Contaminant Attenuation Processes at Mine Sites

The global imprint of acid drainage problems at mine sites is a clear reminder that generally, natural processes do not adequately ameliorate the acidity and metal contamination produced by oxidizing sulfide minerals. Yet at nearly all such sites, natural attenuation processes occur and may contribute to site remediation. Biogeochemical processes can be particularly important in controlling the transport and fate of certain metal and metalloid contaminants, under specific environmental conditions. This paper identifies the major natural attenuation processes that have been documented at mine sites around the world and discusses how monitored natural attenuation is sometimes used in combination with active treatment technologies to achieve site-specific remediation objectives.