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WARNING! Irrigation systems supplied by domestic or private potable water systems are considered to be a potential pollution hazard to the water supply. These systems must include protection to prevent possible backflow of irrigation water into the potable water supply. Federal law requires a proper backflow device to be installed on any watering system to prevent contamination of the supply; whether it be pump or city water. Check your local water authority for installation requirements & codes. In many rural areas; specific requirements for landscape irrigation systems may not be covered in local plumbing codes and/or enforcement may be limited. HOWEVER...limitation in local authority does not alter the basic requirement for protection of the potable water supply.
Reduced Pressure assemblies are approved for backflow prevention of toxic substances (liquid; solid; or gas).