COMPARISON OF ABANDONED MINE DRAINAGE AT BIG MINE RUN (SCHUYLKILL CO) AND STIRLING DISCHARGE IN NORTHAMPTON CO., PENNSYLVANIA

Big Mine Run (BMR) and Stirling Discharge (SD) are both located in the western portion of the middle anthracite field of Pennsylvania. While both stream beds are coated in yellow boy (iron oxyhydroxide precipitate), the drainages differ in their chemistry. On 17 October 2008 we visited both sites and made in situ measurements of pH, temperature, dissolved oxygen (DO), oxidation reduction potential (ORP), and conductivity. Triplicate samples were collected at four stations at BMR and three stations at SD for lab analysis of alkalinity, acidity, sulfate, and various dissolved metals. The filtrand collected in the field was analyzed using scanning electron microscopy (SEM). Values at BMR/SD were as follows: pH= acidic/near neutral; ORP= positive/negative; DO= oxic(close to saturated)/hypoxic. Temperature, conductivity, and acidity were relatively similar at the two sites. Sulfate levels at BMR were greater than or equal to 500 ppm versus about 330 ppm at SD. No measureable alkalinity was observed at BMR versus 40+ ppm (as CaCO₃) at SD. All metals concentrations, except iron, were higher at BMR. Cd and Pb were not detected at either site.