Toronto water is very safe by any standards. The fact that the water came from lake Ontario is no big deal. In some crowds there is some sort of snob appeal to drinking water out of a plastic bottle. That bottle at some point was likely filled from a Toronto tap.
Don't really care where it came from. The water cooler water tastes infinatly better than tap water. The botlled water I buy at Sam's also tastes better than tap. If that's my choice, who cares?
I won't worry about a few petty environmental inefficiencies while I watch every 2nd vehicle on a road being an SUV.