HGL Sovereign 2015 Long_Term_Monitoring_and_Maintenance_Plan Sudbury Devens.pdf

FINAL

FEBRUARY 2015

LONG-TERM MONITORING

AND MAINTENANCE PLAN

FOR

FORMER FORT DEVENS ARMY INSTALLATION

AND

SUDBURY ANNEX

FORMER FORT DEVENS ARMY INSTALLATION, DEVENS, MA

SUDBURY ANNEX, SUDBURY, MA

Prepared for:

U.S. Army Corp of Engineers

New England District

Concord, Massachusetts

Prepared by:

Sovereign Consulting Inc.

and HydroGeoLogic, Inc.

Contract No.: W912WJ-10-D-0003

Task Order: 004

NOTICE

The United States Department of Defense, Department of Army, funded wholly or in part the preparation of this document and work described herein under Contract No. W912WJ-10-D- 0003 and Task Order 004. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

TABLE OF CONTENTS

Section Page

U.S. Army Corps of Engineers-New England District SO1002 i

1.0 INTRODUCTION ...................................................................................................................... 1-1

1.1 PURPOSE ....................................................................................................................... 1-1

1.2 BACKGROUND ............................................................................................................ 1-2

1.2.1 Former Fort Devens Army Installation Main Post Site Summary ............ 1-3

1.2.2 Former Fort Devens Army Installation South Post Impact Area

Site Summary.................................................................................................... 1-3

1.2.3 Former Sudbury Annex Site Summary......................................................... 1-4

1.3 ROD OBJECTIVES AND SELECTED REMEDY ...................................................... 1-4

1.3.1 AOC 57 .............................................................................................................. 1-4

1.3.2 AOC 69W .......................................................................................................... 1-6

1.3.3 AOC 43G ........................................................................................................... 1-6

1.3.4 Devens Consolidation Landfill ...................................................................... 1-7

1.3.5 AOC 32 and 43A .............................................................................................. 1-8

1.3.6 Grant Housing and 37-mm Impact Area ...................................................... 1-9

1.3.7 South Post Impact Area ................................................................................... 1-9

1.3.8 Sudbury Annex .............................................................................................. 1-10

2.0 LONG-TERM MONITORING AND MAINTENANCE PROGRAM ................................. 2-1

2.1 CURRENT AND PROPOSED CHANGES TO THE LONG-TERM

MONITORING AND MAINTENACE PROGRAM................................................. 2-1

2.1.1 AOC 57 .............................................................................................................. 2-1

2.1.1.1 Current Program .............................................................................. 2-1

2.1.1.2 Recommended Changes to Current Program ............................. 2-2

2.1.2 AOC 69W .......................................................................................................... 2-2

2.1.2.1 Current Program .............................................................................. 2-2

2.1.2.2 Recommended Changes to Current Program ............................. 2-3

2.1.3 AOC 43G ........................................................................................................... 2-3

2.1.3.1 Current Program .............................................................................. 2-3

2.1.3.2 Recommended Changes to Current Program ............................. 2-3

2.1.4 Devens Consolidation Landfill ...................................................................... 2-4

2.1.4.1 Current Program .............................................................................. 2-4

2.1.4.2 Recommended Changes to Current Program ............................. 2-4

2.1.5 AOC 32 and 43A .............................................................................................. 2-5

2.1.5.1 Current Program .............................................................................. 2-5

2.1.5.2 Recommended Changes to Current Program ............................. 2-5

2.1.6 Grant Housing Area and 37-mm Impact Area ............................................ 2-5

2.1.6.1 Current Program .............................................................................. 2-5

2.1.6.2 Recommended Changes to Current Program ............................. 2-5

2.1.7 Devens South Post Impact Area (SPIA) ........................................................ 2-6

2.1.7.1 Current Program .............................................................................. 2-6

2.1.7.2 Recommended Changes to Current Program ............................. 2-6

2.1.8 Sudbury Annex ................................................................................................ 2-7

2.1.8.1 Current Program .............................................................................. 2-7

2.1.8.2 Recommended Changes to Current Program ............................. 2-7

TABLE OF CONTENTS (continued)

U.S. Army Corps of Engineers-New England District SO1002 ii

3.0 SAMPLING AND ANALYSIS PLAN FOR GROUNDWATER AND SURFACE

WATER ........................................................................................................................................ 3-1

3.1 OBJECTIVES .................................................................................................................. 3-1

3.2 MONITORING WELL SAMPLING ........................................................................... 3-1

3.2.1 Area of Contamination 57 ............................................................................... 3-2

3.2.2 Area of Contamination 69W ........................................................................... 3-2

3.2.3 Area of Contamination 43G ............................................................................ 3-2

3.2.4 Devens Consolidation Landfill ...................................................................... 3-3

3.2.5 Areas of Contamination 32 and 43A ............................................................. 3-3

3.2.6 Grant Housing Area and 37-mm Impact Area ............................................ 3-3

3.2.7 South Post Impact Area ................................................................................... 3-3

3.2.8 Sudbury Annex (AOC A7) ............................................................................. 3-4

3.3 SURFACE WATER SAMPLING ................................................................................. 3-5

3.4 LEACHATE SAMPLING ............................................................................................. 3-6

3.5 LANDFILL GAS VENT MONITORING ................................................................... 3-6

3.6 SAMPLING FREQUENCY SUMMARY .................................................................... 3-7

3.7 ANALYTICAL METHODS AND ANALYTES ........................................................ 3-7

3.7.1 Groundwater Analytical Methods and Analytes ........................................ 3-7

3.7.2 Surface Water Analytical Methods and Analytes ....................................... 3-9

3.7.3 Leachate Analytical Methods ......................................................................... 3-9

3.8 PRE-SAMPLING ACTIVITIES .................................................................................. 3-10

3.8.1 Equipment and Supplies ............................................................................... 3-10

3.8.2 Site Location, Security and Access .............................................................. 3-11

3.8.3 Initial Well Opening and Inspection ........................................................... 3-11

3.8.4 Water Level Measurements .......................................................................... 3-12

3.8.5 Well Point Installation Methodology .......................................................... 3-12

3.8.6 Methodology for Manganese Evaluation at AOC 43G ............................. 3-13

3.8.7 Methodology for Manganese Evaluation at AOC 69W ............................ 3-13

3.9 SAMPLING PROCEDURES ...................................................................................... 3-13

3.9.1 Equipment Calibration .................................................................................. 3-13

3.9.2 Low-Flow Well Purging ................................................................................ 3-13

3.9.3 HydraSleeve™ Installation ........................................................................... 3-15

3.9.4 Sample Containers and Preservatives ......................................................... 3-15

3.10 SAMPLE COLLECTION ............................................................................................ 3-15

3.10.1 Sample Identification ..................................................................................... 3-16

3.10.2 Quality Assurance/Quality Control Samples ........................................... 3-17

3.10.2.1 Duplicate Sample ........................................................................... 3-17

3.10.2.2 Rinsate Blank .................................................................................. 3-17

3.10.2.3 Trip Blank ....................................................................................... 3-17

3.10.2.4 Matrix Spike/Matrix Spike Duplicates ...................................... 3-18

3.11 POST-SAMPLING ACTIVITIES ............................................................................... 3-18

3.11.1 Total Well Depth Measurement ................................................................... 3-18

3.11.2 Chain of Custody ........................................................................................... 3-18

3.11.3 Sample Delivery/Shipment to Laboratory ................................................ 3-19

3.11.4 Equipment Decontamination ....................................................................... 3-19

3.11.5 Investigation-Derived Waste ........................................................................ 3-20

3.11.6 Data Validation .............................................................................................. 3-21

TABLE OF CONTENTS (continued)

U.S. Army Corps of Engineers-New England District SO1002 iii

3.12 FIELD DOCUMENTATION ..................................................................................... 3-22

3.12.1 Field Logbooks ............................................................................................... 3-22

3.12.2 Field Sample Collection Sheets .................................................................... 3-24

3.12.3 Daily Quality Control Reports ..................................................................... 3-24

3.12.4 Photographic Documentation ...................................................................... 3-24

3.12.5 Project File ....................................................................................................... 3-24

4.0 LAND-USE CONTROL IMPLEMENTATION & MONITORING PLAN ......................... 4-1

4.1 GENERAL ...................................................................................................................... 4-1

4.2 LAND-USE CONTROL INSPECTION ...................................................................... 4-1

4.3 INTERVIEW................................................................................................................... 4-1

4.3.1 Physical On-Site Inspection ............................................................................ 4-2

4.4 GRANT HOUSING AREA AND 37-MM IMPACT AREA LAND USE

CONTROL INSPECTION ............................................................................................ 4-2

5.0 REPORTING REQUIREMENTS .............................................................................................. 5-1

5.1 ANNUAL DATA REPORTS ....................................................................................... 5-1

5.2 ANALYTICAL REPORTS ............................................................................................ 5-1

5.2.1 Analytical Data Format ................................................................................... 5-1

5.2.2 Analytical Data Review ................................................................................... 5-2

5.2.3 Analytical Data Submission ........................................................................... 5-2

5.3 OTHER REPORTS......................................................................................................... 5-2

6.0 HEALTH AND SAFETY ........................................................................................................... 6-1

7.0 REFERENCES ............................................................................................................................. 7-1

LIST OF FIGURES

Figure 1.1a Site Location, Former Fort Devens Army Installation Figure 1.1b Site Location, Sudbury Annex Figure 1.2a Site Layout, Area of Contamination 57 - Area 2 Figure 1.2b Site Layout, Area of Contamination 57 - Area 3 Figure 1.3 Site Layout, Area of Contamination 69W Figure 1.4 Site Layout, Area of Contamination 43G Figure 1.5 Site Layout, Devens Consolidation Landfill Figure 1.6 Site Layout, Areas of Contamination 32 and 43A Figure 1.7 Site Layout, Grant Housing Area and 37-mm Impact Area Figure 1.8 Site Layout, South Post Impact Area Figure 1.9 Site Layout, South Post Impact Area – Area of Contamination 26, Zulu Ranges 1 and 2 Figure 1.10 Site Layout, South Post Impact Area - Area of Contamination 27, Hotel Range Figure 1.11 Site Layout, Area of Contamination A7

LIST OF TABLES

U.S. Army Corps of Engineers-New England District SO1002 iv

Table 3.1 Monitoring Wells, Well Points, Piezometers, Sumps, and Surface Water Locations Selected for Long-Term Monitoring

Table 3.2 AOC 57 - Spring LTM Sample Methods Table 3.3 AOC 69W - Fall LTM Sample Methods Table 3.4 AOC 43G - Fall LTM Sample Methods Table 3.5 DCL - LTM Sample Methods (Groundwater) Table 3.6 AOCs 32 and 43A - Spring LTM Sample Methods Table 3.7 SPIA - Fall LTM Sample Methods Table 3.8 Sudbury AOC A7 – Fall LTM Sample Methods Table 3.9 DCL - Fall LTM Sample Methods (Leachate Discharge) Table 3.10 MassDevelopment Industrial Wastewater Discharge Permit No. 017 Limitations Table 3.11 Sample Preparation and Analysis Methods, Containers, Holding Times and

Preservatives Table 3.12 Action Levels Table 3.13 Surface Water Quality Criteria Table 3.14 SPIA Groundwater Quality Comparison Values Table 3.15 Sampling and Analytical Summary, IDW Sampling and Disposal Table 4.1 ROD Objectives LUCs Table 5.1 Summary of Sampling and Reporting Requirements

LIST OF APPENDICES

Appendix A Optimization Evaluation for Long-Term Monitoring, and Maintenance Former

Fort Devens Army Installation and Sudbury Annex Appendix B Attainment Appendix C Surface Water and Sump Sampling Procedures Appendix D Groundwater Sampling Checklist Appendix E Groundwater Sampling Forms Appendix F USEPA Region 1 Low Stress (Low-Flow) Purging and Sampling Procedures Appendix G September 2007 Addendum for Real Property Master Plan Long Range

Component for Devens Reserve Forces Training Area Appendix H Annual Land Use Control Checklists Appendix I LandTec GEM-500 Calibration Procedure

LIST OF ACRONYMS AND ABBREVIATIONS

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AAFES Army Air Force Exchange Service ADR Automated Data Review AOC area of contamination Army U.S. Army ASTM American Society for Testing and Materials bgs below ground surface BRAC Base Realignment and Closure BTEX benzene, toluene, ethylbenzene, xylenes oC degree Celsius CCS Contract Compliance Screening CERCLA Comprehensive Environmental Response, Compensation and Liability

Act CFR Code of Federal Regulations CMR Code of Massachusetts Regulations COC contaminant of concern COD chemical oxygen demand

DCL Devens Consolidation Landfill Devens former Fort Devens Army Installation DO dissolved oxygen DoD Department of Defense DQCR Daily Quality Control Report DRFTA Devens Reserve Forces Training Area DRMO Defense Reutilization and Marketing Office

EDD electronic data deliverable EM Engineer Manual EOD explosive ordnance disposal EPH extractable petroleum hydrocarbons ESD Explanation of Significant Differences ESMA excavated soils management area

FS Feasibility Study FTP file transfer protocol

GPS Global Positioning System

HGL HydroGeoLogic, Inc.

HLA Harding Lawson Associates

ID identification IDW investigation-derived waste INRMP Integrated Natural Resources Management Plan ITRC Interstate Technology and Regulator Council

LIST OF ACRONYMS AND ABBREVIATIONS (continued)

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L/min liters per minute LEL lower explosive limit LCRS leachate collection and recovery system LCS laboratory control sample LNAPL light non-aqueous phase liquid LTM long-term monitoring LTMM long-term monitoring and maintenance LTMMP Long-Term Monitoring and Maintenance Plan LTMP Long-Term Monitoring Plan LUC Land-Use Control LUCIP Land-Use Control Implementation Plan µg/L milligrams per liter MAROS Monitoring and Remediation Optimization System MassDEP Massachusetts Department of Environmental Protection MCL maximum contaminant level MCP Massachusetts Contingency Plan mg/kg milligrams per kilogram MMCL Massachusetts Maximum Contaminant Level MS matrix spike MSD matrix spike duplicate MWPAR Massachusetts Wetlands Protection Act Regulations

NFA No Further Action NFG National Functional Guidelines NPL National Priorities List NTU nephelometric turbidity units

O&M operations and maintenance ORP oxidation-reduction potential OU Operable Unit

% Percent PARCCS precision, accuracy, representativeness, completeness, comparability, and sensitivity PCB polychlorinated biphenyls PCE tetrachloroethene PID photoionization detector PM Project Manager POL petroleum, oils, and lubricant PPE personal protective equipment PRG preliminary remediation goal

QA Quality Assurance QAPP Quality Assurance Project Plan QC Quality Control QSM Quality Systems Manual

LIST OF ACRONYMS AND ABBREVIATIONS (continued)

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RAO Remedial Action Objective RCRA Resource Conservation and Recovery Act RG remediation goal RI Remedial Investigation ROD record of decision

SA Study Area SEDD Staged Electronic Data Deliverable SI Site Investigation Sovereign Sovereign Consulting Inc.

SOW Statement of Work SPIA South Post Impact Area SPM South Post Monitoring SVE soil vapor extraction SVOC semi-volatile organic compound

TAL target analyte list TCE trichloroethene TCL target compound list TPH total petroleum hydrocarbons TSS total suspended solids

USACE U.S. Army Corps of Engineers USARC U.S. Army Reserve Command USEPA U.S. Environmental Protection Agency UXO unexploded ordnance

VOA volatile organic analyte VOC volatile organic compound VPH volatile petroleum hydrocarbons

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FINAL

LONG-TERM MONITORING AND MAINTENANCE PLAN

FORMER FORT DEVENS ARMY INSTALLATION

DEVENS, MASSACHUSETTS

SUDBURY ANNEX

SUDBURY, MASSACHUSETTS

1.0 INTRODUCTION

1.1 PURPOSE

The U.S. Army Corps of Engineers (USACE)-New England District contracted Sovereign Consulting Inc. (Sovereign) to conduct environmental remediation services required to meet the objectives of the Statement of Work (SOW) for Contract Number W912WJ-10-D-0003. Sovereign and their subcontractor, HydroGeoLogic, Inc. (HGL), hereinafter referred to as the Sovereign team, have prepared this Long-Term Monitoring and Maintenance Plan (LTMMP) to update the current long-term monitoring (LTM) approach for the seven Former Fort Devens Army Installation (Devens) sites and one Sudbury site identified in this LTMMP. The changes to the LTM approach are necessary to account for changes in a particular site’s contaminant distribution and progress towards achieving the goals stated in the site’s Record of Decision (ROD). This LTMMP combines the 2008 Devens Long-Term Monitoring Plan (LTMP) (HGL, 2008), and the 2009 Sudbury Annex LTMMP (HGL, 2009) with additional revisions and optimization recommendations. This combined LTMMP includes new contractor-specific information and site information such as building construction or changes in site use. In addition, well 26-10-09X was added to the LTM Program for the South Post Impact Area (SPIA) Area of Contamination (AOC) 26 as a downgradient sentry well and the SPIA AOC 26 section of the LTMMP was updated accordingly. This LTMMP also incorporates the requirement to perform Land Use Control (LUC) inspections at the former Grant Housing and 37-mm Impact Area located within the former Devens Main Post area. Future planned investigation work at SPIA site AOC 26 may require additional revisions to this LTMMP following the completion of field activities and evaluation of the investigation findings.

The LTM optimization recommendations provided in this revised LTMMP are derived from the recent optimization evaluation requested by the U. S. Army (Army) and performed for the Devens and Sudbury sites and presented as Appendix A to this LTMMP. The optimization was performed using quantitative and qualitative analyses of LTM data collected from 2009 through 2012 and appended to LTM data presented in the 2008 LTMP for the Main Post and SPIA AOCs and the 2009 LTMMP for the Sudbury Annex AOC. The 2008 and 2009 documents presented detailed qualitative analyses of data trends and provided recommendations for LTM optimization. Most of the optimization recommendations presented in the 2008 LTMP have been implemented. The 2009 through 2012 data were added to the previous LTM data set and evaluated to determine if additional optimization was warranted or if new trends were evident that potentially supported performing further optimization, including eliminating sites from the LTM program. The scope of the optimization did not involve detailed statistical analyses, additional risk assessments, or modeling of data to determine future trends; however, analyses

Sovereign and HGL—LTMMP— Former Fort Devens Army Installation and Sudbury Annex

SO1002 1-2

of select data using the Monitoring and Remediation Optimization System (MAROS) were performed to substantiate qualitative interpretations.

The optimization evaluation contains the details of the procedures and rationale used to determine what LTM optimization is appropriate for the Devens and Sudbury sites. This LTMMP revision presents the optimization recommendations determined during performance of the optimization evaluation and does not reproduce the in-depth discussions contained within the optimization report (Appendix A).

1.2 BACKGROUND

Devens is located in the towns of Ayer and Shirley in Middlesex County and Harvard and Lancaster in Worcester County, Massachusetts, approximately 35 miles northwest of Boston, Massachusetts. The installation occupied approximately 9,260 acres. Figures 1.1a and 1.1b provide site locations for the AOCs and other areas discussed in this section and the remainder of this LTMMP. Figures 1.2a through 1.11 provide individual site layout information for the AOCs and other areas discussed in this section and the remainder of this LTMMP. Prior to the official base closure, Devens was divided into the North Post, Main Post, and South Post. The South Post is generally referenced as the SPIA and consists of the portion of the South Post that encompasses the training ranges. The North Post is managed as a separate area and is not included within the scope of this LTMMP. Route 2 divides the South Post from the Main Post.

The Nashua River runs through the North, Main, and South Posts. The area surrounding Devens is largely rural residential property.

Devens was identified for cessation of operations and closure under Public Law 101-510, the Defense Base Realignment and Closure (BRAC) Act of 1990, and officially closed in March 1996.

As part of the Devens BRAC program, portions of the property formerly occupied by Fort Devens were retained by the U.S. Army (Army) for reserve forces training and renamed the Devens Reserve Forces Training Area (DRFTA). Areas not retained as part of DRFTA were, or are in the process of being, transferred to new owners for reuse and redevelopment.

The Sudbury Annex occupies approximately 4.3 square miles in the Massachusetts towns of Hudson, Marlborough, Maynard, Stow and Sudbury. Hudson Road divides the installation into a larger northern section, and a smaller southern section. The Sudbury Annex became part of Fort Devens, now the DRFTA, in 1982. The Sudbury Annex was removed from the National Priorities List (NPL) in January 2002. At that time, 2,205 acres were transferred to the U.S. Fish and Wildlife Service, 4.1 acres were transferred to the U.S. Air Force, and 71.4 acres were transferred to the Federal Emergency Response Agency. In June 2002, all known monitoring wells at the former annex were decommissioned except for those at the one AOC remaining in the long-term monitoring and maintenance (LTMM) program (AOC A7).

A more comprehensive discussion of the Devens and Sudbury background information is provided in Appendix A.

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1.2.1 Former Fort Devens Army Installation Main Post Site Summary

Detailed site information is provided in the Optimization Evaluation attached as Appendix A to this LTMMP. The following sections provide a summary of the sites:

AOC 57: Located between Barnum Road and Cold Spring Brook on the northeast side of what was formerly the Main Post of Devens (Figure 1.1a) and what was used primarily as a storage and maintenance area for military vehicles. The main portion of the site is a former solar panel manufacturing facility. The active portions of AOC 57 consist of Area 2 and Area 3, as depicted on Figures 1.2a and 1.2b, respectively.

AOC 69W: Located at the northeast corner of the intersection of Jackson Road and Antietam Street on the northern portion of what was formerly the Main Post at Devens (Figure 1.1a). AOC 69W consists of the former Devens Elementary School (Building 215) and its associated parking lot and adjacent lawn, extending approximately 300 ft northwest to Willow Brook. The layout of AOC 69W is depicted on Figure 1.3.

AOC 43G: Located in the central portion of the former main post of Devens and consists of the former Army Air Force Exchange Service (AAFES) gas station and historical post gas station. This AOC remains entirely within the Army Garrison property. The layout of AOC 43G is depicted on Figure 1.4.

Devens Consolidation Landfill (DCL): Located in the former Main Post of Devens and constructed at the location of the former golf course driving range between 2000 and 2002 to provide an on-site landfill for debris from six individual remedial areas. DCL is depicted on Figure 1.5.

AOCs 32 and 43A: AOCs 32 and 43A were known as the Defense Reutilization and Marketing Office (DRMO) Yard, and the petroleum, oils and lubricant (POL) storage areas, respectively. AOC 32 consisted of three fenced areas (DRMO west yard, DRMO east yard, and tire recycling area) along Cook Street. AOC 43A was located across Market Street from AOC 32. AOC 43A consisted of a fenced lot located within an industrial area and served as the distribution point for all gasoline and other fuels at Devens from the 1940s to 1996. AOCs 32 and 43A are depicted on Figure 1.6.

Former Grant Housing and 37-mm Impact Area: Between 1917 and the 1930’s, the Grant Housing Area and 37-mm Impact Area (Figure 1.7) were used by the Army as a firing range. From the 1960’s until closure of Fort Devens in March 1996, the Grant Housing Area was used for military housing. The housing area has since been demolished and the area is currently vacant. Former infrastructure, including roadways and partial utilities remain in place.

1.2.2 Former Fort Devens Army Installation South Post Impact Area Site Summary

SPIA: Located in the area known as the South Post of former Fort Devens (Figure 1.8).

The SPIA is a 964-acre area that was historically used for small firearms and grenade training and also for open burning and detonation of explosives. SPIA is currently an active weapons and ordnance discharge area that is used by the Army, U.S. Army Reserve Command (USARC), the National Guard, and local, state, and federal law enforcement agencies. SPIA AOCs addressed in this LTMMP include AOCs 25, 26, 27, SO1002 1-4 and 41. AOC 25 is known as the Explosive Ordnance Disposal (EOD) Range. AOC 26 is known as Zulu Range and includes the Zulu 1 and Zulu 2 ranges. AOC 27 is known as the Hotel Range. AOC 41 is a former general waste disposal area. AOCs 25 and 41 are not actively monitored under the LTM program. AOCs 25 and 41 are shown on Figure

1.8 and AOCs 26 and 27 are depicted on Figures 1.9 and 1.10, respectively.

1.2.3 Former Sudbury Annex Site Summary

Sudbury Annex: AOC A7 is located at the former Sudbury Training Annex in Sudbury, Massachusetts (Figure 1.1b). Site AOC A7 is the only site remaining at the Sudbury Annex that requires environmental monitoring and is depicted on Figure 1.11. AOC A7 is a former waste disposal site in the northern portion of the former training annex. A Resource Conservation and Recovery Act (RCRA) Subtitle C landfill cap was installed in 1996.

1.3 ROD OBJECTIVES AND SELECTED REMEDY

The LTMMP strategies implemented at the Devens and Sudbury sites are driven by each site’s ROD requirements. In general, the objectives of the long-term groundwater monitoring and maintenance program at the Devens and Sudbury sites are to monitor groundwater conditions, monitor for potential off-site contaminant migration, and to document that concentrations of the contaminants of concern (COC) decrease over time to a level that eventually achieves the objectives stated in the particular site’s ROD. The following sections provide a summary of the individual site ROD remedial action objectives (RAO) and their remedy. The RAOs are site-specific, quantitative goals defining the extent of cleanup required to achieve response objectives. The RAOs are formulated to achieve the overall U.S. Environmental Protection Agency (USEPA) goal of protecting human health and the environment. A description of current site LTMM activities is provided in Section 2.

1.3.1 AOC 57

The ROD for AOC 57 was approved in 2001. Per the ROD, the site-specific RAOs defining the extent of clean up at AOC 57 are as follows:

Area 2 – Wetland (aka Flood Plain)

Protect potential construction workers that might work with future recreational (wetlands) areas at Area 2 from ingesting soils containing Aroclor-1260 and lead in excess of preliminary remediation goal (PRG) concentrations considered protective of human health (3.5 and 600 milligrams per kilogram [mg/kg], respectively).

Prevent potential residential receptors from coming in dermal contact with and ingesting Area 2 wetland soils containing Aroclor-1260, arsenic, chromium, lead, and the extractable petroleum hydrocarbons (EPH) C11-C22 aromatic carbon range in excess of PRG concentrations considered protective of human health (0.5, 21, 550, 400, and 930 mg/kg, respectively).

Prevent unrestricted potable use of Area 2 wetland groundwater containing arsenic, tetrachloroethene (PCE) in concentrations that exceed Federal maximum contaminant level (MCL)/Massachusetts Maximum Contaminant Level (MMCL) drinking water standards (50 and 5 µg/L, respectively).

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Area 3 – Upland

Protect potential future commercial/industrial receptors from ingesting upland Area 3 groundwater that contains arsenic, cadmium, and 1,4-dichlorobenzene at concentrations that exceed MCLs and MMCLs for drinking water.

Prevent unrestricted residential potable use of Area 3 groundwater containing arsenic, cadmium, and 1,4-dichlorobenzene at concentrations that exceed MCLs and MMCLs for drinking water.

Area 3 – Wetland (aka Flood Plain)

Prevent unrestricted use residential receptors from coming in dermal contact and ingestion of surface soils containing the EPH C11-C12 aromatic carbon range at concentrations in excess of PRGs considered protective of human health.

Prevent unrestricted residential potable use of Area 3 floodplain groundwater containing arsenic and PCE at concentrations that exceed MCLs and MMCLs for drinking water

(USACE, 2001)

The ROD remedy selected for Areas 2 and 3 consisted of soil excavation and treatment/disposal at an off-site treatment, storage, or disposal facility, Wetlands Protection, Land Use Controls, Environmental Monitoring, LUC Inspections and Five-year Site Reviews (USACE, 2001). The LUCs consist of continued zoning that prohibits residential use of the Area 2 property and deed restrictions that prohibit potable use of Area 2 and 3 groundwater and residential use of the property. The intent of the ROD was primarily to address petroleum contaminated soils and groundwater. The ROD indicates that groundwater and surface water monitoring is a relevant and appropriate response to confirm that COCs are decreasing, the potential for off-site migration via the groundwater to surface water discharge pathway is evaluated, and that Federal MCL and Massachusetts groundwater quality standards are met.

In March 2004, the USACE published an Explanation of Significant Differences (ESD) for AOC

57. The ESD resulted from data collected during soil excavation activities at Area 2. The changes to the selected remedy for Area 2 were:

Increased volume and cost of contaminated soil requiring removal to attain cleanup levels at Area 2;

Inclusion of EPH as a COC for soil at Area 2; and

Inclusion of EPH and polychlorinated biphenyls (PCB) as COCs for Area 2 groundwater.

The original ROD established risk-based cleanup levels for Area 2 at AOC 57 for the PCBs, Aroclor-1260, and lead. Concerns about the persistent separate phase petroleum waste observed during removal and investigation work in 2002-2003 resulted in the addition of C11-C22 aromatic hydrocarbons quantified by EPH (MassDEP EPH Method) as a COC. As a result of the addition of C11-C12 as a COC, the ROD adopted the more stringent S3/GW-1 cleanup level of 200 mg/kg EPH C11-C22 aromatic fraction for Area 2 soils. Subsequently, PCBs were added as a COC because of their association with the petroleum waste oil.

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1.3.2 AOC 69W

The ROD for AOC 69W was signed on June 30, 1999. Per the ROD, the site-specific RAOs defining the extent of cleanup at AOC 69W are as follows:

Restore the aquifer to drinking water standards within a reasonable period;

Monitor potential future migration of groundwater contamination;

Eliminate risk from potential consumption of groundwater; and

Reduce or eliminate the direct contact threat of contaminated soils.

The basis of the RAOs is the potential health risks to individuals based on current and future use scenarios at the site (maintenance worker, school children, etc.) (Harding Lawson Associates

[HLA], 1999).

“Limited Action” was the selected remedy for AOC 69W groundwater and subsurface soils based on the risk assessment results estimating cancer and non-cancer risks associated with the current and future exposure, which were all within acceptable levels. The intent of the ROD was primarily to address soils and groundwater contaminated with fuel oil. To meet Federal MCLs and Massachusetts Drinking Water Regulations 310 Code of Massachusetts Regulations (CMR) 22, the ROD specifies that two actions are to be undertaken. First, long-term groundwater monitoring is to be applied to ensure that contaminants do not migrate off-site, and second, LUCs are to be implemented to prohibit the installation of drinking water wells and prevent exposure. These actions are also qualified by the statement “In addition, arsenic concentrations are expected to decrease following the soil removal which eliminated the source.” According to the ROD, the LTM program was implemented to ensure that contaminants do not migrate off-site, rather than demonstrate that cleanup goals are met.

Additional key components of the Limited Action Remedy, as detailed in the ROD, included development of a Long-Term Groundwater Monitoring Plan and conducting 5-year reviews.

1.3.3 AOC 43G

The ROD for AOC 43G was signed in 1996. Per the ROD, the site-specific RAOs defining the extent of clean up at AOC 43G are as follows:

Protect potential commercial/industrial receptors located on Devens property from exposure to groundwater having chemicals in excess of the following remedial goals (RG): iron (9,100 µg/L), manganese (291 µg/L), nickel (100 µg/L), benzene (5 µg/L), ethylbenzene (700 µg/L), and xylenes (10,000 µg/L).

Protect potential commercial/industrial receptors located off Devens property from exposure to groundwater having chemicals in excess of the above RGs.

Prevent contaminated groundwater having chemicals in excess of RGs from migrating off Army property.

The RGs for benzene, ethylbenzene, xylenes, and nickel are the MCLs and MMCLs in effect at the time. The RGs for iron and manganese are Devens background concentrations, because

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background concentrations exceeded the risk-based concentrations derived from available RfD values at the time of the Remedial Investigation (RI)/Feasibility Study (FS).

The risk assessments did not identify potential risks from exposure to surface soil or subsurface soil, and ambient air monitoring during the RI did not identify airborne contaminants (USACE, 1996).

The ROD documented the selection of intrinsic remediation with LTM as the selected remedy (USACE, 1996). The major components of the selected remedy included intrinsic bioremediation, intrinsic bioremediation assessment data collection and groundwater modeling, installing additional monitoring wells, long-term groundwater monitoring, annual data reports to USEPA and MassDEP, and 5-year site reviews. Intrinsic bioremediation is the principal component proposed to prevent COCs that exceed groundwater cleanup levels from potentially migrating off Army property. The ROD stated that the minimum cleanup criteria will meet drinking water standards. The ROD specifies that if the intrinsic bioremediation assessment results indicate that (1) the groundwater contaminant plume increases in size on Army property, and/or (2) the groundwater contaminant plume remains the same size, but cannot be remediated within 30 years, then a soil vapor extraction (SVE) system will be installed at the existing AOC 43G source area. Furthermore, if at any time during this remedy there is an indication that contaminants are migrating off Army property above drinking water standards (MCLs/MMCL or risk-based concentration [i.e., groundwater cleanup levels]); and/or if the five-year review indicates that the intrinsic remediation alternative is not protective of human health, the Army will implement an additional cleanup action to protect human health and the environment as required under Comprehensive Environmental Response, Compensation and Liability Act (CERCLA).

1.3.4 Devens Consolidation Landfill

The USEPA approved the ROD for DCL sites in July 1999. Per the ROD, the following RAOs were developed to mitigate existing and future potential threats to human health and the environment:

Prevent human exposure to groundwater contaminants released from Devens landfills that exceed acceptable risk thresholds.

Protect human and ecological receptors from exposure to landfills soils having concentrations of contaminants exceeding acceptable risk thresholds.

Prevent landfill contaminant releases to surface water that result in exceedance of ambient water quality criteria or acceptable ecological risk-based thresholds.

Prevent exposure by ecological receptors to landfill-contaminated sediments exceeding acceptable risk-based thresholds.

Reduce adverse impacts from contaminated landfill media to the environment that would reduce the amount of land area available for natural resource use.

Support the civilian redevelopment effort at Devens (USACE, 1999).

The approved remedial alternative documented in the ROD called for No Further Action (NFA) at Study Area (SA) 6, limited removal at SA 12 and AOC 41, and full excavation of AOCs 9, 11, SO1002 1-8 and 40, and SA 13, with on-site consolidation or off-site disposal. The on-site landfill construction alternative was selected as the best value for the DCL contributor sites. The ROD included recommendations for cover system monitoring and maintenance consisting of annual site inspections, mowing of vegetation on the landfill cap, and additional cap inspections and/or maintenance resulting from severe weather events. The ROD also required the collection of samples from groundwater monitoring wells in accordance with 310 CMR 19.132 and the performance of five-year reviews to assess the effectiveness of the remedy.

Post-closure monitoring of the DCL is required for a minimum period of 30 years according to Massachusetts Solid Waste Management Regulations (310 CMR 19.142). However, per 310 CMR 19.142, the post-closure period waiver states that upon request a reduction in the post-closure monitoring period can be obtained if sufficient evidence is reviewed by the Massachusetts Department of Environmental Protection (MassDEP). The review will consist of, but is not limited to, a consideration of the quantity and quality of leachate generated by the landfill, ground water monitoring results, characteristics of the waste disposed, stability of the waste, design of the facility, and location of the site. If the information presented in the demonstration report or tech memo concludes that the site continues to protect public health, safety, and the environment, then a shorter period of monitoring can be implemented. Furthermore, Code of Federal Regulations (CFR) 258.61 states that post-closure monitoring can be decreased by the Director of an approved State if the owner or operator demonstrates that the reduced period is sufficient to protect human health and the environment

1.3.5 AOC 32 and 43A

The ROD for AOC 32 and 43A was signed in 1998. Per the ROD, the site-specific RAOs defining the extent of cleanup of both surface and subsurface soils, as well as, groundwater at AOC 32 and 43A are as follows:

The RAOs for surface and subsurface soils were:

Prevent direct and indirect contact, ingestion, and inhalation of the soil contaminated with COCs at levels that could pose risks to human and ecological receptors.

Prevent erosion and migration of soil contaminated with COCs to storm sewers and surface water bodies.

Prevent COC migration to the groundwater at levels that could adversely affect human health and the environment.

The RAOs for groundwater included the following:

Prevent off-site migration of COCs at levels that could adversely affect flora and fauna.

Prevent lateral and vertical migration of COCs at levels that could adversely affect potential and existing drinking water supply aquifers.

Prevent seepage of groundwater from AOC 32 and 43A that could result in surface water concentrations in excess of ambient water quality standards (Horne, 1998).

The ROD detailed remedies for both soil and groundwater. The selected ROD soil remedial alternative is excavation and off-site disposal. The major components of this selected remedy

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include “excavating contaminated soil, immediately transporting soils to an off-site, nonhazardous landfill for disposal, backfilling the excavated area with clean material and revegatating the area, monitoring groundwater on an annual basis and reviewing the site every 5 years for 30 years until contamination is reduced to acceptable concentrations”. The selected ROD groundwater remedial alternative is “monitored natural attenuation”. The major components of the selected groundwater remedy include establishing land use controls, “installing additional monitoring wells, providing for monitored natural attenuation, collecting data on monitored natural attenuation, assessing the data, and performing groundwater modeling, performing long-term monitoring on an annual basis, reviewing the site every 5 years for 30 years or until contamination is reduced to acceptable concentrations and providing reports to USEPA and MassDEP”.

The ROD for AOCs 32 and 43A specifies that MCLs are the groundwater cleanup goals at the site. The MCLs are consistent with Federal MCLs and State of Massachusetts GW-1 standards that are included in the Massachusetts Contingency Plan (MCP).

1.3.6 Grant Housing and 37-mm Impact Area

The ROD for the Grant Housing Area and 37-mm Impact Area was signed in September 2009.

Per the ROD, the site-specific RAO is to prevent direct contact with unexploded ordnance (UXO) that may remain in the soil at the sites.

The selected remedy for both the Housing Area and 37-mm impact area is the implementation of LUCs. The LUCs provide a blueprint for how the property should be used in order to maintain the level of protectiveness intended by the remedial alternative. The LUCs for Grant Housing Area include: (1) public education to property owners, residents, as well as any construction and/or utility contractors conducting ground intrusive activities on the property.

The intent is to provide education on the potential presence of UXO, how to identify UXO, and what actions to take if suspect UXO is encountered; and (2) a deed notice will be inserted by MassDevelopment into any Grant Housing Area deeds stating that the property with the LUCs is suitable for proposed future us, that there is no evidence of additional UXO present at the site, but that the possibility does remain that UXO could be discovered in the future. On an annual basis, the Army will also conduct annual reviews to confirm the overall effectiveness and compliance with the established LUCs (Weston, 2009). The LUCs are addressed in a Land Use Control Implementation Plan (LUCIP) that was developed following approval of the ROD.

Both sites have a residual UXO risk due to their previous use as a firing range. There is no environmental sampling or monitoring activities associated with these sites. The LUCIP requirement to provide access restriction by placing a fence around the former 37-mm Impact Area and associated signage was accomplished in 2012. Additional LUC requirements are presented in Section 4 of this LTMMP.

1.3.7 South Post Impact Area

The ROD for the SPIA sites was signed in July 1996 documenting “No Action” as the final selected remedy for the SPIA monitored-area and AOC 41 groundwater. “No Action” is also the selected remedy for surface water, soil, and sediment at the EOD, Zulu, and Hotel Ranges.

Under the “No Action” remedy, no formal remedial action is taken and the site is considered to

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be left “as is,” with no additional institutional controls, containment, removal, treatment or other mitigating measures. Because “No Action” was selected and approved as the remedy, a FS was not performed and RAOs were not developed.

As part of the remedy, Fort Devens ensures the following in the ROD:

Groundwater monitoring for potential contaminant migration out of the SPIA monitored-area will continue: (1) Monitoring wells will be used to monitor the groundwater from the EOD Range, Zulu Ranges, Hotel Range, and AOC 41; (2) Monitoring wells will be used to monitor the north, northeast, southeast, and east sides of the SPIA monitored-area.

Monitoring wells will be sampled for explosives, target compound list (TCL) organics, and target analyte list (TAL) metals.

A groundwater monitoring plan for the South Post will be developed that will include detailed groundwater monitoring at discharge points. The plan may include installation of additional monitoring wells to monitor for off-site groundwater flow.

Well D-1 will be sampled and samples will be analyzed for explosives and Massachusetts and federal drinking water requirements (MMCLs/MCLs).

The Army will not develop new drinking water sources within the SPIA monitored area.

An Integrated Natural Resource Management Plan (INRMP) will be developed and implemented to monitor adverse effects on the ecosystem in the SPIA monitored area.

Monitoring reports will include a description of site activities and a summary of analytical results. The Army will submit these reports annually. If there is an indication of contamination emanating from the SPIA monitored-area, the Army will evaluate the need for additional assessment.

As required by CERCLA, the site will be subject to five-year reviews to assess if the No Action remedy remains protective of human health and the environment (Horne, 1996).

The groundwater analytical results at SPIA are compared to the MCP GW-1 and GW-3 standards for comparison purposes only, as the criteria are not considered “clean-up” standards under a “No Action” ROD.

1.3.8 Sudbury Annex

The ROD for the Source Control of the Operable Unit (OU) at AOC A7 was signed in September 1995 and the ROD for Management of Migration was signed in September 1997. Per the ROD, the following RAOs were developed to mitigate existing and future potential threats to public health and the environment:

Eliminate potential risk to human health and the environment associated with exposure to contaminated wastes;

Minimize off-site migration of contaminants; and, Limit infiltration of precipitation to the underlying waste within the landfill area, thereby minimizing leachate generation and groundwater degradation (OHM, 1995).

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The remedy selection for the source control OU for AOC A7 was the installation of an impermeable landfill cover system that met RCRA Subtitle C requirements. The landfill remedy also included the following:

removal and off-site disposal of chemical waste debris in the laboratory dump area;

operations and maintenance (O&M);

LUCs and land use restrictions to limit future use of land at AOC A7;

long-term groundwater monitoring; and five-year reviews to assess whether the remedy remains protective of human health and the environment.

A remedy was also selected by the Army to create a wetland at AOC A7 in the fall of 1996 to replace “Wetland B”, a seasonal wetland that is now incorporated as part of the…