Monday, June 23, 2008 : 2:10 p.m.

Natural Gamma Radiation Logging of Multi-Level Nested Well Bundles to Define Hydrostratigraphy Controlling the Transport of a Fugitive MTBE Plume in the Upper Glacial Aquifer of Long Island

Donald A. Trego1, Jan M. Whitaker1 and Joseph E. Haas II, M.S., PE2, (1)Environmental Assessment and Remediations, (2)New York State Department of Environmental Conservation

MTBE contamination detected in the West Hempstead Water District Birch Street Well Field at a concentration of 154 micrograms per liter (μg/L) at depths of approximately 60 meters was defined utilizing an Expedited Site Characterization (ESC) methodology. The ESC entailed the installation of Multi-Level Nested Well Bundles (MLNWBs) by hollow stem auger techniques. Utilizing hollow stem auger methods allows for the identification of a generalized subsurface geology through the evaluation of auger cuttings; however the delineation of significant stratigraphic units cannot be determined without alternative methods. Based on clay observed during MLNWB installations further definition and correlation of clay was desired to determine impact on the groundwater flow regime and contaminant transport. Utilizing a Mount Sopris Instruments model MGX-2 digital logger equipped with a small diameter sodium iodide scintillation device, natural gamma logs were obtained from the monitoring network.  The raw radiation count data was imported into a three dimensional visualization program to help generate a revised conceptual site model that included a discontinuous semi-confining clay unit. The natural gamma data was instrumental to understanding the contaminant distribution data derived from the three dimensional MLNWB network.

Donald A. Trego, Environmental Assessment and Remediations Don graduated in 1993 from the Pennsylvania State University with a bachelors of science in Environmental Resource Management. He has over 14 years of experience in the groundwater remediation industry. Don has been involved in numerous research initiatives with the New York State Department of Environmental Conservation (NYSDEC), the United States Environmental Protection Agency (USEPA), and the United States Geological Survey (USGS). As project manager, Don was a co-recipient of the 2004 National Ground Water Association’s (NGWA) – Outstanding Groundwater Remediation Project award. He currently is the Vice president of a respected environmental consulting firm located on Long Island, NY.

Jan M. Whitaker, Environmental Assessment and Remediations Jan received her BS in Geology from Stony Brook University in 2005. She has been working with an environmental consulting firm as a Geologist and Project Manager since 2005. In a relatively short time, Jan has accumulated considerable field experience including involvement at the forefront of multiple expedited site characterizations and oversight of several drilling techniques. She is experienced in varied groundwater and soil sampling techniques and interpretation, and supports senior staff in data interpretation and visualization. Jan is also involved with 3-D modeling of geologic and groundwater data for enhancing site conceptualizations to aid in management decision-making.

Joseph E. Haas II, M.S., PE, New York State Department of Environmental Conservation Joe has 19 years experience working as a state regulator managing a remedial section. He holds both Engineering Geologist and Hydrogeologist specialty licenses. Joe has been involved in research with representatives of the United States Environmental Protection Agency. These research efforts have been credited as having made significant contributions to the understanding of the characteristics of MTBE in the sub-surface environment and having influenced the national debate on the use of MTBE in gasoline. The Office of Research and Development acknowledged his contributions, in 2002, in the form of an award for Exceptional Support to ORD.


2008 NGWA Conference on Eastern Regional Ground Water Issues