It's an odd way for a pollution cleanup to go. But that's the way the groundwater cleanup project in southwest Salt Lake County has progressed, most recently with an acid plume just southeast of Copperton.

Water long ago tainted by mining is being pumped from an aquifer and decontaminated. But only now are the bureaucrats at the state Division of Environmental Remediation and Response and the U.S. Environmental Protection Agency wrapping up their contract with Kennecott Utah Copper to finish the job.

By all accounts only formalities remain as regulators negotiate with the mining company over a consent decree for the work, which will continue for decades.

"Things are on a good track," said Kennecott's Kelly Payne.

The work got started more than a decade ago, after state and federal regulators agreed to let Kennecott undertake the initiative in dealing with mining wastes that had penetrated the groundwater 300 to 1,000 feet beneath the southwest valley floor. A formal agreement allowed Kennecott to deal with a number of water-quality problems without the Superfund label and saved the company and the government big legal bills.

Doug Bacon, a project manager for the Utah Division of Environmental Remediation and Response, estimates the many facets of the project have cost $350 million, the Jordan Valley acid plume included.

The latest consent decree is, in effect, a contract between regulators and the mining company that outlines Kennecott's continuing duties in dealing with an acid plume that covers about 4,000 acres southeast of Copperton.

Mining in Bingham Canyon began in the 1860s and made the groundwater so contaminated it cannot meet current water-quality standards. Heavy metals in the water also exceed allowable limits.

Kennecott, under EPA and state supervision, installed five wells that draw up the polluted water.

Two wells send tainted water to the Kennecott tailings pond on the edge of the Great Salt Lake, where it is neutralized. Three wells direct less-contaminated water to the reverse-osmosis plant in South Jordan, where it is transformed into drinking-quality water, enough to serve 3,500 families.

"The problem is being worked on," said Bacon. " The consent decree is simply an enforcement tool."

The paperwork will be filed in federal court sometime this fall, and the public will have 30 days to submit written comments on it.

Lynn de Freitas, executive director of the Friends of the Great Salt Lake, has been one of the environmental community representatives on a panel overseeing all of the southwestern Jordan Valley groundwater cleanup project. She said many of those following it have been concerned that there may not be enough money for the long-term work and "a sense of disquiet" that the cleanup is not tough enough.

"It's a curious beast," she said.

Her group and others promise to look over the final contract to make sure the job gets done right.

fahys@sltrib.com