Environmental Services has begun construction for an inner southeast Portland repair of a deep interceptor sewer line that is deteriorating due to age. The repairs will extend the life of the sewer and protect public health, water quality and the environment. The city built the large-diameter Southeast Interceptor in 1954. It runs parallel to the Willamette River under inner southeast neighborhoods and is between 5 to 6 feet wide and 25 to 54 feet below the surface. Two segments of the Southeast Interceptor require repairs (see map below).
The south segment starts at SE 16th Avenue and SE Pershing Street in the Brooklyn neighborhood. The line follows SE 16th Avenue north to SE Powell Boulevard, continues north along SE 14th Avenue to SE Gideon Street, and travels northwest on SE Gideon Street to SE 11th Avenue. After a short distance on SE 11th Avenue, the line follows the railroad tracks to a point just west of the intersection of SE Division Place and SE Division Street. From there, it follows SE Division Street to the northwest. The south segment ends at SE Division Street and SE Grand Avenue.
The north segment starts at the intersection of SE Grand Avenue and SE Stark Street, follows SE Grand Avenue north to NE Davis Street, and then extends from NE Davis Street west to NE 3rd Avenue.
Construction began in July 2017 and will continue for up to a year.
For traffic safety and to minimize traffic congestion, the city will do night work in the northern project work zones. The city will do daytime work in the southern project work zones. See map for details.
Portland noise code allows construction from 7 a.m. to 6 p.m. Monday through Saturday. Work after 6 p.m. and before 7 a.m. and all hours on Sundays requires a noise variance from the Portland Noise Office. Because construction crews will work past 6 p.m. and on weekends at some locations in this project, Environmental Services applied for and was granted a Noise Variance.
The city's contractor will repair approximately 7,400 feet of the deep and large-diameter Southeast Interceptor sewer line. Crews will access the sewer from manholes along the Interceptor as illustrated on the project map. Crews will drill small holes through the sewer pipe walls and then pump cement grout through the holes to fill voids outside the pipe that have developed over time. This will also stop infiltration leaks that have allowed groundwater to seep into the sewer pipe.
Using equipment that will be contained on a 40-foot semi-tractor trailer, crews will mix the cement grout and then pump it through hoses running down into the sewer pipe and through the small holes they drilled into the pipe walls. This process will require ventilation of the sewer pipe system to provide air supply to crews working inside the pipe.
There will be some around-the-clock, 24/7 pumping of sewage and stormwater. This work will be almost entirely contained within the sewer system below the street surface.
Noise reduction equipment will be used to reduce the noise of the standard generator mounted on a small trailer in the work zone. The generator will sound similar to the noise of standard traffic, a normal conversation, or a power tooth brush. Note that the noise comparisons mentioned above are based on noise measurements taken next to the generator. Noise dissipates quickly with distance, so most adjacent properties should not be disturbed by the generator noise.
Additional noise mitigation measures will further reduce noise from the generator and the vactor truck used to clean the pipes.