CIPP Used to Rehabilitate 80-In. Diameter Storm Pipe in Massachusetts
November 15, 2012
When one of the country’s leading oil companies was having issues with a leaking storm pipe at one of its inactive depots, the use of trenchless technology — specifically cured-in-place pipe (CIPP) — was key to its rehabilitation. US Sewer & Drain, based in Philadelphia, was brought in to help solve the problem. The pipe in question was at a depot that was once used for loading and unloading oil carriers along the Taunton River in Fall River, Mass. An existing 80-in. diameter brick storm pipe was constructed in the early 1930s, prior to the existence of the oil depot.
According to Jeremy Bowman, president of U.S. Sewer and Drain, this pipe would ultimately serve as a collection pipe for a large part of the small town’s streets and lead out to the river. He said that over the years, oil had been penetrating the pipe, ultimately leaking into the river. Needless-to-say, neither the small town of Fall River nor the Department of Environmental Protection were happy with the situation. Once it was recognized as a real environmental problem, the oil company hired US Sewer & Drain to work along with its top engineers to come up with a solution.
Due to the age of the pipe and uncertainty of the stability, safety was the No. 1 concern of the oil company, Bowman said. “Not only would US Sewer & Drain need to focus on a plan to line the pipe, but equally devise a strategy to work safely and up to the standards of the client,” Bowman said, with US Sewer & Drain’s health and safety adviser working with the oil company to make it happen.
A plan was devised to install 800 ft of 80-in. diameter using CIPP, along with a “pre liner” to contain any oil. A thick PVC membrane would be installed prior to the CIPP liner, creating a barrier between the host pipe and liner and allowing the resins to take hold of the host pipe while going through the curing process.
Project Challenges
There was only one small problem with this plan, Bowman said — The existing manholes were only 28 in. in diameter, coming up to grade level. “Talk about trying to fit a square peg in a round hole or in this case 80 in. of lining material through a 28-in. opening,” he said.
Bowman said his crew would have to create a larger manhole for the liner to be pulled into so they excavated the structure to the base of the host pipe and added a 48-in. manhole ring. “This gave us the room we needed to install the 80-in. liner and even with that, it was still very tight and challenging to pull the liner through it,” he said.
Another issue that the US Sewer & Drain crew had to contend with was the tide from the Taunton River; the tide would need to be isolated during the installation period. Using a track hoe, the crew constructed a 15-ft wide, 10-ft high wooden dam at the outfall of the pipe, effectively cutting off the tide from entering the pipe.
Construction of the watertight barrier, as well as a series of pumps, resulted in the water being ultimately contained, allowing the US Sewer & Drain crew to begin installing the liner.
“Constructing that barricade was a feat in itself,” Bowman said, noting that after its construction, sandbags were positioned and the pipe was dewatered.
In order to ensure there was enough time to introduce the resin into the lining material, a refrigerated tent was erected over the loading device at the upstream manhole 800 ft away from the outfall. Once the large pipe was cleaned of all debris and televised, the crew was ready pump some 80,000 lbs of resin into the enormous 80-in. liner. A 20-ton crane was also used to assist the lifting of the material. At the end of the week, the liner was successfully installed by the 10-member crew.
The project was completed over a two-week period and oil company officials were more than pleased with the results, Bowman said.
Sharon M. Bueno is managing editor of Trenchless Technology.
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