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Boron Isotopes as an Artificial Tracer
Author(s) -
Quast Konrad W.,
Lansey Kevin,
Arnold Robert,
Bassett Randy L.,
Rincon Martha
Publication year - 2006
Publication title -
groundwater
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.84
H-Index - 94
eISSN - 1745-6584
pISSN - 0017-467X
DOI - 10.1111/j.1745-6584.2005.00186.x
Subject(s) - tracer , boric acid , sulfate , hydrology (agriculture) , groundwater , structural basin , groundwater recharge , infiltration (hvac) , isotope , delta , boron , isotopes of boron , environmental science , environmental chemistry , chemistry , geology , materials science , geomorphology , geotechnical engineering , aquifer , physics , organic chemistry , quantum mechanics , nuclear physics , engineering , aerospace engineering , composite material
A field study was conducted using a combination of intrinsic and artificial tracers to estimate travel times and dilution during transport of infiltrate from a reclaimed water infiltration basin to nearby monitoring wells. A major study objective was to validate boric acid enriched in 10 B as an artificial tracer. Basin 10E at the Rio Hondo Spreading Grounds in Whittier, California, was the site of the test. The basin normally receives a mixture of treated municipal waste water, purchased State Project water, and local runoff from the San Gabriel River. Approximately 3.5 kg of 10 B‐enriched boric acid was dispersed among 2.05 × 10 5 m 3 of basin water to initiate the experiment. The resultant median δ 11 B in the infiltration basin was −71‰. Prior to tracer addition, the basin water had an intrinsic δ 11 B of +2‰. Local monitoring wells that were used to assess travel times had δ 11 B values of +5‰ and +8‰ at the time of tracer addition. Analytic results supported an assumption that boron is conserved during ground water transport and that boron enriched in 10 B is a useful artificial tracer. Several intrinsic tracers were used to reinforce the boric acid tracer findings. These included stable isotopes of oxygen (δ 18 O) and hydrogen (δD), sulfate concentration, and the boron to chloride ratio. Xenon isotopes, 136 Xe and 124 Xe, also supported boron isotope results. Xenon isotopes were added to the recharge basin as dissolved gases by investigators from the Lawrence Livermore National Laboratory.