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Sonoma County

Terracon

321 Blodgett St, Ste A Cotati, CA 94931-8710

707-796-7170

The Sonoma County Office comprises a team of dedicated Professional Geophysicists and Geologists. We specialize in offering a diverse range of proven geophysical technologies to support geologic, groundwater, environmental, and engineering investigations. Our findings play a pivotal role in the planning, designing, and constructing of critical infrastructure and facilities. Additionally, we assess environmental and archeological conditions and evaluate earth resources.

Our capabilities include state-of-the-art geophysical instrumentation and computer systems for in-field and office data analysis, word processing, and graphics. Founded in 1983, NORCAL Geophysical Consultants, Inc. joins Terracon, aiding their long-time clients with access to expanding geophysical service capabilities. Working with geologists, geotechnical engineers, hydrologists, environmental engineers, archeologists, land planners, government agencies, and property owners has given us vast experience, and we are ready and excited to partner with any client seeking these services. Contact us to find out how the strategic application of geophysics can be a crucial element in ensuring the success of your project!

GEOPHYSICAL

SURFACE GEOPHYSICAL METHODSSurface geophysical methods can be used independently or integrated with other investigative methods such as test borings and other sampling programs for area investigations or site characterization. Surface geophysical methods can be used to:

Determine soil and rock properties
Investigate groundwater basins
Map geologic structure and geologic hazards such as landslides and faults
Delineate and characterize landfills and hazardous waste
Locate buried tanks, utilities, and former excavations
Determine zones of subsurface seepage

Subsurface geophysics methods the Sonoma team provides include:

Electrical Resistivity Profiling
Electromagnetic Terrain Conductivity
Time Domain Electromagnetics
Ground Penetrating Radar
Magnetics
MASW Shear Wave Velocity Determination
Seismic Refraction
Seismic Reflection
Streaming Potential
Utility Locating
Vibration Monitoring

BOREHOLE METHODSBorehole geophysical logging and imaging is used to characterize a variety of specific subsurface conditions. The equipment is very portable and can be easily shipped to distant or difficult to reach sites, including those that require helicopter access. Our latest computer software provides a wide range of data presentation formats and sophisticated 2-D and 3-D modeling capabilities.

Caliper-determine borehole dimensions
E-Log, Induction & Guard Resistivity-define stratigraphy and stratigraphic correlations
Sonic-access casing cement bond; P-wave velocity correlations
P & S wave Suspension Logger-determine compressional and shear wave velocities
Optical and Acoustic Televiewer-delineate fracture patterns and orientations and other structural features
Heat-Pulse Flowmeter-measure vertical groundwater flow
Deviation-determine borehole verticality
Temperature-Differential Temperature Fluid Conductivity-determine groundwater inflow and outflow depth locations
Discrete Water Sampling-profiling of contaminate concentration levels
Borehole and Water Well Inspection