Amendment 0003 ROD.pdf

N00101_004361

NAS SOUTH WEYMOUTH, MA

SSIC 5000-33a

FINAL RECORD OF DECISION NOMANS LAND ISLAND CHILMARK NAS

SOUTH WEYMOUTH MA

01/01/2022

TETRA TECH

Approved for public release: distribution unlimited.

NIRIS Cover sheet rev. 5, Aug 2020

Approved for public release; distribution is unlimited

RCORD OF DECISION

Nomans Land Island

Chilmark MA

FINAL

Version: 0

Prepared for

Department of the Navy Naval Facilities Engineering Systems Command, NAVFAC Mid-Atlantic

9742 Maryland Avenue Norfolk, VA 23511-3095

Remedial Action Contract (RAC) Contract No. N62470-13-D-8007

January 2022

This page intentionally left blank.

RECORD OF DECISION

FOR

NOMANS LAND ISLAND

CHILMARK, MASSACHUSETTS

NAVAL AIR STATION SOUTH WEYMOUTH

WEYMOUTH, MASSACHUSETTS

NAVFAC and BRAC PMO EAST

U.S. NAVY

JANUARY 2022

Approved for public release; distribution is unlimited

This page intentionally left blank.

Record of Decision Final Nomans Land Island, Chilmark, MA January 2022

4659-WE05-22-0003 i

TABLE OF CONTENTS

1.0 DECLARATION

1.1 Site Name and Location

1.2 Statement of Basis and Purpose

1.3 Assessment of Site

1.4 Description of Selected Remedy

1.5 Statutory Determinations

1.6 ROD Data Certification Checklist

1.7 Authorizing Signatures and Support Agency Acceptance of Remedy

2.0 DECISION SUMMARY

2.1 Site Name, Location, and Brief Description

2.2 Site History and Enforcement Activities

2.3 Community Participation

2.4 Scope and Role of Operable Unit or Response Action

2.5 Site Characteristics

2.5.1 Physical Characteristics

2.5.2 Conceptual Site Model

2.5.3 Nature and Extent of UXO

2.6 Current and Potential Future Site and Resource Uses

2.7 Summary of Site Risks

2.7.1 Risk to Human Health

2.7.2 Risk to Public Welfare

2.7.3 Risk to the Environment

2.7.4 Risk of Harm to Public Safety

2.8 Remedial Action Objectives

2.9 Description of Alternatives

2.9.1 Alternative S-1

2.9.2 Alternative S-2

2.9.3 Alternative S-3

2.10 Comparative Analysis of Alternatives

2.10.1 CERCLA Threshold Criteria

2.10.2 CERCLA Primary Balancing Criteria

2.10.3 CERCLA Modifying Criteria

2.10.4 Additional MCP-Specific Criteria

2.10.5 Additional Navy-Specific Criteria

2.11 Principal Threat Waste

2.12 Selected Remedy

2.12.1 Summary of the Rationale for the Selected Remedy

2.12.2 Description of the Selected Remedy

2.12.3 Summary of the Estimated Remedial Costs

2.12.4 Expected Outcomes of Selected Remedy

2.13 Statutory Determinations

2.13.1 Protection of Human Health and the Environment

2.13.2 Compliance with ARARs

4659-WE05-22-0003 ii

2.13.3 Cost Effectiveness

2.13.4 Utilization of Permanent Solutions and Alternative Treatment Technologies or Resource Recovery Technologies to the Maximum Extent Practicable

2.13.5 Preference for Treatment as a Principal Element

2.13.6 5-Year Review Requirement

2.14 Documentation of Significant Changes

3.0 RESPONSIVENESS SUMMARY

3.1 Stakeholder Comments and Lead Agency Responses

3.2 Technical and Legal Issues

4.0 REFERENCES

LIST OF FIGURES

Figure 1-1 Site Location Map Figure 2-1 Conceptual Site Model for the Safety Risk Characterization for Nomans Land

Island Figure 2-2 Refined Conceptual Site Model for the Stage II Environmental Risk

Characterization for Nomans Land Island Figure 2-3 Land Use Control Area Boundary Map (Includes Water Site Restrictions) Figure 2-4 Marine Restricted Areas in the Vicinity of Nomans Land Island

LIST OF TABLES

Table 1-1 ROD Data Certification Checklist Table 2-1 Environmental Investigations and Documentation Table 2-2 Summary of Ordnance Debris Collected from the Island (1998 Ordnance Debris

Clearance RAM) Table 2-3 SEBS Review Item/Additional Areas Summary Table 2-4 Alternative S-1 – Completion Timeline Table 2-5 Alternative S-2 – Completion Timeline Table 2-6 Evaluation Criteria for Remedial Alternatives Table 2-7 Risk to Safety – Remedial Action Alternatives Summary of CERCLA/MCP/Navy

Criteria Evaluation

LIST OF APPENDICES

Appendix A MassDEP Concurrence Letter Appendix B Proposed Remedial Action Plan and Public Notice Appendix C Ecological Risk Assessment Summary Tables Appendix D Cost Estimate Appendix E ARARs Appendix F USFWS UXO Awareness Pamphlet Appendix G Transcript of the Public Hearing on the Proposed Remedial Action Plan and

Reponses to Public Comments iii

4659-WE05-22-0003

ACRONYMS

ARAR applicable or relevant and appropriate requirement BAF bioaccumulation factor BIP blow-in-place BRAC Base Realignment and Closure CERCLA Comprehensive Environmental, Response, Compensation, and

Liability Act CFR Code of Federal Regulations CMR Code of Massachusetts Regulations COC chemicals of concern COPC chemicals of potential concern CSA Comprehensive Site Assessment CSM Conceptual Site Model DDESB United States Department of Defense Explosive Safety Board DoD United States Department of Defense DOI United States Department of the Interior EBS Environmental Baseline Survey EBST Environmental Baseline Survey for Transfer EOD Explosive Ordnance Disposal ERC environmental risk characterizations FDA Former Debris Area FS Feasibility Study HHRA Human Health Risk Assessment LUC land use control LUCIP Land Use Control Implementation Plan MassDEP Massachusetts Department of Environmental Protection MCP Massachusetts Contingency Plan MDAS material documented as safe MEC munitions and explosives of concern NAUL Notice of Activity Use Limitation Navy United States Department of the Navy NCP National Oil and Hazardous Substances Pollution Contingency Plan NOAA National Oceanic and Atmospheric Administration NPL National Priorities List OB/OD open burning/open detonation OHM oil and/or hazardous material O&M Operation and Maintenance QA/QC quality assurance/quality control RAM release abatement measure RAO remedial action objectives ROD Record of Decision ROM rough order of magnitude SEBS Supplemental Environmental Baseline Survey TBC to be considered U.S. United States iv

USCG United States Coast Guard USEPA United States Environmental Protection Agency USFWS United States Fish and Wildlife Service UXO unexploded ordnance VOC volatile organic compound

1.0 DECLARATION

1.1 Site Name and Location

Nomans Land Island Chilmark, Massachusetts Massachusetts Department of Environmental Protection (MassDEP) Release Tracking Number 4-13390

1.2 Statement of Basis and Purpose

This Record of Decision (ROD) presents the Selected Remedy for Nomans Land Island, Chilmark, Massachusetts (referred to as “the Site”) (see Figure 1-1; all figures are provided at the end of the text). The Selected Remedy was chosen in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as codified in 42 United States (U.S.)

Code § 9601 et seq., and amended by the Superfund Amendments and Reauthorization Act, and, to the extent practicable, the National Oil and Hazardous Substances Pollution Contingency Plan (NCP), codified in 40 Code of Federal Regulations (CFR) 300 et seq., as amended. The regulatory program that includes these combined laws and regulations is commonly referred to as “Superfund”. The Selected Remedy was also chosen in accordance with the Massachusetts Contingency Plan (MCP), as the Site is overseen by MassDEP as the agency for regulatory approval, and in accordance with the 2010 Navy Guidance for Optimizing Remedy Evaluation, Selections, and Design as the U.S. Department of the Navy (Navy) is the lead agency for remediation of the Site (Navy 2010).

This decision is based on information contained in the Administrative Record for the Site, copies of which are available for review at the Information Repositories maintained at Aquinnah Town Hall, Chilmark Town Hall, and the Wampanoag Tribe of Gay Head (Aquinnah), all located on Martha Vineyard Island, Massachusetts. The Navy, U.S. Fish and Wildlife Service (USFWS), and MassDEP concur with the Selected Remedy for Nomans Land Island (see Appendix A for the MassDEP concurrence letter). Since Nomans Land Island is not on the National Priorities List (NPL) and is a non-Superfund-financed state-lead enforcement site, U.S. Environmental Protection Agency (USEPA) concurrence is not required.

1.3 Assessment of Site

The remedy selected in this ROD is necessary to protect public health from actual or threatened exposure to surface and subsurface explosives hazards presented by potential munitions on land and in the nearshore marine environment of Nomans Land Island that may present an imminent and substantial endangerment to public welfare.

1.4 Description of Selected Remedy

Nomans Land Island is presently used as an unstaffed wildlife refuge by the USFWS and will continue as such under the transfer agreement between Navy and USFWS. The Selected Remedy, which includes an institutional controls/public awareness and enforcement component, addresses the risk of harm to public safety from explosives hazards related to unexploded ordnance (UXO) in the soil on the island and in the nearshore marine environment near the shoreline. The Selected Remedy for the Nomans Land Island, known as Alternative S-2, will limit access to the Site and risk of harm to public safety using the following institutional controls, public awareness training, and enforcement components:

Selected Remedy for the Terrestrial Portion of the Island

Institutional Controls

- Upland Signage Replacement/Maintenance

- Beach Signage

- Operation and Maintenance (O&M) Plan

- Navy O&M (e.g., Limited Munitions and Explosives of Concern [MEC] Surface

Clearances, UXO Response)

- UXO Response Program

- Land Use Controls (LUCs)

Public Awareness – Restriction and Dangers

- USFWS/Public UXO Awareness Training

- UXO Awareness Pamphlet

Enforcement

- USFWS Violations/Fine System

Selected Remedy for the Nearshore Marine Environment

Institutional Controls

- Restricted Waters Designation

- Upland Signage

- Beach Signage

- Annual Verification

Public Awareness – Restriction and Dangers

- USFWS/Public UXO Awareness Training

- UXO Awareness Pamphlet

Enforcement

- U.S. Coast Guard (USCG)/Massachusetts Environmental Police Coastal Bureau

1.5 Statutory Determinations

The Selected Remedy is protective of human health, complies with federal and state requirements that are applicable or relevant and appropriate to the remedial action, is cost effective, and utilizes permanent solutions and alternative treatment (or resource recovery) technologies to the maximum extent practicable.

The Selected Remedy for the Site does not satisfy the statutory preference for treatment as a principal element of the remedy because the Site risk is a risk of harm to public safety due to the presence of UXO in soil and in sediment within the nearshore marine portion of the Site. Complete removal and neutralization of the UXO in the terrestrial and in the nearshore marine environment was deemed impracticable because it would result in damage to habitat and loss of wildlife, if implemented.

Because this Selected Remedy will result in hazardous substances, pollutants, or contaminants in the form of UXO remaining on site above levels that allow for unlimited use and unrestricted exposure, a statutory review will be conducted within 5 years after initiation of remedial action to ensure that the Selected Remedy remains protective.

1.6 ROD Data Certification Checklist

Table 1-1 includes the ROD certification data as required in USEPA’s Guide to Preparing Superfund Proposed Pans, Records of Decision, and Other Remedy Selection Decision Documents (USEPA 1999). These data also are discussed in the Decision Summary section of this ROD.

Additional information can be found in the Administrative Record files for the Site.

Table 1-1 ROD Data Certification Checklist

ROD Certification Data Location in ROD

Chemicals of concern COCs are not required as the Site risk addressed is the risk of harm due to safety due to the presence of UXO1

Sections 2.5. and 2.7

Baseline risk represented by the chemicals of concern and UXO risk of harm to safety

Section 2.7

Cleanup levels established for COCs and the basis for these levels

Not applicable (no COCs requiring cleanup levels)

How source materials constituting principal threats are addressed

Section 2.11 (No principal threat wastes are present at the Nomans Land Island Site)

Current and reasonably anticipated future land use assumptions and current and potential future beneficial uses of groundwater used in the baseline risk assessment and ROD

Section 2.6

Potential land and groundwater use that will be available at the Site as a result of the Selected Remedy

Section 2.12

Estimated capital, annual O&M, and total present worth costs, discount rate, and the number of years over which the remedy cost estimates are projected

Appendix E

4659-WE05-22-0003

ROD Certification Data Location in ROD

Key factor(s) that led to selecting the remedy (i.e., describe how the Selected Remedy provides the best balance of tradeoffs with respect to the balancing and modifying criteria, highlighting criteria key to the decision)

Section 2.12

Notes:

1 ROD Guidance (USEPA 1999) specifies that ROD data certification requires identification of the COCs and their respective concentrations. However, since COCs were not identified, this section focuses on UXO.

Abbreviations and Acronyms:

COC – chemicals of concern O&M – operation and maintenance ROD – Record of Decision UXO – unexploded ordnance

1.7 Authorizing Signatures and Support Agency Acceptance of Remedy

2.0 DECISION SUMMARY

2.1 Site Name, Location, and Brief Description

Nomans Land Island, Chilmark, Massachusetts, is an uninhabited 628-acre island located in the Atlantic Ocean, lying approximately 2.7 miles south of Aquinnah (Gay Head), Martha’s Vineyard Island. The Site Location Map is provided as Figure 1-1. The Site is listed under the MassDEP Release Tracking Number 4-13390. Nomans Land Island is not listed on the NPL. The Site is defined of as:

All upland soils, sediments, groundwater, and surface water above the mean low water level

The direct near-shoreline marine environment (surface water and marine sediments)

The Navy and the U.S. Department of the Interior (DOI) entered into a Joint Wildlife Management Agreement for Nomans Land Island in 1970, designating the entire island as a National Wildlife Refuge in recognition of known wildlife nesting habitats. The island was transferred in June 1998 (Navy 1998a) from the U.S. Department of Defense (DoD) to the USFWS for the intended use as an unstaffed wildlife refuge (as part of the Eastern Massachusetts National Wildlife Refuge Complex). As part of the transfer agreement, the USFWS is the current owner and operator of the island, and all environmental remediation and MCP work has been and will continue to be conducted and financed by the Navy, the potential responsible party. The Navy is the lead agency for remediation, MassDEP is the approving agency, and USFWS is the supporting agency for Site cleanup.

2.2 Site History and Enforcement Activities

Site activities that led to environmental investigations to address the risk of harm to safety were related to the use of the island by the Navy for air-to-surface bombing and gunnery target exercises, that took place on the island from 1943 through 1996. This activity resulted in the dropping or firing of ordnance onto and into the island which may remain in an unexploded state. Prior to 1943, the island was utilized for various purposes, including fishing and game hunting, and, at one time, a small population of people occupied a portion of the island. No civilians have lived on the island since 1943. The water surrounding the island is a Restricted Waterway, as marked on nautical maps depicting the island and vicinity.

Table 2-1 provides a brief summary of previous investigations and munitions removal actions that have taken place at Nomans Land Island. Results of these activities indicate that the Site poses a “Risk of Harm to Safety” (as described in 310 Code of Massachusetts Regulations [CMR] 40.0900) due to the presence of UXO on site.

Table 2-1 Environmental Investigations and Documentation

Investigation Date

Investigation or Action Document Activities

1986 Environment impact review The Navy began evaluating environmental impacts at NAS South Weymouth, including conducting Site walkovers, reviews of Base records, and interviews.

1995-1996 Final Report, Phase I Environmental Baseline Survey Stone & Webster 1996)

The Navy performed a Phase I EBS to identify potentially contaminated sites requiring further investigation. Nomans Land Island was one of the sites identified for further study.

1995-1998 EBST for Nomans Land Island (including Responsiveness Summary)

(NAVFAC 1998)

This report for the island was developed in support of the Environmental Summary Document for transfer of federal property from one agency to another. The EBST is based on the 1996 EBS - Phase I Report and presents updated information where applicable to reflect additional data and actions concerning conditions at the Site through 1998.

Investigation Date

Investigation or Action Document Activities

1997 Notice of Responsibility (MassDEP 1997)

The MassDEP issued a Notice of Responsibility to the Navy.

1997 ESRP (Radian International LLC 1997) and Explosives Safety Summary Document to Support Proposed Federal to Federal Conveyance of Nomans Land Island, MA (Navy 1998b)

Established objectives and work approach to perform UXO surface clearance approved by the DoD Explosives Safety Board. The Navy Explosive Ordinance Disposal performed munitions investigation and clearance across the island.

1998 Phase I Limited Site Investigation (Foster Wheeler 1998)

The Navy removed ordnance from the surface of the island and removed four USTs. A Phase I Limited Site Investigation was conducted to characterize Site soils, groundwater, surface water, and sediments. A radiological investigation was conducted to ensure that no recovered ordnance exhibited evidence of depleted uranium content.

Addressed nine review items from the Phase I EBS.

Metals were detected in Site soils, groundwater, surface water, and sediment. Explosives were detected in two soils samples and one surface water sample.

1998 Radiological Screening Survey Report (Inter-Link 1998)

Confirmed that ordnance debris tested negative for radiological constituents.

1998 Ordnance RAM Plan (Foster Wheeler 2000)

During the summer of 1998, approximately 671,306 pounds of ordnance debris and 59,847 pounds of scrap were removed from the island surface as part of a MassDEP-approved RAM.

1999 - 2000 Final Phase II Comprehensive Site Assessment (Foster Wheeler 2001)

The Navy conducted a Phase II Comprehensive Site Assessment to further delineate the extent of COPCs in Site soils, groundwater, surface water, and sediments. Human health and ecological risk assessments were performed.

Metals found in soils were determined to be localized to bomb craters/graves. No explosives were detected in soils, sediment, and groundwater. RDX was detected in one surface water body.

2001 Final Phase IIA Comprehensive Site Assessment – Supplemental Investigation (Foster Wheeler 2004a and TtFW 2004a)

An extensive sampling effort at the FDA, located just north of the highest point on the island and upgradient of an extensive emergent wetland that runs west to east and eventually drains into the ocean in the eastern portion of the Site. Sampling was

Investigation Date

Investigation or Action Document Activities conducted to further characterize the FDA and to determine the health of the FDA wetland.

Elevated levels of metals were detected on the island in the FDA. FDA wetland sediments were found to exceed multiple benthic community endpoints. A potential pathway from Site soils to marine environment was identified.

2001 Final Supplemental Environmental Baseline Survey (Foster Wheeler 2003 and 2004b)

The Navy conducted the SEBS, which incorporated and evaluated the airborne geophysical survey data, and included an aerial photographic site analysis, and further public interviews and historical records reviews. The aerial photogrammetric survey established an accurate basemap for the Site. The airborne geophysical survey identified areas containing subsurface metal debris and confirmed the CSM and biased investigation approach.

2003 Final Release Abatement Measure Completion Report (Ordnance Debris Removal) (TtFW 2004b)

The SEBS resulted in the removal and/or closure of 19 additional review items, including one 275-gallon UST, one septic system, and two dry wells. The Navy also conducted a UXO inspection and performed removal activities in accessible upland and near-shoreline marine areas, and remediated 19 cubic yards of contaminated soil.

2004 Final Phase IIB – Supplemental Investigation

- Risk to Safety (TtFW 2006) (EFANW and EFANE 2004)

A Phase IIB Report, focused on the risk of harm to safety on the island due to remaining ordnance, was presented to the Technical Review Committee and submitted to the MassDEP. A UXO Awareness Pamphlet was developed to educate USFWS workers conducting studies on the island.

2005 Final Environmental Risk Management Memorandum (TtEC 2006a)

Per a request from USFWS, the Navy prepared an Environmental Risk Characterization Memorandum to more clearly characterize the risk to the environment on the island. Results revealed that a level of “no significant risk” to the environment associated with chemical contamination was achieved for Site soils. Removal of metal debris from the FDA was recommended.

2006 Final RAM Completion Report (FDA) (TtEC 2006b)

The Navy implemented the FDA RAM, which involved removal of the old Quonset Hut material, believed to be a source contributing to adverse impacts in the downgradient wetland. A total of 1.5 tons of metal debris was removed. Performed field soil screening at Aviation Landing Strip areas.

Investigation Date

Investigation or Action Document Activities

2008 MEC Surface Clearance Completion Report (TtEC 2008)

A MEC surface clearance was performed that resulted in the removal and recycling of 394 munitions-related items and 16,119 pounds of

MDAS.

2010 Nomans Land Island National Wildlife Refuge Comprehensive Conservation Plan (USFWS 2010)

The USFWS Comprehensive Conservation Plan provided long-term guidance for management decisions and set forth goals, objectives, and strategies needed to accomplish refuge purposes and identify the USFWS’s best estimate of future needs.

2014 Limited MEC Surface Clearance Completion Report (TtEC 2016)

A limited MEC surface clearance was performed that resulted in the removal of 164 munitions-related items from 65 acres, and recycling of 3,650 pounds of MDAS.

2020 Final Phase III/Feasibility Study (FS) (TtEC 2020)

A Phase III/FS Report was prepared to present the alternatives to address the risk of harm to safety posed by ordnance remaining on the island. It was recommended that Alternative S-2, Institutional Controls, Awareness, and Enforcement, be the preferred remedy.

2020 Proposed Remedial Action Plan (Navy 2020)

The findings in the Phase III/FS and a description of the selected remedial alternative were provided in the Proposed Remedial Action Plan. A public hearing was conducted and responses to public comments were prepared. Following the public comment and response period, the selected remedial alternative will be incorporated into the ROD.

Abbreviations and Acronyms:

COPC – contaminants of potential concern CSM – Conceptual Site Model DoD – United States Department of Defense EBS – Environmental Baseline Survey EBST – Environmental Baseline Survey for Transfer ESRP – Explosives Safety Remediation Plan FDA – Former Debris Area FS – Feasibility Study MassDEP – Massachusetts Department of Environmental Protection MDAS – material documented as safe MEC – Munitions and Explosives of Concern NAS – Naval Air Station Navy – United States Department of the Navy RAM – release abatement measure RDX – Royal demolition explosive SEBS – Supplemental Environmental Baseline Survey USFWS – United States Fish and Wildlife Service UST – underground storage tank UXO – unexploded ordnance

With regard to the list of documents provided above, enforcement actions for the Site included a Notice of Responsibility, issued by the MassDEP in 1997 (MassDEP 1997). The Notice of Responsibility was issued based on the findings associated with three reports, including the Base

Realignment and Closure Cleanup Plan (dated September 13, 1996) (Navy 1996), the Environmental Baseline Survey (EBS) - Phase I Report (dated November 18, 1996), and the Prescribed Burn Prescription (dated January 7, 1997) (Patterson 1997). The Site was also issued the MassDEP Release Tracking Number of 4-13390.

2.3 Community Participation

The Navy performed public participation activities in accordance with CERCLA and the NCP throughout the site cleanup process at Nomans Land Island. The Nomans Land Island Community Relations and Involvement Plan, dated September 2000 (Navy 2000), formalized the process for involving the Martha’s Vineyard community, interested members of the public, and the extended community in environmental restoration activities for the Site. In 2000, the Navy also established a Technical Review Committee to discuss environmental actions on Nomans Land Island. Public meetings have been held to provide community feedback. Information repositories, including documents from the Administrative Record, have been established for Nomans Land Island at the Aquinnah Town Hall, Chilmark Town Hall, and Wampanoag Tribe of Gay Head (Aquinnah), all located on Martha’s Vineyard Island, Massachusetts.

The Phase III/Feasibility Study (FS) (TtEC 2019) and Proposed Remedial Action Plan (Navy 2020a) for Nomans Land Island were made available to the public in August 2020. The Notice of Availability of these two documents was published in the Vineyard Gazette on August 28, 2020.

The published public comment period was from September 15, 2020 to October 15, 2020, and was extended by the Navy to November 2, 2020 at the time of the public meeting. In addition, a public meeting and hearing were held on September 29, 2020 to present the Proposed Remedial Action Plan to a broader community audience than those that had already been involved at the Site.

During the public hearing portion of the public meeting, the Navy solicited comments and questions concerning issues at the Site and the remedial alternatives detailed in the Proposed Remedial Action Plan. The published Public Notice for the Notice of Availability and the Proposed Remedial Action Plan are provided in Appendix B.

2.4 Scope and Role of Operable Unit or Response Action

Nomans Land Island remediation area is not divided up into operable units or separate response actions. The entire island and near-shoreline marine environment are considered the Site with regard to this ROD. The response action is directed by the Navy as the lead agency for remediation, with concurrence by the MassDEP (since the Site is a state-lead enforcement site), as well as concurrence by the USFWS, as the current owner and operator of the wildlife refuge on the island, to address the risk of harm to public safety due to explosives hazards presented by UXO remaining in the terrestrial onshore environment and in the nearshore marine environment. Specific response action activities include the following:

Institutional Controls Public Awareness – Restriction and Dangers

The risk of harm to public safety will be managed with the use of institutional controls restricting unauthorized access to the island, public awareness of the island’s access restrictions and dangers, and enforcement of access restrictions through surveillance, citations, and fines for violations. The island is currently, and will remain, an unstaffed USFWS wildlife refuge with access restricted to trained and authorized personnel.

2.5 Site Characteristics

This section presents the physical characteristics, Conceptual Site Model (CSM), and nature and extent and fate and transport of UXO in the uplands and in the nearshore environment. Human health and ecological receptors are discussed in Section 2.7. Detailed information about the Site is presented in the documents listed in Table 2-1.

2.5.1 Physical Characteristics

The island is 1.6 miles long, east to west, and slightly more than 1 mile wide, north to south. Two large and many small surface water areas (ponds) are present on the island. One of the large ponds, Ben's Pond, lies just west of the center of the island and is approximately 1,000 feet across, from east to west, and approximately 500 feet across, from north to south. The other large pond, Rainbow Pond, lies on the east end of the island, and is approximately 625 feet across, east to west.

Two extensions of the pond are present to the north and northwest. Many of the small depressions on the island may be the result of bomb craters (live bombing occurred from 1943 to the early 1950s) filled in with rainwater. On occasion during the Phase I and Phase II sampling phases, the rainwater in some of these depressions contained a visible sheen on the surface. Furthermore, many of the temporary small surface water areas and permanent ponds were observed to have a deep reddish tint. These areas were sampled, and the sheens and tints observed were determined to be the result of natural conditions.

Several man-made ponds are also present on the Site and are believed to have been made prior to 1943 by residents excavating down to the groundwater table and then piling up the excavated soil around the outskirts of the excavation in a horseshoe fashion. No evidence has been collected to date that indicates these features were the result of Navy ordnance activity.

The surface of the island is composed of a glacial moraine of sand, gravel, cobbles, and large erratics (boulders) with no apparent outcrops of bedrock. Wetland types range from persistent emergent wetlands to permanently flooded open water. All inland wetlands are classified as palustrine. Cranberry bogs meander over about 200 acres, while shallow ponds or lakes resulting from springs and runoff cover approximately 40 acres. Diking of bog overflow by previous owners, prior to 1943, has created a number of artificial ponds.

The perimeter of the Site is characterized by wave-cut bluffs reaching 50 feet in height, and a narrow beach of coarse gravel, cobbles, and boulders characterizes three sides of the island. The north shore is characterized by a gently sloping, sand-gravel beach with a prominent sand spit. The highest point, 110 feet above sea level, is on the southern half of the island, near the north-south axis of the island. Large placards currently in place along the shoreline warn boaters to stay clear of the island because of its previous use as a military target range.

Nomans Land Island was previously settled by native American Indians and colonial people. There are some archeological remains and a graveyard on the island. A review of historical settlement can be found in the USFWS Nomans Land Island National Refuge Comprehensive Conservation Plan, dated September 2010 (USFWS 2010). The USFWS oversees any archeological or tribal visits to Nomans Land Island.

2.5.2 Conceptual Site Model

The current risk of harm to safety due to explosives hazards presented by UXO addressed in this CSM is shown on Figure 2-1. The CSM relates to assessing the potential risk of harm to safety from explosives hazards associated with UXO located within the accessible soil layer (i.e., 0-3 feet below ground surface and, potentially, at greater depths) and UXO in the marine sediments. The CSM was developed to support the Phase II evaluation of the risk of harm to safety (Foster Wheeler 2001).

The current CSM identifies five human receptor groups that could potentially come into contact with UXO that may currently be present on the island. They are:

1. A USFWS Worker (Routine)

2. A USFWS Worker (Tern Nesting/Special Initiative)

3. An Authorized Visitor

4. An Adult Trespasser

5. A Child Trespasser

2.5.3 Nature and Extent of UXO

Soil was investigated primarily during Phase II sampling at Nomans Land Island. Various investigation, assessment, and remedial programs have been conducted to address risk of harm to safety from explosives hazards due to UXO, as listed in Table 2-1.

The CSM identifies the primary sources of ordnance-related activities, which were or may have been conducted, that resulted in ordnance being present on the island. The primary source of greatest significance was the air-to-surface bombing and gunnery target exercises that took place on the island for many years. This activity resulted in the dropping or firing of ordnance onto/into the island. Historical records indicate that the Navy SeaBees would clear UXO from the island twice a year. Documentation on the final disposition of these materials is not available, although it is likely that the UXO were destroyed in place by detonation. The potential exists for the presence of a burial pit or trench where these items may have been placed, or an area where open burning/open detonation (OB/OD) disposal may have occurred. Ordnance items are often found in or around OB/OD areas due to kick-outs of items caused by the force of the detonations or as the result of incomplete disposal. No evidence of such a pit or disposal area on the island has been observed to date. On Nomans Land Island, these releases would have resulted in potentially energetic UXO items being present in the soil, the upland pond and wetland sediments, and, possibly, the marine sediments.

The ordnance CSM also indicates the anticipated mechanisms by which UXO items may migrate or move from one location to another on the island, or shift from one depth in the soil to another.

These potential transport and migration mechanisms include mechanical redistribution and human activity, precipitation runoff, erosion, frost heave, storm surge, and tidal action. The net result of the original deposition of the UXO items and the localized transport and migration processes over time is a new distribution of items in the surficial and subsurface soil, the upland pond and wetland sediments, and the near-shore marine sediments. In addition, UXO items may become exposed at the surface in or near the upland ponds when water levels on the island drop during prolonged dry weather or a drought. These locations may be locations of direct contact exposure by current or reasonably foreseeable future users of the island. This “baseline” distribution of UXO items on Nomans Land Island was significantly modified in 1998 by the implementation of the Release Abatement Measure (RAM) for Ordnance Debris Removal. This action included the removal of ordnance items and related scrap from the surface of the island, and removal of ordnance items to a greater degree on the unimproved “roads,” including a portion of the northern beach area near the current boat landing area. Based on the transport and migration mechanisms discussed above, UXO migration of location or shift from one depth to another in soil may occur anywhere on the island.

2.6 Current and Potential Future Site and Resource Uses

The current and potential future use of Nomans Land Island is as an unstaffed wildlife refuge.

Currently (and in any scenario or potential future use), access to the island is restricted to specific USFWS and remedial activities. Existing LUCs, set forth as part of the property transfer agreement between the Navy and USFWS, describe those activities that may and/or may not take place at the Site. These activities involve restrictions on site excavation activities, nearshore and offshore lobstering and anchoring, and other USFWS work activities (freshwater/wetland pond work).

2.7 Summary of Site Risks

Site risks to human health, the environment, and public welfare, and harm to public safety were initially assessed in the Phase II Comprehensive Site Assessment (Foster Wheeler 2001). The Phase IIA Comprehensive Site Assessment – Supplemental Investigation (TtFW 2004a) was conducted to further characterize the Site and to determine the risk to the environment. In addition, risk to the environment was further assessed in the Final Environmental Risk Management Memorandum (TtEC 2006a). The risk of harm to public safety was further assessed in the Final Phase IIB – Supplemental Investigation - Risk to Safety (TtFW 2006). Conclusions from these assessments indicated that there was “No Significant Risk” established for human health, the environment, and public welfare associated with chemical contamination. However, a condition of “No Significant Risk” could not be established for risk of harm to public safety associated with UXO in the soil and nearshore marine environment.

2.7.1 Risk to Human Health

The human health risk assessment (HHRA), provided in the Phase II Comprehensive Site Assessment (Foster Wheeler 2001), characterized the potential risks to USFWS workers, adult and child trespassers, and authorized visitors. The HHRA was prepared based on the current and reasonably foreseeable future use of the island as an unstaffed wildlife refuge. No chemicals of concern (COCs) were identified, based on the chemicals of potential concern (COPCs) assessed.

Based on the exposure frequencies and duration associated with these receptors and the contaminated media identified, a condition of “No Significant Risk” was established for human health.

2.7.2 Risk to Public Welfare

In accordance with 310 CMR 40.0994, a characterization of risk to public welfare was also conducted and summarized in the Phase II Comprehensive Site Assessment (Foster Wheeler 2001). This characterization consisted of two aspects – a comparison of the levels of the COCs detected on the island, and an evaluation of nuisance conditions and significant community effects.

A comparison of exposure point concentrations developed for soil and groundwater for each COC indicated that the chemical-specific upper concentration limits for these media were not exceeded.

No specific nuisance or negative impact associated with the conditions on the island were identified. Therefore, a condition of “No Significant Risk” to public welfare can be established for the island based on its current and foreseeable use.

Under the MCP, an assessment of the potential risks to public welfare relative to both the current and anticipated future use of the Site was required. This assessment was conducted to identify and evaluate nuisance conditions, significant community effects, and loss of active or passive property uses. A risk to public welfare exists if:

1. A nuisance condition exists or will result from the release or the threat of a release of an oil and/or hazardous material (OHM);

2. A segment of the community is affected or may reasonably be expected to be affected and experience a significant adverse impact from a release; and

3. An MCP upper concentration limit for soil or groundwater is exceeded.

On Nomans Land Island, no nuisance condition exists or will result from the release or the threat of a release of an OHM, since there are no current potential activities to create releases. The island is unstaffed and has no community that can be affected by a release. MCP upper concentration limits were not exceeded for soil or groundwater. Based on the assessment of the Site conditions and these criteria, a determination was made that the island does not pose a risk to public welfare.

2.7.3 Risk to the Environment

The results of the initial Stage I Environmental Screening, performed as part of the Phase II assessment (Foster Wheeler 2001), indicated a potential risk predominantly based on the levels of metals, including cadmium, copper, chromium, lead, and zinc, present in the soil, sediment, and surface water at the Site. The Stage 1 screening assessment suggested that shallow soils/sediment and surface water may pose a risk to ecological receptors on the island. The ecological CSM suggested that exposure pathways to a number of ecological receptor groups are potentially complete. In particular, it was recommended that the Former Debris Area (FDA) be evaluated for risk to specific receptors. A supplemental investigation, Phase IIA Comprehensive Site Assessment – Supplemental Investigation (TtFW 2004a) was conducted to further characterize the Site and to determine the risk to the environment. A Stage II Environmental Risk Characterization that specifically addressed the FDA and the upland surface water bodies throughout the island was performed; a refined ecological CSM was used for this characterization as an assessment tool (see Figure 2-2). The results of the Stage II Environmental Risk Characterization were further evaluated in the Environmental Risk Management Memorandum (TtEC 2006a). This supplemental evaluation provided a more realistic estimate of exposure by re-evaluating the No Observable Adverse Effects Levels and the Lowest Observable Adverse Effect Levels Hazard Quotients for songbirds through utilization of the mean Bioaccumulation Factor (BAF) and the natural log mean BAF, in addition to the 90th percentile BAF. The memorandum addressed specific locations of concern, impacts, and proposed action, and stated that a level of “No Significant Risk” to the environment had been achieved for this Site. Removal from the FDA of the source material potentially responsible for adverse impacts on local wetlands was summarized in Final RAM Completion Report (FDA) (TtEC 2006b). Following removal of the source material, the refined ecological CSM, shown on Figure 2-2, no longer characterized the Site. The current CSM is defined by risk of harm to safety in Figure 2-1, as described in Section 2.5.2 of this ROD.

Summary environmental risk assessment tables from the Environmental Risk Management Memorandum (TtEC 2006a) are provided in Appendix C.

Stage I (screening level) and Stage II (baseline) environmental risk characterizations (ERCs) conducted for Nomans Land Island consisted of the three steps described below.

Step 1 – Formulate the Problem

The Navy collected and evaluated information regarding the Site conditions (e.g., types of habitat and types of plant and animal species at the Site), the presence of any federal, state, or trust species of concern, the number and types of contaminants potentially present, and potential exposure pathways and mechanisms for wildlife to come into contact with these contaminants. The Navy evaluated the following ecological receptor groups: terrestrial plants and invertebrates, wetland plants and aquatic receptors (benthic invertebrates, other aquatic life and plants), and wetland and terrestrial wildlife present that are exposed to surface water (i.e., freshwater ponds), surface soil, and freshwater and marine sediment. In the FDA, the Navy evaluated wetland plants exposed to sediment; aquatic receptors (invertebrates, plants, and amphibians) exposed to surface water, sediment, and groundwater; and wetland vertebrates exposed to surface water and sediment.

The Navy also conducted a shellfish transplant and monitoring study. This shellfish study involved collecting and analyzing blue mussels from the shoreline of the island to help identify whether any contaminants were migrating off-island and into the near-shoreline marine environment. Sediment samples also were collected from various runoff channels around the island, and shellfish (blue mussels) were transplanted offshore to help aid in this part of the environmental assessment.

Step 2 – Perform Exposure and Effects Assessment

The Navy evaluated the potential exposure of a range of the relevant environmental receptors to COPCs using direct measurement of biological exposure and modeled exposure approaches. The chemical concentrations that environmental receptors would be exposed to were determined by directly sampling environmental media. Exposure modeling also included potential chemical exposure via food-chain interaction, which was estimated using BAFs cited from technical references, and directly assessed using site-specific data. The primary exposure routes that were evaluated in the ERCs included:

Dermal absorption and direct contact with environmental media Dietary ingestion of prey Surface water ingestion Incidental ingestion of environmental media

The exposure assessment looked at individual lines of evidence using a weight of evidence approach. Each line of evidence was assigned a level of significance to assess exposure to the resource values identified as assessment endpoints in the risk assessment.

Step 3 – Characterize Risks to Environmental Receptors

The results from the exposure assessment were used in conjunction with toxicity reference values to assess the extent of potential adverse effects to the ecological receptors present on the island.

In accordance with MCP and CERCLA guidance, a refinement of the conservative exposure assumptions/concentrations for evaluating the potential risks to ecological receptors (i.e., plants, invertebrates, and wildlife receptors) was performed to reduce uncertainties in highly conservative risk estimates derived during the screening-level assessment. The objective of the Stage II or baseline ecological risk assessment refinement was to determine which chemicals contribute to unacceptable levels of ecological risk, and to eliminate from further consideration those COPCs that were retained because of the use of very conservative exposure scenarios. This allowed the ERC to focus on those COPCs that are considered risk drivers for the island environment.

2.7.4 Risk of Harm to Public Safety

An evaluation of the potential risk of harm to safety in consideration of the ordnance that may be present in the subsurface and near-shoreline environment did not find a condition of “No Significant Risk” to public safety. A Phase IIB – Supplemental Investigation - Risk to Safety (TtFW 2006) evaluation was completed to present an expanded CSM to more completely evaluate the Site with respect to explosives safety.

Figure 2-1 provides the current CSM for risk of harm safety. Figure 2-1 includes primary sources, primary release mechanisms, secondary sources, transport and migration mechanisms, exposure media, exposure routes, and potential receptors.

For risk of harm to safety due to UXO, there are no established quantitative methodologies for determining exposure or toxicity assessments to evaluate UXO-related explosives safety or hazard.

However, the CSM provides an effective tool for conducting a qualitative analysis of exposure or risk. The CSM for potential exposure to UXO developed for the original Phase II analysis of risk of harm to safety is provided in Figure 2-1. Examples of the types of UXO found in the soil during the 1998 ordnance clearance RAM are listed in Table 2-2 (Tables 2-2 through 2-7 are provided at the end of the text). In addition, findings related to UXO-, debris-, and ordnance-related soil contamination found during the Supplemental Environmental Baseline Survey (SEBS) in 2003 are listed in Table 2-3. To evaluate risk of harm to safety, the original CSM was expanded to enable a closer evaluation to be made of three of its components with respect to access and interactions between people and the island: the exposure media; the exposure routes; and the receptors themselves. The expanded CSM framework focused on a broader set of factors affecting the level of exposure and explosives hazard posed by the potential presence of UXO on the island uplands and in the nearshore environment. These factors that affect exposure included:

The receptor’s motivation, frequency of access, and the degree to which their activities disturb and intrude into the ground

The set of off-island and on/near island deterrents put in place to control access The Site management procedures to be implemented on the island

Ordnance remaining on the island was considered in the evaluation of risk to public safety. The current and foreseeable use of the island is an unstaffed wildlife refuge, closed to the public, and is compatible with safety risk factors established by the DoD Explosive Safety Board (DDESB).

Mechanisms to deter access to the island by trespassers include posted warning signs placed and maintained by the USFWS, and restricted water around the island. USFWS has the responsibility to limit access on the island and the USCG has the responsibility for enforcing access restrictions to the restricted waters surrounding the island. The DoD and the Navy will retain the responsibility for removal of ordnance that may become exposed, in accordance with the UXO Safety O&M Plan that has been prepared and will be periodically updated by the Navy for USFWS. While a framework to deter unauthorized access to the island has been established, whether this framework will be effective in deterring access remains to be demonstrated. For this reason, the condition “No Significant Risk” to public safety was not established.

2.8 Remedial Action Objectives

The environmental program for the Site has included various investigation, assessment, and remedial activities to address the risk of harm to public safety. The following remedial action objectives (RAOs) focus on reducing the risk of harm to public safety for the island:

Reduce receptor exposure to surface UXO Reduce receptor exposure to subsurface UXO Reduce receptor exposure to near-shoreline/offshore UXO Achieve a permanent solution, with conditions, using the selected remedial action alternative

These RAOs, which are focused on limiting public exposure to UXO onshore and UXO in the near-shoreline around the island to limit the risk of harm to public safety, provide the basis for developing remedial action alternatives. The selected remedial action alternative will work to establish a “Permanent Solutions with Conditions”, per the MCP (310 CMR 40.1012), to address risk of harm to public safety for the island due to UXO. A Permanent Solution with Conditions maintains a level of “No Significant Risk”, in part by relying on a Notice of Activity Use Limitation (NAUL) and/or on assumptions about future conditions and use of the Site. The NAUL is a legal document incorporated into all future deeds, easements, mortgages, leases, licenses, occupancy agreements or any other instrument of transfer.

2.9 Description…