Pentagon Pressured EPA on Perchlorate
By Alex Pulaski, The Oregonian, Portland, Ore.
Jan. 7–The federal government has been inconsistent and at times intentionally silent on how much perchlorate is safe in drinking water.
As a result, environmental groups contend, defense contractors and the government have been indefinitely shielded from cleanup costs while infants and pregnant women are exposed to a chemical that impairs thyroid function and can slow infant brain development.
Industry advocates argue that the science on perchlorate is not precise enough to warrant strong — and extremely costly — remedies.
The U.S. Environmental Protection Agency first placed perchlorate, a component in solid rocket fuel, on a list of potential contaminants in 1998. It required that states monitor drinking water for the chemical’s presence the following year.
In 1999, the agency established what it described as “interim” guidance on how much perchlorate humans could be exposed to each day without suffering long-term harm. The average dosage translated — based on average body weights and water consumption — to a provisional agency conclusion in early 2003 that cleanup might be required of water supplies with levels of perchlorate ranging from 4 to 18 parts per billion.
The 2003 agency memo announcing the policy suggested that federal and state managers “carefully consider” the low end of the range as most protective of human health.
In the meantime, a separate draft assessment by the agency concluded that the public safety standard for drinking water should be even lower, at 1 ppb.
Under pressure from the U.S. Defense Department and contractors facing potential cleanup costs in the billions of dollars, the Bush administration in early 2003 ordered EPA scientists not to publicly discuss perchlorate pollution. The White House also took perchlorate risk analysis out of the EPA’s hands and gave it to the National Academy of Sciences.
In presentations before the academy, the EPA maintained its position that perchlorate levels in drinking water should not exceed 1 ppb. A colonel representing the U.S. Air Force’s environmental law staff, however, argued that the academy could safely adopt a standard as high as 200 ppb.
In early 2005, the EPA adopted the academy’s conclusions on what constitutes a “safe dose” for humans, even though they translated to perchlorate drinking-water levels more than 20 times higher than the 1 ppb standard that the agency had last endorsed. In a rare step, the EPA placed the new dosage on its risk-information Web site without allowing public comment.
By raising the dosage bar to an equivalent of 24.5 ppb in drinking water, the agency cast doubt on whether it would ever establish a legal limit forcing cleanup of water supplies contaminated by perchlorate. The reason is that federal law requires such limits only when significant health benefits will result, and almost all water supplies fall below the threshold of 24.5 ppb.
To illustrate the difference, slightly more than half the wells tested in Morrow and Umatilla counties in 2003 had perchlorate levels higher than 1 ppb. But only one of the 133 wells showed perchlorate levels higher than 24.5 ppb.
The academy reference dose adopted by the EPA has come under fire from toxicologists in states considering adopting their own perchlorate limits in drinking water. They have questioned the validity of studies supporting the standard and the agency’s refusal to accept public comment on it.
Oregon has no standard for perchlorate contamination.
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