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Frequent Questions on Coal Ash Impoundment Assessments
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- General
- What is EPA making available to the public?
- Why do some documents have information that is blacked out?
- How many companies have claimed the information they submitted to be confidential? Will you make this critical information public?
- Some companies have responded by saying some questions are “not applicable” to their unit – what does this mean?
- How have the utilities responded to EPA’s efforts?
- Information Requests
- When and to whom did EPA send its information requests?
- Why did EPA use CERCLA authority for this information request?
- What information did EPA seek in these information requests?
- How many impoundments has EPA identified as a result of your information request? This number is significantly higher than EPA’s earlier estimate of 300. How can you be sure there aren’t more impoundments that have been missed?
- Are you looking at closed impoundments as part of your assessment or the rule? If not, why not? Closed impoundments could still contain coal ash which could release to water bodies or be in flood plains and subject to flooding.
- Are all the responses to the information request letters sent out by EPA posted? Or are there more to come?
- Can you describe or explain the National Inventory of Dams criteria and what it means to be “High,” “Significant,” “Low,” or “Less-than Low.” That is, does this mean how structurally stable the dam is?
- What is EPA doing about those units which have a high or significant hazard potential rating?
- What is EPA doing about the units which have a low or less than low rating?
- What is EPA doing about the units which do not have a rating?
- As background, how many total dams (not just coal combustion residual impoundments) in the United States have a high hazard potential rating?
- Impoundment Assessment Reports
- What are the Impoundment Reports that EPA is making available online? Will EPA be posting additional information?
- What information do these reports contain and how were the evaluations conducted?
- EPA indicates that the rating system used in these assessment reports is modeled after the New Jersey Department of Environmental Protection’s Dam Safety Guidelines. Do other states have similar rating systems and why did EPA select the guidelines developed by New Jersey?
- How were the units rated and what do the ratings of the units mean?
- Some units in the reports are rated poor, which indicates that safety deficiencies are recognized and remedial action is necessary. Why does EPA conclude that this unit is structurally sound?
- Have states been made aware of these reports and the ratings of the impoundments?
- 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?
- What are EPA’s next steps on the units mentioned in the reports?
- Did EPA meet their goal to assess all units with a high or significant hazard potential rating by the end of 2009
- What are EPA’s plans for additional units that receive a high or significant hazard potential rating in the future?
- What can you tell us about the results of the assessments that you have conducted?
- What will EPA do if it finds a unit that poses a threat to human health and the environment?
- Rulemaking
General
What is EPA making available to the public?
EPA is posting information request letters, assessments, and actions plans for coal-fired power plants.
This is part of EPA’s ongoing national effort to assess the management of coal combustion residuals (CCRs) that are managed in surface impoundments and similar management units. This national effort includes the information requests, as well as assessments of the coal combustion units themselves. We have already posted a number of items and we anticipate numerous updates to the web site.
Why do some documents have information that is blacked out?
Blacked out sections contain information which companies have claimed as confidential business information (CBI). All of the CBI information is subject to a review that 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.
How many companies have claimed the information they submitted to be confidential? Will you make this critical information public?
A total of six companies claimed all or part of the information submitted in response to the 104(e) request as confidential. These were:
- Alabama Power
- Duke Energy
- Georgia Power
- Gulf Power
- Mississippi Power
- First Energy Generation
EPA sent letters requesting that the companies substantiate their CBI claims and reviewed the materials that substantiate the CBI claims; EPA must follow the process established in our regulations to determine if the information is entitled to be protected as CBI or not. EPA made this effort a priority and worked expeditiously to make a determination on these claims. Currently, EPA has denied all CBI claims associated with the materials that have been posted to the web for these companies. However, companies may assert CBI on future information that EPA makes publicly available.
Originally, Alliant Energy and Progress Energy claimed information about their facilities was CBI, but they subsequently withdrew their CBI claims.
Some companies have responded by saying some questions are “not applicable” to their unit – what does this mean?
EPA is finding that there are a number of reasons a company responded to a question as “not applicable”: It can mean the unit has no state rating (for the hazard potential determination); the information is not available; the facility is no longer in operation and the question does not apply; or there could be a below grade unit where none of the questions apply to this particular unit.
EPA is following up with companies in cases where the response to a survey question is “not applicable” and will add information as appropriate.
How have the utilities responded to EPA’s efforts?
The utilities have cooperated throughout this process. All utilities responded to EPA’s information request. Utilities have been cooperative in providing access to their facilities, to the coal combustion residual management units, and to additional information in their files.
Information Requests
When and to whom did EPA send its information requests?
On March 9, EPA signed information request letters under the authority of Section 104(e) of the Comprehensive Emergency Response, Compensation and Liability Act (CERCLA) to 162 individual facilities and to 61 utility corporate headquarters offices. EPA obtained its list of facilities from a 2005 Department of Energy Survey of coal burning electric utility facilities. Specifically, we used the 2005 Department of Energy’s Energy Information Agency F767 database, which provides information on the disposition of coal ash from coal burning electricity producers. The database included “steam-electric plants with a generator nameplate rating of 10 or more megawatts.” The term “generator,” means the actual electric generator, not the whole plant. A plant typically will have one or more generators.
EPA sent the letters to corporate offices to make sure that all of their facilities were accounted for due to limitations in the DOE survey.
Based on information received in response to the initial letter to the utility corporate headquarters offices, on April 27, 2009, EPA sent information request letters to an additional 48 facilities that had been identified by the corporate offices. As EPA identifies new facilities, additional information request letters will be sent out.
Why did EPA use CERCLA authority for this information request?
Many statutes provide EPA the authority to request information from regulated entities and often, in specific situations, one or more authorities are available to the agency. EPA, as a general matter, evaluates its authorities and chooses the most appropriate authority given the circumstances. EPA reviewed all of its authorities and determined that CERCLA was the most appropriate authority to use. CERCLA provides EPA with broad authorities. Section 104(e) of CERCLA allows EPA to seek information where there is a reasonable basis to believe there may be a release or a threat of release of a hazardous substance or a pollutant or contaminant. The presence of a hazardous substance or a pollutant or contaminant in coal combustion residuals allows coal combustion residuals to be appropriately covered under the CERCLA information request.
What information did EPA seek in these information requests?
EPA’s information request asked specific questions related to the structural integrity of each surface impoundment or similar diked or bermed management unit(s) or management units designated as landfills which receive liquid-borne material for the storage or disposal of residuals or by-products from the combustion of coal, including, but not limited to, fly ash, bottom ash, boiler slag, or flue gas emission control residuals. This includes units that no longer receive coal combustion residuals or by-products, but still contain free liquids. The specific questions are:
- Relative to the National Inventory of Dams criteria for High, Significant, Low, or Less-than-Low, please provide the potential hazard rating for each management unit and indicate who established the rating, what the basis of the rating is, and what federal or state agency regulates the unit(s). If the unit(s) does not have a rating, please note that fact.
- What year was each management unit commissioned and expanded?
- What materials are temporarily or permanently contained in the unit? Use the following categories to respond to this question: (1) fly ash; (2) bottom ash: (3) boiler slag; (4) flue gas emission control residuals; (5) other. If the management unit contains more than one type of material, please identify all that apply. Also, if you identify “other,” please specify the other types of materials that are temporarily or permanently contained in the unit(s).
- Was the management unit(s) designed by a Professional Engineer? Is or was the construction of the waste management unit(s) under the supervision of a Professional Engineer? Is inspection and monitoring of the safety of the waste management unit(s) under the supervision of a Professional Engineer?
- When did the company last assess or evaluate the safety (i.e., structural integrity) of the management unit(s)? Briefly describe the credentials of those conducting the structural integrity assessments/evaluations. Identify actions taken or planned by facility personnel as a result of these assessments or evaluations. If corrective actions were taken, briefly describe the credentials of those performing the corrective actions, whether they were company employees or contractors. If the company plans an assessment or evaluation in the future, when is it expected to occur?
- When did a State or a Federal regulatory official last inspect or evaluate the safety (structural integrity) of the management unit(s)? If you are aware of a planned state or federal inspection or evaluation in the future, when is it expected to occur? Please identify the Federal or State regulatory agency or department which conducted or is planning the inspection or evaluation. Please provide a copy of the most recent official inspection report or evaluation.
- Have assessments or evaluations, or inspections conducted by State or Federal regulatory officials conducted within the past year uncovered a safety issue(s) with the management unit(s), and, if so, describe the actions that have been or are being taken to deal with the issue or issues. Please provide any documentation that you have for these actions.
- What is the surface area (acres) and total storage capacity of each of the management units? What is the volume of material currently stored in each of the management unit(s)? Please provide the date that the volume measurement(s) was taken. Please provide the maximum height of the management unit(s). The basis for determining maximum height is explained later in this Enclosure.
- A brief history of known spills or unpermitted releases from the unit within the last ten years, whether or not these were reported to State or federal regulatory agencies. For purposes of this question, please include only releases to surface water or to the land (do not include releases to groundwater).
- Identify all current legal owner(s) and operator(s) at the facility.
How many impoundments has EPA identified as a result of your information request? This number is significantly higher than EPA’s earlier estimate of 300. How can you be sure there aren’t more impoundments that have been missed?
Currently, EPA has identified approximately 676 surface impoundments or similar management units which may contain “wet” CCRs from coal-burning electric utilities. EPA has taken a very broad view of what constitutes a coal ash impoundment for purposes of conducting our assessment on the structural integrity of these impoundments and this number includes units that contain any free liquids. For example, EPA has included as impoundments those units which contain water that came in contact with coal ash even if the coal is not placed in the impoundment – as in the case where coal ash is slurried to an impoundment where the ash settles and the clarified liquid is sent to another impoundment as a polishing step before discharge, this would be counted as two impoundments.
Based on this conservative, methodical approach and the numerous interactions with the utilities, EPA believes that we have a good list of the impoundments or similar management units which contain “wet” CCRs from coal-burning electric utilities. However, if new facilities are identified, we will be sending out additional information requests, updating our records accordingly, and conducting new assessments as necessary.
Are you looking at closed impoundments as part of your assessment or the rule? If not, why not? Closed impoundments could still contain coal ash which could release to water bodies or be in flood plains and subject to flooding.
Closed units that still contain free liquid are part of the assessment. EPA specifically stated in the introduction to the questions in our information request letter that “this includes units that no longer receive coal combustion residuals or by-products, but still contain free liquids.”
Are all the responses to the information request letters sent out by EPA posted? Or are there more to come?
EPA is posting all of the responses to the information request letters, with the exception of information claimed as confidential business information. EPA sent out multiple mailings – the first was to a comprehensive list of facilities prepared in 2005 by the Department of Energy and to the 61 corporate offices of the facilities (which sought the names and addresses of any other facilities that we may have missed); the second mailing was to additional facilities identified by the 61 corporate offices; additional mailings are occurring as EPA identifies new facilities. Responses from all mailings are being posted as they are received; these include all responses except for information claimed as confidential.
The information posted to date represents responses that the electric utilities sent back to EPA. This information does not reflect EPA evaluation or assessment.
Can you describe or explain the National Inventory of Dams criteria and what it means to be “High,” “Significant,” “Low,” or “Less-than Low.” That is, does this mean how structurally stable the dam is?
The hazard potential ratings refer to the potential for loss of life or damage if there is a dam failure. The ratings do not refer to the structural stability of the dam.
High Hazard Potential
Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant Hazard Potential
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life, but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas, but could be located in areas with population and significant infrastructure.
Low Hazard Potential
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner’s property.
Less Than Low Hazard Potential
Dams which do not pose high, significant, or low hazard potential.
What is EPA doing about the units which have a high or significant hazard potential rating?
EPA has assessed all units currently identified as having a high or significant hazard potential rating (excluding TVA facilities, which are being separately assessed). EPA is posting the draft reports, state/company/EPA comments, and final reports on those assessments as they are completed.
What is EPA doing about the units which have a low or less than low rating?
For those units that have a low or less than low rating, EPA is reviewing all of the information that we have on these units, as well as other information we can obtain on the area surrounding the unit. EPA will complete its review of these units, and will prioritize these for further attention as appropriate.
What is EPA doing about the units which do not have a rating?
For units that do not have a rating, EPA is reviewing all of the information that we have on these units, as well as other information we can obtain on the area surrounding the unit. From all of this information, we will determine what rating the unit would likely have received if it had been rated. EPA will use this determination to prioritize these units for assessments.
As background, how many total dams (not just coal combustion residual impoundments) in the United States have a high hazard potential rating?
There are more than 12,000 dams in the US with a high hazard potential rating.
Impoundment Assessment Reports
What are the Impoundment Reports that EPA is making available online? Will EPA be posting additional information?
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.
- Summary Table for Impoundment Reports (XLS) - July 31, 2014 (download the free Microsoft Excel viewer)
What information do these reports contain and how were the evaluations conducted?
The reports include 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 the Tennessee Valley Authority (TVA) Kingston Fossil Plant facility’s dam failure. This analysis was conducted by AECOM, a geotechnical engineering firm, for TVA. AECOM determined the unit may have failed because of a combination of four factors: 1) the presence of an unusually weak slimes foundation, 2) the fill geometry and setbacks, 3) increased loads due to higher fill, and 4) hydraulically placed loose wet ash. Based on this analysis, EPA directed its contractors to examine each unit for these characteristics.
EPA indicates that the rating system used in these assessment reports is modeled after the New Jersey Department of Environmental Protection’s Dam Safety Guidelines. Do other states have similar rating systems and why did EPA select the guidelines developed by New Jersey?
Yes, other States have similar guidelines. In developing protocol for conducting the assessments, a standard rating system was needed. 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 New Jersey’s recently revised and updated system.
How were the units rated and what do the ratings of the units mean?
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.
Some units in the reports are rated poor, which indicates that safety deficiencies are recognized and remedial action is necessary. Why does EPA conclude that this unit is structurally sound?
EPA is working closely with the owners of these units to ensure remedial action and/or additional studies are conducted to upgrade the rating of these units and ensure long term stability. 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.
Have states been made aware of these reports and the ratings of the impoundments?
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.
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?
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 performed by EPA contractors provide a rating on the structural stability of each of the impoundments.
What are EPA’s next steps on the units mentioned in the reports?
EPA has sent the final reports to each of the facilities and asked the facilities to provide plans and a schedule for addressing each of the recommendations in the report. We are working with the states and companies to ensure that the recommendations from the assessments are implemented in a timely manner. EPA could decide to take additional action if the circumstances warrant. The final reports as well as the company responses to the report recommendations are being posted online as they become available.
EPA is particularly concerned about units with a poor rating and will be devoting special attention to those units. The Agency 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.
Did EPA meet their goal to assess all units with a high or significant hazard potential rating by the end of 2009?
Yes. EPA has assessed all known units that had a dam hazard potential rating of “high” or “significant” as indicated in the responses provided by electric utilities to EPA’s information request, in addition to any new units discovered during the field assessments. EPA is posting the draft reports, state/company/EPA comments, and final reports on those assessments as they are completed.
Since electric utilities have provided EPA with responses to EPA’s information request, TVA has re-rated five of its units as High Hazard Potential and 13 of its units as Significant Hazard Potential. TVA is assessing the re-rated units. EPA will evaluate the assessments when they are finished and determine the appropriate next steps.
What are EPA’s plans for additional units that receive a high or significant hazard potential rating in the future?
If a unit, particularly one of the units which currently does not have a rating, is identified as having a “high” or “significant ” hazard potential rating, EPA will do an assessment similar to those the Agency has performed for other units.
What can you tell us about the results of the assessments that you have conducted?
So far, EPA has not encountered any unit that poses an imminent threat to public health or the environment. No unit has been rated “unsatisfactory” which would require immediate action on the part of the utility or the federal or state governments.
Typical recommendations include:
- establish grass in bare areas where soil is visible
- control nuisance animal activity
- monitor water pressures in the embankment and foundation
- correct the low areas of the dam crest by placing engineered fill.
Recommendations that are contained in the final reports and company responses to these recommendations are being posted online as they become available.
What will EPA do if it finds a unit that poses a threat to human health and the environment?
If EPA finds that any unit poses a threat to human health and the environment, EPA will take appropriate action to protect public health and the environment. This could include working with the state involved and other federal agencies.
Rulemaking
What are EPA’s current plans/schedule for a CCR rulemaking?
Information on the final rule.