The Tri-State Mining District in parts of southeast Kansas, southwest Missouri, and northeast Oklahoma was the primary source of lead and zinc ore in the world for much of its 120-year history. Commercial mining in the Kansas part of the Tri-State Mining District began in the mid-1870s and lasted until 1970. The environmental degradation caused by 100 years of mining resulted in the U.S. Environmental Protection Agency listing the Cherokee County, Kansas, part of the Tri-State Mining District on its National Priority List as a superfund hazardous waste site in 1983. To assist in the injury determination and quantification step of the natural resource damage assessment for Cherokee County, Kansas, the U.S. Geological Survey in cooperation with the U.S. Fish and Wildlife Service and the Kansas Department of Health and Environment conducted a two-phase study of the occurrence and distribution of contaminated streambed and lake-bottom sediment. Phase I of this study determined concentrations of 28 trace elements and nutrients in streambed sediment at 87 sampling sites in the Spring River and Tar Creek watersheds in Kansas. Phase II determined bottom-sediment concentrations and mass accumulation and historic transport of trace elements into Empire Lake, an impoundment of the Spring River. The purpose of this report is to present the results of phase I of this study. Streambed-sediment samples (98 composite samples) were collected from the upper 0.8 inch of sediment deposition, and the less than 0.063-millimeter (silt-and clay-size particles) fraction was analyzed for selected trace element and nutrient concentrations. Restricting analyses to the silt/clay fraction reduced particle-size induced variability between sampling sites and permitted direct site-to-site concentration comparisons. Concentrations of cadmium, lead, and zinc had much greater ranges in concentrations than any other elements analyzed. Ranges in concentrations were 0.6 to 460 mg/kg (milligrams per kilogram) for cadmium, 22 to 7,400 mg/kg for lead, and 100 to 45,000 mg/kg for zinc, with median concentrations of 13, 180, and 1,800 mg/kg, respectively. Concentrations were largest at sampling sites in the Short, Tar, and Spring Branch Creek watersheds containing the most intensively mineaffected streams. Concentrations of cadmium, lead, and zinc in streambed sediment from sampling sites on the Spring River increased about 18, 7, and 17 times, respectively, within its 22mile length in the study area. This finding may explain a downward trend in mussel diversity and density over the same length of stream as determined by the Kansas Department of Health and Environment. Concentrations of cadmium, lead, and zinc exceeded selected probable effects sediment-quality guidelines (4.98, 128, and 459 mg/kg, respectively) in 64, 56, and 75 percent of samples, respectively, from the 87 sampling sites. These guideline values are not regulatory criteria. Concentrations larger than probable effects guidelines frequently cause toxicological effects to some aquatic-life f...

Nitrogen-enriched groundwater has been proposed as an important anthropogenic source of atmospheric nitrous oxide (N 2 O), yet few measurements of N 2 O in large aquifer systems have been made. Concentrations of N 2 O in water samples collected from the 124 000 km 2 central High Plains aquifer in 1999 ranged from < 1 to 940 nM, with a median concentration of 29 nM (n ) 123). Eighty percent of the N 2 O concentrations exceeded the aqueous concentration expected from equilibration with atmospheric N 2 O. Measurements of N 2 O, NO 3 -, and 3 H in unsaturatedzone sediments, recently recharged groundwater, and older groundwater indicate that concentrations of N 2 O in groundwater increased over time and will likely continue to increase in the future as N-enriched water recharges the aquifer. Large concentrations of O 2 and NO 3 -and small concentrations of NH 4 + and dissolved organic carbon in the aquifer indicate that N 2 O in the central High Plains aquifer was produced primarily by nitrification. Calculations indicate that the flux of N 2 O from the central High Plains aquifer to the atmosphere from well pumping and groundwater discharge to streams was not a significant source of atmospheric N 2 O.

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