Geothermal Upgrades for Northwell Health
Indoor space and process cooling is supplied to all of the 11 buildings on the 10.3-acre Glen Cove Hospital campus in Glen Cove, Nassau County, New York, by two 50-year-old open loop geothermal well systems. PWGC designed and implemented upgrades to this campus-scale system which included abandonment of portions of the existing systems, rehabilitation of several wells, and construction of five new wells, horizontal piping, controls and appurtenances. The design and planning of the upgrades were complicated by a nearby plume from a New York State Superfund site. In addition, some of the existing wells and some of the new wells were installed in the protected Lloyd aquifer, which involved petitioning and approval from the regulatory agency to permit the replacement system under “grandfather” provision. The total groundwater flow through both systems is 850 gallons per minute.
PWGC inspected the existing systems including televised logging of failing wells followed by coordination of interim rehabilitation by a drilling contractor to allow them to function until the new well systems are in service. Regional hydrogeology and environmental conditions were investigated to construct, calibrate, and run a 3-dimensional numerical groundwater model. The model was required by NYSDEC to investigate hydraulic effects on the aquifers and potential to induce contaminant flow from the Superfund site or saltwater intrusion from the nearby marine waters (Long Island Sound).
PWGC was responsible for all regulatory permitting, including preparation of applications for the Long Island Well Permit application required by NYSDEC Division of Water and a Permit to Drill from the NYSDEC Division of Mineral Resources. The permit applications and associated Engineer’s Report were submitted to and approved by both agencies.
Upon determining the best available option during the feasibility study review, PWGC prepared construction documents for the upgrades. PWGC’s design included the construction of five new wells, rehabilitation of several existing wells, and abandonment of five existing wells and existing piping network. PWGC was responsible for design of the wells, selection and design of submersible pumps, piping and control valves, flow meters, variable frequency drives, wiring, and interconnections with the buildings’ heat exchangers. PWGC coordinated with the mechanical engineer for replacement of the interior mechanical equipment including chillers and circulator pumps.
PWGC is presently providing construction administration and resident construction oversight services, which includes review of all contractor submittals and coordination between the regulatory agencies, the hospital administration, and the contractors. Upon completion, PWGC will provide guidance on system operation and periodic maintenance activities.