For the last two years, Pasco, Washington, has had to deal with a recurring water main problem that, according to Trenchless Technology online, involved a leaking 12-inch water pipe located under an active railway intersection on the southeast side of the city. But no longer, a liner has made the entire pipeline completely functional and in just two days.
In 2007, the system had to be rerouted because traditional open-cut methods of construction were impossible. This was due to the continual traffic and the importance of the railway switching yard. Moreover, three of the rails crossed the Columbia River as one of the few bridges providing access to the south of Pasco.
Engineers solved the problem by using cured in place pipe liner (CIPP) technology. First, they divided the project itself into two sections measuring approximately 275 feet each. Then they used a pressure vessel to invert the tube and cure it with steam to a statically self-supporting pipe. Each installation took 12 hours and technicians used seals to join the liner to the existing ductile iron pipe. Shortly thereafter, the pipe went back into service.
Everything went off without a hitch. The only excavation necessary for the entire project involved digging access ways to the pipe on each side of the rail crossing. Better still, no rail traffic was affected by the tailor-made pipelining. This meant business as usual with no financial loss whatsoever.
Money–in particular, the lack of it–is a big issue for cities everywhere. So is decaying infrastructure. Pipe rehabilitation is the answer, but only if it can be done without diminishing the coffers of businesses, homeowners and city governments. Trenchless pipe repair covers all these fronts with ease: it’s the answer for the engineering challenges of a new age.



