Backflow Testing in Gaithersburg, MD

How backflow works in Gaithersburg

The City of Gaithersburg handles building permits, but water comes from WSSC Water, and WSSC's cross-connection control program sets the testing rules. Each year a testable backflow prevention assembly needs a field test by a technician holding WSSC cross-connection certification, and the report travels to WSSC electronically through a registered principal master plumber. WSSC mails reminder letters to customers with assemblies on file, and its program line is 301-206-4004.

Homeowners can do some plumbing under a WSSC homeowner permit, but testable backflow devices are specifically left out of that path, so a qualified plumber handles them. Gaithersburg's housing is younger than the inner suburbs, with a median year built of 1989, which puts many original sprinkler devices in neighborhoods like Kentlands past their best years.

Common devices compared

Signs to call

• A WSSC reminder letter with a due date
• Water spilling from the device whenever the sprinklers cycle
• A failed report that has not been followed by a repair
• A new home purchase with irrigation and no record of a recent test
• A landscaper added zones or moved the device

Timing through the year

Spring start-up is the natural moment for the yearly test, since the system has to be pressurized anyway. Booking soon after the reminder arrives leaves room for a repair and retest if the first try fails. In fall, drain and winterize the sprinkler line before freezing nights arrive; an RPZ should come off and spend the winter somewhere warm. Any assembly that is installed, repaired or relocated during the year needs its own test right after the work, not just at the next annual date.

Older homes near Old Town Gaithersburg and the Frederick Avenue corridor sometimes have irrigation added piecemeal over the years, and a plumber may find more than one device on a lot. Each testable one needs its own yearly report, so ask for a walk-around on the first visit.