Wastewater Engineering

Wastewater engineering in Arizona

MES designs wastewater systems for Arizona land development: sewer collection lines, lift stations and force mains, and treatment and reuse systems. We prepare the permit applications and the plans that go with them.

We work for developers and builders, and for utilities and municipalities. We also give overflow support to engineering firms that need wastewater help.

How ADEQ permits wastewater systems

Arizona regulates wastewater through the Aquifer Protection Permit (APP) program, run by the Arizona Department of Environmental Quality (ADEQ). Small on-site systems use Type 4 general permits. Larger treatment plants need an individual APP.

New sewer lines go through the Type 4.01 general permit. It covers a new collection system or extension that includes a manhole, or a force main or lift station serving more than one home. The owner of the downstream treatment plant must sign a statement that the added flow will not push the plant past its limits.

ADEQ first authorizes construction. After the line is built, a Discharge Authorization lets it operate. In Maricopa County, the county's Environmental Services Department reviews sewer line projects under a delegation from ADEQ.

Reuse has its own rules. Arizona sorts reclaimed water into five classes, A+, A, B+, B and C. Classes A+ and A can serve open access sites such as parks. Classes B+, B and C are for sites where public access is controlled. Direct reuse also needs an ADEQ recycled water permit, individual or general.

Our work in Arizona and nearby

Our Arizona projects today are site civil and utility plans for small commercial sites in the Phoenix area, Tucson and Casa Grande, through a drive-up water kiosk site program.

Nearby, in Colorado, our wastewater design work includes a wastewater lift station in Brighton and a 40,000 gpd replacement plant for an RV park.

Common questions

Does a new sewer line in Arizona need an ADEQ permit?

In most cases, yes. A new collection system or extension that includes a manhole, or a force main or lift station serving more than one home, falls under the Type 4.01 general permit. In Maricopa County, the county handles that review.

Who confirms the treatment plant has room for my flow?

The owner of the downstream plant signs a capacity statement for the Type 4.01 application. We ask for it early, because the application is not complete without it.

Can treated wastewater be reused on an Arizona development?

Yes, with an ADEQ recycled water permit. The reclaimed water class sets which uses are allowed, so we design treatment to the class the reuse needs. Call (214) 833-6748 to talk it through.