Completion of In-Situ Thermal Remediation of PAHs, PCP and Dioxins at a Former Wood Treatment Facility Ralph S. Baker, Ph.D., John M. Bierschenk, P.G., James P. Galligan, P.E., and Ron Young TerraTherm, Inc., FitchburgMassachusetts, USA TerraTherm, Inc., Fitchburg, Massachusetts, USA March 29, 2007

Power distribution system Vapor treatment Knockout pot Blower Water treatment Discharge Heater and vacuum wells Treated vapor to atmosphere Heat exchanger Pump Treatment area foot-print Temperature and pressure monitoring holes (1 of many) Sketch of ISTD Process Power Supply ISTD is the Simultaneous Application of: Thermal Conduction Heating (TCH) Vapor Recovery

What Makes Thermal Conduction Heating (TCH) so Unique?  The Thermal Conductivity of a Wide Range of Soil Materials (gravel, sand, silt, clay) Varies Only by a Factor of ~3  By Contrast:  Hydraulic / Pneumatic Conductivities Vary >10 6 – 10 8  Electrical Conductivities Vary > 10 2  TCH Heats the Entire Target Zone – No Locations are Bypassed or Unaffected  Soil Immediately Adjacent to TCH Wells Dries, Creating Permeability, Assisting Efficient Vapor Recovery  TCH Heaters Can Be Readily Controlled, to Achieve Low, Moderate or Higher Soil Temperatures as Needed

. ISTD Thermal Wells Heater- Vacuum Well Process Trailer  Heater-Only Wells Heater-Vacuum Well Hexagonal Well Pattern Heater-Only Well Heater- Vacuum Well Thermal Destruction Zone

Typical Heating Progression for Various Levels of ISTD Treatment

Contrasting Applications of ISTD/TCH Level of Heating and Contaminant Type Target Treatment Temperature (°C) Thermal Well Spacing (m) Desiccate Target Treatment Zone (TTZ)? Range of Costs (Turnkey)* ($/m) ($/m 3 ) 1. VOCs: Gentle Heating** (BTEX, CVOCs) <100>6No40-240* 2. VOCs (BTEX, CVOCs) Not Necessary * 3. SVOCs (PAHs, PCBs, dioxins) >1002-4Yes * *For volumes > 1,500 m implemented in the U.S. *For volumes > 1,500 m 3, implemented in the U.S. **Thermally enhanced SVE, NAPL recovery, and bioremediation

Shell TerraTherm TerraTherm, Inc. ISTD Development and Deployment Shell R&D 1980’s through 2000’s CVOCs MGP CVOCs PAHs, Dioxins CVOCs PCBs PAHs Chlorinated Benzenes CVOCs Chlorinated Pesticides CVOCs/SVOCs, radionuclides PCBs GRO/DRO, Benzene PCBs Saipan CVOCs 19 Chlorinated Benzenes, PAH, BTEX CVOCs ISTD Projects are also ongoing in Denmark and the U.K. 22

Alhambra, California Site Features Former Wood Treatment Facility n Two Former Full-length Treatment Tanks (~3 x 21 x 1.7 m deep) n Two Former Butt-Dip Tanks (~3 x 14 x 4 m deep) n Former Boiler House and Tank Farm n Decommissioned Pipe Lines n Railroad Spurs

Former Wood Treatment Tanks AOC-2 Treatment Area:  Heterogeneous fine silty sands  2,800 m 2  12,400 m 3  Avg. depth 6 m; max. depth 32 m  Water Table >82 m Former ASTs Former Boiler House Piping Former Railroad Spur

Constituent Max. Conc. (mg/kg) Mean Conc. (mg/kg) Cleanup Standard (mg/kg) TPH50,0002,730N/A Total PAH 35,0002, [B(a)P-Eq] Creosote61,0004,505N/A PCP582.94*2.5 Dioxins (TEQ) *Mean of 15 detects; PCP not detected in 231 samples B(a)P-Eq = Benzo(a)pyrene equivalents TEQ = 2,3,7,8-Tetrachlorodibenzodioxin Toxicity Equivalents Soil Contaminant Concentrations and Cleanup Standards

Alhambra ISTD Design Features n Target temperature (treatability results) of 335  C (635  F), maintained for 3 days n 2.1-m thermal well spacing n 785 thermal wells, total (131 heater-vacuum and 654 heater-only wells) n Insulated surface seal n Two treatment phases

Aerial View – December 2004 Phase 1 Phase 2

Thermal Well Fields Installed Phase 1Phase 2

Air Quality Control System n 24/7 Continuous Manned Operation n Monitoring Well Field Temperatures & Vacuum, Continuous Emissions Monitoring (CEM) of Off-Gas System Parameters Electrical Transformer CEM System Granular Activated Carbon Vessels Air-to-Air Heat Exchanger Regenerative Thermal Oxidizer Inlet Manifold Extraction Blowers Switchgear

Source Testing Results PCB Emission Limit: 2.44  g/dscm PCDD/PCDF Emission Limit: 2 x  g/dscm

Source Testing Results Carcinogenic PAHs MICR = maximum individual cancer risk

Phase 2 Centroid Phase 1 Centroid Well Field Layout and Representative Centroid Locations

Phase 1 Centroid Temperature °F /11/2003 7/1/2003 7/20/2003 8/7/2003 8/26/ /11/ /6/200312/2/ /28/2003 1/14/2004 2/9/2004 3/4/2004 6:00 4/17/2004 T7A4B-4BHK Temperature °F Date Description Target Treatment Temperature 635°F Vaporization of Water Complete, Start of Superheating Attainment of Target Treatment Temperature Heater Circuits Shut Down, Start of Well Field Cool-Down 4/17/20043/4/20042/9/20041/14/ /28/ /2/200311/6/ /11/2003 8/26/20038/7/20037/20/20037/1/20036/11/ /11/2003 7/1/2003 7/20/2003 8/7/2003 8/26/ /11/ /6/200312/2/ /28/2003 1/14/2004 2/9/2004 3/4/2004 6:00 4/17/2004 T7A4B-4BHK Temperature °F Date Description Target Treatment Temperature 335°C Vaporization of Water Complete, Start of Superheating Attainment of Target Treatment Temperature Heater Circuits Shut Down, Start of Well Field Cool-Down 4/17/20043/4/20042/9/20041/14/ /28/ /2/200311/6/ /11/2003 8/26/20038/7/20037/20/20037/1/20036/11/2003

Phase 2 Centroid Temperature °F /22/ :00 7/14/2004 8:00 8/4/2004 6:00 9/3/ :00 10/5/ :30 11/8/ /12/ :30 1/12/2005 8:00 2/6/2005 3/3/ :00 3/26/2005 4/17/2005 8:005/11/2005 6:30 6/7/2005 6/30/ :00 7/23/2005 8/13/ :30 9/5/2005 0:01 9/27/ /17/2005 7:00 T11A2-2HG Temperature °F Date Description Target Treatment Temperature 635°F Vaporization of Water Complete, Start of Superheating Attainment of Target Treatment Temperature 635°F Heater Circuits Shut Down, Start of Well Field Cool- Down 11/17/2005 9/27/2005 9/5/2005 8/31/20057/23/20056/30/2005 6/7/2005 5/11/20054/17/20053/26/2005 3/3/20052/6/2005 1/12/ /12/ /8/200410/5/2004 9/3/20048/4/2004 7/14/20046/22/ /22/ :00 7/14/2004 8:00 8/4/2004 6:00 9/3/ :00 10/5/ :30 11/8/ /12/ :30 1/12/2005 8:00 2/6/2005 3/3/ :00 3/26/2005 4/17/2005 8:005/11/2005 6:30 6/7/2005 6/30/ :00 7/23/2005 8/13/ :30 9/5/2005 0:01 9/27/ /17/2005 7:00 T11A2-2HG Temperature °F Date Description Target Treatment Temperature 335°C Vaporization of Water Complete, Start of Superheating Attainment of Target Treatment Temperature 335°C Heater Circuits Shut Down, Start of Well Field Cool- Down 11/17/2005 9/27/2005 9/5/2005 8/31/20057/23/20056/30/2005 6/7/2005 5/11/20054/17/20053/26/2005 3/3/20052/6/2005 1/12/ /12/ /8/200410/5/2004 9/3/20048/4/2004 7/14/20046/22/2004

Coke from product zone Auger cuttings oxidation vs. pyrolysis Confirmatory sampling in well field ~5.5 m bgs ~2.7 m bgs ~0.3 m bgs

Cleanup Goals 65  g/kg B(a)P 1  g/kg Dioxin 30, N = 60 N = Comparison of Pre- and Post-Treatment Contaminant Concentrations

Summary n Site demob. completed March 2006 n Estimated mass removed via combustion (oxidizer and subsurface) 395,000 kg (CO 2 method) n Additional mass destroyed in situ by pyrolysis (dark soil/coke) n Air emissions were well below compliance requirements n Post–treatment soil sampling results all below stringent clean-up requirements n No Further Action letter (February 7, 2007) from California Department of Toxic Substances Control to Southern California Edison allows unrestricted land use

Cost Implications of Lessons Learned for Future Applications of ISTD at Creosote Sites n Achievement of unrestricted/residential land use by an in-situ remediation method is achievable and practical n ISTD was initially compared and selected over excavation with offsite incineration n ISTD remediation costs exceeded original estimates; however, all-in project cost was still ~40% lower than the excavation alternative n TerraTherm’s estimate for similar site of 12,600 m 3, with one 130-day treatment is $500/m 3 :  Capital cost: $3.9M  Operations, source testing, and electricity: $2.2M  Demobilization, reporting, licensing fee: $0.23M