Mining water use is water used for the extraction of minerals that may be in the form of solids, such as coal, iron, sand, and gravel; liquids, such as crude petroleum; and gases, such as natural gas. The category includes quarrying, milling of mined materials, injection of water for secondary oil recovery or for unconventional oil and gas recovery (such as hydraulic fracturing), and other operations associated with mining activities. Dewatering is not reported as a mining withdrawal unless the water was used beneficially, such as dampening roads for dust control. This web page provides an overview of USGS's research about mining water use. It includes related research and a collection of data and tools (Introduction).