Backflow Prevention

Back-flow contamination of a public water system by contaminants and pollutants through uncontrolled cross connections could occur at any time. This can occur with a reversal of flows caused by fluctuations in water pressure within the system (i.e. main break, fire, etc.). Only an active back-flow prevention program can reduce the likelihood of such an occurrence.

In order to serve and protect its customers and to comply with state and federal regulation,  Marietta Water controls and eliminates possible cross connections in the system. By the method of containment, customer service connections will be isolated from distribution lines with an approved back-flow prevention device.

Service Area Map


As the water purveyor, Marietta Water has many responsibilities to its customers including:
  • Ensuring water quality
  • Enforcing city code
  • Developing and implementing a back-flow prevention program
  • Evaluating and inspecting services and back-flow devices
  • Maintaining records for all back-flow devices
The customer is responsible for protecting the distribution system and users of their system by:
  • Installing approved back-flow prevention devices
  • Annually testing and maintaining these devices
  • Reporting results of testing and maintenance to BLW


Service connections will be evaluated for the degree of hazard that the service represents to the distribution system. There are three levels of hazard: high, medium and low. The required device will be determined by Marietta Water based upon this degree of hazard. All containment back-flow prevention devices should be installed as close as possible following the service meter to provide maximum protection.

Testing & Maintenance

Testable back-flow prevention devices are required to be tested and repaired if necessary on an annual basis to ensure proper working order. A certified tester must perform tests, and a copy of the results must be forwarded to this office.