The U.S. Environmental Protection Agency announced Thursday that it will build a $5.4-million water treatment system at Whittier Narrows, near Pico Rivera, to stop the spread of carcinogens in ground water.
EPA said the cost of the project, including operation of the treatment system for 30 years, will reach $17.8 million.
The treatment system will assure a pure water supply for 17,000 Whittier-area customers of Suburban Water Systems and remove pollutants at a narrow channel where water flows underground from the San Gabriel Valley to the Central Basin, which supplies water to more than 1 million people in the southeastern part of the county.
The EPA plan calls for construction of “air-stripping” towers to remove pollutants through aeration. The towers would be equipped with a system for trapping pollutants from the water before they are transferred to the air.
Water would be piped from wells to the top of towers about 40 feet high and then would flow downward as air is pumped upward, releasing contaminants into the trapping system.
Neil Ziemba, EPA’s remedial project manager, said the U.S. Army Corps of Engineers will design the system. Construction should begin next September and be completed a year later.
The treatment towers initially will serve four wells owned by Suburban Water Systems, but could serve other wells in the Whittier Narrows area. Ziemba said EPA is developing a plan for the entire Whittier Narrows, but decided to concentrate on Suburban’s wells first because they are directly in the path of polluted ground water.
Some Tainted Wells
Large areas of ground water in the San Gabriel Valley are contaminated with volatile organic compounds, such as trichloroethylene and perchloroethylene. Ziemba said the Central Basin has some contaminated wells too, but the problem there is not as widespread.
EPA has estimated that it will take decades and hundreds of millions of dollars to clean up ground water in the San Gabriel Valley.
About 70 wells in the San Gabriel Valley produce water that does not meet state and federal drinking water standards. Some of the wells have been closed and others pump water that is blended with other water to meet the standards.
Reginald Stone, vice president of Suburban Water Systems, welcomed the EPA decision. He said Suburban’s four wells at Whittier Narrows now meet state and federal drinking water standards, but the company had already designed aeration towers to be built if the wells became polluted.
In addition to building the treatment system for Suburban’s wells, Ziemba said, EPA is looking at other ways to control pollution in Whittier Narrows and intends to reach a conclusion by the end of next year. Ziemba said the cost of the additional work could range from $5 million to $50 million.