U.S. ENVIROMENTAL PROTECTION AGENCY
Region 7
11201 Renner Blvd
Lenexa, KS 66219

Addendum to Des Moines TCE Site Five-Year Review Report,

dated April 9,2013

A Five-Year Review addendum is generally completed for remedies where the protectiveness
determination is deferred until further information is obtained. When deferring protectiveness in the
Five-Year Review Report (Report), the U.S. Environmental Protection Agency typically provides a
timeframe for when the information will be obtained and a protectiveness statement can be made. This
addendum describes progress since the Five-Year Review and protectiveness determinations for the
remedies where the statement was deferred in the fifth Report (2013).

The Report for the Des Moines Trichloroethylene (TCE) Site (Site) in Des Moines, Iowa, was signed by
Cecilia Tapia, Director of the Region 7 Superfund Division, on April 9, 2013. The Site consists of four
operable units (OUs). The protectiveness statements outlined in the Report were as follows:

OU1 (Groundwater extraction, treatment, and monitoring)

The remedy at OU1 protects human health and the environment in the short term because exposure
pathways that could result in unacceptable risks are controlled through operation of the groundwater
extraction and treatment system that assists in preventing contaminants from entering the DM WW
infiltration gallery. In order to be protective in the long term, DICO needs to monitor trends and assess
migration potential for 1,2-dichloroethene (DCE) in the groundwater to the south-southeast.

OU2 (Source soils contributing to OU1 contamination)

The remedy at OU2 protects human health and the environment in the short-term because exposure
pathways that could result in unacceptable risks are controlled by isolating contaminants beneath an
asphalt cap and DICO will continue annual inspections and maintenance of the asphalt cap. In order
for the remedy to be protective in the long-term, an institutional control implementation plan with an
environmental covenant for the site needs to be implemented.

OU3 (Groundwater source north of the Site)

A protectiveness determination of the remedy at OU3 cannot be made at this time until further
information is obtained. Further information will be obtained by assessing the potential for exposure to
contaminants through vapor intrusion. Additionally, further monitoring and data collection is required
to monitor trends for 1,2-DCE in groundwater. It is expected that this action will take approximately
two years to complete, at which time a protectiveness determination will be made.

oin

all oi

40510129

0

Superfund


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0U4 (Pesticides, herbicides, metal and polychlorinated biphenyls [PCB] contamination in the buildings
and across the Site)

A protectiveness determination of the remedy at OU4 cannot be made at this time until further
information is collected from the South Pond area. Further information will be obtained by conducting a
baseline ecological risk assessment in the South Pond area. It is expected that these actions will take
approximately two years to complete, at which time a protectiveness determination will be made.
Currently, there is risk to trespassers, including receptors in the indigent community ofDePuydt Woods
located on the site, due to broken windows and unsecured doors in the buildings where the
encapsulation that covers existing contaminated areas has been breached. Broken windows and
unsecured doors in the buildings where the interior protective encapsulation has been breached provide
unauthorized access to trespassers, including members of the indigent community. Continuous
monitoring is recommended to determine the extent of exposure. Risk to trespassers, including receptors
in the indigent community ofDePuydt Wood, would need to be re-evaluated at the next five year review
of the site.

This addendum addresses the Protectiveness Statements for OU3 and OU4.

Progress since the Five-Year Review Completion Date

OU3 - Groundwater Source North of the Site

Issues and Recommendations Identified in the April 2013 Five-Year Review

OU(s): 3

Issue Category: Remedy Performance

Issue: Potential exposure to contaminants in OU3 through vapor intrusion

Recommendation: Assess vapor intrusion potential

Affect Current
Protectiveness

Affect Future
Protectiveness

Implementing
Party

Oversight Party

Milestone Date

Yes

Yes

EPA

EPA

5/2015

Actions Taken Since 2013

Since the last Five-Year Review, additional groundwater sampling has been performed for OU3 by the
Iowa Department of Natural Resources (IDNR). The groundwater data collected from 2012 to 2015 was
evaluated to determine if there is a potential vapor intrusion risk to the buildings overlying the
groundwater contamination. All initial screenings show that any potential risk is below the cancer risk of
lxlO"5 or hazard index of 1 (EPA, 2016a). Soil gas samples have not been collected because the
buildings on site are not in use, nor are there any plans to use the buildings. If future on-site plans
change, additional vapor intrusion investigations may be necessary.

Although at this time it has been determined that there is no unacceptable risk to the vapor intrusion
pathway with the current use on site, since groundwater contamination remains below structures on site,
it is recommended that the site monitoring plan be updated to include a continued evaluation of the
vapor intrusion pathway.

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Issues and Recommendations Identified in the April 2013 Five-Year Review

OU(s): 3

Issue Category: Remedy Performance

Issue: Monitor and assess trends for 1,2- DCE at OU3

Recommendation: Monitor trends for 1,2-DCE

Affect Current
Protectiveness

Affect Future
Protectiveness

Implementing
Party

Oversight Party

Milestone Date

No

Yes

EPA

EPA

5/2015

Actions Taken Since 2013

The EPA performed a Mann-Kendall statistical analysis on the groundwater data north of the Site using
the data from 1989 through 2015 to determine contaminant concentration trends in groundwater for
1,2 DCE (EPA, 2016b). IDNR sampling events analyzed for either total 1,2-DCE or speciated 1,2-DCE,
depending on the event.

1,2-DCE was detected in two wells (NW-34 and NW-36). Well NW-34 contained one detection during
that period and has been non-detect for the last three sampling events. Well NW-36 showed an
increasing trend during the sampling period, although all the concentrations were below the maximum
contaminant level (MCL) of 70 micrograms per liter (ng/L) for cis-l^-DCE1.

Although the concentrations of 1,2 DCE remain below the MCL in all wells sampled, it is recommended
that the site monitoring plan for OU3 be updated to ensure speciated 1,2 DCE is analyzed during future
events.

OU4 - Pesticides, Herbicides, Metal and PCB Contamination in the Buildings and Across the Site

Issues and Recommendations Identified in the April 2013 Five-Year Review

OU(s): 4

Issue Category: Changing Site Conditions

Issue: A Screening Level Ecological Risk Assessment indicates that ecological
risks may have been underestimated in the South Pond Area.

Recommendation: Perform Baseline Ecological Risk Assessment.

Affect Current
Protectiveness

Affect Future
Protectiveness

Implementing
Party

Oversight Party

Milestone Date

No

Yes

DICO

NA

2/2015

Actions Taken Since 2013

Since the last Five-Year Review, an ecological risk assessment has been performed on the South Pond
Area (EPA, 2015). In summary, a significant ecological risk was calculated due to pesticides.

While aldrin is a chemical of concern at the Site, it was aldrin's breakdown product, dieldrin, that was
the primary risk driver in the ecological risk assessment. Dieldrin contamination at the South Pond Area
is widespread, as it was detected in all sediment and soil samples. Dieldrin was also detected in surface
water at two locations. In addition, chlordane was detected in all of the sediment and soil locations and
in one surface water location.

1 Since speciated 1,2-DCE sampling was not performed, concentrations were compared to the cis-1,2-DCE MCL since it is
lower than the MCL for trans-l,2-DCE (100 |xg/L).

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Dieldrin and chlordane identified a potential risk for soil invertebrates and benthic macroinvertebrates
directly exposed to these soils and sediments. In addition, food chain exposure to dieldrin by wildlife
receptors with small home ranges, such as small mammals, is also likely to be significant.

Based on the conclusion of the ecological risk assessment, it is recommended that remedial options be
evaluated to address this risk. In addition, based on a brief review of the pesticide data collected for the
ecological risk assessment, it is recommended that the human health risk assessment be updated to
evaluate potential risks based on future residential, recreational, or industrial use scenarios.

Issues and Recommendations Identified in the April 2013 Five-Year Review

OU(s): 4

Issue Category: Changing Site Conditions

Issue: The broken windows and unsecured doors in the buildings, where the
interior protective encapsulation over existing contamination has been breached,
provide unauthorized access to trespassers, including members of the indigent
community, and subject such individuals to exposure to contamination.

Recommendation: Board up and secure the windows and doors in the buildings
in which the encapsulation has been breached.

Affect Current
Protectiveness

Affect Future
Protectiveness

Implementing
Party

Oversight Party

Milestone Date

Yes

Yes

DICO

EPA

2/2014

In November 2015, the indigent community was removed from the Site and security now patrols the
area in an effort to prevent trespassing.

Although the indigent community has been removed, encapsulated contamination remains in structures
on site. It is recommended that the site be monitored to verify that buildings with encapsulated
contamination continue to be inaccessible to trespassers by the engineering controls in place.

Issues and Recommendations

Based on the activities conducted to date, a number of issues and recommendations were identified:

OU(s): 3

Issue Category: Remedy Performance

Issue: Operation and Maintenance Plan is not sufficient to evaluate all site
contaminants and exposure pathways

Recommendation: Update operation and maintenance plan to include
speciated 1,2 DCE in the list of groundwater analytes and include vapor
intrusion pathway analysis.

Affect Current
Protectiveness

Affect Future
Protectiveness

Party
Responsible

Oversight
Party

Milestone Date

No

Yes

State

EPA

12/31/2017

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OU(s): 4

Issue Category: Remedy Performance

Issue: An Ecological Risk Assessment indicates that unacceptable
ecological risks are present in the South Pond Area.

Recommendation: Evaluate and implement potential remedial options to
address the unacceptable risk.

Affect Current
Protectiveness

Affect Future
Protectiveness

Party
Responsible

Oversight
Party

Milestone Date

Yes

Yes

PRP

EPA

9/30/2017

OU(s): 4

Issue Category: Remedy Performance

Issue: An Ecological Risk Assessment indicates that unacceptable
ecological risks are present in the South Pond Area.

Recommendation: Update the Human Health Risk Assessment on the
South Pond Area to assess potential human health risk.

Affect Current
Protectiveness

Affect Future
Protectiveness

Party
Responsible

Oversight
Party

Milestone Date

No

Yes

PRP

EPA

12/31/2016

OU(s): 4

Issue Category: Remedy Performance

Issue: Potential exposure to contamination encapsulated in buildings on
site.

Recommendation: Verify buildings where contamination is encapsulated
continue to be inaccessible to trespassers to prevent potential exposure to
contamination. This will be necessary as long as the buildings are present.

Affect Current
Protectiveness

Affect Future
Protectiveness

Party
Responsible

Oversight
Party

Milestone Date

No

Yes

PRP

EPA

12/31/2018

Protectiveness Statements

Based on new information and/or actions taken since the Five-Year Review completion date, the
protectiveness statements for OU3 and OU4 are being revised as follows:

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Protectiveness Statemerit(s)

Operable Unit:	Protectiveness Determination:	Planned Addendum

Completion Date:

0U3	Short-term Protective

Click here to enter a
date

Protectiveness Statement: The remedy at OU3 currently protects human health and the
environment because the groundwater is not being consumed and data analysis indicates that
vapor intrusion is not occurring. However, in order to be protective in the long term, the
monitoring plan needs to be updated to ensure that groundwater data is evaluated for speciated
1,2 DCE and that the vapor intrusion pathway continues to be evaluated.

Protectiveness Statement(s)

Operable Unit:

Protectiveness Determina tion:

Planned Addendum



Not Protective

Completion Date:

OU4





Click here to enter a





date

I Protectiveness Statement: The remedy at OU4 is not protective because the ecological risk 1

1 assessment has concluded that there is unacceptable risk in the South Pond Area. Remedial 1

| alternatives will be evaluated to address these risks.



Sitewide Protectiveness Statement

Protectiveness Determination:	Planned Addendum

Completion Date:

Not Protective

Click here to enter a
date

Protectiveness Statement:. Because the remedy at OU4 is not protective, the site is not
protective because the ecological risk assessment at OU4 has concluded that there is
unacceptable risk in the South Pond Area. Remedial alternatives will be evaluated to address
these risks.

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Next Five-Year Review

The next Five-Year Review will be completed by April 9, 2018, five years after the signature of the last
Five-Year Review report.

Director, Superfund Division

Attachments:

EPA 2015. Ecological Risk Assessment for Des Moines TCE Site, Operable Unit 04, U.S.
Environmental Protection Agency, October 2015.

EPA 2016a. Vapor Intrusion Assessment for 5th Five Year Review OU3, Des Moines TCE Site, Des
Moines, IA., U.S. Environmental Protection Agency, April 2016.

EPA 2016b. MAROS Statistical Analysis, OU3, Des Moines TCE Site, Des Moines, IA, U.S.
Environmental Protection Agency, February 2016.

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Ecological Risk Assessment

for

Des Moines TCE Site
Operable Unit 04

October, 2015

Prepared by:

U.S. Environmental Protection Agency Region 7
11201 Renner Boulevard
Lenexa, KS 66219


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Table of Contents

Table of Contents	ii

1.0. INTRODUCTION	5

2.0. SITE BACKGROUND	5

3.0. HABITAT AND ECOLOGY	7

4.0. SITE INVESTIGATION	7

5.0.	PROBLEM FORMULATION	8

5.1.	CONTAMINANTS OF POTENTIAL CONCERN	8

5.2.	CHARACTERIZATION OF ECOLOGICAL EFFECTS OF COPCs	8

5.3.	MIGRATION PATHWAYS	9

5.3.1.	Soil to Surface Water/Sediment Migration	9

5.3.2.	Sediment/Surface Water to Soil Migration	9

5.3.3.	Biological/Food Chain Migration	9

5.4.	ASSESSMENT ENDPOINTS	9

5.4.1.	AE#1 Survival, Growth and Reproduction of Benthic Macroinvertebrates	10

5.4.2.	AE#2 Survival, Growth and Reproduction Soil Invertebrates	10

5.4.3.	AE#3 Survival, Growth and Reproduction of Insectivores	10

5.4.4.	AE#4 Survival, Growth and Reproduction of Carnivores	10

5.4.5.	AE#5 Survival, Growth and Reproduction of Piscivores	 11

6.0.	RISK CHARACTERIZATION	11

6.1.	EVALUATION OF DIRECT EXPOSURE	11

6.1.1.	Calculation of the Exposure Point Concentration	12

6.1.2.	Screening Level Benchmarks	12

6.1.3.	HQ-Based Risk Characterization	12

6.1.4.	Survival, Growth and Reproduction of Benthic Macroinvertebrates	13

6.1.5.	Survival, Growth and Reproduction of Soil Invertebrates	 13

6.2.	FOOD CHAIN EXPOSURE TO WILDLIFE RECEPTORS	14

6.2.1.	Wildlife Exposure Factors	14

6.2.2.	Estimates of Chemical Concentrations in Diet	14

6.2.3.	Toxicity Reference Values	15

6.2.4.	HQ-based Risk Characterization	15

6.2.5.	Survival, Growth, and Reproduction of Terrestrial Insectivores	15

6.2.6.	Survival, Growth and Reproduction of Terrestrial Carnivores	15

6.2.7.	Survival, Growth and Reproduction of Piscivores	16


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7.0.	UNCERTAINTIES	16

7.1.	ANALYTICAL DATA	16

7.2.	UNCERTAINTY OF THE CONCEPTUAL MODEL	16

7.3.	UNCERTAINTIES ASSOCIATED WITH TOXICOLOGICAL STUDIES	17

7.3.1.	Variable Toxicity in the Aquatic Environment	17

7.3.2.	Extrapolation of Laboratory Toxicity Tests to Natural Conditions	17

7.3.3.	Differences between Responses of Test Species and Receptor Species	17

7.3.4.	Differences in Chemical Forms of Contaminants	18

7.3.5.	Variability in Toxicity Reference Values	18

7.3.6.	Extrapolation of Individual Level Effects to Population-Level Effects	 18

7.4.	UNCERTAINTIES ASSOCIATED WITH THE EXPOSURE ASSESSMENT	18

7.5.	UNCERTAINTY IN EVALUATING ECOLOGICAL RISK	19

8.0. SUMMARY AND CONCLUSIONS	19

9.0. REFERENCES	21

APPENDIX A: TOXICITY PROFILE	23

APPENDIX B: FIGURES	30

APPENDIX C: TABLES	39

Table 1. Protected Species and Species of Concern	40

Table 2. Assessment Endpoints and Measures of Exposure and Effects.... Error! Bookmark not
defined.

Table 3. Exposure Point Concentrations for Sediment (pg/kg)	42

Table 4. Exposure Point Concentrations for Surface Water (|ig/L)	49

Table 5. Exposure Point Concentrations for Soil ((ig/kg)	56

Table 6. Screening Level Evaluation of Assessment Endpoint #1 (aquatic macroinvertebrates). 60

Table 7. Expanded Risk Evaluation of Assessment Endpoint #1	61

Table 8. Screening Level Evaluation of Assessment Endpoint #2 (soil invertebrates)	63

Table 8. Screening Level Evaluation of Assessment Endpoint #2 (soil invertebrates)	64

Table 9. Bioaccumulation Factors for Terrestrial Prey	65

Table 10. Bioconcentratrion Factors for Small Fish	66

Table 11. Estimated Concentrations in Prey	67

Table 12. Average Daily Dose Equations	68

APPENDIX D: ProUCL RESULTS	77

APPENDIX E: WILDLIFE EXPOSURE FACTORS	82

APPENDIX F: TOXICITY REFERENCE VALUES	93


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LIST OF ABBREVIATIONS

ADD

Average Daily Dose

AE

Assessment Endpoint

AUF

Area Use Factor

BAF

Bioaccumulation Factor

BCF

Bioconcentration Factor

BW

Body Weight

COPC

Contaminants of Potential Concern

ESB

Equilibrium Sediment Benchmark

ESL

Ecological Screening Level

EPC

Exposure Point Concentration

ERA

Ecological Risk Assessment

FCM

Food Chain Multiplier

HQ

Hazard Quotient

IR

Ingestion Rate

LOAEL

Lowest Observed Adverse Effect Level

log Kow

Octanol-Water Partitioning Coefficient

NOAEL

No Observed Adverse Effect Level

OU

Operable Unit

PCB

Polychlorinated Biphenyls

PEC

Probable Effect Concentration

POP

Persistent Organic Pollutant

RI

Remedial Investigation

SPA

South Pond Area


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1.0. INTRODUCTION

This Ecological Risk Assessment is being conducted as part of the fifth Five-Year Review for
the Des Moines TCE Site. The ERA will be conducted according to the Ecological Risk
Assessment Guidance for Superfund (USEPA, 1997), which includes the following eight steps:

1.	Screening level problem formulation and effects evaluation;

2.	Screening level exposure and risk evaluation;

3.	Baseline risk assessment problem formulation;

4.	Study design and data quality objectives;

5.	Field verification of sampling design;

6.	Site investigation;

7.	Risk characterization;

8.	Risk management.

The objective of this ERA, in particular, is to characterize potential ecological risk to the aquatic
and terrestrial ecosystems associated with Operable Unit 04 (South Pond Area) of the Des
Moines TCE Site.

2.0. SITE BACKGROUND

The Des Moines TCE Site is located in the south-central portion of the city of Des Moines, Iowa,
adjacent to the Raccoon River. The Site includes a portion of the Des Moines Water Works
facility; the Dico, Inc. property; the industrial area north of the Dico property; the Tuttle Street
Landfill east of the Dico property; and the Frank DePuydt Woods south of the Dico property. In
all, the Site encompasses more than 200 acres (Figure 1).

The Dico property has historically been used for a variety of industrial uses, including grey iron
production; steel wheel manufacturing; and chemical and pesticide formulation and distribution.
From the mid-1950s through the early 1970s, pesticide and herbicide formulation was conducted
in Buildings 1 through 5 and the Maintenance Building. The primary formulation activities were
conducted in Buildings 2 and 3, while Buildings 4 and 5 were primarily used for chemical and
product storage. Operable unit two was initially designated to address chlorinated volatile
organic compound impacted source soils and included all soils on the Dico property. Soil
contamination was detected in the saturated zone approximately 30 feet below ground surface.
However, during the OU2 Remedial Investigation, additional contaminants, including pesticides
and herbicides, were discovered in surface soils of OU2 and in several buildings on the Dico
property. OU4 was then designated to address the buildings and surrounding soils and drainage
areas on the Dico property and a drainage ditch just east of the Dico property.

OU4 currently includes portions of the Dico property including Buildings 1 through 3;
foundations of the Maintenance Building; Buildings 4 and 5 and the Western Annex of Building
3; soil and sediment associated with the former aldrin tank; the South Pond Area; the area

5


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associated with completed soil disking operations; and the low-lying area south and east of the
Dico property up to the railroad spurs owned by the Union Pacific Railroad.

The primary contaminants of concern detected in the OU4 buildings (Buildings 1 through 5 and
the Maintenance Building) were aldrin, dieldrin, chlordane, and polychlorinated biphenyls. The
highest levels of aldrin, dieldrin, and chlordane were detected in the concrete floor of the
Maintenance Building, in association with the aldrin tank and annex structure. Lower levels of
these contamination were detected in Buildings 2, 3 and 4. PCBs were detected in the insulation
of Buildings 2, 3, 4, 5 and the Maintenance Building, with the highest concentration being
detected in Building 3. However, the Maintenance Building, Buildings 4 and 5, and the Western
Annex to Building 3 have been demolished.

Contaminants of Potential Concern detected in the surface soils at OU4 included aldrin, dieldrin,
and chlordane. The pesticides were detected above health-based cleanup levels at numerous
locations across OU4. COPCs detected in the surface soils in the SPA of OU4 included aldrin,
dieldrin, and chlordane. These pesticides were detected in the surface soils along the
northwestern edge of the South Pond, in sediment samples from the South Pond, and in samples
collected from the east drainage ditch.

Several removal actions have occurred at the Site to address the contamination in the soils and
buildings. The removal action for the buildings addressed contamination associated with Dico
Buildings 1 through 5, the Maintenance Building, and the former aldrin mixing tank, annex and
surrounding soils. The removal action included the following: cleaning the interior surfaces of
the buildings; removal of surface soils that had been impacted by contaminants released to the
outside; demolition and disposal of the aldrin tank and annex structure; removal of impacted
soils surrounding the aldrin tank; repairing damaged and exposed building insulation and
encapsulation of PCBs contained within the insulation materials; and application of a protective
surface coating to walls and floors to encapsulate any remaining COPC residues and PCBs to
prevent direct contact.

The removal action for the soils included excavation and capping of contaminated soil. Soils
from low lying drainage areas were excavated and disposed of at an offsite facility. An asphalt
cap was constructed over the remaining contaminated impacted soil areas to address the direct
contact exposure route. However, contamination has not been removed from the SPA due to
concerns over impacts to wetlands.

As part of the fifth five-year review, sediment data from the SPA was compared to ecological
screening levels. It was found that the quality of the historic sediment data was an issue.
Detection limits were at times orders of magnitude above ecological screening levels, and only
limited sampling of the pond had been completed. However, even when adequate detection
limits were used, pesticide concentrations exceed ecological screening levels. In the case of
aldrin, in particular, the screening level hazard quotient was over 400,000. The purpose of the
risk assessment is to evaluate risk using data that meets data quality objectives. In turn, this will
enable the EPA to determine the protectiveness of the current remedy.

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3.0. HABITAT AND ECOLOGY

Des Moines has a continental climate that is characterized by hot summers and cold winters.
Precipitation is highest in the summer months. The terrain in and around Des Moines is gently
rolling. Surface water drainage is generally to the southeast, to the Des Moines River and its
tributaries. The Site is located in the floodplain of the Raccoon River, which is a tributary to the
Des Moines River (Figure 1). The surrounding area is industrial and commercial, with some
recreational park land. The Raccoon River is listed as a high priority impaired water due to
bacteria and nutrients.

Given the urban and industrial nature of the Site, permanent habitat for threatened and
endangered species is not likely to exist; however, it is possible that certain threatened and
endangered species are transient at the Site. Table 1 provides information on the protected
species and species of concern in Polk County.

The SPA would be considered a forested palustrine wetland. The ecology of these ponds and
floodplain areas is dominated by woody vegetation. Wetlands function as an important
ecological resource by providing habitat for birds and animals, especially semi-aquatic birds and
mammals, as well as amphibians and reptiles.

4.0. SITE INVESTIGATION

The site investigation included the collection of data necessary to evaluate the exposure and
effects of COPCs on ecological assessment endpoints. Specific information pertaining to field
sampling, including standard operating procedures and quality assurance and quality control can
be found in the field sampling and quality assurance and quality control plans for this site
(USEPA, 2014a; USEPA, 2014b). The following data was collected in April of 2015:

¦	Soil - Seven additional soil samples were collected at the Site to characterize current
conditions (Figure 2). Soil sampling focused on the soil surrounding the South Pond to
determine if contamination from the former facility is impacting surrounding areas due to
deposition and run-off.

¦	Surface Water - Twelve surface water samples were collected to further characterize
current conditions in the South Pond and adjacent drainage way (Figure 2).

¦	Sediment Sampling - Twelve sediment samples were collected to further characterize
current conditions in the South Pond and adjacent drainage way. Sediment samples were
co-located with surface water samples (Figure 2).

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5.0. PROBLEM FORMULATION

The problem formulation phase establishes the goals, breadth, and focus of the ERA (USEPA,
1997). This critical component of the process is the development of assessment endpoints, based
on a well-defined site conceptual model. Defining the ecological problems to be addressed
involves identifying toxic mechanisms of the COPCs, characterizing potential receptors, and
estimating exposure and potential risks.

5.1. CONTAMINANTS OF POTENTIAL CONCERN

Based on sampling events conducted during previous investigations, the primary COPCs are
organochlorine insecticides (aldrin/dieldrin and chlordane). Because PCBs have also been
identified as COPCs in the buildings north of the Site, potential releases of these contaminants
were also evaluated. Additional pesticides were also evaluated at the Site, including heptachlors
and DDT.

5.2. CHARACTERIZATION OF ECOLOGICAL EFFECTS OF COPCs

Organochlorine pesticides are chlorinated hydrocarbons used extensively from the 1940s through
the 1960s in agriculture and mosquito control. Representative compounds in this group include
DDT, methoxychlor, aldrin/dieldrin, chlordane, toxaphene, mirex, kepone, lindane, and benzene
hexachloride. One of the primary mechanisms of toxicity of organochlorine pesticides is that
effectively bind to sodium channels in neurons increasing permeability to sodium. This increased
permeability facilitates uncoordinated discharge of neurons, which leads to the failure of the
central nervous system.

PCBs belong to a broad family of man-made organic chemicals known as chlorinated
hydrocarbons. PCBs were first introduced into commerce in 1929 and became widely used in
electrical transformers, cosmetics, varnishes, inks, carbonless copy paper, pesticides and for
general weatherproofing and fire-resistant coatings to wood and plastic. PCBs have been shown
to have toxic effects on various organs including tissues of the nervous, reproductive, and
immunologic systems.

Both organochlorine insecticides and PCBs are considered Persistent Organic Pollutants. POPs
are toxic chemicals that adversely affect the environment. Because of their chemical structure,
they persist for long periods of time in the environment and can bioaccumulate in the food chain.
The primary COPCs at the site, aldrin/dieldrin, chlordane and PCBs, are on EPA's list of the
"Dirty Dozen." Detailed toxicity profiles for COPCs at the site can be found in Appendix A.

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5.3. MIGRATION PATHWAYS

The sources of contamination in the SPA include the historical pesticide formulation, storage and
handling operations at the Site, as well as the PCBs found in the buildings associated with OU4.
The following migration pathways exist at the Site:

¦	Soil-to-Surface Water/Sediment Migration

¦	Surface Water/Sediment to Soil Migration

¦	Biological/Food Chain Transfer

The following subsections present a discussion of each potential route of contaminant migration
for the Site.

5.3.1.	Soil to Surface Water/Sediment Migration. Contaminants from source areas may be
transported by the wind or surface water runoff and deposited down gradient in the floodplain of
the Raccoon River, including the surface water and sediment of the SPA and soils of the forested
area surrounding the pond.

5.3.2.	Sediment/Surface Water to Soil Migration. Contaminated sediment and surface water
can be a source of contamination to surrounding soils during high water events.

5.3.3.	Biological/Food Chain Migration. Biological migration may occur through uptake,
bioaccumulation, and food-chain transfer. Bioaccumulation can be predicted from log octanol-
water partitioning when the log Kow lies between 2 and 6. The log Kow values for the COPCs at
the site suggest a high potential for bioaccumulation and biomagnification. Further, the COPCs
identified at the Site are listed in Table 4-2 of Bioaccumulative Testing and Interpretation for the
Purposes of Sediment Quality Assessment, Status and Needs (EPA, 2000). The EPA generally
considers contaminants in this list to be of concern for biological transport.

5.4. ASSESSMENT ENDPOINTS

An assessment endpoint is "an explicit expression of the environmental value that is to be
protected" (USEPA, 1992). A measurement endpoint is defined as "a measurable ecological
characteristic that is related to the valued characteristic chosen as the assessment endpoint" and
is a measure of biological effects (e.g., mortality, reproduction, growth) (USEPA, 1992).
Measurement endpoints are frequently numerical expressions of observations (e.g., toxicity test
results, community diversity measures) that can be compared statistically to a control or
reference site to detect adverse responses to a site contaminant.

The conceptual model (Figure 3) establishes the complete exposure pathways that would be
evaluated in the ERA and the relationship of the measurement endpoints to the assessment
endpoints. The relationship of the selected measurement endpoint to the assessment endpoints
are presented in Table 2.

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5.4.1.	AE#1 Survival, Growth and Reproduction of Benthic Macroinvertebrates. Benthic
invertebrate communities are expected to be sensitive to the COPCs at the Site due to direct
exposure to sediment. Therefore, survival, growth and reproduction of benthic macroinvertebrate
communities exposed to COPCs in sediment was selected as an assessment endpoint.

Risk Question: Are concentrations of COPCs in sediment and surface water sufficient to
adversely affect the survival, growth and reproduction of benthic macroinvertebrates?

Measure Effects: The maximum and 95% Upper Confidence Limit of the mean (or similar EPC
term) of measured concentrations of COPCs in sediment and surface water were compared to
toxicity benchmark values for sediment.

5.4.2.	AE#2 Survival, Growth and Reproduction Soil Invertebrates. Terrestrial
invertebrates that are directly exposed to contaminated soil typically have the highest exposure to
the COPCs at the site. Further, aldrin/dieldrin and chlordane are insecticides that are persistent in
the environment. Therefore, survival, growth and reproduction of soil invertebrates exposed to
COPCs in soil were selected as an assessment endpoint.

Risk Question: Are concentrations of COPCs in soil sufficient to adversely affect the survival,
growth and reproduction of soil invertebrates?

Measure Effects: The maximum and UCL95 of measured concentrations of COPCs in soil were
compared to toxicity benchmark values for soil.

5.4.3.	AE#3 Survival, Growth and Reproduction of Insectivores. Food chain transfer of
contaminants from terrestrial soil invertebrates to higher trophic level organisms is an important
exposure pathway given the bioaccumalative nature of the COPCs at the site. Therefore,
survival, growth and reproduction of terrestrial insectivore communities exposed to COPCs is
included as an assessment endpoint. The short-tailed shrew (Blarina brevicauda) and American
woodcock (Scolopax minor) have been selected as receptors for this assessment endpoint.

Risk Question: Are concentrations of COPCs in soil sufficient to adversely affect the survival,
growth and reproduction of insectivores?

Measure Effects: The maximum and UCL95 of measured concentrations of COPCs in soil were
used in food chain models to calculate dietary exposure concentrations for insectivorous birds
and mammals. Receptor species representative of the feeding guilds identified as AEs for this
ERA were selected based on their potential to utilize the site, potential exposure to site-related
COPCs based on feeding habits, and availability of data to determine exposure parameters.

5.4.4.	AE#4 Survival, Growth and Reproduction of Carnivores. Food chain transfer of
contaminants from small mammals, birds and insects to higher trophic level carnivores is an
important exposure pathway given the bioaccumalative nature of the COPCs at the site.
Therefore, survival, growth and reproduction of terrestrial carnivore communities exposed to
COPCs is included as an assessment endpoint. The long-tailed weasel (Mustela frenata) and red-

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tailed hawk (Buteo jamaicensis) have been selected as receptors for this assessment endpoint.

Risk Question: Are concentrations of COPCs in soil sufficient to adversely affect the survival,
growth and reproduction of carnivores?

Measure Effects: The maximum and UCL95 of measured concentrations of COPCs in soil were
used in food chain models to calculate dietary exposure concentrations for carnivorous birds and
mammals. Receptor species representative of the feeding guilds identified as AEs for this ERA
were selected based on their potential to utilize the site, potential exposure to site-related COPCs
based on feeding habits, and availability of data to determine exposure parameters.

5.4.5. AE#5 Survival, Growth and Reproduction of Piscivores. Food chain transfer of
contaminants from fish to higher trophic level carnivores is an important exposure pathway
given the bioaccumalative nature of the COPCs at the site. Therefore, survival, growth and
reproduction of piscivore communities exposed to COPCs is included as an assessment endpoint.
The Great Blue Heron (Ardea herodias) has been selected as receptors for this assessment
endpoint.

Risk Question: Are concentrations of COPCs in sediment sufficient to adversely affect the
survival, growth and reproduction of piscivores?

Measure Effects: The maximum and UCL95 of measured concentrations of COPCs in sediment
were used in food chain models to calculate dietary exposure concentrations for piscivorous
birds. Receptor species representative of the feeding guilds identified as AEs for this ERA were
selected based on their potential to utilize the site, potential exposure to site-related COPCs
based on feeding habits, and availability of data to determine exposure parameters.

6.0. RISK CHARACTERIZATION

In the ecological risk characterization, data on exposure and effects are integrated into a
statement about risk to each assessment endpoint. A weight-of-evidence approach is used to
interpret the implications of different studies and tests for each assessment endpoint. Risk
characterization and the evaluation of potential uncertainties constitute the final phase of the risk
assessment process.

6.1. EVALUATION OF DIRECT EXPOSURE

Direct exposure to contaminated soil and sediment is evaluated for AE#1 and AE#2 using the
Hazard Quotient approach. An HQ is the ratio of the estimated exposure of a receptor at a site to
a benchmark exposure that is believed to be without significant risk of unacceptable adverse
effect on survival, growth, or reproduction. Conservative benchmark values are used to ensure
that potential ecological threats are not overlooked. The benchmarks for chronic No-Observable-
Adverse-Effect-Levels are exposure concentrations at which ecological effects are not expected.

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HQ = Exposure Point Concentration/Screening Level Benchmark
Exposure may be expressed in a variety of ways, including:

•	Concentrations in environmental media (water, soil, sediment, diet)

•	Concentrations in the tissues of the exposed receptor and/or

•	Amount of chemical ingested by a receptor

In all cases, the benchmark toxicity value must be the same type as the exposure estimate.

If the value of the calculated HQ is less than or equal to 1.0, risks to exposed organisms are
thought to be minimal. If the HQ exceeds 1.0, the potential for adverse effects in exposed
organisms may be of concern, with the probability and/or severity of the adverse effect tending
to increase as the HQ value increases.

6.1.1.	Calculation of the Exposure Point Concentration. The SPA is considered a single
exposure area. There are 12 sediment and surface water samples from the pond, and seven soil
samples from the perimeter of the pond (Figure 2). ProUCL version 5.0.0 (USEPA, 2013) was
used to calculate the maximum and UCL95 for all COPCs. Several COPCs had high frequencies
of non-detect values. When all of the reported values are non-detect, one EPC term is estimated
based on the x/i the highest Reporting Limit. If less than four detected values are present in the
dataset, the EPC term is calculated based on the median of the detected and non-detect values
(USEPA, 2013). For datasets with low frequencies of non-detects, the mean and UCL95 are
based on the recommendations provided in ProUCL, generally either Kaplan-Meier or Gamma
statistics. However, when the UCL95 statistic recommended in ProUCL exceeds the maximum
detected value, as was the case for dieldrin and chlordane in soil, the 95% Chebyshev UCL was
used as the EPC term. The EPCs for sediment, surface water and soil can be found in Tables 3-5,
and all ProUCL results can be found in Appendix D.

6.1.2.	Screening Level Benchmarks. The primary ecological effects of interest for the COPCs
at this site are direct toxicity; bioaccumulation within the food chain; and adverse effects on
survival, growth and reproduction of potentially exposed ecological receptors. Direct effects
were evaluated by comparing measured COPCs to screening level benchmarks. Sediment was
screened against consensus-based Sediment Quality Guidelines (Threshold and Probable Effect
Concentrations) (MacDonald et al., 2000) and Equilibrium Partitioning Sediment Benchmarks
(USEPA, 2003a; USEPA, 2008). Ecological Soil Screening Levels (USEPA, 2007a; USEPA,
2007b) were used to screen soil. Finally, USEPA Region 5 Ecological Screening Levels
(USEPA, 2003b) were used for all media when one of the above referenced screening values was
unavailable.

6.1.3.	HQ-Based Risk Characterization. If the maximum concentration did not exceed the
screening level, the COPC was removed from further evaluation at the site. If the maximum

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concentration exceeds screening levels, further risk evaluation was conducted using the UCL95
(or alternative EPC term).

6.1.4.	Survival, Growth and Reproduction of Benthic Macroinvertebrates. Risk to benthic
macroinvertebrates was evaluated by comparing maximum concentrations to conservative
screening levels (TEC or ESL). The TEC is a concentration below which effects are not likely to
occur, and ESLs are similarly protective. Screening level results for AE#1 can be found in Table
6. Only two COPCs were screened out, d-BHC and endrin aldehyde. A screening value is not
available for endrin ketone, therefore it was carried through the screen due to uncertainty.

COPCs that exceeded the TEC or ELS were evaluated further by comparing the UCL95 (or
alternative EPC term) to PECs and ESBs. PECs are concentrations above which effects are
probable (MacDonald et al., 2000). In addition, because organic carbon is a factor controlling the
bioavailability of nonionic organic compounds in sediments, ESBs were calculated on an organic
carbon basis for a number of COPCs and compared to ESBwqcs and ESB-rier2 values (USEPA,
2003a; USEPA, 2008). ESBs were calculated based on the UCL95 for both the COPC and total
organic carbon at the site. The conversion from dry weight to organic carbon- normalized
concentration was done using the following formula:

Hg chemical/goc = Hg chemical/gdw -r (% TOC 4- 100)

Results can be found in Table 7. It should be noted that the PEC and ESB for dieldrin were used
for comparison to aldrin because aldrin is rapidly converted to dieldrin in the environment, and
both have similar chemical structures. Consequently, toxicity data on aldrin is limited. The
primary COPCs at the site (aldrin/dieldrin and chlordane) exceed the PEC and ESB in the SPA.
The elevated HQpec for both compounds indicates risk to benthic macroinvertebrates is probable.
Further, the ESB evaluation shows that the organic carbon in the system is not decreasing the
bioavailability below the ESBs, indicating that these pesticides are partitioning into the
interstitial pore water at concentrations that exceed the final chronic values for water quality. The
results for aldrin, dieldrin and chlordane indicate that the risk to benthic macroinvertebrates is
substantial in the SPA.

Several other pesticides, as well as Aroclors, also exceed either PECs and/or ESBs. However, in
most cases, these results are calculated based on a non-detect EPC term. Consequently, there is
substantially more uncertainty associated with the risk evaluation for these COPCs.

6.1.5.	Survival, Growth and Reproduction of Soil Invertebrates. Risk to soil invertebrates
was evaluated by comparing maximum concentrations to ESLs because Eco-SSLs for soil
invertebrates are not available for the COPCs at the site. Screening level results for AE#2 can be
found in Table 8. The benzene hexachlorides, other than G-BHC, did not exceed ESLs.

Similarly, the metabolites of DDT (DDD and DDE) did not exceed ESLs. Also, endosulfan I and
II, and heptachlor epoxide, did not exceed ESLs.

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Hazard quotients based on the UCL95 (or alternative EPC term) can be found in Table 9. Hazard
quotients for aldrin, dieldrin, chlordane and Aroclor 1260 indicate probable risk to soil
invertebrates. Several other pesticides and Aroclors also exceed ESLs. However, in most cases,
these results are calculated based on a non-detect EPC term. Consequently, there is substantially
more uncertainty associated with the risk evaluation for these COPCs.

6.2. FOOD CHAIN EXPOSURE TO WILDLIFE RECEPTORS

Risks to wildlife were modeled using food chain models rather than comparisons based on direct
exposure. Food chain models are based on ingestion as the primary exposure route. The basic
equation for calculation of the HQ for a wildlife receptor exposed to a chemical via ingestion is:

HQi.j r = Ci.j * (IRj,r/BWr) *AUFr / TRVi.r

Where:

HQi.j.r = HQ for the exposure of receptor "r" to chemical "i' in medium "j"

Cij = Concentration of chemical "i" in medium "j" (mg/kg)

IRj.r = Ingestion rate of medium "j" by receptor "r" (kg/d)

BWr= Body weight of receptor "r" (kg)

AUFr = Area Use Factor of receptor "r" as a fraction of the receptor's home range that is
included in the exposure area being evaluated.

TRVi.r = Oral Toxicity Reference Value for chemical "i' in receptor "r" (mg/kg bw/d)

6.2.1.	Wildlife Exposure Factors. Exposure factors and ingestion rates for each representative
wildlife receptor can be found in Appendix E. Wildlife exposure factors were selected to
represent average year-around exposure to adults. Although AUFs can be adjusted for wildlife
receptors based on home ranges and seasonal use, an AUF of one is used in the dose equations
for this risk assessment.

6.2.2.	Estimates of Chemical Concentrations in Diet. For wildlife, the SPA is considered a
single exposure area. The UCL95 was used to estimate the concentrations of chemicals in the
diet. EPCs for sediment, surface water and soil can be found in Tables 3 through 5. Because data
is only available for soil, sediment and surface water, concentrations in prey items were modeled
based media specific concentrations. For terrestrial receptors, soil-to-invertebrate and soil-to-
mammal Bioaccumulation Factors were used to estimate prey concentrations (HAZWRAP,
1994; USEPA, 2007a; USEPA, 2007b). Soil invertebrate and mammal BAFs are calculated by
dividing the concentration of chemical "i" in tissue by the concentration of chemical "i" in soil.
Where BAFs could not be identified, a default BAF value of 1.0 was used. BAFs can be found in
Table 9, and modeled prey concentrations can be found in Table 11.

For piscivores, COPC concentrations in fish were based on Bioconcentration Factors identified
in the ECOTOX, Version 4.0 database (USEPA, 2015). BCFs are calculated by dividing the
concentration of chemical "i" in tissue by the concentration of chemical "i" in surface water.

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BCF data on small fish species, such as fathead minnows, was used when available. In some
cases, BCFs for larger fish were used due to lack of data on smaller fish. Where Ecotox data
could not be identified, modeled fish concentrations were based on a surrogate chemical. For
example, the BCF for Aroclor 1254, a more highly chlorinated Aroclor, was used to model
concentrations for Aroclor 1221. This was done to maintain conservatism in the risk estimates.
BCFs can be found in Table 10, and prey concentrations can be found in Table 11.

6.2.3.	Toxicity Reference Values. TRVs for wildlife were obtained by conducting a literature
search to obtain information on the ecological effects of COPCs identified at the site. This search
identified mechanisms of toxicity for COPCs and evaluated exposure-response data. TRVs based
on No Observed Adverse Effect Levels and Lowest Observed Adverse Effect Levels for dietary
effect concentrations for avian and mammalian receptors were identified. Detailed information
on TRVs can be found Appendix F. In some cases, a LOAEL value was not available for a
COPC. However, for all COPCs where the LOAEL was not available, the HQnoael did not
exceed one; therefore, a LOAEL value was not necessary for the risk characterization.

6.2.4.	HQ-based Risk Characterization. For assessment of effects to wildlife through the food
chain, if neither the NOAEL nor LOAEL based HQ is greater than or equal to 1.0, it is
concluded that there is no model-calculated risks to the given receptor. If the NOAEL based HQ
is greater than or equal to 1.0, but the LOAEL based HQ is less than one, it is concluded that the
model-calculated risks to the given receptor cannot be determined. If the LOAEL based HQ is
greater than or equal to 1.0, it is determined that there is model-calculated risks to a given
receptor.

6.2.5.	Survival, Growth, and Reproduction of Terrestrial Insectivores.

The short-tailed shrew and American woodcock were selected as receptors for AE#3. Exposure
factors for wildlife receptors can be found in Appendix E, and TRVs for birds and mammals can
be found in Appendix F. The Average Daily Dose equations for terrestrial insectivores can be
found in Table 12. Model-calculated risk to terrestrial insectivores was found for dieldrin, as the
HQloael for both receptors exceeds one. For Aroclor 1248, the HQloael exceeded one for the
short-tailed shrew, indicating model-calculated risk. However, this result is based on non-detect
data, resulting a high degree of uncertainty. For several Aroclors, DDE, and chlordane, the
HQnoaki. exceeds one, but the HQloael did not, indicating unknown risks.

6.2.6.	Survival, Growth and Reproduction of Terrestrial Carnivores.

The long-tailed weasel and red-tailed hawk were selected as receptors for AE#4. Exposure
factors for wildlife receptors can be found in Appendix E, and TRVs for birds and mammals can
be found in Appendix F. The Average Daily Dose equations for terrestrial carnivores can be
found in Table 12. Model-calculated risk to terrestrial carnivores was found for dieldrin, as the
HQloael for both receptors exceeded one. For Aroclor 1221, 1242, and 1248, the HQloael
exceeded one for the long-tailed weasel, indicating model-calculated risk. However, these results
are based on non-detect data, resulting a high degree of uncertainty. For several Aroclors, DDD,
DDE, DDT and chlordane, the HQnoael exceeded one for one or both of the receptors, but the
HQloael did not, indicating unknown risks.

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6.2.7. Survival, Growth and Reproduction of Piscivores

The Great Blue Heron was selected as receptors for AE#5. Exposure factors for wildlife
receptors can be found in Appendix E, and TRVs for birds and mammals can be found in
Appendix F. The Average Daily Dose equations for piscivores can be found in Table 12. Model-
calculated risk to piscivores was found for Aroclor 1016, 1221, 1232, 1248, 1254, and 1260. The
HQloael exceeds one for all of these COPCs; however, these results are based on modeled fish
concentrations from surface water concentrations that are non-detect; therefore, there is a large
degree of uncertainty. For DDE, dieldrin and toxaphene, the HQnoael exceeded one, but the
HQloael did not, indicating unknown risks.

7.0. UNCERTAINTIES

There are inherent uncertainties in the risk assessment process; however, knowledge of the cause
and potential effects of these uncertainties permits the risk assessor and risk manager to interpret
and use the risk assessment in making site management decisions. Sources of uncertainty fall
into several categories including analytical and sampling design, assumptions, natural variability,
error, and insufficient knowledge. Risk assessment is essentially the integration of the exposure
and hazard assessments. Sources of uncertainty associated with either of these elements may
contribute to overall uncertainty. In addition, the risk assessment procedure itself can contribute
to overall uncertainty. Each of these sources of uncertainty can be addressed differently;
therefore, understanding how each of these sources of uncertainty is handled within the risk
assessment is integral to the overall interpretation.

7.1.	ANALYTICAL DATA

The analytical database has inherent uncertainties. For example, the contribution of the chemical
of potential concern across the site was assumed to coincide with receptor contact with
environmental media. The degree to which this assumption is met is not quantifiable and
direction of bias cannot be measured.

In many instances, results were reported as non-detect. In those cases, ProUCL was used to
calculate exposure point concentrations. However, there is substantial uncertainty when using lA
the reporting limit or the median of a dataset in which the majority of the data is non-detect. In
some cases, the reporting limits were reported at up to 20 times the detection limit due to
laboratory interferences. This greatly increased the EPC term for a number of COPCs.

The use of non-detect data to calculate prey concentrations further increases this uncertainty. For
example, model-calculated risk for the heron exposed to Aroclors and toxaphene exceeded one;
however, the entire surface water dataset for these COPCs was non-detect, and the detection
limits for surface water were elevated, resulting in high modeled concentrations in the fish tissue.

7.2.	UNCERTAINTY OF THE CONCEPTUAL MODEL

Organisms use their environment unevenly, and differential habitat use based on habitat quality
is a source of uncertainty. Natural variability is an inherent characteristic of ecological systems
and stressors. Additionally, there is a limit to our understanding of the population dynamics of
most species, and the community interactions that exist between species. Limited knowledge of

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population ecology is fundamental in the interpretation of measurement endpoints as they relate
to the assessment endpoint.

Also, the exposure model is based on the "average" behavior of a species. As such, extremes of
behavior are not incorporated into the overall exposure assessment. While these assumptions
may not apply to all individuals, they are generally applicable at the population level and while
not all of the biological variability is captured in the assessment, no directional bias is
introduced.

Finally, an additional source of uncertainty is the exclusion of the air pathway due not only to
lack of data, but also due to the lack of physiological and toxicological data necessary to evaluate
this exposure pathway. While this may not generate significant amounts of additional COPC
exposure, it may be a contributor to overall risks.

7.3. UNCERTAINTIES ASSOCIATED WITH TOXICOLOGICAL STUDIES

7.3.1.	Variable Toxicity in the Aquatic Environment. There are specific uncertainties related
to toxicity of contaminants in the aquatic environment. Temporal variations and variations
related to climatic conditions can significantly increase or decrease the toxicity of COPCs. These
variations may affect the concentration of individual COPCs, other essential nutrients, and TOC,
which in turn affects toxicity and bioavailability.

7.3.2.	Extrapolation of Laboratory Toxicity Tests to Natural Conditions. The toxicological
data that were used to evaluate the implications of estimated doses to receptors of concern
constitute a source of uncertainty in the assessment. For example, organisms used in toxicity
tests conducted in laboratories are not necessarily subjected to the same degree of non-toxicant
related stress as receptors under natural conditions. In general, laboratory toxicity tests use single
toxicants while receptors in the field are exposed to multiple toxicants. Multiple toxicants can
behave independently (such as when modes of action are very different), they may act additively
(or synergistically), such that expression of effects is driven by several toxicants simultaneously,
or they may interact antagonistically. Cumulative effects of multiple stressors are not necessarily
the same. It is difficult to predict the direction of bias in this case as laboratory conditions and
natural conditions each may stress organisms but the relative magnitude and physiological
implications of these stresses are not actually comparable. Also, due to the differences in the
health of laboratory and field populations, differences in genetic diversity (and hence resistance
to stressors), and possible impacts of non-toxicant stressors, some unavoidable uncertainty exists
when extrapolating laboratory derived data to field situations. Given these factors, the difference
between conducting laboratory tests with single stressors as compared to natural conditions with
multiple stressors adds to the uncertainty regarding the conclusions of this risk assessment. In
addition, although it is believed that the important potential sources of toxicity have been
addressed, it is possible that there are unmeasured or unconsidered stressors at the site.

7.3.3.	Differences between Responses of Test Species and Receptor Species. Toxicological
studies also use species that, while they may be related to the taxa, or species, being evaluated at

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the site, are rarely identical. In general, the greater the taxonomic difference, the greater the
uncertainty associated with the application of study data to the receptors of potential concern.

7.3.4.	Differences in Chemical Forms of Contaminants. Many toxicological studies use
chemical formulations and/or administration methods that do not relate well to field exposures.

7.3.5.	Variability in Toxicity Reference Values. In some cases there may be a significant
difference between the no effect and lowest effect level toxicity reference values used to estimate
risk to a receptor. The actual point at which effects are seen could be anywhere in the range
between these two values. The greater the range between the two values, the greater the
uncertainty associated with the conclusions.

7.3.6.	Extrapolation of Individual Level Effects to Population-Level Effects. Laboratory
based bioassays or toxicity tests measure the response of a laboratory "population" of organisms
to the stressor under consideration. These populations generally represent a low diversity genetic
stock and, as such, probably do not represent the range of sensitivities and tolerances
characteristic of natural populations. As such, there is uncertainty associated with extrapolation
of laboratory population responses to populations in natural systems. This uncertainty is
probably not directionally biased as both sensitive and tolerant individuals may be missing from
the laboratory populations.

7.4. UNCERTAINTIES ASSOCIATED WITH THE EXPOSURE ASSESSMENT

The SPA is less than one acre. It was assumed that the area-use-factor is 100% for each wildlife
receptor. Other than the short-tailed shrew, this assumption likely results in an over-estimate of
risk.

An additional source of uncertainty associated with exposure calculations is that feeding rates
were assumed to not vary with season, breeding condition, or with other local factors. Reported
feeding rates undoubtedly vary with all of these factors because metabolic needs change as does
food availability. Conservative estimates of feeding rates were derived from studies that reported
for multiple seasons.

Further, dietary compositions were simplified for each wildlife receptor. For example, herons
consume a variety of aquatic species, as well as some terrestrial prey. Red-tail hawks are
opportunistic hunters that feed on a variety of small animals, not just small mammals. However,
the direction and magnitude of the uncertainty related to simplifying diets is not known. Finally,
diet composition was assumed to not vary with season or local conditions. As with feeding rates,
this assumption is unlikely to be met but the direction of bias is not measurable.

Finally, all of the prey concentrations were modeled based off of BAFs/BCFs from a variety of
sources (HAZWRAP, 1994; USEPA, 1995, ECOTOX, 2015). Modeling always introduces more
uncertainty in comparison to having data from prey inhabiting the Site. For example, there are a
number of surface water-to-fish BCFs for each COPC available from the ECOTOX database.

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Only one value was selected. Uncertainty was somewhat reduced by selecting BCFs based on
small laboratory fish species; however, there is certainly a range of BCFs and the true
concentration in small fish from the SPA could be more reliably estimated by collection of fish
from the pond, which was not done.

7.5. UNCERTAINTY IN EVALUATING ECOLOGICAL RISK

There is uncertainty associated with the interpretation of hazard quotients. The calculated hazard
quotients are based on a literature benchmark. Data are generally not available on the slope of
the toxicity curve for most contaminants and little is known about the interaction of the
contaminant on the slope of the toxicity curve. For this reason, as well as others discussed in this
section, the numerical value of a hazard quotient has little absolute meaning. For example,
hazard quotients above 1 indicate a potential risk relative to the toxicological benchmark, but a
hazard quotient of 10 does not mean that the risk is 10 times greater.

There is also the issue of immeasurable long-term effects and adaptations. Due to the complexity
of community and population dynamics, it is not currently possible to evaluate all possible
effects by implementation of even the most ambitious studies. The information presented, while
complete and accurate, may miss long-term adverse effects of contaminants on receptors or may
fail to address adaptation to conditions that impart some immunity to contaminant effects. In
addition, ecological functional redundancies contributed by unevaluated species (multiple
species may fill the same niche) may provide resilience against adverse effects at the community
and ecosystem levels and sensitivities may be present in other populations that have not been
evaluated in the current risk assessment. In either case, the results presented are only snap-shots
of conditions as they exist at the site and it is essentially certain that not all of the underlying
variability and stressor effects have been quantified. As such, it is important for the reader to
recognize that large uncertainties exist regarding community and population health, but that
these uncertainties most likely do not directionally bias conclusions.

8.0. SUMMARY AND CONCLUSIONS

The primary COPCs at the site are aldrin, dieldrin, and chlordane. PCBs are also a potential
concern due to their presence in the buildings on the Site. Aldrin tanks were stored at the SPA,
and aldrin contamination is still present at the Site. However, it is Aldrin's breakdown product,
dieldrin that appears to be the primary risk driver. Dieldrin contamination at the SPA is
widespread, as it was detected in all sediment and soil samples. Dieldrin was also detected in
surface water at locations 8 and 11. Modeled-risks are probable for all of AEs, except AE#5
(piscivores), in which the risk is unknown (HQnoael >1, but HQloael < 1). Therefore, it is
concluded that significant ecological risk is likely at the SPA due to dieldrin contamination.
Also, chlordane was detected in all of the sediment and soil locations and in surface water at
Location 8. Potential risk due to Chlordane was identified for soil invertebrates and benthic
macroinvertebrates, but not for wildlife receptors at the site.

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Of the Aroclors evaluated, only Aroclor 1260 was detected in soil and sediment at the site.
Probable risks to soil invertebrates and benthic invertebrates was found for Aroclor 1260. Risks
were unknown for terrestrial wildlife receptors with HQnoael values >1, but HQloael values <
1. Aroclor 1260 was not detected in surface water; therefore, modeled risks to the heron are
highly uncertain. Although potential risk due to other Aroclors was identified for all AEs, this
risk is uncertain, as the data was non-detect.

Other pesticides were evaluated in the risk assessment, even though they were not identified as
site-specific COPCs. Several of these pesticides were detected in soil and sediment. The extent to
which these pesticides were related to intended use in the past is unknown. For example, DDT
may have been applied at the SPA (or in the vicinity). The impact of these additional pesticides
on ecological receptors is likely to be additive to the overall effects of the site-related COPCs at
the Site.

Direct exposure to sediment and soil impacting the soil invertebrate and benthic
macroinvertebrate populations at the SPA is a probable risk at the site. Food chain exposure to
dieldrin to wildlife receptors with small home ranges, such as small mammals, is also likely to be
significant. However, the small size of the site may limit food chain exposure to higher trophic
level wildlife receptors. For receptors with large home ranges (red-tailed hawks, American
woodcocks and long-tailed weasels), true exposure is likely to be less than the exposure assumed
in this risk assessment. The habitat south of the site includes woods and riparian zones that
would also provide areas for foraging, and human encroachment on the SPA may be a deterrent
to wildlife to some degree.

20


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9.0. REFERENCES

HAZWRAP, 1994. Loring Air Force Base Ecological Risk Methodology. Martin Marietta
Energy Systems, Inc.

MacDonald D.D., C.G. Ingersoll, and T.A. Berger. 2000. Development and evaluation of
consensus-based sediment quality guidelines for freshwater ecosystems. Arch. Environ. Contam.
Toxicol. 39:20-31.

USEPA, 1992. Framework for Ecological Risk Assessment. EPA/63-R-92/001.

USEPA, 1997. Ecological Risk Assessment Guidance for Superfund, Process for Designing and
Conducting Ecological Risk Assessments. EPA 540/R97/006.

USEPA, 2000. Bioaccumulation Testing and Interpretation for the Purpose of Sediment Quality
Assessment, Status and Needs. February 2000. EPA 823-R-OO-OOl.

USEPA, 2003a. Procedures for the Derivation of Equilibrium Partitioning Sediment Benchmarks
(ESBs) for the Protection of Benthic Organisms: Dieldrin. EPA/600/R-02/010.

USEPA, 2003b. USEPA Region 5 Ecological Screening Levels.
http://epa.gov/Region5/waste/cars/pdfs/ecological-screening-levels-200308.pdf

USEPA, 2007a. Ecological Soil Screening Levels for Dieldrin. Interim Final. OSWER Directive
9285.7-57.

USEPA, 2007b. Ecological Soil Screening Levels for DDT and Metabolites. Interim Final.
OSWER Directive 9285.7-57.

USEPA, 2008. Procedures for the Derivation of Equilibrium Partitioning Sediment Benchmarks
(ESBs) for the Protection of Benthic Organisms: Compendium of Tier 2 Values for Nonionic
Organics. EPA/600/R-02/016.

USEPA, 2013. ProUCL 5.0.00 User Guide. Statistical Software for Environmental Applications
for Data Sets with and without Nondetect Observations. EPA/600/R-07/041.

USEPA, 2014a. Quality Assurance Project Plan for Field Sampling for Ecological Assessment at
the Des Moines TCE Site Operable Unit 04.

21


-------
USEPA, 2014b. Field Sampling Plan for Ecological Assessment, Des Moines TCE Site,
Operable Unit 04.

USEPA, 2015. ECOTOX Database, http://cfpub.epa.gov/ecotox/

22


-------
APPENDIX A: TOXICITY PROFILES

23


-------
Aldrin/Dieldrin

Based on information from the EcoSSL Toxicity Profile
(USEPA, 2007)

24


-------
Aldrin (1,2,3,4,10,10-hexachloro-1,4,4",5,8,8"-exo-1,4-endo-5,8-dimethano-naphthalene or HHDN)
and its epoxide derivative dieldrin (l,2,3,4,10,10-hexachloro-6,7-epoxy- l,4,4",5,6,7,8,8"-octahydro-
l,4-endo,exo-5,8-dimethanonaphthalene, or HEOD), are man-made chlorinated cyclodiene insecticides
used extensively in the United States from the 1950s to the early 1970s. Aldrin is discussed along with
dieldrin as it readily changes into dieldrin when it enters the environment. The trade names used for
dieldrin included Alvit, Dieldrix, Octalox, Quintox and Red Shield (ATSDR, 2002). Aldrin and
dieldrin were used primarily for the control of termites around buildings, corn pests by application to
soil and in the citrus industry (U.S. EPA, 1980). Other uses included crop protection from insects,
timber preservation and termite-proofing of plastic and rubber coverings of electrical and
telecommunication cables and of plywood and building boards (Worthing and Walker, 1983). The U.S.
Department of agriculture canceled all uses of aldrin and dieldrin in 1970. In 1972, however, EPA
approved aldrin and dieldrin for use in three instances: 1) subsurface ground insertion for termite
control; 2) dipping of non-food plant roots and tops; and 3) moth-proofing in manufacturing processes
using completely closed systems (USEPA, 1980 and 1986). Use for termite control continued until
1987 when the manufacturer voluntarily canceled the registration for use in controlling termites.
Manufacture in the U.S. ceased in 1989 (ATSDR, 2002).

Dieldrin in the soil environment has low to no mobility. Dieldrin is nonpolar, has a strong affinity for
organic matter and sorbs tightly to soil particles. Volatilization is the principal loss process but is slow
due to its low vapor pressure and strong sorption. Dieldrin degrades slowly in soil surfaces with a
reported half-life of about 7 years in field studies. Dieldrin (and aldrin) applied to soil may also
undergo degradation by ultraviolet light to form photodieldrin and this reaction may also occur as a
result of microbial activity. In soil, aldrin is converted to dieldrin by epoxidation (ATSDR, 2002).

Dieldrin bioaccumulates in both terrestrial and aquatic systems. As both plants and animals metabolize
aldrin to dieldrin via epoxidation, significant levels of aldrin are seldom found in biological matrices.
Therefore, most studies focus on dieldrin rather than aldrin. In plants, dieldrin is accumulated primarily
in the roots with aerial parts containing smaller concentrations (ATSDR, 2002). In terrestrial
organisms, accumulation of dieldrin in fat tissues is known to increase with increasing trophic level of
the organism with predators at the top of the food chain tending to have the highest exposure and
greatest risk. In mammals, dieldrin is accumulated in adipose tissue, liver and brain. The neurotoxicity
of dieldrin to the Central Nervous System is well documented. CNS manifestations originate in neural
synapses. Dieldrin prevents the action of the neurotransmitter gamma-aminobutyric acid (GABA) by
binding to the picrotoxin binding site of the GABA-receptor-ionophore complex (Matsurmura and
Giashudding, 1983). GABA is secreted only by nerve terminals in the spinal cord, the cerebellum, the
basal ganglia, the retina, and areas of the cortex. It is thought to cause inhibition of neurotransmission
by binding the complex and creating a structural alteration preventing influx of CI- and repolarization
of the membrane (Bloomquist and Soderlund, 1985). Basal ganglia innervation by GABA neurons
originating from the cortex provide inhibitory input. GABA, therefore, lends stability to motor control
systems (Guyton 1991). Without the inhibitory effect of the GABA transmitter, there is uncontrolled

25


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motor stimulation leading to convulsions and other CNS manifestations of dieldrin. In mammals,
clinical signs of toxicity include depressed activity, followed by hyperexcitability, tremors and
convulsions (Coats, 1990; Matsurmura and Giashudding, 1983).

References:

ATSDR. 2002. Toxicological Profile for Aldrin/Dieldrin. US. Department of Health and Human
Services. September, http://www.atsdr.cdc.gov/toxpro2.html

Bloomquist, J.R., and D.M. Soderlund. 1985. Neurotoxic insecticides inhibit GABA-dependent
chloride uptake by mouse brain vesicles. Biochem. Biophys. Res. Commun. (133). 37-43.

Coats, J.R. 1990. Mechanisms of toxic action and structure-activity relationships for
organochlorine and synthetic pyrethroid insecticides. Environmental Health Perspectives. 87:
255-262.

Guyton, A.C. 1991. Textbook of Medical Physiology. 8th Ed. W.B. Saunders Company.
Harcourt Brace Jovanovich, Inc. Philadelphia, Pennsylvania. Hazardous Substances Database
(HSDB). U.S. National Library of Medicine, http://toxnet.nlm.nih.gov/

Matsumura, F., and S.M. Ghiasuddin. 1983. Evidence for similarities between cyclodiene type
insecticides and picrotoxin in their action mechanisms. J. Environ. Sci.Health. Part B. (B18). 1-
14.

USEPA. 1986. Guidance for the Reregistration of Pesticide Products containing Aldrin as the
Active Ingredient. Case No. 0172. Washington, DC, U.S. EPA Office of Pesticide Programs.

USEPA. 1980. Ambient Water Quality Criteria for Aldrin/Dieldrin. U.S. EPA Criteria and
Standards Division. PB81-11730/OWRS.

Worthing, C.R. and S.B. Walter (eds). 1983. The Pesticide Manual: A World Compendium, 7th
ed. Suffolk, Great Britain: The Lavenham Press Limited.

26


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Aroclors

Based on Information from Eisler (2000)

27


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Aroclor is the trade name used for most of the commercial PCB mixtures created in the United
States by the Monsanto Company. These were sold in the US under the name Aroclor followed
by a 4-digit number. The first two digits represent the number of carbon atoms (12); the second
two digits indicate the percentage of chlorine by mass in the mixture. For example, Aroclor 1260
contains 60% chlorine by mass. Aroclors with lower numbers are "light" oily liquids, while at
the higher end they have a "heavier," more waxy form.

The transport and fate of PCBs in the aquatic environment and their partitioning between
sediment, water and organisms depends largely on sorption reactions. In soils, the sorption and
retention of PCB congeners is influenced by the number of chlorine atoms in the molecule, and
the more highly chlorinated PCBs tend to more strongly bind to soil particles. The soil sorption
capacity and bioconcentration factors of PCBs are strongly related to the octanol-water partition
coefficient (KoW). The higher K,,w values of PCBs is what leads to their bioaccumulation and
biomagnification in the food web.

The amount of chlorine largely determines the physical properties of different Aroclors. The
toxicology of PCBs varies considerably among congeners, depending on the number and
location of chlorines on the biphenyl molecule, and also between animal species due to
differences in absorption, metabolism, mechanism of action, and potential toxic effects.

Common effects of PCB exposure observed in various animals are summarized in the table
below (Hansen, 1994).

System Affected

Specific Effect

Hepatic effects

Hepatomegaly, bile duct hyperplasia;

Widespread (e.g., rabbit) or focal (e.g., mouse) necrosis;

Lipid accumulation, fatty degeneration;

Induction of microsomal monooxygenases and other enzymes;

Decreased activity of membrane ATPases;

Depletion of fat-soluble vitamins;

Porphyria

Gastrointestinal effects

Hyperplasia and hypertrophy of gastric mucosa;

Gastric ulceration and necrosis;

Proliferation and invasion of intestinal mucosa (monkey);
Hyperplasia, hemorrhage, necrosis (hamster, cow)

Respiratory system

Chronic bronchitis, chronic cough

28


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Nervous system

Alterations in catecholamine levels;
Impaired behavioral responses;
Developmental deficits;

Depressed spontaneous motor activity;
Numbness in extremities

Skin

Chloracne;
Edema, alopecia

lmmunotoxicity

Altered levels of circulating steroids;

Estrogenic, antiestrogenic, antiandrogenic effects;

Decreased levels of plasma progesterone;

Adrenocortical hyperplasia;

Thyroid pathology, changes in circulating thyroid hormones

Reproduction

Increased length of estrus;

Decreased libido;

Embryo and fetal effects following in utero exposure

Carcinogenesis

Promoter;

Attenuation of some carcinogens

References:

Eisler, R. 2000. Handbook of Chemical Risk Assessment: Health Hazards to Humans, Plants, 2
and Animals. Volume 2 - Organics. Lewis Publishers, Boca Raton, FL. ISBN 1-56670-506-1.

29


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Chlordane
Based on Information from Eisler (2000)

30


-------
Technical chlordane is an organochlorine compound first introduced into the United States in
1947 in a variety of formulations for use as a broad-spectrum pesticide. By 1974, about 9.5
million kilograms of chlordane were produced annually. Concern over the potential
carcinogenicity of chlordane has led to sharply curtailed production. Since 1983, chlordane use
in the United States has been prohibited, except for control of underground termites.

Technical chlordane consists of about 45 components, primarily cis-chlordane (19%), trans-
chlordane (24%), heptachlor (10%), cis- and trans-nonachlor (7%), and various chlordane
isomers (22%). Chemical analysis of technical chlordane is difficult because of analytical
interferences from other organochlorine compounds, nonstandardization of analytical techniques,
variations in the number and relative composition of components in weathered chlordane, and,
uncertainty of structural formulas and other properties of several compounds present.

Past chlordane use, coupled with atmospheric transport as the major route of dissemination,
produced global contamination of fish and wildlife resources and human populations. The
chemical and its metabolites were frequently detected in all species examined, but usually at low
concentrations. Residues in fish muscle sometimes exceeded the U.S. Food and Drug
Administration action level of 0.3 mg/kg fresh weight recommended for human health
protection. In general, chlordane in animals is highest near areas where the chemical has been
applied to control termites; concentrations are highest in fat and liver, especially in predatory
species.

The half-life of chlordane in water is comparatively short; cis-chlordane, for example, usually
persists less than 18 h in solution. In soils, however, some chlordane isomers persist for 3 to 14
years because of low solubility in water, high solubility in lipids, and relatively low vapor
pressure. There seems to be little accumulation of chlordane in crops grown in contaminated
soils.

Chlordane is readily absorbed by warm-blooded animals through skin, diet, and inhalation, and
distributed throughout the body. In general, residues of chlordane and its metabolites are not
measurable in tissues 4 to 8 weeks after exposure, although metabolism rates varied significantly
between species. Food chain biomagnification is usually low, except in some marine mammals.
In most mammals, the metabolite oxychlordane has proven much more toxic and persistent than
the parent chemical.

Many species of aquatic organisms are adversely affected at concentrations in water between 0.2
and 3.0 pg/L technical chlordane. Sensitive bird species had reduced survival on diets containing
1.5 mg chlordane per kilogram in their diet, or after a single oral dose as low as 14.1 mg
chlordane per kilogram body weight. Chlordane has produced liver cancer in laboratory strains

31


-------
of domestic mice, but carcinogenicity has not been established in other mammals.

Chlordane criteria for protection of marine life (0.004 (Jg/L, 24-h mean; not to exceed 0.09 ng/L)
seem satisfactory. Proposed criteria for freshwater life protection (0.0043 (Jg/L, 24-h mean; not
to exceed 2.4 jig/L) however, overlap the range of 0.2 to 3.0 |ig/L shown to adversely affect
certain fish and aquatic invertebrates, suggesting that some downward modification in the
maximum permissible level is needed. Chlordane criteria for protection of birds and mammals
are inadequate because the data base is incomplete. Until these data become available, a
reasonable substitute is the criteria proposed for human health protection, namely, daily intake
not to exceed 0.001 mg chlordane per kilogram body weight, and diet not to exceed 0.3 mg
chlordane per kilogram fresh weight.

Most authorities agree that more studies are needed in several areas: monitoring of oxychlordane
concentrations in wildlife; interpretation of the biological significance of residue levels found in
wildlife; standardization of analytical extraction and other techniques for quantitation of
chlordane and its metabolites; reexamination of aquatic toxicity data where test concentrations
exceeded the solubility of chlordane in water (6 to 9 (Jg/L); interaction effects with other
agricultural chemicals; reevaluation of the cancer risk of chlordane on representative organisms
at realistic environmental levels; effects of depleted soil fertility from chlordane induced
earthworm suppression; and continuance of epidemiological studies on exposed workers.

Reference:

Eisler, R. 2000. Handbook of Chemical Risk Assessment: Health Hazards to Humans, Plants, 2
and Animals. Volume 2 - Organics. Lewis Publishers, Boca Raton, FL. ISBN 1-56670-506-1.

32


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APPENDIX B: FIGURES

33


-------
34


-------
Foundations;
Buildings" I

1

f . Ra

Raccoon R

South PonC Area

epiK-r «!t»gHr»n^»,&*twi>t«liqrtSe1r?

Figure 1. Des Moines TCE Site.

35


-------
SD11/SW11

S010/SW10

SD12SW12

6S07

SD03SW03

SD09SW09

SD07/SW07

SD06 SW08

SD0*1/SWOlSD02 SW02

SD06 SW06

SD05 SW05

'SS01

SD04 SW04

*71, dW!?[>	sirjtjm

wssmp,	is. tew\,ofio«^an

(Wimnfr-

Figure 2. Sediment, Surface Water and Soil Sampling Locations.

36


-------
37


-------
FIGURE 3. Conceptual Model for hcologlcal Exposure at the l)es Moines TCE Site







Source



Release Mechanism



Potentially Impacted Environmental Media



Exposure Route

Aquatic Receptors

Terrestrial Receptors
(Plants. Invertebrates)

Wildlife Receptors
(Birds. Keptiles,
Mammals)







Amphibians

Bent hie
Organisms

Plants

Soil
Organisms











Dust m Air



Inhalation









X





Direct Contact





X





/

































Deposition in surrounding
soiK from high water events



Surface Soi



Ingestion







X

•









	*



Direct Contact





•

•

X















































Historic Pesticide

strragc and
formulation ami run
off from built lings









Terrestrial Food Items
f Plants, Mammals.
Invertebrates)

















uptake inii> tLssuer



Ingestion







1 . 1





















































Surface Water



Ingestion









•













Direct Contact

•

•





X







Run off from pesticide
storage in buildings and lank







V \

















\





















Aquati: Food Items
(Aquatic Invertebrates.
Plants)

















uptake into tissues

	*

Ingestion

O

O





•













































\





















Sediment



Ingestim

X

X





•









Direct ( omact

X

•





X





















































Pathway is nut complete, no evaluation required









X

Pathway is complete hu probably cannot he evaluated quantitatively











•

Pathway is complete and could he significant, quantiauvc evaluation









O

Pathway is complete, limited quantiativc evaluation may he possWe





38


-------
APPENDIX C:TABLES

39


-------
Table 1. Protected Species and Species of Concern.

TYPE

SCIENTIFIC NAME

COMMON NAME

STATUS

NUMBER
OF

RECORDS

Fish

Ammocrypta Clara

Western Sand Darter

T

1

Reptile

Emydoidea Blandingii

Blanding's Turtle

T

3

Fish

Esox Americanus

Grass Pickerel

T

1

Fish

Notropis Heterolepis

Blacknose Shiner

T

1

Reptile

Ophisaurus Attenuatus

Slender Glass Lizard

T



Mammal

Perognathus
Flavescens

Pocket Mouse

E

1

Butterfly

Poanes Zabulon

Skipper

SC

1

Mammal

Spilogale Putorius

Spotted Skunk

E



Plant

Cirsium Hillii

Hill's Thistle

SC

1

Plant

Cypripedium
Candidum

Small White Lady's Slipper

SC

1

Plant

Opuntia Fragilis

Brittle Prickly Pear

T

1

Plant

Plantathera Praeclara

Western Prairie Fringed
Orchid

T

1

Plant

Spiranthes
Magnicamporum

Plant Great Plains Lady's
Tresses

SC

1



Spiranthes Ovalis

Oval Lady's Tresses

T

7

Endangered

T: Threatened

SC: Special Concern (no protection status)

Source: Iowa Department of Natural Resources, Conservation and Recreation Division

40


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Table 2. Assessment Endpoints and Measures of Exposure and Effects.

Assessment Endpoint

Measures of Exposure/Effects

Survival, growth and reproduction of benthic invertebrates.

Compare maximum and UCL95 concentrations of COPCs in
sediment to screening benchmark values.

Survival, growth and reproduction of soil invertebrates

Compare maximum and UCL95 concentrations of COPCs in soil to
screening benchmark values for soil invertebrates.

Survival, growth and reproduction of insectivorous birds and mammals

Maximum and UCL95 concentrations of COPCs measured in soil
will be used in food chain models to calculate dietary exposure of
selected receptor species. Calculated dietary exposure concentrations
will be compared with TRVs for COPCs obtained from the literature
for birds and mammals.

Survival, growth and reproduction of carnivorous birds and mammals.

Maximum and UCL95 concentrations of COPCs measured in soil
will be used in food chain models to calculate dietary exposure of
selected receptor species. Calculated dietary exposure concentrations
will be compared with TRVs for COPCs obtained from the literature
for birds and mammals.

Survival, growth and reproduction of piscivorous birds.

Maximum and UCL95 concentrations of COPCs measured in surface
water will be used in food chain models to calculate dietary exposure
of selected receptor species. Calculated dietary exposure
concentrations will be compared with TRVs for COPCs obtained
from the literature for birds.

41


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Table 3. Exposure Point Concentrations for Sediment (pg/kg).

Location

Latitude Longitude TOC % Aldrin

Detection
ID

Aroclor 1016

1

41.57647

-93.63753

2.88

3200

J

1200

2

41.57641

-93.63737

5.66

77

J

1700

3

41.57671

-93.63732

2.33

4200

J

780

4

41.57603

-93.63725

3.28

29

J

860

5

41.57635

-93.63799

3.09

25

UJ

850

6

41.57648

-93.63836

4.24

64

J

980

7

41.576525

-93.63864

9.05

89

J

2600

8

41.5765

-93.63773

0.366

490

J

500

9

41.57667

-93.63827

3.99

260

J

1000

10

41.5769

-93.6386

6.24

990

J

3400

11

41.57711

-93.63879

1.5

740

J

690

12

41.57685

-93.63871

5.53

110

J

1700

Maximum
UCL95
Median
1/2 max RL







4200
2600



3400
1700

42

Detection Arocor 1221 Detection Aroclor 1232 Detection

ID	ID	ID

U	1200	U	1200	U

U	1700	U	1700	U

U	780	U	780	U

U	860	U	860	U

U	850	U	850	U

U	980	U	980	U

U	2600	U	2600	U

U	500	U	500	U

U	1000	U	1000	U

U	3400	U	3400	U

U	690	U	690	U

U	1700	U	1700	U

3400	3400

1700

1700


-------
Location

Latitude

Longitude

TOC %

Aroclor 1242

De











ID

1

41.57647

-93.63753

2.88

1200

U

2

41.57641

-93.63737

5.66

1700

U

3

41.57671

-93.63732

2.33

780

U

4

41.57603

-93.63725

3.28

860

U

5

41.57635

-93.63799

3.09

850

U

6

41.57648

-93.63836

4.24

980

U

7

41.576525

-93.63864

9.05

2600

U

8

41.5765

-93.63773

0.366

500

U

9

41.57667

-93.63827

3.99

1000

U

10

41.5769

-93.6386

6.24

3400

U

11

41.57711

-93.63879

1.5

690

u

12

41.57685

-93.63871

5.53

1700

u

Maximum







3400



UCL95











Median











1/2 max RL







1700



Aroclor 1248 Detection Aroclor 1254 Detection Aroclor 1260 Detection

ID	ID	ID

1200	U	580	U	3200	U

1700	U	870	U	870	U

780	U	390	U	390	U

860	U	430	U	430	U

850	U	420	U	420	U

980	U	490	U	490	U

2600	U	1300	U	1300	U

500	U	250	U	250	U

1000	U	520	U	520	U

3400	U	1700	U	1700	U

690	U	340	U	1900

1700	U	860	U	860	U

3400	1700	1900

690

1700	850

43


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Location

Latitude Longitude TOC % A-BHC

Detection B-BHC
ID

1

41.57647

-93.63753

2.88

17

U

58

2

41.57641

-93.63737

5.66

26

U

87

3

41.57671

-93.63732

2.33

12

U

39

4

41.57603

-93.63725

3.28

13

U

43

5

41.57635

-93.63799

3.09

13

u

42

6

41.57648

-93.63836

4.24

15

u

49

7

41.576525

-93.63864

9.05

38

u

130

8

41.5765

-93.63773

0.366

7.5

u

25

9

41.57667

-93.63827

3.99

16

u

52

10

41.5769

-93.6386

6.24

51

u

68

11

41.57711

-93.63879

1.5

10

u

35

12

41.57685

-93.63871

5.53

26

u

86

Maximum







51



130

UCL95













Median













1/2 max RL







25.5



65

44

Detection	D-BHC	Detection G-BHC	Detection

ID	ID	ID

U	23	U	23	U

U	35	U	35	U

U	16	U	16	U

U	17	U	17	U

U	17	U	17	U

U	20	U	20	U

U	51	U	51	U

U	10	U	10	U

U	21	U	21	U

U	100	U	68	U

U	14	U	14	U

U	35	U	35	U

100	68

50	34


-------
Location

Latitude

Longitude

TOC %

Chlordane

Dieldrin

Endc

1

41.57647

-93.63753

2.88

48000

1100

35

2

41.57641

-93.63737

5.66

2700

250

52

3

41.57671

-93.63732

2.33

32000

3200

23

4

41.57603

-93.63725

3.28

260

110

26

5

41.57635

-93.63799

3.09

500

56

25

6

41.57648

-93.63836

4.24

1700

53

30

7

41.576525

-93.63864

9.05

6200

310

77

8

41.5765

-93.63773

0.366

1400

450

15

9

41.57667

-93.63827

3.99

2500

360

31

10

41.5769

-93.6386

6.24

7100

1200

100

11

41.57711

-93.63879

1.5

5400

1100

21

12

41.57685

-93.63871

5.53

3500

290

52

Maximum
UCL95
Median
1/2 max RL







48000
23829

3200
1533

100
50

45

Detection Endosulfan II Detection Endosulfan	Detection

ID	ID	Sulfate	ID

U	35	U	46	U

U	52	U	70	U

U	23	U	31	U

U	26	U	35	U

U	25	U	34	U

U	30	U	39	U

U	77	U	100	U

U	15	U	20	U

U	31	U	42	U

U	100	U	140	U

U	21	U	28	U

U	52	U	69	U

100	140

50

70


-------
Location

Latitude

Longitude

TOC %

Endrin

De











ID

1

41.57647

-93.63753

2.88

46

U

2

41.57641

-93.63737

5.66

70

U

3

41.57671

-93.63732

2.33

31

U

4

41.57603

-93.63725

3.28

35

U

5

41.57635

-93.63799

3.09

34

U

6

41.57648

-93.63836

4.24

39

U

7

41.576525

-93.63864

9.05

100

U

8

41.5765

-93.63773

0.366

20

U

9

41.57667

-93.63827

3.99

42

U

10

41.5769

-93.6386

6.24

140

U

11

41.57711

-93.63879

1.5

28

U

12

41.57685

-93.63871

5.53

69

U

Maximum







140



UCL95











Median











1/2 max RL







70



Endrin	Detection Endrin	Detection Heptachlor	Detection

Aldehyde	ID	Ketone	ID	ID

58	U	46	U	35	U

87	U	70	U	52	U

39	U	31	U	150

43	U	35	U	26	U

42	U	34	U	25	U

49	U	39	U	30	U

130	U	100	U	77	U

25	U	20	U	15	U

52	U	42	U	31	U

170	U	140	U	100	U

34	U	28	U	21	U

86	U	69	U	52	U

170	140	150

33

85	70

46


-------
Location

Latitude

Longitude

TOC %

Heptachlor

Detection

p,p'-[









Epoxide

ID



1

41.57647

-93.63753

2.88

35

U

2900

2

41.57641

-93.63737

5.66

52

U

70

3

41.57671

-93.63732

2.33

23

u

31

4

41.57603

-93.63725

3.28

26

u

35

5

41.57635

-93.63799

3.09

25

u

34

6

41.57648

-93.63836

4.24

30

u

79

7

41.576525

-93.63864

9.05

77

u

100

8

41.5765

-93.63773

0.366

15

u

20

9

41.57667

-93.63827

3.99

31

u

86

10

41.5769

-93.6386

6.24

100

u

190

11

41.57711

-93.63879

1.5

21

u

28

12

41.57685

-93.63871

5.53

52

u

97

Maximum







100



2900

UCL95













Median











75

1/2 max RL







50





47

Detection p,p'-DDE	Detection p,p'-DDT	Detection

ID	ID	ID

190	U	61	U

U	87	U	87	U

U	48	39	U

U	43	U	43	U

U	62	42	U

U	49	U	49	U

U	130	U	130	U

U	25	U	25	U

87	52	U

81	170	U

U	34	U	34	U

U	86	U	86	U

87	170

72

85


-------
Locatior

1

2

3

4

5

6

7

8

9

10

11

12

Maximu

UCL95

Median

1/2 ma>

Latitude

Longitude

TOC %

P,P'-

Detection

Toxaphene

De







Methoxychlor

ID



ID

41.57647

-93.63753

2.88

120

U

1200

U

41.57641

-93.63737

5.66

170

U

1700

U

41.57671

-93.63732

2.33

78

U

780

U

41.57603

-93.63725

3.28

86

U

860

U

41.57635

-93.63799

3.09

85

U

850

U

41.57648

-93.63836

4.24

98

U

980

U

41.576525

-93.63864

9.05

260

U

2600

U

41.5765

-93.63773

0.366

50

U

500

U

41.57667

-93.63827

3.99

100

U

1000

U

41.5769

-93.6386

6.24

340

U

3400

U

41.57711

-93.63879

1.5

69

U

690

U

41.57685

-93.63871

5.53

170

U

1700

U







340



3400









170



1700



48


-------
Table 4. Exposure Point Concentrations for Surface Water (ng/L).

Location Latitude Longitude Aldrin

Detection
ID

Aroclor 1016

1

41.57647

-93.63753

0.05

U

1.0

2

41.57641

-93.63737

0.05

u

1.0

3

41.57671

-93.63732

0.05

u

1.0

4

41.57603

-93.63725

0.05

u

1.0

5

41.57635

-93.63799

0.05

u

1.0

6

41.57648

-93.63836

0.05

u

1.0

7

41.576525

-93.63864

0.05

u

1.0

8

41.5765

-93.63773

0.05

u

1.0

9

41.57667

-93.63827

0.05

u

1.0

10

41.5769

-93.6386

0.05

u

1.0

11

41.57711

-93.63879

0.05

u

1.0

12

41.57685

-93.63871

0.05

u

1.0

Maximum











UCL95











Median











1/2 max RL





0.025



0.5

49

Detection Aroclor	Detection Aroclor 1232 Detection ID

ID	1221	ID

U	1.0	LI	1.0	U

U	1.0	U	1.0	U

U	1.0	U	1.0	U

U	1.0	U	1.0	U

U	1.0	U	1.0	U

U	1.0	U	1.0	u

U	1.0	U	1.0	u

U	1.0	U	1.0	u

U	1.0	U	1.0	u

U	1.0	U	1.0	u

U	1.0	U	1.0	u

U	1.0	U	1.0	u

0.5

0.5


-------
Location Latitude Longitude Aroclor 1242 Detection Aroclor 1248

1

41.57647

-93.63753

1.0

ID

U

1.0

2

41.57641

-93.63737

1.0

U

1.0

3

41.57671

-93.63732

1.0

u

1.0

4

41.57603

-93.63725

1.0

u

1.0

5

41.57635

-93.63799

1.0

u

1.0

6

41.57648

-93.63836

1.0

u

1.0

7

41.576525

-93.63864

1.0

u

1.0

8

41.5765

-93.63773

1.0

u

1.0

9

41.57667

-93.63827

1.0

u

1.0

10

41.5769

-93.6386

1.0

u

1.0

11

41.57711

-93.63879

1.0

u

1.0

12

41.57685

-93.63871

1.0

u

1.0

Maximum
UCL95
Median
1/2 max RL





0.5



0.5

50

Detection Aroclor	Detection Aroclor 1260 Detection ID

ID	1254	ID

U	1.0	U	1.0	U

U	1.0	U	1.0	u

U	1.0	U	1.0	u

U	1.0	U	1.0	u

U	1.0	U	1.0	u

U	1.0	U	1.0	u

U	1.0	U	1.0	u

U	1.0	U	1.0	u

U	1.0	U	1.0	u

U	1.0	U	1.0	u

U	1.0	U	1.0	u

U	1.0	U	1.0	u

0.5

0.5


-------
Location Latitude

1	41.57647

2	41.57641

3	41.57671

4	41.57603

5	41.57635

6	41.57648

7	41.576525

8	41.5765

9	41.57667

10	41.5769

11	41.57711

12	41.57685

Maximum
UCL95
Median
1/2 max RL

Longitude	a-BHC

-93.63753	0.05

-93.63737	0.05

-93.63732	0.05

-93.63725	0.05

-93.63799	0.05

-93.63836	0.05

-93.63864	0.05

-93.63773	0.098

-93.63827	0.05

-93.6386	0.05

-93.63879	0.05

-93.63871	0.05

0.05

Detection b-BHC
ID

U	0.05

U	0.05

U	0.05

U	0.05

U	0.05

U	0.05

U	0.05
0.05

U	0.05

U	0.05

U	0.05

U	0.05

0.025

51

Detection d-BHC
ID

U	0.05

U	0.05

U	0.05

U	0.05

U	0.05

U	0.05

U	0.05

U	0.05

U	0.05

U	0.05

U	0.05

U	0.05

Detection g-BHC
ID

U	0.05

U	0.05

U	0.05

U	0.05

U	0.05

U	0.05

U	0.05

U	0.05

U	0.05

U	0.05

U	0.05

U	0.05

Detection ID

U
U
U
U
U

u
u
u
u
u
u
u

0.025

0.025


-------
Location Latitude

Longitude Chlordane

Detection
ID

Dieldrin

1

41.57647

-93.63753

0.05

U

0.1

1

41.57641

-93.63737

0.05

U

0.1

3

41.57671

-93.63732

0.05

U

0.1

4

41.57603

-93.63725

0.05

U

0.1

5

41.57635

-93.63799

0.05

u

0.1

6

41.57648

-93.63836

0.05

u

0.1

7

41.576525

-93.63864

0.05

u

0.1

8

41.5765

-93.63773

0.13



0.98

9

41.57667

-93.63827

0.05

u

0.1

10

41.5769

-93.6386

0.05

u

0.1

11

41.57711

-93.63879

0.05

u

0.1

12

41.57685

-93.63871

0.05

u

0.1

Maximum
UCL95
Median
1/2 max RL





0.05



0.1

52

Detection

Endosulfan

Detection

Endosulfan

Dt

ID

I

ID

II



U

0.05

U

0.1

u

U

0.05

U

0.1

u

u

0.05

u

0.1

u

u

0.05

u

0.1

u

u

0.05

u

0.1

u

u

0.05

u

0.1

u

u

0.05

u

0.1

u



0.05

u

0.1

u

u

0.05

u

0.1

u

u

0.05

u

0.1

u



0.05

u

0.1

u

u

0.05

u

0.1

u

0.025

0.05


-------
Location	Latitude

1	41.57647

2	41.57641

3	41.57671

4	41.57603

5	41.57635

6	41.57648

7	41.576525

8	41.5765

9	41.57667

10	41.5769

11	41.57711

12	41.57685
Maximum

UCL95
Median
1/2 max RL

Longitude	Endosulfan

Sulfate

-93.63753	0.1

-93.63737	0.1

-93.63732	0.1

-93.63725	0.1

-93.63799	0.1

-93.63836	0.1

-93.63864	0.1

-93.63773	0.1

-93.63827	0.1

-93.6386	0.1

-93.63879	0.1

-93.63871	0.1

0.05

Detection Endrin
ID

U	0.1

U	0.1

U	0.1

U	0.1

U	0.1

U	0.1

U	0.1

U	0.1

U	0.1

U	0.1

U	0.1

U	0.1

0.05

53

Detection

Endrin

Detection

Endrin

Detection ID

ID

Aldehyde

ID

Ketone



U

0.1

U

0.1

U

u

0.1

U

0.1

U

u

0.1

u

0.1

u

u

0.1

u

0.1

u

u

0.1

u

0.1

u

u

0.1

u

0.1

u

u

0.1

u

0.1

u

u

0.1

u

0.27



u

0.1

u

0.1

u

u

0.1

u

0.1

u

u

0.1

u

0.1

u

u

0.1

u

0.1

u



0.05



0.1




-------
Location

Latitude

Longitude

1

41.57647

-93.63753

2

41.57641

-93.63737

3

41.57671

-93.63732

4

41.57603

-93.63725

5

41.57635

-93.63799

6

41.57648

-93.63836

7

41.576525

-93.63864

8

41.5765

-93.63773

9

41.57667

-93.63827

10

41.5769

-93.6386

11

41.57711

-





93.638795

12

41.57685

-93.63871

Maximum
UCL95
Median
1/2 max RL

Heptachlor Detection Heptachor
ID	Epoxide

0.05	U	0.05

0.05	U	0.05

0.05	U	0.05

0.05	U	0.05

0.05	U	0.05

0.05	U	0.05

0.05	U	0.05

0.05	U	0.05

0.05	U	0.05

0.05	U	0.05

0.05	U	0.05

0.05	U	0.05

0.025	0.025

54

Detection p,p'-DDD	Detection p,p'-DDE	Detection ID

ID	ID

U	0.1	U	0.1	u

U	0.1	U	0.1	u

U	0.1	U	0.1	u

U	0.1	U	0.1	u

U	0.1	U	0.1	u

U	0.1	U	0.1	u

U	0.1	U	0.1	u

U	0.1	U	0.1	u

U	0.1	U	0.1	u

U	0.1	U	0.1	u

U	0.1	U	0.1	u

U	0.1	U	0.1	u

0.05

0.05


-------
Location
1

Latitude
41.57647

Longitude
-93.63753

p.p'-DDT
0.1

Detection
ID

U

p,p'-

Methoxychlor
0.5

j

41.57641

-93.63737

0.1

U

0.5

3

41.57671

-93.63732

0.1

u

0.5

4

41.57603

-93.63725

0.1

u

0.5

5

41.57635

-93.63799

0.1

u

0.5

6

41.57648

-93.63836

0.1

u

0.5

7

41.576525

-93.63864

0.1

u

0.5

8

41.5765

-93.63773

0.1

u

0.5

9

41.57667

-93.63827

0.1

u

0.5

10

41.5769

-93.6386

0.1

u

0.5

11

41.57711

-93.63879

0.1

u

0.5

12

41.57685

-93.63871

0.1

u

0.5

Maximum
UCL95
Median
1/2 max RL





0.05



0.25

55

Detection
ID

U

u
u
u
u
u
u
u
u
u
u
u

Detection

ID

U

U

U

U

U

U

U

U

u
u
u
u

Toxaphene

5

5

5

5

5

5

5

5

5

5

5

5

2.5


-------
Table 5. Exposure Point Concentrations for Soil (|ig/kg).

Location Latitude Longitude

1

41.57630

-93.63799

2

41.57640

-93.63836

3

41.57649

-93.63864

4

41.57660

-93.63773

5

41.57680

-93.63824

6

41.57707

-93.63865

7

41.57681

-93.63873

Maximum
UCL95
Median
1/2 max RL

TOC % Aldrin	Detection

ID

4.61	19	UJ

3.27	3.5	J

3.21	3.6	J

1.34	2.2	J

4.26	16	UJ

2.55	770	J

7.69	120	J

770

346.7

Location Latitude Longitude

1

41.57630

-93.63799

2

41.57640

-93.63836

3

41.57649

-93.63864

4

41.57660

-93.63773

5

41.57680

-93.63824

6

41.57707

-93.63865

7

41.57681

-93.63873

Maximum
UCL95
Median
1/2 max RL

TOC % Aroctor 1242	Detection
ID

4.61	630	U

3.27	57	U

3.21	59	U

1.34	49	U

4.26	550	U

2.55	520	U

7.69	700	U

700

350

Aroclor 1016	Detection Aroclor
ID

630	U

57	U

59	U

49	U

550	U

520	U

700	U
700

350

Aroclor 1248	Detection Aroclor
ID

630	U

57	U

59	U

49	U

550	U

520	U

700	U
700

350

Detection	Aroclor 1232	Detection

ID	ID

U	630	U

U	57	U

U	59	U

U	49	U

U	550	U

U	520	U

U	700	U

700

350

Detection	Aroclor 1260	Detection

ID	ID

U	320	U

U	46

U	30	U

U	38

U	270	U

U	1300

U	350	U
1300

270

1221

630

57

59

49

550

520

700

700

350

1254

320

29

30

25

270

260

350

350

175

56


-------
Location

Latitude

Longitude

TOC %

A-BHC

Detection

B-BHC

Detection

D-BHC



Detection

G-BHC

Detection











ID





ID





ID



ID

1

41.57630

-93.63799

4.61

9.5

U



32

U



13

U

13

U

2

41.57640

-93.63836

3.27

0.86

U



2.9

U



1.1

U

1.1

U

3

41.57649

-93.63864

3.21

0.89

u



3

U



1.2

U

1.2

U

4

41.57660

-93.63773

1.34

0.74

u



2.5

U



0.98

U

0.98

U

5

41.57680

-93.63824

4.26

8.2

u



27

U



11

U

11

U

6

41.57707

-93.63865

2.55

7.8

u



26

U



10

U

10

U

7

41.57681

-93.63873

7.69

10

u



35

U



14

U

14

U

Maximum







10





35





14



14



UCL95



























Median



























1/2 max RL







5





17.5





7



7



Location

Latitude

Longitude

TOC %

Chlordane

Dieldrin

Detection ID

Endosulfan

1

Detection

ID

Endosulfan

II

Detection ID



1

41.57630

-93.63799

4.61

750



750



19

U



19

U



2

41.57640

-93.63836

3.27

220



170



1.7

U



1.7

U



3

41.57649

-93.63864

3.21

290



160



1.8

U



1.8

U



4

41.57660

-93.63773

1.34

60



16

J

1.5

U



1.5

U



5

41.57680

-93.63824

4.26

150



50



16

U



16

U



6

41.57707

-93.63865

2.55

13000



15000



16

U



16

U



7

41.57681

-93.63873

7.69

8500



6200



21

U



21

U



Maximum







13000



15000



21





21





UCL95







11963*



12530*















Median



























1/2 max RL















10.5





10.5





*The recommended adjusted Gamma UCL95 exceeded the maximum concentration, therefore, the 95% Chebyshev UCL was selected as the UCL95 term.

57


-------


Latitude

Longitude

1

41.57630

-93.63799

2

41.57640

-93.63836

3

41.57649

-93.63864

4

41.57660

-93.63773

5

41.57680

-93.63824

6

41.57707

-93.63865

7

41.57681

-93.63873

Maximum
UCL95
Median
1/2 max RL

Location Latitude Longitude

1

41.57630

-93.63799

2

41.57640

-93.63836

3

41.57649

-93.63864

4

41.57660

-93.63773

5

41.57680

-93.63824

6

41.57707

-93.63865

7

41.57681

-93.63873

Maximum
UCL95
Median
1/2 max RL

TOC% Endosulfan	Detection

Sulfate	ID

4.61	25	U

3.27	2.3	U

3.21	2.4	U

1.34	2	U

4.26	22	U
2.55 21	U
7.69 28	U

28

14

TOC % Heptachlor	Detection
ID

4.61	19	U

3.27	1.7	U
3.21 1.8	U
1.34 1.5	U
4.26 16	U
2.55 25
7.69 21	U

25

16

Endrin	Detection Endrin	Detection Endrin Ketone	Detection

ID	Aldehyde	ID	ID

25	U	32	U	25	U

2.3	U	2.9	U	2.3	U

2.4	U	3	U	2.4	U
2	U	2.5	U	2	U

22	U	27	U	22	U

21	U	26 U	150

28	U	35	U	28	U

28	35	150

22

14	17.5

Heptachlor	Detection p,p'-DDD	Detection p,p'-DDE	Detection

Epoxide	ID	ID	ID

19	U	33	U	120

1.7	U	5.1	U	18

1.8	U	2.9	U	13

1.5	U	2	UJ	2.5 U

16	U	22	U	72

83	180	U	52

21	U	200	140

83	200	140

99.9

16	22

58


-------
Location

1

2

3

4

5

6

7

Maximum
UCL95
Median
1/2 max RL

Latitude Longitude

41.57630

-93.63799

41.57640

-93.63836

41.57649

-93.63864

41.57660

-93.63773

41.57680

-93.63824

41.57707

-93.63865

41.57681

-93.63873

TOC % p,p'-DDT

4.61

69

3.27

9

3.21

9.5

1.34

2.5

4.26

64

2.55

39

7.69

61



69



47

Detection p,p'-	Detection

ID	Methoxychlor	ID

63	U

5.7	U

5.9	U

U	4.9	U

55	U

U	52	U

U	70	U

70

35

Toxaphene	Detection
ID

630	U

57	U

59	U

49	U

550	U

520	U

700	U
700

350

59


-------
Table 6. Screening level evaluation of Assessment Endpoint #1 (aquatic
macroinvertebrates).

COPC (ng/kg)

Maximum
(W?/kg)

TEC
(Hg/kg)

ESL

(Hg/kg)

HQ

Aldrin

4200



2.0

>1

Aroclor 1016

3400U

601



>1

Aroclor 1221

3400U

601



>1

Aroclor 1232

3400U

601



>1

Aroclor 1242

3400U

601



>1

Aroclor 1248

3400U

601



>1

Aroclor 1254

1700U

601



>1

Aroclor 1260

1900

601



>1

A-BHC

51U



6

>1

B-BHC

130U



5

>1

D-BHC

100U



71500

<1

G-BHC

68U

2.4



>1

Chlordane, technical

48000

3.2



>1

p,p'-DDD

2900

4.9



>1

p,p'-DDE

87

3.2



>1

p,p'-DDT

170U

4.2



>1

Dieldrin

3200

1.9



>1

Endosulfan 1

100U



3.3

>1

Endosulfan II

100U



1.9

>1

Endosulfan Sulfate

140U



34.6

>1

Endrin

140U

2.2



>1

Endrin Aldehyde

170U



480

<1

Endrin Ketone

140U



NA

NA

Heptachlor

150



0.6

>1

Heptachlor Epoxide

100U

2.5



>1

p,p'-Methoxychlor

340U



13.6

>1

Toxaphene

3400U



0.077

>1

1 - TEC based on Total PCBs.

60


-------
Table 7. Expanded Risk Evaluation of Assessment Endpoint #1.

CO PC (Hg/kg)

EPC TERM
(Hg/kg)

PEC
(Hg/kg)

HQpec

ESB

(Hg/g°c)

ESBwqc

(Hg/goc)

ESBTier2
(klg/goc)

HQesb



UCL95

Median

Yt max RL

PEC



Aldrin

2600





61.81

42 1

49

12*



4.1

Aroclor 1016





1700

6762

2.5 \









Aroclor 1221





1700

6762

2.5









Aroclor 1232





1700

6762

2.5









Aroclor 1242





1700

6762

2.5









Aroclor 1248





1700

6762

2.5









Aroclor 1254





850

6762

1.3 1









Aroclor 1260





690

6762

1 :









A-BHC





25.5

NA

NA

0.48



11

<1

B-BHC





65

NA

NA

1.22



11

<1

D-BHC





50

NA

NA

0.94



11

<1

G-BHC





34

4.99

6.8

0.64



0.37

1.7

Chlordane, technical

23829





17.6

1354









p,p'-DDD



75



28

2.7









p,p'-DDE



72



31.3

2.3









p,p'-DDT





85

62.9

i.4 :









Dieldrin

1533





61.8

24.8

28.9

12



2.4

Endosulfan 1





50

NA

NA

0.94



0.33

2.9

Endosulfan II





50

NA

NA

0.94



1.6

<1

Endosulfan Sulfate





70

NA

NA

1.32



0.6

2.2

Endrin





70

207

<1 |

1.3

5.4



<1

Endrin Aldehyde





85

NA

NA









Endrin Ketone





70

NA

NA









61


-------
Heptachlor



33



NA

NA









Heptachlor Epoxide





50

16

3.1









p,p'-Methoxychlor





170

NA

NA

1.6



1.9

<1

Toxaphene





1700

NA

NA !

32.1



10

3.2

Total Organic Carbon

5.3

















1 - Because Aldrin is rapidly broken down to Dieldrin, the PEC and ESB for Dieldrin was used for comparison to Aldrin.
2- PEC based on Total PCBs.

62


-------
Table 8. Screening level evaluation of Assessment Endpoint #2 (soil invertebrates).

COPC (jig/kg)

Maximum
(Ug/kg)

ESL

(Hg/kg)

HQ

Aldrin

770

3.32

>1

Aroclor 1016

700U

0.332

>1

Aroclor 1221

700U

0.332

>1

Aroclor 1232

700U

0.332

>1

Aroclor 1242

700U

0.332

>1

Aroclor 1248

700U

0.332

>1

Aroclor 1254

350U

0.332

>1 ¦

Aroclor 1260

1300

0.332

>1

A-BHC

10U

99.4

<1

B-BHC

35U

3.98

<1

D-BHC

14U

9940

<1

G-BHC

14U

5

>1

Chlordane, technical

13000

224

>1

p,p'-DDD

200

758

<1

P.p'-DDE

140

596

<1

p,p'-DDT

69

3.5

>1

Dieldrin

15000

2.38

>1

Endosulfan 1

21U

119

<1

Endosulfan II

21U

119

<1

Endosulfan Sulfate

28U

35.8

<1

Endrin

28U

10.1

>1

Endrin Aldehyde

35U

10.5

>1

Endrin Ketone

150

NA

NA

Heptachlor

25

5.98

>1

Heptachlor Epoxide

83

152

<1

p,p'-Methoxychlor

70U

19.9

>1

Toxaphene

700U

119

>1

63


-------
Table 8. Expanded Evaluation of Assessment Endpoint #2 (soil invertebrates).

COPC (Mg/kg)

EPC
(Mg/kg)

ESL
(Mg/kg)

HQ

Aldrin

346.7

3.32

104

Aroclor 1016

350U

0.332

1054

Aroclor 1221

350U

0.332

1054

Aroclor 1232

350U

0.332

1054

Aroclor 1242

350U

0.332

1054

Aroclor 1248

350U

0.332

1054

Aroclor 1254

175U

0.332

527

Aroclor 1260

270

0.332

813

G-BHC

7U

5

1.4

Chlordane, technical

11963

224

53.4

p,p'-DDT

47

3.5

13.4

Dieldrin

12530

2.38

5265

Endrin

14U

10.1

1.4

Endrin Aldehyde

17.5U

10.5

1.7

Endrin Ketone

22

NA

NA

Heptachlor

16

5.98

2.7

p,p'-Methoxychlor

35U

19.9

1.8

Toxaphene

350U

119

3

64


-------
Table 9. Bioaccumulation Factors for Terrestrial Prey.

Pesticides/PCBs

Soil-to-lnvertebrate BAFmv

Animal-to-Animal BAFsm

Source

Aldrin

0.56

2.9

HAZWRAP, 1994

Aroclor 1016

5.8*

2.91

HAZWRAP, 1994

Aroclor 1221

5.8*

2.9'

HAZWRAP, 1994

Aroclor 1232

5.8*

2.9'

HAZWRAP, 1994

Aroclor 1242

5.8*

2.91

HAZWRAP, 1994

Aroclor 1248

5.8*

2.9'

HAZWRAP, 1994

Aroclor 1254

5.8

2.9

HAZWRAP, 1994

Aroclor 1260

5.8

2.91

HAZWRAP, 1994

A-BHC

2.6

2.9

HAZWRAP, 1994

B-BHC

2.6

2.9

HAZWRAP, 1994

D-BHC

2.6

2.9

HAZWRAP, 1994

G-BHC

2.6

2.9

HAZWRAP, 1994

Chlordane,
technical

1.6

2.9

HAZWRAP, 1994

p,p'-DDD

11.2

4.83*(11.2*Coii)

US EPA, 2007

p,p'-DDE

11.2

4.83*(11.2*Csoii)

USEPA, 2007

p,p'-DDT

11.2

4.83*(11.2*Csi,ii)

USEPA, 2007

Dieldrin

14.7

1.2*(14.7*Csoii)

USEPA, 2007

Endosulfan 1

5.5

2.9

HAZWRAP, 1994

Endosulfan 1!

5.5

2.9

HAZWRAP, 1994

Endosulfan
Sulfate

5.5

2.9

HAZWRAP, 1994

Endrin

1.9

2.9

HAZWRAP, 1994

Endrin Aldehyde

1.9

2.9

HAZWRAP, 1994

Endrin Ketone

1.9

2.9

HAZWRAP, 1994

Heptachlor

1.0

2.9

HAZWRAP, 1994

Heptachlor
Epoxide

1.0

2.9

HAZWRAP, 1994

p,p'-Methoxychlor

0.57

2.9

HAZWRAP, 1994

Toxaphene

1.0

1.0

default

1 - Aroclor 1254 used as surrogate.

65


-------
Table 10. Bioconcentratrion Factors for Small Fish.

Pesticides/PCBs

Log K0w

BCF

Reference

Aldrin

3.0

3.89e+3

ECOTOX, 2015

Aroclor 1016

5.6

4.25e+4

ECOTOX, 2015

Aroclor 1221*

4.7

1.0e+05

ECOTOX, 2015'

Aroclor 1232

5.1

1.0e+05

ECOTOX, 2015"

Aroclor 1242

5.6

1,3e+04

ECOTOX, 2015

Aroclor 1248

6.2

6.0e+04

ECOTOX, 2015

Aroclor 1254

6.0

1.0e+05

ECOTOX, 2015

Aroclor 1260

7.1

2.7e+05

ECOTOX, 2015

A-BHC

3.8

4.5e+02

ECOTOX, 2015

B-BHC

3.8

4.5e+02

ECOTOX, 20152

D-BHC

4.1

4.5e+02

ECOTOX, 20152

G-BHC

4.1

1.8e+02

ECOTOX, 2015

Chlordane,

5.5

3.78e+04

ECOTOX, 2015

technical







p,p'-DDD

6.0

8.3e+03

ECOTOX, 20153

p,p'-DDE

5.7

4.2e+04

ECOTOX, 2015

p,p'-DDT

6.4

8.3e+03

ECOTOX, 2015

Dieldrin

4.6

1,3e+04

ECOTOX, 2015

Endosulfan 1

3.6

l.le+04

ECOTOX, 2015

Endosulfan II

3.6

9.9e+03

ECOTOX, 2015

Endosulfan

3.1

l.le+04

ECOTOX, 20154

Sulfate







Endrin

5.6

0.3

ECOTOX, 2015

Endrin Aldehyde

3.1

0.3

ECOTOX, 2015 s

Endrin Ketone

3.1

0.3

ECOTOX, 2015 s

Heptachlor

4.3

1,7e+04

ECOTOX, 2015

Heptachlor

5.4

1,44e+04

ECOTOX, 2015

Epoxide







P,P'-

4.8

8.3e+03

ECOTOX, 2015

Methoxychlor







Toxaphene

5.5

4.7e+03

ECOTOX, 2015

1- Aroclor 1254 used as a surrogate.

2- a-BHC used as a surrogate

3	- DDT used as a surrogate.

4	- Endosulfan I used as a surrogate

5	- Endrin used as a surrogate.

66


-------
Table 11. Estimated Concentrations in Prey.

Pesticides/PCBs

Soil

Mammals

Small Fish



Invertebrates

(mg/kg)

(mg/kg)



(mg/kg)





Aldrin

0.19

0.56

0.10

Aroclor 1016

2.03

5.89

21.25

Aroclor 1221

2.03

5.89

50

Aroclor 1232

2.03

5.89

50

Aroclor 1242

2.03

5.89

6.5

Aroclor 1248

2.03

5.89

30

Aroclor 1254

1.04

3.02

50

Aroclor 1260

1.57

4.54

135

A-BHC

0.01

0.04

0.02

B-BHC

0.05

0.13

0.01

D-BHC

0.02

0.05

0.01

G-BHC

0.02

0.05

0.05

Chlordane

19.14

55.51

1.89

p,p'-DDD

0.25

1.19

0.42

P/P'-DDE

1.12

5.41

2.10

p,p'-DDT

0.53

2.54

0.42

Dieldrin

184.2

221.03

1.3

Endosulfan 1

0.06

0.18

0.55

Endosulfan II

0.06

0.18

0.5

Endosulfan

0.08

0.22

0.55

Sulfate







Endrin

0.03

0.08

0.00

Endrin Aldehyde

0.03

0.1

0.00

Endrin Ketone

0.04

0.12

0.00

Heptachlor

0.02

0.05

0.43

Heptachlor

0.02

0.05

0.36

Epoxide







P,P'-

0.02

0.06

2.08

Methoxychlor







Toxaphene

0.35

1.02

11.75

67


-------
Table 12. Average Daily Dose Equations.

Terrestrial Insectivore

IRbiota

1R soil Cinv



Csoil/sed

A DDbiota

Csw

IRsw

ADDtotal

TRVnoael

HQ

TRVloael

HQ

Aldrin

























Woodcock

0.214

0.164

0.19

0.35

0.0538

0.00003

0.10

0.0538

0.07

0.768

0.35

0.154

Shrew

0.209

0.030

0.20

0.35

0.0432

0.00003

0.14

0.0432

0.20

0.216

1.00

0.043

Aroclor 1016

























Woodcock

0.214

0.164

2.03

0.35

0.4467

0.00050

0.10

0.4468

0.18

2.482

1.80

0.248

Shrew

0.209

0.030

2.03

0.35

0.4265

0.00050

0.14

0.4265

1.37

0.311

3.43

0.124

Aroclor 1221

























Woodcock

0.214

0.164

2.03

0.35

0.4467

0.00050

0.10

0.4468

0.18

2.482

1.80

0.248

Shrew

0.209

0.030

2.03

0.35

0.4265

0.00050

0.14

0.4265

0.07

6.273

0.68

0.627

Aroclor 1232

























Woodcock

0.214

0.164

2.03

0.35

0.4467

0.00050

0.10

0.4468

0.18

IN
00

« N

1.80

0.248

Shrew

0.209

0.030

2.03

0.35

0.4265

0.00050

0.14

0.4265

0.07

6 27 J

0.68

0.627

Aroclor 1242

























Woodcock

0.214

0.164

2.03

0.35

0.4467

0.00050

0.10

0.4468

0.41

1090

1.80

0.248

Shrew

0.209

0.030

2.03

0.35

0.4265

0.00050

0.14

0.4265

0.07

6.182

0.69

0.618

Aroclor 1248

























Woodcock

0.214

0.164

2.03

0.35

0.4467

0.00050

0.10

0.4468

0.18

2.482

1.80

0.248

Shrew

0.209

0.030

2.03

0.35

0.4265

0.00050

0.14

0.4265

0.01

42.653

0.1

4.265

Aroclor 1254

























Woodcock

0.214

0.164

1.04

0.18

0.2287

0.00050

0.10

0.2288

0.18

1.271

1.80

0.127

Shrew

0.209

0.030

1.04

0.18

0.2185

0.00050

0.14

0.2185

0.07

3.214

0.68

0.321

Aroclor 1260

























Woodcock

0.214

0.164

1.57

0.27

0.3446

0.00050

0.10

0.3446

0.18

1.915

1.80

0.191

Shrew

0.209

0.030

1.57

0.27

0.3290

0.00050

0.14

0.3291

0.07

4.839

0.68

0.484

a-BHC

























68


-------
Woodcock

0.214

0.164

0.01

0.005

0.0030

0.00005

0.10

0.0030

0.56

0.005

2.25

0.001

Shrew

0.209

0.030

0.01

0.005

0.0027

0.00005

0.14

0.0028

0.01

0.197

0.14

0.020

b-BHC

























Woodcock

0.214

0.164

0.05

0.0175

0.0104

0.00003

0.10

0.0104

0.56

0.018

2.25

0.005

Shrew

0.209

0.030

0.05

0.0175

0.0096

0.00005

0.14

0.0096

0.01

0.688

0.14

0.069

d-BHC

























Woodcock

0.214

0.164

0.02

0.007

0.0041

0.00003

0.10

0.0041

0.56

0.007

2.25

0.002

Shrew

0.209

0.030

0.02

0.007

0.0038

0.00005

0.14

0.0039

0.01

0.275

0.14

0.028

g-BHC

























Woodcock

0.214

0.164

0.02

0.01

0.0041

0.00025

0.10

0.0042

2.00

0.002

20.00

0.000

Shrew

0.209

0.030

0.02

0.01

0.0038

0.00025

0.14

0.0039

8.00

0.000

NA

NA

Chlordane

























Woodcock

0.214

0.164

19.14

11.96

4.5160

0.05000

0.10

4.5210

2.14

2.113

10.70

0.423

Shrew

0.209

0.030

19.14

11.96

4.0754

0.05000

0.14

4.0824

4.60

0.887

9.20

0.444

Dieldrin

























Woodcock

0.214

0.164

184.19

12.53

39.8566

0.00010

0.10

39.8566

0.07

562.153

1.73

23.039

Shrew

0.209

0.030

184.19

12.53

38.5745

0.00010

0.14

38.5745

4.60

8.386

9.20

4.3.93

DDD

























Woodcock

0.214

0.164

0.25

0.02

0.0535

0.00005

0.10

0.0535

0.23

0.236

10.98

0.005

Shrew

0.209

0.030

0.25

0.02

0.0516

0.00005

0.14

0.0516

7.65

0.007

18.83

0.003

DDE

























Woodcock

0.214

0.164

1.12

0.10

0.2432

0.00005

0.10

0.2432

0.23

1.071

10.98

0.022

Shrew

0.209

0.030

1.12

0.10

0.2347

0.00005

0.14

0.2347

7.65

0.031

18.83

0.012

DDT

























Woodcock

0.214

0.164

0.53

0.05

0.1143

0.00005

0.10

0.1143

0.23

0.504

10.98

0.010

Shrew

0.209

0.030

0.53

0.05

0.1103

0.00005

0.14

0.1103

7.65

0.014

18.83

0.006

Endosulfan 1

























Woodcock

0.214

0.164

0.06

0.01

0.0133

0.00005

0.10

0.0133

10.00

0.001

NA

NA

Shrew

0.209

0.030

0.06

0.01

0.0127

0.00005

0.14

0.0127

0.15

0.085

NA

NA

69


-------
Endosulfan II

























Woodcock

0.214

0.164

0.06

0.01

0.0133

0.00005

0.10

0.0133

10.00

0.001

NA

NA

Shrew

0.209

0.0B0

0.06

0.01

0.0127

0.00005

0.14

0.0127

0.15

0.085

NA

NA

Endosulfan Sulfate

























Woodcock

0.214

0.164

0.08

0.01

0.0170

0.00005

0.10

0.0170

10.00

0.002

NA

NA

Shrew

0.209

0.030

0.08

0.01

0.0162

0.00005

0.14

0.0162

0.15

0.108

NA

NA

Endrin

























Woodcock

0.214

0.164

0.03

0.01

0.0062

0.00005

0.10

0.0062

0.01

0.619

0.10

0.062

Shrew

0.209

0.030

0.03

0.01

0.0056

0.00005

0.14

0.0057

0.09

0.061

0.92

0.006

Endrin Aldehyde

























Woodcock

0.214

0.164

0.03

0.02

0.0077

0.00005

0.10

0.0077

0.01

0.773

0.10

0.077

Shrew

0.209

0.030

0.03

0.02

0.0071

0.00005

0.14

0.0071

0.09

0.077

0.92

0.008

Endrin Ketone

























Woodcock

0.214

0.164

0.04

0.02

0.0097

0.00005

0.10

0.0097

0.01

0.972

0.10

0.097

Shrew

0.209

0.030

0.04

0.02

0.0089

0.00005

0.14

0.0089

0.09

0.097

0.92

0.010

Heptachlor

























Woodcock

0.214

0.164

0.02

0.02

0.0040

0.00003

0.10

0.0040

0.28

0.014

1.38

0.003

Shrew

0.209

0.030

0.02

0.02

0.0034

0.00003

0.14

0.0034

0.1

0.034

1

0.003

Heptachlor Epoxide

























Woodcock

0.214

0.164

0.02

0.02

0.0040

0.00003

0.10

0.0040

0.28

0.014

1.38

0.003

Shrew

0.209

0.030

0.02

0.02

0.0034

0.00003

0.14

0.0034

0.1

0.034

1

0.003

Methoxyclor

























Woodcock

0.214

0.164

0.02

0.04

0.0055

0.00025

0.10

0.0055

355.00

0.000

1775.00

0.000

Shrew

0.209

0.030

0.02

0.04

0.0044

0.00025

0.14

0.0044

4

0.001

8

0.001

Toxaphene

























Woodcock

0.214

0.164

0.35

0.35

0.0872

0.00250

0.10

0.0874

2.00

0.044

10.00

0.009

Shrew

0.209

0.030

0.35

0.35

0.0753

0.00250

0.14

0.0757

8

0.009

NA

NA

70


-------
Terrestrial
Carnivores

IRbiota

IR soil

Cinv

Cmom

Csoil/sed

ADDbiota

Csw

IRsw

ADDtotol

TRVnoael

HQ

TRVloael

HQ

Red-tailed Hawk

0.035

0.06

0.19

0.56

0.35

0.0206

0.00003

0.05

0.0206

0.070

0.294

0.35

0.059

Long-tailed

0.130

0.04

0.19

0.56

0.35

0.0752

0.00003

0.11

0.0752

0.200

0.376

1.00

0.075

Weasel



























Aroclor 1016



























Red-tailed Hawk

0.035

0.06

2.03

5.89

0.35

0.2085

0.00050

0.05

0.2085

0.180

1.159

1.80

0.116

Long-tailed

0.130

0.04

2.03

5.89

0.35

0.7673

0.00050

0.11

0.7673

1.370

0.560

3.43

0.224

Weasel



























Aroclor 1221



























Red-tailed Hawk

0.035

0.06

2.03

5.89

0.35

0.2085

0.00050

0.05

0.2085

0.180

1159

1.80

0.116

Long-tailed

0.130

0.04

2.03

5.89

0.35

0.7673

0.00050

0.11

0.7673

0.068

11.284

0.68

1.128

Weasel



























Aroclor 1232



























Red-tailed Hawk

0.035

0.06

2.03

5.89

0.35

0.2085

0.00050

0.05

0.2085

0.180

1.159

1.80

0.116

Long-tailed

0.130

0.04

2.03

5.89

0.35

0.7673

0.00050

0.11

0.7673

0.068

11.284

0.68

1.128

Weasel



























Aroclor 1242



























Red-tailed Hawk

0.035

0.06

2.03

5.89

0.35

0.2085

0.00050

0.05

0.2085

0.410

0.509

4.10

0.051

Long-tailed

0.130

0.04

2.03

5.89

0.35

0.7673

0.00050

0.11

0.7673

0.069

11.121

0.69

1.112

Weasel



























Aroclor 1248



























Red-tailed Hawk

0.035

0.06

2.03

5.89

0.35

0.2085

0.00050

0.05

0.2085

0.180

1.159

1.80

0.116

Long-tailed

0.130

0.04

2.03

5.89

0.35

0.7673

0.00050

0.11

0.7673

0.010

76.732

0.1

7.673

Weasel



























Aroclor 1254



























Red-tailed Hawk

0.035

0.06

1.04

3.02

0.18

0.1070

0.00050

0.05

0.1070

0.180

0.594

1.80

0.059

Long-tailed

0.130

0.04

1.04

3.02

0.18

0.3936

0.00050

0.11

0.3937

0.068

5,789

0.68

0.579

Weasel



























71


-------
Aroclor 1260



























Red-tailed Hawk

0.035

0.06

1.57

4.54

0.27

0.1609

0.00050

0.05

0.1609

0.180

0.894

1.80

0.089

Long-tailed

0.130

0.04

1.57

4.54

0.27

0.5919

0.00050

0.11

0.5919

0.068

8.705

0.68

0.871

Weasel



























a-BHC



























Red-tailed Hawk

0.035

0.06

0.01

0.04

0.01

0.0013

0.00050

0.05

0.0014

0.560

0.002

2.25

0.001

Long-tailed

0.130

0.04

0.01

0.04

0.01

0.0049

0.00050

0.11

0.0050

0.014

0.356

0.14

0.036

Weasel



























b-BHC



























Red-tailed Hawk

0.035

0.06

0.05

0.13

0.02

0.0047

0.00003

0.05

0.0047

0.560

0.008

2.25

0.002

Long-tailed

0.130

0.04

0.05

0.13

0.02

0.0173

0.00003

0.11

0.0173

0.014

1.232

0.14

0.123

Weasel



























d-BHC



























Red-tailed Hawk

0.035

0.06

0.02

0.05

0.007

0.0019

0.00003

0.05

0.0019

0.560

0.003

2.25

0.001

Long-tailed

0.130

0.04

0.02

0.05

0.007

0.0069

0.00003

0.11

0.0069

0.014

0.493

0.14

0.049

Weasel



























g-BHC



























Red-tailed Hawk

0.035

0.06

0.02

0.05

0.007

0.0019

0.00003

0.05

0.0019

2.000

0.001

20.00

0.000

Long-tailed

0.130

0.04

0.02

0.05

0.007

0.0069

0.00005

0.11

0.0069

8.000

0.001

NA

NA

Weasel



























Chlordane



























Red-tailed Hawk

0.035

0.06

19.14

55.51

11.96

1.9836

0.00025

0.05

1.9836

2.140

0.927

10.70

0.185

Long-tailed

0.130

0.04

19.14

55.51

11.96

7.2832

0.00025

0.11

7.2832

4.600

1.583

9.20

0.792

Weasel



























Dieldrin



























Red-tailed Hawk

0.035

0.06

184.19

221.03

12.53

7.8275

0.05000

0.05

7.8300

0.071

110,438

1.73

4.526

Long-tailed

0.130

0.04

184.19

221.03

12.53

28.8038

0.05000

0.11

28.8093

0.015

1920.623

2.28

12.636

Weasel



























DDD



























Red-tailed Hawk

0.035

0.06

0.25

1.19

0.02

0.0421

0.00010

0.05

0.0421

0.227

0.185

10.98

0.004

72


-------
Long-tailed

0.130

0.04

0.25

1.19

0.02

0.1548

0.00010

0.11

0.1548

0.147

1.053

18.83

0.008

Weasel



























DDE



























Red-tailed Hawk

0.035

0.06

1.12

5.41

0.10

0.1912

0.00005

0.05

0.1912

0.227

0.842

10.98

0.017

Long-tailed

0.130

0.04

1.12

5.41

0.10

0.7038

0.00005

0.11

0.7038

0.147

4.788

18.83

0.037

Weasel



























DDT



























Red-tailed Hawk

0.035

0.06

0.53

2.54

0.05

0.0898

0.00005

0.05

0.0898

0.227

0.396

10.98

0.008

Long-tailed

0.130

0.04

0.53

2.54

0.05

0.3308

0.00005

0.11

0.3308

0.147

2.250

18.83

0.018

Weasel



























Endosulfan 1



























Red-tailed Hawk

0.035

0.06

0.06

0.18

0.01

0.0062

0.00005

0.05

0.0062

10.000

0.001

100.00

0.000

Long-tailed

0.130

0.04

0.06

0.18

0.01

0.0229

0.00005

0.11

0.0229

0.150

0.153

NA

NA

Weasel



























Endosulfan II



























Red-tailed Hawk

0.035

0.06

0.06

0.18

0.01

0.0062

0.00005

0.05

0.0062

10.000

0.001

100.00

0.000

Long-tailed

0.130

0.04

0.06

0.18

0.01

0.0229

0.00005

0.11

0.0229

0.150

0.153

NA

NA

Weasel



























Endosulfan Sulfate



























Red-tailed Hawk

0.035

0.06

0.08

0.22

0.01

0.0079

0.00005

0.05

0.0079

10.000

0.001

100.00

0.000

Long-tailed

0.130

0.04

0.08

0.22

0.01

0.0291

0.00005

0.11

0.0291

0.150

0.194

NA

NA

Weasel



























Endrin



























Red-tailed Hawk

0.035

0.06

0.03

0.08

0.01

0.0028

0.00005

0.05

0.0028

0.010

0.275

0.10

0.028

Long-tailed

0.130

0.04

0.03

0.08

0.01

0.0101

0.00005

0.11

0.0101

0.092

0.110

0.92

0.011

Weasel



























Endrin Aldehyde



























Red-tailed Hawk

0.035

0.06

0.03

0.10

0.02

0.0034

0.00005

0.05

0.0034

0.010

0.344

0.10

0.034

Long-tailed

0.130

0.04

0.03

0.10

0.02

0.0126

0.00005

0.11

0.0126

0.092

0.137

0.92

0.014

Weasel



























73


-------
Endrin Ketone



























Red-tailed Hawk

0.035

0.06

0.04

0.12

0.02

0.0043

0.00005

0.05

0.0043

0.010

0.433

0.10

0.043

Long-tailed

0.130

0.04

0.04

0.12

0.02

0.0159

0.00005

0.11

0.0159

0.092

0.173

0.92

0.017

Weasel



























Heptachlor



























Red-tailed Hawk

0.035

0.06

0.02

0.05

0.02

0.0017

0.00005

0.05

0.0017

0.280

0.006

1.38

0.001

Long-tailed

0.130

0.04

0.02

0.05

0.02

0.0061

0.00005

0.11

0.0061

0.100

0.061

1

0.006

Weasel



























Heptachlor



























epoxide



























Red-tailed Hawk

0.035

0.06

0.02

0.05

0.02

0.0017

0.00003

0.05

0.0017

0.280

0.006

1.38

0.001

Long-tailed

0.130

0.04

0.02

0.05

0.02

0.0061

0.00003

0.11

0.0061

0.100

0.061

1

0.006

Weasel



























Methoxyclor



























Red-tailed Hawk

0.035

0.06

0.02

0.06

0.04

0.0021

0.00003

0.05

0.0021

355.000

0.000

1775.00

0.000

Long-tailed

0.130

0.04

0.02

0.06

0.04

0.0077

0.00003

0.11

0.0077

4.000

0.002

8

0.001

Weasel



























Toxaphene



























Red-tailed Hawk

0.035

0.06

0.35

1.02

0.35

0.0365

0.00025

0.05

0.0365

2.000

0.018

10.00

0.004

Long-tailed

0.130

0.04

0.35

1.02

0.35

0.1339

0.00025

0.11

0.1339

8.000

0.017

NA

NA

Weasel



























74


-------
Avian Piscivore
Heron

IRbiota

Cfish

ADDbiota

Csw

IRsw

ADDtotoi

TRVnoael

HQ

TRVloaei

HQ

Aldrin

0.18

0.10

0.0175

0.00003

0.045

0.02

0.07

0.25

0.35

0.05

Aroclor 1016

0.18

21.25

3.8250

0.00050

0.045

3.83

0.18

21.25

1.80

2.13

Aroclor 1221

0.18

50.00

9.0000

0.00050

0.045

9.00

0.18

50.00

1.80

5.00

Aroclor 1232

0.18

50.00

9.0000

0.00050

0.045

9.00

0.18

50.00

1.80

5.00

Aroclor 1242

0.18

6.50

1.1700

0.00050

0.045

1.17

0.18

6.50

1.80

0.65

Aroclor 1248

0.18

30.00

5.4000

0.00050

0.045

5.40

0.18

30.00

1.80

3.00

Aroclor 1254

0.18

50.00

9.0000

0.00050

0.045

9.00

0.18

50.00

1.80

5.00

Aroclor 1260

0.18

135.00

24.3000

0.00050

0.045

24.30

0.18

135.00

1.80

13.50

a-BHC

0.18

0.02

0.0040

0.00005

0.045

0.004

0.56

0.01

2.25

0.002

b-BHC

0.18

0.01

0.0020

0.00003

0.045

0.002

0.56

0.004

2.25

0.001

d-BHC

0.18

0.01

0.0020

0.00003

0.045

0.002

0.56

0.004

2.25

0.001

g-BHC

0.18

0.05

0.0081

0.00025

0.045

0.01

2.00

0.004

20.00

0.000

Chlordane

0.18

1.89

0.3402

0.00005

0.045

0.34

2.14

0.16

10.70

0.03

Dieldrin

0.18

1.30

0.2340

0.00010

0.045

0.23

0.07

3.30

1.73

0.14

DDD

0.18

0.42

0.0747

0.00005

0.045

0.07

0.23

0.32

10.97

0.01

DDE

0.18

2.10

0.3780

0.00005

0.045

0.38

0.23

1.64

10.97

0.03

DDT

0.18

0.42

0.0747

0.00005

0.045

0.07

0.23

0.32

10.97

0.01

Endosulfan 1

0.18

0.55

0.0989

0.00005

0.045

0.099

10.00

0.01

100.00

0.00

Endosulfan II

0.18

0.50

0.0892

0.00005

0.045

0.089

10.00

0.01

100.00

0.00

Endosulfan

0.18

0.55

0.0989

0.00005

0.045

0.099

10.00

0.01

100.00

0.00

Sulfate





















Endrin

0.18

0.0000

0.0000

0.00005

0.045

0.00

0.01

0.00

0.10

0.00

Endrin Aldehyde

0.18

0.0000

0.0000

0.00005

0.045

0.00

0.01

0.00

0.10

0.00

Endrin Ketone

0.18

0.0000

0.0000

0.00005

0.045

0.00

0.01

0.00

0.10

0.00

Heptachlor

0.18

0.43

0.0765

0.00003

0.045

0.08

0.28

0.27

1.38

0.06

75


-------
Heptachlor

0.18

0.36

0.0648

0.00003

0.045

0.06

0.28

0.23

1.38

0.05

Epoxide





















Methoxychlor

0.18

2.08

0.3735

0.00025

0.045

0.37

355.00

0.00

1775.00

0.00

Toxaphene

0.18

11.75

2.1150

0.00250

0.045

2.12

2.00

1.06

10.00

0.21

76


-------
APPENDIX D: ProUCL RESULTS

77


-------
Aldrin - Sediment

Kaplan^Meier (KM) Statistics using Nomd Gribcd Values anddher Nnqnamsbic UCLs

Mean	856.2

SD	1321

95% KM (t) UCL	1575

95% KM (z) UCL	1514

90*/. KM Chebyshev UCL	2056

97.5*4 KM Chebyshev UCL	3354

Standard Error of Mean	400

95*/. KM (BCA) UCL	15G7

95V, KM (Percentile Bootstrap) UCL	1537

95% KM Bootstrap t UCL	3455

95*. KM Chebyshev UCL	2600

99V. KM Chebyshev UCL	4837

Chlordane - Sediment

Gamma Statistics

k hat (MLE) 0519
Theta hat (MLE) 14982
nu hat (MLE) 14.85
MLE Mean (bias corrected) 9272

Adj listed Level of Significance; 0.029

k star (bias corrected MLE)	0.52

Theta star (bias corrected MLE)	17840

nu star (bias corrected)	12.47

MLE Sd (has corrected)	12861

Approximate Chi Square Value (0.05)	5.54

Adjusted Chi Square Value	4.853

Assuming GamnB Distnbuban

95*/. Approximate Gamma UCL (use when n>=50)! 20874

95V. Adjusted Gamma UCL (use when n<50) 23829

Dieldrin - Sediment

Gamma Statistics

k hat (MLE) 0.885 7
Theta hat (MLE) 798
nu hat (MLE) 21 25
MLE Mean (bias corrected) 706.6

Adjusted Level of Significance 0.029

k star (bias corrected MLE) 0.72

Theta star (bias corrected MLE),	981.8
nu star (bias corrected) i 17.27

MLE Sd (bias corrected)	832.9
Approximate Chi Square Value (0.05) 8.867
Adjusted Chi Square Value; 7.963

Assuming Gamma DUdilion

95% Approximate Gamma UCL (use when n>=50); 1376

95"; Adjusted Gamma UCL (use when rx50) 1533

78


-------
Tnt.il i >it aihiMi - Sediment
roc



Notmtil uOf	1«»t

v ., •!	Shapiro W>ft GO! I est

riiicijl Value 0.8S9	Date appear Normal at 5% Sijntieaf

<".t—?r—	ti(i« k»* ' >0! 1«4

1 '« " " .'	I - •!,. -i '! i >' " ' "<» ~-

If.tl.i Mnui. ,1.)! *<	i imlti .
-------
Chlordane - Soil

N onparametiic D istribution Fiee UCLs

95% CLT UCL

6557

95% Jackknife UCL

7152

95% Standard Bootstrap UCL

6348

95% Bootstrap-t UCL

67849

95% Hall's Bootstrap UCL

64849

95% Percentile Bootstrap UCL

6313

95% BCA Bootstrap UCL

6943





90% Chebyshev(Mean, Sd) UCL

9256

95% ChebyshevlMean, Sd) UCL

11963

97.5% Chebyshev(Mean, Sd) UCL

15719

99% Chebyshev(Mean, Sd) UCL

23098

S uggested U CL to U se

95% Adjusted Gamma UCL 28932

Recommended UCL exceeds the maximum observation

Dieldrin - Soil

Nonpaiametiic Distribution Fiee UCLs

95% CLT UCL

6716

95% Jackknife UCL

7355

95% Standard Bootstrap UCL

6562

95% Bootstrap-t UCL

68438

95% Hall's Bootstrap UCL

74167

95% Percentile Bootstrap UCL

6669

95% BCA Bootstrap UCL

8205



90% ChebyshevfMean, Sd) UCL

9619

95% Chebj)shev(Mean, Sd) UCL

12530

97.5% Chebyshev(Mean, Sd) UCL

16570

99% Chebjishev(Mean, Sd) UCL

24506

Suggested UCL to Use

95% Adjusted Gamma UCL 32738

Recommended UCL exceeds the maximum observation

80


-------
DDE - Soil

Rrffti.tfi Mun ? KM i M.tiiMn \ <.	Nivitnl ( 4 7.
-------
APPENDIX E: WILDLIFE EXPOSURE FACTORS


-------
American Woodcock (Scolopax minor)

Food Habits and Diet Composition

Woodcocks feed primarily on invertebrates found in moist upland soils by probing the soil with
their long prehensile-tipped bill (Owen et al., 1977; Sperry, 1940). Earthworms are the preferred
diet, but when earthworms are not available, other soil invertebrates are consumed (Miller and
Causey, 1985; Sperry, 1940; Stribling and Doerr, 1985). Some seeds and other plant matter may
also be consumed (Sperry, 1940). Krohn (1970) found that during summer most feeding was
done in wooded areas prior to entering fields at night, but other studies have indicated that a
significant amount of food is acquired during nocturnal activities (Britt, 1971, as cited in
Dunford and Owen, 1973). A diet of 100 percent earthworms was assumed (Stribling and Doerr,
1985) for the risk assessment.

Food Ingestion Rate

Stickel et al. (1965) reported a mean food ingestion rate of 0.77 g/g BW/day (range, 0.11-1.43
g/g BW/day) in captive woodcocks eating an earthworm diet during the winter in Louisiana. A
normalized food ingestion rate is reported in USEPA, 2003, as 0.214 kg/kg bw/d.

Water Ingestion Rate

No literature data were found concerning water consumption rates in woodcocks. However, most
of the woodcocks' metabolic water needs are reportedly met by their food (Mendall and Aldous,
1943, as cited in Cade, 1985), although captive birds have been observed to drink (Sheldon,
1967). A water consumption rate of 0.1 L/kg BW/day can be estimated (Calder and Braun, 1983)
based on summer body weights from Nelson and Martin (1953).

Soil Ingestion

Soil ingestion was estimated as 0.164 as a percentage of the diet. This estimate is based on
information provided in the Eco-SSL guidance (USEPA, 2005), as reported in Beyer et al.

(1994).

Home Range

Home range values reported in the literature vary considerably by sex and season. Therefore, a
median home range for singing males in Pennsylvania of 10.4 ha, as reported by Hudgins et al.,
1985, is used in the risk assessment. American woodcocks tend to be early spring
migrants,leaving the wintering grounds in February and arriving in breeding territories in early
March. Fall migration begins in October with the timing of the first frosts.

American Woodcock

Value

Reference

Body Weight (kg)

0.176

Nelson and Martin, 1953

Normalized Food Ingestion Rate (kg/kg bw dw/day)

0.214

Stickel et al., 1965

Water Ingestion Rate (L/kg bw/day)

0.10

Calder and Braun, 1983

Fraction Diet Earthworm

100%

Stribling and Doerr, 1985

Soil Ingestion Rate

16.4%

USEPA, 2005

83


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Northern Short-Tailed Shrew (Blarina brevicauda)

Food Habits and Diet Composition

The short-tailed shrew is primarily a carnivore. Common prey items include insects, worms,
snails, and other invertebrates. They may also eat mice, voles, frogs, other vertebrates and some
plants and fungi (Robinson and Brodie, 1982; Hamilton, 1941). For this ERA, a simplified diet
of 100 percent soil invertebrates was used in to calculate the ADD.

Food Ingestion Rate

In laboratory studies, shrews of both sexes fed a diet of mealworms had a food ingestion rate of
0.49 kg/kg bw/day (Barrett and Stuek, 1976). Lab studies using beef liver found that shrews had
a food ingestion rate between 0.49 kg/kg bw/day and 0.62 kg/kg bw/day (Morrison et al., 1957).
USEPA (2005) estimated a food intake rate for shrews of 0.209 kg dw/kg bw/day, based on a
high end point estimate. Therefore, a value of 0.209 kg dw/kg bw/day will be used to estimate
exposure to the short-tailed shrew.

Water Ingestion Rate

The shrew must consume water to compensate for its high evaporative water loss, despite the
fact that it obtains water from both food and metabolic oxidation (Chew, 1951). Deavers and
Hudson (1981) indicated that the short-tailed shrew's evaporative water loss increases with
increasing ambient temperature even within its thermoneutral zone. Therefore, a water ingestion
rate of 0.223 L/kg bw/day is assumed based on a study by Chew, 1951.

Soil Ingestion Rate

Data concerning soil ingestion by short-tailed shrews was based on USEPA, 2003. A soil
ingestion rate, as percentage of diet is estimated to be 0.03 mg/kg bw/d.

Home Range

Short-tailed shrews are found in a wide variety of habitats and are common in areas with
abundant vegetative cover (Miller and Getz, 1977). They inhabit round, underground nests and
maintain underground runaways, usually in the top 10 cm of soil, but sometimes as deep as 50
cm (Hamilton, 1931). Winter, non-breeding home ranges can vary from 0.03 to 0.07 ha at high
prey densities, to 1 to 2.2 ha during low prey densities (Piatt, 1976).

Short-tailed Shrew

Value

Reference

Body Weight (kg)

0.176

Nelson and Martin, 1953

Normalized Food Ingestion Rate (kg/kg bw dw/day)

0.209

Stickel et al., 1965

Water Ingestion Rate (L/kg bw/day)

0.14

Calder and Braun, 1983

Fraction Diet Earthworm

100%

Stribling and Doerr, 1985

Soil Ingestion Rate

3%

USEPA, 2005

84


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Red-tailed Hawk (Buteo jamaicensis)

Food Habits and Diet Composition

Small mammals, including mice, shrews, voles, rabbits, and squirrels, are important prey,
particularly during winter. Red-tails also eat a wide variety of foods depending on availability,
including birds, lizards, snakes, and large insects (James, 1984; Fitch et al., 1946).

Food Ingestion Rates

Food consumption rates of adult red-tailed hawks are estimated to be 0.0353 kg/kg bw/day
(USEPA, 2005).

Water Ingestion Rate

No water consumption data were available for red-tailed hawks. A water consumption rate of
0.05 L/kg BW/day was calculated using the Calder and Braun (1983) equation, and a mean body
weight of 1.13 kg:

WIR = (0.059(BW)""')/BWkg,

Soil Ingestion

No soil ingestion data were found in the literature. Soil ingestion is likely to be negligible and
consist only of that associated with prey that are consumed.

Home Range

Red-tails are found in habitats ranging from woodlands, wetlands, pastures, and prairies to
deserts (Bohm, 1978b; Gates, 1972; MacLaren et al., 1988; Mader, 1978). They appear to prefer
a mixed landscape containing old fields, wetlands, and pastures for foraging interspersed with
groves of woodlands and bluffs and streamside trees for perching and nesting (Brown and
Amadon, 1968; Preston, 1990). Red-tailed hawks are territorial throughout the year, including
winter (Brown and Amadon, 1968). Trees or other sites for nesting and perching are important
requirements for breeding territories and can determine which habitats are used in a particular
area (Preston, 1990; Rothfels and Lein, 1983). Home range size can vary from a few hundred
hectares to over 1,500 hectares, depending on the habitat (Andersen and Rongstad, 1989;
Petersen, 1979).

Red-tailed Hawk

Value

Reference

Body Weight (kg)

1.0

Craighead and Craighead,
1956

Normalized Food Ingestion Rate (kg/kg bw dw/day)

0.0353

USEPA, 2005

Water Ingestion Rate (L/kg bw/day)

0.05

Calder and Braun, 1983

Fraction Small Mammal

100%

Fitch et a/., 1948

Soil Ingestion Rate

0%

USEPA, 2005

85


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Long-tailed Weasel (Mustela frenata)

Food Habits and Diet Composition

Weasels are specialist predators of small, warm-blooded vertebrates (King, 1983). Their diet
consists predominantly of small mammals (50-80 percent of annual consumption) with larger
species consuming larger-sized prey (Polderboer et al., 1941; Svendsen, 1982).

Food Ingestion Rates

Food ingestion is estimated to be 0.13 kg/kg bw/day based on USEPA, 2005.

Water Ingestion Rate

Weasels require a constant supply of drinking water, drinking small amounts frequently
(Svendsen, 1982). Long-tailed weasels are reported to consume 25 mL water/d (Svendsen,
1982). No other literature data were found describing water ingestion by weasels. A water
consumption rate of 0.11 L/kg BW/day was calculated using the Calder and Braun (1983)
equation, and a mean body weight of 0.297 kg:

WIR = (0.099(BW)090 VBWkg,

Soil Ingestion Rate

Soil ingestion rates are estimated to be 0.043 as a percentage of diet (USEPA, 2005).

Home Range

Home ranges of weasels vary by sex, habitat, food availability and season, with smaller species
having smaller home ranges (Svendsen, 1982). Home ranges for long-tailed weasels have been
reported to range from 5-16 ha in Iowa (Polderboer et al., 1941) to 81-121 ha in Michigan and
Colorado (Quick, 1944, 1951).

Long-tailed Weasel

Value

Reference

Body Weight (kg)

0.2-0.34

Burt and Grossenheider,
1976

Normalized Food Ingestion Rate (kg/kg bw dw/day)

0.13

USEPA, 2005

Water Ingestion Rate (L/kg bw/day)

0.11

Calder and Braun, 1983

Fraction Small Mammal

100%

Polderboer et al, 1941

Soil Ingestion Rate

4.3%

USEPA, 2005

86


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Great Blue Heron (Ardea herodias)

Food Habits and Diet Composition

Fish are the preferred prey, but great blue herons also eat amphibians, reptiles, crustaceans,
insects, birds, and mammals (Alexander, 1977; Bent, 1926; Hoffman, 1978; Kirkpatrick, 1940;
Peifer, 1979). To fish, they require shallow waters (up to 0.5 m) with a firm substrate (Short and
Cooper, 1985). Fish up to about 20 cm in length were dominant in the diet of herons foraging in
southwestern Lake Erie (Hoffman, 1978), and 95 percent of fish consumed by great blues in a
Wisconsin population were less than 25 cm in length (Kirkpatrick, 1940). Great blue herons
sometimes forage in wet meadows and pastures in pursuit of lizards, small mammals, and large
insects (Palmer, 1962; Peifer, 1979).

Body Size and Weight

Body weights of adults for both sexes were reported as 2.229 kg (Quinney, 1982). Hartman
(1961) reported body weights of adult females at 2.2 kg and adult males at 2.6 kg. An average
adult body weight of 2.28 kg is used in the ERA.

Food Consumption Rate

There are no studies available that give specific food consumption rates. However, Kushlan
(1978) developed a regression equation relating the amount of food ingested per day to body
weight for wading bird:

log(FI) = 0.966 log(BW) - 0.640

where, FI equals food ingestion in grams per day and BW equals body weight in grams.

The food ingestion rate based on this equation is 0.18 g/g BW/day based on a body weight of
2.28 kg.

Water Ingestion Rate

No literature data were found describing water ingestion by great blue herons. A water
consumption rate of 0.045 L/kg BW/day was calculated using the Calder and Braun (1983)
equation, and a mean body weight of 2.28 kg:

Soil Ingestion

No information was found in the literature on soil ingestion. As a piscivorous, nonfossorial
species, soil ingestion is likely to be negligible.

Home Range

Great blue herons inhabit a variety of freshwater and marine areas, including freshwater lakes
and rivers, brackish marshes, lagoons, mangroves, and coastal wetlands, particularly where small
fish are plentiful in shallow areas (Spendelow and Patton, 1988; Short and Cooper, 1985). Bayer
(1978) reported a mean (SD) feeding territory of 0.6±0.1 ha for great blue herons feeding in
freshwater marshes in Oregon.

87


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Great Blue Heron

Value

Reference

Body Weight (kg)

2.28

Hartman, 1961

Normalized Food Ingestion Rate (kg/kg bw dw/day)

0.18

USEPA, 2005

Water Ingestion Rate (L/kg bw/day)

0.045

Calder and Braun, 1983

Fraction Small Fish

100%

Alexander, 1977

Sediment Ingestion Rate

0%

NA

88


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References

Alexander, G. R.. 1977. Food of vertebrate predators on trout waters in north central lower
Michigan. Michigan Academician 10: 181-195.

Andersen, D. E., and O.J. Rongstad. 1989. Home-range estimates of red-tailed hawks based on
random and systematic relocations. J. Wildl. Manage. 53: 802-807.

Barrett, G. W. and K. L. Stueck, 1976. Caloric ingestion rate and assimilation efficiency of the
short-tailed shrew, Blarina brevicauda. Ohio J. Sci. 76: 25-26.

Bayer, R. D.. 1981. Weights of great blue herons (Ardea herodias) at the Yaquina Estuary,
Oregon. Murrelet 62: 18-19.

Bent, A. C.. 1926. Life histories of North American marsh birds. Washington, DC: U. S.
Government Printing Office; Smithsonian Inst. U. S. Nat. Mus., Bull. 135.

Beyer, W.N., E. Conner, and S. Gerould. 1994. Estimates of soil ingestion by wildlife. J.Wildl.
Manage. 58: 375-382.

Bohm, R. T.. 1978. Observation of nest decoration and food habits of red-tailed hawks.

Loon 50: 6-8.

Britt, T. L.. 1971. Studies of woodcock on the Louisiana wintering ground [master's thesis],
Shreveport, LA: Louisiana State University.

Brown, L. and D. Amadon. 1968. Eagles, hawks, and falcons of the world, v. 1. New York, NY:
McGraw-Hill.

Burt, W. H. and R.P. Grossenheider. 1980. A field guide to the mammals of North America
north of Mexico. Boston, MA: Houghton Mifflin Co.

Chew, R. M.. 1951. The water exchanges of some small mammals. Ecol. Monogr. 21: 215-225.

Craighead, J. C. and F. C. Craighead. 1956. Hawks, Owls and Wildlife. Harrisburg PA, the
Stackpole Co. and Washington DC Wildl. Manage Inst.

Deavers, D. R. and J.W. Hudson. 1981. Temperature regulation in two rodents (Clethrionomys
gapperi and Peromyscus leucopus) and a shrew (Blarina brevicauda) inhabiting the same
environment. Physiol. Zool. 54: 94-108.

Dunford, R. D. and R.B. Owen. 1973. Summer behavior of immature radio-equipped woodcock

89


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in central Maine. J. Wildl. Manage. 37: 462-469.

Fitch, H. S.F. Swenson, and T.F. Tillotson. 1946. Behavior and food habits of the red-tailed
hawk. Condor 48: 205-237.

Gates, J. M.. 1972. Red-tailed hawk populations and ecology in east-central Wisconsin.

Wilson Bull. 84: 421-433.

Hamilton, W. J., Jr.. 1931. Habits of the short-tailed shrew, Blarina brevicauda (Say). Ohio J.
Sci. 31: 97-106.

Hamilton, W. J., Jr.. 1941. The foods of small forest mammals in eastern United States.
J.Mammal. 22: 250-263.

Hartman, F. A.. 1961. Locomotor mechanisms in birds. Washington, DC: Smithsonian Misc.
Coll. 143.

Hoffman, R. D.. 1978. The diets of herons and egrets in southwestern Lake Erie. In: Sprunt,
A.; Ogden, J.; Winckler, S., eds. Wading birds. Natl. Audubon Soc. Res. Rep. 7: 365-369.

Hudgins, J. E.; G.L. Storm; and J.S. Wakeley. 1985. Local movements and diurnal-habitat
selection by male woodcock in Pennsylvania. J. Wildl. Manage. 49: 614-619.

King, C.M.. 1983. Mustela erminea. Mammalian Species. No. 195. American Soc. Mammal.

Kirkpatrick, C. M.. 1940. Some foods of young great blue herons. Am. Midi. Nat. 24: 594-
601.

Kushlan, J. A.. 1978. Feeding ecology of wading birds. In: Sprunt, A.; Ogden, J.; Winckler, S.,
eds. Wading birds. Natl. Audubon Soc. Res. Rep. 7; pp. 249-296.

Krohn, W. B.. 1970. Woodcock feeding habits as related to summer field usage in central Maine.
J. Wildl. Manage. 34: 769-775.

MacLaren, P. A.; S.H. Anderson, and D.E. Runde. 1988. Food habits and nest characteristics of
breeding raptors in southwestern Wyoming. Great Basin Nat. 48: 548-553.

Mader, W. J.. 1978. A comparative nesting study of red-tailed hawks and Harris' hawks in
southern Arizona. Auk 95: 327-337.

Mendall, H. L. and C.M. Aldous. 1943. The ecology and management of the American
woodcock. Orono, ME: Maine Coop. Res. Unit, University of Maine; 201 pp.

Miller, H. and L.L. Getz. 1977. Factors influencing local distribution and species diversity of

90


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forest small mammals in new England. Can. J. Zool. 55: 806-814.

Miller, D. L. and M.K. Causey. 1985. Food preferences of American woodcock wintering in
Alabama. J. Wild], Manage. 49: 492-496.

Morrison, P. R.; M. Pierce; and F.A. Ryser. 1957. Food consumption and body weight in the
masked and short-tailed shrews (genus Blarina) in Kansas, Iowa, and Missouri. Ann. Carnegie
Mus. 51: 157-180.

Nagy, K. A.. 1987. Field metabolic rate and food requirement scaling in mammals and birds.
Ecol. Mono. 57: 111-128.

Nelson, A. L. and A.C. Martin. 1953. Gamebird weights. J. Wildl. Manage. 17: 36-42.

Owen, R. B.; J.M. Anderson; and J.W. Artmann. 1977. American woodcock. In:Sanderson, G.
C., ed. Management of migratory shore and upland game birds in North America. Washington,
DC: Int. Assoc. Fish Wildl. Agencies; pp. 147-175.

Palmer, R. S.. 1962. Handbook of North American birds: v. 1. New Haven, CT: Yale
University Press.

Peifer, R. W.. 1979. Great blue herons foraging for small mammals. Wilson Bull. 91: 630-631.

Petersen, L.. 1979. Ecology of great horned owls and red-tailed hawks in southeastern
Wisconsin. Wise. Dept. Nat. Resour. Tech. Bull. No. 111.

Piatt, W. J.. 1974. Metabolic rates of short-tailed shrews. Physiol. Zool. 47: 75-90.

Polderboer, E.B.; L.W. Kuhn, and G.O. Hendrickson. 1941. Winter and spring habits of
weasels in central Iowa. J. Wildl. Manage. 5: 115-119.

Preston, C. R.. 1990. Distribution of raptor foraging in relation to prey biomass and habitat
structure. Condor 92: 107-112.

Quick, H.F.. 1944. Habits and economics of the New York weasel in Michigan. J. Wildl.
Manage. 8: 71-78.

Quick, H.F.. 1951. Notes on the ecology of weasels in Gunnison County, Colorado. J.
Mammal. 32: 281-290.

Quinney, T. E.. 1982. Growth, diet, and mortality of nestling great blue herons. Wilson Bull.
94: 571-577.

Robinson, D. E. and E.D. Brodie. 1982. Food hoarding behavior in the short-tailed shrew,

91


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Blarina brevicauda. Am. Midi. Nat. 108: 369-375.

Rothfels, M. and M.R. Lein. 1983. Territoriality in sympatric populations of red-tailed and
Swainson's hawks. Can. J. Zool. 61: 60-64.

Sheldon, W. G.. 1967. The book of the American woodcock. Amherst, MA: University of
Massachusetts Press.

Short, H. L. and R.J. Cooper. 1985. Habitat suitability index models: great blue heron. U. S.

Fish Wildl. Serv. Biol. Rep. No. 82(10.99); 23 pp.

Spendelow, J. A. and S.R. Patton. 1988. National atlas of coastal waterbird colonies: 1976-1982.
U. S. Fish Wildl. Serv. Biol. Rep. No. 88(5).

Sperry, C.. 1940. Food habits of a group of shore birds; woodcock, snipe, knot, and dowitcher.
U. S. Dept. Int., Bur. Biol. Survey, Wildl. Res. Bull. I; 37 pp.

Stickel, W. H.; D.W. Hayne and L.F. Stickel. 1965. Effects of heptachlor-contaminated
earthworms on woodcocks. J. Wildl. Manage. 29: 132-146.

Stribling, H. L. and P.D. Doerr. 1985. Nocturnal use of fields by American woodcock. J. Wildl.
Manage. 49: 485-491.

Svendsen, G.E.. 1982. Weasels, pp. 613-628. In Chapman, J.A., and G.A. Feldhamer (eds.),
Wild Mammals of North America. Biology, Management, and Ecomomics. The Johns
Hopkins University Press, Baltimore.

USEPA. 1993. Wildlife exposure factors handbook. Vol. I. EPA/600/R-93/187a. Office of
Research and Development, Washington, D.C.

USEPA. 2005. Guidance for Developing Ecological Soil Screening Levels (Eco-SSLs).
Attachment 4-1. OSWER Directive 9285.7-55.

92


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APPENDIX F: TOXICITY REFERENCE VALUES

93


-------
Wildlife TRVs are derived from three primary sources, including Toxicological Benchmarks for
Wildlife: 1996 Revision (Sample et al. 1996), Ecological Soil Screening Levels for Dieldrin
(USEPA, 2007a); and Ecological Soil Screening Levels for DDT and Metabolites (USEPA,
2007b). When TRVs could not be identified from those sources, a literature search was
conducted.

Two TRVs were identified for each wildlife receptor, including a No Observed Adverse Effect
Level (NOAEL) and a Lowest Observed Adverse Effect Level (LOAEL) (Tables 1 and 2).

Where Sample et al., (1996), or values from the literature were used to derive the TRVs, the
NOAEL and LOAELs are based on the single study method. For each study, the form of the
compound, test species, body weight of test species, study duration, test endpoint, exposure
route, and dosage was identified. NOAEL and LOAELs were then calculated based on the dose
and body weight of the test species. In cases where only a LOAEL is reported, a NOAEL can be
derived by dividing the LOAEL by 10 (USEPA, 1995).

Where Eco-SSLs were used to derive TRVs (USEPA, 2007a; 2007b); the NOAEL was estimated
based on the geometric means of the bounded NOAEL data for growth, reproduction and
survival. However, if this value is higher than the lowest bounded LOAEL for either
reproduction, growth, or survival results, the TRV is equal to the highest bounded NOAEL that
is lower than the lowest bounded LOAEL for reproduction, growth, and survival. For both
Dieldrin and DDT, the NOAEL was based on the highest bounded NOAEL that is lower than the
lowest bounded LOAEL, not the geometric mean. The LOAEL was calculated based on the
geometric mean of the bounded LOAELs for reproduction, growth, and survival. LOAELs for
DDT and metabolites, and dieldrin, can be found in Table 3.

Table 1. TRVs for Mammals

COPC

Test Species

NOAEL

LOAEL

Reference





(mg/kg/d)

(mg/kg/d)



Aldrin

Rat

0.2

1.0

a

Aroclor 1016

Mink

1.37

3.43

a

Aroclor 1221

Oldfield Mouse

0.068

0.68

a1

Aroclor 1232

Oldfield Mouse

0.068

0.68

a1

Aroclor 1242

Mink

0.069

0.69

a

Aroclor 1248

Rhesus Monkey

0.01

0.1

a

Aroclor 1254

Oldfield Mouse

0.068

0.68

a

Aroclor 1260

Oldfield Mouse

0.068

0.68

a1

BHC Mixtures

Mink

0.014

0.14

a

g-BHC

Rat

8.0

NA

a

Chlordane

Mouse

4.6

9.2

a

94


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DDT

NA

0.147

18.8

b

Dieldrin

NA

0.015

2.28

c

Endosulfan I

Rat

0.15

NA

a

Endosulfan II

Rat

0.15

NA

a ~

Endosulfan Sulfate

Rat

0.15

NA

¦>

a**

Endrin

Mouse

0.092

0.92

a

Endrin Aldehyde

Mouse

0.092

0.92

a3

Endrin Ketone

Mouse

0.092

0.92

a3

Heptachlor

Mink

0.1

1.0

a

Heptachlor
epoxide

Mink

0.1

1.0

a4

Methoxychlor

Rat

4.0

8.0

a

Toxaphene

Rat

8.0

NA

a

a - Toxicological Benchmarks for Wildlife: 1996 Revision (Sample et al. 1996)
a1 - Aroclor 1254
a2 - Endosulfan I
a3 - Endrin
a4 - Heptachlor

b - Geometric means of NOAEL and LOAEL values from Ecological Soil Screening Levels for
DDT and Metabolites (USEPA, 2007).

c - Geometric means of NOAEL and LOAEL values from Ecological Soil Screening Levels for
Dieldrin (USEPA, 2007).

Table 2. TRVs for Birds.

COPC

Test Species

NOAEL
(mg/kg/d)

LOAEL
(mg/kg/d)

Reference

Aldrin

Ring Necked Pheasant

0.07

0.35

d

Aroclor 1016

Ring Necked Pheasant

0.18

1.8

a1

Aroclor 1221

Ring Necked Pheasant

0.18

1.8

a1

Aroclor 1232

Ring Necked Pheasant

0.18

1.8

a1

Aroclor 1242

Screech Owl

0.41

1.8

a (a1 LOAEL)

Aroclor 1248

Ring Necked Pheasant

0.18

1.8

a

Aroclor 1254

Ring Necked Pheasant

0.18

1.8

a

Aroclor 1260

Ring Necked Pheasant

0.18

1.8

a1

BHC Mixtures

Japanese Quail

0.56

2.25

a

g-BHC

Mallard Duck

2.0

20.0

a

Chlordane

Red-Winged Blackbird

2.14

10.7

a

DDT

NA

0.227

10.98

b

Dieldrin

NA

0.0709

1.73

c

Endosulfan I

Gray Partridge

10.0

NA

a

Endosulfan II

Gray Partridge

10.0

NA

i

a~

Endosulfan Sulfate

Gray Partridge

10.0

NA

1

a"

Endrin

Screech Owl

0.01

0.1

a

95


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Endrin Aldehyde

Screech Owl

0.01

0.1

a3

Endrin Ketone

Screech Owl

0.01

0.1

a3

Heptachlor

Ring-necked Pheasant

0.28

1.38

d

Heptachlor
epoxide

Ring-necked Pheasant

0.28

1.38

d

Methoxychlor

chicken

355

1775

e

Toxaphene

Black Ducks

2.0

10.0

f

a - Toxicological Benchmarks for Wildlife: 1996 Revision (Sample et al. 1996)
a1 - Aroclor 1254
a2 - Endosulfan I
a3 - Endrin

b - Geometric means of NOAEL and LOAEL values from Ecological Soil Screening Levels for
DDT and Metabolites (USEPA, 2007).

c - Geometric means of NOAEL and LOAEL values from Ecological Soil Screening Levels for
Dieldrin (USEPA, 2007).
d - Hill et al., 1975
e-Wiemeyer, 1996
f - Mehrle et al., 1979

Table 3. LOAEL (mg/kg bw/d) data for growth, reproduction and survival with geometric mean
calculations from the Eco-SSL guidance for DDT and Dieldrin.

DDT AVIAN

DDT MAMMALS

DIELDRIN AVIAN

DIELDRIN MAMMALS

Reproduction

0.40

Reproduction

0.27

Reproduction

0.22

Reproduction

0.03

Reproduction

0.28

Reproduction

0.69

Reproduction

0.52

Reproduction

0.72

Reproduction

0.75

Reproduction

0.74

Reproduction

0.68

Growth

1.96

Reproduction

1.13

Reproduction

1.79

Reproduction

1.70

Growth

2.00

Reproduction

1.97

Reproduction

17.10

Reproduction

1.51

Growth

1.74

Reproduction

0.49

Reproduction

19.00

Reproduction

2.60

Growth

2.05

Reproduction

1.89

Reproduction

99.00

Growth

3.78

Growth

5.22

Reproduction

5.20

Reproduction

50.00

Growth

0.52

Growth

5.22

Reproduction

6.07

Reproduction

85.30

Growth

10.10

Growth

18.00

Reproduction

21.10

Reproduction

38.80

Growth

5.93

Survival

0.23

Reproduction

32.50

Reproduction

95.60

Survival

0.18

Survival

1.33

Reproduction

46.90

Growth

4.19

Survival

3.78

Survival

0.75

Reproduction

42.50

Growth

33.70

Survival

0.54

Survival

2.00

Reproduction

29.00

Growth

96.50

Survival

0.56

Survival

3.92

Reproduction

37.50

Growth

137.00

Survival

1.25

Survival

3.96

Reproduction

51.50

Survival

5.18

Survival

1.70

Survival

1.74

Growth

2.27

Survival

24.39

Survival

2.35

Survival

2.23

Growth

2.79

Survival

25.40

Survival

2.60

Survival

3.53

96


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Growth

2.95

Survival

81.20

Survival

4.15

Survival

5.22

Growth

42.50

Survival

69.70

Survival

4.00

Survival

24.20

Survival

1.30

Survival

137.00

Survival

4.42

Survival

18.80

Survival

4.51



Geomean
18.83

Survival

15.00



Geomean
2.28

Survival

7.54







Geomean
1.73





Survival

5.21













Survival

2.85













Survival

2.93













Survival

20.30













Survival

22.70













Survival

13.80













Survival

130.00













Survival

21.90













Survival

25.10













Survival

85.30













Survival

59.40













Survival

25.00













Survival

43.50













Survival

35.60













Survival

51.50













Survival

58.10













Survival

132.00













Survival

200.00















Geomean
10.98













97


-------
References:

Hill, E.F., R.G. Heath, J.W. Spann, and J.D. Williams. 1975. Lethal Dietary Toxicities of
Environmental Pollutants to Birds. USFWS Special Scientific Report - Wildlife, No. 191.

Mehrle, P.M., M.T. Finley, J.L. Ludke, F.L. Mayer, and T.E. Kaiser. 1979. Bone development in
black ducks as affected by dietary toxaphene. Pestic. Biochem. Physiol. 10:168-173.

Sample B.E., D.M. Opreska, andG.W. Suter., 1996. Toxicological Benchmarks for Wildlife:
1996 Revision. ES/ER/TM-86/R3

USEPA, 2007a. Ecological Soil Screening Levels for Dieldrin. Interim Final. OSWER Directive
9285.7-57.

USEPA, 2007b. Ecological Soil Screening Levels for DDT and Metabolites. Interim Final.
OSWER Directive 9285.7-57.

Wiemeyer SN, Hoffman DJ. 1996. Reproduction in eastern screech-owls fed selenium. J Wildl
Manage 60(2):332-341.

98


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MEMORANDUM - April 2016

SUBJECT: Vapor Intrusion Assessment for Five Year Review Addendum OU3
Des Moines TCE Site, Des Moines, IA

FROM: Dan Nicoski, Geologist
ENSV/EAMB

TO:	Erin McCoy, Project Manager

SUPR/IANE

As requested, an evaluation of the potential for completion of the vapor intrusion
pathway at OU3 was conducted for the above referenced site. This evaluation used
chemicals of concern detected in groundwater collected from OU3 monitoring wells NW-
30, NW-31, NW-32, NW-34, NW-35, NW-36, NW-39 and NW-40. Were appropriate,
the V1SL calculator was used to evaluate the potential for contaminated vapors
partitioning from impacted groundwater into overlying occupied structures above/near
the plume.

As of the last sampling event in November 2015, only cis-l,2-DCE was detected in
groundwater at OU3. The concentration of cis-l,2-DCE was 9 (Jg/L at monitoring well
NW-39. During the prior groundwater sampling event in May 2012, PCE, TCE and total
DCE were detected at concentrations less than their respective MCLs.

Cancer risk and non-cancer hazard index values are not provided in the latest RSL table
(November 2015) for either DCE isomer (i.e., cis or trans). During the latest sampling
event, there were no apparent human health risks from vapor intrusion based on the
above noted detection.

Typically at sites with chlorinated solvents in groundwater, TCE is the driver for risk
management decisions. TCE was last detected during the 2012 groundwater sampling
event at a concentration of 4.8 (Jg/L in well NW-35. Based on the more conservative
residential scenario and an interpolated groundwater temperature of 11°C, the VISL
calculator indicates a potential indoor air concentration of 0.949 |ug/m3 which equates to
a cancer risk of 2.0 E-06 and hazard index of 0.46. This concentration of TCE in
groundwater is less than human health risks.

Based on this VI evaluation, continued periodic groundwater monitoring indicates recent
groundwater COC concentrations do not represent potential indoor air exceedances of
human health risk. Should you have any questions, please contact me at x7230.


-------
Des Moines TCE Statistical Analysis of OU-3 Contamination

INTRODCTION

A statistical analysis was performed on the main chemicals of concern (COCs) for the upgradient
operable unit 3 (OU-3) of the Des Moines TCE Site (Site) to determine if concentrations were increasing
or decreasing.

The Iowa Department of Natural Resources samples the wells for a limited volitale organic carbon (VOC)
list that includes the COCs for the Site. COCs at OU-3 include tetrachloroethylene (PCE),
trichloproethylene (TCE), dichrlorethylenes (DCE), and vinyl chloride (VC). Speciation of DCE was not
performed, so the statistical analysis was performed on total 1,2-DCE concentrations.

A review of the site file showed that several parameters were either unknown at the site, or were over
10 years old. Therefore, some parameters were assumed based on known data. These included:

Parameter

Value

Source

Seepage Velocity

2 feet per day

Assumed based on sand and gravel. Assumed low
due to depositional environment (alluvium and
glacial till combined).

httD://Eroundwater.ucdavis.edu/files/156562.Ddf

Current Plume Length

2000 feet

Combined with Dico plume since no break
between the plumes is found. Measured off map
provided in the Progress Report #29

Current Plume Width

500 feet

Combined with Dico plume since no break
between the plumes is found. Measured off map
provided in the Progress Report #29

Source Well

NW-35

Defined as source well because it contained the
most and highest detections.

Tail Wells

All other wells
evaluated

Defined as tail wells based on definitions in
MAROS software.

Distance to downgradient
receptor and property

1 foot

Minimum value MAROS will accept.

Distance from source to
nearest receptor and
property

1 foot

Minimum value MAROS will accept.

results

Analytical data from July 1989 to November 2015 were evaluated to determine if potential trends exists
using the Mann-Kendall (M-K) Statistic. Established trends are outline below. In order for a trend to be
listed, a minimum of two detections was necessary.

•	Increase

o TCE - NW-34 & NW-36
o DCE - NW-36

•	Decrease

o PCE - NW-35
o TCE - NW-35

February 2016


-------
o DCE - NW-35
• Stable

o PCE - NW-34 & NW-40
o TCE - NW-39

The compliance monitoring recommended sampling for all 4 COCs for at least 1 more year, with several
COCs tested semi-annually for two years.

CONCLUSION

Well NW-35, which is a shallower wells, shows decreasing trends in all of the COCs detected. Well NW-
36, which is the deeper well nested with well NW-35, shows an increase in TCE and DCE. Between 1989
and 2001, only on one detection of TCE and DCE was detected in this well. Since July 2001, DCE has been
detected every sampling event and TCE has been detected in all but two sampling events. This indicates
that contamination in well NW-35 is migrating downward in the aquifer.

Well NW-34 is also a deep well and is located downgradient of well NW-36. PCE concentrations show a
stable trend in this well. TCE has increased in well NW-24, but other COCs, which are breakdown
chemicals of TCE have not increased. In fact, DCE was only detected once in 2008. Vinyl chloride has
never been detected in the well. The concentrations in all wells are below the MCLs.

The increase in DCE concentrations at well NW-35 could indicate that natural dechlorinization is
breaking down TCE. However, breakdown products are not present in downgradient well NW-34 even
though TCE is increasing in this well. Geochemical data has also not been obtained to determine if
conditions are right for dechlorinzation. This indicates that TCE is likely migrating downgradient from
well NW-35 to well NW-34 and that data is not available to support that natural dechlorinization of PCE
and TCE is occurring at OU3.

RECOMMENDATIONS

Based on the statistical analysis, TCE and DCE are migrating downward in the aquifer and TCE is
migrating downgradient, to the south, with only increasing trends determined in deeper wells. However,
concentrations are below the MCLs in all of the wells, showing that contamination, while present, does
not present a potential unacceptable health risk at this time. It is recommended that sampling of wells
in OU3 continue every two to three years so that the trends and potential health risks can continue to
be reviewed.

February 2016


-------
MAROS Mann-Kendall Statistics Summary

User Name: Erin McCoy - EPA
State*. Iowa

Time Period: 7/1/1989 to 11/9/2015
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: 1/2 Detection Limit
J Flag Values : Actual Value

Project: Dico OU03
Location: Des Moines















All





Source/

Number of

Number of

Coefficient

Mann-Kendall

Confidence

Samples

Concentration

Well

Tall

Samples

Detects

of Variation

Statistic

in Trend

"ND" ?

Trend

DICHLOHOETHYLENES

NW-30

T

24

0

1.58

98

99.3%

Yes

ND

NW-31

T

25

0

1.60

114

99.6%

Yos

ND

NW-32

T

25

0

1.60

114

99.6%

Yes

ND

NW-34

T

26

1

1.66

133

99.9%

No

1

NW-35

S

24

22

0.99

153

100.0%

No

D

NW-36

T

25

9

1.62

152

100.0%

No

1

NW-39

T

5

1

1.69

-4

75.8%

No

NT

NW-40

T

16

4

1.05

-27

87.7%

No

NT

TETRACHLOROETHYLENE(PCE)















NW-30

T

24

1

1.51

81

97.7%

No

1

NW-31

T

25

0

1.60

114

99.6%

Yes

ND

NW-32

T

25

0

1.60

114

99.6%

Yes

ND

NW-34

T

26

12

0.77

25

70.0%

No

S

NW-35

S

24

23

1.00

-150

100.0%

No

D

NW-36

T

25

6

1.54

34

77.8%

No

NT

NW-39

T

5

5

0.29

6

88.3%

No

NT

NW-40

T

16

5

0.79

18

77.5%

No

S

TRICHLOROETHYLENE (TCE)















NW-30

T

24

0

1.58

98

99.3%

Yes

ND

NW-31

T

25

0

1.60

114

99.6%

Yes

ND

NW-32

T

25

0

1.60

114

99.6%

Yes

ND

NW-34

T

26

5

1.21

84

96.7%

No

1

NW-35

S

24

23

0.87

-155

100.0%

No

D

NW-36

T

25

7

1.96

121

99.8%

No

1

NW-30

T

5

4

0.24

-1

50.0%

No

S

NW-40

T

16

1

1.06

9

63.9%

No

NT

VINYL CHLORIDE

















NW-30

T

12

0

0.95

8

68.1%

Yes

ND

NW-31

T

13

0

1.00

12

74.5%

Yes

ND

NW-32

T

13

0

1.00

12

74.5%

Yes

ND

NW-34

T

14

0

1.05

14

75.8%

Yes

ND

NW-35

S

12

0

1.09

19

88.9%

Yes

ND

NW-36

T

13

0

1.00

12

74.5%

Yes

ND

NW-39

T

3

0

0.00

0

0.0%

Yes

ND

NW-40

T

13

1

0.91

5

59.4%

No

NT

MAROS Version 2,.2 2006, AFCEE	Monday, February 01, 2016	Page 1 of 2


-------
Project: Dico OU03
Location: Des Moines

User Name: Erin McCoy - EPA
State: Iowa

All

Source/ Number of Number of Coefficient Mann-Kendall Confidence Samples Concentration
j-n Samples Detects of Variation Statistic in Trend "ND" ? Trend

VINYL CHLORIDE

Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A)-
Due to insufficient Data {< 4 sampling events); Source/Tail (S/T)

The Number of Samples and Number of Detects shown above are post-consolidation values.

MAROS Version 2,.2 2006, AFCEE

Monday, February 01, 2016

Page 2 of 2


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