ABSTRACT
Environmental control and containment to prevent contamination of earth and water is nearly always less expensive than remediation after contamination has occurred. Environmental control and containment for ore heap leaching was covered in Chapter 4. Controlling the zone of contamination during in situ leaching was discussed in Chapter 10, primarily using guard wells to prevent flow outside the ore deposit. Several treatment methods for the necessary excess water that is pumped out over that injected, when using guard wells, were shown in Fig. 10.21. In spite of the best practices, contamination of spent ore heaps and solution mined subsurface regions is an inevitable result of many mineral extraction processes. Generally in solution mining, the concern is with toxic metals and chemicals used in the lixiviant. Upon completion of the mining operation, reclamation must occur that includes remediation of contaminated ground, dilute solutions retained in the mine and ore heaps and draining from them, and contaminated groundwater.
