EPA Clu-In 8/27/08

ESTCP

Using the High-Resolution Piezocone to Determine Hydraulic Parameters

and Mass Flux Distribution

Dr. Mark Kram, GroundswellDr. Norm Jones, BYUJessica Chau, UConn

Dr. Gary Robbins, UConnDr. Amvrossios Bagtzoglou, UConn

Thomas D. Dalzell, AMS

EPA Clu-In Internet Seminar27 August 2008

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EPA Clu-In 082708

TECHNICAL OBJECTIVES

• Demonstrate Use of High-Resolution Piezocone to Determine Direction and Rate of GW Flow in 3-D

– Compare with Traditional Methods– Develop Models and Predict Plume Behavior

• Integrate High-Resolution Piezocone and Concentration Data into 3-D Flux Distributions via GMS Upgrades

• Introduce New Remediation Performance Monitoring Concept

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EPA Clu-In 082708

TECHNOLOGY DESCRIPTION

High-Resolution Piezocone:

• Direct-Push (DP) Sensor Probe that ConvertsPore Pressure to Water Level or Hydraulic Head

• Head Values to ± 0.08ft (to >60’ below w.t.)

• Can Measure Vertical Gradients

• Simultaneously Collect Soil Type and K

• K from Pressure Dissipation, Soil Type

• Minimal Worker Exposure to Contaminants

• System Installed on PWC San Diego SCAPS

• Licensed to AMS

Custom Transducer

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EPA Clu-In 082708

SEEPAGE VELOCITY AND FLUX

Seepage velocity ():

                Ki where:     K  = hydraulic conductivity (Piezocone)

            = ------   (length/time)  i   = hydraulic gradient (Piezocone)

                       = effective porosity (Piezocone/Soil)

 

Contaminant flux (F):    F =  [X] where:        = seepage velocity 

                    (length/time; m/s)

(mass/length2-time; mg/m2-s)                      [X] = concentration of solute (MIP, etc.)          (mass/volume; mg/m3)

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EPA Clu-In 082708

CONCENTRATION VS. FLUX

Most contaminated

Least contaminated

Source Zone

ControlPlane

B

A’

A

B’

ContaminantFlux (Jc)

Most contaminated

Least contaminated

Source Zone

ControlPlane

B

A’

A

B’

ContaminantFlux (Jc)

Length F,

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EPA Clu-In 082708

CONCENTRATION VS. FLUX

Most contaminated

Least contaminated

Source Zone

ControlPlane

B

A’

A

B’

ContaminantFlux (Jc)

Most contaminated

Least contaminated

Source Zone

ControlPlane

B

A’

A

B’

ContaminantFlux (Jc)

High Concentration High Risk!!Hydraulic Component - Piezocone

Length F,

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EPA Clu-In 082708

GMS MODIFICATIONS

Gradient, Velocity and Flux Calculations

Convert Scalar Head to Gradient [Key Step!]

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EPA Clu-In 082708

GMS MODIFICATIONS

Gradient, Velocity and Flux Calculations

Convert Scalar Head to Gradient [Key Step!]

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EPA Clu-In 082708

GMS MODIFICATIONS

Gradient, Velocity and Flux Calculations

Convert Scalar Head to Gradient [Key Step!] Merging of 3-D Distributions to Solve for Velocity Merging of Velocity and Concentration (MIP or Samples) Distributions to Solve for Contaminant Flux

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EPA Clu-In 082708

APPROACH

• Test Cell Orientation Initial pushes for well design; Well design and prelim. installations, gradient determination; Initial CaCl2 tracer tests with geophysics (time-lapse resistivity) to determine general flow direction

• Field Installations (Clustered Wells)

• Survey (Lat/Long/Elevation)

• Pneumatic and Conventional Slug Tests (“K – Field”) Modified Geoprobe test system

• Water Levels (“Conventional” 3-D Head and Gradient)

• HR Piezocone Pushes (K, head, eff. porosity)

• GMS Interpolations (, F), Modeling and Comparisons

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CPT-BASED WELL DESIGN

Candidate ScreenZone

Kram and Farrar Well Design Method11

EPA Clu-In 082708

DEMONSTRATION CONFIGURATION

Configuration via Dispersive Model

Utility PoleUtility Shed

Water Storage Tanks

20’

Veh

icle

Gat

e

20’

Veh

icle

Gat

e

4’ P

erso

nn

el

Gat

e100’

60’

Note: Layout displayed with 10’ x 10’ grid

W-3

W-2

W-1

2” Wells from EPA extraction system

1” EPA Hydraulic Test Wells

2” GeoVIS Monitoring Wells

Well cluster: ¾” Deep, Mid & Shallow Piezometers

1

4

3

2

9

5

8

7

6 10

13

12

11

13 Well Clusters, each cluster with a: Shallow Piezometer (8-8.5 ft Screens)Mid Piezometer (10.5-11.0 ft Screens)Deep Piezometer (13.5-14.0 ft Screens)

Clusters set on a 5ft x 5ft grid

5”

5”

Azimuth 234 o

piezometer

N

Utility PoleUtility Shed

Water Storage Tanks

20’

Veh

icle

Gat

e

20’

Veh

icle

Gat

e

4’ P

erso

nn

el

Gat

e100’100’

60’

Note: Layout displayed with 10’ x 10’ grid

W-3

W-2

W-1

2” Wells from EPA extraction system

1” EPA Hydraulic Test Wells

2” GeoVIS Monitoring Wells

Well cluster: ¾” Deep, Mid & Shallow Piezometers

2” Wells from EPA extraction system

1” EPA Hydraulic Test Wells

2” GeoVIS Monitoring Wells

Well cluster: ¾” Deep, Mid & Shallow Piezometers

1

4

3

2

9

5

8

7

6 10

13

12

11

1

4

3

2

1

4

3

2

9

5

8

7

6

9

5

8

7

6 10

13

12

11

10

13

12

11

13 Well Clusters, each cluster with a: Shallow Piezometer (8-8.5 ft Screens)Mid Piezometer (10.5-11.0 ft Screens)Deep Piezometer (13.5-14.0 ft Screens)

Clusters set on a 5ft x 5ft grid

5”5”

5”5”

Azimuth 234 o

piezometer

NN12

EPA Clu-In 082708

FIELD EFFORTS

Site Characterization with High Resolution Piezocone 11/22/04

Well Development & Hydraulic Test 8/24/05

Installation ¾” Wells 7/28/05

1st Wells 12/9/04

Field Demo 6/13/06

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PIEZOCONE OUTPUT

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HIGH RESOLUTION PIEZOCONETESTS (6/13/06)

Head Values for Piezocone

Displays shallow gradient

W1

W3W2

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EPA Clu-In 082708

HEAD DETERMINATION(3-D Interpolations)

• Shallow gradient (5.49-5.41’; 5.45-5.38’ range in clusters over 25’)

• In practice, resolution exceptional (larger push spacing)

Piezo Wells

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EPA Clu-In 082708

COMPARISON OF ALL K VALUES

• Kmean and Klc values within about a factor of 2 of Kwell values;

• Kmin, Kmax and Kform values typically fall within factor of 5 or better of the Kwell values; • K values derived from piezocone pushes ranged much more widely than those derived from slug tests conducted in adjacent monitoring wells; • Differences may be attributed to averaging of hydraulic conductivity values over the well screen versus more depth discrete determinations from the piezocone (e.g., more sensitive to vertical heterogeneities).

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EPA Clu-In 082708

K BASED ON WELLS AND PROBE(Mid Zone Interpolations)

N

Well K Lookup K

Mean KK Max K Min

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VELOCITY DETERMINATION(cm/s)

Well Piezo (mean K)

mid

1st row

centerline

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EPA Clu-In 082708

FLUX DETERMINATION(Day 49 Projection)

Well Piezo (mean K)

mid

1st row

centerline ug/ft2-day

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Scenario Head K Porosity

1 Well Well Average 2a SCAPS SCAPS Kmean SCAPS 2b SCAPS SCAPS Kmin SCAPS 2c SCAPS SCAPS Kmax SCAPS 2d SCAPS SCAPS Klookup SCAPS 3 Well Well SCAPS

4a Well SCAPS Kmean SCAPS 4b Well SCAPS Kmin SCAPS 4c Well SCAPS Kmax SCAPS 4d Well SCAPS Klookup SCAPS 5 Unif. grad. Average Average

MODELINGConcentration and Flux

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EPA Clu-In 082708

Scenario Head K Porosity

1 Well Well Average 2a SCAPS SCAPS Kmean SCAPS 2b SCAPS SCAPS Kmin SCAPS 2c SCAPS SCAPS Kmax SCAPS 2d SCAPS SCAPS Klookup SCAPS 3 Well Well SCAPS

4a Well SCAPS Kmean SCAPS 4b Well SCAPS Kmin SCAPS 4c Well SCAPS Kmax SCAPS 4d Well SCAPS Klookup SCAPS 5 Unif. grad. Average Average

MODELINGConcentration and Flux

Well

Kmean

Klc

Ave K ug/ft2-day ppb

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EPA Clu-In 082708

PERFORMANCE

Performance Summary.

Performance Criteria Expected Performance

Metric Results

Accuracy of high-resolution piezocone for determining head values, flow direction and gradients

± 0.08 ft head values Met Criteria

Hydraulic conductivity (dissipation or soil type correlation)

± 0.5 to 1 order of magnitude

Met Criteria

Transport model based on probes

Predicted breakthrough times and concentrations within one order of magnitude; probe based model efficiency accounts for more than 15% of the variance associated with well based models

Met Criteria

Time required for generation of 3-D conceptual and transport models

At least 50% reduction in time

Met Criteria

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EPA Clu-In 082708

Cost Comparisons(Per Site)

$0

$50

$100

$150

$200

$250

$300

$350

20 50 75

Total Depth (ft)

$K

3/4" DP

2" DP

Drilled Wells

HR Piezocone

FLUX CHARACTERIZATIONCost Comparisons

“Apples to Apples” – HR Piez. with MIP vs. Wells, Aq. Tests, Samples10 Locations/30 Wells

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EPA Clu-In 082708

Early Savings of ~$1.5M to $4.8M

High Res Piezocone Annual Savings - 20 Sites

(Relative to Alternatives)

$0

$1

$2

$3

$4

$5

$6

20 50 75

Total Depth (ft)

$M

3/4" DP

2" DP

Drilled

FLUX CHARACTERIZATIONCost Comparisons

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EPA Clu-In 082708

“Apples to Apples” – HR Piez. with MIP vs. Wells, Aq. Tests, Samples10 Locations/30 Wells

FLUX CHARACTERIZATIONTime Comparisons

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EPA Clu-In 082708

CONTAMINANT FLUX MONITORING STEPS(Remediation Design/Effectiveness)

• Generate Initial Model (Seepage Velocity, Concentration Distributions)

– Conventional Approaches– High-Resolution Piezocone/MIP

• Install Customized 3D Monitoring Well Network– ASTM– Kram and Farrar Method

• Monitor Water Level and Concentrations (Dynamic/Automate?)• Track Flux Distributions (3D, Transects)• Evaluate Remediation Effectiveness

– Plume Status (Stable, Contraction, etc.)– Remediation Metric– Regulatory Metric?

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Future Conceptualization

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Future Conceptualization

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EPA Clu-In 082708

Future Conceptualization

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EPA Clu-In 082708

Future Conceptualization

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EPA Clu-In 082708

FUTURE PLANS

Tech Transfer– Army (Fall ‘08)– Industry Licensing (AMS in Summer ’07; Market Ready by December

‘08)– ITRC Tech Reg– ASTM D6067

Final Reports – Released (May ’08)– Clu-In: http://www.clu-in.org/s.focus/c/pub/i/1558/

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EPA Clu-In 082708

CONCLUSIONS

• High-Res Piezocone Preliminary Results Demonstrate Good Agreement with Short-Screened Well Data

• Highly Resolved 2D and 3D Distributions of Head, Gradient, K, Effective Porosity, and Seepage Velocity Now Possible Using HRP and GMS

• When Know Concentration Distribution, 3D Distributions of Contaminant Flux Possible Using HRP with GMS

• Exceptional Capabilities for Plume “Architecture” and Monitoring Network Design

• Remediation Performance Monitoring Potential

• Significant Cost/Time Saving Potential

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EPA Clu-In 082708

ACKNOWLEDGEMENTS

SERDP – Funded Advanced Fuel Hydrocarbon Remediation National Environmental Technology Test Site (NETTS)

ESTCP – Funded Demonstration

NAVFAC ESC – Manpower, oversight, matching efforts

Field and Technical Support – Project Advisory Committee Dorothy Cannon (NFESC)Jessica Chau (U. Conn.) Kenda Neil (NFESC)Gary Robbins (U. Conn.) Richard Wong (Shaw I&E)Ross Bagtzoglou (U. Conn.) Dale Lorenzana (GD) Merideth Metcalf (U. Conn.) Kent Cordry (GeoInsight)Tim Shields (R. Brady & Assoc.) Ian Stewart (NFESC)Craig Haverstick (R. Brady & Assoc.) Alan Vancil (SWDIV)Fred Essig (R. Brady & Assoc.) Dan Eng (US Army)Jerome Fee (Fee & Assoc.)Dr. Lanbo Liu and Ben Cagle (U. Conn.)

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EPA Clu-In 082708

THANK YOU!

For More Info:

Mark Kram, Ph.D. (Groundswell)805-844-6854

Tom Dalzell (AMS)208-408-1612

EPA Clu-In 082708

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