A Geophysical Program was conducted at 5 groundwater monitoring wells on March 4, 2000 at the Faro Tailings Area, Rose Creek, Faro, Yukon under the auspices of the Yukon Government's Mine Research fund, DIAND Mineral Resources and Environment Canada by EBA Engineering Consultants Ltd.
The EM39 geophysical instrument is able to measure the electrical conductivity of the ground within about 1 metre of the probe. The probe is a cylinder 3.6 cm in diameter and 1.6 m long. The probe is slowly lowered down a water well and as it is lowered, it measures the conductivity of the soils surrounding the well. As the probe is lowered, any changes in the electrical conductivity of the ground indicates either:: 1) changes in the levels of contaminants (metals like zinc in this case) in the ground, or; 2) changes in the type of soil - for example if there is sand and then a layer of clay or silt. In order to distinguish whether the change is due to 1) or 2) a gamma probe was also used. The gamma probe is also slowly lowered down the well and it only measures changes in the type of soil. By comparing the readings of the two probes, one can determine what vertical zones in the soil were being affected by changes in the levels of contaminants in the soil and the soil's groundwater.
