Lan-Del Water District:
Installation Requirements for Backflow Prevention
Assemblies 2" and Smaller
Install a minimum of 6" (Inch) clearance in all directions around the assembly.
Assemblies 2 1/2" and larger
IInstall with a minimum of 12" (inch) clearance in all directions
around the assembly and a minimum of 24" (inches) clearance in front of the assembly, Where testing and repair are performed.
Pressure Vacuum Breaker (PVB)
Must meet the additional requirements of 12" (inches) above the highest point
of water use downstream of the backflow preventer.
Backflow Prevention Assembly (BPA) installed in Lan- Del  Water district
service area must be on the "List of Approved Backflow Prevention A
ssemblies," which is published bye the foundation for Cross Connection
Control  and Hydraulic Research from the University of Southern California.
BPA must be installed per Lan-Del requirements for Cross Connection Control.
BPA must be inspected for compliance with installation criteria including
correct orientation.
BPA must be tested at the time of the installation by a qualified (certified)
tester, then annually thereafter. Test results must be recorded on an
approved test report form and returned to Cross-Connection Control staff
prior to final approval of the installation.
BPA should be re-tested anytime water service to the assembly is disrupted.
Whenever a BPA is installed that could create a closed water system, a
solution for thermal expansion needs to be considered.
In the event there is a conflict between Lan-Del requirements and municipal
plumbing codes, the more stringent requirement will prevail.
Municipal Plumbing codes have been modified to include a maximum
installation height for BPA without providing special access to the BPA
for testing and repair.
A reduced Pressure Assembly (RPA) is designed to discharge water. The
amount of water that may be discharged can vary from:
  • "nuissance Spitting" at the RPA relief port during water Pressure Fluctuations.
  • Major Water Discharge in the event the RPA needs repair.
In response to an actual Backflow situation
Water Meters, as a part of detector assemblies, shall read in gallons per minute (GPM).