We are all used to seeing backflow preventers, even if we didn’t know what they were used for. These complicated assemblies of pipes are designed to prevent water from reversing its course and re-entering the public water supply. Water that has been polluted or contaminated and re-enters the potable water system is a serious public health threat. There are a number of different types, although only one is common in residences. To find out more, take a look at our new article on backflow preventers for inspectors.