They may be out of sight, out of mind after being flushed down the toilet, but disposable wipes are causing headaches for the Calgary team.
“For wastewater treatment plants and even our collection system, it’s becoming a bigger problem,” said Marisa Mitton, head of the city’s wastewater operations and maintenance department.
Wipes, along with a host of other items not meant to be flushed down the toilet or sink, are causing sewer backups in homes and businesses and clogging pipes on city streets.
There were more than 7,200 calls to 311 last year for crews to clear clogs, and when crews get there, Mitton said, “more often than not, we find a build-up of non-flushables, including flushable wipes.”
A mass of tissues and other material is shown coming out of a service pipe into a main sewer. That puts other items at risk of closing as well, the city says. (City of Calgary)
The problem is that unlike a square of toilet paper, which disintegrates in water, a tissue retains its shape and strength as it passes through the sewage system.
“You can put it in a blender and it won’t even fall apart,” Mitton said.
Once down the drain, it will solidify with other items – dental floss, feminine hygiene products, condoms, cotton swabs, human hair, cigarettes, bandages – as well as fats, oils and grease from food waste.
Removing the resulting masses can take hours.
Mitton said that while there is no danger of an island of wet wipes taking over the Bow River, crews are seeing an increasing number of wipes and non-flushable items entering the sewage system.
In addition to causing sewer backups, the wipes get caught at “break points” in pipes where the change in elevation means the sewer must be raised to reach wastewater treatment plants.
The pumps and fins at these junctions are easy places to hang the wipes. So are the large screens in the treatment plants that filter non-flushable elements.
But it’s better to prevent them from getting into the system in the first place, Mitton said.
“You only need to flush the three Ps: pee, paper and poop,” she said. As for everything on this list?
“Just don’t rinse it off. Put it in your black bin, or your blue bin, or your green bin, depending on what the item is.’
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