The second phase of a project to repair a critically deteriorated sewer pipe off of South Glenburnie Road received approval from the New Bern Board of Aldermen this week.
During their June 27 meeting, the board authorized the city manager to execute a contract for Phase II of the Northwest Interceptor Rehabilitation Project. The work will repair approximately 2,000 linear feet of the gravity sewer outfall line located between South Glenburnie Road and Trappers Trail.
The line runs behind a wet, difficult to access area behind the Department of Transportation yard on South Glenburnie Road before coming out behind Trappers Trail.
According to City Engineer Jordan Hughes, hydrogen sulfide gas in the sewer system has deteriorated the section of 36-inch concrete pipe and compromised its structural integrity.
“This is a project we identified a need for quite a few years ago when we had a major sewer collapse along Glenburnie on the Northwest Interceptor,” Hughes told the board. “As part of repairing that we did some closed circuit TV work of the whole interceptor and found a lot of deteriorated concrete in the top of the pipelines.”
Hughes said Phase I of the project relined about 3,000 feet of the most critical section of the pipe and the city has continued to monitor the remaining sections. There has been one additional sewer collapse several years ago near the City of New Bern Water Treatment Plant on Glenburnie Drive that the city was able to repair, he noted.
According to Hughes, Phase II will line about 2,000 feet of 36 inch pipe through some of the hardest to reach sections. The project will use a Cured in Place Pipe (CIPP) lining system to establish a new pipe structure within the existing pipe without the need for excavation.
“These are areas that are deteriorated in very swampy areas and if we were to have a collapse in this portion of the pipeline it would be very difficult and very expensive to get in there and make the repairs,” Hughes said. “We want to try to get this portion of the project done and then continue to monitor before we pull the trigger on Phase III.”
The board approved a contract for Phase II work with Insituform Technologies of Chesterfield, Mo., which submitted the lowest bid of $1,244,166.60. Since the City of New Bern received a $230,000 grant for the project from the NC American Rescue Plan Act funds, the contract with Insituform was tentatively awarded contingent upon approval by the NC Department of Environmental Quality.
Hughes said the city will continue to seek grants and other funding sources to help offset the remainder of the cost for the project. He said the bidding process for the work had been especially difficult due to the nature of the work and the amount of ARPA funded projects available to contractors across the country.
“This is not an easy one, it’s a messy project and a difficult one,” he commented. “We had to bid it twice just to get the two bidders that we got and these prices are quite a bit higher than what we saw in Phase I, about twice what the estimate was from a couple of years ago.”
According to Hughes, Phase III of the Northwest Interceptor Rehabilitation Project will focus on approximately 3,500 linear feet of pipe that comes out of Trapper’s Trail and runs down Oaks Road to the Glenburnie Drive treatment plant.
“That portion of the pipeline is in the best condition of the entire run and it’s the easiest to access,” he said. “If we were to have a problem tomorrow morning on the Phase III section it would be a little easier to mobilize a crew there and make a repair.”
By Todd Wetherington, co-editor. Send an email with questions or comments.