Bay Park Conveyance Project
Greeley and Hansen, A TYLin Company, was the lead designer for the design-build of the 19-mile 150 MGD Bay Park Conveyance system.
Nassau County Department of Public Works (DPW) engaged a design-build team to execute the Bay Park Conveyance Project to improve the water quality and resiliency of the Western Bays of Nassau County in Long Island, NY. In support of the contractor-led team, Greeley and Hansen serves as the lead designer.
The Bay Park Conveyance Project is designed to improve the water quality in Western Bays by reducing 90% of the nitrogen load to the bay and will convey all the dry weather flow and up to 75 MGD of wet weather flow from Bay Park STP to a new receiving station at Cedar Creek STP, to be discharged through an existing 84” ocean outfall for flows up to 150 MGD.
Hydraulic simulations, modeling, and test plans defining the various scenarios to be evaluated were prepared after review of all existing hydraulics modeling reports. A steady-state model was developed considering the appropriate boundary conditions to confirm the size of the transmission system. The steady state model was also utilized to confirm pump operating points and to confirm pump selection. Special consideration was given to pump selection given the unique nature of the pumps and low-head conditions associated with pumping high flows to discharge into a range of tidal levels. A transient hydraulic model was developed and calibrated to mitigate worst-case water hammer effects in Bentley’s HAMMER platform. The model was utilized to run worst-case transient scenarios and size the appropriate appurtenances along the transmission system in order to mitigate detrimental impacts from transient-induced events. Subsequent coordination with a modeling subconsultant for development of computational fluid dynamics and physical modeling for BPEDPS and CCEPS was then conducted.
Design calculations were performed and details developed for required design packages for BPEDPS, CCEPS, and the new receiving station. The design packages have since been completed. Design services during construction and commissioning continues after the design packages are completed.
Project Highlights:
- Addition of a new Effluent Diversion Pump Station (BPEDPS) at Bay Park Sewage Treatment Plant (STP)
- Replacement of the existing effluent pumps (CCEPS) and controls at Cedar Creek STP
- Construction of a new receiving station with a surge tower at Cedar Creek STP
- Rehabilitation of the 72” sunrise highway aqueduct
- New 72” micro tunnel force mains on either end of the aqueduct to connect to the two STPs