I did not have any issue at all with the water on the French route from either the bars, albergue sinks, outdoor water fountains, etc. It all tasted fine to me and I never got sick. I must say that some (many?) outdoor fountains on the Portuguese route looked a little too iffy to try. On the Camino Ignaciano, the problem was more that there were not many communal fountains to be found. But the on the French route, they are plentiful, clean and very good tasting. I avoided the few with non-potable signs but I knew a bunch of fellow pilgrims that even drank that without issue. Drinking probably 8-10 liters per day, I never felt the need to buy bottled water for the whole month.