1

High Resolution Site Characterization Tools and Approaches

December 2, 2015 Seth PitkinSeth Pitkin Federal Remedial Technologies Roundtable: Site Characterization for Effective Remediation

The Problem

One cannot effectively solve a problem which one has not adequately and accurately describedaccurately described

Many Remedial Investigations continue for years or even decades

Many remedies underperform or fail due to a lack of understanding of site conditions and processes

The cost of these failed/underperforming remedies is large

The costs of excessive long term monitoring programs related to investigating sites with monitoring wells is large

The costs of adequate site characterization (currently referred to as High Resolution Site Characterization) which allows one to avoid failed remedies is small in comparison but requires an up front investment to result in lower life small in comparison, but requires an up front investment to result in lower life cycle costs.

2

History and Development of Contaminant Hydrogeology

Historical Perspective – Water Supply

Aqquifers are: • Homogeneous • Isotropic •• Infinite extent Infinite extent

Treated as a single bulk entityy • Transmissivity • Storativity • How much water can we get How much water can we get

out of it?

Area

Pumping Well Land Surface Land Surface

Water Table Aquifer

Confining Unit

Confined Aquifer

10-Year Contributing Screened Interval

3 Introduction AEHS 2015: Site Characterization for DNAPLs

p p y pp p y y

Development of (Contaminant) Hydrogeology Development of (Contaminant) Hydrogeology

~130-Year Era of Homogeneity and Isotropy

1970’s 1856 1870 1980 1986 2004

1863 1935 1979 1981 1994

Our science is a young one. Our thinking on solute transport is powerfully and inappropriately influenced byKey

Point the first 150 years of the development of hydrogeology. Point

4Introduction

unsuitable or m because of the h character of the

p p y pp p y y

Development of (Contaminant) HydrogeologyDevelopment of (Contaminant) Hydrogeology

John Cherry – 1981 “In the early nineteen seventies it became apparent that the approach In the early nineteen seventies, it became apparent that … the approach used in the evaluation of contaminant migration in groundwater… involved direct adaptations of …monitoring methods and …models of the type traditionally used in groundwater resource studies. …the behavior of groundwater flow systems is … such that these direct adaptations are unsuitable or misleading because of the heterogeneous character of theisleading eterogeneous geological deposits and/or the geochemical nature of the contaminant species.”

Our science is a young one. Our thinking on solute transport is powerfully and inappropriately influenced byKey

Point the first 150 years of the development of hydrogeology. Point

5

p p y pp p y y

Development of (Contaminant) HydrogeologyDevelopment of (Contaminant) Hydrogeology

C.V. Theis – 1967 “I consider it certain that we need a new conceptual model, containing the known heteroggeneities of natural aqquifers,, to expplain the phenomenon of transport in groundwater.”

Our science is a young one. Our thinking on solute transport is powerfully and inappropriately influenced byKey

Point the first 150 years of the development of hydrogeology. Point

6

-

HRSC Today

Isotropic,h

Incorporation of major paradigms into CSM (e.g.) • Heterogeneity and Anisotropy • Awareness of spatial structures of key variables • DNAPL • Weak Transverse Disppersion • Matrix diffusion/back diffusion

homogeneous

• Incorporation of geologic interpretation (e.g., sequence stratigraphy) in CSMs to provide framework for flow systems CSMs to provide framework for flow systems

Collaborative use of tools • Direct sensing for screening, NAPL detection

G d t /h d t ti h fili i bl • Groundwater/hydrostratigraphy profiling in permeable zones • Soil coring and sub core profiling for aquitard/low K material • On site analytical chemistry Incorporation of the Triad Approach principles • Dynamic work Strategies •• Real-time data

Anisotropic,heterogeneous

Real time data • Collaborative Data

7

S li

HRSC Addresses Two Critical Issues

Sampling Scale and Data Averaging • Measurements must be made at a scale that is meaningful with respect to

the variability of the quantity being measured Coverage • Profiles and Transects • Horizontal spacing • Vertical spacing

SamplingScale and

Data Averaging

Coverage HRSC Data

8

Depth-Integrated, Flow Weighted Averaging El

evat

ionn

(m)

186 186

184 184

182182

180 180

178178 178178

176 176

1 10 100 1,000 10,000 100,000

10-3 10-2 10-1PCE (ug/L)

Hydraulic Conductivity(cm/sec) HydraulicConductivity(cm/sec)

9

High Resolution (more pixels): Sampling Scale and AveragingSampling Scale and Averaging

10

Sampling Coverage and Density: HRSC Wisdom Through the AgesHRSC Wisdom Through the Ages

Pitkin Cherry Blake

“You never know what is enough unlessYou never know what is enough, unless you know what is more than enough”

Willi BlWilliam Blakke

Key The only way to know what degree of resolution you need is to Key Point

The only way to know what degree of resolution you need is to look at a high level of resolution.

11

)D

epth

(

How Much is Enough? What is Right Vertical Spacing?

A Profile Through PCE Plume in Sandy Aquifer

5 ft. vertical spacingShallow, medium, deep

2

0

m

6

4

m

10

8

14

12

Key The vertical spacing you use determines whether you

16

Key Point

The vertical spacing you use determines whether you understand the nature of the plume or not.

10 ft. vertical spacing 0.65 ft. vertical spacing

PCE µg/LPCE µg/L

12

Multi-Level Sampling Transect PCE i PCE in a SSanddy AAquif ifer

Shallow, medium,

deepp

10 ft10-ft vertical spacing

0.8-ft vertical spacing

13What is HRSC? AEHS 2015 : Site Characterization for DNAPLs

mm-Scale Textural Changes Control DNAPL Migration

Poulsen & Kueper, 1992c

mc

m

~2

5~2

5

Key DNAPL distribution is controlled by capillary pressures that varyKey Point

DNAPL distribution is controlled by capillary pressures that vary at the mm scale. Distribution is very complex.

14

TCETCE DNAPLDNAPL

PlumePlume

Will the aquitardWill the aquitard DNAPLDNAPL the matrix pore waterthe matrix pore water

DNAPLs Commonly Encounter Aquitards

DissolvedDissolved massmass ininDissolvedDissolved massmass inin

stop the DNAPL?stop the DNAPL?( Mackay and Cherry, 1989 )

15

Double Wall, Sealable Joint Sheet Piling Cell Keyed into Aquitard

CFB Borden 9x9 m Cell CFB Borden 9x9 m Cell

Courtesy of Beth Parker

16

9 x 9 Meter Cell Experiment CFB Borden

770 Liters DNAPL PCE770 Liters DNAPL PCE Injected July 1991 DNAPL Distribution after 573 Hours

17

Borden 9x9 m Cell Experiment

DNAPL Injjection 1991

0Aquifer

3.3

6.0 Aquitard

9.0

Auger Holes 1991-94 9x9m Cell

0

DNAPL

Sand microbed zone

DNAPL

Sand microbed zone 11.5 Aquifer 13.5

HSA B HSA Boriing Outtside CCellllO id

Uh Oh!

Courtesy of Beth Parker

18

Areal Distribution of DNAPL within Aquitard

Section 3

DNAPL cell ZONE

DNAPL ONDNAPL ON TOP OF

AQUITARD

Section 2

Section 1

DNAPL

NO DNAPL

Section 2

0 10 m

Courtesy of Beth Parker

19

Structure and Pore Fluids Intact

Small Scale Features are of Great Import

DNAPL (red) migration Sand microbed in sand microbed

Courtesy of Beth Parker

20

Essential Information from Cores

Geologic/hydrogeologic features

Physical, chemical & microbial properties

Contaminant mass distributions (high- & low-K zones)

Contaminant phase distributions (detection of DNAPL)

Concentration gradients/diffusive fluxes

Effectiveness of remedial technologies

21

Soil Core Sampling - NAPL Detection

DNAPLStainless massSteel

Sampler Sorbed mass

Plunger

DissolvedDissolved mass

Sudan IV/OilSudan IV/Oil Red ORed OSample DDyyeeyyvollume

00 4 in4 inSoil coreSoil core Courtesy of Beth Parker

22

Methanol

Example of NAPL Detection

Sudan IV Screening Quantitative TCE Analyses

5 ft 10 ft TCE (ug/g wet soil) 0 100 200 300 400 500 600 700

00 Sudan IV positive

6’0”SudanIV test

) Methanol /L)

20

pth

(ft b

gs)

Extraction

y (1

200

mg/

30D

ep

E So

lubi

lity

Soil Core (SC5) TCE

positivep negative

10 6’1” 6’2”6 2

Sand Sand/siltSand

40

50

0 500 1000 1500 2000

Estimated Porewater TCE Estimated Porewater TCE Courtesy of Beth Parker (mg/L)

23

Groundwater Profiling - WaterlooAPS™ Integrated Data AcquisitionIntegrated Data Acquisition

• Physical Chemical Data

• Physical Chemical DataData

• Concentration Data• Hydraulic Head Data• Index of Hydraulic

Data • Concentration Data • Hydraulic Head Data • Index of Hydraulicy

Conductivity Datay

Conductivity Data

24

WaterlooAPS™ Configurations

Gas-Drive Pump Peristaltic Pump

Sample Line

Nitrogen Line

KPRO Line

KPRO + Sample Line

KPRO Line

1 ¾" Rod

1¾" Rod

Reed Valve

O-rings

¼" Stainless Steel Tubing

FEP Tubing

APS APS APS 225 175 150

25

WaterlooAPS™ Data Acquisition Configuration and ProcessConfiguration and Process

Notebook Data acquisition

electronics String potentiometer on drill computer

electronics rig/ Geoprobe® measures depth

Real-time Ik and Pressure

Reversible variable-speed peristaltic pump

or gas drive pump Water

Flow meter Real time Ik and

water quality data vacuum gauge or gas-drive pump quality sensor

Valve

Measures: Specificconductance pH

Pressure transducer

pH Dissolved O2 Oxidation­reduction potential (ORP)

Compressed nitrogen

Stainless steel pressure vessel with analyte-free

water

1/8” stainless steel tubing

Sample bottles with stainless steel holders

Waterloo profiler tip with stainless steel screened inlet ports

26

Onsite lab

=

-50

Two Uses of IK Data

Sample Depth Selection Chlorobenzene (µg/L) Stratigraphic Interpretation

Upper

0

10ce)

Chlorobenzene (µg/L) 1 10 100 1000 10,000 100,000

Upper ClayUnit

-10

-20

ound

sur

fac

-30

, bel

ow g

ro

Elev

atio

n (f

e

-40

Dep

th (f

eet,

Stratigraphic Interpretation A A’

60

70

60

70

DPTSE27 DPTSE28

DPTSE30 DPTSE26

DPTSE23 DPTSE37 DPTSE21 DPTSE15

10

100 1,000 1,000

100

10,000 20

30

40

50

7J

2J

4J

730

5600

7J

200J

1050

2990

73200 77000

11770

9460

12360

650

<2<2ee

t)20

30

40

50

100 10

ND 100

-10

0

10

20

2J 2J

2J

<2

<2

2J

2J

<2 6J

5J

6J

8J

<2 4J

16

2J

14

200J

42 66

54

42

89

33 41 54 39

103 91 82

51

28

91

38 6260

41 54 56

79 131

12510 12360

48 34 <2

<2

<2

<2

<2

<2

-10

0

10

20

Aquitard

100

-40

-30

-20 2J 7J <2

120

33

<2 27

19

-40

-30

-20

Low Permeability Stratum

Isoconcentration (ug/L)

4900 Profiler Sample Location and Chemical Concentration (ug/L)

LEGEND

Note: MDL = 2 ug/L

100

-50-50 Note: MDL 2 ug/LD

IK Lower Aquitard Chlorobenzene-1-10000 00 100100 200200 300300 400400 500500 606000 770000 800800 900900 11000000 11001100 11200200 13001300 14014000

-60 0 2 4 6 8

IK – Index of Hydraulic Conductivity (unitless) K y y ( ) Horizontal Distance (feet)( )

27

Post-Remedy Investigation Northern England

Key Use of low resolution (conventional) techniques resulted in Key Point

Use of low resolution (conventional) techniques resulted in remedy failure and need for second remedy.

28

OU3 Building 106OU3 Building 106OU3 Building 106OU3 Building 106

have been discontinued after 5 review (2005)

NAS Jacksonville Investigations (J l /A t 2011)(July/August 2011)

OU3 Building 106OU3 Building 106Building 106Building 106 OU3 Building 106OU3 Building 106

• Former dry cleaner (1962 – 1990)

Building 106Building 106

1990) • PCE and TCE released to

shallow aquifer Building removed• Building removed

• Interim remedies (AS, SVE)

yr

GroundwaterGroundwater FlowFlow

5-yr review (2005) • Strong interest in evaluating

MNA as long-term remedy

Detailed study locations

29

NAS Jacksonville: Characterization Methods

Membrane Interface Probe (MIP) screening • Rappid lithology (EC) and contaminant ((ECD, PID)) delineation – qqualitativegy ( )

WaterlooAPS™ (Advanced Profiler System) •• Real time hydrostratigraphyReal-time hydrostratigraphy • Targeted groundwater sampling of higher K zones/interfaces

Geoprobe® HPT (Hydraulic Profiling Tool) • Real time hydrostratigraphy

Continuous cores (Geoprobe® DT System) • Detailed lithology delineation

Subsampling for mass distribution (targeted to lower K zones) • Subsampling for mass distribution (targeted to lower K zones)

Onsite Laboratory

30

- STONE ENVIRONMENTAL

Layout of Points at Each Investigation Location

31

NAS Jacksonville Composite Dataset (OU3(OU3-3 Near Source)3, Near Source)

gs)

?Dep

th (f

t bg

Mass in clay MIP Carry-Down in clayMIP Carry Down

Geoprobe®MIP WaterlooAPS™ Cores HPT

32

OU3-3: Soil and Groundwater Concentrations

543210

Index of Hydraulic Conductivity (Ik)

0 5 10 15 20 25 30

Soil CVOC Concentration (µg/kg)

0 5 10 15 20 25 30

Soil CVOC Concentration (µg/kg)

Soil Lithology

543210

2

0 0 5 10 15 20 25 30 0 5 10 15 20 25 30

NC

bgs)

2

4

SP

SP/CL

Dep

th (m

6 PCE Soil CL

SP/CL

8 Total CVOC Soil

Total CVOC GW (WP) PCE GW (WP)

cDCE GW (WP) TCE GW (WP)

cDCE Soil TCE Soil

SP

Groundwater CVOC

10 Total CVOC GW (Piezo/SP16)

0 30000 60000 90000 120000

cDCE GW (WP)

0 30000 60000 90000 120000

VC GW (WP)

Groundwater CVOCCVOC

Concentration CVOC

Concentration (µg/L) (µg/L)

33

-

Approximate boundaries of low K zone based on soil lithology

OU3-3: MIP (ECD and PID) and Soil Concentrations

High Concentration Location: OU3-3

Electrical Conductivity (mS/m)

High Concentration Location: OU3 3

MIP PID (µV) Soil Total CVOC Concentration (µg/kg) MIP ECD (µV)

Approximate boundary of low-K zone based on soil lithology

pth

(m b

gs)

< 35, sand/gravel 35-70, silty sand 70-105, sandy silt

Dep

105-140, clayey silt > 140, silty clay

Soil Total CVOC Concentration (µg/kg)

34

Collocated Soil Cores Demonstrate Good Correlation

Total Soil [VOC] (µg/g soil)

OC

sog

Tot

al C

VO

(µg/

g)

OU

3-5D

L

pth

(ft b

gs)

OU3-5 Log Total CVOCs (µg/g)

OC

s

Dep

og T

otal

CVO

(µ

g/g)

O

U3-

5D L

o

OU3-5 Log Total CVOCs (µg/g)

35

Dep

th (m

Sign

al (µ

V)

MIP Provides Mass Location But Not Concentration CorrelationConcentration Correlation

MIP: SOIL AT LOCATION OU3-3 MIP: SOIL AT LOCATION OU3-6 (HIGH CONCENTRATION)(HIGH CONCENTRATION) (LOW CONCENTRA(LOW CONCENTRATION) TION) USING OPTIMIZED SOP USING OPTIMIZED SOP

MIP ECD Signal (µV) MIP PID Signal (µV)

REGRESSIONREGRESSION

bgs)

Sign

al (µ

V)

Dep

th (m

bgs)

Log

PID

S

Log

ECD

S

Soil Total CVOC Concentration

Log PCE+TCE+DCE Soil Concentration (µg/kg)

Soil Total CVOC Concentration

Log PCE+TCE Soil Concentration

(µg/kg) (µg/kg) (µg/kg)

36

ee o eso ut o to u de sta d t e ob e t s s S te

Conclusion The purpose of Site Characterization is to understand the pertinent conditions adequately enough to devise an effective remedy. • aka CSM “Standard” approaches such as monitoring wells are not well suited to the development of such an adequate understanding • DepthDepth-integrated, flow weighted averagingintegrated, flow weighted averaging • Large life-cycle expense

S lScale off sampling and d d data coverage (d (densitit y)) must b t be appropriiatte tto theli t th spatial structure of the variable under consideration • Hydraulic conductivity, capillary pressure etc.

Leverage existing data and use screening technologies used to reduce costs associated with definitive sampling/analysis programs

Perhaps it is time to stop calling it “High Resolution” since it is really an adequate degree of resolution to understand the pproblem. It is simp y ply Siteadequate deg Characterization.

37

38

Acknowledgements

Beth Parker – University of Guelph Dave Adamson – GSIDave Adamson GSI Steven Chapman – University of Guelph Mike Singletary – NAVFAC