[D9 (RIP)]

My 0.02, until you get a more permanent solution in place, like verified clean well-water, I think bleach is the best solution to your problem.

1.) It works.

2.) It's always available and cheap.

3.) It's something you can show the LN that they can use later b/c it's easy and available. If they don't choose to, their problem. But you've shown them an alternative.

Filter out the debris by some simple conventional means: fine wire strainer, cheesecloth, cotton, filter paper, etc.

Add bleach and let it sit. You get two 55 gal drums, fill one and treat it. Use it 24 hrs later while you're using the other one.

In very austere environments like that I would be wary of depending on a complicated system b/c of the availability of power or parts. Esp w/ expensive equipment that will likely be stolen if it is not continuously guarded.

Bleach works, is simple, cheap, and available. I would use it in the scenario you describe until something more permanent could be established. Sometimes the simple solution is the good solution.