RISK ASSESSMENT, VOLUME 1 OF 2 · Volume 1 of 2 . o . SDMS DocID ... 4.5.2 Food Chain Transfer 4-49...

ARCS

Remedial Planning Activities at Selected Uncontrolled g' Hazardous Substance Disposal .IM Sites in Region I

Environmental Protection Agency Region I

X i f ARCS Work Assignment No. 26-1 BBS

Risk Assessment Burgess Brothers Superfund Site Woodford and Bennington, Vermont

April 1997

Volume 1 of 2

o SDMS DocID 4 0 3 9

TAMS Consulfanfs, Inc. TRC PEI Associates, Inc. Jordan Communlcatloi Companies, Inc,

RISK ASSESSMENT

BURGESS BROTHERS SUPERFUND SITE

BENNINGTON AND WOODFORD, VERMONT

RISK ASSESSMENT

Prepared for

U.S. ENVIRONMENTAL PROTECTION AGENCY

Waste Management Division

JFK Federal Building

Boston, Massachusetts 02203

Work Assignment No.:

EPA Region:

Contract No.:

TRCC Document No.:

TRCC Project No.:

TRCC Project Manager:

TRCC Telephone No.:

EPA Work Assignment Manager:

Telephone No.:

Date Prepared:

26-1BB5

I

68-W9-0033

L94-651

1-636-0270-1BB5

Diane Stallings

(508) 970-5600

Ronald Jennings

(617) 573-5794

April 18, 1997

TRC ENVIRONMENTAL CORPORATION

Boott Mills South

Foot of John Street

Lowell, Massachusetts 01852

(508) 970-5600

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TABLE OF CONTENTS

Section Page

1.0 INTRODUCTION 1-1

1.1 Overview 1-1

1.2 Site Description 1-5

1.3 Site History 1-8

1.4 Summary of Site Investigations 1-9

2.0 EVALUATION OF SITE CONTAMINATION 2-1

2.1 Data Evaluation 2-1

2.1.1 Data Sources 2-1

2.1.2 Data Review 2-2

2.2 Statistical Analyses 2-20

2.3 Summary of Site Contamination 2-22

2.3.1 Ground Water Contamination 2-22

2.3.2 Soil Contamination 2-26

2.3.3 Surface Water, Sediment, and Leachate Contamination 2-28

2.3.4 Air Contamination 2-30

2.4 Contaminant Fate and Transport 2-30

2.4.1 Known and Potential Source Areas 2-31

2.4.2 Potential Routes of Migration 2-31

2.4.3 Contaminant Transport 2-32

3.0 HUMAN HEALTH RISK ASSESSMENT 3-1

3.1 Selection of Contaminants of Concern 3-1

3.1.1 Background 3-1

3.1.2 Methodology 3-1

3.2 Exposure Assessment 3-2

3.2.1 Introduction 3-2

3.2.2 Characterization of Exposure Setting 3-3

3.2.3 Identification of Exposure Pathways 3-6

3.2.4 Exposure Scenarios 3-9

3.2.5 Quantification of Exposure 3-11

3.3 Toxicity and Dose-Response Assessment 3-15


3.3.2 Carcinogenic Effects 3-16

3.3.3 Noncarcinogenic Effects 3-18

3.3.4 Special Considerations - Dermal Contact 3-20

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TABLE OF CONTENTS (CONTINUED)

Section Page

3.4 Risk Characterization 3-21


3.4.2 General Methodology 3-21

3.4.3 Risk Summary 3-23

3.5 Discussion of Uncertainties 3-33


3.5.2 General Methodological Uncertainties 3-34

3.5.3 Site-Specific Uncertainties 3-38

3.5.4 Data-Related Uncertainties 3-40

4.0 ECOLOGICAL RISK ASSESSMENT 4-1

4.1 Introduction 4-1

4.2 Problem Formulation 4-2

4.2.1 Habitat and Species Characterization 4-2

4.2.2 Hazard Identification 4-14

4.3 Exposure Assessment 4-26

4.3.1 Aquatic Biota Exposure 4-26

4.3.2 Food Chain Exposure 4-26

4.4 Ecological Effects Assessment 4-29

4.4.1 Leachate/Surface Water 4-30

4.4.2 Sediment 4-33

4.4.3 Food Chain Toxicity 4-33

4.5 Risk Characterization 4-35

4.5.1 Aquatic Biota 4-39

4.5.2 Food Chain Transfer 4-49

4.5.3 Discussion of Uncertainties 4-55

5.0 SUMMARY AND CONCLUSIONS 5-1

6.0 REFERENCES 6-1

Appendices

A-1 Risk Assessment Database Summary Statistics

B Human Health Risk Spreadsheets C Toxicity Profiles D Lead lEUBK Model Results E Ecological Risk Tables

A-2 Oversight Data Summary Statistics

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TABLE OF CONTENTS (CONTINUED)

TABLES

Number Page

2-1 Sample Inventory 2-3

2-2 Summary of Wells and Data Used in Statistics for Inorganic Data 2-17

3-1 Contaminants of Potential Concem for Each Medium at the Burgess Brothers

Superfund Site 3-42

3-2 Burgess Brothers Superfund Site: Summary of Exposure Pathways 3-43

3-3 Exposure Pathway: Ingestion of Ground Water by Resident for Future Scenario . 3-46

3-4 Exposure Pathway: Incidental Ingestion of Surface Soils by Trespasser for

Present and Future Scenarios 3-47

3-5 Exposure Pathway: Incidental Ingestion of Surface Soils by Adjacent Resident

for Future Scenario 3-48

3-6 Exposure Pathway: Incidental Ingestion of Soils by Excavation Worker for

Future Scenario 3-49

3-7 Exposure Pathway: Incidental Ingestion of Sediments by Trespasser for Present

and Future Scenarios 3-50

3-8 Exposure Pathway: Dermal Contact with Surface Water by Trespasser While

Wading for Present and Future Scenarios 3-51

3-9 Human Health Toxicity Criteria for Contaminants of Concern at the Burgess

Brothers Superfund Site 3-52

3-10 Potential Carcinogenic Effects ofthe Burgess Brothers Site COCs 3-53

3-11 EPA Weight-of-Evidence for Human Carcinogenicity 3-56

3-12 EPA Carcinogenicity Weight-of-Evidence Criteria for Human and Animal Data . . 3-57

3-13 Carcinogenicity of PAHs Detected at the Burgess Brothers Site 3-59

3-14 Potential Chronic Noncarcinogenic Effects of Burgess Brothers Site COCs 3-60

3-15 Potential Subchronic Noncarcinogenic Effects of Burgess Brothers Site COCs . . . 3-63

3-16 Summary of Carcinogenic Risk Estimated for the Burgess Brothers Site 3-65

3-17 Summary of Noncarcinogenic Hazard Indices Estimated for the Burgess Brothers

Site 3-66

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c TABLE OF CONTENTS (CONTINUED) Number Page

4-1 Potential Ecological Receptors for Burgess Brothers Landfill 4-9

4-2 Selection of Leachate and Surface Water Contaminants of Concem - Ecological

Assessment 4-16

4-3 Selection of Sediment Contaminants of Concem - Ecological Assessment 4-21

4-4 Burgess Brothers: Selection of Surface Soil Ecological Contaminants of Concern 4-23

4-5 Leachate and Surface Water Quality Criteria for Contaminants of Concern,

Burgess Brothers Landfill 4-31

4-6 Leachate and Surface Water Amphibian Toxicity Data for Contaminants of

Concem, Burgess Brothers Landfill 4-32

4-7 Sediment Quality Guidelines for Contaminants of Concem, Burgess Brothers

Landfill 4-34

4-8 Chronic Toxicity Values and Dietary Limits of COCs for Vole, Shrew, and Robin 4-36

4-9 Leachate and Surface Water Ecological Risk Summary 4-41

4-10 Amphibian Risk from Leachate/Surface Water 4-43

4-11 Sediment Ecological Risk Summary 4-47

4-12 Risk Indices for Meadow Vole, Wetlands Soil 4-50

4-13 Hazard Quotients for Short-Tailed Shrew, Wetlands Soil 4-52

4-14 Hazard Quotients for American Robin 4-54

-^gf

FIGURES

Number Page

1-1 Location Map 1-6

1-2 Site Feature Map 1-7

2-1 Site Map with Soil, Groundwater and Air Sample Locations 2-23

2-2 Site Map with Surface Water, Sediment, and Leachate Sample Locations 2-24

4-1 Habitat Cover Type Sketch 4-4

4-2 Onsite Leachate/Surface Water Sampling Locations Exceeding AWQC 4-46

4-3 Onsite Sediment Sampling Locations Exceeding Sediment Guidelines 4-48

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Section 1

1.0 INTRODUCTION

1.1 Overview

The final rule of the National Oil and Hazardous Substances Pollution Contingency Plan

(NCP, 1990) requires that a baseline human health and ecological risk assessment be

conducted as part of the Remedial Investigation/Feasibility Study (RI/FS) at Superfund

hazardous waste sites. The purpose of the baseline risk assessment is to determine

whether contaminants identified at the site pose a current or potential future risk to

human health or the environment in the absence of remediation. The analysis assists in

evaluating whether remediation is necessary.

TRC Companies, Inc. (TRCC), under Work Assignment 26-1BB5 of U.S. Environmental

Protection Agency (EPA) Contract 68-W9-0033, is conducting a baseline human health

and ecological risk assessment to support EPA enforcement activities related to the

Remedial Investigation (RI) at the Burgess Brothers Superfund site (Burgess Brothers),

Woodford and Bennington, Vermont. The human health risk assessment presented in

this report is primarily a quantitative analysis based on RI field sampling and analysis

results. The ecological risk assessment is both quantitative and qualitative; it is based on

previously published information and data collected during the RI.

The risk assessment evaluates actual or potential exposures to site contaminants under

current and future land use scenarios at the Burgess Brothers site and vicinity. Existing

site documents such as the Draft Phase lA-Initial Site Characterization (ISC) Report and

the Remedial Investigation Report prepared by O'Brien & Gere Engineers, Inc. (O'Brien

&. Gere, 1994 and 1996) were consulted to determine demographics of the area and likely

receptors and exposure pathways for current and future land use scenarios. Receptors

evaluated in the human health risk assessment include future residents, current

trespassers, and excavation workers.

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The quantitative human health risk assessment consists of four main components: hazard

identification, exposure assessment, toxicity evaluation, and risk characterization.

Hazard identification involves examining the contamination at the site and selecting the

contaminants of concern (COCs), which are those contaminants likely to pose the

greatest risk to human health. The exposure assessment involves using available data on

chemical releases from the site to estimate exposures to receptor populations. The

toxicity evaluation describes the toxicological effects from exposure to each COC and

summarizes relevant toxicity criteria. The risk characterization then estimates the

carcinogenic risk and potential for noncarcinogenic effects attributable to site-related

contamination, based on toxicity data and calculated exposure doses. Uncertainties

associated with risk estimates are also evaluated as part of the risk characterization.

The ecological risk assessment generally includes the same components as the human

health risk assessment, and consists of four main parts: problem formulation, exposure

assessment, ecological effects assessment, and risk characterization. Problem

formulation describes the ecological characteristics of the site area, including local

habitats and species. This description is based on information available in existing

reports and reference sources. Problem formulation also includes a selection of

contaminants of ecological concem and an identification of possible exposure pathways.

The exposure assessment estimates exposure point concentrations available for uptake by

ecological receptors. The ecological effects assessment identifies medium-specific

criteria or guidance and toxicity information available in scientific literature. Lastly, the

risk characterization evaluates potential risks to biota based on all the above information.

Uncertainties associated with the ecological risk assessment are also discussed as part of

the risk characterization.

This risk assessment was conducted in accordance with the following EPA guidance

documents:

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U.S. EPA Region I Waste Management Division Risk Updates: August 1994 and August, 1995, and November, 1996.

Risk Assessment Guidance for Superfund (RAGS), Volume I: Human Health Evaluation Manual.

(Part A) Interim Final, 540/1/-89, December 1989.

Development of Risk-Based Preliminary Remediation Goals (Part B) publication 9285.7-OlB, December 1991, PB92-963333.

Risk Evaluation of Remedial Alternatives (Part C), publication 9285.7OIC, December 1991, PB92-963334.

Human Health Evaluation Manual, Supplemental Guidance: "Standard Default Exposure Factors" OSWER Directive 9285.6-03 (EPA, March 25, 1991).

Supplemental Guidance to RAGS: Calculating the Concentration Term, (publicarion 9285.7-081, June 22, 1992).

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part 1: Public Health Risk Assessment (EPA 901/5/89-001, June 1989).

Final Guidance Data Useability in Risk Assessment (Part A), (publication 9285.7-09A, April 1992, PB92-963356).

Guidance for Data Useability in Risk Assessment (Part B), (publication 9285.709B, May 1992, PB92-963362).

Dermal Exposure Assessment: Principles and Applications (EPA 600/8-91/01 IB, January 1992).

Air/Superfund National Technical Guidance Study Series, Volumes I, II, III, and IV (EPA 450/1-89-001,002,003,004, July 1989).

Superfund Exposure Assessment Manual. Office of Remedial Response. EPA, 1988. (EPA/540/1-88/001).

Exposure Factors Handbook. Office of Health and Environmental Assessment. EPA, 1989. (EPA/600/8-89/043).

Risk Assessment Guidance for Superfund, Volume U: Environmental Evaluation (EPA 540/1-89/001, March 1989).

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Ecological Assessment of Hazardous Waste Sites: A Field and Laboratory Reference (EPA 600/3-89/013, March 1989).

Ecological Assessment of Superfund Sites; An Overview. Volume I, Number 2. Office of Solid Waste and Emergency Response. EPA, Publication 9345.0-051, December 1991.

Developing a Work Scope for Ecological Assessments. Volume I, Number 4. Office of Solid Waste and Emergency Response. EPA, Publication 9345.0-051, May 1992.

Framework for Ecological Risk Assessment (EPA 630R-92/001, February 1992).

EPA Region I Supplemental Risk Assessment Guidance for the Superfund Program Part 2: Guidance for Ecological Risk Assessment (EPA 90 l/5/89-(X) 1, June 1989).

This report is organized into the following sections:

Section 1 - Introduction (overview, site description, site history, and summary of site investigations)

Section 2 - Evaluation of Site Contamination (data evaluation, statistical analyses, sunmiary of contamination, and fate and transport)

Section 3 - Human Health Risk Assessment Section 4 - Ecological Risk Assessment Section 5 - Summary and Conclusions Section 6 - References

Appendices provide supporting information for relevant sections of the text.

The following sections, 1.2 Site Description, 1.3 Site History, and 1.4 Summary of Site

Investigations, summarize information on the site presented in the Draft Phase 1 A-Initial

Site Characterization (ISC) Report dated January 1994, the Remedial Investigation

Report dated July 1996, and Long Term Monitoring Program (LTMP) reports.

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1.2 Site Description

The Burgess Brothers Superfund site is located in the towns of Woodford and

Bennington, Vermont, about two miles due east ofthe City of Bennington (Figure 1-1).

The site is comprised of an approximately two to three acre section of a 60 acre property

owned by Burgess Brothers, Inc., which currently conducts sand and gravel mining and

metal salvage operations at the property. The site area is located in the northeastern

section of the property, adjacent to the Green Mountain National Forest. Areas

surrounding the property are primarily wooded and undeveloped and are used for

recreational purposes. Portions of the Burgess Brothers property are used for skeet

shooting and as a pistol range by individuals and organizations. Hunters also utilize

areas of the property for big game and small game hunting. Off-road vehicles utilize

trails which cross portions of the property.

The two to three acre site area under investigation consists of a Landfill Area, a 2,000

square foot Former Lagoon Area, a Marshy Area, a Soil Staging Area, and a Hillside

Area (Figure 1-2). A number of drainage swales and intermittent streams discharge into

an unnamed stream which flows along the base of the Landfill Area and into Barney

Brook. Barney Brook discharges to the Walloomsac River South Branch just east of

Bennington Center. Historically the site received primarily municipal-type wastes

which were disposed in the Landfill Area. In the late 1960s through October 1976,

battery processing wastes were disposed in the Former Lagoon Area. Current sand and

gravel excavation and staging operations at the property occur near the Soil Staging Area

of the site.

Waste residues at the site include metals (predominantly lead, nickel, zinc, and

chromium) and volatile organic compounds (VOCs) (trichloroethene, tetrachloroethene,

dichloroethene). The primary source appears to be the Former Lagoon Area.

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BASE MAP IS A PORTION OF THE FOLLOWING USGS 7.5' SERIES QUADRANGLES: POWNAL, VERMONT, 1954; BENNINGTON, VERMONT, 1954

1000 2000 3000

SCALE-feet QUADRANGLE LOCATION

LOCATION MAP TC Companies, Inc. BURGESS BROTHERS SUPERFUND SITE

WOODFORD AND BENNINGTON, VERMONT Figure 1-1.

1-6

( ) ( )

/ / ' / / Source: O'Brien & Gere Engineers, Inc. Sept 1993

SITE FEATURE MAP

BURGESS BROTHERS SUPERFUND SITE WOODFORD AND BENNINGTON, VERMONT

Companies, Inc.

Figure 1-2.

Vertical gradients in the Marshy Area indicate an upward flow of impacted water from

the landfill, with subsequent discharge into the unnamed stream.

Ground water at the site is classified as Class III by the Vermont Agency of

Environmental Conservation (VTAEC) which is defined as: "Suitable as a source of

water for individual domestic water supply, irrigation, agricultural use and general

industrial and commercial use." During previous investigations, a ground water users

survey was conducted to identify and locate residential, commercial, municipal, and

industrial ground water users within a one mile radius of the site. Two municipal water

supply systems were identified as being within a one mile radius of the site (Ryder

Spring and Morgan Spring). Several private water supply well owners were also

identified as being located within a one mile distance and downgradient of the site.

1.3 Site History

The Burgess Brothers, Inc., property has been used as a source of sand and gravel dating

back to the 1940s. In addition. Burgess Brothers, Inc., is reported to have been involved

in the general demolition of buildings and removal of debris and in some oil spill cleanup

and removal of underground and above ground tanks. The site was also used as a metal

salvage facility and as a disposal area for municipal-type wastes including construction

debris. Test pits installed during the RI indicate the presence of typical municipal-type

refuse such as wood, newspaper, steel, cardboard, and cinders.

In the late 1960s, Burgess Brothers, Inc., began accepting lead plater wastes, lead plater

sludge, battery processing waste, and waste solvents from a Union Carbide Plant located

in Bennington. These wastes were reportedly disposed in an unlined bermed pit (the

Former Lagoon Area). Materials disposed included spent solvents (tetrachloroethene and

trichloroethene) in 55 gallon drums, boxed battery wastes (zinc chloride, ammonium

chloride, ammonium hydroxide and acetylene), anode gel and manganese dioxide cells.

It is the recollection of long time Burgess Brothers employees that all of the liquid waste

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and sludge from Union Carbide went into the Former Lagoon Area. The disposal of the

battery processing waste in the Former Lagoon Area continued through October 1976.

1.4 Summary of Site Investigations

The Burgess Brothers site has been under investigarion since 1984 by the VTDEC.

Placed on the National Priorities List as a Superfund site in March 1989, the site is now

also under the oversight of EPA. The EPA and the Burgess Brothers Superfund Site

Steering Conmiittee entered into a Consent Order for a RI/FS of the site, effective

September 4, 1991.

Geraghty & Miller, a Potentially Responsible Party (PRP) consultant, conducted soil

sampling at the site in 1985 and ground water sampling in 1985 and 1988. In February

of 1989, an EPA contractor, Roy F. Weston, Inc., collected surface water samples.

Subsequent to this, Geraghty & Miller collected ground water and surface water samples

in March 1989. In April of 1989, Roy F. Weston, Inc., conducted a soil gas survey and

performed soil sampling for the EPA. In May 1989, Geraghty & Miller published a

report summarizing the 1988 hydrogeologic investigations conducted at the site. The

April 1989 EPA investigation indicated the presence of trichlorethene and

tetrachloroethene in many samples collected in and adjacent to the Former Lagoon Area.

In the March 1989 ground water sampling program conducted by Geraghty & Miller,

VOCs were detected in downgradient wells west of the unnamed stream in quantities

exceeding 10 ppm which confirmed test results dating back to 1985.

A Limited Field Investigation (LFI) was performed by O'Brien & Gere Engineers, Inc.

during December 1991 and January 1992. The Work Plan for the Phase lA-ISC was

developed based on the results of the LFI and was conditionally approved by EPA in

August 1992. A draft report on activities and findings ofthe Phase lA-ISC was prepared

and submitted for review in January 1994. Activities conducted during the ISC included

a seismic refraction survey; additional soil gas sampling; installation of test pits; air

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monitoring; installation of monitoring wells; an ecological assessment; and sampling and

analysis of surface soils, and subsurface soils, surface water, sediments, leachate, and

groundwater.

Data gaps identified during the review of the Phase 1A-ISC results were addressed

during a Phase IB investigation conducted in 1994. Activities conducted during the

Phase IB investigation included the collecrion of additional soil samples from the

Marshy Area and additional ground water samples.

A Long Term Monitoring Program (LTMP) was established by O'Brien & Gere

Engineers, Inc. in April 1994. The purpose of the LTMP is to monitor air, groundwater,

leachate, and surface water quality in order to determine long term changes in

contaminants detected at the site. Sampling is conducted semi-annually and was initiated

in November 1994 (O'Brien & Gere, 1995). Subsequent, groundwater leachate and

surface water sampling was conducted by ERM-New England, Inc. in May 1995 (ERM,

1995) while groundwater and surface water sampling was conducted in the Fall of 1995

and May 1996 (ERM, 1996).

This risk assessment is based on data collected during the RI and as part of the long-term

monitoring program with the following exception: soils data from the landfill and

lagoon areas are not addressed in the risk assessment as EPA has selected a presumptive

remedylandfill cappingfor addressing these source areas.

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bection Z

2.0 EVALUATION OF SITE CONTAMINATION

The following section describes TRCC's review and evaluation of site data, summarizes

the nature and extent of site contamination, and presents an overview of contaminant fate

and transport issues pertinent to the human health and ecological risk assessment.

2.1 Data Evaluation

This section includes a description of data sources and methods used to statistically

analyze and summarize these data.

2.1.1 Data Sources

The environmental data used to create the risk assessment database consists of data

collected as part ofthe Phase 1 A-ISC, the Phase IB Investigation, and the Long-Term

Monitoring Program conducted by O'Brien & Gere Engineers, and ERM-New England,

Inc., from 1992 to the spring of 1996. Sample analysis data for all site media, except for

air, were provided to TRCC on computer diskette.

TRCC compiled summary statistics for the data collected through 1994. Subsequent to

this effort, additional surface water and ground water samples were collected as part of

the Long-Term Monitoring Program (November 1994, May 1996). Ground water

samples were collected using low-flow techniques. Because EPA has determined that the

inorganic data are better represented by the low-flow results, only the low-flow inorganic

data are used in estimating ground water risks. ERM-New England, Inc. compiled the

ground water inorganic summary statistics used in the risk assessment. ERM-New

England, Inc. also provided TRCC with low-flow organic data collected as part of the

Long Term Monitoring Program.

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TRCC also received Phase 1 A-ISC oversight split sample data collected by the EPA

oversight contractor (Metcalf & Eddy).

2.1.2 Data Review

The current risk assessment database presented in Appendix A-1 includes results for

samples from the following media:

ground water (multiple sampling rounds, including low-flow data);

surface soil (depth of less than twelve inches);

subsurface soil (depths of greater than twelve inches but less than 15 feet);

sediments;

surface water;

leachate; and

air.

Appendix A-2 contains the oversight split sample data collected from the above media.

Table 2-1 presents a list of all samples, analytical parameters, and data groupings

evaluated for the human health and ecological risk assessments, including background

samples. It is important to note that because a Presumptive Remedy has been selected

for the landfill and lagoon areas, soil samples from these areas are not included in the

risk assessment and are not listed in Table 2-1. Table 2-2 presents a summary of the

wells and data used to evaluate inorganics in ground water.

Prior to statistical analysis, site data were reviewed, as described in the following

subsections, for the following:

data validation qualifiers;

duplicate sample results;

re-extracted/re-analyzed results;

diluted results; and

detection limits.


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TABLE 2-1 SAMPLE INVENTORY - BURGESS BROTHERS RISK ASSESSMENT

MASTER LIST OF GROUPINGS, SAMPLE NUMBERS, AND ANALYSES

FOR THE BURGESS BROTHERS RISK ASSESSMENT

Sample Grouping

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Deep Ground Water

Sample Number

W-OIB-OI

W-OlB-04

W-04B-01

W-04B-02

W-04B-03

W-04B-04

W-04B-04BD

W-OlDI-05

W-01DI-05BD

W-04DI-01

W-04DI-02

W-04DI-03

W-04DI-04

W-04SI-01

W-04SI-01BD

W-04SI-02

W-04SI-03

W-04SI-04

W-07DI-03

W-07SI-01

W-07SI-02

W-07SI-03

W-07SI-04

W-08B-01

W-08B-02

W-08B-O3

W-GBSI-OI

W-08SI-02

W-08SI-03

W-08SI-04

VOCs

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

SVOCs Pesty Inorganics PCBs

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

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TABLE 2-1 (Continued) SAMPLE INVENTORY - BURGESS BROTHERS RISK ASSESSMENT



Sample Grouping Sample Number VOCs

Deep Ground Water W-09B-0I X

Deep Ground Water W-09B-02 X



Deep Ground Water W-09SI-01 X




Deep Ground Water W-25DI-01 X








Deep Ground Water W-25SI-04BD X

Deep Ground Water W-OlB-02 X

Deep Ground Water W-OlB-03 X

Deep Ground Water W-OlB-11

Deep Ground Water W-OlB-12

Deep Ground Water W-04SI-1I

Deep Ground Water W-04SI-I2

Deep Ground Water W-04SI-12BD

Deep Ground Water W-04SI-13

Deep Ground Water W-04B-11

Deep Ground Water W-04B-12





X

X

X

X

X

X

X

X

X

X

X

X

X


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Sample Grouping Sample Number VOCs SVOCs Pesty Inorganics

PCBs

Deep Ground Water W-09SI-I3 X

Shallow Ground Water W-01-4



Deep Ground Water W-OlDI-12 X

Deep Ground Water W-04DI-1I X


Shallow Ground Water SBW-10-OI X X

Shallow Ground Water SBW-10-OlBD X X

Shallow Ground Water SBW-10-02 X X

Shallow Ground Water SBW-10-03 X X

Shallow Ground Water SBW-11-03 X

Shallow Ground Water W-01-04 X

Shallow Ground Water W-01-05 X

Shallow Ground Water W-OllSI-OI X

Shallow Ground Water w-onsi-02 X

Shallow Ground Water W-01IS1-02BD X

Shallow Ground Water W-OllSl-03 X

Shallow Ground Water W-OlSl-01 X X



Shallow Ground Water W-OlSl-04 X

Shallow Ground Water W-02-01 X X X

Shallow Ground Water W-02-01BD X



Shallow Ground Water W-02-03BD X X X

Shallow Ground Water W-03-0I X X

Shallow Ground Water W-03-02 X X

Shallow Ground Water W-03-03 X X

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Sample Grouping

Shallow Ground Water






























Sample Number

W-03T-01

W-03T-02

W-03T-03

W-04D-01

W-04D-02

W-04D-03

W-04S-01

W-04S-02

W-04S-03

W-04T-05

W-05-01

W-05-02

W-05-02BD

W-05-03

W-06D-01

W-06D-02

W-06D-02BD

W-06D-03

W-06S-01

W-06S-02

W-06S-03

W-07S1-01

W-07S1-02

W-07S1-02BD

W-07S1-03

W-07S1-04

W-08SI-OI

W-08S1-02

W-08S1-O3

W-08S1-04

VOCs

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X


X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X


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Sample Grouping































Sample Number

W-09S1-01

W-09S1-02

W-09S1-03

W-09SI-04

W-llSI-01

W-llSl-02

W-llSl-03

W-llSl-04

W-12S1-01

W-I2SI-02

W-12S1-03

W-I2SI-04

W-22SI-0I

W-22S1-02

W-22S1-02BD

W-22SI-03

W-22SI-04

W-22T-05

W-23T-01

W-23T-02

W-23T-03

W-24T-01

W-24T-02

W-24T-03

W-24T-03BD

W-25S1-0I

W-25S1-02

W-25S1-03

W-25S1-04

W-26T-05

VOCs

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X


X

X

X

X

X

X

X

X

1


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Sample Grouping































Sample Number

W-27T-05

W-OlSl-11

W-OlSl-12

W-23T-12

W-08SI-13

W-08S1-13BD

W-09S1-II

W-09S1-12

W-25S1-II

W-25S1-12

W-25S1-13

W-27S1-11

W-27S1-13

W-06D-12

W-llSl-11

W-11SI-I2

W-01-I2

W-OI-13

W-27T-12

W-22T-11

W-22T-12

W-26T-11

W-04T-11

W-04T-12

W-04T-12BD

W-22S1-11

W-22S1-12

W-22S1-13

W-27S1-13

W-27S1-05

VOCs SVOCs Pesty PCBs

X

X

Inorganics

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X


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PCBs

Soil Boring/Subsurface SB-22-05 4-6' X


Soil Boring/Subsurface SB-23-05-BD 6-7' X

1 Soil Boring/Subsurface SB-24-05 2-4' X


1 Soil Boring/Subsurface SBW-IO 10-12' X X X X

Soil Boring/Subsurface SBW-10 14-16' X X X X

Soil Boring/Subsurface SBW-10 8-10' X X X X

Soil Boring/Subsurface SBW-IOBD 14-16' X X X X

Soil Boring/Subsurface W-OlSI-05 4-6' X

Soil Boring/Subsurface W-01 SI 10-12' X X X

Soil Boring/Subsurface W-01 SI 6-8' X X X

Soil Boring/Subsurface W-03T 10-12' X

1 Soil Boring/Subsurface W-03T 12-14' X

Soil Boring/Subsurface W-03 T 2-4' X

1 Soil Boring/Subsurface W-03 T 6-8' X

Soil Boring/Subsurface W-03 T 8-10' X

Soil Boring/Subsurface W-04 B(AB) 0-3' X

Soil Boring/Subsurface W-04B(AB) 11-13' X





Soil Boring/Subsurface W-04B(AB)9-ir X

Soil Boring/Subsurface W-04 B(AB)BD 9-1 r X

Soil Boring/Subsurface W-1IS12-4' X

Soil Boring/Subsurface W-11SI4-6' X

Soil Boring/Subsurface W-11S16-8' X

Soil Boring/Subsurface W-11S18-10' X

Soil Boring/Subsurface W-22S1 10-12' X


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Sample Grouping

Soil Boring/Subsurface







Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Sample Number

W-22S14-6'

W-22SI6-8'

W-22S1 8-10'

W-22S1BD6-8'

W-23T4-6'

W-23TBD 4-6'

W-24T 10-12'

SP-02 0-10"

SP-02 0-I2"

SP-02 5-7"

SB-22-05 0-2'

SB-23-05 0-2'

SB-24-05 0-2'

SB-25-05 0-2'

SBW-10 0-10"

SBW-13 0-I2"

SBW-13 5-7"

SBW-13BD0-12"

SBW-13BD5-7"

SP-01 O-IO"

SP-01 5-7"

SP-16 0-12"

SP-I6 5-7"

SP-17 0-12"

SP-17 5-7"

SP-18 0-12"

SP-18 5-7"

SP-19 0-12"

SP-19 4-7"

SP-20 0-12"


X

X

X

X

X

X

X

X X

X

X

X

X

X

X

X

X

X X

X

X

X

X

X

Inorganics

X

X

X

X

X

X

X

X

X

X

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Sample Grouping

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil

Surface Soil/Wet Meadow


Surface SoilAVet Meadow



















Sample Number

SP-20 1-7"

SP-21 0-12"

SP-21 5-7"

W-07S2 0-12"

W-07 S2 4-7"

W-08S2 0-12"

W-08 S2 5-7"

W-25S2 0-12"

W-25 S2 5-7"

W-llSlO-2 '

W-04 S2 0-12"

W-04 S2 5-7"

W-12S2 0-12"

W-I2S2 5-7"

SP-07 0-12"

SP-07 5-7"

SP-08 0-12"

SP-08 5-7"

SP-09 0-12"

SP-09 4-7"

SP-10 0-12"

SP-10 5-7"

SP-11 0-12"

SP-115-7"

SP-12 0-12"

SP-12 5-7"

SP-23-05 5-7"

SP-24-05 5-7"

SP-25-05 5-7"

SP-26-05 5-7"


X

X

X

X

X

X

X

X

X X

X

X

X X

X

X X

X

X

X

X

X

X

X

Inorganics

X

X

X

X

X

X

X

X

X

X

X

X


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TABLE 2-1 (Continued) S t . ^ SAMPLE INVENTORY - BURGESS BROTHERS RISK ASSESSMENT




PCBs

Surface Soil/Wet Meadow SP-26-05-BD 5-7" X

Surface Soil/Wet Meadow SP-27-05 5-7" X


Surface SoilAVet Meadow SP-29-05 5-7" X






Surface Soil/Wet Meadow SP-26-05BD0-12" X

Surface SoilAVet Meadow SP-27-05 0-12" X




Leachate LS-1 X X X

Leachate LS-1-02 X

Leachate LS-2 X X X X

Leachate LS-3 X X X X

Leachate LS-3BD X X X X

Background Sediment SED-OlA-01 X X X X

Background Sediment SED-OlA-02 X X X X

Background Sediment SED-OIB-01 X X X X

Background Sediment SED-OlB-02 X X X X

Background Sediment SED-06-01 X X

Background Sediment SED-06-02 X X

Background Sediment SED-13-01 X X X X




Sediment SED-10-01 X X X X

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FOR 1 HE BURGESS BROTHERS RISK ASSESSMENT


PCBs







Sediment SED-04-02BD X X X X










Sediment SED-11-03 X X

Sediment SED-11-03BD X


Sediment SED-12-01 BD X X X X






Sediment SED-15-01 X X X


Background Surface Water SW-OlB-01 X X X

Background Surface Water SW-OlB-02 X X X

Background Surface Water SW-06-01 X X

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TABLE 2-1 (Continued) ^Sm*' SAMPLE INVENTORY - BURGESS BROTHERS RISK ASSESSMENT




PCBs


Surface Water SW-11-03 X


Background Surface Water SW-13-02 X X X X

Background Surface Water Filtered SW-06-03-F X

Background Surface Water SW-08-02 X X X X

Surface Water S W-02-01 X X X X

Surface Water SW-02-02 X X X X



Surface Water SW-03-03 X X



Surface Water SW-04-02BD X X X X











Surface Water SW-10-OlBD X




X

Surface Water SW-12-0I X X X X

Surface Water SW-12-01BD X X X X


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TABLE 2-1 (Continued) ^ w SAMPLE INVENTORY - BURGESS BROTHERS RISK ASSESSMENT




PCBs











Surface Water SW-17-03BD X X


Surface Water Filtered SW-17-03-FBD X X

Surface Water Filtered SW-03-03-F X











Air Exclusion Zone AS-Ol-V X X

Air Downwind AS-07-V X X

Air Upwind AS-02-V X X

Air Upwind AS-04-V X X



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Sample Grouping Sample Number VOCs

Air Downwind AS-06-V X

Residential Wells DICKINSON-05

Residential Wells DICKINSON-03 X


Residential Wells DICKINSON-04BD X

Residential Wells OLIN-03 X


Residential Wells RYDER SPG-04 X

Residential Wells RYDSPR-03 X

Residential Wells RYDSPR-03BD X

Residential Wells Ryder Spring-03



SVOCs Pesty Inorganics

PCBs

X

X

X


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TABLE 2-2

SUMMARY OF WELLS AND DATA USED IN STATISTICS FOR INORGANIC DATA

BURGESS BROTHERS RISK ASSESSMENT

S&*. '

Well Well Classification Identincation

DATA USED

Spring 95 Fall 95 Spring 96

Shallow Kame Sand - Shallow Water Table Wells

W-01 X X

W-Ol-Sl X ^

W.06D X

W-08-S1 X*

W-09-S1 X X

W-ll-Sl x ^

W-22-S1 x X X

W-25-S1 X X X

W-27-S1 X X

Ablation Glacial Till Wells

W.04T X X*

W-22T X X

W-23T X

W-26T X

W-27T X

Deep Weathered Bedrock - Shallow Intermediate Wells

W-04-SI X X* X

W-07-SI X

W-09-SI X X*

Weathered Bedrock - Deep Intermediate Wells

W-Ol-DI X

W-04-DI X X

Competent Bedrock - Bedrock Wells

W-OIB X X

W-04B X X

W-09B X X

*Data used is an average between sample and blind duplicate.

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Validation qualifiers were treated according to EPA guidance (EPA, 1989a). Rejected results ^ w .

("R" qualifier) were eliminated from the risk assessment database. Non-detect results ("U"

qualifier) were included only if other results for a given chemical in a particular medium/area

indicated the chemical was present. In these instances, half the reported sample quantitation

limit was used in the risk assessment. Estimated results, usually indicated by a "J" qualifier,

were treated in the same manner as positive data with no qualifiers (see Appendix A-1).

Duplicates of the following samples were included in the database submitted by O'Brien & Gere:

W-04B-04 and W-04B-04BD

W-04S1-01 andW-04Sl-01BD

W-25S1-04 and W-25S1-04BD

W-04B-04-F and W-04B-04-FBD

W-04Sl-01-FandW-04Sl-01-FBD

W-25S1-04-F and W-25S1-04-FBD

SWB-10-01 andSBW-10-OlBD

W-011 -S1 -02 and W-011 -S1-02BD

W-02-01 andW-02-OlBD

W-02-03 and W-02-03BD

W-05-02 and W-05-02BD

W-06D-02 and W-06D-02BD

W-22S1-02 and W-22S1-02BD

W-24T-03 and W-24T-03BD

SBW-10-Ol-F and SBW-10-Ol-FBD

W-02-03-F and W-02-03-FBD

W-05-02-F and W-05-02-FBD

W-06D-02-F and W-06D-02-FBD

W-24T-03-F and W-24T-03-FBD

SB-23-05 6-7' and SB-23-05-BD 6-7'

SBW-10 14-16' and SBW-IOBD 14-16'

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W-04S1 9-11' and W-04S1 BD 9-11'

W-22 SI 6-8' and W-22 SIBD 6-8'

W-23T 4-6' and W-23TBD 4-6'

SBW-13 0-12" and SBW-13BD 0-12"

SBW-13 5-7" and SBW-13BD 5-7"

SP-26-05 and SP-26-05-BD

LS-3 and LS-3BD

SED-04-02 and SED-04-02BD

SED-11-03 and SED-11-03BD

SED-12-01 and SED-12-0IBD

SW-OlB-02 and SW-01B-02BD

SW-04-02 and SW-04-02BD

SW-10-01 andSW-10-OlBD

SW-12-01andSW-12-01BD

SW-17-03 and SW-17-03BD

W-OlDI-05 and W-01DI-05BD

W-25SI-04 and W-25SI-04BD

W-07-S1-02 and W-07-S1-02BD

W-04B(AB) 9'-l 1' and W-04B(AB)BD 9'-l 1'

SP-26-05 5"-7" and SP-26-05BD 5"-7"

SP-26-05 0"-12" and SP-26-05BD 0"-12"

SW-17-03-Fand SW-17-03-FBD

DICKINSON-04 and DICKINSON-04BD

RYDSPR-03 and RYDSPR-03BD

In most cases, the results of the duplicate samples were averaged. The resulting value

was the arithmetic mean of positive results or the arithmetic mean of the reported

detection limits if both samples were non-detects. However, if a positive value was

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reported for one sample of the duplicate pair and the other value was a negative result * * . -

(non-detect), the positive result was used.

Several samples required re-analysis and/or re-extraction. The decision of whether to use

the original or the re-extracted/re-analyzed result was made by O'Brien & Gere (1994).

Except for duplicates, only one result per sample was used in this risk assessment.

In a few instances mean concentrations exceeded maximum concentrations because of

elevated sample quantitation/detection limits. The elevated detection limits typically

occurred when a chemically similar compound was highly elevated in the same sample.

Matrix interferences may also have contributed. The determination of exposure point

concentrations in these cases is discussed in Section 2.2 below.

2.2 Statistical Analyses

Summary statistics for all chemicals detected in each medium evaluated, except ambient

air, in the human health and ecological risk assessments are presented in Appendix A-1.

Reported detected concentrations of ambient air contaminants, as presented in Tables 42

and 43 ofthe Final Remedial Investigation Report (O'Brien & Gere, 1996), are shown on

the final table of this appendix. Several of the medium-specific summary statistics are

further divided into subgroups. The data groupings are determined by the exposure

scenarios developed in Sections 3.2 and 4.3, Exposure Assessment sections for the

human health and ecological risk assessments, respectively. The data groupings are as

follows:


Deep Ground Water

Surface Soils

Surface and Subsurface Soils

Surface Water (total and dissolved)


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Upgradient Surface Water (total and dissolved)

Sediments

Upgradient Sediments

Leachate

Wet Meadow (combined grouping of surface soils and sediments)

Ambient Air

Appendix A-1 tables, for the media quantitatively evaluated in the risk assessment, list

frequency of detection, number of samples analyzed (excluding rejected sample results),

the lowest and highest detected concentrations, the location of the highest concentration,

the arithmetic mean concentration, the lowest and highest detection limits for non-detect

results, applicable Federal Maximum Contaminant Levels (MCL) and Vermont

Enforcement Standards, number of times reported ground water concentration exceeded

MCLs, and Contaminant of Concern (COC) selection rationale. All data from the Phase

1A and IB Remedial Investigation were analyzed using SAS^" , a widely-used statistical

software package (SAS Institute Inc., 1988). Data from the LTMP (Spring 1995, Fall

1995, and Spring 1996) were compiled by ERM-New England, Inc.

Use of the arithmetic mean concentration to represent the average concentration is based

on EPA-New England risk assessment guidance current during the development phase of

this Risk Assessment, which recommended the arithmetic mean for estimating long-term

average exposure. As directed by EPA-New England, in cases where the average

concentration exceeded the maximum due to elevated detection limits, the average

concentration is set equal to the maximum when quantitatively estimating site risks. The

few instances where this occurred are noted in Section 3.4 Risk Characterization. Risk

calculations for the "average case" scenario were based on the arithmetic mean

concentration. Calculations for the "reasonable worst case" scenario were based on the

maximum detected concentration.

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2.3 Summary of Site Contamination

The following subsections briefly summarize contamination at the Burgess Brothers site,

based on the results ofthe Phase 1 A-ISC, Phase IB Investigation, and LTMP. Sampling

locations are shown in Figures 2-1 and 2-2. Contamination is discussed below for each

evaluated medium: ground water, surface and subsurface soils, surface water, leachate,

sediments, and air. The discussion is based on the summary statistics prepared for the

baseline risk assessment presented in Appendix A-1.

2.3.1 Groundwater Contamination

Shallow Ground Water Contamination

A total of 18 VOCs were detected in 71 shallow ground water samples analyzed for

VOCs (excluding duplicate and rejected sample results during the Phase 1 A-ISC and

Phase IB investigations). Trichloroethene, 1,2-dichloroethene, tetrachloroethene, and

vinyl chloride were detected most frequently, in 40, 33, 19, and 12 samples, respectively.

Three VOCs were detected in only one sample; the remaining VOCs were detected in

two to eight samples.

The four VOCs that were detected most frequently also had the highest maximum

concentrations: trichloroethene (34,000 |ig/L in monitoring well W-22S1-01), 1,2

dichloroethene (22,000 ng/L in monitoring well W-03-01), tetrachloroethene (10,000

|ig/L in monitoring well W-03-01), and vinyl chloride (2,300 pg/L in monitoring well W

1 IS 1-02). The highest detected concentrations of the remaining VOCs ranged from 12

ng/L to 1,600 ng/L.

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( ) ( )

- ^ r z ^ ^ a :

.LEOEND

nCNC WLL

WTTV FDKC ' ^ ' ^ *ATE:Ol*St " T O m M r r KU.MXXSS KM>

rOHI.0 JOXM ,ljUi.L.,AME ANO UNIT (WirCR rWLLJ

WILL iNsiAiu'Li iN OjnoN nix

WtLL WSTALLtn -N LiPPtS PuHllON Of

WIAIMERED BtOHOCl.

WtLl W TAILCO IM LOWEft POKllON ur

nrfLL ihiTALLED IN COUPOENT BEDBOCK

rCM BOHir CiJuPirTTD IN L*NCOiL/S0iL ^rv^NC ^ZA . *irH WtU. PI>LE0(T

IfST BOBWC COMPlTTtD M iJWDfiU WfTKJUT WELL PUCCUOJI

TEST fctRWi

^KAOOdr SURf*LE S*tfL iO"- i ; ' )

t SWIPIINC POINT

aUCD ON PRCVAILINC WIND Dl>CnON

^-7,ri:is:.i:??.'

, ^

- ^ z : ^ * - s :

LEGEND

srac wu

- - ~ , t r , x

WTEKOURSC _ _

f-;*njt5 'CKJJ : > * -)

SAMPLE tL MONITORING WFII LEGEND

SN-OU A SURF*C WATER MO SEDIMOir SAUPIC

*,^

". ? \

//

y sw-w-oi >

The maximum detected concentrations of the following VOCs exceeded Federal

Maximum Contaminant Levels (MCLs) and Vermont Primary Ground Water Quality

Standards by one to five orders-of-magnitude: 1,1-dichloroethene, 1,2-dichloroethene,

benzene, methylene chloride, tetrachloroethene, trichloroethene, and vinyl chloride.

Four other VOCs exceeded drinking water standards by less than an order-of-magnitude,

including 2-butanone, 1,2-dichloroethane, chlorobenzene, and chloroform.

A total of eight base/neutral-acid extractable compounds (BNAs) were detected in 39

shallow ground water samples analyzed for BNAs. Bis(2-ethylhexyl)phthalate was

detected most frequently, in five samples, with a maximum concentration of 7.3 fJg/L.

Most of the other BNAs were detected only once. Phenol and pyrene had the highest

concentrations of all BNAs, at 29 pg/L in monitoring well W-04S-02 and 25 pg/L in

monitoring well W-02-02, respectively. The remaining seven BNAs were all detected at

concentrations equal to or less than 12 pg/L.

A total of 20 inorganic compounds were detected in 25 shallow groundwater samples

analyzed for inorganics. Barium, calcium, and magnesium were detected in all samples.

Ofthe analytes detected, iron, manganese, and thallium exceeded MCLs in 10, 16, and 2

samples, respectively.

Organic data were also collected and analyzed, during the LTMP low-flow sampling

rounds, and provided in Appendix A-3. Detected organic concentrations are comparable

to the results of earlier sampling rounds.

Deep Ground Water Contamination

A total of eight VOCs were detected in 45 deep ground water samples (excluding

duplicate and rejected sample results). Acetone, carbon disulfide, and chloroform were

each detected four times; the remaining five VOCs (1,2-dichloroethene,

tetrachloroethene, toluene, trichloroethene, and xylene) were detected only once.

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Acetone had the highest concentration of all VOCs, at 21 pg/L in monitoring well W

08SI-01. The other VOCs were all detected at concentrations less than 10 pg/L.

Tetrachloroethene was detected at a concentration approximately equal to the Vermont

Enforcement Standard but below the Federal MCL.

Only four BNAs were detected in the 22 deep ground water samples analyzed. Bis(2

ethylhexyl)phthalate was detected most frequently, in 8 ofthe 21 samples. The other

three BNAs were detected in only one or two samples. Benzoic acid showed the highest

concentration, at 33 pg/L in monitoring well W-07DI-03. The other three BNAs were

detected at concentrations less than 10 pg/L.

A total of 16 inorganic compounds were detected in deep groundwater samples analyzed

for inorganics. Of the inorganic compounds detected, iron and manganese exceeded

MCLs in 7 and 6 samples, respectively.

2.3.2 Soil Contamination

Surface Soil Contamination

Surface soil contamination at the Burgess Brothers Superfund site was characterized

using the soil samples collected from 0 to 1 foot below ground surface (BGS). Fifteen

VOCs were detected in the 36 surface soil samples analyzed for VOCs. Acetone was

detected most frequently in 14 of the 36 samples. The remaining VOCs were detected in

one to eight samples. 1,2-Dichloroethene and toluene were detected at the highest

concentrations, at 66,CXX) pg/kg and 15,(XX) pg/kg, respectively. The highest

concentrations of most VOCs were found in sample SP-07 (5-7"), collected just east of

the Former Lagoon Area.

Eleven BNAs were detected in the five samples analyzed for BNAs; all were detected

only once and in sample SP-07 (0-12"). Fluoranthrene, phenanthrene, and pyrene


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^

showed the highest concentrations, at 12,000 pg/kg, 14,000 pg/kg, and 12,000 pg/kg,

respectively.

Twenty-four inorganics were detected in 31 surface soil samples. Sixteen inorganics

were detected in all 31 samples; the remaining inorganics were detected in 1 to 29

samples.

Subsurface Soil Contamination

Samples collected from 12" to 15' BGS were classified as subsurface samples. Nine

VOCs were detected in the 31 subsurface samples analyzed for VOCs. 1,2

Dichloroethene, acetone, tetrachloroethene, and trichloroethene were detected most

frequently, in 8 to 20 samples. The remaining VOCs were detected in one to four

samples. The highest concentrations for most VOCs detected were reported in samples

collected from boring W-11 SI located to the east of the Former Lagoon Area. The

highest concentrations detected were for 1,2-dichloroethene (total) at 620 pg/kg and

tetrachloroethene at 340 pg/kg.

BNAs were not detected in the six samples analyzed for BNAs. Pesticides/PCBs were

also not detected in the three subsurface samples analyzed for these contaminants.

Nineteen inorganics were detected in the six subsurface samples analyzed for inorganics.

Seventeen inorganics were detected in all six samples.

Deep Soil Contamination

Samples collected at depths greater than 15' BGS were classified as deep.

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Only four VOCs were detected in the three deep samples analyzed for VOCs. These

were 1,2-dichloroethene, acetone, tetrachloroethene, and trichloroethene.

Trichloroethene had the highest concentration at 170 pg/kg in W-22T-05 (17 - 19').

Nineteen inorganics were detected in the two deep soil samples. Seventeen of the

inorganics were detected in both samples. Mercury was detected only once (in

W-0 IB).

2.3.3 Surface Water, Sediment, and Leachate Contamination

Surface Water Contamination

Seventeen VOCs were detected in the 34 surface water samples collected at the site.

1,2-Dichloroethene, trichloroethene, tetrachloroethene, and vinyl chloride were detected

most frequently, in 15 to 24 ofthe samples. These constituents also had the highest

concentrations of all VOCs, ranging from 97 pg/L (tetrachloroethene) to 2,623 pg/L (1,2

dichloroethene). The highest concentrations of most VOCs were detected in sample

SW-02-01.

Twenty-two inorganic constituents were detected in the 34 unfiltered surface water

samples analyzed for inorganics. Barium, calcium, iron, magnesium, and manganese

were detected in all samples. Aluminum, lead, and potassium were detected in more than

one half of the samples. The remaining inorganics were detected in 1 to 12 samples.

The highest concentrations of all inorganics detected in the surface water samples

exceeded those detected in the six upgradient unfiltered samples. The highest

concentrations of barium, chromium, iron, and manganese exceeded concentrations

detected in upgradient samples by one order-of-magnitude or more.

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Eight inorganics detected in one or more of the surface water samples, were not detected

in the any of the six upgradient samples. These inorganics are arsenic, cobalt, cyanide,

mercury, nickel, selenium, vanadium, and zinc.

The concentrations of inorganics in the filtered samples for both the surface water

samples and the upgradient samples were generally lower than those detected in the

unfiltered samples.

Sediment Contamination

Eleven VOCs were detected in the 27 sediment samples analyzed for VOCs. Acetone,

trichloroethene, and 1,2-dichloroethene were detected most frequently, in 7 to 17 ofthe

samples. The remaining VOCs were detected from 2 to 6 times. Acetone,

trichloroethene, and 1,2-dichloroethene also had the highest concentrations at 635 pg/kg,

520 pg/kg, and 1,700 pg/kg, respectively.

Four BNAs were detected in 23 sediment samples analyzed for BNAs:

ben2o(b)fluoranthene, fluoranthene, phenanthrene, and pyrene. All four were detected in

sample SED-05-02, with concentrations ranging from 480 pg/kg to 780 pg/kg.

The sediment sample SED-05-02 showed up to 6.4 pg/kg of 4,4'-DDT and 74 pg/kg of

PCB-1254.

Twenty-two inorganic constituents were detected in one or more of the 27 samples

analyzed for inorganics. Over half of the inorganics were detected in all 27 samples.

The highest concentrations of most inorganics detected in the sediment samples were

higher than those detected in the upgradient sediment samples, but by less than one

order-of-magnitude.


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Leachate Contamination

Four VOCs and one BNA were detected in the three leachate samples analyzed,

including 1,2-dichloroethene at up to 1,800 pg/L in LS-3, acetone at up to 21 pg/L in LS

2, tetrachloroethene at up to 9,300 pg/L in LS-3, trichloroethene at up to 26,000 pg/L in

LS-3, and 1,4-dichlorobenzene at up to 16 pg/L in LS-3.

Twenty-two inorganics were detected as well; ten were detected in all three samples.

2.3.4 Air Contamination

The air quality assessment program was designed to monitor worst case conditions at the

Burgess Superfund site. To meet this objective, seven air samples were collected during

invasive activities in the Former Lagoon Area. However, because only one of the air

sampling stations was located downwind of the invasive activities, results may not be

representative of ambient air conditions. Additional studies may be necessary to assess

air quality at locations further downwind of the landfill/lagoon area during invasive

activities conducted in the future.

The following organic constituents were detected in one or more of the air samples

collected: 2-butanone, carbon disulfide, carbon tetrachloride, ethylbenzene, m,p,-xylene,

o-xylene, tetrachloroethene, toluene, and trichloroethene. Toluene and m,p-xylene were

detected in all seven samples. Trichloroethene and tetrachloroethene showed the highest

concentrations from the sample collected in the exclusion zone, at 37 pg/m' and 32

pg/m\ respectively.

2.4 Contaminant Fate and Transport

This discussion integrates the geology, hydrology, and nature and extent of

contamination with physical and chemical characteristics of the contaminants detected.

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The evaluation is qualitative, focusing on the contaminants that are of primary concern

from a human health and ecological risk perspective. The discussion provides a separate

analysis for the following chemical classes: VOCs, BNAs, PCBs/pesticides, and

inorganics.

2.4.1 Known and Potential Source Areas

At the Burgess Brothers site, the principal contamination source area is the Former

Lagoon Area of the landfill where spent solvents and other wastes from local industry

were disposed in an unlined pit. Most notable are the high levels of chlorinated VOCs

(in the ppm range) in this pit and the underlying soils. Other potential sources include

the remaining areas of the landfill itself, as well as the tank salvaging area.

2.4.2 Potential Routes of Migration

Contamination at the site will be transported from source areas to uncontaminated areas

by the movement of contaminated media via several natural processes. Contaminant

transport from the source areas at the Burgess Brothers site may occur through the

following mechanisms:

advective and dispersive transport with ground water in the overburden;

surface water transport in areas where ground water discharges to surface water (e.g.. Marshy Area and unnamed stream);

erosion and transport of contaminated surface soils and sediments via storm water and melt water runoff to drainageways and surface water;

volatilization of VOCs to the atmosphere from contaminated soils or leachate.

Although several potential transport mechanisms have been identified, advective and

dispersive transport through ground water appears to be the primary transport mechanism


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of transport of contaminants from the Former Lagoon Area and other source areas.

Movement of contaminated sediment via erosion, transport, and re-deposition is also

likely but will have less significance since this process generally results in only localized

transport.

2.4.3 Contaminant Transport

VOCs, BNAs, pesticides, PCBs, and inorganics have been identified in ground water,

surface soils, surface water, sediments, leachate, and/or ambient air. Transfer of

contaminants between different media may occur by several processes that will vary for

each class of contaminants. The general processes associated with each contaminant

class are discussed separately. The discussion that follows focuses on the two

predominant transport processes: advective and dispersive transport through ground

water; and erosion, transport, and re-deposition in soils and sediments.

2.4.3.1 Ground Water Transport

The hydrogeologic environment in the immediate site vicinity is defined by several

water-bearing units (aquifers): landfill materials overlying progressively deeper layers of

kame sand deposits, glacial till, weathered bedrock, and competent bedrock. The RI

Report (O'Brien & Gere, 1994) indicates that these five water-bearing units functionally

act as two aquifers because the highly compact, dense glacial till and silty clay in the

weathered bedrock function as low permeability layers separating zones of higher water

conductivity. These low permeability layers are continuous across the Burgess Brothers

site and are 35 to 75 feet thick (till) and 180 to 360 feet thick (weathered bedrock).

Therefore, for the purposes of this discussion, the hydrogeologic environment is defined

by two water-bearing zones: a shallow aquifer consisting of landfill materials, kame

sand deposits, and the loose upper portion of the glacial till; and a deep aquifer composed

of competent bedrock.


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Organic and inorganic contamination has been documented in the shallow aquifer near

known source areas. These contaminants were most likely leached (dissolved) from the

source areas by infiltrating precipitation or migrated downward as free phase product

under the influence of gravity. Dissolved ground water contaminants will be transported

in the direction of shallow ground water flow which trends in a southerly radial pattern

towards the Marshy Area and unnamed stream located south of the landfill.

Contaminants dissolved in ground water are likely to be transported into these surface

water bodies because a component of ground water flows beneath two source areas (the

Landfill Area and Former Lagoon Area) and discharges into the Marshy Area and

unnamed stream. Data on flow directions in the deep aquifer are inconclusive.

2.4.3.1.1 Volatile Organic Compounds

Transport of VOCs in the shallow aquifer ground water occurs primarily by advection

with ground water flow. Lateral spreading generally occurs via hydrodynamic and

molecular dispersion. Ground water flows downgradient from the Landfill Area and

Former Lagoon Area and discharges, at least partially, into the Marshy Area and

unnamed stream. Some component of ground water flow may not discharge to the

surface, but may instead remain below the surface and continue flowing further

downgradient. The detection of trace to low levels of VOCs in the deep bedrock aquifer

suggests that contaminants may be penetrating through the till and weathered bedrock

layers which separate the shallow aquifer from the deep aquifer. Ground water also

discharges to the surface via seeps observed along the base of the landfill.

The highest VOC concentrations in ground water were detected in the Landfill Area and

Former Lagoon Area. Concentrations in ground water generally diminish with

increasing distance from the landfill. The VOCs identified in ground water at the

Burgess Brothers site are moderately to highly soluble in water and are therefore mobile

in ground water. Several factors may contribute to this attenuation, including:


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dispersion; adsorption to subsurface organic matter and colloidal particles; degradation via biotic or abiotic processes; and volatilization.

Dispersion, the diffusion of contaminants from higher concentrations to lower, as a

mechanism of transport, serves to decrease contaminant concentrations in ground water

as the distance from the source increases.

Adsorption to geologic materials in the aquifer is unlikely to retard or otherwise diminish

ground water concentrations since the detected VOCs exhibit little propensity for

sorption.

Contaminant degradation may occur via biotic processes involving microorganisms

(referred to as biodegradation) or by natural chemical degradation processes which do

not involve microorganisms (referred to a abiotic degradation). While both processes

may diminish contaminant concentrations, biotic processes are likely to play the most

significant degradation role because the detected VOCs are easily degraded by

microorganisms and the landfill creates a favorable environment for microbial growth

and activity. The presence of vinyl chloride and dichlorinated ethanes/ethenes in ground

water at the Burgess Brothers site is likely attributed to biotic/abiotic degradation of

trichloroethene or tetrachloroethene. It is likely that the concentrations of vinyl chloride

will increase as the parent and intermediates continue to degrade.

2.4.3.1.2 Base-Neutral/Acid Extractable Organics

Few BNAs (e.g., phenol, 4-methylphenol, dichlorobenzenes, naphthalene, and pyrene)

were identified in shallow or deep ground water. Most concentrations were minimal (at

or near the detection limits). With high water solubilities, phenol and 4-methylphenol

can be readily transported in the direction of ground water flow. Little attenuation will

occur from adsorption given their low organic carbon partition coefficient (Koc) and log


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octanol water partition coefficient (Kow) values of these two compounds. The other

detected BNAs (e.g., pyrene) are not as mobile as the phenolic compounds. The

nonphenolic compounds exhibit moderate to high propensities for sorption to geologic

materials. Therefore, transport of these compounds is expected to be limited.

2.4.3.1.3 Inorganics

Transport of inorganics is most likely to occur in two manners: transport as species

dissolved in ground water and transport as a particulate adsorbed to particulates or

colloids suspended in ground water. In the shallow aquifer, most inorganics appear to be

in the form of suspended material (particulates or colloids) as indicated by the higher

concentrations in the unfiltered (total) samples than in filtered (dissolved) samples. In

the deeper aquifer, concentrations of inorganics in filtered and unfiltered samples are

nearly equivalent suggesting dissolved species as the predominant inorganic form. In the

dissolved from, inorganics are expected to be more mobile than those in the suspended

form. These dissolved inorganics will be transported easily through the aquifer to

downgradient locations. Concentrations will be diminished by dispersion, dilution, and

adsorption to geologic materials. Unlike dissolved inorganics, transport of those in the

suspended form will be impeded by geologic material. Only limited downgradient

transport is predicted for these contaminants.

Inorganic contaminants in ground water are likely to be introduced to the Marshy Area

and unnamed stream as contaminated ground water discharges to these surface water

bodies.

2.4.3.2 Surface Transport

Contaminant transport at the surface of the Burgess Brothers site is controlled by

topographic features as well as soil characteristics (e.g., permeability) and degree of

vegetation. Surface contaminants dissolve in precipitation and infiltrate the ground


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surface when soils are permeable and highly vegetated. As typical of many landfills, the

area of former disposal is mounded. The surface cover atop the Landfill Area is pitched

in a manner that directs runoff away from the center towards the steeply sloped outer toe

of the landfill. Leachate seeps have been observed along all but the eastem and

southeastern toes. The discharging leachate with associated contaminants flows down

the slope of the toe.

Contaminants may be introduced to the surface as ground water and leachate discharges

to the surface in the Marshy Area and drainage swale along the eastern and southern

bases of the landfill. These low-lying areas may also receive contaminants that erode or

dissolve from surrounding source areas which are at higher elevations. Dissolved

contaminants are easily transported with flowing water through the drainage swale and

into the unnamed stream, and may eventually be discharged into Barney Brook. Eroded

contaminants will be transported and redeposited along this drainage system.

Along the western perimeter of the landfill, surface contaminants will either dissolve and

infiltrate into the landfill or erode with runoff and be deposited along the western edge of

the Landfill Area perimeter. Transport could be possible beyond the western edge of the

landfill, if the runoff velocity and volume is sufficient to transport the eroded

contaminants.

At the Former Lagoon Area, the depression that signifies a former lagoon does not

promote runoff so lateral migration transport of insoluble contaminants is expected to be

limited. Soluble surface contaminants are expected to infiltrate to ground water given

that the surface depression and permeable soils are conducive to infiltration.

2.4.3.2.1 Volatile Organic Compounds

Numerous VOCs, particularly the tri- and dichlorinated ethenes and vinyl chloride, were

detected in surface soils. Several compounds (tetrachloroethene, trichloroethene, 1,2

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dichloroethene, vinyl chloride, and acetone) were detected at concentrations exceeding

1,000 pg/kg. These concentrations were found at a surface location directly downslope

of the Former Lagoon Area. These compounds have high vapor pressures (greater than

100 mm Hg) which favor volatilization. Therefore, some portion of these compounds

will volatilize. The high moisture content of the site soils will limit the degree of

volatilization. These compounds are likely to dissolve with infiltrating precipitation and

be transported to ground water given their moderate to high water solubilities.

2.4.3.2.2 Base-Neutral/Acid Extractable Organics

The detected BNAs are all classified as polycyclic aromatic hydrocarbons (PAHs),

common coal, tar, and fuel derivatives. All are moderately to highly sorbed to soil

material as evidenced by K ^ values in excess of 1,000 ml/g and log K^ values greater

than 4. Sorption may dominate the transport process, and can limit lateral and vertical

migration. The sorbed contaminants will be transported with eroded surface material

during runoff events and re-deposited in areas where the runoff velocity diminishes

below the threshold for erosion.

2.4.3.2.3 Inorganics

Inorganics in surface soils and sediments will be transported in much the same way as

BNAs. Inorganic-contaminated soils and sediments are most likely eroded by surface

runoff and subsequently deposited along drainage swales and into low-lying areas with

low stream velocity.

The Marshy Area and the unnamed stream are fed, at least partially, by discharging

ground water. This provides a means for subsurface contaminants to be transported to

the surface where they can be readily contacted by humans and biota. Once discharged

to the surface, the inorganics may dissolve into surface water or precipitate out of

solution as insoluble salts. Precipitated inorganics can potentially be transported further


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downstream as eroded particles during periods of intense rainfall or spring thaw when

stream velocities are capable of eroding materials. Re-deposition is likely in areas where

the stream velocity is insufficient for transporting eroded materials.

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