Plan to Cleanse Water Draws Fire From Crowd in N. Hollywood

A plan to cleanse city water supply wells of toxic chemicals by evaporation to the air drew an overwhelmingly negative response Tuesday night at a public hearing in North Hollywood.

Politicians and representatives of neighborhood and environmental groups came out swinging at the proposal by the Los Angeles Department of Water and Power to build an aeration tower in North Hollywood to purge chemical solvents from eastern San Fernando Valley wells.

“The proposal merely transfers the pollution from one medium to another,” Assemblyman Richard Katz (D-Sepulveda), who represents North Hollywood, complained to the audience of more than 100 at Fair Avenue School. The plan “clearly does not take into account the ever increasing air contamination level the basin is experiencing,” he said.

Patty Prickett, co-chair of Citizens for Safe Drinking Water, said her group supports a speedy cleanup of contaminated ground-water wells. But “we cannot condone taking carcinogenic chemicals out of the water and throwing them into the air,” she said.

Carbon Filters Urged

Duane Georgeson, chief of the water system, said the amount of solvents coming from the aeration tower would be equivalent to emissions from a dry cleaning shop, “of which there are about 200 in the San Fernando Valley.”

But many speakers said that even small amounts of pollution from the tower are unnecessary. They argued that the DWP should be required to use carbon filters to trap escaping vapors or should scrap the tower in favor of direct filtration of the polluted water.

One speaker argued, “Why have a little bit of poison when we can have none at all?”

The hearing was convened by the South Coast Air Quality Management District, which is considering a DWP request for a permit to operate the 45-foot aeration tower at 11845 Vose St. The air district is likely to reach a decision this summer. If approved, the tower could be in operation by late 1987.

The $2.2-million project is meant to slow the spread of chemicals--principally the suspected cancer-causing compounds trichloroethylene and perchloroethylene--that are invading more of the Valley wells. The wells furnish 15% of the city’s drinking water supply. Some of the most contaminated wells have been knocked out of service and officials fear continued spread of tainted ground water could severely constrain future supplies.

An aeration--or air-stripping--tower essentially converts small amounts of chemical solvents in water to lower levels in air by accelerating the natural tendency of the solvents to evaporate.

Polluted water would be pumped to the top of the tower and blasted with a stream of air, causing the solvents to leave the water in vapor form.

50 Cents a Year

Although there are ways to clean the well water without polluting the air, DWP officials have said there is no need to pursue these slightly more costly alternatives.

Capturing solvent vapors would increase the cost by about $20,000 to $30,000 per year--or about a nickel a year for the average customer. Direct water filtration would cost more than twice as much as the aeration tower, but no more than 50 cents more per year per customer.

However, DWP officials contend that they should not accept such costs because the tower presents no health risk.

A few speakers supported the DWP plan, including Jeff Olin, executive vice president of the Universal City-North Hollywood Chamber of Commerce.

Jill Dovre, a research assistant with Citizens for a Better Environment, presented petitions to air district officials opposing ground-water cleanup measures that add pollutants to the air. The petitions had 2,000 signatures, she said.

Little Risk Seen

State health officials have agreed with the DWP that solvent concentrations near the tower would be too low to cause any short-term illness, such as headaches or nausea.

Moreover, state health officials said, even a person living and working next door to the tower would not raise his risk of getting cancer by more than one chance in a million.

The U.S. Environmental Protection Agency late last year announced plans to list TCE and PCE as hazardous air pollutants. The listing could lead to controls on airborne emissions of those chemicals.

Cleaning water by transferring pollution to the air “is the kind of thing that we’re trying to avoid,” EPA official Robert Schell said.

But Schell said it is uncertain whether such regulations would cover very low emissions--such as those predicted from the aeration tower.