Senators Ask EPA to Raise Perchlorate Standards

New study links low levels of exposure to thyroid problems in
women
By Tony Burchyns Staff Writer

Morgan Hill – California Senators Barbara Boxer and Dianne Feinstein sharply criticized the U.S. Environmental Protection Agency’s cleanup “guidance” for perchlorate in drinking water, writing in a letter to EPA Administrator Stephen Johnson that the guidance does not protect vulnerable children and pregnant women.

Even minute traces of the rocket-fuel chemical lowers essential thyroid hormones in women, the senators wrote Wednesday, citing a study published this month by the Centers for Disease Control and Prevention.

“Given the serious health threat posed by widespread perchlorate exposure, we request that you take immediate steps to incorporate the information from the CDC study in a health advisory and new perchlorate standards and goals,” wrote the senators, requesting a response from the agency by next Monday.

Perchlorate contamination is found nationwide, with federal tests showing 160 public water systems in 22 states are contaminated with the chemical. Hundreds of South County wells were contaminated with perchlorate that leached into the soil at Olin Corporation’s now-defunct road-flare plant in Morgan Hill. The plume stretches south through San Martin and northeast of Gilroy. Throughout California, perchlorate has been found in 450 wells and other water sources. 

In July, Massachusetts set the nation’s first drinking water standard for perchlorate of 2 parts per billion. The California Department of Health Services is considering a standard in drinking water of 6 ppb for perchlorate.

The senators also cited the concerns of the EPA’s Children’s Health Protection Advisory Committee, which in March stated the EPA’s guidance was “not supported by the underlying science and can result in exposures that pose neurodevelopment risks in early life.”

Perchlorate is primarily used by the U.S. Department of Defense to make rocket and missile fuel. The inorganic chemical is also used in explosives, fireworks, road flares and airbag inflation systems. Most contamination comes from military bases. It is also widely found in produce, including oranges, grapes, melons, lettuce, tomatoes and spinach. Santa Clara County Agricultural Commissioner Greg Van Wassenhove said there’s a growing need for a risk assessment for perchlorate in irrigation systems. 

The CDC team analyzed urine samples from more than 1,100 women for perchlorate, and then looked to see if perchlorate exposure could predict thyroid hormone levels. They found a significant link between perchlorate levels as low as 3 ppb. The federal “safe dose” level is more than 10 times this dose.