PV has a state of the art purification system. BUT I have never found any back flow prevention devices in Puerto Vallarta Im sure there are some. So that means that a farmer or other person could put his water hose in a very bad place and if the water line broke or some other event happened that caused a back flow event, ( the water being sucked back into the hose and into the main water supply) the water from your faucet could be contaminated with ?)&$#@!(> if you know what i mean. We live there 6 months a year and still drink bottled water or our water that has been purified thru our own filtration system installed in our condo. Your choice