EPCOR Drainage Service
Ph: (780) 509-8080
On October 8, 2020, during an inspection of a sewer trunk line that runs 23 metres below 61 Ave, a 2.5 metre long opening was discovered along the top of the sewer trunk line. Further investigation into the emergent issue revealed that materials surrounding the trunk line had eroded, creating an underground void above the trunk line at the intersection of 61 Ave and 109 St. The sewer trunk line is 1650mm in diameter and carries both storm and sanitary flows.
There is no structural risk to homes and businesses in the area. Based on assessments, it appeared the void area was limited to a section under 61 Ave. We continue to monitor the roadway and surrounding infrastructure for any changes.
What's happening now
EPCOR is in the process of repairing the sewer trunk line and the void above the trunk line. Due to additional ground stabilization work and challenges with the extreme cold temperatures in February, the intersection is now expected to reopen at the end of July 2021. After drilling shafts 23 metres deep to reach the trunk line, we removed debris from the line with high pressure flushing and installed a bypass. A bypass takes flows from the below-ground drainage system and brings them above the ground in a pipe to discharge the flows away from the work site. The void that had formed above the trunk line was filled in December 2020. In January 2021, a ground stabilization study was done to confirm the void was filled. The study determined that air pockets still remained below the surface, making the work area unstable and unsafe for our crews to work underground to install the new fiberglass pipe. The work to fill the additional air pockets was completed in early March 2021. Additional cleaning of the trunk line is currently underway and the installation of the new pipe is expected to be complete at the end of April. Crews will then work to re-connect the repaired pipe to the existing infrastructure. Once connected, the bypass will be removed. This is anticipated to be completed in mid-May. Next, crews will build up and convert the shafts that were constructed for the repair and bypass into manholes for future access to the trunk line for inspections and maintenance. The road will then be restored and the intersection reopened, with the expected completion of the entire project at the end of July 2021.