Legal Documents of Maryville

Acceptable installation of backflow prevention assemblies shall meet the criteria of the State of Tennessee and the following requirements:

1. All backflow prevention assemblies installed on fire protection systems must be performed by person(s) possessing a fire sprinkler contractor license.
2. All assemblies shall be installed in accordance with the manufacturer's installation instructions and by the State of Tennessee's installation guide unless such instructions are in conflict with the ordinance set forth by the city, in which case the city ordinance shall control. All assemblies shall possess all test cocks and fittings required for testing the assembly.
3. Reduced pressure principle backflow prevention assemblies installed inside a premises shall be located so that the relief valve discharge port is a minimum of twenty-four inches (24"), plus nominal diameter of the supply line, above the finished floor level. The maximum height above the finished floor level shall not exceed seventy-two inches (72") and be positioned where discharge from a relief port will not create any adverse or undesirable conditions.
4. Any backflow prevention assembly(s) installed inside a premises (i.e., basements, closets, fire riser rooms, mechanical rooms, etc.) shall have adequate lighting to provide for inspections and/or repairs.
5. Backflow prevention assemblies installed outside a premises (i.e., irrigation devices, domestic assemblies located outside a facility or fire protection system assemblies) shall be located so that the relief valve discharge port of reduced pressure principle backflow prevention assemblies or lowest point of double check valve assemblies is a minimum of fourteen inches (14"), plus nominal diameter of the supply line, above the finished grade level/surface. The maximum height above the finished grade level shall not exceed seventy-two inches (72").
6. All reduced pressure principle backflow assemblies installed inside a premises shall have adequate drainage and be equipped with a drain line from the relief valve that is a minimum of two (2) times the nominal diameter of the supply line of the backflow assembly.
7. Clearance from wall surfaces or other obstructions for backflow prevention assemblies shall be a minimum of six inches (6"). However, if a person must enter an enclosure to repair or test, the minimum distance shall be twenty-four inches (24").
8. Backflow prevention assemblies devices shall be adequately protected from freezing, vandalism, theft, and mechanical abuse, overgrowth of vegetation and from any corrosive, sticky, greasy, abrasive or other damaging substances.
9. Backflow prevention assemblies devices shall be accessible to the city at all times. Assemblies shall not be installed in areas such as locked enclosures, fenced areas, backyards, pool houses, garages, under decks, porches, or in heavy shrubbery that could be damaged due to the testing process.
10. An approved air gap shall separate the relief port from any drainage system. Such air gap shall not be altered without the specific approval of the city.
11. Backflow prevention assemblies devices shall be located in an area free from submergence or flood potential and cannot in any circumstances be located in a pit or hole.
12. All backflow prevention assemblies devices shall be adequately supported to prevent sagging or swaying.
13. An approved strainer shall be installed immediately upstream of all backflow prevention assemblies or shutoff valve, except on fire lines, using only noncorrosive fittings in the device's assembly.
14. Where the use of water is critical for the continuance of normal operations, the protection of life, property and/or equipment, including, but not limited to, apartment or residential housing buildings, barber shops or beauty salons with four (4) or more chairs, dental or medical facilities, multi-tenant buildings served by a single water service line or restaurants, duplicate backflow prevention assemblies shall be provided to avoid the necessity of discontinuing water service to test or repair the backflow prevention assembly(ies).
15. A device for the control of thermal expansion shall be installed on the customer's water system where the thermal expansion of the water in the system will cause the water pressure to exceed the pressure setting of the pressure relief valve of the water heater. The thermal expansion device shall control the water pressure to prevent the pressure relief valve of the water heater from discharging.
16. Fire hydrant drains/weep holes shall not be connected to the sanitary sewer.
17. Full-open valves, followed by a drain plug, shall be installed on the supply line of every irrigation system whether supplied off the customer's main domestic service line or by its own separate city public water supply meter prior to the irrigation backflow prevention assembly.
18. Full-open valves shall also be installed on the discharge side of every irrigation backflow prevention assembly and must meet all requirements set forth in the city's Rules, Regulations, Rates and Policies manual.
19. Where compressed air is used to winterize irrigation systems, proper fittings must be installed downstream of the irrigation backflow prevention assembly for that purpose.
20. Irrigation backflow prevention assemblies must be installed and have water service up to the number two (2) shutoff valve of the assembly, whether or not the irrigation system is activated or in use, no later than May 1 of each year and remain in service until September 30 of each year to allow for required annual inspection and testing of the backflow prevention assembly. Irrigation systems with backflow prevention assemblies not installed or not in service during said period will be viewed as a failure of the annual inspection.
21. Installation shall be at the sole expense of the owner or occupant of the premises. (1999 Code, § 18-304)