Jim Eckberg, PhD,
Director of Science and Innovation
Dairy Business Association
Collaboration between farmers and conservationists on science-based policy is critical to protecting groundwater in Wisconsin. Solutions that do not include a consortium of stakeholders from policy makers to farmers risk being ineffective and not having the staying power needed to address long-term water quality issues.
The recent report titled “Nitrates on Tap: The Cost of Nitrate Contamination in Wisconsin’s Drinking Water” makes several claims and policy recommendations to address groundwater nitrate contamination. The report claims that “…an estimated 16 million pounds of nitrogen was applied beyond crop needs. This excess application of nitrogen is a significant cause of nitrate leaching to groundwater and runoff to surface water systems”.
The authors base this claim on a comparison between the tonnage of nitrogen purchased statewide versus the total crop acres and nutrient needs according to USDA 2022 Census of Agriculture and University of Wisconsin nutrient application guidelines. This approach of using statewide averages does not consider the complex pathways from fertilizer application to groundwater contamination necessary to estimate the impacts of field nitrogen applications on groundwater. Groundwater contamination is highly variable across the state depending on soil type, topography, weather and many other biophysical factors. Conservation practices and cropping systems, including nutrient management planning and manure treatment technology, influence nitrogen uptake and losses, e.g., leaching, and runoff. Biophysical modelling that evaluates atmospheric, water, soil and crop interactions is needed to understand the relationships between fertilizer application and groundwater nitrates. These considerations are not made in the analysis presented in the report to substantiate the claim of nitrogen over-application or its effects on groundwater nitrate levels.
Using the statewide assessment and claims, the report recommends that the state begin “standardizing when large animal operations are required to implement on-farm groundwater monitoring” and calls on the Wisconsin Department of Natural Resources to develop a standardized approach that would “reduce the ability of permittees to challenge WDNR’s decision to require groundwater monitoring,” by focusing on reducing the “strength of the legal arguments on which to challenge the decision.” These regulatory recommendations focus on large animal operations (CAFOs) without establishing the contribution of CAFOs to groundwater contamination. Also, the report does not address how such required monitoring activity or data would be applied to solve the issue of groundwater contamination at the source, which was the original objective of the report. Central questions, such as how monitoring will establish baseline conditions, detect statistical changes in nitrates, infer causation or implement within crop field mitigation practices are not discussed.
In summary, the report has major gaps in understanding of the issue and workable solutions for agriculture.
Independent scientific expertise is critical to finding solutions to groundwater contamination that work for farmers, regulators and the general public. The report lacks input or review from experts in relevant agriculture, biogeochemistry, or hydrological fields. Most notably missing is input from the agricultural community. Engagement with farmers and organizations representing them is needed to solve these large and complex issues.
The report claims that “current state policies and voluntary programs have failed to curb this problem”. Missing, however, is a quantitative assessment of the impact of voluntary programs to address water quality or the potential effects of new regulation on clean water. In a recent publication I co-authored titled “Glass half full: A framework for setting realistic water quality conservation targets,” which was published in the peer-reviewed Journal of Environmental Quality, my co-authors and I developed a framework demonstrating how voluntary, farmer-led programs can make meaningful progress toward water quality targets. Such approaches are critical to identifying the needed investment and collaboration with the farm community. This stands in contrast to the Nitrates on Tap report, which does not address how proposed policy changes, e.g. groundwater monitoring, would address the clean water issues.
The authors quote Rissman et al 2024, a policy brief by the University of Wisconsin Madison, to support their argument on the effects of dairy farms on water quality impacts. Rissman et al 2024 does not provide substantiative data to support the authors claim regarding the impact of dairy on water quality. On the contrary, Rissman et al 2024 contradicts the authors’ view of voluntary programs by calling for incentives to farmers in the form of “performance-based approaches” that link “payment to performance to cost share,” “engaging private sector supply chains,” “advancing norms and farmer networks” and “enhancing capacity for implementation and technical assistance” to close the gap on clean water targets.
The Rissman brief concludes that “better understanding community member perspective on policy options can help identify disconnects and innovations for helping improve water quality and reduce farmer nutrient costs while continuing Wisconsin’s proud agricultural traditions.” I agree that such nuances and complexities have to be addressed for sensible policy that is scientifically informed.
The Dairy Business Association believes that solving water quality is about treating the root cause and not treating the symptoms. We agree that more progress is needed, and that progress will come by being scientifically rigorous and collaborative with the farm community. The rapid expansion of the number of farmer-led watershed groups in Wisconsin in recent years demonstrates the growing commitment of farmers to conservation practices. Farmers’ demand for this state-supported program currently outstrips the grant funding.
Innovative practices farmers are implementing to improve nutrient management and mitigate leaching is mostly unaddressed in the Nitrates on Tap report. We have demonstrated through peer reviewed research how such farmer adoption of conservation practices can contribute to meaningful progress toward clean water targets in the Lake Michigan Watershed basin (Summers et al 2025). Engaging these issues as a consortium of stakeholders that includes farmers will accelerate collective action and progress. The contrast proposed by Nitrates on Tap has high potential to reinforce old battle lines between agriculture and the non-farming public and stifle innovative solutions.