English

Abstract

The Tar Creek Superfund Site is a portion of the abandoned lead and zinc mining area known as the Tri-State Mining District (OK, KS and MO) and includes approximately 104 km 2 of disturbed land surface and contaminated water resources in northeastern Oklahoma. Underground mining from the 1890s through the 1960s degraded over 1000 surface ha, and left nearly 500 km of tunnels, 165 million tons of processed mine waste materials (chat), 300 ha of tailings impoundments and over 2600 shafts and boreholes. The site was listed on the National Priorities List (NPL) in 1983 and received a Hazard Ranking System score of 58.15. Initial remediation efforts in the 1980s focused on addressing surface and ground water quality. In 1993, an Indian Health Service study demonstrated that 35% of children had blood lead levels above thresholds dangerous to human health. Since 1995, the focus has been excavation and replacement of contaminated residential soils. In 2004, the University of Oklahoma (OU) and Oklahoma Department of Environmental Quality (ODEQ) began a series of related projects to demonstrate applicable technologies and establish a longer-term remediation and restoration process. The site was divided into five perimeter areas where initial projects would be focused and a single core area, based loosely on watershed and community boundaries. OU is leading projects on i) construction and evaluation of a passive treatment system to address contaminated mine drainage, ii) establishment and assessment of a test road section incorporating chat into asphalt pavement and iii) remediation and restoration monitoring in support of all projects, including collection of water quality, hydrology, air quality, soil ,chat, fine tailings and meteorological data. ODEQ projects include i) mine hazard attenuation (i.e., closing open shafts and boreholes), ii) chat utilization as fill and in pavement, iii) land reclamation to productive use and iv) stream restoration. Initial projects are anticipated to be completed in 3-5 years.