More than 200 of Iowa’s community water systems struggle with agricultural runoff, periodically issuing “Do Not Drink” orders because of high levels of nitrates. The state is the second-largest contributor in the Mississippi River Basin of nitrates that end up in the Gulf of Mexico. “The good news is that researchers have a pretty good handle on how to solve Iowa’s water problem,” reports Elizabeth Royte in FERN’s latest story, with National Geographic.
She points out that in 2014, the state released a nutrient reduction strategy that calls for slashing nitrate runoff by 41 percent. “The plan lists a suite of tools that farmers can use to hit this mark, from applying fertilizer more sparingly — crops take up, on average, only half the nitrogen that’s applied to fields — to planting cover crops, to allowing strips of farmland to revert to unfertilized prairie,” she writes.
But because these recommended approaches are voluntary, relatively few of Iowa’s 88,000 farmers practice them. Therein lies the problem.
Nationwide, utilities spent $4.8 billion to remove nitrates from public drinking water supplies in 2011, the last year for which data are available. Des Moines is the poster child in that effort. In 2015, the Des Moines Water Works spent $1.5 million to strip nitrates from the water; it was also facing a roughly $15 million bill to revamp the denitrification equipment that burned out in the process. The utility pursued a landmark lawsuit against three upstream drainage districts, representing more than 2,000 farmers, to try and reduce ag pollution flowing downstream. Ultimately, however, the suit was dismissed.
Another Iowa city, Cedar Rapids, is trying a different approach, Royte writes. The Middle Cedar Partnership Project is supporting farmers willing to try some of the practices laid out in the state’s nutrient reduction strategy, such as planting cover crops — a practice that, while useful, has been adopted on less than 3 percent of state farmland. Others have tried filtering runoff through wood chips, or engineering wetlands to filter out pollutants.
“When it comes to polluting the air and the water, agriculture has, to some extent, gotten a pass in this country. No one wants to stick it to a farmer. In the current political climate, there seems little prospect of increased government regulation of nutrient runoff — yet voluntary measures clearly haven’t cut it so far. If nothing else, the Des Moines Water Works suit has energized public discussion of the question: Who will pay to keep nitrates out of our rivers?” she writes.
The story is also available at FERN.