My wife accidentally ruined my childhood

The strongest my immunity got was during the two months I became the "hands on" operator at a fabric filter package wastewater plant that had rotary sprayers to aerate the water. But for all intents and purposes, properly operated municipal water is best. But all water systems get some kind of biomass growing in the system. Monthly routine e.Coli bacterial tests let the people that run it know when there is a problem.