A syndicated and widely circulated story last week on NPR reported how New York’s Newtown Creek Wastewater Treatment Plant is now processing food scraps to create renewable energy. The full story provides a glimpse into the growing trend of co-digesting food scraps with sewage sludge to boost biogas production with anaerobic digestion.
Wastewater treatment plants protect human health and the environment by efficiently processing raw sewage. Anaerobic digestion is simply one part of the treatment system used to reduce harmful pathogens and the overall volume of solids left at the end of the process that must be managed. In New York, some biosolids are beneficially used (land applied as fertilizer), and some are landfilled as far away as Pennsylvania and Virginia.
In reading some of the comments, I am reminded how sewage treatment is out of sight and out of mind, and largely taken for granted by the public.
Newtown Creek is simply utilizing existing infrastructure to maximize its potential. What is unique is that the system is relying on separate collection of the food scraps from commercial establishments, which then must be processed to remove contaminants and be converted into pumpable slurry for injection into the digesters.
InSinkErator’s new Grind2Energy™ system prepares pumpable, contaminant-free slurry ready for anaerobic digesters, completely eliminating the need for pre-processing at a wastewater treatment plant. David Krems, Business Development Director for Grind2Energy™ said, “Food waste to energy via anaerobic digestion is in the nascent stage in the U.S. – however new technologies and businesses such as Grind2Energy™ offer food waste generators an alternative to divert their food scraps from landfills and create renewable energy within local communities!”
Missing in the story is that food waste disposers already divert residential food scraps from homes in New York directly to Newtown Creek. A prohibition on residential disposers was lifted in 1997.