The text
(a)
Backflow preventers. All installed backflow preventers shall conform to the latest revision of the American Water Works Association (AWWA) Standard C506, the latest revision of the applicable standard of the American Society of Sanitary Engineering (ASSE) or the latest revision of the Foundation for Cross-Connection Control and Hydraulic Research of the University of Southern California standards.
(b)
Strainers. All new retrofit installations of reduced pressure principle devices and double check valve backflow preventers shall include the installation of strainers located immediately upstream of the backflow device. The installation of strainers will preclude the fouling of backflow devices due to both foreseen and unforeseen circumstances occurring to the water supply system such as water main repairs, water main breaks, fires, periodic cleaning and flushing of mains, etc. These occurrences may "stir up" debris within the water main that will cause fouling of backflow devices installed without the benefit of strainers.
(c)
Existing in-use backflow prevention devices. Any existing backflow preventer shall be allowed by the department to continue in service unless it has been determined by a certified tester that the device is no longer effective or will result in an unreasonable risk to the public health. In the case of a residential installation converting to a business establishment, an existing backflow preventer must be upgraded to a reduced pressure principle device, or a reduced pressure principle device must be installed in the event that no backflow device was present.
(Ch. 356, § I, 9-20-05)