Monday, November 5, 2007 : 12:50 p.m.

Contamination Distribution and Mass Estimate via Kriging: Pitfalls and Lessons

Meng Ling, Ph.D., PE, Jeffrey A. Johnson, Ph.D., PG and Xiaohua Lin, Ph.D., Acton Mickelson Environmental Inc.

Determining the volume and mass of soil/dissolved contaminants is an important component in characterization and remediation design. The distribution and magnitude of detected concentrations are the basis from which the estimate of volume and mass are determined. Computer technologies have enhanced the capabilities of conducting the analysis by coupling three dimensional interpolation with visual imagery. Three dimensional kriging is a particularly useful interpolation technique as it not only provides a quantitative estimate but also enables an assessment of uncertainty. Evaluating uncertainty in the volume and mass estimate is an important component of the analysis as it allows quantitative assessment of the reliability. This understanding can then be incorporated into other analyses such as fate and transport modeling, delineation of treatment zone, and sizing of the remedial system. Although computer technologies have facilitated conducting these volume and mass analyses, caution should be exercised as vastly erroneous estimates can result from unforeseen conceptual and technical errors. The errors normally occur during domain selection, nondetects quantification, use of control points, and confidence interval estimate. This paper documents the application of three dimensional kriging coupled with state-of-the-art visualization for a complex dissolved MTBE plume. The various pitfalls and lessons of the analyses are presented, with emphasis on how potential errors can significantly alter the results.

Meng Ling, Ph.D., PE, Acton Mickelson Environmental Inc. Dr. Meng Ling is an Environmental Engineer and has 9 years of research and professional experience in water resources engineering and environmental engineering. He specializes in statistical and geostatistical data analyses, monitoring program optimization, groundwater fate and transport modeling, and computer visual imagery. Dr. Ling’s expertise also includes multi-phase flow and transport (NAPL) modeling, database development and management, and remedial system design.

Jeffrey A. Johnson, Ph.D., PG, Acton Mickelson Environmental Inc. Dr. Jeffrey A. Johnson has over 25 years of professional experience in natural resource assessment, site characterization, remedial operations, and technical analyses. He has worked on various projects throughout North America for major petroleum corporations, legal firms, manufacturing companies, and the U.S. Environmental Protection Agency. For the past 10 years, he has worked extensively in the characterization and remediation of LNAPL and DNAPL sites. He is a Senior Technical Consultant for Acton-Mickelson Environmental, Inc. Dr. Johnson holds a Ph.D. in Geology from the University of California, Berkeley, and is a Certified and Registered Professional Geologist and a Licensed Remediation Specialist.

Xiaohua Lin, Ph.D., Acton Mickelson Environmental Inc. Dr. Xiaohua Lin is an Environmental Engineer at Acton Mickelson Environmental, Inc. Dr. Lin has 8 years of research and professional experience in environmental engineering. She specializes in groundwater fate and transport modeling, subsurface site characterization and remediation. Dr. Lin’s expertise also includes perchlorate and nitrate bio-treatment, water quality monitoring and eutrophication studies. Dr. Lin received her Ph.D. from the University of Houston.


[ Manuscript ] Manuscript

Petroleum Hydrocarbons and Organic Chemicals in Ground Water: Prevention, Detection, and Remediation® Conference