The U.S. Environmental Protection Agency (EPA) released plans developed by 20 electric utilities with 70 coal ash impoundments that describe how the facilities will make their impoundments safer. The plans are in response to EPA’s final assessment reports on the structural integrity of these impoundments, which the agency made public in May 2010.
In addition to the plans, EPA released assessment structural integrity reports of an additional 38 coal ash impoundments at 17 facilities. Of these units, nine received a “poor” rating. EPA said the poor rating was not because the impoundments are unsafe, but because they lack engineering documentation. None received an “unsatisfactory” rating.
Since May 2009, EPA has been conducting on-site structural integrity assessments of coal ash impoundments and ponds at electric utilities.
An impoundment holding disposed coal ash waste generated by the Tennessee Valley Authority failed in 2008, creating a spill in Kingston, Tenn. that released more than 5 million cubic yards of coal ash. Shortly afterwards, EPA began overseeing the cleanup, as well as investigating the structural integrity of coal ash storage impoundments.
The assessment reports were completed by firms under contract to EPA that are expert in the field of dam integrity and reflect the best professional judgment of those engineering firms.
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