Geotechnical engineering that keeps your project moving.

Often, but not always. The California Building Code requires a geotechnical investigation for new foundations, but the building official can waive it for small, simple structures where the soil conditions are already known. In practice, whether you need one depends on where you are and what you're building:

• Detached ADUs and new two-story structures usually do need a soils report, especially in Lancaster, Palmdale, and unincorporated LA County areas with known collapsible or expansive soils.
• Garage conversions that reuse the existing foundation often do not.
• Your architect or structural engineer may want one even when the city doesn't, so they can design a smaller, cheaper foundation instead of assuming worst-case soil.

If you're not sure, call us with the address. We'll tell you honestly whether you're likely to need one.

They answer different questions. A soils report (geotechnical investigation) tells your engineer how strong and stable the ground is — whether it can carry a foundation, whether it will settle, shrink, or swell, and how it must be graded and compacted. A percolation test measures how fast water soaks into the ground, which determines whether a septic system will work on your lot and how large the leach field or seepage pit must be.

If you're building on a lot with no sewer connection, you may need both. See the side-by-side comparison on our homeowners page.

For a typical residential project: fieldwork is usually a single day on site, laboratory testing takes roughly one to two weeks, and the stamped report follows after the lab results are in. Commercial and public-works projects scale with the number of borings and the analyses required.

Contact us for a project-specific timeline. If you have a plan-check deadline, tell us up front — we'll say plainly whether we can meet it before you sign anything.

Yes — that's the normal way we work. We'll coordinate directly with your architect, structural or civil engineer, and contractor, send them the report in the format they need, and answer plan-check comments that relate to the soils. You stay in the loop on every email, but you don't have to be the go-between.

We're based in Lancaster. Proudly serving Los Angeles County and the Antelope Valley, including Lancaster, Palmdale, Quartz Hill, Littlerock, Lake Los Angeles, Acton, Santa Clarita, Pasadena, and Rosemead, with additional services throughout Ventura, Santa Barbara, Kern, Inyo, San Bernardino, Riverside, Orange, San Diego, and Imperial Counties.

If your project is somewhere else, call us anyway — we'll tell you if we can serve it well or refer you to someone who can.

Yes. Titan's reports are prepared under the responsible charge of, and stamped by, Mohammed Khalid, MS, PE — a California Registered Professional Civil Engineer (PE No. C94550) with over 10 years of geotechnical engineering experience. You can verify any California engineering license on the Board for Professional Engineers, Land Surveyors, and Geologists (BPELSG) license lookup at bpelsg.ca.gov.

Usually not. We need clear access to the area where the work will be done, a gate code or unlocked gate if the lot is fenced, and the location of any known underground utilities, septic tanks, or irrigation lines. We call Underground Service Alert (DigAlert, 811) before any drilling. Most homeowners are at work while we're there; we'll call you when we arrive and before we leave.

It can be. Much of the valley floor is desert alluvium — sandy, silty soils that can be dense and strong when dry but collapse (settle suddenly) when they get wet for the first time from irrigation, a broken pipe, or poor drainage. Other areas, especially near the old lakebeds, have expansive clays that swell and shrink. Parts of the valley have also experienced ground subsidence tied to groundwater pumping, and the San Andreas Fault runs along the southern edge near Palmdale. A local soils report exists to catch exactly these conditions before they show up as cracks in your slab.

For a basic residential soils report in the Antelope Valley — a single-family home, addition, or ADU on a relatively flat lot — Southern California fees commonly fall somewhere around $2,500 to $5,000. The number moves with how many borings are needed, how deep they go, whether the site needs a drill rig or can be hand-sampled, what lab tests the soils call for, and whether the plan checker will want extra analysis (slopes, fill, or a nearby fault zone).

Contact us for a project-specific quote. Every quote is a fixed written fee for a defined scope — send us the address and plans and we'll give you an exact number before any work starts.

Percolation testing costs depend on the type of testing required, the number and depth of test locations, site accessibility, and whether drilling equipment is needed. For a typical residential project in Southern California, percolation testing and the associated report generally range from approximately $3,000 to $5,000. Contact Titan Geotechnical Engineering for a project-specific quote.