DISCLAIMER: I've not used this product and I can't speak to whether it works or not... YMMV
https://www.waterfilters.news/2018-03-29-scientists-create-a-cheap-paper-water-filter-that-removes-lead-arsenic-bacteria.htmlIt is, now, relatively cheap AND something which has a prepper utility.
Too bad it's only available from Amazon at the time of writing of the article.
If this flies, I would expect to see it appear in other retail outlets. Cross your fingers.
IF this is true, I would certainly have a large supply in my prepper stocks, along with containers designed to be used with the filter material. That includes test kits to check for Arsenic, Lead and perhaps various bacterial contaminants. "Trust, but verify"...