Despite opposition from the Pentagon, the Schwarzenegger administration is planning to issue safety guidelines Friday for ammonium perchlorate, a toxic ingredient of rocket fuel, munitions and fireworks that has tainted drinking water supplies in 29 states.
The pending guidelines would make California the first state in the nation to regulate perchlorate. The federal government has yet to act.
Environmentalists, however, have criticized California's pending standards as being too lenient.
Studies of laboratory rats have shown that even tiny doses of perchlorate can affect the thyroid's production of hormones that are critical to early childhood development, which suggests that the pollutant could be particularly threatening to pregnant women and young children. However, the level at which perchlorate poses a danger to human beings remains unclear.
The California Office of Environmental Health Hazard Assessment, which conducts research into potentially harmful pollutants, has called for a health goal of 6 parts per billion for perchlorate, according to several officials in the California Environmental Protection Agency.
That figure -- equivalent to roughly six drops of water in a typical home swimming pool -- would become the basis for a final regulation by the California Department of Health Services limiting how much of the chemical can remain in drinking water supplies.
Military contractors and the Pentagon, whose Cold War-era activities are responsible for most of the perchlorate pollution, have heavily lobbied the Schwarzenegger administration to delay setting a standard. Cleaning it up could cost them billions.
Environmental groups are also unhappy, contending that the governor who touted his green credentials during last year's recall campaign appears to have watered down the health goal at the last minute.
"It sure looks like bending in the direction of industry, and that is not what we were promised," said Bill Magavern, a Sacramento lobbyist for the Sierra Club.
Perchlorate, which has been used to power missiles and the booster rockets that help propel the space shuttle, has become the focus of a nationwide controversy. It is unregulated, though California has been recommending that water agencies shut down wells that contain perchlorate at 40 ppb or higher.
The entire lower Colorado River, which supplies water to more than 15 million people in the Southwest, including Southern California, is tinged with perchlorate that is leaking out of a former rocket fuel factory in Nevada.
Dozens of water wells in California have also become contaminated, mostly near San Jose, Sacramento, the San Gabriel Valley and the Inland Empire.
Perchlorate has also been discovered in lettuce and milk, suggesting that it is in crops and livestock that receive contaminated water. Most of the nation's winter vegetables are grown in California and Arizona with Colorado River water.
As a result, California's Office of Environmental Health Hazard Assessment announced this month that it will consider whether vegetables and other supermarket products containing perchlorate must carry warning labels under Proposition 65, a voter-approved state law that requires public notice of pollutants that are believed to cause cancer or developmental problems in children.
"Can you imagine putting a label on these products? I think that works against public health," said Hank Giclas, vice president of the Western Growers Assn., which represents the farmers who grow, pack and ship nearly half of the nation's fresh fruit, nuts and vegetables. "These are foods that every health expert says we should be eating more of, and we are worried that people could get frightened away from eating them."
Until the 1960s, perchlorate was used by doctors to treat Graves' disease, a disorder that caused an overproduction of thyroid hormones, so its effect on the thyroid gland is well known. However, whether perchlorate causes health problems in the relatively low levels found in tainted water supplies remains the subject of intense debate.
Government scientists at the U.S. Environmental Protection Agency at one point stated that perchlorate could be harmful in drinking water levels as low as 1 ppb.
That alarmed military contractors and the U.S. Defense Department, which contends that harmful effects have only been proved at 200 ppb. They persuaded the White House to postpone a pending federal perchlorate regulation until the National Academy of Sciences could conduct an independent review of the federal agency's research.
The defense industry was hoping for a similar delay in California, where officials had announced that they were considering a health goal of 2 to 6 ppb for perchlorate. To plead its case, the industry hired James Strock, former head of the California EPA under Republican Gov. Pete Wilson, and an advisor to the Schwarzenegger administration during its transition to power after the recall.