Benefits of Dairy Digesters
Profitability – Digesters have multiple revenue sources that support the sustainability of California farms. Energy revenue allows farmers to diversify their business away from dependence upon the single, commodity price of milk.
Regulatory Compliance – Developing a dairy digester usually requires Dairies to be updated to the most recent regulatory and environmental safety compliance provided by the Water Board and Air Resources Board. This is particularly true when government agencies and incentive programs provide financial assistance.
Renewable Energy – Biogas captured by digesters can be used to produce vehicle fuels, generate electricity, provide on-site natural gas replacement, or be injected into the utility pipeline. One cow’s manure in a digester can supply the equivalent of 180 gallons of gasoline per year. Four or five cows can supply enough electricity to power a house. The result is a reduced dependence on fossil fuels and other carbon intensive power sources.
Greenhouse Gas (GHG) Reductions – Methane is a greenhouse gas that is naturally produced through conventional manure storage. By employing manure digesters, the methane is captured to produce renewable energy instead of venting into the atmosphere. Each cows’ manure processed in a digester removed greenhouses gases equivalent to approximately one automobile—roughly 4 metric tons of CO-2 equivalent per year.
Reduced Pathogen Application – Anaerobic digestion has been shown to reduce pathogens such as fecal coliform, Enterococci, E-coli, MAP, and bovine enterovirus by over 90%. This leads to substantially healthier farm, soil, and crops.
Reduced Chemical Oxygen Demand – According to the EPA, anaerobic digestion reduces the manure’s chemical oxygen demand by over 50%. This has a direct effect on water quality improvements and leads to healthier crops and nearby aquatic wildlife.
Reduced Runoff Risk – The digestion process makes the nutrients of manure more readily available to crops allowing them to consume the manure more rapidly. This improves natural fertilizer value and greatly reduces the opportunity for unconsumed manure running off into streams and contaminating groundwater during rainy seasons.
Economic and Community Benefits
Job Creation - Each California digester creates new local jobs for mechanics, technicians, parts suppliers, managers, etc.
Monetary Output - A digester’s construction and operation requires the assistance of multiple vendors and contractors that stimulates the economy in communities that are in traditionally low-income, agricultural areas.
Odor/Vector reduction – By covering otherwise exposed lagoon manure, digesters trap much of the odorous gasses produced at dairies while also prevent propagation of flies and other disease vectors. This leads to cleaner air in the surrounding community.