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.

In the PNW I'd go for rainwater collection, even during the summer you are seldom without. Compared to drinking polluted river water, I'll take my chances drinking potential pollutants flowing off a roof and originating in Far Eastern pollution sources coming over on the jet stream. You can also minimize contamination from a local roof source by putting down the proverbial large blue tarp - and if my neighbor's are gone, to heck with the issues around what will the neighbor's think. They've never lived in Australia, that's for sure. Rain is good...

I think that with all the materials laying about in an abandoned city, a large solar still could be quite easy to make.

With enough fuel and a good thermometer you could distill water and have a very strong chance of removing chemical pollutants. It would also inactivate any biological contaminants.

Man that show was like 3-4 years ago? I did see they are showing it again. I liked the first season over the second.

I probably would have drank the water the way they did on the show, it was in LA, wasn't it? I think your concerns over what wasn't filtered out is a valid thought that I would have had too but no I do not believe they were given any outside assistance with food and water. That filter was quite large IIRC.

water could be separated from dissolved ionic compounds by simple distillation... if there were dissolved gas or liquid portions, these should be removed prior to the distillation process if possible...pure substances have unique boiling points, and if the bp of the gas or liquid is less than water it can be separated by boiling in a container open to the atmosphere first...

I've been playing with very small scale solar distillation units for the last couple of summers (yields less than 300ml a day)... from my limited attempts, the best collector is of the "water cone" variety, where a very steep elevated center cone of the glazing material ( transparent/translucent plastic sheeting)causes an immediate run off of the condensed liquid... a circumferential collecting trough probably will work best for a large scale unit...my best attempt utilized a hanging non potable reservoir with fill tube... a dark wicking cloth draped over an elevated center to increase the evaporative surface... standoff ring circling edge of reservoir to hold an exterior translucent trash bag away... open bag is tied shut at vertex of the hanging reservoirs support arms, and weighted at corners of bag to hold in position... water condenses and runs to the weighted corners..

I'm curious, Chisel, do you have sort of idea of how much water you could produce for your mega solar still idea? I'm always disappointed at how little solar stills produce, and I wouldn't be surprised if scaling it up even much larger still yields a pretty meager amount of water.

You would probably net a whole lot more potable water by going out and finding bottled water, or even draining water heaters. One big, commercial water heater could last quite a while. Security may be an issue with going out, but even at "the colony" they still had to worry about outsiders breaking in, so even a solar still inside your compound could make a juicy target that needs a lot of resources to defend, especially if word of its existence gets around. Anyway, just some musings.

Arney...there is a pretty clever terracotta solar still that claims 5 liters a day output.... appears relatively small in pictures, about 1.5m in diameter.... look up "eliodomestico"

Wow, an incredible benefit to many, many millions of people in the world if it can get anywhere near 5 liters a day--and from salt water to boot! I tried scanning through a bunch of citations but I haven't seen any third parties actually doing a performance review, particularly about the output, so I don't know if it really works that well yet.

Yes, Arney . I know how little water it produces , but for the limited amount of work and skill necessary to make it, it was worth it to give it a try.

In the first season of Colony they constructed a shower with water tank/solar heater on the roof of the building. In the 2nd season, they constructed a windmill on the roof. IMO, it was also worth it to construct a mega distillation or at least 3-4 solar distillation systems on the roof. Most of the matrial was available.

In addition, they wasted lots of energy on non-essential stuff!! so why not solar stills ? IMO, if they had enough energy to make such unnecessary gizmos like the sun-tracking-rotator for the solar panels ( which is ridiculous IMO, with all my respect to John Cohn, the professor, whom I admire), they would be wiser to spend the resources on mega or multiple solar stills to , at least, supplement their drinking water.

If they made 4 solar stills on the roof and each of them produced 2 liters a day, that is eight liters. Almost one liter per person a day.

Off course, they should have improved their rain catching system too. In Season 2 , a cistern was constructed to hold around 400 gallons of rain. In season 1 , they has the "luxury" of the rain gutters pouring rain INSIDE the building. So, collecting rain would have been safer and easier. But they just collected rainwater in ice chests and other containers. They could have made a cistern in season 1, but it seems to me that if it didn't involve electronics and lots of welding, they didn't want to do it. LOL