Most believe reducing nutrients in Iowa's drinking water will take decades
Weather a complicating factor, as is cost, reliance on voluntary strategies
On the last day of February, the Des Moines River at Des Moines carried almost 1,000 metric tons of nitrate — enough to raise bumper corn crops on 10,000 acres.
That single-day nitrate load — greater than the entire February monthly load in 32 of the last 42 years — provides insights into the impact weather can have on nutrient pollution as well as the difficulty in measuring progress in reversing that pollution.
Record-high nitrate loads this winter on both the Des Moines and Raccoon rivers — source water for the Des Moines Water Works and its 500,000 customers — also illustrate the Iowa Nutrient Reduction Strategy’s lack of progress and provide continuing justification for the utility’s controversial lawsuit, according to Bill Stowe, its CEO and general manager.
Two-and-a-half years into the nutrient reduction strategy, one of its principal authors says Iowans accustomed to rapid gratification and a 24/7 news cycle might be inclined to ask, “Are you done yet?”
But accomplishment of the strategy’s overarching goal — a 45 percent reduction in nutrient pollution — will likely take generations and cost billions, according to John Lawrence, associate dean, Department of Economics, Iowa State University.
University of Iowa hydrologist Keith Schilling says Lawrence is right.
“This is a long-term process to measure (nutrient reduction) progress at the large watershed scale. It will take many years, if not decades, to see changes,” Schilling said.
It would take a 20-year perspective just to even out the variability caused by wet and dry cycles, he added.
Recent history, Schilling said, is replete with examples of huge fluctuations in nutrient loads — including the current pulse on the Des Moines and Raccoon rivers — that have much more to do with weather than with agricultural practices.
A prime example, he said, is the drought of 2012, in which nutrients accumulated unused in the soil, followed by an extremely wet 2013, in which those excess nutrients leached out of the soil into surface water.
All that weather variability complicates the detection of actual long-term, large-scale changes in nutrient levels, he said.
Looking back to records dating to 1998, Schilling said “there really has not been much change at all (in nutrient loads or concentration) on a statewide basis.”
Changes could be more easily observed by monitoring subwatersheds closer to installed conservation practices, he said.
“The public is dying to see water quality improvements, but our monitoring is not geared up to show it,” Schilling said.
ISU’s Lawrence, speaking Feb. 17 at the Iowa Soybean Association’s annual research conference in Des Moines, said Iowa has taken a “logic model” approach to measuring water quality improvements.
“Ultimately, we want to see a reduction in nutrients in the water, but first we need to see changes on the land and in municipal water treatment facilities,” he said.
Logic models, he said, describe the logical pathway to a long-term goal and define indicators for steps along the path.
With a long-term goal of reducing nitrates and phosphorous in surface water, the steps preceding actual changes in the water, in the order in which they must occur, he said, are changes in people, changes in inputs and changes on the land.
No sense of urgency
Ann Robinson, agriculture policy specialist with the Iowa Environmental Council, acknowledges that reducing nutrient pollution is a long-term project requiring patience, but she wishes leaders would demonstrate a heightened sense of urgency.
The council also believes, she said, that project leaders should be “less fearful about measuring what’s happening with the water.”
When public money is spent in pursuit of a public goal, aggregated data documenting progress — or lack of it — should be made available to the public, Robinson said.
State Sen. Rob Hogg, D-Cedar Rapids, the author of one of several plans before the Legislature to dramatically increase state funding for water quality improvements, also recognizes that it will take many years to accomplish the strategy’s goals.
“But that should not take away from the sense of urgency needed to get it done,” he said. “We need to get on a trajectory that shows progress.”
Will voluntary work?
Both Stowe, of the Des Moines Water Works, and Francis Thicke, a former candidate for Iowa agriculture secretary, say the nutrient reduction strategy, with its voluntary conservation practices, is doomed to failure.
“We’ve got to stop kidding ourselves about this voluntary thing,” said organic dairy farmer Thicke.
Thicke, of rural Fairfield, proposes that farmers be required to formulate and adhere to a water quality plan that would contribute to the goals in the nutrient reductions strategy.
Farmers would have the flexibility to determine how to achieve a tolerable level of nutrient loss. Cost-share programs could provide incentives, he said.
Stowe said taking generations to solve a public health problem is not an acceptable outcome for the Water Works.
“The lack of progress is exactly why we took legal action in the first place,” Stowe said, referring to the utility’s lawsuit against three northwest Iowa counties. The suit contends upstream underground tile drainage systems contribute to nutrient pollution, which threatens the Water Works’ customers’ health and increases Des Moines’ water treatment costs.
Record nitrate loads
Depending upon whom you consult, the lawsuit has either driven a wedge between farmers and city dwellers, jeopardizing the cooperation needed to reduce nutrient pollution, or provided a much needed sense of urgency in efforts to do so.
Sixty percent of Iowans support the utility’s lawsuit as the right approach, according to a recent Des Moines Register/Mediacom Iowa Poll.
Stowe said record nitrate loads this winter in the Des Moines and Raccoon rivers underscore that Iowa “is headed the wrong direction on water quality.”
During January 2016, the nitrate loads in both rivers were far bigger than the comparable loads for every other January dating back to 1974, according to Chris Jones, a research engineer with the University of Iowa’s Hydroscience and Engineering Department.
The load, a measurement of the weight of nitrates in the water, is affected by both the concentration of nitrates in the water and the volume of the water, both of which were dramatically increased by heavy December rains in the Des Moines and Raccoon watersheds.
Those watersheds, Jones said, received from 4 to 8 inches of rain during December. With no living crops to take up water or nutrients and a mild winter to keep tile lines flowing, large volumes of water with high nutrient concentrations poured into the rivers all winter, Jones said.
On the Raccoon River at Des Moines, the average nitrate concentration during the month was 11.5 parts per million, which compares with the average January concentration of 6.6 ppm in the years dating back to 1974. The level exceeds the federal safe drinking standard of 10 ppm.
The Raccoon’s nitrate load in January 2016 was 4,700 metric tons, nearly three times that of the previous record load of 1,721 metric tons in January 1983 and more than 10 times higher than the average January load of 417 metric tons.
January nitrate concentrations and loads also established records this year on the Des Moines River at Des Moines, according to Jones.