Backflow Prevention and Cross Connection Control Definitions
Cross Connection. Any actual or potential connection between a drinking water system and any other source or system through, which it is possible to introduce any used water, industrial fluid, gas or substance other than intended for drinking water.
Backflow.The undesirable reversal of flow of water or mixtures of water and other liquids, gases, or other substances into the distribution pipes of the potable water supply from any source.
Back-pressure. Occurs when the customers pressure is higher than the water systems supply pressure. Backpressure can be caused by a unprotected cross connection to a boiler, pressurized irrigation system, pressurized industrial process, elevation differences, air and steam pressure, use of booster pumps.
Back-siphonage. A reduction in water system pressure, which causes a vacuum (subatmospheric pressure). This can be caused by large water demands down stream such as fighting a fire, water line breaks, or heavy water usage.
Degree of Hazard. This is the degree of threat to public health through a cross connection. Health Hazard (contaminant) is something that will cause illness and possibly death. Non Health Hazard (pollutant) does not create a threat to public health, but does adversely affect the aesthetic qualities such as taste, smell and odor.
Backflow prevention device. A backflow preventer that is not testable, and specific installation requirements in order to operate properly.
Air Gaps. The physical separation between the discharge end of a water supply, and the flood rim of an open or non pressure receiving vessel.
Flood Rim. The top edge or the highest point of a receptacle to which the water will rise before overflowing.
Certified Backflow Technician. An individual who has met the requirements and successfully completed the course of instruction and certification requirements for Class I, II or III backflow technician certification.