1. The required backflow prevention assemblies for containment shall be installed in horizontal plumbing immediately following the meter or as close to that location as deemed practical by Water Works. In any case, it shall be located upstream from any branch piping. Installation at this point does not eliminate the responsibility of the customer to protect the water supply system from contamination or pollution between the backflow prevention assembly and the water main.
2. Reduced pressure principle backflow prevention assemblies shall be installed so as to be protected from flooding.
3. Reduced pressure principle backflow prevention assemblies shall not be installed in underground vaults or pits.
4. All backflow prevention assemblies shall be protected from freezing. Those devices used for seasonal water services may be removed in lieu of being protected from freezing; however, the devices must be reinstalled and tested by a registered backflow prevention technician prior to service being reactivated.
5. If hot water is used within the water system, thermal expansion shall be provided for when installing a backflow prevention assembly for containment.
6. Provisions shall be made to convey the discharge of water from reduced pressure principle backflow prevention assemblies to a suitable drain.
7. No backflow prevention assemblies shall be installed in a place where it would create a safety hazard, such as, but not limited to over an electrical panel, or above ceiling level.
8. If interruption of water service during testing and repair of backflow prevention assemblies for containment is unacceptable, another backflow prevention assembly, sized to handle the temporary water flow needed during the time of test or repair, should be installed in parallel piping.
9. All backflow prevention assemblies shall be installed so that they are accessible for testing.
10. All shut-off valves shall conform to the current edition of the Manual of Cross Connection Control (University of Southern California) requirements for either ball or resilient seat gate valves at the time of installation. Ball valves shall be used on assemblies installed in piping two inches and smaller and resilient seat gate valves on assemblies installed in piping larger than two inches.
11. Location and protection of the containment assembly shall be approved by Des Moines Water Works prior to installation.