SEDIMENT CONTAMINANT DISTRIBUTION AND CHEMICAL BEHAVIOR FROM THE TRI-STATE LEAD AND ZINC MINING DISTRICT

Historic mining of lead and zinc in the late 1800’s and early 1900’s in the Tri-State area (Kansas, Missouri, and Oklahoma) had major impacts on the environment and health of local residents. Picher, Oklahoma was a very productive town during the decades of mining. However, this small area of northeastern Oklahoma was determined to be uninhabitable due to the dangerous health risks of metal contaminants that leached into the groundwater. A study in 1996 revealed that 34% of the children in this community had lead poisoning. Due to the environmental and health impacts of the mine, officials evacuated the residents of Picher in the 1990’s. Picher, Oklahoma and areas downstream are primary locations for our study.

In this study we determined the extent of mine waste and contaminants migrated downstream, and determined if the contaminants were the original mine tailing material or if the metals were released from the mining material then adsorbed to the surface of sediments. We collected sediment samples at mine tailings piles in Picher, OK, and then traveled approximately 50 miles south sampling along the banks of Lytle Creek, the Spring River, and the Neosho River. We are using the field data and laboratory testing to determine the extent of contaminants downstream from the mine, as well as the chemical behavior of the contaminants when released. Thirteen sediment samples were collected, stored, dried, and prepared for sequential leaching analysis from various locations downstream. Sediment samples were sieved into six size fractions ranging from <63µm to >1000µm for each site sample. Then the samples were leached with the Tessier (1979) leaching procedure for the 1) Exchangeable, 2) Carbonate, and 3) Fe-Mn Oxide fractions. The results from these experiments will enable a better understanding of contaminant distribution and behavior, as well as better monitoring of the contamination near mining sites.