Kansas Water Science Center
Period of Project: 2004 to present
Historical lead and zinc mining in the Tri-State Mining District (TSMD) (located in southeast Kansas, southwest Missouri, and northeast Oklahoma) has left a legacy of contamination in Cherokee County, Kansas. To accomplish restoration objectives, information on the magnitude and extent of mining-related contamination is needed. To provide some of the required information, the U.S. Geological Survey is conducting studies to define sediment contamination in streambeds, lakebeds, and flood plains, and quantify the transport of contaminated sediment, in and near the Cherokee County superfund site.
Photos of Interest
For the Cherokee County superfund site, background concentrations of cadmium, lead, and zinc were estimated to be 0.6, 20, and 100 mg/kg, respectively. Streambed-sediment samples collected at 87 sites in the Spring River and Tar Creek basins within the superfund site indicated substantial mining-related contamination. For cadmium, the median and maximum sediment concentrations were 13 and 460 mg/kg. For lead, the median and maximum sediment concentrations were 180 and 7,400 mg/kg. For zinc, the median and maximum sediment concentrations were 1,800 and 45,000 mg/kg. Generally, 100 percent of the sampling sites in the areas most affected by mining had concentrations of cadmium, lead, and zinc that exceeded general probable-effects guidelines for adverse aquatic biological effects (Pope, 2005).
For Empire Lake, the total volume and mass of contaminated sediment stored in the lake was estimated to be 44 million cubic feet and 2,400 million pounds, respectively. The bottom sediment was estimated to contain 78,000 pounds of cadmium, 650,000 pounds of lead, and 12 million pounds of zinc. Cadmium concentrations in the bottom sediment ranged from 7.3 to 76 mg/kg with a median of 29 mg/kg. Lead concentrations ranged from 100 to 950 mg/kg with a median of 270 mg/kg. Zinc concentrations ranged from 1,300 to 13,000 mg/kg with a median of 4,900 mg/kg. The bottom-sediment concentrations of cadmium, lead, and zinc have decreased with time but still exceed the general probable-effects guidelines for adverse aquatic biological effects (Juracek, 2006, 2008).
Downstream at Grand Lake O’ the Cherokees in northeast Oklahoma, mining-related contamination was substantially less compared to Empire Lake. Cadmium concentrations in the bottom sediment ranged from 2.3 to 3.6 mg/kg with a median of 3.5 mg/kg. Lead concentrations ranged from 35 to 102 mg/kg with a median of 59 mg/kg. Zinc concentrations ranged from 380 to 986 mg/kg with a median of 765 mg/kg. Cadmium concentrations were substantially less than the general probable-effects guideline (4.98 mg/kg) and a TSMD-specific guideline (11.1 mg/kg). Lead concentrations were substantially less than both the general (128 mg/kg) and TSMD-specific (150 mg/kg) probable-effects guidelines. Zinc concentrations typically exceeded the general probable-effects guideline (459 mg/kg) but were substantially less than a TSMD-specific guideline (2,083 mg/kg) (Juracek and Becker, 2009).
Flood-plain contamination along the Spring River, its major tributaries, and Tar Creek was assessed within the superfund site. Typically, surficial soils on the Spring River flood plain had lead and zinc concentrations that were less than the general probable-effects guidelines. The largest lead and zinc concentrations usually were located close to the channel. Lead and zinc concentrations greater than the general probable-effects guidelines were infrequent at depth in the Spring River flood plain and, when present, typically was confined to the upper 2 feet or less. Tributaries with extensive lead- and zinc-mined areas in the basin—Shoal Creek, Short Creek, Spring Branch, Tar Creek, Turkey Creek, and Willow Creek—had lead and zinc concentrations that frequently or typically exceeded the general and (or) TSMD-specific probable-effects guidelines. The largest flood-plain lead and zinc concentrations were measured for Short and Tar Creeks. For the flood-plain soils, both the coarse (larger than 63 micrometers) and fine particles (less than 63 micrometers) contained substantial lead and zinc concentrations (Juracek, 2013).