Des Moines, IA – The Izaak Walton League of America (IWLA) has accessed and analyzed nitrate data gathered under the former IOWATER program and has found some unsettling trends across the state.
Data gathered by Iowa’s own citizen scientists from 1999-2017 show nitrate concentrations increasing over time in many watersheds around the state, with some concentrations reaching alarming levels that pose threats to human and environmental health. Average nitrate concentrations surpassed the maximum level allowed by the Safe Drinking Water Act in 14 of Iowa’s watersheds in at least one year during the study period, and six of these watersheds surpassed the limit in multiple years.
Eighty-seven percent of these high yearly averages occurred in the last five years of the nearly twenty-year-long IOWATER program, even as monitoring decreased across the state. This suggests that there are more and bigger problems that have not yet been revealed, and it highlights the need for increased monitoring and creative solutions to address this water quality, public health, and financial problem. The Izaak Walton League is now re-engaging volunteers across Iowa to continue the important work of collecting and sharing water quality data from our communities’ streams.
Nitrate in the water is relevant to every Iowan. A variety of environmental issues, from harmful algae blooms in Iowa lakes to oxygen-starved dead zones in the Gulf of Mexico, are caused or exacerbated by excessive nitrate loads in Iowa’s waters.
However, the biggest threat from nitrates is to public health. Nitrate is often found in surface water, like rivers and lakes, but it also readily travels into groundwater supplies, meaning that no source of drinking water is safe from potential nitrate contamination. It is well-known in the scientific community that too much nitrate in drinking water can impair the body’s ability to effectively distribute oxygen, especially in infants.
For this reason, the U.S. Environmental Protection Agency (EPA) mandates that the nitrate concentration in drinking water does not exceed 10 milligrams per liter. However, researchers working with the University of Iowa’s Center for Health Effects of Environmental Contamination have published studies indicating that prolonged exposure to drinking water containing nitrate levels below EPA’s threshold of 10 milligrams per liter was associated with increased risks of thyroid disease, central nervous system birth defects, and colorectal, bladder, ovarian, and kidney cancers. With science now showing that the current standard may not be stringent enough to protect people, the fact that 14 Iowa watersheds have not consistently met the current inadequate standard becomes even more concerning.
On top of that, the economic costs of removing nitrate from drinking water and installing taxpayer-funded nitrate reduction practices on the land affect everyone’s pocketbooks. In 2015, Des Moines Waterworks filed a lawsuit against upstream drainage districts in response to the costly process of removing excess nitrate from source water collected from the Raccoon River. Taking on these higher costs wasn’t optional for the Waterworks: Under the Safe Drinking Water Act, all drinking water treatment plants must meet EPA requirements. These requirements put a strain on smaller municipalities and rural water treatment plants facing source water contaminated with high concentrations of nitrates, and the resulting higher operation costs inevitably get passed on to rate-payers.
A better solution is to keep nitrates from reaching Iowa’s streams and rivers in the first place. Practices that achieve that goal can also help farmers increase their bottom line. A host of agricultural practices – like cover crops, no till or conservation tillage, and rotational livestock grazing – can help farmers improve their soil health and decrease applications of chemical fertilizers, which are the source of much of the nitrate in our streams. The Izaak Walton League educates farmers, as well as the general public, about sustainable farming practices and regenerative soil health initiatives that provide many benefits to soil and water, including nitrate reduction.
Now, IWLA has analyzed the average annual nitrate concentrations in Iowa’s watersheds from each year of the nearly twenty years of monitoring under the Iowa Department of Natural Resources’ IOWATER program. The results show that the nitrate issue was getting worse, not better, right before state-sponsored volunteer monitoring was dropped. During several recent years, the average nitrate concentrations in the Floyd, Rock, South Skunk, and Upper Cedar River watersheds reached dangerous levels (above 10 milligrams per liter). Several other watersheds in Iowa had similarly high average concentrations of nitrate during at least one year of the IOWATER program.
“We have almost twenty years of data collected by Iowa’s own citizens,” said Zach Moss, IWLA Save Our Streams Coordinator. “In most of our watersheds, we didn’t see many yearly nitrate averages higher than 10 milligrams per liter for the first 10-15 years. However, an alarming trend emerges in the last several years of the program, when Iowans were detecting average annual nitrate concentrations in watersheds that consistently exceeded EPA’s drinking water threshold. To have 87 percent of those instances occur in the last five years of IOWATER’s lifespan is definitely an alarming trend.”
As the IOWATER program neared its end, the data indicated that the nitrate issue was getting worse, and we now have fewer volunteers monitoring Iowa’s waters to document whether this trend is continuing or reversing. Without more volunteers monitoring Iowa’s streams and reporting what they find, the state’s citizens have no way to be sure if this problem, and the associated risks, is getting better, getting worse, or staying the same. We need more citizen scientists gathering and reporting water quality data to monitor these trends, and the Izaak Walton League is stepping up to get those volunteer water guardians on the ground.
“We had thousands of volunteer monitoring locations and tens of thousands of water quality data results being reported under IOWATER, and those numbers dropped instantly to zero after the program was ended,” said Moss. “That’s why the Izaak Walton League is taking action now to train and coordinate Iowa volunteer water quality monitors again through our Save Our Streams program. There are so many Iowans who care about our state’s water, landscape, and environment, and we’re here to encourage, train, and support these people again.”
IWLA has put IOWATER monitoring sites back on the map with our publicly-accessible national water quality database, the Clean Water Hub. IWLA’s Save Our Streams program is now training and coordinating volunteer water quality monitors to re-adopt old IOWATER monitoring sites, start their own new monitoring sites, and share their biological diversity and chemical data on the Clean Water Hub. In times like these, when gathering in groups is discouraged, chemical monitoring – including testing for nitrates – can be done individually by people of all ages without special training! To get involved with chemical monitoring, visit the Save Our Streams website.
Get more information on water quality in Iowa.
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Founded in 1922, the Izaak Walton League of America protects America's outdoors through education, community-based conservation, and promoting outdoor recreation.