Surface Water Quality and Aquatic Ecological Health in Central Appalachian Streams
Cook, Nicholas Alexander
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The Central Appalachian region is home to several resource-extraction industries, a host of globally unique aquatic wildlife species, and region-wide poverty. These overlapping circumstances make solving environmental issues in the region challenging. Of particular focus is the coal mining industry, both because of its prevalence and because of controversial methods of practice such as mountain top mining. One of the primary concerns in the region is the extirpation of sensitive aquatic macroinvertebrate species. Several studies have suggested the primary driver of this loss of biodiversity is due to increased conductivity in streams impacted by these mining practices. The reality is that several pollutant sources coexist in these Central Appalachian watersheds. Because of geographic isolation, many headwater communities lack proper sewerage and discharge directly into nearby waterways, compounding potential effects of upstream mining activities. Additionally, several legacy sites exist throughout the Appalachian region, both underground and surface mining in nature. To best mitigate ecological impacts of all of these pollutant types, relative contributions of each must be understood, as well as the nature of the pollution contributed by each. As a contribution towards this region-wide need for better information on pollution, the studies comprising this dissertation seek to better understand the composition of these different pollutant sources and their in-stream contributions to conductivity. The first paper found that these sources are indeed distinct in their inorganic ion make-up: surface coal mining was found to contribute primarily Ca, K, Ni, Se, and SO₄⁻², while untreated household waste (UHW) was primarily associated with P. HCO₃⁻ Mn, and Si were found to be associated with a legacy underground discharge. The second and third scientific studies included here analyzed conductivity's effect on Virginia Stream Condition Index (VSCI) versus other water quality and habitat parameters as well as the effect of specific ion suites on VSCI score. Findings indicated that excellent habitat extends species resilience against elevated conductivity, with passing VSCI scores found at conductivity in the 600-800 µs/cm range in cases of excellent habitat metric scores. Meanwhile, VSCI score suppression was highly related to surface mining-related inorganic ions (Ca, K, Mg, Ni, and SO₄⁻²), but also negatively correlated with ions related to UHW (P and Na). These results indicate the need for quantification of biological responses to specific ions in order to initiate targeted mitigate of pollutants in Central Appalachian watersheds.
- Doctoral Dissertations