Is manure a major cause of groundwater or surface water pollution?
A. Manure management systems that are properly managed do not contaminate groundwater or surface water resources. Properly constructed lagoons, particularly those with liners, thermal aeration systems, and other technologies, remove nutrients naturally present in manure before it is applied to soil or ground. The pork industry prides itself on its zero discharge standard. Other sources typically contribute to elevated nitrate levels. They include naturally occurring background levels in wetland areas, human sewage systems, and runoff from commercial fertilizers. Well depth and its proximity to operational areas significantly affected nitrogen levels in groundwater. When wells are placed and installed properly, natural attenuating factors in groundwater systems effectively reduce the nutrient and bacteria concentrations to safe, typically nondetectable concentrations.
