Maricopa County Septic and Well Requirements for a New Home

A new home on rural Maricopa County land usually has no city sewer line and no city water main, so you provide both yourself: a septic system for wastewater and a private well for water. These are two separate approvals from two different agencies, and neither comes with the building permit. The county handles septic. The state handles wells. This page explains what each one requires, in what order, and how they tie back to your building permit.

The septic side: a county onsite wastewater permit

Wastewater on a rural lot goes to an onsite system, a septic system, permitted by Maricopa County Environmental Services. The county runs septic approval in phases, starting with proving the soil can absorb the wastewater, then designing a system that fits. The county lists the applications you submit through its Permit Center:

Phase I - Site and Soils Evaluation Application. Phase II - Conventional System Design Application. Phase II - Alternative Systems Design application. Septic Permit Application.

In plain terms, the path runs like this. Phase I is the site and soils evaluation: the county or a registered professional checks the lot for limiting conditions and measures how fast the soil absorbs water. That absorption test is the perc test , short for percolation test, where water is timed draining from test holes in the proposed disposal area. The result sets a soil absorption rate. Phase II is the system design, sized to that rate and to your home's number of bedrooms. After the system is installed and inspected, you file a Request for Discharge Authorization, and the county signs off so the system can be used.

Here is a concrete example. Say your five-acre parcel near Rio Verde Foothills has tight, clay-heavy soil that drains slowly. The perc test returns a slow rate, so the conventional gravity leach field would have to be very large, or the lot cannot fit one. The county may then require an alternative system, which costs more. This is why the soils evaluation comes first: it can change your system type, your budget, and even where the house sits on the lot.

The well side: an ADWR Notice of Intent to Drill

Water on a rural lot usually comes from a private well, and the well is authorized by the Arizona Department of Water Resources (ADWR), not the county. Before any drilling, you file paperwork with the state. ADWR states the rule directly:

Notice of Intent to Drill must be filed with ADWR. Forms are available on this site and must be submitted to ADWR accompanied by the appropriate filing fee. Authority to deepen an existing well or drill a new well will be valid for one year. After that, a new Notice of Intent must be filed. A licensed well-drilling contractor must perform the work.

A typical home well is an exempt well, which ADWR defines as a well with a pump capacity of no more than 35 gallons per minute used for domestic purposes. Filing the Notice of Intent registers the planned well and gives you a registration number, after which the licensed driller has one year to complete the work. One catch matters for small lots: if the well serves a parcel of 5 acres or fewer, the local health authority must review the application before it goes to ADWR. Much of Maricopa County also sits inside the Phoenix Active Management Area, which adds groundwater rules on top of the basic exempt-well process.

When this comes into play

These two approvals govern any rural build with no municipal utilities:

• Buying the land. Before you close on a lot, the perc result and the odds of a good well are part of whether the land is even buildable. A failed perc or a dry-hole risk can sink a deal, so this work belongs in your due diligence, not after.
• Designing the home. Your septic disposal area, your well, and your house all share the lot and have to keep required separation distances ( setbacks ) from each other and from property lines. The septic field and the well cannot sit on top of each other.
• Sequencing the build. The county septic permit and the ADWR well authorization run in parallel with your county building permit, and all three appear on the same site plan.

What this means for you

Treat septic and well as their own projects with their own timelines and budgets, separate from the house. Start the perc test early, ideally during your due diligence before you buy, because a slow or failing result changes your system type and cost and can decide whether the lot works at all. File the Notice of Intent to Drill with ADWR and hire a licensed driller, and remember the registration is good for one year. If your parcel is 5 acres or smaller, expect the local health review step before ADWR. Put the septic field, the well, and the house on one site plan so the separation distances all work together.

This entry covers the rural-utility half of the Maricopa County module. The permit that ties them together is in Maricopa County Residential Building Permit Requirements , and the codes your home is built to are in Maricopa County Adopted Building Codes . For the full rural picture, see what you need to build on rural land in Rio Verde and how to buy land to build a house in Arizona .

Source

The septic applications and phased process are published by Maricopa County Environmental Services: Onsite Wastewater Forms and Applications on maricopa.gov . The well requirements are published by the state: Well Drilling in Arizona and the ADWR Permitting and Wells FAQ .

This page is general information, not a substitute for the agencies' current rules. Septic phases, well filings, and fees change, so confirm the live requirements with Maricopa County Environmental Services and the Arizona Department of Water Resources before you rely on them.