ASSESSING THE SCARLIFT 15 AMD TREATMENT SITE, NORTHUMBERLAND COUNTY, PA

Acid Mine Drainage (AMD) can be disastrous to aquatic environments and AMD is a major problem though out the state of Pennsylvania. Scarlift-15, an AMD treatment site in Ranshaw, PA, was created to raise alkalinity and reduce the levels of dissolved metals coming from the abandoned Excelsior-Corbin colliery, one of many mine drains in the Shamokin Creek watershed. For this study, water samples were collected from Shamokin Creek both upstream and downstream of the treatment system, and at eight locations on site to assess the system’s current effectiveness. Conductivity, dissolved oxygen, pH, and temperature were measured in situ. Samples were collected in 4-liter acid-washed bottles and stored on ice for analysis. Triplicate analyses of turbidity, acidity (Hach method 8203), and alkalinity (Hach methods 8201/8202) were performed in the field on filtered samples. Non-filtered and filtered acidified samples were transported in ice to the laboratory for storage and later triplicate metals analyses using inductively coupled plasma – optical emission spectroscopy. Alkalinity more than tripled during treatment, from about 10 mg/L as CaCO3 to about 35 mg/L, and pH showed a modest improvement from 4.5 at the inflow to almost 5 at the outflow. Iron was reduced by nearly 80% from 21 to 4.6 mg/L . Aluminum was reduced by more than 50% from 2.7 mg/L to 1.2 mg/L, thought the outflow concentration was still higher than the 2001 TMDL allowable long term average (LTA) concentration of 0.74 mg/L. Manganese concentrations were not substantially affected by the treatment system (2.7mg/L at the inflow, and 2.5 mg/L at the outflow), and were well above both the 2001 LTA of 0.85 mg/L and the PA Human Health Toxics Criterion of 0.3 mg/L. This study indicates that although the treatment system is increasing pH and alkalinity and decreasing metals concentrations as designed, the treatment discharge still does not meet the requirements of the TMDL.