The Commission's Backflow Coordinator will make a determination of the type of device to be installed based on a Cross-Connection Control Questionnaire.


Air Gap:  

Air gap separation offers the highest level of protection from backflow and may be necessary in the following applications.

  • Tankers
  • Agricultural & Commercial Fill Stations
  • Hydro-Seeders

This form of protection is highly desired for our Transient Hydrant Usage Policy.

Vacuum Breaker:  

Can only provide protection against back siphonage.  Use of these devices is highly encouraged by the Commission for the purposes of internal protection, but is not to be the sole form of protection.

Residential Dual Check:  

Residential Dual Checks are installed on all 3/4" and 1" meters by the Commission (where the Commission does not have a DCVA installed).  These devices are routinely checked for damage or signs of improper functioning.

Double Check Valve Assembly:  

All DCVA's shall be on the SCDHEC's list of approved devices.  These devices shall be installed on the following:

  • All Commercial Buildings
  • Churches
  • Mobile Home Parks
  • Interconnects with other water systems
  • Dedicated Fire Lines
  • Lawn Irrigation Systems installed after June 13, 2000

The Commission will install, test and maintain DCVA's on all new residential meters/services installed after July 1, 2004.

Reduced Pressure Assembly:  

All Reduced Pressure Assemblies shall be on the SCDHEC list of approved devices.  These devices shall be installed at all high hazard connections, as determined by the Commission's Backflow Coordinator.  Examples of high hazards include, but are not limited to:

  • Carwashes
  • Funeral Homes
  • Hospitals
  • Industries

‚ÄčAll backflow prevention devices must be approved by the Commission's Backflow Coordinator prior to installation.