Please join EPA Region 9 and GEO Inc. for a technical presentation on In Situ Gas Thermal Remediation (GTR™) and thermal conductive heating (TCH) that will provide regulators, consultants, and field applicators with an understanding of the primary thermally enhanced contaminant removal mechanisms and will help distinguish three types of In Situ Thermal Remediation available commercially in the U.S. and internationally. Additionally, benefits from heat generation, such as increased rates of naturally occurring processes (including hydrolysis, increased bio-availability, and different forms of bio-degradation at various temperature regimes) will be highlighted. In order to identify when In Situ Thermal is appropriate, important design factors will be discussed for their applicability and operation including developing a comprehensive and high resolution conceptual site model through the use of passive soil gas sampling, MIP, LIF, and other high resolution techniques.

1. Speaker
 Lowell Kessel, P.G.
 GEO Incorporated - Gas Thermal Remediation Services

2. Challenging Sites
 Limited access- no
excavation
 Source zone mass removal
 Complex mix of COCs
 DNAPL below the water
table
 LNAPL smear zones
 Clay lithology- diffusion
limited condition
 Fractured bedrock
 Other options failed
Challenging Goals
 Rapid schedule (<90 days)
 Low clean-up standards in
soil, GW or VI
 High probability of success

3.  Vapor pressure of organic
materials increase
 Viscosity of separate phase
liquids decrease
 Increases desorption
 Diffusion rates increase
 Solubility increases
 Increases biodegradation
 Rates of Hydrolysis
increase
 Thermal Oxidation

4.  Thermal conductivity = measure of the ability of a
material to conduct heat. How quickly heat
migrates through it.
 Thermal Diffusivity = measure of the ability of a
material to conduct heat relative to its ability to
store heat. How quickly the temperature of the
material increases.
◦ Thermal diffusivity (m2/s) = thermal conductivity
(W/mK)
volumetric heat capacity
4

5. Heat Transport Equation:
Soil Thermal conductivity
(l)
[W/mK]
Permeability
[m2]
Clay (dry) 0.15-1.8 10-16-10-20
Water saturated clay 0.6-2.5
Sand 0.15-0.77 10-10-10-12
Water saturated sand 2-4
Gravel (dry) 0.7 10-7-10-9
Water saturated gravel 1.7-4
Fractured Bedrock (Granite) 1.4-4.0
ACE EE 2009
http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html

6.  Diffusion limited remediation progress
◦ Enemy #1 for In Situ Remedies
 ISCO
 ISCR
 MPE / SVE
 P&T
1 mm
[Udell et al. 1999; Alameda Point SEE demonstration]
Heat transfer occurs
about 10,000 times
faster than aqueous
diffusion in porous
media and rocks

7. NAPL
SOIL
MINERALS
ORGANIC
MATERIAL
H2O
Micropores

8. The influence from enthalpy of
water vaporization
Time (Days)
Temperature (°C)

9.  Propane/Natural gas/Diesel
 Closed-loop heating system >> No pollution emissions
 Soil and groundwater heated by thermal conduction
 Treatment temperatures from 50°C to >400°C
 Treat sand, silt, CLAY, Bedrock, and Groundwater
 Vapor extraction wells remove VOCs
 VOCs treated by vapor treatment system

10. Natural gas, propane,
diesel, gasoline,
ethanol, etc
National Avg: April 2014
Natural Gas per kWh is ~$0.05
Propane per kWh is ~$0.07
AC per kWh is ~$0.10
http://www.eia.gov/electricity/monthly/epm_table_grapher.cfm?t=e
pmt_5_6_a
http://www.consumersenergy.com/apps/gasvalues/index.aspx?ekfr
m=1654
Flexibility has been key for many
projects internationally!

11. Outer tube Inner tube

17. Level of
Heating &
Contaminant
Target
Treatment
Temperature
(°C)
Heating
Well
Spacing
(m)
Desiccation
of Zone?
Range of
Costs (all
inclusive)
($/m3)
1. VOCs:
Gentle
Heating
(BTEX, CVOCs)
<100 4 – 6 No 40-200
2. VOCs
(CVOCs, BTEX)
>100 2 – 4 Depends 60-300
3. SVOCs
(PCBs, PAHs,
BaP, dioxins)
200-300 1.5 – 3 Yes 150-600

18.  Faster (Rapid mobilization,
smaller footprint, & usually no
electrical installation required)
 Scalable (Can be applied to very
small and very large projects)
 Pilot Tests for less than
$200,000
 Full Scale for less than
$500,000

20. N
 Vapor Treatment system
permitted with BAAQMD
 Onsite Liquid Treatment
 Utilities?
 Existing Natural Gas
Connection
 Existing Electrical
Connection

21. Bathroom
TCU-1-2
(Before July 8, 2012)
TCU-1
(After July 8, 2013)
TCU-2
T9 Wall
SVE-1 TCU-3
SVE-2
SVE-3
SVE-4
SVE-5
SVE-6 SVE-12
SVE-7
SVE-8
SVE-10
SVE-9
TCU-1 SVE-11
(Before July 8, 2013)
TCU 1-2
(After July 8, 2013)
T10 Wall
T1
T2
T3
T5
T4
T6
T7
T8
TCU-1-1
TCU-3-1
TCU-3-2
TCU-2-1
TCU-2-2
0 40
Scale In Inches
 100°C target
treatment
temperature
 9 GTR Heater Wells
 12 Vapor Extraction
Points (dual nested)
 10 TPMPs

22. 0"
20"
40"
60"
80"
100"
120"
14(May"
21(May"
28(May"
4(Jun"
11(Jun"
18(Jun"
25(Jun"
2(Jul"
9(Jul"
16(Jul"
23(Jul"
30(Jul"
6(Aug"
13(Aug"
20(Aug"
27(Aug"
3(Sep"
10(Sep"
17(Sep"
24(Sep"
1(Oct"
8(Oct"
15(Oct"
22(Oct"
29(Oct"
5(Nov"
12(Nov"
19(Nov"
26(Nov"
3(Dec"
10(Dec"
17(Dec"
24(Dec"
31(Dec"
7(Jan"
PPMV$
Influent$Vapor$Sampling$Results$
PCE"
0"
50"
100"
150"
200"
250"
300"
350"
400"
12(May" 1(Jul" 20(Aug" 9(Oct" 28(Nov"
Well$Head$VOC$Data$in$Parts$Per$Million$by$Volume$(PPMV)$
SVE$Well$Head$VOC$Data$
Head$VOC$Data$in$Parts$Per$Million$by$Volume$(PPMV)$
300"
sve"1"
sve"2"
sve"3"
250"
sve"4"
sve"5"
sve"6"
sve"7"
sve"8"
150"
sve"9"
sve"10"
sve"11"
Well$100"
sve"12"
50"
0"
12(May" 1(Jul" 20(Aug" 9(Oct" 200"
350"
400"
Individual SVE Wells
SVE$Well$Head$VOC$Data$

23.  100°C Treatment Temperature in Vadose Soils Maintained for
185 days.
 2,938 Pounds of PCE, cis-1,2-DCE, and Vinyl Chloride
Recovered as DNAPL from vapor treatment (condensation)
system
 1 month post-remediation vapor results 180 ug/m3.
 3 month post-remediation vapor results 70 ug/m3.
 825 pore volume steam exchanges (calculated) in treatment
zone.
 5,944 gallons aqueous phase liquid (water) recovered and
treated onsite.

24.  Specialized Equipment Needed to Access
Interior Through Standard 3ft wide Door.
 High resolution site characterization is key to
design and cost management
 Site remediation goals driven by Vapor Intrusion
Risk and achieved!

25.  Benzo(a)pyrene and related MGP COCs,
Naphthalene, TPH-g, TPH-d impacts above residential
limits, TPH-mo impacts also present.
 Impacts from surface to 15 ft bgs.
 Sandy, gravely soils; GW at >90 ft bgs.
 Residential Goals:
◦ Combined B(a)P, Naphthalene, and MGP SVOCs: >0.9 mg/kg
◦ TPH-d: >1,000 mg/kg
◦ TPH-mo: >10,000 mg/kg

26.  14 GTR Heater Wells
 15 Vapor Extraction Points
 4 TPMPs
 Onsite Liquid Treatment
 C2 Technology Vapor Condensation Unit
(100 scfm) with VGAC
 Adjacent, Existing Natural Gas Connection
 Adjacent, Existing Electrical Connection

27. TC-1
TCU
11
TC-2
TC-3
TCU
5
TC-4
CHINA ALLEY
BT01 BT02
Holding
Tank
Chiller
Skid
SVE
Skid 1
VGAC2
Heater
Fan
VGAC1
TCU
TCU 1
2
TCU
TCU
12
TCU 14
3
TCU
10
TCU
8
TCU
7
TCU
4
TCU
6
TCU
13
SVE
SVE
Skid 2
TCU
9
LGAC
TITLE:
TCH Equipment As Built
SVE Skid 1: After Cooler
Knock Out Tank
Chiller Skid: Chiller
Knock Out Tank
SVE Skid 2: Blower
After Cooler
LGAC: 200 lbs
VGAC 1: 400 lbs
VGAC 2: 200 lbs
Holding
Tank: 650 gal Tank
BT01: 2500 gal Tank
BT02: 1000 gal Tank
Legend
TCH / Co-Located Vapor
Extraction Well (Total: 14)
Vapor Extraction Well
1 10
Scale in Feet
Pilot Test Treatment Zone
Conveyance Line
Equipment
* Well and Equipment Locations are Approximate

30. 0
5
10
15
20
0 100 200 300 400 500 600
T1 60day T2 60day T3 60day T4 60day
T1 120day T2 120day T3 120day T4 120day
°C
T4
T2
T1
T3
Depth (ft bgs.)

31. 100
10
1
0.1
0.01
BaP BaP Eq.
10000
1000
100
Max. Conc.
(mg/kg) Pre-
Treatment
Max. Conc.
(mg/kg) Post-
Treatment
10
1
TPH-d TPH-mo
Target
Treatment
goal lines
Max. Conc.
(mg/kg) Pre-
Treatment
Max. Conc.
(mg/kg) Post-
Treatment

32. 60
40
20
0
1
0.1
0.01
0.001
Post =
0.01 lbs
before =
51.43 lbs
BaP Equivalent TPH
Post = ND
before =
1.47 lbs
BaP Equivalent mass (lbs)
TPH mass (lbs)
Remedial Objectives Exceeded by Order of Magnitude in 130 Days of ISTD Operation.

33. 1. Greater than expected water content of soil (20% versus anticipated
10%) and higher water production impacted heating schedule for
superheated phase.
2. Electrical interruption caused down time, and thereby impacted
system heating capabilities (downed power line offsite) – recommend
providing backup generators
3. Longer heating duration increased heat lost to surface – installed
thermal blankets. Recommend higher R value ‘air entrained’ material
to improve overall thermal efficiencies

34. GTR© ISTCH Individual Burner System:
1. Applicability: soil temperatures < 70°C to > 325°C
2. Speed: Mobilize and commence GTR operations in
Weeks not months
3. Scalability: small pilots to acre size projects
4. Economics: No waiting/paying for electrical
utilities, transformers, switchgear, third party
inspections.
5. Performance Guarantees available