I got interested in the Colony show for many reasons.

Let's forget the "show" part, and assume we are the colonists and had to live in a similar setup ( season 1 ) for a few months perhaps. One of the commenting "experts" on the show said that the "river" (actually more like a small creek) was quote ( a stew of pollutants). Those pollutants are not only bacteria and viruses, but chemicals as well.

I don't know if those guys have really been drinking that water or maybe they sneaked - off camera- and drank some bottled water hidden in some corner. But if I was a colonist, I will not drink it even after that sand and charcoal filtration. Such treatment is not adequate to remove much petrochemicals or other pollutants.

Question to all.
If you were in such a survivor colony (season 1), what would you do to purify water ??

IMHO, if I was one of them , I would work with Joey to make another "bath" , but instead of showers , the purpose is to make a mega-sized solar still. I would collect all the glass or plastic sheets I can find, and build a long narrow room with lots and lots of glass surface. Water collected from the river will be dumped in that 1 cubic meter ( 220 gallon ) tank they found, and let it seep slowly into the solar still and collect on the other side as PURE water.

Only then, I would feel comfortable to drink it.