Cross Connections and Backflow Prevention
Controlling potentially hazardous cross-connections is required by Washington Administrative Code 246-290-490. West Sound Utility District (WSUD) strives to provide quality drinking water from its source to every customers meter. A cross-connection in private water pipes on the customer side of the meter can threaten the quality of the drinking water of the affected customer first, then the rest of the district after that. During a backflow event, if there is a cross-connection present it could affect your drinking water.
A cross-connection is a situation where some substance other than potable drinking water can enter the water pipes, coming into contact with your drinking water thus contaminating it. There are many common places around your property that could result in a hazardous cross-connection. Some examples are:
- Fire sprinkler systems
- Lawn irrigation systems
- Auxiliary water supplies (wells)
- Hot tubs, spas and swimming pools
- Hose bibs and garden hoses
- Carbonation Equipment
Backflow is the undesirable reversal of the flow of water from its intended direction in any pipeline or plumbing system. This can be caused by back pressure or back siphonage. Back pressure is when the downstream pressure is greater than the pressure of the water in the mains. This can be caused by things like the expansion of water caused by a water heater or pumps connected to the water supply. Back siphonage is when there is a vacuum or partial vacuum from negative pressure in the water mains. This can be caused by a water main break outside the site or even the use of a fire hydrant to fight a fire.
Due to the hazard this presents to all of our customers any site that is identified as having either a permanent or the high probability of a cross-connection hazard must be isolated using some sort of backflow prevention device. All backflow prevention devices must be inspected by WSUD at the time of installation or modification. Additionally each of these devices must tested on an annual basis by a certified backflow prevention assembly tester to ensure their ongoing functionality.
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