Onsite Wastewater Treatment

Onsite wastewater treatment refers to a conventional septic tank system or alternative system installed at a site to treat and dispose of wastewater, predominantly of human origin, generated at that site. ADEQ has authority for issuing permits for operating these systems. 

Program Summary

The permitting program requires applicants to submit a Notice of Intent to Construct an onsite wastewater treatment facility that meets state design requirements. When an application is approved, construction is authorized and the applicant is given two years to construct the facility.  Once construction, inspection, and testing of the facility is complete, the applicant submits a Notice of Intent to Discharge.  A Discharge Authorization is issued once all the requirements for the design, construction, testing and operation are verified.

Why do I need a permit? Learn more >

Rule Clarification Form

Before submitting a permit application, you may request a clarification or interpretation of the statute, rule, delegation agreement or substantive policy statement(s) related to the onsite wastewater treatment program | View/Download Form >

Delegated Authority

We delegate regulatory functions for onsite wastewater systems to county environmental and health departments. If seeking a permit for an onsite system, please apply to the county in which the property is located.

Not sure where you need to submit your engineering review paperwork?

See listing of delegated agencies >

Complaint Form

If a person has a complaint regarding the ongoing implementation of the Onsite Wastewater Treatment Program by a delegated county, they may escalate their concerns to ADEQ | View/Download Form >

Notice of Transfer and Inspection

Arizona’s statewide inspection program for onsite wastewater (septic) treatment facilities requires inspection upon the resale of a home by the owner or with the assistance of a real estate professional. The inspection requirement applies to any property served by a conventional septic tank system or an alternative onsite system | Learn about the Inspection Program >

List of Proprietary Products

The list of proprietary and other reviewed products may include manufactured systems, subsystems or components within the treatment works and disposal works if the products significantly contribute to the treatment performance of the system or provide the means to overcome site limitations. The designer must select treatment systems from this list based on identified site-limiting conditions and applicant requirements.

View Listing | View >

Onsite Wastewater Advisory Committee

ADEQ established the Onsite Wastewater Advisory Committee (OWAC) to provide input and feedback on elements of the onsite wastewater treatment program | Learn More >

Get Involved | Path Forward and Rulemaking

In January 2021, ADEQ began the process of updating AAC Title 18, Chapter 9, as it applies to onsite wastewater treatment systems.¹ To learn how you can get involved and stay current with rulemaking updates, please visit our stakeholder engagement page | View Rulemaking Page >