When Sharon Steel Corp. shut down in 1992 it abandoned several uncontrolled hazardous waste sites southwest of the plant in Farrell, Wheatland and Hermitage and along the west side of the Shenango River.

Because the company filed bankruptcy, the U.S. Environmental Protection Agency has taken over the sites and after years of investigating contamination on the nearly 400 acres, the EPA has proposed a plan to clean up the area.

For decades, slag and sludge were disposed of at the Sharon Steel Farrell Works site and millions of gallons of spent pickle liquor acid were dumped over the slag.

The EPA found higher-than-acceptable levels of heavy metals, poly-aromatic hydrocarbons, pesticides and poly-chlorinated biphenyls there after running series of tests from 1999 to 2004.

Human and animal health risks are high at the site, mainly due to the metals in the air and water, EPA Region III Remedial Project Manager Rashmi Mathur said at a meeting Wednesday in Stey-Nevant Public Library in Farrell.

“There’s not a tremendous risk currently,” said EPA Community Involvement Coordinator Carrie Deitzel. “But we’re looking at the future.”

The risk “to the general community and site workers involved could create a problem,” said Gary L. Mechtly, solid waste supervisor of the Environmental Cleanup Program of the state Department of Environmental Protection.

The shallow groundwater is contaminated, but flows away from residences and into the river, Ms. Mathur said. Also, those homes with wells draw water from the deeper bedrock aquifer, which is not contaminated.

The southern part of the area contains about 100 acres of wetlands that act as a natural filtration system before the hazards can get into the river, she said.

There is also concern for human health exposure to dust from the site, Ms. Mathur said, and the EPA’s remediation plan will control short- and long-term risks. Dust-suppression measures will be taken during cleanup as well.

The EPA is proposing a cleanup that includes regrading and contouring the contaminated slag and sludge source, covering it with a Class A biosolid and planting vegetation on the cap. Poplar trees are on the list of plants for the site because they swallow a large amount of groundwater.

Biosolids are solids — fecal matter — processed from wastewater that are rich in nutrients and used most often for agriculture. The EPA’s Environmental Response Team is testing site samples to determine an optimum mix to blanket the area, said team member Harry Compton. A more mature compost would be used along the river banks, he said.

The Proposed Remedial Action Plan also includes stabilizing the eroded river banks, long-term monitoring of the river and the groundwater and prohibiting the on-site groundwater for drinking and any land use that would damage the remedy.

That plan is the cheapest of the alternatives the EPA considered, and the $10.7 million to implement it would come from the agency’s Superfund program.

Phase one of the cleanup covers 61.4 acres in the northern area of the site. The design phase can take up to a year and it will likely be early 2008 before the plan is put into place.