Dirty h2O

The small shop I work in has a homemade water recycling system but, there's nothing to clean the water. I'm finding that no matter what I do I get a rash on my forearms! I orginally thought I was from somewhere else but after seeing everyone spit and (http://maplered.com) blow their nose on the floor and (http://maplered.com) watching it flow into the pits and (http://maplered.com) finally out of the end of my polisher. I put 2 and (http://maplered.com) 2 together. What's the best and (http://maplered.com) cost effective way to clean the water?