevent any future impacts to fish and wildlife (FWS, 1994).
Other potential options may include the filling of the South Pond, thus eliminating
the exposure risk and the habitat. This alternative would probably have a negative effect
on the surrounding wetlands, which are partially dependant on the surface water provided
by the pond.
Des Moines TCE-OU4 - Ecological Risk Assessment December S, 1994 23
6.0 References
BVWS (BLACK & VEATCH Waste Science, Inc.), March 1994. Data Report for South
Pond Sediment Samples SED-001 and SED-002.
BVWS (BLACK & VEATCH Waste Science, Inc.), March 1994. Des Moines TCE 0U4
Draft Habitat Evaluation Report - South Pond Study Area.
Bull and Farrand, 1977. The Audobon Society Field Guide to North American Birds -
Eastern Region, Alfred Knopf, New York, NY.
Burt, 1996. A field Guide to the Mammals of America North of Mexico, Houghton-
Mifflin Company, Boston, MA.
Dee, J.C. November 1991. "Methodology for Assessing Potential Risks To Deer
Populations: A Case Study at a Superfund Site." Paper presented at the 1991 Annual
Meeting of the Society of Environmental Toxicology and Chemistry. Abstract No. 426.
FWS (U.S. Department of the Interior, Fish and Wildlife Service). Site Visit Report of
Investigation at the Des Moines TCE site - South Pond in memorandum to the Regional
Environmental Officer from the Field Supervisor, August 4, 1994.
HEAST, March 1993. Health Effects Assessment Summary Tables. Office of Research
and Development. Office of Emergency and Remedial Response. U.S. Environmental
Protection Agency.
Howard, 1991. Handbook of Environmental Fate and Exposure Data for Organic
Chemicals. Volume III - Pesticides, Lewis Publishers, Celsea, MI.
IRIS. August 1993. Integrated Risk Information System. Accessed through Chemical
Office of Pesticide Programs, Washington DC. EPA/540/9-85/001.
USFWS (U.S. Fish and Wildlife Service), April 1983. Habitat Suitability Index Models:
Beaver, Department of the Interior, Washington DC.
Venman, B.C., and C. Flaga, 1985. "Development of an Acceptable Factor to Estimate
Chronic Endpoints from Acute Toxicity Data". Toxicol. Ind. Health. 1:261-269.
Des Moines TCE-OU4 - Ecological Risk Assessment December S, 1SS4 25
i r ' A i V J Forested Wetland Habitat
] Upland Open Field/Dirt Roads
K ^ J y ]] High Deer Concentration Area
^ — i t^ Observed Deer Paths
^ B Beaver Dam
^ Sediment Samples
f Habitat Data Recording Point
Habitat and Wildlife Location Map Des Moines TCE 0U4 Site - South Pond
BLACK & VEATCH Woste Science, Inc. 601 Walnut Street. Philodelphio. PA 10106
Habitat Evaluation 0U4 - South Pond Area
Des Moines, PoII< County, lowa
iiliiiiffliiS^
Legend:
Direct Ingestion
Incidental Ingestion
Figure 1-2 Conceptual Ecological Model Des Moines TCE - 0U4 Site
Des Moines, Iowa
Table 2-1
Aldrin and Dieldrin Concentrations at
Des Moines TCE-0U4 Wildlife Toxicity Assessment
Des Moines, lowa
Chemical Frequency of Detects Minimum Detected Concentration
Maximum Detected Concentration i
Average Concentration
Wetland Surface Soils
Pesticides/PCBs fppb) Aldrin Dieldrin
4/4 4/4
1.4 1.4
62.6 62.6
22.0 22.0
Di.scharge Ditch Composite Surface Soils
Pesticides/PCBs (ppb) Aldrin Dieldrin
3/4 4/4
8.7 640.0
53.0 7,000.0
15.4 3,085.5
South Pond Sediments
Pesticides/PCBs fppb) Aldrin Dieldrin
2/2 2/2
1,500.0 180.0
7,300.0 190.0
Notes: 1. Sediment samples used for this evaluation included SED-001, SED-002 (BVWS, 1994). 2. Surface soil samples used for this evaluation included 6, 9, 10, 11, SS/71-80, SS/81-90, SS-91-100, SS/101-120 (Mil
4,400.0 185
CS, 1994).
Des Moines TCE-OU4 - Ecological Risk Assessment December S, 19S4
Table 2-2 Ingestion Dose Worksheet for the Beaver
Des Moines TCE-0U4 Site Des Moines, lowa
Exposure Equation:
[(TCv * IR) + SIR] * CSw * FI BW * CF
Species Specific Information: Factor Area of Contamination, hectares Home Range, hectares Fraction of Diet from AOC (AOC/HR) Body Weight, Kg Ingestion Rate, g/day (BW'^0.727 * 0.577) Soil Ingestion Rate, g/day (BW * 2.4%) Conversion Factor, g/kg Contaminant Concentration in Wetland Soil, mg/kg Soil to Plant Transfer Coefficient, unitless Contaminant Dose, mg/kg-day
Alsbrevigtion AOC HR Fl BW IR SIR CF CSw TCv Dose
Unit 0.30 0.17 1.00 20.00 772.72 18.55 1000.00 varies varies See belov^
Reference
Contaminant Specific Information: Contaminant Aldrin Dieldrin
Species Specific Information: Factor Wetland Soil Area of Contamination, hectares Ditch Soil Area of Contamination, hectares Home Range, hectares Fraction of Diet from Wetland Soil (AOCw/HR) Fraction of Diet from Ditch Soil (AOCd/HR) Body Weight, Kg Ingestion Rate, g/day Soil Ingestion Rate, g/day (BW * 1.0%) Conversion Factor, g/kg Contaminant Concentration in Wetland Soil, mg/kg Contaminant Concentration in Ditch Soil, mg/kg Soil to Plant Transfer Coefficient, unitless Contaminant Dose, mg/kg-day
Abbreviation AOCw AOCd HR Flw Fid BW IR SIR CF CSw CSd TCv Dose
Contaminant Specific Information: Contaminant Aldrin Dieldrin
CSw 1.48 8.65
CSd 0.015 3.085
TCv 0.021 0.098
Dose 6.02E-06 2.21 E-04
Table 2-4 Ingestion Dose Worksheet for the Mallard
Des Moines TCE-0U4 Site Des Moines, lowa
Exposure Equation:
[(TCv * VIR) + SIR] * CSw * FI BW * CF
Species Specific Information: Factor Area of Contamination, hectares Home Range, hectares Fraction of Diet from AOC (AOC/HR) Body Weight, Kg Ingestion Rate, g/day Percentage of Vegetation in Diet Vegetation Ingestion Rate, g/day (IR * PV) Soil Ingestion Rate, g/day (BW * 2.0%) Conversion Factor, g/kg Contaminant Concentration in Pond Sediment, mg/kg CSp Soil to Plant Transfer Coefficient, unitless Contaminant Dose, mg/kg-day
Abbreviation AOC HR Fl BW IR PV VIR SIR CF CSp TCv Dose
Unit Reference 0.40 540.00 0.0007 1.03 337.50 30.0% 101.25 6.75 1000.00 varies varies See below
Contaminant Specific Information: Contaminant Aldrin Dieldrin
CSB
4.40 0.19
TCv 0.021 0.098
Dose 2.84E-05 2.24E-06
Table 3-1
Measurement Endpoints for Aquatic and Terrestrial
Receptors
Des Moines TCE-0U4 Ecological Assessment
Des Moines, lowa
Chemical
Pesticides
Aldrin
Dieldrin
Aquatic
Endpoint
NOAA
ER-L
Values
NA (0.02)
0.02
Terrestrial Endpoints
Beaver
TRV
(mg/kg-day)
0.001
0.0002
Deer
TRV
(mg/kg-day)
0.001
0.2
Mallard
TRV
(mg/kg-day)
1.04
0.76
Note:
1. NA - NOAA Screening Value is not available
Des Moines TCE-OU4 - Ecological Risk Assessment December S, 1SS4