Pipelining: Investing in the Future


Our sewer system in Saint Paul is aging rapidly, most of the system is at least 50 years old, and nearly half of it is 75-125 years old. Conventional "dig-and-replace" rehabilitation of failing and fragile sewer lines is very expensive, disruptive to property owners, cumbersome and labor intensive.

To maintain the integrity of our system and at the same time address the challenges inherent in sewer replacement, the Sewer Utility Division relies on a process that is known in the construction industry as cured-in-place pipe (CIPP) renewal. Cured-in-place pipe technology involves the use of a resin-coated polyester tube that is pulled through the existing pipe and is then cured with the use of steam or hot water. The curing forms a jointless, seamless pipe within a pipe. This process addresses broken and failing pipes, reduces infiltration and intrusion, results in minimal excavation and is environmentally friendly, making it much less expensive than the dig-and-replace method.

CIPP Project Index Maps