EPA said today that most cleanup activities associated with the Feb. 8 oil release from Caterpillar's Joliet facility are now complete. The work was performed with support from Illinois EPA and the U.S. Coast Guard.

The poisoning of the river occurred when Caterpillar Corps waste oil/water separation system failed. Two waste oil collection pits containing about 65,000 gallons of oil overflowed, spilling onto a parking area and an embankment leading down to the Des Plaines River.

Up to 6,000 gallons of the oil flowed into the river. About 90 percent of the spilled oil collected in a gravel parking area and on the embankment. Light river surface "sheening" was spotted several miles downstream from the Caterpillar facility.

The Coast Guard and Caterpillar contractors captured most of the off-shore spill with an absorbent pad system.

Later in the week, the parking area and shoreline impacted by the spill were monitored for additional releases. Runoff from recent rains was monitored to prevent recontamination of the cleaned areas. Next, Caterpillar will submit for EPA review a follow-up water and land sampling plan. Laboratory analysis of this work should be complete by April or May 2009. About 200 cubic yards of oil-stained parking lot gravel and other debris is now staged in rolloff boxes awaiting treatment and/or landfill disposal.