Gas Management System Rehabilitation and Improvements
The Sacramento Regional County Sanitation District operates a digester gas management system (GMS) for treatment, delivery, and disposal of the sludge gas produced by the anaerobic digesters. Changes in digester gas production and consumption has resulted in periodic uncontrolled venting from the digesters. ICS was retained to execute a rehabilitation and improvement project that will prevent periodic uncontrolled venting of digester gas and to bring the GMS into compliance. The project includes phased improvements to the MSG building; ground flares & waste gas burners (WGBs); LSG scrubbers; LSG, MSG, and FSG condensate systems; and LSG holders and Horton spheres piping. Project work was performed while the GMS remained in operation.
- Removed obsolete WGBs and associated piping, valves, electrical, control panel and conduits.
- Installed new WGBs, new above-grade 24-inch & 20-inch Stainless Steel 316L WGB header piping, new below-grade 24-inch WGB header piping and associated parts. Parts included supply air lines, supply piping, natural gas piping, above- and below-grade feed piping and condensate drainage, above-grade manifold piping, valves including LSG Fire Rated valves, conduits, wiring, flow meter, pressure transmitter, pilot systems, backpressure control valve, and control panel and sub-panels.
- Constructed new concrete pad to house the control panel and sub-panels.
- Cap and Abandoned in place WGB underground looped header, 16-inch buried line, and replace old WGB flowmeter structure with new structure to house the new WGB system.
- Upgraded the ground flare system with new pressurized FSG condensate tank and associated piping, valves, and control panel for each flare. Work included excavation and installation of 2-inch HDPE piping for condensate drain and abandon in place old gas holders and associated piping. This phase was completed within the required 48-hour period.
- Replaced the LSG, MSG, and FSG condensate systems which included installation of new drains, valves and supply lines, MSG & FSG piping, and conduit and wiring in the MSG compressor building for the new valves and flow meters.
- Remained in compliance with air quality permit conditions throughout the project.