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U.S. EPA makes atrazine adjustment

A weed scientist says the U.S. EPA’s announcement it’s raising the levels atrazine would adversely affect aquatic plants could be considered good news for corn farmers.  

Aaron Hager with the University of Illinois says the change was made from a report from a scientific advisory panel.

“They were proposing 3.4 micrograms per liter, which was extremely low, but the announcement earlier this week was 9.7 micrograms per liter, which is a much more feasible or workable number to maintain the, you know, the use and utility of atrazine,” he says.

Atrazine is widely used to help control problematic broadleaf weeds in corn and Hager says it’s also one of the most studied herbicides.

“There’s always been some concern with certain groups, certain papers about, you know, potential effects, non-intentional effects of atrazine, whether it be in aquatic systems, whether it be effects on invertebrates etcetera,” he says.

The EPA says the updated concentration levels have resulted in the removal of millions of acres of land from the 2022 watershed map and the agency says they’ve added a smaller number of acres in other parts of the country.

He says if the EPA would have regulated lower concentration levels for atrazine, it would have limited the use of the herbicide by many corn farmers in the Midwest.

“9.7 is a number that’s much more reasonable, much better based on the actual science that goes into the studies and in the calculation of that value,” he says.

The EPA says it plans to update its 2022 atrazine mitigation proposal later this year to reflect the revised level of concern, any modeling corrections and to incorporate feedback from the comments received on 2022 proposed revisions.

Click here to read a memorandum from the EPA with more details.