A case study of the economic feasibility of anaerobic digestion of dairy manure and food waste (co-digestion) on a Northern New York dairy farm was conducted that considered two scenarios. Scenario One analyzed the use of the farm's existing anaerobic digester to electricity system processing manure from it's herd of 1,860 lactating cow equivalents to take in a local source of cheese whey in a ratio of 20% by volume in the digester. Scenario Two analyzed the economic feasibility of a new anaerobic co-digestion system at the same size and location dairy farm that would take in 50% by volume of mixed food waste from local food and beverage manufacturers with the dairy's manure. Scenario Two included biogas upgrading to renewable natural gas (RNG) or biomethane for injection into the adjacent utility gas pipeline and sale to a third party. Net present value and the benefit-to-cost ratio are presented with the detailed capital and operating costs and benefits for each scenario.