GEOCHEMICAL ANALYSIS OF TOMHICKEN CREEK, LUZERNE AND SCHUYLKILL COUNTIES, PA

Tomhicken Creek, coldwater fishery and major tributary of Catawissa Creek, is listed as impaired, due to the biological, chemical, and physical changes caused by drainage from abandoned anthracite coal mines of the late 1800s to early 1900s. Unlike many anthracite area AMD sites, the two mines draining into Tomhicken Creek have relatively low iron and are impaired primarily by aluminum. This project allows us to compare a snapshot of water quality in Fall of 2023 to the condition of Tomhicken Creek 20 years ago, as reported in the PADEP TMDL published in 2003. Stream samples were collected at five 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. Despite contributions from two mine drains (Oneida #1 and Oneida #3), the pH at all sample sites was between 7 and 7.6. Acidity values at all sample locations were also below the allowable long term average concentration described in the 2003 TMDL. This suggests that treatment systems at the two mine drainages are successfully reducing some of the impairments identified in Tomhicken Creek 20 years ago.