To enhance the resiliency and redundancy of New York City’s water supply system, the New York City Department of Environmental Protection (NYCDEP) is creating a 2-mile tunnel linking two important facilities in Westchester County: the Kensico Reservoir and the Catskill/Delaware Ultraviolet (CDUV) Facility. When finished, the tunnel will additionally allow other facilities to be periodically taken out of service for maintenance.

EnTech provided environmental consulting services for the project. As part of the CEQR process, the firm performed a Phase I ESA, Phase II ESA, and hazardous materials investigation. Major components of the project include a 2,400-mgd tunnel, two tunnel shafts, a new screen chamber, modifications to the upper effluent chamber (UEC) at Kensico Reservoir to increase hydraulic capacity, and shoreline stabilization at the reservoir.

The Phase I ESA spanned from the Kensico Reservoir to the CDUV site. It included an investigation of 21.5 acres of forested land on the Kensico site, and 31.5 acres of heavily vegetated land on the CDUV site. The firm led a Phase II ESA comprised of a field sampling investigation at proposed boring locations. The firm performed hazardous materials sampling, risk and permit management, and generated technical reports.