re: 'Final Wildlife Toxicity Assessment for the Des … · f • FINAL WILDLIFE TOXICITY ASSESSMENT...

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FINAL WILDLIFE TOXICITY ASSESSMENT

for the

DES MOINES irCE-0U4 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

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December 9, 1994

30221199

Superfund

Contents Page N°.

1.0 Problem Formulation 1 1.1 Objectives of the WTA 1 12 Scope of the WTA 1 1.3 Chemicals Data Collection and Evaluation 2 1.4 Habitat Evaluation 2

1.4.1 Aquatic Habitat 3 1.4.1.1 South Pond 3 1.4.1.2 Emergent Wetlands 3 1.4.1.3 Forested Wetlands 3

1.4.3 Terrestrial Habitat 3 1.4.3.1 Upland Forest. . 3 1.4.3.2 Upland Open Field 4

1.4.4 Wildlife Usage 4 1.4.5 Rare, Threatened, and Endangered Species 5

1.5 Exposure Pathway and Receptor Analysis 6 1.5.1 Exposure to Species/Habitats of Concem 6

1.5.1.1 South Pond 7 1.5.1.1.1 Mallard 7

1.5.1.2 Forested Wetlands 7 1.5.1.2.1 Beaver 7 1.5.1.2.2 White-tailed deer 8

1.5.1.3 Drainage Ditch 8 1.6 Endpoints 8

1.6.1 Assessment Endpoints 8 1.6.2 Measurement Endpoints 9

1.6.2.1 Aquatic Receptor Measurement Endpoints 9 1.6.2.2 Terrestrial Receptor Measurement Endpoints 10

2.0 Exposure Assessment 11 2.1 Ecological Chemicals of Potential Concem 11 2.2 Exposure Point Concentrations 11 2.3 Exposure and Intake Assumptions 11

2.3.1 Plant Uptake 12 2.3.2 Beaver Exposure 12 2.3.3 White-Tailed Deer Exposure 12 2.3.4 Mallard Exposure 13 2.3.5 Benthic Community Exposure 13

Dee Moines TCE-OU4 - Ecological Risk Assessment Decembers, 1994

9 Contents (cont'd)

3.0 Ecological Effects Assessment 14 3.1 Toxicity Characterization 14 3.2 Toxicological Safety Factors 14 3.3 Ecological Effects Characterization 15

3.3.1 Beaver 15 3.3.2 White-Tailed Deer 16 3.3.3 Mallard 16 3.3.4 Benthic Macroinvertebrate Community 17

4.0 Risk Characterization 18 4.1 Risks to Aquatic Wildlife 18

4.1.1 Beaver 18 4.1.2 Mallard 18 4.1.3 Benthic Macroinvertebrate Community 19

4.2 Risks to Terrestrial Wildlife 19 4.2.1 White-Tailed Deer 19

4.3 Uncertainty 19 4.3.1 Endpoint Comparison Uncertainty 20 4.3.2 Exposure Assessment Uncertainty 20 4.3.3 Ecological Effects Assessment Uncertainty 21 4.4.4 Wildlife Toxicity Assessment Uncertainty 21

5.0 Conclusions and Ecological Significance 22 5.1 Aquatic Receptor Measurement Endpoints 22 5.2 Terrestrial Receptor Measurement Endpoints 22 5.3 General Conclusions 23 5.4 Recommendations 23

6.0 References 24

Des Moines TCE-OU4 - Ecological Risk Assessment December 9, 1994

Figures and Tables

Figures

Figure 1-1. Sample and Habitat Location M ^ Figure 1-2. Ecological Conceptual Site Model

Tables

Table 2-1 Table 2-2. Table 2-3 Table 2-4.

Table 3-1

Table 4-1 Table 4-2.

Aldrin and Dieldrin Exposure Point Concentrations Ingestion Dose Worksheet for the Beaver Ingestion Dose Worksheet for the White-Tailed Deer Ingestion Dose Worksheet for the Mallard

Measurement Endpoints for Target Species/Communities

Quotient Indices for Wildlife Quotient Indices for Benthic Macroinvertebrates

Des Moines TCE-OU4 • Ecological Risk Assessment Decembers, 1994

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1.0 Problem Formulation

A semi-quantitative baseline wildlife toucity 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 tiie 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 t i ie 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 • •ay 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

1.3 Chemicals Data Collection and Evaluation Ecological chemicals of potential concem (ECOPCs) may often include more

individual chemicals than the human health assessment because the screening criteria for

himian 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 concentrations and

concentrations in the drainage ditch, from South Pond. Sediment data was only obtained

for the sediments within South Pond. There were approximately two sediment samples,

four wedand surface soil samples, and four drainage ditch composite surface soils used

in this WTA (BVWS, 1994; Miles Corp., 1994). The development of the ECOPCs is

addressed in detail in Section 2.0 of this WTA.

1.4 Habitat Evaluation The Habitat Evaluation was performed in February 1994 as part of Operable Unit

4 of the site remediation under the BLACK & VEATCH Waste Science, Inc. (BVWS)

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 northem

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 including: (1) Aquatic (South

Pond), (2) Emergent Wetlands, (3) Forested Wedands, (4) Upland Forest, and (5) Upland

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 imiform 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.


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1.4.1 Aquatic Habitat The aquatic habitat observed within the study area consists of South Pond, the

Emergent Wetlands, and the Forested Wetlands.

1.4.1.1 South Pond. The aquatic habitat observed within the study area consists of

the South Pond. South Pond was frozen and covered with approximately 14 to 16 inches

of ice and an additional eight inches of snow during the site reconnaissance. As a result,

very little information conceming the physical and biological components of this habitat

were obtained. The water depth in the center of South Pond was approximately 3 feet

deep. The substrate of the pond was observed to be a very soft sediment that had a

strong petroleum-like odor.

1.4.1.2 Emergent Wetlands. The emergent wetland areas were located along the

fringes of the South Pond, around the low channel that periodically drains the pond to the

east, and in an open area at the northem comer of the low-lying areas. These emergent

wetlands were dominated by smartweeds (Polygonum spp.), cattail (Typha latifolia), and

reed canary grass (Phlaris arundinacea).

1.4.1.3 Fores ted Wetlands. The forested wetlands were located in a contiguous band

stretching from the southern bank of the South Pond, along the west bank, and just around

the northem comer of the pond. The dominated overstory species in the forested wedands

were silver maple, green ash (Fraxinus pennsylvanica), white ash (Fraxinus americana),

and American elm (Ulmus americana). Dominant shrub and vine species included red

mulberry (Morus rubra), grape (Vitis sp.), and silver maple saplings.

1.4.3 Terrestrial Habitat The terrestrial habitat observed within the study are? c^'^sists of upland forest and

upland open field.

1.4.3.1 Upland Forest . There were two large blocks of upland forest located in the

study area which were dominated by different tree species and subject to different

physical conditions.

The eastern upland forest area had an overstory dominated by cottonwood (Populus

deltoides). The dominant shrub, sapling, and vine species include cottonwood saplings,

red mulberry, silver maple, grape, and poison ivy (Toxicodendron radicans). Herbaceous

Des Moines TCE-OU4 - Ecological Risk Assessment December 9, 19S4 3

species dominant within this area include Japanese knotweed (Polygonum cuspidatum), (^~^

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 boimdary

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

cheny (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.

i.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 imidentified 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

(Odocoileus virginianus), beaver (Castor canadensis), songbirds (Passeriniformes),

American crows (Corvus brachyrhynchos), housecat (Felis domesticus), and Canada goose

(Branta canadensis). No other signs of any other wildlife species were observed during

the habitat evaluation. Wildlife was observed in all habitats in the study area.

Deer were the most common wildlife species in the study area. Deer were observed

in all habitats except the aquatic habitat. Based on observation of tracks, ruts, and

bedding, the deer appear to utilize the upland forest areas for sleeping areas, feeding, and

breeding. Deer appear to utilize the other habitat on the site to pass between forested

areas. A large portion of the eastern upland forest area appears to provide excellent

habitat for a large (10-20) deer herd. This area was almost completely covered with deer

tracks, scat, urine, ruts, and bedding areas. The vegetation in this habitat provides an

excellent food source for deer, which generally feed on twigs, shmbs, fungi, grass, and

herbs.

Chewed trees, saplings, and a dam were evidence of a beaver population in the study

area. The chewed saplings and dam were located in an area of emergent and forested

wedands in the southem end of the South Pond. The dam was partially within the South


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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 pro^'ide 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-0U4 - Ecological Risk Assessment Decembers, 1994

o 1.5 Exposure Patiiway 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 concem. 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 Wedands, 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 conceming 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 concem. 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

imderestimate the overall risks to those species of concem.

1.5.1 Exposure to Species/Habitats of Concern F'~sed on the findings of the habitat evaluation and the environmental analytical data

available at the site, there were three habitats of concem evaluated in this WTA including

the South Pond, the Forested Wedands, 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 concem.

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.


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I 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 WeUand is primarily camivore/grazer

habitat; however, there are no known carnivorous species present on the site. These a;c::^,

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

concem subject to exposure to contaminated surface soils in the wedand.

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 Wedand area. Additionally, there

Des Moines TCE-OLI4 - Ecological Risk Assessment December 9. 1994 7

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 Wedand. The white-tailed deer

may spend a portion of its time feeding on shrubs, grasses, and leaves in wedands

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 camivore/grazer habitat; however, there are no known camivorous

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 concem 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 concem

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 .LT; -ildlife 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 concem. 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


Forested Wedands

Herbivorous Species Viability

Drain ap.e 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 m 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 wedand 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, 1SS4 9

soils and sediments 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.

1.6.2.2 Terrestrial Receptor Measurement Endpoints . Terrestrial habitats present

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 concem (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.


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2.0 Exposure Assessment

The exposure assessment is conducted to estimate the magnitude of actual or potential

exposure of specific receptors to contaminants associated with the site along with the

related uncertainties involved with the assessment. Development of these exposure route

is discussed in Section 1.5 of this WTA. A graphical ecological conceptual model

illustrating the exposure routes assessed in this WTA is presented in Figure 1-2.

2.1 Ecological Ciiemicals of Potential Concern The sediments and surface soils of the South Pond, Forested Wedand, and the

Drainage Ditch were sampled and analyzed for a wide range of chemicals. However, the

most potentially significant chemicals, in terms of ecotoxicology, were determined to be

aldrin and dieldrin. While other contaminants were present in the area evaluated, these

were not significant toxicants when compared to aldrin and dieldrin.

2.2 Exposure Point Concentrations The exposure point concentration is the concentration of a chemical in an

environmental media to which a specific receptor is exposed. It is generally calculated

using statistical methodology from a set of data derived from environmental sampling.

There were relatively few samples obtained in locations necessary to fully evaluate the

exposure point concentrations. Therefore, for the purposes of this WTA, the average of

the concentrations obtained in each of the three habitats of concem was used as the

exposure point concentration.

There were approximately two sediment samples, four wetland surface soil samples,

and four drainage ditch composite surface soils used in this WTA (BVWS, 1994; Miles

Corp., 1994). The exposure point concentration for aldrin and dieldrin in each habitat

under evaluation are shown in Table 2-1.

2.3 Exposure and intat(e Assumptions Total exposure of three terrestrial target wildlife species (beaver, white-tailed deer,

and mallard) to aldrin and dieldrin in surficial soils and sediments was determined by

estimating the chronic daily intake (CDI) dose. The equations used to estimate the CDI

vary slighdy between species. These exposure equations for each of the three wildlife

species are shown on the worksheets in Tables 2-2, 2-3, and 2-4.

Des Moines TCE-OU4 - Ecological Risk Assessment December 9, 1994 1 ]

O' The wildlife species selected included both herbivorous and insectivorous species;

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.

Other exposure pathways at the site include dermal absorption and inhalation. Both

of these exposure pathways are difficult to quantify due to a lack of scientific data.

Additionally, aldrin and dieldrin are not expected to significantly volatilize and would not

be expected to present an inhalation hazard to the species of concem. Therefore, for the

purposes of this WTA, these exposure pathways were not evaluated.

2.Z.i Plans UpSak©

*. Plant tissue concentrations of aldrin and dieldrin were estimated by using soil to plant

transfer coefficients (TCv), developed from the octanol/water coefficient for each chemical

(Travis 1988; Howard, 1991). The TCv generally indicated the amount of contaminant

present in plant tissues given a known soil concentration. The values for TCv are shown

on the worksheets in Tables 2-2, 2-3, and 2-4.

2.3.2 Beaver Exposure ( ^ The beaver feeding rate was estimated from a general feeding rate value for

herbivorous mammals to be 772.72 grams/day (USEPA, 1993). The beaver is a strict

herbivore, obtaining 100% of its diet from plant sources (USFWS, 1983). The body

weight of the beaver is estimated to be approximately 20.0 kg (Burt, 1976). The home

range of the beaver is approximately 0.17 hectares (USFWS, 1983). The beaver is

estimated to incidentally ingest soil at a rate of approximately 2.4% of its overall

ingestion rate or 18.55 grams/day (USEPA, 1983).

2.3.3 White-Tailed Deer Exposure The white-tailed deer feeding rate is 1,600 grams/day (Dee, 1991). The white-tailed

deer is a strict herbivore, obtaining 100% of its diet from plant sources (Burt, 1976). The

body weight of the deer is estimated to be approximately 45.40 kg (Burt, 1976). The

home range of the deer is approximately 183.70 hectares (Dee, 1991). The deer is

estimated to incidentally ingest soil at a rate of approximately 1.0% of its overall

ingestion rate or 16.0 grams/day (USEPA, 1993).

Des Moines TCE-OU4 - Ecological Risk Assessment Decembers, 1994 12

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2.3.4 Mallard Exposure The mallard feeding rate was estimated to be approximately 337.5 grams/day

(USEPA, 1993). The mallard is omnivorous, obtaining approximately 30% of its diet

from plant sources and the remaining 70% from insects and benthic invertebrates

(USEPA, 1993). The body weight of the mallard is estimated to be approximately 1.03

kg (USEPA, 1993). The home range of the mallard is approximately 540.0 hectares

(USEPA, 1993). The mallard is estimated to incidentally ingest soil at a rate of

approximately 2.0% of its overall ingestion rate or 6.75 grams/day (USEPA, 1993).

2.3.5 Benthic Community Exposure The NOAA ER-L criteria will be used as a benchmark to establish adverse effects to

the benthic community for South Pond sediment aldrin and dieldrin concentrations.

Actual exposure surrogate organisms "in South Pond will not be determined for this

evaluation since the screening values used to develop QIs are based on field toxicity

studies, and there is litde specific information available in the scientific database.


3.0 Ecological Effects Assessment r~\

3.1 Toxicity Cliaracterization In this ecological effects assessment, information on the toxicity of aldrin and dieldrin

to ecological receptors is presented. The toxicity information is used in the development

of toxicological reference values (TRVs) (i.e., acceptable daily doses or media

concentrations) for selected target species. A comprehensive literature and database searc'i

was performed to identify relevant toxicological data for the target receptors. The data

sources that were reviewed included:

Chemical Abstracts (CA Service)

• Integrated Risk Information System (IRIS)

• Health Effects Assessment Summary Tables (HEAST)

• Hazardous Substances Data Base (HSDB)

• Phytotox

In addition to these databases, toxicity information was obtained from a variety of

primary literature sources as presented throughout the following subsections.

3.2 Toxicological Safety Factors Species-specific toxicity data for target wildlife species often were not available for

the chemicals of potential concem. Thus, where possible, toxicity values from the

literature were selected using the most closely related species. Data for chronic toxicity

were preferentially used, when available. Toxicity values selected for the assessment were

the lowest exposure doses reported to be toxic or the highest doses associated with no

adverse effect.

Since toxicity data for terrestrial wildlife are not neai.y as complete as that found for

laboratory and aquatic species, extrapolation of toxicity data from other animal studies is

often necessary. Because of the uncertainty associated with these extrapolations, safety

factors are applied to toxicological data to derive TRVs.

For those chemicals for which only acute lethality values were available, toxicity

values for this assessment were derived by dividing the acute toxicity value by the

appropriate safety factors. Based upon the guidance provided by the USEPA (1986c), a

median lethal dose (LDJQ) may be extrapolated to an acute toxicity threshold by dividing


o

o

9 die LDjo by a safety factor of 5. This safety factor is based on an analysis of

dose-response data for pesticides. A dose-response five times lower than the LDjo would

be expected to result in a mortality rate of about 0.1% under typical conditions, and up

to 10% when the responses in the test population are highly variable. Protection of 90 to

99% of a population is expected to provide an adequate margin of safety. In the absence

of similar information from chronic studies, a safety factor of 5 was also applied in the

extrapolation of a chronic lowest-observable-adverse-effect-level (LOAEL) to a chronic

no-observable-adverse-effect-level (NOAEL). This type of approach has been routinely

used in aquatic toxicology, and was also adopted for use in this assessment.

There is currently no USEPA guidance available for the extrapolation of acute

toxicity data to chronic NOAELs. However, several studies have evaluated the

relationship between LD50 values and chronic NOAELs for the same chemical in small

mammals (Venmen and Flaga, 1985; Layton et al., 1987) and have found that the ratio

of LDJO to a chronic NOAEL (LDj,/NOAEL) typically ranges from 10 to 1000. For die

purpose of this ecological assessment, a safety factor of 500 (5 for LDjo --> acute toxicity

threshold, and 100 for acute toxicity threshold ~> chronic NOAEL) was used to

extrapolate from an LD50 concentration to a chronic NOAEL. An additional safety factor

of 5 was applied in these cases when the test species differed from the target species

selected for the site, since animal species can exhibit differences in sensitivity to a

chemical.

3.3 Ecological Effects Ciiaracterization The potential ecological effects to the benthic macroinvertebrate community of South

Pond was evaluated by comparing known contaminant concentrations in sediment to EPA,

State, or other appropriate regulatory screening values. The potential ecological effects

to the three terrestrial target species was evaluated by comparing the known contaminant

concentrations to existing scientific literature and by comparing the exposure doses to

TRVs. These TRVs and screening values are the measurement endpoints used in this

WTA and are summarized in Table 3-1.

3.3.1 Beaver Chemical-specific toxicity data for the beaver was not found in the literature.

Altematively, beaver TRVs for aldrin and dieldrin were extrapolated from the LOAEL

values for laboratoiy rats, 0.025 and 0.005 mg/kg-day, respectively. The rat and the

beaver are both members of the order Rodentia, although they are members of different

Des Moines TCE-OU4 - Ecological Risk Assessment December 9, 1SS4 15

o families within the order. Additionally, the diet and digestive tract of these two species

is somewhat different. Because of the uncertainty involved in extrapolating between

species, a safety factor of 5 was applied to the rat LOAELs to develop NOAELs and a

safety factor of 5 was applied to these NOAELs to derive TRVs for the beaver. The TRV

for aldrin in the beaver was estimated to be 0.001 mg/kg-day. The TRV for dieldrin in

the beaver was estimated to be 0.0002 mg/kg-day.

LOAEL^ - 5 - > NOAEL^ + 5 - > TRVfc„,„

3.3.2 White-Tailed Deer Chemical-specific toxicity data for aldrin in the white-tailed deer was not found in

the literature. Altematively, a TRV for aldrin was extrapolated from the LOAEL values

for laboratory rats, 0.025 and 0.005 mg/kg-day, respectively. The rat and the white-tailed

deer are both members of the phylogenic class Mammalia although they are members of

different orders within this class. Additionally, the diet and digestive tract of these two

species is somewhat different. Because of the uncertainty involved in extrapolating

between species, a safety factor of 5 was applied to the rat LOAEL for aldrin to develop

a NOAEL and a safety factor of 5 was applied to this NOAELs to derive a TRV for the

white-tailed deer. The TRV for aldrin in the deer was estimated to be 0.001 mg/kg-day. f J

LOAEL„, -5 - > NOAEL„, - 5 ~> TRVd„,

Chemical-specific toxicity data for dieldrin in the white-teiiled deer was not found in

the literature,; however, there was specific toxicity data for the mule deer, a member of

the same genus as the white-tailed deer. The TRV for dieldrin was extrapolated from the

minimum LDjg for the mule deer, 100 mg/kg. The safety factor for converting the LDJQ

to a chronic NOAEL was 500. The TRV for dieldrin in the deer was estimated to be 0.2

mg/kg-day.

LD3o.-^500->TRV,„,

3.3.3 Mallard Chemical-specific toxicity data for aldrin and dieldrin in the mallard was found in the

literature. The TRV for aldrin and dieldrin in young mallards was extrapolated from the

LD50, 520 and 381 mg/kg. The safety factor for converting the LDJQ to a chronic NOAEL

Des Moines TCE-OU4 - Ecological Risk Assessment Decembers, 1S94 16

o

• was 500. The TRV for aldrin in the mallard was estimated to be 1.04 mg/kg-day. The

TRV for dieldrin in the mallard was estimated to be 0.76 mg/kg-day.

LDJO * 5 0 0 - > TRV,^^a

3.3.4 Benthic Macroinvertebrate Community The toxicity of dieldrin to benthic macroinvertebrates was assessed by comparing

sediment concentrations in South Pond to the National Oceanic and Atmospheric

Administration (NOAA) lowest observed effects-range (ER-L) toxicological data for

benthic macroinvertebrates in aquatic sediments. The NOAA ER-L for dieldrin in aquatic

sediments is 0.02 parts per billion (ppb) (USEPA, 1991).

There was no NOAA or other toxicological data located for aldrin to benthic

macroinvertebrates. Since aldrin is chemically related to dieldrin, the dieldrin NOAA ER-

L was used for aldrin for the purposes of this WTA.


4.0 Risk Characterization O

The risk characterization portion of the WTA estimates baseline risks to specific

receptors or individuals representative of a trophic groups of receptors based on the

information gathered during the exposure and toxicity assessments. In instances where

ARAR's have been developed for specific chemicals of concem, a comparison of ARAR's

and risk based remediation goals will be made. Also included in the risk characterization

section, wall be a evaluation of the uncertainty associated with the calculations and

assumptions made throughout the WTA.

Risk characterization is the final phase of a risk assessment. It is at this phase that

the likelihood of adverse effects occurring as a result of exposure to a stressor are

evaluated.

Quotient indices (QIs) were calculated in sediment for benthic macroinvertebrates and

in surface soil for terrestrial receptors. A quotient index of less than 1 is not considered

to be indicative of risk. Quotient indices exceeding 1, but less than 10 indicate a small

risk of ecological effects. Quotient indices exceeding 10 indicate a significant risk of

ecological effects. Quotient indices exceeding 100 indicate a critically significant risk of

ecological effects.

It is important to note that the actual or estimated NOAEL values used in establishing ( ~~\

risk in this WTA are representative of chronic effects. As such, the HQ generated for the

contaminants at the site may not be indicative of current conditions, rather, those that may

occur over time. As the HQ increases, the risk of long-term, chronic effects on the

receptors of concem would increase.

4.1 Risl(S to Aquatic Wildlife 4.1.1 Beaver

Potential risk to the beaver inhabiting the South Pond and adjacent wetlan*^ » - - was

estimated by comparing the estimated daily dose of aldrin and dieldrin (in wedand soils)

with the TRVs derived for the beaver. As shown in Table 4-1, the quotient indices for

aldrin and dieldrin in the beaver are less than unity (1). These QIs would suggest little

risk to the beaver and other aquatic mammals that may be present at the site.

4.1.2 Mallard Potential risk to the mallard, which may inhabit South Pond was estimated by

comparing the estimated daily dose of aldrin and dieldrin (in South Pond sediment) with

Des Moines TCE-OU4 - Ecological Risk Assessment December 9, 1994 18 o

9 t 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 Rislcs to Terrestrial Wildlife 4.2.1 White-Tailed Deer

Potential risk to the white-tailed deer inhabiting the uplands and wedands adjacent

to South Pond was estimated by comparing the estimated daily dose of aldrin and dieldrin

(in 'V ''and 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 necessaiy 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.

Des Moines TCE-OU4 - Ecological Risk Assessment December S, 1994 19

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 potential 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 environmental 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 concems 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 and 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 concem. 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

9

#

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 imd 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 jmd 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 LDJQS, LOAELs, and NOAELs to TRVs specific to each wildlife 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 ex])osure 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.


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 iVIeasurement 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 IVIeasurement 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 die 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 wedand 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

I 5.3 General Conclusions In general, the QIs for the benthic macroinvertebrate community of South Pond are

very high, based on the concentrations of a}!drin and dieldrin in South Pond sediment.

There appears to be little risk posed by the chemical concentrations in the wedands

surface soils and drainage ditch surface soils.

The ecological effects assessment indicates that the concentrations of aldrin and

dieldrin present in the South Pond sjdiment 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. These 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 offish

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 impa.' 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 altemative would probably have a negative effect

on the surrounding wedands, which are partially dependant on the surface water provided

by the pond.

•

Des Moines TCE-OU4 - Ecological Risk Assessment December 9, 19S4 23

6.0 References

BVWS (BLACK & VEATCH Waste Science, Inc.), March 1994. Data Report for Soudi

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 -

Eastem 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 die 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

Information Systems, Inc., Baltimore, MD.

Layton, D.W., B.J. Mullon, D.H. Rosenblatt, and M.J. Small, 1987. "Derivin Allowable

Daily Intakes for Systemic Toxicants Lacking Chronic Toxicity Data". Regulatory

Toxicology and Pharmacology, 7:96-112.

Des Moines TCE-OLI4 - Ecological Risk Assessment Decembers, 1994 2 4

( Miles Corporation, July 1994. Data Report of Surficial Soil Samples from Wedand Soils

and the Drainage Ditch at the Des Moines TCE Site - 0U4.

Travis, Curtis C. and Angela Arms, 1988. "Bioconcentration of organics in Beef, Milk,

and Vegetation". Environmental Science Technology. Vol 22, No. 3

USEPA (U.S. Environmental Protection Agency), December 1993. Wildlife Exposure

Factors Handbook, Volumes I and II, Office of Health and Environmental Assessment,

Washington, DC.

USEPA (U.S. Environmental Protection Agency), February 1992. Peer Review Workshop,

Report on a Framework for Ecological Risk Assessment, Risk Assessment Forum,

Washington, DC.EPA/625/3-91/022.

USEPA (U.S. Environmental Protection Agency), July 1994. Region III Interim

Ecological Risk Assessment Guidelines, Technical Support Section, Superfund Program

Branch, Philadelphia, PA.

USEPA (U.S. Environmental Protection Agency), April 1991. Suggested Guidance for

Evaluating Sediment Concentration Data, Region IV Contaminated Sediments Workgroup,

Adanta, GA.

USEPA (U.S. Environmental Protection Agency), 1986c. Ecological Risk Assessment,

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 9, 1994 2 5

t'"'':S:l.>j Forested Wetland Habitat

K . - i l l r j Upland Forest HabKat

Upland Open Field/Dirt Roads

K^ Jy^U High Deer Concentration Area

^-^-"X Observed Deer Paths

^ B Beaver Dam

A Sediment Samples

' J Habitat Data Recording Point

Habitat and Wildlife Location Map Des Moines TCE 0U4 Site - South Pond

Figure 1-1

•

^ BLACK & VEATCH Woi te Science, Inc. 6 0 1 Wolnul Street . Philodelphio. PA 10106

Habitat Evaluation 0U4 - South Pond Area

Des Moines, Polk County, lowa

^

• r

Legend:

Direct Ingestion

- Incidents! 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 Wildlife Toxicity Assessment Des Moines, lowa

y •':•••'R Chemical ••• Frequency of Detects Minimum Detected ^ Concentration

Maximum Detected Concentration ••

[•RRR:VA\en^ ; | ;;::•: 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

Discharge Ditch Composite Surface Soils ||


3/4 4/4

8.7 640.0

53.0 7.000.0

• 15.4

3.085.5

South Pond Sediments


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, SS/71-80, SS/81-90. SS-91-100. SS/101-120 (Miles. 1994).


si««gss»lo^p«jJsi. • il

Table 2-2 Ingestion Dose Worksheet for the Beave;

Des Moines TCE-0U4 Site Des Moines, lowa

Exposure Equation:

[fTCv * IR^ + sm] * CSw * FI BW*CF

Species Specific Information: Factor Abbreviation Unit Area of Contamination, hectares AOC 0.30 Home Range, hectares HR 0.17 Fraction of Diet from AOC (AOC/HR) Fl 1.00 Body Weight. Kg BW 20.00 Ingestion Rate, g/day (BW*0.727 • 0.577) IR 772.72 Soil Ingestion Rate, g/day (BW * 2.4%) SIR 18.55 Conversion Factor, g/kg CF 1000.00 Contaminant Concentration in WeUand Soil, mg/kg CSv/ varies Soil to Plant Transfer Coefficient, unitiess TCv varies Contaminant Dose, mg/kg-day Dose See below

Reference

Contaminant Specific Information: Contaminant CSw JQy Ppse Aldrin 1.48 0.021 2.57E-03 Dieldrin 8.65 0.098 4.08E-02

Table 2-3 Ingestion Dose Worksheet for the Deer


Exposure Equation:

(fCSw * FIw^ + fCSd * Ffd^ + [SIR * (Flw + FId>]) * TCv *IR BW*CF

Species Specific Information: Factor Wetiand Soil Area of Contamination, hectares Ditch Soil Area of Contamination, hectares Home Range, hectares Fraction of Diet from Wetiand 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

] M 1.00 1.00 183.70 0.0054 0.0054 45.40 1600.00 16.00 1000.00 varies varies varies See below

Reference

Contaminant Specific Information: Contaminant Aldrin Dieldrin

C5W 1.48 8.65

CSd 0.015 3.085

ICy 0.021 0.098

Dose 6.02E-06 221 E-04

Table 2-4 Ingestion Dose Worksheet for the Mallard


Exposure Equation:

[fTCv * VIR) + SIR] * CSw * FI B W * C F

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, unitiess 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

CSp 4.40 0.19

TCv 0.021 0.098

Doss 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 9, 1994

Table 4-1

Quotient Indices for Wildlife Species

Des Moines TCE-0U4 Site

Des Moines, lowa

; Species,:;

Beaver

Deer

Mallard

Contaminan ' .RR.::-:t- ',-R\

Aldrin

Dieldrin

Aldrin

Dieldrin

Aldrin

Dieldrin

.:.:••. • : b o s e ^ v ^ : ' mg/kg/day :

0.0000382

0.0000943

0.000000147

0.0000598

0.0000284

0.0000224

TRV

0.001

0.002

0.001

0.2

1.04

0.76

::;: Effects ^ i R

LOAEL„, modified to NOAEL ^^^

LOAEL„. modified to NOAEL ^„„

LOAEL„. modified to NOAEL ^

LD50j„ modified to NOAELj^

LD50„„.^ modified to NOAEL„n«d

LD50,„.n„j modified to NOAEL^,^

ii 1

Quotient

Index (QD

0.0382

0.0472

0.000147

, 0.000299

0.0000273

0.0000295

i|?|i|:-j;j;;:|j|^.:a

0.0854

0.000446

0.0000568


Table 4-2

Quotient Indices for the Benthic Macroinvertebrate Community of South Pond

Des Moines TCE-0U4 Site

Des Moines, lowa

V;: Species'•.:•;?::.•-:•••:":• V

Benthic Macroinvertebrates

Contaminan

t •:••

/ trin

Dieldrin

Sediment

Concentratio

n (ppb) R:R

4,400

185

NOAA

ER-L

0.02

(NA)

0.02

;:;-;;--v>V;^^

Increased benthic mortality,

decreased benthic

abundance

Increased benthic mortality,

decreased benthic

abundance

:..;;:;;• Quotient j^ ; ; ; ; :

;:;:index;(QD ::;;::•;

220,000.00

9,250.00

X' Wfi:

229,250.00


Date post:	28-Sep-2018
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