Source(s) of High Concentrations of Atmospheric Nitrates in the Lower Yakima River Basin, Washington
Document Type
Thesis
Date of Degree Completion
Winter 2014
Degree Name
Bachelor of Science
Committee Chair
Dr. Carey Gazis, Department of Geological Science
Second Committee Member
Dr. Anne Egger, Department of Geological Science
Third Committee Member
Dr. Audrey D. Huerta, Director Science Honors Research Program
Abstract
Public outcry in early 2008 spurred recent studies to determine the concentration and source of nitrates in the Lower Yakima Valley groundwater. One study, conducted by the Environmental Protection Agency (EPA), used a variety of geochemical techniques to determine the source of these nitrates, which are likely from one or more of the following: dairy waste lagoons, fertilizers, septic systems, and other agricultural processes. In the study, they found that nitrate in a few groundwater samples had an isotopic signature that suggested an atmospheric source of nitrate. An atmospheric source is not common in terrestrial settings, but the most likely contributors are anthropogenic activities and direct deposition. Direct deposition may occur as NO3 gas interacts with surface soils and waters and in arid environments is incorporated into a soil precipitate, such as caliche. In this research, isotopic and major anion analyses were used to try to identify the source(s) of atmospheric nitrate found in the EPA study. Caliche layers within soils, in particular, were targeted as a potential source.
Recommended Citation
Cavanaugh, Gabrielle, "Source(s) of High Concentrations of Atmospheric Nitrates in the Lower Yakima River Basin, Washington" (2014). Undergraduate Honors Theses. 62.
https://digitalcommons.cwu.edu/undergrad_hontheses/62
Comments
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