If we were forced to use our pools for drinking water, how would we be able to safely do so? Chlorine is self limiting, and depending on your level on any given day, would quickly drift down.(Federal guidelines for drinking water chlorine levels list the recommended upper level at about 4 ppm.) CYA, from what I have read, is essentially non-toxic, unless mixed with Melamine-is that true? For Borates, the LD 50 is 2.66g/kg in rats; how that would that work out in a human at 50 ppm? (Would Borates be stored by the body, or eliminated?) Salt is rather self-explanatory. You would have to assume that you would be supplying adults, children, and animals, as you would quickly become a community supply point.
So, hypothetical situation as follows. Power is down, no potable water available except your pool, which you suspect is not quite potable. What methods would you use to make it potable, based on, say: FC 4, CYA 40, Borates 50, pH 7.4, CH 300, TA 100. You could also work the problem with sodium 3000 ppm, just for additional complexity. (We'll hypothesize that since you use BBB, you have no algaecide in your water...)