SOILS SOUTHWEST
Geotechnical · Since 1984
Call
(909) 370-0474 Request a proposal
Geotechnical · Soils · Materials · Environmental

We do the groundwork.

Geotechnical, soils, materials, and environmental engineering for the Inland Empire and beyond — the investigations and reports that take your project from raw site to plan-check approval. Trusted by developers, contractors, and engineers since 1984.

Request a proposal Explore services
0' 5' 10' 15' 20' 25' 30' FILL SANDY CLAY SILTY SAND WX BEDROCK BORING B-1 · LOG (ILLUSTRATIVE)
1984
Established
40+
Years in the field
SoCal
Service area · IE & beyond
In-house
Materials & soils laboratory
What we do

Full-scope geotechnical services, site to sign-off.

One firm for the subsurface work behind your project — from the first feasibility question through construction in the field. Reports written to clear the building department the first time.

01

Preliminary soils & foundation evaluations

Early-stage assessments that tell you what a site can carry — before you're committed. The answer that shapes feasibility and budget.

FEASIBILITY · DUE DILIGENCE
02

Geotechnical investigations

Subsurface exploration, drilling, and engineering analysis producing the design-level geotechnical report your structural and civil teams build from — bearing pressure, settlement, seismic, and earthwork.

BORINGS · ANALYSIS · DESIGN REPORT
03

Materials & soils laboratory testing

An in-house lab for shear strength evaluation, consolidation evaluation, expansion, sieve analysis, maximum density, aggregate materials testing, and more — fast turnaround, no outside queue.

IN-HOUSE LAB · QC/QA
04

Infiltration & percolation testing

Field testing and design support for stormwater compliance — WQMP and BMP infiltration rates that satisfy the water-quality requirements on virtually every development today.

WQMP · BMP · STORMWATER
05

Seismic studies

Seismic hazard evaluations — the specialized studies required to develop safely across Southern California's active fault country.

SEISMIC HAZARD · FAULT STUDIES
06

Construction observation & testing

Grading, compaction, and foundation observation through construction — the field presence that keeps the work consistent with the report and the as-built record clean.

FIELD OBSERVATION · COMPACTION
Where we work

Southern California builds on our reports.

Four decades across the sectors that shape the region — from a single tract home or ADU to logistics, energy, and public works. Whatever sits on the surface, the work starts in the same place: the ground beneath it.

Tract & single-family homesProduction subdivisions and individual residences.
ADUs & residential additionsAccessory dwelling units, additions, and remodels.
Hillside & custom homesSlope stability, grading, and hillside development.
Multifamily & podium housingApartments, townhomes, and infill housing.
Hospitality, commercial & retailHotels, mixed-use, and commercial buildings.
Industrial & logisticsWarehouse, distribution, light industrial.
Self & truck storageSelf-storage and industrial outdoor / trailer storage.
Energy & storageSolar and battery energy storage (BESS) sites.
Public & institutionalMunicipal, civic, and public-agency projects.
Why Soils Southwest

The judgment that only comes from decades in the same ground.

A.

Four decades of Inland Empire subsurface

The expansive clays, alluvial soils, and fault systems of San Bernardino and Riverside counties aren't textbook — they're what we've worked in since 1984. Local ground knowledge that shortens the path to a defensible report.

B.

Work in responsible charge of a licensed engineer

Every report is prepared and stamped under the responsible charge of a California-licensed professional engineer — real engineering judgment behind the signature, never a rubber stamp.

C.

In-house laboratory, faster turnaround

Soils and materials testing under our own roof means results on your schedule, not an outside lab's backlog — and one accountable team from boring to final report.

D.

Written to clear plan check

We know what San Bernardino, Riverside, and the local building departments look for. Reports built to get through review the first time — protecting your schedule and your budget.

How an engagement runs

From first call to final field report.

01

Scope & proposal

We learn the site, the project, and the agency requirements, then scope the investigation precisely — no padding.

02

Field exploration

Borings, sampling, and percolation testing carried out to capture what the design team actually needs.

03

Laboratory testing

Samples analyzed in-house for strength, compaction, expansion, and classification.

04

Engineering & report

Analysis and recommendations assembled into a stamped report your team and the agency can build from.

05

Construction observation

On-site through grading and foundations to keep the build consistent with the report.

Representative experience

The ground under thousands of Inland Empire projects.

A cross-section of the work — by sector and scope. Swap these for real named projects and field photography to maximize credibility with referred clients and on SOQ submittals.

Multifamily

Apartment / townhome community

Scope: Geotech investigation · percolation · observationRegion: Inland Empire, CA
Logistics

Distribution / warehouse facility

Scope: Foundation eval · earthwork · materials testingRegion: San Bernardino County
Energy / BESS

Battery storage & solar site

Scope: Geotech · seismic · pad & foundation supportRegion: Inland Empire, CA
Storage

Self / truck storage facility

Scope: Soils · pavement · infiltration testingRegion: Riverside County
Hospitality

Hotel development

Scope: Geotech investigation · foundation recommendationsRegion: Inland Empire, CA
Fault study

Alquist-Priolo fault evaluation

Scope: Fault-rupture investigation · seismic hazardRegion: Southern California
// Placeholder portfolio. Replace each card with a real project name, a field photo, and one line of scope. A handful of real, recognizable jobs does more for credibility than a dozen generic ones.
The firm

Solid ground since 1984.

Soils Southwest was founded in 1984 to give Inland Empire builders straight answers about what's beneath their projects. Four decades later, that's still the work — geotechnical, soils, materials, and environmental engineering, done by people who know this region's ground.

Most of our work comes the way good engineering work always has: by referral, from the engineers, contractors, and developers we've delivered for. As the region grows into new sectors, the firm is investing in its next generation of leadership and capability — carrying forward the standards Soils Southwest has been trusted for since the beginning.

Established1984
HeadquartersColton, California
Service areaAll of Southern California
DisciplinesGeotech · Soils · Materials · Env.
LaboratoryIn-house
EngineeringCalifornia-licensed
Moloy Gupta, founder of Soils Southwest, Inc.
Our founder

Moloy Gupta, P.E.

Soils Southwest was founded in 1984 by Moloy Gupta — a geotechnical engineer who earned his master's at West Virginia University and a second, specializing in geotechnical engineering, at UCLA. He built it into one of Southern California's preeminent geotechnical engineering firms, and in 2013 was inducted into the West Virginia Academy of Civil Engineers. The firm continues to practice by the standards he set.

West Virginia Academy of Civil Engineers · Inducted 2013
Get in touch

Have a site? Let's talk about what's under it.

Call
(909) 370-0474
Fastest way to reach us — most projects start with a call.
Email
info@soilssouthwest.com
Send the site address and project type for a fast proposal.
Office
897 Via Lata, Ste N
Colton, CA 92324 — serving all of Southern California.

Request a proposal

Tell us the site location, the project type, and your target schedule. We'll scope the geotechnical work and get a proposal back to you quickly — usually within a couple of business days.

Email a proposal request
SERVICE AREA
Headquartered in Colton — serving all of Southern California:
San Bernardino · Riverside · Los Angeles · Orange · Ventura ·
San Diego · Imperial · Kern · Santa Barbara · San Luis Obispo