slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Innovative High Resolution Electrical Resistivity Imaging (ERI) (Aestus’ GeoTrax Survey™) Used to Detect Soil/Ground PowerPoint Presentation
Download Presentation
Innovative High Resolution Electrical Resistivity Imaging (ERI) (Aestus’ GeoTrax Survey™) Used to Detect Soil/Ground

Loading in 2 Seconds...

play fullscreen
1 / 37

Innovative High Resolution Electrical Resistivity Imaging (ERI) (Aestus’ GeoTrax Survey™) Used to Detect Soil/Ground - PowerPoint PPT Presentation


  • 187 Views
  • Uploaded on

Innovative High Resolution Electrical Resistivity Imaging (ERI) (Aestus’ GeoTrax Survey™) Used to Detect Soil/Groundwater Contamination From Leaking USTs and Other Sources. Presented by Stuart W. McDonald, P.E. President, Aestus, LLC. The 11th National Israeli NDT conference

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Innovative High Resolution Electrical Resistivity Imaging (ERI) (Aestus’ GeoTrax Survey™) Used to Detect Soil/Ground' - dwight


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

Innovative High Resolution

Electrical Resistivity Imaging (ERI)

(Aestus’ GeoTrax Survey™)

Used to Detect Soil/Groundwater Contamination

From Leaking USTs and Other Sources

Presented by

Stuart W. McDonald, P.E.

President, Aestus, LLC

The 11th National Israeli NDT conference

Tuesday, April 27, 2010; Tel Aviv, Israel

slide2

Topics Covered Today

PROBLEM

  • Conventional environmental site characterization techniques are and are not producing satisfactory results; Site cleanup too costly
  • Other historically available technology such as conventional geophysical tools (GPR, EM, Seismic, etc.) not helping enough
  • Need new approach/tools – look at other industries faced with similar problems (oil/gas; medical)

SOLUTION

  • Environmental consulting and non-traditional geophysics experts from Aestus/Oklahoma State University teamed to develop a subsurface scanning tool that works at virtually any site
  • This tool has changed paradigms of contamination behavior/distribution in subsurface
  • Yields lower project costs and faster cleanup
slide3

Topics Covered Today (continued)

PROOF THAT IT WORKS ● EXAMPLES ● COSTS

  • Review Case Studies
  • Validation by EPA’s Ada, Oklahoma laboratory
  • Validation by State Regulators
  • Validation by Environmental Consultants
  • Backed up by University Research and Peer Reviewed Publications

QUESTIONS & ANSWER SESSION

slide4

Monitoring Well (Typ.)

Monitoring Well (Typ.)

LNAPL

GW Level

Soil Core

Previously Unknown LNAPL

?

?

?

Interpreted Contact

Confirmed Contact

Typical Site Characterization

slide5

Recovery/monitoring Well (Typ.)

Defined Contact Location

Actual image from a refinery LNAPL recovery system

Previously Unknown LNAPL

…and thus allows reality-based decisions

slide6

WOULD YOU HAVE SURGERY WITHOUT A CAT-SCAN/MRI/X-RAY?

Why do this with your environmentally impacted sites?

slide7
Medical

X-ray

MRI

Sonogram

Petroleum

Seismic

Gravity

Magnetics

Environmental

Drill

Probe

Excavate

  • Environmental
    • Drill
    • Probe
    • Excavate
  • Medical
    • X-ray
    • MRI
    • Sonogram
  • Petroleum
    • Seismic
    • Gravity
    • Magnetics

And you thought

medical surgery

is expensive!

Sampling array at the Cape Cod Site;

over 10,000 subsurface sampling ports. –USGS-

slide8

What is Electrical Resistivity Imaging (ERI)?

  • Based on
    • DC resistivity techniques (>100 yrs old)
    • Computing/electronics power (<10 yrs old)
  • Instead of 10’s of data, collect thousands (high data density)
  • Analogous to “Geological Digital Photography”
  • Provides map of electrical properties of the subsurface
slide9

Aestus

Proprietary

Supplemental

Field

Equipment

Proprietary

OSU/Aestus

Data

Acquisition

Algorithms

Proprietary

OSU/Aestus

Data

Reduction/

Processing

Standard

Electrical

Resistivity

Techniques

High Resolution Subsurface Image

That is “Drillable”

slide10

How ERI Works – “Setting Up The Camera”

  • 56 Electrode Stakes (3/8-inch diameter) Hammered Into Ground
  • Geophysical Cables Attached to Electrode Stakes
  • Data Collection Starts (~1-2 Hours; Site Dependent)

“Take Only Pictures…Leave Only Footprints”!

slide11

How ERI Works – “Taking the Picture”

Four Electrodes Yield One Measurement Data Point (“pixel”)

One Data Point or “Pixel”

slide12

How ERI Works – “Focusing the Camera”

(1.5 m Survey) 271 feet long

54 feet deep

(2.0 m Survey) 361 feet long

72 feet deep

(2.5 m Survey) 451 feet long

92 feet deep (* Optimal Choice)

(3.0 m Survey) 541 feet long

108 feet deep

Target

Imaging

Depth

slide13

Iterative Measurements Yield Matrix of Data Points or “Pixels”

Proprietary Software Generates Subsurface 2-D Image from Data Set

Suspected

LNAPL “Blob”

Below LUST

Depth (feet)

A “Kilo-pixel” Digital Camera Taking Electrical Picture of Subsurface

How ERI Works – “Developing the Film”

slide14

How ERI Works – Viewing Multiple “Pictures” Together

3-D Perspective View - GeoTrax SurveysTM

(From Above and Looking North at All On-Site Surveys)

LEGEND:

Current UST Tank Basin

Former UST Basins

Existing Remediation Wells

NAPL “Blobs”

Below LUST’s

ERI Output – 2-D Data “Fences” in 3-D Space

slide15

How ERI Works – Viewing the Data in 3-D & 4-D

Pre-Remediation

36 ohm-m ~ 20,000 mg/kg TPH

2-D Data Fences

7 mos. into Remediation

46 ohm-m ~ Free Product (LNAPL)

Pre-Remediation

46 ohm-m ~ Free Product (LNAPL)

slide16

NAPL “Blobs”

Shown in 3-D

3-D ERI Model Output from GeoTrax SurveyTM Data

How ERI Works – Viewing the Data using 3-D Model

slide17

Technological Progression

  • Data acquisition now 100x faster than 1990
  • Data processing now 350x faster than 1990
  • Images were not “drillable”

– OSU/Aestus created dramatically improved images

– Images can “see” resistive subsurface targets others can’t

slide18

Standard ERI methods barely able to detect “blob” with the highest concentration of LNAPL detected on this site

  • Second LNAPL “blob” does not show up using standard ERI

LNAPL

21,283 mg/kg TPH

45 mg/kg TPH

  • OSU’s/Aestus’ ERI Methods detect both LNAPL “blobs” present
  • Image shows concentrations in a semi-quantitative manner
  • Images are “Drillable”

LNAPL

21,283 mg/kg TPH

45 mg/kg TPH

* Confirmation Drilling Data Collected by EPA;

Images from Golden, OK Site Case Study

slide19

after Halihan et al, 2005

“Simple” LNAPL plume:

  • Undergone pump-and-treat and a surfactant flush
  • At least 92 wells on the site
  • Is the site “clean” now?
slide20

SB-1

SB-1

268

50 ft wide x

25 ft depth

SB-2

SB-2

Total Petroleum Hydrocarbons (TPH in mg/kg) vs. Depth

slide21

SB-3

22

SB-3

SB-4

2.5

SB-4

Total Petroleum Hydrocarbons (TPH in mg/kg) vs. Depth

slide22

Separate “Blobs”

SB-5

SB-6

Total Petroleum Hydrocarbons (TPH in mg/kg) vs. Depth

SB-5

SB-6

0.4

45

slide24

0

Depth (ft)

30

0

Distance (ft)

180

(meters)

(meters)

Data Density Comparison – NAPL Site

Sampling data indicate that these monitoring wells are clean….

0

Depth (ft)

LNAPL

21,283 mg/Kg

LNAPL

45 mg/Kg

30

0

180

Distance (ft)

Aestus’ GeoTrax Survey™ shows that monitoring well

data was not representative of site conditions

Actual Research Site - Anomaly soil sampling data provided by EPA Ada, OK Laboratory

slide25

0

Depth (ft)

30

To approach the data density of an Aestus GeoTrax Survey™, approximately 35 monitoring wells/soil borings would be required

every ~5 feet along a 185 ft transect

0

180

Distance (ft)

At ~US$3,500 per monitoring well, cost would be ~US$122,500 and takes weeks

At ~US$2,500 per GeoTrax Survey™, cost would be US$2,500 and take only 2-3 hours

* Above budgetary costs do not include mobilization/demobilization; survey costs vary depending on site constraints

slide26
This is a “magic bullet” 

SB-2

This is not

Complex sites are still complex, you just have a better tool to obtain sufficient data.

slide27
Every site is different- there are infinitesimal combinations of lithology, pore fluids, pore structure, contamination, and previous remediation attempts.

We don’t have a “magic” resistivity scale that categorizes every site.

Images MUST be calibrated in order to provide the best interpretation.

slide28

Other Potential Applications in Israel

  • Sinkhole Detection
  • Clandestine Tunnel Detection
slide29

For Finding Tunnels/VoidsIn Subsurface

Computer Modeling Predicts:

  • Success Using GeoTrax Survey™
  • Failure Using Standard ERI
slide31

(Not enough resolution to detect small tunnels;

confirmed by Israel MOD testing)

(GeoTrax Survey™)

(Data indicates probable success; untested to date)

slide32

TunnelTrax Survey™(Conceptual Approach)Scale-Up to Provide Continuous Subsurface Scanningat Country Border

slide34

Located Caves in Anhydrite Gypsum

Located Coal Mines Below Former Gas Station

  • Suspected LNAPL
  • “Blobs”
  • Suspected
  • Locations of Flooded Coal Mines
slide35
Sink hole detection

Homeland Security – Terrorist Tunnels; Illegal Immigration Tunnels

Brownfields Site Characterization for Property/Liability Transfer

Point of Compliance Site Boundary Monitoring (Dedicated System)

Groundwater/Surface Water Interaction

Optimize Locations for Water Wells

Salt Water Intrusion into Drinking Water Wells

Geotechnical Engineering

Landfill Leakage

Others

slide36

Thank You

AdditionalQuestions?

Stop Drilling Blind!

slide37

Dr. Todd Halihan

Oklahoma State University

School of Geology

105 Noble Research Center

Stillwater, OK 74078

todd.halihan@okstate.edu

Stuart W. McDonald, P.E.

Aestus, LLC

2605 Dotsero Court

Loveland, CO 80538

1.888.Geo.Trax or

(970) 278-4090

swm@aestusllc.com

www.aestusllc.com