A diesel fuel spill from C.L. Custer and Sons in Harrisonburg sent 553 gallons of petroleum into sewer drains on West Market Street and Garbers Church Road.
Clean-up crews are attempting to stop the leak with oil-absorbent sheets, but the situation is still being monitored.
Captain Arthur Miller of the Harrisonburg Fire Department said that there is no further leak at this point, but there is a significant amount of gas in the waterway.
"We've traced the spill as far downstream as Heritage Oaks Golf Course," he said.
The leak came from a tanker that was accidentally overfilled. Officials say nearby residents shouldn't be bothered by the spill other than the smell. The DEQ is still investigating the case and says it should take about a week to clean up.