Predicting Potential Aluminum Contamination of Surface and Ground Waters from Acid Sulfate Enriched Drainages Emanating from Low Neutralization Capacity Watersheds

The composition of soil solutions and surface waters emanating from unreclaimed, or partially reclaimed, strip-mined watersheds with low buffering capacity in Kentucky were compared with soil solution compositions of unaffected strata in the watershed. The data suggest that almost 20 years after mining, most soil solutions and surface waters of the disturbed areas still contain high levels of dissolved Al, controlled primarily by the solubilities of a jurbanite-like mineral (upper limit) and alunite (lower limit). Soluble Al in solutions of undisturbed areas was consistent with the solubility of kaolinite or gibbsite. The absence of jurbanite x-ray diffraction peaks suggested the presence of an amorphous mineral or one stoichiometrically similar to jurbanite. Despite greater residence times for soil solutions as compared to surface waters, their compositional differences were insignificant. The control of soluble AL by basic aluminum sulfate minerals was not affected by the variable mineralogical and textural composition of soil and geologic strata in the watershed. Apparently, this is the result of low buffering capacity. At pH 4, pH and sulfate activities can be used to accurately predict the levels of soluble Al3+ in surface and ground waters of the watersheds. Similar predictions from pH and SO2-/4 activities can also be made for dissolved Fe3+ levels, supporting the stoichiometry but a much higher solubility than that of jarosite

Predicting Potential Aluminum Contamination of Surface and Ground Waters from Acid Sulfate Enriched Drainages Emanating from Low Neutralization Capacity Watersheds

The composition of soil solutions and surface waters emanating from unreclaimed, or partially reclaimed, strip-mined watersheds with low buffering capacity in Kentucky were compared with soil solution compositions of unaffected strata in the watershed. The data suggests that almost 20 years after mining, most soil solutions and surface waters of the disturbed areas still contain high levels of undissolved Al, controlled primarily by the solubilities of a jurbanite-like material (upper limit) and alunite (lower limit)

Impact of Riparian Grass Filter Strips on Surface-Water Quality

The effectiveness of natural riparian grass filter strips in removing sediment and agricultural chemicals from surface runoff was studied using no-tillage and conventional-tillage erosion plots. Runoff from the tillage plots was directed onto 4.57, 9.14, and 13.72 m (15, 30, and 45 ft.) length filter strips, where the inflow and outflow concentrations and sediment size distributions were measured. Trapping efficiencies for sediment and agricultural chemicals typically ranged near or above 90 percent, mainly because of high infiltration rates. The filters also significantly reduced peak discharge concentrations, which reduced the impact of sediment and agricultural chemicals on receiving surface waters