Composite analysis of slug interference test results to determine aquifer vertical anisotropy, using a single-well multilevel monitoring well system
- Pacific Northwest Lab., Richland, WA (United States)
- Westbay Instruments Inc., North Vancouver, British Columbia (Canada)
Determining aquifer vertical anisotropy (i.e., ratio of the vertical to horizontal hydraulic conductivity) is important for selection and design of remediation technologies at contaminated ground water sites. At hazardous waste sites, regulatory constraints may inhibit or eliminate the possibility of conducting pumping tests because of the disposal of contaminated ground water. Slug interference testing provides an alternative to pumping tests for obtaining intermediate-scale aquifer hydrologic properties without extracting large volumes of ground water. The tests are conducted by instantaneously changing the water level in a well and monitoring the response at one or more observation wells. The technique used to analyze slug interference responses in confined and unconfined aquifers is based on the mathematical conversion of slug interference responses to an equivalent constant-rate pumping test response. Diagnostic analysis of log-log plots of the equivalent response and its derivative for individual monitoring zones can then be used to determine test and formation characteristics, as is commonly done for constant-rate pumping tests. If the diagnostic analysis of data from different monitoring intervals indicates similar test/formation characteristics, converted slug interference responses can be plotted compositely and analyzed simultaneously to provide aquifer hydraulic properties, including vertical anisotropy. Recent developments in modular multilevel monitoring equipment enable this type of detailed hydraulic characterization to be extended to individual observation wells, allowing multiple isolated depth intervals to be monitored within a single well.
- OSTI ID:
- 122462
- Report Number(s):
- CONF-9510211-; ISSN 0017-467X; TRN: IM9547%%42
- Journal Information:
- Ground Water, Vol. 33, Issue 5; Conference: 1995 Association of Ground Water Scientists & Engineers (AGWSE) educational program, Indianapolis, IN (United States), 28-30 Oct 1995; Other Information: PBD: Sep-Oct 1995
- Country of Publication:
- United States
- Language:
- English
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