Approximately 150 people gathered at Drake University in Des Moines for the “Challenges to Providing Safe Drinking Water in the Midwest-A Symposium” on September 21 and 22. Sponsored by several University of Iowa centers including the Environmental Health Sciences Research Center (EHSRC), Center for Health Effects of Environmental Contamination (CHEEC), Center for Global and Regional Environmental Research (CGRER), and the UI Public Policy Center, the event featured thirteen speakers.
Four plenary discussions about topics such as the health impacts of nitrate in drinking water, how to communicate with the public about water quality, unregulated contaminants in drinking water and more.
A new report out of a non-partisan Iowa City-based research center, Iowa Policy Project, states that drainage districts have the power to improve water quality in the state.
About one-third of cropland in Iowa is tiled for drainage. Agricultural drains channel water, which often carries heavy nitrate loads, from fields into local water waterways. Iowa’s nitrate runoff is a primary contributor to the growing Dead Zone at the mouth of the Mississippi River.
Researchers Sarah Garvin, Michael Burkart and David Osterberg recommended using Iowa’s “quasi-governmental” drainage districts an agent of change. The report explains that the districts have the statutory authority to mitigate nitrate runoff by “requiring water quality monitoring and reporting, wetland conservation and restoration, and mandating the installation of bioreactor at discharge points to reduce nitrate loads.”
The report also points out that under statutory mandate, drainage should be “a public benefit and conducive to the public health, convenience and welfare.” Nitrate levels in water at or below the Environmental Protection Agency’s standard of 10 mg/L is considered safe for consumption. However, some new research suggests that nitrate levels below this can pose some health threats. In either case, the report reads,”Public health and welfare should be interpreted to mean keeping our waterways free of nitrate pollution.”
David Osterberg, lead energy and environment researcher at Iowa Policy Project, said, “It’s going to require managers of drainage districts to step up at a time when their county supervisors cannot, even if they wanted to, and at a time the state legislature has stood in the way of local authority on industrial agriculture.” He added, “In this case, with drainage districts, the authority to take some steps already exists.”
Experts in fields from agriculture, energy and environment, higher education and healthcare gathered in Cedar Rapids for The Gazette’s Iowa Ideas Conference September 21 and 22.
The two day conference was presented as an opportunity “to connect with fellow Iowans and develop solutions for key issues facing our state.”
Dr. Chris Jones, a University of Iowa researcher and CGRER member proposed one solution that would reduce nitrate runoff in Iowa’s waterways by 10 to 20 percent within one year. The IIHR-Hydroscience and Engineering research engineer stated that Iowa farmers should avoid planting crops on flood plains and stop tilling their land in the fall because it makes soil more susceptible to erosion if they want to see a reduction in nutrient runoff.
According to a report in The Gazette, Jones said, “It’s difficult for me to understand why these things continue. If we could do those two things, we would have a 10 to 20 percent reduction in one year.”
The Iowa Department of Natural Resources reports that there has been a 6 million acre increase in no-till farmland since 1987.
Chris Jones further discusses the science behind nitrate pollution and what it means for Iowa’s natural resources in episode one of Iowa Environmental Focus’ Nitrate Series.
A recent study found that increased precipitation due to climate change will lead to markedly increased nutrient runoff.
Nitrogen rich fertilizers are widely used by U.S. farmers. Many times, more fertilizer than crops can use are applied to the land and the excess runs off into local waterways, eventually draining into the ocean. Excessive nutrient enrichment, also known as eutrophication, decreases available oxygen in the water and kills off aquatic species, resulting in “dead zones.”
Warmer temperatures associated with climate change are expected to continue producing heavier rainfall, thereby increasing nutrient runoff by up to twenty percent by 2100. Anna Michalak, a professor of global ecology at the Carnegie Institution for Science at Stanford and one of the authors of the study, told the New York Times, “When we think about climate change, we are used to thinking about water quantity — drought, flooding, extreme rainfall and things along those lines. Climate change is just as tightly linked to issues related to water quality, and it’s not enough for the water to just be there, it has to be sustainable.”
Researchers concluded that the Upper Mississippi Atchafalaya River Basin, the Northeast and the Great Lakes basin are likely to see the largest increases in nutrient runoff because these areas of the country are already creating hypoxic dead zones. Climate change will likely compound these effects.
While the study focused on the continental U.S., the researchers did apply their model to parts of the world most similar to it. They found that large areas of East, South and Southeast Asia will likely see nutrient runoff surges similar to those in the U.S. Given that some people in these regions depend on surface water to survive, the impacts of nutrient pollution there may be especially lethal.
Iowa farmers planted 600,000 acres of cover crops last fall. This is an increase of over 60,000 acres, but covers just 2.6 percent of the 23.4 million acres of corn and soybean crops in the state.
Various state and federal conservation programs provided funding for 353,000 of these acres, including a cost-share program through the Iowa Department of Agriculture and Land Stewardship, as part of the Iowa Water Quality Initiative to meet the needs of the Iowa Nutrient Reduction Strategy.
Cover crops provide land with a vegetative cover during the months that crops are not actively growing, between the harvest and replanting. This helps to reduce the amount of nutrients that are washed into Iowa’s water bodies from agricultural lands, ultimately protecting the water quality. According to a report by the Environmental Working Group, cover crops can reduce the amount of nitrates leaching from the soil by 35 percent, and they are the the most effective practice for retaining nitrogen in the soil.
Washington County leads the state with the most acres of cover crops planted, followed by Cedar and Iowa counties, Wallaces Farmer reports.
Iowa Agriculture Secretary Bill Northey told Wallaces Farmer that he is encouraged by the increase in the practice.
“It’s obvious with the interest we’ve seen over the past few years that farmers are seeing the benefits that cover crops provide,” Northey said to Wallaces Farmer. “Cover crops are an important tool to help improve water quality and soil health in Iowa, and it is great to see an increasing number of farmers use this practice.”
New research shows that soybeans may play a key role in the transport of nitrate from farmed fields to the stream network.
As Iowa farmers have planted more acres of corn to meet the increasing demand, many models predicted that nitrate concentrations in Iowa streams would increase as a consequence. However, a new study conducted by the UI’s IIHR-Hydroscience & Engineering group and the Iowa Soybean Association, published in the Journal of Soil and Water Conservation, challenges many of these predictions.
As the amount of corn planted increased and the amount of soybeans decreased, fertilizer application increased by 24 percent in the watershed. Surprisingly, the nitrate levels in the river saw no increase and in some cases saw slight decreases.
The study evaluated 7,000 water samples in the Raccoon River Watershed from 1999- 2014 and had access to fertilization data for 700 fields in the watershed. The result from the study has led researchers to believe that nitrate levels are less dependent on corn production than previously thought.
IIHR —Hydroscience & Engineering researcher Chris Jones says that clues to the reduction in nitrate levels can be found in the differences between corn and soybean growth, soil chemistry, and the decay of other crop residues. Conversely, the dead and decomposing soybean plants can increase the amount of nitrate in the soil vulnerable to loss.
“We know we can’t just focus on fertilization of corn. We need a systems approach to improve water quality. It also demonstrates the power of monitoring water quality. Without this data, we could easily have missed this important and counter-intuitive conclusion.”
As a result, Jones says he believes that declining amount of soybeans planted may have reduced the cropped areas most susceptible to nitrate loss, more than compensating for the increased fertilizer inputs on corn production.