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On April 23, 1997, Lawrence P. Kolb, Acting Executive Officer for the Los Angeles Regional Water Quality Control Board, issued guidelines for implementing the non-purge method of sampling groundwater as well as for identifying conditions where purging of groundwater monitoring wells are required. The Western States Petroleum Association (WSPA), composed of the major oil refining and transportation companies operating in the western states, commissioned the report, "The California Groundwater Purging Study for Petroleum Hydrocarbons." The non-purge method and concerns about the study methodology were outlined in the Spring 1997 issue of HydroVisions. Based on numerous requests, GRA has sent out copies of the study for a nominal fee with Dr. Michael Barcelona's comments attached. Michael Barcelona, Ph.D., formerly with the Illinois Water Survey and now Director of the "National Center for Integrated Bioremediation Research and Development" at the University of Michigan, Ann Arbor, was asked to peer review the study. Dr. Barcelona reviewed the initial workplan and the final report. Dr. Barcelona also reviewed Mr. Kolb's guidelines and wrote to both Mr. Kolb and Mr. James Giannopoulos, Chief Regulatory Programs, California State Water Resources Control Board. The letters were essentially identical. HydroVisions received a copy of both letters. The following is a copy of Dr. Barcelona's response to Mr. Giannopoulos. June 3, 1997 Mr. James Giannopoulos
Dear Mr. Giannopoulos: I am writing to you as an educator, researcher and ground water professional who has often provided sampling guidance and workshops across the country. I have always had an appreciation for the eagerness with which local and state governments have embraced the results of research to improve the efficiency of their programs. California government, in particular, has been a stand out in this regard, until very recently. The April 23, 1997 memo, "Use of Non-Purge Method for Sampling of Ground Water Monitoring Wells at Gasoline Impacted Sites" written by the L.A. Regional Water Quality Board's Executive Officer was very disappointing reading. Indeed the "method" is a fraud. I can understand an interest in reducing the costs of monitoring. However, given that the designated wells are "impacted" the annual costs of remediation should no doubt be considerably greater than the total long-term monitoring costs. The facts as I see them are: 1) The WSPA study (conducted by SECOR over the past year) was flawed from the beginning since it is not possible to bail a well to "purge" stagnant water from wells. This has been shown by numerous, peer-reviewed papers in the last 15 years. Purging poorly creates very high variance in results which makes it impossible to show significant differences between unpurged (biased) samples and those after purging with very disruptive techniques (i.e. bailing or vacuum truck). 2) The most volatile compounds (e.g. MTBE and benzene) are also the most mobile and likely to be lost from stagnant or poorly purged water in wells. They also can drive further cleanup action given their biological effects which may influence risk evaluations. These evaluations should be based on the most reliable samples possible. 3) Wells screened across the water table aren't very useful to determine the chemical and hydrogeologic conditions in the subsurface. (As opposed to multiple discrete completions above, in, and below the "plume".) They cannot be tested for hydraulic conductivity testing. and, 4) The WSPA study design and the results were reviewed, but the comments of experienced critical reviewers were ignored at both stages I can tell you with confidence that, having been the editor of a major journal, "Ground Water Monitoring and Remediation" for over five years, the results of this study should not be expected to be favorably peer reviewed towards publication. I urge you to carefully review the facts in this matter and resist lobbying or interests that would have us give leave of our logic and commitment to high quality, consistent environmental monitoring. Thank you for your consideration of my thoughts. Sincerely, Michael J. Barcelona, Ph.D.
Dr. Barcelona seems to be the best credentialed critic of the WSPA study. I have read his comments and WSPA's response. Dr. Barcelona has repeatedly demonstrated how the fundamentals of the study were flawed. It's unfortunate that "poor science" is being used to justify a "no-purge" option. The inherit bias of a bailer as a sampling device makes it a poor candidate to demonstrate that purging is not necessary. GRA is attempting to help disseminate information by making Dr. Barcelona's comments available, as well as the WSPA study. If you would like a copy of the study and Dr. Barcelona's comments, please send $5.00 to GRA to cover reproduction and mailing costs. |