Tar Creek Basics

Subsidence and Collapsing Mine Near Picher, OK

Image and Animation © G. Manders

Rain collects in the mine tailings, known as ‘chat.' When it drains from the chat piles, the heavy metal residue is transported with the tailings. The residue is transferred from the piles by water to soil. One of the most significant of these problem areas is Tar Creek, in Ottawa county of Northeast Oklahoma.

The Tar Creek Superfund Site is a part of the vacated lead and zinc mining area in The Tri-State Mining District. Roughly speaking, it includes 104 square km of traumatized land and polluted water in the northeastern-most part of Oklahoma.

Tar Creek is named for the polluted stream that meanders through the area. More than 1.3 million tons of lead and 5.2 million tons of zinc were produced.  The abandoned mines and shafts are a concern for residents and to the State of Oklahoma due to stability and subsidence problems and pollution.

Mining operations degraded the surface, left 165 MM tons of mine and mill tailings in chat piles or settling ponds. Also abandoned were approximately 300 miles of tunnels and more than 2600 shafts and boreholes. Many of these mines are under residences and other community areas and there are many millions of cubic meters of contaminated ground water.

In the late 1970s, metal-infused waters began to discharge into surface waters from springs, bore holes and mine shafts. The site was listed on the Environmental Protection Agency's National Priorities List in 1983. Acid Mine Water that circulated through the abandoned mines has contaminated Tar Creek, raising concern for human and animal life in the area.  Lead-contaminated soils and chat piles are also a means of exposure to the area's population, especially to young children. 

People who live in Tar Creek, especially residents of Picher and Cardin, may still be exposed to contaminants because they may live close to chat piles, mill and mine residues, and flotation ponds.  Many Picher and Cardin homes are within 250 feet of tailings. The tailings reach residences due to airborne dust from tailings piles and ponds and use of chat as fill and for surfacing driveways.

Approximately 70% of the Superfund site is Native American owned. Northeastern Oklahoma is the home to many tribes and the contamination of soil, water and vegetation leaves their members at risk due to involvement of the land in their ceremonies.

The district is one of the largest Superfund sites in the United States covering about 50 square miles. Oklahoma's Superfund cost estimates for remediation and ongoing supervision of the area range from over $500 million to billions of dollars.

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