Tar Creek Superfund site
Tar Creek Superfund site is a United States Superfund site, declared in 1983, located in the cities of Picher and Cardin, Ottawa County, in northeastern Oklahoma. From 1900 to the 1960s lead mining and zinc mining companies left behind open chat piles that were heavily contaminated by these metals, cadmium, and others. Metals from the mining waste leeched into the soil, and seeped into groundwater, ponds, and lakes. Elevated lead, zinc and manganese levels in Picher children have led to learning disabilities and other health problems. The EPA declared Picher to be one of the most toxic areas in the United States.
The Quapaw Tribe of Oklahoma originally owned the area and leased property to mining companies. Government rules restricted many Quapaw landowners from realizing money from royalties, which companies paid on these leases. The people have suffered adverse health effects, including high rates of miscarriage and neurological damage to children, as a result of the unregulated mining activities. The Tar Creek Superfund site is the Oklahoma section of four National Priority List Superfund Sites that together encompass the Tri-State mining district, an old lead and zinc mining district divided by the EPA into the Tar Creek Site, Cherokee County Site, the Orongo-Duenweg Site, and the Newton County Mine Tailings Site.
Origins
Tar Creek is an area of 1,188 square miles located in Ottawa County, Oklahoma, within the Tri-State district of lead and zinc mining in Northeastern Oklahoma, Southwestern Missouri, and Southeastern Kansas.The first mining took place in Missouri around 1850. By 1908, sites had been started in Miami, Picher, and Commerce. The construction of railroads in the area stimulated production, increasing access to markets. Mining quickly had a high economic impact, and by 1924 most of the young, American-born whites in the district were employed by the mining industry. The Quapaw tended to be excluded by discrimination in the industry.
When mining began in the area, most of the land was owned by the federally recognized Quapaw tribe. Following the Oklahoma Organic Act, an 1897 court ruling would allow allotted land to be leased for the purpose of mining but would later be curtailed by numerous subsequent lawsuits. Only about one sixth of Quapaw landowners would ever receive land lease payments and mined mineral royalties. Between 1915 and 1930, decreasing demand and production caused mining companies to buy the land rather than lease it, which led to high consolidation of companies.
During World War I, the region supplied 45 percent of the lead and 50 percent of the zinc used by the U.S. Zinc and lead were used for bullets during both World Wars. Advances in technology increased production. 1926 was the highest year of production in the area, and Ottawa County became the world's largest source of lead and zinc, employing 11,000 men in almost 250 mills. Between 1908 and 1950, the entire Tri-State Mining Region had generated over an estimated 1 billion U.S. dollars. After 1950, many mines were shut down, largely because their adverse environmental impacts on soil, groundwater and air had been found.
National and state intervention
In the 1960s and 1970s, health and environmental hazards were found at mining and industrial sites across America, such as Times Beach and Love Canal. On December 11, 1980, Congress passed the Comprehensive Environmental Response, Compensation, and Liability Act. CERCLA´s environmental programs and initiatives are referred to as the Superfund: hazardous sites were identified and financing was allocated to remediate them. The EPA established a Hazard Ranking system and a National Priorities List in 1981 and 1982, respectively.On September 8, 1983, the Tar Creek site was designated a Superfund site, with the USGS, the Oklahoma Department of Environmental Quality, and the Quapaw Tribe acting as the cleanup oversight agencies
In 1984, work on the first Operable Unit began.
Thirty years later, in 2004, the state of Oklahoma enacted the "Oklahoma Plan For Tar Creek", but by 2006, most of this money was allocated to a buy out and relocation program, because of the immediate health hazards to people still living in the area.
Health and environmental hazards
"Dry" and "wet" methods were used by mining companies to extract pure lead from ore. Dry methods produced chat piles, large mounds of mining waste, and wet methods required tailing ponds to process ore into a usable product. The Oklahoma Plan for Tar Creek claimed around 75 million tons of chat piles exist, while the exact amount of tailings is unknown. It was not uncommon for children in the area to play around the chat piles, such as riding bikes up and down the large piles or swimming in waters contaminated by their dust or groundwater effects. Some of the piles were used for school students for track practice.Lead poisoning is especially hazardous to children under six years of age. High levels of lead at this age can produce impaired neurological development that results in lifelong problems. A 1996 study showed 43% of children ages 1–5 had blood lead concentrations above the threshold considered dangerous by federal standards though more recent reports show this number to be lower. Another indication of hazard is the 24% miscarriage rate for women in the area, compared to a national average of 10%.
Empty mines present an immediate danger due to mine collapses. One collapse in 1967 took nine homes.
Between 2002 and 2011 pregnant Mothers of the Tar Creek area and their infants enrolled into a study and were followed until children were 2 years old. The concentration of manganese in the Tar Creek mother´s blood at or near the time of delivery was associated with lower neurodevelopment scores at 2 years of age.
Damage to water resources and aquatic life
To keep groundwater from saturating the mines while they were active, water was pumped out of mines. This created a large depression where mining activities occurred. waste materials and poor quality ore were stored in Mined-out portions or exploration holes dug to map out mining areas, instead of removing them from the mines. These waste materials reacted with moist air and oxidized.When mining ceased in the 1960s, so did the active pumping of water out of the mines. Thus, water flowed back into the depressions, the mines flooded and reacted with the oxidized and now more reactive heavy metals left over. Eventually, enough water filled the mines allowing water to travel to the surface, forming "springs" of contaminated water at the site of the exploratory drilling holes. In 1979, the first contaminated springs of water were documented.
In 1980, Picher first recorded contaminated water drawn from the town's aquifer.
Lead has marked adverse environmental impacts in aquatic systems. Water from the region eventually drains into the Grand Lake o' the Cherokees, which has raised lead levels. A health advisory warns people to limit the number of fish they consume from this area.
Estimates in 1982 showed lead and cadmium levels in the underground aquifer of Picher were five times the national standards for drinking water. Mine water has to be treated to prevent its contaminating other clean water sources, such as nearby Grand Lake, which already has elevated levels of lead due to mining activities. Photosynthetic organisms in the water have no means to dispose of heavy metals they absorb and accumulate these. Any animal or fish that feeds on this primary producer accumulates the higher concentrations of these contaminants, as the primary producer has a higher concentration of heavy metals relative to the water. Secondary and tertiary consumers accumulate even higher concentrations of such metals in a process called biomagnification). Since humans consume fish rather than phytoplankton, they are considered a secondary consumer, and are at high risk of lead poisoning from fish taken from contaminated lakes.
Clean up, 1983–present day
Since the passage of CERCLA, numerous clean up efforts have been made in the area. Some of the surface water contamination was dealt with in the 1980s and 1990s, and in 2000, Governor Frank Keating commissioned development of a cleanup plan, later known as the "Oklahoma Plan". In 2002, DEQ studied fish from waters in the Tri-State mining district. Tar Creek issued a fish consumption advisory. The State of Oklahoma restored 329 acres of contaminated land in 2005, and the following year offered a voluntary buyout to affected families with children. The EPA got involved in 2010, offering additional voluntary buyouts and doing additional cleanup.The Oklahoma Plan for Tar Creek has listed four main objectives in the process: improving surface water quality, reducing exposure to lead dust, attenuating mine hazards, and land reclamation.
The University of Oklahoma's Department of Civil Engineering and Environmental Science has implemented a 1.2 million dollar passive water treatment system. The system bioremediates ground water from abandoned mines using a series of ponds to naturally remove lead, zinc, cadmium and iron from the water. It discharges into a tributary of Tar Creek. It uses gravity and renewable energy to flow water through a filtration system, composed of aerobic and anaerobic bacteria treatments, and periodic oxidation of treated waters. It has greatly reduced heavy metals in treated waters.
To reduce lead dust, the Oklahoma plan proposes to pave over chat roads and otherwise encapsulate chat. A chat and asphalt mixture may also be used to fill mines, which will reduce the threat of mine hazards—namely, the collapse of mines and/or the exposure to lead due to open or collapsed mines.
Finally, the plan calls to restore and revegetate the land damaged by mining activities. New soil will be brought in to replace removed soil. One 2011 estimate claims an additional 3.2 million dollars will be sufficient to remediate the more than 400 mining sites remaining in the area.
The municipality of Picher was officially dissolved in November, 2013.
EPA chief Scott Pruitt was still being criticized by local residents in 2017 for the way in which the 33-year cleanup has been conducted.
On September 17, 2019 the EPA, in cooperation with the state of Oklahoma and the Quapaw Nation, released the Final Tar Creek Strategic Plan to advance the cleanup of the Tar Creek Superfund site. The EPA indicated while great progress had been made, much work was yet to be done, and the Plan was a commitment to accelerate the cleanup.