Southern Ontario sewage helps Sudbury nickel miner regreen its tailings

As part ofa green solution to mining pollution, truckloads of sewage are heading to nickel minerVale'stailings 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 mixingbiolsolidswith straw, hay and yard waste and using it to help re-greenthousands of hectares of sandy, acidic mining waste.

• FAQ: Tailings ponds for mining and oilsands waste

"Tough place to be a tree,"says Vale's superintendent ofdecommission and reclamationGlen Watson.

"Thebiosolidsends 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.

"Biosolidshave 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 millionon a new biosolids plant, which opened a year ago.

So, when Marc Laplante wholives in Livelynear 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 areaparts of which look more like a forest or a farmer's field than a mining waste dump.

During the last two years thatVale hasbeen using the sewage, they've seen trees, grass and other vegetation sprout much faster than before onthe tailings, Watson said.

And Mother Nature seems to approve.Watson said Vale workers areseeing deer, birds and other animals returning to the regreened areas of the tailings.

He added the company haslong-term plans to farm hay and straw, which Vale will useto control dust.