Because of excessive water impairment, federal and state agencies have enacted regulations to reduce water pollution from animal feeding operations. Many of the regulations are based on numbers of animals rather than the potential of an operator to impair water quality. To enhance efficiency, critical production indicators and location screening factors might be used to exempt operations that are not significantly impairing water quality. In this manner, regulations could avoid imposing unnecessary costs on the regulated public and more effectively target monitoring and enforcement resources of the regulatory agency.