Backflow Prevention and Cross Connection Control

What Is Backflow?

Backflow is the undesirable reversal of flow of nonpotable water or other substances through a cross-connection and into the piping of a public water system or consumer’s potable water system. There are two types of backflow-backpressure backflow and backsiphonage.

What Are Backflow Preventers?

A backflow preventer is a means or mechanism to prevent backflow. The basic means of preventing backflow is an air gap, which either eliminates a cross-connection or provides a barrier to backflow. The basic mechanism for preventing backflow is a mechanical backflow preventer, which provides a physical barrier to backflow. The principal types of mechanical backflow preventer are the reduced-pressure principle assembly, the pressure vacuum breaker assembly, and the double check valve assembly. A secondary type of mechanical backflow preventer is the residential dual check valve.

Why Do Backflow Preventers Need Testing?

Mechanical backflow preventers have internal seals, springs, and moving parts that are subject to fouling, wear, or fatigue. Also, mechanical backflow preventers and air gaps can be bypassed. Therefore, all backflow preventers have to be tested periodically to ensure that they are functioning properly. A visual check of air gaps is sufficient, but mechanical backflow preventers have to be tested with properly calibrated gauge equipment.

Backflow Preventer Testing Requirements

Commercial Properties: Once Annually


These testing requirements are specified in the American Water Works Association (AWWA) M14 manual of water supply practices which the City of West Melbourne code of ordinances (Section 90-52.(g) - Backflow preventers) require compliance.

The following link can be used to download the form required for submitting backflow preventer testing results to the City:

More Information

For additional information regarding backflow preventers within the City of West Melbourne, please see the City Ordinance (Section 90-52. - Backflow preventers) addressing this topic:

For general information regarding backflow preventers, please refer to the Florida Department of Environmental Protection guidelines (Chapter 62-555) addressing this topic: