Abstract:
An investigation into the geology, hydrology, and ground-water quality in the vicinity of the Linn County Landfill was conducted from July, 1988 through June, 1989. The landfill is located in an area that was strip mined for coal in the 1950s and 1960s and is operated as a sanitary landfill. An analysis of water levels from nine temporary wells, nine monitoring wells, and strip-mine ponds indicates that ground-water flow in the shallow aquifers studied is to the southwest in the southwestern part of the landfill and to the northeast in the northeastern part of the land~ill. A county road acts as a barrier to shallow ground water flowing southwest from the landfill and seasonal variations may also occur in the pattern of ground-water flow.
Analysis of water samples from the nine monitoring well s, an up-gradient pond, and two public-water supplies indicates that, based on major ion ratios, four water types exist in this area. They are: calcium sulfate, calcium magnesium sulfate, magnesium calcium sulfate, and sodium potassium sulfate. Volatile organic compounds were detected in four of the monitoring wells and the two public-water supplies. None of the inorganic or organic compounds detected exceeded Kansas primary drinking-water standards. Concentrations of total hardness, sulfate, dissolved solids, iron, and manganese exceeded Kansas secondary standards in some or all of the monitoring wells and in the up-gradient pond water. Landfill leachate is affecting ground-water quality, as indicated by larger concentrations of organic compounds, iron, and manganese in water wells in or down gradient from landfill wastes. Leachate could migrate west or northwest from the current landfill area and will have the potential to migrate north from the landfill extension. Water levels and chemical concentrations indicate that a hydraulic connection exists between the coal-mine spoil material and the underlying limestone and also between the spoil material and the horizontally adjacent bedrock.
