A plan for cleaning up toxic waste sites at Hill Air Force Base, in the works for two years, has been given tentative approval by federal and state agencies.

"Basically, it's a signed agreement," said Bob James, project manager for the basewide cleanup.The project would deal with seven major areas on the base and cover removal of potential or suspected environmental hazards at other HAFB sites.

Formal signing of the document by representatives from Hill, the Environmental Protection Agency and the Utah Department of Health will be April 10.

Officials will then hold off implementing the plan for 45 days for public comment and fine-tuning, James said.

"It's our bible of how we're going to go through the cleanup," James told the base's Technical Review Committee, which includes representatives from Hill, federal and state environmental regulators and Davis and Weber county governmental agencies.

The agreement provides a blueprint for resolving agency disputes and establishes priorities and deadlines for funding and implementing the projects.

At the top of the list is cleanup of chemicals and solvents that have leaked into nearby wells, said Capt. Ed Heyse, chief of the base's restoration division. The solvents were used to clean grease and oil from planes,locomotives and heavy equipment.

Prior to the 1980s, the solvents, including the suspected cancer-causing agent trichloroethylene, or TCE, were disposed of by burial in base landfills.

In recent years, trace amounts of those chemicals have been found in a few shallow wells and springs in neighboring communities.

The water isn't used for drinking and none of the chemicals has shown up in culinary supplies, he said.

The goal is to prevent the solvents from leaching into the aquifer several hundred feet underground.

The first major project will be construction of a complex to suck up to 250,000 gallons of solvents and other liquids buried in an area called Operable Unit No. 2, east of Hill's runway and overlooking the South Weber area.