caa a22 4500 445815469 CHVBK 20180317145226.0 cr unu---uuuuu 170323e20110801xx s 000 0 eng 10.1007/s10040-011-0736-z doi (NATIONALLICENCE)springer-10.1007/s10040-011-0736-z Impacts of agricultural irrigation recharge on groundwater quality in a basalt aquifer system (Washington, USA): a multi-tracer approach [Elektronische Daten] [Kyle Brown, Jennifer McIntosh, Laura Rademacher, Kathleen Lohse] Impacts de la recharge par irrigation agricole sur la qualité des eaux souterraines d'un système aquifère basaltique (Washington, Etats-Unis): une approche multi-traceurs Irrigation in semi-arid agricultural regions can have profound effects on recharge rates and the quality of shallow groundwater. This study coupled stable isotopes (2Η, 18O), age-tracers (3H, CFCs, 14C), 87Sr/86Sr ratios, and elemental chemistry to determine the sources, residence times, and flowpaths of groundwater and agricultural contaminants (e.g. NO 3 - ) in the Saddle Mountains Basalt Aquifer in central Washington, USA, where over 80% of the population depend on groundwater for domestic use. Results demonstrate the presence of two distinct types of water: contaminated irrigation water and pristine regional groundwater. Contaminated irrigation water has high NO 3 - concentrations (11-116 mg/l), 87Sr/86Sr ratios (0.70659-0.71078) within range of nitrogen-based fertilizers, detectable tritium (2.8-13.4 TU), CFC ages 20-40years, high δ18O values (−16.9 to −13.5‰), and ∼100 percent modern 14C. Pristine regional groundwater has low NO 3 - concentrations (1-5 mg/l), no detectable tritium (≤0.8 TU), low δ18O values (−18.9 to −17.3‰) and 14C ages from ∼15 to 33ky BP. Nitrogen and oxygen isotopes of NO 3 - , combined with high dissolved oxygen values, show that denitrification is not an important process in the organic-poor basalt aquifers resulting in transport of high NO 3 - irrigation water to depths greater than 40m in less than 30 years. Springer-Verlag, 2011 Agriculture nationallicence Hydrochemistry nationallicence Groundwater age nationallicence Stable isotopes nationallicence USA nationallicence Brown Kyle Department of Hydrology and Water Resources, University of Arizona, 1133 East James E. Rogers Way, 85721, Tucson, AZ, USA aut McIntosh Jennifer Department of Hydrology and Water Resources, University of Arizona, 1133 East James E. Rogers Way, 85721, Tucson, AZ, USA aut Rademacher Laura Department of Earth and Environmental Sciences, University of the Pacific, 3601 Pacific Avenue, 95211, Stockton, CA, USA aut Lohse Kathleen School of Natural Resources and the Environment, University of Arizona, Biological Sciences East, 85721, Tucson, AZ, USA aut Hydrogeology Journal Springer-Verlag 19/5(2011-08-01), 1039-1051 1431-2174 19:5<1039 2011 19 10040 https://doi.org/10.1007/s10040-011-0736-z text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10040-011-0736-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Brown Kyle Department of Hydrology and Water Resources, University of Arizona, 1133 East James E. Rogers Way, 85721, Tucson, AZ, USA aut NATIONALLICENCE 700 1- McIntosh Jennifer Department of Hydrology and Water Resources, University of Arizona, 1133 East James E. Rogers Way, 85721, Tucson, AZ, USA aut NATIONALLICENCE 700 1- Rademacher Laura Department of Earth and Environmental Sciences, University of the Pacific, 3601 Pacific Avenue, 95211, Stockton, CA, USA aut NATIONALLICENCE 700 1- Lohse Kathleen School of Natural Resources and the Environment, University of Arizona, Biological Sciences East, 85721, Tucson, AZ, USA aut NATIONALLICENCE 773 0- Hydrogeology Journal Springer-Verlag 19/5(2011-08-01), 1039-1051 1431-2174 19:5<1039 2011 19 10040 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer