Anacostia River tests positive for petroleum, then doesn’t

The U.S. Coast Guard is investigating a sheen on the Anacostia River that stretched several miles northeast from the 11th Street Bridge on Tuesday.

Coast Guard officials said Tuesday the black sheen, which by midday had moved toward the New York Avenue Bridge, is not an oil slick, despite witnesses reporting a petroleum smell coming from the river as early as Monday night.

Lt. Cmdr. Randall Brown, with the Coast Guard’s incident-response department in Baltimore, said water samples taken by the D.C. Fire and Emergency Medical Services Department near Benning Road tested positive for the presence of petroleum. However, Coast Guard officials taking additional tests in the area “were not able to get the same positive” results, Cmdr. Brown said.

Though the Coast Guard says it found no presence of oil, environmentalists are concerned.

“It may be very stressful for aquatic animals or may even kill them,” said Masaya Maeda, water-quality specialist for the Anacostia Watershed Society.

Mr. Maeda acknowledged that heavy rain this week churned up sediment and turned the river brown, but he said he thinks the sheen is oil, not sediment or runoff, based on the odor he smelled.

Crews dropped orange booms — floating barriers — along the river early Tuesday morning to stop the sheen from spreading, said D.C. Fire and EMS spokesman Pete Piringer, but the river was open to boat traffic by midday.

According to the watershed’s 2010 Anacostia River Report Card, the river scored a failing grade based on its water quality and clarity.