HR: 09:03h
AN: H41K-05 INVITED    [Abstracts]
TI: Isotopic Discrimination of Perchlorate Sources in Ground Water
AU: * Bohlke, J
EM: jkbohlke@usgs.gov
AF: U.S. Geological Survey, 431 National Center, Reston, VA 20192, United States
AU: Hatzinger, P B
EM: Paul.Hatzinger@shawgrp.com
AF: Shaw Environmental, Inc., 17 Princess Road, Lawrenceville, NJ 08648, United States
AU: Sturchio, N C
EM: sturchio@uic.edu
AF: University of Illinois at Chicago, 845 West Taylor Street, MC-186, Chicago, IL 60607, United States
AU: Gu, B
EM: gub1@ornl.gov
AF: Oak Ridge National Laboratory, P.O. Box 2008, MS-6036, Oak Ridge, TN 37831, United States
AU: Jackson, W A
EM: andrew.jackson@ttu.edu
AF: Texas Tech University, MS 41023, Lubbock, TX 79409, United States
AU: Abbene, I J
EM: iabbene@usgs.gov
AF: U.S. Geological Survey, 2045 Route 112, Coram, NY 11727, United States
AB: Perchlorate has been detected in ground water and drinking water in many areas of the U.S. during the past decade. Sources of potential perchlorate enrichment in ground water include releases from past military activities, fireworks manufacture and display, fertilizer applications, discarded road flares, and local atmospheric deposition. Here we present analyses of stable isotopes (δ³⁷Cl, δ¹⁸O, and Δ¹⁷O) of dissolved perchlorate, along with other supporting environmental tracer data, from selected occurrences in ground water in the U.S. The isotope data indicate that both synthetic and natural perchlorate are present in ground water, and that multiple sources are present locally in some areas. The sampled ground waters generally were oxic and the perchlorate isotopes generally were not affected substantially by biodegradation. In some areas, natural perchlorate, with Δ¹⁷O = +7 to +10 ‰, can be attributed to agricultural applications of atmospherically derived natural nitrate fertilizer imported from South America (Atacama Desert, Chile). In at least one agricultural area in New York, concentrations of perchlorate increase with depth and ground-water age, possibly because of decreasing application rates of Atacama nitrate fertilizer and(or) decreasing perchlorate concentrations in the imported fertilizer products in recent years.
DE: 1803 Anthropogenic effects (4802, 4902)
DE: 1806 Chemistry of fresh water
DE: 1831 Groundwater quality
SC: Hydrology [H]
MN: 2007 Fall Meeting