BC Hydro is looking for an exemption from the city’s noise bylaw to allow drilling through the night as part of the John Hart Dam Generating Station project.
Stephen Watson, spokesperson for BC Hydro, said construction of the two kilometre, eight diameter tunnel – which will replace the three 1.8 km pipelines – will require crews to work extended hours.
“What we’re seeking is to allow Saturday blasting and night blasting,” Watson said at a council meeting Tuesday night. “We’re looking to also work 24/7, essentially 24 hours a day, seven days a week.”
The city’s public nuisance bylaw restricts blasting on Saturday and at night and limits construction work hours.
Watson said BC Hydro, through the winning project team (expected to be announced in late summer) can work on mitigating options such as only doing underground blasting at night and limiting the amount of work trucks travelling through the area at nighttime.
Watson said the tunnel will be between 40 and 90 metres underground so nearby residents shouldn’t feel any impacts from the blasting.
“It is well below the surface,” Watson said. “I’m not sure if it will be drilling, a boring machine, or if it will be controlled blasting. We don’t want to have any ground vibrations, so people won’t feel the blasts – it’s all underground except for some minor works on the surface.”
The project also involves constructing a new, earthquake-proof generating station beside the existing one.
Watson said blasting and excavation is needed to construct the base for the new generating station but the isolated location and number of trees should keep noise levels at bay.
The closest residence to the construction site is approximately 1.4 kilometres away along the Quinsam River but Watson noted a diesel truck travelling 65 kilometres on the highway just 15 metres away emits a sound recording of 84 decibels.
Watson said construction on the generating station is not expected to exceed 80 decibels and it would be further away than the truck on the highway.
The closest residence to the north of the construction site is 2.1 kilometres away.
Coun. Ron Kerr was concerned that residents may still have complaints.
“As you know it’s not always the decibel level that’s the factor, it can be the constancy or the frequency,” Kerr said. “Do you have any idea of the frequency?”
Watson replied that the noise would not be constant.
“It’s a construction site so the sounds will change,” he said. “I think what’s happened in our favour is the distance from the residences. It’s quite a significant distance and there’s trees.”
Watson also pointed out that blasting and excavating would not be ongoing throughout the entire five-year project but during the two-year tunnel construction phase.
Watson said Thursday morning that “BC Hydro is currently working with city staff to provide additional information so that city council can make an informed decision on the bylaw variances” to allow for extended blasting hours.
The project is currently in the preliminary stages but BC Hydro hopes to have the first replacement generating unit in service by 2017. The winning project team is expected to be revealed in late summer and an open house will follow in the fall as an opportunity for businesses to meet the contractor. Construction could begin shortly after.
Site preparation work got underway earlier this month with tree removals for the new parking lot off Woodstave Road, just off Brewster Lake Road near Highway 28. Hydro will construct an access road, 80-spot parking lot and trail to provide public access into the Elk Falls Provincial Park. These new public access works into the park will be in place for the up to three-year road closure to Brewster Lake Road, which may begin as early as this fall.