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Frequent Questions About Coal Ash Reports

1. Why do some assessment reports contain information that has been blacked out?

Answer:   Blacked out sections contain information that companies have claimed as confidential business information (CBI).  All of the CBI is subject to a review which will determine if the company’s CBI claims are justified.  If the claims are determined to be justified, the information will not be released.  If the claims are not justified, the information will be posted.

2.  What are the Coal Ash Reports that EPA is making available online?  Will EPA be posting additional information?

Answer:  EPA is making available the final contractor reports assessing the structural integrity of impoundments or other similar management units containing coal combustion residuals at electric utility facilities that were rated as either "significant" or "high" hazard potential.  These reports have been prepared by engineering firms, under contract to EPA, who are experts in the field of dam integrity. EPA has released reports for the facilities listed below. To read the full reports, please visit the coal ash reports page.

List of Impoundments with High or Significant Hazard Potential Rating
Company Location Facility Name Date of Assessment Date Posted Online
Alabama Power Co. Parrish, Alabama Gorgas Electric Generating Plant June 9, 2009 Sept. 21, 2009
American Electric Power Cheshire, Ohio General James Gavin Power Plant June 1-2, 2009 Sept. 16, 2009
American Electric Power Lawrenceburg, Indiana Tanner Creek Power Plant June 1-2, 2009 Sept. 16, 2009
Arizona Public Service Fruitland, New Mexico Four Corners Power Plant May 19-20, 2009 Sept. 16, 2009
Duke Energy Belmont, North Carolina Allen Steam Station June 12, 2009 Sept. 21, 2009
Duke Energy Spencer, North Carolina Buck Stream Station June 9-10, 2009 Sept. 21, 2009
Duke Energy Eden, North Carolina Dan River Steam Station May 27-28, 2009 Sept. 21, 2009
Duke Energy Catawba County, North Carolina Marshal Steam Station May 28, 2009 Sept. 21, 2009
Duke Energy Mt. Holly, North Carolina Riverbend Steam Station June 4-5, 2009 Sept. 16, 2009
Dynegy Midwest Havana, Illinois Havana Power Station May 27, 2009 Sept. 21, 2009
Dynegy Midwest Alton, Illinois Wood River Power Station May 27-28, 2009 Sept. 21, 2009
Georgia Power Cartersville, Georgia Plant Bowen May 26-27, 2009 Sept. 21, 2009
Indiana-Kentucky Electric Madison, Indiana Clifty Creek Power Station June 10-11, 2009 Sept. 21, 2009
Louisville Gas & Electric Bedford, Kentucky Trimble County Station June 1-2, 2009 Sept. 16, 2009
PacifiCorp Energy Point of Rocks, Wyoming Jim Bridger Power Station June 9-10, 2009 Sept. 16, 2009
PPL Montana Colstrip, Montana Colstrip Power Plant June 2-3, 2009 Sept. 16, 2009
Progress Energy Buncombe County, North Carolina Asheville Electric Plant May 27-28, 2009 Sept. 16, 2009
Progress Energy Moncure, North Carolina Cape Fear Power Station June 15-17, 2009 Sept. 21, 2009
Progress Energy Roxboro, North Carolina Mayo Power Station June 3, 2009 Sept. 21, 2009
Tri-State Escalante McKinley County, New Mexico Generating Station June 2-3, 2009 Sept. 16, 2009
Vectren Mount Vernon, Indiana Brown Power Station June 4, 2009 Sept. 21, 2009
Westar Energy St. Mary's, Kansas Jeffrey Energy Center May 19, 2009 Sept. 21, 2009

Summary Table for First Round of EPA Coal Ash Site Investigations Web Posting Version 9.21.09 (XLS) (Excel Spreadsheet 30K)

3.  What information do these reports contain and how were the evaluations conducted?

Answer:   These reports contain an assessment of the structural integrity of impoundments or other similar management units containing coal combustion residuals and provide a rating for each unit. 

The independent evaluations were conducted using standard accepted engineering practices, including a visual assessment of the site and each unit; interviews with facility personnel; a review of geotechnical reports and studies conducted by the company related to the design, construction, and operation of the units, if available; and a review of any past state or federal inspections of the units.  While EPA contractors did not conduct any physical drilling, coring, or sampling while on site, they did review studies which may have included such information.   EPA modeled its rating criteria based on those used by the State of New Jersey. 

In addition, EPA reviewed the results of the Root Cause Analysis of TVA’s Kinsgton dam failure.  This analysis was conducted by AECOM, one of the nation’s leading geo-technical engineering firms, for the Tennessee Valley Authority.  One of the key findings was that the unit may have failed because the embankment was built upon an unusual bottom layer of wet ash and silt (referred to as “slimes” composed of fine-size sediments having a slippery, viscous consistency). Based on this analysis, EPA directed its contractors to address, for each unit, whether the embankment construction occurred over such unsuitable materials. 

4.  EPA indicates that the rating system used in these assessment reports is modeled after the New Jersey’s Department of Environmental Protection Dam Safety Guidelines.  Do other states have similar rating systems and why did EPA select the guidelines developed by New Jersey?

Answer: Yes, other States have similar guidelines.  In developing its protocol for conducting these assessments, EPA believed it was necessary to have a standard rating system.  To develop this, EPA consulted with the Association of State Dam Safety Officials.  The Association suggested that EPA use a State rating system that had recently been updated or revised.  EPA reviewed the rating systems from a number of States and selected the system used by New Jersey since it had been revised and updated most recently.

5. How were the units rated and what do the ratings of the units mean?

 Answer:  Each CCR management unit was rated using the following categories: *

SATISFACTORY
No existing or potential management unit safety deficiencies are recognized. Acceptable performance is expected under all applicable loading conditions (static, hydrologic, seismic) in accordance with the applicable criteria. Minor maintenance items may be required.

FAIR
Acceptable performance is expected under all required loading conditions (static, hydrologic, seismic) in accordance with the applicable safety regulatory criteria. Minor deficiencies may exist that require remedial action and/or secondary studies or investigations.

POOR
A management unit safety deficiency is recognized for a required loading condition (static, hydrologic, seismic) in accordance with the applicable dam safety regulatory criteria. Remedial action is necessary. “Poor” also applies when further critical studies or investigations are needed to identify any potential dam safety deficiencies.

UNSATISFACTORY
Considered unsafe. A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution. Reservoir restrictions may be necessary.

*Taken from the New Jersey Department of Environmental Protection Dam Safety Guidelines for the Inspection of Existing Dams, January 2008.

In summary, 43 waste management units were evaluated at 22 facilities. They were rated by EPA contractors as follows:

6.  One of the units in the reports made available on September 16, 2009 is rated poor, which indicates that safety deficiencies are recognized and remedial action is necessary.  Why does EPA conclude that this unit is structurally sound?

Answer: There is a difference between a “poor” and an “unsatisfactory” rating.  A poor rating indicates that remedial action is necessary, but there is not an immediate safety threat.  An unsatisfactory rating, however, indicates that immediate or emergency corrective measures are necessary—in fact, the dam or unit is considered unsafe.   EPA continues to review these reports, but in the interest of making the information available quickly, EPA is releasing the reports. 

7. Have states been made aware of these reports and the ratings of the impoundments?

Answer: Yes.  EPA has been working closely with the States throughout this effort.  All of the States were contacted prior to the on-site assessments and State officials accompanied our contractor on most of the visits.  Further, State officials have reviewed and commented on the draft reports.

8.  Previously, you provided criteria developed by the National Inventory of Dams which rated dams into four categories:  high hazard potential, significant hazard potential, low hazard potential, and less than low hazard potential.  How is the rating system or criteria discussed in the reports different from these criteria?

Answer:  The criteria developed for the National Inventory of Dams does not refer to the structural stability of the dams, but the potential for loss of life or damage if there is a failure of the dam.  The criteria discussed in the reports available online provide a rating on the structural stability of each of the impoundments.

9.  What are EPA’s next steps on the units mentioned in the reports?

Answer:  EPA has sent the final reports to each of the facilities and has asked that they provide their plans and a schedule for addressing each of the recommendations in the report.  EPA asked for a response within 14 days of the facilities’ receipt of the reports.  EPA will be closely monitoring the facilities’ implementation of the recommendations and could decide to take additional action if the circumstances warrant.

EPA is particularly concerned about those units with a poor rating and will be devoting special attention to those units and may take additional action in any case where the facility owner does not promptly take action to correct identified deficiencies that caused a unit to be given a “poor” rating. 

10.  What are EPA’s plans to complete the site assessments of all the units with a high or significant hazard potential rating?

Answer: 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 information request.

Since electric utilities have provided EPA with responses to EPA’s information request, the Tennessee Valley Authority (TVA) has re-rated 5 of its units as High Hazard Potential and 13 of its units as Significant Hazard Potential.  TVA is assessing its CCR management units and in 2010, EPA will evaluate reports on those units and all of the information available on the TVA units and determine the appropriate next steps. 

All field work is being conducted by engineering firms with specific experience in determining the structural stability of the impoundments.

If a management unit has a hazard potential rating of high or significant and had  not undergone a state or federal dam structural integrity inspection (that is,an inspection where the unit was looked at for structural issues, as opposed to regulatory compliance issues) since March 2008, that unit was selected for a site assessment.  The scope of these assessments includes a visual evaluation of the unit as well as well a review of materials on the design, operation, maintenance, and prior inspections and dam safety analyses.  Based on this information, recommendations are provided regarding corrective actions or additional analyses that need to be conducted. 

If a facility with a high or significant hazard unit was inspected by a state or federal government agency, we are conducting a “desk top” review to familiarize ourselves with the facility.  State reviews provide equivalent information to the visual evaluations that the EPA contractor was directed to conduct at those locations where EPA did on-site assessments.  We are currently conducting desk top reviews.  We will visit each of these facilities to ensure that the State reports are consistent with the current status of these units and to evaluate their integrity.

11. What are EPA’s plans to complete the site assessment of additional units that receive a high or significant hazard potential rating in the future?

Answer:  If a unit, particularly one of the units which currently does not have a rating, receives a high or significant rating, EPA will do an assessment similar to those we are currently conducting. 

Since releasing the list of 44 High Hazard Potential units in June, the Tennessee Valley Authority (TVA) has re-rated 5 of its units as High Hazard Potential and 13 units of its units as Significant Hazard Potential.  Currently, TVA is assessing its CCR management units.   In 2010, we will evaluate the reports conducted by TVA or its contractors on those units and all of the information available on the TVA units and determine the appropriate next steps.

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