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 solid
waste containment area at the Tennessee Valley Authority's
Kingston Fossil
Plant
in Roane County
, Tennessee
, USA
. 1.1 billion gallons (4.2 million 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
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
A collapsed house inundated by the
spill
The TVA and
Environmental
Protection Agency initially estimated that the spill released
1.7 million
cubic yards (1.3 million m³)
of sludge, which is gray in color. After an
aerial survey, the official estimate was more
than tripled to 5.4 million cubic yards (4 million m³) on
December 25, 2008. The spill covered surrounding land with up to
six feet (1.8 m) of sludge. 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.. 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.
The unlined aboveground ash fill, which was situated above the ash
pond and above the Emory River winter level, above sea level(needs
new reference), contained a watery slurry of fly ash generated by
the burning of finely ground coal at the
steam power plant. The fly ash, which
is the consistency of
face powder, 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. Once the particulate matter settles out, it is
dredged to drying cells. The dredge cell was surrounded by 60-foot
(20 m) tall earthen walls, which had twice developed leaks since
2002. Although the land surrounding the power plant is largely
rural rather than residential, the spill caused a
mudflow wave of water and ash that covered 12 homes,
pushing one entirely off its foundation, rendering three
uninhabitable, and caused some damage to 42 residential properties.
It also washed out a road, ruptured a major
gas line,, obstructed a rail line, downed trees,
broke a water main, and destroyed power lines. Though 22 residences
were evacuated, nobody was reported to be injured or in need of
hospitalization. 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 (1.2
million m³) of liquid coal waste.
The 1.1 billion gallons of sludge were
enough to fill 1,660 Olympic-size swimming pools, and
the volume released was about 50 times larger than the 1989
Exxon Valdez oil
spill
. 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, which would
later be found to cover an area of .
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. The containment area affected was one of three;
the other two stayed intact, while only the retaining wall for the
solid waste containment area was affected.
The spill killed a "tremendous" number of fish, according to the
Chattanooga Times Free
Press. Although residents feared water contamination, early
tests of water six miles upstream of the ash flow showed that the
public water supply met drinking water standards. A test of river
water near the spill showed elevated levels of
lead and
thallium, and "barely
detectable" levels of
mercury and
arsenic.
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.
The Kingston Fossil Plant received a total of 6.48 inches
(16.5 cm) of rain between December 1 and December 22, plus
1.16 inches (2.9 cm) on November 29 and 30. This rain
combined with temperatures were identified by TVA as factors that
contributed to the failure of the earthen embankment. An October
2008 inspection report had identified a "minor leak" in the faulty
wall, but the report was not finalized. 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.
A TVA news release confirmed that there had been two prior cases of
seepage, in 2003 and 2006.
Response
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." 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 toxic pollutant by the EPA.
However,
OSHA does consider coal fly ash a
"hazardous chemical." 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. On January 1, 2009, the TVA disseminated a fact sheet
stating that the ash is "not hazardous."
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. 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 of
sludge covered tracks. By the afternoon of that day,
dump trucks were being used to deposit rock into
the Clinch River to prevent the further downstream contamination.
The TVA has also slowed river flow, for the same purpose. The
slurry that was cleared from Swan Pond Road was brought back to one
of the plant's intact containment ponds. 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. 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".
A wall of ash approximately from the
retention pond
Lisa
Evans, an attorney for Massachusetts
-based environmental group Earthjustice, 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." 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." 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. 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. The site may be slated as a
Superfund site, although no decision regarding
this has yet been made. 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. The TVA released an
inventory of the plant's byproducts on December 29, 2008; it
included arsenic, lead,
barium,
chromium, and
manganese.
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.
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, 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. The power plant continues to
operate, with waste being sent to one of the two remaining intact
containment ponds.
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. Tennessee governor
Phil Bredesen toured the spill site on
December 31, 2008. 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.
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. 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.
Legal actions
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. On December 30, 2008 a group of landowners filed suit
against the TVA for $165 million in Tennessee state court. 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."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."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."
Mode and mechanism
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.
Plant and spill location
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 upstream from the latter's mouth along the
Tennessee River.
Watts Bar Dam
, located along the Tennessee downstream from the
mouth of the Clinch, impounds a reservoir (Watts Bar Lake) that
spans a stretch of the Tennessee (to Fort Loudoun Dam
), the lower of the Clinch (to Melton Hill
Dam
), and the lower 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
.
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). 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.
See also
Video
Notes
-
http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=25082
-
http://www.google.com/hostednews/ap/article/ALeqM5iOLulOeBmhUe7rCz8Lt2RB9MNd2QD95N35SG2
- http://wvgazette.com/News/200901140232
- http://www.tva.gov/kingston/rca/
- 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.
- Ibid., 116.
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