NEW YORK — The New York City Department of Environmental Protection (DEP) completed a $700,000 project to repair a 14-inch water main that runs under the East River near East 111th street in Manhattan. The restoration and reopening of this distribution line restores service to a critical water main connecting Manhattan to Ward’s and Randall’s Islands, and providing water to the Ward’s Island Wastewater Treatment Plant, various sports fields, maintenance facilities, and office buildings. The underwater repair began in late January and required a specialized crew, which included two underwater divers. Workers removed a 16-foot section of cast iron pipe and replaced it with a ductile conduit.
“DEP repairs water mains under streets frequently but this project was unique, involving a nearly century old pipe buried 21 feet below the East River,” said Commissioner Carter Strickland. “The skill, experience, and expertise required to investigate the unusual situation and make a repair like this are remarkable.”
The water main was first installed in 1927 and has been disconnected since September 2012, when a New York City Park’s Department contractor reported unusual swirling and bubbling along the surface of the East River close to East 111th Street. A DEP investigation, which included feeding a video camera through the main, revealed a 15-inch long by 4-inch wide hole in the 14-inch cast iron pipe, which was buried 21 feet beneath the river bed.
Due to murky water conditions which limited visibility, divers excavated and repaired the water main primarily by touch, communicating with crews at the surface using radios in their scuba masks. The repair also required specialized power tools designed to work underwater and the use of turbidity curtains that help to contain debris to avoid disturbances to the surrounding water and marine life. Special shoring was also constructed around the excavation site to protect the divers working on the main. In addition, to ensure the divers remained warm in the 40-degree river water, heated water was continuously pumped into their wetsuits.
After the 16-foot section of the water main was replaced, workers pressurized the pipe and performed a final video inspection to check for leaks. The excavated material was then backfilled into the site, burying the pipe.