NYCDEP Rehabilitation of Delaware Aqueduct Shafts 9, 10 & 17 and Other Related Facilities

The Facility was built between 1939 and 1945, the 85-mile long Delaware Aqueduct supplies up to 1.2 billion gal/day of drinking water from upstate reservoirs to 9 million residents of New York City and its suburbs. Numerous shafts along the tunnel route provide access for maintenance and repair, flow measurement and control, and the addition of water treatment chemicals. Shafts 9, 10 and 17 are three major facilities located along the Delaware Aqueduct System in Westchester County. These facilities control water flow into the West Branch Reservoir at Shaft 9, out of the West Branch Reservoir at Shaft 10, and into the Kensico Reservoir at Shaft 17. The shaft structures, which were constructed in the 1940’s, have been in continuous operation since the installation of the mechanical equipment in the early 1950’s. Although the shafts still provide relatively reliable service, they clearly show their age, and they contain materials that pose a potential health risk. The goals of the project are to put the shafts in a condition to serve for many years into the future and comply with a consent order between the EPA, the NYSDOH and NYCDEP. 

Site modifications vary by location and are as follows: 
Shaft 9: Included replacing all existing sluice gates and operators; Remediate hazardous materials including lead paint, asbestos, mercury and PCBs; Install a mobile dechlorination feed facility including chemical unloading station; Construct a new water quality station; Replace un-watering pumps. Provide improved entrance road and parking area; Stabilize eroded embankment; Upgrade electrical and HVAC systems including back-up power; Shaft 10: Replace all existing sluice gates and operators; Remediate hazardous materials including lead paint, asbestos, mercury, and PCBs; Replace existing incremental valves and piping; Replace existing manually cleaned screens with mechanically cleaned screens. Install a new chlorination feed system in a building addition; Install a chlorine gas scrubber; Replace all un-watering and sump pumps ; Replace house water system, including a new separate potable water system; Construct a new water quality station. Provide improved entrance and parking area; Install a new emergency power generator in a dedicated structure; Dredge influent channel of sediment; Upgrade electrical and HVAC systems; Shaft 17: Replace all existing sluice gates and operators; Remediate hazardous materials including lead paint, asbestos, mercury and PCBs; Replace chemical feed and storage facilities, including chemical unloading stations; Replace all un-watering and sewage pumps; Install a new water quality station; Install a separate potable water system; Replace the flat roof over the Operator Building; Install an emergency power generator in a dedicated structure; Provide improved entrance and parking area; Upgrade electrical and HVAC systems; Stabilize eroded embankment.