Abstract⎯The hardware complex that was produced by OOO Polynom, Khabarovsk, for registration of the level, temperature, and electrical conductivity of ground water in wells and meteorological parameters (atmospheric pressure, air temperature) at a measurement frequency from 5 min to 1 h is described. The equipment is installed in the wells of Kamchatka and has been used for several years to register variations caused by earthquakes in the parameters of ground waters. Different variations in measured parameters of ground waters due to strong earthquakes of February 28, 2013, M W = 6.8 and May 24, 2013, M W = 8.3 are registered with this equipment in wells YuZ-5 and E-1. The registered variations and their systematization are described taking into account the mechanisms of a seismic impact on the state of the well-water-saturated rock system. Keywords: well, water level, electrical conductivity, hardware complex, earthquake, Kamchatka DOI: 10.3103/S0747923917040065 INTRODUCTION Strong earthquakes can be accompanied by different variations in the levels, temperature, and chemical composition of ground water in wells. In Kolylova (2006Kolylova ( , 2010, we termed them hydrogeoseismic variations and showed that the features of their manifestation are determined by different seismic impacts on the state of the "well-water-saturated rock" system.The changes in the static stress field during the formation of ruptures in the earthquake foci and corresponding variations in the stress-strain state of the water-saturated rocks manifest themselves in coseismic jumps of the increase or decrease in the water level during the first few minutes after the arrival of seismic waves. Dynamic strain of water-saturated rocks and shaking of a well bore can also be accompanied by various co-and postseismic effects in the changes of levels and chemical composition of ground waters under the passage of seismic waves from strong earthquakes. Such effects are described in numerous works, e.g., Kopylova, 2001Kopylova, , 2006Kopylova et al., 1994;Wang and Manga, 2010. When studying them, the researchers focus their attention primarily on the explanation of hydrogeodynamic and hydrogeochemical processes of their formation and general estimation of an impact of strong earthquakes on the state of the fluid-saturated geological medium.