Characterizing water utilization in modern US dairies to identify opportunities for reutilization

Abstract. Excessive water use and waste in concentrated animal feeding operations (CAFOs), and especially in water scarce places represent a challenge to future sustainability. Dairies have an extensive need for water for milking parlor cleaning, milk cooling, evaporative cooling, manure flushing and general barn cleaning. Thus, proper water reutilization methods could be beneficial to the US dairy industry for reducing water waste and increasing water use efficiency. In some cases, reutilization may also increase energy efficiency, enhance environmental sustainability and conserve dwindling groundwater resources. Potential opportunities for water reutilization come from many sources on a typical dairy farm, such as general cleaning water, flushing water, water for milk cooling, and lagoon low-nutrient concentration streams. To identify opportunities for water reutilization and water waste reduction in dairies, a comprehensive understanding of water use in US dairies is first needed. This effort characterizes the water utilization situation in modern US dairy farms, including summary process diagrams that depict water use in identified representative farms.