Aboriginal crew delivers the right gravel for BC Hydro substation
It takes a certain crush of rock to resist a dangerous transfer of electricity
Paul Rind fights to catch his breath as he climbs a snow-sprinkled slope above Kamloops Lake, where he and his nephews are gathering firewood on the Skeetchestn reserve near Savona, B.C. But for the moment, his mind is nearly 100 kilometres away – at a BC Hydro substation near Clinton.
"Before I started working there, I had no idea that they tested the rock," says Rind, who worked this past summer as part of a crew from the Skeetchestn Indian Band that spent three months dumping and spreading gravel for a resurfacing project at BC Hydro's Kelly Lake substation. "I thought they just dug gravel out, sifted it and sent it out, but there's quite a science to it. It's quite amazing."
The project to resurface the Kelly Lake substation cost just a small part of the estimated $2.4 billion a year BC Hydro is spending on capital projects across B.C. But it was a huge job, as the substation covers more than 10 hectares – or more than 10 soccer fields lined up side-by-side. The Skeetchestn-owned Painted Rock Aggregates crew needed to transport more than 500 truckloads of gravel to the work site, but the toughest job was ensuring the size and resistivity – basically the ability of the rock to limit the transfer of electrical current – to meet safety standards for the site.
If at first you don't succeed...crush it again
Depending on a customer's needs, the particles of rock used in gravel can range in size from sand particles to boulders larger than 10 inches in diameter. The size of the rocks is seldom more important than when the gravel is used in the potentially lethal areas under and around a 500-Kilovolt substation like Kelly Lake.
While paving is used in some areas of substations, including at Kelly Lake, the go-to material is gravel. The empty spaces between particles of gravel are important as they reduce the amount of electricity that can be transferred between a worker's boot and the ground. The gravel must also enable heavy trucks to access the substation, prevent dangerous puddles from forming (electricity travels much easier through water than through gravel), and inhibit weed growth.
But as Rind and the rest of the Painted Rock Aggregates crew discovered, even the rock used to cover access roads at the substation – so-called "road mulch" – requires careful thought and preparation. After laying down a section of road mulch, resistivity testing showed that it wasn't up to standard. It had to be ripped up, shipped back out, and replaced.
"Immediately, Andrew [Dunlop] at Painted Rock started looking into alternatives," recalls BC Hydro Construction Services project coordinator Brendan Macdonald. "After spending several days trying out various alternatives, he came up with a double crushed product that they were able to produce that would meet the stringent specifications."
While the bulk of gravel for Kelly Lake came from Painted Rock's gravel pit on the Skeetchestn Reserve near Savona, Painted Rock needed to source a specialty aggregate from Coast Range Contracting's gravel pit near Ashcroft to increase the resistivity of the gravel.
"I used every combination to create a scientific blend," says Painted Rock's Dunlop, with a laugh. "We put the road mulch down on test pads, packed it down with a water truck and tested how it performed. We drove our trucks over it just to make sure that when you turn your wheels, it can't move, or it just creates a mess for the substation."
A guy shows up to help renovate a home, winds up at a gravel pit
Paul Rind's three-month experience at Kelly Lake has since translated into a regular job, mainly as the guy testing the gravel at the Painted Rock gravel pit. It amounts to a surprising turn of events for a 51-year-old man whose previous job was working at an Alberta homeless shelter – he had returned to Skeetchestn to help his sister do some home renovations.
"I just happened to land this job – I was going to go back to Alberta but I think I'll stay here and work for Painted Rock," he says. "I still have a lot to learn."
That's good news for Andrew Dunlop, a former stockbroker who has helped make more viable the gravel pit and other Skeetchestn business ventures – including the Big Sky gas station along Highway 1 on the reserve. He's the director of the Knucwentwecw Development Corp., which oversees business development on the reserve.
"We're building through skills and capacity," he says. "None of the jobs here are meaningless. Here, you can come in and learn how to run and service heavy equipment and learn how to find the right blend of rock to put through."
You might just call it the School of Rock.