The eyes of dead fish and the message “know what you drink” adorn a new billboard near Avoca that urges Iowans to monitor nitrate levels in their water.
The billboard is the first of several that the Nishnabotna Water Defenders, a nonprofit organization advocating for water quality in southwest Iowa, plan to install.
The group formed in March 2025, a year after a couple hundred thousand gallons of fertilizer polluted the East Nishnabotna River and resulted in more than 750,000 dead fish.
Terry Langan, co-president of the organization, said the purpose of the billboards is to inform locals of what is in their water, alert them to the free nitrate testing kits available from the Izaak Walton League of America and to key them in on other water quality issues in the region.
“We don’t want people to be poisoned; we don’t want people to have rising cancer rates,” Langan said.
Izaak Walton League’s Nitrate Watch program equips citizens with nitrate test strips so they can test and report the levels in the streams around them. According to the citizen-scientist data, nitrate levels in the Nishnabotna rivers exceeded concentrations of 10 milligrams per liter at various points this year.
The U.S. Environmental Protection Agency holds that concentrations above 10 mg/L can cause adverse health effects, specifically an illness known as blue-baby syndrome, which can be fatal to infants.
Some research, however, has found that exposure at even lower levels could be linked to preterm birth and low birth weights and certain types of cancer.
Water quality experts have said the high concentrations in the rivers this summer is linked to the heavy rains this year that followed years of drought conditions. Scientists in a comprehensive study of water quality in Polk County predicted that climate change will cause more of these weather patterns.
The report, in correlation with a lawn watering ban in Des Moines and surrounding communities due to high nitrate concentrations in the Raccoon and Des Moines rivers, have generated greater awareness of nitrate pollution in the water.
“I think a lot of people operate under the assumption that everything was cool and the water is great, and it’s not,” Langan said. “That’s becoming very well known.”
The report from Polk County pointed to agriculture as the primary contributor to nitrate pollution in the river. Langan said Iowans are “suffering” from the “corporate capture” the agricultural industry has in Iowa.
Scott Kovarovics, the executive director at the Izaak Walton League of America, said in a press release that nitrate pollution is a “serious” problem in Iowa, but also in other communities across the country.
“When local groups put up billboards along the highway, you know they are not just concerned— they’re fed up,” Kovarovics said of the Nishnabotna group’s actions.
In addition to the partnership with Izaak Walton League to provide nitrate testing kits, Langan said Nishnabotna Water Defenders is working to raise funds to provide testing kits for other water pollutants that are also impacting the watershed.
The first billboard is located on U.S. Highway 59, outside of Avoca. Jodi Reese, Nishnabota Water Defender’s secretary, said the group chose that location because it’s near the Flying J gas station that spilled petroleum into the nearby West Nishnabotna River.
Reese said the billboard highlights the “habitat death” of these spills and gets “people to think about what they’re drinking and what’s going on with their water.”
The group’s next billboard is slated to go up near Shenandoah, which – prior to the heavy rains this summer – had been under water conservation orders for more than a year. That billboard is also near Clarinda, where an algal bloom in the Nodaway River recently contaminated the city’s water supply.
“This level of violence against the environment is not sustainable,” Langan said. “There are universal laws that are being violated. We’re going to end up – on this trajectory – in a wasteland.”
Langan hopes the billboards can extend beyond the Nishnabotna watershed and pop up in communities across the state. The group is hosting an event Oct. 12 in Red Oak to raise funds for additional water testing materials and the billboard initiative.
“There’s nothing more ubiquitous than water,” Langan said. “There’s nothing more sacred to us and more of a necessity – it literally runs through our bodies and through our neighborhoods.”
A billboard near Avoca encourage Iowans to monitor their water for nitrate. (Photo by Taylor Thomas/Nishnabotna Water Defenders)
