In many areas of Canada, like Ontario, the levels of potentially pathogenic microbes can flourish and overwhelm our water treatment system leading to boil water orders or worse, outbreaks. These moments are thankfully rare in part to the addition of a particular chemical, chlorine. For decades, chlorine has been used to keep drinking water safe and is standard practice in many parts of Canada and the world. But it's not a perfect system and faces many hurdles. The most important of these is ensuring water is safe over the tens to hundreds of kilometres of pipes from the facility to the tap.