Sen. Tim Wirth, D-Colo, has questioned the Environmental Protection Agency's ability to monitor emissions at hazardous waste incinerators like the one proposed for Cisco, Utah.

Wirth has opposed the Cisco facility, which would be built about 40 miles from the Colorado border.In a letter to EPA Administrator Lee M. Thomas, Wirth asked the agency to improve its method of identifying the chemicals emitted from incinerators, and he asked whether EPA could assess the environmental and health risks posed to nearby communities.

"Siting a hazardous waste incinerator near the Colorado border could have significant impacts on the health of Coloradans and on the state's efforts to promote the outstanding recreational opportunities and quality of life in Grand Junction and other cities and towns along the Western Slope," Wirth said in a press release from his Washington, D.C., office.

The 60,000-square-foot, $30 million Cisco facility was proposed last year by CoWest Incinerator Corp. It would be capable of burning a ton of hazardous waste each hour, Wirth said.

Wirth said not enough is known about the types and amounts of the emissions, and cited a 1985 report by EPA's Science Advisory Board identifying several deficiencies in EPA's data collection and regulations.

"The agency continues to experience difficulties both in assessing and managing hazardous waste incineration programs," the report concluded.

EPA evaluates hazardous waste incinerators by studying the results of trial burns under controlled conditions, Wirth said. It requires the elimination of at least 99.99 percent of the hazardous materials introduced into the incinerator.