KGS 2020a Area 1 PSCS for PFAS.pdf

JUNE 2020

Prepared for:

U.S. Army Corps of Engineers

New England District Concord, Massachusetts

Prepared by:

KOMAN Government Solutions, LLC

293 Boston Post Road West, Suite 100 Marlborough, MA 01752

Contract No.: W912WJ-18-C-0011

AREA 1 PRELIMINARY SITE CHARACTERIZATION

SUMMARY

PER- AND POLYFLUOROALKYL SUBSTANCES

(PFAS) REMEDIAL INVESTIGATION

FORMER FORT DEVENS ARMY INSTALLATION, DEVENS, MA

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-18-C- 0011. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.

Area 1 Preliminary Site Characterization Summary

Per- and Polyfluoroalkyl Substances (PFAS) Remedial Investigation

Former Fort Devens Army Installation

Devens, Massachusetts

June 2020

CERTIFICATION:

I hereby certify that the enclosed Report, shown and marked in this submittal, is that proposed to be incorporated with Contract Number W912WJ-18-C-0011. This document was prepared in accordance with the U.S. Army Corps of Engineers (USACE) Scope of Work and is hereby submitted for Government approval.

Reviewed By:

06/03/2020

KGS Project Manager Date

Received By:

USACE Project Manager Date

TABLE OF CONTENTS

Section Page i June 2020

1.0 INTRODUCTION ...................................................................................................................... 1-1 INVESTIGATION APPROACH ................................................................................. 1-1 REPORT ORGANIZATION ........................................................................................ 1-2

2.0 FORMER FORT DEVENS SITE LOCATION AND DESCRIPTION .................................. 2-1 PHYSICAL CHARACTERISTICS ............................................................................... 2-1 GEOLOGY ..................................................................................................................... 2-1 REGIONAL HYDROGEOLOGY ................................................................................ 2-3

3.0 AOC 57 PRELIMINARY SITE CHARACTERIZATION SUMMARY ................................ 3-1 SITE DESCRIPTION ..................................................................................................... 3-1 FACILITY HISTORY AND UTILITIES ...................................................................... 3-1 REMEDIAL STATUS .................................................................................................... 3-2 PFAS FIELD INVESTIGATION .................................................................................. 3-2

Existing Wells ................................................................................................... 3-3 Surface Water and Sediment .......................................................................... 3-3 DPT Vertical Profiles ....................................................................................... 3-3 DPT Soil Borings .............................................................................................. 3-4 Monitoring Well Installation and Vertical Profiling with Sonic ............... 3-5 Synoptic Water Level Surveys ....................................................................... 3-5

NATURE AND EXTENT ............................................................................................. 3-5 Groundwater .................................................................................................... 3-5 Soil ............................................................................................................... 3-7 Surface Water and Sediment .......................................................................... 3-8

4.0 AOC 74 PRELIMINARY SITE CHARACTERIZATION SUMMARY ................................ 4-1 SITE DESCRIPTION ..................................................................................................... 4-1 FACILITY HISTORY AND UTILITIES ...................................................................... 4-1 PFAS FIELD INVESTIGATION .................................................................................. 4-1

Irrigation Well .................................................................................................. 4-1 Surface Water and Sediment .......................................................................... 4-2 DPT Vertical Profiles ....................................................................................... 4-2 Soil Borings ....................................................................................................... 4-3 Monitoring Wells and Piezometers ............................................................... 4-3 Synoptic Water Level Event ........................................................................... 4-3

NATURE AND EXTENT ............................................................................................. 4-3 Groundwater in Overburden ......................................................................... 4-3 Groundwater in Bedrock ................................................................................ 4-5 Soil ............................................................................................................... 4-5 Surface Water and Sediment .......................................................................... 4-5

5.0 AOC 75 PRELIMINARY SITE CHARACTERIZATION SUMMARY ................................ 5-1 SITE DESCRIPTION ..................................................................................................... 5-1 SITE HISTORY AND UTILITIES ................................................................................ 5-1 AOC 75 FIELD INVESTIGATION .............................................................................. 5-2

DPT Vertical Profiles ....................................................................................... 5-2 DPT Soil Borings .............................................................................................. 5-3 ii June 2020

Monitoring Well, Piezometer Installation and Vertical Profiling with Sonic ............................................................................................................... 5-3

Synoptic Water Level Event ........................................................................... 5-4 Surface Water and Sediment Sampling ........................................................ 5-4

NATURE AND EXTENT ............................................................................................. 5-4 Groundwater in Overburden ......................................................................... 5-4 Groundwater in Bedrock ................................................................................ 5-5 Soil ............................................................................................................... 5-5 Surface Water and Sediment .......................................................................... 5-6

6.0 GROVE POND AREA PRELIMINARY SITE CHARACTERIZATION SUMMARY ....... 6-1

SITE DESCRIPTION ..................................................................................................... 6-1 FACILITY HISTORY AND UTILITIES ...................................................................... 6-1 REMEDIAL STATUS .................................................................................................... 6-1 PFAS FIELD INVESTIGATION .................................................................................. 6-2

Existing Wells ................................................................................................... 6-2 Surface Water and Sediment .......................................................................... 6-2 DPT Vertical Profiles ....................................................................................... 6-2 DPT Soil Borings .............................................................................................. 6-3 Monitoring Well, Piezometer Installation and Vertical Profiling with

Sonic ............................................................................................................... 6-3 Synoptic Water Level Surveys ....................................................................... 6-3

NATURE AND EXTENT ............................................................................................. 6-3 Groundwater in Overburden ......................................................................... 6-3 Groundwater in Bedrock ................................................................................ 6-5 Soil ............................................................................................................... 6-5 Surface Water and Sediment .......................................................................... 6-5

7.0 PATTON WATER SUPPLY WELL AREA AND AOC 40 PRELIMINARY SITE

CHARACTERIZATION SUMMARY...................................................................................... 7-1

SITE DESCRIPTION ..................................................................................................... 7-1 FACILITY HISTORY AND UTILITIES ...................................................................... 7-1 REMEDIAL STATUS .................................................................................................... 7-1 PFAS FIELD INVESTIGATION .................................................................................. 7-2

DPT Vertical Profiles ....................................................................................... 7-2 DPT Soil Borings .............................................................................................. 7-2 Piezometer and Staff Gauge Installation ...................................................... 7-2 Synoptic Water Level Surveys ....................................................................... 7-3 Surface Water and Sediment .......................................................................... 7-3 Irrigation Well Sampling ................................................................................ 7-3

NATURE AND EXTENT ............................................................................................. 7-3 Groundwater .................................................................................................... 7-3 Soil ............................................................................................................... 7-4 Surface Water and Sediment .......................................................................... 7-4

8.0 SHABOKIN WATER SUPPLY WELL AREA PRELIMINARY SITE

CHARACTERIZATION SUMMARY...................................................................................... 8-1 iii June 2020

SITE DESCRIPTION ..................................................................................................... 8-1 FACILITY HISTORY AND UTILITIES ...................................................................... 8-1 REMEDIAL STATUS .................................................................................................... 8-1 PFAS FIELD INVESTIGATION .................................................................................. 8-1

DPT Vertical Profiles ....................................................................................... 8-1 Piezometers and Monitoring Well ................................................................. 8-2 Synoptic Water Level Survey ......................................................................... 8-2

NATURE AND EXTENT ............................................................................................. 8-2 Groundwater .................................................................................................... 8-2

9.0 AOC 43J PRELIMINARY SITE CHARACTERIZATION SUMMARY ............................... 9-1 SITE DESCRIPTION ..................................................................................................... 9-1 FACILITY HISTORY AND UTILITIES ...................................................................... 9-1 REMEDIAL STATUS .................................................................................................... 9-1 PFAS FIELD INVESTIGATION .................................................................................. 9-2

Existing Wells ................................................................................................... 9-2 NATURE AND EXTENT ............................................................................................. 9-2

Groundwater .................................................................................................... 9-3

10.0 REFERENCES ........................................................................................................................... 10-1 iv June 2020

TABLES

Table 1-1 Select PFAS criteria

Table 2-1 Bedrock Elevations Table 2-2 Synoptic Water Level Event Grove Pond Area, October 2, 2018 Table 2-3 Synoptic Water Level Event AOC 74/Grove Pond Area March 19, 2019 Table 2-4 Synoptic Water Level Event Patton Well Area/AOC 40 January 2-3, 2020 Table 2-5 Synoptic Water Level Event Area 1, March 12-13, 2020 Table 2-6 Vertical Groundwater Gradients

Table 3-1 AOC 57 Field Activities Table 3-2 AOC 57 Summary of PFAS Exceedances from Vertical Profile Samples Table 3-3 AOC 57 Summary of PFAS Exceedances from Monitoring Wells

Table 4-1 AOC 74 Field Activities Table 4-2 AOC 74 Summary of PFAS Exceedances from Vertical Profile Samples Table 4-3 AOC 74 Summary of PFAS Exceedances from Monitoring Wells

Table 5-1 AOC 75 Field Activities Table 5-2 AOC 75 Summary of PFAS Exceedances from Vertical Profile Samples Table 5-3 AOC 75 Summary of PFAS Exceedances from Monitoring Wells in Overburden

Table 6-1 Grove Pond Area Field Activities Table 6-2 Grove Pond Area Summary of PFAS Exceedances from Vertical Profile Samples Table 6-3 Grove Pond Area Summary of PFAS Exceedances from Monitoring Wells in

Overburden

Table 7-1 Patton Well Area/AOC 40 Field Activities Table 7-2 Patton Well Area/AOC 40 Summary of PFAS Exceedances from Vertical Profile

Samples

Table 8-1 Shabokin Well Area Field Activities Table 8-2 Shabokin Well Area Summary of PFAS Exceedances from Vertical Profile Samples Table 8-3 Shabokin Well Area Summary of PFAS Exceedances from Monitoring Wells

Table 9-1 AOC 43J Area Field Activities Table 9-2 AOC 43J Summary of PFAS Exceedances from Monitoring Wells

FIGURES

Figure 1-1 Devens PFS Remedial Investigation Areas

Figure 2-1 Nashua River Watershed Figure 2-2 Surface Water Bodies Figure 2-3 USGS Overburden Geology Figure 2-4 Bedrock Geology Figure 2-5 Bedrock Contours v June 2020

Figure 2-6 Groundwater Elevation Contours Grove Pond Area, October 2, 2018 Figure 2-7 Groundwater Elevation Contours AOC 74/Grove Pond Area, March 19, 2019 Figure 2-8 Groundwater Elevation Contours Patton Well Area/AOC 40, January 2-3, 2020 Figure 2-9 Groundwater Elevation Contours Area 1, March 12-13, 2020 Figure 2-10 Groundwater Elevation Contours AOC 74/Grove Pond Area, March 12-13, 2020 Figure 2-11 Groundwater Elevation Contours AOC 75, March 12-13, 2020 Figure 2-12 Shallow Water Table Elevation Area of Contamination 57 – Area 2 March 2020 Figure 2-13 Deep Water Table Elevation Area of Contamination 57 – Area 2 March 2020 Figure 2-14 Shallow Water Table Elevation Area of Contamination 57 – Area 3 March 2020 Figure 2-15 Deep Water Table Elevation Area of Contamination 57 – Area 3 March 2020 Figure 2-16 Devens Groundwater

Figure 3-1 AOC 57 1992 Aerial Imagery Figure 3-2 AOC 57 Area Historic Subsurface Features Figure 3-3 AOC 57 Area Current Subsurface Features Figure 3-4 AOC 57 Field Activities Figure 3-5 AOC 57 Area 2 Field Activities Figure 3-6 AOC 57 Area 3 Field Activities Figure 3-7 AOC 57 Groundwater Results Figure 3-8 AOC 57 Area 2 Groundwater Results Figure 3-9 AOC 57 Area 3 Groundwater Results Figure 3-10 AOC 57 Cross Section Location Map Figure 3-11 AOC 57 Cross Section A-A’ Figure 3-12 AOC 57 Cross Section B-B’ Figure 3-13 AOC 57 Cross Section C-C’ Figure 3-14 AOC 57 Area 2 Soil Results Figure 3-15 AOC 57 Area 3 Soil Results Figure 3-16 Northern Extent Cold Spring Brook PFAS Results in Surface Water and Sediment

Samples

Figure 4-1 Grove Pond Area/AOC 74 1992 Aerial Imagery Figure 4-2 Grove Pond and AOC 74 Area Historic Subsurface Features Figure 4-3 Grove Pond and AOC 74 Area Current Subsurface Features Figure 4-4 AOC 74 Field Activities Figure 4-5 AOC 74 Groundwater Results Figure 4-6 AOC 74 Cross Section Location Map Figure 4-7 AOC 74 Cross Section A-A’ Figure 4-8 AOC 74 Cross Section B-B’ Figure 4-9 AOC 74 Area Soil Results

Figure 5-1 AOC 75 1992 Aerial Imagery Figure 5-2 AOC 75 Area Historic Subsurface Features Figure 5-3 AOC 75 Area Current Subsurface Features Figure 5-4 AOC 75 Field Activities Figure 5-5 AOC 75 Groundwater Results Figure 5-6 AOC 75 Cross Section Location Map vi June 2020

Figure 5-7 AOC 75 Cross Section A-A’ Figure 5-8 AOC 75 Cross Section B-B’ Figure 5-9 AOC 75 Cross Section C-C’ Figure 5-10 AOC 75 Soil Results

Figure 6-1 Grove Pond Area Field Activities Figure 6-2 Grove Pond Area Groundwater Results Figure 6-3 Grove Pond Area Cross Section Locations Figure 6-4 Grove Pond Area Cross Section A-A’ Figure 6-5 Grove Pond Area Cross Section B-B’ Figure 6-6 Grove Pond Area Cross Section C-C’ Figure 6-7 Grove Pond Area Cross Section D-D’ Figure 6-8 Grove Pond Area Soil Results Figure 6-9 Grove Pond and Balch Pond PFAS Results in Surface Water and Sediment Samples

Figure 7-1 Patton Well Area/AOC 40 1992 Aerial Imagery Figure 7-2 Patton Well Area/AOC 40 Historic Subsurface Features Figure 7-3 Patton Well Area/AOC 40 Current Subsurface Features Figure 7-4 Patton Well Area/AOC 40 Field Activities Figure 7-5 Patton Well Area/AOC 40 Groundwater Results Figure 7-6 Patton Well Area/AOC 40 Cross Section Location Map Figure 7-7 Patton/AOC 40 Cross Section A-A’ Figure 7-8 Patton Well Area/AOC 40 Soil Results Figure 7-9 Southern Extent Cold Spring Brook, Cold Spring Brook Pond, and Mirror Lake

PFAS Results in Surface Water and Sediment Samples

Figure 8-1 Shabokin Well Area and AOC 43J 1992 Aerial Imagery Figure 8-2 Shabokin Well Area and AOC 43J Historic Subsurface Features Figure 8-3 Shabokin Well Area and AOC 43J Current Subsurface Features Figure 8-4 Shabokin Well Area Field Activities Figure 8-5 Shabokin Well Area Groundwater Results Figure 8-6 Shabokin Well Area Cross Section Location Map Figure 8-7 Shabokin Well Area Cross Section A-A’ Figure 8-8 Shabokin Well Area Cross Section B-B’

Figure 9-1 AOC 43J Site Layout Figure 9-2 AOC 43J Groundwater Results

Plate 1 Sample Locations Plate2 Groundwater Results

APPENDICES

Appendix A Monitoring Well Field Sheets Appendix B Synoptic Water Level Event Field Sheets Appendix C Surface Water and Sediment Field Sheets Appendix D Vertical Profiling Field Sheets vii June 2020

Appendix E Soil Boring Logs Appendix F Monitoring Well and Piezometer Construction Logs Appendix G Grain Size Results Appendix H Analytical Results H-1 PFAS in Groundwater at Existing and New Monitoring Wells PFAS in Groundwater at Existing and New Monitoring Wells at AOC 57 PFAS in Groundwater at New Monitoring Wells at AOC 74 PFAS in Groundwater at New Monitoring Wells at AOC 75 PFAS in Groundwater at Existing and New Monitoring Wells at the Grove Pond Area PFAS in Groundwater at New Monitoring Wells at Shabokin Well Area PFAS in Groundwater at Existing Monitoring Wells at AOC 43J PFAS in Groundwater at Irrigation Well Patton Well Area H-2 PFAS in Groundwater at Vertical Profile Locations PFAS in Groundwater at Vertical Profile Locations at AOC 57 Area 1 PFAS in Groundwater at Vertical Profile Locations at AOC 57 Area 2 PFAS in Groundwater at Vertical Profile Locations at AOC 57 Area 3 PFAS in Groundwater at Vertical Profiling Conducted during Well Installation at

AOC 57 Area 2 PFAS in Groundwater at Vertical Profile Locations at AOC 74 PFAS in Groundwater at Vertical Profile Locations at AOC 75 PFAS in Groundwater at Vertical Profiling Conducted during Well Installation at

AOC 75

PFAS in Groundwater at Vertical Profile Locations at Grove Pond Area PFAS in Groundwater at Vertical Profiling Conducted during Well Installation at the

Grove Pond Area PFAS in Groundwater at Vertical Profile Locations at Patton Well Area/AOC 40 PFAS in Groundwater at Vertical Profile Locations at Shabokin Well Area H-3 PFAS in Groundwater at Water Supply Wells PFAS in Town of Ayer Grove Pond Water Supply Wells PFAS in Patton Water Supply Well PFAS in Shabokin Water Supply Well H-4 PFAS in Surface Water and Sediment and TOC in Sediment H-5 PFAS in Soil PFAS Results in Soil Samples at AOC 57 Area 2 PFAS Results in Soil Samples at AOC 57 Area 3 PFAS Results in Soil Samples at AOC 74 PFAS Results in Soil Samples at AOC 75 PFAS Results in Soil Samples at Grove Pond Area PFAS Results in Soil Samples at Patton Well Area/AOC 40 H-6 TOP Assay Results AOC 57 TOP Assay Soil Results AOC 74 TOP Assay Soil Results AOC 75 TOP Assay Soil Results Grove Pond TOP Assay Soil Results AOC 57 Top Assay Groundwater Results AOC 75 Top Assay Groundwater Results viii June 2020

Grove Pond Top Assay Groundwater Results H-7 Total Organic Carbon in Soil Sampled Collected During Drilling AOC 57 TOC Soil Results AOC 74 TOC Soil Results AOC 75 TOC Soil Results Grove Pond TOC Soil Results H-8 Total Organic Carbon in Groundwater AOC 57 TOC Groundwater Results AOC 75 TOC Groundwater Results Grove Pond TOC Groundwater Results ix June 2020

ACRONYMS AND ABBREVIATIONS

ABB ABB Environmental Services, Inc.

AFFF aqueous film forming foam AOC area of contamination Army U.S. Army BERS-Weston BERS-Weston Services JVA, LLC bgs below ground surface BRAC Base Realignment and Closure BTEX benzene, toluene, ethylbenzene, and xylene CERCLA Comprehensive Environmental Response, Compensation, and Liability Act CSMS Consolidated Support Maintenance Shop DPT direct push technology DRFTA Devens Reserve Forces Training Area DQO data quality objectives E&E Ecology and Environment, Inc.

EPA U.S. Environmental Protection Agency ESD Explanation of Significant Differences FOSET Finding of Suitability for Early Transfer FS Feasibility Study FSP field sampling plan ft feet GAC Granular Activated Carbon GERE Grant of Environmental Restriction and Easement gpm gallons per minute GW-1 Massachusetts Contingency Plan Method 1 Groundwater HLA Harding Lawson Associates H&S H&S Environmental, Inc.

J estimated result KGS KOMAN Government Solutions, LLC LHA lifetime health advisory LTM long-term monitoring MAARNG Massachusetts Army National Guard MassDEP Massachusetts Department of Environmental Protection MassDevelopment Massachusetts Development and Finance Agency MCP Massachusetts Contingency Plan MNA monitored natural attenuation NAVD88 North America Vertical Datum 1988 ng/L nanograms per liter PA Preliminary Assessment PCB polychlorinated biphenyls PFDA perfluorodecanoic acid PFAS per- and polyfluoroalkyl substances PFHpA perfluoroheptanoic acid PFHxS perfluorohexanesulfonic acid PFNA perfluoronanoic acid PFOA perfluorooctanoic acid PFOS perfluorooctanesulfonic acid PSCS preliminary site characterization summary RI Remedial Investigation ROD Record of Decision x June 2020

SA Study Area SSSL site-specific screening level S&W Stone and Webster Environmental Technology and Services S-1 MCP Method 1 S-1 Soil Category TCRA time-critical removal action TOP total oxidizable precursor µg/kg micrograms per kilogram USACE U.S. Army Corps of Engineers UST underground storage tank

1-1 June 2020

1.0 INTRODUCTION

KOMAN Government Solutions, LLC (KGS), on behalf of the U.S. Army Corps of Engineers (USACE) New England District, has prepared this Preliminary Site Characterization Summary (PSCS) for the Per-and Polyfluoroalkyl Substances (together, “PFAS”) Remedial Investigation (RI) at the former Fort Devens Army Installation (Devens) located in Devens, Massachusetts.

The PSCS summarizes data that have been collected at numerous Areas of Contamination (AOC) identified in the Draft Remedial Investigation Work Plan for Per- and Polyfluoroalkyl Substances (PFAS) (KGS, 2018a) and as shown on Figure 1-1.

To expedite the field investigations, the identified AOCs, Grove Pond wellfield, and MacPherson, Patton, and Shabokin water supply well areas were grouped into three areas (Areas 1, 2, and 3). This PSCS addresses Area 1 and part of Area 2 as indicated below. Future PSCS submittals will include the remainder of Area 2 and Area 3.

Area 1:

AOC 57 Building 3713 Fuel Oil Spill Site;

AOC 74 Barnum Road Firefighting Exercise Site;

AOC 75 Former Building T-1445 Warehouse Fire; and, Grove Pond wellfield.

Area 2 (partial):

AOC 40 Cold Spring Brook Landfill;

AOC 43G Historical Gas Station G;

AOC 43J Historical Gas Station J;

Patton water supply well; and, Shabokin water supply well.

The PSCS is a summary of site data following completion of the initial field sampling and analysis (EPA, 1988). The intent is to better understand and assess any potential data gaps remaining at the AOCs, and determine additional data gathering activities. The U.S. Army (Army) will prepare a bulleted list of data gaps following discussions at the Base Cleanup Team (BCT) meetings, which will be used to develop specific Data Quality Objectives (DQO) for the development of an RI Addendum work plan.

Investigation Approach

The initial field activities for the RI were detailed in the Draft Remedial Investigation Work Plan for Per-and Polyfluoroalkyl Substances (PFAS) (KGS, 2018a), the Area 1 Field Sampling Plan Addendum to Remedial Investigation Work Plan for Per- and Polyfluoroalkyl Substances (PFAS) (KGS, 2018b), and the Area 2 Field Sampling Plan (FSP) Addendum to Remedial Investigation Work Plan for Per- and Polyfluoroalkyl Substances (PFAS) (KGS, 2018c). The initial activities were planned based on results from the Final Base-Wide Preliminary Assessment for Evaluation of Perfluoroalkyl Substances (KGS, 2017), the Site Inspection (SI) Addendum for Additional Per- and Polyfluoroalkyl Substances (PFAS) Sampling at Area of Contamination (AOC) 76-Devens Fire Department and Long Term Monitoring (LTM) Wells at AOCs 57, 43G, 43J, 32, 43A, 50 and Shepley’s Hill Landfill (SHL) Former Fort Devens Army Installation Devens, Massachusetts (BERS-Weston, 2018a), and the Final Site Inspection Report for Per- and Polyfluoroalkyl Substances (PFAS) at Former Fort Devens Army Installation, Devens, MA (BERS-Weston, 2018b). Knowledge of the sites through previous investigations, operation and maintenance activities, and long-term monitoring activities, which included various groundwater models were also used to plan field activities.

The field work was conducted in an iterative manner. The field work commenced with the work detailed in the Area 1 Field Sampling Plan Addendum to Remedial Investigation Work Plan for Per- and Polyfluoroalkyl Substances (PFAS) (KGS, 2018b). While executing the field work, analytical data from

1-2 June 2020 sampling of existing monitoring wells, groundwater vertical profiling, soil sampling, and surface water and sediment sampling was shared with U.S. Environmental Protection Agency (EPA) and Massachusetts Department of Environmental Protection (MassDEP) as it was received from the laboratory. The results were discussed with EPA and MassDEP and additional activities, not detailed in the FSP, needed to achieve the study goals and DQOs were recommended. The recommendations were developed based on review of the analytical data and understanding of groundwater flow direction based on analysis of field data or review of information from previous field investigations or groundwater flow models. Additional activities included additional vertical profiles, additional soil borings, additional surface water and sediment sampling, sampling of additional existing monitoring wells, installation of piezometers, synoptic water level surveys, and selection of samples to be analyzed for total oxidizable precursor (TOP) assay. As additional results were received and reviewed, further work was conducted, which sometimes resulted in numerous phases of field activities at different AOCs. The field work at each AOC is discussed in subsequent sections.

Review of the data was also used to develop addendums to the FSPs. The Final Area 2 Field Sampling Plan Area of Contamination 40 Addendum (KGS, 2020a) details activities at AOC 40. The Remedial Investigation Work Plan for Per- and Polyfluoroalkyl Substances (PFAS) Area 1 Field Sampling Plan Addendum No. 2 (KGS, 2020b) details activities in Cold Spring Brook. The Addendum to Remedial Investigation Work Plan for Per- and Polyfluoroalkyl Substances and the Area 1 Field Sampling Plan – Monitoring Well Plan Addendum Remedial Investigation Work Plan for PFAS (KGS, 2019b) details additional drilling activities at the Area 1 AOCs using a variety of drilling techniques (sonic, drive and wash, and direct push technology), specific activities included: 1) overburden and bedrock groundwater monitoring well installation; 2) piezometer installation; 3) groundwater vertical profiling using direct push technology, 4) deep groundwater vertical profiling; 5) soil core collection for field lithologic classification (with grain size and total organic carbon sample collection), and 6) confirmation of bedrock.

After existing monitoring wells were sampled in Area 1 and Area 2, additional sampling of existing monitoring wells was detailed in the Work Plan for Additional Sampling of Existing Wells to Support the PFAS Remedial Investigation Former Fort Devens Army Installation, Devens, MA (KGS, 2019c). This supplemental sampling of existing monitoring wells is intended to provide additional data regarding the nature and extent of PFAS at these sites for the RI and can be used to support evaluation of trends in PFAS concentrations in groundwater over time.

There were minor deviations to the FSPs and FSP addendums related to locations of drilling activities, additions and deletions of locations, or activities at specific locations. As is typical with field investigations, some locations were adjusted based on field conditions (e.g., steep terrain, proximity to wetlands, safety considerations). None of the adjustments to the locations negatively impacted meeting the DQOs. There were no major deviations to the methods detailed in the work plan, FSPs, and FSP addendums.

Report Organization

The site characteristics, general geology, and regional hydrogeology at former Fort Devens are described in Section 2. The results of synoptic water level events conducted in the areas addressed in this report are reported in Section 2 and site-specific groundwater flow conditions are described in the subsequent site-specific sections. Sections 3 through 9 each address a specific area of investigation listed above. The PFAS results related to each area of investigation are discussed in the applicable section. The PFAS results in various media are described in each applicable section with respect to the media-specific criteria (Table 1- 1). The field sheets, soil boring logs, well construction logs, and results are presented in appendices.

2-1 June 2020

2.0 FORMER FORT DEVENS SITE LOCATION AND DESCRIPTION

Devens is located in the towns of Ayer and Shirley in Middlesex County, and the towns of Harvard and Lancaster in Worcester County, Massachusetts, approximately 35 miles northwest of Boston, Massachusetts. The installation occupied approximately 9,260 acres. Fort Devens was divided into the North Post, Main Post, and South Post. 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 primarily comprises rural residential properties. Portions of Devens have been redeveloped for commercial/industrial use.

Camp Devens was established in 1917 as a temporary training area for soldiers during World War I. In 1932, the site was named Fort Devens and made a permanent installation with the primary mission of commanding, training, and providing logistical support for non-divisional troop units. Fort Devens was used for a variety of training missions between 1917 and 1990. Pursuant to the CERCLA, Fort Devens was placed on the National Priorities List on November 21, 1989, due to environmental contamination at several sites.

Fort 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 Devens were retained by the U.S.

Army for reserve forces training and renamed the Devens Reserve Forces Training Area (DRFTA). Areas not retained as part of the DRFTA were transferred to new owners, the Massachusetts Development and Finance Agency (MassDevelopment), U.S. Department of Labor, U.S. Department of Justice, and the U.S.

Fish and Wildlife Service, for reuse and redevelopment. In 2009, the DRFTA was renamed the U.S. Army Garrison Fort Devens.

Physical Characteristics

Devens lies within the Nashua River basin. The Nashua River flows north through the former North, Main, and South Posts (Figures 2-1 and 2-2). The Nashua River forms the western installation boundary on the former Main Post. Other notable surface water features include: Grove Pond located north of the Grove Pond wellfield, Plow Shop Pond located west of Grove Pond, Nonacoicus Brook flowing from Plow Shop Pond to the Nashua River, Cold Spring Brook located east of AOCs 57, 74, and 75, an unnamed stream located east of AOC 43G, Robbins Pond located east of AOC 43G, Willow Brook flowing north from Robbins Pond to Nonacoicus Brook, Cold Spring Brook Pond (AOC 40), and Mirror Lake and Little Mirror Lake located between Patton and Shabokin wells. The specific surface water bodies and their relations to specific areas of investigation are discussed in applicable sections.

The geography of Devens is characterized by undulating glacial terrain. The landforms are products of glacial erosion and deposition on a crystalline bedrock terrain. Terrain at Devens falls generally into three types. The least common is bedrock terrain, where rocks that have been resistant to both glacial and fluvial erosion remain as topographic highs, sometimes thinly veneered by glacial deposits. A more common terrain at Devens consists of tills deposited by glaciers. These landforms often conform to the shape of the underlying bedrock surface. They range from areas of comparatively low topographic relief to elongated hills (drumlins) [Harding Lawson Associates (HLA), 2000].

The most common terrain at Devens was formed by sediment accumulations in glacial-meltwater streams and lakes (glaciofluvial and glaciolacustrine deposits). Other prominent glacial meltwater features are kame and kettle topography present on the former Main Post near Mirror Lake and Little Mirror Lake located between the Patton and Shabokin wells.

Geology

The major glacial units consist of till, deltaic deposits from former glacial Lake Nashua, and deposits from glacial meltwater streams (Figure 2-3). Glacial till at Devens consists of unstratified gravel to silt and typically contains boulders. The till at the site is typically approximately 10 feet thick but is up to 60 feet

2-2 June 2020 thick in the cores of drumlins. The glacial lake deposits consist chiefly of sand and gravelly sand. Lake bottom deposits consist of sand, silt, and clay. Post-glacial deposits consist of river terrace sands and gravels, fine alluvial sands and silts, as well as peat and silt and sands in swampy areas. Generalized surficial geology by AOC is described below and is based on the Geologic Map of the Ayer Quadrangle, Massachusetts, Surficial Geology (Jahns, 1953).

AOC 57 and 75 – Primarily coarse terrace deposits, chiefly kame terraces, with some shore and near-shore deposits of Glacial Lake Nashua along the edge of Cold Spring Brook and swamp deposits, chiefly muck and peat in Cold Spring Brook.

AOC 74 – Similar to AOCs 57 and 75, but generally missing the shore and near-shore deposits of Glacial Lake Nashua.

Grove Pond Area - Primarily coarse terrace deposits, with lesser amounts of kame deposits and shore and near-shore deposits of Glacial Lake Nashua along the shoreline of Grove Pond.

AOC 40 – Primarily coarse kame-plain or ice-contact plain deposits, with some kame deposits, shore and near-shore deposits of Glacial Lake Nashua, and swamp deposits (chiefly muck and peat).

AOC 43G – Mix of coarse kame deposits, terrace and delta-outwash plain deposits, bottom sands and clays of Glacial Lake Nashua, and artificial fill.

AOC 43J – Primarily coarse terrace and delta-outwash plain deposits, and kame deposits, with some shore and near-shore deposits of Glacial Lake Nashua, as well as bottom sands and clays of Glacial Lake Nashua.

Patton Well Area – Primarily coarse kame, kame-plain, or ice-contact plain deposits, with some swamp deposits (chiefly muck and peat), shore and near-shore deposits of Glacial Lake Nashua, and terrace deposits.

Shabokin Well Area - Primarily kame-plain or ice-contact plain deposits, with some kame deposits, bottom sands and clays of Glacial Lake Nashua, wind deposits (chiefly dune sand), and shore and near-shore deposits of Glacial Lake Nashua.

Bedrock beneath the portion of Devens covered under this PSCS has been mapped as part of the Preliminary Bedrock Geologic Map of the Ayer Quadrangle, Massachusetts (Kopera, 2006). Bedrock chiefly consists of low-grade metasedimentary rocks, gneisses, and granites. The principal bedrock units are described below and illustrated on Figure 2-4.

The Oakdale Formation underlies AOCs 57, 74, 43G, 43J, and the Shabokin well areas. The formation is described by Kopera as thinly laminated, light tan micaceous quartz-muscovite-ankerite siltstone and quartzite interbedded with thin, dark greenish-grey, chlorite-muscovite-quartz- ankerite phyllite. At biotite and actinolite grade, consists of fine grained reddish and greenish siltstone granofels.

The Devens Gneiss Complex underlies AOCs 40, 75, Grove Pond area, and Patton Well area and is believed to be of Silurian age. The unit is described by Kopera as light to medium grey, buff to pink weathering, coarse-grained quartz-potassium (k)-spar biotite granite-gneiss, with subordinate tonalitic and dioritic gneiss near Harvard Center. Biotite content varies locally as much as approximately 15 percent. Sheared to a medium to dark grey fine- to medium-grained S/C mylonite with k-spar porphyroclasts near the Clinton-Newbury fault zone. Intruded by the Ayer Granite.

Other bedrock units beneath or in the general vicinity of Devens and depicted on Figure 2-4 include:

The Ayer Granite of Silurian age and described by Kopera as light to dark grey, buff weathering, coarse-grained, porphyritic quartz-k-spar biotite granite with distinctive k-spar megacrysts up to 8

2-3 June 2020 cm in diameter. Locally foliated, sheared and altered to an augen gneiss and talc-bearing schist near the Clinton-Newbury fault zone. A non-porphyritic phase has been mapped separately northwest of Harvard center.

The Chelmsford Granite of Devonian age and described by Kopera as white to buff weathering, light grey medium- to coarse-grained feldspar-quartzbiotite granite. Biotite occurs in isolated rusty weathering clots. Commonly contains screens and xenoliths of presumed Berwick formation.

Distinctive quartz veins, up to 2 cm in width and several meters in length, are common. Locally foliated and/or sheared near the Clinton-Newbury fault zone. Also includes a medium grey, buff weathering, fine- to medium-grained quartz-feldspar-muscovite-biotite granite-gneiss, and a well-foliated light grey k-spar-quartz-muscovite granite-gneiss near the Clinton-Newbury fault. Intrudes the Ayer granite and Devens gneiss complex.

The Berwick Formation of Silurian age and described by Kopera as thinly to massively bedded, light green-grey, fine-grained metamorphosed calcareous siltstone, quartzite, and quartzo-feldspathic granofels. Also contains a fine-grained, massively bedded muscovite-quartz-biotite quartzite and schist containing distinctive 1-mm knots of biotite.

The Tadmuck Brook Schist is possibly of late Proterozoic or early Paleozoic age. The formation is described by Kopera as rusty weathering, sulfidic, quartz-muscovite-biotite with or without sillimanite, andalusite, or staurolite, schist. Metamorphic grade increases from west to east across strike.

The bedrock elevation contours were mapped using data gathered as part of the PFAS RI, previous investigations at Devens, well drilling records available through the Massachusetts Energy & Environmental Affairs Data Portal (eeaonline.eea.state.ma.us), and Massachusetts Geological Survey (Figure 2-4, Table 2-1). There is significant relief in bedrock elevations across Devens and the surrounding area. The area shown has bedrock elevations ranging from -49 feet (ft) North America Vertical Datum 1988 (NAVD88) to 408 ft NAVD88.

Regional Hydrogeology

The Nashua River is the eventual discharge locus for surface water and groundwater flow at Devens. The tributaries of the Nashua River at Devens are Nonacoicus Brook and Walker Brook on the former North Post; Cold Spring Brook (which is a tributary of the Nonacoicus Brook through Grove Pond and Plow Shop Pond) on the former Main Post. There is also a lesser stream, Willow Brook that discharges to Nonacoicus Brook to the north. Willow Brook originates from Robbins Pond and is fed by Robbins Pond, surface water runoff, storm water discharge, and groundwater. The groundwater flow direction at each AOC is addressed in applicable sections.

Glacial meltwater deposits constitute the primary overburden aquifer at Devens. Groundwater also occurs in the underlying bedrock; however, flow is limited because regional bedrock lacks primary porosity and/or has been affected by metamorphism that limits transmissivity (an example would be the degree of development of transmissive partings parallel to layering). The result is bedrock groundwater flow that is primarily via fractures and dissolution voids.

The zones of highest transmissivity within the overburden are found in areas of thick glacial meltwater (outwash) deposits on the former Main Post at Devens, and these encompass deposits in which the Shabokin, Patton, MacPherson, and Grove Pond water supply wells are screened (Figure 2-16). Due to the high transmissivity of these overburden deposits, these areas are preferential groundwater flow areas. The zones of lowest transmissivity are typically associated with exposed till and bedrock.

Groundwater recharge occurs in upland areas and groundwater flows generally from the topographic highs to topographic lows. Groundwater discharges in wetlands, ponds, streams, and directly into the Nashua River.

2-4 June 2020

The synoptic water level measurements taken for the PFAS RI in the areas addressed in this report are presented in Tables 2-2 through 2-5. The groundwater elevation contour maps based on those measurements are on Figures 2-6 through 2-15 The contour intervals vary between figures based on the level of scale and area of interest. The vertical gradients are presented in Table 2-6. The groundwater flow directions and gradients are discussed in the applicable sections.

The Devens Groundwater Use and Value is categorized as “High” as determined by MassDEP (MassDEP, 2003) and the MassDEP groundwater classification of GW-1 is applied throughout Devens. The MassDEP approved water supply Zone I’s and Zone II’s, as well as the potentially productive aquifer areas, and the Devens Aquifer Protection and Watershed Protection Districts are shown on Figure 2-16.

3-1 June 2020

3.0 AOC 57 PRELIMINARY SITE CHARACTERIZATION SUMMARY

Site Description

AOC 57 was first identified for investigation of PFAS based on analysis of groundwater samples collected from existing long-term monitoring (LTM) wells at the site in December 2017/January 2018. AOC 57 consists of three sub-areas (Area 1, Area 2, and Area 3) that are located between Barnum Road and Cold Spring Brook, south to southeast of former Building 3713 (Figure 3-1). The three sub-areas are located on undeveloped MassDevelopment land designated as Open Space/Recreational. The three sub-areas are all in areas that are sloped downward to Cold Spring Brook in varying degrees. The elevation of the brook is approximately 220 ft NAVD88. The areas upslope of the AOC 57 sub-areas are generally flat at approximately 240 ft NAVD88, have all been developed, and are privately owned or owned by the Army.

The current and previous subsurface features are shown on Figures 3-2 and 3-3. There is a large storm water detention area that was constructed between AOC 57 Area 1 and Area 2 between 2003 and 2005 (Figure 3- 3).

Facility History and Utilities

Area 1 is a storm water drain that collects rainfall from the paved areas around Building 3713. The runoff from the storm drain flows to the outfall at Area 1, and eventually into Cold Spring Brook (HLA, 2000).

Area 2 is located 800 feet northeast of Area l, and adjacent to a vehicle storage yard associated with the former motor repair shops (Figure 3-1). Area 2 formerly consisted of an eroded drainage ditch created by periodic rain runoff. Area 3 is located approximately 600 feet to the northeast of Area 2, south of former vehicle maintenance motor pools and north of the Cold Spring Brook floodplain. The site is characterized by a historical garage and vehicle waste disposal area (HLA, 2000). Area 3 was identified after test pits were excavated east of Area 2 where soil staining was identified on historical photographs, which was later determined to be an area impacted by total petroleum hydrocarbon and chlorinated volatile organic compounds in 1995 (Harding, 2001).

In 1977, an estimated 50 to 100-gallon spill of No. 4 fuel oil was discharged through the Area 1 outfall (Harding, 2001). The fuel oil spill occurred from an overfilled underground storage tank (UST) at Building 3713 into a nearby storm drain (HLA, 2000). Approximately 3,000 gallons of impacted mixed soil and water were removed through use of containment dikes and absorbent booms set up across Cold Spring Brook adjacent to Area 2 in 1977 (Harding, 2001). The remediation, investigations and monitoring of AOC 57 related to the fuel oil spill is discussed in Section 3.3.

The property at 112 Barnum Road was sold through the base closure process. Evergreen Solar constructed a manufacturing facility at 112 Barnum Road in 2008/2009 to manufacture silicon wafers used in solar power systems (Figure 3-2). The building was constructed with oversized/complex air handling and humidification, air and process cooling, power supply and distribution, compressed air production and distribution, specialty gas distribution, and wastewater and hazardous material treatment systems.

Evergreen Solar went bankrupt in 2011 and the property was sold to Calare Properties/Hackman Capital Properties. In 2012, Calare leased half the facility to Saint-Gobain Ceramics & Plastics. Saint-Gobain upgraded the facility for the manufacture of components used in LED lights. In 2013, Calare leased the other half of the building to Nypro Healthcare. In 2014, Nypro started manufacturing of precision plastic products for customers in the healthcare, packaging, and consumer electronics industries (e.g., medical device manufacturing). In August 2014, Saint-Gobain ceased operations and Nypro moved into their space.

In May 2015, Calare sold the property to an LLC/institutional buyer.

The property at former Building 3713 was retained by the Army during the base closure process. Building 3713 was demolished and the Major David S. Connolly Armed Forces Reserve Center was constructed on the property between 2008 and 2010.

3-2 June 2020

The current and previous subsurface features are shown on Figures 3-2 and 3-3. The historic storm sewer system drained paved and unpaved areas and a discharge point to Cold Spring Brook near AOC 57 Area 1.

The system was revised and there are numerous detention pond areas across the area.

Remedial Status

In September 1992, an investigation was performed at Area 1 and 2 to determine the presence or absence of environmental contamination at AOC 57 resulting from the 1977 fuel oil spill. Polycyclic aromatic hydrocarbons and total petroleum hydrocarbon content, possibly associated with fuel oil, were detected at Area 1; however, a preliminary risk evaluation indicated that there was no unacceptable risk for presumed commercial/industrial site reuse (HLA, 2000). At Area 2, naphthalene and total petroleum hydrocarbon content were detected in surface soils, and fingerprint analysis of soil indicated contaminated soil was most likely derived from lubricating oil, possibly from the release of vehicle crank case oil and not likely related to the No. 4 fuel oil release.

In 1994, a soil removal action was conducted at Area 2 in response to newly promulgated MCP standards (Harding, 2001). During the removal action, it was discovered that the soil and groundwater contamination were more widespread than expected, the soil removal was stopped after 1,300 cubic yards of soil were excavated, and AOC 57 Area 2 was administratively transferred to the RI/feasibility study (FS) process.

Following the soil removal action, the area was regraded, and a stone drainage swale was installed that discharges into Cold Spring Brook (HLA, 2000).

In 1997, excavation of Area 1 outfall soil was conducted to address soil contamination resulting from releases of petroleum oil in response to newly promulgated MCP standards (HLA, 2000). The time-critical removal action included excavation of a 22-foot by 22.5-foot area to a maximum depth of 3 feet below ground surface (bgs) at the outfall location, approximately 25 cubic yards of contaminated soil were removed (Harding, 2001).

In the spring of 1999, a total of 1,860…