Serious Questions Remain About EPA Atrazine Proposal

August 1, 2024

Growers received good news in early July when EPA proposed an increase in the atrazine aquatic level of concern (CE-LOC) from the ultra-low 3.4 parts per billion (ppb) level to a new level of 9.7 ppb. This announcement came on the heels of a Scientific Advisory Panel (SAP) for atrazine held last August. The Triazine Network, an alliance of grower organizations including IL Corn had requested the SAP last year and met with EPA in mid-July to discuss this latest proposal.

 

Now for the bad news. While the CE-LOC moved from 3.4 ppb to 9.7 ppb - nearly three times higher - the mitigation maps of impacted areas only minimally changed. EPA’s flawed mitigation maps and modeling would negate the positive impacts of the higher CE-LOC. Unfortunately, EPA continues to ignore 20 years of actual water monitoring data from states, and from its own programs.

 

Growers, through the Triazine Network, had also asked EPA to review two studies not included in the SAP. The worst of the two studies is extremely low quality and continues to significantly impact the atrazine CE-LOC. Because of the continued use of that flawed study, the CE-LOC remains under 10 parts per billion.

 

“The change in the CE-LOC is good, but if EPA continues to use the flawed modeling methodology resulting in bad mitigation maps, they null any progress made and fail to rely on sound science.” said IL Corn Growers Association President Dave Rylander. “It is a positive step that EPA appears to be open to taking our concerns into consideration before they release their final proposal."

 

EPA officials said they will open a comment period following the final atrazine proposal later this year.

tara at white sox stadium
By Tara Desmond • October 16, 2026
Five years at IL Corn with farming, farmers, corn, and storytelling—with a few hot dogs, viral videos, and plenty of Midwestern waves.
Mexican CANAMI (National Chamber of Industrialized Corn) members at Illinois farm
By Tara Desmond • October 15, 2026
IL Corn & USGBC hosted Mexican masa millers on southern Illinois farms and river terminals, strengthening ties with our top corn customer.
holding a cover crop
By IDOA & Tara Desmond • October 15, 2026
Pre-enrollment opens Nov. 30 for IDOA’s Fall Covers for Spring Savings program, worth up to $5/acre off 2027 crop insurance premiums.
Josh Linville and Collin Watters
By Tara Desmond • October 15, 2026
What’s really driving your fertilizer bill? StoneX’s Josh Linville breaks down global supply, competition, and the long-term fix on IL Corn TV.
thumbnail of Megan and Jared
By Tara Desmond, Megan Dwyer and Brownfield Ag • October 15, 2026
Illinois Corn and U of I built lease addenda to help farmers and landowners build cover crops, soil health and nutrient goals into rental agreements.
headshot of Jenny Webb IFCA president
By Tara Desmond • October 15, 2026
Jenny Webb has spent her career in Illinois agriculture. Now she’s about three months into a new job as president of the Illinois Fertilizer & Chemical Association (IFCA), the group that represents the ag retailers, applicators and suppliers who get fertilizer and crop protection products to your farm when you need them. Webb came to IFCA from Illinois Farm Bureau. She’s new to the fertilizer and chemical side of the business, but not to farmers or to the policy and regulatory issues that affect them. IL Corn sat down with her to talk about what she’s learned so far, the issues facing Illinois ag retailers, and why the work happening behind the scenes deserves more credit than it gets.
Show More