Cross-Connection Control Terms
A back-siphonage condition can occur whenever there is a lowered pressure between the potable and non-potable supply piping. Such conditions typically occur during periods of high demand in the public water main, lowering the supply pressure. For instance during the demands imposed by fire fighting operations, or in the event of a water main break, which suddenly and significantly lowers the city water pressure below that of the non-potable system. This results in a partial vacuum being drawn on the non-potable system, and siphons the pollutants or contaminants into the potable water system through an unprotected cross connection, such as a hose bib or hydronic system make-up connection. Back-siphonage may also occur when a high velocity stream of water passes by a small pipe outlet, such as a residential service tap, due to the "venturi" effect.
Who Needs a Backflow Device?
District's Policy on Backflow Devices
Installation of an approved backflow prevention assembly is required at the service connection to any premise where there is an auxiliary supply or system - even if there is no connection or cross-connection. For example, anyone with an alternate source of water such as a well, spring, stream, etc., or anyone with an irrigation system, Residential or Commercial Fire Sprinkler System, or two or more meters serving one parcel must have a backflow prevention device. Commercial and professional buildings with lab equipment, boilers, chemicals etc., are further examples of premises that require a backflow prevention device.
The State of California Administrative Code, Title 17 and Rule 11-16 of the Rules and Regulations of the Paradise Irrigation District, require the owner of any premises on which protective devices are installed to have certified annual inspections made of such devices for their water tightness and reliability. The device shall be serviced, overhauled, or replaced whenever found to be defective. Certified records of such inspections and/or repairs are required to be submitted to the District. You may engage any Backflow Prevention Tester who is USC and AWWA certified to perform the test, or you may have one of our certified employees perform the test. However, PID will not be responsible for any repairs, re-testing, or any plumbing problems that may occur on your premises due to the testing procedures.