The Huff Run Watershed, located in Mineral City, Ohio, was mined for coal, limestone, and clay from 1853 to the late 1970s. Mine spoil is left scattered on the surface of about one third of the watershed, contributing to metal leaching to the watershed. Although the mine spoil has had time to become vegetated, camouflaging itself among the native landscape, the disturbed pyrite from coal layers is exposed to water and oxygen leading to a chain of chemical reactions, resulting in the production of potentially acidic and metal-rich porewater, which can infiltrate into the groundwater and streams. Remediation efforts for this watershed have totaled around 4.5 million dollars, but most of the remediation is focused on the point sources of contamination. Runoff from the spoil is a nonpoint source of contamination, and most areas are left untreated. These untreated areas can affect the immediate area and many kilometers downstream of the leaching. For this project, soil samples were collected from a vegetated mine spoil hill and a vegetated shale hill in this watershed, to make a physical and chemical comparison of the soils and their pore water. Solid phase characterization included particle size analysis, bulk X-ray powder diffraction, and loss on ignition (LOI). Soil pore water was collected from suction lysimeters installed at different depths (10, 40, 80, and 120 cm) at the two sites. Field-based water quality analyses included pH, dissolved oxygen (DO), electrical conductivity, and temperature; collected samples were analyzed for metals by inductively coupled plasma-optical emission spectrometry (ICP-OES), anions by ion chromatography, and dissolved organic carbon (DOC). The speciation of Al, Fe, and Mn was also determined by a sequential extraction procedure. The particle size distribution showed a sandy loam, with an overall average of 4.4% clay, 47.7% silt, and 47.9% sand in the high wall (HW) and 6.3% clay, 41.8% silt, and 51.9% sand in the mine spoil (MS). The bulk mineralogy was dominated by quartz (30.6 – 43.3 % HW; 27.5 – 49% MS) and muscovite (34.9 – 42.6% HW; 29.1 – 45.0 MS). LOI values ranged from 4.27– 8.53% in the HW and 5.35– 15.48% in the MS, with the LOI being fairly uniform throughout the vertical profile in the HW and found in high percentages of the MS in areas of residual coal. DOC values were highest in the first 10 cm of the HW (91.45 ± 23.61 mg/L), 5 times higher than the first 10 cm of the MS. Although mineralogy and particle size analysis between the two sampling sites were very similar, metal leaching and mobility were different based upon whether organics were plant-derived such as the thick organic layer on the native hill, or vs. rock-derived organics from the residual coal in layers found from 50 – 100 cm in the mine spoil hill. Aqueous Al, Fe, and Cu were highest in the first 10 cm of the HW, indicating that they are readily released from soil into solution when exposed to plant-derived organic matter, and at this depth and location increased in concentration over the field season (were fairly constant at other locations). Aqueous Mn, Ni, and Zn were found in higher concentrations in the MS. Mn and Ni concentrations at both sites and all depths decreased over the field season and Zn did not show a temporal trend. Evidence of coal in the mine spoil is found through higher LOI values (approximately 10% in MS vs. 5% in HW), and extractable Fe and Mn having its highest concentrations at depths where rock-derived organics were highest, lower levels of dissolved oxygen, and overall higher concentrations of extractable Al, Fe, and Mn. Al, Fe, and Mn were all found in highest concentrations in the reducible fraction, indicating the formation of (oxy)hydroxides after pyrite dissolution in the MS. Using the results, there is potential to quantify the amount of metal leaching from non-point source mine spoil hills the and pH changes that take place during the months of May – October and evaluate the potential for metal leaching over greater lengths of time.