close menu
This website uses cookies to store your accessibility preferences. No personal / identifying information is stored. More info.

Backflow Prevention

Overview of Backflow Prevention

Protecting the McBee Public Water System is an essential part of our mission to safeguard public health.

Every connection to our system presents an opportunity for non-potable water to enter the public water system.

To protect against this, South Carolina's mandated "Cross Connection Control / Backflow Prevention" program is designed to protect the public's drinking water from contamination by identifying and eliminating cross connections.

What is "Backflow"?

Backflow occurs when changes in the water pressure creates a suction effect, which can cause water to reverse flow and backflow into the public water system.

Water normally flows in one direction, from the public water system through the customer's cold or hot water plumbing to a sink tap or other plumbing fixture.  The plumbing fixture is the end of the potable water system and the start of the waste disposal system.

When there is a loss of water pressure in the water distribution system, a backflow may occur.  Loss of water pressure may occur due to a high withdrawal of water for fire protection, a water main or plumbing system break, or a shutdown of a water main or plumbing system for repair.  If a hose faucet was open and the hose is submerged in a wading pool during these conditions, the non-potable water (the pool water) would be siphoned into the house's plumbing and back into the public water system.

Without barriers to prevent this, water from the private plumbing system could flow into the public water system.

This is why South Carolina and Federal laws require water utilities to identify all connections to the public water system and have a program in place to prevent backflow.  

Where are Cross Connections Found?

Cross connections are found in all plumbing systems.

It is important that each cross connection be identified and evaluated as to the type of backflow protection required to protect the public water system.  Some plumbing fixtures have built in backflow protection in the form of a physical air gap.  However, most cross connections will need to be controlled through the installation of an approved mechanical backflow prevention device assembly.  These devices can be purchased at your local plumbing supply store.

Common Cross Connections

Cross connections can be found in plumbing and water systems, such as

  • Wash basins and service sinks
  • Hose faucets
  • Irrigation sprinkler system
  • Auxiliary water supply (Well)
  • Laboratory and aspirator equipment
  • Photo developing equipment
  • Processing tanks
  • Boilers
  • Water recirculation systems
  • Swimming pools, hot tubs, landscape ponds
  • Solar heat systems
  • Fire sprinkler systems
McBee's Cross Connection Control

The McBee Utility Department administers the Town's backflow prevention program in accordance to SC DHEC regulations.  This includes:

  • Determining whether a customer must install a backflow prevention device, and if so, which type.
  • Developing and maintaining specifications for installing backflow prevention assemblies.
  • Inspecting newly installed backflow devices.
  • Maintaining records of all customer backflow preventors in our service area and annual backflow test results for each.
Customers are responsible for having their backflow device installed according to our specifications and getting it tested annually by a third-party tester from the approved "Tester List".  Backflow devices are part of a customer's private plumbing system.