A. Approved Backflow Prevention Devices.
1. Only backflow prevention devices which have been approved by the city shall be acceptable for installation by a water user connected to the city's potable water system.
2. The city will provide, upon request, to any affected customer a list of approved backflow prevention devices.
B. Backflow Prevention Device Installation.
1. Backflow prevention devices shall be installed in a manner prescribed in Section 7603, Title 17, of the California Administrative Code of Regulations. Location of the devices should be as close as practical to the user's connection. The city engineer shall have the final discretionary authority in determining the required location of a backflow prevention device.
a. Air-gap Separation (AG). The air-gap separation shall be located on the user's side of and as close to the service connection as is practical. All piping from the service connection to the receiving tank shall be above grade and be entirely visible. No water use shall be provided from any point between the service connection and the air-gap separation. The water inlet piping shall terminate a distance of at least two pipe diameters of the supply inlet, but in no case less than one inch above the overflow rim of the receiving tank.
b. Reduced Pressure Principle Backflow Prevention Device (RP). The approved reduced pressure principle backflow prevention device shall be installed on the user's side of and as close to the service connection as is practical. The device shall be installed a minimum of twelve inches above grade and not more than thirty-six inches above grade measured from the bottom of the device and with a minimum of twelve inches side clearance. The device shall be installed so that it is readily accessible for maintenance and testing. Water supplied from any point between the service connection and the RP device shall be protected in a manner approved by the city engineer.
c. Double Check-Valve Assembly (DC). The approved double check-valve assembly shall be located as close as practical to the user's connection and shall be installed above grade, if possible, and in a manner where it is readily accessible for testing and maintenance. If a double check-valve assembly is put below grade it must be installed in a vault such that there is a minimum of six inches between the bottom of the vault and the bottom of the device, so that the top of the device is no more than eight inches below grade, so there is a minimum of six inches of clearance between the side of the device with the test cocks and the side of the vault, and so there is a minimum of three inches clearance between the other side of the device and the side of the vault. Double check-valve assemblies of the "Y" type must be installed on their "side" with the test cocks in a vertical position so that either the check-valve may be removed for service without removing the device. Vaults which do not have an integrated bottom must be placed on a three-inch layer of gravel.
C. Backflow Prevention Device Testing and Maintenance.
1. The owners of any premises on which, or on account of which, backflow prevention devices are installed, shall have the devices tested by a person approved by the city engineer. Backflow prevention devices must be tested at least annually and immediately after installation, relocation or repair. The city engineer may require a more frequent test schedule if it is determined to be necessary. No device shall be placed back in service unless it is functioning as required. A report in a form acceptable to the city engineer shall be filed with the city each time a device is tested, relocated or repaired. These devices shall be serviced, overhauled or replaced whenever they are found to be defective and all costs of testing, repair and maintenance shall be borne by the water user.
2. The city will supply affected water users with a list of persons acceptable to the city to test backflow prevention devices. The city will notify affected customers by mail when annual testing of a device is needed and also supply users with the necessary forms which must be filled out each time a device is tested or repaired.
D. Backflow Prevention Device Removal.
1. Approval must be obtained from the city before a backflow prevention device is removed, relocated or replaced.
a. Removal. The use of a device may be discontinued and the device removed from service upon determination by the city engineer that a hazard no longer exists or is not likely to be created in the future.
b. Relocation. A device may be relocated following confirmation by the city engineer that the relocation will continue to provide the required protection and satisfy installation requirements. The city engineer shall require a retest following the relocation of the device to verify the required level of protection.
c. Repair. A device may be removed for repair, provided the water use is either discontinued until repair is completed and the device is returned to service, or the service connection is equipped with other backflow protection approved by the city. The city engineer shall require a retest following the repair of the device to verify the required level of protection.
d. Replacement. A device may be removed and replaced provided the water use is discontinued until the replacement device is installed. All replacement devices must be approved by the city engineer and must be commensurate with the degree of hazard involved.
(Ord. 89-09-1041 § 1 (part))