How to Permit a Composting Toilet in Arizona (What I’ve Learned)
This page documents what I learned while permitting a composting toilet in Arizona using an approved system. This is based on my personal experience and publicly available information, and it’s meant to help you understand the process before you walk into your local county health department.
Permitting rules can vary by county, and requirements can change over time. Always confirm current requirements with your local authority before building or submitting paperwork.
Important Reference (State Documentation)
UPDATE (7/14/22): Arizona composting toilet packet from the state
The information below was originally sourced from watershedmg.org. If any of this feels complicated, don’t worry — your local county health department can provide the correct paperwork and walk you through the process.
In short: Arizona offers a free permit for approved composting toilet systems. If you use scrap or low-cost materials, it’s possible to build and permit a compliant system for very little money.
Related Videos
Video: How I built this composting toilet system using scrap materials
Video: How the system actually works
Basic Materials (Single-Person System)
- Two 55-gallon plastic barrels
- Two 2-inch 90-degree PVC elbows
- One 3-inch PVC T
- One sheet of OSB large enough to cover the barrel lid
- Three 3-inch hose clamps
- A toilet lid (or equivalent)
- One 1-inch x 1/4-inch gasket
- Three springs to hold OSB to barrel
- 16-gauge wire mesh (to keep bugs out)
The unit does not need to be painted unless it will be in direct sunlight.
You are not required to build a shed to enclose the toilet. If you do build one, the shed does not need to be inspected.
What Inspectors Typically Look For
- Toilet lid sealed with a gasket or heavy lid to prevent insects
- OSB sealed to the barrel with a gasket
- Vent openings covered with mesh
- Toilet height between 12 and 16 inches above ground
Permitting Notes & Disclaimers
This document is meant to help you navigate the permitting process for composting toilets. It is not a comprehensive guide and does not guarantee permitting approval.
This system falls under an Alternative Onsite Wastewater Treatment Facility as a Type 4 General Aquifer Protection Permit under Arizona Administrative Code (AAC) R18-9-A301.
Additional State & County References
1. Arizona approved proprietary composting toilet products:
http://static.azdeq.gov/pub/list_prop_products.pdf
2. Counties that handle permits locally include: Apache, Cochise, Coconino, Gila, Greenlee, La Paz, Maricopa, Mohave, Navajo, Pima, Pinal, Yavapai, and Yuma.
Application submission reference
If you live outside those counties, applications are submitted to ADEQ’s Southern Regional Office in Tucson.
New Construction vs Existing Homes
If this system is part of new construction, additional requirements may apply — especially if sewer connection waivers are involved. If you already have septic or sewer service, you may still need a waiver depending on your jurisdiction.
Always confirm requirements with your county before proceeding.
If you’re new to off-grid planning, you may also want to start here:
Off-Grid Living: Start Here
8 comments
How do you fill out the long application form for a toilet you’re building yourself?
Thanks for this info, definitely comes in handy!
William, thanks for sharing.
I built a composting outhouse at my original off grid homestead in Apache county. It was a “ two holer” utilizing cut down blue poly barrels accessed from outside via a screwed down door panel. The seat board was 1/2 inch plywood with regular toilet seats screwed down. The barrel chamber was vented with black PVC pipe that went out through the side wall to an elbow then up the sunny side to about two feet above the roof line, terminated in another elbow with mesh to keep critters out. The black PVC made it a natural chimney in the sunlight. Never an issue with odor. The rest of the shed was tight enough to keep out any fly infestation. There was enough room to keep a bag of wood shavings which I would purchase periodically from a local saw mill.
When one side was filled up it became the aging barrel, and so on. When the second side filled the first got swapped for a third cut down barrel via the back door panel and the full barrel partially of aged humanure wheeled on a flat bed garden cart that just happened to be the perfect height to a dug down and double side raised compost bin for final aging. A small rototiller was periodically employed to aerate and mix in a few shovels of soil and the droppings from the little hen house. Sometimes some horse manure would go in too, as an additional carbon source.
Not very scientifically managed, but it all worked and the county assessor who came out and looked around once a year seemed to have no problem with it.
Grey water from the kitchen sink and the shower went into a buried tank and then out through two leach pipes into a drainage ditch full of crunched up aluminum cans then covered with weed cloth and buried. This also served as the occasional drain for my RV holding tank, but very infrequently used.
Hi Stephen, yes the urine just goes inside. If you have heavy usage or more women on the homestead because men often just pee on a tree. You may want to install the optional urine diverter. This would keep the compost from getting saturated.