Dr. Ralph Baker, Dr. Gorm Heron and Mr. John LaChance, TerraTherm, Fitchburg, MA

In-Situ Thermal Remediation (ISTR) comprises several robust technologies that have been proven to be able to clean up DNAPL source zones in a wide range of subsurface settings.  These include Steam Enhanced Extraction (SEE), Electrical Resistance Heating (ERH) and In-Situ

Thermal Desorption/Destruction (ISTD).  This workshop will present the following topics:

• overview of temperatures achieved in the field; 

• physicochemical mechanisms underlying ISTR technologies; what happens to the NAPL?; 

• in-situ destruction reactions; 

• how to optimize operations to achieve maximum remedial efficiency; 

• overview of SEE, ERH, ISTD, and combined approaches, including Dynamic Underground Stripping (DUS); 

• case studies of SEE, ERH, DUS and ISTD, including both low and high-temperature applications; 

• how to choose the optimal heating technique for a site, including data needed for technology screening, cost evaluation, and design.   

10) Applied Chemical Fingerprinting in Environmental Forensics  

Scott A. Stout, Gina M. Plantz, Gregory S. Douglas, and Stephen Emsbo-Mattingly, NewFields Environmental Forensics Practice LLC, Rockland, MA

Growth in the application of environmental forensics continuously expands the depth of our understanding about the sources, fate and transport of man-made chemicals in soil, sediment, water, and air.  This workshop reviews fundamental chemistry and forensic data analysis techniques used in the study of (1) volatile and semi-volatile hydrocarbons associated with petroleum fuels and MGP tars and (2) polychlorinated biphenyls (PCBs).  Illustrative case studies reliant upon a high-quality chemical fingerprinting data interpreted in light of site-specific conditions, regulatory history, and the environmental processes affecting chemical fingerprints (e.g., weathering and partitioning) will be presented on subjects that include:

• Gasoline fingerprinting and age-constraining

• Fingerprinting soil gas and indoor air

• Distillate fuel fingerprinting and age-constraining

• Distinguishing PAH sources in soils and sediments 

• Fingerprinting electric insulating fluids / PCB weathering  

11) Utilization of Stable Isotopes in Environmental and Forensic Geochemistry Studies   

Paul Philp, University of Oklahoma

Stable carbon and hydrogen isotopes have been used for many decades in the petroleum industry but the development of combined gas chromatography-isotope ratio mass spectrometry (GCIRMS) has lead to a virtual explosion in applications of this technique not only in petroleum exploration but in the environmental and forensic geochemical fields. This workshop will present an introduction to stable isotope geochemistry and discuss applications of stable isotopes to various environmental problems, including their potential for monitoring attenuation of volatile compounds such as PCE, MTBE, BTEX, etc. Topics to be covered will include an introduction to the concept of stable isotopes, with particular attention to carbon, hydrogen, and, to a lesser degree, chlorine. Techniques for determination of bulk isotope values will be described along with the advantages and disadvantages of the GCIRMS approach.  

Examples on the use of bulk isotopic data combined with other techniques such as GC or GCMS for the purpose of determining whether or not contaminants are related to each other or not will be given. This is particularly important where there might be multiple sources potentially responsible for a particular spill and it is necessary to see whether any of them were actually responsible for the spill. In cases where the contaminant has multiple components, and the GC and GCMS data are not particularly useful for correlation purposes, relationships between source and product might only be determined through the stable isotopes of individual compounds. GCIRMS is also extremely valuable for single component contaminants, such as MTBE or PCE, where GC and GCMS will be of no use for correlation. In this workshop, particular emphasis will be placed on the chlorinated compounds. There are a number of examples that have already been published where GCIRMS has been used to both differentiate sources of PCE/TCE as well as studying natural attenuation at the contaminated sites. These examples will be discussed in detail.  

Most of the applications of stable isotopes to environmental problems have been limited to the use of carbon, and to a lesser extent, hydrogen isotopes. However efforts are also being used to introduce the use of chlorine isotopes as an additional tool for monitoring the chlorinated compounds. The approach is not as mature as the use of carbon and hydrogen isotopes but the methodology involved will be discussed along with problems associated with the use of chlorine isotopes.

Finally the use of the various fingerprinting techniques described above in monitoring attenuation at sites undergoing remediation will be discussed. The combined use of the stable isotopes, GC and GCMS can be extremely valuable tools monitoring remediation as well as determination of the onset of natural attenuation.

12) Professional Ethics, Professional Conduct, and Environmental Professionals  

Dr. Gail Batchelder, Technical Director of Hydrogeology, Loureiro Engineering Associates; Robert C. Luhrs, Senior Manager, Remedial Programs, Raytheon Company; and Janine Commerford, Assistant Commissioner, Bureau of Waste Site Cleanup, MassDEP

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