Joppatowne resident Thomas Mathison had one main question at a hearing on the Army's plans to clean up two contaminated sites at Aberdeen Proving Ground.
Why, Mathison asked, has the Army waited so many years to start the work?
Mathison was one of about a dozen citizens attending Monday's public hearing on the Army's proposals to clean up the sites, both of which are at the Edgewood Area of the proving ground.
Residents attending the hearing did not question the Army's general plan for the cleanup. But some expressed concern about the possible effect contamination at the sites might have on the Chesapeake Bay and area rivers.
The sites, which may contain unexploded ammunition, laboratory waste and other potentially hazardous materials, were active as far back as the 1920s, Army officials said.
"I still can't understand why it's still lying there and never been touched," Mathison said. "Somebody must have known about this for many, many years."
Army representatives said they are unsure why the Army did not move earlier to clean up the contamination.
"I wish it didn't happen," said Ken Stachiw, chief of the Army's Installation Restoration Branch. "The fact is, it's there, and we're attempting to do this in the safest manner possible."
Both sites are on the federal Environmental Protection Agency's Superfund list of hazardous waste sites. Monday's hearing was one of the requirements for Superfund sites, which get federal money for cleanup operations.
Army officials believe that the sites do not pose an immediate threat to humans or wildlife. However, they are uncertain of the extent of contamination at the sites.
One resident asked whether the contaminants could harm boaters, fishermen and swimmers using the Bush and Gunpowder rivers.
Donald Green, an APG environmental scientist, said any contaminants that reach the rivers would be diluted to a point where they would not be harmful.
One site, called the Bush River-26th Street Disposal Site, is a 1-acre area used between the 1920s and 1970s to burn gas mask canisters.
The canisters were commonly burned in packed wooden boxes, and the unburned portions were left in a ditch at the dump, according to an Army report. The site may be contaminated with heavy metals, such as copper, silver and chromium.
Another part of the site, in a remote area north of Kings Creek, was used as a dump. It is believed to contain scrap metal, incinerated grenades and laboratory waste.
The Army report says the potential exists for contaminants at the site to migrate to the nearby Bush River and surrounding wetlands.
The second site, called the J Field, contains numerous pits used to burn toxic materials between the 1940s and 1960s. The 1-acre field is at the tip of the Edgewood peninsula, off of the Gunpowder River.
Munitions, chemical wastes, nerve agents and riot-control chemicals were among the materials burned at the site, the Army said. The site is believed to contain heavy metals and chemical compounds, such as lead and vinyl chloride.
The banks along the Gunpowder have eroded by as much as 25 feet in some places near the burning pits, threatening to spill the pits and any contaminants into the river, the Army said.
The Army is planning to stabilize the banks as part of its cleanup plan.
Also, soil and ground water at the burning pits will be tested for contaminants. A separate study will be prepared to handle any tainted soil and ground water.
The Army's plans for the sites are classified as "removal actions." Each is expected to cost less than $2 million, and both are to be finished within a year.
Once the projects are done, the Army will determine whether further steps are needed to remove contamination from the sites.
As a "worst-case scenario," Stachiw said, the cleanup of the sites could cost as much as $43 million and take until the year 2010 to finish.
The Army does not have a target date for starting the projects.
Copies of the Army's report on the sites can be reviewed at the Edgewood and Aberdeen libraries. Copies also are available at the APG public affairs office: 278-2012.