Long Term TCE Source Area Remediation using Short Term Emulsified Edible Oil Substrate (EOS^(R)) Recirculation
M. Tony Lieberman, Solutions Industrial & Environmental Services, Inc., Raleigh, NC

Real-Time DNAPL Source Delineation Using the Triad Approach
Michael A. Singletary, Navel Facilities Engineering Command, North Charleston, SC

Surgical Implementation of Blast Fractured Bedrock Trench Technology at an Active Chemical Plant
Richard H. Frappa, Geomatrix Consultants, Inc., Amherst, NY

How Clean Can It Get?- Critical Review of Mechanisms and Results Achieved Using Thermal Remediation and Where You can Go Wrong
Gorm Heron, TerreTherm, Inc., Bakersfield, CA

"Low-Quality" Steam injection To Enhance Conventional In Situ Remedial Technologies
Daniel Groher, ENSR International, Westford, MA

Yakima Valley Spray Facility Cleanup

Richard H. Bassett, Washington State Department of Ecology Toxics Cleanup Program, 15 W. Yakima Avenue, Suite 200, Yakima, WA, 98902-3452, Tel: 509-454-7839, Fax: 509-575-2809, Email: rbas461@ecy.wa.gov

A pesticide formulator-distributor, Yakima Valley Spray (YVS), operated in Yakima, Washington from 1908 to 1974.  A large bulk fuel distributor operated immediately next to YVS during a similar timeframe.    A remedial investigation conducted on these properties identified more than sixty contaminants, pesticides, hydrocarbons, volatile organic compounds, and metals that had been released to the soil and groundwater.  Nine indicator contaminants would eventually drive the cleanup.  The greatest health and environmental threats in soil and groundwater were aldrin, dieldrin, and arsenic.

Site groundwater annually fluctuates from 13 to 21 feet below ground surface.  An annual 60 degree direction change in flow occurs too.  From an irrigation influence, groundwater fluctuations created a ‘smear zone’ that contributed contaminants to downgradient receptors.  Site cleanup was complicated by contamination under two storage buildings, under two adjacent railroad spurs, an upgradient unknown source of perchloroethylene, a sewer line, buried fuel tanks, and an irrigation canal.  A two-year break occurred after the remedial investigation when the site became a Washington State Legislature ‘pilot’ site.

The Cleanup Action Plan gave the responsible parties options of (1) minimal excavation with long-term bioventing and biosparging, or (2) maximum excavation to low winter groundwater.  The parties chose maximum excavation as the cheaper alternative and to expedite facility cleanup.

A consent decree was signed between the ten responsible parties and the State of Washington.  Building demolition, temporary track removal, and excavation occurred from January, 2004, to May, 2004.  Excavation and transport of about 80,000 tons of contaminated soil to appropriate landfills occurred.  Still to be completed are two years of quarterly confirmation samplings and analyses from 17 monitoring wells to determine the success of the source removal.  Cleanup cost is estimated at 10-12 million dollars.

Long Term TCE Source Area Remediation using Short Term Emulsified Edible Oil Substrate (EOS^®) Recirculation.

M. Tony Lieberman, RSM, Solutions Industrial & Environmental Services, Inc., 3722 Benson Drive,   Raleigh, NC 27609, Tel: 919-873-1060, Fax: 919-873-1074, Email: tlieberman@solutions-ies.com
Dr. Robert C. Borden, P.E., Solutions Industrial & Environmental Services, Inc., 3722 Benson Drive, Raleigh, NC 27609, Tel: 919-873-1060, Fax: 919-873-1074, Email: rcborden@solutions-ies.com
Christie Zawtocki, P.E., Solutions Industrial & Environmental Services, Inc., 3722 Benson Drive,      Raleigh, NC 27609, Tel: 919-873-1060, Fax: 919-873-1074, Email:  czawtocki@solutions-ies.com
Ira May, Army Environmental Center, SFIM-AEC-CDT, 5179 Hoadley Road, Aberdeen Proving Ground, MD  21010-5401, Tel: 410-436-3152, Fax: 410-436-1548, Email: ira.may@us.army.mil
Clifton C. Casey, P.E., Naval Facilities Engineering Command, Southern Division, 2155 Eagle Drive, North Charleston, SC 29419-9010, Tel: 843-820-5561, Email: cliff.casey@navy.mil

Solutions Industrial & Environmental Services, Inc. (Solutions-IES) designed effective treatment approaches using emulsified edible oil substrate (EOS^®) to remediate trichloroethene (TCE) source areas at two Department of Defense installations.  Each site posed unique design challenges and permitting constraints.  The Army Environmental Center retained Solutions-IES to treat a 10,000 ft² source area, approximately 15 feet thick, at the former Tarheel Army Missile Plant in Burlington, NC.  At this site, the low concentrations of TCE and related contaminants were present in complex saprolite with low well yields and subsurface structures were located nearby.  Solutions-IES’ ESTCP-funded pilot test at the Naval Weapons Station in Charleston, SC is located in a heavily wooded area with higher contaminant concentrations, a low yielding aquifer and shallow groundwater gradient.

At each site, temporary recirculation systems were used to spread EOS^® throughout the desired treatment zone.  The systems were designed to minimize operation and maintenance needs and were effective in smearing the substrate throughout the subsurface as evidenced by increased levels of total organic carbon in the aquifer.  Decreased DO and ORP levels confirmed that anaerobic reducing conditions were quickly established at both sites.  Corresponding decreases in TCE were also observed.  At the Tarheel Army Missile Plant, TCE concentrations were reduced from 1,690 µg/L to non-detectable levels within 2 months of the EOS^® injection.  Six months post-injection at the Charleston Naval Weapons Station TCE concentrations have been reduced from 18,700 µg/L to 4,300 µg/L.  The pilot tests clearly show the effectiveness of EOS^® for treating TCE-contaminated groundwater in a variety of source area configurations. 

Real-Time DNAPL Source Delineation Using the Triad Approach

Michael A. Singletary, Southern Division, Naval Facilities Engineering Command, P.O. Box 190010, North Charleston, SC, 29419, Tel: 843-820-7357, Fax: 843-820-7465, Email: michael.a.singletary@navy.mil.
Michael J. Maughon, Southern Division, Naval Facilities Engineering Command, P.O. Box 190010, North Charleston, SC, 29419, Tel: 843-820-7422, Fax: 843-820-7465, Email: michael.maughon@navy.mil.
Maxie R. Keisler, Southern Division, Naval Facilities Engineering Command, P.O. Box 190010, North Charleston, SC, 29419, Tel: 843-820-7322, Fax: 843-820-7465, Email: maxie.keisler@navy.mil.

A focused, real-time investigation of a dense non-aqueous phase liquid (DNAPL) source zone was conducted at the Solid Waste Management Unit 1 (SWMU1), Naval Air Station Pensacola, Florida.  During the 1950’s and 60’s, SWMU1 received industrial waste from painting and electroplating operations.  Chlorinated solvents, including trichloroethene (TCE), were released to the subsurface from drying beds used to dewater sludges generated by wastewater treatment processes.  DNAPL is suspected to be present as disconnected residual at the base of the unconfined aquifer at 40 to 44 feet below ground surface.  In 1998-99, approximately 10,000 gallons of hydrogen peroxide/iron catalyst solution were injected into the aquifer as part of a source reduction strategy to reduce TCE levels below the default natural attenuation concentrations established by the state regulatory agency.  Within two years of hydrogen peroxide injection, TCE concentrations rebounded to initial levels.  Based on an evaluation of remedy effectiveness, it appeared that poor remedy performance was due to incomplete characterization of the DNAPL source zone as well as the short-lived nature of the oxidant solution.  As part of an on-going optimization study of the SWMU1 groundwater remedy, a focused characterization study was planned using the Triad Approach as guidance.  A direct-push rig equipped with a membrane interface probe (MIP) for DNAPL detection and an electrical conductivity detector for soil stratigraphy mapping was used to delineate the zone of DNAPL residual.  The number and location of data collection points were decided by a team of scientists and engineers as the investigation progressed based upon the collection of real-time data and a continuously updated conceptual site model.  Following the initial MIP survey, a mobile laboratory, capable of producing data of quality equal to that of a fixed-base laboratory, was used to collect confirmation samples during the same mobilization.  By combining the use of field analytical techniques with more traditional fixed-based laboratory methods in a single field mobilization, the DNAPL source zone was delineated at considerable cost savings, while still achieving project data quality objectives.

Surgical Implementation of Blast Fractured Bedrock Trench Technology at an Active Chemical Plant

Richard H. Frappa, P.G., Geomatrix Consultants, Inc., 90B John Muir Drive, Suite 104, Amherst, NY, 14228, Tel: 716-565-0624, Fax: 716-565-0625, Email: rfrappa@geomatrix.com
Paul F. Mazierski, Dupont Corporate Remediation Group, Buffalo Avenue & 26^th Street, Niagara Falls, NY, 14302, Tel: 716-278-5496, Fax: 716-408-9426, Email: Paul.F.Mazierski@usa.dupont.com
Craig T. Taylor, URS Corporation, 77 Goodell Street, Buffalo, NY  14203, Tel: 716-923-1332, Fax: 716-856-2545, Email: Craig_Taylor@urscorp.com
Daniel M. Sheldon, URS Diamond, Buffalo Avenue & 26th Street, Niagara Falls, NY, 14302, Tel: 716-278-5170, Fax: 716-408-9434, Email: Daniel.M.Sheldon@usa.dupont.com

An Administrative Consent Order (ACO) executed by the New York State Department of Environmental Conservation (NYSDEC) required enhancement of the hydraulic efficiency of the existing Groundwater Remediation System (GWRS) at a large, active chemical plant located in New York State.  A technology assessment identified groundwater recovery from blast-enhanced fractured bedrock trenches (BFBTs) as the preferred remedial option to improve control of a chemical plume in approximately 5 acres of the southwestern portion of the Plant.  BFBTs have proven to be effective in hydraulically controlling the spread of groundwater contamination, however, technology implementability in a chemical plant setting in close proximity to vibration sensitive processes and equipment owned by a business other than the property owner presented significant technical challenges.  A Pilot Scale Technology Demonstration (PSTD) was implemented at the Plant to demonstrate that the technique would not only facilitate hydraulic control of groundwater, but could be implemented safely without impacting Plant equipment or structures.

A significant aspect of the demonstration included an extensive assessment of peak particle velocities (PPV) and ground vibration frequency to assess vibrations produced by blasting.  PSTD blast vibration monitoring involved: an assessment of background vibration levels at the Plant, on-site blast vibration level predictions produced during blasting, and real-time monitoring of blast vibrations during the PSTD for comparison to predicted blast vibration levels.  Real-time vibration monitoring was used to evaluate design parameters for the blast program.  The PSTD was successful and provided information required to implement full scale design for safe, bedrock blasting within 25-feet of sensitive Plant chemical operations and directly beneath high voltage power transmission lines.

The PSTD and full-scale technology implementation produced two, 200-foot long BFBTs.  Although originally intended as an enhancement, analysis of hydraulic performance data indicated that higher BFBT pumping rates may actually serve to replace operation and maintenance (O&M) of nearly a dozen conventional pumping wells in the existing GWRS.  Benefits of the blast-fractured bedrock trenches include increased mass removal, more efficient formation of continuous hydraulic capture zones, and significantly lower O&M costs compared to the existing GWRS.  This work demonstrates the safety and predictability of detonating explosives to create blast-fractured bedrock trenches in sensitive settings, thereby potentially increasing use of this technology in maintaining cost-effective, long-term hydraulic control at process sensitive industrial operations.

How Clean Can it Get? – Critical Review of Mechanisms and Results Achieved using Thermal Remediation – and Where You can go Wrong

Gorm Heron, TerraTherm, Inc., 10554 Round Mountain Road, Bakersfield, CA 93308, Tel. and Fax: (661) 387-0610, Email: gheron@terratherm.com
Ralph S. Baker, TerraTherm, Inc., 356 Broad Street, Fitchburg, MA 01420, Tel: 978-343-0300, Fax: 978-343-2727, Email: rbaker@terratherm.com
John M. Bierschenk, TerraTherm, Inc., 356 Broad Street, Fitchburg, MA 01420, Tel: 978-343-0300, Fax: 978-343-2727, Email:jbierschenk@terratherm.com
John C. LaChance, TerraTherm, Inc., 356 Broad Street, Fitchburg, MA 01420, Tel: 978-343-0300, Fax: 978-343-2727, Email: jlachance@terratherm.com

Recently, results from sites that were heated and treated using thermal remediation have indicated impressive removal rates for dense non-aqueous phase liquid (DNAPL) source zones in soil and groundwater.  Results from both a DOE site (Young-Rainey STAR Center), and an industrial facility in the Midwest, have been published, stating mass removal efficiencies in the 99.9 percent range. Soil concentrations below or near non-detect are reported, and groundwater concentrations near or below MCL have been observed inside the original source zones. These results appear almost unrealistic, considering the recalcitrant nature of DNAPLs in the subsurface, long-term diffusion processes, heterogeneity of most source zones, and frequently raised questions about DNAPL capture at thermal sites. Other site reports, particularly from sites where Electrical Resistance Heating was used, have reported much less impressive results, sometimes less than 90% mass removal. As more data is emerging, it is becoming evident that thermal remediation spans a wide range of heating methods, and that applications vary from very robust, effective systems to poorly designed and ineffective systems.

This presentation will review the mechanisms behind thermal remediation critically, focusing on exactly what happens at the pore and micro-scale, as well as larger scale during heating. It will review ways for the contaminants to be contacted, vaporized, transported under various gradients, and show the most proper design for vapor recovery and capture systems. Several typical design flaws will be presented, in an attempt to explain why not all thermal projects have achieved the success made possible by the theory. Finally, a list of typical quality control issues are provided – hopefully leaving the audience with direction for better evaluating thermal remediation proposals and applicability. The authors have worked on approximately 20 field-scale sites where steam enhanced remediation, electrical resistance heating, and thermal conduction heating have been implemented.

“Low-Quality” Steam Injection To Enhance Conventional In-Situ Remedial Technologies

Daniel Groher, PE, ENSR International, 2 Technology Park Drive, Westford, MA, 01886, Tel: 978-589-3030, Fax: 978-589-3705, Email: dgroher@ensr.com
Timothy Adams, PG, ENSR International, 27755 Diehl Road, Warrenville, IL, 60555, Tel: 630-836-1700, Fax: 630-836-1711, Email: tadams@ensr.com

Conventional remediation technologies such as soil vapor extraction (SVE), multi-phase extraction (MPE), and groundwater pump and treat can be thermally‑enhanced to achieve remedial closure objectives that might otherwise be infeasible or too slow.  Thermal enhancement can help mobilize light non-aqueous phase liquids (LNAPLs) that are otherwise too viscous to effectively recover; can increase the volatility of target compounds to increase the mass rate of vapor extraction; and can accelerate in-situ biodegradation.  Thermal enhancement can be distinguished from thermal remediation by the scale and cost of the heating processes.  Full-scale thermal remediation tends to add 100’s to 1,000’s of kilowatt-hours of energy per cubic yard (KWH/yd³) of soil to increase subsurface temperatures in the treatment volume to greater than 212°F.  These high temperatures and aggressive heat input are often required to reach very stringent treatment goals and/or destroy contaminants in-situ, typically in  low permeability soil.  In contrast, thermally-enhanced remediations tend to require heat inputs of 10 to 100 KWH/yd³ and may only increase subsurface temperatures by 20° to 100°F.  The lower energy input for thermally-enhanced remediation often has lower capital and operational costs than full-scale thermal remediation.  However, thermal enhancement is most appropriate for a more select range of soil conditions and more flexible remedial objectives.  

ENSR has successfully applied low-quality steam (i.e., low temperature and pressure) at three sites with heat input less than 30 BTU/hr/yd³, including: (1) product recovery of No. 6 fuel from a site undergoing re-development in Massachusetts; (2) MPE remediation of chlorinated solvents in groundwater in Illinois; and (3) SVE of toluene and styrene in a former industrial setting in Massachusetts.  These remedies will be contrasted with higher heat input full‑scale thermal remediation applications.

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