Center for Biological Diversity

For Immediate Release, April 29, 2020


Nathan Donley, (971) 717-6406,

Trump Administration Cuts Requirement to Monitor Atrazine in Midwest Rivers, Streams

WASHINGTON— The Trump administration has lifted a long-standing requirement that pesticide maker Syngenta must monitor rivers, streams and lakes in the Midwest for dangerous levels of atrazine.

Citing the COVID-19 crisis, the Environmental Protection Agency granted Syngenta a reprieve from the monitoring requirement for the rest of 2020.

Due to atrazine’s well-documented links to reproductive harm in people and wildlife, Syngenta since 2004 has had to closely track the pesticide’s levels in waterways across much of the Great Plains and Midwest, where it is sprayed on corn. If water monitoring revealed that safety thresholds were exceeded, Syngenta was required to take steps to bring those waterways back into compliance.

The waiver of that requirement went into effect April 1 but the document was only recently posted on

“The public will now have no idea whether dangerous levels of atrazine are reaching rivers and streams throughout the Midwest. That’s absurd and reckless,” said Nathan Donley, a senior scientist with the Center for Biological Diversity. “Syngenta should suspend the sale and use of this extremely toxic pesticide until it can safely ensure it’s not polluting Corn Belt waterways.”

The EPA’s decision to grant Syngenta’s request to suspend monitoring comes less than seven months after the agency denied the pesticide maker’s request for a permanent waiver from the Atrazine Ecological Exposure Monitoring Program. The monitoring program identifies areas where water quality criteria are exceeded and mandates action from Syngenta to bring those waterways back into compliance. Without data from this program there is no way to know if rivers, lakes or streams are being contaminated with high levels of atrazine, and no mitigations will be taken.

Atrazine, the nation’s second most-used pesticide after glyphosate, is banned in Europe but widely present in U.S. waterways and drinking-water supplies. Independent research and an EPA multi-year risk assessment found it to be extremely harmful to fish, frogs and other aquatic animals.

The monitoring program was implemented in 2004 as part of a condition of the atrazine reapproval that occurred during that year. In August 2019 Syngenta requested that the requirement be eliminated. The EPA denied that request because it “…has continued to show atrazine concentrations of potential ecological concern in the most vulnerable watersheds, even when stewardship programs are employed.”

The monitoring program’s importance was highlighted late last year when the EPA proposed a 50% increase in the amount of atrazine allowed in waterways across the United States. In increasing the amount of atrazine considered safe for frogs and other aquatic organisms, the Trump EPA’s plan reversed a 2016 EPA plan to reduce the levels by threefold.

In 2016 the EPA found that atrazine is commonly present in water at levels much higher than what kills frogs and other amphibians, whose populations are declining steeply across the United States. Numerous studies have shown that atrazine chemically castrates and feminizes male frogs, even at concentrations lower than the level currently allowed in drinking water by the EPA.

California_red_legged_frog_Gary_M_Fellers _USGS_FPWC -lpr.jpg
California red-legged frog/Gary Fellers, USGS Image is available for media use.

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 1.7 million members and online activists dedicated to the protection of endangered species and wild places.

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