Evaluating Animal Agriculture Impacts on Water Quality: Data Gaps in a West Central Minnesota Case Study

Abstract

Balancing the economic and food system contributions of animal agriculture with negative impacts such as water quality degradation has been a recurring question in Minnesota and other agricultural states (e.g., Iowa and North Carolina). Over the past 15 years significant federal- and state-level changes in the regulation of animal feeding operations (AFOs) and associated practices have attempted to improve water quality. The impacts of these changes are unclear; therefore, the main purpose of this project was to evaluate policies designed to protect water quality from manure runoff and spills within the context of a manageable geographic area. Project work was based on manure reports and other publicly available data (2010–2011) on large AFOs in nine counties that encompass the Pomme de Terre River and Chippewa River watersheds in west central Minnesota. Based on summarizing and evaluating the completeness of annual manure reports, and an understanding of the distribution of and practices surrounding manure in the study area, it is clear that there has been progress in the form of collecting more information about manure generation and related practices, as well as keeping large AFOs farther from open water and perennial streams. However, there are still major data gaps (e.g., incomplete information about application methods, and a lack of water quality monitoring during the manure application season) that prevent more thorough evaluation of the effectiveness of manure application practices and AFO siting policies. Funding is required from the Minnesota legislature to enable the Minnesota Pollution Control Agency, local watershed groups, and producers to collaboratively address these data gaps; to compile, compare, and evaluate manure application best practices; and to revisit state policy related to siting AFOs near conduits to surface waters. The research in this article was supported by a grant from CURA’s Faculty Interactive Research Program.