This project was commissioned to develop the first comprehensive life cycle assessment (LCA) of a large-scale US organic diary that includes energy, greenhouse gas, water use, nutrient use and waste generation impacts from organic milk production.  Environmental performance indicators for operational management were also developed to complement the full LCA impact assessment by providing managers with immediate and simplified environmental assessment on a continual basis.  Research methodology was based on a wide range of established conventions like IPCC greenhouse gas reporting and the LCA framework as well as novel techniques for quantifying water use, nutrient use and waste generation impacts based on available literature, expert consultation, and primary data sources.  The results from this study will help assuage the dearth of available LCA literature on the impacts of US organic food production and help advance novel research methodologies related to water use, nutrient use and waste generation.