Commissioner of Finance Greg Yeomans says there will be a 25 to 50 per cent increase in what you pay for water.
That would put the flat water and sewage rate at about $1,350 by 2018.
However, officials estimate the flat rate would be about $1,100 at that time if the city didn't go ahead with water treatment.
Mayor Ivan Court says an extra $250 dollars is a small price to pay for clean drinking water.
