Startup of Anaerobic Mesophilic Digesters

Many operators have started up mesophilic digesters, but everyone has differing stories and experiences. This paper is a combination of the startup of several mesophilic anaerobic digesters, with very low seeding to fully seeded conditions. Upper Occoquan Sewage Authority (UOSA) operates the Millard H. Robbins Water Reclamation Plant. UOSA started three anaerobic digesters between August 2000 and March 2001 as part of a major expansion which brought the permitted capacity of the facility from 32 to 54 million gallons per day (mgd). Alexandria Sanitation Authority (ASA) operates the ASA Advanced Wastewater Treatment Plant with an average plant influent flow of 54 mgd. ASA started four anaerobic digesters between May and October 2005 as part of a solids upgrade that added pre-pasteurization and two new anaerobic digesters. This paper will provide a useful roadmap for digester startups for all operators.