The hole was caused by a 2.5 metre hole opening in the top of a sewer trunk line located under the street. This caused the materials around the hole to erode, creating a deep void.
A custom-ordered pipe has arrived in Edmonton after Epcor determined it was needed to fix a sinkhole at a busy intersection in the city’s south end.
The 23-metre deep sinkhole opened up at the intersection of 61 Avenue and 109 Street last October. Epcor spokeswoman Laura Ehrkamp said Thursday the hole was caused by a 2.5 metre hole opening in the top of a sewer trunk line located under the street. This caused the materials around the hole to erode, creating a deep void.
Ehrkamp said the exact cause of the trunk line opening cannot be confirmed but it is believed hydrogen sulfide gas present in the sanitary system may have caused erosion of the sewer line.
Due to the unique oval shape of the trunk line, crews were challenged to find the correct product for the repairs. Epcor reached out to several companies and found the pipe from Dubai was the best fit. Erkhamp said she could not disclose the cost of the pipe due to confidential procurement processes.
“Very few companies in the world manufacture non-circular fiberglass pipes such as these,” said Erkamp in an email. “Ordering the pipe from Dubai was determined to be the best option; given that the manufacturer was able to construct and deliver the custom pipe in accordance with the unique specifications and in the shortest timeframe.”
The pipe has been delivered to Edmonton and is scheduled to be installed next month.
When the sinkhole opened, the utility company said they expected to have work completed on it by May, 2021, they now believe the intersection will re-open in late July.
“Emergencies are not predictable. Initial timeline estimates in an emergency are always tentative, as the condition of the assets are unknown and the full scope of work could expand as the emergency evolves, ” said Ehrkamp.
Erhkamp said a ground stabilization study found additional air pockets existed after crews had worked to fill the void around the trunk line. She said the cold temperatures the city experienced in February also caused stabilization work to be delayed.
“We recognize the delay continues to affect traffic flow in the area and we thank motorists, residents and area business owners for their patience and understanding while our crews continue to complete this emergency work,” said Erkhamp.