A Pima County health official last night opposed a federal plan for cleaning southside ground water polluted by TCE.
The U.S. Environmental Protection Agency plan would send the chemical into the air, said the official, John Mann.
Mann, enforcement supervisor for the county Air Quality Control District, said he believes that it would be "morally wrong" to clean ground water by putting TCE into the air, even if the plan did not violate county health limits.
The proposed plan, however, would send 3.2 pounds of TCE a day into the air, exceeding the county air limit of 2.4 pounds a day, Mann said at a public hearing on the EPA plan.
TCE, or trichloroethylene, is an industrial solvent and is listed as a probable human cancer-causing agent.
Mann was cheered last night by many of the roughly 50 people who attended the hearing, and several southside residents also formally opposed the EPA cleanup proposal because of its air emissions of TCE.
People are also reading…
EPA officials said the cleanup plan is not final.
The plan calls for sinking five new wells that would be used to pump tainted water to near the top of an 18-foot treatment tower just north of West Irvington Road and west of Interstate 19.
Air would be blown into the bottom of the tower, through contaminated water. It would exit the top of the tower, carrying TCE with it.
The cost of the system, which would operate for an estimated 20 years, is $4.7 million.
Treated water would be sent into the Tucson Water system.
As an extra feature, carbon filters could be put in the top of the tower between the treatment area and the, vent to capture the TCE, EPA officials said. Dirty filters would go to a hazardous waste landfill, they said.
The cost of the system with filters is $6.4 million.
TCE has polluted ground water in a finger-shaped southside area more than four miles long and up to a mile wide. Nine wells once operated in the area.
The area reaches from the U.S. Air Force weapons plant operated by Hughes Aircraft Co. to Michigan Street. The EPA plan is for the portion from Los Reales Road northward.
Hughes and the Air Force have a $28 million water-cleaning system for TCE near the Hughes plant. Thea system is expected to operate for 20 to 30 years.