The Central Coast Branch is pleased to have Dr. John Izbicki join us to discuss the topic of environmental tracers. Dr. Izbicki has worked for the U.S. Geological Survey for more than 30 years in Maryland, Massachusetts, and California. In 2000, while working for the USGS, he obtained his Ph.D. in Soil Physics from University of California, Riverside. Within California, Dr. Izbicki’s studies have focused on understanding the physical hydrology of coastal and desert aquifer systems primarily through the application of chemical and isotopic tracers. Recent work includes studies of managed aquifer recharge, trace-element occurrence and management in aquifers, submarine groundwater discharge, and bacterial source identification in urban streams and near-shore ocean water. Dr. Izbicki has several patents, published more than 100 U.S. Geological Survey reports and journal articles, and worked with the International Atomic Energy Agency and the Indian Government.

Contaminants such as perchlorate and hexavalent chromium can move almost unattenuated with groundwater in some cases creating large contamination plumes that extend for miles downgradient from source areas. In areas where a high background from natural or other anthropogenic sources is present it may be difficult to identify plume margins and determine the extent of contamination at a site. Chemical and isotopic environmental tracers can be used to identify the source and hydrologic history, including age (time since recharge), of water and contaminants within large plumes and the processes affecting contaminant concentrations. The use of these environmental tracers coupled with hydrologic data will be examined at selected sites in southern California.