Several mines in the western United States have developed large well fields, up to 70,000 gpm capacity, to intercept inflow and divert groundwater from the workings. Keeping the working conditions relatively dry and maintaining the stability of the excavation or opening. Operating costs and production rates are directly influenced by working conditions. Wet floors and working faces create poor ground conditions for heavy loading and hauling equipment. They also increase tire wear, reduce cycle times and impact tonnage factors.
Safety becomes a direct issue if electric powered machinery is used.
In the worst case, a submerged working level becomes inaccessible and production is halted. The stability of open pit walls and underground openings is of vital concern for safety and economic reasons. Adequate drainage must occur in order to keep pore pressure at acceptable levels based on geotechnical stability analysis. General Types of Mines and Groundwater Control Methods Mines are either open pit excavations or underground excavations, or both. In some cases large scale open pit mines have succeeded prior episodes of underground mining in the same area.