Over one-third of Portland’s 2,500 miles of sewer pipes are more than 80 years old. Projects to replace or repair aging sewers are important for protecting water quality, public health, and the environment.
Environmental Services often uses a sewer repair technique called cured-in-place pipe-lining (CIPP) to repair aging sewers.
Cured-in-place pipe-lining doesn’t require digging a trench. Work crews access the sewer from manholes to insert a flexible liner inside the old pipe. Hot water or steam inflates and cures the liner, which gradually hardens to form a rigid, smooth surface that seals cracks and restores the pipe to near-new condition.
People who live and work near a CIPP repair project can sometimes smell a chemical odor during the pipe-lining work. The odor is from the chemical styrene, which is in the resin liner installed inside the pipe. The odor dissipates quickly once the installation process is complete. The amount of airborne styrene the repair process produces is not a human health risk.
This short animated film shows how the CIPP process works.
More Styrene Information Online
- United States Department of Labor
- Environmental Protection Agency
- Centers for Disease Control and Prevention
- Styrene Forum
- Styrene Material Safety Data Sheet