Vandals are being blamed for releasing contaminated liquid from tanks that the Environmental Protection Agency had been using as part of emergency cleanup operations at the Petro Chem Recycling Corp.'s Salt Lake City plant.

But EPA officials who have been on-site since late last week in connection with the cleanup, say the incident, which occurred late Thursday night or early Friday morning, poses no danger to area businesses and residents.Hays Griswold, a member of the EPA's Emergency Response Team said monitoring of the air is continuing, although current levels of organic vapors and hydrogen sulfide aren't sufficient to cause alarm.

Peter Stevenson, on-site coordinator for the EPA response team, said the contents of the tanks is unknown, although samples will be taken immediately. How much liquid was released by the vandals is also uncertain, although none of it escaped from the site. One estimate placed the amount between 40,000 and 50,000 gallons.

Stevenson said someone apparently gained entrance to the site at 1628 N. Chicago St. late Thursday night or early Friday morning, and opened the valves on several temporary storage tanks and a number of permanent facility tanks holding contaminated liquid. The vandalism was discovered about 7:30 a.m.

"It's a mystery," Stevenson said of the release. He said the police were notified and their investigation is still in process.

Wendy Olson, community relations director for the Bureau of Solid and Hazardous Waste, said the FBI, which had been looking into the Petro Chem operation, was also notified of the vandalism.

The Utah Health Department's Division of Environmental Health originally requested the EPA's involvement to stabilize the plant area, which was the former site of the Ekotek refinery. The site still contains substantial amounts of stored used petroleum products in tanks and drums, some of which are now leaking.

The state found aged and petroleum products present in groundwater both inside and adjacent to the Petro Chem property. Ignitable materials in the above-ground storage tanks were also apparently leaking from the tanks, pipes and fittings. A larger tank is was leaking hydrogen sulfide gas, too.

Brent C. Bradford, director the the state Bureau of Solid and Hazardous Waste, said an order was issued in March 1988 detailing steps needed to bring the site in compliance with the law, but Petro Chem failed to conform to the provisions of the order.

As many as 2,500 to 3,000 different companies and individuals, including waste generators, transporters and owners/operators of the refinery, involved with the site could be held responsible for the ultimate cost of the cleanup, which is now being paid for out of the EPA's Superfund.

A similar action was taken three years ago at Wasatch Chemical.

Stevenson said the vandalism will likely delay the original cleanup 24 hours.