ALS Ice Bucket Challenge

I just saw that, in Canada alone, the ALS ice bucket challenge raised $16.2 million.
I started thinking (surprise) and bouncing a few numbers around in my noodle. I think it's a reasonable guess that it took about 1 litre of potable water per dollar raised. 
That's, conservatively, enough drinking water for 43000 people for a year. 

It's not that ALS isn't a worthy cause. I'm not even talking about the pop-culture moment that was the ice bucket challenge. It's the cost that I'm having trouble reconciling.