A coalition of communities in six Midwestern states filed a federal lawsuit Monday seeking to force the manufacturer of a widely-used herbicide to pay for its removal from drinking water.

Atrazine, a weed-killer sprayed primarily on cornfields, can run off into rivers and streams that supply municipal water systems. As the Huffington Post Investigative Fund reported in a  series of  articles last  fall, the U.S. Environmental Protection Agency failed to notify the public that atrazine had been found at levels above the federal safety limit in drinking water in at least four states.

The lawsuit was filed in U.S. District Court for the Southern District of Illinois by 16 cities in Kansas, Illinois, Indiana, Ohio, Missouri, and Iowa.  The communities allege that Swiss corporation Syngenta AG and its Delaware counterpart Syngenta Crop Protection, Inc. reaped billions of dollars from the sale of atrazine while local taxpayers were left with the financial burden of filtering the chemical from drinking water.

Many water utility managers  told the Investigative Fund that they could not afford the expensive carbon filters that are needed to remove atrazine.

Syngenta spokesman Paul Minehart told the Investigative Fund that the company had not yet received word of a federal action, but said that current levels of atrazine in drinking water are safe.

"What Syngenta can say is that EPA re-registered atrazine in 2006, stating it would cause no harm to the general population," Minehart said. "In the current economy many organizations, including water systems, are looking for additional sources of revenue.  It is not surprising that some water systems would say they cannot afford additional filtering but, for atrazine, there is no need."

Atrazine has long been a controversial product. The European Union in 2004 banned its use, saying there was not enough information to prove its safety. The EPA recently  announced that it would be re-evaluating the herbicide's ability to cause cancer and birth defects, as well as its potential to disrupt the hormone and reproductive systems of humans and amphibians.

Last week, a study published in the Proceedings of the National Academy of Science  reported that male frogs exposed to levels of atrazine below federal limits could become functional females, with the ability to mate and lay eggs.

Citizens in all sixteen of the cities named in the lawsuit get their drinking water from sources next to or surrounded by agricultural fields where farmers use atrazine. Some of these cities sell their water in bulk to other nearby towns.

According to EPA data from 2008, at least two of the cities -- Coulterville, Ill. and Monroeville, Ohio -- found atrazine in their river water at levels above 30 parts per billion (ppb). To comply with federal law, the level of atrazine in drinking water must not exceed 3ppb on annual average.

Lawyer Stephen Tillery, who is representing the sixteen cities in this complaint, said that these cities alone have spent upwards of $350 million trying to filter atrazine from their drinking water.

Investigative Fund reporter Danielle Ivory discussed atrazine last fall on the TV program Democracy Now. To watch, click  here.

Illinois Class Action Complaint Against Syngenta