GEOCHEMICAL ANALYSIS OF CATAWISSA CREEK, LUZERNE, SCHUYLKILL AND COLUMBIA COUNTIES, PA

Catawissa Creek, a tributary of the Susquehanna River, originates in Luzerne County, flows through Schuylkill County, and empties into the Susquehanna in Columbia County, PA. Catawissa Creek is impaired by abandoned mine drainage from historic anthracite coal mining operations. This project allows us to compare a snapshot of water quality in Fall of 2023 to the condition of Catawissa Creek 20 years ago, as reported in the PADEP TMDL published in 2003. Stream samples were collected at six locations previously sampled for the TMDL study. At each location, pH, conductivity, dissolved oxygen, and temperature were measured in situ. Samples were collected in 4-liter acid-washed bottles and stored in ice for transport to the laboratory. Triplicate analyses of turbidity, acidity (Hach method 8203), and alkalinity (Hach methods 8201/8202) were performed in the lab on filtered samples. Additional samples were preserved and stored for later triplicate analyses of filtered and unfiltered metals by inductively coupled plasma – optical emission spectroscopy, and common cations and anions by ion chromatography. Conductivity and acidity were highest (141 uS/cm and 32 mg/L as CaCO₃) at the upstream location, which is closest to three major mine drainages. Values decreased with distance from these inputs, and acidity values at all locations were below the allowable long term average concentrations specified in the TMDL. The pH and alkalinity values, conversely, were lowest at the upstream location, and increased with distance from the upstream sampling site. Samples near the mouth of the Creek were near neutral pH (6.8). Comparing our data to that used in the TMDL, acidity has decreased and pH has increased since 2003. Alkalinity values, however, were slightly lower. This suggests that treatment and restoration efforts in the watershed have been somewhat successful and that Catawissa Creek may be slightly less impaired today than it was 20 years ago.