Methods for hydrologic monitoring of surface mining in the central-western United States

Abstract

Concern over the possible hydrologic impacts of surface mining has resulted in the Surface Mining Control and Reclamation Act of 1977 (Public Law 95-87). This law is administered by the U.S. Office of Surface Mining Reclamation and Enforcement and a designated State agency. The regulations promulgated pursuant to the Surface Mining Control and Reclamation Act require the monitoring of potentially impacted hydrologic systems before, during, and after mining operations. Regional and local differences in hydrologic systems prevent the law from directly addressing the specific requirements regarding how, when, and where to monitor. This report details characteristics and processes that commonly determine the most acceptable approaches to hydrologic monitoring in the arid and semiarid central-western United States. No single approach is best for all hydrologic systems; consideration of basin characteristics, regulatory requirements, and regional patterns in hydrologic systems is necessary in any well-designed monitoring program for hydrologicimpact assessment. This report describes processes and characteristics that control the surface and subsurface hydraulics, as well as the water quality, of typical hydrologic systems being mined in the central-western United States. After a discussion of these processes and characteristics, three examples are presented that describe acceptable, but nonexclusive, approaches to hydrologic monitoring network design.