Ensuring High-Quality Drinking Water for Staten Island

摘要

In New York, the single tunnel replacement of two siphons from Brooklyn to a pump station on Staten Island feeds into Staten Island's Silver Lake Reservoir. The tunnel is critical to ensuring a backup water supply to Staten Island. The new 12.5-ft-dia, 9,500-ft-long tunnel located in the Upper New York Harbor provides 5 million gallons per day (MGD) of daily water supply between Brooklyn and Staten Island under normal conditions. In emergency situations, up to 150 MGD can be supplied, thus ensuring a redundant and reliable supply of water to Staten Island residents. The new tunnel extends through silts, clays, glacial soils, and weathered and decomposed rock. Upon completion, a 72-ft-dia steel water transmission pipeline was installed. To connect the new siphon to the existing water supply system, an additional 4,000 ft of steel trunk main and 4,000 ft of transmission main was installed in the adjacent mainland area. The work in Staten Island included a 330-ft-long micro-tunnel and a 170-ft-long micro-tunnel below the active Staten Island Railroad tracks, which was installed with the use of a pressurized-face micro-tunnel boring machine.