AmerenUE Cites Significant Differences between Sept. 25 Wave Action at Taum Sauk Upper Reservoir and Dec. 14 Overtopping/Flooding Incident

Jan 19, 2006, 00:00 ET from AmerenUE

    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.
 25 event:
     -- 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
 the breach."
     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.