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IntroductionThis fact sheet provides information on the Impact Area Groundwater Study Program's ongoing investigation and clean up at Demolition Area 1 (Demo 1) and the Revised Draft Feasibility Study Demo 1 Groundwater Operable Unit. The Revised Draft Feasibility Study provides an overview and comparison of comprehensive cleanup alternatives for groundwater contamination migrating from Demo 1. This summer, the Groundwater Study Program is scheduled to begin an interim or Rapid Response Action clean up of groundwater contamination at Demo 1, using a modular system with both granular activated carbon and ion exchange mediums for treatment. U.S. Environmental Protection Agency (EPA) and Massachusetts Department of Environmental Protection (MADEP) approvals and public input on the Revised Draft Feasibility study will be obtained prior to selection of a preferred alternative. The preferred alternative and the rationale for its selection will be presented in the "Remedy Selection Plan." (See page 4 for further information on public comment periods and future steps in the decision-making process.) Information RepositoriesInformation Repositories have been established in four local libraries. The repositories are updated regularly to ensure that all necessary documents associated with the cleanup program (including copies of workplans, sampling results, site reports, fact sheets, meeting minutes, and other materials) are available to the public. Information repositories locations:
The Draft J-3 Range Rapid Response Action Plan as well as fact sheets on contaminants of concern, including RDX and HMX is available at these locations and on our web site. For More InformationContact the following individuals for more information:
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Revised Draft Feasability Study Demo 1 Groundwater Operable UnitJune 2004 Fact Sheet 2004-04 Demolition Area 1Demolition Area 1 is a 7.4-acre site located approximately one mile south of the Camp Edwards Impact Area. Demo 1 is located in a natural topographic depression or kettle hole. The site was used from the mid 1970s to late 1990s primarily for open burning and disposal of munitions, and training of explosive munitions disposal technicians. Groundwater Study Program investigations have identified and delineated a plume of groundwater contamination emanating from the Demo 1 site that extends more than 9,200 feet west. It is approximately 1,400 feet wide and 100 feet deep in the aquifer. Specific contaminants of concern for groundwater at Demo 1 include the explosives chemicals RDX and TNT, and perchlorate, a water-soluble salt used as an oxidizer. Detections of RDX in the Demo 1 plume range from the detection limit of 0.25 parts per billion (ppb) to 370 ppb. Perchlorate detections range from the detection limit of 0.35 ppb to 500 ppb. The lifetime federal health advisory for RDX in drinking water is 2 ppb. There currently is no federal or state drinking water standard for perchlorate. EPA interim guidance on perchlorate would equate to a range of 4 to 18 ppb in drinking water. The MADEP perchlorate advice level for sensitive populations (children, pregnant women and individuals with hypothyroidism) is 1 ppb.
Feasibility StudyThe Feasibility Study is the formal process used to evaluate and select final cleanup solutions for the reduction and cleanup of contamination from a site. The EPA Administrative Order requires the development of a range of remedial alternatives that reduce contaminant concentrations to different cleanup goals within different timeframes. The Revised Draft Feasibility Study Demo 1 Groundwater Operable Unit evaluates six alternatives proposed by the Impact Area Groundwater Study Program for addressing groundwater contamination at Demo 1 (See attached). Following a public comment period (see page 4) an alternative will be selected and presented to the public for review before finalization of the Remedy Selection Plan for Demo 1 groundwater cleanup. The six alternatives presented in the Revised Draft Feasibility Study Demo 1 Groundwater Operable Unit are designed to prevent the potential ingestion of water containing contaminants that represent an unacceptable human health risk and to restore the aquifer to its beneficial use as a drinking water supply within a reasonable timeframe. Evaluation CriteriaThe Revised Draft Feasibility Study Demo 1 Groundwater Operable Unit evaluates and compares the six alternatives with respect to the following criteria:
Two other criteria - state and community acceptance - will be accessed based upon input to the Revised Draft Feasibility Study. Proposed AlternativesAll six alternatives include long-term monitoring and implementation of legal or other measures to prevent groundwater use for any water supply purpose until the remedial goals are achieved. The extraction, treatment and reinjection systems will all use granular activated carbon and ion exchange resin to remove contaminants. [Please click here to see a summary table detailing the design alternatives for remediating RDX and Perchlorate.] Alternatives 2 - 6 also include a new permanent structure to house the treatment system. Variations in the alternatives include: Alternative 1 - Minimal ActionAlternative 1 is a minimal action alternative. This alternative calls for:
Alternative 2 - BaselineAlternative 2 provides a baseline alternative that makes use of the Rapid Response Action systems as a final cleanup solution. (See the Alternative 2 - Baseline Map.) This alternative includes:
This alternative would return groundwater to regulatory and risk-based concentrations for contaminants of concern within 36 years. Regulatory and risk-based concentrations for the contaminants of concern are:
Alternative 3 - BackgroundAlternative 3 provides an alternative that would be expected to return groundwater to regulatory and risk-based concentrations for the contaminants of concern in less than 23 years and the alternative goal of background levels in less than 30 years. (See the Alternative 3 - Background Map.) This alternative would include:
Proposed background levels 0.25 ppb for RDX and TNT and 0.35 ppb for perchlorate. Alternative 4 - 10 YearAlternative 4 provides the most aggressive cleanup scenario evaluated in this Feasibility Study. It is designed to achieve regulatory and risk-based standards for the contaminants of concern within 10 years. (See the Alternative 4 - 10 Year Map.) This alternative calls for:
The following Additional Alternatives present design variations that also achieve regulatory and risk-based concentrations for contaminants of concern. Alternative 5 - Additional Alternative AAlternative 5 provides a variation of Alternative 4 that is expected to achieve regulatory and risk-based standards for the contaminants of concern within approximately 14 years, by reducing pumping rates. (See the Alternative 5 - Additional Alternative A Map.) This alternative calls for:
Alternative 6 - Additional Alternative BAlternative 6 provides a design that is expected to return groundwater to regulatory or risk-based standards for the contaminants of concern in approximately 13 years. (See the Alternative 6 - Additional Alternative B Map.) This alternative includes:
Next Steps/Upcoming Activities
Next steps toward conducting the Rapid Response Action for groundwater at the J-3 Range include:
Opportunities for Public CommentThere will be opportunities for the public to provide comment on the Revised Draft Feasibility Study Demo 1 Groundwater Operable Unit and the Draft Remedy Selection Plan for Demo 1 Groundwater Operable Unit. A 15-day public comment period will be held on the Revised Draft Feasibility Study June 22 - July 7, 2004. Information on the 30-day public comment period for the Remedy Selection Plan will be announced when the Plan is ready for review. During public comment periods, comments can be submitted as follows:
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