In July of 1993 an underground coal mine owned and operated by Southern Ohio coal company (SOCCO) underwent emergency recovery operations due to flash flooding of the mine from an adjacent abandoned mine. During mine dewatering operations, approximately 132,650 liters per minute of acid mine water was released into the Parker Run tributary draining into Leading Creek. The 24.2-km section of Leading Creek was heavily impacted eradicating most aquatic organisms. An acutely toxic impact resulted from the discharge of high conductivity (~6000µmhos), low pH (2.5-3.1 pH units), high metal concentrations (iron and iron floc, manganese, copper, nickel, zinc and aluminum, mg/L) and high total suspended solids (TSS). Through the process of a Consent Decree, a proactive plan was developed for monitoring the recovery in Leading Creek and to develop an enhancement plan for the watershed. SOCCO set aside $1.9 million that has grown to $2.5 million to cover the costs of implementing specific enhancement measures in the watershed. The primary goal of the enhancement plan was to describe actions that could reasonably be taken to affect measurable ecological rehabilitation or enhancement of the Leading Creek stream system so it attains the highest Ohio EPA aquatic life use designation possible. The objectives of this research project were to identify specific ecosystem stressors affecting the habitat quality within the watershed preventing Leading Creek from attaining either the Warmwater Habitat (WWH) or the Excellent Warmwater Habitat (EWH) designation and to provide potential remediation techniques to address the identified stressors. Although natural processes have lead to partial recovery in Leading Creek from the impact of dewatering, reconnaissance has shown significant problems relating to toxicity and habitat degradation in the watershed. Seventeen tributaries and ten mainstem stations were chosen to receive monthly monitoring as point source discharges, including biological, chemical, toxicological, and hydrological sampling. Specific ecotoxicological parameters studied included water and sediment quality, algal colonization upon artificial substrates, benthic macroinvertebrate sampling (qualitatively and quantitatively), acute water column toxicity, sediment chronic toxicity and </i>in situ</i> clam toxicity. Evaluation of habitat impairment included habitat assessments, in-stream riparian surveys and land use analysis. Through the analysis of laboratory and field data, agriculture and Abandoned Mined Land (AML) were identified as the two main stressors in the watershed. Agricultural practices contributed chronic toxicity through habitat degradation identified from benthic macroinvertebrate data and sediment depth measurements. AML impacted several tributaries and the Leading Creek mainstem by degrading water quality through the introduction of acidic waters, high in conductivity and heavy metals. Acid Mine Drainage (AMD) from the AML areas was pinpointed through acute testing with <i>Ceriodaphnia dubia</i> and </i>in situ</i> testing with the Asian clam, </i>Corbicula fluminea</i>. Active mining effluents from the Meigs #2 and Meigs #31 mines influenced the Ogden Run and Parker Run tributaries with conductivity values ranging from 2000 to 6000 μmhos/cm, respectively. The influence of the active mine effluents was observed down the mainstem from LCS6 to LCS10 in the form of high conductivity (~1200 μmhos/cm) and increased pH values (~8.0). Development of the enhancement plan began with the ranking of the ten mainstem stations and 17 tributary stations based on prioritization of impact parameters using an Ecotoxicological Rating (ETR) developed specifically for the Leading Creek watershed. The ETR included biological, toxicological, chemical and physical data to integrate a complete description of the impacts affecting the Leading Creek watershed. The 23 parameters in the ETR for the mainstem stations were; sediment depth, acidic pH, quantitative Invertebrate Community Index (ICI) scores, conductivity, clam <i>in situ</i> survival and growth, </i>Daphnia magna</i> and <i>Chironomus tentans</i> sediment toxicity, stormwater acute toxicity, qualitative invertebrate richness and Ephemeroptera, Plecoptera and Trichoptera (EPT) abundance, percent AML area, concentrations of sodium, copper, zinc, iron, manganese, chloride, nitrate/nitrite, ammonia, TSS, plus Qualitative Habitat Evaluation Index (QHEI) and United States Environmental Protection Agency (US EPA) habitat scores. For the mainstem stations, low flow in the summer was substituted for quantitative ICI scores. The ETR provided a single numerical score of 200 points that allowed comparisons to be made between sites within Leading Creek and tributaries within the watershed. Stressors identified within the watershed and used in the ranking of sites included agricultural sedimentation, sedimentation from AML, poor water quality from AMD and multiple toxic inputs such as acute stormwater runoff. Remediation techniques and costs were described to address poor agricultural practices and designed to alleviate sedimentation within the mainstem. Remediation techniques for AMD were described but due to the enormous amount of AML within the Leading Creek watershed, costs and specific projects were deemed beyond the scope of this research project. / Ph. D.

The Clinch River, Virginia is known for high aquatic biodiversity, particularly Unionidae which are declining at remarkable rates. Studies conducted on the mainstem have only addressed effects of point-source stressors (various toxic spills and effluents from the Clinch River Plant (CRP), Carbo, Virginia) that have been introduced into the Clinch River. It is hypothesized that the tributaries of the Clinch River deliver a variety of stressors to the mainstem, which may affect the diverse fauna. The aquatic health of 19 upper Clinch River tributaries, Virginia, was assessed via ecotoxicological ratings that indicated the least healthy catchments were associated with mining activity (Dumps, Russell and Coal Creeks). Tributaries were categorized by land use and mining streams were significantly different from agricultural and forested streams (F = 9.63, p<0.0001). Tributaries with ecotoxicological ratings (ETR) <80 from 100 were deemed suboptimal and thus studied further. Using identical response variables and upstream and downstream sites, resulting ETRs for nine streams indicated no model significance regarding land use, year, or site. Variability within treatments and low sampling sizes contributed to lack of significance, and results indicate that future studies need to be designed incorporating sites with analogous land use stressors. This first assessment of upper Clinch River tributaries indicates the catchments requiring remediation are Dumps, Russell and Coal Creeks, while tributaries requiring extensive evaluations are Big, Lick, Swords, Big Spring, Guest River, Cavitts and Middle Creeks. Tributaries that were deemed healthy (ETRs >80) were Big Stony, Copper, Indian, Stock, Little River and Cove Creeks. / Master of Science

Acid mine drainage (AMD) results from the oxidation of pyretic mineralogy, exposed by mining operations to oxygen and water. This reaction produces sulfuric acid and liberates heavy metals from the surrounding mineralogy and impairs water quality and freshwater communities. The U.S. Army Corps of Engineers has begun an ecosystem restoration project to remediate the abandoned mine land (AML) impacts to the North Fork Powell River (NFP) and is utilizing the ecotoxicological rating (ETR) system to delineate these affects to focus restoration efforts. The ETR was developed to summarize the integrative data into a single number ranging from 0 to 100, which is descriptive of the environmental integrity of a sampling station. The ETR is conceptualized to work as an academic grading scale (0 through 100), rating reference stations with A's (90-100) and B's (80-89) and impacted stations with C's (70-80), D's (60-70) and failures (F = 60). Two rounds of ETR investigations have evaluated seven headwater tributaries to the NFP including investigations of Ely and Puckett's Creek from 1997 and 1998. This thesis contains the results of the second series of ETR investigations at 41 stations in Cox Creek, Jone's Creek, Reed's Creek, Summers Fork, Straight Creek, and areas in the NFP. Eight stations were recommended for reclamation; CC 03, JCRF2 02, JCRF2 01, RCPS 09B, RCPS 11B, SULF 01, SU 02, and SU 01. Summers Fork was the most severely impacted watershed of the second round of ETR investigations. An effort to streamline the ETR to the most ecologically predictive parameters was successful in creating a system more time and cost efficient then the initial ETRs and exclusive of benthic macroinvertebrate surveys. The Modified ETR streamlined the ETR to just 5 parameters including; mean conductivity, mean Asian clam survival, mean aluminum (Al) and manganese (Mn) in the water column, and mean habitat score to describe the AMD impacts to small headwater streams. Also, an investigation was conducted to determine the mode of toxicity, (i.e., exposures to metal contaminated surface waters or sediments) by which Al and iron (Fe) dominated AMD impairs benthic macroinvertebrate communities. It was found that water column exposures both within and beyond the zone of pH depression are the most likely mode by which AMD impairs the benthic macroinvertebrate communities of the NFP. / Master of Science