Delineating the Vertical Extent of a Saline Plume
Borehole geophysical logging systems for groundwater contaminant delineation are highly portable, use small diameter tools that can fit into a 2-inch piezometer, and can be run in PVC casing. Here, natural gamma and formation conductivity logs are being run. The gamma log will distinguish sands from clays. The induction log will measure the formation conductivity beyond the borehole. Where high formation conductivities correlate with sands, elevated salinities are very likely present. Data are collected every 2.5 cm in the borehole. A 30 m deep PVC-cased monitoring well can be easily logged in less than one hour. The equipment can be moved in a small vehicle, on a hand pulled toboggan, or carried on foot.