Project of the Year – Rehabilitation
Newark (N.J.) 108-in. CIPP
The City of Newark, N.J., is in the middle of a long-term program to bring its vast network of aging brick sewers up to acceptable structural standards. Construction of Newark’s brick sewers, which comprise 68 miles of the City’s 410-mile collection system, began in the mid-1800s, with the oldest sections in service for approximately 150 years. These brick sewers include a range of sizes from 20 to 120 in. in round, egg-shaped, horseshoe and elliptical shapes.
Phase III/IV included the CIPP lining of a 400-ft sectionof 108-in. diameter pipe, the largest CIPP installation
completed in the United States.
In the 1980s, the City recognized that a comprehensive evaluation and rehabilitation program was needed to reduce the potential for blockages and road collapses. The program was established in five phases. Phase I was initiated in 1990 with the evaluation of 13.3 miles of sewer. Phase II was conducted in 1993-94 with the inspection of an additional 14.4 miles. These first two phases resulted in the rehabilitation of approximately 10 miles of sewer at a cost of $24 million.
Phase III/IV, which began in 1997 and is currently in the final stages, involved the inspection of 21.3 miles of existing brick sewer, nearly 12 miles of which were targeted for rehabilitation. This phase included the cured-in-place pipe (CIPP) lining of a 400-ft section of 108-in. diameter pipe, the largest CIPP installation completed in the United States. As a result of the successful completion of this challenging project, it has been selected as Trenchless Technology’s Project of the Year-Rehabilitation for 2004.
Phase III/IV Background
For Phase III/IV, the City contracted the services of CDM, Edison, N.J., as its primary consultant. The entire program included a detailed structural evaluation and prioritization of the sewers using defect codings based on WRc standards.
CDM created a geographic information system (GIS) database and utilized a five-tier priority rating system, with Priority 1 used to designate sewer segments that appeared to be in the worst structural condition and Priority 5 designating sewers that were in good overall condition.
The 12 miles of sewer designated for repair under Phase III/IV were divided into 14 separate construction projects, spread over three years. For the larger pipe, the City and CDM solicited bids based on CIPP and fiberglass-reinforced plastic lining methods to ensure the most economical structural rehabilitation was obtained. To date, 13 of the 14 contracts have been awarded (12 complete) with all of them utilizing CIPP.
Large Diameter Lining
The most technically challenging project of Phase III/IV was the lining of a 400-ft stretch of 108-in. sewer located off Dr. Martin Luther King Jr. Boulevard, north of Interstate 280. The sewer, which runs underneath the parking area of an apartment complex, needed a structural solution to repair an area where the crown of the brick sewer was subsiding. The depression — the origins of which are unknown — caused the 108-in. circular sewer to deform to 94 in. high by 120 in. wide.
Like the other projects in Phase III/IV, this repair was bid allowing multiple technologies, but the contractor, Spiniello Companies, Fairfield, N.J., opted for CIPP. In this case, CIPP was not only more economical, but it also allowed for a liner that fit closely to the pipe to ensure maximum capacity. CIPP’s ability to conform to the host pipe was also an ideal solution for the change of shape in the area of the depression.
The non-invasive nature of trenchless technologies was essential given the location. “One of the primary considerations for this contract was allowing the residents of the apartment complex to get to and from their homes,” said Rob Pennington, project manager for CDM’s Edison, N.J office.
The project required digging a 16-ft by 16-ft pit into which the 14-ft wide, 2.65-in. thick bag could be inverted. Because of the logistical problems presented by transporting a liner of this size replaced with 200,000 lbs of resin, the only feasible option for applying the resin was an over-the-hole wetout.
Because of the size of the line and the capacity of stormwater it was designed to carry, Spinello decided to wait until weather forecasts called for a five-day window of dry weather. Spiniello proceeded the week of June 23, 2003.
It took three days to wet out and invert the bag, a day to heat the resin to the proper temperature and another day to cool down before laterals could be reinstated.
Under the same contract, Spiniello lined an 86-ft stretch of 105-in. diameter sewer in July. This sewer is in a high-profile area at Park Place and Center Street in front of the New Jersey Performing Arts Center. CIPP allowed the project to be completed with minimal traffic disruption in this busy downtown location.
“By using CIPP, we were able to get the large jobs completed within a week vs. one or two months for open-cut,” Pennington said.
Under this same contract, Spiniello lined a 2,400-ft section of 76-in. by 64-in. sewer from a single manhole.
Future Work
The City and CDM are currently conducting Phase V of the brick sewer rehabilitation program, which consists of sewers not accessible during previous phases. The final phase of the program covers approximately 8.3 miles of pipe.
in a busy downtown location with minimal traffic disruption.
The successful completion of the large-diameter CIPP projects gives the City proven options for upcoming work. “As the technology has improved and our familiarity with CIPP increases, we feel that our limited funding can be effectively utilized in even larger installations,” said Alvin L. Zach, P.E., consultant to the City of Newark Water and Sewer Utility.
The large-scale CIPP projects also push the envelope for cured-in-place lining projects. “There were many people who said that pipes of this size couldn’t be lined — that they were too big,” said Sam Silva, project manager for Spiniello. “This shows that not only can they be done, but they can also be done cost-effectively.”
To ensure the integrity of the liner, samples were sent for lab analysis to test for flexural strength and modulus. In addition, inspectors in the field made sure the liner was tight and laterals were opened properly.
According to Zach, the cured-in-place piping met the critical criteria the City demanded. “Safety is crucial and the integrity of the sewer system is critical,” he said. “This provided a structural solution that would reduce the possibility of road collapse, as well as providing a conduit for wastewater that provides equal or increased flow capacity based on the improved hydraulics.”
And, perhaps more important, the projects have extended the service life of critical sewer infrastructure between 50 and 100 additional years.
“Although Newark is one of the oldest cities in America, the maintenance of our infrastructure — which will keep our renaissance moving — is vital for our future,” Mayor Sharpe James said.
Source: Trenchless Technology Int. Magazine, October 2004