Overview and details of the sessions of this conference. Please select a date or location to show only sessions at that day or location. Please select a single session for detailed view (with abstracts and downloads if available).
Session Chair: David Hammond, City of Portland BES;
10:30am - 11:15am
Construction Surprises: Lessons Learned Repairing the Inverness Force Main
Michael Pyszka1, Kelly Wood2, Niall Boggs1, Peter Hesford2
1Parametrix; 2City of Portland Bureau of Environmental Services; ,
Dual force mains cross the Columbia Slough mounted under a pedestrian bridge. When the 30-inch diameter Concrete Cylinder Pipe (CCP) force main failed and leaked into the Columbia Slough, flow was temporarily transferred to the parallel 20-inch diameter CCP force main. A CCTV inspection revealed multiple leaks over 90 feet of the CCP at the south end of the pedestrian bridge. Through an extensive evaluation process, the team selected sliplining as the preferred repair alternative. However, once the design was completed and the contractor selected, the team encountered some surprise challenges during construction when they discovered failed pipe supports under the bridge.
To avoid shutdown of the 20-inch diameter force main and any delays delay, the client, consultant, and contractor collaborated to design a unique pipe support repair process. By modifying the existing supports, the team kept the project moving forward without shutting down the force main.
Construction was successfully completed, and flow rerouted to the new 24-inch HDPE. The parallel 20-inch CCP was exhibiting similar signs of deterioration, so the team designed a preventative repair. Crews will begin construction on the parallel CCP in March 2019.
11:15am - 12:00pm
Bridging the Gap of Diverse Perception
Birol Shaha1, Nathan Hardy2
1City of Bellevue; 2Murraysmith, Inc.; ,
As Bellevue City Parks progressed through master planning and designing a major expansion of Meydenbauer Bay Beach Park along the shores of Lake Washington, Bellevue Utilities seized that opportunity to replace a portion of the heavily deteriorated lake line fronting the Bellevue Marina and Meydenbauer Bay Park. But the only way this could happen was to bridge the gap of diverse perception of siting a wastewater facility within the City’s signature waterfront park. And that’s what the two departments of the City of Bellevue did, came up with a win-win solution – relocating a segment of aging lake line from along the shores of Lake Washington onto the newly expanded park with a new lift station completely hidden from view, yet meeting all the functional and operation requirements of an active wastewater facility.
From the technical aspects, this 1,200-foot sewer and pump station project had it all: gravity sewer, lift station, force main, in-water work, trenchless construction under an active residence, contaminated soils, potential cultural resources, steep slopes and artesian ground water conditions. The timing of the Meydenbauer Park project required an accelerated schedule for the sewer project resulting in the pre-procurement of equipment and inter-departmental collaboration from design through construction.
This presentation will discuss the project challenges and how the two City departments bridged their differing and unique priorities and worked together to successfully deliver the project.