MAPPING THE SUBSURFACE FLOW PATHWAYS OF NANTICOKE CREEK, NANTICOKE, LUZERNE COUNTY, PENNSYLVANIA

The Nanticoke Creek is one of many waterways in the Wyoming Valley that is impacted by the damaging repercussions of the anthracite coal mining industry. Nanticoke Creek in Luzerne County, PA seeps into the subsurface through a fracture near its headwaters, interacts with mine pools, and then resurfaces down gradient at the Askam Borehole as Abandoned Mine Drainage (AMD). The subsurface flow pathways to and through the mine pools are unknown. Characterization of subsurface flow pathways for the Nanticoke Creek can be determined using chemical water tracers and electrical geophysical techniques. A map of the creeks flow pathways in the subsurface can be used to develop plans for mitigating the AMD contamination. In this study, we use Rhodamine WT, and salt and electrical resistivity (ER) surveys to understand the timing and subterranean flow pathways through the abandoned mines. Rhodamine WT is the first water tracer that is used, which can help determine the amount of time it takes for the water to flow through the subsurface mine system from the fracture to the borehole. This time frame is used to plan the timings of a salt tracer and electrical surveying study, which will determine the exact flow pathways through the subsurface mines. The electrical resistivity equipment used in this study is a Syscal Kid Switch with 24 electrodes that are spaced evenly apart. Survey depths reached approximately 18 meters depth with this configuration. At each selected survey location, an ER survey is conducted before and after the salt tracer is added to the system. By subtracting the resistivities of the ‘before’ survey from the ‘after’ survey, the location of the salt water tracer is highlighted, and thus the location of the flow path is inferred. Multiple surveys capture the flow pathways along the proposed creek path so that a three-dimensional map of the subterranean flow can be constructed. In the future, this may be used to develop mitigation plans, such as controlling the amount of water that flows through the mines to lessen the amount of AMD. It could also be used to develop site specific methods for reducing the amount of abandoned mine drainage flowing to the surface, such as capture and treat.