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Septic Design & Perc Testing in Florence

Q: Do I need a perc test to build in Cactus Forest or off Diffin Road?

Yes. Those parcels are zoned General Rural with a 1.25-acre minimum and have no public water or sewer, so every new home needs its own well and septic system. Before Pinal County permits the septic side, Arizona Administrative Code R18-9-A310 requires a site investigation with soil and percolation data from your specific lot. You apply through the county's Aquifer Protection Division in downtown Florence, not through ADEQ directly. We produce the soil report and design your application is built on.

Q: Is Anthem at Merrill Ranch on septic?

No. Anthem at Merrill Ranch is served by EPCOR, which took over the former Johnson Utilities system in January 2021, so homes there connect to private-utility sewer. The town core is covered by Town of Florence utilities. Septic applies to parcels outside both service areas: county-zoned acreage along SR 79, Diffin Road, Cactus Forest, and similar rural ground around Florence.

Q: What if my test hole hits hardpan at 18 inches?

It happens around Florence. The Cipriano series mapped near Merrill Ranch carries a cemented caliche duripan starting anywhere from 4 to 20 inches down, and the county's namesake Pinal series averages a pan at 12 to 18 inches. Shallow refusal does not kill the project; it changes the design. We document exactly where the pan sits on your lot, and when conventional trenches will not work above it, we design the alternative system that will.

Q: How quickly can I file with the county after you test?

Fieldwork to permit-ready report typically runs 48 hours, and the package is formatted to what Pinal County reviewers expect, so it goes into your application as delivered. We design only and never bid installations, which means there is no reason for us to slow your project down or steer the system choice.

Perc testing and stamped septic design for Florence, Cactus Forest, and the SR 79 corridor. Permit-ready reports in 48 hours from a firm that only designs and never bids installs.

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A Copper Town Making Room for 30,000 Rooftops

Florence watched a mine wake up this year. Florence Copper, owned by Trekor Metals, started copper production in February 2026 and harvested its first cathodes that March at its in-situ recovery operation just north of town, a facility rated for 85 million pounds of copper a year over a 22-year mine life, with about 200 jobs on site and roughly 800 across the state. Housing is moving with it. The town's 2026 State of the Town counted more than 240 single-family homes permitted in 2025, 65 final plats reviewed across communities like Mesquite Trails, Florence 287, Monarch, and Attaway Crossing, 200 acres annexed for the Skyview Farms PUD, and potential for roughly 30,000 new homes over the next 10 to 15 years.

Now look at the sewer map, because it splits Florence three ways. Town of Florence utilities cover the historic core, with a water service area that runs east of Felix Road and two town-owned wastewater plants, the North and South plants, recharging treated water back into the aquifer. West of Felix Road, EPCOR handles service, including the Anthem at Merrill Ranch community on its San Tan system. Homes inside those boundaries connect to sewer and never call us. Everything outside them is a different story. Cactus Forest, about 6.7 miles southeast of town and two miles off Highway 79, is zoned General Rural with a 1.25-acre minimum lot size, and a new build there needs its own well and its own septic system. Similar well-and-septic parcels are commonly marketed along Diffin Road and the Pinal Pioneer Parkway frontage south of town.

If you own one of those parcels, your septic permit starts with soil data, and that is the work we do. Perc Test AZ runs the percolation test, evaluates the soil, and delivers the stamped design that goes into your Pinal County application, typically within 48 hours of fieldwork. We are a design-only firm. We never bid the installation, so the system on your plans is the one your dirt justified, not the one somebody wanted to sell you.

Caliche on One Side of Town, Deep Loam on the Other

Run the USDA soil survey across Florence and the map refuses to give one answer. Under the town core and south along the SR 79 corridor sit the Dateland, Marana, and Denure series, deep loamy basin-floor soils that usually drain at rates a conventional trench can work with, broken up by the lime-rich Gunsight and Pinamt series. Head northwest toward the Hunt Highway side and the Casa Grande series takes over, Arizona's official state soil, a fine-loamy profile with a sodium-loaded clay layer running from about 5 to 39 inches and permeability the USDA rates slow to very slow. Around Anthem at Merrill Ranch the survey adds Momoli, Contine, and Cipriano to the mix.

Cipriano is the one that stops backhoes. Its cemented silica-lime duripan, the hard caliche layer, starts anywhere from 4 to 20 inches down, usually capped by a thin laminar crust. The county's namesake Pinal series behaves the same way, with a pan averaging 12 to 18 inches that older surveys said took ripping or blasting to modify. Sodic clay creates the opposite problem: instead of refusing the shovel, Casa Grande series soil refuses the water, percolating too slowly for a standard trench and pushing designs toward larger disposal fields, chambers, or alternative systems. And a few hundred yards away, a deep Dateland loam may pass every test without drama.

That parcel-to-parcel swing is the whole reason Pinal County requires a site investigation before it permits anything. Our test holes settle the question for your lot specifically. We record each soil layer, note the exact depth where any hardpan begins, run the percolation measurements, and convert the results into the absorption rates that size your disposal field. If the numbers fail conventional criteria, the alternative design comes out of the same site visit.

What We Do in Florence

Perc & Soil Testing

Perc tests and soil investigations on Florence-area lots, from 1.25-acre Cactus Forest splits to SR 79 acreage, with permit-ready reports usually out within 48 hours.

Septic System Design

Conventional and alternative system designs, stamped, sized to your test results, and formatted for review by the Pinal County Aquifer Protection Division.

For Contractors

Builders and installers: we test and design only. Your client stays your client, and the installation bid stays yours.

Who Issues the Permit: Pinal County, Right Downtown

Every septic permit around Florence is issued by the Pinal County Aquifer Protection Division, working under authority delegated by the Arizona Department of Environmental Quality, and its office sits at 85 N Florence Street, First Floor, in downtown Florence. Not many landowners can walk into the building that reviews their file; here you can, a few blocks from the town core. The division permits conventional systems up to 24,000 gallons per day and alternative systems up to 3,000 gallons per day, and it also reviews well applications on parcels of five acres or smaller, which covers most General Rural splits in the area. The counter is open Monday through Thursday, 7:00 a.m. to 5:30 p.m. For how the division handles the rest of the county, see our Pinal County service page.

The rule that drives the paperwork is Arizona Administrative Code R18-9-A310. It requires a site investigation before any system is permitted: a qualified investigator has to characterize the surface and subsurface of your lot and document anything that could interfere with a disposal field. That investigation is the perc test and soil report we deliver, and our field packet is built around the rule so nothing bounces back for missing soil data. To see the whole sequence from application through final inspection, our step-by-step Pinal County septic permit guide walks through every stage of the county process.

Florence Septic Questions

Do I need a perc test to build in Cactus Forest or off Diffin Road?

Is Anthem at Merrill Ranch on septic?

What if my test hole hits hardpan at 18 inches?

How quickly can I file with the county after you test?

Testing a Lot in Florence?

Call (602) 584-7430 or tell us about your parcel online. We schedule fieldwork fast and deliver permit-ready reports in 48 hours.

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