EPA LIMITS TO GUIDE CLEANUPS PERCHLORATE CONTAMINANT STATUS WEIGHED.

Byline: Staff and Wire Services

The Environmental Protection Agency's new limit for what it considers a safe-exposure level of perchlorate will be used in guiding cleanups and determining whether the agency should go a step further and regulate the rocket-fuel byproduct as a drinking-water contaminant.

The limit, which would allow up 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 the EPA proposed two years ago.

Across California, more than 350 wells and other drinking-water sources are contaminated. Most are in Los Angeles, Riverside and San Bernardino counties, where dozens of aerospace factories opened during World War II.

Perchlorate has been found in groundwater in Simi Valley at levels ranging from 4 to 19 parts per billion and up to 58,000 ppb at the former Whittaker-Bermite explosives factory in Saugus.

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, such as in the Bermite case. 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, criticized the EPA's new standard as too high 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 the EPA chose.

But even with its own standard, California still could have higher levels of perchlorate contamination from the Colorado River that comes from a former rocket fuel plant in Nevada.