Final Decision Document.pdf

US Army Corps of Engineers /Final Decision Document / June 2019 i

Final Decision Document

FORMER NIKE BATTERY PR-58 AND

DISASTER VILLAGE TRAINING AREA,

QUONSET POINT NAVAL AIR STATION,

NORTH KINGSTOWN, RHODE ISLAND

FUDS Project Number: D01RI0029 05

June 2019

US Army Corps of Engineers New England District 696 Virginia Road Concord, MA 01742-2751

Table of Contents

US Army Corps of Engineers /Final Decision Document / June 2019 ii

TABLE OF CONTENTS

EXECUTIVE SUMMARY .................................................................................................................. VI

LIST OF ACRONYMS ............................................................................................................. XIV

1. THE DECLARATION

1.1 Project Name and Location

1.2 Statement of Basis and Purpose

1.3 Assessment of the Project

1.4 Description of the Selected Remedy

1.5 Statutory Determinations

1.5.1 Protectiveness of Human Health and the Environment

1.5.2 Compliance with ARARs

1.5.3 Cost-Effectiveness

1.5.4 Utilization of Permanent Solutions and Alternative or Resource Recovery Technologies

1.5.5 Statutory Preference for Treatment as a Principal Element of the Remedy

1.5.6 Applicability of Five-Year Review Requirements

1.6 Data Certification Checklist

1.7 Authorizing Signatures

2 THE DECISION SUMMARY

2.1 Property Name, Location, and Description

2.2 Property History and Enforcement Activities

2.2.1 History of the Property and Vicinity

2.2.2 Prior Investigations and Studies

2.2.3 Remedial Investigation Sampling Strategy

2.2.4 Regulatory Background

2.3 Community Participation

2.4 Scope and Role of Response Action

2.5 Project Physical Characteristics

2.5.1 Topography, Natural Features, and Climate

2.5.2 Surface Water and Drainage

2.5.3 Geology

2.5.4 Surficial Soils

2.5.5 Unconsolidated Deposits

2.5.6 Bedrock

2.5.7 Hydrogeology

2.6 Nature and Extent of Contamination

2.6.1 Potential Sources of Contaminant Releases on the Property

2.6.2 Potential Contaminant Releases to the South and East of the Property

2.6.3 Identification of Property-Related Contaminants of Potential Concern

2.7 Conceptual Site Model

2.7.1 Source Area

2.7.2 Extended Groundwater Plume

2.7.3 Surface Water and Sediment

2.7.4 Soil Gas

US Army Corps of Engineers / Final Decision Document / June 2019 iii

2.8 Current and Potential Future Property and Resource Uses

2.8.1 Property Uses

2.8.2 Resource Uses

2.8.3 Areas of Archaeological or Historical Importance

2.9 Summary of Site Risks

2.9.1 Human Health Risk Assessment

2.9.2 Screening Level Ecological Risk Assessment

2.9.3 Basis for Action

2.10 Remedial Action Objectives

2.10.1 Media and Chemicals of Concern

2.10.2 Remedial Action Objectives for Groundwater

2.10.3 Remedial Goals

2.11 Remediation Target Areas

2.12 Common Elements of the Remedial Alternatives

2.12.1 Groundwater Extraction and Treatment System

2.12.2 Air Sparging and Soil Vapor Extraction

2.12.3 Institutional Land Use Controls

2.12.4 In Situ Thermal Treatment

2.12.5 Reductive Dechlorination Treatment

2.12.6 Monitored Natural Attenuation

2.13 Description of Alternatives

2.14 Comparative Analysis of Alternatives

2.14.2 Compliance with ARARs

2.14.3 Long-Term Effectiveness and Permanence

2.14.4 Reduction of Toxicity, Mobility or Volume through Treatment

2.14.5 Short-Term Effectiveness

2.14.6 Implementability

2.14.7 Cost

2.14.8 State Acceptance

2.14.9 Community Acceptance

2.15 Principal Threat Wastes

2.16 Selected Remedy

2.16.1 Summary of the Rationale for the Selected Remedy

2.16.2 Description of the Selected Remedy

2.16.3 Statutory Determinations

2.16.4 Expected Outcomes of Selected Remedy

2.17 Documentation of No Significant Changes

3 RESPONSIVENESS SUMMARY

3.1 Introduction

3.2 Technical and Legal Issues

3.3 Comment Responses

3.3.1 Verbal Comments

4. REFERENCES

FIGURES

TABLES

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APPENDICES

APPENDIX A : RHODE ISLAND DEPARTMENT OF ENVIRONMENTAL MANAGEMENT

LETTER OF NON-CONCURRENCE

APPENDIX B : APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS

List of Figures

Figure 1: Property Location Map

Figure 2: Map of Property and Vicinity

Figure 3: Historical Property MapFigure 4: Location of Source Area and Extent of Dissolved Plume

Figure 5: Locations of Private Wells

Figure 6: Designated Exposure Areas for Risk Assessment

Figure 7: Remedial Action Objectives Pertinent to Exposure Areas

Figure 8: Institutional Control Zone

Figure 9: Conceptual Design of Selected Remedy

List of Tables

Table 1: Summary of Previous Investigations

Table 2: Human Health Risk Assessment Summary

Table 3: Remedial Action Objectives Identified to Select the Remedy

Table 4: Sitewide Groundwater Cleanup Objectives for UU/UE for Former Nike Battery PR-58 and Disaster Village Training Area and Vicinity

Table 5: Comparative Summary of the Detailed Analysis of Remedial Alternatives

Table 6: Detailed Cost Estimate for Selected Remedy

US Army Corps of Engineers /Final Decision Document / June 2019 v

Executive Summary

US Army Corps of Engineers / Final Decision Document / June 2019 vi

EXECUTIVE SUMMARY

This Decision Document sets forth the final remedy selected by the U.S. Army Corps of Engineers (USACE) for the Former Nike Battery PR-58 and Disaster Village Training Area (the Property) for addressing the chlorinated volatile organic compound (CVOC) contamination in groundwater in the overburden and bedrock. The Property is a Formerly Used Defense Site (FUDS) (D01RI0029 05), once part of Quonset Point Naval Air Station (NAS), located in North Kingstown, Washington County, Rhode Island. The U.S. Army (Army) is the lead agency and USACE has mission execution authority for implementation of the environmental program at the Property under the FUDS program.

Remedial Investigations (RI) on the Property included evaluations of potential historical sources of contamination, sampling and analysis of groundwater, soil, surface water, and sediment for contamination with volatile and semi-volatile organic compounds (VOCs and SVOCs), metals, polychlorinated biphenyls (PCBs) and pesticides. Human health and ecological risk assessments were conducted and potential future uses of the Property were evaluated. The RI identified the presence of CVOCs, potentially in the form of dense nonaqueous phase liquid (DNAPL) near the center of the Property, and a dissolved contaminant plume in the overburden and bedrock groundwater extending out beyond the Property boundary to the north, east, and south. Therefore, the extent of contamination resulting from historical releases at the Property has not been confined to the Property. The area beyond the Property that encompasses the extent of contamination resulting from releases on the Property is referred to as the “Vicinity” of the Property. This document addresses the Property and Vicinity.

Historically, the Property was occupied by the U.S. Navy (Navy) as Camp Thomas from 1942 until the end of World War II; the Army as Nike Battery PR-58, equipped with Ajax missiles from 1954 through 1956;

the Navy for disaster recovery training from 1964 through 1974; owned but unoccupied by U.S. General Services Agency from 1974 through 1978; and transferred to Rhode Island Economic Development Corporation (RIEDC) in 1978. RIEDC leased 2.2 acres of the Property to Peabody Clean Industries (PCI) as hazardous waste storage and transfer facility between 1980 and 1982. Since the early 1980s, various environmental studies and demolition of buildings and remedial measures have been performed. Only one building, located in the southwest corner of the Property (former Building 343), remains from the historical uses of the Property. This building and 1.7 acres in the southwest corner of the Property (211 Babcock Road) is currently owned by Chipster, LLC, and operated as Pro-Paint Plus. With the exception of recreational fields on the western portion of the Property, the rest of the Property remains unused, under ownership of the Quonset Development Corporation (QDC), a real estate development and management subsidiary of RIEDC.

The bedrock beneath the Property and the surrounding area is quartzite and phyllite of the Rhode Island Formation. The unconsolidated deposits overlying bedrock are a mixture of glacial ice contact tills, sands and gravels, and fluvial estuary or lacustrine finer grained deposits. On the Property, the shallow unconsolidated deposits are predominantly sands and sand and gravel outwash and extend to a variable depth of 10 to 30 feet below ground surface (ft bgs). The deeper unconsolidated deposits are less permeable and consist of basal glacial till and weathered bedrock. These strata overlie the competent

US Army Corps of Engineers / Final Decision Document / June 2019 vii bedrock which was typically encountered at a depth of approximately 30 to 50 ft bgs in borings advanced on the Property.

Groundwater beneath the Property in the shallow and deep unconsolidated deposits and the bedrock generally flows from a groundwater high located near the center of the Property (the location of the Source Area) toward the east, southeast, south, and southwest. However, during very dry conditions, as experienced during the September 2013 monitoring event, groundwater from the Property appears to also flow toward the north and northeast. Vertical gradients are typically downward in the center of the Property but reverse to upward as the groundwater approaches the surface water bodies located south and east of the Property.

The majority of the remedial investigations were performed between 2008 and 2016 and included sampling of soil, overburden and bedrock groundwater, surface water, sediment, soil gas, and indoor air. Over 100 soil borings were completed and over 200 monitoring wells were installed during this time. The RI concluded that the predominant contaminants on the Property are CVOCs. In addition to CVOCs, non-chlorinated VOCs (such as BTEX), total petroleum hydrocarbons (TPH), SVOCs, PCBs, and pesticides have been detected infrequently and at relatively low concentrations in soil and groundwater at the Property. Based on frequency of detection and/or detection within the range of background soil concentrations, no metals have been identified in environmental media at concentrations that are consistent with a release of hazardous materials from previous operations at the Property.

Only eight CVOCs have been consistently detected in soil and groundwater samples collected at the Property and Vicinity in soil gas, groundwater, surface water, and sediment samples, at concentrations greater than applicable screening and regulatory levels. These eight CVOCs – 1,1,2,2-tetrachloroethane (TeCA), tetrachloroethene (PCE), trichloroethene (TCE), 1,1,2-trichloroethane (1,1,2-TCA), 1,1-dichloroethene (1,1-DCE), cis-1,2-dichloroethene (cis-1,2-DCE), trans-1,2-dichloroethene (trans-1,2- DCE), and vinyl chloride (VC) – are the hazardous substances that were carried forward as the focus of the Feasibility Study (FS).

Numerous activities conducted at the Property and Vicinity posed the potential for historical releases of contaminants, and include former Nike Battery PR-58 operations, Navy disaster recovery training, and Peabody Clean Industries (PCI) hazardous waste management activities. Potential contaminants associated with historical activities and operations on the Property include the chlorinated solvents carbon tetrachloride, PCE, TeCA, TCE, and 1,1,2-TCA. There were also multiple documented and/or suspected hazardous materials releases on the Naval Construction Battalion Center (NCBC) property to the south and east of the Property. Historical uses, as well as circumstantial evidence of the use and disposal of hazardous substances, such as DANC (decontamination agent, non-corrosive) at NCBC, may have resulted in releases of contaminants to the environment that have commingled with the downgradient Property-related plume.

A Conceptual Site Model (CSM), based upon available data, was developed to describe the contaminant source, hydrogeology, and the contamination nature, extent, fate and transport. Waste containing non-aqueous phase TeCA, PCE, and TCE was likely released to the ground surface near the center of the Property (Source Area) in the form of DNAPL. The waste percolated downward through the vadose zone until it reached the water table. At the water table the DNAPL continued to move downward through groundwater due to its greater density until it reached a lower permeability layer where it would then

US Army Corps of Engineers / Final Decision Document / June 2019 viii

“pool.” A trail of residual DNAPL was initially left behind but likely dissolved away over time, particularly in the shallow, more hydraulically conductive units. Once the DNAPL stopped migrating, it began to dissolve into passing groundwater forming an extended dissolved plume. The glacial till and weathered bedrock, both low permeability materials overlying the competent bedrock became a reservoir for contaminant mass and likely still contain residual DNAPL. However, this low permeability layer did not prevent the continued downward migration of the DNAPL into bedrock fractures beneath the center of the Source Area. Many of the fractures in the Source Area are either vertical or have very high angle dips which provided pathways for DNAPL migration into the bedrock aquifer. Due to the preponderance of vertical fracture connectivity and limited horizontal fracture connectivity, the DNAPL source zone in bedrock appears to be relatively limited horizontally as downward migration was favored over horizontal migration.

Groundwater gradients reverse from downward on the Property to upward to the south allowing contaminated groundwater from the dissolved plume to migrate upward beneath the Department of Public Works (DPW) property. This introduces the potential for vapor intrusion from shallow groundwater contamination on the DPW property and the potential for future discharges of contaminants to the surface water and sediment in Hall Creek and Davol Ponds.

The baseline human health risk assessment (BHHRA) evaluated current and potential future risks to human health from detected contaminants in soil, groundwater, and indoor air. The BHHRA concluded that groundwater and soil vapor from off-gassing groundwater contamination were the only contaminated media and CVOCs were the only contaminants that presented potential unacceptable human health risks (cancer risk greater than 10-4 and non-cancer risk greater than a hazard index of 1).

The Screening Level Ecological Risk Assessment (SLERA) was performed to assess ecological risks for the ecological resources and terrestrial and aquatic receptors located on, adjacent to, or under the influence of the Property. The SLERA concluded that ecological threats to terrestrial and aquatic receptors are negligible, with the exception of potential future discharges of the groundwater plume to the Hall Creek System.

The basis for the remedial action is to ensure that public health and environmental receptors are protected from potential risks posed by contaminated media at the Property and Vicinity. Specifically, unacceptable human health risks were identified for potential future residential exposure from the use of potable groundwater on the Property, in the commercial/industrial areas east and south of the Property, and in the offsite residential area north of Perimeter Road. In addition, unacceptable potential indoor vapor intrusion risks were identified on the Property and on the DPW property. Use of groundwater for irrigation on the Property was also identified to present unacceptable risks due to inhalation of volatilized contamination. Potential discharges of CVOC contaminated groundwater to the Hall Creek System, potentially resulting in future adverse ecological effects to aquatic receptors, were also a component of the basis for remedial action.

Six Remedial Action Objectives (RAOs) were established for the Property and Vicinity.

RAO No. 1: Improve groundwater quality so that RIDEM Class GB groundwater objectives are met in the areas on the Property and Vicinity designated as Class GB.

US Army Corps of Engineers / Final Decision Document / June 2019 ix

RAO No. 2: Prevent or reduce exposure of current or future Indoor Workers and potential future Daycare Children to TCE through vapor intrusion (VI) into building from shallow groundwater that causes unacceptable risk (total excess lifetime cancer risk [ELCR] greater than 1×10-4 or HI greater than 1).

RAO No. 3: Prevent or reduce exposure of recreators and commercial industrial workers to TCE and TeCA that cause unacceptable risk (total ELCR greater than 1×10-4 or HI greater than 1) due to inhalation exposure from groundwater used for irrigation water.

RAO No. 4: Prevent discharge of groundwater with TCE, TeCA, 1,1,2-TCA, PCE, and 1,1-DCE to the Hall Creek system at concentrations that would result in surface water contamination in excess of RIDEM aquatic water quality criteria (AWQC) for aquatic life criteria for chronic exposure to freshwater.

RAO No. 5: Prevent or reduce exposure of current or future residents to TCE, 1,1,2-TCA, cis- 1,2-DCE, trans-1,2-DCE, PCE, 1,1-DCE, and VC at concentrations above their MCLs resulting from the use of groundwater as a potable drinking water source. Prevent or reduce exposure of current or future residents to TeCA at concentrations resulting in unacceptable risks (total ELCR greater than 1x10-4) based on ingestion, absorption, and inhalation of volatile organics from groundwater.

RAO No. 6: Attain MCLs in the Industrial Area east of the Property and south of the Property along Hall Creek where the plume currently exceeds MCLs or could potentially migrate in the future.

To achieve the RAOs, numerical remediation goals (RGs) were established based on ARARs (USEPA MCL, and RIDEM GB groundwater objectives) and risk-based calculations based on toxicity data. Table 3 contains a summary of the RGs established for the eight contaminants of concern for each of the six RAOs which were used to develop and screen the remedial alternatives. Table 4 summarizes the site-wide cleanup objectives for the eight COCs in groundwater for the unlimited use and unrestricted exposure (UU/UE) condition that the selected remedy is intended to achieve. These cleanup objectives satisfy or exceed each of the RAOs presented in Table 3.

A total of six alternatives were developed to address the six RAOs. These alternatives were evaluated with respect to the following nine criteria, in accordance with USEPA guidance for CERCLA sites:

Threshold Criteria:

Overall protection of human health and the environment

Compliance with ARARs

Balancing Criteria:

Long-term effectiveness and permanence

Reduction of toxicity, mobility, or volume through treatment

Short-term effectiveness

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Implementability

Cost

Modifying Criteria:

State acceptance

Community acceptance

A summary of the six alternatives and the detailed analysis of each with respect to the nine criteria is provided below.

Alternative 1: No Action Alternative. This alternative is insufficient for protection of human health, would not comply with the chemical specific ARARs, and does not include any Land Use Controls (LUCs) that will ensure protection of public health in the future.

Alternative 2: Pump and Treat of the Source Area, Along the GA Boundary, and within the Plume, Air sparging / Soil Vapor Extraction (AS / SVE) Upgradient of the Hall Creek system, Monitored Natural Attenuation (MNA), and Institutional Land Use Controls (ILUCs). This alternative would take an estimated 200 years to meet the remedial goals, would require operating and maintaining mechanical systems for this extended length of time, and would be the most costly of the 6 alternatives.

Alternative 3: Thermal Treatment of the Source Area, Reductive Dechlorination along the GA Boundary, AS / SVE Upgradient of the Hall Creek system, MNA, and ILUCs. This alternative would aggressively treat the source area with thermal treatment, but less aggressive treatment of the dissolved groundwater plume, resulting in a remedial timeframe that was almost twice as long as Alternative 6.

Alternative 4: Thermal Treatment of the Source Area, Pump and Treat along the GA Boundary, AS/ SVE Upgradient of the Hall Creek system, MNA, and ILUCs. Due to less intensive treatment of the dissolved plume, this alternative would also have a remedial timeframe that was almost twice as long as Alternative 6, while requiring long term operation of mechanical systems, and having a cost similar to Alternative 6.

Alternative 5: Reductive Dechlorination within the Source Area and the Plume, MNA, and ILUCs. This alternative does not include aggressive treatment of the Source Area with thermal technology, and therefore would be expected to have a remedial timeframe twice as long as Alternative 6.

Alternative 6: This alternative is the UU/UE alternative which will achieve MCLs in groundwater throughout the Property and Vicinity, thereby exceeding the RAOs. It will incorporate Thermal Treatment with SVE for Vapor Collection in the Source Area and Reductive Dechlorination in the Plume, MNA, and ILUCs. Through aggressive source area treatment and intensive treatment of the dissolved plume, this alternative offers the best balance of achieving remedial goals in the shortest timeframe at a cost that is competitive with other less aggressive treatment alternatives. Treatment of the dissolved plume would preclude future potential adverse effects of the plume on surface waters and aquatic

US Army Corps of Engineers / Final Decision Document / June 2019 xi receptors. In addition, Alternative 6 is the only alternative that would remove ILUCs in a reasonable timeframe once remedial actions have been completed and cleanup objectives have been achieved, ultimately allowing unrestricted use of the Property and Vicinity, and returning the associated groundwater resources to beneficial use.

Below is a summary of the cost estimates and remedial timeframes for each of the alternatives to achieve cleanup objectives.

Alternative Capital Cost Periodic Costs Total Cost Estimated Duration Alternative 1 $0 $0 $0 500 years Alternative 2 $11.3 M $43.8 M $55.1 M 200 years Alternative 3 $16.0 M $11.0 M $26.9 M 100 years Alternative 4 $18.8 M $17.5 M $36.2 M 100 years Alternative 5 $8.1 M $10.1 M $18.2 M 120 years Alternative 6 $35.0 M $7.6 M $42.7 M 60 years

The Selected Remedy, Alternative 6, consists of in situ thermal treatment in the Source Area, reductive dechlorination throughout the rest of the plume, MNA, and ILUCs until cleanup objectives have been attained. Key elements of the Selected Remedy include:

ILUCs that will notify property owners and occupants, annually, of risks of exposure from FUDS Property CVOCs until cleanup objectives are attained.

Pre-design investigations conducted to:

o Further refine the understanding of the Source Area;

o Determine the resistivity of the bedrock in the Source Area;

o Further refine the understanding of the nature and extent of the plume;

o Further refine the understanding of the geochemistry in the areas planned for treatment; and o Further refine the understanding of the hydrogeology of the different units where injections are planned.

In situ thermal treatment in the Source Area where CVOCs are present at the highest concentrations in the deep overburden and bedrock. The specific thermal technology will be selected during remedial design and will likely consist of electrical resistivity heating (ERH) or thermal conduction heating (TCH). Soil vapor extraction (SVE) will be performed to collect vapors released from the thermal treatment process.

Reductive dechlorination treatment will be conducted throughout the plume and will consist of injection of treatment amendments into the overburden and bedrock. The specific amendments injected will be selected during remedial design, but could include zero valent iron (ZVI), electron donor materials or other amendments depending on the

US Army Corps of Engineers / Final Decision Document / June 2019 xii microbiology and geochemistry in the areas being treated. A series of ten rounds of injections over a period of 40 years is estimated.

Monitoring of the plume for system performance and natural attenuation purposes. An estimated ten year period of MNA is assumed to follow the 50 years of active remediation to ensure RGs are attained and rebound of contaminant concentrations do not occur.

The suspected presence of DNAPL in the Source Area constitutes a “principal threat waste,” which is highly toxic and mobile. The Selected Remedy addresses the principal threat waste in the Source Area through thermal treatment, which is capable of reducing CVOC concentrations to attain the remedial action objectives.

The selected remedy will achieve a condition of UU/UE for the Property. The total estimated time to achieve the cleanup objectives listed in Table 4 is estimated to be 60 years and the estimated cost of implementing the Selected Remedy is $42.7 million. Five-Year Reviews will be conducted until UU/UE is achieved to ensure that the remedy is protective while remediation is ongoing, and to evaluate whether the remedy is performing as intended. The selected remedy meets the statutory determinations required under CERCLA §121 and the NCP. It is protective of human health and the environment;

complies with ARARs; is cost-effective; utilizes permanent solutions and alternative treatment technologies or resource recovery technologies to the maximum extent practicable; and satisfies the statutory preference for treatment as a principal element of the remedy.

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List of Acronyms

US Army Corps of Engineers / Final Decision Document / June 2019 xiv

LIST OF ACRONYMS

% percent

1,1-DCA 1,1-dichloroethane

1,2-DCA 1,2-dichloroethane

1,1-DCE 1,1-dichloroethene

1,2-DCE 1,2-dichloroethene

1,1,1-TCA 1,1,1-trichloroethane

1,1,2-TCA 1,1,2-trichloroethane

AE Assessment Endpoint amsl above mean sea level

Army United States Army

ARAR Applicable or relevant and appropriate requirements

AS air sparging

AST Aboveground Storage Tank

ATSDR Agency for Toxic Substances and Disease Registry

AWQC&G Ambient water quality criteria and guidelines

BRAC Base Realignment and Closure

BRHHA Baseline Human Health Risk Assessment

BTAG Biological Technical Assistance Group

BTEX benzene, toluene, ethylbenzene, and xylenes

CAL EPA California Environmental Protection Agency

CENAE Corps of Engineers, New England District of the North Atlantic Division

CERCLA Comprehensive Environmental Response, Compensation, and Liability Act

CFR Code of Federal Regulations cis-1,2-DCE cis-1,2-dichloroethene

CHA Carriage Hill Association cm centimeter cm/sec centimeters per second

COC contaminant of concern

COPC chemical of potential concern

COPEC Compound of Potential Ecological Concern

CSEM Conceptual Site Exposure Model

US Army Corps of Engineers / Final Decision Document / June 2019 xv

CSF cancer slope factor

CSM conceptual site model

CVOC chlorinated volatile organic compound

DANC Decontamination agent, non-corrosive

DCE Dichloroethene

DERP Defense Environmental Restoration Program

DNAPL dense, non-aqueous phase liquid

DOD Department of Defense

DPW Department of Public Works

DVTA Disaster Village Training Area

EA EA Engineering, Science, and Technology, Inc.

ELCR excess lifetime cancer risk

ELUR Environmental Land Usage Restriction

EPC exposure point concentration

ERA Environmental Resources Associates, Inc.

ERAGS Ecological Risk Assessment Guidance for Superfund

ERH electrical resistivity heating fbgs feet below ground surface

FS Feasibility Study ft feet/foot

FUDS Formerly Used Defense Site

GAC granular activated carbon

GSA United States General Services Agency gpm gallons per minute

GWETS groundwater extraction and treatment system

Hart Fred C. Hart Associates, Inc.

HEAST Health Effects Assessment Summary Tables

HHRA Human Health Risk Assessment

HI Hazard Index

HQ Hazard Quotient

ICZ Institutional Control Zone

ILUC Institutional Land Use Control

IRIS Integrated Risk Information System

JCO The Johnson Company

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Kg Kilogram

L Liter

LIFOC Lease in Furtherance of Conveyance

LS Lacustrine sands

LSC Lacustrine silt and clay

LTM Long term monitoring

LUC land use control μg/Kg microgram per kilogram μg/L microgram per liter

M million

ME Measurement Endpoints

MCL maximum contaminant level mg/Kg milligrams per kilogram mg/L milligrams per liter

MNA monitored natural attenuation

NAS Naval Air Station

NAVD North American Vertical Datum

Navy United States Navy

NCEA National Center for Environmental Assessment

NCBC Naval Construction Battalion Center (Davisville)

NCP National Contingency Plan

NPDES National Pollutant Discharge Elimination System

NPL National Priorities List

NRCS Natural Resources Conservation Service

O&M operation and maintenance

OSWER Office of Solid Waste and Emergency Response

PCB polychlorinated biphenyl

PCE tetrachloroethene

PCI Peabody Clean Industries

POTW publicly-owned treatment works

PPRTV provisional peer reviewed toxicity value

PRP Potentially Responsible Party

PVC Polyvinyl Chloride

QDC Quonset Development Corporation

US Army Corps of Engineers / Final Decision Document / June 2019 xvii

RAO Remedial action objective

RBC Risk Based Concentration

RfCs Reference Concentrations

RfDs Reference Doses

RGs Remedial goals

RI Remedial Investigation

RIDEM Rhode Island Department of Environmental Management

RIEDC Rhode Island Economic Development Corporation

RME Reasonable Maximum Exposure

RSL Regional Screening Level

SARA Superfund Amendments and Reauthorization Act

SEC Sirrine Environmental Consultants sec Second

SER Steam Enhanced Remediation

SG sand and gravel outwash

SLERA Screening Level Ecological Risk Assessment

STG Basal glacial till/ weathered bedrock

Stone Stone Environmental, Inc.

SVE soil vapor extraction

SVOC Semi-Volatile Organic Compound

TCA trichloroethane

TCE trichloroethene

TCH thermal conduction heating

TeCA 1,1,2,2-tetrachloroethane

TMV toxicity, mobility, or volume

TOC total organic carbon

TPH total petroleum hydrocarbons trans-1,2-DCE trans-1,2-dichloroethene

UCL Upper Contaminant Levels

UIC Underground Injection Control

UR Inhalation Unit Risk

USACE United States Army Corps of Engineers

USEPA US Environmental Protection Agency

UU/UE unlimited use and unrestricted exposure

US Army Corps of Engineers / Final Decision Document / June 2019 xviii

VC vinyl chloride

VISL Vapor Intrusion Screening Level

VOC volatile organic compound yd3 cubic yards

ZVI zero-valent iron

The Declaration / 1

US Army Corps of Engineers / Final Decision Document / June 2019 1

1. THE DECLARATION

1.1 PROJECT NAME AND LOCATION

The Former Nike Battery PR-58 and Disaster Village Training Area (the Property) is located in what was once Quonset Point NAS in North Kingstown, Washington County, Rhode Island (see Figure 1). The Property is a Formerly Used Defense Site (FUDS) (D01RI0029 05). The extent of contamination resulting from historical releases at the Property has not been confined to the Property. The area beyond the Property that encompasses the extent of contamination resulting from releases on the Property is referred to as the “Vicinity” of the Property. This document addresses the Property and Vicinity.

1.2 STATEMENT OF BASIS AND PURPOSE

This Decision Document presents the final remedy selected for the Property and Vicinity (Selected Remedy), which was developed in accordance with the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA), as amended, 42 U.S.C. §§ 9601 et seq. and the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) as amended, 40 Code of Federal Regulations Part 300 (USEPA, 1990). This final decision for the Property and Vicinity is based on the Administrative Record file which was developed in accordance with Section 113(k) of CERCLA and is available for public review at the North Kingstown Free Library, 100 Boone Street, North Kingstown, RI 02852, and the U.S. Army Corps of Engineers (USACE) New England District (NAE) Office, 696 Virginia Road, Concord, MA 01742-2751.

The U.S. Army is the lead agency and USACE has mission execution authority for FUDS. USACE is responsible for implementation of the environmental program at the Former Nike Battery PR-58 and Disaster Village Training Area (DVTA) under the FUDS program. The Deputy Commanding General for Military and International Operations has been delegated the authority to approve this Decision Document. The Selected Remedy for the Property and Vicinity has been selected by the USACE.

Although the Rhode Island Department of Environmental Management (RIDEM) agreed with the overall remedial approach for this FUDS, they disagreed fundamentally on USACEs approach to institutional controls and selection of Applicable or Appropriate and Relevant Requirements (ARARs), and therefore did not provide concurrence on this Decision Document. Appendix A contains a copy of RIDEM’s Letter of Non-concurrence.

1.3 ASSESSMENT OF THE PROJECT

The response action selected in this Decision Document is necessary to protect the public health or welfare or environment from actual or threatened releases of hazardous substances into the environment.

1.4 DESCRIPTION OF THE SELECTED REMEDY

This Decision Document sets forth the final remedy selected by the USACE for the Property and Vicinity for addressing the chlorinated volatile organic compound (CVOC) contamination in groundwater in the overburden and bedrock. The Selected Remedy consists of in situ thermal treatment in the Source Area, reductive dechlorination throughout the rest of the plume, monitored natural attenuation (MNA), and

US Army Corps of Engineers / Final Decision Document / June 2019 2

Institutional Land Use Controls (ILUCs) through the establishment of Institutional Control Zones (ICZs) which will be established during the remedial design phase.

Key elements of the Selected Remedy include:

ILUCs through annual notification to all property owners, both current and future within the ICZs that will discourage the use of groundwater for any purpose other than for sampling and remedial purposes. The discouraged uses include, but are not limited to o Residential use of contaminated groundwater as a potable water supply;

o Recreator and worker exposure to irrigation using contaminated groundwater; and o Exposure to groundwater via industrial use for non-irrigation purposes such as manufacturing and geothermal heating/cooling applications.

ILUCs through annual notification to all property owners, both current and future within the ICZs, that will notify property owners and occupants of the potential of exposure of indoor workers in the commercial/industrial area (including the DPW), daycare children, and residential occupants to potentially harmful indoor vapors; and

Pre-design investigations conducted to:

o Further refine the understanding of the Source Area;

o Determine the resistivity of the bedrock in the Source Area;

o Further refine the understanding of the nature and extent of the plume;

o Further refine the understanding of the geochemistry in the areas planned for treatment; and o Further refine the understanding of the hydrogeology of the different units where injections are planned.

In situ thermal treatment in the Source Area where CVOCs are present at the highest concentrations in the deep overburden and bedrock. The specific thermal technology will be selected during remedial design and will likely consist of electrical resistivity heating (ERH) or thermal conduction heating (TCH). Soil vapor extraction (SVE) will be performed to collect vapors released from the thermal treatment process.

Reductive dechlorination treatment will be conducted throughout the plume and will consist of injection of treatment amendments into the overburden and bedrock. The specific amendments injected will be selected during remedial design, but could include zero valent iron (ZVI), electron donor materials or other amendments depending on the microbiology and geochemistry in the areas being treated.

Monitoring of the plume for system performance and natural attenuation purposes.

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Annual inspections by the government of the properties within the ICZs to evaluate whether groundwater is being used for any purposes other than those stipulated in this Decision Document and to assess whether occupants are exposed to vapor intrusion.

Investigations in the Source Area on the Property identified the presence of CVOCs, potentially in the form of dense, nonaqueous phase liquid (DNAPL). The suspected presence of DNAPL constitutes a “principal threat waste,” which is highly toxic and mobile. The Selected Remedy addresses the principal threat waste in the Source Area through thermal treatment which is capable of reducing CVOC concentrations to attain the cleanup objectives.

The selected remedy will achieve a condition of unlimited use and unrestricted exposure (UU/UE) for the Property and Vicinity. The total estimated time to achieve UU/UE conditions is 60 years and the estimated cost of implementing the Selected Remedy is $42.7 million.

1.5 STATUTORY DETERMINATIONS

Under CERCLA §121 and the NCP, the lead agency must select remedies that: are protective of human health and the environment; comply with applicable or relevant and appropriate requirements (ARARs)

– unless a statutory waiver is justified; are cost-effective; utilize permanent solutions and alternative treatment technologies or resource recovery technologies to the maximum extent practicable; and satisfy the statutory preference for treatment as a principal element of the remedy. This section discusses how the Selected Remedy meets these statutory requirements. Because the remedy will take more than 5 years to achieve UU/UE, policy reviews will be conducted at five-year intervals from initiation of construction until UU/UE is achieved to ensure that the remedy is, or will be, protective of human health and the environment while remediation is ongoing.

1.5.1 Protectiveness of Human Health and the Environment

The Selected Remedy is protective of human health and the environment. Groundwater concentrations would be reduced through thermal treatment in the Source Area, and throughout the rest of the groundwater plume through reductive dechlorination, and natural attenuation. Reductions in groundwater CVOC concentrations will also address potential vapor intrusion risks in buildings on the Property and Vicinity. Monitoring will be performed to evaluate the progress of natural attenuation processes and detect potential migration of CVOCs.

Land Use Controls (LUCs) are a proven method for preventing unnecessary human exposure to contaminants while a Selected Remedy is being implemented, before cleanup objectives have been attained, provided they are properly and consistently enforced.

Environmental Land Use Restrictions (ELURs) are deed restrictions used in the State of Rhode Island that prevent specific uses or activities at a property in order to minimize or prevent human risk. ELURs are recorded within a property’s municipal land record and are generally the most utilized LUC for environmental remediation projects in Rhode Island. However, ELURs must be recorded by a property owner and since USACE does not own any of the impacted properties associated with the FUDS, it is USACE’s policy that ELURs cannot be utilized as part of the remedial effort at a FUDS Property.

In lieu of ELURs, USACE has determined that utilizing ILUCs would offer properties a similar level of protection. The ILUCs for the Property would include:

US Army Corps of Engineers / Final Decision Document / June 2019 4

• The establishment of ICZs. ICZs are areas in which notifications are recommended to advise property owners that their property may be potentially impacted by the presence of FUDS Property contaminants,

• A requirement for annual notifications to properties within ICZs that the use of groundwater for any purpose other than those expressly identified in this Decision Document is un-advisable and could result in exposure to FUDS Property contaminants,

• A requirement for annual notifications to properties within ICZs of the need to prevent occupant exposure to vapors inside buildings by utilizing engineering or administrative controls to minimize exposure to FUDS Property contaminants, and

• An evaluation of the applicability and effectiveness of the ILUCs during Five-Year Reviews.

1.5.2 Compliance with ARARs

Contaminant concentrations in groundwater would be reduced through thermal treatment in the Source Area, reductive dechlorination, and natural attenuation. Therefore, this alternative would meet chemical-specific ARARs for groundwater. Applicable location and action-specific ARARs would be followed. The ARARs identified for this alternative are summarized in Appendix B.

1.5.3 Cost-Effectiveness

In the lead agency’s judgment, the Selected Remedy is cost-effective and represents a reasonable value for the money to be spent.

1.5.4 Utilization of Permanent Solutions and Alternative or Resource Recovery Technologies

The Selected Remedy would provide thermal treatment to volatilize potential residual DNAPL in the Source Area, collect it on granular activated carbon and ship it off-site for destruction of the CVOCs. The reductive dechlorination process will destroy the CVOCs in situ. Reductive dechlorination treatment would consist of direct injection of amendments to degrade toxic COCs via abiotic or biotic processes to benign end products, such as ethene and ethane, which pose no unacceptable risk. USACE has determined that the Selected Remedy represents the maximum extent to which permanent solutions and alternative or resource recovery technologies can be utilized in a practicable manner at the Property and Vicinity.

1.5.5 Statutory Preference for Treatment as a Principal Element of the Remedy

The Selected Remedy will result in the permanent removal of the contaminants through treatment, thereby meeting the statutory preference for reduction of toxicity, mobility, or volume (TMV) through treatment.

1.5.6 Applicability of Five-Year Review Requirements

Because this remedy will result in hazardous substances, pollutants, or contaminants remaining on-site in excess of levels that allow for unlimited use and unrestricted exposure for a period of approximately 60 years before all cleanup objectives have been attained, a policy review will be conducted a minimum of every 5 years after initiation of the remedial action to ensure that the remedy is, or will be, protective of human health and the environment.

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1.6 DATA CERTIFICATION CHECKLIST

The following information is included in the Decision Summary section of this Decision Document (Section 2.0). Additional information can be found in the Administrative Record file for the Property and Vicinity.

Chemicals of concern and their respective concentrations (Subsection 2.10.1).

Baseline risk represented by the chemicals of concern (Subsection 2.9).

Cleanup levels established for chemicals of concern and the basis for these levels (Subsection 2.10.3).

How contaminants of concern will be addressed (Section 2.12).

How source materials constituting principal threats are addressed (Subsection 2.15).

Current and reasonably anticipated future land use assumptions and current and potential future beneficial uses of groundwater used in the baseline risk assessment (Subsections 2.8).

Potential land and groundwater use that will be available at the Property and Vicinity as a result of the Selected Remedy (Subsection 2.16.4).

Estimated capital, annual operation and maintenance (O&M), and total present worth costs, discount rate, and the number of years over which the remedy cost estimates are projected (Subsections 2.14.7 and 2.16.1).

Key factor(s) that led to selecting the remedy, i.e. a description of how the Selected Remedy provides the best balance of tradeoffs with respect to the balancing and modifying criteria (Subsection 2.16.1).

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2 THE DECISION SUMMARY

2.1 PROPERTY NAME, LOCATION, AND DESCRIPTION

The Former Nike Battery PR-58 and Disaster Village Training Area is located in North Kingstown, Washington County, Rhode Island (see Figure 1). The Property is a FUDS Site (D01RI0029 05).

The portion of FUDS property historically occupied by the former Nike Battery PR-58 and DVTA is referred to in this document as the “Property”. The Property location is shown on Figure 1. The Remedial Investigation (RI) for the Property and Vicinity has resulted in characterization of environmental conditions and of the extent of contamination resulting from historical releases at the Property. The extent of contamination is not confined to the Property; the area that encompasses the extent of contamination resulting from historical releases at the former Nike Battery PR-58 Property and DVTA is referred to in this document as the “Vicinity” of the Property.

Figure 2 is a site plan showing the Property and the surrounding area. The Property, which comprises approximately 44 acres, is bounded by the former Perimeter Road (now a bike path) to the north, Seabee Avenue to the east, Newcomb Road to the west, and Babcock Road to the south. Most of the Property is currently owned by the Quonset Development Corporation (QDC), a special purpose subsidiary of the Rhode Island Economic Development Corporation (RIEDC), except the approximately

1.7 acres in the southwest corner of the Property (shown as Plat 191, Lot 15 on Figure 2) that was purchased by Chipster, LLC in 2008. The U.S. Army Corps of Engineers (USACE) is the lead agency. The U.S. Environmental Protection Agency (EPA) and the Rhode Island Department of Environmental Remediation (RIDEM) are support agencies for this Project. Funding for cleanup activities at the Property and Vicinity is being provided by the Defense Environmental Restoration Program (DERP) Formerly Used Defense Sites (FUDS) Program.

2.2 PROPERTY HISTORY AND ENFORCEMENT ACTIVITIES

2.2.1 History of the Property and Vicinity

The following subsections describe the history of the Property and other properties in the Vicinity that have been impacted by releases on the Property and on which remedial actions will be implemented as part of the Selected Remedy.

2.2.1.1 History of the Property

Prior to 1942, the Property was a mostly-wooded area surrounded by farmland. A road ran roughly east-west through the center of the Property and cleared/disturbed areas were present in the northeast corner and east-central portions of the Property.

In November 1942, the U.S. Navy (Navy) established Camp Thomas, which occupied 142 acres that included the Property and land to the east as far as present-day Marine Road. The Property was drained, largely cleared, and filled during the construction of Camp Thomas. Stormwater collection, water supply, and wastewater sewer systems were installed as well. The camp included 800 Quonset huts serving as barracks, mess halls, galleys, recreation rooms, and latrines. Camp Thomas was demolished after World

The Decision Summary

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War II and vegetation was allowed to take over the area with little management. The Property was not used again until 1954.

Between 1954 and 1956, the U.S. Army (Army) constructed Nike Battery PR-58 on the Property, which was equipped with Ajax missiles (armed with conventional, non-nuclear warheads), and was never part of the Nike Hercules Program. A large area on the western half of the Property was cleared and modified, but the eastern half remained wooded. Nike missile batteries consisted of two principal but geographically separated operational areas: a battery control area and a launch area, which included an adjacent assembly/service area. The Property contained the launch and assembly/service area for Nike Battery PR-58. Launch area operations included assembling, servicing, maintaining, and preparing the Ajax missiles for the firing battery. The launch and assembly/service area included three underground missile magazines, a missile refueling area located south of the magazines, a missile assembly and test building, and a generator building (EA Engineering, Science, and Technology [EA], 2001). An additional building in the southwest corner of the Property (Building 343) initially was used as a personnel building and then for training classroom space. Use of the Nike Battery PR-58 by the Army ended in 1962 (EA, 2001).

In 1964, the Property was transferred from the Army to the Navy and became part of Quonset Point NAS. The Navy used the Property for disaster recovery training from 1964 until 1974 when Quonset Point NAS was decommissioned. During this period, the Navy constructed five to six buildings for nuclear, chemical, and biological warfare training. In this area of the Property, 30 steel pipes rose above grade. The pipes were arranged in six rows of five pipes each, stenciled with the words “Chemical Agent.” Whether or not actual chemicals were used in the training is not known; however, the Navy found an empty 5-gallon can labeled as “DANC” on the Property in 1995 (EA, 1998a). DANC (decontamination agent, non-corrosive), is a mixture of 1,1,2,2-tetrachlorethane (TeCA) and 1,3-dichloro-5,5-dimethylhydantoin that reportedly was stored in the training area (EA, 1998a). In addition to using the cleared area west of the former Nike missile magazines for disaster recovery training, the Navy cleared the northeast quadrant of the Property and a small area in the southeast quadrant at the intersection of Seabee Avenue and Parade Road. In 1974, land to the west of Seabee Avenue (including the Property) was transferred to the U.S. General Services Agency (GSA). In 1978, the GSA transferred ownership of the Property area to the RIEDC.

The Property remained unused by RIEDC until 1980, when RIEDC…