GRA conducted a one-day seminar on testing and modeling of low yield aquifers. The Seminar was held at the Embassy Suites in Walnut Creek, California on April 26 and at the Hilton in Glendale, California, on April 27.

The major topics included in the Seminar were pre-aquifer test design considerations; methods for analyzing existing site data; pumping test analysis considerations (including review of conventional analyses, casing storage effects, unconfined aquifers and special low yield aquifer considerations); capture zone analysis (including determination of capture zones, well spacing, 3-D effects and re-injection); groundwater modeling techniques to analyze groundwater problems; and test pump design and considerations.

Lectures on the above topics were presented during the morning and afternoon sessions. The instructors presented case studies and examples. Participants were encouraged to bring their own case studies for discussion.

Program Agenda

David Schafer has worked in the groundwater industry for 33 years and is a recognized expert in well design and construction, and groundwater hydraulics. He worked for a major well equipment manufacturer for 20 years where he designed high capacity water supply wells, specializing in the practice of deep well design; consulted in well construction, development and rehabilitation; designed dewatering systems; and performed pumping test analyses. He served for 10 years as a senior expert in groundwater hydraulics for ARCADIS Geraghty & Miller. He has run his own consulting business for four years; specializing in groundwater flow and transport modeling, aquifer testing and analysis, capture zone analysis, and water well design, construction and development. Throughout his career, Mr. Schafer has published numerous technical articles on groundwater and well applications and has lectured regularly on well design, capture zone analysis and groundwater hydraulics.

Peter Leffler is a hydrogeologist and has worked in the groundwater consulting industry for 15 years. He has a B.S. degree in Geology, M.S. degree in Hydrogeology, and is a Registered Geologist/Certified Hydrogeologist in the State of California. Mr. Leffler has worked the last two years in the Fugro West Water Resources Group and the previous nine years with Todd Engineers. He has practical experience working in low yield aquifer environments ranging from clays to fractured bedrock. He has extensive experience in well installation and aquifer testing in these low permeability environments associated with landfills, fuels/solvent leaks, and groundwater supply from fractured bedrock.

William Gustavson has 35 years of experience in the water supply, well drilling and pump installation/maintenance, and consulting industries. His experience includes several years as the Assistant Systems Engineer for a major Northern California investor-owned water utility responsible for a new development, operations and maintenance for 15 water systems, several years as a Project Manager and Sales Engineer for the Layne Western Company (now Layne Christensen) in the states of California, Washington, Oregon, Idaho and Montana, designing and installing water well and pumping systems and, for the last two decades, he has been at Luhdorff and Scalmanini Consulting Engineers, currently as a Partner and principal Project Manager. He specializes in designing water wells, pumping systems, including well pumps for permanent installations and aquifer testing, treatment systems, and water distribution and storage systems. He will provide introductory material on pump design and operation, theory of operation, selection of appropriately sized pumps, and pump problems that impact aquifer test analysis during low yield aquifer testing.