The present study was conducted in the Bartin region of Turkey, which has active coal mining. Coal veins are generally located between elastic layers, which are overlain by volcanics. Correlation and factor analyses were applied in order to determine the processes controlling the chemical composition of groundwater. The findings show effects on the physicochemical composition of groundwater of coal level and volcanic rocks. Theses results showed a contamination by Al, Fe, Mn, Pb, B and As, of water discharging from coal levels and volcanics. Al, Fe, Mn, Pb (in one spring) concentrations in these waters exceeded Turkish and WHO drinking water standards, and As concentrations were higher than in other waters. Some of these waters are used by surrounding towns for drinking, domestic and irrigation purposes. Springs discharging from the volcanic Yemislicay Formation have Na-HCO3 facies, and waters discharging from other geological formations have Ca-HCO3 facies.