APPLICATION OF BORON ISOTOPE RATIOS FOR IDENTIFYING NITRATE CONTAMINATION SOURCES IN THE GROUNDWATER OF AVRA VALLEY, ARIZONA
The stable isotopes of the conservative element boron, 11B and 1°B, have been employed as co- migrating isotopic tracers to determine the origin of nitrate observed in groundwater from a large capacity (2500 gpm) irrigation well in the Avra Valley of southeastern Arizona. The isotopic ratios of t...
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| Language: | en_US |
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Department of Hydrology and Water Resources, University of Arizona (Tucson, AZ)
1994
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| Subjects: | |
| Online Access: | http://hdl.handle.net/10150/617638 http://arizona.openrepository.com/arizona/handle/10150/617638 |
| Summary: | The stable isotopes of the conservative element boron, 11B and 1°B, have been
employed as co- migrating isotopic tracers to determine the origin of nitrate observed in
groundwater from a large capacity (2500 gpm) irrigation well in the Avra Valley of
southeastern Arizona. The isotopic ratios of the conservative element, boron, provided an
identifying signature for various nitrate rich source waters. Additional chemical
parameters were also examined to corroborate the isotopic indications.
Findings of this investigation indicate that most of the nitrate observed in
groundwater from well CMID 18 at the beginning of the 1993 irrigation season was due
to municipal wastewater contamination. As the irrigation season progressed, an increasing
proportion of nitrate was contributed by irrigation return flow from neighboring
agricultural fields. |
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