The 1,600 gallons of diesel fuel that spilled at a DelDOT facility near St. Georges this past weekend was caused by a broken pipe.
Drivers had fueled their vehicles at the location of the spill during storm operations this past weekend, DelDOT officials said in a press release late Monday.
Officials said Tuesday that a pipe connected the tank to the fuel pump was broken, and appears to be the cause of the spill.
The incident is still under investigation though.
DelDOT officials became aware of the extent of the spill Monday morning, which was contained by a nearby retention pond.
As part of their Hazardous Material plan, DelDOT personnel contacted the Department of Natural Resources and Environmental Control to report the incident.
Officials also contacted Guardian Environmental Services, a contractor for DelDOT, who had a team on site within 30 minutes to contain and clean up the spill.
Environmental experts at the scene said they were confident most of the fuel would be recovered.
Clean-up costs are estimated to be about $50,000.
DelDOT is cooperating with DNREC's Environmental Crimes Unit to determine the cause of the spill, officials said.