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Food Waste Co-Digestion at Water Resource Recovery Facilities: Business Case Analysis


Carol Adaire Jones, Craig Coker, Ken Kirk, and Lovinia Reynolds

Date Released: 

December 2019

Co-digestion of food wastes with wastewater solids at water resource recovery facilities (WRRFs) can provide financial benefits to WRRFs as well as a broad range of environmental and community benefits. Co-digestion is a core element of the wastewater sector’s “Utility of the Future” initiative, which envisions a new business approach for pioneering WRRFs to create valuable energy and nutrient products via the recovery and reuse of residuals from the wastewater treatment process. With fewer than 1 in 10 WRRFs using anaerobic digestion to process wastewater solids, and about 1 in 10 of those co-digesting high strength organic wastes, there appears to be significant untapped potential for co-digestion. A contributing factor is the various financial, operational, regulatory, stakeholder/political, and organizational risks and impediments WRRFs may face with the adoption of co-digestion and energy generation projects, which are outside core wastewater treatment services. This report offers general principles and case study examples of how to create value and manage the risks of adopting co-digestion of food waste (e.g., fats oils and grease, food manufacturing residuals, and food scraps) with wastewater solids to enhance recovery of biogas, soil amendments, and nutrient products. The report also presents a diagnostic framework for WRRFs to analyze the opportunities and business case for co-digestion in their own organizational, market, and policy contexts and, if indicated, to develop a long-term business strategy that advances their mission and long-term goals.

The Environmental Law Institute gratefully acknowledges the Water Research Foundation’s financial and administrative assistance in funding the project through which this information was discovered, developed, and presented.

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