Pollution spotted over the weekend at three marinas on the Ashley River came from the Medical University of South Carolina.

MUSC officials said a malfunctioning generator fuel pump atop the Institute of Psychiatry was the source of the diesel fuel leak into Charleston Harbor. The generator apparently failed to shut off and leaked diesel fuel into a storm drain that emptied into the harbor.

Employees of MUSC's physical plant turned off the generator when the leak was discovered during regular maintenance rounds and the university notified the S.C. Department of Health and Environmental Control of the incident immediately, according to a statement from MUSC.

University officials are working to determine the cause of the generator malfunction and determine how much fuel was leaked, according to the statement.

A boater first spotted the fuel Saturday night. The Coast Guard found traces of it at the Bristol, Ashley River and Charleston City marinas but was unable to find the source, Petty Officer 1st Class Lauren Jorgensen said.

Crews deployed booms and absorbent pads Sunday, but much of the fuel had dissipated with the heavy rainfall during the weekend, the Coast Guard said.

Boaters, though, still reported an overwhelming stench from the spill.

Andrew Knapp contributed to this report.