Environmental Services is constructing a project to repair approximately 6,800 linear feet, over one mile, of public sewer pipes in downtown Portland. These pipes are 50 to 140 years old, in deteriorating condition, and are showing signs of cracks, breaks, holes, offset pipe connections, and root and grease obstructions. The project will also repair or replace 29 manholes. These improvements will protect the public and the environment by reducing the possibility of sewage releases to buildings and streets.
The Project is in the Portland State University (PSU) area and is generally bounded by SW Mill Street to the north, I-405 to the south, SW 16th Avenue to the west, and SW Harbor Drive to the east. The project also includes work on W Burnside and SW Columbia streets.
Pre-construction activities began in February 2019. Major pipe repairs began in late spring when weather is more conducive to pipe lining work. The project is expected to be completed by June 2020.
Approved Night Work
The Portland Noise Office granted Environmental Services a Noise Variance to enable the city’s contractors to work both days and nights. Daytime construction hours are from 7 a.m. to 6 p.m. Monday through Friday, and Saturdays as needed. Nighttime construction hours are from 6 p.m. to 7 a.m. Monday through Saturday. Night work reduces traffic congestion, creates a safer work zone, and allows sufficient time for a new sewer pipe lining to harden.
Equipment that generates noise will include sewer cleaning trucks, compressors, light tower trucks, generators, pumps, and ventilation fans.
The city uses many construction methods to repair or replace sewer pipes. For this project, the city plans to use Cured-in-Place-Pipe Lining (CIPP) and Open Trench Excavation. To learn more about each of these construction methods and view photos from previous projects, go to www.portlandoregon.gov/bes/methods.
During CIPP, crews work from a manhole to insert a flexible liner inside the old pipe. Crews then inflate the liner and use hot water, steam, or ultraviolet light to cure the liner, forming a rigid, smooth surface that seals cracks and restores the pipe to near-new condition.
When heat (steam) is used to cure or harden the liner during CIPP, people who are nearby may smell an odor that is often described as being similar to plastic or glue. The odor is from the chemical styrene, which is in the resin of the liner. The resin is the part of the liner that reacts with heat and hardens.
While unpleasant for some, the amount of airborne styrene generated by the CIPP process is not a health risk at the levels observed by the City of Portland and tested and monitored by an independent industrial hygienist. The odor dissipates quickly once the process is complete.
Phases and Duration of CIPP Work
The CIPP sewer pipe lining process occurs in phases:
- One day to inspect pipe conditions to confirm construction methods
- One day to remove roots from the pipe and clean the pipe
- One day or night to set up the bypass service that provides uninterrupted sewer service
- One day or night to line the sewer pipe and cure the lining so it hardens in place
- One day or night to reinstate the service lateral connections and remove the bypass system
What to Expect during Construction
You can expect the following activities and impacts during construction:
- Work Hours: Crews will work both days and nights, with the pipe lining and curing process occurring at night.
- Phases of Work: Businesses and residents should expect periods of inactivity between phases of work.
- Traffic Delays: Expect traffic delays in and near the work area.
- Temporary Street Closures: Street closures may be required for manhole access and the sewer bypass pumping system. Where needed, local access will be provided by flaggers.
- Driveway Access: Construction may temporarily block your driveway when crews are working in front of your property.
- No Parking: Little or no on-street parking will be allowed in and near work zones, especially during work hours.
- Equipment Storage: Equipment and materials may be stored on streets overnight.
- Services Maintained: Sewer, water, and other utilities are expected to remain in service during construction.