Thanks to diligent research by city officials into an increasingly popular no-dig water main rehabilitation solution using cured-in-place piping (CIPP), and their successful experience with recent projects that have been completed on time and on budget, it is most likely to continue to be used as a tool to rehabilitate water mains.
What exactly is no-dig or trenchless rehabilitation with CIPP? To briefly explain and understand why this approach is becoming more the norm than traditional methods when rehabilitating failing water mains, consider these features and benefits:
Minimally invasive ? small access pits are excavated instead of trenches.
In areas where water mains are located under buildings, parks, trees, etc., robots and special relining processes do the work within existing pipes.
Less disruptive ? citizens and building owners experience minor water service interruptions. Traffic can also move freely.
In all but the most extreme cases, projects are completed on time, much quicker than full replacement and within budget limitations. There are also options to save even more money with CIPP technologies if the town or city wants to use its own workers to undertake certain tasks.
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Team efforts between, Sanexen Aqua-Pipe (Montreal, Canada), patent-holders of special CIPP technology, and Fer-Pal Infrastructure (Taylor, Mich.), one of many Sanexen licensees, are two firms that stand out in this area. They are steadily becoming acknowledged and used in Columbus and elsewhere as firms that offer advanced technology to give new life to water mains throughout the U.S. and Canada. This work has been performed at hundreds of sites, offering greatly reduced costs as compared to digging trenches and replacing old pipe.
According to Timothy E. Huffman, P.E., project engineer with the City of Columbus Public Utilities Division of Water, Water Distribution Design Group, ?Columbus now has yet another ?tool in our toolbox? to combat leaking, deteriorating or tuberculating water mains. That tool employs a no dig approach combined with cured-in-place pipe (CIPP), giving our water mains at least another 50 years of useful life.?
Huffman notes he and other colleagues learned about CIPP at a No Dig show, and after putting out for bids, hired Sanexen Aqua-Pipe/Fer-Pal Infrastructure to structurally enhance and reline two water mains, one 3,000 ft and another 4,600 ft. Based on the success of these projects, which were completed on time and within budget, a third and much larger project was put out to tender early in 2013.
Fer-Pal Infrastructure, using CIPP technologies from Sanexen Aqua-Pipe, took on the 12,640-ft project in a 300-plus home residential neighborhood that saw its share of water main breaks to its 6-in. cast iron pipe. Residents were used to frequent disruptions. Rehabilitation this time, however, promised to be different. Here?s what took place after city officials and Fer-Pal personnel located the pipe:
- Temporary water bypass was installed with hoses hooked up to each home and business.
- Access pits were dug at each end of the lining sections.
- Special equipment was then used to clean the pipe. This was followed up by an inspection of the pipe and plugging the service connections.
- The unique Sanexen Aqua-Pipe liner was installed and cured to form a structurally strong inner pipe.
- A hydrostatic pressure test was undertaken to confirm water tightness.
- Service connections were reinstated from inside the pipe.
- The new structurally enhanced pipe with the new liner was disinfected to AWWA C651 standards.
- The site was restored.
Huffman emphasized that city officials made it a point to bolster its staff to not only monitor progress to learn about the technology, but also to remain close to residents to minimize and address any problems or complaints they had. He readily admits that the lower costs versus other rehabilitation methods enabled the city to realize a savings of 17 to 20 percent. Even more savings on future water main rehabilitation projects are expected.?
Naturally, the relatively small access pits had to be restored and paved over. But, as compared to having to re-pave over the long trenches needed for other methods, the disturbance was minimal, according to the Columbus project engineer.? While not a factor in these projects, water mains that go underneath or through parks, forests, creek crossings, easements or railway crossings can be easily renewed with CIPP technology as well.
During the Columbus projects, city officials organized special jobsite visits so that officials from neighboring cities and towns could view and experience the CIPP technology at work. Sanexen Aqua-Pipe and Fer-Pal Infrastructure are now working with representatives of these towns and cities to undertake projects or programs for them.
Beno?t C?t? is vice president of Sanexen Aqua-Pipe.?
