Plumbing has been around as long as there have been houses to put it in, nothing has changed. The job is still the same and the knowledge required to fulfill that purpose is in unchanged. Backflow can occur because of a lawn sprinkler system, or by a loss of pressure. It's not something that you want in your home, and you don't want to put your community's water at risk.
Texas Lonestar — A+ Service, would definitely call again for plumbing issues! When everyone else was 2-3 weeks out, Holey Plumbing found time