FREDERICK, Md. — The U.S. Army says it is making progress in the long-running effort to address groundwater contamination at part of Fort Detrick that was used as a test site for the Army's biological warfare program.

The Army has been studying the groundwater problems on and around the "Area B" portion of the Maryland base for over a decade. Joseph Gortva, chief of Fort Detrick's Environmental Management Division, recently told the Frederick News-Post he is "cautiously optimistic" the Army will complete field work at the site within the next two years.

It will likely take another year or two beyond that for officials to finish a report summarizing what they've learned, the newspaper reported. Then the Army would move to the "feasibility study" phase of the cleanup. That would involve evaluating potential methods of addressing the contamination.

The cleanup process for the site's groundwater has been in the "remedial investigation" phase since 2010, the newspaper reported.

The U.S. Environmental Protection Agency has designated the Area B groundwater as a Superfund site. Most drinking water wells near Fort Detrick have been closed, according to the newspaper.