1994-09-19_HYDROLOGY - M1977378 ‎(2)‎

• Permit No: M1977378
• IBM Index Class Name: HYDROLOGY
• Doc Date: 9/19/1994
• Doc Name: Suitability of Bromide as a Ground-Water Tracer
• From: Hydro-Search, Inc.
• To: DMG
• Permit Index Doc Type: Hydrology Report
• Media Type: D
• Archive: No

which required 32 days to complete, was then simulated using a
three-dimensional advection-dispersion model with a longitudinal
dispersivity of 0. 15 m, a transverse dispersivity of 0. 005 m, and
the permeability distribution being measured independently in a
single-well test. (Single-well test results, which involved a
travel distance of 5.5 m, indicated that the hydraulic
conductivity varied by about a factor of 4 throughout the aquifer
thickness. ) The two-well test simulation, made without knowledge
of the test results, and without any calibration, was remarkably
good. Local hydrodynamic dispersion was negligible, so that the
concentration versus time breakthrough at the withdrawal well
could be simulated just as well with a quasi-three-dimensional
advection model having zero hydrodynamic dispersion. This implies
that over the travel distances applicable to the two-well test
the spreading of the slug in the aquifer depended mainly on
macroscopic velocity variations that were quantifiable in terms
of the inferred permeability distribution.--Modified journal
abstract.
DE: ground-water; surveys-; Alabama-; hydrogeology-;
Mobile-County; Southern-U.S. ; United-States; Mobile-; aquifers-;
simulation-; testing-; tracers-; wells-; hydraulic-conductivity;
three-dimensional-models; models-; permeability-;
experimental-studies; dispersion-; advection-; pollution-;
transport-; movement-; southwestern-Alabama
DT: Analytic; Serial
CC: 21-Hydrogeology-and-hydrology
SB: B; Bibliography and Index of Geology (1969-present)
IS: 0043-1397
GEOREF Disc 2
38 of 60
AN: 86-27828
TI: Design and performance of single-well tracer tests at the
Mobile site.
AU: Molz-F-J; Melville-J-G; Gueven-O; Crocker-R-D; Matteson-K-T
OS: Auburn Univ. , Dep. Civ. Eng. , Auburn, AL, United-States
SO: Water-Resources-Research. 21. (10) . p. 1497-1502 .
9 Refs.
CO: WRERAQ
YR: 1985
PD: illus. , 2 tables
LA: English
AB: In a given observation well, a total of 7 sampling zones were
isolated using inflatable packers and silicone rubber plugs. All
instrumentation was contained within a removable insert that
extended from the well bottom to the land surface. Each sampling
zone contained an electrical conductivity probe and was connected
to the surface with two lengths of vacuum tubing. When combined
with peristaltic pumps, the tubing allowed mixing of the sampling
zone contents as well as water sample collection. A total of 5
experiments were performed using bromide as a conservative
tracer. Results showed that the sampling zones were well isolated
and that sampling zone mixing was necessary to achieve results
that were independent of probe placement within a given zone.