Section 890.760  Pressure Type Water Treatment Units

Wash water and rinse water drain lines from water softeners and other types of water treatment units shall discharge through a vertical air gap at least twice the diameter of the pipe, but not less than two (2) inches.  Any water softening unit which depends on a venturi created by the flow of water from the water supply line to the softener, for the purpose of siphoning brine solution for regeneration, shall not be required to have a backflow preventer on the water supply line.  All other types (those that depend on internal check valves to prevent backflow and/or have the inlet supply of water stopped during regeneration) shall have a double check valve backflow preventer assembly installed on the inlet water supply line.