465393.pdf

Final Regional Compliance Restoration Program Preliminary Assessment/Site Inspection Bangor Air National Guard Base Bangor, Maine

DA004 – Downing Street Dump Site

TU003 – UST 510

OW005 – Former Fire House

July 2015

Contract No. W912DR-12-D-0014 Task Order No. 0001

Submitted to U.S. Army Corps of Engineers 10 South Howard Street Room 1000-S Baltimore, Maryland 21201

Contract No. W912DR-12-D-0014 Task Order No. 0001

Submitted by

AECOM

3101 Wilson Boulevard, Suite 900 Arlington, Virginia 22201

Final Regional Compliance Restoration Program Preliminary Assessment/Site Inspection Bangor Air National Guard Base Bangor, Maine

DA004 – Downing Street Dump Site

TU003 – UST 510

OW005 – Former Fire House

AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine i

Table of Contents

EXECUTIVE SUMMARY ............................................................................................................................................................ V 1 INTRODUCTION ............................................................................................................................................................... 1-1

1.1 Project Objectives and Scope ................................................................................................................................... 1-1

1.2 Report Organization .................................................................................................................................................. 1-1

2 INSTALLATION DESCRIPTION....................................................................................................................................... 2-1

2.1 Location ..................................................................................................................................................................... 2-1

2.2 Organization and History ........................................................................................................................................... 2-1

2.2.1 DA004 – Downing Street Dump Site .................................................................................................................. 2-1

2.2.2 TU003 – UST 510 .............................................................................................................................................. 2-1

2.2.3 OW005 – Former Fire House ............................................................................................................................. 2-1

3 ENVIRONMENTAL SETTING........................................................................................................................................... 3-1

3.1 Climate ...................................................................................................................................................................... 3-1

3.2 Base Topography and Drainage ................................................................................................................................ 3-1

3.3 Geology ..................................................................................................................................................................... 3-1

3.4 Soil ............................................................................................................................................................................ 3-1

3.5 Groundwater/Hydrogeology ....................................................................................................................................... 3-1

3.6 Surface Water Hydrology .......................................................................................................................................... 3-2

3.7 Critical Habitats /Threatened Endangered Species ................................................................................................... 3-2

4 PRELIMINARY ASSESSMENT ........................................................................................................................................ 4-1

4.1 Previous Investigations.............................................................................................................................................. 4-1

4.1.1 DA004 – Downing Street Dump Site .................................................................................................................. 4-1

4.1.2 TU003 – UST 510 .............................................................................................................................................. 4-3

4.1.3 OW005 – Former Fire House ............................................................................................................................. 4-5

4.2 Regulatory Framework .............................................................................................................................................. 4-8

4.3 PA/SI Work Plan Recommendations ......................................................................................................................... 4-9

5 SI FIELD OPERATIONS ................................................................................................................................................... 5-1

5.1 General Approach ..................................................................................................................................................... 5-1

5.1.1 Field Sampling .................................................................................................................................................... 5-1

5.1.2 Deviations from the Work Plan ........................................................................................................................... 5-1

5.1.3 Data Analysis ..................................................................................................................................................... 5-2

5.1.4 Data Validation ................................................................................................................................................... 5-2

5.2 Investigation Derived Waste ...................................................................................................................................... 5-2

5.3 TU003 – UST 510 ..................................................................................................................................................... 5-2

5.3.1 Field Sampling .................................................................................................................................................... 5-2

5.3.2 Results ............................................................................................................................................................... 5-2

5.4 OW005 – Former Fire House .................................................................................................................................... 5-7

5.4.1 Field Sampling .................................................................................................................................................... 5-7

5.4.2 Results ............................................................................................................................................................... 5-7

6 AREA OF CONCERN PATHWAY AND ENVIRONMENTAL HAZARD ASSESSMENTS ............................................... 6-1 7 CONCLUSIONS AND RECOMMENDATIONS ................................................................................................................. 7-1

7.1 Conclusions ............................................................................................................................................................... 7-1

7.1.1 TU003 – UST 510 .............................................................................................................................................. 7-1

7.1.2 OW005 – Former Fire House ............................................................................................................................. 7-1

7.2 Recommendations .................................................................................................................................................... 7-1 8 REFERENCES .................................................................................................................................................................. 8-1

AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine ii

Appendices

Appendix A Historical Documents Appendix B Field Documentation

Boring Logs Appendix B-1

List of Tables

Table 4-1. Maximum VOC Detections in Soil at DA004 ....................................................................................................................4-1 Table 4-2. Maximum SVOC Detections in Soil at DA004 ..................................................................................................................4-1 Table 4-3. Maximum Metals Detections in Soil at DA004 .................................................................................................................4-2 Table 4-4. Maximum TPH Detections in Soil at DA004 .....................................................................................................................4-2 Table 4-5. Maximum Metals Detections in Groundwater at DA004 ..................................................................................................4-3 Table 4-6. Maximum TPH Detection in Groundwater at DA004 .......................................................................................................4-3 Table 4-7. Maximum VOC Detections in Soil at TU003 ....................................................................................................................4-4 Table 4-8. Maximum SVOC Detections in Soil at TU003 ..................................................................................................................4-4 Table 4-9. Maximum TPH Detection in Soil at TU003 .......................................................................................................................4-4 Table 4-10. Maximum VOC Detections in Soil at OW005 .................................................................................................................4-5 Table 4-11. Maximum SVOC Detections in Soil at OW005 ..............................................................................................................4-5 Table 4-12. Maximum Metals Detections in Soil at OW005 ..............................................................................................................4-6 Table 4-13. Maximum TPH Detections in Soil at OW005 .................................................................................................................4-7 Table 4-14. Maximum SVOC Detections in Groundwater at OW005 ...............................................................................................4-7 Table 4-15. Maximum Metals Detections in Groundwater at OW005 ...............................................................................................4-8 Table 4-16. Maximum TPH Detections in Groundwater at OW005 ..................................................................................................4-8 Table 4-17. Summary of the Recommendations from the Preliminary Assessment ........................................................................4-9 Table 5-1. Detected Analytes in Soil at TU003 at Bangor ANGB .....................................................................................................5-3 Table 5-2. Detected Analytes in Soil at OW005 at Bangor ANGB ....................................................................................................5-9 Table 5-3. Detected Analytes in Groundwater at OW005 at Bangor ANGB .................................................................................. 5-11

List of Figures

Figure 1-1. Bangor Air National Guard Base Vicinity Map ................................................................................................................1-3 Figure 2-1. Bangor ANGB AOC Locations ........................................................................................................................................2-3 Figure 5-1. TU003 SI Field Sampling Locations at Bangor ANGB ....................................................................................................5-5 Figure 5-2. OW005 SI Field Sampling Locations at Bangor ANGB ............................................................................................... 5-13

Appendix B-2 Instrument Calibration Appendix C Analytical Data Packages Appendix D Data Validation Report Appendix E HRS Quickscore Report Appendix F Remedial Action Cost Engineering Requirements Worksheets Appendix G NFA Concurrence Letter, State of Maine, Department of Environmental Protection

AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine iii

List of Acronyms and Abbreviations

ANG Air National Guard ANGB Air National Guard Base AOC Area of Concern bgs Below Ground Surface BmB Bangor Silt Loam BTEX Benzene, Toluene, Ethylbenzene, and Xylene

COPCs Chemicals of Potential Concern CRP Compliance Restoration Program

DoD Department of Defense DPT Direct Push Technology

EBS Environmental Baseline Survey EPA Environmental Protection Agency EPH Extractable Petroleum Hydrocarbon ft Feet

HRS Hazard Ranking System

LOD Level of Detection LOQ Level of Quantitation

MCL Maximum Concentration Level MD Made Land MEDEP Maine Department of Environmental Protection MEGs Maine Exposure Guidelines mg/kg Milligrams per Kilogram MS/MSD Matrix Spike/Matrix Spike Duplicate

NFA No Further Action NPL National Priorities List

PA Preliminary Assessment PA/SI Preliminary Assessment/ Site Inspection PAH Polycyclic Aromatic Hydrocarbon PALs Project Action Limits PID Photoionization Detector

QA Quality Assurance QC Quality Control

RAGs Remedial Action Guidelines RSL Regional Screening Level

SI Site Inspection SVOCs Semivolatile Organic Compounds

Tkb Thorndike Very Rocky Silt Loam TPH-DRO Total Petroleum Hydrocarbons – Diesel Range Organics TPH-GRO Total Petroleum Hydrocarbons – Gasoline Range Organics

USACE United State Army Corps of Engineers USFWS United States Fish and Wildlife Services UST Underground Storage Tank

AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine iv

VOCs Volatile Organic Compounds VPH Volatile Petroleum Hydrocarbon

WP Final Preliminary Assessment/Site Inspection Work Plan

AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine v

Executive Summary

This Preliminary Assessment/Site Inspection (PA/SI) Report presents the results of and recommendations from the 2014 PA/SI activities conducted at the Bangor Air National Guard Base (ANGB) in Bangor, Maine as part of the Compliance Restoration Program (CRP). The project objective was to determine the presence or absence of contamination and either (1) obtain a No Further Action (NFA) decision for the areas of concern (AOCs) at Bangor ANGB, with regulatory concurrence from the Maine Department of Environmental Protection (MEDEP) or (2) identify the data quality objectives required for conducting a follow-on remedial investigation at the AOCs that did not meet the criteria for NFA.

The three AOCs addressed by the PA/SI at Bangor ANGB are:

• DA004 – Downing Street Dump Site

• TU003 – UST 510

• OW005 – Former Fire House

Based on recommendations from previous investigations and the PA, additional SI activities were not warranted for DA004. NFA was previously established for this site based on MEDEP concurrence during the PA/SI Work Plan Stage (AECOM, 2014).

Concentrations of chemicals of potential concern (COPCs) detected in soil samples collected from the AOCs during the 2014 SI were compared to the project action limits (PALs) for Bangor ANGB. The PALs for the soil samples are the MEDEP Tier 1 Direct Contact Soil Remediation Guidelines for Smaller Petroleum Contaminated Sites, MEDEP Tier 1 Soil Remediation Guidelines Based on Petroleum Leaching to Groundwater, MEDEP Remedial Action Guidelines (RAGs) for Sites Contaminated with Hazardous Substances, MEDEP Development of Risk-Based Cleanup Levels for Petroleum Hydrocarbons Measured as DRO and GRO, and EPA regional screening levels (RSLs) for residential soils. The PALs for the groundwater samples are the Maine CDC Maximum Exposure Guidelines for Drinking Water, the EPA maximum contaminant levels (MCLs) for drinking water, and the EPA RSLs for tap water.

Four soil borings were advanced at TU003 and eight soil samples were collected. Detected COPC concentrations did not exceed the respective PALs in any of the soil samples.

Five borings were advanced at OW005 and eight soil samples and three groundwater samples were collected. Benzo(a)pyrene was detected at a concentration exceeding the PAL in one soil sample. C11-C22 aromatic hydrocarbons, vinyl chloride, and 2,4-dinitrotoluene were detected at concentrations exceeding their respective PALs in at least one sample. HRS scoring was conducted for this AOC. Due to the detection of COPCs at concentrations exceeding PALs, the EPA Hazard Ranking System (HRS) score was determined for OW005 using HRS Quickscore software. HRS Quickscore assigns a number to risk for each pathway of exposure for a source, and then calculates a site score, which represents the risk that a nearby population will be exposed to high concentrations of the COPCs. A site score of 28.50 is necessary for the site to be placed on the National Priorities List (NPL).The groundwater migration pathway received a score of zero, the soil exposure pathway received a score of 1.20, and the overall site score was 0.60.

Based on the results of PA activities and SI sampling, NFA under the CRP is recommended for TU003 and OW005.

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AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine 1-1

1 Introduction

This Preliminary Assessment/Site Inspection (PA/ SI) Report presents the results of and recommendations from the 2014 PA/SI activities conducted at the Bangor Air National Guard Base (ANGB) in Bangor, Maine as shown on Figure 1-1. This project was completed by AECOM under contract to the United States Army Corps of Engineers (USACE) Baltimore District and the Air National Guard (ANG).

A detailed description of the field procedures and scope of work performed during this SI is included in the Final Preliminary Assessment/Site Inspection Work Plan (WP; AECOM, 2014). Field activities for the SI were conducted on 6-8 October 2014. This PA/SI report describes the investigation activities conducted at the site of the areas of concern (AOCs) and presents the analytical results of the soil sampling. Finally, it provides conclusions and recommendations based on the results of the investigation.

1.1 Project Objectives and Scope

The project objective was to determine the presence or absence of contamination and either (1) obtain a No Further Action (NFA) decision for the AOC sites, with regulatory concurrence from the Maine Department of Environmental Protection (MEDEP) or (2) identify the data quality objectives required for conducting a follow-on remedial investigation at the AOC sites if they did not meet the criteria for NFA.

The scope of work included the installation of soil borings and collection of soil and groundwater (if present) samples to evaluate concentrations of chemicals of potential concern (COPCs) and screen for the presence or absence of contamination. The resulting data were used to make recommendations supporting NFA or additional remedial investigation activities. The scope of work for the project also included a PA to confirm the scope of the SI. The results of the PA for this project were presented in Section 5 of the WP (AECOM, 2014) and are summarized in Section 4 of this report.

1.2 Report Organization

This SI Report is organized into the following sections:

Section 1 Introduction - Introduces the project including the scope and objectives.

Section 2 Installation Description – Presents the description and history of the installation.

Section 3 Environmental Setting - Describes the geographic and environmental setting of the Base. Information on the regional and local climate, topography, geology, hydrogeology, hydrology, and soil is provided.

Section 4 Preliminary Assessment - Summarizes the results of PA.

Section 5 SI Field Operations - Details the AOC-specific field investigation activities and methods and summarizes the results.

Section 6 Area of Concern Pathway and Environmental Hazard Assessments – Details the purpose of HRS Quickscore and how it is used for this installation.

Section 7 Conclusions and Recommendations - Summarizes the PA/SI conclusions and recommendations for either NFA or additional investigation of each AOC.

Section 8 References - Provides a list of references used in this PA/SI Report.

The following appendices are included in this PA/SI Report:

Appendix A Historical Documents Appendix B Field Documentation Appendix C Analytical Data Packages Appendix D Data Validation Report Appendix E Hazard Ranking System (HRS) Quickscore Report

AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine 1-2

60308608

A. Weber

M. Donahue

1" = 1000' 1 of 1 Fig_1-1_Bangor_ANGB_Vicinity.mxd

Bangor Air National Guard Base

Figure 1-1 Bangor Air National Guard Base

Vicinity Map Bangor, Maine

CONTRACT NO

CARTOGRAPHY BY

CHECKED BY DATE

SCALE SHEET

December 2013

± 0 1,000 2,000500 Feet

VT

NH

ME

Bangor Air National

Guard Base

Legend Bangor ANGB Boundary

A t l a n t i cA t l a n t i c O c e a nO c e a n

Canada

Source: Microsoft, 2010; AMEC, 2009;

Bangor ANGB GIS, 2014.

AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine 1-4

AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine 2-1

2 Installation Description

2.1 Location

The 101st Air Refueling Wing is located at the Bangor International Airport in Penobscot County immediately west of downtown Bangor, Maine as shown in Figure 1-1.

2.2 Organization and History

The airfield was initially developed in the 1920s for civilian use, and was followed by the construction of the City of Bangor Airport in 1931. The Air Force used the airport as a military air base (Dow Field) during World War II and continued operations there until 1968. Subsequently, the Bangor ANGB was established in 1970.

The primary mission of the Bangor ANGB is to support aerial refueling operations. Those operations require the capability to store, transport and dispense significant volumes of jet fuel and petroleum products (AMEC, 2009). Based on findings from the Environmental Baseline Survey (CEC, 2001), a One Clean program Trip Report completed in 2008 (BB&E, 2008) and a Site Investigation in 2009 (AMEC, 2009), brief histories of the three AOCs identified for this PA/SI are provided below.

2.2.1 DA004 – Downing Street Dump Site

The Downing Street Dump Site is an existing former dump site on parcels located on either side of Downing Street on the Base.

Prior to government acquisition of this area, it was a small privately owned woodlot where a portable sawmill may have been operated (CEC, 2001). No evidence of landfilling has been noted. Discarded and abandoned equipment and debris have been previously removed from the parcel (AECOM, 2013; AMEC, 2009) as well as several areas of surface soil stained with oil or fuel from leaking machinery (CEC, 2001). Disturbed soil, felled trees and timber, and discarded chunks of concrete were observed in the area west of Downing Street during the AECOM site visit in November 2013.

2.2.2 TU003 – UST 510

Two former underground storage tanks (USTs) that served Building 510 with heating oil were closed in place by the Air Force in the 1990s. However, soil sampling data generated from the closure process could not be located for review (AMEC, 2009).

2.2.3 OW005 – Former Fire House

There are two areas within this AOC: the grit trap in the former fire house Building 512 and the sanitary sewer line trench.

According to information provided by the ANG and referenced in previous reports (BB&E and 2009 SI) an employee received chemical burns while cleaning out the grit trap in Building 512. Analysis of samples from the trap in 1989 (CEC, 2011) indicated several contaminants including tetrachloroethene and trichloroethene. The source of these chlorinated compounds was thought to be firefighting chemicals used in the 1970s that was disposed of down the trap. In the area south of the former fire house, contaminated soil was observed in trenches being excavated to install new sewer lines.

AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine 2-2

60308608

B. Perrigo

K. Kwasniak

1" = 700' 1 of 1 Fig_2-1_Bangor_ANGB_AOC.mxd

Bangor Air National Guard Base

Figure 2-1 Bangor Air National Guard Base

Areas of Concern Locations Bangor, Maine

CONTRACT NO

CARTOGRAPHY BY

CHECKED BY DATE

SCALE SHEET

January 2015

± 0 700 1,400350 Feet

Legend Bangor ANGB Boundary

See Figure 5-2

See Figure 5-1

TU003

OW005

Service Layer Credits: Source: Esri, DigitalGlobe, GeoEye, Earthstar Geographics, CNES/Airbus DS, USDA, USGS, AEX, Getmapping, Aerogrid, IGN, IGP, swisstopo, and the GIS User Community; AMEC, 2009; Bangor ANGB GIS, 2014.

DA004 - NFA

Recommended

AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine 2-4

AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine 3-1

3 Environmental Setting

3.1 Climate

The average January low temperature in Penobscot County is 4.9ºF and the average July high temperature is 79.2ºF. Both of these averages are less than the averages for the United States. The average annual rainfall is 41.6 inches and the average annual snowfall is 80.4 inches.

3.2 Base Topography and Drainage

Bangor ANGB is located in the Lower Penobscot watershed in Penobscot County. Consistent with its location at an airport, the Base is relatively flat, although some gradual sloping to the east towards the Penobscot River is likely. Runoff is captured by the installation’s drainage and stormwater network that drains into one main outfall that exits the Base at the intersection of Union Street and Godfrey Drive. There it enters a culvert and eventually discharges to the northeast to Kenduskeag Stream about ½ mile northeast of the Base and drains to the Penobscot River approximately 3.5 miles southeast of the Base (CEC, 2001). The Penobscot River drains to Penobscot Bay and Atlantic Ocean (PEER, 1998). The Penobscot River is not used as a drinking water supply (CEC, 2001).

3.3 Geology

Bangor ANGB is located in south-central Maine where the bedrock in the area consists of Ordovician-Silurian marine sandstone and slate that grades to a gneiss and schist to the southwest (AMEC, 2009). Depth to bedrock ranges from 6 to 8 feet (ft) below ground surface (bgs) as determined from borings drilling across base and averages 4 ft bgs in many areas.

3.4 Soil

Soil types at the Base consist of Thorndike very rocky silt loam (Tkb), the Bangor silt loam (BmB), and Made Land (MD). The Tkb is described as having a slope between two and eight percent and is somewhat excessively drained with some slightly decomposed plant materials. The BmB is described as well drained and the MD is moderately well drained. The source of sediments in the area consists of glacial till or glacial marine deposits (AMEC, 2009).

3.5 Groundwater/Hydrogeology

Groundwater in Maine primarily occurs in unconsolidated deposits of glacial origin (nonstratified till, stratified outwash, stratified ice-contact, and glacial marine deposits) and in the underlying consolidated crystalline bedrock formations (metamorphic and igneous rocks). The bedrock aquifers generally have a lower water yield capacity with respect to the stratified glacial aquifers, but overall capacity can be significant as a result of their extensive aerial occurrence (CEC, 2001).

According to the EBS (CEC, 2001), the crystalline bedrock aquifer supplies small amount of water to few private residences within 4 miles of the air field, but the vast majority are served by city water originating from Floods Pond north of the Base and on the other side of the Penobscot River.

Groundwater underlying Bangor ANGB has previously been encountered between 3.2 and 6.0 ft bgs (AMEC, 2009). No significant amount of water has been found in the bedrock at this Base as reported in the Installation Restoration Program report (PEER, 1988); however, fracturing and faulting was noted in previous borings, suggesting zones of preferential groundwater flow may exist along these structural features. Unconsolidated glacial deposits from discontinuous water bearing till units and are limited sources of water (CEC, 2001). Shallow groundwater in these till areas is generally encountered at the ground surface to depths of 3 ft bgs. The general groundwater flow direction is to the northeast (CEC, 2001), but local groundwater flow conditions in the overburden till may be locally influenced by base construction.

AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine 3-2

3.6 Surface Water Hydrology

The AOCs are not located near a surface water/sediment body. Surface runoff into Kenduskeag Stream, located about ½ mile away from the Base, and is directed through the installation’s drainage and stormwater network that leaves the Base through an offsite outfall. Surface water and sediment are not anticipated to be migration or exposure pathways for the AOCs.

3.7 Critical Habitats /Threatened Endangered Species

According to the U.S. Fish and Wildlife Service (USFWS), there are three endangered species found in Penobscot County: the Red knot, Atlantic salmon, and the Canada Lynx (USFWS, 2014). The Red knot is a species of bird whose status is proposed threatened. The Atlantic salmon is a species of fish whose status is endangered. The Canada Lynx is a species of mammal whose status is threatened. However, since the area around the ANGB is developed, it is unlikely to find any of these species in the area.

AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine 4-1

4 Preliminary Assessment

The PA included interviews, records searches, and visual surveys to review available information, evaluate current site conditions and develop recommendations for additional SI activities or NFA for identified AOCs. On-site PA activities were conducted in conjunction with an Installation-specific kickoff meeting at Bangor ANGB on 7 November 2013.

Data from the previous investigations and recommendations for additional investigation were presented and discussed in the WP (AECOM, 2014). The findings and SI recommendations are summarized below. Values presented represent the maximum detections. Complete analytical results can be found in the historical documents in Appendix A.

4.1 Previous Investigations

4.1.1 DA004 – Downing Street Dump Site

Soil Sampling

Six soil borings were installed at the site in June 2009. Groundwater was encountered at approximately 4 and 5 ft bgs in soil borings SB01 and SB02, respectively. Groundwater was not encountered in the remaining four borings. Twelve soil samples were collected and submitted for analysis of volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), metals, Total Petroleum Hydrocarbons – Diesel Range Organics (TPH-DRO), and TPH – Gasoline Range Organics (GRO). Two intervals were sampled from five of the six borings at 0 to 2 ft bgs and 2 to 4 ft bgs intervals, and one sample was collected from 0 to 2 ft bgs in the remaining boring (SB06) due to auger refusal. Carbon disulfide and toluene were each detected in one sample.

Acetone and bis(2-ethylhexyl)phthalate were detected in five or more samples and are suspected of being laboratory artifacts. Di-n-butylphthalate was detected in the two soil samples. Metals at a range of concentrations were found in the soil samples. The DRO fraction of petroleum hydrocarbons was detected in all but one soil sample and GRO fraction was detected in two samples.

Comparison of maximum detected concentrations with soil screening criteria are presented in the following tables. Arsenic is the only constituent detected above screening criteria. It was detected in all soil samples west of Downing Street at concentrations ranging from 13.3 milligrams per kilogram (mg/kg) to 24.9 mg/kg and east of Downing Street at concentrations ranging from 10.1 mg/kg to 15.8 mg/kg. Soils in Maine often have naturally occurring levels of arsenic that exceed Remedial Action Guidelines (RAGs) (MEDEP, 2013).

Table 4-1. Maximum VOC Detections in Soil at DA004

Detected Analytes

Maximum Detected Concentration1

(mg/kg)

Screening Criteria2 (mg/kg)

Maximum Detection Location

Boring Location Interval (ft bgs) Start End

Acetone 0.350 J 10,000 DA004 – SB06 0 1 Carbon Disulfide 0.0022 J 10,000 DA004 – SB05 0 1

Toluene 0.0033 10,000 DA004 – SB04 0 1 Notes:

1SI Report (AMEC, 2009) 2Maine RAGS for the Soil Exposure Pathway by Exposure Scenario (Residential Soil) (MEDEP, 2013).

J = Estimated result; the detection was above the method detection limit but below the laboratory’s reporting limit.

Table 4-2. Maximum SVOC Detections in Soil at DA004

Detected Analytes Maximum Detected

Concentration1 (mg/kg)

Screening Criteria2 (mg/kg)

Maximum Detection Location Boring

Location Interval (ft bgs)

Start End Bis(2-ethylhexyl)phthalate 0.198 J 770 DA004 – SB02 2 4

Di-n-butylphthalate 0.0892 10,000 DA004 – SB01 2 4 Notes:

1SI Report (AMEC, 2009) 2Maine RAGS for the Soil Exposure Scenario (Residential Soil) (MEDEP, 2013).

J = Estimated result; the detection was above the method detection limit but below the laboratory’s reporting limit.

AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine 4-2

Table 4-3. Maximum Metals Detections in Soil at DA004

Detected Analytes

Maximum Detected Concentration1

(mg/kg)

Screening Criteria2 (mg/kg)

Maximum Detection Location

Boring Location Interval (ft bgs) Start End

Aluminum 24,700 170,000 DA004 – SB05 0 1

Antimony 1.2 J 68 DA004 – SB03

DA004 – SB04

Arsenic 24.9 1.4 DA004 – SB04 2 4 Barium 42.2 10,000 DA004 – SB02 0 1

Beryllium 0.60 340 DA004 – SB05 0 1 Calcium 648 --3 DA004 – SB03 2 4

Chromium 35.2 10,0004

5105 DA004 – SB05 0 1

Cobalt 23.2 51 DA004 – SB04 2 4 Copper 42.5 2,400 DA004 – SB04 2 4

Iron 41,200 J 120,000 DA004 – SB04 2 4 Lead 17.8 340 DA004 – SB06 0 1

Magnesium 6,670 --3 DA004 – SB04 0 1 Manganese 2,590 4,100 DA004 – SB05 1 2

Mercury 0.13 J 516 DA004 – SB05 0 1 Notes:

1SI Report (AMEC, 2009) 2Maine RAGS for the Soil Exposure Scenario (Residential Soil) (MEDEP, 2013), unless otherwise noted.

3Essential nutrients that do not have regulatory screening values.

4Chromium (+3) 5Chromium (+6) 6Maine RAG for Mercuric chloride and other inorganic mercury compounds.

J = Estimated result; the detection was above the method detection limit but below the laboratory’s reporting limit.

Bold indicates exceedance of screening criteria.

Table 4-4. Maximum TPH Detections in Soil at DA004

Maximum Detected

Concentration1 (mg/kg)

Screening Criteria2 (mg/kg)

Maximum Detection Location Boring

Location Interval (ft bgs)

Start End

TPH - DRO (C10-C28) 219 J

10,0004

3,6495

DA004 – SB06 0 1

TPH - GRO (C4-C12) 19.8

1,4006

2,7007

3,7105

DA004 – SB02 0 1

Notes:

1SI Report (AMEC, 2009).

2Maine RAGSD for the Soil exposure Scenario (Residential Soil) (MEDEP, 2013), unless otherwise noted.

3C9-C10 Aromatics and C11-C22 Aromatics 4C19-C36 Aliphatics 5MEDEP Development of Risk-Based Cleanup Levels for Petroleum Hydrocarbons Measured as DRO and GRO 6C5-C8 Aliphatics 7C9-C12 Aliphatics and C9-C18 Aliphatics

Groundwater Sampling

Groundwater was encountered in soil borings SB01 and SB02 at depths of approximately 4 and 5 ft bgs, respectively. Temporary monitoring wells were placed into these two boreholes following soil sample collection. Groundwater samples were submitted for analysis of VOCs, SVOCs, metals, TPH-DRO, and TPH-GRO. The only detection of organic constituents in groundwater samples was the TPH-DRO at SB02. Eleven metals were detected in one or both of the groundwater samples.

AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine 4-3

Comparisons of the maximum detected concentrations in groundwater with groundwater screening criteria are presented in the following tables. Antimony was detected slightly above the screening criteria in the sample from SB01. Manganese was detected above the state screening criteria at SB02. Cobalt was detected in both groundwater samples at concentrations below the state screening criteria, which is likely more representative of Maine groundwater than is the lower EPA criteria. The detected levels for other metals and TPH-DRO were below the screening criteria.

Table 4-5. Maximum Metals Detections in Groundwater at DA004

Maximum Detected

Concentrations1 (µg/L)

Screening Criteria (µg/L) Maximum Detection Location MEDEP2 EPA3

Aluminum 36.7 7,000 20,0004 DA004 – SB02 Antimony 3.2 J 3 6 DA004 – SB01 Barium 15.69 J 1,000 2,000 DA004 – SB02 Calcium 2,680 J --5 --5 DA004 – SB02 Cobalt 6.7 J 10 64 DA004 – SB02

Iron 102 5,000 14,0004 DA004 – SB02 Magnesium 938 J --5 --5 DA004 – SB02 Manganese 838 500 4304 DA004 – SB02

Nickel 7.3 J 206 3904,6 DA004 – SB02 Potassium 2,640 J --5 --5 DA004 – SB01

Zinc 9.5 J 2,000 6,0004 DA004 – SB02 Notes:

1SI Report (AMEC, 2009).

2Maine Exposure Guidelines (MEGs) for drinking water (Maine CDC, 2012), unless otherwise noted. Maine RAGs for the Groundwater Exposure Pathway by Exposure Scenario (Residential Groundwater) (MEDEP, 2013) were developed to not exceed MEGs for residential groundwater and have the same screening criteria levels as MEGs.

3U.S. EPA (2012) maximum contaminant levels (MCLs), unless otherwise indicated.

4Screening toxicity values from the U.S. EPA (May 2014) regional screening level (RSL) tables for tap water, at a cancer target risk level of 1x10-6 and noncarcinogens adjusted to a hazard quotient of 1.0 5Essential nutrients that do not have regulatory screening values.

6Criteria for nickel soluble salts.

J = Estimated result; the detection was above the method detection limit but below the laboratory’s reporting limit.

Table 4-6. Maximum TPH Detection in Groundwater at DA004

Detected Analytes Maximum Detected Concentrations1 (µg/L) Screening Criteria2 (µg/L) Maximum Detected

Location

TPH-DRO (C10-

C28) 85.3 J

10,0005

DA004 – SB04

Notes:

1SI Report (AMEC, 2009).

2Maine RAGs for the Groundwater Exposure Pathway by Exposure Scenario (Residential Groundwater) (MEDEP, 2013).

3C9-C10 Aromatics and C11-C22 Aromatics 4C9-C18 Aliphatics 5C19-C36 Aliphatics

4.1.2 TU003 – UST 510

Soil Sampling

In 2009, four soil borings (SB01 through SB04) were installed in the area of the USTs associated with Building 510. The depth of the former USTs was not known; however, soil borings were advanced until auger refusal, which was between 5 to 9 ft bgs.

Groundwater was encountered in two of the four borings at approximately 6 ft bgs. A total of eight soil samples (2 from each boring ) were collected and analyzed for VOCs, SVOCs, TPH-DRO, and TPH-GRO. Surface soil samples from 0 to 2 ft bgs were collected from each boring except SB01; the second samples were collected at 2-foot intervals between 4 and 10 ft bgs. Two ketones (acetone and 2-butanone) were detected in 3 soil samples. Seven polycyclic aromatic hydrocarbon (PAH) compounds

AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine 4-4 were detected in two soil samples and TPH-DRO was detected in one sample. VOCs and TPH-GRO were not detected in any of the soil samples.

Comparison of maximum detected concentrations with soil screening criteria are presented in the following tables. All of the organic constituents detected were below screening criteria.

Table 4-7. Maximum VOC Detections in Soil at TU003

Concentration1 (mg/kg)

Screening Criteria2 (mg/kg)

Maximum Detection Location Boring

Location Interval (ft bgs)

Start End Acetone 0.200 J 10,000 TU003 – SB04 0 2

2-Butanone 0.0254 10,000 TU003 – SB04 0 2 Notes:

1SI Report (AMEC, 2009).

2Maine RAGs for the Soil Exposure Pathway by Exposure Scenario (Residential Soil) (MEDEP, 2013), unless otherwise noted.

J = Estimated result; the detection was above the method detection limit but below the laboratory’s reporting limit.

Table 4-8. Maximum SVOC Detections in Soil at TU003

Maximum Detected

Concentration1 (mg/kg)

Screening Criteria2 (mg/kg)

Maximum Detection Location Boring

Location Interval (ft bgs)

Start End Benzo(a)anthracene 0.062 2.6 TU003 – SB04 0 2

Benzo(a)pyrene 0.0542 J 0.26 TU003 – SB04 0 2 Benzo(b)fluoranthene 0.0538 J 2.6 TU003 – SB03 0 2

Benzo(g,h,i)pyrene 0.0534 J 3,700 TU003 – SB03 0 2 Chrysene 0.102 J 260 TU003 – SB03 0 2

Fluoranthene 0.0989 J 5,000 TU003 – SB03 0 2 Pyrene 0.0846 J 3,700 TU003 – SB03 0 2

Notes:

1SI Report (AMEC, 2009).

2Maine RAGs for the Soil Exposure Pathway by Exposure Scenario (Residential Soil) (MEDEP, 2013).

J = Estimated result; the detection was above the method detection limit but below the laboratory’s reporting limit.

Table 4-9. Maximum TPH Detection in Soil at TU003

Maximum Detected

Concentration1 (mg/kg)

Screening Criteria2 (mg/kg)

Maximum Detection Location Boring

Location Interval (ft bgs)

Start End

TPH-DRO (C10-C28) 131 J

10,0004

3,6495

TU003 – SB03 0 2

Notes:

1Si Report (AMEC, 2009).

2Maine RAGs for the Soil Exposure Scenario (Residential Soil) (MEDEP, 2013), unless otherwise noted.

3C9-C10 Aromatics and C11-C22 Aromatics 4C19-C36 Aliphatics 5MEDEP Risk-Based Cleanup Levels for Petroleum Hydrocarbons Measured as DRO and GRO J = Estimated result; the detection was above the method detection limit but below the laboratory’s reporting limit.

Groundwater Sampling

Groundwater was encountered in soil borings SB03 and SB04 at a depth of approximately 6 ft bgs. Temporary monitoring wells were placed in these two boreholes following soil sample collection. Groundwater samples were analyzed for VOCs, SVOCs, TPH-DRO, and TPH-GRO; however, results for TU003 did not report detections at or above the method detection limit.

AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine 4-5

4.1.3 OW005 – Former Fire House

Soil Sampling

In 2009, six soil borings (SB01 – SB06) were installed in the area of the former firehouse grit trap and sewer trench excavation.

Soil borings were advanced to auger refusal, which ranged between 13 to 15 ft bgs for borings at OW005. Groundwater was encountered in four of the six borings at approximately 3 to 6 ft bgs. A total of eight soil samples (two samples per boring) were collected and analyzed for VOCs, SVOCs, TPH-DRO, and TPH-GRO. The borings were advanced below asphalt pavement with the first sample collected from 3 to 5 ft bgs and a second deeper 2-foot interval sample collected between 6 and 12 ft bgs.

Acetone, which was detected in all of the samples, is suspected of being a laboratory artifact. Trichloroethene was detected in two samples located near the former grit trap, the deepest sampling intervals at SB02 (6 to 8 ft bgs) and SB03 (10 to 12 ft bgs).

Benzene, toluene, Ethylbenzene, and total xylene (BTEX) were found in the deep sampling interval (7 to 9 ft bgs) at SB05, which was located near the sewer trench. Carbazole, dibenzofuran, and eighteen PAHs were detected in soil samples from borings near the sewer trench, SB05 and SB06. The highest concentrations and most number of PAHs detected occurred in the 3 to 5 ft bgs sample from SB05. One PAH was detected in one sample from near the former grit trap, SB02 (6 to 8 ft bgs). For petroleum hydrocarbons, the diesel range was detected in soil from both sampling intervals in two borings near the former grit trap (SB02) and both borings near the sewer trench (SB05 and SB06). Gasoline range petroleum hydrocarbons were detected in two samples: SB01 (3 to 5 ft bgs) and SB05 (7 to 9 ft bgs). Metals at a range of concentrations were found in the soil samples.

Comparison of maximum detected concentrations in soil with soil screening criteria are presented in the following tables.

Benzo(a)pyrene was above the screening criteria in one sample (3 to 5 ft bgs at SB05) and three metals were above the screening criteria. Arsenic at a range of 8.60 to 16.7 mg/kg was above the screening criteria. New England soils are naturally high in arsenic (Ayotte, 2003; Robinson, 2006), and soils in Maine often have naturally occurring levels of arsenic that exceed RAGs (MEDEP, 2013). Thallium, which was also above the screening criteria, was only detected in one soil sample at a depth of 6 to 8 ft bgs at SB01. The VOCs and TPHs that were detected were below the screening criteria.

Table 4-10. Maximum VOC Detections in Soil at OW005

Maximum Detected

Concentration1 (mg/kg)

Screening Criteria2 (mg/kg)

Maximum Detection Location

Boring Location Interval (ft bgs) Start End

Acetone 0.118 J 10,000 OW005 – SB06 3 5 Benzene 0.243 85 OW005 – SB05 7 9

Ethylbenzene 0.0373 1,300 OW005 – SB05 7 9 Toluene 0.0191 10,000 OW005 – SB05 7 9

Trichloroethene 0.00900 85 OW005 – SB02 6 8 Xylene (Total) 0.0617 10,000 OW005 – SB05 7 9

Notes:

1SI Report (AMEC, 2009).

2Maine RAGs for the Soil Exposure Scenario (Residential Soil) (MEDEP, 2013), unless otherwise noted.

J = Estimated result; the detection was above the method detection limit but below the laboratory’s reporting limit.

Table 4-11. Maximum SVOC Detections in Soil at OW005

Maximum Detected

Concentration1 (mg/kg)

Screening Criteria2 (mg/kg)

Maximum Detection Location

Boring Location Interval (ft bgs) Start End

Acenapthene 0.0421 J 7,500 OW005 – SB05 3 5 Acenapthylene 0.128 J 7,500 OW005 – SB05 3 5

Anthracene 0.134 J 10,000 OW005 – SB05 3 5 Benzo(a)anthracene 0.645 2.6 OW005 – SB05 3 5

Benzo(a)pyrene 0.688 0.26 OW005 – SB05 3 5 Benzo(b)fluoranthene 0.735 2.6 OW005 – SB05 3 5 Benzo(g,h,i)perylene 0.521 3,700 OW005 – SB05 3 5 Benzo(k)fluoranthene 0.607 26 OW005 – SB05 3 5 Butylbenzylphthalate 0.0362 J 5,700 OW005 – SB06 7 9

Carbazole 0.0763 J 540 OW005 – SB05 3 5 Chrysene 0.845 260 OW005 – SB05 3 5

Dibenz(a,h)anthracene 0.100 J 0.26 OW005 – SB05 3 5 Dibenzofuran 0.0604 J 130 OW005 – SB05 3 5

AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine 4-6

Fluoranthene 1.630 5,000 OW005 – SB05 3 5 Fluorene 0.137 J 5,000 OW005 – SB05 3 5

Indeno(1,2,3-cd)pyrene 0.689 2.6 OW005 – SB05 3 5 2-Methylnapthalene 0.0285 J 500 OW005 – SB05 3 5

Naphthalene 0.0331 J 2,500 OW005 – SB05 7 9 Phenanthrene 0.796 3,700 OW005 – SB05 3 5

Pyrene 1.450 3,700 OW005 – SB05 3 5 Notes:

1SI Report (AMEC, 2009).

2Maine RAGs for the Soil Exposure Scenario (Residential Soil) (MEDEP, 2013).

J = Estimated result; the detection was above the method detection limit but below the laboratory’s reporting limit.

Table 4-12. Maximum Metals Detections in Soil at OW005

Maximum Detected

Concentration1 (mg/kg)

Screening Criteria2 (mg/kg)

Maximum Detection Location

Boring Location Interval (ft bgs) Start End

Aluminum 15,100 J 170,000 OW005 – SB01 3 5 Antimony 1.00 J 68 OW005 – SB06 3 5 Arsenic 16.7 1.4 OW005 – SB01 3 5 Barium 40.4 10,000 OW005 – SB01 3 5

Beryllium 0.440 J 340 OW005 – SB01 3 5 Cadmium 0.110 J 11 OW005 – SB02 6 8 Calcium 25,900 J --3 OW005 – SB02 6 8

Chromium 28.7 10,0004

5105 OW005 – SB01 6 8

Cobalt 14.1 51 OW005 – SB01 3 5 Copper 22.7 2,400 OW005 – SB02 6 8

Iron 28,700 J 120,000 OW005 – SB02 6 8 Lead 27.2 340 OW005 – SB06 3 5

Magnesium 6,940 J --3 OW005 – SB02 6 8 Manganese 1,140 J 4,100 OW005 – SB02 3 5

Mercury 0.042 516 OW005 – SB06 3 5 Nickel 44.1 510 OW005 – SB02 6 8

Potassium 1,930 --3 OW005 – SB02 6 8 Silver 0.120 J 850 OW005 – SB04 6 8

Thallium 0.390 J 0.787 OW005 – SB01 6 8 Vanadium 24.4 1,200 OW005 – SB06 3 5

Zinc 60.9 J 10,000 OW005 – SB06 3 5 Notes:

1SI Report (AMEC, 2009).

2Maine RAGs for the Soil Exposure Scenario (Residential Soil) (MEDEP, 2013), unless otherwise noted.

3Essential nutrients that do not have regulatory screening value.

4Chromium (+3) 5Chromium (+6) 6Maine RAG for Mercuric chloride and other inorganic mercury compounds.

7Screening toxicity values from the U.S. EPA (May 2014) RSL tables for Residential Soil, at a cancer target risk level of 1x10-6 and noncarcinogens adjusted to a hazard quotient of 1.0. [thallium (soluble salts)].

J = Estimated result; the detection was above the method detection limit but below the laboratory’s reporting limit.

AECOM Regional CRP PA/SI at Bangor Air National Guard Base, Bangor, Maine 4-7

Table 4-13. Maximum TPH Detections in Soil at OW005

Detected Analytes Maximum Detected

Concentration1 (mg/kg)

Screening Criteria2 (mg/kg)

Maximum Detection Location

Boring Location Interval (ft bgs) Start End

TPH-DRO (C10-C28) 137 J

10,0004

3,6495

OW005 – SB02 6 8

TPH-GRO (C4-C12) 9.42

1,4006

2,70047

3,71035

OW005 – SB05 7 9

Notes:

1SI Report (AMEC, 2009).

2Maine RAGs for the Soil Exposure Scenario (Residential Soil) (MEDEP, 2013), unless otherwise noted.

3C9-C10 Aromatics and C11-C22 Aromatics 4C19-C36 Aliphatics 5MEDEP Risk-Based Cleanup Levels for Petroleum Hydrocarbons Measured as DRO and GRO 6C5-C8 Aliphatics 7C9-C12 Aliphatics and C9-C18 Aliphatics.

Groundwater Sampling

Groundwater was encountered in soil borings SB02, SB03, SB04, and SB06, at depth ranging from 3 to 6 ft bgs. Temporary monitoring wells were placed in each borehole where groundwater was encountered following soil sampling. Groundwater samples were collected and analyzed for VOCs, SVOCs, metals, TPH-DRO, and TPH-GRO. VOCs were not detected in groundwater samples. Seven PAHs and two phthalates were detected in groundwater samples. With the exception of butylbenzylphthalate, all of the detects were found in the groundwater sample collected at SB02. Both TPH-DRO and TPH-GRO were also detected at SB02. Ten metals were also detected in the groundwater samples.

Comparison of maximum detected concentrations with groundwater screening criteria are presented in the following tables. Four of the PAHs detected at SB02 were at concentrations above screening criteria. Detection of TPH-DRO above screening criteria and a highly elevated detection of TPH-GRO were also found at SB02.