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Washington Graywater Codes


Chapter 3, Section 8 - Permit by Rule Greywater Added - Policy 11.1

Greywater defined:

  1. Household wastewater which has not been contaminated by toilet discharge (blackwater). Greywater includes wastewater from baths, showers, bathroom wash basins, clothes washing machines, sinks (including kitchen sinks) and laundry tubs.

Greywater re-use systems that match the following conditions will be permitted on a "permit by rule" system as described in chapter 16 of the State of Wyoming Water and Wastewater Rules. That is to say that no application for a permit or fee is required if all the following conditions are met:

  1. Human contact with the greywater will be minimal.

  2. Water which has been used to wash diapers or similarly soiled or infectious garments is not allowed into the grywater system unless the greywater system is designed to prevent human or animal contact.

  3. Greywater does not come in direct contact with or adversely impact surface or groundwater.

  4. The potable water system must be isolated from the greywater system by the appropriate backflow methods and devices.

  5. Greywater does not leave the property on which it is generated without written, legally recorded, permission from all land owners affected.

  6. Water which contains hazardous materials cannot be disposed of in a greywater system.

  7. Greywater sprayed into the air for irrigation or other purposes during high wind conditions cannot come into contact with humans, domestic animals or the edible portion of food crops during normal operation.

  8. The application of greywater minimizes the pooling of water on the ground surface.

  9. Greywater holding tanks, if used, shall be covered or otherwise protected from access by mosquitoes, children, animals, or other life forms.

  10. The volume of greywater produced does not exceed an average of 2000 gallons per day.

  11.  In addition, at least one of the following conditions must also be met:


(a) The greywater system has been constructed to allow diversion ofthe flow to the black water disposal system, and the blackwater system (septic tank, sewer, etcetera) is sized adequately for both greywater and blackwater or:

(b) The greywater system has been constructed to allow diversion of the flow to a secondary greywater disposal system, and the second greywater system is constructed and operated within the guidelines defined above. The secondary system shall be designed and operated in such a manner that extended freezing temperatures will not cause failure. This option is required when a traditional blackwater disposal system is not present, such as when an incinerating toilet or composting toilet is utilized.

Greywater systems that do not meet the above criteria shall submit a permit application to the State of Wyoming Department of Environmental Quality to be evaluated on an individual basis.

IrriGRAY University

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