Water Treatment Plant Makes Haste, Not Waste : North Hollywood: DWP officials dedicate a new facility that can filter 2,000 gallons a minute and turn pollutants into harmless components.
Los Angeles water officials Thursday dedicated an innovative new treatment plant in North Hollywood that they said could become a model for ground-water cleanup efforts throughout the country.
The new plant in the 11400 block of Vanowen Street will cleanse about 2,000 gallons of ground water per minute, removing chemical solvents that have forced the Department of Water and Power to close many of its drinking water wells in North Hollywood and near Griffith Park.
Officials said the technology used in the $2.5-million project avoids a major drawback of conventional ground-water treatment--the production of hazardous wastes.
“The biggest advantage is this: no hazardous byproducts,” said Ali A. Karimi, of the DWP’s water engineering design division.
At a ceremony attended by Mayor Tom Bradley and about 80 DWP employees and visitors, officials said the new plant blends solvent-tainted ground water with hydrogen peroxide and bubbles of ozone gas, converting the chemical pollutants to harmless byproducts, including water, carbon dioxide and chloride ions such as those found in table salt.
Conventional ground-water treatments remove solvents with filters that then must be recycled or disposed of as hazardous waste.
DWP officials praised the new method as an effective, environmentally responsible, and economic means of cleansing San Fernando Valley ground-water supplies, on which the city relies for about 15% of its water. They said that if the plant meets expectations, they may eventually build more like it or install small-scale units on individual wells.
About 30 of the DWP’s 90 water supply wells are shut down because of excessive levels of trichloroethylene or perchloroethylene, also known as TCE and PCE. Widely used in dry cleaning and metal degreasing, the chemicals over time seeped through soil to pollute a vast supply of water underlying the Valley. Health authorities believe that people who drink water containing low levels of these compounds over a period of years slightly increase their risk of cancer.
The pollution has idled the wells of several utilities and led the U.S. Environmental Protection Agency to designate a large area of North Hollywood, Burbank and Glendale for cleanup under the federal Superfund program.
Elsewhere, water utilities and private companies are attempting to use combinations of ozone and peroxide and in some cases ultraviolet light to cleanse ground water. But Tom Rulla, project engineer for DWP, said the new plant may be the largest of its kind now operating.
Although billed as a demonstration project, the new plant, running since July, is producing enough drinking water to meet the needs of about 30,000 people.
“It may have impact nationally” if “this can be accepted as proven technology,” said Gary Yamamoto, an engineer with the state Department of Health Services office of drinking water, which issued a temporary permit allowing the DWP to sell the treated water to customers.
“We’re just looking forward to those results within a year, along with the rest of the country, and hopefully it will prove itself out.”
Among other things, researchers are studying the possibility that chemical reactions from the treatment process may produce minute traces of new pollutants while destroying PCE and TCE.
However, Yamamoto said health officials “feel confident enough” about the purity of the water to allow it to be supplied to consumers.
In comments to the gathering, Bradley called the project “the cutting edge” and praised DWP staff for showing “they know how to tackle a problem and solve it.”
His remarks, however, reflected the common misconception that San Fernando Valley wells serve Valley residents--when in fact almost all of the water is pumped to customers on the other side of the Santa Monica Mountains.
He said the project was a boon to the Valley and other parts of the city, “which may, from time to time, have need of that water supply.”
The ceremony took place under a billowy tent pitched beside the treatment works--a labyrinth of pipes, pumps, valves and gauges surrounding two project buildings.
One of the buildings houses the machinery that produces the ozone gas. Erected in Cincinnati on the bed of a 40-foot trailer, the ozone generator was trucked to North Hollywood, left on the trailer and the building built around it. According to a DWP official, the wheels and axles have been saved so the plant could be transported to another area.
The ozone used in the treatment process is the same as the ozone that is a major pollutant
of Los Angeles air. A DWP official said the ozone concentrations escaping from the new plant are considerably below those in the surrounding air.
The new plant is a few blocks from another DWP demonstration plant that has operated for several years in the 11800 block of Vose Street. That plant, which also treats 2,000 gallons of ground water per minute, uses an aeration process to remove solvents in the form of a gas that is captured by air filters.
Construction of a larger aeration treatment complex is expected to begin next year in Burbank, where municipal water supply wells have been idled by solvent contamination. The project will be managed by Lockheed Corp., whose Burbank aerospace complex caused at least part of the pollution.
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