Dairies produce a lot of poop. Managing it is essential to the well-being of the farm and the environment. There are a few different ways of managing manure, and all are acceptable ways to handle it.
Waste Storage Pond
A storage pond is a short-term storage area for manure, flush water, and polluted runoff. Storage typically lasts 90-180 days, then the waste must be removed. It is typically applied to land. It retains much of its fertilizer nutrients (including nitrogen), thus must be applied at a lesser volume than waste from a lagoon. Say you spread waste from a lagoon over 1 acre of cropland. That same amount of waste from a storage pond should be applied to 2.5 or more acres. Storage ponds must be impermeable to prevent groundwater contamination. They also produce an odor and therefore must be located downwind of neighbors or any public structures.
Waste Lagoon and Anaerobic Digesters
Lagoons are a long-term storage option for manure. They are typically earthen and are designed to prevent leakage of waste into the groundwater. They are often biologically treated, or have bacteria added to digest the organic matter. This biological action reduces odor and nitrogen content, which greatly reduces the land area needed for application.
Composting is an appropriate manure management system for dairies in any location and of any size. It reduces volume of manure by up to 50% and produces a saleable product. Composting essentially transforms raw manure into a biologically stable material that makes a great soil amendment. The product is consistent and can be applied to land or sold to horticultural markets, landscaping companies, homeowners, or even neighboring dairies. It can create more work for dairy workers, especially if the goal is to create a saleable product. Specialized equipment may be needed, such as an impermeable surface on which to build the compost piles. However, if you are just starting out, using a simple frontloader to turn the piles is acceptable.
Only 12-14% of excreted manure are solids. Add in bedding from the freestall barn or housing system, and the capacity of the lagoon or storage pond can be greatly reduced. Separating solids and liquids with either a settling basin or mechanical separators can reduce up to half of the solids in a waste stream. This system feeds well into multiple systems, with the solids being able to be composted and the liquids finding their way to the lagoon or storage pond.