Rethinkng Grey Water Use

The University of Alberta has teamed up with the government  to create the Resource Recovery Centre, a  facility where the method of separation of 'black water' and 'grey water' will be tested.

Millions of litres of clean, treated drinking water gets flushed down toilets every day, and Nicholas Ashbolt thinks that's incredibly wasteful.

"We are flushing our feces down the toilet with high-quality drinking water," said Ashbolt, who works at the school of public health at the University of Alberta. "It's a crying shame, in many ways, when you think about it.

"It's such a waste of resource. There's so much energy, so much technology that has gone into producing that water, and then 25 per cent of household water is just flushed down the toilet."

Ashbolt and his team are working on a better, more cost-effective way to treat and use water.

"At the moment, all houses have sewer pumps connecting their toilets, and all drain pipes connect into that one sewer."

He thinks we should separate what's known as "black water" from what is called "grey water."

"The black water is the easier one to recover the energy and nutrients from, so why dilute it with the bulk of the water in the sewer, which is in fact the grey water? So we keep black water separate, so we can recover energy and nutrients from that stream."

Black water produces methane, which can be used to generate electricity and create heat, and the waste can be treated and turned in an ammonium-phosphate compound called struvite that's used on farmers fields.

The city is not yet in a position to implement a system like that in new developments and homes.

So the University of Alberta has teamed up with the government and public and private groups to create the Resource Recovery Centre, a $4-million facility on the outskirts in Strathcona County, where the method will be tested on a smaller scale.

Ken Pacholak will manage the new facility, and hopes the idea, if successful, will be used in new homes as the city grows.

"All levels of the government know that we have to do things differently," said Pacholak. "The issue is, how do we do them? How do we do them in a cost-effective manner? In a manner that protects the environment and protects the public safety.

Construction on the facility is set to begin in September. 

Source: CBC News