Estimating the Timing of a Chlorinated Solvent Release: A Case Study
David Langseth, Gradient Corporation, Cambridge, MA

Polycyclic Aromatic Hydrocarbon Characterization in Differing Watersheds in Northwest Ohio
Deanna M. Bobak, University of Toledo, Toledo, OH

DNA Fingerprinting- Tools of Tomorrow's Forensics
Ioana G. Petrisor, DPRA Inc, San Marcos, CA

Environmental Forensic Methods for Soil Gas and Vapor Intrusion Investigations
Stephen Emsbo-Mattingly, NewFields Environmental Forensics Practice, LLC, Rockland, MA

Differentiation of PAHs from Coal, Creosote, and Combustion-related Background Sources in Stream Sediments
Helder J. Costa, Blasland, Bouck & Lee, Inc., New Bedford, MA

Is this Diesel Mine?:  Advances in Forensic Identification of Petroleum Related Releases into the Environment

Ken Scally, ALcontrol Laboratories Ireland, Unit 18a, Rosemount Business Park, Ballycoolin, Dublin 11, Ireland, Tel: 00-353-1-8829893, Fax 00-353-1-8829895, Email: ken.scally@alcontrol.ie 
Paul Nathanail, Land Quality Management, University of Nottingham, UK, Email: paul@lqm.co.uk
Jim Jones, ALcontrol Laboratories Chester, Chester Street, Saltney, Chester, CH4 8RD, England, Tel: 0044-1244-671121, Fax 0044-1244-683306, Email: jim.jones@alcontrol.co.uk 
Myles Keogh, Galway-Mayo Institute of Technology (GMIT), Dublin Road, Galway, Ireland, Tel: 00-353-91-753161, Fax: 00-353-91-751107, Email: myles.keogh@gmit.ie 
Gay Keaveney, Galway-Mayo Institute of Technology (GMIT), Dublin Road, Galway, Ireland, Tel: 00-353-91-753161, Fax: 00-353-91-751107, Email gay.keaveney@gmit.ie

Recent developments in forensic hydrocarbon fingerprint analysis have enabled specific markers found in diesel to be characterized and identified.  The fingerprinting and data interpretation techniques include the recognition of distribution patterns of hydrocarbons (alkylated naphthalene, phenanthrene, dibenzothiophene, fluorene, chrysene and phenol isomers); analysis of “source-specific marker” compounds (individual saturated hydrocarbons, including n-alkanes (n-C₅ through n-C₄₀), alkylcyclohexane, homologues series, recalcitrant isoprenoids: pristane and phytane); the determination of diagnostic ratios of specific petroleum and non-petroleum constituents; and the application of various statistical and numerical analysis tools (Compound Ratio Analysis Technique (CORAT)).  A spill sample was analysed to identify the possible source and origin of the diesel.  Samples were subjected to analysis by Iatroscan, and gas chromatography, utilising both flame ionisation and time of flight mass spectral detection techniques (TOF-MS) in comparison to known reference materials.  The analysis showed that the diesel came from the suspected source which allowed the regulator to prosecute.

Estimating the Timing of a Chlorinated Solvent Release: A Case Study

David Langseth, Gradient Corporation, 20 University Road, Cambridge, MA 02138, Tel: 671-395-5536, Fax: 617-395-5001, Email: dlangseth@gradientcorp.com
Andrew Nicholson, Geomega Environmental Consulting, 2995 Baseline Road, Suite 202, Boulder, CO 80303, Tel: 303-938-4083, Fax: 303-938-8123, Email: andrew@geomega.com

Soil and ground water samples on- and off-site implicated a solvent recycling facility as the source of chlorinated solvents on and downgradient of the facility in soil and ground water.  The timing of the releases, however, was a factor in determining liability for remediation at the site.  In particular, whether the releases occurred before or after 1990 was in question.  The primary solvents released at the facility were believed to be PCE, TCE, and 1,1,1-TCA.  Four methods were used to assess the likely timing of the releases.  The site operational history, focusing on materials handling and spill control procedures, was evaluated.  Second, locations at which contamination was found were evaluated in the context of the site development and grading history.  Third, transport rates in the vadose and saturated zones were evaluated to determine the likely time required for chlorinated solvents to move from the source locations to the locations at which they were found in samples from monitoring wells and surface water.  Fourth, a sequential degradation model incorporating both biotic and abiotic degradation pathways was used to estimate the amount of time chlorinated solvents in ground water had been undergoing degradation.  Degradation rates were estimated from a combination of site and literature data.  The abiotic degradation rate of 1,1,1-TCA to 1,1-DCE was based on rates reported in the literature, and other degradation rates were constrained by a rates reported in the literature taken in context of the site geochemical conditions.  The model was calibrated by varying degradation rates, within appropriate constraints, until the variation in the estimated time of degradation for compounds reported in each well was minimized.  These four methods each supported the hypothesis that there were significant chlorinated solvent releases prior to 1990. 

Polycyclic Aromatic Hydrocarbon Characterization in Differing Watersheds in Northwest Ohio

Deanna M. Bobak, The University of Toledo, Department of Earth, Ecological and Environmental Sciences, 2801 W. Bancroft Street, MS #604, Toledo, OH 43606-3390, Tel: 419-530-2009, Fax: 419-530-4421, Email: dbobak@utnet.utoledo.edu
Dr. Alison L. Spongberg, The University of Toledo, Department of Earth, Ecological and Environmental Sciences, 2801 W. Bancroft Street, MS #604, Toledo, OH 43606-3390, Tel: 419-530-4091, Fax: 419-530-4421, Email: alison.spongberg@utoledo.edu

Polycyclic aromatic hydrocarbons (PAH) are ubiquitous contaminants traceable to both pyrogenic (natural) and anthropogenic (human-related) sources.  Characterization of their sources can be determined using a modified method described by Stout et al. (2001).  PAH contamination was characterized in three unique watersheds in Northwest Ohio.  Otter Creek, deemed a dead stream, is an Area of Concern in Lucas County that has been highly altered from its original wooded character by human activities.  Seven miles long, it passes through urban and industrial areas to empty into Maumee Bay and Lake Erie.  The Maumee River, carrying the highest sediment load in the region, passes through rural, agricultural areas.  The Ottawa River, also an Area of Concern, runs through industrial areas and municipal landfills.  Sediment samples taken from both the river bottoms and 15 cm depths were collected in late 2004 and early 2005 from several sites along the waterways.  The relative abundances of specific branched and unbranched PAH compounds denote their industrial, petrogenic, or biogenic origins.

DNA Fingerprinting - Tools of Tomorrow’s Forensics

Ioana G. Petrisor, DPRA Inc., 100 San Marcos Blvd., Suite 308, San Marcos, CA 92069, Tel: 760-752-8342 ext.12; Fax: 760-752-8377, E-mail: Ioana.Petrisor@dpra.com

Microorganisms, being ubiquitous in any environment, extremely diverse and versatile, may record any effect of present or past contamination. Finding the right tools to look into microbial changes in environment will offer powerful forensic methods. Modern DNA fingerprinting techniques, using PCR reaction to amplify the targeted gene require tiny amount of sample, may be automated and are very specific, providing such forensic tools. To date, in forensic studies, DNA fingerprinting techniques are commonly used to track down criminals, test the parentage of children, and to follow the evolution of species.  In environmental forensics, DNA fingerprinting is yet to be used. So far, the study and monitoring of microbial communities in different contaminated environments based on DNA fingerprinting methods have been well established and applied. Based on such studies, the changes induced by different contaminants may be monitored, too. Since microbial communities contain groups with ability to metabolize basically any contaminant present, specific changes or shifts in microbial population will be induced by specific contaminants. The potential to track the passage of contaminants even long time after they are gone by DNA fingerprinting of a certain gene responsible for metabolizing the contaminant, is very high. So is the potential of tracking the source and age of contamination.

This presentation will review some of the main DNA fingerprinting methods available (PCR based) to monitor microbial changes in the environment with potential environmental forensics applicability. Some practical applications of DNA fingerprinting technique in criminal forensics and environmental studies will be also presented. It is our hope and conviction that such methods will be the basis for developing standardized forensic techniques of tomorrow, applicable in any environment and for any contaminants.

Environmental Forensic Methods for Soil Gas and Vapor Intrusion Investigations

Stephen Emsbo-Mattingly, M.S., NewFields Environmental Forensics Practice, LLC, 100 Ledgewood Place, Suite 302, Tel: 781-681-5040
Kevin McCarthy, B.S., NewFields Environmental Forensics Practice, LLC, 100 Ledgewood Place, Suite 302, Tel: 781-681-5040
Allen Uhler, Ph.D., NewFields Environmental Forensics Practice, LLC, 100 Ledgewood Place, Suite 302, Tel: 781-681-5040
Scott Stout, Ph.D., NewFields Environmental Forensics Practice, LLC, 100 Ledgewood Place, Suite 302, Tel: 781-681-5040
Gregory Douglas, Ph.D., NewFields Environmental Forensics Practice, LLC, 100 Ledgewood Place, Suite 302, Tel: 781-681-5040

Powerful methods are available for differentiating hydrocarbon contaminated soil gas from ambient chemicals in indoor air.  However, the techniques used during many soil gas and indoor air quality assessments lack a standard approach that can differentiate household chemicals from vapor derived from subsurface hydrocarbon contamination.  Consequently, environmental contaminants like benzene from in-house sources could be inaccurately attributed to emission from subsurface NAPL.  This problem becomes even more complex in the presence multiple subsurface vapor plumes derived from fugitive gasoline, fuel products, and tar.  The primary obstacle is that standard methods for characterizing the composition of indoor air, potential sources, and background air do not adequately measure a sufficient number of chemicals to accurately determine makeup and—and hence sources—of chemicals found in indoor air.

The selection of appropriate analytical methods is critically important in the source identification of indoor air chemicals.  Standard Methods such as EPA TO-14 that are used for measuring regulated compounds include few of the diagnostic hydrocarbons required for source identification and differentiation purposes.  As a result, the application of standard methods must be extended to include additional compounds needed for source identification purposes.  In addition, the sensitivity of the standard methods must be increased to detect diagnostic compounds at low concentrations approximately 1,000 times lower than most site assessment techniques.   Recent advances in measurement methods using EPA TO-15 have demonstrated critical improvements in sensitivity and analyte richness for improved hydrocarbon source identification.  Two case studies demonstrate the improved capability of TO-15 enhancements for the differentiation of gasoline, diesel and tar vapors from background signatures in indoor air.

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