EPA Criticized on Contaminants Decision

The Environmental Protection Agency has decided not to add any new contaminants to the list of substances regulated in drinking water, angering conservation groups who assert that the EPA’s own scientific research shows that the rocket fuel ingredient perchlorate presents a public health threat.

Perchlorate, a type of salt used by the U.S. government to help power the space shuttle, missiles and munitions, has become a pressing concern in California amid evidence showing its widespread presence in the state’s water supplies. The Colorado River, the main water source for millions of Californians and most of the nation’s winter vegetable farms, is tainted with perchlorate that is seeping from a former rocket fuel factory.

State and federal environmental officials have determined that perchlorate may cause health problems, even in trace amounts. Because it is known to affect the production of thyroid hormones, which are critical to early brain development, government researchers believe perchlorate exposure may be especially dangerous for pregnant women and young children.

Those claims are disputed by the Pentagon and its defense contractors, whose scientists say perchlorate is only dangerous in higher concentrations.

As part of the Safe Drinking Water Act, the EPA is required every five years to review whether additional contaminants need to be regulated. Friday, seven years after that rule went into effect, the EPA issued a decision concluding that the list of regulated substances did not need to be expanded.

Environmentalists lashed out at the EPA on Tuesday.

“I don’t think too many scientists within the EPA would dispute that perchlorate is bad and that we know enough to begin placing some regulations on it,” said Bill Walker of the Environmental Working Group, which earlier this year found perchlorate in lettuce purchased at some California supermarkets.

A spokesman for Sen. Dianne Feinstein (D-Calif.) called the EPA decision “very troubling” and said the lawmaker planned to demand an explanation.