The cancer-causing chemicals fouling the San Gabriel Basin's water supply usually get most of the attention, but now officials are developing a plan of attack against the basin's other pollution enemy, nitrates.
A $100,000 state grant will pay for a yearlong study of nitrate contamination, which results from the runoff of agricultural fertilizers, livestock wastes and septic tanks.
The problem is a common one for water supplies throughout the nation, and the San Gabriel Valley, once an agricultural belt replete with abundant orange groves, is believed to be particularly nitrate-ridden, health and water officials say.
Because of this, the state Department of Health Services has recently awarded the grant to the Main San Gabriel Basin Watermaster, the local water agency that oversees the pumping of water from Alhambra to La Verne.
Nitrate contamination has forced the closure of 30 of the basin's 400 wells, mostly in the 1970s. A key aspect of the study will focus on how the nitrates can be cleaned up at the same time as the more serious pollution, caused by such carcinogens as trichloroethylene and perchloroethylene, which are known as volatile organic chemicals.
Federal officials in 1984 put the basin on the Superfund list of environmental disaster sites. Since then, local, state and federal officials have been debating about how to solve the problem, considered one of the worst of its kind in the West.
Although nitrate contamination is less serious, high levels in drinking water can pose health problems to infants. Excessive levels have been linked to "blue baby syndrome," an anemic condition caused by high nitrate levels reacting with hemoglobin in the blood of some infants up to a year old.
Even though the nitrate problem here is considered serious, San Gabriel Valley water supplies meet state and federal water regulations, which prohibit such high levels.
To cope with nitrates, water companies often shut down contaminated wells or drill wells deeper than the pollution (which tends to remain close to the surface) or mix polluted water with purer water in an effort to meet state and federal health standards. The most expensive solution is to build treatment facilities. The facilities could be used to treat both kinds of pollution--carcinogenic chemicals as well as nitrate contamination--but the nitrate treatment would add substantially to the cost.
"It's a pretty pervasive problem," Robert G. Berlien, an official with the watermaster's office, said of the nitrates.
State and federal officials in April recommended that as part of the cleanup of the broader pollution problem, nitrates should be considered, including installation of water treatment facilities that would solve both types of the pollution problems.
"You can't address the overall cleanup without addressing the issue of nitrate treatment," said Tim Jochem, project manager for the watermaster. "There has been very, very little research on nitrates in the San Gabriel Basin. We're starting at square one."
One of the study's goals is to identify the location of clusters, or plumes, of nitrate contamination and see if they overlap with the four main plumes of pollution from the volatile organic chemicals.
Tracking these clusters, Jochem said, can form the basis for further studies that will help water officials consider where and how to proceed with cleaning up particular underground sections of the water supply.
Another goal of the study is to locate any sources and stem the pollution.
Crop fertilizers and livestock wastes from the 1920s to the 1960s account for much of the San Gabriel Basin's nitrate problem, Jochem said. However, less is known about the sources of modern-day nitrate contamination, the degree of which is unknown.
As part of the study, Jochem said he hopes to swap data with the Metropolitan Water District, the Three Valleys Municipal Water District and the Pomona Water Department. Earlier this year, the three water agencies began a nitrate study in communities in eastern Los Angeles County.
Officials in the Pomona-area study say that remedying the nitrate problem there may cost anywhere from $100,000 to several million dollars. But the officials say Pomona alone might save as much as $350,000 to $450,000 a year in water costs, if the pollution were reduced.
Water officials said that both the costs of solving the problem throughout the San Gabriel Valley and the potential savings are magnified many times over from the Pomona example.