Backflow Testing in Pullman, WA
Protect Pullman's municipal drinking water supply and keep your property compliant with Washington Department of Health annual backflow prevention testing, rebuilds, and installations.
Washington State Purveyor Compliance
Under Washington Administrative Code (WAC 246-290-490), all cross-connection control backflow devices must be inspected and certified annually by a licensed tester.
- Certified Backflow Assembly Testers (BAT) on staff
- Testing for Double Check Valves (DCVA) & RPZ assemblies
- Complete municipal test report submission to City of Pullman
- Fast rebuilds, internal check valve replacements, and spring overhauls
Why Annual Backflow Testing Is Mandatory in Pullman
Preventing contaminated irrigation water and industrial fluids from siphoning into clean public drinking lines.
In any municipal water distribution grid, pressurized potable water flows in a single direction from city mains into homes and commercial facilities. However, when sudden pressure drops occur—such as during a water main break, firefighting operations near WSU, or heavy seasonal irrigation draws—a vacuum condition called back-siphonage can develop.
Without a properly functioning mechanical backflow preventer assembly, stagnant water from lawn sprinkler lines containing fertilizers, pesticides, animal waste, or industrial boiler chemicals can be drawn backward into the potable drinking supply.
Systems Requiring Annual Testing in Pullman:
- Lawn & Landscape Sprinkler Systems: Underground irrigation systems equipped with Double Check Valve Assemblies (DCVA) or Pressure Vacuum Breakers (PVB).
- Commercial Restaurants & Food Service: Soda fountain carbonators, commercial dishwashers, and grease interceptors along the Grand Avenue corridor.
- Medical & Veterinary Facilities: Laboratories, dialysis clinics, and sterilizers requiring high-hazard Reduced Pressure Zone (RPZ) devices.
- Multi-Family Residential Buildings: Fire suppression systems and dedicated boiler loops on College Hill.
The Certification & Reporting Process
During an annual backflow inspection, our certified tester connects calibrated differential pressure test gauges to the assembly's test cocks. We measure line pressure differentials across internal check valves and verify relief valve opening points.
Upon successful testing, we file the official compliance documentation directly with the City of Pullman Public Works Department and provide you with a copy for your records.
Winter Freeze Damage on Backflow Assemblies
Backflow assemblies installed in unheated outdoor meter vaults or exposed basements frequently freeze during sub-zero Palouse cold snaps. We carry factory rebuild kits to replace cracked brass bodies and warped rubber seals.
Pullman Plumbing Services
Reliable diagnostics, certified repairs, and code-compliant installations engineered for Palouse winter freezes, hard mineral water, and Whitman County rental homes.
Pullman & Palouse Regional Service Areas
Direct mobile plumbing dispatch serving residential neighborhoods, university quarters, and Whitman County communities.