One of the most valuable shared resources in our community lies right beneath our feet.
Clark County is fortunate to have a large and high-quality aquifer to rely on for its drinking water supply. We can help protect our water by being mindful of what goes into it.
One of the most important things home and property owners can do is ensure their backflow prevention devices are regularly tested and kept in top shape.
“Backflow prevention devices prevent pollutants from getting sucked back into the water supply,” said Gary St John, water quality specialist at Clark Public Utilities. “Not every home has one, but every irrigation, automatic lawn sprinkling system or large dedicated fire suppression system should have backflow preventers installed. And they should be inspected and tested at least once a year.”
Backflow prevention assembly testing is required by law. Clark Public Utilities recommends testing in the spring, just before the irrigation season begins. It’s quick and doesn’t cost much.
Backflow occurs at the customer’s end of the tap when water flows opposite of its intended direction. That phenomenon can pull harmful substances into a water supply.
Typically, backflow is rare. It’s most likely to occur just after a significant impact to the water system — like a main break or a large firefighting effort near your connection. When it does occur, irrigation systems pose some of the greatest risks of contamination. Without a functioning backflow blocker, they can draw in harmful lawn and garden chemicals.
“Many of our customers who either just moved here or just bought a new property had never heard of backflow prevention or backflow testing until we they spoke to us,” St John said.
To find out if your irrigation system has a backflow prevention device look for an in-ground, green-lidded rectangular box near the water meter or close to the house. If you have one, it’ll be in there.
Clark Public Utilities water customers who aren’t sure if they have a backflow assembly can call the utility’s dedicated backflow line at 360-992-8589. If there’s not a record of a backflow prevention device at your address, a serviceman can come to inspect the system.
“We can only check backflow status for our water service customers,” St John said. “Other folks should check with their specific water provider.”
Clark Public Utilities offers a convenient annual backflow testing program for its water customers. Every year a certified backflow assembly tester is contracted at a set rate to test every participant’s backflow device. To participate, call the utility’s backflow line mentioned above.
A list of some backflow assembly testers can be found on the Clark Public Utilities website. It’s not a recommendation or warranty of any kind — but it is a helpful place to start looking for a professional.
Properties without irrigation systems probably needn’t worry about backflow. Residential and most commercial plumbing fixtures have air gaps that stop it. Many lawn sprinkler systems are equipped with atmospheric vacuum breakers, or AVBs that do the same.
The one place the average homeowner could see backflow is at the garden hose. Homes built before the 1990s might not have vacuum breaker-equipped hose spigots. Replacing those will eliminate the risk. But if that’s not an option, the hose should never be submerged after it’s been shut off.
Energy Adviser is written by Clark Public Utilities. Send questions to ecod@clarkpud.com or to Energy Adviser, c/o Clark Public Utilities, P.O. Box 8900, Vancouver, WA 98688.
