E NVIRONMENTAL TRENDS & TECHNOLOGIES

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1 E NVIRONMENTAL TRENDS & TECHNOLOGIES Co Published by DPRA Inc. and ZymaX Forensics Laboratories Spring 2010 In This Issue: ZymaX Forensics Gains U.S. EPA s Recognition by Using Carbon, Chlorine and Hydrogen Isotopes in Chlorinated Solvent Investigations Fuel Fingerprinting Part II: Middle Distillates, pg.2 Use of Stable Isotopes to Aid Site Remediation, pg.3 ZymaX Forensics Gains U.S. EPA s Recognition by Using Carbon, Chlorine and Hydrogen Isotopes in Chlorinated Solvent Investigations By Yi Wang, PhD The 2009 fall meeting of U.S. EPA s Technical Support Project (TSP) was held jointly with the annual meeting of the State Coalition for the Remediation of Drycleaners (SCRD) in San Antonio, TX. For the 3 day meeting, the TSP and SCRD pooled training resources and exchanged information on the assessment and cleanup of sites contaminated with chlorinated solvents. Joint training included sessions on environmental forensics, as well as case studies on innovative cleanups. Presentations are available online ( download/2009_november_meeting/ index.html). As seen in Figure 1, Hydrogen isotope ratios of TCE further indicate that the TCE in the above TCE plume has not migrated into adjacent wells. Well DEC 08, which is relatively close to the above TCE plume, also contains TCE with a similar 13 C ratio to DEC 04 and DEC 05. However, the TCE in DEC 08 could also be the product of degradation of the PCE in this well. The source of the TCE in DEC 08 was resolved by measuring the 2 H ratio of TCE in DEC 08, and comparing the ratios with that in DEC 05. The hydrogen isotope ratio of TCE in DEC 08 (+55 ), in fact, was very different from that in DEC 05 (+397 ). 600 S. Andreasen Dr. Suite A Escondido, CA Tel Fax S. Andreasen Dr. Suite B Escondido, CA Tel Fax Dr. Yi Wang, Director of ZymaX Forensics Isotope Laboratory, a recognized expert in environmental isotope forensics, was invited by the U.S. EPA and SCRD to give training presentations to more than 100 attendees from the EPA and various State Agencies. In his presentation entitled Fundamentals and Application of Environmental Isotopes in Chlorinated Solvent Investigations, Dr. Wang gave detailed information on what environmental isotopes are, why isotopes are useful in environmental forensics, how to choose and collect samples for isotope analysis, how to do Three Dimensional Compound Specific Isotope Analysis (3D CSIA) of 13 C, 37 Cl, and 2 H, and finally how to interpret isotope data. Dr. Wang explained that 3D CSIA data may be used to distinguish different sources of a chlorinated solvent release. Dr. Wang showed promising case studies on 3D CSIA of 13 C, 37 Cl, and 2 H for comprehensive PCE/TCE plumes. For example, at an architecture operation site, six groundwater samples were collected for isotope analysis of dissolved PCE, TCE and cis DCE. CSIA of 13 C and 37 Cl indicate that the chlorinated solvents at this site have at least three sources represented by two PCE plumes and one TCE plume (wells DEC 04 and DEC 05) ( Figure 1). Dr. Wang also explained how 3D CSIA may guide remedial decisions and optimize remediation strategy by providing another line of evidence supporting the site model for biodegradation remedy choice, thus avoiding unnecessary or redundant monitoring and remediation costs. For example, 3D CSIA may answer the following questions: 1.) DNAPL: Is there progress? DNAPL acts as a seemingly unlimited source of PCE and/or TCE, so even if it is degrading, the dissolved concentration won t go down. But 3D CSIA information can tell if there is degradation. 2.) Pump and Treat Shutoff? 3D CSIA can tell if there is already pre existing biodegradation, which can shorten the time until biodegradation alone can be protective. 3.) What is the degradation mechanism? Many site managers can t get closure because they can t prove a mechanism. 3D CSIA can help achieve site closure by differentiating between lost contaminant and degraded contaminant. (Continued on page 2) Page 1

2 (Continued from page 1) DEC 05 DEC 04 DEC 08 Figure 1. Architecture Operation Site, East Coast ` 4.) Is there successful degradation? 3D CSIA proves the concentration decreased because the contaminant was destroyed. CSIA of 13 C, 37 Cl, and 2 H for chlorinated solvents in soil and groundwater at drycleaner sites, which are often the focus of environmental litigation. 5.) Are the current existing remediation strategies effective? 3D CSIA can assess the extent and rate of degradation. In July 2009, ZymaX Forensics isotope lab became the first commercial lab offering reliable and efficient full scale 3D For more information, please visit ZymaX Forensics website, or contact Dr. Yi Wang at Yi.Wang@zymaxusa.com, or by phone at ext.43. Dr. Yi Wang is the Director of ZymaX Forensics Isotope Laboratory. He has a B.S. in Environmental Science, an M.S. in Environmental Chemistry, and a Ph.D. in Environmental Geochemistry. He has worked for over 20 years in the environmental field on issues related to soil and water contamination. He developed Compound Specific Isotope Analysis techniques at Brown and Princeton University and applied isotope forensics in the environmental field. Dr. Wang is a specialist in the analysis of isotope ratios for carbon, chlorine, hydrogen, nitrogen, oxygen, and sulfur. He has published over 45 articles and books on soil and water contamination topics and shared this information via lectures throughout the world. Dr. Wang has served as an expert for the U.S. Environmental Protection Agency (EPA) and the State Coalition for Remediation of Drycleaners (SCRD) on chlorinated solvent cases where environmental forensics was used to allocate responsibility and optimize remediation strategy. Fuel Fingerprinting Part II: Middle Distillates By Alan Jeffrey, PhD In the Summer 2009 edition of Environmental Trends & Technologies, fuel fingerprinting of gasoline was discussed Temperature (ºF) Gasoline (C 4 -C 11 ) ºF Naphtha (C 8 -C 12 ) ºF Kerosene and Jet fuels (C 10 -C 16 ) ºF Diesel and Fuel oils (C 11 -C 24 ) ºF Heavy fuel oils (C 12 -C 30 ) ºF Lubricating oils (C 25 -C 40 ) 800+ ºF Middle Distillates Figure 1. Hydrocarbon Composition and Boiling Ranges for Major Refined Fuels and several examples of how fingerprinting could be used to identify fuel release sources were given. As with Gasoline, fuel fingerprinting works just as well with heavier petroleum products, such as diesel fuel, jet fuel, kerosene, bunker oil, and crude oil (Figure 1). For example, the chromatograms of samples 9 and 11, Figures 2 and 3, respectively, are fingerprints of fresh jet fuel and diesel fuel, from different storage tanks. Sample 10 (Figure 4) is free product from a monitoring well that was identified as a mixture of the two petroleum products. As with gasoline, weathering can alter the fingerprint of these middle distillate fuels. With these products, it results in lower amounts of n alkanes, such as n C17. (Continued on page 3) 2 Page 2

3 (Continued from page 2) n C17 Pristane n C18 Phytane n C17 Pristane n C18 Phytane Figure 2. Sample 9 Figure 4. Sample 10 n C17 Pristane n C18 Phytane This can be seen in the lower n C17/Pristane ratio in sample 10 (the monitoring well free product). Fortunately, however, diesel fuel also has a ratio (Pristane/Phytane) that is relatively unaffected by weathering. The similarity in this ratio (1.3 and 1.4) in samples 10 and 11 confirms that the monitoring well free product contains diesel fuel that was likely sourced in the storage tank. By using fingerprinting ratios, one can determine the potential source of spilled petroleum products, including middle distillates. Alan.Jeffrey@DPRA.com for more information. Figure 3. Sample 11 Dr. Alan Jeffrey has a BS in Biochemistry, an MS in Organic Chemistry and a PhD in Oceanography. Dr. Jeffrey has over 20 years of US and international experience in environmental science and geochemistry. At ZymaX Forensics, Dr. Jeffrey focuses on the use of geochemical techniques to solve environmental problems, including sources of spilled hydrocarbon fuels, nitrates, and fugitive methane seeps. Dr. Jeffrey interacts with clients to determine the particular forensic issues at a site and sets up site specific forensic analytical schemes to clarify these issues. He has prepared over 100 proprietary reports for clients that interpret analytical data, place data in the context of other site information, and answer questions such as the identity of spilled petroleum products, the similarity or difference of the products in separate plumes, and the time of release of the products. Dr. Jeffrey has served as an expert witness, been deposed and testified at trial in cases involving petroleum product spills, and is the author of fourteen publications on oceanography, petroleum geochemistry and environmental monitoring. He has conducted workshops in environmental forensics and has given numerous presentations at scientific meetings in the USA, Europe and Asia. Use of Stable Isotopes to Aid Site Remediation By Gregory J. Smith, PE, and Yi Wang, PhD INTRODUCTION The common solvents perchloroethylene (PCE), trichloroethylene (TCE), trichloroethane (TCA), carbon tetrachloride (CT), chloroform (CF), and dichloromethane (DCM), are the most frequently detected groundwater contaminants in the United States (Squillace et al., 1999). These compounds are designated as priority pollutants by the U.S. Environmental Protection Agency and are known or suspected to be carcinogenic or mutagenic in humans. They are readily transported by groundwater and are not reduced to acceptable concentrations for human consumption by most municipal water supply treatment systems. Natural attenuation processes, including dilution, dispersion, sorption, volatilization, and biotic and abiotic transformations can reduce the concentrations of chlorinated aromatic hydrocarbons (CAH) in groundwater (Wiedemeier et al., 1999). In cases where natural attenuation processes are insufficient to reach the desired level of CAH reduction, engineered in situ remediation approaches (such as electrical resistance heating, steam injection, in situ chemical oxidation or reduction, and alcohol or surfactant flooding) have been employed (Leeson and Alleman, 1999). A significant problem encountered with both natural attenuation processes and engineered in situ remediation approaches is determining effectiveness using conventional monitoring practices. This is because it is difficult to distinguish, for example, dispersion or dilution from biodegradation simply on the basis of concentration measurements. Further, Hunkeler, et al., (2005) note that where multiple sources consisting of different industrial degreasing solvents are present it may be (Continued on page 4) 3 Page 3

4 (Continued from page 3) difficult to differentiate these sources. They note one site where TCE was determined to be the result of intrinsic biodegradation of 1,1,2,2 perchloroethane, rather than a daughter compound from PCE. This changed the data interpretation significantly since it showed that the chlorinated ethanes were being actively biodegraded, while the chlorinated ethenes were not. The need for a better method of monitoring the effectiveness of natural attenuation and engineered in situ remediation provided the motivation for exploring the applications of stable isotope ratio measurements of C and Cl in the diagnosis of CAH behavior in the environment. STABLE ISOTOPES Stable isotopes are different types of atoms (nuclides) of the same chemical element, each having a different number of neutrons. While not considered radioactive, a few may be theoretically unstable with exceedingly long half lives. About two thirds of the elements have more than one stable isotope. Different isotopes of the same element (whether stable or unstable) have nearly the same chemical characteristics and therefore behave almost identically. The mass or scale differences resulting from a variance in the number of neutrons result in partial separation of the light isotopes from the heavy isotopes during physical, chemical and biological reactions. This process, called isotope fractionation, is used by ZymaX in its new analysis service. Compound Specific Isotope Analysis (CSIA) data can be used to distinguish between the same chlorinated solvents, such as PCE and TCE, from different sources. For example, CSIA can be used to determine: If PCE or TCE in one plume is from one or more sources: Use CSIA for 13 C and 37 Cl If PCE or TCE in separate plumes are from the same source or different sources: Use CSIA for 13 C and 37 Cl If TCE in a PCE plume is from degradation of PCE or from a separate TCE source: Use CSIA for 13 C, 37 Cl, and 2 H FIELD APPLICATIONS Known magnitudes and directions of the environmental influences on stable isotopes derived from CAH can be used to distinguish biodegradation and evaporation to track their reaction progresses. Source Differentiation of TCE at a Piedmont Site A former manufacturing facility within the Inner Piedmont Belt of South Carolina was investigated with two separate sampling trips during 9/98 and 3/99. The sampling was performed to determine if the two known sources were isotopically different and if so, whether contributions to offsite impacts could be discerned. Some TCE contamination was found on adjacent private property; a second manufacturing facility that also had a history of TCE use adjoined this private property as well. Most (>95%) of the CAH contamination of ground water at the site is TCE. Carbon and chlorine isotope data for bulk CAH in ground water from 13 wells and 2 springs at the site are shown in Figure 1. These data show evidence for at least two distinct TCE sources (Factory A and Factory B), as well as the apparent occurrence of extensive microbial degradation and significant volatilization. It appears that TCE from both (Continued on page 5) biodegradation 25% -19 Factory A 13 C (PDB) Source B mixing 75% Property Factory B Surface Water Source A 10% 1% evaporation Cl (SMOC) FIGURE 1. Carbon (δ 13 C, ) vs. chlorine (δ 37 Cl, ) isotope data for bulk CAH (> 95% TCE) from ground water and surface water samples from Piedmont site. Also shown for comparison are: an evaporation trajectory for residual TCE from Source A, using our preliminary data for aqueous phase evaporation, with residual TCE labeled at, 10%, and 1%; a microbial degradation trajectory using C data for TCE from Sherwood Lollar et al. (1999) and Cl data for DCM from Heraty et al. (1999), with percentages of residual TCE labeled at 75%,, and 25%; and a line indicating possible mixtures of sources A and B. ` 4 Page 4

5 (Continued from page 4) sources has mixed and that the private property may have been contaminated by TCE from both sources biodegradation 35% -19 Engineered Remediation of TCE and TCA at a Midwestern Site A former electronics manufacturing plant in the Chicago area was investigated with five separate sampling trips during 1/98, 4/98, 8/98, 12/98, and 1/99. Carbon and chlorine isotope data for bulk CAH extracted from groundwater from four wells at the Chicago area site are shown in Figure 2. The isotopic compositions of C and Cl in the bulk CAH varied significantly over this time period. The details of the variations within each well yield information on the identity and the extent of the CAH attenuation processes that were occurring. For example, well J3 initially had associated with it a pool of DNAPL measuring approximately 0.3 m thick. This location was intensely heated with steam over a period of approximately 6 years, with well J3 itself used for steam injection during a portion of this treatment. The isotopic data reflects this history, in that the samples exhibit CAH evaporation followed by biodegradation. Well D3 appears to have experienced biodegradation first, followed by evaporation. Throughout the steam and enhanced biodegradation treatment, this well showed progressively higher concentrations, suggesting the mobilization of DNAPL to this location. This location was dewatered and intensely heated with steam, and DNAPL was observed to flow from this well for a period of approximately 1 month. This well was also subsequently heated using electrical resistance heating (ERH), with the ERH taking place during the sampling period. C DNAPL SOURCE 75% 75% Cl closed end catch basin which was identified as a source of TCE and 1,1,1 TCA to the subsurface. It is believed that the closed end catch basin acted as a heat sink throughout the steam injection process, allowing the heat from the steam injection to be dissipated to the atmosphere. Heating was apparently insufficient to affect significant evaporation as evidenced from the isotopic data. The heating may have been sufficient to stimulate biodegradation, however. This area was also intensely heated during the ERH treatment, but shows no evidence of evaporation. CONCLUDING REMARKS 25% The results of the laboratory and field investigations show that stable isotope ratio analyses of C, Cl, and H can play an important role in site characterization and monitoring for 10% evaporation 5% Ca6 F3 D3 J3 ` Figure 2. Carbon (δ 13 C, ) vs. chlorine (δ 37 Cl, ) isotope ratios of bulk CAH extracted from ground water from wells at a Chicago site during remedial activities. Also shown for comparison are the trajectories of TCE evaporation and biodegradation (as in Figure 1), with residual TCE percentages indicated. Arrows indicate time sequence. Well F3 appears to have experienced biodegradation first, followed by solubilization of CAH during heating, then evaporation. This well location was initially interpreted to be on the perimeter of the treatment area, hence subject to biodegradation rather than DNAPL removal. A separate source was discovered adjacent to this location in 1994, and the mode of treatment was converted to steam injection. Steam injection was limited at this location due to the presence of a subsurface void, which limited the steam pressure that could be achieved, and hence temperature. This area was treated using ERH during the isotope sampling period. remediation of CAH contaminated aquifers. The additional compositional dimensions provided by the isotope ratios of C, Cl and H allow increased confidence to be placed on interpretations of the rates and mechanisms of CAH attenuation in the environment and as a result provide a decision making tool to discontinue active remediation. Further, source areas can be differentiated to better focus remediation efforts. This reduction in uncertainty can help to guide remedial strategy and can lead to significant cost savings in cleanup efforts. Greg.Smith@DPRA.com for more information. Well CA6, where pure phase DNAPL was observed in the initial baseline sampling, was located adjacent to a deep (Continued on page 6) 5 Page 5

6 (Continued from page 5) REFERENCES Heraty, L. J., Fuller, M. E., Huang, L., Abrajano, T., and Sturchio, N. C Carbon and chlorine isotopic fractionation during microbial degradation of dichloromethane. Org. Geochem. 30: Hunkeler, D., R. Aravena, K. Berry Spark and E. Cox (2005). Assessment of Degradation Pathways in an Aquifer with Mixed Chlorinated Hydrocarbon Contamination Using Stable Isotope Analysis. Environ. Sci. Technol., 2005, 39 (16), Sherwood Lollar, B., Slater, G. F., Ahad, J., Sleep, B., Spivack, J., Brennan, M., and MacKenzie, P Contrasting carbon isotope fractionation during biodegradation of trichloroethylene and toluene: Implications for intrinsic bioremediation. Org. Geochem. 30: Smith, G.J. (2010). Changes in Geochemistry during Enhanced Reductive Dehalogenation and Impacts on Stable Isotopes of Carbon and Chlorine. Proceedings of the First International Network of Environmental Forensics, Calgary, Alberta, August 31 September 3, Squillace, P. J., Moran, M. J., Lapham, W. W., Price, C. V., Clawges, R. M., and Zogorski, J. S Volatile organic compounds in untreated ambient groundwater of the United States, Environ. Sci. Technol. 33: Wiedemeier, T. H., Rifai, H. S., Newell, C. J., and Wilson, J. T Natural Attenuation of Fuels and Chlorinated Solvents in the Subsurface. Wiley, New York, 617. Greg J. Smith, P.E., P.G. is a Senior Hydrogeologist at DPRA with more than 20 successful DNAPL site closures starting with the industry s first in 1999 at the former AT&T Skokie Works in Illinois where regulatory standards were reached. Mr. Smith has also employed other remediation technologies, including in situ biodegradation, permeable reactive barriers, as well as conventional recovery methods including groundwater pump and treat and soil vapor extraction. Mr. Smith has worked with researchers at the California State University at Los Angeles, University of Illinois at Chicago and Argonne National Laboratory performing stable isotope surveys ( 87 Sr/ 86 Sr, 37 Cl and 14 C) to determine fate and transport of contaminant plumes in groundwater in California, Missouri, Illinois and South Carolina. Mr. Smith has provided expert witness testimony on the fate and transport of chlorinated solvents in federal court in Michigan. He has published more than 20 articles on various aspects of soil and groundwater remediation, including a chapter on Coupled Electrokinetics Thermal Desorption, in a book entitled: Electrochemical Remediation Technologies for Polluted Soils, Sediments and Groundwater, and co authored the Encyclopedic Dictionary of Hydrogeology. 6 Page 6