A top Environmental Protection Agency official told a Senate committee Tuesday that there was "a distinct possibility" that the agency would not limit the amount of perchlorate, a toxic ingredient of solid rocket fuel, that is allowable in drinking water.
State officials and water suppliers across the nation have been waiting for the EPA to set a standard for several years because perchlorate has contaminated the water supplies of at least 11 million people. Last year, California, impatient with the EPA's indecision, set its own standard.
Benjamin H. Grumbles, the EPA's assistant administrator for water, said the EPA would decide by the end of the year whether to regulate perchlorate. Scientific studies have shown that the chemical blocks iodide and suppresses thyroid hormones, which are necessary for the normal brain development of a fetus or infant.
"We know that perchlorate can have an adverse effect and we're concerned about that," Grumbles told the Senate Committee on Environment and Public Works.
Sen. Barbara Boxer (D-Calif.), who chairs the committee, told Grumbles that she heard from EPA staffers that there was a strong likelihood that the agency would decide against setting any standard.
In response, Grumbles said that was "a distinct possibility."
Boxer reacted angrily, saying the EPA is leaving Congress with little choice but to act on its own. She has introduced two bills that would order the testing of water supplies for perchlorate and require the EPA to set a standard within one year, based on scientific evidence showing what levels can cause harm to fetuses.
"Congress will not sit idle while EPA fails to adequately protect our children. We must step in to require action that will ensure that our children and families can turn on their taps and be assured that what comes out is safe to drink," Boxer said.
Much of the water contamination comes from military bases and aerospace plants, as well as fireworks companies.
The Pentagon and its contractors for years have been lobbying against a federal standard, saying there are no proven health effects at levels to which people are exposed, and that cleaning up perchlorate could cost billions of dollars.
At the hearing, Sen. Christopher S. Bond (R-Mo.), a committee member, said telling the EPA when and how to act was "the very definition of political regulation. It is politicians here in the Senate dictating the outcome of EPA's environmental decision-making."
Sen. James M. Inhofe (R-Okla.), the committee's ranking minority member, said it was "no secret that the scientific process can be tedious and cumbersome, but that in itself is no reason for political interference."
Grumbles told the Senate committee that Congress should not impose a deadline because if the EPA acted too fast, the result might not hold up in court. He said his staff was analyzing data that showed how much perchlorate people were exposed to by water and food.
Several experts, however, told the committee that there was enough evidence for the EPA to act now.
George Alexeeff, deputy director of California's Office of Environmental Health Hazard Assessment, told the committee that California had "sufficient data" to act two years ago, when his agency determined how much perchlorate was safe.
Alexeeff said the state was particularly concerned because the Colorado River, a primary drinking water source for Southern California, is contaminated. Contamination is also widespread in much of the Los Angeles region, particularly in Riverside and San Bernardino counties.
The chemical also is found in dairy products and food crops, as well as human breast milk and baby formula. Scientists reported in 2005 that it was contaminating "virtually all" human breast milk samples.