Poison is leaking into the ground water around two dumps at Fort Meade, and the U.S. Army is going to test nearby private wells to see if any have been contaminated.
Officials don't know if the pollutants have spread beyond Fort Meade's boundaries to affect nearby private wells or the Patuxent and Little Patuxent rivers.
"At this time, we don't have any evidence that there's contamination off-post," said Bob DeMarco, administrator of the state Department of the Environment program monitoring the cleanup.
Pesticides, metals and chemicals found in fuels have been detected around the fort's Active Sanitary Landfill, west of Odenton, and its Clean Fill Dump, west of Woodwardville.
Several contaminants were found at levels above federal limits in monitoring wells on the fort's eastern edge, he said. However, there is no immediate threat to public water supplies.
Trichloroethane, or TCE, a carcinogen, was detected at 6.1 parts per billion. The EPA standard for TCE in drinking water is 5 parts per billion.
Benzene also was found at 7.5 parts per billion. The federal standard is 5 parts per billion.
Chromium, which has a federal standard of 100 parts per billion, was detected at 133 parts per billion. Lead was also found at 44 parts per billion. The federal standard is 15 parts per billion.
Several nearby residential wells will be tested during the last two weeks of this month so officials can find out how far the pollution has spread and whether it has contaminated any private drinking water supplies.
The results will be made public "as soon as the results are received," about four weeks after samples are taken, according to an Army statement.
The Army will then propose a plan to contain the pollution. The state will review the plan and monitor the work.
"We are working very closely with the EPA and the MDE and the Anne Arundel County health people," said Fort Meade spokesman Don McClow.
Mr. DeMarco said the Little Patuxent River already contains some of the poisons found in the landfills. However, officials don't know if the landfills are the source of the contamination.
The pollutants could have come from the National Security Agency or some other site on Fort Meade, Mr. DeMarco said.
John Fairbank, head of MDE's federal facilities section, said lead and chromium occur naturally in Maryland.
Scientists will have to find out the natural measures of the two metals before they can say if the landfills contributed to the area's high levels.
The Active Sanitary Landfill opened in 1958 and is still being used. The Clean Fill Dump was used between 1972 and 1985.
"We're looking at sins that were committed, perhaps, before they were known to be sins," Mr. DeMarco said.
Nobody knows how long the landfills have been leaking. However, a 1992 Army report identified them as potential sources of pollution. It was not clear yesterday why no action was taken until now.
The Army will pay for cleanup work for "any conditions attributable to Fort Meade operations," according to an Army statement.
However, Mr. McClow noted that there are other industrial sites in the area, and that even if nearby wells are contaminated, identifying the culprit may be difficult.
Fort Meade has had a history of problems involving the handling and disposal of hazardous materials.
This summer, the MDE fined the fort $10,000 for 82 counts of improper hazardous waste management dating to 1989.