Arizona has applied a 3 tier approach, based on volume of graywater per day,
and level of treatment required.
- Graywater may not be used for food production, other than citrus and nut trees.
- Irrigation by flood or drip only.
- Arizona does allow individual jurisdictions to modify the code „C. Towns, cities, or counties may further limit the use of gray water described in this Section by rule or ordinance.‟
Tier 1 (less than 400 gallons per day) does not require a permit.
Subsurface dripperline irrigation possibly can be used for vegetable irrigation.
R18-9-711. Type 1 Reclaimed Water General Permit for Gray Water
A Type 1 Reclaimed Water General Permit allows private residential direct reuse of gray water for a flow of less than 400 gallons per day if all the following conditions are met:
- Human contact with gray water and soil irrigated by gray water is avoided;
- Gray water originating from the residence is used and contained within the property boundary for household gardening, composting, lawn watering, or landscape irrigation;
- Surface application of gray water is not used for irrigation of food plants, except for citrus and nut trees;
- The gray water does not contain hazardous chemicals derived from activities such as cleaning car parts, washing greasy or oily rags, or disposing of waste solutions from home photo labs or similar hobbyist or home occupational activities;
- The application of gray water is managed to minimize standing water on the surface;
- The gray water system is constructed so that if blockage, plugging, or backup of the system occurs, gray water can be directed into the sewage collection system or on-site wastewater treatment and disposal system, as applicable. The gray water system may include a means of filtration to reduce plugging and extend system lifetime;
- Any gray water storage tank is covered to restrict access and to eliminate habitat for mosquitoes or other vectors;
- The gray water system is sited outside of a floodway;
- The gray water system is operated to maintain a minimum vertical separation distance of at least five feet from the point of gray water application to the top of the seasonally high groundwater table;
- For residences using an on-site wastewater treatment facility for black water treatment and disposal, the use of a gray water system does not change the design, capacity, or reserve area requirements for the on-site wastewater treatment facility at the residence, and ensures that the facility can handle the combined black water and gray water flow if the gray water system fails or is not fully used;
- Any pressure piping used in a gray water system that may be susceptible to cross connection with a potable water system clearly indicates that the piping does not carry potable water;
- Gray water applied by surface irrigation does not contain water used to wash diapers or similarly soiled or infectious garments unless the gray water is disinfected before irrigation; and
- Surface irrigation by gray water is only by flood or drip irrigation.
Prohibitions. The following are prohibited:
- Gray water use for purposes other than irrigation, and
- Spray irrigation.
Towns, cities, or counties may further limit the use of gray water described in this Section by rule or ordinance