A GEOCHEMICAL INVESTIGATION OF SPRINGS WITHIN THE OTTER CREEK WATERSHED: WAYNE COUNTY, SOUTHEASTERN KENTUCKY

This geochemical ‘snap shot’ of data during January of 2012 reveals variations in geochemistry and hydrology within fifteen springs distributed within the Otter Creek watershed southern Wayne County, Kentucky and builds upon baseline geochemistry and hydrology data from previous abstracts. The Otter Creek watershed, a tributary of the Cumberland River at the margin of the Cumberland Plateau contains sinking streams, sulfur seeps, integrated cave systems, and Kentucky’s largest sinkhole.

In this investigation, we measured temperature (T), dissolved oxygen (DO), pH, and specific conductance (SpC) using a YSI Pro Plus. Concurrent water samples were analyzed using a HACH titration kit for concentrations of Ca and Mg. Concentrations of SO₄ and H₂S were determined using a HACH DR 2800 portable spectrophotometer. Our results cluster into three groups, traditional karst springs, tufa (travertine) springs, and sulfur seeps, each influenced by the underlying geology and the length of the flowpath.

Springs classified as sulfur seeps have higher sulfide concentrations (mean = 14.50 mg/L), sulfate concentrations (mean = 580 mg/L), warmer temperatures (mean = 13.23°C), and lower dissolved oxygen levels (mean = 1.993 mg/L). This result may be linked to nearby brines associated with reservoirs of petroleum exploited during the early 20^th Century. Tufa springs have higher pH values (mean = 8.25), relatively high alkalinity (mean = 153 mg/L), and super-saturation with respect to calcite. These springs probably resurge from long flowpaths likely along the strike of the Sunnybrook Anticline. Our mean measurements for traditional karst springs, temperature (11.66°C), pH (7.88), alkalinity (81.78 mg/L), dissolved oxygen (11.00 mg/L) and specific conductance (208.11 µS/cm), are typical of measurements in earlier studies and represent waters during the winter high flow season that are undersaturated with respect to calcite.