As part of EPA’s ongoing national effort to assess the management of coal combustion residuals, EPA is releasing the final contractor reports assessing the structural integrity of 17 impoundments and similar management units containing coal combustion residuals, commonly referred to as coal ash, at nine facilities. These 17 impoundments have a “high” or “significant” hazard potential rating. A high hazard potential rating is not related to the stability of those impoundments but to the potential for harm should the impoundment fail. A significant hazard potential rating means impoundment failure can cause economic loss, environmental damage, or damage to infrastructure.
The assessments have rated the structural integrity of seven impoundments as “satisfactory,” nine units as “fair,” and one unit as “poor.” None of the units assessed received an “unsatisfactory” rating. According to dam safety experts, only impoundments rated as unsatisfactory pose immediate safety threats.
The assessment reports have been completed by firms, under contract to EPA, who are experts in the field of dam integrity and reflect the best professional judgment of those engineering firms. A draft of these reports has been reviewed by the facilities and the states for factual accuracy; their comments on the draft reports are also posted on EPA’s website. EPA continues to review the reports and technical recommendations, and is working diligently with the facilities to ensure that the recommendations are implemented in a timely manner.
EPA has provided a copy of the final report to each facility and has requested that the facility implement the recommendations contained in the reports and provide its plans for taking action. Should facilities fail to take sufficient measures, EPA will take additional action, if the circumstances warrant, and will be devoting special attention to those facilities receiving a poor rating.
These reports include complex engineering evaluations and use terms that may be unfamiliar to the general public. Impoundment ratings noted in the reports should be taken in the proper context, since a structurally sound unit may receive a fair or poor rating based on other factors, such as whether structural reports were kept.
EPA will assess by the end of the calendar year all of the units that had a dam hazard potential rating of high or significant in the responses provided by electric utilities to EPA’s previous information requests, and will release additional reports as they become available.
As announced by Administrator Lisa P. Jackson on March 9, 2009, EPA, together with other federal agencies and states, is working to ensure that tragedies like the coal ash spill in Kingston, Tenn. last December are avoided through the proper management of coal combustion residuals.
EPA reports on dam integrity assessments at 17 coal ash impoundments (9/17)
September 17, 2009