Coconino County, Arizona septic permits and requirements

Permitting authority

Coconino County Community Development — Environmental Quality Division

Coconino County Community Development, Environmental Quality; 2500 N. Fort Valley Road, Building 1, Flagstaff, AZ 86001; 928-679-8850. Applications and wastewater information requests are handled through the county online portal.

Arizona permitting framework

ADEQ has statewide authority for onsite wastewater treatment facilities and states that permitting authority is delegated to each of Arizona’s 15 counties. ADEQ rules continue to apply statewide, while delegated counties may have additional local requirements. Applicants should therefore use the county process for the property location unless the county or ADEQ identifies a project that remains under direct state jurisdiction.

State construction and discharge sequence

Arizona’s Type 4.02–4.23 general-permit framework covers many residential and light-commercial onsite systems up to 24,000 gallons per day. The state process requires authorization before construction and a discharge-authorization step after construction, inspection, and testing; county delegation and local limits determine which agency performs those steps for a particular project.

County authority has an explicit system-size boundary

ADEQ delegates Coconino County authority for all conventional septic systems and some alternative onsite systems up to 3,000 gallons per day. The county states that larger systems, including specified community systems, are regulated by ADEQ, so applicants should confirm jurisdiction for larger or unusual projects.

Environmental Quality performs the full county permit sequence

For systems in county jurisdiction, Environmental Quality performs site investigations, reviews permit applications, issues construction authorizations, inspects newly constructed systems, issues discharge authorizations, and records ownership transfers.

A site investigation report is required with the onsite wastewater application

Coconino County’s March 27, 2026 Site Investigation Information Sheet states that a Notice of Intent to Discharge application for an onsite wastewater system requires a site investigation report and will not pass administrative completeness review without one.

Site investigation is initiated through the online portal

The county directs applicants to apply for the Site Investigation permit online, prepare test holes before the scheduled inspection, and coordinate inspection through the portal. The county investigator documents subsurface and relevant surface conditions in the resulting report.

Existing conventional systems can require pump-out and county inspection

Coconino County’s current guidance for permitting an existing conventional septic system requires tank pumping by a qualified provider, documentation of tank condition and capacity, an effluent filter, and county inspection; a site investigation can also be required depending on available records and site conditions.

Official sources

SepticScope summarizes public-agency information for planning purposes. The permitting agency's current instructions control if they differ from this guide.