British Columbia

B.C. drought: could bath water be the answer?

A Vancouver engineer and expert on grey water is calling on the province to implement a system to allow people to use their bathwater for other purposes.

Expert questions why many B.C. municipalities don’t allow grey water to be used for toilets, lawns

A child looks up from a bathtub with rubber duckies.
A Vancouver engineer and expert on grey water is calling on the province to implement a system to allow people to use their bathwater for other purposes. (Getty Images/RooM RF)

Every day, gallons of grey water from sinks and baths get flushed down the drain. But according to one expert, a lot of that wasted bath water is safe to use elsewhere and would be resource-smart at a time when many fear a potential California-style drought may move north of the border to B.C. 

"It's logical that one should be able to take the same bath water that the kids just bathed in, and be able to use it safely,"  says Troy Vassos, a UBC adjunct professor of civil engineering and principal with Vancouver-based Golder Associates company that specializes in grey water reclamation.

Vassos says a person uses 100 litres of water on average daily between bathing and using the toilet, which is a waste of the resource. He wants municipalities to implement a system whereby grey water can be used in toilets and to water lawns. 

"It's safe. Eventually you'll get rain water that will help dilute the soaps, but the soaps will dilute in the soil."

Most B.C. municipalities not doing it

Using recycled water rather than fresh water for secondary needs would help considerably with the water restrictions across Metro Vancouver and the Fraser Valley, he says. But while it may sound like a simple solution, current bylaw regulations in most B.C. municipalities won't allow it.

"Currently in B.C. we have plumbing codes that allow us to have dual plumbing. What we lack from a health perspective is a policy and framework that can help municipalities be able to safely use this non-potable water."

He says the current plumbing code allows municipalities to accommodate that, but "the problem is it's up to the municipalities to adopt that code for use.

"Many municipalities are not very familiar with the idea of water reclamation so it's not done."

He points to Nanaimo as one of the exceptions. The city has implemented an installation process allowing residents who want a grey water system to have it inspected by city officials to ensure it follows building code guidelines.

Vassos says he wants the reuse of grey water to be more widely accepted across the province.

"It's a very safe and reasonable  thing to do if you're trying to conserve water. That effort alone could cut your water consumption by a third so it's a fairly reasonable thing to do."


To hear more, listen to the audio labelled: How to reuse your grey water.