Say the words "rocket fuel" and people think of flame and heat; mention the word "perchlorate," however, and those in the know think of lawsuits and red tape. The chemical, which has been used since the 1950s in rocket fuel, munitions and fireworks, prevents the human thyroid from absorbing iodine. In adults, that can cause fatigue, weight gain and hair loss; in children, exposure to perchlorate affects their ability to learn, and at high levels, causes mental retardation.
According to the U.S. Environmental Protection Agency, perchlorate has contaminated drinking water, groundwater or soil in 44 states. Most of it has come from the military and its contractors, but the Pentagon and industry have done their best to avoid the billions of dollars in cleanup costs — and the military has repeatedly lobbied Congress for exemptions from liability for perchlorate (HCN, 4/28/03: Perchlorate: It’s not just for rocket fuel anymore).
Furthermore, disputes over acceptable doses are keeping the EPA from actually regulating the chemical. Two years ago, the EPA released a draft dose recommendation of 1 part per billion (ppb), saying that the equivalent of one drop of perchlorate in a swimming pool of water is safe for humans. But the Bush administration yanked that report and sent it to the National Academy of Sciences for review, effectively delaying regulation and cleanup of perchlorate across the nation.
Even as the debate continues about exactly how much perchlorate is harmful, there isn’t any doubt that the chemical is dangerous. "Perchlorate is an unusual contaminant because we know a lot about it," says Gina Solomon, a physician with the Natural Resources Defense Council. She adds that the "swimming pool" analogy is misleading: "That one drop of perchlorate isn’t evenly distributed: It’s like an iron filing to a magnet, it goes right to your thyroid."
In light of that danger, California, which currently has 350 of its drinking-water sources contaminated with the chemical, decided it could no longer wait for federal guidance. In mid-March, the state’s Office of Environmental Health Hazard Assessment announced a "public health goal" for perchlorate at 6 ppb.
It’s not a "goal" that state officials can actually enforce; a legally enforceable standard won’t come out until next year at the earliest. But what disturbs critics is the fact that the state’s new goal is weaker now than it was: Since 1997, the advisory level has been 4 ppb. Now, almost half the wells previously tagged for cleanup fall off the list, says Sujatha Jahagirdar, clean water advocate for Environment California.
The state has promised to reconsider its goal if new information becomes available. That’s good news for public health advocates, says Bill Walker of the Environmental Working Group, which has released its own studies of perchlorate in lettuce (HCN, 4/28/03: Cold War toxin seeps into Western water). But it’s also good news for the military, industry and agriculture — all of which are busy with studies of their own.
"The law is supposed to represent the best available science that shows what will protect people," says Walker. "But in that contest, the chemical companies, defense contractors and the Pentagon have a lot more clout than the public health advocates."
Meanwhile, on the lower Colorado River — where water with perchlorate levels between 4 and 8 ppb is delivered to 21 million people and thousands of farms in California and Arizona — the new public health goal is meaningless.
Perchlorate in the Colorado is seeping from a leak at a former rocket fuel plant in Las Vegas, where defense contractor Kerr-McGee has so far spent about $61 million to fix the problem. By the time the Metropolitan Water District of Southern California — which supplies drinking water to Los Angeles and San Diego — has to meet California’s as-yet-undefined legal minimum standard, the Colorado’s perchlorate levels will be even lower.
Instead of blending Colorado River water with water from other sources to reduce the level of perchlorate, the Met can essentially ignore the problem until it goes away. "The state didn’t totally capitulate (to industry)," says Jahagirdar. "What they did do was set the goal at 6 parts per billion. What that means is the Colorado River (water delivered to customers) may not see meaningful cleanup."
The author is HCN’s assistant editor.