New York City Department of Environmental Protection (DEP) in the US has announced plans for a US$1.2bn (£906M) water tunnel.
The 3.2km tunnel, between Kensico Reservoir and the Catskill-Delaware ultraviolet light disinfection facility in Eastview, will improve operational flexibility to provide drinking water more than 9M people in New York City and Westchester County.
The Kensico-Eastview Connection (KEC) project will include construction of the new tunnel, facilities to draw water from Kensico Reservoir and move water into the ultraviolet plant, and other infrastructure work.
The 3.2km tunnel will start from an intake chamber on the western side of Kensico Reservoir to a connection point at the ultraviolet disinfection facility. When complete the 8.2m diameter tunnel will run 121m to 152m below ground, and be large enough to carry a maximum of 9.8bn litres of water each day.
DEP commissioner Vincent Sapienza said: “The Kensico-Eastview Connection is a critical investment in the long-term resiliency of New York City’s water supply system. By providing an additional connection between Kensico Reservoir and our treatment facilities to the south, this new tunnel will further guarantee the reliable delivery of water to New York City and population centres in Westchester County, including New Rochelle, White Plains and Yonkers. We look forward to working with our neighbours in Westchester County to ensure that the City’s waterworks continue to supply high-quality drinking water to more than 9.6M New Yorkers every day.”
The project also includes new facilities and site work at Kensico Reservoir and the ultraviolet treatment plant. A century-old intake chamber at Kensico Reservoir will be upgraded and enlarged to draw water into the new tunnel, whilst the reservoir’s shoreline around that intake chamber will also be improved to prevent sediment from getting into the new tunnel.
A new screen chamber to remove debris from the water will be constructed and an interconnection for the Town of Mount Pleasant water supply will also be incorporated into the screen chamber. The chemical feed systems at Kensico Reservoir will be upgraded to provide the proper treatment of drinking water in the new tunnel and existing ones, and work at Kensico Reservoir will also include a range of grading, drainage, stormwater and utility improvements.
In addition to the work at Kensico Reservoir, DEP will also build a connection chamber at the ultraviolet plant to receive water from the new tunnel. The chamber will connect to a number of existing pipes at the ultraviolet facility that were installed at the time of its construction. Work at this site will also include a number of projects related to drainage, stormwater and utility improvements.
In 2017, DEP collected soil and bedrock samples from the area to support the design of the project, which has already begun. Construction on the first portions of the KEC project are expected to start in approximately five years, with work on the tunnel itself is expected to begin around 2025. The DEP expects to finish the project around 2035.