Potential of closed water systems on dairy farms

A more sustainable water management on dairy farms is necessary because of rising tap water production costs and exhaustion of groundwater resources i n an increasing number of areas. Alternative water sources like rain water collected from roofs and yards and effluents from on-site wastewater treatm ent should be considered. The objective of this paper is to discuss options for closed water systems on dairy farms. Animal drinking and cleaning of m ilking equipment are major water demands on dairy farms. In some regions la rge volumes are needed for grassland irrigation or manure flushing. Treatme nt of dairy farm wastewater in constructed wetland systems seems to produce good quality effluents. The most plausible options for closed water system s on dairy farms are the collection and use of rain water and treatment and reuse of wastewater for irrigation, manure flushing and animal drinking wa ter. Whether effluents are safe to be used as animal drinking water should be subject to further research. (C) 1999 IAWQ Published by Elsevier Science Ltd. All rights reserved.