Maricopa County No Longer Permits Wastewater Treatment Facilities: What Changed and What You Still Need
As of June 24, 2026, Maricopa County no longer permits or inspects wastewater treatment facilities. The Arizona Department of Environmental Quality (ADEQ) is now the sole regulator. Existing county construction and operational permits are being closed out, but ADEQ's Aquifer Protection Permit is still required before construction. Here is what changed and what you still need.
What changed
On June 24, 2026, the Maricopa County Board of Supervisors approved EROP Case ES-2025-005, which removes the Maricopa County Environmental Services Department (MCESD) from permitting and inspecting wastewater treatment facilities. The change took effect immediately.
For construction, the county will no longer accept new submittals or issue Approvals to Construct (ATCs) or Approvals of Construction (AOCs) for wastewater treatment facilities. Any open construction permits are being closed out, wherever they happen to be in the review or approval process.
For operations, all existing MCESD operational permits for these facilities are closed out as well. That means the monthly water quality reports facilities used to file with the county and the county's routine inspections are no longer required.
Why the county made this change
The short version is that two agencies were doing the same job. Maricopa was the only county in Arizona running its own wastewater treatment engineering review program, which meant the county and ADEQ were both reviewing plans and inspecting the same facilities. That overlap created duplicate work for the agencies and the facilities they regulate. Removing the county's role clears it up and leaves a single regulator handling wastewater treatment plants.
Do you need to do anything right now?
For most facilities, no. If you have an open construction permit with the county, you do not need to take any action. MCESD is closing those permits out and will reach out directly, so there is nothing to file or withdraw on your end. If you operate a facility, you can stop submitting monthly water quality reports to the county and you will no longer see the county's routine inspections.
One thing to be clear on, though: this is not a drop in oversight. Wastewater treatment facilities are still regulated, just by one agency instead of two. ADEQ's requirements are unchanged, which brings us to what you still need to have in place.
What has not changed: ADEQ still regulates this
It is worth stating plainly, because it would be easy to read this news as one less permit to worry about. It is not. ADEQ's requirements for wastewater treatment facilities are fully intact.
You still need an Aquifer Protection Permit (APP) from ADEQ before construction. ADEQ also keeps responsibility for MAG 208 conformance verification and for operational inspections of treatment facilities. The board's action only removed the county's duplicate layer, and it has no effect on ADEQ's jurisdiction or permitting requirements. If anything, ADEQ's role is now more central, since it is the only agency overseeing these facilities.
The county still permits other water infrastructure
The change applies specifically to wastewater treatment facilities, not to water infrastructure across the board. MCESD still issues ATCs and AOCs for several project types, and those processes are unchanged.
The county still permits sewer collection system infrastructure, including pipelines, manholes, lift stations, and force mains, along with drinking water treatment facilities, reclaimed water infrastructure, and non-hazardous liquid waste transfer stations. If your project falls into one of those categories, your submittals still go to the county exactly as before. So depending on what you are building, you may be dealing with the county, with ADEQ, or with both, which makes it more important than ever to route each submittal to the right agency the first time.
What this means if you are building or operating in Maricopa County
For wastewater treatment facilities, two regulators just became one, and that is genuinely simpler. But the bigger permitting picture in Maricopa County did not get simpler across the board. The county still handles sewer, drinking water, reclaimed water, and waste transfer infrastructure, while ADEQ handles treatment facilities and the Aquifer Protection Permit. A single project can touch both.
That split is where time gets lost. Send a submittal to the county that should have gone to ADEQ, or vice versa, and you do not find out until it bounces back, after the wait. Knowing which agency owns which piece, and getting each submittal to the right desk the first time, is what keeps a project moving.
That is the part we handle for clients building and operating in the Phoenix metro. Our infrastructure and commercial permitting teams track which agency regulates what, so your sewer and water infrastructure submittals go to the county and your treatment facility and APP requirements go to ADEQ, without the back-and-forth.
Key takeaways
As of June 24, 2026, Maricopa County no longer permits or inspects wastewater treatment facilities.
ADEQ is now the sole regulator for wastewater treatment plants in the county.
Existing county construction and operational permits are being closed out automatically, so applicants and operators do not need to take action.
ADEQ's Aquifer Protection Permit (APP) is still required before construction, and ADEQ keeps MAG 208 conformance and operational inspections.
The county still permits sewer collection infrastructure, drinking water treatment, reclaimed water infrastructure, and non-hazardous liquid waste transfer stations.
Frequently asked questions
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As of June 24, 2026, the Arizona Department of Environmental Quality (ADEQ) is the sole regulator for wastewater treatment facilities in Maricopa County.
The county Environmental Services Department no longer permits or inspects these facilities.
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Yes. While the county no longer issues Approvals to Construct or Approvals of Construction for wastewater treatment facilities, ADEQ's Aquifer Protection Permit (APP) is still required before construction.
The permitting did not go away, it consolidated under ADEQ.
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No. The county is closing out all open construction permits on its own and will contact applicants directly.
You do not need to file or withdraw anything.
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No. With county operational permits closed out, monthly water quality reports to the county and the county's routine inspections are no longer required.
Note that ADEQ retains its own operational inspection responsibilities.
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Yes. The change applies only to wastewater treatment facilities.
The county still issues ATCs and AOCs for sewer collection infrastructure, drinking water treatment facilities, reclaimed water infrastructure, and non-hazardous liquid waste transfer stations.
Submittals for those still go to the county as before.
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It is the Enhanced Regulatory Outreach Program case the Maricopa County Board of Supervisors approved on June 24, 2026, removing the county's permitting and inspection requirements for wastewater treatment facilities and leaving ADEQ as the sole regulator.