In this study, water quality variation in borehole groundwaters and surface leachate waters were investigated on a seasonal sampling and remote monitoring basis within the waste impoundments at the Geopung mine site where previous rehabilitation measures were unsuccessful to prevent acidic drainage. All groundwaters were typical acidic drainage with acidic pH (3.3${sim}$4.6) and high TDS (338${sim}$3330 mg/L) values during the dry season, but increases in metal contents (TDS 414${sim}$4890 mg/L) and decrease of pH (2.7${sim}$3.6) were observed during the rainy season. Surface leachate waters showed a similar pattern in water quality variation. Surface runoff waters during rain events had acidic pH (3.0${sim}$3.4) through direct reactions with waste rocks. Good correlations were found between major and trace elements measured in water samples, but no significant seasonal variation in chemical compositions was shown except relative changes in contents. It can be suggested that dissolution of soluble secondary salts caused by flushing of weathered waste rocks and tailings directly influenced the water quality within the waste impoundments. Increases in acid and metal concentrations and their loadings from mine wastes are anticipated in the rainy season. More appropriate cover systems on waste rocks and tailings necessitate consideration of more extreme conditions in the study mine.