Anerobic Digester CHP Project

About The Project

RVE, Authority Engineer to the Gloucester County Utilities Authority (GCUA), managed the energy efficiency improvements and anaerobic digestion, along with the combined heat and power (CHP) upgrade at the GCUA. This $50 million project consisted of six construction contracts and was funded through one New Jersey Infrastructure Bank grant cycle. Professional services included survey, civil/site, structural, mechanical, electrical, plumbing, environmental, process, geotechnical and hydraulic engineering. The digestion system consists of 3.2 million gallons of liquid sludge volume shared by two egg shaped anaerobic digesters and one 900,000-gallon sludge storage tank. This digestion system was put online under three other contracts (foundation, process, integration with existing facility) to expedite the decommissioning of the facility sewage sludge incinerator. The system boiler was designed for unconditioned gas until the future conditioning system is operational, then the boiler will be offline once the CHP units are commissioned in 2020. Two additional contracts incorporated an overhaul on the plant secondary clarification and grit systems to improve energy efficiency and optimize plant solids control. The final contract was a significant energy improvement and process control as the plant aeration system was converted from manual valve control with constant speed blowers to an automated process.

Project Gallery

In 2018, the digestion process began commissioning as the aeration system modifications neared completion. This enabled the facility incinerator to come offline almost four months ahead of regulatory requirements with biosolids being beneficially reclaimed at the County landfill as daily cover in place of disposed ash.

This project is unique in that it created a brand-new State of the Art Egg Shaped digestion process for the Authority for the processing of their bio-solids. The system has a unique mixing system to enhance volatile solid reduction and increase Bio-gas production.

GCUA is committed to providing educational opportunities for this unique project with many presentations at in state seminars such as NJWEA, NJWEA Technology Transfer, and AWWA detailing the construction and design considerations of the projects. GCUA has sponsored on site a local symposium to educate the local college and engineering community on the status of the capital improvements at the Authority.

ACECNJ 2020 Engineering Excellence Awards Honor Award, Non-Transportation Category