The City of Longview maintains a standing requirement for all new and existing backflow assemblies to undergo annual testing by a State of Washington certified backflow assembly tester. According to the city’s website, these regulations are designed to prevent non-potable water or toxins from being drawn back into the municipal distribution system during pressure fluctuations.

For residents in Longview, the requirement applies to common household fixtures that create cross-connections between drinking water and other substances. Typical residential examples include lawn irrigation systems, swimming pools, jacuzzis, hose bibs, and toilet ball-cocks. The city identifies backflow as a risk when the main distribution system loses pressure due to water main breaks or the withdrawal of large volumes of water for firefighting.

Under these conditions, unprotected fixtures can allow substances to be siphoned into the public supply. The city cites the example of a garden hose with a plant food applicator; if water is siphoned out of the home system, the chemicals enter the distribution lines, potentially reaching neighboring taps. Back-siphonage can also occur if a hose is left in standing water, such as a pool or hot tub. Additionally, back-pressure may be created if a pump on a private property generates pressure greater than that of the city distribution system.

Compliance requires that all test reports be submitted on the City of Longview Backflow Preventer Inspection and Field Test Report Form. Completed forms must be emailed to the city’s dedicated backflow department or mailed to the Utility Operations Center at PO Box 128. The city maintains a list of certified testers operating in Cowlitz County and surrounding areas to assist property owners in meeting the annual requirement. Residents seeking further information may contact the Utility Operations Center at 1460 Industrial Way.