Assessing Potential Impacts of Livestock Management on Groundwater

TitleAssessing Potential Impacts of Livestock Management on Groundwater
Publication TypeReport
Year of Publication2014
AuthorsHarter, T., Kourakos G., & Lockhart K.
Series TitleNicholas Institute for Environmental Policy Solutions
Document NumberNI R 14-03 Supplemental Paper 2
Date Published03/2014
InstitutionNicholas Institute for Environmental Policy Solutions, Duke University
CityDurham, NC
Report NumberNI R 14-03 Supplemental Paper 2
Keywordsagriculture, groundwater, livestock, Thomas Harter
AbstractThis supplemental paper provides a brief review of the potential for groundwater pollution from animal feeding operations (AFOs). Management activities that address surface water quality may reduce nutrient loads, but they may also lead to a deterioration of groundwater quality as well as additional methane emissions. Groundwater pollutants may eventually compromise surface water quality when a portion of the groundwater returns to the stream as baseflow. These cross-media effects are important to consider within a holistic review of the sustainability of AFO measures. We outline the potential risk of groundwater quality degradation from proposals to improve surface water quality. A review of methods to quantify the potential damage to groundwater from surface water programs indicates such research would require significant groundwater monitoring and a coupling of the findings with integrated assessment and models. We discuss methods of monitoring groundwater discharge from AFOs, including discharge from associated croplands receiving manure applications. We also summarize modeling tools used to assess the impact of management measures on groundwater quality. Our findings indicate that appropriate models exist to simulate the pollutant source, to simulate processes within the root zone and in the unsaturated zone below the root zone, and to assess transport in groundwater discharging into wells, streams, and springs. Research on the integration of these models—coupling source systems with root zone/unsaturated zone pollutant fate and transport models, with groundwater models, and with surface water models—is not as well defined. This report shows an overwhelming lack of groundwater-related data on the effects of management practices in animal operations, including nutrient management practices in crops involving manure applications. Significant additional regulatory, funding, programmatic, and research resources are needed at the federal level to address groundwater-quality concerns.