Backflow Assembly Installation Guide

• The backflow assembly should be as close to the water meter
  as possible. In all cases it shall be before the first branch in the
  water service. Call the City for more information about isolation
  backflow assemblies.
• The double check valve and reduced pressure assemblies shall
  be installed at least 12 inches above the finish grade, flood level
  or floor.
• Pressure vacuum breaker assemblies (PVB) shall be installed at
  least 12 inches above the highest water outlet. When installing a
  PVB on an irrigation system consider the placement of sprinkler
  heads on hills and slopes. PVB shall not be installed at a lower
  level than the highest outlet.
• The maximum installation height of a backflow assembly is sixty
  inches.
• An enclosure shall be provided that protects the assembly from
  theft, vandalism, tampering, weather, and frost.
• In the floor, underground and vault installations are prohibited.
• There shall be 24 inches clearance on all sides of the assembly.
• Electrical equipment, outlets and breaker boxes shall not be
  located beneath the assembly.
• Only in-line testable assemblies approved by the USC Foundation
  for Cross Connection Control or ASSE shall be accepted.
• The type of assembly shall be appropriate for the hazard as
  identified by the Cross Connection Control Office.
• Prior to installing assemblies it is recommended that the Cross
  Connection Control Office be contacted to verify that the type of
  assembly being used is appropriate for the hazards.
• Installation, relocation, or replacement of backflow prevention
  assemblies requires a City of Wilmington permit and inspection
  and a separate New Hanover County plumbing permit and inspection.
  Water meters will not be set until the City has inspected and approved
  the backflow assembly and its installation.
• Backflow assemblies shall be tested by a certified tester within
  30 days of the installation and annually thereafter.