Increased public awareness of the potential for surface and groundwater contamination from agricultural sources has led to a heightened sensitivity concerning the safety of water supplies. Environmental concerns have in turn led to increased regulation of our nation's farmers. Proper on-farm management will minimize localized environmental damage from barnyards, silage storages, milking centers, and manured fields. Liquid manure may be defined as any liquid that is contaminated from the animal production system. The on-farm management of liquid manure and other farm effluents presents an important opportunity to curtail agricultural nonpoint source pollution. Emphasizing basic principles, this design manual provides the agricultural community and support industry with current research and industry experience in applying liquid animal manures (and other wastewater mixtures) to farmland. This manual provides guidelines for the design of liquid manure application systems.