Engineers with the Regional Municipality of York, north of Toronto, had to plan a two-kilometre cured-in-place pipe relining job, with half of it crossing St. Andrew’s Valley Golf Club, an 18-hole course that straddles both Aurora and Newmarket.
To paraphrase an old riddle: when is a sewer pipe like a golf game? Answer: when you have a hole in one.
That’s just the situation York Region engineers hoped to avoid when they planned a two-kilometre cured-in-place pipe relining job on an aging sewer line. The twist? Half of the project length crosses St. Andrew’s Valley Golf Club, an 18-hole course that straddles both Aurora and Newmarket.
The golf course portion of the project was the first phase of the $10.5-million contract undertaken by Capital Sewer Services Inc., with head office in Hamilton.
The concrete sewer line was installed roughly 50 years ago, during an infrastructure boom, but was suffering increased internal damage due to corrosion from hydrogen sulfide gas generated by sewage.
“We chose to rehabilitate the line proactively using a structural epoxy felt liner inserted trenchlessly through the manholes,” says Mike Rabeau, manager of engineering, Environmental Services with York Region. “On a golf course, that sure beats dig and replace. Once the lining is complete, we should get 50 additional years of service out of it.”
A series of 25 manholes is also being simultaneously rehabilitated using an applied spray coating.
“The existing sewer line cuts through holes two and three of the golf course. The project began with the construction of a by-pass system from the nearest pumping station to divert sewage during the pipe relining process.”
“The line runs from 1,050 to 1,200 millimetres in diameter and required a significant by-pass operation,” says Rabeau. “We used five noise suppression pumps to keep the operation as quiet as possible and three or four massive 450-millimetre pipelines to create enough capacity to move not only the existing sewage, but to prepare for any extreme weather event.”
Although the operation was trenchless, the engineering design of the job required contractors to access the sewer line on the course itself. That required construction of a temporary manhole in order to insert by-pass equipment.
The course is famous for its challenging water features, which also challenged project engineers.
“In order to reach that access point and get construction equipment properly located, we had to build a temporary road across the green and a temporary bridge to cross a stream that runs through the golf course,” says Rabeau.
“The golf course management understood the need for the rehabilitation project. They certainly wanted to avoid a potential sewer line leak on the green due to corrosion and they were fully supportive of the work and our approach to the project.”
The work began in March and finished up in early June.
“The idea was to get out before the golf season really got started and minimize disturbance,” says Rabeau. “But the good weather encouraged early golfing so we had to share the course with golfers for the start of the season. As it turned out, the contractor and the golfers co-operated well with each other. We were joking that the design capacity of the by-pass pumps could handle any rogue golf balls that might get into the sewage system.”
The second phase of the project will include an additional kilometre of cured-in-place pipe rehabilitation along a busy section of Yonge Street in Richmond Hill, south of the golf course. The project also includes a significant above ground HDPE (high-density polyethylene) by-pass.
“That’s a fairly congested corridor,” notes Rabeau. “We’re working along the northbound lane of Yonge, and running the by-pass above and below ground, threading it underneath driveways to avoid inconveniencing businesses as much as possible. The by-pass also requires a sophisticated series of air valves to help control the air in the system.”
Work on the second phase of the rehab project is expected to take approximately 14 weeks.
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