Pollution mapping case study

This exploration survey used the cross-hole resistivity method to detect if there was industrial waste water leakage from an industrial waste water process pond. Chemical analyses concluded that this specific waste water has a much lower resistivity than normal water.

The figure below shows that the area above 45m is a relatively high resistive zone made of limestone. Below this depth is a middle resistive zone with some low resistivity spots or bands visible; they are the source of possible leaks or fracture zones.

A borehole between ZK7 and ZK8 was drilled to test one of these low-resistivity locations, and polluted water was found at a depth of 52m. Figure below shows a consistency among joints is also evident between each adjacent cross-hole. Detailed geological information can thus be obtained from this kind of resistivity survey.