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HomeMy WebLinkAboutStaff Report 7600 City of Palo Alto (ID # 7600) City Council Staff Report Report Type: Informational Report Meeting Date: 3/6/2017 City of Palo Alto Page 1 Council Priority: Environmental Sustainability Summary Title: Annual Update on Energy/Compost Technologies Title: Annual Update on Energy/Compost Technologies and the Organics Facilities Plan From: City Manager Lead Department: Public Works Recommendation This report is provided for information only and requires no Council action. Executive Summary This report provides an annual update on the City programs that, as directed by Council, were implemented in 2016 or are being developed to extract energy and compost from the City’s organic residuals (wastewater solids, food scraps and soiled paper, and yard trimmings). Progress includes: 1. Completing CEQA and the design for a sludge dewatering and haul-out facility for the Palo Alto Regional Water Quality Control Plant (RWQCP) and issuing an Invitation for Bid (IFB) for the project’s construction; 2. Implementing the first phase of a new Recycling and Composting Ordinance; and 3. Investigating new technologies that include gasification of wood waste and gasification of biosolids. Background In May 2014, Council approved a four component Organics Facilities Plan (OFP) City of Palo Alto Page 2 (Staff Report #4744) to direct the processing of wastewater biosolids, food scraps, and yard trimmings. 1. Component One: Biosolids Dewatering and Truck Haul-Out Facility. 2. Component Two: Wet Anaerobic Digestion Facility utilizing the thermal hydrolysis process. 3. Component Three: Food Preprocessing Facility; preprocessed food scraps would then be fed into the anaerobic digester (component two above). 4. Component Four: The pursuit of technologies to harness the energy and resource potential of yard trimmings. Council directed staff to look first at Component Four as a composting option for yard trimmings on the 10-acre Measure E site. Council approved using existing facilities to process food scraps and yard trimmings (Staff Report #5182) and directed staff to return to Council annually with an update on new organics processing technologies and opportunities. This report is that annual update. The previous update from February 22, 2016, is Staff Report #6503. Discussion Biosolids Processing In 2016, the design and environmental documentation for the sludge dewatering and truck loadout facility was completed and partner agencies pledged to repay construction loan payments for the project. An IFB was issued in November 2016 with bid opening scheduled in February 2017. Construction is expected to be complete two years after the Notice to Proceed is issued. Upon facility completion and successful startup, the sewage sludge incinerators will be decommissioned; thereafter RWQCP sludge will be hauled to nearby facilities for final treatment and disposal. Although Class A biosolids and energy via onsite anaerobic digestion with pretreatment via thermal hydrolysis was the preferred long-term biosolids treatment solution at the time the Biosolids Facilities Plan was completed, later evaluation in a preliminary design reported a final cost estimate of $75 million for the complete system, significantly higher than the originally estimated $57 City of Palo Alto Page 3 million. During and especially since the time of the original long-term biosolids evaluation, City staff and partner agency officials have monitored, with interest, emerging technologies such as gasification and pyrolysis, which may be more compatible with RWQCP’s footprint constraints. Staff will continue to work with neighboring plants and regional technology providers on emerging technologies and cooperative treatment/disposal solutions to maximize the cost efficiency of biosolids disposal for environmental benefit. An update to the Biosolids Facilities Plan will be performed to re-evaluate the best long-term onsite treatment option. Food Scrap Collection and Processing Since July 1, 2015, curbside compostables, including food scraps from both residential and commercial customers collected in the green containers by GreenWaste of Palo Alto, the City’s contract solid waste hauler, have been processed at the Zero Waste Energy Development Facility (ZWED) in north San Jose. ZWED is a dry anaerobic digestion facility that creates renewable energy and compost from food scraps. In April 2016, the first phase of the Recycling and Composting Ordinance went into effect requiring approximately 650 customers to subscribe to compost service and sort their waste properly. Phase 1 customers include all food service establishments, all multi-family customers, and the largest waste generators in the City (customers with 8 or more cubic yards of weekly garbage service). Phase 2 of the ordinance was recently implemented (January 1, 2017) for mid-sized customers, and Phase 3 will begin implementation on January 1, 2018. In 2016, these two food scrap programs (residential and commercial) resulted in a reduction of over 5,000 tons of material sent to the Sunnyvale Material and Recovery Transfer (SMaRT) Station and ultimately landfilled – about 10% reduction in total landfilled tons. New Technologies Gasification is a thermal process that uses high temperatures and a minimal amount of oxygen to transform a solid carbon substance (like wood waste or biosolids) into a clean-burning gas that can be combusted in an engine or into biochar that can be used as a soil amendment. While gasification is an old, proven technology, few commercial-scale facilities have been built, especially to treat biosolids which contain more water, needing a greater supply of dewatering City of Palo Alto Page 4 energy than other organic feedstocks. Wood waste collected from City crews and City contractors, about 1,000 tons annually, could be a candidate for a small scale gasification system. Staff is working with GreenWaste on developing a pilot gasification system at ZWED to determine the feasibility and cost effectiveness of this process. Biosolids, a material with a tremendous amount of energy potential, have long been considered a potential fuel in gasification systems. Currently, the regional wastewater treatment plant in Redwood City (Silicon Valley Clean Water (SVCW)) is in partnership with BioForceTech Corporation of Redwood City to develop a low-energy use, biosolids dryer and gasifier. The dryer is currently in operation and the gasifier is in construction. Dewatered wastewater solids from RWQCP have been sent to SVCW for testing, results were promising, and the BioForceTech technology is a potential candidate for onsite treatment of RWQCP sludge. The output of biochar from the facility is slated to be sold as a soil amendment. RWQCP also participates in the 19-member Bay Area Biosolids to Energy (BAB2E) Coalition. BAB2E works to build state and federal legislative and financial support for new biosolids processing technologies, funds biosolids research initiatives, and helps facilitate public-private partnerships between wastewater treatment plants and technology providers. The coalition is currently involved in six different projects, including the SVCW-BioForceTech project. Staff will continue to follow the development of these technologies and report accordingly.