The paper presents an overview of the available results of geotechnical investigations that precede the construction of substations of voltage level 35: 110: 220 and 400 kV, and the possibility of their application to solve the grounding system. The work is divided into four basic parts. As the work focuses on the implementation of investigative works, the first part deals with known research methods, the program, scope and types of soil testing. An overview of geophysical, geotechnical, geological, geomechanical and hydrological tests and the available results found in the geotechnical report - a document that processes and presents the state of the location for the construction of the substation - is presented. In the second chapter, specific geotechnical investigation works on the location of the future substation contained in parts of the geotechnical study are presented. A model for the inclusion of electrical engineers in the task of engineering geological research is proposed. His task would be active involvement throughout all three phases of the works, which by nature belong to the geological engineer. In the first phase of formulating the research, in the second phase of collecting data and in the third phase of analyzing and interpreting the data for the purpose of using them for the purpose of solving the grounding system. It also emphasizes the importance of solving the grounding system of substations and gives some specific examples of network grounding systems for which the results that can be perfectly used for the analysis and modeling were obtained during geological investigation works carried out for the very location where the future substation will be built. The third chapter presents examples of the analysis of the dynamic response of a vertical tube earthing switch, for which the results show influential quantities that, by coincidence, are excellently processed and can be optimized on based on the involvement of electrical engineers in the phase of conducting geotechnical works and preparing grounding studies. The fourth chapter presents examples of complex grounding conductors, laid in multi-layered soil with uniform characteristics in the horizontal direction, and calculations of potential and propagation resistance in the UZEM program. The conclusion provides examples of the possible use of geotechnical investigation boreholes for the application of vertical tube earthing rods, and concludes that when dimensioning earthing rods for lightning protection, it is advisable to use multiple shorter, spaced vertical tubes.