ISTR Technologies: Feasibility and Limitations, and Overview of SEE

Gorm HeronTerraTherm, Inc.Keene, California, USAgheron@terratherm.com

MechanismsTreatment area and volumeThermal technologiesHow to select?

Mechanisms – for VOCs

1 mm

01234567

0 20 40 60 80 100Hen

ry's

law

con

stan

t ( -

)

0.00.20.40.60.81.01.21.41.6

0 20 40 60 80 100

Vapo

r pre

ssur

e (a

tm)

oCoC

TCE

PCE

H2OPCE

TCE

Oils - Viscosity reduction

0

2

4

6

8

10

12

14

0 20 40 60 80 100 120 140

Temperature (oC)

Vis

cosi

ty (c

St)

0

50

100

150

200

250

300

350

400

20 60 100 140

Temperature (oC)

Vis

cosi

ty (c

p)

Fuel oil, 14 gravity No. 5 fuel oil

Light ends are removed at 100 oC or higherTypical Soil ChromatogramBefore SEE

Soil Residual ChromatogramAfter SEE

Chromatograms from TPH analysis of soils from Alameda Point, CA (Udell et al. 2000)

Vapor Pressure vs. Temperature

0

100

200

300

400

500

0 50 100 150 200 250 300 350 400 450Temperature (°C)

Vapo

r Pre

ssur

e (m

m H

g)

Vapor pressures increase exponentially with temperature

ERH, SEE, TCH TCH

5

325oC

100oC

70oC

Level 2

Level 3Level 1

Thermally enhanced NAPL recovery

In‐Situ Stabilization/ Solidification

Complete COC removal/destruction

Challenge

• Will make COCs mobile• Steam and COC vapors generated• NAPL may move• Groundwater concentrations may increase• Groundwater permeability increases

• Better treat the right volume• Pneumatic and hydraulic control = capture

Treatment Area and Volume (and goals)

Aerial View of Memphis Site(During Demob)

367 heaters

68 extraction wells

Example:  NASA Michoud• Objectives:

– Determine top and bottom of treatment zone– Determine areal extent and shape of treatment zone– Provide a mass estimate for TCE and other CVOCs

Method:  MIP with soil and groundwater sampling, variable

Characterization area

Conceptual source area as start

Max ECD response and suggested next pushes

Final MIP results

Original conceptual area

Geological conceptual model

Conceptual model w/MIP profiles

Selection of Treatment Zone

Need quick tools (screening OK) – hundreds of data points 

Most widely used:

MIP for screening (LIF if looking for aromatics)GeoProbe w/grab samplesRotosonic drilling w/grab samples

Conceptual model important

Pick TTZ which exceeds the remedial goalsSoil (mg/kg)GW (mg/L)Soil gas (mg/m3)Mass reductionFlux reduction

Thermal Technologies and Providers

ERH/ET‐DSP TRS, CES, McMillan‐McGeeISTD 100 C TerraThermISTD dry and hot TerraTherm, TPSSEE TerraTherm, ERM, others?RF/MW heating Kasevich, ERMSTARS/smoldering SiREMHot water flushing ?Hot air injection ?

Sand

Silt

Silt

GW

19

Example source zone

ISTD/TCH - Heating governed by thermal conductivity (f~3) nearly uniform

ISTD = In Situ Thermal DesorptionTCH = Thermal Conduction Heating

SVE Well

Groundwater Level

Heater Well Source Area

20

TerraTherm ISTD Heaters

Covered by one or more of the following: U.S. Patent Nos. 5,190,405, 5,318,116, 6,485,232 and 6,632,047. International patents (e.g., EPC 1272290).

21

ERH/ET-DSP - Heating governed by electrical conductivity (f~200) may require stacked electrodes

ERH = Electrical Resistance HeatingET-DSP™ = Electro-Thermal Dynamic Stripping Process

Silt

Silt

Sand

MPE WellElectrode Well (shown w/3 electrodes)Groundwater

Level

Source Area

23

ET‐DSP™ Electrodes

(McMillan-McGee Corp.) 24

ET‐DSP™ Wellfield

MPEWell

StackedElectrodes

StackedElectrodes

Power Control Unit forElectrodes

Vapor Manifold

Liquid Manifold

25

SEE - Heating governed by hydraulic conductivity non-uniform steam flow

SEE = Steam Enhanced Extraction

Silt

Silt

Sand

Groundwater Level

MPE Well Source Area

Steam Injection Well

26

Steam Enhanced ExtractionNew tools for environmental application

Pressure cycling

Limitations – low K sites and fractured rock

Combinations with TCH and resistive heating

28

Oil field well patterns5‐spot

7‐spot

Line drive

Alameda Point

Creosote DNAPL to +140 ft depth

Alluvial sands and gravels with clays

Both LNAPL and DNAPL

Approaching MCLs in 2002

160,000 gallons removed from subsurface

Superfund Site delisted

UC Berkeley – LLNL - SCE

Visalia Pole Yard ‐SEE

16°C

26°C

36°C

46°C

56°C

66°C

76°C

86°C

96°C

5 days 12 days 30 days 45 days

0 4 8-14.0

-12.0

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-8.0

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-2.0

0.0

0 4 8-14.0

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

0 4 8-14.0

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

0 4 8-14.0

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

Depth (m

)

Tempe

rature

0 2 4 6-14.0

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

0 2 4 6-14.0

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

0 2 4 6-14.0

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

0 2 4 6-14.0

-12.0

-10.0

-8.0

-6.0

-4.0

-2.0

0.0

100 kPa

111 kPa

123 kPa

134 kPa

145 kPa

157 kPa

168 kPa

180 kPa

191 kPa

Length (m)

Depth (m

)

Length (m) Length (m) Length (m)

Pressure

Example steam modeling

Guadalupe project – Diluent and crude oil

SEE: Pressure cycling to optimize vaporization and to achieve

diminishing returns

0

1 0

2 0

3 0

4 0

5 0

6 0

1 0 / 1 1 0 / 1 1 1 0 / 2 1 1 0 / 3 1 1 1 / 1 0 1 1 /2 0 1 1 / 3 0 1 2 / 1 0 1 2 / 2 0 1 2 / 3 0 1 / 9 1 / 1 9 1 /2 9 2 /8 2 /1 8 2 / 2 8

Estim

ated

VO

C ra

te (p

ound

s pe

r hou

r)

0

5 0 0

1 , 0 0 0

1 , 5 0 0

2 , 0 0 0

2 , 5 0 0

3 , 0 0 0

3 , 5 0 0

4 , 0 0 0

4 , 5 0 0

5 , 0 0 0

1 0 / 1 1 0 / 1 1 1 0 / 2 1 1 0 / 3 1 1 1 / 1 0 1 1 / 2 0 1 1 / 3 0 1 2 / 1 0 1 2 / 2 0 1 2 / 3 0 1 / 9 1 / 1 9 1 / 2 9 2 / 8 2 / 1 8 2 / 2 8

Inje

ctio

n ra

te (l

bs/h

r)

Time (4.5 months total)

CVOC removal (lbs/day)

Steam injection rate 

(lbs/hr)

Pressurization DepressurizationP

T

P

T

Edwards AFB Site 61Fractured granite(quartz monzonite)

39

ERT data planes

VEA-5

VEA-4

VEA-3 VEA-1

VEA-2

ERT data planes

0 0.5 1 1.5 2 2.5 3

DIstance into matrix (m)

0

0.5

1

1.5

2

2.5

Dis

tanc

e fro

m in

ject

ion

hole

(m)

Temperature distribution after 30 days of steam injection into a 100 um fracture at 50 ft depth, using 0.8 psi/ft

Heat conduction into matrix from a steam‐filled fracture

(simulated using a modified Marx‐Langenheim solution; TomHeron et al. 1999)

Q = K x dT/dx

dT/dx = 60 K/m

WHY?

RF Heating• Preferentially heat polar molecules• Limited full-scale applications• Cost?• Limited to small sites?• Gentle heating (40-50°C) to

enhance hydrolysis, biodegradation, and ISCO?

Figures courtesy of JR Technologies, LLC42

Gas Thermal Remediation (GTR©)

• New TCH/ISTD kid on the block• Limited in-situ applications • Limited application in US• Permitting concerns

– Air discharge– City building/fire

• Hundreds of gas connections and fittings

• Natural gas availability• Advantage? Fuel cost?

Figures courtesy of TPS Tech America, Inc. 43

ComparisonTCH/ISTD ‐ Heating governed by thermal conductivity 

ET‐DSP/ERH ‐ Heating governed by electrical conductivity

(max temp = boiling point)

SEE ‐ Heating governed by hydraulic conductivity

(max temp = boiling point)

How to Select Heating Method?

Are the COCs volatile?

Is there a high-flow aquifer?

ISTD, ERH or ET-DSPTM

(100oC)

ISTD 100oC

ISTD >100oC

SEE combined with ISTD, ERH or ET-DSPTM (100oC)

Is there a thick clay layer?SEE

Simplified decision tree for identifying applicable thermal technologies for a site

No

No

No

No

Yes

Yes

Yes

No

Yes

YesStringent COC soil treatment criteria?

Start

Is bedrock present in the treatment zone?

Primary Factors Affecting Selection of Treatment Technology/Approach

- BP/VP of COCs- Cleanup Criteria - GW flux- Bedrock- Stratigraphy

45

Fill

Sand/silt

Clay

Gravel/weathered rock aquifer (v>1 ft/d)

Fractured bedrock

Example source area DNAPL and VOC distribution

Fill

Sand/silt

Clay

Fractured crystalline bedrock

TCH/ERH/ET‐DSP

SEE/TCH/ERH/ET‐DSP

SEE

TCH, ET‐DSP?

Applicable technologies in each zone

Gravel/weathered rock aquifer (v>1 ft/d)

TCH CVOC BTEXChloro-

benzenes Gasoline DieselOils > 50

cpCreosote, 10-100 cp

MGP coal tar,

viscous

Sand, vadose EffectiveSand, saturatedSilt, vadose Promising/site specificSilt, saturatedClay, vadose Problematic/unprovenClay, saturatedCrystalline rock Will not be effectiveCemented sedimentary rockOrganic rock

ERH/ET-DSP CVOC BTEXChloro-

benzenes Gasoline DieselOils > 50

cpCreosote, 10-100 cp

MGP coal tar,

viscous

Sand, vadose EffectiveSand, saturatedSilt, vadose Promising/site specificSilt, saturatedClay, vadose Problematic/unprovenClay, saturatedCrystalline rock Will not be effectiveCemented sedimentary rockOrganic rock

SEE CVOC BTEXChloro-

benzenes Gasoline DieselOils > 50

cpCreosote, 10-100 cp

MGP coal tar,

viscous

Sand, vadose EffectiveSand, saturatedSilt, vadose Promising/site specificSilt, saturatedClay, vadose Problematic/unprovenClay, saturatedCrystalline rock Will not be effectiveCemented sedimentary rockOrganic rock

TCH+SEE CVOC BTEXChloro-

benzenes Gasoline DieselOils > 50

cpCreosote, 10-100 cp

MGP coal tar,

viscous

Sand, vadose EffectiveSand, saturatedSilt, vadose Promising/site specificSilt, saturatedClay, vadose Problematic/unprovenClay, saturatedCrystalline rock Will not be effectiveCemented sedimentary rockOrganic rock

Extraction

Top soil/clay

Permeable zone

Clay

Power

Vapor cap

Steam Power Power Steam

TCHTCH

SteamSteam

ISTD+SEE or ET-DSP+SEE in Complex Stratigraphy

49

Knullen site, Denmark

Cla

yey

till

Fill

Sand

/gra

vel

BuildingDepth bgs

0 m / 0 ft1 m / 3 ft

11 m / 36 ft

14 m / 46 ft

Vertical temperature profiles

Jord & Grundvand

0,00

2,00

4,00

6,00

8,00

10,00

12,00

14,00

16,00

0,0 20,0 40,0 60,0 80,0 100,0 120,0

Temperatur (C)

Dyb

de (m

)

01-07-2008 03-07-2008 07-07-2008 10-07-2008 17-07-2008 24-07-2008 31-07-2008 08-08-200814-08-2008 25-08-2008

Clay till

Aquifer

Jord & Grundvand

0,00

2,00

4,00

6,00

8,00

10,00

12,00

14,00

16,00

0,0 20,0 40,0 60,0 80,0 100,0 120,0

Temperatur (C)

Dyb

de (m

)

01-07-2008 03-07-2008 07-07-2008 10-07-2008 17-07-2008 24-07-2008 31-07-2008 08-08-200814-08-2008 25-08-2008

Clay till

Aquifer

Temperature (C)

Dep

th (m

)

52

0

25

50

Depth (ft)

TCH heater boring

Steam injection well

Multiphase extraction well

Horizontal vapor extraction well

Surface cover

Confidential site, Florida

How to choose?

1. Conceptual site model crucial

2. Let the site conditions dictate

3. Request feasibility screening info from expertsWill it work?

Preliminary design

Cost estimates

4. Move to RFP or final proposal stage for viable alternatives

SEE

ERH/ET‐DSP

ISTD

Performance monitoring during thermal

1. Operate equipment per specs (performance based; energy in, rates out, compliance)

2. Hydraulic and pneumatic control3. Subsurface temperatures4. Mass removal5. Soil concentrations6. Groundwater concentrations

Operational range Other

ISTD system 1000‐1500 kW Safety checks OK

Vapor treatment system

1250 scfm vapor750 non‐condensable

Comply with air discharge std

Liquid treatment system

30 gpm water1 gpm NAPL

Comply with water discharge std

Monitoring system 95% up‐time on sensors

Data web‐site current

Hydraulic control

0 20 40 60 80 100 120 140 1600

20

40

60

80

100

120

140

160

0

20

40

60

80

100

120

140

160

0 20 40 60 80 100 120 140 160

EE‐2

EE‐3

EE‐1

EE‐5

EE‐4

EE‐6

EE‐7

EE‐8

EE‐9

EE‐10

EE‐11

EE‐12EE‐13

EE‐14

EE‐15

EE‐16

EE‐17

EE‐18EE‐19

EE‐20

EE‐21

EE‐22

EE‐23

EE‐24

EE‐25

EE‐26

EE‐27

EE‐28

05600561

0563

056205640565

05660567

Hydraulic control

Pneumatic control

Subsurface temperatures

Mass Removal During Treatment

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

0 15 30 45 60 75 90 105 120 135 150

Days after Initial Startup (Jan 29, 2007)

Rem

oval

Rat

e (lb

s/hr

)

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

Tota

l Rem

oved

(Ton

s)

Removal Rate Total Removed

~12,000 lbs ofTCE

0.0

2.0

4.0

6.0

8.0

10.0

12.0

14.0

16.0

18.0

0 15 30 45 60 75 90 105 120 135 150

Days after Initial Startup (Jan 29, 2007)

Rem

oval

Rat

e (lb

s/hr

)

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

Tota

l Rem

oved

(Ton

s)

Removal Rate Total Removed

~12,000 lbs ofTCE

30 4515 60 75 90 105 120 135 1500

62

Soil sampling

ISTD Results: CVOCs (100°C)

Site Volume (yd3)

Major Contam-

inant

Concentration (mg/kg)

Pre-Treatment

Remedial Goal

Mean Post-

Treatment

Portland, IN 5,000 PCE 3,500 8.0 0.53

Midwest #1 7,882 TCE 4,130 1.0 0.07

Midwest #2 1,730 TCE 20.7 1.0 0.48

Midwest #3 1,338 TCE 12.6 1.0 0.10

Richmond, CA 7,000 PCE 34.2 2.0 0.012

Carson, CA 6,700 1,2-DCA 902[1.0]

(pilot)0.23

SC 8,230 TCE 10,000 0.06 0.01

64

0

1

2

3

4

5

6

7

8

0 1 10 100 1,000 10,000 100,000 1,000,000 10,000,000

Soil Concentration - g/kg

Dep

th B

elow

Gro

und

Surf

ace

- m

Pretreatment - PCEPost Treatment - PCE

Bottom of Treatment Zone

Bottom of Heated Zone

Point Richmond TCH Site, CASoil PCE Concentration (g/kg)

Treatment Objective: 2,000 ug/kg 65

Groundwater samplingExample:  Young‐Rainey STAR Area A (SEE‐ETDSP combo)

NAPL Remediation GoalsGroundwater MCLS:

Date Apr 16-17 May 13-14 July 23-24 Apr 16-17 May 13-14 July 23-24 Apr 16-17 May 13-14 July 23-24 Apr 16-17 May 13-14 July 23-24 Apr 16-17 May 13-14 July 23-24

PIN15-CS-01 ND 3.3 76 ND 0.40 JB ND ND ND 0.20 J ND 0.58 J 12 ND ND NDPIN15-CS-02 ND 0.74 J 52 ND 0.49 JB ND 0.24 J 0.38 J ND ND 0.13 J 8.0 ND 320 NDPIN15-CS-03 ND ND 16 ND 1.2 JB 11 1.3 ND ND ND ND 1.2 340 510 2000PIN15-CS-04 0.3 J 0.45 J 0.18 J ND 1.3 JB ND 4.1 2.5 ND ND ND ND 120 J 970 910PIN15-CS-05 23 9.9 8.6 13 3.8 JB ND 1.5 0.83 J ND 0.63 J 0.35 J ND 3,200 6,800 1300PIN15-CS-06 0.5 J 36 27 4.2 J 150 B 12 0.59 J ND ND ND 2.7 3.6 120 J 140 J NDPIN15-CS-07 ND .22 J 0.83 J 0.48 J 1.2 JB ND 1.4 7.0 6.8 ND ND ND 1,000 6,700 9500PIN15-CS-08 2.4 1.8 2.1 ND 1.8 JB ND 17 8.3 7.6 ND 2.0 0.44 J 210 J 580 1700PIN15-CS-09 ND ND ND 0.52 J 1.4 JB ND 1.4 1.8 ND ND ND ND 400 740 260 JPIN15-CS-10 ND ND 0.65 J 0.82 J ND 0.62 J 1.4 1.2 1.7 ND ND ND 180 J 340 1200PIN15-CS-11 ND ND ND ND ND ND 0.49 J 1.5 1.1 ND ND ND 110 J 270 J 140 JPIN15-CS-12 0.43 J 0.45 J 0.24 J 0.74 J 1.1 JB 0.51 J 4.5 2.5 3.2 0.28 J 0.42 J ND 490 980 1300PIN15-CS-13 ND ND ND 0.62 J 1.7 JB 0.30 J 1.3 0.85 J 0.58 J ND ND ND 240 J 580 NDPIN15-CS-14 ND 0.30 J 0.16 J 0.78 J 1.7 JB ND 1 ND 0.75 J ND 0.11 J ND 120 J 400 NDPIN15-CS-15 ND ND ND 0.68 J ND ND 4.7 ND 1.1 ND ND ND 1,000 2,400 2600PIN15-CS-16 1.3 1.2 7.5 0.8 J 0.75 JB ND 4.5 38 23 ND 29 6.8 ND 190 J 110 J

(µg/L)

50,0005,000*

Samples Inside Remediation Area A

(µg/L)cis-1,2-Dichlorethene

70

Methylene Chloride(µg/L)

20,0005

Toluene TCE

50,000 5,500 11,0001,000 3

(µg/L) (µg/L)Florida Petroleum Range

Location TCEToluene

MeCl2Cis‐1,2‐DCE FL‐PRO

Conclusions

Conceptual model crucialTreat right volumePick heating method to matchCapture mobilized COCsData quality/metrics