Indirect and Special Wastes; Gray Water and Reclaimed Water
Indirect waste
An indirect waste connection discharges through an air gap or air break into a receptor; it is never piped directly into the drainage system. The receptor is sized for the discharge and the gap is maintained above the flood level rim. Typical indirect wastes include ice machines, food-service refrigeration, steam tables, sterilizers, condensate, water-treatment backwash, and pool or boiler discharges. Where a receptor cannot be used, an air gap fitting is required.
Gray water
- Gray water comes from lavatories, showers, bathtubs, and laundry - not from water closets, urinals, kitchen sinks, or dishwashers.
- The system is separate from potable water and from blackwater, with no cross-connection; any potable makeup requires approved backflow protection.
- Storage, treatment, and disinfection requirements apply, and irrigation is typically subsurface rather than spray, with restrictions near food crops and wells.
- Plans and permits are required before installation, and labeling identifies nonpotable piping.
Reclaimed water
Reclaimed water uses purple pipe and fittings marked with a caution label reading approximately "CAUTION: RECLAIMED WATER - DO NOT DRINK." Cross-connection testing and signage at points of use are part of the inspection. Hose bibbs and connections that could be mistaken for potable are prohibited.
Worked example
An ice machine drain is hard-piped into a floor drain's branch line. That is a direct connection and a violation. Correct it by terminating the drain with an air gap or air break above the floor drain receptor, keeping the discharge above the flood level rim so backsiphonage cannot reach the ice.
Traps
- Assuming purple pipe alone satisfies the reclaimed water rules without labels and testing.
- Routing a kitchen sink or dishwasher to gray water.
- Allowing an indirect waste pipe to be trapped and connected directly.