IEC Calls on DNR to Set Water Quality Standards for Nitrogen and Phosphorus

The Iowa Department of Natural Resources (DNR) recently released its draft triennial review work plan. The federal Clean Water Act requires states to review their water quality standards at least once every three years to seek public input and evaluate what changes are needed. The work plan sets out the DNR’s priorities for water quality standards development over the next three years. The plan then undergoes required public hearings to gain input on the DNR’s plan. According to the DNR, the triennial review is “designed to be a tool for the public to have an active role in the state’s water quality standards program.”

Nutrient pollution (excess nitrogen and phosphorus) is the state’s most severe water quality problem, but, surprisingly, (or not surprisingly given the state’s stance on addressing nutrient pollution over the last decade), the DNR did not include nutrient pollution among its planned water quality standard work over the next three years. Currently, Iowa has narrative criteria for nutrients, which are inherently subjective and difficult to measure. For example, a lake cannot have “nuisance aquatic life” like algae, but how much is too much? There is nothing objective to measure against. 

With numeric nutrient criteria (NNC), DNR would establish numerical nitrogen and phosphorus limits for specific water bodies. Everyone could see how each waterbody compares to the standard. Last week, IEC and partner Environmental Law and Policy Center (ELPC) submitted written comments asking for DNR to include NNC in the triennial review work plan.

This is not the first time IEC has asked DNR to include numeric nutrient criteria in its triennial review. IEC and other groups have been calling for the DNR to adopt NNC, particularly in Iowa lakes, for years. IEC and ELPC have twice petitioned the Environmental Protection Commission (EPC), a citizen board that oversees DNR, to direct DNR to begin developing numeric nutrient criteria. The EPC denied both petitions based on the DNR’s argument that the Iowa Nutrient Reduction Strategy (NRS) exists and should be given more time to work.

When asked during a stakeholder meeting last month why DNR did not include NNC in its work plan for the next three years, Roger Bruner (DNR Water Monitoring Supervisor) again stated that the DNR supports the NRS as the state’s policy for addressing nutrient pollution in Iowa. This explanation doesn’t make much sense, considering that the NRS itself includes NNC as a tool for reaching 45% nutrient pollution reduction.

The NRS is not a water quality standard under the Clean Water Act, and the NRS’s statewide nutrient reduction target is not a substitute for waterbody-specific standards. Establishing numeric criteria would provide numeric limits to measure against, and under the Clean Water Act there would be required actions to address and mitigate excess pollution in individual waterbodies that exceed those limits. Conversely, the nonpoint source NRS policy is completely voluntary and does not place any requirements on agricultural pollution sources, which account for roughly 80% of phosphorus and 92% of nitrogen pollution in the state.  

Most importantly, the DNR should develop and implement NNC because the NRS is not actually reducing nutrient pollution. Consider the following: 

• Despite the 2035 target year for achieving 45% nutrient reduction in Iowa, based on current implementation rates it would take 85 years to achieve the target cover crop acres and 942 years to install the necessary number of wetlands. 
• According to the most recent available NRS annual report data from 2019, the state has roughly 8% of the cover crop acres necessary to achieve a 45% reduction in nutrient pollution. 
• The five-year running average nitrate load entering the Upper Mississippi Watershed from Iowa is up 72% since 2003.    
• Financial incentives don’t appear to be motivators for significant change, as $2 million for conservation project funding in the North Raccoon River Watershed remained unclaimed 2020, despite a 90% cost-share offer. That cost-share means landowners would only need to pay 10% of the costs to implement conservation practices.    

IEC recently released a report detailing the NRS’s shortcomings and offering five policy recommendations that would lead to nutrient pollution reductions, one of which is setting numeric nutrient criteria. As noted in the report, developing and implementing NNC is quite practicable. Neighboring states such as Minnesota, Wisconsin, Illinois, and Missouri have NNC and a state NRS.

In 2008, Iowa convened a scientific advisory board to evaluate and recommend numeric nutrient criteria for lakes, but the DNR never implemented those recommendations. The U.S. Environmental Protection Agency (EPA) is also supportive of states setting NNC and is working on scientifically-based guidance for states to adopt NNC. The Iowa DNR has been working with EPA in developing this guidance, so it is strange that they would not include acting on such guidance in their standards planning over the next three years.  

The DNR does not need to wait for EPA guidance to set numeric nutrient criteria, however. The DNR has had ample time and has the findings of the scientific advisory committee to move forward with developing NNC. What appears to be missing is the will of the DNR, the state agency tasked with environmental protection, to move forward with setting rules that would protect the environment. 

In its response to IEC’s comments asking for numeric nutrient criteria in the triennial review, the DNR asserted that because there was not “consensus” among stakeholder groups, it would not adopt our comments. When asked during a stakeholder meeting what consensus means, Bruner stated that everyone, meaning all stakeholder groups, must agree before the DNR adopt a proposed action. This is patently absurd and renders the public hearings, required by the Clean Water Act, nothing more than public participation theater.

DNR has every reason to include NNC in its triennial review, and its repeated refusal to move forward with using all the tools at its disposal to address the state’s nutrient pollution crisis undermines public confidence in the department’s willingness and ability to protect Iowa’s waters. This is yet another example of DNR exercising its discretion in the least environmentally protective way, and communities across the state will suffer the consequences of DNR’s inaction.

1. clean water
2. clean water act
3. dnr
4. harmful algal blooms
5. microcystin
6. nitrate pollution
7. nutrient reduction strategy
8. phosphorus pollution
9. toxic algae