High levels of a previously unseen contaminant have been found at a Fort Meade groundwater monitoring site near the border of the military post, where neighbors depend on private wells for their water, according to an Army report.
The contaminant, carbon tetrachloride, was discovered in a monitoring well north of a post landfill near Routes 32 and 175. The Army recently reported finding 91 micrograms per liter of the contaminant - used as a cleaning solvent 50 to 60 years ago - in deep water aquifers there.
Under federal guidelines, the maximum contaminant level of the chemical acceptable for drinking water is five micrograms per liter.
The wells in which the contamination was found are not used for drinking, but the Maryland Department of the Environment is investigating the source of the contamination and whether it would affect neighbors.
One state official said the fact that the chemical, which hasn't been used for decades, is just showing up in monitoring wells might indicate that the contamination spreads slowly.
"It's probably taken it a long time to get where it is right now, so the ground flow velocity is probably very slow," said Edward Dexter, a chief in MDE's Solid Waste Division.
But Zoe Draughon, who heads the Army's Restoration Advisory Board, a civilian watchdog group that monitors the Army's environmental activities, said she is concerned about the finding, which was announced last month.
"How many people have been told that they're sitting this close to contamination?" she asked. "We have people who live right there."
Carbon tetrachloride is a manufactured compound most often found as a colorless gas.
High exposure can damage the liver, kidney and central nervous system, according to the Agency for Toxic Substances and Disease Registry.
But if exposure is low and stops, the liver and kidney can repair damaged cells.
Officials are not certain whether the source of the contamination is on or off the Army base, but do not think it came from the landfill. The groundwater from the landfill does not flow in the direction of the monitoring well in which the chemical was found, Dexter said.
Fort Meade's environmental conditions have been closely monitored by federal and state officials, because the post is a part of the Superfund list, or the Environmental Protection Agency National Priorities List. Since it was named a Superfund site in 1998, the post has been working vigorously on environmental cleanup projects.
One of the monitored sites is the sanitary landfill, located on a southeast corner of the base. Deep groundwater monitoring wells north of the landfill picked up the high level of contamination in June, according to Army officials.
Although carbon tetrachloride has been found in water or soil at about 22 percent of the waste sites investigated under Superfund, it is a rare find in Maryland, said one state environmental official.
"I have never seen this in any monitoring well in Maryland," Dexter said. "Carbon tetrachloride has not been used in decades."
`You have to fight'
This is not the first time that environmental concerns in that area have put residents on guard.
In 1994, traces of the weed killer Atrazene were found in drinking wells of eight Odenton families on Old Waugh Chapel Road.
For several months, while the Army investigated whether the landfill was a source of the contamination, it supplied drinking water to those affected. The Army determined that the contamination did not come from the landfill, and the county connected those families to public water.
Although many families now have public water service from the county, they are concerned about reports of contamination, especially residents who believe the Army is reluctant to discuss environmental hazards.
"You have to put them in a forced mode to get them to do anything. You have to fight," said Carol Lehtma, a 30-year resident.
Draughon agreed, saying public officials must be vigilant in investigating the contamination and whether it will affect neighbors.