June 1999

Proposed Plan for Cleanup Related to FS-1

The Preferred Alternative
After completing two studies called the Remedial Investigation Report (RI) and the Feasibility Study for Fuel Spill 1 (FS-1) groundwater plume and source area, the Air Force Center for Environmental Excellence (AFCEE) has identified a preferred remedial action. The preferred remedial action will reduce potential risks from groundwater and surface water from FS-1.

The AFCEE preferred remedial action for groundwater and surface water is Alternative 3B Axial and Leading Edge Extraction, Treatment and Reinjection/Discharge, as identified in the Feasibility Study. In the opinion of AFCEE, this alternative best meets Remedial Action Objectives (RAOs). Alternative 3B includes active remediation of groundwater in the downgradient impacted areas and groundwater monitoring in the source area. No action is warranted for source area soils or subsurface soils.

The final configuration will be developed in the remedial design phase of the program. The key elements of the preferred alternative are:

1. Continue operation of the current Leading Edge ETR system that is presently operating in the Quashnet River cranberry bogs and evaluate the effectiveness and ecological impact of that ETR system.
   
2. Remedial design and construction of a system to be located in the body of the plume that is designed to meet the objective outlined in the 3B remedial alternative with respect to restoration timeframe, total mass removal and plume capture.
   
3. Monitoring of source area groundwater.
   
4. Long-term monitoring, and operation and maintenance of preferred remedial alternative.
   
5. Institutional controls to reduce the risk of current and future exposure to contaminated groundwater until cleanup goals are achieved.
   
6. Five-year reviews after initiation of remedial action to ensure that the remedy continues to provide adequate protection of human health and the environment.

Words that appear in italics are defined in the Glossary at the end of this page.

Learn More About AFCEE’s Proposed Plan
AFCEE will describe the Proposed Plan for cleanup of the FS-1 site at a poster session, which will be followed by a presentation with an informal question and answer session at a public information meeting.

A public meeting will be held on
Thursday, June 3, 1999
Mashpee Town Hall, Room #2
Mashpee, MA
Poster session: 6:00-6:30 p.m.
Informational meeting: 6:30-8:00 p.m.

For additional information concerning the meeting, please call the Installation Restoration Program (IRP) Community Involvement Office at (508) 968-4678.

What Do You Think?
AFCEE is accepting formal comments on this Proposed Plan including all alternatives evaluated for FS-1, supporting technical documents from June 4, 1999, through July 3, 1999, during the public comment period. You do not have to be a technical expert to comment. If you have a concern or a preference, AFCEE, the U.S. Environmental Protection Agency (EPA), and the Massachusetts Department of Environmental Protection (DEP) want to hear it before making a final decision on how the cleanup should proceed to protect your community. Your formal comments will be included in the Administrative Record for FS-1.

A public hearing will be held on
Wednesday, June 23, 1999
Mashpee Town Hall, Room #2
Mashpee, MA
Poster session: 6:00-6:30 p.m.
Public hearing: 6:30-7:30 p.m.

Page 9 of this Proposed Plan describes various ways you can submit your formal comments during the public comment period. You do not have to be present at the Public Hearing to submit a formal comment.

Introduction
In accordance with Section 117(a) of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), this Proposed Plan (1) describes the remedial alternatives AFCEE evaluated to address groundwater and surface water contamination associated with FS-1 and (2) identifies AFCEE’s preferred alternative and explains AFCEE’s rationale for that preference.

The EPA placed the Massachusetts Military Reservation (MMR) on the National Priorities List in 1989 for investigation under CERCLA. A Federal Facility Agreement, signed in 1991 and subsequently amended, requires AFCEE to take the lead in cleanups at MMR, including FS-1. AFCEE’s activities to date, carried out under the Installation Restoration Program (IRP), include the performance of a Site Inspection (SI), and a Remedial Investigation (RI) at, and downgradient of, FS-1 to characterize the nature and extent of contamination. Risk Assessments were performed as part of the RI to identify potential risks from exposure to contaminants associated with FS-1. The risk assessments evaluated the potential present and future risks to human health and the environment that may be posed by existing conditions, assuming no remedial action is taken. Cancer and non-cancer risks were evaluated. Additional activities included preparation of a Feasibility Study to develop and evaluate remedial action alternatives to reduce estimated present and future risks.

This Proposed Plan summarizes the information in the RI and Feasibility Study and presents remedial alternatives that were evaluated for cleanup of the groundwater and surface water related to FS-1. Figure 1 shows the area of groundwater and surface water in the Quashnet River and associated cranberry bogs that are addressed by the recommended remedial action in this Proposed Plan.

After careful consideration of the four remedial alternatives evaluated in the Feasibility Study, AFCEE believes Alternative 3B, with refinements, provides the best balance of the nine criteria to protect human health and the environment and will comply with environmental laws and regulation.

Description and History of FS-1
The FS-1 source area is located in the southeastern portion on MMR adjacent to Taxiway E of MMR in the town of Mashpee, Massachusetts. FS-1 was used by the 551st Airborne Early Warning and Control Wing to test fuel dump valves between 1955 and 1970. The valves were opened and the fuel was allowed to drain onto concrete. Initially, records suggest the fuel was hosed off the concrete. Records also indicate that the fuel was collected in 55-gallon barrels. The exact quantity of fuels released onto the concrete is unknown.

Groundwater Plume
The FS-1 groundwater plume is now detached from the source area and extends from approximately 2,000 feet south of the source area to an upwelling area at the Quashnet River cranberry bogs (Figure 1). The contaminated groundwater currently is not used as a public water supply. The Town of Mashpee has made plans to potentially install a drinking water supply well east of the FS-1 contaminated groundwater plume.

Figure 1. FS-1 EDB Plume and Source Area.

History of Investigation
Investigative work at FS-1 includes a records search, a Site Investigation (SI), and a Remedial Investigation (RI). Data from other investigations not directly related to FS-1 were also incorporated into the RI because those studies contribute to an understanding of FS-1. The following items summarize the history of investigations related to FS-1.

• 1983 A records search was performed using the Hazard Assessment Rating Methodology, which indicated the need for further investigation at FS-1.
• 1985 An initial environmental investigation (Phase II, Stage I study) was performed in the source area. Explorations included eight test pits and one water table well. No contamination was identified.
• 1989 An SI was performed in the source area. Explorations included 30 soil gas sampling points, 1 soil boring, and 3 monitoring wells. Fuel-related compounds were detected in groundwater above safe drinking water standards know as Maximum Contaminant Levels (MCLs).
• 1990 An initial RI was performed. Seven source area wells were installed, and two source area soil borings were completed. Twelve downgradient wells were installed in two well fences. Four additional water table wells were installed to aid in determining local groundwater flow. Source area wells contained fuel-related compounds.Of these, only toluene and lead were above MCLs. Downgradient wells did not contain levels of fuel-related compounds above the MCL. Because of the absence of fuel-related compounds in downgradient groundwater, it was hypothesized that the fuel compounds had degraded.
• 1993 A basewide ethylene dibromide (EDB) study included collection and analyses of groundwater for EDB from seven FS-1 source area wells. EDB was not detected in the samples.
• 1995 A Geoprobe investigation was performed to track a potential path of fuel contamination from FS-1. Twenty multi-level locations were sampled for fuel constituents and indicators of fuel biodegradation. Additionally, three new wells were installed and five surface soil samples were collected in the source area. No contamination was identified.
• 1997–1998 Additional downgradient groundwater and surface water investigations were performed as a result of public comments concerning FS-1. Thirty-two downgradient wells were installed along a path that had not been investigated. Thirty-nine surface water samples and seven sediment samples were collected from the Quashnet River and the Quashnet River cranberry bogs. This investigation identified a plume of EDB-contaminated groundwater discharging into the Quashnet River cranberry bogs.
• 1999 Selected source area wells were resampled in 1999 to resolve issues of source area detections of lead, toluene, and methylene chloride in groundwater samples collected in 1989 and 1990.

Summary of Site Characteristics
From 1997 through early 1999, AFCEE completed a Remedial Investigation/Feasibility Study for FS-1. The Remedial Investigation/Feasibility Study was conducted to identify the types, quantities, and location of contamination and to develop possible ways to address the contamination problems. A summary of the contamination issues follows.

• Source Area Surface Soils: Surface soil samples (less than 24 inches from the surface) at the source area did not contain significant levels or quantities of organic compounds. Some metals were detected at levels above background, but do not represent a risk to human health in a utility worker scenario and the environment. Because of the lack of contamination, source area surface soils do not require cleanup.

• Source Area Subsurface Soils: Minimal levels or quantities of contaminants were identified in source area subsurface soils (24 inches or deeper). No contaminants were present in subsurface soils at the source area in concentrations that would cause continuing degradation of groundwater. Only one compound, methylene chloride, was quantified at elevated levels. The methylene chloride was identified in samples from approximately 60 feet below ground surface. It was not retained as a contaminant of concern (COC) because there is no history of use of this chemical at this source area and it is a common laboratory contaminant introduced into samples as part of lab procedures. Because of the lack of compounds that would continue to degrade groundwater, subsurface soils do not pose a threat of contaminating groundwater.

• Source Area Groundwater: Source area groundwater contained methylene chloride, lead and toluene at levels exceeding MCLs during the 1989 sampling round. Methylene chloride was not retained as a COC because there is no history of site use and the 1999 groundwater samples did not contain methylene chloride. Iron, thallium, toluene and lead were also at elevated levels in some groundwater samples collected from the source area. Based on 1999 sampling, toluene, lead and thallium were retained as COCs for source area groundwater.

• Downgradient Groundwater: Thirty-two wells installed to monitor downgradient groundwater contained EDB at concentrations up to 10 micrograms per liter (Fg/L). The EDB plume is approximately 6,950 feet long, 600 to 1200 feet wide, and 50 to 150 feet thick. The upper edge of the plume is 80 to 100 feet below ground surface and over 50 feet below the water table except in the vicinity of the Quashnet River bogs where the plume rises to the surface and discharges to the bogs. The maximum thickness of the plume occurs in the area of the Quashnet River bogs. During modeling of the plume, affected groundwater volume was estimated at 4,000 acre feet (1.3 billion gallons) and the average EDB concentration within the plume was estimated at 0.2 Fg/L. The total volume of EDB contained in the plume was estimated at 0.35 gallons. The federal MCL for EDB is 0.05 mg/L and the state MCL is
  0.02mg/L. A single detection of arsenic was identified above MCLs, at a depth of 180 feet below ground surface. Arsenic was detected in one out of 32 samples, however it was not retained as a COC because of the low detection frequency and it is not related to FS-1.

• Surface Water: Surface water in the Quashnet River cranberry bogs contained EDB at concentrations up to 1.43 m g/L in the area of groundwater discharge. EDB concentrations dissipate rapidly downstream of the Quashnet River cranberry bogs.

• Sediment: A single detection of EDB of 0.075 ug/kg was found in one of the seven sediment samples from the Quashnet River Bogs.

Summary of Potential Site Risks
A risk assessment was conducted for FS-1 to determine the potential current and future impacts of contamination on human health and the environment. The risk assessment evaluated potential health effects to residents, utility workers, cranberry workers, recreational youth, and recreational fishermen as a result of possible exposure to contaminants at FS-1 within soils, groundwater, sediments, and surface water. Human health impacts were evaluated for both maximum and average concentrations of contaminants. The ecological sections of the risk assessment evaluated potential effects of contaminated soils, sediments, and surface water on representative aquatic, semiaquatic, and terrestrial wildlife and plants.

Calculations of these risk scenarios did not produce an unacceptable human health risk to utility workers as a result of exposure to contamination related to FS-1 source area surface soils. Risks to cranberry workers and recreational youths exposed to EDB in surface water were within EPA's risk range of 10-6 to 10-4, and less that the MADEP target risk level of 10-5.

Total potential cancer risks exceed EPA and MassDEP target risk levels for future residents potentially exposed to groundwater. The primary routes of exposure contributing to this were ingestion of groundwater and inhalation of vapors if showering with contaminated groundwater. The downgradient groundwater COC was EDB. EDB contributed 98% of the total possible future carcinogenic risk estimated from exposure to the contaminated groundwater. Toluene, lead, and thallium are source area COCs. Total potential non-cancer risks from possible future exposure to groundwater exceed MADEP and USEPA target risk levels for EDB and toluene. Maximum concentration of lead in groundwater could pose a potential health concern to children based on Integrated Exposure Uptake Biokinetic (IEUBK) modeling. Thallium in the source area groundwater exceeded its MCL in several wells.

Potential cancer risks for future recreational fisherman, who may wade in the river or eat fish from the Quashnet River and associated cranberry bog area exceeded the MADEP target risk level of 10-5. The majority of the potential cancer risk is from the ingestion of fish that may contain EDB in edible tissue.

The ecological risk assessment concluded that it is unlikely that the contaminants present in soils, sediments, ground-water, and surface water are likely to cause adverse effects in animals or plants.

How Does AFCEE Choose a Final Cleanup Plan?
AFCEE uses nine criteria, required by law, to select a cleanup plan or remedy that has the best balance of protecting human health and the environment, maintaining protection over time, and minimizing untreated waste. The following list highlights the questions AFCEE must consider in selecting a cleanup plan. More detailed definitions are contained in the Feasibility Study Report for FS-1.

Threshold Criteria

1. Overall protection of human health and the environment: Will the alternative protect human health and plant and animal life on and near the site? AFCEE must choose a plan that meets this criterion.
2. Compliance with Applicable or Relevant and Appropriate Requirements (ARARs): Does the alternative meet all pertinent federal and state environmental statutes, regulations, and requirements? AFCEE must choose a plan that meets this criterion.

Balancing Criteria

3. Long-term effectiveness and permanence: How reliable will the alternative be at long-term protection of human health and the environment? Is site contamination likely to present a risk again? This criterion also takes into consideration the subcriteria of 100 percent capture and treatment to background.
4. Reduction of toxicity, mobility, or volume through treatment: Does the alternative incorporate treatment to reduce the harmful effects of the contaminants, their ability to spread, and the amount of contaminated material present?
5. Short-term effectiveness: How soon will site risks be adequately reduced? Are there short-term hazards to workers, the community, or the environment that could occur during the cleanup process?
6. Implementability: Is the alternative technically and administratively feasible? Are the goods and services (e.g., treatment machinery, space at an approved disposal facility) to implement the alternative readily available?
7. Cost: Costs presented in this document represent the present worth value for both capital and operations and maintenance costs incurred over the anticipated lifecycle of the alternative.

Modifying Criteria

8. State acceptance: Do state environmental agencies agree with AFCEE’s recommendations? What are their preferences and concerns?
9. Community acceptance: What suggestions or modifications do residents of the community offer during the comment period? What are their preferences and concerns?

Of these nine criteria, protection of human health and the environment and compliance with ARARs are considered threshold criteria that must be met for a candidate cleanup alternative to be selected. The next five criteria, called balancing criteria, are used to evaluate and compare the alternatives. This comparison assesses which alternative provides the best balance of trade-offs with respect to long-term effectiveness and permanence; reduction of toxicity, mobility, or volume through treatment; short-term effectiveness; implementability; and cost. State and community concerns are considered modifying criteria factored into a final balancing of all criteria to select a remedy. Consideration of state and community comments may prompt AFCEE to modify aspects of the preferred alternative or decide that another alternative provides a more appropriate balance.

Remedial Action Objectives
The following Remedial Action Objectives (RAOs) were developed to reduce or eliminate identified potential risks.

• Prevent or reduce exposure to groundwater contaminants of concern exceeding cleanup standards in groundwater.
• Restore the aquifer to beneficial uses within a reasonable time frame.
• Prevent or reduce worker and recreational youth and adult wader contact with Quashnet River water containing unacceptable concentrations of EDB, and ingestion of fish exposed to Quashnet River water containing unacceptable concentrations of EDB.

Development and Comparison of Alternatives
Potential remedial alternatives for the FS-1 plume are discussed in detail in the Feasibility Study. Alternatives were initially screened based on required EPA criteria including: effectiveness, implementability, and cost in accordance with USEPA guidance. Alternatives that were considered potentially acceptable based on the initial screening were then evaluated further in a detailed analysis. The detailed analysis used seven of the nine EPA required criteria for evaluation and comparison. Those criteria are: overall protection of human health and the environment; compliance with applicable or relevant and appropriate requirements (ARARs); long term effectiveness and permanence; reduction of toxicity, mobility, or volume through treatment; short-term effectiveness; implementability; and cost. The remaining two EPA criteria, state acceptance and community acceptance will be evaluated after the public comment period. Only those alternatives that received detailed analysis are discussed in this Proposed Plan. Alternative names and numbers used in this Proposed Plan are the same as those used in the Feasibility Study. The sections of the Feasibility Study providing full discussion of the alternatives are referenced in the text and table of this Proposed Plan.

Remedial Alternatives for FS-1 Plume
The COC in the off-base FS-1 plume is EDB. Active remediation alternatives are designed to extract and treat that portion of the plume containing EDB. Toluene, thallium and lead are restricted to the on-base source area. Because there are no current groundwater exposure pathways and these contaminants are not mobile, active remedial alternatives were not developed for the source area groundwater. All alternatives, except alternative 1, include institutional controls, five-year reviews, and monitoring to ensure that the contaminants have not migrated.

AFCEE has evaluated four alternatives in detail for the FS-1 plume.

Alternative 1: No Action. This alternative is included for comparative purposes as required by CERCLA guidance. Under this alternative, no action would be taken to reduce risk from the plume. This alternative is not protective of human health or the environment but is included as a baseline for comparison of other alternatives.

Alternative 2B: Limited Action with Leading Edge Extraction, Treatment, and Reinjection/Discharge. Alternative 2B would include active ETR of groundwater in the immediate vicinity of the bogs plus construction of berms to isolate areas of the bog to which the FS-1 plume discharges. The ETR system would consist of one high-volume extraction well (EW-5) and 135 shallow extraction well points. The combined extraction system would extract approximately 600 gallons per minute (gpm). The extracted groundwater would be treated in a treatment plant using granulated activated carbon (GAC) and reintroduced into the bogs and the aquifer; 400 gpm would be discharged to surface water in the bogs and 200 gpm would be reinjected to the aquifer beneath the bogs. This alternative is currently undergoing pilot testing as the Pilot Test/Bog Separation work. Modeling for Alternative 2B indicates that within 11 years the extraction of groundwater in the bog area would result in the capture of approximately 68% of EDB presently contained in groundwater. Approximately 18% of the EDB would escape the extraction system and discharge naturally into the Quashnet River; 14% of the EDB would remain in the aquifer. The extraction system is located at the toe of the plume and as a result, cleanup relies on movement of contamination along the full length of the plume before contaminants enter the extraction wells. In addition to the active remediation, Alternative 2B includes institutional controls to prevent consumption of contaminated groundwater, contact with surface water and consumption of fish in contaminated surface water until active remediation is complete. The authority for institutional controls for FS-1 involve on-base and off-base authorities. For source area groundwater, there is no immediate risk. Residents and workers on the base obtain drinking water from the base water supply system. Construction projects on MMR, including water supply wells, require written approval from the Base Civil Engineer. Construction of a new drinking water supply well for MMR would also require MassDEP permission. For downgradient groundwater and surface water, institutional controls must ba enacted by the Town of Mashpee. Mashpee has placed a moratorium on wells impacted by contaminated groundwater and has posted the Quashnet River cranberry bogs. Alternative 2B also includes groundwater monitoring at the on-base source area to ensure that toluene, thallium, and lead at the source area do not migrate.

Alternative 3: Axial Well Extraction, Treatment, and Reinjection/Discharge. Alternative 3 would include active ETR of groundwater from a well field that would be located down the center of the groundwater plume. The extraction system would be composed of 20 wells pumping a total of 600 gpm. Extracted groundwater would be treated with a GAC system and reintroduced into the bogs; 400gpm would be discharged to surface water and 200 gpm would be reinjected to the aquifer beneath the bogs. Estimates derived from modeling of similar scenarios indicates that 83% of the EDB would be captured by the extraction system, 11% of the EDB would escape the extraction system and discharge naturally into the Quashet River, and 6% of the EDB would remain in the aquifer after 7 years of operation. In addition to the active remediation, Alternative 3 would include institutional controls to prevent consumption of contaminated groundwater, contact with surface water and consumption of fish in contaminated surface water until active remediation is complete. The authority for institutional controls for FS-1 involve on-base and off-base authorities. For source area groundwater, there is no immediate risk. Residents and workers on the base obtain drinking water from the base water supply system. Construction projects on MMR, including water supply wells, require written approval from the Base Civil Engineer. Construction of a new drinking water supply well for MMR would also require MassDEP permission. For downgradient groundwater and surface water, institutional controls must be enacted by the Town of Mashpee. Mashpee has placed a moratorium on wells impacted by contaminated groundwater and has posted the Quashnet River cranberry bogs. Alternative 3 also includes groundwater monitoring at the on-base source are to ensure that contaminants do not migrate and RAOs are achieved.

Alternative 3B: Axial and Leading Edge Extraction, Treatment, and Reinjection/Discharge: (Preferred) This alternative is a combination of Alternative 2B and Alternative 3. Alternative 3B would include ETR of groundwater extracted from along the axis of the plume and in the immediate vicinity of the bogs. It would also include construction of berms to isolate areas of the bog to which the FS-1 plume discharges. The ETR system would consist of multiple extraction wells along the axis of the plume, 1 high-volume extraction well (EW-5) in the vicinity of the bog, and 135 shallow extraction well points in the vicinity of the bogs. The combined extraction system would extract approximately 1,000 gpm. Modeling performed during the feasibility study included 20 wells. However, the final number of extraction wells would be determined during remedial design after data gap work and additional numerical modeling. The extracted groundwater would be treated in a treatment plant using GAC and reintroduced into the bogs and the aquifer; 600 gpm would be discharged to surface water in the bogs and 400 gpm would be reinjected beneath the bogs. The leading edge aspect of this alternative is currently undergoing pilot testing as the Pilot Test/Bog Separation work. The model estimates that within 7 years, 83% of the EDB would be captured by the extraction system, 11% would escape the extraction system and discharge naturally, and 6% would remain in the aquifer adsorbed to sediments or in dead end pores. In addition to the active remediaton, Alternative 3B would include institutional controls to prevent consumption of contaminated groundwater, contact with surface water and consumption of fish in contaminated surface water until active remediation is complete. The authority for institutional controls for FS-1 involve on-base and off-base authorities. For source area groundwater, there is no immediate risk. Residents and workers on the base obtain drinking water from the base water supply system. Construction projects on MMR, including water supply wells, require written approval from the Base Civil Engineer. Construction of a new drinking water supply well for MMR would also require MassDEP permission. For downgradient groundwater and surface water, institutional controls must be enacted by the Town of Mashpee. Mashpee has placed a moratorium on wells impacted by contaminated groundwater and has posted the Quashnet River cranberry bogs. Alternative 3B also includes groundwater monitoring at the on-base source area to ensure that contaminants do not migrate and RAOs are achieved.

Evaluation Criteria	1 No Action	2B Limited Action with Leading Edge Extraction, Treatment, and Reinjection/ Discharge	3 Axial Well Extraction, Treatment, and Reinjection/ Discharge	3B Axial and Leading Edge Extraction, Treatment, and Reinjection/ Discharge
Feasibility Study Section	7.2.1	7.2.3	7.2.4	7.2.5
Threshold Criteria
Overall Protection of Human Health and the Environment
Compliance with ARARs
Primary Balancing Criteria
Long-Term Effectiveness and Permanence
Reduction of Toxicity, Mobility, or Volume Through Treatment
Short-Term Effectiveness
Implementability
Cost ($ in millions)	$ 0	$ 9.4	$ 8.7	$10.5
Modifying Criteria
State Acceptance	TBD	TBD	TBD	TBD
Community Acceptance	TBD	TBD	TBD	TBD
Meets or exceeds criteria     Partially meets criteria or is less effective or        more difficult to implement    Does not meet criteria		ARARs = applicable or relevant and appropriate requirements TBD = to be determined

AFCEE's Preferred Alternative
AFCEE’s preferred alternative for the FS-1 plume is Alternative 3B because it is protective of human health and the environment and has advantages over Alternatives 3 and 2B with respect to the amount of EDB removed from the aquifer and the reduced time for the cleanup. If implemented, Alternative 3B will restore the aquifer to cleanup standards and all other RAOs. The leading edge extraction, treatment and reinjection system portion of Alternative 3B is presently extracting and treating groundwater at the Quashnet River cranberry bogs. The system was installed as part of the pilot test.

Steps to Achieving Remedial Action Objectives
The following steps will be taken during active remediation.

1. Remediate the aquifer to federal and state drinking water standards (MCLs).
   
2. When MCLs are achieved in groundwater and before the cleanup system is shut off, perform a risk assessment to determine if unacceptable ecological or human health risks remain. If unacceptable potential risks are present, continue system operation and/or pursue additional measures as required to achieve acceptable risks.
   
3. Once acceptable risks have been achieved, evaluate the technical and economic feasibility of additional remediation to approach or achieve background concentrations.

This three step process has been agreed to solely at MMR due to the unique circumstances presented by the location of the FS-1 plume within the sole source aquifer of Upper Cape Cod.

How To Submit a Formal Comment?
During the public comment period AFCEE will accept formal written comments on the Proposed Plan and will hold a public hearing to accept either verbal or written comments. It is important to 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's responses will be documented in the Responsiveness Summary.

Formal comments and responses will become part of the Administrative Record. AFCEE will consider all formal comments received during the public comment period before making a final decision. You can submit comments several ways:

1. Submit written comments during the public comment period that extends from June 4 to July 3, 1999 to

   HQ AFCEE/MMR
   Attn: FS-1
   322 East Inner Road
   Otis ANGB, MA 02542-5028

2. Offer verbal comments during the Public Hearing to be held Wednesday, June 23, 1999.
3. Submit comments by fax to (508) 968-4673.
4. Submit comments by electronic mail to doug.karson@mmr.brooks.af.mil
5. Submit a comment using the comment form on the MMR website (http://www.mmr.org)

Why Submit Formal Comments?
Your comment will become part of the official public record, a crucial element in the decision-making process. AFCEE, EPA and MassDEP will consider all formal comments received at the public hearing and all written comments received during the public comment period before making the final decision on the most appropriate remedial action for cleanup of FS-1.

A transcript of the hearing and a record of all formal comments and AFCEE’s written responses will be issued in a document called a Responsiveness Summary which will accompany the Record of Decision for FS-1. AFCEE expects to complete review of all comments, select a remedial alternative for FS-1, and issue the Record of Decision documenting AFCEE’s choice in December 1999. At that time, copies of the Responsiveness Summary will be mailed to everyone who submits a formal comment during the comment period and copies will also be placed in local libraries. In addition, AFCEE will announce the decision in a fact sheet through the local news media and site mailing list.

For Further Information
This Proposed Plan summarizes the information that can be found in greater detail in the FS-1 RI and Feasibility Study reports. The RI and Feasibility Study reports are included in the Administrative Record for FS-1.

The Record of Decision and Responsiveness Summary will be added to the Administrative Record upon completion of those documents. The public is invited to review the Administrative Record and comment on it and this Proposed Plan during the public comment period. The Administrative Record is available for review at the IRP Office, located at 322 East Inner Road. The IRP office is open 7:30 a.m.–4:30 p.m. Monday through Friday. The Administrative Record is also available for review at the Falmouth Public Library, located at 123 Katharine Lee Bates Road. Call (508) 457-2555 for library hours. Information and technical documents, including the RI and Feasibility Study, are also available at the main libraries in Bourne, Mashpee, and Sandwich; and at the U.S. Coast Guard library on base. Information is also available on the web site at http://www.mmr.org.

For further information, please contact:

Doug Karson
Community Involvement Specialist
HQ AFCEE/MMR
322 E. Inner Road
Otis ANG Base, MA 02542-5028
Tel: (508) 968-4678, ext. 2
fax: (508) 968-4673
doug.karson@mmr.brooks.af.mil

Jim Murphy
Community Involvement Coordinator
USEPA
1 Congress Street Suite 1100
Boston, MA 02114-2023
Tel: (617) 918-1028
fax: (617) 918-1029
murphy.jim@epa.gov

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

Visit the Massachusetts Military Reservation Installation Restoration Program on the World Wide Web: http://www.mmr.org

GLOSSARY

Administrative Record: A collection of documents that explains how a decision was arrived at, and includes records of investigations, engineering documents, regulator comments and correspondence, and public comments. The Administrative Record is maintained at a public location for public review.

ARAR: Applicable or relevant and appropriate requirements.

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

Contaminant of Concern (COC): Substance or element that may cause adverse impacts to human health or the environment as determined by a risk assessment.

Feasibility Study: A study that identifies and evaluates potential alternatives for remedial actions that may be taken to reduce risk to human health or the environment.

Federal Facility Agreement: An agreement between EPA and individual federal facilities that establishes a procedural and legal framework for investigating sites and performing remedial actions at Superfund sites.

Installation Restoration Program (IRP): The Department of Defense program implemented at military bases to identify, investigate, and perform remedial actions at Superfund sites.

Institutional Controls: Stipulations which reduce or eliminate exposures such as deed restrictions, covenants, or land use restrictions.

Integrated Exposure Uptake Biokinetic (IEUBK): An EPA model which estimates levels of lead in children's blood if those children are exposed to lead.

Long-term Effectiveness and Permanence: A performance criteria that addresses whether there are any risks to human health or the environment after a remedial alternative is complete and if the reduction of those risks is permanent.

Maximum Contaminant Levels (MCLs): Safe drinking water standards established by either federal or state environmental agencies that reflect the maximum allowable safe concentration of chemicals in drinking water.

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

Proposed Plan: A document that summarizes for the public the preferred remedial action for a site and presents the rationale for the preference, summarizes the nature of the site and describes other alternatives evaluated.

Record of Decision (ROD): A document that presents the remedial action selected in agreement with regulatory agencies.

Remedial Action: Actions taken to reduce or eliminate the long-term risk to human health or the environment from exposure to contamination.

Remedial Action Objective (RAO): The desired end result of remedial action.

Remedial Investigation (RI): An investigation to gather and analyze the data necessary to determine the nature and distribution of contamination at a site and to provide information to develop alternatives in the Feasibility Study.

Responsiveness Summary: A document presenting responses to formal public comments on proposed remedies.

Risk Assessment: An evaluation of potential human health or ecological risk resulting from exposure to a chemical or pollutant.

Short-term Effectiveness: A performance criteria that addresses the risks to human health and the environment during construction and operation of a remedial alternative.

Site Inspection (SI): An initial investigation involving collection and analyses of environmental samples to determine the necessity of further study in a Remedial Investigation.