Cross-connection control management is sometimes a complex job. Backflow Academy is here to help answer your questions regarding cross-connection control and backflow management.

What is a cross-connection?

A cross-connection is any actual or potential connection between the public or consumer’s potable water system and any non-potable source or substance that present a hazard to the quality of the public or consumer’s potable water system. Therefore, cross-connection control is the management or “control” of these cross-connections to protect public safety by preventing backflow incidents within the public or water consumer’s potable water system.

What Is backflow?

Typically, water will flow from the public water supply to the consumer’s plumbing distribution system. Backflow is the undesirable reversal of this flow of water and undesirable substances from the non-potable source to the potable source.

Are all backflow incidents the same?

No!!! Depending on the non-potable source or what the substance is, cross-connections are generally classified as high hazard or low hazard. Since there is no consensus, national standards for defining and differentiating between a high and low hazard, each state (and on occasion the local public water supply) will define for themselves the criteria for each hazard. However, there is a commonality among the definitions.

  • High hazard may also be referred to as toxic, health or contamination hazard where a backflow incident may pose a serious threat to the public water supply.

  • Low hazards, on the other hand, are non-health hazards that are considered aesthetically objectionable or a pollution hazard that will not have serious affects.

  • Seldom used classifications used by some water authorities might include very low, moderate, or lethal.

What causes backflow incidents to occur?

Backflow incidents are caused by either backpressure or backsiphonage.

a diagram of a backflow event and how it could happen
  • Backpressure is created when the pressure within the customer’s system becomes greater than the water supply pressure. Elevated tanks, heating systems and booster pumps are some of the main causes of backpressure.

  • Backsiphonage is created when there is a negative or reduced pressure in the water supply main. Water main breaks or hydrant flushing are two of the main causes of backsiphonage.

How are cross-connections protected to prevent backflow incidents from occurring?

Cross-connections are protected either through containment or isolation. Ideally for an effective cross-connection control program, there will be a mix of both containment and isolation protection working in correlation.

  • Containment is cross-connection protection located at the consumer’s water service or meter. This level of protection contains the entire facility and protects the public water supply from the consumer’s plumbing system. However, it does not provide cross-connection protection internally within the facility.

  • Isolation is cross-connection protection located within the water consumer’s facility and isolates the hazard at the point of use. This protects the individuals within a facility from contamination or pollutant hazards from entering their internal plumbing system.

How to Prevent Backflow Incidents

Backflow prevention methods can be implemented either at the service meter, called containment protection, or at the point of water use at the fixture, called isolation protection. These backflow prevention methods can be divided into 4 basic categories – elimination, backflow devices, backflow assemblies and air gap

Common Backflow Types

Backflow Assembly Testing FAQ

Who has responsibility for an approved and effective cross-connection control program?

EVERYONE!!!  The water purveyor, local plumbing authority, water consumers and all individuals performing backflow prevention assembly installation, testing and repairs have some level of responsibility for ensuring an effective cross-connection control program.

  • Develop an approved ordinance to govern the program in accordance with state cross-connection guidelines or regulations.

  • On-site facility surveys to make the proper determination of hazard and method of protection required.

  • Document and maintain all records pertaining to the field surveys.

  • Maintain an accurate inventory of all backflow assemblies, and in some jurisdictions, backflow devices.

  • Developing a testing schedule of all testable backflow assemblies.

  • Notifying the water consumer when assemblies are due for testing.

  • Retain all assembly test reports.

  • Non-compliance enforcement action.

The local plumbing authority is responsible for implementing and enforcing the local plumbing codes.

The water consumer is responsible for preventing unprotected cross-connections and maintaining protected cross-connections within the water consumer’s facility.  This should include the following:

  • Maintaining backflow devices ensuring cross-connections do not pose a risk to the water distribution system.

  • Ensuring backflow assemblies are tested and maintained according to the testing schedule of the water purveyor by hiring qualified personnel in accordance with the local jurisdiction’s criteria.

The individuals performing backflow prevention assembly installation, testing and repairs are responsible for following all codes and regulations as outlined by the local cross-connection control program.  This should include the following:

  • Holding all necessary and required credentials to properly install, test and maintain backflow assemblies.

  • Ensuring backflow assembly testing equipment is calibrated and working properly.

  • Testing the backflow assemblies in accordance with the proper testing procedures.

  • Repairing backflow assemblies in accordance with manufacturer’s authorized repair procedures.

  • Properly identifying and documenting all backflow assembly information such as hazard, size, make, model, serial number, location, etc.

  • Documenting the results of the backflow assembly test.

  • Submitting test reports to the water purveyor within the required time frame.

  • Provide to the water consumer a copy of the test results for their records.