Cleanup from mining in Kansas

Lead and zinc mining

The legacy of lead and zinc mining in southeast Kansas, which began in 1870 and ended 100 years later, includes a number of physical hazards and environmental problems that endured long after operations ceased. Open and collapsed mine shafts and areas of surface subsidence have claimed lives and caused property damage. As recently as 2009, an apartment building in Galena partially collapsed after the ceiling of a mine dug under the town gave way.

The final phase of mining, known as "robbing the pillars," caused much of the subsidence. In that process, the pillars of rock that had been left standing to support a mine roof were removed. Without supports, a roof eventually collapses and the surface subsides into the resulting void.

In the early 1980s, the U.S. Bureau of Mines, in cooperation with state geological surveys, conducted detailed studies of the physical hazards associated with the Tri-state mining area, which includes the southeast tip of Kansas and parts of Oklahoma and Missouri. The studies identified more than 1,500 open shafts and nearly 500 subsidence collapse features in the Tri-state area, including 599 mine hazards in and around Galena. Many there were concentrated in an area known as "Hell's Half Acre," which has since been cleaned up. In 1994 and 1995, the U.S. Environmental Protection Agency (EPA) and local citizens filled in all the mine collapses and shafts in Galena and new top soil was hauled in.

Serious environmental problems also were addressed. After the mines closed and the pumping stopped, the abandoned tunnels filled with water, which became contaminated with iron sulfide (from pyrite and marcasite) and other metallic sulfides in the mines. Water seeping and flowing from the mines, in turn, contaminated local streams, springs, and groundwater resources.

Huge piles of crushed rock, called tailings, left on the surface after mining also contributed to the contamination because water leached lead, zinc, and cadmium out of the tailings. Wind-blown dust from tailings piles and roads paved with the tailings spread the contaminants to nearby non-mined areas. During the 1980s, this part of the Tri-state mining district was considered one of the most environmentally blighted regions in the country.

Much of the cleanup effort was funded through the EPA Superfund. Because the area in and around Galena had some of the worst contamination, early cleanup efforts were centered there. Chief among them was the provision of a safe water supply for rural residents whose wells had been contaminated.

In 2008, the EPA provided $8 million, mostly Superfund money, to buy out and relocate about 1,600 residents of Picher, Oklahoma, just south of the Kansas state line. Mountains of tailings towered above the town, and water and soil contamination was excessively high. In 2009, the EPA allocated $3.5 million to the Kansas Department of Health and Environment to buy out and relocate about 100 remaining residents of Treece, Kansas, not far from Picher and also highly contaminated.

Coal mining in Kansas

Coal mining, too, resulted in environmental issues in Kansas.

Coal beds too thin to be mined underground were stripped by power shovels, some of which dug to depths of almost 100 feet. One of the world's largest power shovels, Big Brutus, used in Cherokee County, is now part of a museum with exhibits on coal mining and southeastern Kansas.

Strip mining left the land marked with deep ditches and high ridges. As the shovels removed the overburden, they created trenches up to 100 feet wide and as much as 100 feet deep. Before widespread land reclamation was required in 1969, this land was abandoned and left to grow back to trees and brush while the trenches filled with groundwater.

The Kansas Department of Wildlife, Parks and Tourism now manages 14,500 acres of unreclaimed land and lakes in southeast Kansas as the Mined Land Wildlife Area. The area includes rugged hills created by strip mining and more than 1,000 lakes that developed in unreclaimed ditches.

Gob piles, the piles of discarded coal waste and fractured rock, were another problem associated with abandoned coal mines. These gob piles contained iron pyrite, sometimes called fool's gold because of its yellow metallic luster. When exposed to water and oxygen, pyrite undergoes a chemical reaction that produces sulfuric acid, iron oxides, and hydroxides. Sulfuric acid pollutes both the water and soil around the mines. The iron oxides and hydroxides, similar to common rust, tint gob piles red.

In 1969, the Kansas Legislature passed regulations requiring coal companies to reclaim the land. Subsequently, more stringent federal regulations were enacted. Today strip mines must be converted into useful productive land. Once an area has been mined, companies must smooth out the ditches, replace the topsoil, and plant grass or crops similar to what was present prior to mining. In theory, once the land is leveled, it can be used for farming or grazing. However, pyrite left behind from the coal mining must be buried because when exposed it increases the acidity of the soil.