What Happens When You Flush?
I recently set up a tour of the Annacis Island Water Treatment plant for volunteers as an opportunity to keep learning about topics that are relevant to the Fraser River Discovery Centre. I was unable to attend, but the volunteers said it was extremely informative and the tour guide was fantastic.
Mike Hoyer, one of the volunteers, wrote a blog about the trip:
Ten volunteers at the Fraser River Discovery Center recently went to see the Annacis Island Waste and Water Treatment Plant. There are 5 such plants around Vancouver, servicing all the effluent which collects here. Each of the homeowners in Greater vancouver contributes about $280 annually in taxes to run these services.
Coming in via underground pipe from all over the city, the water passes a screen which takes out all the
rocks, rags, plastic and other large debris which seems to make it down the toilet or sewers. This goes to landfill sites. My parents being environmentally minded in the 1950′s had three old oak casks from wine making and we used them to collect rainwater. Just imagine what could be saved if we all did this. I used to paint the things all sorts of colors every year and we were known for our multi-colored rain barrels.
The water then passes through a second filter where grit – coffee grinds, sand, and other particles are removed. Grit also goes to landfill. Metro wants to educate people on what should and should not go down a water drain.
The sludge settles to the bottom and the scum floats to the top. This is removed and goes to a digester where bacteria is renders it harmless, a by-product, methane gas, is used to generate heat and electricity (co-generation) used by the plant.
There are huge trickling filters which consumes organic material clings to filters. All those oils, soaps, chemicals, garburator and dishwasher waste should have been removed by now.
More scum which is siphoned off and redistributed to previous stages for collection.
At this stage, the clarifiers, the water is starting to look good. At each stage it is tested daily to meet
certain government criterion for bacteria, and other contents. One drop of motor oil contaminates 50 liters of water, making it uninhabitable for aquatic vegetation and animal life.
We are talking 440 billion liters of water a year passing through these systems. Water fit for human use is sent into the river, well below the river in pipes which slowly let it percolate back to the running river.
Left over organic solid material is picked up by trucks in the lower half and distributed to golf courses, land reclamation projects and wherever it is useful for life.
This is one of the chlorinator stations which balance the waters pH and other chemical levels to acceptable animal levels. It takes about 60 people to run this monstrosity in daylight, keeping eyes on the controls and levels and maintaining the system with repairs and regular check-ups. Just getting around the whole place took us nearly 3 hours. We had a very knowledgeable and enthusiastic guide – something we all can learn from in our roles as interpreters at the Discovery Center.
