MILFORD, Conn. (WTNH) — A rollover crash on Interstate 95 South in Milford caused heavy delays — and led to a mess on the roadway.

The state transportation department said the crash happened around 9:30 a.m. between Exits 38 and 36. Traffic was congested for nearly four miles between Exits 41 and 36.

About 100 gallons of used cooking oil spilled during the crash. The van involved had an additional 500 gallons onboard, according to the Connecticut Department of Energy and Environmental Protection, which responded to the crash.

DEEP worked with Environmental Services, Inc., to clean the interstate and pump the remaining cooking oil out of the containers on the van.