Natural Attenuation of Acid Mine Drainage: Column Studies of Sulfate Reducing Bacteria 
Mercedita Monserrate, University of Massachusetts, Amherst, MA
Sarina Ergas, University of Massachusetts, Amherst, MA  

Full-Scale Phase 1 Results of ISTD Treatment at Former Alhambra, California Wood Treatment Site
John M. Bierschenk, TerraTherm, Inc., Fitchburg, MA
Ralph S. Baker, TerraTherm, Inc, Fitchburg, MA
Robert J. Bukowski, TerraTherm, Inc., Fitchburg, MA
Ken Parker, TerraTherm, Inc., Fitchburg, MA
Ron Young, TerraTherm, Inc., Fitchburg, MA
Jenny King, Southern California Edison Company, Rosemead, CA  
Tony Landler, Southern California Edison Company, Rosemead, CA

Monitored Natural Attenuation (MNA) – Where it Works and Where it Doesn’t Using Case-history Examples 
Edward Van Doren, Shaw Environmental, Inc., Andover, MA
Olaf Westphalen, Shaw Environmental, Inc., Andover, MA

In-Situ Thermal Destruction (ISTD) of MGP Waste in a Former Gasholder: Design and  Operation
Ralph S. Baker, TerraTherm, Inc., Fitchburg, MA
John C. LaChance, TerraTherm, Inc., Fitchburg, MA
Mark W. Kresge, TerraTherm, Inc., Fitchburg, MA
James P. Galligan, TerraTherm, Inc., Fitchburg, MA
Myron Kuhlman, MK Tech Solutions, Houston, TX
Edward H. White Jr., National Grid USA, Westboro, MA

In Situ Thermal Remediation of NAPL Using Electrical Resistance Heating at an Active U.S. Army Installation
Pat Cossins, Thermal Remediation Services, Inc., Austin, TX
Greg Beyke, P.E., Thermal Remediation Services, Inc., Memphis, TN
Michael Dodson, Thermal Remediation Services, Inc., Longview, WA
David Fleming, Thermal Remediation Services, Inc., Snoqualmie, WA
Rich Wilson, Ft. Lewis Public Works, Ft. Lewis, WA,

Assessing the Performance of Thermal Conductive Heating for Remediation of  Chlorinated  VOCs in Saturated and Unsaturated Settings
John C. LaChance, TerraTherm, Inc., Fitchburg, MA
Ralph S. Baker, TerraTherm, Inc., Fitchburg, MA
James P. Galligan, TerraTherm, Inc., Fitchburg, MA
John M. Bierschenk, TerraTherm, Inc., Fitchburg, MA

Remote Telemetry Board Performance
Susan Sitkoff, BEM Systems, Inc., Orlando, FL  

Natural Attenuation of Acid Mine Drainage: Column Studies of Sulfate Reducing Bacteria

Mercedita Monserrate, Research Assistant, MS candidate, Environmental Engineering, University of Massachusetts, Amherst, 24 Marston Hall, Amherst, MA 01003, Tel: 413-545-3898, 413-222-1661, Email: merce@acad.umass.edu
Sarina Ergas, Associate Professor, Civil and Environmental Engineering, University of Massachusetts, Amherst, 18B Marston Hall Box 35205, Amherst, MA 01003-5305, Tel: 413-545-3424, Email: ergas@ecs.umass.edu

Acid mine drainage (AMD) a complex contamination problem that occurs due to mining activities, can be naturally attenuated if the proper environmental conditions are present.  Natural attenuation of acid mine drainage results in the decrease in concentration of contaminants through naturally occurring processes.  Sulfate reducing bacteria are the key players in the natural attenuation in the field site of Davis Mine located in Rowe, Massachusetts, decreasing the amount of acidity and metal contamination present.  Some of the characteristics needed for sulfate reduction include a large enough population of sulfate reducing bacteria and the proper substrate and environmental conditions for the bacteria to grow and multiply.  Site characterization was done by collecting groundwater and microbial samples from the Davis mine site regularly for analysis.  Chemical analysis of groundwater included anions, metals and organic carbon.  Together with field measurements of temperature, pH oxidation reduction potential and conductivity, these measurements were used to describe the evolution of microbiology and the geochemistry in the Davis Mine site.  Column studies were used to replicate the conditions in the Davis mine site and to provide a controlled environment for the analysis of the system.  The central goal of this research was to understand the chemical, structural and microbial factors that control the speciation of sulfur and iron and provide perspectives on remediation processes by the analysis of the field data and column studies.  The use of flow-through columns provided a very important link between the microbiological analyses and the field scale modeling.  Tracer studies were performed to measure transport parameters using a non-sorbing tracer (potassium bromide).  A one-dimensional conservative model was used to estimate a dispersion coefficient of 5.5E-7 m²/sec and an apparent longitudinal dynamic dispersivity of 0.011m.   Sulfate and sulfide concentrations analyzed together with pH and ORP values suggested sulfate reduction in columns and in the field, and thus the natural attenuation of the mine site.

Full-Scale Phase 1 Results of ISTD Treatment at Former Alhambra, California Wood Treatment Site

John M. Bierschenk, P.G., MBA, TerraTherm, Inc., 356 Broad St., Fitchburg, MA 01420, Tel: 978-343-0300, Email: jbierschenk@terratherm.com
Ralph S. Baker, Ph.D., TerraTherm, Inc., 356 Broad St., Fitchburg, MA 01420, Tel: 978-343-0300, Email: rbaker@terratherm.com
Robert J. Bukowski, P.E., M.S., TerraTherm, Inc., 356 Broad St., Fitchburg, MA 01420, Tel: 978-343-0300, Email: rbukowski@terratherm.com
Ken Parker, TerraTherm, Inc., 356 Broad St., Fitchburg, MA 01420, Tel: 978-343-0300, Email: kparker@terratherm.com
Ron Young, TerraTherm, Inc., 356 Broad St., Fitchburg, MA 01420, Tel: 978-343-0300, Email:  ryoung@terratherm.com
Jenny King, Project Manager, Southern California Edison Company, 2244 Walnut Grove Avenue, Rosemead, CA  91770, Tel: 626-302-4257, Email: kingjj@sce.com
Tony Landler, Project Engineer, Southern California Edison Company, 2244 Walnut Grove Avenue, Rosemead, CA  91770, Tel: 626-302-8692, Email: landleaj@sce.com

At a wood treatment facility for utility poles that Southern California Edison (SCE) operated from 1921 to 1957, subsurface soils are contaminated primarily with polyaromatic hydrocarbons (PAHs), and dioxins and furans (PCDD/PCDF).  Approx. 12,390m³ (16,200 cubic yards) of predominantly silty soil requires treatment, to an average depth of 6 m (20 ft) and a maximum depth of 30 m (100 ft).  The CA Department of Toxic Substances Control (DTSC) established soil treatment standards of 0.065 mg/kg benzo(a)pyrene [B(a)P] Equivalents and 1.0 mg/kg dioxin, expressed as 2,3,7,8-tetrachlorodibenzodioxin (TCDD) Toxic Equivalents (TEQ).  A feasibility study led to the selection of TerraTherm’s patented In-Situ Thermal Destruction (ISTD) technology, which utilizes simultaneous application of Thermal Conduction Heating (TCH) and vacuum to treat contaminated soil without excavation.  The applied heat volatilizes organic contaminants within the soil, enabling them to be carried in the vapor stream toward heater-vacuum wells.  Because vapors are drawn through superheated (500-700°C) soil in proximity to the heater-vacuum wells, most of the contaminant mass present in the subsurface is destroyed in situ, as evidenced by 11 completed ISTD/TCH projects.  Contaminants not destroyed in situ are removed with the vapor stream and treated in an Air Quality Control (AQC) system. 

TerraTherm installed 785 thermal wells, including 654 heater-only and 131 heater-vacuum wells, in a hexagonal pattern at 7.0-foot spacing.  TerraTherm is carrying out the heating in two phases, shakedown of the first phase of which concluded in June 2003.  Each phase requires achievement of inter-well soil temperatures of 325°C (620°F).  Subsurface temperature monitoring tracks the progress of heating.  The AQC system includes a regenerative thermal oxidizer with demonstrated capability of achieving 99.9% Destruction and Removal Efficiency (DRE); heat exchanger; and granular activated carbon (GAC).  A process blower maintains the entire system under vacuum, while a continuous emission monitoring system measures stack emissions.  In accordance with DTSC requirements, an independent air measurements contractor is carrying out several rounds of source testing.  Results of the first two rounds indicated that the AQC system is meeting all performance standards.  Specifically, measured emissions of PCDD/PCDF expressed as 2,3,7,8-TCDD TEQ averaged 0.0113 ng/dscm, relative to a regulatory standard of 0.2 ng/dscm. 

The results of soil sampling of Phase 1a indicated that although pre-treatment concentrations were 30.6 mg/kg B(a)P Equivalents (mean of 47 samples), post-treatment concentrations were 0.022 mg/kg (mean of 10 samples), well below the stipulated goal of 0.065 mg/kg.  Similarly, post-treatment concentrations of PCDD/PCDF were 0.48 mg/kg 2,3,7,8-TCDD TEQ (mean of 4 samples), well below the stipulated goal of 1.0 mg/kg.  It is expected that ISTD remediation at the site will be completed by March 2005.

Monitored Natural Attenuation (MNA) – Where it Works and Where it Doesn’t Using Case-history Examples 

Edward Van Doren, Shaw Environmental, Inc., 3 Riverside Drive, Andover, MA 01810, Tel: 978-691-2130, Fax: 978-691-2101, Email: Edward.vandoren@shawgrp.com
Olaf Westphalen, Shaw Environmental, Inc., E Riverside Drive, Andover, MA 01810, Tel: 978-691-2136, Fax: 978-691-2101, Email: olaf.westphalen@shawgrp.com

Monitored Natural Attenuation (MNA) is often selected as a comprehensive remedial action thought to be capable of achieving a permanent solution.  However, not often enough are the site conditions properly characterized to justify MNA.  For example, sufficient data to demonstrate that the plume is shrinking is a must.  Other indirect evidence of biodegradation should also be obtained in order to demonstrate that biodegradation is occurring.  Also, time-series data should be acquired to calculate the length of time necessary to achieve cleanup goals.  These calculations are necessary to compare to other possibly feasible cleanup alternatives.  Through the use of several case-history examples, this presentation will provide insight as to what conditions are a prerequisite for an MNA solution.  Also, some general rules of thumb and red-flags for MNA will be provided.  MNA case-history examples will include releases of naphthalene, petroleum, and solvents.

In-Situ Thermal Destruction (ISTD) of MGP Waste in a Former Gasholder: Design and  Operation

Ralph S. Baker, Ph.D., TerraTherm, Inc., 356 Broad St., Fitchburg, MA 01420, Tel: 978-343-0300, Email: rbaker@terratherm.com
John C. LaChance, M.S., TerraTherm, Inc., 356 Broad St., Fitchburg, MA 01420, Tel: 978-343-0300, Email: jlachance@terratherm.com
Mark W. Kresge, B.S., TerraTherm, Inc., 356 Broad St., Fitchburg, MA 01420, Tel: 978-343-0300, Email: mkresge@terratherm.com
James P. Galligan, P.E., B.S., TerraTherm, Inc., 356 Broad St., Fitchburg, MA 01420, Tel: 978-343-0300, Email: jgalligan@terratherm.com
Myron Kuhlman, Ph.D., MK Tech Solutions, 12843 Covey Lane, Houston, TX  77099, Tel: 281-564-8851, Email: mikuhlman@aol.com
Edward H. White Jr., National Grid USA, 25 Research Drive, Westboro, MA 01582, Tel: 508-389-4295, Email: edward.white@us.ngrid.com

In Situ Thermal Desorption (ISTD) also known as In-Situ Thermal Destruction is being used to remediate a gas holder containing residual coal tar at a former manufactured gas plant  (MGP) in North Adams, Massachusetts.  When the 62-ft (18.9-m) diameter by 18-ft (5.5-m) deep gas holder was decommissioned, it was backfilled with soil and debris.  Water was found to be present at a depth of approximately 0.9 m (3 ft) below ground surface (bgs) within the brick-lined gas holder.  Based on soil investigations within the gas holder, residual coal tar was present throughout the soils, and the bottom 1.2 m (4 ft) of soil was saturated with coal tar present as a dense non-aqueous phase liquid (DNAPL).  The soil volume requiring treatment totals 2,010 cy (1,537 m³).  National Grid selected ISTD to remediate the gas holder and achieve Massachusetts soil cleanup standards with respect to polyaromatic hydrocarbons (PAHs) and other compounds of concern that are protective of human health and groundwater. 

At ambient temperatures, it had been the site owner’s experience that the coal tar at this site was minimally recoverable as a liquid.  Laboratory results on a sample of the coal tar indicated, however, that a modest increase in temperature from 10 to 66°C (50 to 150°F) would result in a substantial decrease in viscosity, from 400 to 25 centipoise.  Thus, TerraTherm proposed that gentle heating would increase the fluidity and recoverability of the tar, after which ISTD would proceed.  During the remedial design, TerraTherm and MKTS utilized numerical simulations to optimize the placement of thermal wells and the heating sequence.  TerraTherm then installed 25 thermal wells, 16 temperature and 3 pressure monitoring points, two liquid extraction points, an insulating surface seal, electrical distribution equipment, and both liquid and vapor treatment equipment.   TerraTherm’s remedial operations sequence is as follows: (1) dewatering of the gas holder and treatment of the liquid effluent prior to discharge; (2) gentle heating to remove recoverable tar from the gas holder via two liquid extraction wells; and, (3) ramping up the heaters to their full operating temperature of 650-800°C (1200-1500°F) and heating the soil to an interwell target temperature of 325°C (617°F).  In the process, soil in close proximity to the heater wells will become superheated, resulting in substantial in-situ destruction by oxidation and pyrolysis of PAHs and other organic compounds that are volatilized and drawn to the heater-vacuum wells.  Air will be injected around the heater-vacuum wells to prevent coke from forming and obstructing subsurface vapor flow.  The project is scheduled for completion by early Fall 2004, and is being conducted under a guaranteed remediation contract.

In Situ Thermal Remediation of NAPL Using Electrical Resistance Heating at an Active U.S. Army Installation

Pat Cossins, Thermal Remediation Services, Inc., Austin, TX
Greg Beyke, P.E., Thermal Remediation Services, Inc., Memphis, TN
Michael Dodson, Thermal Remediation Services, Inc., Longview, WA
David Fleming, Thermal Remediation Services, Inc., 7421 A Warren Ave SE, Snoqualmie, WA 98065, Tel: 425-396-4266, Email: dfleming@thermalrs.com
Rich Wilson, Ft. Lewis Public Works, Ft. Lewis, WA, USA

A full-scale Electrical Resistance Heating (ERH) and Multi-Phase Extraction (MPE) system is being implemented for the in situ thermal remediation of non-aqueous phase liquids (NAPL), primarily trichloroethylene (TCE), as well as other chlorinated solvents of concern, at the East Gate Disposal Yard (EGDY), Ft. Lewis, Tacoma, Washington. The ERH system includes 106 electrode and MPE locations for the first phase of the project designated as NAPL Area 1, which covers approximately 25,400 square feet with an estimated NAPL mass of 210,000 pounds. The estimated treatment volume for the ERH system is 31,040 cubic yards. This remediation work is being conducted for Ft. Lewis under the direction of the U.S. Army Corps of Engineers, Seattle District (USACE).

In addition to the ERH and MPE system, a liquid waste management system (LWMS) for removal and disposal of NAPL liquid is operating and tied into the ERH process. This project also includes operating a hydraulic control system to maintain a depressed groundwater table within the treatment area to eliminate groundwater migration. 

The remediation of NAPL Areas 1, 2, and 3 will include presentation of daily, weekly, and monthly reports regarding sample and process monitoring data. Reports are being presented in an electronic format on a dedicated project website, enabling USACE and the ERH team to analyze and monitor the progress of the remediation.

The work is being conducted in phases starting with the treatment of NAPL Area 1.  As the ERH project at Ft. Lewis is a performance-based contract; ERH operations will be continuously evaluated.  Based on the performance of the ERH system at NAPL Area 1, USACE and Ft. Lewis will determine if the process will be continued for treatment of the subsequent NAPL Areas.

This remediation is presently underway with remediation operations concluding in NAPL Area 1 in the spring of 2004. Remediation in NAPL Area 2 is expected to begin this summer. It is expected that operational data and results from NAPL Area 1 and possibly Area 2 will be available in time for this conference. Specific operational design parameters as well as results and lessons learned will be presented.

Assessing the Performance of Thermal Conductive Heating for Remediation of Chlorinated  VOCs in Saturated and Unsaturated Settings

John C. LaChance, M.S., TerraTherm, Inc., 356 Broad St., Fitchburg, MA 01420, Tel: 978-343-0300, Email: jlachance@terratherm.com
Ralph S. Baker, Ph.D., TerraTherm, Inc., 356 Broad St., Fitchburg, MA 01420, Tel: 978-343-0300, Email: rbaker@terratherm.com
James P. Galligan, P.E., B.S., TerraTherm, Inc., 356 Broad St., Fitchburg, MA 01420, Tel: 978-343-0300, Email: jgalligan@terratherm.com
John M. Bierschenk, P.G., MBA, TerraTherm, Inc., 356 Broad St., Fitchburg, MA 01420, Tel: 978-343-0300, Email: jbierschenk@terratherm.com

TerraTherm’s Thermal Conduction Heating (TCH) technology, also known as In-Situ Thermal Desorption (ISTD) was recently used to remediate three separate source zones contaminated with chlorinated volatile organic compounds (CVOCs) at an active manufacturing facility in the USA.  Soils within two of the source zones were unsaturated while soil within the third source zone was saturated with water.  The total volume of soil remediated within the three source zones was 10,950 cubic yards (8,372 m³).  The results indicate that attaining an interwell soil temperature of 210°F (99°C), the boiling point of water at the site, was effective in reducing CVOCs from maximum pre-treatment concentrations for trichloroethene (TCE) of 4,130 mg/kg to 0.07 mg/kg (average of 54 samples).  The post-treatment sampling results were significantly below the remedial goal for TCE of 1 mg/kg and were achieved following 150 days of soil heating.  Effective treatment of the source zones provided the basis for a No Further Action (NFA) letter for soils at the site. 

TerraTherm installed temperature monitoring points equipped with thermocouples near thermal wells and at representative centroid locations to monitor the progress of heating and to ensure that the coolest locations achieved the target temperature.  Pressure monitoring points were located throughout the thermal well fields to monitor the effectiveness of the vapor control/collection system.

Based on the results of the clients’ confirmatory soil sampling program, all three source zones achieved the remedial goals for TCE of < 1.056 mg/kg; for 1,1,1-trichloroethane of  < 28,500 mg/kg; and for tetrachloroethene of < 5.95 mg/kg.  Although nearly all of the targeted soil volume achieved the boiling point of water, the cleanup was accomplished while boiling off only a small fraction of the water content within the TTZ.  Monitoring of subsurface conditions enabled TerraTherm to optimize the application of TCH/ISTD to address infiltration and heat losses identified during the remediation, while still enabling achievement of the guaranteed project goals.

Remote Telemetry Board Performance

Susan Sitkoff, BEM Systems, Inc., 930 Woodcock Road, Suite 101, Orlando, FL 32803, Tel: 407-894-9900 x 126, Fax: 407-894-1089, Email: ssitkoff@bemsys.com

A remote telemetry board was installed on and existing horizontal and vertical air sparge system to immediately notify personnel when the system falls out of normal operating ranges and allow personnel to reprogram or restart the system remotely. After installation, an analysis of the system performance parameters have indicated that the PLC board has some additional benefits: improving the system efficiency and effectiveness. Since the implementation of the PLC board, the system ware has run more consistently and shows an increase in the VOC degradation in this vicinity. The remote operation and monitoring of this system has resulted in a decrease in labor costs for the system, as unscheduled site visits are no longer required to check on the system operation or to inspect the system after a failure.

Operations and maintenance activities has been performed on the system for 3 years. Initially the system was operating with one 2-inch leg and one 3-inch leg running in tandem. The airflow was manually changed from the sets of legs on a rotating basis and the system ran with each set of legs operational for approximately 24 to 48 hours. After the implementation of the remote board, the run time for the legs was reduced to 4 hours. The pressure required to overcome the groundwater infiltration into the air pathways after 24 to 48 hours of non-operation previously resulted in stress to the system. Since the installation of the unit, a steady decline in the airflow has been observed, consistent with the required vane replacements that have been scheduled on a quarterly basis. The shorter runtime has minimized the stress to the system and enabled it to run more efficiently.

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