Kingston Fossil Plant coal fly ash slurry spill

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Aerial photograph of site taken the day after the event

The TVA Kingston Fossil Plant coal fly ash slurry spill occurred just before 1 a.m. on Monday December 22, 2008, when an ash dike ruptured at an 84-acre (0.34 km2) solid waste containment area at the Tennessee Valley Authority's Kingston Fossil Plant in Roane County, Tennessee, USA. 1.1 billion US gallons (4,200,000 m3) of coal fly ash slurry was released. The coal-fired power plant, located across the Clinch River from the city of Kingston, uses ponds to dewater the fly ash, a byproduct of coal combustion, which is then stored in wet form in dredge cells. The slurry (a mixture of fly ash and water) traveled across the Emory River and its Swan Pond embayment, on to the opposite shore, covering up to 300 acres (1.2 km2) of the surrounding land, damaging homes and flowing up and down stream in nearby waterways such as the Emory River and Clinch River (tributaries of the Tennessee River). It was the largest fly ash release in United States history.

Details[edit]

A collapsed house inundated by the spill.

The Tennessee Valley Authority (TVA) and Environmental Protection Agency (EPA) initially estimated that the spill released 1.7 million cubic yards (1.3 million m³) of sludge, which is gray in color.[1][2] After an aerial survey, the official estimate was more than tripled to 5.4 million cubic yards (4 million m³) on December 25, 2008.[1][3] The spill covered surrounding land with up to six feet (1.8 m) of sludge.[4] The EPA first estimated that the spill would take four to six weeks to clean up; however, Chandra Taylor, the staff attorney for the Southern Environmental Law Center, said the cleanup could take months and possibly years.[5] As of June 2009, six months following the spill, only 3% of the spill had been cleaned and is now estimated to cost between $675 and $975 million to clean, according to the TVA.[6]

The 84-acre (0.34 km2) unlined aboveground ash fill, which was situated 60 feet (18 m) above the ash pond and 74 feet (23 m) above the Emory River winter level, 741 feet (226 m) above sea level,[7] contained a watery slurry of fly ash generated by the burning of finely ground coal at the steam power plant.[8] Fly ash is the fine particulate pollutants produced by the combustion of coal, which are collected rather than allowing them to escape into the atmosphere, then mixed with water so they can be pumped into the retaining pond.[9] Once the particulate matter settles out, it is dredged to drying cells.[9] The dredge cell was surrounded by 60-foot (18 m) tall earthen walls, which had twice developed leaks since 2002.[10] Although the land surrounding the power plant is largely rural rather than residential, the spill caused a mudflow wave[11] of water and ash that covered 12 homes,[12] pushing one entirely off its foundation, rendering three uninhabitable,[3] and caused some damage to 42 residential properties.[13] It also washed out a road,[9] ruptured a major gas line,[11] obstructed a rail line, downed trees, broke a water main,[14] and destroyed power lines. Though 22 residences were evacuated,[15] nobody was reported to be injured or in need of hospitalization.[12] It was the largest coal-related slurry spill in United States history, more than three times the size of the Martin County sludge spill of 2000, which spilled 306 million US gallons (1,160,000 m3) of liquid coal waste.[5] The 1.1 billion US gallons (4,200,000 m3) of sludge were enough to fill 1,660 Olympic-size swimming pools,[5] and the volume released was about 101 times larger than the 1989 Exxon Valdez oil spill (1.1 billion/10.9 million=100.9). On December 23, 2008, a TVA spokesman, Gil Francis Jr., stated that, at the time of the spill, the area contained about 2.6 million cubic yards (2.2 million m³) of ash, and that two-thirds of that had been released,[4] which would later be found to cover an area of 300 acres (1.2 km2).[7] The New York Times noted that the amount spilled is larger than the amount stated to have been in the pond before the spill, a discrepancy the TVA was unable to explain.[3] The containment area affected was one of three; the other two stayed intact, while only the retaining wall for the 84-acre (0.34 km2) solid waste containment area was affected.[16]

The confluence of the Clinch and Emory Rivers, with the Kingston Fossil Plant in the distance, five days after the spill. The white foam floating on the water consists of cenospheres, which are a component of the ash.

The spill killed a "tremendous" number of fish, according to the Chattanooga Times Free Press.[17] Although residents feared water contamination, early tests of water six miles (10 km) upstream of the ash flow showed that the public water supply met drinking water standards.[15] A test of river water near the spill showed elevated levels of lead and thallium, and "barely detectable" levels of mercury and arsenic.[3] On January 1, 2009 the first independent test results, conducted at the Environmental Toxicology and Chemistry laboratories at Appalachian State University, showed significantly elevated levels of toxic metals (including arsenic, copper, barium, cadmium, chromium, lead, mercury, nickel, and thallium) in samples of slurry and river water.[18]

The Kingston Fossil Plant received a total of 6.48 inches (16.46 cm) of rain between December 1 and December 22, plus 1.16 inches (2.95 cm) on November 29 and 30.[19] This rain combined with 12 °F (−11 °C) temperatures were identified by TVA as factors that contributed to the failure of the earthen embankment.[20] An October 2008 inspection report had identified a "minor leak" in the faulty wall, but the report was not finalized.[15] Local residents said that the spill was not a unique occurrence; the 1960s-era pond had been observed leaking, and being repaired, nearly every year since 2001.[9] A TVA news release confirmed that there had been two prior cases of seepage, in 2003 and 2006.[21]

Response[edit]

"We deeply regret that a retention wall for ash containment at our Kingston Fossil Plant failed, resulting in an ash slide and damage to nearby homes."

Tennessee Valley Authority statement[5]

TVA spokesman Gil Francis Jr. said that the TVA was "taking steps to stabilize runoff from this incident." In response to a video that showed dead fish on the Clinch River, which had received runoff from the spill, he 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."[15] 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."[5] Nevertheless, due to pressure exerted in 2000 by utilities, the coal industry, and Clinton administration officials, fly ash is not strictly regulated as a toxic pollutant by the EPA.[22] Residents and environmental groups expressed concern that the fly ash slurry could become more dangerous once it dries out, but have as yet received no information about this from the TVA.[23] On January 1, 2009, the TVA disseminated a fact sheet stating that the ash is "not hazardous."[24]

Meanwhile, the EPA and Tennessee Department of Environment and Conservation awaited the results of soil and water testing to judge their response, while the Tennessee Emergency Management Agency indicated that barriers would be constructed to stop the ash from reaching the Tennessee River.[15] By early on December 24, 2008, a flyover by The New York Times did note repair work being done on the nearby railroad, which had been obstructed when 78,000 cubic yards (60,000 m3) of sludge covered tracks.[2][15] By the afternoon of that day, dump trucks were being used to deposit rock into the Clinch River to prevent the further downstream contamination.[22] The TVA had also slowed river flow, for the same purpose.[9] The slurry that was cleared from Swan Pond Road was brought back to one of the plant's intact containment ponds.[25] By December 30, 2008, the TVA had announced it was requesting the assistance of the Army Corps of Engineers to dredge the ash-filled Emory River to restore navigation.[26] On January 1, 2009 the TVA announced that rather than attempting to clear away all the slurry, they would be spraying seed, straw, and mulch on top of much of it, "to combat dust and erosion".[5][27]

A 25-foot (7.6 m) wall of ash approximately 1 mile (1.6 km) from the retention pond

Lisa Evans, an attorney for the environmental group Earthjustice (headquartered in Oakland, CA), spoke out against the government, accusing them of lax regulations on the issue. She also blamed the industry for ineffective safeguards, citing other similar cases. She stated that "The saddest thing is this is entirely avoidable. These people in these communities don't have to be in harm's way. This is not some complicated problem like nuclear waste. This is something the utilities know how to do."[28] Thomas J. FitzGerald, the director of the environmental group Kentucky Resources Council and an expert on coal waste, told The New York Times that the ash should have been buried in lined landfills to prevent toxins leaching into the soil and groundwater (as recommended in a 2006 EPA report), and stated that "I find it difficult to comprehend that the State of Tennessee would have approved that as a permanent disposal site."[15] Tennessee governor Phil Bredesen, on-site the week of the spill, acknowledged that the Tennessee Department of Environment and Conservation, which regulates coal disposal, may have relied too much on TVA’s own inspections and engineering studies about the ash ponds and dredge cells.“Believe me, there will be a full-bore look at this to understand the causes of this thing and to try to make sure it never happens again,” he said.[29] Concern has also been expressed by environmental groups and local residents that no warnings were issued to residents living in the area about the potential dangers of the site.[22] The site may be slated as a Superfund site, although no decision regarding this has yet[when?] been made.[9] On December 27, 2008 the TVA issued a list of precautions to residents, but did not provide information about specific levels of toxic materials in the ash, although Stephen Smith of the Southern Alliance for Clean Energy and Chris Irwin of United Mountain Defense told The Tennessean newspaper that they believe the TVA knows what is in it, due to the TVA having tested it prior to the spill.[30] The TVA released an inventory of the plant's byproducts on December 29, 2008; it included arsenic, lead, barium, chromium, and manganese.[31] Because the pond contained decades worth of ash from coal of several different types, it is believed that the area of the spill may contain "hot spots" of higher toxicity.[30]

In response to independent attempts at sampling of the water quality and the taking of photos, the TVA illegally detained, for approximately one hour, two members of the Knoxville, Tennessee-based environmental organization United Mountain Defense who were traversing public land in the area of the spill,[32] and cited three other individuals, warning them that any attempt to enter the public waterway again would lead to prosecution.

TVA president Tom Kilgore said that, in light of the spill, the Authority would consider switching the Kingston plant over to "dry" byproduct methods, which would reduce the chances of another spill. Five TVA-operated plants use this method, while Kingston and another five use a "wet" process.[28] The power plant continues to operate, with waste being sent to one of the two remaining intact containment ponds.[9]

On December 26, 2008 the Tennessee Department of Environment and Conservation stated that it was satisfied with the water quality in the wake of the spill but that it will continue to examine and deal with the potential for chronic health effects.[23] Tennessee governor Phil Bredesen toured the spill site on December 31, 2008.[33] The U.S. Senate Environment and Public Works Committee, which oversees the TVA, held a hearing on January 8 to examine the disaster. The environmental activist Erin Brockovich was invited to Tennessee to survey the disaster site, and announced plans to visit during the second week of January 2009.[34]

At her Senate confirmation hearing on January 14, 2009, Lisa P. Jackson, Barack Obama's choice to head the EPA under his administration, stated her intention to immediately review coal ash disposal sites across the country.[35] Also on January 14, 2009, Nick J. Rahall, a U.S. Representative from West Virginia and the chairman of the United States House Committee on Natural Resources, introduced a bill to regulate coal ash disposal sites across the United States.[36]

Legal actions[edit]

On December 23, 2008 the environmental group Greenpeace asked for a criminal investigation into the incident, focusing on whether the TVA could have prevented the spill.[37][38] On December 30, 2008 a group of landowners filed suit against the TVA for $165 million in Tennessee state court.[39] Also on December 30, 2008 the Southern Alliance for Clean Energy announced its intention to sue the TVA under the federal Clean Water Act and the Resource Conservation and Recovery Act.[39]

"On February 4, 2009, EPA, pursuant to Executive Order 12088, and TDEC issued a letter to TVA in which EPA provided notice to TVA that EPA considers the release to be an unpermitted discharge of a pollutant in contravention of the Clean Water Act."[40]

On May 11, 2009 "TVA and the federal Environmental Protection Agency announced today an EPA Order and Agreement that documents the relationship between TVA and EPA in managing the clean-up of the Kingston ash spill and further ensures that TVA will meet all federal and state environmental requirements in restoring affected areas."[41]

The primary objective of the time critical phase of the EPA Order was to expedite the removal of ash from the Emory River. The ash resided in the Emory River subject to significant migration in heavy storms. Over 3.5 million cubic yards were removed in a 12 month period with 85% being removed in a 10 month time frame. The time critical phase accelerated the removal of ash from the river by 75% over original expectations and safely transported it to a permanent, lined and leachate collecting facility in Perry County, Alabama called Arrowhead landfill. Arrowhead landfill is located on a thick layer of Selma chalk. Significant benefits were derived by the receiving community in both jobs and county improvements. The once closed Emory River was reopened in late spring 2010 and has been reopened for full community use with only minor wake zone restrictions. Drinking water continues to remain safe for consumption and air quality associated with the site continues to meet federal standards. The time critical phase removed 90% of the ash located in the Emory River leaving about 500,000K cubic yards of material which will be addressed in the next phase of the clean-up. A more comprehensive report of the actions was finalized in March 2011 and can be found at EPA OSC Report for the Time Critical Removal Action

In August 2010, the non time critical phase began removing ash from the remaining, more contained embayment and began preparations for closing out the failed dredge cell with an earthquake proof subsurface wall and cap. In addition, the non time critical phase is conducting ecological evaluations concerning the remaining risks of the ash in the river.

Mode and mechanism[edit]

According to the AECOM report commissioned by TVA and released June 25, 2009, failure occurred due to a variety of causes, primarily due to liquefaction of layers of "slimes" and other water-saturated materials deep within the growing ash pile. Collapse occurred over the course of approximately one hour in consecutive waves of breaking away and sliding.[42]

Plant and spill location[edit]

Original design of the ash disposal area

The Kingston Fossil Plant is located on a peninsula at the junction of the Emory River (to the north) and Clinch River (to the south and east), just over 4 miles (6.4 km) upstream from the latter's mouth along the Tennessee River. Watts Bar Dam, located along the Tennessee 38 miles (61 km) downstream from the mouth of the Clinch, impounds a reservoir (Watts Bar Lake) that spans a 72-mile (116 km) stretch of the Tennessee (to Fort Loudoun Dam), the lower 23 miles (37 km) of the Clinch (to Melton Hill Dam), and the lower 12 miles (19 km) of the Emory. The plant, originally known as the Kingston Steam Plant, was built in the early 1950s primarily to provide electricity to atomic energy installations at nearby Oak Ridge.[43]

The plant's ash pond disposal area is located immediately north of the plant along the peninsula's Emory River shore. The ponds were originally created by diking off part of the lake at the Emory's confluence with Swan Pond Creek, which flows down from Harriman (just over the ridge to the northwest).[44] The disposal area consists of the main ash pond (where ash is initially dumped), which is flanked on the southeast by a stilling pond (where water from the main pond is placed to further separate it from the ash) and on the northwest by "dredge cells," where ash from the main pond is placed to further solidify. The dike breach occurred at the northwest corner of the dredge cell area, overlooking the Swan Pond Creek spillway.[45]

See also[edit]

Aerial footage of the spill.


References[edit]

  1. ^ a b Reilly, Michael (2008-12-25). "Tenn. Sludge Spill Challenges 'Clean Coal' Future". Discovery Channel. Retrieved 2009-01-09. 
  2. ^ a b "Ash spill: TVA triples amount of sludge released". Knoxville News Sentinel. 2008-12-26. Retrieved 2009-01-09. 
  3. ^ a b c d Dewan, Shaila (December 28, 2008). "Tennessee Ash Flood Larger Than Initial Estimate". The New York Times. Retrieved 2009-01-09. 
  4. ^ a b Flory, Josh (2008-12-24). "TVA looks to similar case for costs of removing fly ash". Knoxville News Sentinel. Retrieved 2008-12-25. 
  5. ^ a b c d e f "Tennessee sludge spill runs over homes, water". CNN. 2008-12-22. Retrieved 2008-12-25. 
  6. ^ "TVA to ship spilled coal ash". Chattanooga Times Free Press. 2009-06-06. Retrieved 2009-06-14. 
  7. ^ a b Dave Flessner and Sohn, Pam (2009-01-05). "Early warnings on ash pond leaks; TVA, state inspections show repairs, suspension of deposits at Kingston ash pond". Chattanooga Times Free Press. Retrieved 2009-01-09. 
  8. ^ "Fly Ash definition". Environmental Protection Agency. 
  9. ^ a b c d e f g Anne Paine and Sledge, Colby (December 23, 2008). "Flood of sludge breaks TVA dike". The Tennessean. Retrieved 2009-01-09. [dead link]
  10. ^ Barker, Scott (2008-12-25). "TVA working to repair damage to area after pond breach". Knoxville News Sentinel. Retrieved 2008-12-25. 
  11. ^ a b "EPA’s Response to the TVA Kingston Fossil Plant Fly Ash Release". Environmental Protection Agency. 2008-12-24. Retrieved 2009-01-09. [dead link]
  12. ^ a b Mansfield, Duncan (2008-12-22). "Tennessee Dam Bursts, Hundreds Of Acres Flooded With Toxic Slurry Of Ash". Associated Press. Retrieved 2008-12-25. 
  13. ^ "Nation's Largest Public Utility to Test Water After Coal Ash Spill". Fox News Channel. 2008-12-29. Retrieved 2009-01-09. 
  14. ^ Simone, Samira J. (2008-12-28). "Tennessee sludge spill estimate grows to 1 billion gallons". CNN. Retrieved 2009-02-28. [dead link]
  15. ^ a b c d e f g Dewan, Sheila (2008-12-23). "Water Supplies Tested After Tennessee Spill". New York Times. Retrieved 2008-12-25. 
  16. ^ "Ash Release at TVA’s Kingston Fossil Plant". Tennessee Valley Authority. 2009-01-15. Retrieved 2009-02-28. 
  17. ^ "Environmentalists Concerned On Effects Of Huge TVA Coal Ash Spill". The Chattanoogan. 2008-12-25. Retrieved 2009-01-09. 
  18. ^ Dewan, Shaila (2009-01-01). "Metal Levels Found High in Tributary After Spill". New York Times. Retrieved 2009-01-09. 
  19. ^ "Valley Precipitation". Tennessee Valley Authority. Retrieved 2009-01-09. 
  20. ^ Hall, Kristin M. (December 27, 2008). "Group: Stronger warnings needed in Tenn. ash spill". Associated Press. Retrieved 2009-01-09. 
  21. ^ Sharp, Stoney (December 23, 2008). "TVA: Structure had smaller failures before". WBIR-TV. Retrieved 2009-01-09. 
  22. ^ a b c Dewan, Shaila (2008-12-25). "Massive coal-ash spill causes river of sludge and controversy". The Seattle Times. Retrieved 2009-01-09. 
  23. ^ a b "Coal Ash May Pose Health Hazard". National Public Radio. 2008-12-26. Retrieved 2008-12-26. 
  24. ^ "EPA found high arsenic levels day after ash spill". Knoxville News Sentinel. 2009-01-03. Retrieved 2009-01-09. 
  25. ^ Matheny, Jim (2008-12-28). "Crews storing ash sludge nearby". WBIR-TV. Retrieved 2009-01-09. 
  26. ^ Flessner, Dave (2008-12-30). "Tennessee: Corps to dredge river around Kingston plant". Chattanooga Times Free Press. Retrieved 2009-01-09. 
  27. ^ Balloch, Jim (2009-01-01). "TVA to spread seed and straw at Kingston spill site". Knoxville News Sentinel. Retrieved 2009-01-09. 
  28. ^ a b Duncan Mansfield (2008-12-24). "Cleanup begins in wake of Tennessee ash pond flood". Associated Press. Retrieved 2008-12-25. [dead link]
  29. ^ Flessner,Sohn (2009-01-05). "Tennessee: Early Warning on Ash Leaks". 
  30. ^ a b Paine, Anne (2008-12-28). "Coal ash precautions issued around spill". The Tennessean. Retrieved 2009-01-09. [dead link]
  31. ^ Dewan, Shaila (2008-12-29). "At Plant in Coal Ash Spill, Toxic Deposits by the Ton". New York Times. Retrieved 2009-01-09. 
  32. ^ "Environmentalists Detained for Photographing Tennessee Ash Spill". Softpedia. 
  33. ^ Lakin, Matt (2009-01-01). "Bredesen visits site of retention pond spill". Knoxville News-Sentinel. Retrieved 2009-01-09. 
  34. ^ "Brokovich Blog". Erin Brokovich. 2008-12-30. Retrieved 2009-01-09. [dead link]
  35. ^ http://www.google.com/hostednews/ap/article/ALeqM5iOLulOeBmhUe7rCz8Lt2RB9MNd2QD95N35SG2[dead link]
  36. ^ http://wvgazette.com/News/200901140232
  37. ^ "Greenpeace calls for criminal investigation into coal ash spill". Greenpeace. 2008-12-23. Retrieved 2009-01-09. 
  38. ^ "Sludge from dike is twice the original estimate". Associated Press. 2008-12-26. Retrieved 2009-01-09. 
  39. ^ a b "Landowners Sue TVA for $165M Over Coal Ash Spill". Associated Press. 2008-12-30. Retrieved 2009-01-09. [dead link]
  40. ^ "Administrative Order and Agreement on Consent U.S. EPA Region 4 and Tennessee Valley Authority". 2009-05-06. Retrieved 2009-05-30. 
  41. ^ "TVA, EPA Sign Agreement on Site Clean-up at Kingston". 2009-05-11. Retrieved 2009-05-30. 
  42. ^ http://www.tva.gov/kingston/rca/
  43. ^ Tennessee Valley Authority Office of Engineering Design and Construction, The Kingston Steam Plant: A Report on the Planning, Design, Construction, Costs, and First Power Operations (Tennessee Valley Authority Technical Report no. 34, 1965), pp. 1–12.
  44. ^ Ibid., 116.
  45. ^ "Site of the Spill, and How Fly Ash Is Produced". The New York Times. 2008-12-25. Retrieved 2009-01-09. 

External links[edit]

Video

Coordinates: 35°54′53″N 84°30′44″W / 35.91472°N 84.51222°W / 35.91472; -84.51222