I did not drink any but I assure you it was cold. It's coming off of a mountain in a deep gorge so I imagine if you filtered it your filter would not pick much up. I found it hard to shoot as the only time the sun reaches the floor is when it's directly overhead. And after it dips past the rim of the gorge, things get dark fast. I agree that the best shot is the 1st and that shot was taken when the sun dipped behind a cloud.