No doubt residents of Dalton Road in Sutton , Ont. heaved a sigh of relief late last fall when a major two-year $14-million water and sewer replacement was completed.
This closely coordinated York Region/Town of Georgina project included the open cut installation of just over three kilometres of watermains consisting of 400- and 300-mm sections, 120- metres of a 200- mm diameter sanitary forcemain and a 120-long, 300-mm diameter sanitary sewer.
Significant above-ground works were also completed, including a complete repaving of Dalton Road and installing AODA- (Accessibility for Ontarians with Disabilities Act) compliant crosswalks, says York Region manager of engineering Nick Colarusso.
Memme Excavation Company Limited was the general contractor and the design consultant was Cole Engineering.
Dalton Road is a fairly busy thoroughfare with many homes and businesses and is the main route for boaters, fishing enthusiasts, and tourists heading to the nearby Lake Simcoe recreation area during the summer months.
Combined with a relatively narrow right-of-way, that traffic volume made construction staging particularly challenging for Memme. It was also trying for residents and business owners who were occasionally without water, sometimes for more than a few hours, he concedes.
But the project was necessary to replace aging and deteriorating watermains and sewer mains, which in some cases date back to the 1960s, and to accommodate future growth in Sutton and throughout the Town of Georgina, says Colarusso.
To minimize the impact of the construction several measures were put in place including conducting planned shutdowns in service at night. The shutdowns were necessary to make connections with the existing water distribution system, says regional environmental Services Design technologist Greg Caruso.
At least three of the water service disruptions were due to breaks of the existing watermains and not related to the construction, says Caruso highlighting the state of the old infrastructure.
A major complication for the contractor was that several utility lines and even some of the local connections were not in the identified locations.
“Some of the as-built drawings were dated from the 1960’s when records were not quite as accurate as today,” says Caruso.
Another complication was that partial closures of Dalton Road were necessary to complete some watermain connections. To meet that particular challenge paid duty police officers and the contractor’s traffic control personnel worked together to ensure vehicle traffic, public transit, pedestrian movement, road winter maintenance, garbage collection progressed without interruption, he says.
In addition to the combination of the lane closures, the night work, and the mistakenly identified utility locations, the contractor also had to contend with Caruso describes as “unforeseen soil conditions”.
Soil containing high levels of benzopyrene, a hydrocarbon, was discovered along the route. But this was in very specific area and did not impact the pace of the project, he says.
Asked how the old system was taken out of service, he explains that once the new one was operational, many sections were decommissioned and capped by grouting the valve chambers. But there were also many spots where the decades-old pieces had to be removed because they would have interfered with the new water and sewer mains, says Caruso.
The origins of the project actually began with the 2012-2014 design of a new York Region feedermain. But once design was completed the Town of Georgina requested that the project be redesigned and expanded to include a new town watermain and a section of a sanitary gravity sewer forcemain as well, says engineering manager Colarusso.
“It just sense to do everything at once to help reduce costs.”
An added benefit of the redesigned and more encompassing project was the inclusion of the AODA-compliant sidewalks which wasn’t included in the original design, says Colarusso.