User:Lillianm55/Kingston Fossil Plant coal fly ash slurry spill

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Kingston Fossil Plant coal fly ash slurry spill The Kingston Fossil Plant coal fly ash slurry spill was an environmental and industrial disaster that occurred on Monday December 22, 2008, when a dike ruptured at a coal ash pond at the Tennessee Valley Authority's Kingston Fossil Plant in Roane County, Tennessee, releasing 1.1 billion US gallons (4.2 million cubic metres) of coal fly ash slurry. The coal-fired power plant, located across the Clinch River from the city of Kingston, used a series of ponds to store and dewater the fly ash, a byproduct of coal combustion. The spill released a slurry of fly ash and water, which traveled across the Emory River and its Swan Pond embayment, onto the opposite shore, covering up to 300 acres (1.2 km2) of the surrounding land. Coal fly ash is known to comprise of many trace elements that at high enough concentrations are harmful to organisms, such as Arsenic, Selenium, Mercury, Copper, Chromium, Strontium, Nickel and Uranium . The spill damaged multiple homes and flowed into nearby waterways including the Emory River and Clinch River, both tributaries of the Tennessee River. The coal ash from the spill also raised short-term and long-term ecotoxicological concerns for the Emory, Clinch, and Tennessee River systems . It was the largest industrial spill in United States history.

Background
Kingston Fossil Plant coal fly ash slurry spillThe initial spill, which resulted in millions of dollars worth of property damages and rendered many properties uninhabitable, cost TVA more than $1 billion to cleanup, and was declared complete in 2015. TVA was found liable for the spill in August 2012 by the U.S. District Court for the Eastern District of Tennessee. The initial spill resulted in no injuries or deaths, but several of the employees of an engineering firm hired by TVA to clean up the spill developed illnesses, including brain cancer, lung cancer, and leukemia, as a result of exposure to the toxic coal ash, and by the ten year anniversary of the spill, more than 30  had died. In November 2018, a federal jury ruled that the contractor did not properly inform the workers about the dangers of exposure to coal ash and had failed to provide them with necessary personal protective equipment.

Kingston Fossil Plant coal fly ash slurry spillTVA had reportedly known about the dangers of using wet storage ponds for coal ash since a 1969 spill in Virginia in which coal ash seeped into the Clinch River and killed large numbers of fish. TVA officials were also confirmed to have been aware of the toxicity of coal ash as early as 1981. In the 1980s, TVA engineers raised concerns about the stability of ash ponds. The utility repeatedly found leaks in levees and seepage in the soil at many of their ash ponds, including the ones at Kingston. However, TVA continued to make small repairs instead of switch to dry storage systems in an effort to reduce costs. At the time of the disaster, TVA was using wet storage at six of their 11 coal-fired power plants.

Environmental Effects
Kingston Fossil Plant coal fly ash slurry spill The initial spill reportedly killed and buried multiple deer and at least one dog, and ejected fish from the Emory River onto the river bank as far as 40 ft from the shore. The contamination effects in the rivers killed an extremely large number of fish and other marine life. Large numbers of dead fish were reported as far as the Tennessee River and other area tributaries in the aftermath of the spill. '''The EPA flagged Arsenic, Selenium, and Mercury as contaminants of concern because of their known toxicity and potential to bioaccumulate and/or biomagnify in ecosystems. The long-term ecotoxicological effects from these contaminants have been studied for multiple species at varying trophic levels, including the Fathead Minnow, freshwater turtles , redear sunfish, white crappie, bluegill, and largemouth bass , tree swallows and benthic invertebrates , and periphyton. These reports found low levels of bioaccumulation from contaminants in varying trophic levels that do not appear to pose any serious long-term threats to the ecosystem. The bioavailability and mobility of these contaminants is largely dependent on the ambient water pH, redox potential, and physical disturbance of the environment '''.

Long-Term Concerns
'''The chemical structure and therefore the mobility and bioavailability of legacy elements like Mercury, Selenium, and Arsenic can change over time due to abiotic and biotic factors. Arsenic is likely to form precipitate s at low and high pH levels and can be reduced to arsenite or oxidized to arsenate depending on the oxygen levels and microbial activity .'''   '''Different chemical forms pose varying risks to organisms within the ecosystem and can impact organisms directly or indirectly. Selenite and arsenite are the dominant chemical forms found in the post-spill sites and are more biologically available than selenate and arsenate. Selenite and Arsenite are more readily up-taken by organisms and have a higher risk of bioaccumulation in food webs. Bioaccumulation of arsenite and arsenate disrupt different parts of glycolysis, impairing an organisms ability to produce energy'''. Exposure to high levels of Selenium were of concern because this can lead to reproductive failure or lower fertility in organisms . '''The long-term concerns after the Kingston spill mostly focus on contaminants that bind to sediment that remained after remediation efforts were finished. Researchers have posed a few potential explanations for why no long term adverse effects have been observed in the Emory or Clinch river ecosystems. One study proposed that it is possible that the dredging and remediation activities were sufficient in reducing the risk from the coal ash. Another study proposed that the contaminants of concern may take time to bioaccumulate to a harmful degree, so continued monitoring is necessary .'''

Kingston Fossil Plant coal fly ash slurry spill Controversy Over Coal ash
The spill immediately reignited the debate about the regulation of coal ash. In response to a video that showed dead fish on the Clinch River, which had received runoff from the spill, TVA spokesman Gil Francis Jr. stated "in terms of toxicity, until an analysis comes in, you can't call it toxic." He continued by saying that "it does have some heavy metals within it, but it's not toxic or anything." Chandra Taylor, an attorney with the Southern Environmental Law Center, called this statement irresponsible, and stated that coal fly ash contains concentrated amounts of mercury, arsenic, and benzene. She added, "These things are naturally occurring, but they concentrate in the burning process and the residual is more toxic than it starts." Nevertheless, due to pressure exerted in 2000 by utilities, the coal industry, and Clinton administration officials, fly ash is not strictly regulated as a hazardous waste by the EPA. '''Since then, the EPA administrator signed the Disposal of Coal Combustion Residuals final rule in 2014 that created requirements for the safe disposal of coal ash from coal-fired power plants. These requirements are currently listed under subtitle D as special waste in the EPA's Resource Conservation and Recovery Act .'''