Estimating the social costs of nitrogen pollution

Agricultural expansion can degrade water quality and related ecosystem services through increased export of nutrients. Such damages to water quality can negatively affect recreation, property values, and human health. While the relationship between agricultural production and nitrogen export is well-studied, the economic costs of nitrogen loss are less well understood. We present a comprehensive assessment of the full costs associated with nitrate pollution from agricultural sources in Minnesota. We found that the most significant economic costs are likely from groundwater contamination of nitrate in public and private wells. For example, we estimated that loss of grassland to corn cultivation in Minnesota between 2007 and 2012 is expected to increase the future number of domestic wells exceeding nitrate concentrations of 10 ppm by 31%. This increase in contamination is estimated to cost well owners $1.4 to 19 million (present values over a 20 year horizon) through remediation, avoidance, and replacement. Our findings demonstrate linkages between changes in land use, water quality, and human well-being.