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Pima County, Arizona
Geotechnical Engineering in Pima County, AZ
Subsurface investigations, laboratory soils testing, and geotechnical reporting to characterize site conditions before design and verify them during construction. Pima County is covered on a project basis through our Phoenix, AZ regional hub.
- Dispatched from
- Phoenix, AZ regional hub · project-based mobilization
- Lead time
- Set in the proposal, with mobilization planned around your pour and earthwork schedule
- Laboratory
- Sugar Land, TX laboratory under chain of custody, or a mobile laboratory for large projects
- Reporting
- Reviewed and issued under a documented quality system; formatted for owner, engineer, and building-official review
- Serving
- Pima County, AZ — Phoenix, Tucson, Mesa
- Coverage
- Arizona statewide · 27 regional hubs
- Technicians
- ACI- and NICET-certified field staff; licensed professionals in Arizona
- Call us
- (346) 420-5425
Scope
Geotechnical services in Pima County
- Soil borings and sampling programs sized to the structure and site
- Laboratory index testing: Atterberg limits (ASTM D4318), moisture content (ASTM D2216)
- Moisture-density relationships and bearing evaluation for foundations and pavements
- Expansive-soil characterization for slab and pavement design
- Construction-phase verification: proof rolls, subgrade acceptance, fill placement observation
ASTM D4318ASTM D2216ASTM D698ASTM D1557
Full scope, standards list, and pricing basis: Geotechnical Engineering.
Local conditions
Geotechnical conditions in Pima County
Pima County sits within the Basin and Range geologic province, where sites can transition quickly from dense caliche layers and expansive clayey soils to loose alluvial fan deposits — sometimes within the same parcel. Add the Sonoran Desert's pronounced wet-dry cycles, monsoon-season saturation events, and high evapotranspiration rates, and the subsurface conditions shaping your foundation design are rarely straightforward. Before a structural engineer can specify bearing capacity or a civil engineer can size a retention system, someone has to characterize what is actually below grade. That is what our geotechnical team does for projects throughout Pima County: conducting subsurface investigations, performing laboratory soils testing under a documented quality system, and delivering engineering reports that give design and construction teams the site-specific data they need. Coverage for Pima County is dispatched through our Phoenix regional hub, with scheduling coordinated in advance to match your project timeline.
Pima County soils frequently include caliche horizons of variable thickness and strength, as well as expansive fine-grained soils that respond to moisture changes — both conditions that can significantly affect foundation type selection, slab design, and grading plans. The region's monsoon season can temporarily alter near-surface moisture conditions, so the timing of a subsurface investigation relative to seasonal precipitation patterns is worth discussing with the project engineer.
FAQ · Pima County
Pima County has a lot of caliche. How does that affect my subsurface investigation?
Caliche layers vary widely in thickness, cementation, and continuity across the Tucson basin and surrounding areas. During a subsurface investigation, our team documents caliche depth, thickness, and approximate hardness in boring and test pit logs. This information directly influences excavatability assessments, foundation bearing recommendations, and drainage design. ASTM D1586 standard penetration testing and ASTM D2487 soil classification are used to characterize these materials consistently.
My site has expansive soils. What testing do you run to quantify the risk?
For sites with suspected expansive or highly plastic fine-grained soils — common in parts of Pima County — we typically run Atterberg limits testing per ASTM D4318, swell potential testing per ASTM D4546, and grain-size analysis per ASTM D6913 and ASTM D7928. Results feed directly into IBC Section 1803 requirements and allow the geotechnical engineer to recommend appropriate foundation systems or soil treatment measures.
How does monsoon season affect when I should schedule a geotechnical investigation?
Monsoon-season infiltration can temporarily elevate near-surface moisture content, which affects in-situ density readings and may not represent dry-season baseline conditions. While investigations can be conducted year-round, your geotechnical engineer should know the recent precipitation history at the time of the investigation so that moisture data is interpreted in the correct context. We coordinate scheduling with your project engineer to account for these variables.
Which office covers geotechnical in Pima County, AZ?
Field work in Pima County is dispatched through the Phoenix, AZ regional hub, about 106 miles away. Laboratory testing is performed in Sugar Land, TX under chain of custody, or in a mobile laboratory mobilized to large Pima County projects.
Are the technicians you send to Pima County certified?
Field sampling and testing in Pima County are performed by our ACI- and NICET-certified technicians. Geotechnical engineering and professional services are delivered with professionals licensed in Arizona, coordinated under one proposal.
Scheduling & proposals
Need geotechnical engineering in Pima County?
Call to schedule a technician, or send project documents for a written proposal.