Using Age Tracers and Decadal Sampling to Discern Trends in Nitrate, Arsenic, and Uranium in Groundwater Beneath Irrigated Cropland
| Autor: | Lonna M. Frans, Jonathan V. Haynes, Bruce D. Lindsey, Christopher M. Hobza, John E. Solder, Karen R. Burow, Anthony J. Tesoriero |
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| Rok vydání: | 2019 |
| Předmět: |
inorganic chemicals
Hydrology Crops Agricultural Nitrates chemistry.chemical_element General Chemistry Groundwater recharge Uranium Arsenic chemistry.chemical_compound Nitrate chemistry Groundwater pollution Environmental Chemistry Environmental science Water quality Surface water Groundwater Water Pollutants Chemical Environmental Monitoring |
| Zdroj: | Environmental sciencetechnology. 53(24) |
| ISSN: | 1520-5851 |
| Popis: | Repeat sampling and age tracers were used to examine trends in nitrate, arsenic, and uranium concentrations in groundwater beneath irrigated cropland. Much higher nitrate concentrations in shallow modern groundwater were observed at both the Columbia Plateau and High Plains sites (median values of 10.2 and 15.4 mg/L as N, respectively) than in groundwater that recharged prior to the onset of intensive irrigation (median values of1 and4 mg/L as N, respectively). Repeat sampling of these well networks indicates that high nitrate concentrations in modern, shallow groundwater have been sustained for decades, posing a future risk to older, deeper groundwater used for drinking water. In fact, nitrate concentrations in older modern water (30-60 years since recharge) at the High Plains site have increased in the past decade. Groundwater irrigated areas in the Columbia Plateau tend to have higher nitrate concentrations in groundwater than surface water irrigated areas, suggesting repeated dissolution of land applied fertilizer during recirculation may be an important factor causing high nitrate concentrations in groundwater. Mobilization of uranium and arsenic by land surface activities is suggested by the higher concentrations of these constituents in modern, shallow groundwater than in older, deeper groundwater at the Columbia Plateau site. Bicarbonate concentrations in modern groundwater are positively correlated with uranium ( |
| Databáze: | OpenAIRE |
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