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Water Services

333 West Avenue, Building E
Grand Junction, CO 81501
Email: water@gjcity.org

Backflow Design Requirements


All sprinkler systems must be equipped with a backflow preventer.  There are three different types of backflow preventers to choose from.  PVB and RPB backflow preventers must be tested annually by a state-certified tester.   The Cross Connection Control Coordinator has a list of approved backflow preventers since not all devices sold locally are approved for use.

Pressure Vacuum Breaker Assembly (PVBA)

  • Only one PVB is required to serve the whole system. Control valves may be located downstream of (after) the PVB.
  • PVBAs must be installed a minimum of 12" above the highest point of water they serve.
  • PVBAs must be tested by a state-certified tester at the time of installation, annually, and when moved or repaired.
  • No chemical or fertilizer may be introduced into an irrigation system equipped with PVBAs.
  • No pumps or backpressure sources are permitted on the downstream side of (after) a PVBA.

PVBA

Reduced Pressure Backflow Assembly (RPBA)

  • Only one RPBA is required to serve the whole system; control valves can be located downstream of (after) the RPBA.
  • RPBAs must be installed a minimum of 12" above ground level.
  • RPBAs must be tested by a state certified backflow preventer tester at the time of installation, annually, and when moved or repaired.
  • In an RPBA-equipped system, fertilizer and other agricultural chemicals may be introduced downstream of (after) the RPBA.
  • Basement installations are all right as long as proper drainage and high water alarms exist.

RPBA

Maximum design flow for residential systems on a ¾ inch service and meter should not exceed 15 gallons per minute (gpm). Higher flows can damage the meter.  All devices should be installed in a manner that allows adequate clearance for testing and repairs.  Before installing a new sprinkler system that will use domestic water, you are required to get a building permit from the Mesa County Building Department .

For information regarding flows for larger meters email the Cross Connection Control Coordinator or call 970-256-4101.