Septic permit rules and requirements in Arizona

Who decides a septic permit in Arizona

Your county health or environmental agency issues an ordinary residential permit. For some systems the state issues it itself. The state sets the floor through the Arizona Department of Environmental Quality.

The rule requires a permit for a septic system.

Arizona Administrative Code, R18-9-A309 — General Provisions for On-site Wastewater Treatment Facilities · checked 2026-09-12

The floor state law sets

The rules that govern every septic system in Arizona are A.A.C. Title 18, Chapter 9, Article 3 — Aquifer Protection Permits, General Permits. Every local permit is issued under them.

Article 3, Part A sets the rules for septic permits.

Arizona Administrative Code, Title 18, Chapter 9 — Department of Environmental Quality, Water Pollution Control · checked 2026-09-23

What state law requires

Does Arizona require a septic permit?

Arizona requires a permit to build or run a septic system. A repair also needs a permit if it changes the treatment or disposal method.

Arizona Administrative Code, Title 18, Chapter 9 — Department of Environmental Quality, Water Pollution Control · checked 2026-09-23

Does Arizona require a percolation test?

Arizona requires a site test before it issues a permit. The test is a soil test, a percolation test, or a seepage-pit test.

Arizona Administrative Code, Title 18, Chapter 9 — Department of Environmental Quality, Water Pollution Control · checked 2026-09-23

The minimum septic tank size Arizona allows.

1,000 gallons.

Applies to a 3-bedroom house with 21 or fewer plumbing fixtures.

Arizona Administrative Code, Title 18, Chapter 9 — Department of Environmental Quality, Water Pollution Control · checked 2026-09-23

How far a system must sit from a well in Arizona.

100 feet.

Applies to the general rule. The department may set a different distance for one site or one permit.

Arizona Administrative Code, Title 18, Chapter 9 — Department of Environmental Quality, Water Pollution Control · checked 2026-09-23

How far a system must sit from the property line in Arizona.

5 feet.

Applies to a property line not shared with a lot served by a well or a shared drinking water system.

Arizona Administrative Code, Title 18, Chapter 9 — Department of Environmental Quality, Water Pollution Control · checked 2026-09-23

Does Arizona require an inspection when a home is sold?

The seller of a home with a septic system must hire an inspector. The inspector must check the system within six months before the sale.

Arizona Administrative Code, Title 18, Chapter 9 — Department of Environmental Quality, Water Pollution Control · checked 2026-09-23

Must the installer be licensed in Arizona?

For an alternative system, the report must name the installer. It must also give the "Registrar of Contractor's license number" that office issued.

Applies to a system built under R18-9-E303 through R18-9-E323, not the standard gravity tank under R18-9-E302.

Arizona Administrative Code, Title 18, Chapter 9 — Department of Environmental Quality, Water Pollution Control · checked 2026-09-23

Counties with rules of their own

The state writes the code. Each county below adds rules of its own. Open the county to read them with their sources.

Sources

State records only. Each figure above has a government source and a checked-on date. County figures live on the county pages.

1. Arizona Administrative Code, Title 18, Chapter 9 — Department of Environmental Quality, Water Pollution Control · checked 2026-09-23