Percolation tests and permit-ready septic designs for acreage around Toltec, Sunland Ranches, and Sunland Gin Road, where the sanitary district's pipes do not reach. 48-hour reports from a design-only firm.
Start Your ProjectArizona City started in 1959 as a resort-style land development, complete with a 48-acre man-made lake and an 18-hole golf course that opened in 1963. It never incorporated, so there is no city government and no city sewer. The only entity running pipe here is the Arizona City Sanitary District, a special district formed in 1968 that operates roughly 90 miles of gravity sewer, two lift stations, and a treatment plant permitted for 1.5 million gallons a day. All of that serves a developed area of about six square miles, essentially the original platted core around the lake and golf course. Inside that core, the district's Sanitary Code makes it unlawful to keep a septic tank where sewer is available. Outside it, septic is how everything gets built.
Here is what that means if you are shopping acreage. Section 9.03 of the Sanitary Code says a parcel outside the district boundary cannot apply for sewer service until owners of at least 51 percent of the property petition for annexation, and the Board accepts only when extending mains is economically feasible. For one five-acre lot near Toltec or a homesite in Sunland Ranches, that math almost never works. Demand for that land keeps arriving anyway. Lucid Motors cut the ribbon on a 3-million-square-foot expansion of its Casa Grande plant in January 2024, about 15 minutes north, and winter residents swell the community by as much as 5,000 people. Buyers priced out of Casa Grande keep landing here at the I-8 and I-10 junction, roughly 60 miles from both Phoenix and Tucson.
That is the work Perc Test AZ exists for. We handle the two documents Pinal County requires before a shovel hits an unsewered parcel: the percolation test and the septic system design. We are design-only. We never bid the installation, so the soil numbers and the system sizing in your report are not inflated to sell a bigger job. The permit-ready report reaches you within 48 hours of fieldwork, and any licensed installer can build from it. Call (602) 584-7430 before you close on land outside the district line.
Arizona City sits on the Santa Cruz Flats, a basin floor of old irrigated farm ground built from stream alluvium. This is not the decomposed granite people picture when they hear Arizona desert. USDA soil mapping across the community returns a shortlist of recurring series: Marana silty clay loam under the platted core, Casa Grande clay loam and Casa Grande fine sandy loam wrapping the north and west sides toward I-10 and Toltec, Glenbar clay loam to the southeast, and pockets of Gilman fine sandy loam, Laveen loam, and Cashion clay across the south side.
Each of those names carries a perc expectation. The Casa Grande series is the troublemaker: a sodic soil with a clay-packed natric horizon, rated slow or very slow permeability, with sodium climbing sharply at depth and lime accumulations approaching 19 percent. Ground mapped in it on the north end commonly percs poorly and pushes designs toward oversized disposal fields or alternative systems. Marana and Glenbar both rate moderately slow, workable but hungry for trench footage. Gilman fine sandy loam is the coarsest of the group and typically tests best. One more local wrinkle: the Toltec series, named for the community at Arizona City's north edge, is defined by silica-lime cemented pan fragments at roughly 36 inches, so excavators around here can strike caliche chunks right at trench depth.
You do not have to guess which soil you bought. Arizona Administrative Code R18-9-A310 requires a site investigation with real soil data before Pinal County approves any system, and producing that data is the entire job. We dig test holes at disposal-field depth, run the percolation measurements, and log what the ground actually does rather than what the survey map suggests. A parcel mapped as Casa Grande clay loam can carry a sandier surface layer that passes cleanly, and a Gilman lot can hide a clay lens. The measured rate sets the trench sizing in your design, and the report is in your hands within 48 hours of the fieldwork.
Test holes dug at disposal-field depth on your Arizona City parcel, measured perc rates on Marana and Casa Grande clay loams, documented for the county.
Complete septic system designs sized to your tested perc rate and formatted to clear Pinal County Aquifer Protection Division review the first time.
Builders and installers: we test and design only. Your client stays your client, and the installation bid stays yours.
Every septic permit in Arizona City is issued by the Pinal County Aquifer Protection Division, operating under authority delegated by ADEQ. The office is at 85 N Florence Street in Florence, and it reviews conventional systems up to 24,000 gallons per day and alternative systems up to 3,000 gallons per day. On parcels of five acres or less, the county also reviews the well permit, which matters because acreage around Toltec and Sunland Gin Road is commonly sold as well-and-septic land. Our reports are formatted to the county's checklist so they move through review without a redesign round. Coverage details for the whole county are on our Pinal County service page.
The sequence is short. Site investigation and perc test first, then the design, then the county application with both attached, then a construction inspection once your installer digs. Most delays trace back to thin soil work or sizing that does not match the tested rate, which is exactly the failure a design-only firm is built to prevent. For the full walkthrough, application forms to final inspection, read our step-by-step Pinal County septic permit guide.
Almost certainly not. Section 9.03 of the district's Sanitary Code requires owners of at least 51 percent of the property to petition for annexation before you can even apply for service, and the Board accepts only when the extension is economically feasible.
For a single acreage parcel beyond the roughly six-square-mile core, that bar is rarely met, so plan on a septic permit through Pinal County.
Usually, but slowly. Marana and Glenbar soils rate moderately slow and typically support a conventional system with a generously sized disposal field, while the sodic Casa Grande series north toward Toltec rates slow to very slow and fails more often.
The only way to know your parcel's actual rate is to dig and measure it, which is exactly what the test does.
Yes. Arizona Administrative Code R18-9-A310 requires a site investigation with supporting soil data before any onsite wastewater system is approved, and a percolation test is the standard way to produce that data on Arizona City parcels.
The measured rate also determines how large your disposal field has to be, so it drives the design, not just the permit.
The permit-ready report is delivered within 48 hours of the fieldwork. It includes the soil log, the measured percolation rate, and the documentation the Aquifer Protection Division needs with your application.
If you are working against a close of escrow, tell us the date when you call (602) 584-7430 and we will schedule around it.
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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