LAND USE MAPPING TO DETERMINE POTENTIAL IMPACTS TO STREAMS, PIKE RUN, WASHINGTON COUNTY, PA

In Southwestern Pennsylvania, drainage from abandoned coal mines and runoff from agriculture pose potential threat of contamination to small tributaries as well as larger streams. Water quality testing was conducted along Pike Run, which flows into the Monongahela River at California, PA. Pike Run's watershed was subdivided into four sub-watersheds based on named tributaries of the local USGS quadrangle. Land use was determined for each sub-watershed, calculated as area percentages for each, with categories of deciduous forest (37 - 55%), cultivated crops (16 - 24%), pasture (10 - 21%), and developed land (7 – 10%). Based on these land use values, along with the history of underground and surface coal mines, throughout the watershed, iron, magnesium, nitrate, sulfate, and chloride were identified as potential contaminants. Water samples were tested during Fall 2023 using a field spectrophotometer to determine which source posed the greatest threat to water quality. Iron, magnesium, nitrate, and chloride measured at low or non-detectible concentrations within each sub-watershed. Sulfate tested relatively high, with concentrations between 150 – 210 mg/L at each location. Although measurements were higher for sulfate, they were below the EPA standard of 250 mg/L. With all measured contaminants below maximum concentrations as set by EPA water quality standards, it would suggest that Pike Run is not significantly contaminated by agricultural runoff or mine drainage. However, further testing, particularly considering seasonal dynamics, may be necessary to highlight contaminants related to leaking mine seals, agricultural activity, and road salt application.