This project was by the Onondaga County, Department of Water Environment Protection (County/Owner), as part of a Consent Decree with USEPA to upgrade sewer facilities and improve the combined sewer infrastructure in Syracuse, New York to mitigate untreated storm related discharges to Onondaga Creek and Onondaga Lake.
Subsurface conditions at the site consist of glacial-fluvial gravel laden strata and glacio-lacustrine clay. The project includes new gravity conveyance sewer pipes which range in diameter from 36 inches to 96 inches that connect existing combined sewer lines to the new Storage Facility. Additionally, a 16-inch diameter force main was to convey stored effluent to the main interceptor sewer.
The combined storage capacity for the facility is approximately 5.8 million gallons. Storage Tunnels consist of three parallel 15-ft wide by 19-ft high box tunnels each being approximately 850-ft in length. The three storage tunnels were constructed within a groundwater management system consisting of slurry wall (diaphragm wall construction) along the perimeter and a jet grouted base that formed a bathtub.
Brierley Associates was retained by the joint venture project designers, EEA, to provide a full array of underground engineering and field services during geotechnical construction.