Pollution monitors added at Meade

Army seeks sources of ground water chemicals

Benzene, PCBs levels elevated

Fort Meade

August 21, 2002|By Rona Kobell | Rona Kobell,SUN STAFF

Hoping to solve the 2-year-old mystery of how several contaminants turned up in Fort Meade's ground water wells, Army officials are installing more monitoring wells near the base's boundary.

Fort Meade's environmental office hopes the five wells it installed Thursday near Old Waugh Chapel Road and Piney Orchard Parkway will help determine why a well on the post documented elevated levels of benzene and polychlorinated biphenyls, or PCBs.

Benzene and PCBs are industrial chemicals that can pose a cancer risk to humans. Area residents use public water so no danger exists that the contaminants could affect drinking water.

Federal and state officials have been closely watching the base's environmental conditions since it was placed on the Environmental Protection Agency's Superfund list of the nation's most hazardous sites in 1998.

One of the monitored sites is a closed sanitary landfill on a southeast corner of the base. Ground water wells there are tested twice a year, and the last several tests of one well near the landfill have shown the level of benzene and PCBs to be rising, said Fort Meade environmental engineer Jim Gebhardt.

"Before it gets to the point where it gets really bad, we need some more information," he said.

Because the monitoring well is on the southern border of the base, near an Amtrak yard, Gebhardt said he is not sure whether the benzene and PCBs are from the base or from industrial activity in the rail yard.

Gebhardt said the new wells, which cost the Army about $20,000 each, can monitor at a depth of 200 feet. If contamination shows up in the wells, Gebhardt said, the Army will have a better idea which direction it is flowing and how to stop it.

A bigger mystery seems to be the presence of carbon tetrachloride, which Army engineers also discovered about two years ago in a monitoring well near the landfill. The substance, once common in dry cleaning and auto-parts cleaning, hasn't been used since the 1960s. High exposure can cause damage to the liver, kidneys and central nervous system.

The carbon tetrachloride levels in the Fort Meade monitoring well have fluctuated, but were as high as 91 micrograms per liter last year - nearly 20 times the level deemed acceptable under federal guidelines.

This month, as they installed the monitoring wells on Old Waugh Chapel, Army workers also added eight wells on the landfill's north side, along its boundary with Route 175.

The landfill wells are the latest tool in a two-year hunt that has sent Army officials and other environmental regulators looking in unusual spots for the carbon tetrachloride's source. They have delved into their historical archives, studying old aerial photos and maps in hope of determining whether a long-closed mechanic's shop or a dry cleaner could be responsible.

Last year, they turned to a sophisticated tool when the U.S. Army Corps of Engineers created a computerized water flow tracker to help find the source. While the model didn't pinpoint the source, Gebhardt said, it gave officials an indication of where to place more wells.

Gebhardt said he expects the new wells to give some indication of the sources - and where the contamination is headed - in the next few months.

"We're full of scenarios," he said. "We just need to find an answer."

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