The HPT is a direct push tool that produces a hydrostratigraphic log by measuring the response of soil to the injection of water as the HPT probe is advanced in the soil. HPT usage for site characterization has been growing both as a stand-alone logging tool and as an add-on tool to MIP. Geoprobe Systems® Geologist Wes McCall has many years of experience working with the HPT logging system. Wes will start this webinar with the principles of operation of the HPT, show special functions such as hydrostatic measurements and K estimations, and then show example logs from a variety of geologic settings. This training webinar will be useful to consultants and regulators who specify the usage of HPT logging on their sites and for field operators of HPT tools.