Sampling Plan Optimization: A Data Review and Sampling Frequency Evaluation Process

ABSTRACT

Lawrence Livermore National Laboratory (LLNL) uses a cost-effective sampling (CES) methodology to evaluate and review ground water contaminant data and optimize the site's ground water monitoring plan. The CES methodology is part of LLNL's regulatory approved compliance monitoring plan (Lamarre et al., 1996). It allows LLNL to adjust the ground water sampling plan every quarter in response to changing conditions at the site. Since the use of the CES methodology has been approved by the appropriate regulatory agencies, such adjustments do not need additional regulatory approval. This permits LLNL to respond more quickly to changing conditions. The CES methodology bases the sampling frequency for each location on trend, variability, and magnitude statistics describing the contaminants at that location, and on the input of the technical staff (hydrologists, chemists, statisticians, and project leaders). After initial setup is complete, each application of CES takes only a few days for as many as 400 wells. Effective use of the CES methodology requires sufficient data, an understanding of contaminant transport at the site, and an adequate number of monitoring wells downgradient of the contamination. The initial implementation of CES at LLNL in 1992 produced a 40% reduction in the required number of annual routine ground water samples at LLNL. This has saved LLNL $390,000 annually in sampling, analysis, and data management costs.

Keywords:

• sampling plan
• optimization
• data analysis
• statistical evaluation

ACKNOWLEDGMENTS

This work was made possible by support from Lawrence Livermore National Laboratory's Environmental Restoration Division, under the auspices of the U.S. Department of Energy under contract W–7405-ENG–48. (UCRL-JC-148734.) Portions were originally published in Proceedings of HAZMACON® '95, Hazardous Materials Management Conference and Exhibition, April 4–6, 1995, San Jose, California.

Reprinted from Ground Water Monitoring & Remediation with permission of the National Ground Water Association. Copyright 2004.