NEWS RELEASE
2004-06 Massachusetts
Military Reservation (MMR), Cape Cod, Mass. — Officials of the Air Force Center
for Environmental Excellence (AFCEE) recently announced that the remaining part of the
Storm Drain-5 (SD-5) groundwater treatment system was turned-off on February 25, 2004.
The extraction well, located on Hooppole Road, in Mashpee started operating in
2000, and pumped contaminated groundwater to the Sandwich Road treatment system.
Recent monitoring data indicated that there was no further need to operate this
well because of the low or non-existent contaminant concentrations. Mr. Jon Davis,
Program Manager of the Installation Restoration Program (IRP) stated, “All parts of
the cleanup system for the SD-5 plume have reached cleanup goals sooner than we predicted.
We continue to use the extensive amount of monitoring data we collect from nearby
wells to adjust our cleanup program for the unique situation of each plume we deal with at
the MMR.” Although the interim SD-5 treatment systems have met their goals, the
SD-5 plume has areas of lingering contamination that remain and are being monitored.
These areas will be addressed as part of the final SD-5 cleanup plan (Record of
Decision) that will be presented within the next year. The public will have an
opportunity to provide comments and help reach the final decision for cleaning up the SD-5
plume. The United States Environmental Protection Agency (EPA) and the Massachusetts
Department of Environmental Protection (DEP) have concurred with the AFCEE decision to
shutdown this extraction well. Mr. Jon Davis
added, “We have cleaned up the majority of the entire SD-5 groundwater plume and we
owe a great deal of our success to the cooperation of the Briarwood neighborhood and the
Town of Mashpee. It’s very exciting to see the cleanup progress made with this
plume over a small number of years and it marks a new stage of our cleanup work with IRP
treatment systems. In the last few years we have been able to modify (optimize), or
shutdown treatment systems or portions of treatment systems, like with SD-5.”
In most cases, treatment system designs are considered successful when treatment
systems are shutdown, because it means that the system was effective at removing the
contamination it was targeted to cleanup. BACKGROUND: For ease of
treatment, because of its large size and location, the SD-5 groundwater plume was broken
up into two parts: North and South. The northern portion of the plume (SD-5N) has
been defined as the part of the plume located on-base and the southern portion (SD-5S)
defined as the part that flows off-base and moves under the Briarwood neighborhood in
Mashpee. The most southern part of the SD-5S plume flows into the bottom of Johns
Pond near the end of the State boat ramp on Hooppole Road. There have never been
detections of SD-5 chemicals in surface waters of Johns Pond, primarily because the
already low concentrations are diluted by pond water. The first part
of the SD-5 cleanup system was located just south of the base boundary and consisted of a
row of ten extraction wells and eight re-injection wells that started treating the SD-5N
plume in August 1997. The extracted groundwater was pumped to the Sandwich Road
treatment plant and the clean water returned to the aquifer through the re-injection
wells. The cleanup goal of this system was to contain all of the SD-5N plume at the
base boundary. Between 1997 and 2003, the treatment system worked to cleanup the
SD-5N plume. The last extraction well for the SD-5N plume was turned-off in late
August 2003 because the system performed as designed and cleaned up the groundwater,
located near the extraction wells, to below state and federal drinking water standards.
To prevent
further groundwater contamination, a small portion of contaminated soil, located north of
the SD-5N extraction wells, was treated with a soil vapor extraction (SVE) system that
operated for approximately seven months from August 2002 through March 2003. A SVE
system cleans up the soil thereby preventing further groundwater contamination. The
SVE technology vacuums the soil, removing contaminated vapor, and treats it with granular
activated carbon. A small area,
with low-level concentrations of the SD-5N groundwater plume, still exists north of the
treatment system and is monitored on a regular basis to ensure that it does not flow
off-base. Recent sampling results from monitoring wells near this area confirm that
groundwater quality continues to exceed state and federal standards, but has not migrated
near the base boundary. Portions of the SD-5 South plume located in the Briarwood neighborhood (SD-5S) were cleaned up using two recirculating well treatment systems and one extraction well. The two recirculating well treatment systems (located beneath Wheeler Road and Hillside Avenue in Mashpee) started operating in June 1999 and were shutdown in December 2000 and April 2003, respectively, because contamination in the area was below state and federal drinking water standards. Both recirculating wells systems were removed and the vaults were filled-in with concrete during December 2003. For more information, please contact Mr. Douglas Karson, AFCEE/MMR Community Involvement Specialist, at (508) 968-4678, extension 2; Fax (508) 968-4673; or E-mail doug.karson@mmr.brooks.af.mil.
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