Gray Water

Gray water

What is Gray Water?

This is water from your bathroom sinks, tubs, showers and laundry that may be redirected to your landscapes.

Sample Gray Water Systems

Can I Use My Gray Water?

Yes, but there are rules.

In Arizona, the Arizona Department of Environmental Quality (ADEQ) issued regulations for all types of reclaimed water effective January 1, 2001. Those regulations include guidelines for the use of residential gray water.  The regulations use non-technical terms and make it very simple and affordable for the resident to use gray water, saving money and our valuable water.

Before using your gray water (includes water from clothes washers, bathtubs, showers and baths and does not include water from kitchen sinks, dishwashers or toilets), check with your local governing body to ensure there are no additional requirements in place. In Cochise County, Arizona, call the County Health Department Environmental Specialist at 800-423-7271.

After checking with your local government, you can use your gray water if you answer "yes" to the following questions:

YES if:

  • I use my gray water for my own private residence.
  • I use my gray water directly on my own landscape for irrigation.
  • My family uses less than 400 gallons of graywater per day (35 gallons per day x number of family members = how much gray water your family creates in a day).
  • I avoid direct contact with my gray water and do not allow others to contact it directly.
  • All my gray water originates from my residence and is used within the property boundary for household gardening, composting, lawn watering or landscape irrigation.
  • My gray water is not used for irrigation of food plants except for citrus and nut trees.
  • I don't allow my gray water to 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 home occupational activities.
  • I apply my gray water to my landscape in such a way that it minimizes standing water on the surface.
  • My gray water system is constructed so that in the case of a blockage, plugging or backup of the system, all my 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 the opportunity for plugging and to extend the life of the system.
  • If I have gray water storage, it is covered to restrict access and to eliminate habitat for mosquitoes or other vectors.
  • My gray water system is sited outside of any floodway.
  • My gray water system is operated so as to maintain a minimum vertical separation distance of at least 5 feet from the point of gray water application to the top of the seasonally high groundwater table.
  • If I use any pressure piping in my gray water system that might be susceptible to cross connection with a potable water system, it is clearly marked.
  • My gray water does not contain water from a washing machine that is used to wash diapers or similarly soiled or infectious garments unless gray water is disinfected before irrigation.
  • My gray water irrigation is only by flood or drip. I do not spray irrigate with my gray water.

(Text courtesy of WATER CASA - Water Conservation Alliance of Southern Arizona)

Water CASA has an excellent booklet on gray water systems.