Further Analysis of the Distribution and Fractionation of Trace Metals in Relation to Other Soil Properties Along a Stream Impacted By Acid Mine Drainage.

Acid mine drainage (AMD) affects over 4700 miles of streams in the mid-Atlantic region, yet there have been few investigations on the impact of AMD on the surrounding soils, especially around mineral mines. Contrary Creek is a relatively short but significantly contaminated stream located in Louisa County, Virginia. Our research has shown that the soils along Contrary Creek are also severely affected by the AMD that is a relic of the pyrite mining that took place there from 1880 to 1923. The tailing wastes and exposed rocks produced almost a century ago continue to adversely affect the creek and its surrounding ecosystem. Most evident are high concentrations of numerous metals and low to very low pH values. The metals accumulating in the soil due to the AMD are associated with different soil fractions, properties, and depth, with each association holding various environmental implications. For the past four years, environmental samples (soils, sediments, streamwater) were collected from sites along Contrary Creek and analyzed for trace metals, pH, organic matter, clay, phosphorus, sulfur, and other properties. An adapted sequential extraction method was used to separate the different fractions of metals in soil layers of 0-10 cm, 10-20 cm, 20-30 cm, and 30-40 cm. Further analysis of the soils and data evaluates correlations with various soil properties to better understand the nature of the contamination. Results show an ongoing adverse impact, including very acidic conditions and high metal concentrations, with depth and along the stream that prompt more research questions about the trends in the trace metal contamination at this AMD site.