Mount Rainier borders the District but is served by WSSC Water, so WSSC's cross-connection rules apply: testable assemblies, such as irrigation vacuum breakers, RPZs and some home fire sprinkler double checks, are tested yearly and after installation or repair by a WSSC-registered plumber with cross-connection certification. WSSC does not test devices itself. Call the number on this page to be connected with a local plumber in Mount Rainier.
Mount Rainier's setting
Mount Rainier began as an early-1900s streetcar suburb on the DC line next to Woodridge, and much of the town is a National Register historic district full of Sears kit houses and Craftsman homes. The median home was built in 1952. Lots are compact and few original houses came with irrigation, so many homeowners here never have a testable assembly. They appear more often on storefronts and mixed-use buildings along US 1, on apartment buildings, and in homes that added a boiler with chemical treatment or a fire sprinkler line during renovation.
Because the town sits in Prince George's County, plumbing permits and inspections come from WSSC, which also covers all natural gas and LP gas work. The City's Code Compliance Department issues city building permits, and some permits come from the county, so a renovation that adds a backflow device can involve more than one office. The county's cross-connection line is 301-206-8601.
WSSC's tap water reports put Potomac plant water at about 140 mg/L of hardness on average and Patuxent plant water near 65 mg/L, without saying which plant serves which street. Mineral deposits are one of several reasons a check valve stops sealing over time.
Testable or not?
| Device | Testable? | Who handles it |
|---|---|---|
| RPZ on a boiler or business line | Yes, yearly | Certified cross-connection technician |
| Double check on a fire sprinkler line | Yes, yearly | Certified cross-connection technician |
| Vacuum breaker on irrigation | Yes, if it has test cocks | Certified cross-connection technician |
| Non-testable dual check | No | Homeowner or plumber may rebuild or replace |
| Hose bib vacuum breaker | No | Replace when it leaks |
Signs it needs attention
- A WSSC notice for an annual test
- Water running from the relief port or bonnet
- Pressure loss on the protected line
- Green corrosion or a cracked casting
Timing
Book irrigation tests at spring start-up and boiler or fire-line tests whenever the yearly date comes around. Before winter, drain any outdoor device so a hard freeze doesn't split the body. If you're renovating, schedule the test right after installation, and keep the report with the rest of the project paperwork so a future buyer can see the device's history.
Backflow Testing questions in Mount Rainier
Do I need a permit to install or replace a backflow preventer?
Does an ordinary house need a yearly backflow test?
Who pays for the test and any repairs?
Can I rebuild or replace a backflow device myself?
More plumbing services in Mount Rainier
Backflow Testing nearby
Helpful guides
Sources
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