Anaerobic Digestion at AA Dairy

Abstract

AA Dairy is a 600-cow dairy operation located on 2,200 acres in the town of Candor in Tioga County, New York The dairy began operating in the summer of 1993. Odor issues began to cause local concern, and thus, the decision was made to construct an anaerobic digester The digester was commissioned in June 1998 Benefits (other than odor control) derived from this digester include: Electricity and heat generated from the biogas Compost from the post-digested separated solids Irrigation liquid from the separated liquid effluent The electricity produced by burning biogas in the engine-generator set, is used for on-farm needs and any excess is sold to New York State Electric and Gas (NYSEG) under the provisions of the New York State Net Metering law (See Fact Sheet NM-1) The post-digestion separated solids are cured and marketed as compost to local buyers under the name “Field of Dreams Compost” The separated liquid effluent, mixed with milk house wastewater, flows by gravity to an HDPE-lined long-term storage, and is eventually land applied by tanker truck or irrigation by way of underground piping