Cured-in-Place-Pipe Lining (CIPP) is a trenchless method of sewer construction. It requires little or no digging and significantly less time to complete than other sewer repair methods. It is suitable for repairing both short and long runs of pipes that do not need to be upsized. CIPP involves inserting a flexible liner inside the existing pipe, inflating the liner, and exposing it to heat or ultraviolet light to "cure," or harden, the liner inside the pipe. The liner essentially forms a smooth surface inside the existing pipe, restoring it to near-new condition.
The work involves the following steps:
Remove roots from the pipe and flush debris from the pipe
- Set up a sewer bypass system, if necessary, to re-route wastewater to other nearby pipes during the pipe lining process
- Set up and run a vactor truck, or sewer vacuum, to keep the pipe free of debris and water during pipe lining process
- Insert liner into the sewer pipe from the surface through a manhole
- Expose the liner to heat or ultraviolet light to cure, or harden, the liner inside the pipe
- Open and reinstate sewer service lateral connections that were covered by the pipe lining
- Remove the bypass system, if any
- Conduct quality control inspections
Limit Water Use During CIPP
For single-family homes where crews will be repairing sewer pipe using CIPP, residents will be asked to limit use of appliances that use large amounts of water—like showers, baths, washing machines, and dishwashers—and to turn off all sump pumps connected to the sewer line. This is because private property connections to the public sewer will be temporarily sealed off during the pipe lining process. Using less water is necessary to prevent water from filling up a private sewer line and backing up into a home during the pipe lining process. Residents may, however, wash their hands and flush their toilets. Residents may resume normal water use after the pipe lining process is complete and crews have left the work zone.
Unpleasant Odors and How to Prevent Them
During the pipe lining process, residents may smell an odor like plastic or glue. This will dissipate quickly once the process is complete. The odor is from chemicals in the liner resin. The amounts detected by an independent industrial hygienist are below health risk levels.
To keep resin odors from entering a home or business through the private sewer line, fill any floor drains and infrequently used sinks with a small amount of water. This water will collect in the bend in the drain, called a "P-trap," and block odors from the sewer.
If a resin odor is already in a home or business, cover basement floor drains and open windows to allow ventilation. If the odor continues, phone or email the contacts provided on the contractor's construction notice, or call Environmental Services at 503-865-4300 and leave a message with the address, project name, and name and phone number for follow-up.