Uncertainty in Stabilization/Solidification Effectiveness Using the Toxicity Characteristic Leaching Procedure
Robert W. Fuessle, Department of Civil Engineering and Construction, Bradley University, Peoria, IL
Max. A. Taylor , Department of Chemistry and Biochemistry, Bradley University , Peoria , IL

Surfactant Enhanced Remediation of DNAPL Contaminated Soil and Groundwater Refinery Site Case Study
George A. Ivey, B.Sc., CEC, CES, CESA, Ivey International Inc., Campbell River, BC 
Martin Beaudoin, Sanexen Environmental Services Inc., Varennes , Quebec

Full Scale Implementation of Sulfate Enhanced Biodegradation to Remediate Petroleum Impacted Groundwater in Upstate New York
James F. Cuthbertson, P.E.,  Delta Consultants, Novi , Michigan
Mark Schumacher, Delta Consultants, Syracuse , New York

Field Comparison of Four Technologies to Treat TCE in Groundwater
Jessica Skeean, P.E., CH2M HILL, Charlotte , NC
Christopher Bozzini, P.E., CH2M HILL, Charlotte , NC
Monica Tiburzi, P.E., CH2M HILL, Charlotte , NC
Daniel Hood, NAVFAC Mid-Atlantic, Norfolk , VA
Bob Lowder, Camp Lejeune EMD, Camp Lejeune , NC

Comparison of BTEX Attenuation Rates under Anaerobic Conditions
Lyle Bruce, Ph.D., BP Remediation Management, Warrenville , IL

Case Studies:  Closing Solvent Sites Using Activated Carbon Impregnated with Iron
Thomas A. Harp, P.G., LT Environmental, Inc., Arvada , CO

Uncertainty in Stabilization/Solidification Effectiveness Using the Toxicity Characteristic Leaching Procedure
Robert W. Fuessle, Department of Civil Engineering and Construction, Bradley University, 1501 W. Main, Peoria, IL 61625, USA, Tel: 309-677-2778, Fax: 309-677-2867, Email: fues@bradley.edu
Max. A. Taylor, Department of Chemistry and Biochemistry, Bradley University, 1501 W. Main, Peoria, IL 61625, USA, Tel: 309-677-3026, Fax: 309-677-3023, Email: mtaylor@bradley.edu

Stabilization/Solidification (S/S) is designated by EPA as the “Best Demonstrated Available Technology” for 68 waste codes described by the Resource Conservation and Recovery Act, and it is the second most-used technology at Superfund sites.  EPA supports performance-based measurement systems in which the cost effectiveness and scientific defense of remediation designs is founded on the information and decision-making value of a representative data set.  The quality of the data should match its use in support of project goals and needs for S/S treatment.  This paper describes the effect of certain sources of error and variability on the determination by TCLP of treatment effectiveness of S/S samples aged with laboratory ambient air.  Sources of error and variability include material non-homogeneity, random placement due to mixing, chemical analyses, and curing age in ambient laboratory air.  Knowledge of the source and magnitude of these errors and variability can improve monitoring and risk assessment procedures for the long-term effectiveness of S/S treatment.  The importance of long-term assessments of S/S wastes is heightened by the risks and costs to future generations because of present hazardous waste treatment practices.  Potential migration of contaminants from S/S sites may contaminate surrounding soils and aquifers resulting in expensive remediation and threats to human health.  S/S is practiced world-wide because of its low cost and moderate technical requirements; hence the importance of long-term S/S assessments is further emphasized by potential risks and costs around the world.

Surfactant Enhanced Remediation of DNAPL Contaminated Soil and Groundwater Refinery Site Case Study
George A. Ivey, B.Sc., CEC, CES, CESA, Ivey International Inc., PO Box 706, Campbell River, BC  V9W 6J3, Canada, Tel:  250-923-6326, Fax:  250-923-0718, E-mail:  budivey@island.net
Martin Beaudoin, Sanexen Environmental Services Inc., 1471 Lionel-Boulet Blvd., Suite 32, Varennes, Quebec  J3X 1P7, Canada, Tel:  450-652-9990, Fax:  450-652-2290, E-mail:  mbeaudoin@sanexen.com.

This paper will focus on the in-situ application of surfactant technology at an active refinery site near Montreal , Canada . The surfactant was applied to improve the mass recovery of chlorinated contaminants resulting from an historical DNAPL spill that impacted local soil and groundwater. The client had attempted several remediation technologies at significant cost, without success, before attempting site remediation with surfactants. In brief, the surfactants increased the rate of contaminant mass recovery by greater than 800% - 1200% from the designated soil and groundwater DNAPL plume contamination that was posing a significant risk to a nearby municipal groundwater aquifer. 

The case study provides an overview of site conditions, sources and extents of contaminant plumes, in-situ surfactant system designs, installation, detailed mass recovery data, and the application process design resulting in significant time and cost savings for the client.

A brief overview of the surfactant technology, along with several graphical surfactant injection and contaminant recovery plots, with the associated mass recovery for individual chlorinated compounds, are also detailed within the paper

Full Scale Implementation of Sulfate Enhanced Biodegradation to Remediate Petroleum Impacted Groundwater in Upstate New York  
James F. Cuthbertson, P.E.,  Delta Consultants, 39810 Grand River Avenue, Suite C-100, Novi, Michigan, 48375, Tel: 248-699-0259, Fax: 248-699-0232, Email:  jcuthbertson@deltaenv.com
Mark Schumacher, Delta Consultants, 104 Jamesville Road , Syracuse , New York , 13214 , Tel: 315-445-0224, Fax: 315-445-0793, Email:  mschumacher@deltaenv.com

Anaerobic degradation is the dominant driving force in natural attenuation of petroleum contamination in the subsurface. The contribution to natural attenuation by electron acceptors other than oxygen, such as nitrate, iron III, manganese IV, sulfate, and even carbon dioxide, has been the subject of considerable research in recent years.  The addition of these alternative electron acceptors has been shown to have many potential advantages over the traditional approach of attempting to add dissolved oxygen to the plume.  Kolhatkar et al. (2000), Wiedemeier et al. (1999), and Wilson et al. (2002) have shown that of these natural anaerobic processes, sulfate reduction accounts for most of the degradation.  Cuthbertson et al. (2006 and 2007) presented case studies that demonstrated the benefits of using Magnesium Sulfate solution to stimulate the biodegradation of petroleum contaminants in groundwater under field conditions at various sites. 

Following a successful on site treatability study in 2005, full scale groundwater remediation using Delta’s Patented Sulfate Enhanced Biodegradation (SEB) process was initiated in 2006 at a large former service station and bulk storage facility in Upstate New York.  Applications of a concentrated solution of magnesium sulfate (Epsom Salt) in water were made in 2006 and 2007.  The applications were highly successful for remediation of MTBE, as well as, other petroleum constituents.  The results obtained from this site represent the first field scale demonstration of MTBE remediation utilizing this technique.  A detailed evaluation of the results of this remedial effort along with the associated costs will be presented. 

Field Comparison of Four Technologies to Treat TCE in Groundwater
Jessica Skeean, P.E., CH2M HILL, 4824 Parkway Plaza Blvd Suite 200 , Charlotte , NC 28277 , Tel: 704-329-0073, Email:  Jessica.Skeean@ch2m.com
Christopher Bozzini, P.E., CH2M HILL, 4824 Parkway Plaza Blvd Suite 200 , Charlotte , NC 28277 , Tel: 704-329-0073, Email: Chris.Bozzini@ch2m.com
Monica Tiburzi, P.E., CH2M HILL, 4824 Parkway Plaza Blvd Suite 200 , Charlotte , NC 28277 , Tel: 704-329-0073, Email:  Monica.Tiburzi@ch2m.com
Daniel Hood, NAVFAC Mid-Atlantic, Norfolk , VA
Bob Lowder, Camp Lejeune EMD, Camp Lejeune , NC , Email:  Robert.A.Lowder@usmc.mil

Site 89 at Camp Lejeune , North Carolina , is the former Defense Reutilization and Marketing Office (DRMO). Historic operations used or stored various industrial solvents, such as trichloroethene (TCE) and 1,1,2,2‑pentachloroethane (PCA). These historic operations resulted in significant site contamination. The dissolved groundwater plume at the site covers approximately 7.2 acres and has TCE and PCA concentrations up to 21,000 micrograms per liter (mg/L) and 14,000 mg/L, respectively. Due to the large volume of contaminated groundwater and potentially high remedial cost, four technologies were field tested to select the best approach to address the groundwater plume. The four technologies evaluated were Enhanced Reductive Dechlorination (ERD) substrate injections, Ferox™ injections, air sparging via horizontal well, and permeable reactive barrier (PRB).

The ERD study consisted of injecting a blend of 50 percent sodium lactate and 50 percent of emulsified oil at four locations from 10 to 25 feet below ground surface (bgs) using direct push technology. The Ferox™ study used pneumatic fracturing to inject zero valent iron (ZVI) from 12.5 to 25 feet bgs at four locations. The air sparge study included installation of a horizontal directionally drilled well approximately 600 feet long, with 250 feet of screen at 40 feet bgs. After operating the air sparge system for 3 months, pneumatic fracturing was completed in four borings above the sparge well, and the system was operated for an additional 3 months. The PRB study involved the installation of a 210‑foot-long, 2-foot-wide, and 25-foot-deep “wall” containing a mixture of 40 percent compost and 60 percent aggregate.

Groundwater monitoring was conducted for a 6-month period to evaluate contaminant reduction. TCE reduction ranged from nil (Ferox™) to 90 percent and greater (air sparge, ERD substrate injections, and within the PRB). The greatest zone of influence observed was approximately 60  feet (air sparging).

Comparison of BTEX Attenuation Rates under Anaerobic Conditions
Lyle Bruce, Ph.D., BP Remediation Management, 28100 Torch Parkway, Warrenville, IL 60555, Tel: 630-836-7104, Email: lyle.bruce@bp.com
Arati Kolhatkar, M.S., BP Remediation Management, 501  Westlake Park Boulevard, Houston ,TX 77079, Tel: 281-366-5596, Email:  arati.kolhatkar@bp.com
Jim Cuthbertson, P.E., Delta Consultants, 39810 Grand River, Suite C-100, Novi, MI 48375, Tel: 248-699-0259, Email: jcuthbertson@deltaenv.com

Over the last decade data have been published that demonstrate that natural attenuation of hydrocarbons in the subsurface is dominated by anaerobic processes.  Some data have indicated that benzene is recalcitrant; some have shown it degrades but at a slower rate than alkyl benzenes (primarily TEX ) under anaerobic conditions.  Many natural attenuation studies have pointed to the sequential order of attenuation.  This paper evaluated data from four sites in the Midwestern U.S. ( Illinois , Indiana, Michigan , and Missouri ) that explain and contrast existing impressions.  Although the actual attenuation rates varied from site to site, primarily dependent upon the relative availability of electron acceptors, data from these sites indicated that attenuation of BTEX compounds under anaerobic conditions is concurrent.  The benzene attenuation rate appeared to be a function of the relative abundance of TEX.  The ratios of attenuation rates between the compounds, however, appear to be relatively constant within certain brackets.  For example, of the BTEX compounds, toluene appears to attenuate at the highest rate followed by benzene which tends to attenuate at rates between 50 and 75% of toluene, xylenes which attenuate at rates between 30 and 100% of toluene (which may be dependent upon which xylenes are most abundant), and lastly ethylbenzene which attenuates at rates 10 to 50 percent as high as toluene.  These were observed at both natural and sulfate-enhanced attenuation sites. 

Case Studies:  Closing Solvent Sites Using Activated Carbon Impregnated with Iron
Thomas A. Harp, P.G., LT Environmental, Inc., 4600 West 60th Avenue, Arvada, CO 80003, Tel: 303-433-9788, Fax: 303-433-1432, Email: tharp@LTEnv.com

Sites impacted by even extremely high concentrations of chlorinated solvents are being closed using a specially-prepared, activated carbon impregnated with an iron salt that is pyrolized into nano-sized deposits of porous, metallic iron.  Contaminants are adsorbed by the carbon catalyst and quickly and efficiently treated via reductive dechlorination by the iron.  Until the advent of this new trap-and-treat technology (BOS 100®), reactive iron alone was the material most commonly used to induce reductive dechlorination.  Although effective in reducing “mother products” such as perchloroethene or trichloroethene (TCE), placing “raw iron” in the subsurface can result in slow or incomplete treatment because the period of time in which the solute and iron are co-located is primarily dependant upon seepage velocities.  If the contact time is insufficient, then the dechlorination process can be prematurely interrupted leaving derivative “daughter products” (e.g. vinyl chloride) that can cause greater health risks and/or increase cleanup costs.  These deficiencies are avoided by the innovative combination inherent to BOS 100® in that the carbon carrier ensnares the initial contaminant (and continues to hold kinetically-generated byproducts) during the cleanup cycle.  The resident solutes are then reduced to innocuous end products via adequate contact with the interstitial iron.

When the carbon-iron injectate is placed in the subsurface where chloroethenes/chloroethanes and elemental iron co-exist in the carbon pore network, the dechlorination process is a surface reaction whereby iron molecules are oxidized and the chlorine molecules are replaced by hydrogen molecules derived from hydrolyzed slurry water.  The rate of reaction is dictated by the local concentration of the solute and the amount of available surface area of the iron.

As chloroethenes/chloroethanes diffuse into the carbon, the solute concentrations within the pore network are substantially higher than concentrations that existed in the surrounding soil or groundwater.  Thus, the rates of dechlorination within the activated carbon are significantly faster than rates commonly observed using reactive iron alone or other dechlorinating reagents due to the concentrating effect and the substantial surface area offered by the reactive iron.  The final step in the dechlorination sequence is the generation of end-product hydrocarbons (ethene or ethane) which, due to very high vapor pressures and low affinity, escape the matrix and allow for “fresh” contaminant to be adsorbed by the carbon catalyst. 

LT Environmental, Inc. has pioneered the TerraCert™ program for implementing remedies using this carbon-iron injectate.  The remedies have resulted in the closure of or the initiation of closure monitoring at all contracted sites in months rather than years.  Case studies involving field-scale applications include a former industrial facility in Denver , Colorado where initial groundwater concentrations of TCE in the percent level, i.e. 1,280,000 parts per billion (ppb), were reduced to concentrations below the maximum contaminant level of 5 ppb.  Half of the 2.3 acre plume was closed under the Colorado State Voluntary Cleanup Program in just 20 months (which included one year of closure monitoring).  A 2-year, closure-monitoring program has commenced on the remaining portion of the plume, where a no-further-action determination is expected by the end of 2009.