The semi-arid landscape of Casper, Wyoming presents a unique challenge for geotechnical engineers — a region where the North Platte River carved through ancient sedimentary formations, leaving behind interbedded sandstones and shales whose permeability can vary by orders of magnitude across a single site. When a project demands accurate hydraulic conductivity data, laboratory tests on small specimens simply cannot capture the influence of fractures, bedding planes, and secondary porosity that dominate flow in the Casper Sandstone and underlying units. The Lefranc and Lugeon in-situ permeability methods address this gap directly, measuring water intake at discrete intervals within a borehole under controlled head conditions. In our experience working across Natrona County, from the river terrace deposits near downtown to the higher benches east of Casper Mountain, understanding how water moves through the subsurface often determines whether a foundation design succeeds or fails.
What makes Casper unique is the Casper Sandstone’s dual-porosity behavior — matrix permeability is often negligible until fractures are intersected, at which point the Lugeon value can jump two orders of magnitude.
