EPA INVESTIGATING DISAPPEARING CASE OF PCBS WITH LIME

CHICAGO, Ill. -- Environmental Protection Agency officials here say they're stumped by the disappearance of PCBs from two hazardous waste sites in the agency's Region 5, where lime was used over a period of two years. They admit a promising technique for destroying the cancer-causing substances may be in the making.

"We have some good preliminary information from the Indiana site," said John Perrecone, a spokesman for the Region 5 EPA Public Affairs office here. "We're hoping we can eventually award a research contract to investigate what happened there, and what it can mean for the future."

Perrecone explained that the former Cam-Or Oil Refinery Site near Westville, Ind., which once contained more than triple the concentration of PCBs allowed by law, now appears to be free of the contaminants.

"Jack Barnette, an EPA supervisor for emergency response, helped oversee the containment and temporary cleanup project in which crews combined three infested lagoons, drained and treated the waste water and added lime to help solidify the waste," noted Perrecone.

The EPA then covered the new lagoon with a tarpaulin to prevent rain from washing contaminants out of it and left it covered for two years.

When EPA officials returned to test the lagoon in mid-1988, they found the oil sludge intact but the PCBs gone.

The monitoring of well water around the site show the chemicals did not seep out of the lagoon, noted Perrecone. "The PCBs appear to have disintegrated into harmless chemical components."

Perrecone said the leading theory is that high heat and low moisture during a long drought in 1988 could have combined to make the contaminants disintegrate.

He added that if a research project can be arranged, the EPA will be taking a long look at weather conditions, what type of lime was used, what grades of lime, and how much was used.

The polychlorinated biphenyls, once used as insulators in electrical transformers, were banned by the federal government in the 1970s. They are chemically stable compounds and have been considered nearly impossible to destroy.

At a similar site in Toledo, Ohio, also in Region 5, where the EPA started a cleanup effort just after the one at Cam-Or, lime was used to harden sludge, and the PCBs disappeared.

"We are not sure if it was the environment or the lime, or the combination, but from now we'll be using lime when we deal with PCBs," said another EPA spokesman.

"This could be big step in PCB control," said Perrecone. "Anything to help achieve PCB control is a big step."

PCB problems have resulted in some high costs in the Cape Girardeau and nearby Southern Illinois areas. A cleanup of contaminates at the Missouri Electric Works is now under way, with an estimated cost of about $10 million over a 15-year period. This project is being conducted out of EPA's Region 7 office in Kansas City.

The Ilada Energy Co. site cleanup between East Cape and Thebes, Ill. was conducted through the Division 5 office. That cleanup was paid through private companies.