Each spring, the chemical herbicide atrazine is spread on corn and sorghum fields throughout eastern Kansas.

When the rains come, atrazine residue is washed away, traveling into surface water and eventually winding its way into many public water supply systems.

The chemical’s presence in drinking water has come under scrutiny from the Natural Resources Defense Council. Kansas is among the Midwestern states most at risk for contamination, the NRDC reports.

The NRDC claims the Environmental Protection Agency isn’t collecting data that take into account spikes in atrazine levels occurring during spring runoffs.

“It’s kind of worse than ignoring the spikes. They are averaging them away,” said Andrew Wetzler with the NRDC.

A report recently released from the NRDC raises concerns that peaks in atrazine levels are a health risk to some groups and they aren’t being reported to those drinking the water.

The chemical’s largest manufacturer, Syngenta, and the agriculture industry say that atrazine levels aren’t violating EPA standards. And the EPA, an agency that typically errs on the side of caution, has spent years researching the chemical’s harmful effects.

After 50 years of use and 6,000 studies, atrazine has proven to be safe, Syngenta spokesman Steven Goldsmith said.

“We know that levels of atrazine are significantly below the average set by the EPA. And on top of that, (the EPA) provides for a significant safety factor,” he said.

Important to farmers

With 60 million to 80 million pounds of atrazine applied each year, the chemical is the most widely used herbicide in the United States. Atrazine, which is applied at the start of the growing season, is used for killing broadleaf weeds.

“The only reason atrazine is so important to farmers today is that no other product has come along that replaces it,” said Jere White, executive director of the Kansas Corn Growers Association and the Kansas Grain Sorghum Producers Association.

Not using the herbicide would cost corn and sorghum farmers about $20 to $30 an acre, which would translate into a $120 million loss each year for Kansas farmers.

“There are many years where $30 an acre might be the difference between a profit and a loss. And just to lay that on the table when the science is not there to justify it should be a concern to every farmer,” White said.

Because of its wide use and classification as an endocrine disrupter, atrazine has been at the top of the list of NRDC’s concerns for a number of years, Wetzler said. Endocrine disrupters can mimic and affect the normal hormonal function of organisms, which can alter the reproductive systems.

Studies have shown that concentrations of atrazine as low as 0.1 part per billion have altered the development of sex characteristics in male frogs, causing female sex characteristics, hermaphrodites or the presence of eggs, the NRDC reported. These findings indicate that during periods of development for brain and reproductive organs, the timing of exposure to atrazine might be more critical than the amount.

“Relying on an annual running average, the EPA is essentially allowing very large spikes … of a chemical that can be very disruptive to pregnant women and young people during the stages of development,” Wetzler said. “Is it a huge cause for concern for a 70-year-old, 180-pound white man? Probably not. Would I want my pregnant wife drinking it? No.”

Atrazine levels in Kansas

Under the Safe Drinking Water Act, public water systems are required to test for atrazine levels quarterly. For water systems that have demonstrated compliance with the act, tests can occur once a year. Water systems can’t exceed an annual average of 3 parts per billion.

In 2003 as part of an agreement with the manufactures of atrazine to re-register the herbicide, the EPA created a program to monitor between 90 and 150 communities on a weekly basis during spring runoff, and biweekly during the rest of the year. More than 30 public water systems in Kansas were part of this program in 2008.

Lawrence isn’t one of the communities. In 2008, the city reported that its highest level of atrazine detected was 1.4 ppb.

Test results from the monitoring program are reported directly to the EPA. Five year’s worth of data is available on the agency’s Web site, epa.gov, but the numbers are not reported to water customers.

From this data, the Lawrence Journal-World found that one-day atrazine levels spiked as high as 56.74 ppb in Baxter Springs, in the southeast corner of the state, and 41.61 ppb in Beloit, in north-central Kansas.

In the Franklin County town of Richmond, levels exceeded 3 ppb 38 times, with the highest level recorded at 15.85. In Valley Falls, 3 ppb was passed more than 40 times, with the highest level at 8.22 ppb.

Water managers at the Beloit, Richmond and Valley Falls facilities said they hadn’t notified customers of these high levels, but they also said they weren’t in violation of any EPA standards.

Since 2001, the Kansas Department of Health and Environment has reported fewer than five violations.

In 2003, the EPA approved the re-registration of atrazine after extensive research. According to the EPA, the exposure that the EPA allows is at least 300 to 1,000 times more protective than levels where the agency saw no adverse effects.

Along with the annual average of 3 ppb, the EPA said concentrations of atrazine and its metabolites must be below an average of 37.5 ppb for a 90-day period. One-day levels can’t exceed 298 ppb.

“Drinking water standards are vigorously monitored … and we believe the EPA sides on the ultra-conservative side in setting the standard,” said Elmer Ronnebaum, general manager for the Kansas Rural Water Association.

For White and the farmers he represents, the science backing the use of atrazine is well established.

“I’m not sure what kind of products farmers will have in the future if you can’t defend atrazine with the science that is there,” White said.

Future of atrazine

Controversy concerning atrazine in Kansas sprung up earlier this year when two cities, Marion and Hillsboro, entered into a class-action lawsuit against the makers of the chemical. The communities were solicited by the Dallas-based law firm Baron and Budd.

Hillsboro City Administrator Larry Paine said the city doesn’t exceed the EPA’s 3 ppb annual average, but it does have peaks during spring runoff. To remove the chemical from the water would require a filtration system that a small rural utility like Hillsboro can’t afford, he said. The attorneys are suing the manufacturer for the cost of putting in those filtration systems.

“We are looking at it as a way to do something to protect our customers from being exposed,” Paine said.

The city’s decision caught heat from local farmers. Shortly after being solicited by the same attorneys, the Kansas Rural Water Association sent out a letter cautioning its water utilities to look closely at the contract with the law firm. Ronnebaum worries about the precedent the lawsuit could set.

“What recourse would ratepayers have against you?” Ronnebaum asked.

Ultimately, the NRDC would like to see atrazine phased out in the United States. The herbicide is banned in the European Union. The organization believes the EPA should monitor all vulnerable watersheds and publish the results of samples taken from those watersheds and public water systems.

Until those changes are made, the NRDC recommends that the public buy simple and economical household water filters and contact their water utilities to find out what treatments they use and how well atrazine is being removed from their drinking water.

“We think there have to be a number of reforms with these kinds of chemicals,” Wetzler said.