After Alberta flood waters recede, what’s left behind may prove to be worse

The waters may have receded in southern Alberta, but the residents returning to homes and businesses are finding that the flood left behind a lot more than just wet homes and belongings. A layer of sludge has collected on streets and properties, in basements and in parking garages, and what's in the sludge can turn it into a toxic hazard.

Bob Godfrey drove his vacuum truck from Kamloops, BC to Calgary, to help with recovery efforts in the city, and his latest efforts have been to drain this sludge from underground parking garages.

"We've been going since last Sunday 12 hours a day," he told the National Post on Friday, remarking about how it only takes about an hour to fill his truck with the sludge. "There’s still a lot left, actually. The lower levels of the parkades are just one foot, two-feet deep in mud."

[ Related: Calgary flood infographic illustrates the city’s plight ]

The sludge collected by Godfrey, along with every other vacuum truck operator working in the area, is being deposited at a location that's more used to seeing piles of white than brown, as it's typically where snow removal crews dump their loads after clearing Calgary's streets during a snowstorm. The sludge delivered here is dumped out so that the water can drain off for treatment, and city officials plan on taking whatever remains to a landfill once it's dry.

There's a lot more than just dirt and water in this sludge, though. With water backing up sewers, stranding cars and flooding basements, there's a potentially-toxic combination of human waste, household chemicals, fuel, paint, trash, and a host of other possible contaminants to worry about.

"If it was just clean river water, that’s no problem. You can pump it back into the road," said Sean Somers, a spokesperson for the city of Calgary’s transportation department, according to the National Post. "But if the flood hit a basement full of contaminants, say paint cans or gasoline or what have you, that has to be treated."

For the sludge that's in people's basements, the City of Calgary Facebook page issued a reminder to residents, saying: "Remember mud, solid and slurry waste from basements could contain contaminants and should NOT be dumped into our river systems. The City of Calgary has provided two emergency dumping facilities at Spring Gardens and Highfield/Bonnybrook for this waste."

Calgary isn't the only place affected by this, of course. Anyone whose house or business experienced flooding likely has at least some of this sludge. Not only do residents need to worry about what may have ended up in the sludge from their own basement, but also what ended up there from any basement in the surrounding area. Residents further downstream — especially downstream of Calgary — may even have the worst of this, as the flood waters that inundated their homes would have contained a cumulative buildup of more and more chemicals and other toxins as it flowed through all the upstream communities.

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For Paul and Theresa Hogan and their three children, cleaning up their High River home isn't going to be easy.

"The whole basement is destroyed. The furnace and fridge are ripped out, cabinets ripped right out of the walls, a whole wall came down. All the flooring lifted up and there are about six inches of mud and [sewage]," Theresa Hogan told the Winnipeg Press on Saturday.

"There's sludge all over everything. The yard is caked in mud and they can't even get the mud out [of the house]. They've tried with shovels, but it's just impossible, it's so thick," she added. "They're waiting for a vac truck to come. We're hoping today or tomorrow, but you can't do anything; you can't clean anything until that mud gets out of there."

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