Monday, April 25, 2016: 2:00 p.m.
Confluence Ballroom C (The Westin Denver Downtown)
Patrick Longmire, PhD
,
New Mexico Environment Department, DOE Oversight Bureau, Los Alamos, NM
Michael R. Dale, MS
,
New Mexico Environment Department, Hazardous Waste Bureau, Los Alamos, NM
Kim P. Granzow, BS
,
New Mexico Environment Department, DOE Oversight Bureau, Los Alamos, NM
David Fellenz
,
New Mexico Environment Department, DOE Oversight Bureau, Los Alamos, NM
Stephen M. Yanicak
,
New Mexico Environment Department, DOE Oversight Bureau, Los Alamos, NM
Megan Green
,
New Mexico Environment Department, DOE Oversight Bureau, Los Alamos, NM
Los Alamos National Laboratory (LANL) is an operating nuclear site that has released treated effluents from three plutonium-processing facilities since the mid 1940s. The radioisotope 129I (T1/2 = 15.7 Myrs) derived from235U and 239Pu processing at LANL is locally detected in groundwater above background concentrations. This isotope provides a unique tracer for groundwater investigations conducted at LANL that helps to identify source releases linked to groundwater-flow paths in aquifers subject to binary and ternary mixing of natural- and industrial-derived waters containing chromate and other chemicals. Bromide, chlorate, chloride, nitrate, perchlorate, sulfate, and tritium were associated with multiple outfalls at LANL and, therefore, do not provide unique chemical signatures identifying a specific point of release or source. Natural and anthropogenic ratios of 129I/127I measured in groundwater samples collected at LANL were quantified using accelerator mass spectrometry at Purdue Rare Isotope Measurement Laboratory, Purdue University. Anthropogenic ratios of 129I/127I range from 1,252 X 10-15 to 17,367 X 10-15 within perched-intermediate groundwater present in volcanoclastic and basalt aquifers (210 – 216 m depth). Anthropogenic ratios of 129I/127I range from 359 X 10-15 to 4,350 X 10-15 within the regional aquifer (280 m depth) consisting of volcanoclastic sediments of variable hydraulic properties. Local background ratios of 129I/127I have a narrow range of 171 X 10-15 to 378 X 10-15 in the regional aquifer. Dissolved iodide measured in groundwater at LANL is stable dominantly as iodate. Background concentrations of dissolved iodate (0.1 to 33.2 nM) are less variable compared to anthropogenic iodate (8.0 to 246 nM) in groundwater at the site. Variability in concentrations of anthropogenic iodate is controlled by heterogeneous source releases of iodate over time and non-uniform mixing of groundwater in the different aquifers.
Patrick Longmire, PhD, New Mexico Environment Department, DOE Oversight Bureau, Los Alamos, NM
Patrick Longmire is an aqueous geochemist with 38 years of experience in chemical characterization of aquifer systems. His expertise includes field and experimental investigations on the fate and transport of inorganic chemicals, reactive transport modeling, and stable isotope geochemistry. Longmire has taught short courses on groundwater geochemistry for the National Ground Water Association since 1987.
Michael R. Dale, MS, New Mexico Environment Department, Hazardous Waste Bureau, Los Alamos, NM
Michael Dale is a hydrogeologist with the New Mexico Environment Department. He conducts hydrogeochemical investigations, including measuring naturally-occurring perchlorate and delineating groundwater flow paths using isotopic and chemical tracers. Dale has 16 years of experience in the fields of hydrochemistry and hydrogeology.
Kim P. Granzow, BS, New Mexico Environment Department, DOE Oversight Bureau, Los Alamos, NM
Kim Granzow is an environmental scientist/geologist with the New Mexico Environment Department. She specializes in environmental monitoring for naturally occurring and anthropogenic contaminants such as perchlorate and plutonium, and uses Geographic Information Systems (GIS) in hydro-contaminant investigations. Granzow has 15 years of experience in the field of geology and eight years of experience in GIS.
David Fellenz, New Mexico Environment Department, DOE Oversight Bureau, Los Alamos, NM
David Fellenz is a hydrogeologist with the DOE Oversight Bureau in Los Alamos, New Mexico. His research interests include groundwater chemistry, fate and transport of contaminants, and groundwater hydrology. Mr. Fellenz holds a BA in Geology from Lawrence University in Appleton, WI. Mr. Fellenz has seven years of experience in hydrology, including conducting site investigations and detailed groundwater sampling at Los Alamos National Laboratory.
Stephen M. Yanicak, New Mexico Environment Department, DOE Oversight Bureau, Los Alamos, NM
Stephen Yanicak is a Natural Science Manager and geologist with the New Mexico Environment Department at Los Alamos. He manages a team of scientists that have been supporting State and DOE/UC groundwater investigations at Los Alamos National Laboratory for the past 13 years. Hydrologists staffed at the State Environment Department office in Los Alamos specialize in evaluating and delineating radionuclides and other isotopic and chemical tracers on the Pajarito Plateau within the vicinity of Los Alamos National Laboratory. Yanicak has an M.S. from New Mexico State and a B.S. from Sonoma State.
Megan Green, New Mexico Environment Department, DOE Oversight Bureau, Los Alamos, NM
Megan Green is a hydrogeologist with the DOE Oversight Bureau, New Mexico Environemnt Depart in Los Alamos, New Mexico. Her research interests include groundwater chemistry, fate and transport of contaminants, and groundwater hydrology. Ms. Green holds a MS in Geology from Northern Arizona University, Flagstaff, AZ. Ms. Green has eight years of experience in hydrology, including conducting site investigations and detailed groundwater sampling at Los Alamos National Laboratory.
