is an aerial photograph of an abandoned gold mine refinery site near Phillipsburg, Montana.
The waste rock pile at the site was mainly composed of pebble to boulder size crushed clean granite. The original creek channel had been diverted as
the rock was dumped at the site, shifting it to the south.
A developer used most of the rock to build roads on the property and had
excavated to nearly the original ground level to build the pond shown here.
While excavating the pond a spring was uncovered which proved to be a real
gusher. The situation developed into a legal issue of importance and it became
necessary to locate the source of the water without doing any further
Our hydrologic review of the sight suggested that the source could be the
old creek channel suggested above (Paleochannel). Another view was that
the developer had installed a French drain from the existing creek location
without the proper permits or water rights.
ECHOTECH conducted two resistivity profiles; one along the present creek
embankment (Line 1), and the other across the entire drainage and both proposed
sources (Line 2).
The first profile showed the presence of the paleochannel as predicted.
Profile 2 showed the paleochannel again, but also showed the presence of water
at the location of the suspected French drain. The size of this feature,
however, was much larger than expected.
We concluded from this that a French drain had not been constructed
recently, but that the entire waste rock pile was a huge rock drain capable of
channeling water through the porous matrix.