USGS - science for a changing world

USGS Groundwater Information: Branch of Geophysics

*  Home *  Resources *  Research *  Publications *  About *  Contact Us *  Groundwater Information

Use of single- and cross-hole flowmeter logging for investigations in contaminated fractured-rock aquifers

by Carole D. Johnson, John H. Williams, and James Alton Anderson
U.S. Geological Survey

Abstract

Single- and cross-hole flowmeter logging are valuable methods for investigating contaminated fractured rock. Flowmeter logs collected in single boreholes under ambient and stressed conditions are used to identify vertical flow and the most transmissive fractures that intersect the borehole. Using numerical modeling methods and single-hole flowmeter data, the transmissivity and head of discrete fracture intervals can be estimated. In addition, cross-hole flowmeter tests can be used to identify and characterize the hydraulic connections between the boreholes, by logging transient flow in one borehole while pumping or injecting from another borehole.

Three case studies demonstrate the importance of single- and cross-hole flowmeter methods for improved site characterization. In the first case, the single-hole tests were used to characterize discrete-interval head and transmissivity. Flowmeter methods produced transmissivity and head values similar to hydraulic tests that used straddle packers for the most transmissive fractures in the borehole. In the second case, cross-hole flowmeter logging was used to produce more robust interpretations of open-hole pumping test data conducted in a well field. The transient flow response was used to identify and characterize a hydraulic connection that was not obvious from the open-hole water-level response to pumping from a nearby extraction well. In the third case, the flowmeter methods were used to identify and hydraulically characterize aquifer flow zones at a fractured-rock site that was to be treated with chemical oxidation methods. In each case, flowmeter methods provided valuable information for 1) site characterization, 2) conceptual modeling of ground-water flow and advective transport, 3) evaluation of cross-connections within boreholes and the potential impact on open-hole sampling, and 4) characterization of hydraulic connections between the boreholes. Collectively, these data are critical for effective design and implementation of monitoring and remediation programs.


Final copy as submitted to Geological Society of America Northeast Section Annual Meeting, March 12-14, 2007, for publication as: Johnson, C.D., Williams, J.H., and Anderson, J.A., 2007, Use of single- and cross-hole flowmeter logging for investigations in contaminated fractured-rock aquifers [abs.]: Proceedings of the Northeast Section Annual Meeting, Durham, New Hampshire, March 12-14, 2007, Geological Society of America.


For further information, contact:

Chief
U.S. Geological Survey
Branch of Geophysics
11 Sherman Place
Unit 5015
Storrs, Connecticut 06269

USGS Home Water
Climate and Land Use Change Core Science Systems Ecosystems Energy and Minerals Environmental Health Natural Hazards

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo USA.gov logo U.S. Department of the Interior | U.S. Geological Survey
URL: http://water.usgs.gov/ogw/bgas/publications/GSA_2007_Johnson/index.html
Page Contact Information: Contact the OGW Branch of Geophysics
Page Last Modified: Wednesday, 26-Feb-2014 18:46:42 EST