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Graywater System Requirements

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Example System Components between Clothes Washer and Landscape
  • The graywater system and parts thereof must be on the same lot (parcel) as the building or structure that discharges the graywater. 
     
  • Graywater must be distributed at least
    • 18 inches from the property line (Note: this minimum distance requirement shall be increased if the adjacent property is downhill from the graywater distribution point(s).); 
    • 2 feet from buildings; 
    • 50 feet from any septic tank or leach field; and 
    • 100 feet from wells, waterways, or other water sources. 
       
  • Graywater piping/tubing and the diverter (3-way) full-port ball valve shall be the same diameter as or larger than the clothes washer drain hose. Typically, 1-inch diameter. 
     
  • The end of the main-line tubing shall be left fully open (allow a continuous unobstructed graywater route from the clothes washer to the landscape; never use a valve or plug on the distribution point furthest away from the clothes washer.). 
     
  • The graywater system shall: 
    • Not include a potable water connection, filters, nor a pump. (Note: The pump in a clothes washer is not considered part of the graywater system.) 
    • Not connect to overhead (spray) irrigation nor to a conventional irrigation system. 
    • Be designed to prevent clogging of any emitters. 
    • Be designed and installed to prevent contact with humans and pets. 
    • Be labeled on every 5 feet of exposed graywater piping with, “Caution: Nonpotable graywater. Do not drink.” Labels may be provided upon request. 
    • Include a diverter (3-way) full-port ball valve to allow the user to direct the flow of graywater between the graywater system and the sanitary sewer/septic system. 
    • Include an auto vent (or an in-line vent or an air-admittance valve). 
       
  • The diverter valve and auto vent assembly
    • Must be installed at least 6 inches above the flood rim (typically the top) of the clothes washer. 
    • Must be easily accessible and labeled. Labeling shall indicate which direction to turn the diverter valve’s handle to send graywater to either the landscape or the sanitary sewer/septic system, respectively. Example labeling may be provided upon request. 
    • Shall be used to direct to the sanitary sewer/septic system all wastewater derived from activities that could create health issues. These activities include, but are not limited to: 
      • Washing diapers or similarly soiled garments, 
      • Washing greasy or oily rags, 
      • Cleaning car parts, 
      • Disposal of waste solutions from photo labs, and 
      • Other activities that contain hazardous chemicals
         
  • Any perforations in the building created during installation are properly sealed or patched. 
     
  • The finished system must include an operating and maintenance manual. The manual is to remain with the building throughout the life of the system. Upon change of ownership or occupancy, the new owner or occupant shall be notified that the structure contains a graywater system and provided the manual. A template manual may be provided upon request.
     
  • To facilitate future maintenance, the operating and maintenance manual shall include a diagram depicting the final locations of graywater piping, distribution points, and mulch basins with respect to the property line and landscape.