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April 22, 1970, was no ordinary day in the bustling city of St. Louis. On this first Earth Day, streets filled with rallies, and lecture halls were packed with attendees. Most famously, rows of students marched through the streets wearing gas masks, protesting air pollution.

Around that time, John E. Franz was brewing up something dark in the depths of Monsanto’s St. Louis lab: glyphosate, an herbicide since linked to widespread environmental harm, cancer concerns and more than 100,000 lawsuits. 

While other countries have regulated or limited glyphosate production, the U.S. has largely ignored the problem. In February, President Donald Trump issued Executive Order 14387 to promote the production of glyphosate and security for its producers.

The U.S. is increasingly dependent on glyphosate, and its overuse is becoming a serious concern. Amid the many environmental issues competing for attention, glyphosate deserves a prominent place this Earth Day, especially in Wisconsin.

Why Wisconsin? Glyphosate levels in groundwater aren’t being consistently monitored in the state’s highest-risk areas — its CAFO counties.

From fields to faucets 

Wisconsin farmers apply millions of pounds of glyphosate each year, primarily to fields growing soybeans and corn — the state’s two biggest crops. Those crops are used to feed animals at Wisconsin’s 293 concentrated animal feeding operations, or CAFOs. 

After animals eat glyphosate-treated crops, the chemical can reemerge in their manure. This is a problem, considering that mismanagement of CAFO waste frequently leads to groundwater contamination. 

Seems like something that should be setting off red flags, right?

Monitoring falls short in Wisconsin

The Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) oversees groundwater and surface water testing for agrichemicals. The agency monitors pesticides and agricultural runoff through a private well sampling program, a field-edge monitoring program and random well sampling conducted every five to 10 years.

However effective these programs may appear, a closer look at where Wisconsin’s CAFOs are located compared with where monitoring occurs reveals a stark mismatch.

The three counties with the most CAFOs — Manitowoc (25), Brown (22), Kewaunee (19) — are all located in the Northeast Lakeshore region, where none of DATCP’s 22 field-edge monitoring wells are located, according to a 2023 report, the most recent available. The state’s monitoring system misses areas at highest risk for aquifer contamination.

Unfortunately it gets worse. DATCP’s Targeted Sampling Program also does not cover the entire Northeast Lakeshore Watershed, and these sampling panels do not test for glyphosate or its byproducts, the agency’s most recent program report shows.

The solution? Advocacy

Glyphosate usage has increased 15-fold since the 1990s. It will continue to go unchecked if more research and monitoring aren’t conducted to track where this chemical ends up.

What can citizens do? Write, speak and act.

1. Monitor the DNR’s hearing and meetings calendar for groundwater-related meetings you can attend.
   
2. If you’re a private landowner with a well, write to DATCP and volunteer to have your well sampled.
   
3. Universities such as University of Wisconsin-Oshkosh and UW-Green Bay also play a role. DATCP already partners with both on research. Contact leaders of their water-related programs.

Why glyphosate still matters

To be sure, glyphosate is not the only problematic agrichemical. But it is by far the most widely used herbicide in U.S. agriculture, and its scale alone warrants closer monitoring of its spread in aquifers.

Still not convinced? Consider the many other contaminants that can leach into groundwater from CAFO manure — including other agrichemicals, pharmaceuticals, heavy metals and bacteria. Glyphosate is just one of many reasons stronger groundwater monitoring is needed in this region.

We’re not asking for much.

Glyphosate well testing is relatively inexpensive and should not strain government resources. Progress will depend on public pressure: Concerned citizens must keep pushing until stronger monitoring is in place across all at-risk areas of this beautiful state we call home.

Allison Gilmeister is a graduate student at Yale University studying religion and ecology. She grew up in Appleton. 

In Wisconsin’s CAFO counties, glyphosate monitoring gaps threaten groundwater is a post from Wisconsin Watch, a non-profit investigative news site covering Wisconsin since 2009. Please consider making a contribution to support our journalism.