What is Backflow?

Backflow is the unwanted flow of water, other liquids, solids or gases into the distributing pipes of a potable water supply. Back siphonage is one type of backflow. Back siphonage is the flowing back of used, contaminated, or polluted water from a plumbing fixture or vessel into a potable water supply due to a negative pressure in the pipe.

What Causes backflow?

Backflow can only occur when a sudden drop in water pressure in the drinking water system affects an area not protected by backflow prevention devices. Some examples are a car hitting and breaking a hydrant, a hose left attached to an outside faucet, and an improperly positioned drain hose from a clothes washer.

Austin Utilities requirements

The Austin Utilities Board of Commissioners has agreed that the most effective method of preventing backflow in commercial and industrial locations is to require the installation of an appropriate backflow preventer immediately down line from the water meter. Austin Utilities will work with its customers to determine the appropriate device for the business. This policy places an equal burden on all businesses and provides a consistent, reliable, and verifiable measure of safety for the residents of Austin. These devices will be installed and maintained at the owner's expense. Austin Utilities requires written proof of installation and annual inspection of the assembly by a licensed plumber certified in installing, maintaining, and inspecting backflow preventers. A list of such contractors is available through Austin Utilities. Compliance with this safety code is mandatory, and Austin Utilities may discontinue water service to any location which poses a contamination threat to the public water supply.