Backflow - Frequently Asked Questions

WHAT IS  BACKFLOW?

Backflow is the undesirable reversal of flow in a potable water distribution system through a cross-connection. A cross-connection is an actual or potential link connecting a source of pollution or contamination with a potable water supply. Backflow may allow liquids, gases, non-potable water and other substances, from any source, to enter a public water system.

HOW DOES BACKFLOW OCCUR?

Backflow may occur due to a high pressure on the customer side, or low pressure in the water system. Backflow through a cross-connection can contaminate the potable water in a building, on a block, or throughout an entire water system.

WHAT IS BACKFLOW PREVENTION?

Backflow prevention protects public water systems from contamination or damage through cross-connections located in customer facilities. Backflow prevention is typically achieved by placing a backflow prevention assembly between the customer and the public water system. This is called containment backflow prevention.

MUST MY HOME OR BUSINESS HAVE BACKFLOW PREVENTION?

Many businesses must have backflow prevention. Common examples are manufacturing and processing plants, medical facilities, labs, and buildings that have boilers, fire sprinkler systems and irrigation systems. At this time, MS residents are exempt from having to have a backflow.

MUST I HAVE MY BACKFLOW PREVENTION ASSEMBLY INSPECTED?

Yes. To ensure the device is functioning properly, a certified tester must test it at least annually. For new facilities, the assembly must be tested when installed. If the tester finds the assembly is not working, you must arrange to have it repaired and tested again. It is your responsibility to pay for the test and repairs. The tester is required to provide a copy of the test report to you and the water supplier.

DOES THE BACKFLOW PREVENTION ASSEMBLY PROTECT MY ENTIRE FACILITY?

No. The required backflow prevention assembly provides containment and it protects the public water system from hazards in your facility. Cross-connections in your own plumbing may allow contaminants to backflow from hazardous processes to drinking  water taps in your building.

Information on the Cross-Connection Control Program from the MS Dept of Health