Thanks to EPA You May Be Unknowingly Drinking Water Contaminated With Weed Killer

One of the nation's most widely-used herbicides has been found to exceed federal safety limits in drinking water in four states, but water customers have not been told and the Environmental Protection Agency has not published the results.

Records that tracked the amount of the weed-killer atrazine in about 150 watersheds from 2003 through 2008 were obtained by the Huffington Post Investigative Fund under the Freedom of Information Act. An analysis found that yearly average levels of atrazine in drinking water violated the federal standard at least ten times in communities in Illinois, Indiana, Ohio, and Kansas, all states where farmers rely heavily on the herbicide.

In addition, more than 40 water systems in those states showed spikes in atrazine levels that normally would have triggered automatic notification of customers. In none of those cases were residents alerted.

In interviews, EPA officials did not dispute the data but said they do not consider atrazine a health hazard and said they did not believe the agency or state authorities had failed to properly inform the public. "We have concluded that atrazine does not cause adverse effects to humans or the environment," said Steve Bradbury, deputy office director of the EPA's Office of Pesticide Programs.

Officials at Syngenta, the Swiss company that manufactures atrazine, declined requests for interviews about the testing results. In a statement on its Web site, the company says that atrazine "poses no threat to the safety of our drinking water supplies. In 2008, none of the 122 Community Water Systems monitored in 10 states exceeded the federal standards set for atrazine in drinking water or raw water."

Atrazine has become an issue of concern for environmentalists and consumer groups as the use of the herbicide has soared in the United States over the past few decades. Some scientists who have studied atrazine said the information about its higher levels in drinking water should be made public.

For more background on the story of atrazine, watch our video: "How Safe Is Atrazine?”

"This is an issue of the EPA not being forthright about what they know," said Robert Denver, a neuroendocrinologist at the University of Michigan who has served on two of the EPA's scientific advisory panels on atrazine.

"It is the responsibility of the EPA and Syngenta to inform the public of accurate levels of atrazine in their drinking water," said Jason Rohr, a specialist in ecotoxicology at the University of South Florida who studies the effects of atrazine in animals, and who served on the EPA's atrazine panel this past spring.

Atrazine is sprayed on cornfields and other major crops during the summer months and can run off into rivers and streams that supply drinking water. It is also commonly used on golf courses.

Studies of atrazine's potential links to prostate and breast cancer have been inconclusive. Based on the recommendations of its scientific advisory panels in 2000 and 2003, the EPA has listed atrazine as "not likely" to be a carcinogen but does officially consider it to be a potential hormone disruptor – a risk factor explored by researchers testing animals.

In recent years atrazine has been the subject of intensive debate among scientists about its effects on the reproductive systems of frogs and other vertebrate animals. In some studies, male frogs that were exposed to high levels of atrazine have been documented to grow eggs.

In 2004, the European Union banned atrazine because it was consistently showing up in drinking water and health officials, aware of ongoing studies, said they could not find sufficient evidence the chemical was safe.

State regulators in the U.S. test their local water systems for atrazine a maximum of four times a year, under the federal Safe Drinking Water Act. In 2003, the EPA again approved atrazine for use in the United States but it made some demands of Syngenta for the re-registration.