Elemental Contamination of an Ancient Copper Mine in Killarney National Park, Killarney, Ireland

Ross Island Copper Mine, located in Killarney National Park, Killarney, Ireland, is known for archeological artifacts of copper from the Bronze Age. Copper production surged in the late 1700s and into the mid-1800s. The mine included both open pits (e.g. Blue Hole) and underground excavations (e.g. Western Mine). Copper veins were found in the Mississippian-aged limestone bedrock along with chalcopyrite and tennantite ore. In 1912, tourism had become the main source of income in the area, and the mines and the land surrounding them were remediated and became a part of the national park. Mine shafts were filled in, waste piles were moved or disposed of, and trees were planted. Little remediation has been done since the original work in 1912. The purpose of this study is to investigate the levels of contamination in the soil and water in and around mine sites. Twelve water samples and four soil samples were taken from Blue Hole, Western Mine, Lough Leane (the nearby lake), and River Laune, located several miles downstream from the national park. The water samples were dried on micro-carry filter papers and analyzed in an XRF spectrometer for S and Cu. Soil samples, mostly of a sand or silt texture, were dried and pressed into pellets for XRF analyses of S, Pb, Cu, and Zn. Water samples had low concentrations of both Cu and S (\u3c4 and 23 ppm, respectively). Much higher concentrations of S and heavy metals were observed in soil samples, with maximum concentrations of S \u3e134,000 ppm, Zn \u3e63,000 ppm, Pb \u3e62,000 ppm, and Cu \u3e17,000 ppm. These high levels may be of concern, although leaching of these metals is unlikely to adversely affect local aquifers or wells because of dilution in nearby Lough Leane. There is no immediate threat to humans from contaminated soil, though the health of some plant species could be compromised, especially with high levels of Pb and Zn