'Flushable' wipes causing growing number of clogs for Calgary wastewater crews

Though their packaging might say they're flushable, clumps of stubborn wet wipes clogging up thousands of sewer pipes a year show otherwise.

City responded to over 7,200 calls of sewer backups last year, many caused by unflushable items

This clump of "flushable" wipes from a house service line in Calgary took wastewater operations and maintenance crews four hours to clear. (City of Calgary)

They might be out of sight, out of mind once they're flushed down the toilet, but single-use wipes are causing a headache for Calgary wastewater crews.

"For the wastewater treatment plants and just even our our collection system, they are becoming more and more of a problem," says Marissa Mitton, leader of the city's Wastewater Operations and Maintenance department.

The wipes, along with a whole host of other items not meant to be sent down the toilet or the sink, cause sewer backups in homes and businesses and clog pipes along city streets.

There were over 7,200 calls to 311 last year for crews to clear blockages, and when crews get there, said Mitton, "more often than not, we do find a buildup of unflushable items, including flushable wipes."

A mass of wipes and other material is shown coming out of a service line into a main sewage line. This poses a risk of getting other items hung up as well, says the city. (City of Calgary)

The problem is that unlike a square of toilet paper, which disintegrates in water, a wipe retains its shape and strength as it travels through the wastewater system.

"You could put it in a blender and it won't even break down," said Mitton.

Once down the drain, it will congeal with other items — dental floss, feminine hygiene products, condoms, cotton swabs, human hair, cigarettes, bandages — as well as fat, oils and grease from food waste.

The resulting masses can take hours to remove.

Mitton said while there isn't a danger of a wet wipe island taking over the Bow River, crews are seeing an increasing number of wipes and unflushable items showing up in the wastewater system.

In addition to causing sewer backups, wipes get caught at "stop points" in the pipes, where a change in elevation means sewage has to be lifted to make its way to the wastewater treatment plants.

Pumps and propellers at these junctions are easy spots for the wipes to snag. So are the large screens at the treatment plants that filter out unflushable items.

But it's better to prevent them from getting in to the system in the first place, said Mitton.

"You should only flush the three Ps: pee, paper and poo," she said. As for anything that's not on that list?

"Just don't flush it. Put it in in your black bin or the blue bin or the green bin, depending on what that item is."

With files from Diane Yanko


To encourage thoughtful and respectful conversations, first and last names will appear with each submission to CBC/Radio-Canada's online communities (except in children and youth-oriented communities). Pseudonyms will no longer be permitted.

By submitting a comment, you accept that CBC has the right to reproduce and publish that comment in whole or in part, in any manner CBC chooses. Please note that CBC does not endorse the opinions expressed in comments. Comments on this story are moderated according to our Submission Guidelines. Comments are welcome while open. We reserve the right to close comments at any time.

Become a CBC Member

Join the conversation  Create account

Already have an account?