Remediation of Legacy Arsenic Mining Areas in Yunnan Province, China

Background. Three villages in Yunnan Province were identified to have abandoned arsenic mines severely contaminating the local water supplies. Other villages in the Province had similar problems causing the Yunnan Environmental Protection Bureau (YEPB) to seek assistance in developing a remedial strategy. Objectives. Identify the immediate hazards, develop practical remedial approaches, with focus on human health impacts associated with contaminated drinking water. Develop a blueprint for dealing with other isolated mine pollution problems in the mountains of Yunnan. Materials & Methods. A technical team from Blacksmith Institute, TerraGraphics Environmental Engineering and Yunnan Environmental Protection Bureau (YEPB) visited the sites and conducted environmental sampling. TerraGraphics prepared a technical review of each site, a discussion of human health risks and objectives for remedial actions, using United States Environmental Protection Agency (USEPA) guidance for waste site evaluations. From the recommended interventions for each site, YEPB selected a site for construction remediation. Results. Samples of wastes, soils and water indicated high metals contamination at all three sites. The closed arsenic refinery in Wenshan County was selected for a demonstration cleanup project. Subsequent analyses showed significant improvements in metals levels and achievement of remedial objectives. The site is recognized as a model for other mining sites in Yunnan. Conclusions. The success of the demonstration project was recognized and has provided direction and momentum for a wider effort by the Province to address mining pollution and water contamination challenges. It demonstrates the success of using known techniques for environmental remediation in the US, with local partners in China responding to their communities’ health and environmental problems.