Confined animal feeding operations (CAFOs) can contaminate aquifers and thus impose health risks and welfare losses on those who rely on groundwater for drinking water or other uses., which causes a blue-gray skin color, irritableness or lethargy, and potentially long-term developmental or neurological effects. Generally, once nitrate intake levels are reduced, symptoms abate. EPA's proposed revisions to the National Pollutant Discharge Elimination System (NPDES) regulation and effluent guidelines would affect the number and type of facilities subject to regulation as CAFOs, and would also introduce new requirements governing the land application of manure. As a result, EPA anticipates that its regulatory proposal will reduce nitrate levels in household wells. In light of clear empirical evidence from the economics literature that households are willing to pay to reduce nitrate concentrations in their water supplies - especially to reduce concentrations from above the MCL to below the MCL - the anticipated improvement in the quality of water drawn from private domestic wells represents a clear economic benefit. This report estimates these benefits for each of the 12 regulatory scenarios evaluated.