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Highlights
- Integrated geological and geophysical regional evaluation
of groundwater potential
- Test well drilling, geophysical logging and construction
- Test pumping and determination of safe yield.
Background
The need to identify alternative water supply sources for
the Peak Hill gold mine led to a series of staged geological
and hydrogeological studies.
C. M. Jewell & Associates was commissioned to identify
and prove sustainable groundwater supply for the mine. The
studies covered three prospective zones selected on the
basis of desktop evaluation, geological inference and regional-scale
geophysical surveys. Initial scoping studies of each site
indicated that the fractured sandstones of the Hervey's
Range offered the best prospect of locating the required
water supply.
Hydrogeological Environment
The Herveys Range is composed of Palaeozoic metasediments
and intermediate volcanic rocks. These are both folded into
a synclinal feature, and faulted and fractured under tectonic
stresses. Groundwater yield is related to the density and
intersection of faults and joints. Interconnection of fracture
sets is the main determinant of groundwater yield.
Scope
Following the selection of the Herveys Range site, which
included evaluation of existing geological maps, the aeromagnetic
survey of the district and mapping of inferred fracture
lineament, the location of drilling sites was chosen. Five
boreholes penetrating to depths of between 79 and 115 metres
were drilled. Three boreholes were developed as wells and
pump tested to assess of long-term yield. Subsequent analysis
of test results led to the adoption of an optimal, cyclical
pumping schedule for long-term production. 
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Projects