GEOCHEMICAL ANALYSIS OF SHAMOKIN CREEK IN NORTHUMBERLAND COUNTY, PA

Shamokin Creek, a tributary of the Susquehanna River, is located in Northumberland County, PA, and is impacted by abandoned mine drainage from various mine workings and mine tailings sites in the western middle anthracite field. A major in-depth study of water quality in the Creek was completed in 2001. This study attempts to determine whether the Creek’s condition have improved or worsened since then. Water samples and in-situ data (temperature, conductivity, dissolved oxygen, and pH) were collected in October of 2021 from seven easily accessible sites distributed across the watershed. The average pH values at all but one site were near neutral (6.7-6.9). Conductivity ranged from 332 to 629 uS/cm, and dissolved oxygen varied from 9.7 to 10.3 mg/L. Lab analyses were conducted to determine turbidity, acidity, and alkalinity. The most alkaline water was sampled downstream from limestone riprap on the side of the creek channel. Metal constituents were determined by ICP-OES, and common anions were identified using ion chromatography. Samples were analyzed for Al, As, Ba, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn, but only non-filtered Al (431-1623 ppb), and both filtered and non-filtered Mn (1836-2695 ppb), Fe (7110-11374 ppb), and Ni (59-111 ppb) were detected at concentrations above PA DEP drinking water standards and/or EPA freshwater chronic exposure criteria for aquatic life. Since the 2001 study, conditions appear to have improved somewhat, but a more in-depth study of both stream and mine drains would be beneficial.