Potentially unsafe levels of arsenic and radon have been found near a public trail and stream adjacent to the Forest Glen Annex in Silver Spring, according to new Army data.

Project Manager Mike Ervine of AECOM, a contractor hired by the Army to conduct assessments of possible contaminants at the Army installation, presented preliminary data on two sites to the Forest Glen Annex Restoration Advisory Board Thursday evening. The board includes representatives from the Army, the Maryland Department of the Environment, the U.S. Environmental Protection Agency, local government officials and community members.

AECOM’s data reveal arsenic in sediment near a stream that winds along the Ireland Drive trail. The amount of arsenic exceeds limits set by the Environmental Protection Agency for residential soil and industrial soil.

Two locations along the southern edge of Ireland Drive also tested positive for radium. According to Army documents, the annex once housed a nuclear reactor. But the extent of AECOM’s current data collection does not include analysis or determination of possible causes.

“These results will eventually be used for cleanup decisions,” Ervine said. “Currently, our data is under validation.”

Six sites on the annex have been identified as areas for review, including three landfills, a car wash area, the site of an oil leak and a streambed contaminated with suspected carcinogens. Ervine presented results on two of the six sites at Thursday’s meeting. In December, the site of a petroleum spill was determined to pose little risk to public health.

Site Two contains two baseball diamonds and multiple dumps of construction, household and medical waste. According to William Crane, garrison manager for the Forest Glen Annex, the diamonds are only used during the summer months for intramural teams visiting from Walter Reed Medical Center.

By following historical records, the contractor assessed that waste was disposed in the area between the 1940s and 1960s, Ervine said. However, “there is not a lot of great documentation to support that,” he said.

A preliminary outline of the dump sites includes a small portion of forested land just outside the Forest Glen Annex’s security fence. Medical waste was found in that area, which was subsequently marked off with orange tape, then a chain-link fence, Crane said.

Although Ervine could not definitively say how much waste was found and removed from the site, AECOM’s geophysical survey found that the waste extended slightly beyond the perimeter shown in historical records. The area has been fenced off, and waste found on the surface was removed.

Crane said he put up a sign near the trail last month, warning people and their pets not to drink from the stream.

Site Six, possibly contaminated with polychlorinated biphenyls, or PCBs, is located between the Beltway and Linden Lane. PCBs, which are suspected of causing cancer, are often used in transformers, insecticides and coolant fluid.

PCBs were most recently found in 2009 near a salt dome on Forest Glen Annex property. Fort Detrick, a military installation in Frederick, assumed control of the Forest Glen and Glen Haven areas, totalling 147 acres, in October 2008.

According to Bob Craig, Fort Detrick’s chief environmental officer, a pile of mulch had concealed three transformers, two of which were leaking fluids. The fluid spilled onto nearby pavement, which tested positive for PCBs. Craig said part of the pavement and the adjacent hillside had since been removed to get rid of the contamination.

PCBs were also detected in groundwater behind the National Park Seminary. The Army once owned the seminary and it was excessed in 2002. It occupies more than 20 acres, according to documents from the Maryland Historical Trust’s Inventory of Historic Properties.

Ervine said four new testing wells have been installed in that area to get a better picture of the contamination.

AECOM’s current assessment of Site Six will include further investigation of the salt dome area and possible lingering contaminants. The contractor is now working to validate samples of soil that had been sent to a laboratory for analysis.

A Silver Spring resident, Clara Witt, expressed concern about future construction on the annex, especially on top of pockets of potential contamination. Underneath the nearby National Museum of Health and Medicine, built on the annex in 2011, the groundwater is “grossly contaminated,” Craig said.

Witt said Montgomery County officials told residents there would be no further development on the annex.

“There’s a bad taste in many of our mouths about the veracity of those statements,” Witt said.

Crane said no moratorium on construction had ever been conducted. The Army has plans to build a childcare center on top of land that has tested clean of contaminants.

“We will continue to build things as long as there’s money, but right now there’s no money,” Crane said.

The Forest Glen Restoration Advisory Board will next meet in May, when the Army plans to finalize an assessment of the data on Site Two and Site Six.

scarignan@gazette.net