AURORA, Ill. (CBS) — Cleanup continues in Aurora Thursday, following a diesel fuel spill in the Fox River.

As WBBM Newsradio’s Bernie Tafoya reports, large booms are being used to contain and absorb the 1,500 gallons of diesel fuel that were accidentally allowed into Fox River Wednesday, via the Aurora storm sewer system.

LISTEN: WBBM Newsradio’s Bernie Tafoya reports

Aurora police spokesman Dan Ferrelli says the fuel came from a Federal Aviation Administration facility. Around 1 a.m. Wednesday, the fuel overflowed through the top of a malfunctioning underground fuel storage tank onto the pavement and into a Fox Metro Water District sanitary sewer.

Ferrelli said the Illinois Environmental Protection Agency is overseeing the cleanup and progress is being made.

Originally, the FAA estimated that only 20 to 100 gallons of fuel had spilled. Since a spill of that size would be categorized as small and did not necessitate an immediate cleanup, fire personnel informed Fox Metro and plans were made to address it later in the morning, the city said.

But around 10 a.m. Wednesday, the FAA revised the estimate to between 1,000 and 1,500 gallons. The final estimate was 1,459 gallons.

Upon receiving the revised information from the FAA, the city dispatched crews from the Fire, Water and Sewer, and Water Production departments and notified the IEPA.

The FAA contracted with a private, IEPA-approved environmental mitigation firm, which soon arrived. Absorbent booms were placed at the entrances and exits of the affected storm sewer lines in order to absorb the fuel.

Ferrelli says the water supply in Aurora has not been threatened, because the spill is far enough away from the water treatment plant. But there is a 1.5 mile-long oil slick on the Fox River, which has left an approximately 8-foot wide sheen on the river’s west bank.

Cleanup has been in progress since the spill Wednesday morning.

The Aurora Beacon-News contributed to this report, via the Sun-Times Media Wire.