I used to have a camping water purifier from MSR that they developed with a company called MIOX. It ran on batteries and had a little catalyst and you put salt

I used to have a camping water purifier from MSR that they developed with a company called MIOX. It ran on batteries and had a little catalyst and you put salt solution in and it fizzed and produced chlorine that you poured into your water bottles. It smelled like a pool. As long as you had batteries and salt you could make an infinite amount of chlorine. It looks like MIOX is still around [0], they make portable units for the military and for temporary installation but I imagine this approach isn't cost effective for a permanent facility. [0] https://www.miox.com/ https://www.miox.com/