Cross Connection and Backflow

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ConnectionThe District goes to great lengths to ensure that the water delivered to our customers is of the highest quality. A vital link in this effort is the District’s Cross-Connection Control and Backflow Prevention Programs.

Water distribution systems are designed to flow in one direction from the main to the customer. When the direction of flow is reversed due to pressure differences, (such as fire fighting efforts, a water main break, or consumer high side pressure (pumped)), backflow can allow contaminants to enter the potable drinking water system through cross-connections. When this happens, any substance that may be in contact with the water supply main or line could be siphoned into the public water system.

Backflows due to cross-connections are serious plumbing problems; however, they can be avoided by using the proper protection devices.

Be involved in keeping your water safe from contamination
Without proper protection devices, something as useful as your garden hose has the potential to contaminate your home's water supply. In fact, over half of the nation's cross-connections involve unprotected garden hoses. Without a backflow prevention assembly between your hose and hose-bibb (spigot or outside faucet), the contents of the hose and anything it is connected to can backflow into the piping system and contaminate your drinking water. This hazardous situation sometimes can affect more than a single home. Each spigot at your home should have a hose-bibb vacuum breaker installed. This is a simple, inexpensive device which can be purchased at any plumbing or hardware store. Installation is as easy as attaching your garden hose to a spigot.

Cross-Connections are any unprotected connection or structural arrangement between a public or a consumer's water system and any other source or system where it is possible to introduce any water or substance other than the intended potable water. Bypass arrangements, jumper connections or any other temporary or permanent connections through which backflow can occur are considered to be cross-connections.

Backflow is the undesirable reversal of flow of water or mixtures of water and other liquids or substances into the distribution pipes of the potable supply of water from any source or sources. If a cross connection exists in a system, it does not mean that there will be a backflow every time. But, where cross connections exist, there is always the possibility.

Federal and State laws require water purveyors to protect their system from cross-connections and backflow. To do this, we work closely with consumers, architects, contractors, and engineers to insure that all laws are met and the potential for water contamination is minimized. The District has developed and implemented an ordinance that requires all industrial, commercial, irrigation customers, and some homeowners to install approved backflow prevention assemblies. These assemblies must be installed on the customers' property before branching to a private system.


Frequently asked Questions

What is a backflow assembly? Backflow assemblies are devices placed on potential cross-connections to prevent water from flowing back into the public water system. Different types of backflow prevention assemblies are required depending on the degree of hazard. Please call the Engineering Department if you have any questions regarding the type of device required for your particular situation. 

Who is required to have a backflow prevention assembly? Most multi-family units, as well as all commercial and industrial properties are required to have a backflow prevention assembly. Also, any single-family residence that has a sewage lift pump, fire sprinkler system, or a direct connection to a pool or fountain.

Where are common cross connections found? Wherever a plumbing fixture is connected to the drinking water supply, a potential cross connection exists. Some examples are: Wash basins, sinks, dishwashers, garbage disposals, showers, bathtubs, toilets, and hose bibbs (faucet to which a hose may be attached or buried yard hydrants).

Does my backflow assembly need to be tested? Yes. State law requires that a certified tester check all backflow assemblies at the time of installation and annually thereafter. The Engineering Department has a list of current certified testers in the Orange County area as well as lists of approved Backflow Prevention Assemblies for your information. 

What happens if I do not test a backflow assembly when notified by the Water District? If you do not test your backflow assembly on an annual basis, and when notified to do so by the District, you may be cited and fined for non-compliance. Also, your water service may be terminated to protect the public water system. For more information about this program, please contact the District at 949-464-3117.