Environmental Services has started construction on a project to replace a cracked and deteriorating 24-inch sewer pipe built in 1929 underneath SW Capitol Highway and Terwilliger Boulevard. The project will take up to five months to complete.
Noise Variance and Night Work
The Portland Noise Office granted Environmental Services a noise variance for construction on this project after normal work hours. Because of high daytime traffic volumes on SW Capitol Highway and Terwilliger Boulevard, there may be some overnight construction. The noise variance allows up to seven days of night work at SW Vincent and Terwilliger and up to 14 days of night work at SW Capitol Highway and Terwilliger.
The contractor will install a temporary sewage diversion pipe under SW Terwilliger Boulevard and two nearby pedestrian trails. A pump with a generator will operate around the clock for up to 60 days to move sewage around the construction area.
Restoring Native Plants
Environmental Services will remove invasive vegetation and restore native plants in the work areas. Revegetation will include planting 645 native trees and 1,217 shrubs and plants. Environmental Services will maintain the new plantings during the initial establishment period.
Environmental Services will use jack and bore construction to replace the pipe underneath SW Capitol Highway. The city's contractor will excavate a launch shaft in the vegetated pedestrian island on the north side of the highway and a receiving shaft on the south side. The contractor will bore underneath the highway horizontally from the launch shaft to the receiving shaft and push sewer pipe into place behind the boring machine without disturbing the surface.
The contractor will also replace a sewer pipe next to SW Vincent Place. This will require installing a temporary pipe in Terwilliger Boulevard and the pedestrian trail in George Himes Park to pump sewage around the construction area. Once the temporary pipe is installed, a pump and generator will operate around the clock until the sewer repair is complete. Bypass pumping could take from 60 to 75 days.
SW Capitol,Terwilliger and George Himes Park will remain open during construction. Environmental Services has obtained permits from the Bureau of Development Services and Portland Parks & Recreation to work in the park and in an environmental zone.
When construction is complete, Environmental Services will replant the pedestrian island with native vegetation.
Water Bureau and Transportation Work
Environmental Services is coordinating this project with the Portland Water Bureau and the Portland Bureau of Transportation. Following sewer construction, the Water Bureau will install a 24-inch water pipe to connect with the Burlingame water supply pipe and build service vaults in the pedestrian island between SW Terwilliger and SW Capitol. Water Bureau work is tentatively scheduled for 2014. For more information about this work contact the Portland Water Bureau at 503-823-7404.
In the project's final phase, the Portland Bureau of Transportation will reconstruct the sidewalk, curbs and the path through the pedestrian island. Transportation work will follow the sewer and water construction. For more information contact the Portland Bureau of Transportation at 503-823-5185.