The Environmental Protection Agency filed a civil suit Friday in U.S. District Court against Sharon Steel Corp., seeking a cleanup of the Midvale slag site.

The suit also names as defendants UV Industries Inc., UV Industries Inc. Liquidating Trust, Valley Materials Corp., Littleson Inc., Century Terminals Inc. and Blackhawk Slag Products Inc.An EPA fact sheet issued in August 1988 said tailings at the 260-acre site of the steel mill, which has been idle since 1971, may pose a danger to human health and the environment. The site is bordered by Main Street on the east and the Jordan River on the west and south.

State officials sampled the tailings in the summer of 1982 and found them to contain high levels of lead, which is a hazardous waste. Tests of windblown tailings dust from along the highway showed arsenic, cadmium, copper, lead, zinc and chromium at levels higher than natural.

A study in 1983 found high levels of these contaminants in the tailings and actual or potential contamination of soil, air and groundwater nearby.

The EPA suit asks the court to find the defendants individually liable for any imminent and substantial endangerment to the public health or welfare or the environment caused by their respective contributions to contamination at the site.

It also asks the court to require the defendants to remedy an endangerment to the public health and asks that the U.S. be reimbursed for all costs incurred for response activities.