NAC445A.67215. Cross-connections and backflow: Service connection to fire sprinkler system.

     1. A supplier of water shall ensure that:

     (a) An appropriate assembly for the prevention of backflow is installed at each service connection between the public water system and a fire sprinkler system; and

     (b) The assembly is:

          (1) Tested upon installation; and

          (2) Maintained and tested, and the results of those tests logged, annually.

Ê The testing required by this subsection must be conducted by a certified backflow prevention assembly tester.

     2. An assembly for the prevention of backflow installed on a service connection between a public water system and a fire sprinkler system must:

     (a) Be of such a type and installed in such a manner that the assembly:

          (1) Protects the public water system; and

          (2) Does not interfere with the capability of the fire sprinkler system, as engineered, to protect the safety of persons in the public or private facility in which the fire sprinkler system is located; and

     (b) Prevent any pollution or contamination of drinking water, by any nonpotable water contained in the fire sprinkler system, which may be caused by any backpressure or backsiphonage that may occur during normal or abnormal operation of the fire sprinkler system or the public water system.

     3. The supplier of water shall determine the type of assembly required on a particular service connection between the public water system and a fire sprinkler system based upon the degree of risk posed by the fire sprinkler system to the supply of potable water, considering the chemical and biological contents of the fire sprinkler system, the materials used to construct the fire sprinkler system and the possibility that backflow will occur.

     4. Any reduced pressure principle assembly or reduced pressure detector assembly used on a service connection between a public water system and a fire sprinkler system must not have any holes drilled in the check valve clappers.

     (Added to NAC by Bd. of Health, eff. 2-20-97)