The entry of the substance into the creek was traced to an industrial park in Lawrence, off Enterprise Avenue.
LAWRENCE -- An oily substance flowed into the Assunpink Creek from a storm pipe in Lawrence Friday morning and made it downstream to Trenton and into the Delaware River before it was contained, officials said.
The Trenton Fire Department was first to respond to the incident, reported at about 8:30 a.m., and firefighters first spotted a sheen in the creek water near South Warren Street. The source was soon tracked to a Lawrence industrial site.
New Jersey Department of Environmental Protection (DEP) spokeswoman Caryn Shinske said the U.S. Coast Guard was called in to monitor the sheen flowing into the river in Trenton, and by 12:30 p.m. Friday it was starting to dissipate.
At 4 p.m., the Delaware River was free of the oil sheen and specialists had contained the substance in Lawrence, Shinske said.
Trenton Battalion Chief Steve Coltre said early Friday that city firefighters initially tracked the oil upstream into Hamilton and finally to Lawrence, and notified fire companies in both towns as they monitored it.
In the Lawrence Industrial Park, on Enterprise Avenue, firefighters found a suspicious substance coming from a storm pipe flowing into the creek, and notified the state DEP.
Firefighters also found a mass of an oily substance on a nearby bank, Coltre said.
Meanwhile, firefighters in Trenton placed absorbent booms in the creek to try and stem the flow of as much of the substance as possible, Coltre said. The same was done in Lawrence at the entry point.
DEP authorities were still on scene at the Lawrence location all day Friday.
Shinske said Friday evening that the original source of the substance is still under investigation.
Editor's Note: This story has been updated to include additional information from the state Department of Environmental Protection.
Kevin Shea may be reached at kshea@njadvancemedia.com. Follow him on Twitter@kevintshea. Find The Times of Trenton on Facebook.