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Cross Connection and Backflow Prevention

West Virginia American Water’s cross connection control program is designed for containment protection of the distribution system. Customers with the highest potential for contamination are required to take steps to protect cross connections and prevent backflow to the water system. This includes the installation of an approved backflow prevention device based on the degree of hazard, in addition to annual testing. The customers associated with the highest risk of contamination are most often non-residential customers. This practice follows guidelines as set under West Virginia Bureau for Public Health Legislative Rule 64CSR15.

Containment devices are required on the customer’s main domestic, fire, or irrigation line(s), as close to the water meter as possible, but before any branch off of the water occurs. West Virginia American Water can help to determine if you are in compliance with the regulations, and we are available to answer any questions that you may have related to backflow prevention.

What is a cross connection and backflow?

A cross connection is any actual or physical connection between a potable (drinkable) water supply and any source of non-potable liquid, solid or gas that could contaminate drinking water under certain circumstances.

Backflow is the reverse flow of water or other substances into the treated drinking water distribution system. There are two types of backflow: backpressure and backsiphonage.

  1. Backpressure happens when the pressure of the contaminant source exceeds the positive pressure in the water distribution main. An example would be when a drinking water supply main has a connection to a hot water boiler system that is not protected by an approved and functioning backflow preventer. If pressure in the boiler system increases to where it exceeds the pressure in the water distribution system, backflow from the boiler to the drinking water supply system may occur.
  2. Backsiphonage is caused by a negative pressure (vacuum or partial vacuum) in the water distribution system. This situation is similar in effect to the sipping of water through a straw. Negative pressure in the drinking water distribution system can happen because of a water main break or when a hydrant is used for fire fighting.

Why backflow prevention is important

Drinking water that meets regulations leaving the water treatment facility can become contaminated in the distribution (pipeline) system by backflow when:

  • A drinking water distribution main is unprotected because of the lack of a properly installed and functioning backflow prevention device on the service connection at the customer's supply.
  • A physical cross connection is made between the drinking water distribution main and a contaminant source.
  • Backflow conditions occur.

How to prevent backflow contamination

Backflow contamination can be prevented. All non-residential water utility customers are required to have approved and functioning backflow prevention devices installed. Installation of backflow prevention devices can be completed by an independent plumbing contractor. The cost of the device and installation is the responsibility of the customer. We recommend that customers obtain cost estimates before installation. In addition to installing these devices, regulation mandates that non-residential water customers have these devices tested on an annual basis by a state certified tester. For a list of certified testers, please see the links below. Other steps to prevent backflow situations in your home or business include:

  • Be aware of and eliminate and/or protect cross connections.
  • Maintain air gaps on sinks and when using hoses.
  • Do not submerge hoses or place them where they could become submerged.
  • Use hose bib vacuum breakers on fixtures (hose connections in the basement, laundry room, and on outside faucets/spigots).
  • Install approved backflow prevention devices on lawn irrigation systems and on fire sprinkler system services.
  • Never create a connection between an auxiliary water system (well, cistern, body of water) and the water supply plumbing.

Prohibited Connections

West Virginia legislative code mandates that no secondary source of water supply be physically connected on the customer service line to or into the facility.


We will work with you to answer any questions you may have regarding backflow prevention and the corrective actions necessary to ensure compliance. Below are additional resources that may be helpful.

If you have any questions, please contact our Cross Connection Department:

West Virginia American Water
Cross Connection Department
1600 Pennsylvania Ave
Phone: (304) 340-2070
Fax: (304) 340-2071