Balch Consolidation Conduit

The Balch Consolidation Conduit is part of the City of Portland's 20-year program to control combined sewer overflows (CSOs). The 84-inch diameter pipe will carry sewage and stormwater runoff from the Balch Drainage Basin to the West Side Big Pipe (see aerial photo), which collects combined sewage from the west side of the Willamette River for transport to the Columbia Boulevard Wastewater Treatment Plant.

Pipeline Route

After detailed analysis and a third party engineering review, the Bureau of Environmental Services selected the best alignment for building the Balch Consolidation Conduit in the Northwest Industrial area (see map). Criteria used to choose the pipeline route included: 

• Public impact - traffic, property access, utility relocations and safety during construction
• Risk - soft Guild's Lake fill and soils, surface settlement, and potential for delays
• Constructability - shaft site flexibility, construction method constraints and safety
• Cost - pipeline length and depth, easements needed, on-going maintenance and operations

Please contact us if you have concerns about construction impacts and traffic issues, or ideas about how we can mitigate impacts to your property or business. Balch Consolidation Conduit construction began in June 2009. For more information, please contact Diana Hinton of Environmental Services at 503-823-1975.

Underground Construction Minimizes Inconvenience

Environmental Services will use a tunnel boring machine to install the pipeline to minimize surface disruption. The pipeline will be nearly 6,400 feet long and from 30 to 70 feet deep. Most of the work will be underground. There will be above ground construction at six tunnel access shaft sites, and to install additional pipelines that connect to the tunnel (see map above and fact sheet links below).

Photo Fact Sheets

^{Shaft GLI}

^{Shaft B} 

^{Industrial Line 29}

^{Shaft C}

^{Shaft L} 

Traffic Impacts

Construction started in spring 2009 and is scheduled to be completed in fall 2011. Some of the shaft sites are on or near roadways and will temporarily affect freight, bus, commuter and customer traffic along with some street parking. Project team members will continue meeting with neighbors in and around the project area to ensure reasonable traffic flow, efficient access and worker safety at each construction site.

Night Work and Noise

The contractor will do some of the work at night in order to finish the project on schedule and minimize daytime impacts to traffic and businesses. Environmental Services received a noise variance that allows work outside of normal construction hours. Click here for more information about Portland's Noise Control Program, or call 503-823-7350.

Keeping You Informed

City staff will continue keeping the community informed through presentations, mailings and one-on-one conversations. Project team members will continue to visit neighboring businesses, and are available to make presentations for your organization or business. If you would like to receive email notices during construction, need more information, or want to arrange a presentation or project team visit, call Diana Hinton at 503-823-1975. Click here to submit your email address and receive project updates by email.

Schedule 

• Spring 2009 - Final design complete, construction began in June
• September 2011 - Construction completed