The government on Friday issued its first safety standard for perchlorate, a toxic chemical used in rocket fuel and explosives and blamed for widespread contamination of drinking water especially near many military sites.
The Environmental Protection Agency’s new limit for what it considers a safe exposure level will be used in guiding Superfund cleanups and determining whether the agency should go a step further and regulate perchlorate as a drinking water contaminant.
The limit, which translates to 24.5 parts per billion in drinking water, is the same level recommended by the National Academy of Sciences in January but higher than what EPA proposed two years ago.
Perchlorate is a chemical found in nature, but the academy said its presence in the environment is mainly from its use in rocket fuels, fireworks and explosives. It has been linked to thyroid ailments, and is considered particularly dangerous to children.
“This reference dose is protective for all populations including the most sensitive,” EPA spokeswoman Cynthia Bergman said.
The EPA issued a preliminary recommendation two years ago for an exposure level that translated into 1 part per billion. The Pentagon had criticized that EPA standard as too stringent.
Erik Olson, an attorney with the Natural Resources Defense Council, said the exposure level the EPA considers safe is too lenient for protecting those most vulnerable — infants and pregnant women.
If used as a benchmark for cleaning up Superfund and military sites, Olson said, the standard “really puts potentially hundreds of thousands if not millions at risk.”
States and local governments have been trying to get defense contractors and the Pentagon to pay for the huge cleanup costs of removing the chemical from groundwater. California and Massachusetts have proposed limits on perchlorate contamination far more restrictive than the level EPA chose.
But even with its own standard, California could still have higher levels of perchlorate contamination from the Colorado River that comes from a former rocket fuel plant in Nevada.
EPA background is online at http://www.epa.gov/fedfac/documents/perchlorate.htm.