Fast-Track Remedial Design of Full-Scale ISCO Application Using Pilot Scale Testing and Field Screening Parameters
Paul M. Dombrowski, AECOM Environment, Wakefield, MA
Barbara A. Weir, AECOM Environment, Wakefield, MA
Kara M. Kelly, AECOM Environment, Wakefield, MA
James Brown, US EPA, Region 1, Boston, MA

A Multi-faceted Approach to Optimization of a Groundwater Remedial System       
Nigel D Tindall, CH2M HILL, Otis ANG Base, MA
Rose Forbes, Air Force Center for Engineering and the Environment, Otis ANG Base, MA  

Magnesium Corrosion and Stabilization/Solidification Effectiveness Using the Toxicity Characteristic Leaching Procedure      
Laura Nicklaus, Bradley University, Peoria, IL
Mariana Caffaro, Bradley University, Peoria, IL
Robert W. Fuessle, Bradley University, Peoria, IL
Max. A. Taylor, Bradley University, Peoria, IL

Status of In-Situ Thermal Remediation Technologies for CVOC DNAPL (with 3 examples)
Ralph S. Baker, TerraTherm, Inc., Fitchburg, MA 
Gorm Heron, TerraTherm, Inc., Keene, CA 
John M. Bierschenk, TerraTherm, Inc., Fitchburg, MA
John LaChance, TerraTherm, Inc., Fitchburg, MA 

DNAPL Remediation at Camp Lejeune Using ZVI-Clay Soil Mixing
Monica Fulkerson, CH2M HILL, Charlotte, NC     
Jessica Skeean, CH2M HILL, Charlotte, NC
Christopher Bozzini, CH2M HILL, Charlotte, NC
Gary Tysor, NAVFAC Mid-Atlantic, Norfolk, VA
Bob Lowder, Camp Lejeune EMD, Camp Lejeune, NC

Field-scale Pilot Test of a Reactive Core Mat to Address MGP Coal Tar Seepage
Sean M. Carroll, Haley & Aldrich, Inc., East Hartford, CT
James K. Barrett, Haley & Aldrich, Inc., Manchester NH
William J. Haswell, Haley & Aldrich, Inc., Manchester NH
Marc B. Okin, NiSource, Inc., Columbus, OH  

Fast-Track Remedial Design of Full-Scale ISCO Application Using Pilot Scale Testing and Field Screening Parameters

Paul M. Dombrowski, PE, AECOM Environment, 701 Edgewater, Wakefield, MA 01880, USA, Tel: 781-224-6585, Fax: 781-224-6542, Email: paulm.dombrowski@aecom.com
Barbara A. Weir, PhD, PE, LSP, AECOM Environment, 701 Edgewater, Wakefield, MA 01880, USA, Tel: 781-224-6585, Fax: 781-224-6542, Email: barb.weir@aecom.com
Kara M. Kelly, AECOM Environment, 701 Edgewater, Wakefield, MA 01880, Tel: 781-224-6585, Fax:781-224-6542, Email: kara.kelly@aecom.com
James Brown, PE, US EPA, Region 1, 1 Congress Street, Boston, MA 02114, USA, Tel: 617 918-1308, Fax: 617-918-1291, Email: brown.jim@epa.gov 

As a result of drum re-finishing operations, soil and groundwater at the Ottati and Goss Superfund Site in Kingston, NH are contaminated with chlorinated VOCs, BTEX, and 1,4-dioxane.  After re-evaluation of the selected remedy for groundwater, pump and treat, EPA changed the remediation approach to in-situ chemical oxidation (ISCO) through an Amended Record of Decision in September 2007, and at that time established a goal that the site attain construction complete status within one year, by September 2008. 

 Activated persulfate was selected as the chemical oxidant for its capability to oxidize 1,4-dioxane, in addition to the other VOC contaminants of concern.  Bench scale and field pilot scale testing were completed in three source areas to collect site-specific information to evaluate persulfate's ability to destroy site contaminant and optimize full-scale remediation design.  Base-activated persulfate was injected into two areas in December 2007, and pilot test injection was completed in a third source area in early February 2008.  Groundwater sampling for laboratory analysis was proposed for 6 and 12 weeks after injection; however, it was assumed during pilot test planning that the full-scale design would need to be completed before all laboratory results would be available.  To complete the design, an intensive evaluation of field geochemistry parameters and field screening chemical analysis was performed to assess radius of influence, oxidant persistence, and aquifer behavior.  Field screening analyses included residual persulfate via a permanganate titration, sulfate via spectrometry, and sodium via an ion-selective electrode.  The field screening and field geochemistry results were used heavily in completing the full-scale ISCO design.  When laboratory analytical results were reported, significant decreases in concentrations of chemicals of concern were noted in wells where geochemistry and field parameters were observed to change.  This presentation will cover pilot test planning, performance monitoring, and full-scale design for fast-track remediation.  The full-scale application was completed between July and September 2008, and was the third largest single-site application of persulfate performed to date.   

A Multi-faceted Approach to Optimization of a Groundwater Remedial System

Nigel D Tindall, P.G., CH2M HILL, 318D East Inner Road, Otis ANG Base, MA 02542-5028, Tel:  508-968-4670 x 5620, Fax:  508-968-4916, Email: ntindall@ch2m.com
Rose Forbes, P.E., Air Force Center for Engineering and the Environment, 322 East Inner Road, Otis ANG Base, MA 02542-5028, Tel:  508-968-4670 x 5613, Fax:  508-968-4476, Email:  rose.forbes@brooks.af.mil

The Air Force Center for Engineering and the Environment began remediating the Ashumet Valley groundwater contaminant plume in 1999 through the operation of an extraction, treatment and infiltration (ETI) remedial system.  The source of this volatile organic compound (VOC) plume at the Massachusetts Military Reservation was the disposal of treated wastewater from the former base sewage treatment plant between 1936 and 1995 and residuals from fire training activities.  Assessment of the performance monitoring data indicated that the efficiency of the ETI system was declining as the plume cleanup progressed.  System influent concentrations had shown steady declines since startup and the groundwater monitoring data suggested the plume was collapsing both vertically and horizontally in the aquifer, primarily due to the extraction stresses imposed by the remedial system.  Therefore, a remedial system optimization evaluation was performed with the primary objectives of determining an operational condition that: (i) shortened the plume cleanup timeframe and therefore the lifecycle costs of the system; (ii) improved the operational efficiency of the system as defined by reduced carbon usage (through increased treatment efficiency or reduced flow), reduced power consumption (through operating fewer wells or at reduced rates), and reduced well maintenance (in the event extraction wells could be shut off); and (iii) meets the remedial goal of restoring the aquifer within a reasonable timeframe with minimal impacts to the surrounding environment.  The optimization evaluation combined groundwater fate and transport modeling, piping system modeling, field flow testing, a hydraulic evaluation to provide validation of the modeling results, and an economic evaluation to assess system performance and potential cost savings.  This evaluation resulted in a revised operating condition for the ETI system that was accepted by the regulatory agencies and is predicted to return annual savings in excess of $200,000 through reduced power consumption, carbon usage, and system maintenance.

Magnesium Corrosion and Stabilization/Solidification Effectiveness Using the Toxicity Characteristic Leaching Procedure 

Student Presenter

Laura Nicklaus, Department of Civil Engineering and Construction, Bradley University, 1501 W. Main, Peoria, IL 61625, USA, Tel: 309-677-2778, Fax: 309-677-2867
Mariana Caffaro, Department of Civil Engineering and Construction, Bradley University, 1501 W. Main, Peoria, IL 61625, USA, Tel: 309-677-2778, Fax: 309-677-2867
Robert W. Fuessle, PhD, 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, PhD, 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.  Binders for S/S are frequently proprietary, but they often include Portland cement and pozzolans such as fly ash.  The advantages of using fly ash are twofold: a reduction in cost of materials as the waste fly ash partially replaces cement, and an improvement in the microstructure of the binder as the pozzolan reacts with calcium hydroxide to create additional calcium silicate hydrate (CSH).  CSH represents about 65% by volume of normal completely-hydrated cements.  CSH is largely responsible for concrete strength and impermeability. These potential improvements are offset by deleterious elements frequently found in hazardous wastes.  Past research in S/S has focused on regulated metals and their effects on cement microstructure.  However, less dangerous metals such as magnesium frequently found in hazardous wastes have not received the same level of scrutiny.  In recent years, research in cement has investigated the mechanisms of magnesium corrosion; magnesium reacting with CSH and destroying its durability.  Relatively high levels of magnesium may be found in certain cements, or it may penetrate cements from seawater or soils.  Magnesium is especially harmful in conjunction with sulfate, another common industrial waste component.  Recent research indicates that magnesium corrosion may be less harmful for cements without pozzolans.  This research investigates how magnesium and fly ash addition impacts S/S treatment effectiveness after short and long-term curing.

Status of In-Situ Thermal Remediation Technologies for CVOC DNAPL (with 3 examples) 

Ralph S. Baker, TerraTherm, Inc., 10 Stevens Road, Fitchburg, MA 01420, Tel: 978-343-0300, Fax: 978-343-2727
Gorm Heron, TerraTherm, Inc., 28900 Indian Point, Keene, CA  93531, Tel and Fax: 661-823-1620
John M. Bierschenk, TerraTherm, Inc., 10 Stevens Road, Fitchburg, MA 01420, Tel: 978-343-0300, Fax: 978-343-2727
John LaChance, TerraTherm, Inc., 10 Stevens Road, Fitchburg, MA 01420, Tel: 978-343-0300, Fax: 978-343-2727

We will review the principles of in situ thermal remediation (ISTR), including the dominant changes that occur in the physical and chemical properties of contaminants during heating, and methods for delivering heat and for recovery of the contaminants at the field scale.  Three case studies of treatment of chlorinated volatile organic compounds (CVOCs) will illustrate state-of-the-art ISTR field applications in fractured rock, tight clay and permeable sand aquifers.

The first case study is a deep fractured rock site in the Southeastern US, treated to 90 ft using In Situ Thermal Desorption (ISTD), which combines thermal conduction heating (TCH) and vacuum recovery.  The gneiss bedrock heated at least as fast as the overlying saprolite and fill material.  Target temperatures of 100°C were reached in the entire treatment volume, and approximately 15,000 lbs of TCE were removed.  TCE concentrations were reduced from DNAPL-levels to an average of 0.017 mg/kg in soil and rock samples, after 150 days of thermal treatment.

The second case study covers eight CVOC source areas treated simultaneously using ISTD/TCH at Dunn Field in Memphis, TN.  Funding was provided by the U.S. Air Force.  We treated a volume of 49,900 cubic yards of soil in 174 days of heating.  After removal of 12,500 lbs of CVOC mass, soil concentrations in all eight areas met the remedial standards.  Soil CVOC concentrations were reduced from levels as high as 2,850 mg/kg to below 1 mg/kg in all samples, with an overall mass reduction on the order of 99.99%.  Turnkey unit treatment costs were $80 per cubic yard.

The third case study presents a unique combination of steam-enhanced extraction (SEE) and TCH at a site in Denmark.  A thick PCE-impacted clay was heated by TCH, while an underlying high-yield aquifer was heated and treated using SEE.  The thermal remediation took place under an active, occupied dry cleaning facility.  Extremely limited access was overcome by the use of compact drilling machines and custom designed conveyance piping.  Again, stringent remedial goals were achieved.  A detailed survey confirmed that no significant settlement or damage to the building took place.

In situ thermal technologies have matured and consistent results are being produced using both TCH and SEE. It is now common that DNAPL source areas are completely restored, with removal of between 99 and 100% of the mass.

DNAPL Remediation at Camp Lejeune Using ZVI-Clay Soil Mixing

Monica Fulkerson, P.E., CH2M HILL, 11301 Carmel Commons Blvd, Suite 304, Charlotte, NC, USA, Tel: 704-544-4040, Fax: 704-544-4041, Email: Monica.Fulkerson@ch2m.com
Jessica Skeean, P.E, CH2M HILL, 11301 Carmel Commons Blvd, Suite 304, Charlotte, NC, USA, Tel: 704-544-4040, Fax: 704-544-4041
Christopher Bozzini, P.E., CH2M HILL, 11301 Carmel Commons Blvd, Suite 304, Charlotte, NC, USA, Tel: 704-544-4040, Fax: 704-544-4041
Gary Tysor, NAVFAC Mid-Atlantic, Norfolk, VA
Bob Lowder, Camp Lejeune EMD, Camp Lejeune, NC

Site 89 is the former Defense Reutilization and Marketing Office (DRMO) aboard Marine Corps Base Camp Lejeune in Jacksonville, North Carolina.  Historical activities at Site 89 resulted in the release of trichloroethene (TCE) and 1,1,2,2-tetrachloroethane (PCA).  The source area contamination extends to approximately 25 feet bgs.  The volume of contaminated soil in the source area is 30,000 cubic yards. There is approximately 31 tons of solvents within the treatment area.  From May through August 2008 the dense non-aqueous phase liquid (DNAPL) plume was treated using soil mixing with zero valent iron (ZVI) and bentonite. ZVI reacts with contaminants to destroy the contaminant compounds, while bentonite promotes uniform distribution of the ZVI during mixing and reduces the hydraulic conductivity of the source zone, so that contaminant discharge is reduced.

 A 10-foot diameter auger was used to mix soil while injecting the slurry of ZVI and clay. Treatability tests indicated the optimum mix was 2% ZVI and 3% clay. A total of 900 tons of ZVI and 1,082 tons of bentonite were mixed into 515 overlapping columns.  Off-gas was collected and treated with activated carbon.

Upon completion of the field activities, quarterly monitoring of soil and groundwater was initiated. After three months, the results of the treatment are encouraging, with up to 99.98 percent reduction of total VOCs in some locations and the average groundwater concentration being reduced by 92%. Monitoring will be complete in August 2009. This presentation will examine the results of the soil mixing application and provide lessons learned.

Field-scale Pilot Test of a Reactive Core Mat to Address MGP Coal Tar Seepage

Sean M. Carroll, Haley & Aldrich, Inc., 800 Connecticut Blvd., Suite 100, East Hartford, CT 06108-7303, USA, Tel: 860-290-3140, Fax: 860-290-3190, Email: scarroll@HaleyAldrich.com
James K. Barrett, Haley & Aldrich, Inc., 340 Granite St., 3rd Floor, Manchester NH 03102-4004, USA, Tel: 603-391-3317, Fax: 973-263-2580, Email: jbarrett@HaleyAldrich.com
William J. Haswell, Haley & Aldrich, Inc., 340 Granite St., 3rd Floor, Manchester NH 03102-4004, USA, Tel: 603-391-3304, Fax: 973-263-2580, Email: whaswell@HaleyAldrich.com
Marc B. Okin, NiSource, Inc., 200 Civic Center Drive, Columbus, OH 43215, USA, Tel: 614- 460-4722, Fax: 614-460-6971, Email: mokin@Nisource.com

Historical operation of Manufactured Gas Plant (MGP) sites typically generated oily and tarry byproducts. These MGP residuals have the potential to migrate to sediments (as LNAPLs and DNAPLs) into water bodies located adjacent to former MGP sites.  Remediation of such water bodies often must address both existing impacts in sediments and active seepage of tars, oils, and groundwater containing polycyclic aromatic hydrocarbons (PAHs) and volatile compounds such as benzene.

This is a status report on an ongoing field pilot demonstration of the use of a permeable Reactive Core Mat (RCM) containing an Organoclay absorbent to intercept coal tar seepage into a river adjacent to an MGP Site in northern Indiana.  The RCM pilot test is being conducted in conjunction with an in-situ soil solidification remedy of the source areas on the upland portion of the Site.  The goals of the pilot test are two-fold: to serve as a cost-effective, interim remedy to address coal tar seepage while the upland source remedy is installed and takes effect, and evaluate whether the RCM technology is appropriate as a longer term solution to blebbing & sheen conditions resulting from coal tar seepage.

This project began with extensive delineation of MGP impacts to the riverbed and sediments, including a river bottom survey, sediment sampling, Geoprobe sampling, Laser-induced fluorescence probing, and intensive observation of sheen activity on the river surface.  The Conceptual Site Model incorporates riverbed and overall Site geological conditions, which provided insight into the migration pathways through which DNAPL reaches the river.  Additional work is planned to assess the rate at which the absorptive capacity of the RCM is exhausted (either occupied with coal tar or bio-fouled), project the useful lifetime of the mat, and evaluate the feasibility of a larger scale implementation as part of a permanent Site remedy.

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