Extended Abstract In the southern part of Bavaria, several dozen un- derground pitch coal mines have been mined on an industrial scale between the 19th and the 20th century (Figure 1). Yet, first reports of coal mining date back as early as the 16th century, but their use has been locally restricted. In the 1960ies, due to political and economical reasons, the Bavarian Government and the mine operators decided to close down the remaining mining operations. Consequently, the last Bavarian pitch coal mine at the Hohenpeißenberg closed in 1971. A total of 17 mine water samples was taken in 2008 and analysed chemically. Electrical conductivities of the mine waters range between 407 and 4884 µS/cm with a mean of 1458 µS/cm and therefore significantly exceed the maximum electrical conductivity of 207 µS/cm reported for the hydrogeological sub- unit (Faltenmolasse) in which the mines occur. Also the temperature is slightly increased (a mean of 10.8 °C compared to 8.4 °C), whereas the pH shows no deviation from the normal hydrogeolog- ical situation (7.48 compared to 7.45). Those data are a clear indication for an alteration compared to the normal hydrogeological situation in the subunit (Tab. 1). Based on the Furtak & Langguth classification within the Piper diagram, ten waters are normal earth alkaline waters predominantly bicarbonatic, five are earth alkaline waters with higher alkali amounts predominantly sulphidic, one is a nor- mal earth alkaline water bicarbonatic-sulphidic, and another one is an earth alkaline water with higher alkali amounts predominantly bicarbon- atic. All the mine waters falling into the predomi- nantly sulphidic category are at the same time characterized by electrical conductivities above 2 mS/cm and elevated trace element contents. Those waters, emanating from the Marienstein Aachen, Germany IMWA 2011 “Mine Water – Managing the Challenges” Rüde, Freund  Wolkersdorfer (Editors) 639 Mine Water Discharges of the Southern Bavarian Pitch Coal District Christian Wolkersdorfer Cape Breton University, Industrial Research Chair in Mine Water Remediation & Management, PO Box 5300, Sydney, NS, B1P 6L2, Canada, christian@wolkersdorfer.info Key Words mine water; Bavaria; historical mining; hydrogeochemistry Figure 1 Location of the Southern Bavarian coal mining district south of Munich. Main locations: circles with red and orange crosses; the main syncline hosting the coal deposits is marked in brown.