Most water systems come in 2 parts. The storm system which is basically rain from outside (house roof run off road drains, etc) and the sanitary sewer which is always anything that comes from the home, toilets, sinks, tubs, washing machines. you piss in the shower it will get processed just like if you piss in your to toilet. Piss away MerrillMost municipalities in the US reclaim drainage water. It’s not the same as “black water” or sewage. That’s a totally different treatment facility. Once both have been treated, guess where it goes?