Fact Sheet #2000-01 Chemical Spill 10 (CS-10) Plume Update A fact sheet providing updated information on the Chemical Spill 10 South/Southwest groundwater plume cleanup. The purpose of this fact sheet is to provide updated information to the public regarding the cleanup of the south and southwest areas of the Chemical Spill 10 (CS-10) groundwater plume. In addition to this fact sheet, we encourage you to read fact sheet #99-08, Chemical Spill-10 Source and Plume Update, which provides background information. We also encourage you to read Recreational Use of Water Bodies on or near the Massachusetts Military Reservation (MMR), a Massachusetts Department of Public Health Fact Sheet related to MMR contamination and recreation at nearby ponds. Words in italics are defined in the glossary at the end of this fact sheet. Background/History The primary source of the CS-10 groundwater plume is the 38-acre area of the former Boeing Michigan Aerospace Research Center (BOMARC) Missile Site and Unit Training Equipment Site (UTES) located along the northeast edge of MMR. The primary contaminants of the CS-10 plume are trichloroethylene (TCE) and perchloroethylene (PCE). Ethylene dibromide (EDB) has been detected sporadically within the CS-10 plume area. In 1998, a TCE plume was identified as upwelling into the western portion of Johns Pond. It has continued to be studied as the potential leading edge of the CS-10 plume. Based on studies conducted during the summer and fall of 1999, portions of the CS-10 plume also have been identified as upwelling into the northwest corner of Ashumet Pond (refer to Figure 1).
Plume Cleanup During 1997, extensive public dialogue was held on options to clean up the CS-10 groundwater plume. After consideration of public comments, representatives from the Air Force Center for Environmental Excellence (AFCEE), US Environmental Protection Agency (EPA), and the Massachusetts Department of Environmental Protection (DEP) agreed, by consensus, that extraction, treatment and reinjection (ETR) technology would be used to clean-up the CS-10 groundwater plume. Three distinct ETR systems would be required to clean-up the entire CS-10 plume. The first, the Sandwich Road treatment system, began operating May 18, 1999. The second, the In-Plume treatment system, began operating June 24, 1999. The third system, which currently is under construction, will clean-up the south and southwest areas of the CS-10 plume. An enforceable milestone of April 30, 2000 has been set for this system to start operating. South/Southwestern System In the spring of 1999, AFCEE funded the Enviro Tech Center (ETC) at MMR to conduct a technology demonstration project involving state-of-the-art, computer-based pump and treat optimization. To complete the demonstration, ETC retained the services of two researchers affiliated with the University of Alabama and Utah State University. The CS-10 plume project was selected as a case study with the objective of demonstrating the technology and providing input to AFCEE during the summer of 1999 to aid in the treatment system final design. The work led to enhancements in pumping rates for the existing In-Plume extraction wells, a reduction in the number of extraction wells needed for the CS-10 South/Southwest treatment system and enhancements in the associated pumping rates. The CS-10 South/Southwest system is expected to operate for approximately 30 years. The CS-10 South/Southwest system will extract contaminated groundwater from the aquifer using three extraction wells and will pump the water to an on-base treatment plant. A total of approximately 20,000 feet of piping will be installed for this treatment system. Two modular treatment plants, each containing two carbon vessels, will be constructed on a paved lot adjacent to the existing CS-10 In-Plume treatment plant buildings. The contaminants are filtered from the water by granular activated carbon stored in the 20,000-pound carbon vessels. The CS-10 South/Southwest system has been designed to treat 778 gallons per minute (gpm) of groundwater to non-detectable concentrations of contaminants. The treated water is returned to the aquifer through two infiltration trenches, which allow the treated water to infiltrate naturally back to the groundwater table. The total pumping rate of the CS-10 In-Plume treatment system is currently 1200 gpm. As part of the CS-10 South/Southwest system installation, the pumping rate of the CS-10 In-Plume system will be increased to 1922 gpm. The existing CS-10 In-Plume infiltration trenches will be extended to accommodate the combined total flow of 2,700 gpm from the CS-10 In-Plume and South/Southwest treatment systems. The infiltration trenches will be constructed to a total length of approximately 2,400 feet. The infiltration trenches are located south of the southern and southwestern areas of the CS-10 groundwater plume on MMR property. No impacts to rare species and their habitats will occur as a result of project construction activities. Every attempt has been made to use developed areas so the amount of vegetation cleared during construction work is minimized. Ecological Monitoring The design for the CS-10 South/Southwest treatment system reflects an attempt to minimize ecological impacts while effectively capturing and treating contaminated groundwater from the CS-10 plume. In order to assess potential impacts on aquatic ecosystems from the operation of the CS-10 South/Southwest treatment system, field surveys for all surface water bodies were conducted in 1997. Generally, surface water bodies are connected to the groundwater, so areas where potential hydraulic impacts from pumping and/or infiltrating water were surveyed. Ashumet Pond and Johns Pond, as well as Osborn and Edmunds Ponds, are located within areas that computer modeling has shown might be affected hydraulically from operation of the CS-10 South/Southwestern treatment system. AFCEE currently monitors areas in and around Ashumet and Johns Ponds, associated with the CS-10 plume, following a monitoring program outlined in the Final Ashumet and Johns Ponds Area Ecological Sampling Plan. In order to reduce duplication of monitoring efforts, this plan presents sampling strategies for multiple plumes that may affect the same surface water bodies. Under this monitoring program, potential changes in water levels associated with the operation of several treatment systems will be measured and assessed. Data will be used for monitoring potential ecological impacts from operation of the entire CS-10 treatment system. Next Steps
Glossary ethylene dibromide (EDB): a man-made additive that was formerly used in aviation gas to control the buildup of lead in engines. perchloroethylene (PCE): also referred to as tetrachloroethene; a man-made solvent used to dissolve or disperse substances such as oil; often used in metal degreasing and for dry-cleaning clothes. trichloroethylene (TCE): a man-made solvent used to dissolve or disperse substances such as oil; often used in metal degreasing. For More Information Doug Karson, Community Involvement Specialist Jim Murphy, Community Relations Coordinator Ellie Grillo, Community Involvement Coordinator
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