Backflow Prevention Installation & Inspection Requirements
Irrigation Systems – Commercial and Residential
All new irrigation systems installed on a lot that is platted and recorded after July 1, 2009, must be connected to
a separate irrigation meter installed by Charlotte Water.
Application Process
To inquire about fees and obtaining a metered connection with Charlotte Water, call 311(locally) or 704432-2854 and ask for New Services. A Backflow Service Application (BSA) will be required to be completed
and turned in with appropriate fees. This BSA acts as a Charlotte Water backflow permit request. Charlotte
Water will install the irrigation meter. Once the irrigation meter is in place, the irrigation water service piping can
be installed by your contractor.
Installer must be currently licensed by the appropriate North Carolina Licensing Board.
Water Service Piping (From meter to and including the Reduced Pressure Principle Backflow Preventer)
Work must be permitted through Mecklenburg County Code Enforcement using a licensed plumbing or public
utilities contractor.
Irrigation System
Work must be conducted by a licensed irrigation contractor. Once installed and Code Enforcement
inspection is completed and “passed”, contact Utilities for an inspection of backflow prevention assembly.
Inspection requests for both installations should be coordinated to minimize delays. Once the work has
passed inspection, the meter will be activated by the Charlotte Water backflow inspector. After the
inspection, an initial test of the backflow assembly is required, and the original test form must be submitted
to: email – backflowtests@charlottenc.gov , Fax – 704-632-8362, or mail – Charlotte Water c/o Account
Services - Backflow, 5100 Brookshire Blvd., Charlotte, NC 28216.
To inquire about obtaining approval and/or permits from Mecklenburg County Code Enforcement
Department, call 704-336-3829 or visit the Commercial Technical Assistance Center (CTAC) at 700 N. Tryon
Street in Charlotte.
To schedule the inspection contact Utilities Backflow Prevention at 704-391-5188.
All other metered connections (Excluding Single Family or Duplex Residential)
All piping connected between the building and the Charlotte Water meter must be installed per any applicable NC
Building Code and inspected by Mecklenburg County Code Enforcement Department according to its requirements.
A permit from Code Enforcement is required. Code Enforcement will inspect the work and release the permit holds it
controls. As part of the permitting and/or meter application process with Charlotte Water, a Backflow Service
Application (BSA) will be required to be completed and returned with appropriate documents and/or fees. This BSA
becomes a Charlotte Water backflow permit request to install the backflow preventer. This work involves the
backflow preventer and the piping five feet before and five feet after the backflow preventer. Charlotte Water needs
to inspect all work involved with installing the backflow preventer. Once the work has passed inspection, the
Backflow Hold controlled by Charlotte Water will be released by the Installations and Development Services Section
of the Engineering Division. After the inspection, an initial test of the backflow assembly is required and the original
test form must be submitted to: email – backflowtests@charlottenc.gov, Fax – 704-632-8362, or mail – Charlotte
Water c/o Account Services - Backflow, 5100 Brookshire Blvd., Charlotte, NC 28216.
Call Charlotte Water - Backflow Inspections at 704-391-5188 to verify status of a Backflow Hold or to
schedule a backflow inspection. Installation requirements and standard details can be obtained at
http://backflow.charmeck.org or from Charlotte Water.
Operated by City of Charlotte
Rev Jan. 2015
Backflow Inspection Checklist
Once your Backflow Prevention Assembly has been installed, please review
the following checklist of requirements before requesting an inspection from
Mecklenburg County Code Enforcement or Charlotte Water:
Irrigation System Requirement
 Mecklenburg County Code Enforcement will inspect all piping from the
Charlotte Water installed meter up to and including the Reduced
Pressure Principle (RP) backflow assembly. An open ditch is needed for
the inspection. A meter will be required to pass inspection. It will be
important to coordinate activities to minimize conflicts with the open
ditch. Once Code Enforcement’s inspection is completed, Charlotte
Water will inspect the RP backflow assembly and activate meter upon
acceptance.
Piping Material
 For ¾” to 1” Piping Material: Type K or Type L Copper Tubing, 1”
min. Galv. Steel Pipe, or Sch. 40 PVC (conforming to ASTM D1785,
pressure rated for water, using 1120 PVC compounds). When using
Sch. 40 PVC pipe, Sch. 80 PVC fittings are required. When using PVC,
vertical support at backflow assembly will be required and horizontal
support is recommended. Proper priming (purple color) of PVC is
required.
 For 11/2” to 2” Piping Material: Type K or Type L Copper Tubing or
Galv. Steel Pipe
 For 2 ½” to 12” Piping Material: Ductile Iron Pipe(minimum pressure
Class 350), Type K or Type L Copper Tubing
Backflow Assembly
 Correct type assembly installed as required by Charlotte Water
Concrete Pad
 All backflows 1½” and greater in size require a minimum of 4” thick
concrete pad
 All backflow smaller than 1½” requires a minimum of 4” thick washed
stone
Cover
 Above Ground Installations need an insulated cover meeting ASSE
1060 requirements
 If it is an RP, the cover should provide drainage per Charlotte Water
requirements
Non-removable enclosures
If the structure is non-removable and must be entered in order to test or
repair the assembly, the same minimum and maximum clearance that is
specified for vault installations shall apply.
Vault
 Below Ground Installations requires a vault with a concrete or stone
bottom
 All vaults must have drains according to Charlotte Water requirements
Clearances / Location
 Make sure you meet all minimum required clearances
FOR REDUCED PRESSURE PRINCIPLE ASSEMBLIES
Installed upright horizontal - aboveground outside zoning setback according
to Utilities standard details; Min. height from relief port to the ground 12” and
max. 30”
Inside Building / Partially Buried Vault (special approval needed)
Size
Minimum clearance
¾”-2”
30” from wall or any obstruction on the side utilized for
testing and 6” from other side
2½” -12”
30” from wall or any obstruction on the side utilized for
testing and 12” from other side
All
4” from wall to shut off valve
All
Floor drain or air-gap drain
FOR DOUBLE CHECK VALVE ASSEMBLIES
Must be Installed upright horizontal - above or below ground; outside zoning
setback if above ground according to Charlotte Water standard details. If
below ground, device must be installed in vault with a concrete or stone
bottom and provide for drainage to free atmosphere. Min. height from
bottom of assembly to the ground 12” and max 30”
Vault
¾”-1”
8” from wall or any obstruction on the side utilized for
testing and 4” from other side
11/2”-2”
12” from wall or any obstruction on the side utilized for
testing and 6” from other side
4” clearance on each end
2½”-12”
30” from wall or any obstruction on the side utilized for
testing and 12” from other side
8” clearance on each end
Inside building (special approval needed)
All
4” from wall to shut off valve
¾’-2”
30” from wall or any obstruction on the side utilized for
testing and 6” from other side
2½”-12”
30” from wall or any obstruction on the side utilized for
testing and 12” from other side
Operated by City of Charlotte
Rev Jan. 2015