A. Approved Backflow Prevention Assemblies.

1. Only backflow prevention assemblies which are listed on the "List of Approved Backflow Prevention Assemblies" published by the Foundation for Cross-Connection Control and Hydraulic Research, University of Southern California, shall be acceptable for installation by a water user connected to the city of Columbia Falls water department potable supply.

2. Upon request, the city of Columbia Falls water department will provide a list of approved backflow prevention assemblies to any interested person.

B. Existing Backflow Prevention Assemblies. Approved backflow prevention assemblies that are currently in service shall be tested and if found to be in serviceable condition can be left in service after certain information (make, model, size, serial number, and test results) has been provided to the city of Columbia Falls water department. The assembly must then be tested yearly by a certified backflow prevention assembly tester (see Section 13.24.080) or more frequently if determined necessary by the city of Columbia Falls water department. Existing backflow prevention assemblies found to be unserviceable or whose application has been misapplied shall be removed and replaced with an appropriate assembly approved by the city of Columbia Falls water department.

C. Backflow Prevention Assembly Installation. Backflow prevention assemblies shall be installed in a manner prescribed by the city of Columbia Falls water department. Location of the assemblies should be as close as practical to the user’s connection. The city of Columbia Falls water department shall have the final authority in determining the required location of a backflow prevention assembly.

1. 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 above the supply inlet, but in no case less than one inch above the overflow rim of the receiving vessel. Properly installed, the air gap may be used to protect against all levels of backflow hazards.

2. Reduced pressure zone backflow prevention assembly (RP). The approved reduced pressure zone backflow prevention assembly shall be installed on the user’s side and as close to the service connection as is practical. The assembly shall be installed a minimum of twelve inches above grade and not more than thirty inches above grade measured from the bottom of the assembly and with a minimum of twelve inches side clearance. The assembly shall be installed in a horizontal position and be readily accessible for maintenance and testing. Water supplied from any point between the service connection and the RP assembly shall be protected in a manner approved by the city of Columbia Falls water department. The water user must provide adequate drainage to prevent flooding in the event the RP assembly bypasses water to atmosphere and sufficient protection to prevent the assembly from freezing. Properly installed, the RP may be used to protect against all levels of hazard under both backpressure and backsiphonage conditions.

3. Double check valve assembly (DCA). 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 bottom of the assembly and so that the top of the assembly is no more than a maximum of eight inches below grade. Also, there must be a minimum of twenty-four inches of clearance between the side of the assembly with the test cocks and side of the vault, and also a minimum of twelve inches clearance between the other side of the assembly and side of the vault. Special consideration must be given to double check valve assemblies of the "Y" type. These assemblies must be installed on their "sides" with the test cocks in a vertical position so that either check valve may be removed for service without removing the assembly. Vaults which do have an integrated bottom must be placed on a three inch layer of gravel. The water user must provide adequate drainage to prevent flooding in the event the assembly leaks or to accommodate spillage during testing and repairs. The water user is responsible for providing adequate protection to prevent freezing of the assembly. The DCA may be used to protect against a non-health hazard under both backpressure and backsiphonage conditions.

4. Pressure Vacuum Breaker (PVB). The approved pressure vacuum breaker assembly shall be located as close as practical to the user’s connection or meter and shall be installed at least twelve inches above all downstream plumbing and the highest fixture flood level rim, outlet, or highest point of water use. In no case should the PVB assembly be used if backpressure could develop in the downstream piping. The PVB shall be installed inline in a vertical position with adequate space to facilitate maintenance and testing. The PVB shall be installed in an area where water spillage through the vacuum relief valve (air inlet) is not objectionable. Adequate drainage to floor drains should be provided to accommodate this spillage. The PVB shall not be installed in a vent hood or where toxic or objectionable fumes or substances could enter and contaminate the potable water piping. Prior to installation, refer to the manufacturer’s literature concerning temperature ranges. The PVB must be protected from freezing temperatures and if installed where temperatures will reach one hundred twenty degrees Fahrenheit or forty-three degrees Celsius or above, the hot water type of assembly must be used. Properly installed, the PVB may be used to protect all levels of hazard under backsiphonage conditions only.

5. Atmospheric Vacuum Breaker (AVB). The approved vacuum breaker assembly shall be located as close as practical to the user’s connection or meter and shall be installed at least six inches above all downstream piping and the highest fixture flood level rim, outlet or highest point of water use. In no case should the AVB assembly be used if backpressure could develop in the downstream piping. The AVB shall be installed inline in a vertical position with adequate space to facilitate maintenance and testing. The AVB shall be installed in an area where water spillage through the vacuum relief valve (air inlet) is not objectionable. Adequate drainage to the floor drain must be provided to accommodate this spillage. The AVB shall not be installed in a vent hood or where toxic or objectionable fumes or substances could enter and contaminate the potable water piping. The AVB shall not be installed where it will be in continuous operation or under continuous pressure for more than twelve consecutive hours. When used for long periods of time the air inlet valve could become stuck in the closed position. The AVB shall not have any valves installed downstream from the assembly (the discharge side of the plumbing should be exposed to the atmosphere). Prior to installation, refer to the manufacturer’s literature for temperature ranges. The AVB must be protected from freezing temperatures and if installed where temperatures will reach one hundred ten degrees Fahrenheit or forty-three degrees Celsius or above, the hot water type of assembly must be used. Properly installed, the AVB can be used to protect against all levels of hazard under backsiphonage conditions only.

D. Backflow Prevention Assembly Testing and Maintenance.

1. The owners of any premises on which, or on account of which, backflow prevention assemblies are installed, shall have the assemblies tested by a person who holds a current certificate from any state certification program authorizing the person to test backflow prevention assemblies or who holds a current certificate from the American Society of Sanitary Engineers, American Backflow Prevention Association, Foundation for Cross-Connection Control and Hydraulic Research, or the American Water Works Association. Backflow prevention assemblies must be tested at least annually and immediately after installation, relocation or repair. The city of Columbia Falls water department may require a more frequent testing schedule if it is determined to be necessary. The city of Columbia Falls water department will maintain records regarding the inspection, testing, repair, and location of backflow assemblies on customer premises. No assembly shall be placed back in service unless it is functioning as required. A report in a form acceptable to the city of Columbia Fails water department shall be filed with the city of Columbia Falls water department each time the assembly is tested, relocated or repaired. These assemblies shall be serviced, over-hauled, or replaced whenever they are found to be defective and all costs of testing, repair and maintenance shall be borne by the water user. All repair and maintenance of backflow prevention assemblies shall be done by a person meeting all state and local requirements. If a water user has a water service considered critical, i.e. a water service that can’t be shut off, even for a few moments at any time, the city of Columbia Falls water department will require either two services to the facility, each having equal backflow protection determined by the degree of actual or potential hazard, or the user may install two assemblies in parallel on the existing service. One assembly can provide water service to the user while the other is tested and/or repaired.

2. The city of Columbia Falls water department will notify affected customers by mail when annual testing of an assembly is needed and also supply users with the necessary forms which must be filled out each time an assembly is tested or repaired.

3. Upon request, the city of Columbia Falls water department will provide a list of persons qualified to test backflow prevention assemblies.

E. Backflow Prevention Assembly Removal. Approval must be obtained from the city of Columbia Falls water department before a backflow prevention assembly is removed, relocated, or replaced.

1. Removal. The use of an assembly may be discontinued and the assembly removed from service upon verification by the city of Columbia Falls water department that a hazard no longer exists or is not likely to be created in the future.

2. Relocation. An assembly may be relocated following confirmation by the city of Columbia Falls water department that the relocation will continue to provide the required protection and satisfy installation requirements. A retest will be required following the relocation of the assembly.

3. Repair. An assembly may be removed for repair provided the water use is either disconnected until repair is completed and the assembly is returned to service, or the service connection is equipped with other backflow protection approved by the city of Columbia Falls water department. A retest will be required following the repair of the assembly.

4. Replacement. An assembly may be removed and replaced provided the water use is discontinued until the replacement assembly is installed. All replacement assemblies must be approved by the city of Columbia Falls water department and be commensurate with the degree of hazard involved. The replacement assembly must be tested prior to being put into service. (Ord. 624 § 1(part), 2000)