Annandale is unincorporated Fairfax County on Fairfax Water, so testable backflow assemblies on sprinklers, pools, directly connected hot tubs and fire sprinklers must be tested at installation, after repairs and at least yearly by a certified tester on the County's authorized list. For a test, a rebuild or a replacement, call the number on this page to be connected with a local plumber in Annandale.
Local conditions in Annandale
Annandale is one of the older inner-ring parts of Fairfax County. It grew quickly after World War II, and its median home was built in 1968, so neighborhoods such as Ravensworth and the streets around Lake Barcroft have houses where sprinkler systems were added decades after the plumbing. Retrofitted irrigation is where backflow devices tend to be missing, mounted in odd spots or long overdue for a test.
Fairfax Water supplies the area from the Potomac River and the Occoquan Reservoir and, with Fairfax County Land Development Services, runs cross-connection control. Testers must hold the DPOR Backflow Prevention Device Worker certification and be on the County's authorized vendor list, and a new or replacement irrigation assembly needs a County plumbing permit. Fairfax Water owns the meter; the line from the meter to the house, and any device on it, belongs to the owner. In houses from the 1970s the meter is often inside, which can change where an assembly fits. Restaurants and shops along Little River Turnpike in the Koreatown business district can have their own assemblies on equipment or service lines, which also need testing.
Rebuild or replace?
| Situation | Usually a rebuild | Usually a replacement |
|---|---|---|
| Relief port drips steadily | Clean or reseat the first check and relief valve | Seats pitted beyond cleaning |
| Check will not hold pressure | New discs and springs from a kit | Parts no longer made for an old model |
| Brass body cracked after a freeze | Not repairable | New assembly, permit and test |
| Shutoff valves stuck or leaking | Valve repair on newer units | Corroded valves on an aging device |
| Device sized wrong for the line | Not a rebuild issue | Correctly sized assembly |
Signs it needs attention
- No one has a test record for the sprinkler or pool assembly
- Water runs from the device while zones operate
- A test cock or fitting is green with corrosion
- Irrigation pressure fell after the last repair
- A pool, hot tub or boiler fill was connected without protection
Timing notes
Drain an outdoor assembly before the first hard freeze and test it when you start the system up in spring. Fairfax Water's moderately hard to hard water can leave deposits on check seats, so an older device that barely passed last year is a good candidate for a rebuild. If a test fails, schedule the repair right away rather than letting the device run unprotected through another season.
Backflow Testing questions in Annandale
Who pays for the test and any repairs?
Why is water dripping or spraying from my backflow device?
What does a backflow test actually involve?
Does an ordinary house need a backflow test every year?
More plumbing services in Annandale
Backflow Testing nearby
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