|
|
|
|
Fanno Pump Station and Pressure Sewer ImprovementsFanno Pump Station Improvements Construction Plans and Schedules Fanno Creek Pump Relief System Public Notification of Pump Relief System BackgroundIn 2000, the City of Portland finished construction on the Fanno pump station, the Fanno Pressure Sewer, and a gravity sewer line in SW Vermont Street. The total construction cost was about $18 million. The Fanno projects replaced a system that relied on five old pump stations.
Pressure pipeline breaks in late 2005 and early 2006 caused sewage leaks to nearby properties and ditches. Each required the pipeline to shut down for about two weeks. After another pipeline failure in March 2008, Environmental Services deactivated the Fanno Pump Station and pressure sewer and began diverting the flow to a gravity line that conveys wastewater to the Clean Water Services Durham Treatment Plant in Washington County.
Pipeline SolutionsThe Fanno Pressure Sewer is made up of two sections, each constructed of different materials. The Multnomah section is a 30-inch diameter polyvinyl chloride (PVC) plastic pipe. The Garden Home section is a 32-inch diameter pipe made of a different type of plastic, high-density polyethylene (HDPE).
Environmental Services examined several different repair options and decided that replacing the Fanno Pressure Sewer is the best way to ensure reliable operation in the future. Environmental Services is designing projects to replace both the Multnomah and Garden Home sections with two 30-inch metal pipes. Two pipes are needed to accommodate additional flows in the Fanno Basin system. Work on the Multnomah segment will begin in fall 2009, and construction on the Garden Home segment will begin in spring 2010.
The City of Portland is seeking to recover costs from companies responsible for the design and construction of the line that has failed.
Fanno Pump Station ImprovementsEnvironmental Services is also designing a pump station expansion project on the southeast corner of the existing Fanno Pump Station property at the south end of SW 86th Avenue near the Portland Golf Club. The project will increase pumping capacity to ensure the pump station can accommodate additional wastewater flow during large storm events.
The new pump station building and associated facilities will be roughly the same size as the existing facility. The new structure will be located entirely on existing pump station property. The first phase of the pump station project starts in spring 2010 and will take about one year to complete. A second construction phase will start in spring 2011 and be complete in summer 2012.
Multnomah Boulevard Stormwater Improvements The Fanno project includes construction of ten stormwater management facilities in the public right of way along SW Multnomah Boulevard. The facilities will collect and filter stormwater runoff to protect Fanno Creek water quality.
Questions and AnswersWhat types of permission does Environmental Services need for the pump station project?Environmental Services will apply to Washington County for a land use review and related permits to construct the new pump station. The application will include a grading plan, revegetation plan, site plan, and environmental mitigation plan.
Tree removal will be reviewed as part of the application. Environmental Services will also apply to the county for a permit regulating erosion control for the project. Environmental Services has not yet applied for any of these permits.
The project will also require permits from the U.S. Army Corps of Engineers and the Oregon Department of State Lands. This work will not raise the flood plain in the area. Who is paying for the project?Portland sewer rate payers pay for all Environmental Services projects. No federal money or grant funds will be used for this work. Will the project need Portland City Council approval?Environmental Services will ask the City Council to pass an ordinance authorizing the award of a construction contract to the lowest responsive bidder. Will the public have a chance to comment on the project?Washington County will notify the public and hold a public hearing as part of the permit process. The Department of State Lands will notify the public and accept public comment as part of the permitting process. Because Environmental Services has not yet submitted permit applications, no public hearings or comment periods are yet scheduled.
Is the project scheduled for discussion at a meeting of any public body or board?Environmental Services staff will attend the monthly CPO 3 meeting on Wednesday, January 21, 2010 to provide an update on the pump station project and the repair of the Fanno Pressure Sewer. Staff will continue to provide updates via email, the internet, local newspapers, and by attending a variety of neighborhood meetings. Is a draft site plan available for public review?Click here to download the current draft site plan. When the project reaches 30% design in October, Environmental Services will post an updated site plan draft.
Construction Plans and ScheduleGarden Home Segment
In spring 2010, a contractor hired by the city will begin replacing the Garden Home segment of the Fanno Pressure Sewer. Construction will last until November 2010.
Multnomah Segment
A contractor hired by the city began work on the Multnomah segment of the Fanno Pressure Sewer in February 2009. Click here for project updates.
Noise Variance For Night Work on Multnomah Boulevard and Truck Haul Route
The City of Portland Noise Review Board has granted a noise variance for work on the Multnomah segment. The noise variance allows the contractor to work at night for 150 nights. The Noise Review Board granted the variance with these conditions:
Traffic Control Plan
One lane of Multnomah Boulevard will remain open during daytime construction hours, 8:00 a.m. to 4:00 p.m., with flaggers controlling traffic movement. During night work hours, 7:00 p.m. to 6:00 a.m., parts of Multnomah Boulevard will close to through traffic, but flaggers will maintain local access.
There will be signed detours during night work but no detours are scheduled for daytime work. All traffic lanes will be restored during non-working hours. City code allows work to occur Monday through Saturday. No work is currently planned on Sundays.
Related ProjectsBurlingame Trunk Sewer Improvements The gravity sewer that the Fanno pressure sewer empties into isn’t large enough to handle additional flows once the Fanno pressure sewer and pump station improvements are complete. Environmental Services will install a larger gravity sewer in SW Multnomah Boulevard between SW 31st and SW 20th avenues using open cut construction.
This project includes rehabilitating a downstream section of the gravity sewer lining the existing pipe. Environmental Services is designing the project and will begin construction in fall 2010. Public OutreachEnvironmental Services outreach staff have been in frequent communication with area neighbors, businesses, neighborhood associations, community organizers, and relevant agencies. Outreach staff plan to attend area neighborhood and business association meetings each quarter during the design and construction phases of these projects. Environmental Services will distribute additional information through area newspapers, newsletters, direct mail, and this website.
Interim MeasuresWhile replacement of the Fanno Pressure Sewer Line is in design and construction, the City of Portland is sending its sewage from southwest Portland and eastern Washington County to the Durham Advanced Wastewater Treatment Plant operated by Clean Water Services. A 32-inch gravity sewer is carrying the flow to a 60-inch interceptor pipe that conveys it to the Durham plant.
When the weather is dry, the gravity sewer system is large enough to carry Portland's additional flow. During wet weather, ground and surface water enter the sewer system and increase flow in the interceptor pipe. During an extreme rain storm that produces more than two inches of rain in 24 hours, the added flow from Portland's system could exceed the capacity of the Clean Water Services sewer system.
Fanno Creek Pump Relief SystemEnvironmental Services has installed back-up measures if the pressure sewer doesn't operate properly over the next two years during an extreme rain storm. Environmental Services installed a pumping and screening system next to the Fanno Pump Station, located next to Fanno Creek at the south end of SW 86th Avenue near the Portland Golf Club.
If the Fanno Pressure Sewer is activated during an extreme rain storm to pump sewage to the Portland sewer system, and if the pressure sewer fails after being activated, this backup system will pump some sewage from the gravity system to relieve pressure on the sewer and prevent uncontrolled overflows downstream. The sewage pumped from the gravity line at the Fanno Pump Station will flow through an aboveground, screened vault to remove solids and debris.
The highly diluted, partially treated wastewater will then be discharged to Fanno Creek. This relief system will remain in place for the next two years, until the project to replace the Fanno Pressure Sewer is complete. The repaired Fanno Force Main has been activated twice, once in January 2009 and February 2009. The relief system has not been activated.
Public Notification of Pump Relief SystemSending partially treated wastewater into Fanno Creek would only occur during an extreme rain storm and if the Fanno Pressure Sewer fails to operate as planned. An extreme rain storm is likely to occur only once every two years on average.
Environmental Services will notify people who live near Fanno Creek when a rain storm that could produce more than two inches of rain in 24 hours is forecast. Environmental Services has developed a list of residents who want to be notified by email, and will post notifications online.
Click here If you would like to be notified by email when an extreme rain storm is forecast or if there is a bypass to Fanno Creek.
If Environmental Services activates the Fanno Pump Station, the bureau will post notification on this page (www.portlandonline.com/bes/fanno) and send an email notification. If relief pumping into Fanno Creek occurs, Environmental Services will post notification on this page (www.portlandonline.com/bes/fanno), send an email notification, and post warning signs at possible public access points along Fanno Creek to warn the public of an increased amount of bacteria in the creek.
OversightEnvironmental Services is working with the Oregon Department of Environmental Quality (DEQ) and Clean Water Services to manage wastewater flows during wet weather. The DEQ is overseeing the operations and construction that will take place during the next two years. For More InformationFor more information or to be included on an email notification list, contact Stephen Sykes at 503-823-7898 or stephen.sykes@bes.ci.portland.or.us.
|
