Adding sufficient dilution water to manure results in a mixture that can be handled in a manner similar to water. For ease of handling and efficient pump operation, the solids content of these liquid manure systems should be less than 4 percent. Due to the volume, lagoons are commonly used to store and treat the liquid manure. Proper design and management of anaerobic lagoons is critical to minimize odor problems and to obtain maximum decomposition of swine manure. Recommended minimum design volumes for single-cell anaerobic lagoons are 2 cubic feet per pound of hog.
Additional volume is required for spillage, wash water, flushing water, precipitation and freeboard.
Liquid manure handling systems often use a partially or totally slatted floor and a shallow pit or gutter to provide temporary storage of the manure. Another popular method for transferring manure from a building to a lagoon is the flushing gutter. This system incorporates a shallow channel which is flushed periodically, usually 2 to 6 times per day. Two types of tanks designed for flushing are the tipping bucket and the dosing siphon. Flushing is done in open gutters or under slats.