March 1998

Proposed Plan For Area of Contamination (AOC) CS-3 United States Coast Guard

Summary

After a study of the source area known as Area of Contamination (AOC) Chemical Spill 3 U.S. Coast Guard [CS-3 (USCG)], the Air Force Center for Environmental Excellence (AFCEE) is proposing that all activities associated with the investigation and cleanup of the source area are complete and no further action is necessary.

Because of its history as a full-service automobile shop and gasoline station from 1951-1979, this site was identified as an area that could potentially be contaminated and was, therefore, listed as an AOC. The primary environmental concern with the site was the potential for release of fuels, lubricants, waste oils, and other similar products that are associated with full-service automobile stations. The site is currently a gasoline station, convenience store, and garden shop known as the "3-in-1."

Soil and groundwater were sampled to locate any contamination at the CS-3 (USCG) source area. A risk assessment also was performed to determine what level of risk the site may pose. Groundwater results indicated that the site is not a significant source of groundwater contamination. Low levels of soil contamination that remain at the site do not pose a human health risk under current and future use scenarios. The chemicals and contaminant concentrations remaining in the soil are described on pages 4 and 5.

In actions separate from the Remedial Investigation, underground storage tanks (USTs) and surrounding soils were removed. In addition, contaminated soils were removed from a drainage structure, called a leaching well, located at one end of the site. The leaching well was cleaned and filled with concrete.

These activities, as well as others described in this fact sheet, significantly reduced risk to human health and the environment, leading AFCEE to recommend no further action at the CS-3 (USCG) source area.

Words that appear in italics are defined in the glossary at the end of this proposed plan.

This proposed plan was prepared by the Air Force Center for Environmental Excellence, in consultation with the U.S. Environmental Protection Agency (USEPA) and Massachusetts Department of Environmental Protection (DEP).

Learn More About AFCEE’s Proposed Plan

A public meeting will be held to discuss this proposed plan for CS-3 (USCG) on:

Wednesday, April 1, 1998
Barnstable County Fairgrounds
Administration Building
Falmouth, Massachusetts

Poster Session 6-7 PM
Information Meeting 7-8 PM

For additional information on the meeting, call Jerry Whitaker, AFCEE Community Involvement Specialist, at (508) 968-4678, extension 3.

What Do You Think?

AFCEE is accepting formal public comments on the proposed plan from April 2 through May 1. You don’t have to be a technical expert to comment-- if you have a concern or preference, AFCEE would like to hear it before making a final decision on how to address this AOC. Page 7 of this proposed plan describes how to submit a formal comment.

A public hearing will be held on:
Wednesday, April 22, 1998
Barnstable County Fairgrounds
Administration Building
Falmouth, Massachusetts

Poster Session 6-7 PM
Public Hearing 7-8 PM

Introduction

The Massachusetts Military Reservation (MMR) is located in western Cape Cod, Massachusetts. It occupies approximately 22,000 acres (35 square miles) within the towns of Bourne, Sandwich, Mashpee, and Falmouth in Barnstable County.

Military use of MMR began in 1911, although the majority of activity took place after 1935. MMR supports operations of the U.S. Army, Coast Guards, Air Force, Marine Corps, and the Air and Army National Guard. Ongoing operations at the MMR include Air and Army National Guard training, U.S. Army Reserve training, USCG Air Station Cape Cod, U.S. Air Force Precision Acquisition Vehicle Entry-- Phase Array Warning System (PAVE PAWS) missile and space vehicle tracking system, and the Massachusetts National Cemetery run by the Department of Veterans Affairs.

The Federal government has designated the groundwater aquifer underlying MMR and the surrounding area a sole-source aquifer. Drinking water for residents of the MMR and upper Cape Cod is supplied by this aquifer.

AOC Description

CS-3 (USCG) is located on Lee Road, in the southern central portion of the MMR in the town of Bourne, as presented in Figure 1. The site is the location of a former automobile service and gasoline station that operated from 1951 to 1979. Currently, the 3.5-acre site is mostly paved with a landscaped grassy area and gravel parking lot in the eastern portion of the site. On site, Building 5202 houses the "3-in-1" store which includes an operating gasoline station, convenience store, and garden shop. A series of above-ground fuel storage tanks are located in the west-northwest corner of the site. Access to the site is unrestricted. Site structures are shown in Figure 2.


Figure 1

History of Investigation

Following is a summary of investigation activities and results.

1986 A Preliminary Assessment (PA), which is a record search and interviews with past and present base personnel, was performed. It identified CS-3 (USCG) as an area that could potentially be contaminated.
1989 MMR was listed on the National Priorities List (NPL) making it a Superfund site. This designation requires sites to be investigated and cleaned up under the regulatory authority of USEPA, and under the law governing cleanup of old sites, known as the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) or Superfund law.
1991 The Federal Facilities Agreement (FFA) was signed, which identified sites to be investigated, including CS-3 USCG, and defined responsibilities and schedules for addressing sites at the MMR.

The same year, sampling for the Site Investigation (SI) was performed. The SI is an investigation to find contamination, if it is there, but not necessarily to determine how much contamination is there, or how far it may have gone.

The primary environmental concerns at CS-3 (USCG) were potential impacts to soil and groundwater associated with the operations of:

  • A total of five underground storage tanks (USTs) known as Current Product Tank 40 (CPT-40), CPT-41, CPT-42, CPT-43, and Abandoned Tank 23 (AT-23), and the associated fueling systems.
  • A leaching well and associated drainage pipes.
  • Petroleum contaminated soils which had been excavated from another AOC, known as Fuel Spill 27 (FS-27), located east of the Otis Golf Course, and used as fill material north of Building 5202 on the site.

As a result of the findings of the SI, a Remedial Investigation (RI) was required to determine more fully the extent of contamination and the level of potential risk posed by the site.
1993/4 The RI, which determines where contamination is and how much is there, was performed. An RI also includes a risk assessment, which considers the contaminants present and their toxicity, as well as potential receptors and how they might be exposed, in order to determine the potential risk the site poses to human health or the environment.

In 1994, three USTs, (CPT-40, 41, and 42), which had been used for storing gasoline, were removed and replaced with above-ground tanks. Some contaminated soils also were removed. The tanks (two 10,000-gallon and one 6,000 gallon) were not thought to be leaking; however, they were removed as part of a nationwide Air Force initiative to remove all USTs and replace them with above-ground tanks. Figure 2 shows the former locations of the three tanks that were removed. Table 1, below, presents the concentrations of contaminants found in soil and groundwater at and downgradient of these three USTs after the tanks were removed.

Table 1: Results from CPT 40, 41, and 42

Contaminant

Highest Concentration

Action Level

Soils
Total Petroleum Hydrocarbons (TPH) 160 mg/kg 500 mg/kg
Total xylene 8.4 mg/kg 500 mg/kg

MW-6 (Groundwater)
1,2 Dichloromethane 0.6 m g/L 5.0 m g/L
Lead (filtered) 1.3 m g/L 15 m g/L

MW-2 (Groundwater)
Acetone 6.1 m g/L 3,000 m g/L
Ethylbenzene 1.4 m g/L 70 m g/L
Total Xylenes 26 m g/L 10,000 m g/L
Mercury 1.6 m g/L 2.0 m g/L
Total Trimethylbenzene 129 m g/L 200 m g/L
A 1,000-gallon UST (AT-23), located under the north side of Building 5202, was used to hold waste oils and other similar products from 1953 to 1983. In 1985, when the tank was pressure-tested and found to be leaking, the UST and associated petroleum-contaminated soils were removed from the site. An above-ground tank replaced the UST. The location of the UST was re-evaluated during the RI. Only trace levels of contamination were detected indicating that the removal was successful and no further action is necessary. Table 2 presents the concentrations of contaminants found in soil and groundwater at and downgradient of the former UST.

Table 2: Results from AT-23

Contaminant

Highest Concentration

Action Level

Soils
TPH 22 mg/kg 500 mg/kg
Bis 2)Ethyl Hexyl Phthalate 37 m g/kg 6280 m g/kg
Ketones 0.01 mg/kg .3 mg/kg

MW-4 (Groundwater)
No contamination detected.
Another 10,000-gallon UST (CPT-43) was reportedly installed in the 1970s for storing diesel fuel. However, there is no record that the tank was ever used. In spite of the use of ground-penetrating radar, the tank was never located during the study.

Because plans were underway to remove the leaching well located at the west end of Building 5202 as part of the Drainage Structure Removal Program (DSRP), the RI did not investigate soils around the leaching well. The DSRP is a program under which all of the drainage structures on the base with the potential for causing environmental problems were removed. Although soils were not sampled, monitoring wells were sampled immediately downgradient of the leaching well to ensure protection of groundwater. Table 3 presents the concentrations of contaminants found in groundwater downgradient of the well.

Table 3: Results from Leaching Well Area

Contaminant

Highest Concentration

Action Level

MW-3 (Groundwater)
Thallium 2.5 m g/L* 2.0 m g/L
No organic compounds detected.
* This concentration, above the MCL, occurred in only one well. A duplicate sample taken from the same well at the same time came up non-detect. Samples from the five surrounding wells were all non-detect for thallium.
A stockpile of soils that had been excavated from another AOC on the base (FS-27) is located north of Building 5202. Sampling during the RI revealed only trace contamination, except for one sample that had elevated concentrations of petroleum hydrocarbons. However, this sample contained pieces of asphalt pavement which caused the high results. Table 4 presents the concentrations of contaminants found in soil and groundwater at and downgradient of this fill area.

Table 4: Results from FS-27 Soils Fill Area

Contaminant

Highest Concentration

Action Level

Soils
TPH 242 mg/kg 500 mg/kg
1,2 Dichloromethane 0.6 m g/kg 5.0 m g/kg

MW-5 (Groundwater)
Acetone 4 m g/L 3,000 m g/L
1996 Although the original plan was to remove the leaching well as part of the DSRP, a portion of it underlies the eastern end of Building 5202 which made the removal prohibitive. Contaminated sediments and sludge in the leaching well were removed and the leaching well was cleaned and filled with concrete. Table 5 presents the concentration of contaminants found in soils around the leaching well.

Table 5: Results from Leaching Well Area

Contaminant

Highest Concentration

Action Level

Soil Around Leaching Well
Chlordane 18.6 m g/kg 1000 m g/kg
DDT 14 m g/kg 6280 m g/kg
Toluene 1m g/kg 1000 m g/kg
2 Butanone 4 m g/kg 10,600 m g/kg
Benzo (a) Pyrene 140 m g/kg 5000 m g/kg
Benzo (b) Fluoranthene 320 m g/kg 5000 m g/kg
TPH 41 mg/kg 500 mg/kg
Results of the Risk Assessment

The RI for CS-3 (USCG) included the evaluation of potential risks to human and ecological receptors. The risk assessment examined the potential current exposure pathways for utility workers and children wandering onto the site, as well as future residential exposure scenarios for children and adults. Risk levels for soil were below federal and state guidelines under the current and future use scenarios. As measured by hazard indexes, non-cancer effects are determined to be unlikely for either utility workers or children on the site.

The ecological risk assessment results suggest some potential risk to certain terrestrial species (i.e., white-footed mouse, meadow vole, short-eared owl, northern cardinal, upland sandpiper, northern short-tailed shrew, red fox) from exposure to metals and surface soils. However, when site contamination was compared to background levels in MMR soils, results indicate that, for most metals, background soil concentrations on the MMR are comparable to those at CS-3 (USCG). Background concentrations accounted for all or nearly all of the risk for the terrestrial species, suggesting that further investigation of this potential risk was not warranted.

In summary, the risk assessment concluded that no significant risk or harm to potential receptors exists at the site and therefore no further remedial action is recommended. The RI concluded that there was no risk to human health and the environment; therefore, a Feasibility Study (FS) was not prepared.

Acronyms

AFCEE: Air Force Center for Environmental Excellence
AT: Abandoned Tank
CPT: Current Product Tank
DSRP: Drainage Structure Removal Program
FS: Fuel Spill
MADEP: Massachusetts Department of Environmental Protection
MMR: Massachusetts Military Reservation
PAVE PAWS: Precision Acquisition Vehicle Entry--Phase Array Warning System
TPH: Total Petroleum Hydrocarbons
USCG: U.S. Coast Guard
USEPA: U.S. Environmental Protection Agency
UST: Underground storage tank

How to Submit a Formal Comment

During the public comment period, AFCEE will accept written comments on the proposed plan, and will hold a public hearing to accept either verbal or written comments. Please note that there is a distinction between formal comments received during the public comment period and informal comments received outside of the comment period. AFCEE is required to respond in writing to formal comments when a final decision is made.

Formal comments will become part of the official public record. AFCEE will consider all formal comments received during the public comment period prior to making the final decision for the site.

A transcript of all formal comments and AFCEE’s written responses will be issued in a document called the Responsiveness Summary that will accompany the Record of Decision for CS-3 (USCG). Copies of the Responsiveness Summary will be mailed to everyone who submits a formal comment. In addition, AFCEE will announce the decision through the local news media and the site mailing list. AFCEE will publish a formal response for late comments.

You may submit a formal comment in any of the following ways:

  1. Submit written comments during the public comment period that will extend from April 2 through May 1 to:
    HQ AFCEE/MMR
    Attn: CS-3 (USCG)
    322 East Inner Road
    Otis ANGB, MA 02542-5028
  2. Offer verbal comments during the public hearing to be held on April 22, 1998, 7-9 PM.
  3. Submit comments by fax at (508) 968-4673.
  4. Submit comments by electronic mail addressed to jwhitaker@mafmh.ang.af.mil
  5. Send a message using the comment form on the MMR website (http://www.mmr.org).

For More Information

This proposed plan summarizes the information that can be found in greater detail in the RI for CS-3 (USCG). The RI and proposed plan are contained in the Administrative Record (AR) file for this site.

The Record of Decision and Responsiveness Summary will be added to the AR upon completion. The public is invited to review the AR and comment on this proposed plan during the public comment period.

The AR is available for review at the Installation Restoration Program (IRP) Office, which is located at 322 East Inner Road and is open Monday-Friday, 8:00 AM-4:30 PM. It is also available for review at the Falmouth Public Library, located at 123 Katharine Lee Bates Road. Call (508) 457-2555 for the library’s hours.

Information and technical documents, including the RI, also are available at the main libraries in Bourne, Falmouth, Mashpee, and Sandwich; at the USCG library on base; and on the MMR website at http://www.mmr.org

Glossary

Action Levels: the existence of a contaminant concentration in the environment high enough to warrant action or trigger a response.

Administrative Record (AR): a collection of documents generated during the investigation of the site placed in a central location for public review.

aquifer: an underground geological formation containing usable amounts of groundwater that can supply wells and springs.

Area of Contamination (AOC): a portion of a Superfund site where investigations have established that contamination exists and requires further assessment.

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA): a law, commonly known as Superfund, that authorizes the Federal government to respond directly to releases of hazardous substances that may endanger public health or the environment.

Feasibility Study (FS): a report that identifies and screens potential cleanup alternatives for a site that requires further remedial action.

Federal Facilities Agreement (FFA): an agreement between USEPA and individual federal facilities which establishes a procedural and legal framework for investigation and performing remedial actions at Superfund sites.

Installation Restoration Program (IRP): the Department of Defense program implemented at United States military bases to identify, investigate, and cleanup contamination resulting from past operations.

National Priorities List (NPL): USEPA list of uncontrolled or abandoned hazardous waste sites that are priorities for long-term remedial evaluation and response. NPL sites are eligible to receive federal funds for investigation and cleanup under the Superfund program.

Organics: Carbon and hydrocarbon-based compounds, such as fuels, oils, and solvents.

Preliminary Assessment (PA): the process of collecting and reviewing available information about a suspected hazardous waste site to determine whether the site requires further study.

proposed plan (PP): a document that summarizes for the public the preferred remedial action for a site and presents the rationale for the preference.

Record of Decision (ROD): a document presenting the remedial action selected under agreement with the regulatory agencies.

Remedial Action: remediation conducted to reduce or eliminate the long-term risks to human health or the environment from exposure to contaminants.

Remedial Investigation (RI): an investigation to gather and analyze the data necessary to determine the nature and extent of contamination at a site, and to provide information for identifying and evaluating options for remedial action.

Responsiveness Summary: a document presenting formal comments received during the public comment period with responses.

Risk Assessment (RA): an evaluation to determine the risk posed to human health and the environment as a result of exposure to a contaminant.

Site Investigation (SI): an investigation to find contamination, if it is there, but not necessarily to determine how much contamination is there, or how far it may have gone. It is used to determine whether further investigation is required.

For additional information, please contact:

Jerry Whitaker
Community Involvement Specialist
HQ AFCEE/MMR
322 East Inner Road
Otis ANGB, MA 02542-5028
Phone: (508) 968-4678 ext. 3
FAX: (508) 968-4673
jwhitaker@mafmh.ang.af.mil

Johanna Hunter
Community Relations Manager
USEPA Region I
JFK Federal Building, RAA
Boston, MA 02203
Phone: (617) 565-3425
FAX: (617) 565-3415
jhunter@epamail.epa.gov

Ellie Grillo
Community Involvement Coordinator
MassDEP
20 Riverside Drive
Lakeville, MA 02346
Phone: (508) 946-2866
FAX: (508) 947-6557
Ellie.Grillo@state.ma.us