Unfortunately I'm drinking out of a water bottle while I write this. Gasp, I know after all that I am drinking out of a plastic water bottle. Why am I saying this? Because I'm not perfect, we can all point fingers and claim to always use reusable water bottles but the truth is each and everyone of us has slipped. Personally I'm drinking out of a plastic water bottle because where I live the tap water looks more like milk when its poured into a glass. The water has been tested here and its aok but really drinking water that looks like milk and tastes well like pipes, not so much fun.
"42. Therefore, plain bottled water sold in a single serving size bottle (i.e., less than 600 mL) is taxable. When plain bottled water is sold in manufacturers' packages of two or more single serving bottles, or in a bottle that exceeds a single serving, it is zero‑rated."
More Info on Canadian Water:
Info on Taxable Groceries in Canada:
Canada Revenue Agency