By Christopher Pollon , TheTyee.ca
DANGER: Drinking this toilet water could be hazardous to your health.
That's the message required above every rainwater-flushing toilet installed at Vancouver's Olympic Village, where water is collected from the roof, stored in a giant holding tank, and pumped as needed for each flush.
The sign is necessary, because bringing rain indoors breaches a fundamental orthodoxy of the North American plumbing world: behind the walls, pipes carrying potable municipal water mingle with those carrying potentially unsanitary rain. On paper, building codes for Vancouver and elsewhere in B.C. do not currently allow the practice of indoor rain water plumbing; in a post- Walkerton regulatory environment, there is immense discomfort on the part of building inspectors at the prospect of mixing private and public water supplies. (See sidebar.)
In spite of this, there are about 25,000 rain water capture systems operating across B.C. today - used to water lawns and crops, flush toilets and provide drinking water for people and livestock. There are about 5,000 rain systems on Vancouver Island and the Gulf Islands alone, in areas where seasonal droughts and dodgy well water make it a necessity.
As municipalities and cities explore ways to work with the deluge of water that falls from the sky (more than a metre of rain typically falls annually in Vancouver), the most promising use will be for irrigation of lawns and gardens in the near future. Which could be good and bad.
"I have a worry that rainwater is starting to get trendy," says Bob Burgess, a B.C. rainwater harvesting pioneer and founder of The Rainwater Connection which designs and builds all sorts of rain capture systems. "More and more people are doing it, and doing terrible jobs of it. It may not be too long before we have our little Walkerton for rainwater."
Looking to the skies
A basic rain harvesting system captures water from a roof and channels it to a storage tank, where it is then pumped to where it is needed. Along the way, the rain undergoes any number of different filters and cleaning methods depending on the end use: to make it potable for drinking, it will require filtration and any combination of UV sanitizing and chlorine-injection; water strictly for watering plants will be cleaned less.
Big municipal fleets are among the early adopters: White Rock currently washes some of its trucks with rain, as does Vancouver; the Regional District of Nanaimo captures rain off two large Parksville recycling transfer buildings and uses it to wash the interior concrete floors.