News Release: New economic report from ISU's CARD highlights costs of nutrient pollution across the state

The multimillion-dollar cost to treat pollution flowing from Iowa’s agricultural landscape into central Iowa drinking water sources has attracted widespread attention in the last few years. A new report, “The Economic Benefits of Nitrogen Reduction in Iowa” by economists with the Center for Agricultural and Rural Development (CARD) at Iowa State University makes the case that reducing nutrient pollution would have substantial economic benefits all across the state.

“The report acknowledges the tremendous benefits of Iowa agriculture to the state, national and global economy,” said Gabriel Lade, one of the CARD report’s lead authors. “However, these activities are not without cost to society.  Our report takes a first step towards accounting for local benefits from reducing nutrient pollution in Iowa. These benefits include reduced nitrate removal costs to small- and mid-size community water systems and well-owners. Beyond drinking water, reducing nutrients in Iowa’s waters will also increase recreational benefits from Iowa’s natural resources, and may reduce adverse health impacts from nitrate exposure in drinking water.”

“The focus of Iowa’s Nutrient Reduction Strategy (INRS) is on reducing the extent of hypoxia in the Gulf of Mexico. Our report highlights how, in addition to reducing the Gulf hypoxic zone, meeting the INRS targets would also benefit Iowans in important ways here at home,” said Lade.

The report evaluates the fiscal impact of nitrate pollution to medium and small water supplies across the state, with short case studies of several communities with elevated nitrates in their source water. The researchers report that out of the state’s 1,850 public water supplies, 49 systems, serving over 10 percent of the state’s citizens, treat water for nitrates either by blending or using nitrate removal equipment.

Many Iowans in rural areas are exposed to elevated nitrate concentrations in drinking water because they rely on private wells, which are unregulated and often go untested. Water quality in private wells also depends on such factors as well depth, construction method and the proximity to contaminant sources such as feedlots, septic systems and crop fields.

CARD reports that the trend for private wells with unsafe levels of nitrate statewide has been increasing: from 9-12 percent in the period 2001-2007, to 13-18 percent in 2015-2016. In some areas of the state that rely on vulnerable shallow wells, up to 25 percent of wells may exceed the recommended safe nitrate level.  For families and communities that face this situation, the costs of a new well or a replacement water supply can be substantial.

The CARD researchers also discuss likely costs related to adverse human health impacts from elevated nitrate levels in drinking water, although they report that more research is needed to investigate the relationships between nitrate exposure and health, and resulting costs to families and society.  These health concerns include increased risks for bladder cancer and birth defects from prenatal exposure.

The CARD report also estimates lost benefits of approximately $30 million per year to communities from recreation-based tourism related to Iowa’s lakes and beaches. Nutrient pollution contributes to the development of harmful algal blooms (HABs) from noxious forms of algae that can be harmful to human and animal health and discourage visitors from enjoying recreational assets.

“The report makes it clear that nutrient pollution costs drinking water customers beyond central Iowa -- and most affected communities have far fewer resources to pay for expensive treatment options than here in Des Moines,” says Iowa Environmental Council Director Jennifer Terry. “The report also points out that we often pay for pollution multiple times, since most nitrate treatment systems remove the nitrate, but then discharge it back into streams. It makes a strong case for addressing our water pollution problems at the source, and not sending them downstream where other communities and families must bear the burden. Clearly, the existing system that depends completely on a voluntary approach is not working —and we’re all paying the price.”

The Center for Agricultural and Rural Development (CARD) conducts innovative public policy and economic research on agricultural, environmental, and food issues. CARD uniquely combines academic excellence with engagement and anticipatory thinking to inform and benefit society.

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