ASSESSMENT OF WATER QUALITY AND MICROBIAL POPULATIONS OF ACID MINE DRAINAGE ENTERING AND EXITING A VERTICAL FLOW WETLAND TREATMENT SYSTEM NEAR RANSHAW, PA (NORTHUMBERLAND COUNTY)

Acid mine drainage (AMD) is a serious pollution problem in Pennsylvania waterways, with over 3,000 miles of streams impacted by it (Urban 2012). AMD results when iron-sulfide bearing rocks are exposed to water and oxygen, creating an orange precipitate called “yellow boy” through a series of oxidation-reduction reactions. Our project was based in Northumberland County, PA, and its goal was to assess both the water chemistry and associated microbial populations in samples of yellow boy taken both before entering and after exiting a gravity-fed vertical flow wetland AMD treatment system (Scarlift 15). The AMD originates from the abandoned Corbin Mine Pool and discharges into Shamokin Creek just outside Ranshaw, PA, in the Middle Anthracite Belt. Dissolved oxygen (DO), oxidation-reduction potential (ORP), pH and conductivity were measured in-situ, and large volume water samples as well as samples of yellow boy were collected and returned to the lab for analysis for turbidity, alkalinity, simple cations and anions, and a suite of 11 metals. Yellow boy samples were frozen and the genetic material later isolated and sent to GENEWIZ, Inc. (Suzhou, China)for analysis using their 16S EZ metagenomics protocol. Results indicated that concentrations of dissolved aluminum and iron were reduced by the system 16.7 to 2.66 ppm for iron, 3.8 to 0.029 ppm for aluminum, and the pH and alkalinity were raised from 4.46 to 7.53 and 19 to 363 mg/L as CaCO₃, respectively, consistent with results from previous years and indicating continued functioning of the treatment system. Genetic analyses indicated 37 Operational Taxonomic Units (OTUs) unique to the inflow samples and 149 OTUs unique to the outflow samples, as well as 131 OTUs common to both. This study is the first assessment of microbes important to the iron and sulfur cycles at the Scarlift 15 Treatment System and will be expanded to analyze microbes in AMD discharges from other mine pools in the Middle Anthracite Belt of Pennsylvania.