Two months ago I made a post about using resevoirs in chlorine to kill germs in water, I called it the "Septic System"
Note the V3 is meant for maps with infected polluted water geysers. Scrool down to the bottom of the post to see a "simple septic system" design meant for disinfecting PW from bathrooms
Since them I have updated it to run more smoothly and use less power
Thanks to @suicide commando for giving me a tip about disabling reservoirs by opening horizontal doors undern