The final phase of a sewer relining project along major routes in the city's southeast is set to take place this summer. Phases of the South Central Sanitary Trunk line from Carry Drive to Trans-Canada Way along Southview Drive are set to be repaired. Similar work - to coat the inside of pipes with an an epoxy-like coating - took place along Carry Drive in 2018 (pictured).--NEWS FILE PHOTO
cgallant@medicinehatnews.com@CollinGallant
Sewer mains will be relined along most of Southview Drive this summer in the final portion of a major multi-year project across the city’s southeast and the first major project of 2021.
In a full-presentation to council on Monday, engineering manager Sandra Plank described how the environmental utilities department schedules and determines projects, and went in depth on construction techniques that avoid major trenching.
The lining process is cheaper and causes less disruption that comes with digging up pipes that are usually located below major roads.
The process, which became common in the city seven years ago, sees crews dig down to strategic points, then roll out a heavy-felt “sock” that is infused with epoxy the length of the pipe.
It is then activated using steam, and the hardened material acts as a new structural support.
The line, known as the South Central Sanitary trunk line, carries from Trans-Canada Way, west of 13th Avenue to Dunmore, but inspections of the concrete pipe showed structural damage.
In previous years the city relined major sewer lines along Carry Drive, which complete the south central trunk, for similar reason.
In that case hydrogen sulphide that built up from low flow of sewage pitted the concrete pipe.
Plank said the city’s entire sewer system, measuring 400 kilometres, has a replacement value today of $4.7 billion. In 2020 the department budgeted $14.46 million for water and sewer main replacement.
As well on Monday, council approved bids to complete the work on Southview Drive.
Two companies bid on the job, a process that closed on Feb. 4. Instiform Technologies’ low bid of $1.75 million was accepted and should complete the work by mid-November.
The entire three-phase trunk rehabilitation project was originally budgeted to cost $3 million, but will actually cost about $250,000 less. The difference will be carried forward and applied to future projects.
