ECA

Geophysics
Intelligent Geophysical Surveys

ECA Geophysics, a registered subsidiary of Environmental Compliance Associates, LLC, provides geophysical services that include ground-penetrating radar (GPR), electromagnetic induction, electrical resistivity, magnetic, seismic refraction, gravity and VLF surveys throughout the United States, including Alaska, Arkansas, California, Colorado, Idaho, Louisiana, Montana, Oregon, South Dakota, Utah, Washington and Wyoming.h

Call us, when you need an intelligently designed, economic Geophysical Survey.


ECA Geophysics home page

Associate Firms

 Magnetic gradiometer survey at Holloman Air Force Base in New Mexico Gravity survey on Mt Shasta, California ReMi seismic refraction survey at a proposed Wind Farm GPR survey at Galena Air Force Base in Alaska EM-61 metal detection survey in Omak, Washington EM-34 electromagnetic survey in Washington State EM-31 electromagnetic survey in the Mojave Desert
Geophysical survey services provided by ECA Geophysics

Feedback from satisfied clients

"Mr. Smith was hired by the Columbia Generating Station (nuclear facility) to provide ground (penetrating) radar (GPR) detection services for a 16-acre evaporation pond project for which I was the lead engineer. Mr. Smith worked with the project schedule that required him to use GPR to survey rolling terrain that was the 30-year old construction preparation site for the nuclear plant. Mr. Smith worked alone crisscrossing the site in over 100 F heat for over a week locating all the buried debris and electrical wiring that served the old trailers. Mr. Smith was conscientious and timely, as well as flexible when areas of concern were further investigated. The resultant location of the hidden obstructions was very helpful as the multiple pond construction project was carried out.
I would not hesitate to re-hire Mr. Smith, if GPR services were again required."

Steve J. Strecker, PE, Contract Engineer for the Columbia Generating Station

"ECA Geophysics has done excellent work for Black & Veatch on our US Air Force range site. The geophysical data set collected in the field by ECA Geophysics was used to locate buried debris and anomalies and was considered very thorough and complete. The knowledge and experience ECA Geophysics provided helped to guide the investigation and proved invaluable."
Jennifer Canfield, Black & Veatch Special Projects Corporation

"AECOM conducted an RFI at Galena, Alaska.  Galena is located in a remote part of Alaska.  Due to its remote location and harsh environment, field work must be completed efficiently as possible, including “one-time, get it right” equipment mobilization.   ECA Geophysics was selected to perform geophysical surveys during the Summer of 2009.  ECA Geophysics was up to the call and provided timely, cost effective  and efficient survey results at a most challenging jobsite."
Collen J. Brownlow, PE, AECOM Technical Services


Mr. Smith, the Managing Principal, is a HAZWOPER-trained Professional Environmental Engineer who is qualified to write Health and Safety Plans (HASPs), as needed, when geophysical surveys are performed at hazardous waste or CERCLA sites.

Our surveys are designed and performed by senior geophysicists having excellent academic training and professional experience (please visit ECA Geophysics website). Mr. Smith and his associates all have advanced degrees in the Earth Sciences and possess decades of valuable professional experience.

Our professional associates have advanced geophysics degrees and professional registrations in such States as California, to enable us to legally and ethically practice our skills. Because of their excellent academic training and experience, our Geophysical Surveyors genuinely understand Nyquist Sampling Theory and other geophysical science fundamentals. Through academic and professional affiliations such as the Colorado School of Mines and the Environmental and Engineering Geophysical Society (EEGS), we access a "brain trust" of equally-qualified geophysicists.

We eliminate costly and cumbersome manual grids, by utilizing DGPS guided surveys that are based upon geodetic coordinate systems such as the State Plane, WGS 84 or UTM. All of our georeferenced data can be seamlessly incorporated into your GIS and AutoCAD databases.

ECA Geophysics performs ground-penetrating radar (GPR) surveys, seismic refraction and ReMi surveys, magnetic surveys, gravity surveys, electromagnetic surveys and multi-electrode electrical resistivity surveys nationwide.


HYDROGEOPHYSICS (GROUNDWATER GEOPHYSICS): SuperSting R8™Multi-electrode Electrical Resistivity Surveys at a Closed Refinery

PROJECT:
Multi-electrode SuperSting geophysical surveys at a complex abandoned petroleum refinery site in Montana
LOCATION:
Montana (specific location is Confidential, per client's request)
PROJECT DESCRIPTION: Designed and performed SuperSting 56-electrode geophysical surveys across approximately 50 acres of land that once supported a long-established liquid fuels and gas refinery. The resistivity data provided the client with bedrock depth and water-bearing zone information that will enable better placement of future groundwater monitoring wells required to meet State regulatory compliance guidelines.

Resistivity-based Bedrock Surface Map Resistivity data quality crossplot Electrical resistivity profiles (pseudosections) Resistivity-based Groundwater Depth Map
Electrical resistivity survey by ECA Geophysics


HYDROGEOPHYSICS: VLF / SuperSting™Multi-electrode Electrical Resistivity Surveys

PROJECT:
VLF and multi-electrode SuperSting surveys at a large tract of farmland
LOCATION:
California (specific location is Confidential, per client's request)
PROJECT DESCRIPTION: Designed and performed a reconnaissance VLF survey and subsequent exploratory SuperSting 84-electrode geophysical surveys across a suspected water-bearing trend occurring within a large tract of farmland at a confidential location in California. The resistivity data enabled the owner to install a water-well that is producing at a satisfactory flow rate of 200 gpm!

VLF Anomaly Map Geophysicist overseeing acquisition of SuperSting resistivity dataElectrical resistivity profile (pseudosection)
Electrical resistivity survey by ECA Geophysics


GEOTECHNICAL GEOPHYSICS: Seismic Refraction and Refraction Microtremor (ReMi™) Surveys

ReMi™ Surveys are superior to MASW Surveys in the following ways:

  • Ambient (ie, traffic and aircraft) “noise” is a hindrance to MASW surveys, yet is readily embraced / utilized by “passive” ReMi surveys

  • Longer ReMi data records (ie, 30 seconds vs 8 seconds or less with MASW) capture lower frequency events
  • We introduce high frequency impulsive energy that augments low frequency data to obtain excellent bandwidth
  • Accurate Dispersion Curves and Velocity-Depth displays

Utilizing state-of-the-art data processing technology and field equipment, ECA's geophysicists accurately determine:

  • Depth to bedrock
  • Bedrock rippability
  • Shear wave (Vs) / Compressional wave (Vp) information for foundation design
  • NEHRP / IBC site classifications

GEOTECHNICAL GEOPHYSICS: ReMi™ Survey at a Hazardous Waste Landfill

PROJECT:
ReMi™ surveys at a closed waste disposal site
LOCATION:
The Dalles, Oregon
PROJECT DESCRIPTION: Designed and performed ReMi™ Surveys at a closed 8-acre waste disposal site to passively measure microtremors within the upper 55 feet of the subsurface, in order to determine the depth to competent (non-rippable) basalt bedrock.

ReMi seismic profile locations at Oregon landfill ReMi seismic refraction 2D profiles at Oregon landfill
ReMi survey by ECA Geophysics


GEOTECHNICAL GEOPHYSICS: ReMi™ Surveys for Retail Store Expansions

PROJECT:
Refraction Microtremor (ReMi™) surveys at active national chain stores
LOCATIONS: Wenatchee, Washington / Woodinville, Washington / Yakima, Washington
PROJECT DESCRIPTION: Designed and performed ReMi™ Surveys for active retail properties to passively measure microtremors within the upper 100 feet (30 meters) of the subsurface, in order to acquire Vs, the average shear-wave velocity required to ascertain the proper NEHRP / IBC site class. This information provided to the client's design team an ACCURATE (vs asumed) seismic site classification from which to design the safest and most cost-effective extensions to the active store buildings.

Geophysicist overseeing acquisition of ReMi refraction data ReMi refraction Dispersion Plots ReMi Vs velocity model
ReMi surveys by ECA Geophysics


GEOTECHNICAL GEOPHYSICS: Refraction / ReMi™ Surveys at a Proposed Wind Farm

PROJECT: Refraction and ReMi™ geophysical surveys at a proposed Wind Farm
LOCATION: West of Ellensburg, Washington
PROJECT DESCRIPTION: Designed and performed seismic refraction / ReMi™ surveys at 22 proposed Wind Turbine Generator sites for the primary purpose of obtaining shear-wave (Vs) and compressional-wave (Vp) velocities. This information enabled the client (major geotechnical firm) to augment their drilling information and present accurate subsurface design criteria recommendations to their client.

ReMi and standard refraction data acquisition Field playback of seismic refraction data

Seismic refraction Vp velocity model ReMi Velocity Dispersion Plot ReMi Vs Velocity Model ReMi Vs30 explanation
Refraction and ReMi geophysical surveys by ECA Geophysics

GROUND-PENETRATING RADAR (GPR)n WA, ID, SD, WY, AK

Utilizing state-of-the-art equipment,
ECA Geophysics utilizes GPR to assist clients in the following ways:

  • Locate shallow metallic (and nonmetallic) pipes, drums and tanks

  • Utility and rebar locating

  • Locate buried infrastructure and voids


    GPR Survey to Locate Underground Fuel Lines and USTs at a Closed Air Force Base

    PROJECT: GPR Survey of a closed Air Force base
    LOCATION: Galena, Alaska
    PROJECT DESCRIPTION: Designed and performed GPR surveys of 14 areas of concern regarding the possible presence of buried underground fuel storage tanks (USTs), fuel lines, piping and electrical conduit. Performed detailed surveys so as to provide accurate locations to Client for subsequent environmental drilling and sampling activities.

    Closed Air Force Base in Galena, Alaska Geophysicist performing GPR Survey in Alaska

    GPR Anomaly Map for Air Force Base in Galena, AlaskaGPR images (radargrams) for Galena Air Force Base, Alaska
    GPR geophysical survey by ECA Geophysics


    GPR Survey to Locate Rebar and Utility Piping at a Nuclear Power Plant

    PROJECT: Concrete Scanning Survey of a large concrete slab at an active nuclear power plant
    LOCATION: United States
    (specific location is Confidential, per client's request)
    PROJECT DESCRIPTION: Designed and performed a GPR survey over an approximate 127-ft long by 44-ft wide concrete slab, for the purpose of imaging embedded linear features such as rebar, wire mesh and utility piping. Performed 2-ft spaced GPR traverses in N-S and E-W directions, in order to acquire sufficient data from which to create accurate, detailed plan view depth "slice" images, that will help Client avoid coring into said features.

    GPR concrete scanning survey - 6-inch depth slice
    6-inch Depth Slice: 12-inch spaced rebar (left, lower central, upper right)

    GPR concrete scanning survey - 12-inch depth slice
    12-inch Depth Slice: 6-inch spaced wire mesh (upper central, lower right)

    GPR concrete scanning survey - 20-inch depth slice
    20-inch Depth Slice: Presumed utility piping (left, middle, right)

    Concrete scanning survey by ECA Geophysics


    GPR Survey to Locate ReBar and Conduit within a Telecommunications Center

    PROJECT: GPR Survey of AT&T Building
    LOCATION: Yakima, Washington
    PROJECT DESCRIPTION: Designed and performed a Hi-Res (1.6 GB antenna) GPR survey of a concrete floor to locate and identify embedded rebar and conduit. Performed detailed survey that enabled the safe cutting of floor for follow-up construction activities.

    High-frequency GPR radargram of rebar within concrete floor
    GPR survey by ECA Geophysics


    GPR Survey to Locate USTs and Piping for Hanford Area Sites

    PROJECT: GPR survey of Hanford Area sites, on behalf of Mission Support Alliance (MSA)
    LOCATION: Hanford Nuclear Reservation, Washington
    PROJECT DESCRIPTION: Designed and performed GPR surveys of the 200 Area, traffic corridors along Routes 3 and 4 and the Waste Sampling and Characterization Facility (WSCF). Performed instrument calibrations with known onsite buried features, to establish reliable depth estimates.

    Site Map of GPR Survey Area - Hanford Nuclear Reservation, Washington GPR images (radargrams) at Hanford Nuclear Reservation, Washington
    GPR survey by ECA Geophysics


    GPR Survey to Locate USTs and Piping for Hanford Area Facilities

    PROJECT:
    GPR survey of Hanford Area facilities, on behalf of the Port of Benton
    LOCATION: Richland, Washington
    PROJECT DESCRIPTION: Designed and performed a GPR survey of industrial sites, to determine the presence of buried USTs, piping and electrical conduit. Performed onsite instrument "calibration" with known onsite buried features, to establish reliable depth estimates.

    Site Map of GPR Survey Area - Port of Benton - Richland, Washington GPR images (radargrams) at Richland, Washington
    GPR geophysical survey by ECA Geophysics


GPR Survey to Locate Underground Fuel Lines and USTs at Vacant Retail Buildings

PROJECT: GPR Survey of vacant retail buildings and surrounding property
LOCATION: Cheyenne, Wyoming
PROJECT DESCRIPTION:
Performed GPR surveys of two vacant retail buildings, to enable a subsequent safe drilling program within the survey areas. Surveys identified buried electrical conduit and a drainage line but confirmed the absence of underground fuel storage tanks (USTs), 55-gallon drums and fuel lines. Identified anomalous features (anomalies) were referenced to an onsite grid, for later reacquisition, as needed.

Site Map for GPR Survey in Cheyenne, Wyoming GPR radargrams for ground beneath retail building
GPR survey by ECA Geophysics


GPR Survey to Delineate Abandoned Trenches at an Unpermitted Disposal Site

PROJECT: GPR survey with confirmatory excavations at contaminated farmland
LOCATION: Grandview, Washington
PROJECT DESCRIPTION: Performed a saturation GPR survey of farmland (suspected of having illegally buried drums of herbicides and pesticides) to identify / locate the edges of trenches. Recommended excavation locations that enabled client to obtain evidence for subsequent legal actions. Excavations confirmed trench edges and buried drums identified by GPR surveying.

GPR survey area at unpermitted dumping site in Grandview, WashingtonGPR images of illegally buried waste - ECA Geophysics project Excavated debris identified by GPR Survey Level B personal protective equipment at GPR Survey site
GPR survey by ECA Geophysics


GPR Survey to Delineate Edges of USTs at a Gas Station

PROJECT:
GPR survey with confirmatory drilling
LOCATION: Moyie Springs, Idaho
PROJECT DESCRIPTION: Performed a saturation GPR survey of an active gas station, to identify / locate the edges and ends of three inactive closed-in-place USTs. Performed onsite instrument "calibration" with active UST, to establish reliable depth estimates. Recommended desired drilling locations (within 2-3 feet of tank ends) for environmental sampling required to obtain regulatory tank closure. Drilling confirmed near-tank backfill and never breached any of the tanks.

Cross-sectional GPR radar images of underground storage tank (UST) for Idaho gas station Axial GPR radar images of underground storage tank (UST) for Idaho gas station
GPR survey by ECA Geophysics


GPR Survey to Identify Cultural and Archaeological Features

PROJECT:
GPR survey with confirmatory digging
LOCATION: Olmstead State Park, Washington
PROJECT DESCRIPTION: Performed a reconnaissance GPR survey of an historical homestead, to identify / locate prospective locations of historical privies, wells and debris middens. Recommended digging locations within an area that was tantamount to finding a "needle within a haystack". Digging confirmed better than 50 percent success rate.

Olmstead State Park, Washington - GPR survey site GPR images from survey taken at archaeology site
GPR geophysical survey by ECA Geophysics


GPR Survey to Locate USTs and Piping at a Retail Facility

PROJECT:
GPR survey with confirmatory drilling + soil and water sampling / analysis
LOCATION: Spokane, Washington
PROJECT DESCRIPTION: Designed and performed a tight-line / saturation Ground Penetrating Radar (GPR) survey of an active retail property, to determine the presence, if any, of buried 1950s-vintage underground storage tanks (USTs). Performed onsite instrument "calibration" with known onsite buried features, to establish reliable depth estimates. Directed drilling contractor in the strategic placement of soil borings, to confirm GPR interpretations. Successfully confirmed the absence of USTs at key locations having GPR anomalies solely attributable to an eroded bedrock surface. Directed subsequent groundwater sampling activities.

Environmental drilling at GPR survey site - ECA Geophysics project GPR radargram of subsurafce at retail facility in Washington Perched groundwater sampling at GPR survey site - ECA Geophysics project Groundwater sampling at GPR survey site - ECA Geophysics project
GPR survey by ECA Geophysics


GPR Survey to Locate USTs and Piping at a Retail Facility

PROJECT:
GPR survey of a retail facility
LOCATION: Spokane, Washington
PROJECT DESCRIPTION: Designed and performed a tight-line / saturation Ground Penetrating Radar (GPR) survey of an active retail property, to determine the presence, if any, of buried 1950s-vintage underground storage tanks (USTs). Performed onsite instrument "calibration" with known onsite buried features, to establish reliable depth estimates. Successfully confirmed the absence of USTs at locations having GPR anomalies attributable to an eroded bedrock surface.

GPR survey at car wash facility in Spokane, Washington GPR radargram image of basalt knob - ECA Geophysics project
GPR geophysical survey by ECA Geophysics

INTEGRATED GEOPHYSICS: Combining methods to obtain a better perspective

The combined information from different geophysical surveying methods often allows ECA's geophysicists to provide interpretations with much greater confidence.

  • Magnetics with Electromagnetic Induction (EMI)
  • GPR with Magnetics and/or EMI
  • GPR with Metal Detection (EMI or EM-61)
  • Seismic with EMI

INTEGRATED GEOPHYSICS: Magnetic / EMI Surveys at an Air Force Base

PROJECT:
EMI and Magnetic surveys at closed waste disposal sites
LOCATION:
Holloman Air Force Base near Alamogordo, New Mexico
PROJECT DESCRIPTION: Designed and performed total-field magnetometer surveys in tandem with EM-31 terrain conductivity (EMI) surveys of approximately 53 acres of closed landfills at an Air Force base in New Mexico.  Survey was designed to detect buried metallic debris and soil conductivity. The magnetic method successfully identified numerous burial locations and the EM-31 method successfully delineated boundaries of old landfilling sites. Performed detailed data reduction and provided Client with line-contour and color-contour maps with Latitude-Longitude coordinates.


Magnetic gradiometer survey at Holloman Air Force Base EM-31 EMI survey at Holloman Air Force Base, New Mexico Residual magnetic Anomaly Map - ECA Geophysics project Terrain Conducitvity Anomaly Map - ECA Geophysics project
Magnetic and electromagnetic geophysical surveys by ECA Geophysics


INTEGRATED GEOPHYSICS: GPR and EMI Surveys at an Air Force Site in the Mojave Desert

PROJECT:
GPR and EMI surveys at closed waste disposal sites
LOCATION:
Cuddeback Air-to-Ground Gunnery Range in the Mojave Desert near Ridgecrest, California
PROJECT DESCRIPTION: Designed and performed a GPR survey in tandem with an EM-31 terrain conductivity survey of nine closed landfilling areas at an abandoned Air Force gunnery range located in the Mojave Desert of California and just east of the film location for the movie Hidalgo.  Surveys were designed to detect burial trenches in general and buried metallic debris in particular. The GPR method successfully identified numerous trench locations and the EM-31 method successfully confirmed metallic debris contained therein. Performed detailed data reduction and provided Client with GPR profiles and color-contour maps with Universal Transverse Mercator (UTM) coordinates.

Kangaroo Rat at Geophysical Survey in the Mojave Desert Endangered Desert Tortoise at Geophysical Survey in the Mojave Desert

EM-31 electromagnetic survey in the Mojave Desert - ECA Geophysics project EMI Anomaly Map - ECA Geophysics project GPR Anomalies (radargrams) from Mojave Desert site - ECA Geophysics project GPR survey in the Mojave Desert - ECA Geophysics project
Electromagnetic (EM-31) and GPR geophysical surveys by ECA Geophysics


INTEGRATED GEOPHYSICS: GPR and EMI Surveys at an Air Force Base

PROJECT:
GPR and EMI surveys at closed metallic waste disposal sites
LOCATION:
Hill Air Force Base Annex near Ogden, Utah
PROJECT DESCRIPTION: Designed and performed a GPR survey in tandem with an EM-31 terrain conductivity survey regarding two suspected Mg/Th aeronautical debris dump sites at an Air Force base in Utah.  Survey was designed to detect buried non-ferrous metallic debris. The in-phase component of the EM-31 method identified suspected locations of non-ferrous metals and the GPR method identified suspected burial locations. Performed detailed data reduction and provided Client with color-contour maps with UTM coordinates.

EMI (EM-31) Survey Site Map for Air Force Base Annex in Ogden, UtahGPR images for Air Force Base in Ogden Utah - ECA Geophysics project
Electromagnetic (EM-31) and GPR geophysical surveys by ECA Geophysics


INTEGRATED GEOPHYSICS: EMI and ReMi™ Surveys at a Hazardous Waste Landfill

PROJECT:
EMI and ReMi™ surveys at a closed hazardous waste disposal site
LOCATION:
The Dalles, Oregon
PROJECT DESCRIPTION: Designed and performed a 5-ft spaced EMI survey in tandem with ReMi™ surveys at a closed 8-acre waste disposal site. The goals of this integrated geophysical investigation were to 1) detect landfill boundaries, 2) identify locations of buried metallic debris / drums and 3) to determine the depth to competent (non-rippable) basalt bedrock. All three goals were successfully achieved!

EM-31 Survey Traverses Map for Oregon landfill ReMi refraction seismic profiles - ECA Geophysics projectEMI (EM-31) Anomaly Map for Oregon landfill
Electromagnetic (EM-31) and ReMi surveys by ECA Geophysics


INTEGRATED GEOPHYSICS: Magnetic and EMI Surveys at a Solid Waste Landfill

PROJECT:
Magnetic and EMI surveys at a closed municipal solid waste landfill site
LOCATION:
Pasco, Washington
PROJECT DESCRIPTION: Designed and performed a total-field magnetometer survey in tandem with an EM-31 terrain conductivity survey of a closed municipal solid waste landfill located east of Pasco, Washington.  Survey was designed to detect buried metallic debris and drums. The in-phase component of the EM-31 method successfully identified locations of ferrous and non-ferrous metals and the magnetic method confirmed the burial locations of suspected 55-gallon drums. Performed detailed data reduction and provided Client with color-contour maps with UTM coordinates.

In-phase EMI (EM-31) anomaly map at Pasco Landfill, Washington Magnetic anomaly map at Pasco Landfill, Washington
Electromagnetic and magnetic surveys by ECA Geophysics


INTEGRATED GEOPHYSICS: GPR and Metal Detection Surveys at a Retail Facility

PROJECT:
GPR and EMI surveys at an active Safeway grocery store parking lot
LOCATION:
Rapid City, South Dakota
PROJECT DESCRIPTION: Designed and performed a GPR survey in tandem with an EM-61 metal detection survey of a parking lot for a Safeway store in Rapid City, South Dakota. Surveys were designed to detect buried metallic and non-metallic drums and piping apparently left from a previous gas station removal. The GPR method successfully identified numerous non-metallic pipe runs and the EM-61 method successfully confirmed metallic debris contained therein and elsewhere. Performed detailed data reduction and provided Client with GPR profiles and a color-contour map with internally referenced coordinates.

GPR site survey map - Rapid City, South Dakota GPR images (radargrams) at Safeway store in Rapid City, SD EM-61 (metal detection) anomaly map - ECA Geophysics project
GPR and electromagnetic (EM-61) surveys by ECA Geophysics


POTENTIAL-FIELD METHODS

Magnetic Surveys

Designed and performed a total-field magnetometer survey of a
26-acre wood-waste landfill in Omak, Washington. This magnetic survey was designed to detect buried metallic debris to a depth of 12 feet and was augmented by an EM-34 soil conductivity (soil mapping) survey.

Total Field Magnetic Survey - Omak, WashingtonDesigned and performed (utilizing a total-field magnetometer) a gradiometer survey of an asphalt-paved parking lot for a US Bank property in Spokane, Washington. The presumed target was an underground storage tank (UST) and associated fuel lines. Processed data to isolate residual anomalies and successfully and accurately located an abandoned fuel line and associated tank removal debris.

Designed and performed a total-field magnetic survey at an abandoned Atlas Missile silo located north of Reardan, Washington. Processed data to isolate residual anomalies and determined that no suspected metallic debris existed at survey location.

Designed and performed a high resolution total field magnetic survey of an abandoned dump site at a pulpwood processing facility in Louisiana. Processed data to isolate residual anomalies, which were correctly interpreted to be buried metallic debris occurring within ten feet of the surface. Woodward-Clyde Consultants project.

Designed and performed (utilizing a two-sensor magnetometer) a gradiometer survey of an abandoned dump site at a pesticides manufacturing facility in Arkansas. Correctly interpreted depth and location of buried metallic debris and utilized such findings to direct a safe environmental drilling operation. This (gradiometer) method enabled an effortless, yet effective removal of the considerable cultural "noise" that existed adjacent to the project area. Woodward-Clyde Consultants project.

Designed and performed a total-field magnetic survey in northwest Arkansas, in order to augment existing data (U.S. Geological Survey) that strongly indicate a large igneous mass at depth. All survey "loops" were properly closed and double checked for accuracy before leaving the project area. Manually reduced data and performed forward modeling of same in order to determine the vertical distance to the top of the body; interpreted to be approximately 17,000 feet deep. Colorado School of Mines project.


Electromagnetic (EMI) Surveys

EMI (EM-34) surveyDesigned and performed an EM-34 soil conductivity (soil mapping) survey of a 26-acre wood-waste landfill in Omak, Washington.  This soil mapping survey was designed to detect buried drums at a depth of 60 feet and was augmented by a total-field magnetometer survey.

While employed with the Arkansas Department of Environmental Quality (ADEQ), performed approximately 40 reconnaissance EM-31 soil conductivity surveys of proposed landfill sites throughout the State of Arkansas.

Performed an EM-31 soil conductivity survey of the U.S. Navy's Strategic Petroleum Reserve in Hackberry, Louisiana. Survey results enabled the prime contractor (Fluor Daniel) to design an effective perimeter warning system for the facility. Woodward-Clyde Consultants project.

Designed and performed an EM-61 metal detection survey of a 26-acre wood-waste landfill in Omak, Washington.  Survey was designed to detect buried
EMI (EM-61) survey metallic debris to a depth of 12 feet and was augmented by a total-field magnetometer survey.  Innovative in-field adjustments were made to address omnipresent data artifacts attributed to high brush, steep hummocks, and poor traction due to loose soil.

Performed an EM-34 soil conductivity (soil mapping) survey of a proposed 80-acre extension to an existing landfill in Little Rock, Arkansas. Results enabled prime contractor to locate ancient stream channels buried beneath the project area. Performed as a subcontractor to Browning Ferris Industries.

Designed and performed an EM-31 soil conductivity (soil mapping) survey at a convenience store (Little Rock, Arkansas) having significant hydrocarbon contamination of the near surface water table. Subsurface consisted of exposed vertical beds which disallowed otherwise predictable diffuse flow patterns. Survey results provided a plausible explanation for apparent conduit flow of contaminants; recommended recovery well locations were given to the client. Woodward-Clyde Consultants project.


Though informed that success of applied geophysics would be no greater than 50 percent, the construction client nonetheless requested that ECA Geophysics perform an EM-61 metal detection survey at the Denver Federal Center in Lakewood, Colorado to locate buried utilities. High complexity of buried utilities, coupled with poor soil conditions yielded indeterminate findings.

ELECTRICAL METHOD

Vertical Electrical Soundings - Designed and performed vertical electrical soundings (VES) for proposed landfilling sites, utilizing an electrical resistivity system to determine depth to the water table. ADEQ project.

Electrical Resistance Tomography - Participated in the Leak Detection Monitoring and Mitigation (LDMM) Project that utilized Electrical Resistance Tomography (ERT) developed by the Lawrence Livermore National Laboratory and implemented at the Hanford Nuclear Reservation located in south-central Washington State.

SEISMIC REFLECTION METHOD

Compiled and rigorously edited stacking velocity data to produce velocity maps at specified travel time intervals. These maps were verified to be extremely accurate, enabling exploration staff at AMOCO Production's Alaska North Slope group to make much needed time-depth conversions.

Produced time-structure Maps via interpretation of Gulf Coast seismic reflection data while employed with Conoco, Inc.

Produced time-structure Maps via interpretation of complex Overthrust Belt seismic reflection data for a graduate school project at the Colorado School of Mines.

Coordinated the processing of complex trace seismic reflection data for the Lafayette, LA, Corpus Christi, TX and Houston, TX exploration divisions. Efforts yielded more cost-efficient data processing and concurrently provided exploration staff with significantly enhanced data displays; often enabling more rapid prospect generation times for the company. Recognized by Corpus Christi Division Manager for enabling the early AFE (Authorization for Expenditure) for an oil well in that area.

While employed at Woodward-Clyde Consultants, critiqued shallow seismic reflection data acquired and processed by an independent geophysics contractor, regarding a proposed landfill site in northwest Arkansas. Recommended that client request contractor to reprocess data in order to better isolate refraction "first breaks" needed to determine the soil-bedrock interface.

Worked on a geophysics Vibroseis crew in Wyoming when employed with Conoco, Inc. Worked on a seismic reflection survey in the Front Range in Colorado, while assisting a fellow graduate student at the Colorado School of Mines.

GRAVITY METHOD

Gravity survey - Brett D. Smith thesis area, Colorado School of Mines - 1984Designed and performed multiple-traverse surveys across the geologic boundary between the Eastern Klamath Mountains / Cascade Range provinces. Elevation surveying of gravity stations was performed utilizing non-GPS elevation surveying equipment. All survey "loops" were properly closed and double checked for accuracy before leaving the project area. Data processing incorporated sophisticated computerized terrain-corrections at all gravity stations, utilizing high resolution digital elevation data. Performed forward modeling of reduced (Complete Bouguer Anomaly) data to yield a geologically plausible interpretation of the complex subsurface geology in the Mt. Shasta area of northern California. Master's thesis, Colorado School of Mines.

Designed and performed "piggybacked" gravity traverses above and within the Department of Defense's experimental tunnel at Idaho Springs, Colorado. This graduate school project (Colorado School of Mines) was an attempt to determine the apparent density of the tunnel overburden. Location and elevation surveying was performed at all stations, in order to eliminate terrain related effects. Received an A+ grade for this innovative and unique project.

BOREHOLE LOG INTERPRETATION

While employed with Conoco, Inc. analyzed and correlated well-log data in order to produce geologic structural maps of subsurface horizons in Louisiana and Oklahoma, for the purpose of oil and gas prospect generation.

Analyzed and correlated well-log data in order to map the top of a highly permeable subsurface formation that was utilized as an injection zone for the disposal of brines generated by an aluminum recycling facility in southern Arkansas. Woodward-Clyde Consultants project.


 

Environmental Compliance Associates, LLC
ECA Geophysics


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