Everything Flows Downstream: Clean Drinking Water in an Agricultural Watershed
In 2015, the Des Moines Water Works filed a lawsuit against upstream drainage districts, claiming that they were sending water heavily polluted with nitrates, a nutrient commonly found in fertilizer and pig manure, into the city’s source water in the Root River. While that lawsuit was eventually dismissed, it brought to light a growing problem in a state where 92 percent of the land is farm land – runoff from ag is contaminating water supplies and municipal water districts are paying the price of getting that water back to acceptable quality for human consumption. We heard how two cities – Des Moines and Cedar Rapids – have worked with upstream communities to reduce runoff into their source water supplies.
Nitrates 101: Where They Come from, How They Move and Human Health Impacts
In an effort to better understand problem areas for nitrate pollution and the hydrology of how the nutrient ends up in Iowa waterways, the Iowa Flood Center at the University of Iowa developed the Iowa Water Quality Information System, a real-time map of stream-monitoring data and nitrate levels. Many see the work being done at the Flood Center as vitally important to human health as some studies have linked nitrates in drinking water to issues like ovarian cancer and birth defects.
Cover Crops, Bioreactors and Precision Guidance Tractors: Modern Farming Tackles Its Nitrate Problem
In a state where 92 percent of the land is cropland or pasture, taking land out of agriculture seems unlikely – which means that the solutions to Iowa’s water woes lies somewhere on the farm. Some farmers have embraced this challenge and are adopting practices unheard of when their parents ran the show. We headed to Washington County, which leads the state in the number of acres of cover crops planted and visit a farm using cover crops, pollinator plantings and the county’s first bioreactor – a low-tech way of removing nitrates from the water draining off corn and soybean fields. We also visited with a farmer who has embraced a more high-tech solution, using precision guidance systems on his tractors to apply fertilizers more efficiently and hear about his new idea to grow barley as a cover crop that he can then use to feed his hogs.