The substance on the surface of the Anacostia River isn't an oil spill after all, according to the U.S. Coast Guard, which is leading the investigation.
The substance seeped into the river near the 11th Street Bridge and quickly spread as far north as New York Avenue Monday night.
The D.C. Department of Environment, along with the Environmental Protection agency and the Coast Guard, were called at about 6 p.m. and remained on scene most of Monday night trying to contain it.
Booms were placed near the 11th Street Bridge and Benning Road to stop what was initially described as a petroleum-based substance from traveling any further north.
The U.S. Coast Guard and the fire department collected water samples all day Tuesday. Those are being tested by the EPA and the fire department hazmat team. The Coast Guard continued sampling Wednesday.
“We are going to continue tracking the material to identify what it is and how to minimize its impact,” Coast Guard Lt. Cmdr. Randall Brown said.
Officials are still trying to determine where the substance came from and just home many gallons were spilled.
Officials said the spill was 3 nautical miles long.