ST. LOUIS, Jan. 19 /PRNewswire/ -- Ameren Corporation Chief Operating
Officer Thomas R. Voss announced that the company submitted a report today
with the Federal Energy Regulatory Commission indicating that water spilled
from the upper reservoir of Taum Sauk Plant on Sept. 25 was the result of wave
action due to high winds from Hurricane Rita and slightly elevated reservoir
levels. This incident was not the result of plant operators pumping water
over the top of the reservoir, as has been alleged.
"The Sept. 25 event was distinctly different from the Dec. 14 reservoir
failure that resulted in significant flooding," says Voss. "In addition,
contrary to news reports, the integrity of the reservoir structure was not
weakened by the Sept. 25 wave action."
He adds that in the days and weeks following the Sept. 25 event, the plant
was closely monitored and after the event, the company immediately took
several remedial actions, including dropping the water levels by two feet to
avoid overtopping the reservoir.
"At every step of the way, on and after Sept. 25, our employees took steps
they believed were sufficient to protect the facility's safety," Voss says.
"In hindsight, those steps proved inadequate to avoid the Dec. 14 overtopping
that resulted in significant damage to the Johnson's Shut-Ins state park and
injury to a family of five."
Here are key findings from AmerenUE's initial investigation of the Sept.
-- Contrary to media reports, the Sept. 25 event did not cause the event
of Dec. 14 and was not a result of pumping water over the top of the
reservoir; instead, the water spilled on Sept. 25 was the result of
wave action due to high winds from Hurricane Rita and slightly elevated
reservoir levels. In addition, the company has found no evidence to
indicate that water had ever been pumped over the top of the upper
reservoir prior to Dec. 14.
-- Following the Sept. 25 incident, the company reviewed instrumentation
reports, discovered problems with the sensors indicating water levels
in the upper reservoir and lowered set points for those water levels.
-- AmerenUE did not report the wave action of Sept. 25 to FERC because the
company did not believe that this condition was a reportable incident.
-- FERC last inspected the facility in August 2005---before the wave
action event on Sept. 25.
Voss also added that the company has always accepted full responsibility
for the Dec. 14 breach. Since Dec. 14, company officials have enlisted the
help of a number of experts and worked with local, state and federal agencies
to determine the cause of the incident and the next steps for repairing the
damage to the state park and the Black River. Some of the accomplishments of
state and company representatives assigned to the project include:
-- With the Missouri Department of Natural Resources, Ameren staff and
contractors have been working seven days a week to remove soil and
trees from roadways, parking lots, trails and other areas of the park.
Approximately 122,000 cubic yards of woody debris have been mulched.
More than 6,000 cubic yards of sediment have been removed. Most of the
paved areas within the park have been cleared.
-- The goal of much of the restoration effort is to prevent additional
sediment from entering the Black River and any bodies of water feeding
into the Black River. Crews have been lowering the water level of a
six-acre pond formed at the base of the mountain by the force of the
water coming down the mountain. This is being done to make sure that
any future natural high water events do not wash silt into the East
Fork of the Black River.
-- Crews have rebuilt walkways and are cleaning up campground buildings
and other facilities and have replaced fencing around a cemetery.
-- To restore the highly valued "fen" -- a forested wetlands with distinct
features and vegetation -- crews have been removing debris and sediment
manually, literally by hand. Crews are evaluating use of vacuum
devices to remove sediment from surfaces.
-- AmerenUE applied for, and was granted, permission to treat the lower
reservoir with materials (alums) that will cause the fine clay
particles that are suspended in the water to clump together and fall to
the bottom of the reservoir. This will keep these particles from going
into the East Fork of the Black River and further muddying that river.
An implementation plan developed and filed with the Missouri Department
of Natural Resources is being reviewed. The plan could be implemented
as early as next week.
At a Dec. 14 media conference call, Ameren Chairman and CEO Gary Rainwater
shared preliminary thoughts about the cause of the breach---an instrumentation
failure causing water to be pumped over the top of the reservoir. However, he
emphasized then and again stressed today that those statements were
"We now need to allow representatives from several state and federal
regulatory agencies to fully analyze the incident and complete their review
before we can precisely establish the cause and determine the best course of
action," he said. "The FERC will issue a full report and share that publicly
after it has been independently reviewed. That effort could take weeks. And
while we do this exhaustive analysis, we do not think it is constructive for
the company or others to speculate about the cause of this incident.
"Finally, there have been allegations in the media that the Federal Energy
Regulatory Commission or some state agency should have acted to prevent the
Taum Sauk disaster. We don't believe that any governmental agency was at
fault in this incident. We have assumed responsibility for the effects of the
breach and are moving as quickly as possible to repair the damage caused by
Rainwater requested continued patience on the part of the public as all
regulatory agencies and the company work to complete this investigatory
On Dec. 14 the AmerenUE Taum Sauk Plant experienced a breach in the upper
reservoir that caused flooding in the Johnson Shut-ins and resulted in the
closing of one road. The plant's 1.5-billion-gallon upper reservoir
experienced a rupture in the northwest corner causing water to flow downward.
The company implemented its emergency plan and assembled a multi-disciplinary
team of experts, company officials and consultants to analyze the event and
determine next steps.
Built in 1963, AmerenUE's Taum Sauk is a "pumped-storage" hydroelectric
plant. It stores water from the Black River in the upper reservoir, built
atop 1,590-foot-high Proffit Mountain, and releases the water to generate
electricity when power is needed. The plant employs 12. The water flows down
a mile-long tunnel inside the mountain, turning turbine-generators to produce
electricity. When power demand is low, the same turbines run in reverse to
pump water back to the upper reservoir.
AmerenUE is a subsidiary of St. Louis-based Ameren Corporation. Ameren
companies serve 2.3 million electric customers and 900,000 natural gas
customers in a 64,000-square-mile area of Missouri and Illinois.