PACE is providing engineering design services as part of the Engie design-build team that is upgrading the sludge and solids processing at WCW’s 12.5 MGD Water Quality and Resource Recovery Plant (WQRRP). The upgrades will improve the energy efficiency of the plant through the design and installation of new process equipment, including pumps and aeration blowers, and the addition of Variable Frequency Drives (VFDs) that allow greater process control. The project will replace the two existing secondary digesters as they have reached their end of useable service life; the new digesters will be supported by new deep foundation drilled displacement columns that provide the requisite support for the new digester tanks to meet the current code. A new solids handling building was designed to provide space for two centrifuges that will take digested sludge to 20% solids content and a new dryer system that will further dry the sludge to 80% solids content. The solids building will also have a gas cleaning room that cleans the gas from the top of the digesters that will then be used in two cogeneration systems that each produce 1 MW of energy. PACE is also providing a design to convert three of the WQRRP’s sludge drying lagoons into a new influent equalization basin to store high seasonal flows into the plant to prevent disruption to the treatment process.
ENGIE Services U.S.