Water Conservation Alliance of Southern Arizona
TITLE 18. ENVIRONMENTAL QUALITY
Back to Residential Graywater Reuse Study
CHAPTER 9. DEPARTMENT OF ENVIRONMENTAL QUALITY WATER POLLUTION CONTROL
The specific authority for the rulemaking, including both the authorizing statute (general) and the statutes the rules are implementing (specific):
Authorizing statute: A.R.S. § 49-203(A)(6)
ARTICLE 7. REGULATIONS FOR THE DIRECT USE OF RECLAIMED WATER
R18-9-701. Definitions
Definitions given in R18-11-301 and applicable state statutes will apply to those words and phrases when used in this Article. In addition, the following apply:
"Graywater" means wastewater that originates from residential clothes washers, bathtubs, showers, and sinks, but does not include wastewater from kitchen sinks, dishwashers and toilets.
R18-9-714. Type 1 - RECLAIMED WATER GENERAL PERMIT: GRAYWATER
A. A Type 1 Reclaimed Water General Permit is established for private residential direct reuse of graywater for a flow of less than 400 gallons per day provided all of the following conditions are met:
- Human contact with graywater and soil irrigated by graywater should be avoided.
- The graywater originates from the residence and is used and contained within the property boundary for household gardening, composting, lawn watering, or landscape irrigation.
- Surface application of graywater shall not be used for irrigation of food plants except for citrus and nut trees.
- The graywater shall not contain hazardous chemicals derived from activities such as cleaning of car parts, washing of greasy or oily rags, or disposal of waste solutions from home photo labs or similar hobbyist or home occupational activities.
- Graywater systems which are used for disposal rather than irrigation are prohibited.
- Application of graywater shall be managed to minimize standing water on the surface.
- The graywater system is constructed so that in the case of blockage, plugging or backup of the system, graywater can be directed into the sewage collection system or on-site wastewater treatment and disposal system, as applicable. The graywater system may include a means of filtration to reduce the opportunity for plugging and to extend the system lifetime.
- Any graywater storage tank shall be covered to restrict access and to eliminate habitat for mosquitoes or other vectors.
- The graywater system is sited outside of any floodway.
- The graywater system is operated so as to maintain a minimum vertical separation distance of at least 5 feet from the point of graywater 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 graywater system shall not change the design, capacity, or reserve area requirements for the on-site wastewater treatment facility at the residence, thus ensuring that the facility can handle the combined black water and graywater flow if the graywater system fails or is not fully used.
- Any pressure piping used in a graywater system that might be susceptible to cross connection with a potable water system shall be clearly marked.
- Graywater applied by surface irrigation shall not contain water from a washing machine that is used to wash diapers or similarly soiled or infectious garments unless the graywater is disinfected before irrigation.
- Surface irrigation by graywater shall be by flood or drip irrigation only. No spray irrigation is allowed.
B. Towns, cities, or counties may further limit the use of graywater described in this Section through passage of a rule or ordinance.