EFFECTS ON SOIL OF COAL METHANE DISCHARGE WATERS

Coal-bed discharge waters near Gillette Wyoming, having a high electrical conductivity (EC) and sodium contents (high SAR), have been discharged on soil, causing elevated exchangeable Na contents (high ESP) and EC values to these soils. Our purpose was to characterize the extent of soil alteration, including the accumulation of Na and the effect that Na has on the soil fertility and other selected chemical and physical properties. Impacted areas have sufficient sodium accumulations to classify them as saline - sodic soils, reducing their agricultural value. The soils are Mollisols with substantial clay (montmorillonite)contents. Unimpacted soils similarly have appreciable EC and ESP contents, although less than impacted areas, a feature attributed to the sodic shale parent materials. Gypsum admendments promote cation exchange reactions that alleviate the electrical conductivity and soil SAR values, promoting the regrown the range plants.