Understanding Septic System Permits in Pima County

If your property in Tucson or the surrounding areas relies on a septic system, permits are not just a formality—they’re the framework that keeps your home safe, protects groundwater, and ensures your system meets Arizona’s environmental standards. This guide walks you through when permits are required, who issues them, and how the process typically works in Pima County’s delegated program. You’ll also learn how real estate transactions trigger special rules, so you can plan confidently and avoid costly delays.

When Do You Need a Septic Permit in Pima County?

You will generally need county approval any time you install a new system or make significant changes to an existing one. Common trigger points include:

• Building a new home or accessory dwelling on a parcel without sewer connection
• Replacing a failed or end‑of‑life septic tank or drain field
• Adding bedrooms or fixtures that increase design flow (e.g., a major addition or remodel)
• Relocating system components to accommodate construction or property improvements
• Converting from a conventional system to an alternative technology (e.g., aerobic)

Minor repairs that do not change design flow or system layout may not require a full permit, but you should always confirm with Pima County before starting work. A quick conversation up front can save weeks on the back end.

Who Issues Septic Permits? ADEQ + Pima County’s Delegated Program

In Arizona, onsite wastewater (septic) systems are regulated under the state’s Type 4 General Permit program. The Arizona Department of Environmental Quality (ADEQ) sets the rules, but Pima County is a delegated program—meaning the County reviews most residential onsite projects locally. For a typical home system, you will apply through Pima County’s Onsite Wastewater program, which evaluates your submittal for compliance with ADEQ’s standards.

The Two Key Approvals: Construction Authorization & Discharge Authorization

Think of permitting in two phases:

• Construction Authorization (CA) – The County’s approval to construct or replace the system based on your site conditions and design.
• Discharge Authorization (DA) – The approval to use the system after it passes final inspection and meets operating requirements.

You must obtain the CA before building. After construction and a successful final inspection, the County issues the DA—only then can the system be buried and placed into service.

Step‑by‑Step: How to Get Permitted in Pima County

1) Site Evaluation & Design

A qualified designer evaluates your property to determine soil characteristics, setbacks, topography, and design flow (based on bedroom count and fixtures). This investigation informs the system type (conventional vs. alternative), tank size, trench dimensions, and drain field layout. For some projects, a Uniform Site Investigation or soils report is included in your submittal.

2) Application Submittal

Your designer compiles the permit package—application forms, design drawings, supporting calculations, and any manufacturer documentation—and submits it to Pima County. Because the County is a delegated reviewer for ADEQ’s Type 4 program, many residential systems are handled entirely at the County level.

3) County Review & Corrections

The County reviews the submittal for code compliance, environmental protection, and constructability. If corrections are needed, you’ll receive comments to address. Respond to these promptly to keep your project timeline on track.

4) Construction Authorization (CA)

Once the review is complete and fees are satisfied, the County issues the Construction Authorization. This approval allows your contractor to begin installation in accordance with the approved plans. Keep your stamped plans on site during construction.

5) Construction & Required Inspections

Your installer builds the system per the approved design. Before backfilling, the County or your engineer conducts required inspections to verify that key components (tank, baffles, piping, trench layout, distribution) are installed correctly. Taking photos and keeping daily notes can speed up final approval.

6) Final Field Inspection & Discharge Authorization (DA)

After construction passes its final field inspection and all paperwork is complete, the County issues the Discharge Authorization. Only then should the system be buried and put into service. Keep the DA in your records—it’s an important document for future real estate transactions and maintenance planning.

Real Estate Transactions: Transfer of Ownership Rules

Arizona law requires a special inspection when a property served by an onsite system is sold. Here are the essentials for Pima County sellers and buyers:

• An onsite system inspection must be performed within six months prior to transferring ownership.
• After closing, the buyer (transferee) must submit a Notice of Transfer to Pima County—generally within 15 calendar days.
• Pima County does not charge the separate $50 Notice of Transfer fee that some materials reference; do not include payment with the submittal.

These requirements ensure the system is documented, functional, and properly registered with the County. If the system recently received a Discharge Authorization and has not yet been used, an inspection may not be required—but the buyer still submits the Notice of Transfer. Check with Pima County for current details.

Common Permit Delays (and How to Avoid Them)

• Incomplete applications (missing drawings, signatures, or design calculations)
• Unclear site maps—include distances to structures, wells, washes, and property lines
• Design flows that do not match the bedroom/fixture count in the building plans
• Attempting construction before receiving the Construction Authorization
• Burial of components before the final field inspection
• Skipping required paperwork after construction, which delays the Discharge Authorization

Costs, Timelines, and Planning Tips

Permit fees and review times vary based on project complexity, staffing levels, and whether corrections are required. To keep your project moving:

• Engage your designer early—ideally before you finalize building plans.
• Answer County correction comments quickly and completely.
• Schedule inspections a few days in advance and coordinate with your installer.
• Keep records of your CA, DA, drawings, and inspection reports for future sales or renovations.

How Tucson Septic Systems Can Help

As the septic division of Curtis Plumbing, we guide Tucson homeowners through the entire permitting lifecycle—from site evaluation and design coordination to installation, inspections, and final Discharge Authorization. We understand Pima County’s submittal requirements and ADEQ’s Type 4 standards, so your project moves smoothly with fewer surprises.

Ready to Get Started?

If you’re planning a new build, replacing a failing system, or preparing to sell your home, our team can help you navigate permits with confidence. Call Tucson Septic Systems to schedule a consultation and get a clear plan for permitting, construction, and long‑term care.