State health officials are letting Cotter Corp. dump 90,000 gallons of radioactive sludge and solvents from its uranium mill into an impoundment pond the agency knows to be leaking.

Colorado Department of Public Health and Environment officials say this won’t worsen groundwater contamination near Cañon City because underground barriers would confine it near the impoundment.

But a lawsuit filed by Cañon City- based Citizens Against Toxic Water and other environmental advocates seeks judicial review of this and other decisions made by the state as the mothballed Cold War-era plant is dismantled.

A judge on June 3 rejected a request by the state health department and Cotter to dismiss the residents’ lawsuit.

Members of the residents group include “those affected and aggrieved by past, present and threatened impacts of radioactive waste” and therefore have standing to press their case, wrote Denver District Court Judge Robert Hyatt in his decision.

The lawsuit alleges Cotter is dismantling the mill without a properly approved plan as required and that state regulators made an informal deal with Cotter to reduce the bond Cotter must submit to guarantee cleanup to $20.8 million from $43.7 million.

While federal environmental laws govern Superfund cleanups, the U.S. Environmental Protection Agency entrusted the state health department with oversight of the reclamation, which is now entering its 27th year.

The lawsuit names Steve Tarl ton, manager of Colorado’s radiation control unit, within the health department’s hazmat division. A May 3 letter from Cotter advised state officials that contractors would dispose of sludge and solvent on site because off-site disposal of the radioactive material would cost considerably more.

Cotter disputes leaks

The tailings impoundment at Cotter is about 157 acres and includes two retention areas. One is closed and contains about 2 million cubic yards of material. The second area is open and receiving materials related to the mill demolition, including the 90,000 gallons of sludge. It contains about 2 million cubic yards of material and is about half full, according to the health department.

Cotter’s vice president for milling operations, John Hamrick, said the sludge is about 95 percent kerosene, used to process uranium. Before the sludge is moved to the impoundment, it will be mixed with another material.

“It’s like kitty litter,” Hamrick said Monday. “It becomes a solid.”

Eventually, new sludge and solvents dumped into the leaky impoundment will be neutralized, health department spokeswoman Jeannine Natterman said. “More contamination is not going into that (Cañon City) area.”

Hamrick said Cotter disputes the health department’s assessment of the impoundment. “We disagree with the state, that the impoundments are leaking,” he said.

Attorney General John Suthers, representing the health department in the case, late last week answered the claims in the suit, acknowledging that closure and decommissioning plans are required, claiming such plans exist, and accepting that dismantling will cost “tens of millions of dollars.” State health officials contend that groundwater cleanup will not add significantly to those costs.

“Cotter has expertly gamed the system, and the health department isn’t willing to confront Cotter,” said Jeff Parsons, a Western Mining Action Project attorney representing residents. “The current bond in place is not enough. The longer (Cotter) is able to string this out, the longer taxpayers stand to be liable for the cleanup.”

Still testing plumes

The mill was built in 1958 with federal support to process uranium for the nation’s Cold War nuclear arsenal and nuclear power plants. Between 1958 and 1978, liquid waste laced with radioactive material was sent to 11 unlined ponds. Well tests showed contamination of groundwater, and federal officials in 1984 designated the site a national priority for a Superfund cleanup.

State officials then allowed Cotter to keep an operating licence. The mill continued to process ore until about five years ago.

Toxic plumes have been detected moving underground toward Cañon City and the Arkansas River. Most recently, officials disclosed that the cancer-causing chemical trichloroethylene has been detected in groundwater at concentrations up to 360 times federal health limits.

“It has been confirmed that no trichlroethylene has gotten into Lincoln Park (neighborhood in Cañon City),” Natterman said. Cotter officials “are still poking holes, taking samples” to characterize that plume, she said. “Cotter is responsible for all the sampling and analysis. All data have to be quality-controlled by us.”

Bruce Finley: 303-954-1700 or bfinley@denverpost.com