Backflow Prevention

What is backflow?

Backflow is “a reversal of the normal direction of flow within a piping system” or as “the flow of water or other liquids, mixtures or substances into the distribution system from any source other than the intended source of the potable water supply”

The probability of backflow taking place at any single outlet may actually be very small; but in the large view of the entire public water system due to the number of connections the probability overall becomes significant. 

How does backflow occur?

Cross-Connection: Any arrangement of pipes, fittings, fixtures, or devices that connects a non-potable water system to a potable water system.

Cross-Connections can be a variety of different things but the most common are cisterns or wells, irrigation systems and fire protection systems.

Backpressure: A reversal of the normal direction of flow in a piping system due to a downstream pressure that is greater than the supply pressure.

Back-Pressure can be created by boilers, chillers, internal plumbing systems or any other system that can create a water pressure greater than the normal supply pressure.

Back-Siphonage: A reversal of the normal direction of flow in a piping system due to a drop in the supply pressure to the point that a vacuum, partial vacuum or negative pressure occurs in the upstream piping.

Back-Siphonage can be created by a drop in the supply pressure in the water main or in the water user’s internal piping system.

What is the law?

Ohio Administrative Code Chapter 3745-95 requires public water suppliers to protect their water systems from cross-connections and prevent backflow situations. Public water suppliers must conduct cross-connection control inspections of their water customers’ property to evaluate cross-connection hazards and ensure containment devices are tested annually.

How to comply

Residential Compliance: Ensure your irrigation system has an approved, testable device that is tested annually (before June 30th), and results sent to The City of Avon Utilities Department. City of Avon standards are all irrigation systems must have a Pressure Vacuum Breaker (ASSE 1020) or Reduced Pressure (ASSE 1013) back flow device. All outdoor spigots should be protected with a hose bib pressure vacuum breaker, residents can purchase these at most hardware stores or online. See below for picture

Commercial Compliance: All commercial properties in the City of Avon are required to have a Reduced Pressure (ASSE 1013) backflow device on the domestic water service and any fire line services must have a Double Check Detector Check (ASSE 1048) or a Reduced Pressure (ASSE 1013) backflow assembly.