This blog was inspired by this fact:
The New York City water supply system leaks at a rate of up to 36 million US gallons (140,000 m^3) per day.
Our water is extensively purified, and is completely safe to drink, but how can it be safe if some of the biggest supply pipes have holes all over?
Besides the full -on sanitation of the water, one part of the solution is that our water supply contains some residual chlorine and other chemicals that stop bacteria growth from occurring in tap water. Any pipe leaks/breaks that occur in supply lines that can actually affect water quality can be isolated and the water diverted until a replacement segment is installed. also, the pipes are pressurized to a level where nothing could get into the system through a hole because of the pressure difference. This is visualized by seeing water leak OUT of a pipe, and not seeing things go in.
By the way, tap water is safer than bottled water and is subject to stricter regulations in many different tests.