Environmental Forensic Characterization of Chlorinated Hydrocarbon Sources
Richard C. Bost, Environmental Resources Management, Houston, TX

Use of PCB Congener and Homolog Analysis in Source Apportionment at a Rail Yard Superfund Site
Eric Butler, Gradient Corporation, Cambridge, MA

Assessing the Extent and Distribution of a Crude Oil Spill in Chalmette, Louisiana following Hurricane Katrina- The Role of Chemical Fingerprinting
Scott A. Stout, Newfields, Rockland, MA

Using the Abiotic Transformation Rate of 1,1,1-Trichloroethane to Estimate the Date of Discharge
Richard D. Britton, The Whitman Companies, Inc., East Brunswick, NJ

Integrated PAH Profiles and Compound-Specific Stable Carbon Isotope Analysis for Identifying Sources of PAH in Urban Background near Former MGP Sites
David Mauro, META Environmental, Inc., Watertown, MA

Perchlorate Forensics - Sources and Investigation Methods: Theory and Application for Identification of New Sources

Ioana G. Petrisor, Robert D. Morrison, DPRA, Inc. 100 E San Marcos Blvd, Ste 308 , San Diego, CA  92069, Tel: 760-752-8342 ext 12; Fax: 760-752-8377, Email:  Ioana.Petrisor@DPRA.com

Perchlorate is rapidly gaining dominance as a global contaminant of the 2000’s. Although manufactured and used for a long time (since 1940s in the U.S.), perchlorate has only recently emerged as contaminant of concern, in close connection with the advances in knowledge and analysis methods. The increasing number of perchlorate detections in water wells, vegetal and animal products, its alleged health impacts at low concentrations potentially affecting human metabolism, along with its environmental persistence and travel-capacity in water without retardation are all concurring, transforming the way we visualize the impact of perchlorate in the environment. Environmental forensics plays an important role in any investigations concerning perchlorate but our understanding of the sources and environmental fate of perchlorate is still limited.

This presentation will review the known sources of perchlorate (both natural and anthropogenic) and the available forensic techniques.  Finally, the application of such knowledge in a forensic investigation leading to the discovery of a new source of perchlorate in Southern California will be presented and discussed. The main forensic techniques applicable to perchlorate include: stable isotopic analysis (³⁷Cl/³⁵Cl, ⁸⁷Sr/⁸⁶Sr, ¹⁶O/¹⁷O), surrogates analysis, historical information assessment (aerial photography, propellant use and chemistry, firing range usage), geologic analysis, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The application of some of these methods in a recent forensic investigation resulted in the identification of a new source of naturally occurring perchlorate associated with the Mission Valley Formation outcrop in San Diego California (a carbonate rich marine layer).  Modification of existing agricultural soil sampling techniques USDA 60-6(26) and USDA 60-6(27a) were used for sample preparation along with EPA Standard Method 314.0 for extract analysis.  No statistical relationship between major ions (sulfate, total nitrate, chloride) and perchlorate in soil was identified. The discovery of naturally occurring perchlorate in the marine layer within the Mission Valley Formation, CA in addition to its presence in Texas and New Mexico suggests that large portions of the southern United States or similar areas (i.e., semi-arid) may contain natural sources of perchlorate.

Environmental Forensic Characterization of Chlorinated Hydrocarbon Sources

Richard C. Bost, Environmental Resources Management, 15810 Park Ten Place, Houston, Texas 77084, Tel: 281-600-1218, Email: rick.bost@erm.com
Robert Perry, Environmental Resources Management, 15810 Park Ten Place, Houston, Texas 77084, Tel: 281-600-1218

Environmental Forensics entails the application of various potential techniques for identifying and characterizing the historical sources of releases at sites with hazardous substances in the soil and/or ground water.   They can be particularly useful in better characterizing chlorinated solvent sites. The techniques include 3-D examination of historical aerial photographs, chemical fingerprinting, interviews, research of historical documents and industrial processes, waste volume calculations, degradation studies and fate and transport evaluations.  Currently, efforts are underway via an ASTM standards development subcommittee to develop guidance for the application of environmental forensic techniques.  The authors are reviewers involved in the process and offer this paper to illustrate the importance of these techniques in scoping site characterization and remedial evaluation studies and, in particular, in characterizing sources of chlorinated hydrocarbons.  By understanding the source of the chlorinated hydrocarbons, one can better interpret the effects of disposal and natural degradation processes on the material and predict the ultimate fate of the material at a site.

This paper provides an overview of how the field of environmental forensics has evolved and examples of various techniques to illustrate their application. The authors will provide examples of the misapplication of these techniques and note the importance of developing multiple lines of evidence to support conclusions. A recent case example of the application of these techniques in the identification, characterization and assessment chlorinated hydrocarbons is given to illustrate the importance of the techniques.  These techniques were applied as part of site characterization and remedial evaluations and are discussed from both a technical and legally defensible perspective.

Use of PCB Congener and Homolog Analysis in Source Apportionment at a Rail Yard Superfund Site

Eric L. Butler, Gradient Corporation, 20 University Road, Cambridge, MA, Tel:  617-395-5000, Fax:  617-395-5001, Email:  ebutler@gradientcorp.com
Tarek Saba, Exponent®, Inc., 3 Clock Tower Place, Suite 205, Maynard, MA 01754, Tel:  978 461-1233, Fax:  978 461-1223, Email:  tsaba@exponent.com

After almost two decades of cleaning up the PCB contamination at the Paoli Rail Yard, SEPTA, Conrail and Amtrak resolved their allocation claims against American Premier Underwriters (APU), the successor corporation to Penn Central, the prior owner/operator of the rail yard.  Chemical analyses, records research, worker testimony, and other evidence were woven into a persuasive cost allocation that resulted in a recovery of $38 million.  Congener specific chemical fingerprinting of the PCB molecules found in the soil at the Rail Yard:  confirmed the Aroclor identification of historical investigations; found little weathering of either Aroclor 1254 or 1260; and confirmed that the vast majority (over ninety percent) of the PCBs were of a chemical formulation which dated from the Penn Central era, i.e., before 1976.  Applying a two-end member mixing model, both the congener analysis and the homolog analysis yielded equivalent results as to the relative proportion of Aroclor 1254 and 1260 present in the soil.  These scientific findings, coupled with an allocation model which took into account the rail car histories and worker practices at the Yard, led to the historic settlement.  Another key contribution was the testimony of several retired railroad engineers, who revealed a keen memory of the historic use and handling of PCBs at the site, including the deliberate PCB dumping there, which took place during the early Penn Central era. 

Assessing the Extent and Distribution of a Crude Oil Spill in Chalmette, Louisiana following Hurricane Katrina - The Role of Chemical Fingerprinting

Scott A. Stout, NewFields, 100 Ledgewood Place, Suite 302, Rockland, MA 02370, Tel: 781-681-5040, Fax: 781-681-5048, Email: sstout@newfields.com
Glenn C. Millner, Center for Toxicology and Environmental Health, LLC, 615 W. Markham St., Little Rock, AR 72201, Tel: 501-614-2834, Fax: 501-614-2835, Email: gmillner@cteh.com
Dyron Hamlin, Center for Toxicology and Environmental Health, LLC, 615 W. Markham St., Little Rock, AR 72201, Tel: 501 614-2834, Fax: 501 614-2835, Email: dhamlin@cteh.com
Bo Liu, NewFields, 100 Ledgewood Place, Suite 302, Rockland, MA 02370, Tel: 781 681-5040, Fax: 781 681-5048, Email: bliu@newfields.com

Floodwater associated with the Hurricane Katrina’s storm surge (August 29, 2005) displaced and damaged a 250,000 gallon above ground storage tank at Murphy Oil Corporation’s Meraux Refinery in Chalmette, Louisiana.  Crude oil was released and was dispersed into the nearby and evacuated residential and commercial area by the retreating floodwaters.  The circumstances of this oil spill investigation are unprecedented – as was the subsequent environmental assessment.  The assessment, which began September 18, involved biased sampling and “chemical fingerprinting” of interior and exterior wipe samples (from the visually-evident “bathtub rings” on structures) and interior and exterior sediments from over 3000 homes, businesses, churches, and schools.  Crude oil from the failed tank was thoroughly characterized using chemical fingerprinting.  Over 10,000 Tier 1 (GC/FID) chromatographic (EPA Method 8015B) analyses were conducted as a means of mapping the overall lateral extent, concentration, and continuity of the crude oil impact.  These Tier 1 GC/FID analyses – when evaluated spatially using Geographic Information System (GIS) – largely revealed the extent of crude oil contamination in the area – as well as the widespread occurrence of (1) non-crude oil, petroleum-derived contamination (e.g., engine lube oils, hydraulic oils, diesel fuel, household lubricants) and (2) allochthonous natural organic matter (e.g., peat and plant materials) from surrounding marshes that was carried and dispersed by the floodwater.  More advanced Tier 2 fingerprinting, involving quantitative petroleum biomarker data generated using GC/MS-SIM (modified EPA Method 8270), was conducted on a selected subset of samples.   When the biomarker-based diagnostic ratios were evaluated statistically using the revised Nordtest oil spill identification protocol (Daling et al., 2002), the presence/absence of the crude oil, even at concentrations below residential standards, was established.  This information was used to develop and govern a settlement and remedial program with the affected property owners, and to defend against claims brought by unaffected parties.

Using the Abiotic Transformation Rate of 1,1,1-Trichloroethane to Estimate the Date of Discharge

Richard D. Britton, P.G., The Whitman Companies, Inc. 116 Tices Lane, Unit B-1, East Brunswick, NJ 08816, Tel: 732-390-5858, Fax: 732-390-9496, Email: Rbritton@whitmanco.com

The primary contaminant identified in a shallow water-bearing zone at an industrial site located in Central New Jersey was 1,1,1-Trichloroethane (TCA).  The discharge date of TCA to ground water was established in order to evaluate the legitimacy of an insurance coverage claim. 

The age of TCA in ground water was determined by employing the fact that when dissolved in water, TCA is transformed chemically (abiotically) into 1,1-Dichloroethene (1,1-DCE) via an elimination reaction, and acetic acid (HAc) via hydrolysis.  The reaction yields 22% 1,1-DCE and 78% HAc.     

The transformation rate (k) is a function of temperature ( ) where A and E are constants, and K is the temperature in degrees Kelvin.

Using the first order rate equation, , where C_t is the concentration of TCA at any time t, and C_o represents the initial TCA concentration at t=0, and then using the 1,1-DCE/TCA concentration ratio measured during ground water sampling to derive the C_o/C_t TCA ratio, the age of TCA in ground water (t) for each of thirteen monitoring wells was calculated.

The calculated age of TCA in each monitoring well was then subtracted from the sampling date to arrive at the date that TCA was first dissolved in ground water. 

The earliest discharge date using this method was April 1984.  The average discharge date using ground water data from three different ground water sampling events spanning a forty month period was July 1985 with a standard deviation of 9.5 months. 

Potential interferences using this method include anaerobic biodegradation of TCA to 1,1-Dichloroethane (1,1-DCA) and production of 1,1-DCE from the biodegradation of Trichloroethene (TCE).  However, these interferences were not a concern due to low TCE concentrations observed at the site, and the absence of anaerobic conditions as indicated by the presence of high dissolved oxygen concentrations and the absence of vinyl chloride.

Integrated PAH Profiles and Compound-Specific Stable Carbon Isotope Analysis for Identifying Sources of PAHs in Urban Background near Former MGP Sites

David Mauro, META Environmental, Inc., 49 Clarendon Street, Watertown, MA, 02472, Tel: 617-923-4662, Email: dmauro@metaenv.com
Diane Saber, Gas Technology Institute, Des Plains, IL

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