Characteristics of hydrochemical variations and contaminant load during rainfall in an acid mine drainage-impacted watershed, Korea

Abstract

Acid mine drainage (AMD) refers to the outflow of acidic water from usually abandoned metal mines. Since AMD is closely related to the rainfall–runoff process, it is important to monitor rainfall events for its characterization. This work aims to study the characteristics of hydrochemical variations of metals during rainfall in the Geopung Mine Watershed, Korea. Eleven dry-weather and five rainfall event monitorings were conducted in 2010 at two locations (GP-1 and GP-2). At GP-1, concentrations significantly increased during the fifth event, which was the largest one (As from 0.0003 to 0.0046 mg/l; Cd from 0.0114 to 0.2188 mg/l; Cu from 0.0206 to 3.1512 mg/l; Pb from 0.0006 to 0.1857 mg/l; Zn from 0.5823 to 15.9194 mg/l; Ni from 0.0011 to 0.0294 mg/l). Similar though less-marked trend of increase in metal concentration was found at GP-2 during the fifth rainfall event. As for the load, as much as 62–97% of the annual metal loads were accounted for by rainfall at GP-1 and GP-2. This pattern implies that most of the metals in AMD are brought into the stream by rainfall.

Keywords:

• Acid mine drainage
• Hydrochemical variation
• Metal load
• Rainfall

Acknowledgments

This research was financially supported by the National Institute of Environmental Research and Guem-River Environment Research Center. This research was also supported in part by a grant from Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (2013R1A1A4A01007676) and by a grant (13CRTI-B052117-01) from Regional Technology Innovation Program (RTIP) and another grant from Advanced Water Management Research Program funded by Ministry of Land, Infrastructure and Transport of Korean government.

Notes

Presented at the 5th IWA-ASPIRE Conference, 8–12 September 2013, Daejeon, Korea