Regulations
No person shall install any water-operated equipment or mechanism, or use any water-treating chemical or substance, if it is found that such equipment, mechanism, chemical, or substance causes pollution or contamination of the domestic water supply. Such equipment or mechanism shall be permitted only when equipped with an approved backflow prevention device or assembly.

Devices or assemblies installed in a potable water supply system for protection against backflow shall be maintained in good working condition by the person or persons having control of such devices or assemblies. Such devices or assemblies shall be tested at the time of installation, repair, or relocation and not less than on an annual schedule thereafter. If the device is found defective or inoperative, the device or assembly shall be repaired or replaced.

Testing
Testing shall be performed annually by a certified backflow assembly tester. For a detailed and complete explanation outlining backflow devices and backflow device applications, refer to the Uniform Plumbing Code, Chapter 602.3 through 603.4.7 as well as table 6-2.