Southern Ontario sewage helps Sudbury nickel miner regreen its tailings
Treated sewage is commonly used on farms in other parts of the province
As part of a green solution to mining pollution, truckloads of sewage are heading to nickel miner Vale's tailings ponds in Sudbury, Ont. But unlike the stinky, untreated haul that once came from the city's sewage treatment plants, this sewage comes from southern Ontario.
The black, manure-like biosolids are normally spread on farms in the south as fertilizer, but during the winter or other times it can't be used for agriculture.
Since 2014, the company has been mixing biolsolids with straw, hay and yard waste and using it to help re-green thousands of hectares of sandy, acidic mining waste.
"Tough place to be a tree," says Vale's superintendent of decommission and reclamation Glen Watson.
"The biosolids ends up being an all-in-one solution for us, because the tailings themselves are very nutrient-poor and they're metal rich. You can amend the surface of the tailings much like a farmer would."
And much like a farm, there is a manure-like smell that sometimes wafts into the surrounding neighbourhoods.
"Biosolids have a unique smell to it, [but] not like the sewage sludge that was coming from the city — that's for sure," Watson added.
For years, Lively was plagued by the stench from that liquid, untreated sewage for years, eventually forcing the City of Greater Sudbury to spend $63 million on a new biosolids plant, which opened a year ago.
So, when Marc Laplante — who lives in Lively near the tailings — recently caught a whiff of an outhouse-like smell, he feared this was the return of the bad old days.
"[My] first thoughts were, 'What is happening? Not this again — the sewage sludge smell.' But I noticed it had a different odour to it, like manure," he said.
Laplante is still wary of truckloads of sewage being dumped nearby, but he said he's happy to hear that Vale is using it to re-green its tailings area — parts of which look more like a forest or a farmer's field than a mining waste dump.
During the last two years that Vale has been using the sewage, they've seen trees, grass and other vegetation sprout much faster than before on the tailings, Watson said.
And Mother Nature seems to approve. Watson said Vale workers are seeing deer, birds and other animals returning to the regreened areas of the tailings.
He added the company has long-term plans to farm hay and straw, which Vale will use to control dust.