Dentures, tires, 2x4s: Not the kind of crap we want in London's sewers

When it comes to what Londoners choose to flush down their toilets, Kirby Oudekerk asks that everyone keep in mind the "Three Ps."

Those are, in no particular order, pee, poo and paper. And paper means toilet paper only.

Any material that isn't the three Ps has the potential to cause big problems when it reaches the treatment plants.

To illustrate his point, Oudekerk gave CBC News a tour inside the screening room at the Greenway plant, which is the largest of London's five treatment plants. 

"The screening room is where we try to take out those big, inorganic solids. The things that get into the sewer system that shouldn't really get in there," he said. 

So what gets into the intake screens? 

Bits of tires, food, toothbrushes, dentures, even chunks of 2x4 have all been found in the intake room. The screened-out material fills dumpsters. 

Oudekerk said a common misconception is that single-use disposable products such as tampons, paper towels and condoms are OK to go down the toilet. 

They're not, and if they end up in the sewer, they can cause big problems in the pipes or at the treatment plants. 

"If our pumps get plugged or go out of service, it can jeopardize everything," he said. 

"Our big message is that toilets are not garbage cans," said Oudekerk. "If it's going to go down the toilet, it has to be one of the three Ps."