Using ToughAsNails-1.9.4-1.0.11 in Forge 1.10.2-12.18.1.2073 and no other mods, I have found that drinking dirty water applies a Thirst status effect, turns the thirst bar green, and then nothing happens. I would assume it would be a Hunger-like effect where my droplets rapidly deplete, but they remained unchanged.

The same is true with both dirty water bottles and dirty canteens.

Other effects related to body stuff--hypothermia, heat stroke, dying of thirst, etc. etc.--all work fine still. It only seems to be the Thirst effect which does nothing.