Backflow Prevention

Modern Electric Water Company’s water system is designed to keep water flowing from our distribution system to you, the customer. Backflow can occur due to high pressure on the customer side, or low pressure in the Company’s water system. Backflow is the undesirable reversal of water flow in a potable water system through a cross-connection. This situation may allow liquids, gases, non-potable water, and other substances, from any source, to enter a public water system.

A cross-connection is a point in a plumbing system where the potable water supply is connected to a non-potable source. Briefly, a cross-connection exists whenever the drinking water system is or could be connected to any non-potable source (plumbing fixture, equipment used in any plumbing or irrigation system). Pollutants or contaminants can enter the safe drinking water system through uncontrolled cross connections when backflow occurs.

This program is required by the State of Washington to detect and prevent possible sources of non-drinking water from entering a public drinking water system. The program is a combined cooperative effort between plumbers, health officials, water system operators, property owners, and certified testers to follow guidelines for controlling cross-connections and implementing means to ensure their enforcement so that the public drinking water supply will be protected both in the city main and within private facilities. The elements of a program define the type of protection required and responsibility for the administration and enforcement. Other elements ensure continuing education programs.

Every water system has cross-connections. Plumbing codes and State drinking water regulations require cross-connections to be controlled by approved methods (physical air gap) or approved mechanical backflow prevention devices or assemblies. The various types of mechanical backflow preventers include: reduced pressure backflow assembly (RPBA), reduced pressure detector assembly (RPDA), double check valve assembly (DCVA), double-check detector assembly (DCDA), pressure vacuum breaker assembly (PVBA), spill-resistant vacuum breaker assembly (SVBA) and atmospheric vacuum breaker (AVB). For a backflow preventer to provide proper protection, it must be approved for backflow protection, designed for the degree of hazard and backflow it is controlling, installed correctly, tested annually by a State certified tester, and repaired as necessary.

Visit the Washington State Department of Health's page on Cross-Connection and Backflow Prevention for more information.

The ordinary garden hose is used to create the most common form of cross-connection. A hose can be easily connected to the drinking water supply and used for a variety of potentially dangerous applications. An example would be a garden hose attached to a service sink with the end of the hose submerged in a tub full of detergent. Another example would be a garden hose attached to a faucet and the other end lying in a swimming pool. Another example would be a garden hose attached to a faucet and the other end attached to a fertilizer/pesticide handheld sprayer.

No, all public water systems are required to implement cross-connection control programs in the State of Washington.

Backflow preventers will be required if an actual or potential hazard for a cross-connection exists. A few examples of hazards include:

• Commercial and Residential Irrigation Systems
• Fire Sprinkler Systems
• Medical Facilities
• Processing Plants

Modern Electric Water Company will determine which type of protection is required based on the degree of hazard that the property represents to the drinking water supply.

A backflow issue exists if a lawn irrigation sprinkler malfunctions and a water main breaks at the same time. When the water pressure drops, it creates a vacuum that sucks some water, which may be contaminated, into the water supply.

An example of this situation includes customers observing yellow water flowing from a drinking fountain and green ice rolling out of an ice machine. The contaminants were traced to an error by a maintenance person. A pump for the air conditioning system burned out and the maintenance person, unaware of the danger, connected the system to another pump used for potable water. The result caused large doses of bichromate of soda to be forced into the drinking water supply, causing the dramatic appearance of yellow water and colored ice cubes.

Soft drink dispensers (post-mix carbonators) use carbonated water mixed under pressure with syrup and water to provide soft drink beverages. Many, if not most internal water pipes, are made of copper. When carbonated water comes into contact with copper, it chemically dissolves the copper from the pipe. This copper-carbonate solution has been proven to be a risk to the digestive system.

There is no “grandfathering” of backflow devices which are out of compliance with current regulations. The State considers backflow regulations to be a health and safety issue. These issues must be addressed in a timely matter for the safety of the public water supply and the health of our customers.

The Environmental Protection Agency (EPA) enforces the backflow regulations by delegating the responsibility to the State. The Washington State Department of Health/Office of Drinking Water then enforces the backflow regulations by requiring the water purveyors to administer the backflow program locally. Modern must report to the State annually to determine it is administering the program according to regulations.

It is the responsibility of the customer to ensure that the backflow prevention assembly is in proper operating condition at all times. Modern sends notices to customers reminding them when a test is due.

All devices are required to be tested upon installation of the device and annually thereafter. Any time a device is worked on or repaired it must also be retested.

Backflow devices are mechanical devices with working internal pieces. A piece of debris or the calcification of water can cause the device to stop working.

Any certified backflow prevention assembly tester who is registered may be called on to test the device. If the device is located on a fire system, the tester must be employed by an Approved Fire line Tester. The tester will return the original report of the test to Modern and will give the customer a copy of the test report.

The cost of having a device tested varies among testers. The cost is also dependent on several factors, including the size of the device, where the device is located, the type of device, etc. You may want to call several Certified Testers to obtain quotes for your test.

Modern Electric Water Company may be reached at (509) 928-4540 or by emailing backflow prevention.