Water pollution north of Los Reales Road
The Environmental Protection Agency said yesterday that it prefers to clean up southside TCE ground-water pollution by allowing the chemical to evaporate into the air.
That announcement at a meeting last night drew immediate objections from members of Tucsonans for a Clean Environment, a southside group formed to protest the TCE pollution.
"We don't know the health effects of TCE in the air; there hasn't been enough study," said Guillermo Robles, a spokesman for the southside group.
"What about the people livings near the treatment facility," he asked. "They (EPA officials) say there isn't the same risk as drinking TCE-polluted water, but I don't think they have enough information to say that."
TCE, trichloroethylene, is an industrial solvent that causes cancer in laboratory animals and is listed as a probable human cancer-causing agent.
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Health-risk factor
Daniel Opalski, remedial projects manager for the EPA's San Francisco office, said the agency believes the air-dispersion cleanup method presents little health risk while saving money.
A public hearing on the proposal is set tentatively for March 15.
The agency rejected a similar cleanup system that would have added carbon filters to trap TCE after it evaporates but before it reaches the outside.
The EPA's favored method would cost an estimated $4.7 million to build and operate for 20 years; with the carbon filter addition, the cost would be $6.4 million, Opalski said.
The cleanup program calls for construction of one or more towers on a plot of "city-controlled" land between the Santa Cruz River and Interstate 19 north of Irvington Road, Opalski said.
Towers at Hughes
The contaminated water would be exposed to air in the towers. The pollutant combines easily with air and would evaporate.
Hughes Aircraft Co. and the U.S. Air Force built similar towers outside their southside plant to clean TCE from ground water. The towers have carbon filters.
Opalski said TCE concentrations are greater in the Hughes area.
The larger Hughes-Air Force system, which also cleans chromium from the water, cost $28 million and is to operate for up to 30 years. It is to clean TCE-polluted water south of Los Reales Road.
The EPA system is to clean TCE from ground water north of Los Reales.