Today, one of the biggest sources of water pollution in Iowa and throughout the Mississippi River Basin is agricultural non-point source pollution. Eroded sediment from farmland and the nutrients nitrogen and phosphorus from fertilizer and manure are of greatest concern.
Controlling this pollution is problematic because agricultural runoff is mostly exempt from controls under the Clean Water Act that apply to cities and industries. That law does call on Iowa to set limits for nitrogen and phosphorous in waterways, but the process to do this has been slow. For example, the federal government first called on states to develop numeric pollution limits in 1998, but in the years since, only 8 states have done so.
Under these conditions, the Council and its partners along the Mississippi River have begun to consider what state-level authorities beyond the Clean Water Act may help address the problem. These discussions involve a policy with two parts:
- Implementation of basic stewardship plans on all farmland where farmers work with conservation planners to set goals to prevent soil erosion and protect water resources, and
- Development of new mechanisms to encourage farmers to participate with cities and industries in watershed–based cleanup plans to ensure all sources are accountable for reducing their share of pollutants necessary to restore the health of downstream waters.
It is possible to make significant gains for clean water in Iowa, and our knowledge of what will be necessary is increasing over time. For example, a science team at Iowa State University is evaluating practices that can be applied in different types of agricultural operations and landscape settings to cumulatively produce significant reductions in nitrogen and phosphorus losses from farmland.
The Council supports policies to ensure this increasing knowledge is applied to land management in Iowa. Increasingly, conservation professionals are able to provide farmers with science-based solutions that are compatible with agricultural production and significantly reduce agriculture’s impact on water quality. It is time for farmers to join with other businesses, industries, and municipalities to be accountable for controlling their pollution and helping to meet water quality goals.