Can a washer drain to the yard in Arizona without a permit?

ADEQ answers it directly on its gray water page: "No, as long as you are only using gray water at your private residence, you only need to follow some required best management practices." Washer water counts. ADEQ defines gray water to include water from "washing machines (clothes only), bathtubs, showers or sinks."

The rule behind that is R18-9-D701, the Type 1 Recycled Water General Permit for Gray Water. It allows "private residential use of gray water for a flow of less than 400 gallons per day if all the following conditions are met." Note the word all. Use outside a private residence, or a flow of 400 gallons a day or more, needs a different authorization; see commercial graywater permits. Our Arizona graywater overview covers showers and tubs too. This page sticks to the washer.

Here's every condition in R18-9-D701(A), shortened but with nothing dropped:

1. 1Gray water from the home is used and contained within the property boundary, for household gardening, composting or landscape watering.
2. 2Human contact with gray water and the soil it waters is avoided.
3. 3Surface-applied gray water isn't used on food plants, except trees and shrubs whose edible part doesn't touch the gray water.
4. 4No hazardous chemicals, such as water from cleaning car parts, washing greasy or oily rags, or dumping hobby or home-business solutions.
5. 5No water used to wash diapers or similarly soiled or infectious garments.
6. 6Standing water is minimized: avoid overwatering, spread it beneath mulch or other cover, and improve the soil so it soaks in.
7. 7If the system blocks, backs up or overloads, gray water distribution stops until it's fixed.
8. 8Any surge tank is covered to keep out mosquitoes and other vectors, and holding time is kept short to avoid odors.
9. 9The system is outside a floodway.
10. 10At least five feet of separation between where gray water is applied and the top of the seasonally high groundwater table.
11. 11On a septic system, gray water use can't change the septic system's design, capacity or reserve area requirements, and the system must handle the combined black water and gray water flow.
12. 12Pressure piping that could be cross-connected with drinking water is clearly marked as not potable.
13. 13Surface application is by flood or drip only. Mulch basins and swales count as flood methods.

The rule also flatly prohibits two things: gray water use "for purposes other than watering and composting," and "Application of gray water by a spray method."

A hose tossed onto the lawn often fails the test. If the water runs down the driveway to the street or into the neighbor's yard, it isn't contained within your property. If it ponds, that's the standing water the rule tells you to minimize. Spraying it through a sprinkler is prohibited outright.

What usually passes is a line to mulch basins around trees and shrubs, buried under mulch, sized so a full load soaks in. Condition 7 and the diaper rule also mean you need a way to send a load to the sewer instead. ADEQ says diaper wash water "must be discharged to a residential sewer line." A diverter valve at the washer drain gives you that switch.

Watch the detergent, too. ADEQ warns against gray water "with elevated levels of chlorides, sodium, borax or sulfate that has a high pH, which could be harmful to your plants." And it lists antifreeze, mothballs and solvents as chemicals gray water can't contain.

It depends on the city. The state limits how far cities can go on the use itself. A.R.S. 49-204 says a city, town or county "may not limit the use of gray water by rule or ordinance" except in one narrow case: an initial active management area with a safe-yield groundwater goal that contains no part of the Central Arizona Project aqueduct, where effluent has been included in an assured water supply determination and gray water use would reduce the effluent available for it. The pipe work to divert the washer still falls under each city's building code, and cities handle that differently:

Scottsdale's exemption reads: "Single graywater discharge line from a single-family clothes washer to exterior for landscape irrigation with a maximum discharge rate of 160 gallons per day." Phoenix's plumbing exemptions cover things like clearing stoppages and fixing leaks "provided such repairs do not involve or require the replacement or rearrangement of valves, pipes or fixtures." Rerouting a washer drain outside is a rearrangement, so ask Phoenix Planning and Development before you cut in. In any other city, check its permit exemptions the same way.

1. 1Check your city's exemption list for a gray water or clothes washer line.
2. 2Plan where the water goes: mulch basins on your own lot, away from edible plants that would touch the water, with no runoff.
3. 3Keep a sewer option for diaper loads, oily rags and backups.
4. 4Pick plant-safe detergent low in chlorides, sodium, borax and sulfate.

If the drain itself is giving you trouble first, start with why a washing machine drain overflows. Thinking of a utility sink at the same time? See laundry room sink drain options. If you'd rather have a licensed plumber handle the diversion, we're licensed and insured, and estimates are free.