An economic analysis of energy generation and food waste diversion for enhanced biogas production at a colorado wastewater treatment facility

Food waste diversion to enhance biogas production for energy generation in municipal wastewater treatment plants (WWTPs) is an emerging trend in the United States. Using an interested WWTP in Fort Collins, Colorado a study was completed to determine the efficacy and viability of implementing a food waste diversion program utilizing food waste as a feedstock in their existing anaerobic digesters to enhance biogas production. The results of the study concluded that a food waste diversion program would result in a loss of approximately $2.5 million over a 20 year period making the program unfeasible currently. However, the use of excess biogas produced in the plant's anaerobic digesters from the processing of the municipal solid waste stream (MSW) to fuel a reciprocating engine energy generation technology would result in an estimated return on investment of $1.63 million, and an estimated return on investment of $1.25 million for a microturbine energy generation technology over the same 20 year time period. Changes to multiple variables in the economic analysis such as higher energy costs and higher landfill tipping fees could result in a more positive outlook for a future food waste diversion program in Northern Colorado. This study can be used by other WWTPs in the US and other countries as a model to determine the initial economic feasibility of a food waste diversion program in their area. WWTPs in locations with greater costs associated with energy and tipping fees than those reported in this study may find a food waste diversion program economically viable and beneficial.