Metro plans to plead guilty to charges it released hazardous chemicals into the sewer system in 2003, according to court documents.
The charges in federal court in Greenbelt were made public Thursday, the Washington Post reported. Prosecutors accuse the transit agency of violating the Clean Water Act by releasing the chemicals over a six-day period.
According to court documents, polluted water left over after Metro cars were washed at Maryland rail yards was released into sewer pipes without being properly treated. A contractor hired in to clean the cars used chemicals including hydrofluoric acid.
Metro spokeswoman Lisa Farbstein said the agency stopped using the hydrofluoric acid to wash cars when the problem was discovered in 2003.