Most parts of the US and Canada have safe drinking water if filtered properly by the city. The SDWA (Safe Drinking Water Act) was passed by Congress in 1974 which sets limits on levels of harmful contaminants but it’s only tested for 91 chemicals. There are still many that may be undetected and could be consumed.

If water leaves the treatment facilities that they’re purposely meant to pass through then tap water can easily become contaminated. The best way to protect yourself and others from these contaminants is by installing your own water purifying system that filters tap water.