The deterioration of the South Street interceptor sewer near the Port of South Street Sea, in the Manhattan financial district, had all the facilities in a mess.
Located almost 30 feet below the occupied road, which is based on the viaduct of Driving FDR, the 60 -year concrete walls of the almost 1,000 feet of Longi infiltration from the river is adjacent, increasing the risk of overflow. Although rehabilitation was desperately needed, the New York City Design and Construction Department acknowledged that the complexities of such a large project would only increase the inherent inherent effects of a conventional opening of open Trinxes repair.
The infiltration was controlled and inspected for leaks for five consecutive days before the workers proceeded to install the spiral presentation coating above this section in the interceptor sewer.
Photo of Yor/JWP, courtesy the New York Design and Construction Department
“It would be noisy and dangerous and would require closing the street for months, if not years,” says Iyad Marzouq, the director of the Infrastructure Agency. “Design should also consider the foundations of Unit FDR, any number of adjacent utility lines and other factors.”
Marzouq adds that the deactivation of the interceptor for an prolonged period would require a temporary Bypass system to provide a pumping to the 40 million gallons series, adding at least $ 12 million to the global cost of the project.
At the end of 2024, however, few people who lived or led through the neighborhood probably realized that the rehabilitation project of almost $ 29 million was taking place under their feet and was on the way to finish, which is expected This year.
The workers installed uniform coating material on the interceptor sewer and successfully aligned the repair of infiltration, completing almost 350 feet of uniform sewerage.
Photo of Yor/JWP, courtesy the New York Design and Construction Department
The key is the decision of the city to use an innovative method of trenches called a spiral wound lining, in which a continuous strip of polyvinil chloride (PVC) is mechanically rolling through a pipeline to form a uniform coating. A cement league is then pumped into the empty space between the new rounded coating and the existing rectangular sewerage structure.
The spiral wound coating was one of the various alternatives of repair and resignation to the department that he had carefully evaluated for several years to address the many interceptor problems. Unlike other non -trenched methods that would have a significantly reduced interceptor capacity, the spiral wound coating process can occur in humid conditions through submersible equipment adapted to the pipeline configuration. This allows the interceptor to remain in service during the construction.
David Beesley, vice president and projects manager of the contractor Coppola Services, Ridgewood, NJ, says that Flow Velocity is the critical factor. “Whenever the speeds are between 1 and 2 feet per second, we can work safely at flow levels up to 18 to 24 inches,” he says.
To help ensure optimum working conditions, Coppola’s scheduled work for hours during the night when flowing levels are usually lower, installing a 30-line-pepper-made partial Bypass line to temporarily redirect 17 , 6 million gallons of Interceptor Flow Day Line While Working.
After each turn, the coating equipment would be deactivated and the interceptor returned to the entire capacity. “Some nights, the level would be as low as 6 inches,” says Beesley.
As the South Street interceptor would be different from the previous spiral wound lining projects, Coppola was prepared for the work through a mockup of the interceptor that was built in the yard of the company’s team. .
“We had not made a mockery of this ladder before, but we wanted to be ready for what we would meet in South Street,” says Beesley.
The team resolved the problem of wall construction in narrow conditions, digging or screaming at the existing host interceptor sewer pipe in about 1.5 inches.
Photo of Yor/JWP, courtesy the New York Design and Construction Department
Raising problems
Even with extensive preparation, the South Street Interceptor project did not mean surprises: including a ten -month permission and coordination process of permit and coordination that also required the approval of the city’s environmental protection department, which operates the Sewing system. The construction finally began by the beginning of 2024 with the partial Bypass connection. In May, Coppola was ready to start making work five nights a week, with a goal of promising about 20 linear feet per shift.
“In some nights, we would get the production we expected, but in others, only a fraction,” says Beesley, quoting remains of the flows of the normal period of the line as a constant challenge. “Things are built so quickly, especially because of the machine’s position,” he says. “Maintaining the clean team was longer than we expect.”
Time has been another concern. The added rainwater of heavy rains has sometimes cost the team or part of a turn. Coppola also encountered unforeseen changes in the size of the interceptor due to the aging irregular material and the accumulation of sediments that required workers to eliminate the concrete of the walls and the ceiling so that the coating machinery could pass.
The project near the South Street Seaport, in the lower part of Manhattan, involves the first use of the spiral lining city that allows the team to fix a major sewer leakage without excavating a trench.
Image courtesy the New York Design and Construction Department
While the Coppola team adapted to the conditions and made progress by installing the coating, the most significant problem of the project was waiting at about 300 feet: a 3-in. by 8 in. The wall cavity that published up to 100 gallons of water from the East river every minute to the sewer.
Marzouq says that the leak, who was the main catalyst for the project, repeatedly challenged the team’s attempts to solve. “It was like applying a bandage,” he says. “Because there was so much pressure on the river, everything we tried to seemed to fail in a few days.”
After four months of trial and error, the department says that the cavity was finally sealed by a combination of hydrophobic material and resins activated by expandable humidity. They were then covered with hydraulic cement and wire mesh. The final step, making a 96 in. x 43-in. The aluminum metal plate on the interceptor wall was completed long before the Coppola coating machine arrived.
“Filtration did not delay this part of the work,” says Beesley, who adds that the repair approach will probably be used again for another infiltration leak below.
Installing the coating of the spiral wings involves using a waterproof machine, built in the sewer, to create a new structure within the existing one.
Image courtesy the New York Design and Construction Department
Gaining impulse
At the end of 2024, Coppola approached the point at the middle of the coating installation and had begun work. Plans ask that the remaining interceptor section coat is complete this summer.
So far, the department is satisfied with the operation of the spiral wound lining. Marzouq sees other potential applications for more underground infrastructure rehabilitation projects in the city where an open approach would be problematic. “The project provides many lessons that should help things move faster in the future,” he says.
“There is no way to do a project like this with a conventional method,” adds Beesley, noting that the project team found a series of public services to simply excavate 20 inches to install the Bypass line.
“At least we could cover this cut with dishes and keep the street open,” he says. “To go 30 meters underground throughout the length of the project would require a mass excavation and cannot be said what you would find along the way.”
