GEOCHEMICAL ASSESSMENT OF THE ONEIDA #3 TUNNEL AMD TREATMENT SYSTEM IN SCHUYLKILL CO, PA

Located in the eastern middle anthracite field near Hazleton, PA, the Oneida #3 mine discharge drains into Little Tomhicken Creek, which is listed as impaired due to acid mine drainage. Discharge from the Oneida #3 tunnel has been known for high concentrations of dissolved aluminum, low alkalinity and low pH. These issues have caused problems downstream from the discharge site and have also affected the aquatic life in Little Tomhicken Creek, which is designated as a cold water fishery. Samples were collected from the tunnel outflow, locations within the treatment system, and LittleTomhicken Creek both upstream and downstream of the system to assess the system’s effectiveness and its impact on the creek. In situ measurements included pH, turbidity, conductivity, dissolved oxygen, and temperature. Samples were collected in 4-liter acid-washed bottles and stored on ice for field analysis and transport back to the laboratory. Triplicate analyses of acidity (Hach method 8203) and alkalinity (Hach methods 8201/8202) were performed in the field on filtered samples. Triplicate analyses of metals were performed on acidified samples (both filtered and unfiltered) using inductively coupled plasma – optical emission spectroscopy. Conductivity is higher in the creek than in the treatment system at about 275 uS/cm vs. about 75 uS/cm, respectively. Manganese, nickel, and zinc concentrations increase through the treatment system. Aluminum concentrations decline in both filtered and non-filtered samples. The increase in pH through the system is modest (about 0.4 pH units). Detected concentrations of iron, manganese, aluminum and acidity did not exceed the 2003 TMDL-defined allowable long term average concentrations.