Heavy Metal Content in Stream Sediments Adjacent to the Wright County, Missouri, Sanitary Landfill

Stream sediments from two intermittent streams located adjacent to a sanitary landfill were analyzed for copper, zinc, lead, barium, and chromium using atomic absorption spectrophotometry. The purpose was to determine if leachate emitted from the landfill transported these metals in solution and affected the stream sediments by adsorption or precipitation of these metals onto the surfaces of the sediments. Stream sediments from a third intermittent stream unaffected by leachate from the landfill was used as a control for the analysis. The two sediment size fractions used in the heavy metal analysis were the \u3c 63 micron and the 150-250 micron size. The mean element content for each of the five metals was higher in the \u3c 63 micron size fraction than in the 150-250 micron size fraction in the sediments of each individual stream. The mean metal content for all five metals in the sediments of the stream directly draining the landfill was significantly higher compared to the control stream sediment values for the finer grain size fraction. Similar results were obtained for the coarser grain size fraction. The mean metal content values for all five elements in the stream influenced by shallow groundwater flow were similar to the values obtained for the control stream sediments when the analytical precision of the method was taken into account. This was observed for both grain size fractions suggesting that the stream influenced by groundwater flow may not have been affected by leachate from the landfill. This method of analyzing stream sediments for heavy metals using atomic absorption spectrophotometry may be a valuable tool for the resource planner inevaluating the design and operation of a sanitary landfill