SEWER LATERAL REHABILITATION
PROJECT NAME: SANITARY SEWER LATERAL REHABILITATION (EXCAVATION REPAIRS AND LINING)
LOCATION: VARIOUS ADDRESSES ACROSS THE CITY OF OTTAWA
OWNER: CITY OF OTTAWA
START DATE: MARCH 2009

The project was the City of Ottawa’s first contract calling for the CIPP rehabilitation of residential sewer laterals while also requiring spot repair excavations prior to lining.

Fifty addresses were selected by the City of Ottawa for this contract. Due to breaks and sumps, the sewer laterals could not be rehabilitated by CIPP without a prior spot repair excavation. Similarly, these laterals could not be repaired entirely by conventional trenching excavation methods for a number of reasons including the presence of trees. The City of Ottawa outlined specific requirements for each address in order to minimize inconveniences to the individual homeowners, and to minimize site disruptions and damages to surrounding trees and the surrounding environment, while at the same time minimizing overall costs.

In one instance, the sewer lateral ran under a cement porch, then under grass and under a large city tree before reaching the City main. There was a break in the pipe beneath the grass, including the presence of a highly invasive network of roots. There were cracks and fractures at various locations along the length of the pipe. The solution was to excavate and repair the break, and then install a CIPP liner over the entire length of pipe from the cleanout to the City main. In this case excavation was required because the liner could not be installed through the broken section, given that the stated obstacles could not be disturbed.

CWW engaged the services of a sub-contractor for the excavation portion of the project. The work was coordinated by CWW and involved first inspecting the pipe, locating the section of sewer that required excavation, spot repair, landscaping reinstatements, the rehabilitation by CIPP, and the final video inspection.

SEWER LATERAL REHABILITATION
PROJECT NAME: 2008 TRENCHLESS SERVICE REHABILITATION
LOCATION: VARIOUS ADDRESSES ACROSS THE CITY OF OTTAWA
OWNER: CITY OF OTTAWA
START DATE: JUNE 2008

This project consisted of the CIPP rehabilitation of approximately 600 residential sewer laterals from the existing cleanout to the City main. The full length of over 9,000m of sewer first had to be televised, cleaned, and prepped before the liner installation.

The most common defect in lateral sewers is the presence of roots, which can easily be removed by using our 15,000-psi high-pressure water unit. When further investigation of the lateral was required, CWW depended on its LAMP (Lateral and Mainline Probe) camera, which provides total inspection of the lateral from the main sewer.

CWW uses a felt liner impregnated with epoxy resin, which is then inverted with air and cured with hot water. The rehabilitation of sewer laterals by CIPP is a prudent and cost-effective alternative to the conventional dig-and-replace method, as costs associated with the reinstatement of existing landscaping, trees, utilities and roadways is eliminated. Further, our experienced technicians often complete the entire CIPP process in less than 5 hours.

CWW reinstated weeping tile connections internally through the use of a robotic cutter. It is also important to note that the CIPP process remains unaffected by colder weather, which is another significant advantage over traditional excavation methods.