New technology used to replace sewer lines

The City of Charlottetown is spending $3 million to replace old sewer mains in two areas of the city.

Ottawa-based Clean Water Works is working in two neighbourhoods — Parkdale, which will cost $2.5 million, and Brighton, which will take the remaining $500,000.

The project is a sewer main relining project. Traditionally, this type of work would have been completed by digging up the old line and putting in a new line, but a city spokesperson says Clean Water Works uses trenchless technology. That means there is far less excavation work completed in the city’s streets.

The lines will be repaired by pulling a tube, similar to a sock filled with resin, through the old line.

“We will then inflate the tube and heat the resin, curing it in place,’’ the city spokesperson said in an email. “This creates a solid new pipe on the inside of the old pipe. A robot will then be sent down into the line and cut holes out where customer sewer laterals join into the sewer main.’’

The technology is known as curedin-place pipe (CIPP) lining. CIPP is a resin-saturated felt tube or robust sleeve composed of polyester that is inverted or pulled into aging and damaged sewer pipes. Typically, the CIPP lining tube is inserted into the damaged pipe with either air pressure or water pressure. Hot water or steam is then to cure the resin which then forms a solid, impregnable mass that lines the interior dimensions of a sewer pipe, taking the form of the pipe and providing a seamless, tightfitting and corrosion-resistant lining.