Ground Water Sampling - A Workshop Summary
Monitoring purposes have evolved in the past decade reflecting an increasing emphasis on assessment and remedial action performance over detection monitoring. The recognition of many potential contamination sources as well as the regulatory inclusion of a large number of sites in need of investigation have spurred this evolution in practice. New more efficient methods and tools for hydrogeochemical characterization have been developed which can make site investigations more reliable and cost-effective. Improved field screening techniques, geophysical, portable analytical, and computerized hydrologic data acquisition systems, lighter drilling and boring tools, multi-level samplers, and hydraulic “push” technologies are some of the tools which may be applied to subsurface studies. Professional practices and standards for all monitoring have lagged behind methodological research and development. Regulatory acceptance of new tools and methods has been slow in general. However change is inevitable and, if properly implemented, could lead to more uniformly reliable and less expensive investigations. Improved training and certification of hydrogeologic professionals could also aid in this regard. Decreased reliance on wells as primary data collection points follows on the recognition that many inorganic and most organic contaminants have an appreciable fraction of their mass associated with subsurface solids. Also, wells designed for detection and assessment monitoring purposes frequently become obsolete when vadose or saturated zone remedial action has begun. It may be anticipated that as the familiarity with and supporting documentation for more effective methods grow, more stringent standards of professional practice will evolve as well. In summary, the state of current monitoring practice is steadily changing to more reliable, cost-effective techniques which should improve the spatial coverage, accuracy and precision of data collection efforts.