Optimizing Solvent Extraction of PCBs from Soil
Student Presenter
Maureen O’Connell, University of Waterloo, Waterloo, ON, Canada  
Dr. Neil R. Thomson, University of Waterloo , Waterloo , ON , Canada

The ART Technology Success in Treating Petroleum & Chlorinated Compounds, MTBE and 1, 4 Dioxane….How Does it Work?
Marco M. Odah, Ph.D., P.E., Accelerated Remediation Technologies, Inc., Overland Park, KS  

Pulsed Biosparging of a Residual Fuel Source Emplaced at CFB Borden
Student Presenter
Jennifer Lambert, Department of Earth and Environmental Science,University of Waterloo , Waterloo , Ontario , Canada
Tianxiao Yang, Department of Earth and Environmental Science, University of Waterloo, Waterloo, Ontario, Canada
Neil R. Thomson, Department of Civil Engineering, University of Waterloo, Waterloo, Ontario, Canada
James F. Barker, Department of Earth and Environmental Science, University of Waterloo , Waterloo , Ontario , Canada

Addition of 1,4-Dioxane Treatment to a Chlorinated Solvent Groundwater Extraction and Treatment System
David Dedian, Woodard & Curran, Portland, ME
Peter Herlihy, Applied Process Technology, Inc., West Chester, OH

Remediation of TCE Plume Discharging to a Stream 
Paul M. Dombrowski, Metcalf & Eddy / AECOM, Wakefield, MA
Lucas A. Hellerich, PhD, PE, Metcalf & Eddy / AECOM, Wallingford, CT
Christopher A. Shores, Metcalf & Eddy / AECOM, Wallingford, CT
John L. Albrecht, LEP, Metcalf & Eddy / AECOM, Wallingford, CT
Dave Hart, Noranda Metals Industries, Inc., New Madrid, MO  

An Integrated Site Wide Approach Chlorinated Solvent Source Remediation in an Active Manufacturing Facility
James R. Dickson, P.E., CTI and Associates Inc., Cleveland, WI
Drew Lonergan, PG, CTI and Associates Inc., MI  
Rob Stenson, CPG, CTI and Associates Inc., Cleveland , WI
Chris Winklejohn, P.E., CTI and Associates Inc., Brighton, MI

Optimizing Solvent Extraction of PCBs from Soil
Student Presenter
Maureen O’Connell, Department of Civil and Environmental Engineering, University of Waterloo, 200 University Ave West, Waterloo ON, Canada N2L 3G1, Tel: 519-888-4567 Ext 33847, Fax: 519-888-4349, Email: msoconne@engmail.uwaterloo.ca
Dr. Neil R. Thomson, Department of Civil and Environmental Engineering, University of Waterloo, 200 University Ave West, Waterloo, Ontario, N2L 3G1, Canada, Tel: 519-888-4567 Ext 32111, Fax: 519-888-4349, Email: nthomson@civmail.uwaterloo.ca

Polychlorinated biphenyls (PCBs) are carcinogenic persistent contaminants and although their manufacturing in North America ceased in the late 1970s, their high heat resistance made their use widespread over their production lifetime. PCB contaminated soil or sediments on industrial and other sites have historically been dealt with through excavation followed by off-site disposal or incineration. One potential technology that has shown some demonstrated success in the southern United States is solvent extraction. Although successful at removing a large quantity of PCBs from soil, this technology can be improved upon by making the extraction more complete, efficient and suitable for in a variety of climates. Research underway at the University of Waterloo will identify the factors controlling PCB extraction with solvents in order to optimize PCB extraction as it is applied on different soil types and in various climates. The collected data will be used to develop a temperature-corrected kinetic model to better represent the extraction process. As past research has shown that weathered PCB in soil is more difficult to remove, contaminated field samples from Southern Ontario , Canada are being used for this work, rather than synthetically prepared samples. Initial screening experiments consisted of mixing a solvent with contaminated soil while varying factors potentially influencing the extraction, such as moisture content, solvent type, and grain size. Additional experiments were conducted to discover if the influence of factors controlling PCB extraction was temperature dependent. This presentation will include a discussion of the experiments underway, factors influencing solvent extraction, and the expected form of the kinetic model.

The ART Technology Success in Treating Petroleum & Chlorinated Compounds, MTBE and 1, 4 Dioxane….How Does it Work?
Marco M. Odah, Ph.D., P.E., Accelerated Remediation Technologies, Inc. 10107 W. 105th Street, Overland Park, Kansas 66212, Tel: 913-438-4384 ext 102, Fax: 913-599-6688, Email: modah@artinwell.com

Many sites impacted with a wide range of contaminants are in need of comprehensive treatment measures that can treat constituents including petroleum and chlorinated compounds along with recalcitrant constituents such as MTBE and 1,4 dioxane.  The ART technology combines in situ air stripping, air sparging, soil vapor extraction, enhanced bioremediation/oxidation and subsurface circulation in an innovative wellhead system.  The multiple remediation concepts combined within the ART Technology are attacking contaminants on a number of fronts.  The multiple, in-well stripping passes and high air to water ratio achieved in the well are integral to the physical removal of contamination.  The subsurface circulation process flushes residual contamination from the soil matrix and draws it to the well for treatment.  The circulation and extraction processes provide significant dissolved oxygen (DO) boost throughout the radius of influence, enhancing bioremediation/oxidation of the hydrocarbon compounds.  In summary, as the physical technologies are flushing and moving contaminants back to the well for stripping, the DO boost is enhancing the bioactivity and oxidizing the contamination. 

The in well air-sparging component results in decreased water density, mounding of the water table and a net negative gradient back towards the well and creates the in-well packer component between the lower and upper parts of the screen.  Vacuum pressure is applied atop of the well point to extract vapor from the unsaturated zone and the well annulus.  The negative pressure from the vacuum extraction results in water suction that creates additional water mounding (lifting) and compounds the net negative gradient towards the well. A submersible pump is placed at the bottom of the well to recirculate water to the top for downward discharge through a spray head.  The stripped water cascades down the interior of the well and over the “mounded” water back in to the aquifer.  Enhanced stripping via air sparging near the bottom of the well occurs simultaneously. The ART technology has been implemented at hundreds of installations worldwide.  Dramatic, immediate reduction of contaminant concentrations has occurred. Project summaries and case studies will be presented. 

Pulsed Biosparging of a Residual Fuel Source Emplaced at CFB Borden
Student Presenter
Jennifer Lambert, Department of Earth and Environmental Science, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1, Email: lambert_j_m@yahoo.com
Tianxiao Yang, Department of Earth and Environmental Science, University of Waterloo , 200 University Avenue West , Waterloo , Ontario , Canada N2L 3G1, Email: t8yang@sciborg.uwaterloo.ca
Neil R. Thomson, Department of Civil Engineering, University of Waterloo , 200 University Avenue West , Waterloo , Ontario , Canada N2L 3G1 , Email: nthomson@civmail.uwaterloo.ca
James F. Barker, Department of Earth and Environmental Science, University of Waterloo , 200 University Avenue West , Waterloo , Ontario , Canada N2L 3G1 ,Tel: 519-888-4567 x 32103, Fax: 519-746-7484 Email: jfbarker@sciborg.uwaterloo.ca

Biosparging enhances both aerobic biodegradation and volatilization and is commonly applied to residual hydrocarbon source zone remediation. This technology was applied in pulsed mode to a known source of gasoline contamination in order to quantify the extent of remediation achieved in terms of both mass removed and reduction in chemical mass discharge into groundwater.  The gasoline source zone was created in the sandy research aquifer at CFB Borden, Canada . About 50 L of gasoline with 10% ethanol was injected in small volumes from 24 injection points below the water table in 2004. The downgradient plume is still being monitored and the source area was cored in 2007. In 2008, a single-point, biosparge system is being operated, with soil venting to capture and monitor off-gases. The use of conservative tracers (He, SF6) with hydrocarbon gas monitoring facilitates the assignment of mass removal to volatilization. Monitoring of CO2 in the offgas will confirm the extent of biodegradation of hydrocarbons. Post-remediation core analysis and downgradient monitoring of groundwater is being used to define the extent of remediation and to attribute mass removal to biodegradation and volatilization. Groundwater monitoring uses conventional wells, multilevel wells, as well as time-integrating dosimeters placed in a screened well.

Addition of 1,4-Dioxane Treatment to a Chlorinated Solvent Groundwater Extraction and Treatment System
David Dedian, Woodard & Curran, 41 Hutchins Drive, Portland, ME US 04102, Tel: 207-774-2112, Email: ddedian@woodardcurran.com
Peter Herlihy, Applied Process Technology, Inc., P.O. Box 8005, West Chester, OH 45069-8005 US Tel: 513-759-5333, Email:  PHerlihy@aptwater.com

In September 1993, the New Hampshire Department of Environmental Services (NHDES) contracted with Woodard & Curran to operate the groundwater extraction and treatment system at the Keefe Environmental Services Superfund Site, a former solvent recycling facility.  At completion of the one year system start-up and prove-out, the treatment system was determined to be operational and functional and the 10-year Long-term Response Action (LTRA) period began for the federally funded remediation.  The contaminants of concern (COCs) were volatile organic compounds, and the selected remedy consisted of groundwater extraction followed by air stripping and vapor-phase carbon adsorption, and on-site discharge of treated effluent.  Site clean-up progress was proceeding well, and it appeared feasible to shut down the treatment system by the end of the LTRA.  However, in 2003 the USEPA requested that 1,4-dioxane be added to the analyte list, and analytical data subsequently indicated the widespread presence of 1,4-dioxane.  With less than six months remaining in the LTRA, the NHDES was faced with the dilemma of how to handle this new COC that the existing system was not able to treat.  The USEPA granted a nine month extension of the LTRA for evaluation, design, and installation of additional equipment that could efficiently treat 1,4-dioxane.  Four treatment alternatives were evaluated: 1) hydrogen peroxide/ozone oxidation, 2) hydrogen peroxide/UV oxidation, 3) photocatalytic destruction, and 4) activated carbon adsorption.  The first option was selected based on technical feasibility, effectiveness, and cost.  An Applied Process Technology HiPOx unit came on line in January 2005.  It has operated well and has complied with the NHDES effluent standard of 3 ug/l for 1,4-dioxane.  Rebound testing began in December 2006, and results to date indicate that limited rebound has occurred within the Groundwater Management Zone (GMZ), and 1,4-dioxane concentrations outside the GMZ have stayed below 3 ug/l. 

Remediation of TCE Plume Discharging to a Stream 
Paul M. Dombrowski, Metcalf & Eddy / AECOM, 701 Edgewater, Wakefield , MA 01880 , Tel: 781-224-6585, Fax: 781-224-6542, Email: paulm.dombrowski@m-e.aecom.com
Lucas A. Hellerich, PhD, PE, Metcalf & Eddy / AECOM, 860 North Main Street Extension, Wallingford , CT 06492 , Tel: 203-741-2821, Fax: 203-269-8788, Email: lucas.hellerich@m-e.aecom.com
Christopher A. Shores, Metcalf & Eddy / AECOM, 860 North Main Street Extension, Wallingford, CT 06492, Tel: 203-741-2821, Fax: 203-269-8788, Email: chris.shores@m-e.aecom.com
John L. Albrecht, LEP, Metcalf & Eddy / AECOM, 860 North Main Street Extension, Wallingford, CT 06492, Tel: 203-741-2826, Fax: 203-269-8788, Email: john.albrecht@m-e.aecom.com
Dave Hart, Noranda Metals Industries, Inc., P.O. Box 70, New Madrid, MO 63869, Tel: 573-643-6763,  Fax: 573-643-6715, Email: DHart@xstrata.ca

A TCE plume emanating from a former manufacturing facility, that covers an area of approximately 7 acres (TCE > 100 ug/L), eventually discharges into an unnamed wetland stream at concentrations as high as 2 mg/L.  The unnamed stream forms the downgradient receptor for the plume, and VOC concentrations decrease sharply in groundwater monitoring in wells located on the opposite side of the stream.  An investigation of stream sediment and sediment pore water at 50 foot intervals along the length of the stream was completed to assess where solvents are discharging to the stream.  In addition, stream flow measurements were collected on several dates and hydrogeologic data was collected from groundwater monitoring wells in the wetland area to estimate groundwater plume flow into the stream. 

The target cleanup criterion for the solvent plume is the groundwater discharging to surface water.  In accordance with state environmental regulations, alternative water quality protection criteria were developed for discharge of groundwater into the unnamed stream for use as remediation criteria.  The alternative criteria calculations were based on several lines of evidence including dilution ratio of measured flow rate in the stream and calculated groundwater plume flow; ratio of concentrations of chlorinated VOCs in groundwater monitoring wells alongside the stream to concentrations in surface water; and ratio of concentrations in sediment pore water to concentrations in surface water. 

Using the alternative water quality criteria, an in-situ enhanced biodegradation remediation plan was designed to treat the plume and mitigate impacts of TCE discharging to the stream.  The remedial approach consists of a series of biobarriers that will progressively treat contaminated groundwater as it travels through several of these zones such that remedial goals will be attained when groundwater reaches the discharge to the unnamed stream.  Using results from site-specific enhanced biodegradation pilot testing and groundwater flow modeling, the placement and sizing of the biobarriers in the wetland were designed to attain an anticipated cleanup time of 10 years.

An Integrated Site Wide Approach Chlorinated Solvent Source Remediation in an Active Manufacturing Facility
James R. Dickson, P.E., CTI and Associates Inc., 1202 West Washington Ave. (PO Box 276), Cleveland, WI 53015-0276, USA, Tel: 920-560-1820, Fax: 414-433-4812,Email: jdickson@cticompanies.com
Drew Lonergan, PG, CTI and Associates Inc., 12482 Emerson Drive, Brighton, MI 48116, USA, Tel: 248-264-4015, Fax: 248-486-5050, Email: dlonergan@cticompanies.comRob Stenson, CPG,  CTI and Associates Inc., 1202 West Washington Ave. (PO Box 276), Cleveland, WI 53015-0276, USA, Tel: 920-560-1820, Fax: 414-433-4812, Email: rstenson@cticompanies.com
Chris Winklejohn, P.E., CTI and Associates Inc., 12482 Emerson Drive, Brighton , MI 48116 , USA, Tel: 248-264-4038, Fax: 248-486-5050, Email:cwinklejohn@cticompanies.com

The discovery of chlorinated volatile organic compounds (CVOCs) in the aquifer underlying a manufacturing facility prompted the initiation of an aggressive voluntary site wide soil and groundwater cleanup. Given a large number of potential source areas within the plant, delineation of CVOC impacts to the unsaturated zone was performed by the installation of an innovative soil vapor extraction system, rather than performing extensive soil sampling within the operating manufacturing facility.  The system was designed with a pneumatically actuated valve manifold system to cycle the 120 extraction points which allowed for delineation of impacts, targeting hot spot source area removal, and overall contaminant reduction while remaining below regulatory discharge requirements, thereby eliminating the need for more costly air treatment.  The innovative system design reduced equipment size by 80% while improving system recovery by operating in the most productive range of the removal curve.  The groundwater remediation system, consisting of 6 extraction wells and 7 injection wells, is capable of extracting up to 600 gallons per minute (gpm) of groundwater.  Up to 200 gpm of the extracted groundwater is treated by shallow tray air strippers with subsequent discharge via NPDES permitted outfall and re-injection of up to 400 gpm of substrate augmented groundwater into the upgradient portion of the plume.  The net loss from the NPDES discharge provides capture and treatment of offsite groundwater downgradient of the site.  The groundwater remediation system operates as a closed loop bioreactor allowing downgradient microbial seed to be recycled into the up gradient heart of the plume to increase the rate and effectiveness of CVOC removal via reductive dechlorination.  Operations have so far have removed over 900 pounds of CVOCs from the unsaturated zone and over 1500 pounds CVOCs from the groundwater within the treatment zone.  Groundwater treatment is ongoing.