Contaminants at the Forest Glen Annex in Silver Spring continue to spread from an unknown source, according to new U.S. Army data released Thursday.
Tetrachloroethylene, a substance commonly used for dry cleaning, was found in 2012 in groundwater at higher levels than previously measured between 2002 and 2010. The U.S. Environmental Protection Agency identifies the substance as a potential hazard for drinking water and a possible carcinogen. According to the EPA, no amount of tetrachloroethylene is safe for drinking water.
Project Manager Mike Ervine of AECOM, a contractor hired by the Army to conduct assessments of possible contaminants at the Army installation, presented AECOM’s 2012 findings on contaminants in two landfill sites underneath the Forest Glen Annex at a quarterly meeting on May 2. Ervine said there are no drinking water wells within a half mile of the assessed sites.
AECOM gives a quarterly update on its investigation to the Forest Glen Annex Restoration Advisory Board, which includes representatives from the Army, the Maryland Department of the Environment, the Environmental Protection Agency, local government officials and community members.
Fort Detrick, a military installation in Frederick, assumed control of the Forest Glen and Glen Haven areas, totalling 147 acres, in October 2008.
The landfill under the commissary, termed “Site 3,” covers about 14 acres, and is mostly covered by pavement and buildings, he said. The Site 3 landfill also runs underneath the National Museum of Health and Medicine.
Tetrachloroethylene and chloroform were found on the edge of the Site 3 landfill, between the museum and the adjacent railroad, and north of Linden Lane. Ervine said the chloroform might be coming from a leaking municipal water pipe, but the source has not officially been determined.
The source of the tetrachloroethylene appears to be outside the annex’s boundaries. Unless the Army can get permission to install groundwater testing wells on commercial or private property, Ervine said, it is unlikely that the source will be found.
Joe Gortva, environmental restoration program manager for Fort Detrick, said the source of the tetrachloroethylene is probably not an Army activity or resource.
“Nobody here is saying it’s not ours ... but it’s probably not,” Gortva said.
Even if the Army finds chemicals that exceed EPA screening levels, Gortva said, that doesn’t immediately trigger a cleanup. The state and the Army would have to go through an evaluation process to assess what the best solution is for the site, he said.
The landfill under the research institute, “Site 4,” covers about six acres and, like Site 3, is covered by pavement and buildings.
Waste was likely disposed at the two landfill sites on the annex — one near the commissary and one near the Walter Reed Army Institute of Research — from the 1940s to the 1960s. The landfills probably contain construction debris, medical waste, incinerator ash, household waste and office waste, Ervine said.
“We don’t know what’s in the landfills, exactly,” he said.
AECOM will not conduct an “intrusive investigation” into the landfills, Ervine said. The purpose of the study was to characterize the size of the landfills and potential contamination risks, not what the landfills contain. When AECOM’s workers found landfill waste while digging wells, Ervine said, they were instructed to stop digging and find another location.
Benzoapyrene, a byproduct of burning organic substances, was found in the soil throughout Site 3. Especially high levels were found between the museum and adjacent railroad track.
“It’s not the highest I’ve ever seen, but it’s pretty high,” Ervine said.
The amount found exceeds the EPA’s limits for acceptable quantities of chemicals in residential and industrial areas. AECOM also found arsenic and lead in exceedance of EPA limits.
The benzoapyrene is likely “related to railroad usage,” Ervine said.
Ervine said the soil there also was tested in 2009, before the museum was built.
“They knew they were putting a museum on top of a landfill, so they wanted to collect some data,” Ervine said. Elevated levels of chromium and arsenic were found east of the museum in 2009.
Gortva said a vapor barrier was installed during the museum’s construction to minimize the possibility of landfill materials contaminating indoor air.
“That appears to be working,” Gortva said.
Pesticides found under a parking lot near the research institute could have come from a former farm site, said Donald Hall, co-chair of the Restoration Advisory Board. Before the construction of the annex, the entire area was a farm, where pesticides were likely used on orchards. The historic farm also might account for the elevated arsenic found in the area, Hall said, but the Army has not determined a source.
The Forest Glen Annex Restoration Advisory Board is scheduled to meet again in August.