ECA

GEOPHYSICS



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ECA's advanced degreed geophysicists will design, perform, and interpret geophysical surveys that best meet your field investigation needs.
 If geophysics is not the best way to spend your field dollars, WE WILL TELL YOU!

ECA performs ground penetrating radar (GPR) surveys, seismic refraction surveys, ReMi surveys for IBC site class, gravity surveys, magnetic surveys, and electromagnetic surveys nationwide.

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

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

  • Depth to bedrock
  • Shear wave (Vs) / Compressional wave (Vp) information
  • NEHRP / IBC site classifications
    

GEOTECHNICAL GEOPHYSICS: Seismic Refraction Microtremor (ReMi™) Survey at Closed Landfill

PROJECT:
ReMi™ surveys at a closed waste disposal site in Oregon
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.


GEOTECHNICAL GEOPHYSICS: Seismic Refraction Microtremor (ReMi™) Surveys at National Retail Stores

PROJECT:
ReMi™ surveys at active national chain stores
LOCATION: Wenatchee / Woodinville / 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.



GEOTECHNICAL GEOPHYSICS: Seismic Refraction and ReMi™ Surveys at Proposed Wind Energy Project

PROJECT: Refraction and ReMi™ 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.


GROUND PENETRATING RADAR (GPR)

Utilizing state-of-the-art equipment,
ECA 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 in the Alaskan Interior

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.


GPR Survey to Locate USTs and Piping for Hanford Area Facilities

PROJECT: GPR survey of Hanford Area facilities
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.


GPR Survey to Delineate Abandoned Trenches at Unpermitted Disposal Site

PROJECT: GPR survey with confirmatory excavations
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 to Delineate Edges of USTs at an Active Gas Station Facility

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.


GPR Survey to Identify Cultural (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.


GPR Survey to Locate USTs and Piping at an Active 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.


GPR Survey to Locate USTs and Pipng at an Active Retail Facility

PROJECT: GPR survey of a commercial property
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.

INTEGRATED GEOPHYSICS: Combining several 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 and EMI Surveys at Closed Landfills at an Air Force Base in New Mexico

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.




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

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 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.



INTEGRATED GEOPHYSICS: GPR and Electromagnetic Surveys at an Air Force Base in the United States

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 the United States.  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.


INTEGRATED GEOPHYSICS: Electromagnetic (EMI) and ReMi™ Surveys at an Abandoned Waste Disposal Site

PROJECT:
Electromagnetic (EMI) and ReMi™ surveys at a closed waste disposal site in Oregon
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 was 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!


INTEGRATED GEOPHYSICS: Magnetic and Electromagnetic Surveys at a Closed Municipal Waste Landfill

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.


INTEGRATED GEOPHYSICS: GPR and Metal Detection Surveys at an Active Retail Facility

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.


POTENTIAL-FIELD METHODS

Magnetic Surveys

Designed and performed a total-field magnetometer survey of a 26-acre wood-waste landfill. 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.

Designed and performed (utilizing a total-field magnetometer) a gradiometer survey of an asphalt-paved parking lot for a US Bank property. 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 in eastern 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 Surveys

Designed and performed an EM-34 soil conductivity (soil mapping) survey of a 26-acre wood-waste landfill.  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 Pollution Control & Ecology (ADPC&E), performed approximately 40 reconnaissance EM-31 soil conductivity surveys of proposed landfill sites.

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.  Survey was designed to detect buried
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. 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 site 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.

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. Arkansas Department of Environmental Quality (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

Designed and performed a multiple-traverse gravity survey across the geologic boundary between the Eastern Klamath Mountains and the 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
8524 West Gage Boulevard, Bldg A-132
Kennewick, WA 99336
Fax: (509) 396-0805
Voice: (509) 628-9959
Cell: (509) 366-1205

ecabrett@charter.net