Abstract Landfilling wasted food (WF) is a significant source of greenhouse gas emissions. Anaerobic digestion (AD) is emerging as a promising alternative to jointly manage WF and generate bio-based energy, yet its widespread adoption is limited by transportation and operating costs. To reduce costs, AD facilities must be sited reasonably close to WF sources, energy transmission infrastructure, and available cropland for managing digestate, the liquid by-product from AD. Nutrient-rich digestate can displace synthetic fertilizer use on farms but can also runoff and create ecological risks, depending on location and application rate. Here, we introduce a multi-criteria geospatial model to assess the placement of future AD systems relative to (1) the distance over which AD feedstocks and products must be transported and (2) ecological risks created by land-application of digestate. Using Western New York State as a case study, we show that only 12% of land within the study area is suitable for siting AD systems. Further, the distance that digestate can be transported for land application is constrained to between 6 and 15 km to avoid exceeding crop nutrient demand. However, runoff modeling using the long-term hydrological impact analysis (L-THIA) tool showed that even sites with sufficient capacity to accept digestate could be sources of downstream water quality risk. This type of integrated analysis of ecological and economic constraints to AD siting is critical for sustainable food waste management strategies.
Armington et al. (Fri,) studied this question.