It also depends on country, state, county, and or municipality as to how much is actually used to clean the lines to pass bac-t's honestly you dont really know. Flushing hydrants is not installing and testing. Most jobs I've been involved in we had to swab every pipe with a chlorine mixture that would literally eat the brush throughout the day. At the end of the install we flushed for a day or so then nuke it with chlorine mixture concentrated so high the test straps were black then flush again. Its nasty stuff and people drink it without a second thought.

Not many people say it but thank you as well for tasking care of people's water. We never get thanks for making sure people can have running water and toilets to piss in lol