The removal of a nonrenewable natural resource such as metals or petrochemicals hardly meets the definition of "sustainable". However the methods used to extract the materials can be designed for overall environmental protection. Theoretically controllable variables include water use, transportation methods, and potential remediation/landscape alteration for the postclosure period. Further, in the case of metals, recycling means that the long-term sustainability of such resources can be realized. Amezaga et al. review how mining practices have evolved to consider sustainability over the last few decades and remark on what challenges still need to be overcome.