A Message from the Program Manager Robert M. Gill

Thank you for your interest in the Air Force Center for Environmental Excellence (AFCEE) cleanup program at the Massachusetts Military Reservation (MMR). We strive to keep the community informed and involved in every step of the cleanup process. The information contained in this fact sheet is one of the ways we do that. This fact sheet was developed to provide the most current information on the CS-4, CS-20, CS-21, FS-13, FS-28 and FS-29 groundwater plumes (see Figure 1). This area was formerly known as the Southwest Operable Unit (SWOU). We hope you find this fact sheet informative and we encourage your feedback on the cleanup program. Please visit our web site at www.mmr.org or contact Doug Karson at (508) 968-4678 ext.2 for more info. - Robert M. Gill

Figure 1: CS-4, CS-20, CS-21, FS-13, FS-28 and FS-29 groundwater plumes

Current Status - CS-4, CS-20, CS-21, FS-13 & FS-29:

• In August 2001, AFCEE will complete the first of a two-part field investigation that started in April 2000. This new data will supplement data already collected in 1998 for the SWOU Remedial Investigation. It will be used to support the design of the groundwater remediation systems for CS-4 (modified), CS-20, CS-21 and FS-29.

• Annual long-term monitoring for FS-13 began in November 2000.

• The CS-4 extraction fence continues to operate at 145 gallons per minute (gpm).

  FS-28:

• The FS-28 treatment system (installed in October, 1997) effectively removes ethylene dibromide (EDB), the primary contaminant of the FS-28 plume, to non-detectable levels

• EDB has not been detected in surface water samples collected from the Coonamessett River since May 1999.

• Monitoring continues for the plume and treatment system including a small portion of the plume which is outside of the current capture zone of the treatment system. This portion eventually will discharge to the Coonamessett River at concentrations expected to be non-detectable.

• With AFCEE funding, the Town of Falmouth is connecting approximately 250 residences between the FS-28 and FS-29 plume areas to municipal water supply. This work is ongoing and is expected to be completed by 2002

After considering public comments received during a 60-day comment period and at a public hearing, an agreement to clean up the CS-4, CS-20, CS-21 and FS-13 groundwater plumes was finalized by the signing of a Record of Decision (ROD) between AFCEE and the U.S. Environmental Protection Agency (EPA) on February 18, 2000. With the FS-28 and FS-29 groundwater plumes, there was a 75-day comment period and the ROD was signed on October 23, 2000. The Massachusetts Department of Environmental Protection (DEP) concurred with both decisions. The following actions were specified:

CS-4, CS-20, CS-21 & FS-13:

• Discontinue use of the existing CS-4 plume extraction well fence and install new extraction wells along the axis of the plume. Extracted water will be treated at the current CS-4 treatment plant and discharged at the existing CS-4 infiltration gallery.
• Construct an axial extraction well system and granular activated carbon (GAC) treatment plant for the CS-20 plume. Treated water will be discharged to infiltration galleries
• Construct an axial extraction well system and GAC treatment plant for the CS-21 plume. Treated water will be discharged to infiltration galleries.
• Institute permit restrictions on agricultural and private water wells to reduce the risk of current and future exposure to contaminated groundwater in the FS-28 plume until cleanup levels are attained. The Commonwealth of Massachusetts will be responsible for enforcing institutional controls on public water supplies within the Crane Wildlife Management Area. The Town of Falmouth will be responsible for implementing and enforcing restrictions, such as installing a private well near a plume area within the town. AFCEE will coordinate with the Falmouth Board of Health periodically (but not less than annually) to ensure the Town knows of any changes to the CS-4, CS-20, or CS-21 plume configuration and contaminant concentrations.
• Conduct five-year reviews to ensure that the remedy continues to be protective of human health and the environment. The next five-year review is scheduled to occur in 2002.
• Conduct long-term monitoring for FS-13.
• 
  
  FS-28:
  
  
• Continue operation of the extraction, treatment, and discharge system at the leading edge of the plume to capture EDB in groundwater before it enters the Coonamessett River
• Continue to maintain the wellhead treatment system for the Coonamessett Public Water Supply Well.
• Maintain the berms and vinyl sheet pilings that have been installed to separate the bogs from the Coonamessett River water.
• Continue to supply clean water to the agricultural users on the Coonamessett River.
• Continue long-term monitoring of groundwater, surface water, and the FS-28 treatment system.
• Continue to monitor Coonamessett River water for EDB to ensure that the FS-28 treatment system is operating as designed.
• Refer to #s 4 and 5 on the CS-4, 20, 21 & FS-13 plumes.
• 
  
  FS-29:
  
  
• Conduct additional site characterization and modeling to better understand the FS-29 plume dimensions and hydraulic conditions.
• Design and construct a groundwater extraction well system within the leading portion of the plume.
• Conduct long-term monitoring.
• Refer to #s 4 and 5 on the CS-4, 20, 21 & FS-13 plumes.

FS-28: In October 1997, AFCEE began operation of an extraction well system (EW-1) in an area that would remove the highest concentrations of EDB before this contamination could reach the river. Contaminated groundwater is treated to remove EDB to non-detectable concentrations. The treated water is then discharged to the Coonamessett River via a bubbler, which ensures oxygen concentrations in the water are safe for the environment.

In April 1999, AFCEE expanded the EW-1 system to extract contaminated groundwater by constructing 204 shallow well-points; (86 currently are being used.) These well-points were installed directly in a cranberry bog where EDB was found to be upwelling (see Figure 1). The total system currently treats approximately 750 gallons per minute, of which 400 gpm is from EW-1 and 300 gpm is from the shallow well-points. Through May 2001, the FS-28 system has treated over 1.23 billion gallons of groundwater, removing 7.8 pounds of EDB.

FS-28: In November 1993, the CS-4 treatment system began operation. Thirteen extraction wells were installed, of which eight currently are operating. Treated water is discharged via two infiltration galleries. Currently, the CS-4 system treats 145 gallons per minute. Through May 2001, the CS-4 system has treated over 572 million gallons of groundwater, removing 16.5 pounds of contaminants.

Next Steps

• Groundwater model: The geologic and hydrologic data collected during the current field investigation will be used, together with older data, to develop a detailed groundwater model in the area around the CS-4, CS-20, CS-21 and FS-29 plumes. The groundwater model will be used to test various configurations of wellfield designs. This testing will be completed by Spring 2002
• Phase 2 fieldwork: In the summer of 2002, AFCEE will conduct the last pre-design field work, followed by more groundwater modeling to finalize the precise locations of the extraction wells, treatment buildings, and infiltration galleries.
• Wellfield design (CS-4, CS-20, CS-21 & FS-29): In the Spring of 2003, the wellfield design is scheduled to be completed and work to engineer and construct the treatment systems will begin.
• FS-13 & FS-28 monitoring: AFCEE plans to continue to operate the current FS-28 groundwater treatment system. AFCEE also plans to continue monitoring the surface water of the Coonamessett River. It is estimated that the FS-28 plume will be cleaned up in 15-18 years. AFCEE also will continue to sample FS-13 groundwater wells in the annual long-term monitoring program.
• Residential hookups: AFCEE has negotiated an agreement with the Town of Falmouth to install water mains and convert private wells in Hatchville to town water. The area to be covered under this negotiation is bounded primarily by Route 151 on the north, Sam Turner Road on the west, Sandwich Road on the east, and the intersection of Hatchville Road and Sandwich Road on the south. There are several streets outside this general area that are also covered under this agreement. This work currently is in progress by the Town of Falmouth and is expected to be completed by 2002.
• Community updates will be provided through monthly Plume Cleanup Team (PCT) meetings.

ethylene dibromide (EDB): an additive in aviation gas to control the build-up of lead in the engines. EDB is a probable human carcinogen.

groundwater plume: a body of groundwater containing contaminants that exceed federal and state drinking water levels or other risk-based levels at multiple test well locations. Contaminated water can result when fuels, solvents, or other contaminants are spilled or released on the ground. When these materials filter through the sandy Cape Cod soil, they encounter groundwater, or the water table, where the soil is saturated with water. As the groundwater moves, the contaminants are carried with it, creating a groundwater plume.

infiltration gallery: A technology used to reintroduce treated water back into the aquifer by the use of a network of perforated pipes buried below the frost line.

institutional controls: non-engineering measures which reduce or eliminate exposures such as deed restrictions or land use restrictions.

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

well-points: small-diameter metal pipes with screened bottoms used for monitoring water levels or removing groundwater for analysis or treatment. The shallow well-points at FS-28 are approximately 13 feet deep, with screens of 2.3 or 3.0 feet in length. All well-points being used are connected together and water is extracted through them by a single vacuum pump.

For more information, please visit the IRP web site at: www.mmr.org or contact the following

Doug Karson, Community Involvement Specialist
HQ AFCEE/MMR
322 East Inner Road
Otis ANGB Base, MA 02542-5028
Phone: (508) 968-4678 x 2 Fax: (508) 968-4673
e-mail: doug.karson@mmr.brooks.af.mil

Jim Murphy, Community Involvement Coordinator
USEPA New England Region, Suite 1100
One Congress St (RAA)
Boston, MA 02203
Phone: (617) 918-1028 Fax: (617) 918-1029
Toll free # (888) 372-7341 ext. 81028
e-mail: murphy.jim@epa.gov

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