The story of the Cape Cod aquifer in the 20th century is the story of a plot of land now identified as the Massachusetts Military Reservation (MMR). The MMR on western Cape Cod covers an area of about 34 square miles. It includes parts of the towns of Bourne, Sandwich, Mashpee, and Falmouth. The present MMR area has been in existence since 1912. Over the years, it has been occupied by many tenants and been called by many names. In the 1940's, it was Camp Edwards. From 1948 until 1973, it was Otis Air Force Base. Since 1973, the MMR has been used primarily by the Massachusetts National Guard and the U.S. Coast Guard.
During the late 1970's and early 1980's, Upper Cape residents began to discover how the long history of the MMR had affected the land it occupied and the area around it. They discovered that activities at the MMR have contaminated the ground water. Over the years, those using the MMR have dumped or disposed of many toxic substances, including jet fuel, solvents, and industrial chemicals. Most of these substances were disposed of during the last 50 years and have been percolating down through the Cape's sandy soil ever since. These chemicals dissolved into and moved with the ground water; contaminant plumes formed, much like the plumes coming from smokestacks.
One of the earliest casualties of the contaminant plume from the reservation was a public water-supply well in Falmouth.This large well was pumped strongly enough to draw a plume of treated sewage from the base into its intake pipe, while individual household wells continued to tap the clean water above the plume.The town of Falmouth lost 25 percent of its water supply when the sell was shut down in 1975.
After much alarm and much civic action, a report on the extent of the contamination on the MMR was published in 1986. The report listed many areas with many problems and used abbreviations to describe them:
- SD sites were storm drainage ditches that caught the contaminated runoff, which then seeped into the ground water.
- LF stood for landfills that had been used for disposing of everything from household waste to explosives to entire trucks.
- CS meant chemical spill - including fuels, battery acid, and unburned gunpowder.
- FS sites were fuel spills, such as the runways where planes tested their fuel-dump valves.
- FTA's were fire training areas, which are large, squared-off patches of ground where fuels and other chemicals were spilled and then burned to give firefighters practice in extinguishing fires.
Each of the kinds of sites listed above has contributed to the spread of plumes of underground contamination. Almost a decade of study has led to the documentation of 11 major contaminant plumes that move off the base. These plumes threaten ponds, beaches, individual wells, and town water supplies alike. The plumes are large and have traveled far because the sandy soil allows the ground water to move quickly. Although parts of the plumes are very dilute, with small "hot spots" that contain high levels of contaminants, large volumes of water can be rendered unfit for drinking and sensitive ecosystems can be harmed by contact with small amounts of the industrial solvents and other organic chemicals contained in the plumes. The plumes are now well documented, but many problems remain to be resolved: demand for water continues to increase, and plumes move more than a foot a day and contaminate additional acres of aquifer each day. Other unknown contamination sites may exist, waiting to be discovered. New methods are needed to clean up the plumes in accordance with stringent water-quality standards.
In 1996, the U.S. Air Force Center for Environmental Excellence (AFCEE) assumed responsibility for cleanup of ground water at the MMR. By late 1996, dozens of pumping wells were being drilled to stop the advance of the plumes, the base landfill had been capped to stop leachate from reaching the ground water, and contaminated soils at several sources had been treated to remove solvents and fuels. A long-term plan is being developed by AFCEE, the U.S. Environmental Protection Agency, and the Massachusetts Department of Environmental Protection to clean up the plumes and to provide safe drinking water to the base and surrounding communities. Additional information about the plan can be obtained from the Installation Restoration Program (IRP).
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