Deep Soil Amendment Alternative for Foundation Construction & Treatment of LNAPL Impacted Soil Deposits
Brandon J. Fagan, Haley & Aldrich, Inc., Boston, MA

Remediation of Trichloroethene DNAPL and Groundwater Plume Using Enhanced Anaerobic Degradation Technology and Natural Attenuation
Charla Reinganum, P.E., Phoenix Environmental Associates, Inc., Highland Park, IL

Electrical Resistance Heating of Soils at C-Reactor at the Savannah River Site
Robert Blundy, Washington Savannah River Company

An Overview of CERCLA Process Remedial Action for a Navy Base Realignment and Closure (BRAC)-closed Facility Site
Scott Gromko, U.S. Navy, BRAC PMO West, San Diego, CA

Nanomaterials for Remediation: Applications and Implications
Brenda E. Barry, ENSR, Westford, MA

The Effect of Coal Tar on Geomemberane/Geosynthetic Clay Liners in Coal Tar Impacted Soil

Adam P. Chen, Joe A. Chittet, Joel D. Krueger, Burns & McDonnell Engineering, Inc., 1431 Opus Place, Suite 400, Downers Grove, Illinois 60515, Tel: 630-724-3200, Fax: 630-724-3201
Joan V. Gonzalez, Burns & McDonnell Engineering, Inc., 1431 Opus Place, Suite 400, Downers Grove, IL 60515, Tel: 630-724-3200, Fax: 630-724-3201
Amine Dahmani, Ph.D, Hanibal Tayeh, Ph.D, Spectrum Analytical, Inc., 11 Almgren Drive , Agawam , MA 01001 , Tel: 800-789-9115, Fax: 413-789-4076

Vertical containment barriers have often been considered for use at former manufactured gas plant (MGP) sites as an interim measure or as a permanent remedy to contain coal tar dense non-aqueous phase liquid (DNAPL), coal tar impacted soils and/or groundwater. The design and implementation of these vertical containment barriers must be carefully considered to meet site remediation objectives and site conditions.  Traditionally sheet pile walls were the standard protocol when it came to installing a vertical barrier.  However, the rising cost of steel and associated installation costs have made this option economically undesirable.  Recent advances in technology have introduced alternative media such as geomembrane/geosynthetic liners (GM/GSL).  Unfortunately, selecting an appropriate GM/GSL is very difficult due to a lack of chemical compatibility data between the commercially available GM/GSL and coal tar DNAPL.  This paper presents a compatibility study conducted to evaluate different GM/GSL for their compatibility with coal tar DNAPL.

The study simulated the emplacement of the GS/GSL in the granular unit that is impacted with coal tar DNAPL and determined the effect of coal tar DNAPL interaction with the GS/GSL.   The GS/GSL were evaluated based upon both visual observations such as deformation and breakage and laboratory tests such as tensile strength and tear resistance.  Nine (9) different commercially available GM/GSL were evaluated in the study.  This paper will explain the containment approach, present the design elements of the containment and compatibility testing, and discuss the results of the chemical compatibility studies conducted in the laboratory.

Deep Soil Amendment Alternative for Foundation Construction & Treatment of LNAPL Impacted Soil Deposits

Brandon J. Fagan, PG, LSP, Mark Balfe, P.E, Haley & Aldrich, Inc., 465 Medford Street, Suite 2200, Boston, MA 02030, Tel: 617-886-7400, Fax: 617-886-7791

State building code allowances limited construction of a building addition on filled soils with spread footings.  Construction of the structure over a 4-acre LNAPL plume would limit future access to remediation.  Site conditions included a 9 foot deep urban fill soil deposit over a conductive glacio-fluvial formation abutting a four story historic building. The site area was underlain by a weathered No. 6 fuel oil LNAPL plume impacting soils at a depths of 13 to 18 feet below ground surface.  Existing building foundations constructed with dry field stone foundations supporting the institutional building represented potential building instabilities with excavation.

Selected treatment under the proposed building to establish a permanent solution was evaluated after exhaustive evaluations of alternative locations.  Facing limitations on capacity for services in the dining area/facilities, design development was undertaken to institute combined soil strength improvement of the fill, foundation reinforcement and in-situ solidification/immobilization of the LNAPL source utilizing jet grouting techniques.  Environmental considerations for soil solidification for performance validation of LNAPL treatment utilized an alternative to TCLP analysis - a modified ANSI 16.1 Static Leaching Procedure to validate t jet grout soil excavation in addition to  replacement of the LNAPL soil horizon with a low permeability grout mix (k<10^-6 cm/s). 

Success of the project was measured based on treated soils meeting MA Method 1, S-1 soil standards.  The soil treatment was validated based on extractable petroleum hydrocarbon (EPH) procedures and analysis and comparison of the residual saturation of the solidified matrix with field samples. Building underpinning using the same solidification mix met soil strength improvement to excesses of 300 psi unconfined compression strength without building movement.   The fill matrix was stabilized from jetting for building construction with spread footings matching existing foundation depths and structural design soil bearing capacity of 0.5 tsf for a 2 story addition.

Remediation of Trichloroethene DNAPL and Groundwater Plume Using Enhanced Anaerobic Degradation Technology and Natural Attenuation  

Charla Reinganum, P.E., Phoenix Environmental Associates, Inc., 530 Audubon Place , Highland Park, IL  60035, Tel: 847-266-0650, Fax: 847-266-0651
Curtis R. Michols, Abbott Laboratories, 200 Abbott Park Road, Dept. 539, AP52-S, Abbott Park, IL 60064-6212, Tel:  847-937-0863, Fax: 847-937-9679
Michael Stanforth, P.E., Excel Environmental Associates, PLLC, 625 Huntsman Court, Gastonia , NC 28054, Tel:  704-853-0800, Fax: 704-853-3949

Enhanced in situ reductive dechlorination of a TCE DNAPL source and 900-foot TCE groundwater plume using a combination of HRC^® and HRC-X™ was performed at a former pharmaceutical facility over a 46-month treatment period.  The maximum observed initial TCE groundwater concentration in the source area was 390,000 µg/L, despite eight years of prior remediation efforts that included a pump and treatment system.  Initially, 39,600 lbs of HRC® were injected into 133 borings in a combination of a grid and barrier applications covering a 40,000 ft², treatment area.  After 18 months, 31,290 lbs of HRC‑X™ were injected into 123 injection borings that expanded the treatment area to cover approximately one third of the total plume area.  Groundwater performance monitoring has been performed plume-wide throughout the treatment period.  The maximum observed TCE groundwater concentration after the 46-month treatment period has been reduced to 29,000 µg/L and the calculated total mass of TCE (sorbed and dissolved) in the most heavily impacted portion of the plume, approximately 16,000 ft², has been reduced by 90%.  The reduction in the TCE mass fits a first‑order degradation model extremely well, with a R² value of 0.92.  Complete degradation of TCE within the groundwater plume has been demonstrated based on observed reductions in the total molar concentration of TCE and its daughter compounds and the detection of ethene in post-application groundwater samples.  Site-specific BIOCHLOR groundwater modeling and empirical data indicate that intrinsic reductive dechlorination is robust in the downgradient portions of the TCE plume.  A natural attenuation remedy based on site-specific source area TCE point decay rate constants and groundwater modeling is planned to meet the state TCE groundwater standard of 2.8 µg/L near the downgradient property boundary and achieve site closure.

Electrical Resistance Heating of Soils at C-Reactor at the Savannah River Site

Robert Blundy, Washington Savannah River Company, Savannah River Site, Tel: 803-952-6788, Fax: 803-952-6628  
Michael R. Morgenstern, Bechtel Savannah River Co., Tel: 803-952-6698, Fax: 803-952-6628          
Joseph A. Amari, Bechtel Savannah River Co., Tel: 803-952-6698, Fax: 803-952-6628
Anna Marie M. Herb, Savannah River National Laboratory, Tel: 803-725-1942, Fax: 803-725-9753
Mark E. Farrar, Savannah River National Laboratory, Tel: 803-725-1786, Fax: 803-725-1744
Terry P. Killeen, Washington Savannah River Co., Tel: 803-952-6850, Fax: 803-952-6849 
Paul A. Eisenstat, Bechtel Savannah River Co., Tel: 803-952-6467, Fax: 803-952-9268

Chlorinated solvent contamination of soils and groundwater is a significant problem at the Savannah River Site, and originated as by-products from the nuclear material process.   Five nuclear reactors at the Savannah River Site (SRS) produced special nuclear materials for the nation’s defense program throughout the cold war era.  An important step in the process was thorough degreasing of the fuel and target assemblies prior to irradiation.  Discharges from this degreasing process resulted in significant groundwater contamination that would continue well into the future unless a soil remediation action was performed.  The largest reactor contamination plume originated from C-Reactor and an interim action was selected in 2004 to remove the residual trichloroethylene (TCE) source material by electrical resistance heating (ERH) technology.  This would be followed by monitoring to determine the rate of decrease in concentration in the contaminant plume.  Because of the existence of numerous chlorinated solvent sources around SRS, it was elected to generate in-house expertise in the design and operation of ERH, together with construction of a portable ERH system that could be deployed at multiple locations around the site.  This paper describes the waste unit characteristics, the ERH system design and operation, together with extensive data accumulated from the first deployment adjacent to the C-Reactor building.  The installation heated the vadoze zone down to 62 feet bgs over a 60 day period during summer of 2006 and raised soil temperatures to over 200 oF.  A total of 730 lbs of TCE were removed over this period and subsequent soil sampling indicated a removal efficiency of 99.4%.

An Overview of CERCLA Process Remedial Action for a Navy Base Realignment and Closure (BRAC)-closed Facility Site

Scott Gromko, U.S. Navy, BRAC PMO West, 1455 Frazee Road, Suite 900, San Diego, CA 92108, Tel: 619-532-0933, Fax: 619-532-0995, Email: david.gromko@navy.mil

Take a series of ditches used for stormwater control, four different property owners, numerous regulatory agencies, stakeholders and community members – then throw in denizens including sensitive species , contaminants such as Aroclor-1260 and 1254, DDT and lead, and a tight cleanup window, and you have Site 27, the “Northern Channel.”  Site 27 is one of several sites making up the BRAC-closed facility, former Naval Air Station Moffett Field, located adjacent to   Mountain View , Calif.   Since base closure in 1994, the Navy has been removing contamination in the soils, such as PCBs and lead, left over from Navy activity dating back to 1933.  Contamination from the stormwater drainage system and flood control system had migrated and settled in the sediment and posed a threat to the western pond turtle, killdeer and burrowing owl, among others.  The environmental investigation and restoration at Site 27 were conducted as part of the Navy’s Installation Restoration Program and carried out under the authority of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA).  This process began in 2001 and included working closely with the four property owners and regulatory agencies, while keeping the public informed and gathering their comments.  Using a traditional “dig and haul” method, the Navy began cleanup of the site in 2006, but because the site still functions as a stormwater drainage system, the sediment had to be removed during the dry months.  Project planning and implementation required the utmost efficiency and on-the-ground creative solutions to unexpected problems.  This presentation will describe the design, construction methods, disposal techniques and teamwork that accomplished removal of approximately 85,000 cubic yards of sediment right on time.  Through it all, strong working relationships with the property owners and regulatory agencies have been maintained and the project objectives were met.  More importantly, the environmental benefits demonstrate the viability of well-planned and collaborative cleanup efforts.

Nanomaterials for Remediation: Applications and Implications

Brenda E. Barry, ENSR, 2 Technology Drive, Westford, MA 01886, Tel. 978-589-3075, Fax 978-589-3100, Email: bbarry@ensr.aecom.com
Betsy Ruffle, ENSR, 2 Technology Drive, Westford, MA 01886, Tel. 978-589-3071, Fax 978-589-3100, Email: bruffle@ensr.aecom.com
Art Taddeo, ENSR, 2 Technology Drive, Westford, MA 01886, Tel. 978-589-3095, Fax 978-589-3100, Email: ataddeo@ensr.aecom.com

Nanotechnology is a current source of exciting and novel materials with numerous potential applications for remediation of contaminated soils and water. Nanomaterials (NM) include an array of engineered materials that, by definition, are designed and produced to have at least one dimension that is 100 nanometers (nm) or less (1,000 times smaller than the width of a human hair). The variety of NM that have been used or are in development for remediation purposes include nanoscale zerovalent iron, reactive nanoscale iron particles, dendritic NM and carbon nanotubes (CNT) embedded within filtration media; some of their applications include removal of contaminants, such as chlorinated hydrocarbons and arsenic, as well as water filtration, purification and desalination. However, the unique NM properties that contribute to both their beneficial aspects and their potential toxicity are the enhanced reactivity due to the large surface area relative to size and the fact that even common elements like carbon behave differently at the nanoscale level. An important question that emerges regarding application of NM for remediation is whether their use will present new and unanticipated risks for human health and the environment. This presentation will review the types of NM that can be used for remediating soils and water, results of case studies using specific NM, recent information on NM toxicology, and up-to-date positions of federal agencies regarding potential risks for the use of NM. Understanding both the benefits and risks of these new NM can inform good-decision-making regarding the use of these innovative materials to address environmental concerns.

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