Backflow can cause safety issues not only for the localized owner where the event occurs, but also to a broader neighborhood depending on the severity of the event.  Cities should have backflow prevention programs in place to limit risk associated with backflow.  If a city does not have a program in place, health issues and corresponding legal issues could occur.  

What does a quality backflow prevention program look like?

DrinkTap.org provides the information below about how water providers should be working to prevent backflow.  

Cities should have a maintained inventory of all backflow devices within their jurisdiction, and they should be actively managing the testing of all those devices.  Education is also an important component of any backflow prevention program.  Partnering with backflow testers and owners of backflow devices while proactively governing all aspects of a backflow prevention program ultimately helps ensure everyone is protected.

According to the the American Backflow Prevention Association, a large number of backflow incidents may not be reported.  This can be due to several items.  The short duration of the incident could make it difficult to detect in the first place, but customers may also not know that they should report the issue or even know where to report the issue. In other situations, the customer may be nervous about liability concerns.

To read about all of the concerns in this space, feel free to review the American Backflow Prevention Association's page on backflow incidents.

In general, it is important to realize that while we may not hear about a high volume of backflow-related incidents, it is likely that many events are actually occurring that are not reported.  When major incidents do occur, they can be severe and pose considerable risk to municipalities who are responsible for protecting their citizens.