The type of prevention device required depends on the degree of hazard that exists:
A. An air gap separation or reduced principle backflow prevention assembly shall be installed where the water supply may be contaminated by sewage, industrial waste of a toxic nature or other contaminant which could cause a health or system hazard.
B. In the case of a substance which may be objectionable but not hazardous to health, an air gap separation or a reduced pressure principle backflow prevention assembly, or a double check valve assembly, shall be installed.
C. Lawn sprinkler systems which are supplied by city water only shall be required to have either a double check valve backflow prevention assembly or a pressure vacuum breaker assembly or atmospheric vacuum breaker assembly depending on the design of the sprinkler system and potential risk to the potable water supply. The design of backflow prevention assemblies larger than one inch (1") will be submitted and approval made by the public works director. All backflow prevention assemblies shall be of a type approved by the state department of environmental quality. (Ord. 452, 1-7-2014)