1

Comment Summary and Response Document

Hazardous and Solid Waste Management System;

Identification and Listing of Special Wastes; Disposal of 

Coal Combustion Residuals from Electric Utilities; 

Proposed Rule

(Docket # EPA-HQ-RCRA-2009-0640

Docket # EPA-HQ-RCRA-2011-0392

Docket # EPA-HQ-RCRA-2012-0028)

Volume 7: Operating Criteria: Endangered species/Surface 

water/Inspections/Run-on Run-off

December 2014
2

Background

The U.S. Environmental Protection Agency (Agency or EPA) proposed regulations for 

the management of coal combustion residuals (CCRs) which was published in the Federal 

Register on June 21, 2010. This proposal, under the Resource Conservation and Recovery Act 

(RCRA), addressed the risks from disposal of CCRs generated from the combustion of coal at 

electric utilities and from independent power producers. Two regulatory options were proposed. 

Under the first option, EPA proposed to reverse its August 1993 Bevill Regulatory and May 

2000 Bevill Regulatory Determinations regarding CCR and to list CCRs as special wastes 

subject to hazardous waste regulations under subtitle C of RCRA when destined for disposal in 

landfill or surface impoundments. Under the second option, EPA proposed to leave the Bevill 

determination in place and regulate the disposal of CCR as non-hazardous solid waste under 

subtitle D of RCRA by issuing minimum national criteria. Both options would require 

composite liners, groundwater monitoring, structural stability requirements, corrective action, 

and closure/post closure care. 

EPA also solicited comments on all aspects of both proposed options. The Agency received over

450,000 comments on the proposed rule. The majority of the comments focused on which

regulatory path the Agency should pursue for regulating CCRs, i.e., RCRA’s subtitle C or

subtitle D. EPA also conducted eight public hearings and took additional comments on the

proposed rule. EPA has established three dockets for this regulatory action under Docket ID No.

EPA-HQ-RCRA-2009-0640, Docket ID No. EPA-HQ-RCRA-2011-0392, and Docket ID No.

EPA-HQ-RCRA-2012-0028. All documents in these dockets are available at

http://www.regulations.gov. Although listed in the index, some information is not publicly

available, e.g., Confidential Business Information (CBI) or other information whose disclosure is

restricted by statute. Certain other material, such as copyrighted material, is not placed on the

Internet and will be publicly available only in hard copy form. Publicly available docket

materials are available either electronically in http://www.regulations.gov or in hard copy at the
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OSWER Docket, EPA/DC, WJC West Building, Room 3334, 1301 Constitution Ave., NW,

Washington, DC. The Public Reading Room is open from 8:30 a.m. to 4:30 p.m., Monday

through Friday, excluding legal holidays. The telephone number for the Public Reading Room is

(202) 566–1744, and the telephone number for the OSWER Docket is 202–566–0276.

After reviewing all the comments and additional data received, EPA is promulgating a 

final rule to regulate the disposal of CCR as solid waste under Subtitle D of RCRA. This rule 

addresses the risks from structural failures of CCR surface impoundments, groundwater 

contamination from the improper management of CCR in landfills and surface impoundments 

and fugitive dust emissions. 

The Agency has developed seventeen volumes of summarizing comments on major 

topics covered in the proposed rule (see table below) and the Agency’s responses to those 

comments, as well as a separate volume summarizing comments provided during public 

hearings. Since EPA is finalizing a rule under subtitle D of RCRA, only those comments 

submitted on the proposed subtitle C rule that are also applicable to the final rule are addressed 

in the comment and response documents.

Volume Topic

1 General Comments 

2

RCRA Subtitle D Regulatory Approach (Legal issues/Self-implementing 

Design/Reliance on Certifications by an Independent Professional 

Engineer/Recordkeeping, State Submissions, Posting to the 

Internet/Finance Assurance/Alternative Approaches) 

3

Scope and Purpose/Effective Dates/Applicability/Off-site 

Disposal/Definitions 

4 Location Restrictions 

5 Design Criteria: Liners and Leachate Collection Systems

6 Design Criteria: Structural Integrity 

7

Operating Criteria: Endangered species/Surface water/Inspections/Run-on 

Run-off 
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Volume Topic

8 Operating Criteria: Air Criteria 

9 Groundwater and Corrective Action 

10 Closure and Post-Closure Care 

11 Additional Comments including Overfills/ Harmonization with ELG. 

12 Beneficial Use 

13 Risk Assessment 

14 State Authorities, Programs and Regulations 

15 Compendium of Damage Cases 

16 Regulatory Impact Analysis (RIA) 

17 EPA’s Assessment Program 

This volume summarizes comments received on the operating criteria related to 

Endangered species, Surface water, Inspections, and Run-on Run-off.

Section 4.4.6 - Operating requirements (35203-35204)

Total Number of Submissions: 4

Total Number of Comments: 4

Comment Number: EPA-HQ-RCRA-2009-0640-06313-114

Organization1:Earthjustice et. al.

Commenter1: Lisa Evans

Commenter Type: Advocacy Group

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Other Sections: 4.4.5

Comment Excerpt Text:

What prohibitions or performance standards, if any, should be applied to existing landfills? 

Performance standards should include the following at a minimum: 

• Same siting requirements as proposed landfills,
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• Treatment of wastes to comply with 40 CFR 268.40 as needed, 

• Groundwater monitoring, 

• Run-off and run-on control should be implemented within 6 months of the passage of the rules, and 

• Daily cover or dust control operational requirements must be used to meet the applicable air quality 

standards.

EPA Response: First, we would note that the Agency was not consistent in discussing the effective date of 

the RCRA subtitle D rules in the proposal. Specifically, in the regulatory text to proposed 257.40(a)(2), 

the Agency stated that “Except as otherwise specified in this Subpart,1all of the requirements in this 

subpart are applicable [date 180 days after the effective date of the final rule.] On the other hand, in the 

preamble to the proposed rule under section X (How would the proposed subtitle D regulations be 

implemented?), the Agency noted that the “RCRA subtitle D alternative, if this alternative is ultimately 

promulgated, would be 180 days after promulgation of a final rule. 75 FR 35210. The date noted in the 

regulatory text at 257.40(a)(2) is not correct and is inconsistent with RCRA section 4004(c), which 

provides that rules under 4004(a) become effective six months after publication in the Federal Register. 

42 USC 6944(c). 

Consistent with 4004(c), EPA will require that CCR landfills install run-on and run-off controls 

within one year of the effective date of the rule. EPA has determined that this is a sufficient amount of 

time to install run-on and run-off controls, taking into consideration construction seasons in cold-weather 

and high precipitation regions. Also, many of these CCR disposal units should already be subject to runon and run-off controls under the 40 CFR part 257 regulations. However, if final run-on and run-off 

controls can’t be put in place by this timeframe, the record demonstrates that hydrologic and hydraulic 

measures can be taken in the short term and implemented within 6 months of the date of promulgation of 

the rule, while long-term measures are designed and constructed to meet run-on and run-off control 

requirements.

Specifically, in order to meet the timeframes being finalized in today’s rule, CCR landfills can 

implement short-term measures to manage and prevent the flow of storm water peak discharge, while 

long-term, permanent structural and non-structural measures are taken to meet the run-on and run-off 

controls of the final rule. Typically, these short-term measures are easily implemented and minimally 

costly. Short-term measures may include temporary installation of diversion dikes, straw bales, brush 

barriers, silt fences, bundles, wattles, or fascines, amongst others. Some examples of long-term structural

controls that can be implemented at CCR landfills include appropriate grading, interceptor ditches, 

seepage ditches, sedimentation basins, silt traps, check dams, or drainage swales. Long-term nonstructural measures include operation and maintenance procedures, vegetation control, and routine 

vigilance. EPA understands that often construction cycles require seasonal scheduling, and so it can take 

months to implement the long-term run-on and run-off control structures. However, EPA has determined 

that short-term measures can be taken in the interim, while long-term run-on and run-off controls can be 

permitted, designed, and constructed to meet the requirements of the rule.

 

1 The run-on/run-off controls are not otherwise specified as having a different effective date.
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Comment Number: EPA-HQ-RCRA-2009-0640-06723-22

Organization1:West Virginia Department of Environmental Protection (WVDEP)

Commenter1: Gary Casto on behalf of Randy C. Huffman

Commenter Type: State Government

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Other Sections: 4.4.6.2

Comment Excerpt Text:

Section 257.81 specifies that CCR landfills and surface impoundments should contain 25 year/24 hour 

stormwater runon and runoff controls. Stormwater runon and stormwater runoff controls are not needed at 

existing or proposed impoundments because the impoundments are designed to impound and discharge 

storm events far in excess of a 25 year/24 hour storm event. Stormwater runon controls are appropriate 

only during and after the closure of surface impoundments. Furthermore, this section states that runoff 

from the active portion of the CCR landfill or surface impoundment must be handled in accordance with 

the 257.3-3; this section is not included in the proposed regulation.

EPA Response EPA disagrees with the comment asserting that storm water controls are only 

appropriate during and after closure of CCR surface impoundments. Hydrologic and hydraulic 

capacity, as determined by an effective design flood control system, is an essential element of the 

overall structural integrity and safety of a CCR surface impoundment. CCR surface 

impoundments are subject to any number of stresses throughout their operational life; one of the 

most common causes of a dike or embankment failure being the inability of the CCR unit to 

adequately pass or manage flood flows resultant from direct or indirect precipitation. These 

failures can occur at any point in the CCR unit’s life, not solely during and after closure, and are 

usually due to inadequate hydrologic and hydraulic capacity, leading to internal erosion due to 

seepage and piping, erosion of spillways, overtopping erosion, and overstressing of the 

embankment. Furthermore, according to the U.S. Bureau of Reclamation, a common dam failure 

mode is due to overtopping, accounting for 30% of the failures in the U.S. over the last 75 years.2 

Overtopping is the direct result of lack of adequate hydrologic and hydraulic capacity of a dam 

or surface impoundment. Therefore, EPA is not modifying the regulation as suggested by the 

commenter.

Section 3.4.1.3 - Special requirements for stability of CCR SIs and dam integrity (e.g., 

inspections, design plans, closure plans, annual certification) (35175-35176)

Total Number of Submissions: 13

Total Number of Comments: 16

 

2 http://www.usbr.gov/ssle/damsafety/Risk/BestPractices/16-FloodOvertoppingPP20121126.pdf
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Comment Number: EPA-HQ-RCRA-2009-0640-01746-4

Organization1:LGM Engineers, LLC

Commenter1: Larry G. Mrazek

Commenter Type: Beneficial User

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

the failure of the impoundment containing coal ash was a disaster and caused pollution of the 

adjacent waterways. However, this should not be the basis for declaring flyash a hazardous 

waste. More concern should be given to dam safety and the design & construction of 

impoundments, etc.

EPA Response: EPA has adopted in today’s final rule specific technical criteria intended to ensure

adequate dam safety of CCR surface impoundments, throughout the design, construction, operation, 

maintenance, and closure of the CCR unit. Today’s final rule includes design requirements for structural 

stability and operating requirements for hydraulic and hydrologic capacity, inspection requirements, air 

criteria, and recordkeeping.

Comment Number: EPA-HQ-RCRA-2009-0640-03028-4

Organization1:CS Energy Ltd

Commenter1: Peter Heeley

Commenter Type: Beneficial User

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Other Sections: 4.4.5.2

Comment Excerpt Text:

The storage of surplus ash in a dam is a geotechnical or structural engineering issue. A risk 

management approach is essential to ensure the consequences of failure are considered in design 

and maintenance of these structures. If dams can fail in a 1st world country (eg Kingston) how 

much higher risks exist in 3rd world countries where regulation and oversight are far less 

controlled. 

Clearly Kingston was a disaster which must never be repeated. But this was a system failure 

caused by inadequate structural engineering. Designation of ash as a hazardous material would 

not have lessened the engineering risks of a structural failure.

EPA Response: EPA has adopted in today’s final rule specific technical criteria intended to ensure 

adequate dam safety of CCR surface impoundments, with specific regard for the structural, geotechnical, 

and hydraulic and hydrologic engineering adequacy of the CCR unit. Today’s final rule has adopted 

design and operating requirements which require owners and operators of CCR surface impoundments to 

insure the dam safety of the CCR unit throughout the unit’s design, construction, operation, and 
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maintenance. Today’s final rule includes design requirements for structural stability, including 

requirements to ensure both the structural and geotechnical stability of the CCR unit, and operating 

requirements for hydraulic and hydrologic capacity, inspection requirements, air criteria, and 

recordkeeping

Comment Number: EPA-HQ-RCRA-2009-0640-03300-2

Organization1:Synthetic Materials, LLC

Commenter1: Alex Hohne

Commenter Type: Beneficial User

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

While the need to properly manage the disposal of these materials is undisputed, it does not seem 

reasonable that a mechanical failure of an impoundment would lead to the classification of what 

have been historically safe materials as hazardous.

EPA Response: EPA has adopted in today’s final rule specific technical criteria intended to ensure 

adequate dam safety of CCR surface impoundments, with specific regard for the structural, geotechnical, 

and hydraulic and hydrologic engineering adequacy of the CCR unit, which EPA reasonably intends to 

prevent mechanical, or structural, failures. Today’s final rule has adopted design and operating 

requirements which require owners and operators of CCR surface impoundments to insure the dam safety 

of the CCR unit throughout the unit’s design, construction, operation, and maintenance. Today’s final rule 

includes design requirements for structural stability, including requirements to ensure both the structural 

and geotechnical stability of the CCR unit, and operating requirements for hydraulic and hydrologic 

capacity, inspection requirements, air criteria, and recordkeeping

Comment Number: EPA-HQ-RCRA-2009-0640-03300-5

Organization1:Synthetic Materials, LLC

Commenter1: Alex Hohne

Commenter Type: Beneficial User

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

It would seem more reasonable that the issue of the mechanical failure of the impoundment be 

addressed rather than the nature of the materials contained therein. While Synmat will not argue 

that the failure resulted in release of large quantities of ash in an uncontrolled manner into the 

river and the surrounding area, the release does not make what has been historically classified a 

non hazardous material hazardous.

EPA Response: EPA has adopted in today’s final rule specific technical criteria intended to ensure 

adequate dam safety of CCR surface impoundments, with specific regard for the structural, geotechnical, 

and hydraulic and hydrologic engineering adequacy of the CCR unit, which EPA reasonably intends to 
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prevent mechanical, or structural, failures. Today’s final rule has adopted design and operating 

requirements which require owners and operators of CCR surface impoundments to insure the dam safety 

of the CCR unit throughout the unit’s design, construction, operation, and maintenance. Today’s final rule 

includes design requirements for structural stability, including requirements to ensure both the structural 

and geotechnical stability of the CCR unit, and operating requirements for hydraulic and hydrologic 

capacity, inspection requirements, air criteria, and recordkeeping.

Comment Number: EPA-HQ-RCRA-2009-0640-06313-100

Organization1:Earthjustice et. al.

Commenter1: Lisa Evans

Commenter Type: Advocacy Group

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

Plans required for surface impoundments under 265.1303(b), which include the design, 

construction, and maintenance of existing CCR surface impoundments of a size greater than 

specified in 265.1303(b)(1) and (2), should already be in the possession of any responsible owner 

or operator. There is no reason to allow for up to 1 year for the submission of such plans. Even if 

the plans may need to be updated or supplemented, 3 months should be more than adequate to 

submit such plans, which are essential to protect people and the environment downstream of the 

surface impoundment. 

EPA Response: Although the commenter is referring to requirements for documentation of design and 

construction history of the CCR unit proposed under the Subtitle C proposed rule, EPA has adopted 

similar requirements for the documentation of design and construction history under today’s Subtitle D 

final rule. The final rule requires the owner or operator of CCR units exceeding the specified size 

threshold to compile and place in the operating record design and construction information pertaining to 

the CCR unit. Among other things, this provision requires the following documentation to be provided 

by the owner or operator: (1) the name of the owner or operator of the unit; (2) the name of the unit; and 

(3) any identification number assigned by the state. In addition, it requires that the owner or operator 

identify: (4) provide a description of the physical and engineering properties of the foundation and 

abutment materials on which the CCR unit is constructed; (5) the location of the CCR unit on a U.S. 

Geological Survey Map or a topographic map of equivalent scale; (6) provide dimensional drawings of 

the CCR unit with pertinent engineering structures and appurtenances identified; (7) describe the purpose 

of the CCR unit; and (8) identify the name and size of the watershed affecting the CCR unit, if any. 

Detailed information is also required documenting: (9) the design and construction of the unit including 

dates and descriptions of each zone or stage constructed; (10) instrumentation used to monitor the 

operation of the CCR unit, (11) spillway and diversion design descriptions and construction 

specifications; (12) provide a description of the physical and engineering properties of the materials used 

in construction each zone or stage of the CCR unit; and (13) provisions for surveillance, maintenance and 

repair of the CCR unit. 
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Through EPA’s CCR Surface Impoundment Assessment effort, EPA identified that a significant number 

of CCR surface impoundments lacked sufficient design and construction documentation. EPA agrees with 

the commenter that this information should be made available to the owner or operator of the CCR unit. 

However, EPA is requiring owners or operators of existing CCR surface impoundments to compile this 

information within one year of the effective date of the rule. EPA notes that some of this information 

which may not currently be available for the CCR unit, specifically dimensional drawings of the unit, 

design and construction descriptions including each zone or stage of the unit, spillway diversion design 

descriptions and construction specifications, and descriptions of the physical and engineering properties 

of the materials which make up the abutments, foundation, and each zone of the CCR surface 

impoundment, may take significant time in coordinating and compiling. 

Comment Number: EPA-HQ-RCRA-2009-0640-06517-18

Organization1:

Commenter1: Anonymous

Commenter Type: Anonymous

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

Also, neither of the regulations concerning inspections, 40 CFR 264.1304 and 40 CFR 265.1304, 

require owners to develop or submit inspection plans. Please clarify this in the final rulemaking.

EPA Response: Although the commenter is referring to requirements for inspections of the CCR unit 

proposed under the Subtitle C proposed rule, EPA has adopted similar requirements for inspections under 

today’s Subtitle D final rule. This rule requires all CCR surface impoundments to be examined by a 

qualified person at least once every seven days for any appearance of actual or potential structural 

weakness or other conditions that are disrupting or that have the potential to disrupt the operation or

safety of the CCR unit. The results of the inspection by a qualified person must be recorded in the 

facility’s operating record. Additionally, EPA is requiring the monitoring of all instrumentation 

supporting the operation of the CCR unit to be conducted by a qualified person no less than once per 

month. The results of the monitoring of all instrumentation by a qualified person must be recorded in the 

facility’s operating record. Furthermore, the rule requires owners or operators of any CCR surface 

impoundments exceeding the MSHA size threshold (i.e., a height of five feet or more and a storage 

volume of 20 acre-feet or more; or a height of 20 feet or more) to conduct annual inspections of the CCR 

unit throughout its operating life. The owner or operator of existing CCR surface impoundments must 

ensure that the initial annual inspection by a qualified professional engineer is completed and documented 

with a report no later than three months after the effective date of the rule. The report which the qualified 

professional engineer has documented must be placed in the facility’s operating record and placed on the 

facility’s publicly accessible internet site. An annual inspection is considered complete when the 

inspection report has been placed in the facility’s operating record.

Comment Number: EPA-HQ-RCRA-2009-0640-06517-26

Organization1:
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Commenter1: Anonymous

Commenter Type: Anonymous

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

Also, proper construction of surface impoundments is as important as proper design. Please 

consider revising this subsection to include a requirement that owners place in the operating 

record a certification by an independent registered professional engineer that all surface 

impoundment systems and components were constructed in accordance with the design 

developed under subsection 264.1303(b).

That last part of paragraph 264.1303(e)(17) describes a report that can be included in lieu of the 

certification if additional work is necessary to meet the requirements. However, if this rule 

stands, it would apply only to new surface impoundments in the design phase, so these issues 

should have been resolved in the design process. Please consider deleting the last part of this 

paragraph that begins with the words “..or, in lieu of the certification...”

EPA Response: EPA agrees with the commenter that proper construction of surface impoundments is as 

important as proper design. EPA would go further and acknowledge the operation and maintenance of the 

CCR unit is equally important to its design and construction. EPA has adopted requirements that require 

a periodic structural stability assessment and a periodic safety factor assessment of all CCR surface 

impoundments exceeding the size threshold of today’s final rule to ensure that the design, construction, 

operation, and maintenance of the CCR unit is consistent with recognized and generally accepted good 

engineering practices. The periodic stability assessment and periodic safety factor assessment must 

include certification from a qualified professional engineer stating that the initial assessment of the CCR 

unit and each subsequent assessment was conducted and meets the requirements of today’s rule. 

Additionally, these assessments must comply with the recordkeeping requirements of the final rule, which 

includes placement in the facility’s operating record. 

EPA has revised the language of the final rule that requires all CCR surface impoundments exceeding the 

size threshold of the final rule to conduct periodic structural stability and safety factor assessments, 

including certification by a qualified professional engineer. EPA has removed the phrase “or, in lieu of 

the certification...” from today’s final rule 

Comment Number: EPA-HQ-RCRA-2009-0640-06517-30

Organization1:

Commenter1: Anonymous

Commenter Type: Anonymous

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:
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40 CFR 264.1304 Inspection requirements for surface impoundments

40 CFR 265.1304 Inspection requirements for surface impoundments

Table 9 – CCR Rule Requirements, on page 35191 of the Federal Register, indicates that surface 

impoundment owners will have one year from the effective date of the rule to adopt and submit 

to the EPA a plan for carrying out the surface impoundment inspection requirements of 40 CFR 

264 1304 and 40 CFR 265 1304. However, neither of these proposed rules requires an inspection 

plan. Please clarify this.

EPA Response: Although the commenter is referring to requirements for inspections of the CCR unit 

proposed under the Subtitle C proposed rule, EPA has adopted similar requirements for inspections under 

today’s Subtitle D final rule. This rule requires all CCR surface impoundments to be examined by a 

qualified person at least once every seven days for any appearance of actual or potential structural 

weakness or other conditions that are disrupting or that have the potential to disrupt the operation or 

safety of the CCR unit. The results of the inspection by a qualified person must be recorded in the 

facility’s operating record. Additionally, EPA is requiring the monitoring of all instrumentation 

supporting the operation of the CCR unit to be conducted by a qualified person no less than once per 

month. The results of the monitoring of all instrumentation by a qualified person must be recorded in the 

facility’s operating record. Furthermore, the rule requires owners or operators of any CCR surface 

impoundments exceeding the MSHA size threshold (i.e., a height of five feet or more and a storage 

volume of 20 acre-feet or more; or a height of 20 feet or more) to conduct annual inspections of the CCR 

unit throughout its operating life. The owner or operator of existing CCR surface impoundments must 

ensure that the initial annual inspection by a qualified professional engineer is completed and documented 

with a report no later than three months after the effective date of the rule. The report which the qualified 

professional engineer has documented must be placed in the facility’s operating record and placed on the 

facility’s publicly accessible internet site. An annual inspection is considered complete when the 

inspection report has been placed in the facility’s operating record.

Comment Number: EPA-HQ-RCRA-2009-0640-06869-4

Organization1:

Commenter1: Dalia Patino Echeverri and Varun Kumar

Commenter Type: Private Citizen

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Other Sections: 3.7.2

Comment Excerpt Text:

For these reasons, we believe federal oversight is required for the implementation of preventive 

measures- such as the assessment of structural stability in nearby surface impoundments, or the 

monitoring of ground water quality. 

EPA Response: Regarding the need for federal oversight, the commenter is referred to the discussion in 

Unit V of the preamble that discusses the regulatory authority to develop and promulgate the national 

criteria governing the disposal of CCR in landfills and surface impoundments under subtitle D of RCRA.
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EPA has adopted in today’s final rule specific technical criteria intended to ensure adequate structural 

stability of CCR surface impoundments, throughout the design, construction, operation, maintenance, and 

closure of the CCR unit. Today’s final rule includes design requirements for structural stability and 

operating requirements for hydraulic and hydrologic capacity, inspection requirements, air criteria, and 

recordkeeping.

Comment Number: EPA-HQ-RCRA-2009-0640-09239-45

Organization1:Prairie State Generating Company, LLC (PSGC)

Commenter1: Keith Bastian

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

Inspection Requirements (40 C.F.R. §§ 264.1304 and 265.1304)

These sections should be deleted. The general inspection requirements set forth in Section 

264.15 and the contingency plan requirements set forth in Section 264.51 require facilities to 

perform regular inspections and to develop a plan to minimize hazards to human health and the 

environment. The existing Subtitle C requirements therefore are sufficiently protective. Theses 

sections are superfluous and should be deleted. If these sections are not deleted, then the 

requirement to notify the EPA Regional Administrator and the state when the certification is 

placed in the operating record (40 C.F.R. §§ 264. 1304(a)(5) and 265. 1304(a)(5)) should be 

deleted. It creates an administrative burden upon both the Regional Administrator and the state 

without providing any environmental benefit. Having the information available for inspection 

should be adequate.

EPA Response: Although the commenter is referring to requirements for inspections of the CCR unit 

proposed under the Subtitle C proposed rule, EPA has adopted similar requirements for inspections under 

today’s Subtitle D final rule. This rule requires all CCR surface impoundments to be examined by a 

qualified person at least once every seven days for any appearance of actual or potential structural 

weakness or other conditions that are disrupting or that have the potential to disrupt the operation or 

safety of the CCR unit. The results of the inspection by a qualified person must be recorded in the 

facility’s operating record. Additionally, EPA is requiring the monitoring of all instrumentation 

supporting the operation of the CCR unit to be conducted by a qualified person no less than once per 

month. The results of the monitoring of all instrumentation by a qualified person must be recorded in the 

facility’s operating record. Furthermore, the rule requires owners or operators of any CCR surface 

impoundments exceeding the MSHA size threshold (i.e., a height of five feet or more and a storage 

volume of 20 acre-feet or more; or a height of 20 feet or more) to conduct annual inspections of the CCR 

unit throughout its operating life. The owner or operator of existing CCR surface impoundments must 

ensure that the initial annual inspection by a qualified professional engineer is completed and documented 

with a report no later than three months after the effective date of the rule. The report which the qualified 

professional engineer has documented must be placed in the facility’s operating record and placed on the 
14

facility’s publicly accessible internet site. An annual inspection is considered complete when the 

inspection report has been placed in the facility’s operating record.

Comment Number: EPA-HQ-RCRA-2009-0640-09349-20

Organization1:Santee Cooper

Commenter1: Jay Hudson

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Other Sections: 4.4.5.2

Comment Excerpt Text:

40 CFR 257.83 (35245) and 40 CFR 264.1304 (35257) propose inspection requirements for 

surface impoundments under subtitle D and subtitle C respectively. While the importance of dam 

safety inspections is generally understood, the proposed inspection requirements are neither 

appropriate nor adequate.

Readily accessible and routinely used guidance documents including manuals, guides, reports, 

and videos such as the widely used Training Aids for Dam Safety (TADS) are available free of 

charge from FEMA. These resources provide comprehensive descriptions and guidelines for 

performing the various types of dam safety inspections used for hydroelectric and water storage 

dams; and are suitable to develop appropriate and adequate inspection and documentation 

requirements for surface impoundments. In addition to the actual physical inspection, these 

resources provide guidance on properly documenting and reviewing the inspection findings.

The principal classifications for inspections include the following excerpts from the

TADS publication:

• Formal inspections which are recurring and "coincide with advancements in the state-of-the-art 

in design, analysis, and construction that are applicable to the dam under review." A reasonable 

frequency can be every 5 to 10 years depending on the operation frequency;

• Periodic inspections are performed between formal inspections typically every I to 2 years and

• focus on the current status of the dam and its features;

• Routine inspections provide a continual check on the condition of the dam and are usually 

performed by operators or on-site personnel who are familiar with the dam;

• Special inspections are conducted for particular features or when opportunities allow the 

inspection of features not normally accessible; and

• Emergency inspections should be performed whenever the safety of the dam is of concern or 
15

the occurrence of a significant event such as an earthquake.

EPA is proposing a weekly inspection, without requiring any documentation. In theory, a short 

inspection interval should increase the chances of finding an adverse condition. In reality, the 

judgment of a qualified engineer to establish the frequency and focus as well as the purpose of 

the dam safety inspection is most effective in detecting and preventing the development of a 

potentially adverse situation.

EPA Response: EPA agrees with the commenter that FEMA documentation includes valuable information 

regarding dam safety design, construction, operation, and maintenance. EPA has largely based dam safety 

requirements of the final rule on just such guidance. EPA is requiring “formal inspections,” including 

hazard potential assessment, structural stability assessment, and factor of safety assessment, at a 

frequency of not more than 5 years by a qualified professional engineer for CCR units meeting or 

exceeding the size threshold of the final rule in order to mirror the recommendations made by dam safety 

guidance such as FEMA Federal Guidelines for Dam Safety. Additionally, EPA is requiring annual 

inspection and records review by a qualified professional engineer of CCR units meeting or exceeding the 

size threshold of the final rule.

EPA is also requiring routine inspections, in order to provide an “as-close-as-practicable” a continuous 

observation of all CCR units, conducted by a qualified person, i.e., weekly inspections. While EPA 

acknowledges that deferring to the judgment of a qualified professional engineer to establish the 

frequency and focus, in addition to the purpose, of the dam safety inspection, EPA has chosen to maintain 

the requirement of all CCR surface impoundment owners and operators to conduct at least weekly 

inspections of the CCR surface impoundment by a qualified person. Several commenters suggested that 

EPA consider adding regulatory language or preamble discussion to assist owners or operators of CCR 

surface impoundments in interpreting the specific technical requirements in the regulation. Additionally, 

EPA identified through the CCR Surface Impoundment Site Assessment effort that the scope and detail of 

the type of inspection required by the final rule, i.e., informal inspection, is of a nature to provide 

significant beneficial information and proactive response actions at minimal expense and effort to the 

owner or operator. EPA observed that a majority of facilities had in place a routine, frequent inspection 

program for all CCR surface impoundments at the facility. Routinely, EPA made recommendations to 

implement an informal inspection program at facilities that may be lacking such a program. Based on the 

comments received requesting additional language for technical requirements and information garnered 

from the CCR Surface Impoundment Site Assessment effort, EPA has maintained the requirement that a 

qualified person conduct weekly inspections of the CCR surface impoundment.

Comment Number: EPA-HQ-RCRA-2009-0640-10239-2

Organization1:Lake Wylie Marine Comission

Commenter1: Ronald H. Wanless

Commenter Type: Local Government

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:
16

Other Sections: 4.4.5.2

Comment Excerpt Text:

3. The fundamental problem we need to address, as a result of the Tennessee impoundment 

failure, is how do we limit the damage done by impoundment failures. It should be understood 

that impoundments will always eventually fail.

4. An engineering approach for impoundment design that would limit the damage is that of 

"design to fail gracefully". The following criteria can form the backbone of such an approach.

A. Limit the volume of primary containment ponds to 10 acre feet. If we further limit the depth 

to 10 feet then the surface would need to be an acre or less. This would have the effect of 

limiting the pressure on the impoundment walls while also reducing the amount of slurry 

released in a failure. Clearly the 5.4 million cubic yards released in Tennessee was far too much.

B. Surround the array of these smaller ponds with a secondary containment wall. 

C. Each of the primary containment ponds should be lined with an impermeable liner to prevent 

unobserved leaks and progressive damage to the dyke wall.

D. The array of ponds should be located well away from water courses and separated from all 

occupied structures by sufficient level fields to dissipate the flow energy of any containment 

failure. This addresses the damage done to structures by the lahar flow from the breached dyke.

E. Lastly the plants producing the CCRs should be tasked with operating the plant in a manner to 

maximize the saleability of their CCRs for use in concrete. This will make it possible to 

minimize the amount of CCR slurry on site at one time.

EPA Response: EPA disagrees with the suggestion that the Agency finalize a mandatory size limitation 

for operating CCR surface impoundments. While limiting the volume of CCR surface impoundments to 

ten acre-feet would limit the volume of CCR released in the event of a structural failure, limiting the size 

of CCR surface impoundments to 10 acre-feet may not always be practicable; nor does EPA believe that 

such a restriction is truly necessary to ensure that the section 4004(a) standard will be met. Many CCR 

surface impoundments are much larger than ten acre-feet and have been operating for many years without 

a structural failure. While EPA acknowledges that this fact in no way guarantees that a failure will not 

occur, the Agency is convinced that the implementation of all of the combined regulatory requirements in 

this rule (e.g., location criteria, structural integrity, inflow design flood controls and inspection 

requirements) provides the necessary safeguards that will ensure that CCR surface impoundments are 

designed, constructed, operated, and maintained to minimize the risks associated with a catastrophic 

release of impounded CCR due to structural failure. While limiting the size of CCR surface 

impoundments will reduce risks because there will be a lower volume of waste in the unit, the Agency is 

not convinced that, in practice, such a requirement would meaningfully reduce the risks at many facilities. 

EPA expects that such a restriction would only cause facilities to construct either several small units or a 

multi-unit system. Failure of one unit can lead to progressive failure of other units in the system, and 

thus, ultimately this may not reduce the total volume of waste that could be released into the environment. 
17

Comment Number: EPA-HQ-RCRA-2009-0640-10346-3

Organization1:

Commenter1:Edward M. Hull

Commenter Type: Private Citizen

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Other Sections: 4.4.5.2

Comment Excerpt Text:

3. Thefundamental problem we need to address, as a result ofthe Tennessee impoundment 

failure, is how do we limit the damage done by impoundment failures. It should be understood 

that impoundments will always eventually fail. 

4. An engineering approach for impoundment design that would limit the damage is that of 

"design to fail gracefully". Thefollowing criteria canform the backbone of such an approach. 

A. Limit the volume of primary containment ponds to 10 acre feet. Ifwefurther limit the depth to

10 feet then the surface wouldneed to be an acre or less. This would have the effect oflimiting 

the pressure on the impoundment walls while also reducing the amount ofslurry released in 

afailure. Clearly the 5.4 million cubic yards released in Tennessee was far too much. B. Surround 

the array ofthese smaller pondswith a secondary containment wall. C. Each ofthe primary 

containment ponds should be lined with an impermeable liner to prevent unobserved leaks. D. 

Thearray ofpondsshould be located well away from water courses and separated from all 

occupied structures by sufficient level fields to dissipate the flow energy of any containment 

failure. E. Lastly the plants producing the CCRs should be tasked with operating the plantin a 

manner to maximize the saleablity oftheir CCRs for use in concrete. This will make it possible to 

minimize the amount of CCR slurry on site at anytime. 

Dikes and Dams are barely addressed by either Subtitle C or D. Minimum engineering design 

standards must be set for all retaining walls and clear Inspection standards must be set. All water 

that is running off of CCR storage must be controlled and monitored.

EPA Response: EPA disagrees with the suggestion that the Agency finalize a mandatory size limitation 

for operating CCR surface impoundments. While limiting the volume of CCR surface impoundments to 

ten acre-feet would limit the volume of CCR released in the event of a structural failure, limiting the size 

of CCR surface impoundments to 10 acre-feet may not always be practicable; nor does EPA believe that 

such a restriction is truly necessary to ensure that the section 4004(a) standard will be met. Many CCR 

surface impoundments are much larger than ten acre-feet and have been operating for many years without 

a structural failure. While EPA acknowledges that this fact in no way guarantees that a failure will not 

occur, the Agency is convinced that the implementation of all of the combined regulatory requirements in 

this rule (e.g., location criteria, structural integrity, inflow design flood controls and inspection 

requirements) provides the necessary safeguards that will ensure that CCR surface impoundments are 

designed, constructed, operated, and maintained to minimize the risks associated with a catastrophic 

release of impounded CCR due to structural failure. While limiting the size of CCR surface 

impoundments will reduce risks because there will be a lower volume of waste in the unit, the Agency is 
18

not convinced that, in practice, such a requirement would meaningfully reduce the risks at many facilities. 

EPA expects that such a restriction would only cause facilities to construct either several small units or a 

multi-unit system. Failure of one unit can lead to progressive failure of other units in the system, and 

thus, ultimately this may not reduce the total volume of waste that could be released into the environment. 

EPA has adopted in today’s final rule specific technical criteria intended to ensure adequate dam safety of 

CCR surface impoundments, throughout the design, construction, operation, maintenance, and closure of 

the CCR unit. Today’s final rule includes design requirements for structural stability and operating 

requirements for hydraulic and hydrologic capacity, inspection requirements, air criteria, and 

recordkeeping. Additionally, EPA has adopted requirements in the final rule for run-on and run-off from 

CCR landfills and hydraulic and hydrologic capacity requirements for CCR surface impoundments to 

ensure the appropriate management of all water which is running off of CCR storage units. This volume 

of water must be handled in accordance with appropriate regulatory requirements of the Clean Water Act.

Comment Number: EPA-HQ-RCRA-2009-0640-10550-4

Organization1:Lake Wylie Marine Commission (LWMC)

Commenter1: H. S. Hanks

Commenter Type: Local Government

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Other Sections: 4.4.5.2

Comment Excerpt Text:

Dikes and dams are barely addressed by either Subtitle C or D. Minimum engineering design 

standards must be set for all retaining walls and dam inspection standards must be set. All water 

that is running off of CCR storage must be controlled and monitored.

EPA Response: EPA has adopted in today’s final rule specific technical criteria intended to ensure 

adequate dam safety of CCR surface impoundments, throughout the design, construction, operation, 

maintenance, and closure of the CCR unit. Today’s final rule includes design requirements for structural 

stability and operating requirements for hydraulic and hydrologic capacity, inspection requirements, air 

criteria, and recordkeeping.

Section 3.8.2.4 - Inspection requirements

Total Number of Submissions: 9

Total Number of Comments: 9

Comment Number: EPA-HQ-RCRA-2012-0028-0059-10

Organization1:Commonwealth of Kentucky

Commenter1:Anthony Hatton

Commenter Type: State Government

Classification: NODA2 Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:
19

Comment Excerpt Text:

The Commonwealth believes, from years of solid waste permitting experience, that a site 

designed by a professional engineer includes unit dewatering and sufficient stability making 

weekly unnecessary. The Commonwealth believes that annual inspections should be sufficient

EPA Response: EPA disagrees with the commenter that unit dewatering and sufficient stability 

make weekly inspections unnecessary. The final rule requires weekly inspections to be 

conducted for all CCR surface impoundments. Periodic inspections of all CCR units are a 

necessary practice to ensure that the overall structural integrity of the CCR unit is maintained 

and that actual and potential structural weaknesses and other hazardous conditions are quickly 

identified and remediated throughout the active life of the unit. All CCR surface impoundments 

pose some risk of release—whether from a catastrophic failure or from a more limited structural 

failure, such as occurred at Duke Energy’s Dan River plant. Periodic inspections are a generally 

accepted, prudent engineering practice that will significantly reduce the risks of such failures; 

during the Impoundment Assessment Program, EPA discovered that many facilities routinely 

conduct some sort of periodic inspection and monitoring, although the frequency varied widely 

between facilities. The final rule merely codifies this practice, by establishing a consistent 

minimum. EPA is therefore requiring that all CCR surface impoundments be inspected by a 

qualified person weekly (for visual signs of a potentially adverse condition). Consistent with the 

proposed rule, EPA is also requiring annual inspections for all CCR surface impoundments that 

exceed the specified size threshold of: (1) a height of five feet and a storage capacity of 20 acrefeet; or (2) a height of 20 feet, must also be inspected no less than annually by a qualified 

professional engineer. These inspection requirements are generally being promulgated as 

proposed, with minor technical clarifications. 

EPA has concluded, consistent with FEMA guidelines, that routine inspections of all CCR units 

are necessary to ensure that the units are safely operated and that issues that could disrupt the 

safety and continuing operation of these units are promptly identified and remediated. 

Accordingly, the final rule requires weekly inspections to be conducted at all CCR surface 

impoundments to confirm that they are operating safely. These inspections must be conducted 

by a qualified person trained to recognize specific signs of structural instability and other 

hazardous conditions by visual observation and if, applicable monitor instrumentation. 

Comment Number: EPA-HQ-RCRA-2012-0028-0109-6

Organization1:Hoosier Energy Rural Electric Cooperative, Inc. (Hoosier)

Commenter1:Michalene Reilly

Commenter Type: Electric Utility Company

Classification: NODA2 Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:
20

Comment Excerpt Text:

On structural integrity, weekly inspections are more than should be required for any facility, 

although we agree that unusual weather or seismic conditions should trigger immediate 

inspections. Hoosier believes that inspection requirements are site specific and can be made part 

of any permit, with a minimum annual requirement.

EPA Response: The final rule requires weekly inspections to be conducted for all CCR surface 

impoundments. Periodic inspections of all CCR units are a necessary practice to ensure that the 

overall structural integrity of the CCR unit is maintained and that actual and potential structural 

weaknesses and other hazardous conditions are quickly identified and remediated throughout the 

active life of the unit. All CCR surface impoundments pose some risk of release—whether from 

a catastrophic failure or from a more limited structural failure, such as occurred at Duke 

Energy’s Dan River plant. Periodic inspections are a generally accepted, prudent engineering 

practice that will significantly reduce the risks of such failures; during the Impoundment 

Assessment Program, EPA discovered that many facilities routinely conduct some sort of 

periodic inspection and monitoring, although the frequency varied widely between facilities. 

The final rule merely codifies this practice, by establishing a consistent minimum. EPA is 

therefore requiring that all CCR surface impoundments be inspected by a qualified person 

weekly (for visual signs of a potentially adverse condition). Consistent with the proposed rule, 

EPA is also requiring annual inspections for all CCR surface impoundments that exceed the 

specified size threshold of: (1) a height of five feet and a storage capacity of 20 acre-feet; or (2) a 

height of 20 feet, must also be inspected no less than annually by a qualified professional 

engineer. These inspection requirements are generally being promulgated as proposed, with 

minor technical clarifications. 

EPA has concluded, consistent with FEMA guidelines, that routine inspections of all CCR units 

are necessary to ensure that the units are safely operated and that issues that could disrupt the 

safety and continuing operation of these units are promptly identified and remediated. 

Accordingly, the final rule requires weekly inspections to be conducted at all CCR surface 

impoundments to confirm that they are operating safely. These inspections must be conducted 

by a qualified person trained to recognize specific signs of structural instability and other 

hazardous conditions by visual observation and if, applicable monitor instrumentation. 

Section 4.4.5.2 - Stability requirements for CCR SI and dam integrity, including design 

certification by independent PE, weekly inspections, annual re-certification (35203)

Total Number of Submissions: 23

Total Number of Comments: 29

Comment Number: EPA-HQ-RCRA-2009-0640-05906-2

Organization1:Associated Electric Cooperative, Inc. (AECI)

Commenter1: Brent Ross

Commenter Type: Electric Utility Company
21

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Other Sections: 4.1.1

Comment Excerpt Text:

AECI recognizes the magnitude of the TVA ash spill of 2008 and that this spill was a result of 

poor engineering and inspection practices that resulted from poor dam safety oversight. AECI 

agrees that any development of federal regulation for coal CCRs should be under RCRA Subtitle 

D non-hazardous waste rules and should include impoundment stability criteria.

EPA Response: EPA has adopted in today’s final rule specific technical criteria intended to ensure 

adequate dam safety of CCR surface impoundments, with specific regard for the structural, geotechnical, 

and hydraulic and hydrologic engineering adequacy of the CCR unit under RCRA Subtitle D. Today’s 

final rule has adopted design and operating requirements which require owners and operators of CCR 

surface impoundments to insure the dam safety of the CCR unit throughout the unit’s design, 

construction, operation, and maintenance. Today’s final rule includes design requirements for structural 

stability, including requirements to ensure both the structural and geotechnical stability of the CCR unit, 

and operating requirements for hydraulic and hydrologic capacity, inspection requirements, air criteria, 

and recordkeeping

Comment Number: EPA-HQ-RCRA-2009-0640-06198-12

Organization1:Ameren Corporation

Commenter1: Paul R. Pike

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

In addition to the above, Ameren believes that the requirement to monitor instrumentation once 

every seven days under proposed 40 C.F.R. § 257.83(a)(2) (75 Fed. Reg. at 35245) is excessive. 

A weekly instrumentation inspection obligation is clearly unwarranted for all dams. Even the 

FEMA Federal Guidelines for Dam Safety do not contemplate a monitoring frequency of this 

magnitude, suggesting that the frequency of instrumentation monitoring "may be reduced after 

the project has been in operation for an extended time and performance observation data 

indicates that readings have stabilized." The FEMA guidelines appropriately recognize that there 

is not a one-size-fits-all monitoring frequency for instrumentation, but rather that such an 

obligation should be tailored to reflect the stage of the dam (e.g., construction, first filling, longterm), its function, and its hazard rating. Therefore, we recommend that EPA amend this 

condition to require equipment inspections once a month for dams with a dam hazard potential 

rating of "high" and quarterly for impoundments with a dam hazard potential rating of 

"significant."

EPA Response: EPA agrees with commenters that it is unnecessary and impractical to require weekly 

monitoring of instrumentation at CCR surface impoundments. EPA acknowledges the number and variety 
22

of monitoring and instrumentation present at CCR surface impoundments is significant and that weekly 

monitoring of instrumentation is excessive. EPA has modified language in the final rule to require that 

instrumentation at CCR surface impoundments be monitored and recorded at an interval not to exceed 

one month.

EPA believes it important to conduct frequent, consistent monitoring of existing and new CCR 

surface impoundments to help identify and prevent potentially harmful conditions from developing, as 

well as create a body of data that can be used to assess the long-term performance of the structure. As we 

have stated previously, EPA has determined that all CCR surface impoundments must be subject to some 

form of inspection and monitoring. EPA recognizes that CCR surface impoundments are often subject to 

build-out, and the size of these impoundments may increase as the demands for capacity from the facility 

grow. Because it is essential to establish an operating record of CCR surface impoundments, EPA has 

concluded that monitoring of instrumentation must be undertaken for all CCR surface impoundments, not 

simply those of Significant and High Hazard Potential Classifications. EPA has also determined that it 

would be advantageous to require specific inspection and monitoring requirements to document an 

operating history prior to expansion. 

EPA does, however, agree with the commenter that a requirement to monitor instrumentation 

once every seven days is excessive because of the number and variety of instrumentation that may be 

present at the CCR surface impoundment and the commonly gradual changes that occur over time in the 

readings of most instrumentation. EPA acknowledges that in the case of most instrumentation, weekly 

instrumentation monitoring is unlikely to indicate significant, detectable changes to readings. EPA 

acknowledges that the monthly time frame is more likely to be an appropriate interval for monitoring of 

instrumentation given the nature of instrumentation present at CCR surface impoundments. Therefore, 

EPA has changed the monitoring instrumentation requirements for all CCR surface impoundments to a 

frequency of not more than 30 days and immediately following unusual events, such as large floods, 

earthquakes, suspected sabotage, and vandalism. EPA has determined, based partly on FEMA Federal 

Guidelines for Dam Safety and EPA’s CCR Dam Assessment effort that scheduled monitoring of 

instrumentation is more practical on a monthly basis. Additionally, EPA believes that conservative 

practices warrant the monitoring of instrumentation following unusual events which may induce abnormal 

or unanticipated stresses on the CCR surface impoundment.

Comment Number: EPA-HQ-RCRA-2009-0640-06298-30

Organization1:Tennessee Department of Environment and Conservation (TDEC)

Commenter1: Paul L. Sloan

Commenter Type: State Government

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Other Sections: 4.4.5.1 4.4.7.4 4.4.8.2 4.4.9.1

Comment Excerpt Text:

Surface impoundments receiving CCR for treatment or disposal should be regulated from initial 

design through completion of post-closure monitoring requirements. For existing CCR surface 

impoundments there should be two categories; (1) CCR waste surface impoundments to be used 
23

for no more than five additional years from the effective date of the Final EPA CCR Rule, and 

(2) CCR surface impoundments that will be used five years after the effective date of the EPA 

CCR Final Rule.

(1) Regulations for existing CCR surface impoundments to be closed within five years of the 

effective date of the Final EPA CCR Rule should include structural analysis with 

repair/improvements required to meet a dam safety factor of 1.2. Additional requirements should 

include inspections quarterly, installation of groundwater monitoring wells, semiannual 

groundwater monitoring, closure plan, post-closure monitoring and maintenance and financial 

assurance in an amount sufficient to cap the surface impoundment and to perform environmental 

investigation and cleanup should the surface impoundment fail or have releases to groundwater 

and surface water. The CCR surface impoundment owner should be required to submit a 

statement committing to closure of the surface impoundment within five years and acknowledge 

the responsibility to comply with (2) below should the surface impoundment not be closed on 

schedule.

(2) Regulations for existing CCR surface impoundments to be operated for more than five years 

after the effective date of the Final EPA CCR Rule should include a structural analysis with 

repair/improvements required to meet a dam safety factor of 1.5. These surface impoundments 

should be retrofitted with a synthetic liner to prevent failure migration of CCR contaminants into 

ground water. The CCR surface impoundment owner should be required to obtain a solid waste 

processing/disposal permit following the RCRA Subtitle D public participation process. 

Additional recommended requirements are quarterly inspections, installation of groundwater 

monitoring wells, semi-annual groundwater sampling, annual estimation of remaining life, 

closure plan with cap, post-closure monitoring and maintenance plan and financial assurance 

sufficient to perform environmental investigation and clean up should the surface impoundment 

fail or release contaminants to groundwater or surface water.

EPA Response: EPA agrees with the commenter that there should be specific factors of safety which CCR 

surface impoundments must meet. EPA has adopted, in a departure from the proposed rule, specific 

factors of safety which must be met or exceeded by the dike of the CCR surface impoundment. These 

factors of safety for existing CCR surface impoundments are: : (1) a static factor of safety under the longterm, maximum storage pool loading condition equal to or exceeding 1.50; (2) a static factor of safety 

under the maximum surcharge pool loading condition equal to or exceeding 1.40; (3) a calculated seismic 

factor of safety equal to or exceeding 1.00; and for units that are constructed of soils which are 

susceptible to liquefaction, (4) a liquefaction factor of safety equal to or exceeding 1.20. The factors of 

safety for new CCR surface impoundments are: (1) the calculated static factor of safety under the longterm, maximum storage pool loading condition equaling or exceeding 1.50; (2) the calculated static factor 

of safety under the maximum surcharge pool loading condition equaling or exceeding 1.40; (3) the 

calculated static factor of safety under the end-of-construction loading condition equaling or exceeding 

1.30; (4) the calculated seismic factor of safety equally or exceeding 1.00 and; for units that are 

constructed of soils which are susceptible to liquefaction, (5) a liquefaction factor of safety equal to or 

exceeding 1.20. EPA has adopted these factors of safety from a combination of guidance, including US 

Army Corps of Engineers Engineer Manual EM 1110-2-1902“Slope Stability” (October 2003), and EM 

1110-2-1902 “Stability of Earth and Rock-Fill Dams” and FEMA Federal Guidelines for Dam Safety: 

Earthquake Analysis and Design of Dams.
24

Additionally, consistent with FEMA Federal Guidelines for Dam Safety, today’s final rule requires a 

range of inspections and assessments from weekly to annual to quinquennial. The requirements of the 

final rule require that these inspections and assessments vary in the scope and detail of the inspection or 

assessment and with who is qualified to conduct the inspection or assessment. Today’s final rule requires 

that all CCR surface impoundments be inspected by a qualified person at intervals not exceeding 7 days 

for any appearances of actual or potential structural weakness and other conditions which are disrupting 

or have the potential to disrupt the operation or safety of the CCR unit. Additionally, at intervals not 

exceeding 7 days, all CCR surface impoundments must be inspected to ensure that all outlets of hydraulic 

structures which pass beneath the base of the surface impoundment or through the dike of the CCR unit 

are free from abnormal discoloration, flow or discharge of debris or sediment. All CCR surface 

impoundments in excess of the size threshold of today’s final rule must be inspected annually by a 

qualified professional engineer to identify signs of distress or malfunction of the CCR unit and 

appurtenant structures, all hydraulic structures underlying the base of the CCR unit or passing through the 

dike of the CCR unit for structural integrity and continued safe and reliable operation, and must review all 

available information regarding the status and condition of the CCR unit. Finally, all CCR surface 

impoundments in excess of the size threshold of today’s final rule must undergo a formal assessment at an 

interval not to exceed 5 years by a qualified professional engineer. This formal assessment must include a 

structural stability assessment, a hazard potential assessment, and a safety factor assessment. 

EPA has modified today’s rule language from the proposal to require documentation of the weekly and 

special inspections. EPA is requiring that the results of the inspection by a qualified person must be 

recorded in the facility’s operating record. These recorded results of weekly and special inspections must 

additionally be reviewed by the qualified professional engineer during the annual inspection and the 

periodic structural stability assessment for CCR surface impoundments which are subject to those 

requirements, i.e., units which meet or exceed the size threshold of today’s final rule.

Comment Number: EPA-HQ-RCRA-2009-0640-06298-31

Organization1:Tennessee Department of Environment and Conservation (TDEC)

Commenter1: Paul L. Sloan

Commenter Type: State Government

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Other Sections: 4.4.4.1 4.4.5.1 4.4.7.1 4.4.8.2 4.4.9.1

Comment Excerpt Text:

New CCR surface impoundments should be permitted following the EPA Subtitle D criteria for 

solid waste landfills. The regulations should include:

-Public Notice of intent to construct.

-Demonstration of suitable geologic conditions for construction.

-An engineering design which includes a geologic buffer, synthetic liner, leachate collection 

system, groundwater monitoring system with a minimum of four wells, buffer zones, 

construction with a dam safety factor of 1.5, estimated disposal capacity of the surface 

impoundment, seismic analysis and seismic safety factor of 1.5, closure plan, post-closure 

monitoring and maintenance plan and financial assurance in an amount sufficient to complete 

environmental investigation and cleanup should the surface impoundment fail or have releases to 

groundwater and/or surface water.

-The initial plans should indicate whether the surface impoundment will be used for CCR 
25

treatment or for waste treatment and CCR disposal.

EPA Response: EPA agrees with the commenter that there should be specific factors of safety which CCR 

surface impoundments must meet. EPA has adopted, in a departure from the proposed rule, specific 

factors of safety which must be met or exceeded by the dike of the CCR surface impoundment. These 

factors of safety for existing CCR surface impoundments are: : (1) a static factor of safety under the longterm, maximum storage pool loading condition equal to or exceeding 1.50; (2) a static factor of safety 

under the maximum surcharge pool loading condition equal to or exceeding 1.40; (3) a calculated seismic 

factor of safety equal to or exceeding 1.00; and for units that contain soils which are susceptible to 

liquefaction, (4) a liquefaction factor of safety equal to or exceeding 1.20. The factors of safety for new 

CCR surface impoundments are: (1) the calculated static factor of safety under the long-term, maximum 

storage pool loading condition equaling or exceeding 1.50; (2) the calculated static factor of safety under 

the maximum surcharge pool loading condition equaling or exceeding 1.40; (3) the calculated static factor 

of safety under the end-of-construction loading condition equaling or exceeding 1.30; (4) the calculated 

seismic factor of safety equally or exceeding 1.00 and; for units that are constructed of soils which are 

susceptible to liquefaction, (5) a liquefaction factor of safety equal to or exceeding 1.20. EPA has adopted 

these factors of safety from a combination of guidance, including US Army Corps of Engineers Engineer 

Manual EM 1110-2-1902“Slope Stability” (October 2003), and EM 1110-2-1902 “Stability of Earth and 

Rock-Fill Dams” and FEMA Federal Guidelines for Dam Safety: Earthquake Analysis and Design of 

Dams.

Comment Number: EPA-HQ-RCRA-2009-0640-06398-104

Organization1:Duke Energy

Commenter1: Mike Stroben

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

Duke Energy supports the development of appropriate structural integrity standards for CCR 

surface impoundments.

EPA Response: EPA has adopted in today’s final rule specific structural stability requirements intended to 

ensure adequate dam safety of CCR surface impoundments, throughout the design, construction, 

operation, maintenance, and closure of the CCR unit. Today’s final rule includes design requirements for 

structural stability and operating requirements for hydraulic and hydrologic capacity, inspection 

requirements, air criteria, and recordkeeping.

Comment Number: EPA-HQ-RCRA-2009-0640-06398-62

Organization1:Duke Energy

Commenter1: Mike Stroben

Commenter Type: Electric Utility Company

Classification: Substantive
26

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

Duke Energy also believes that the requirement to perform inspections and monitor 

instrumentation once every seven days under proposed 40 C.F.R. § 257.83(a)(2) is excessive for 

most dams. Clearly, there are times when frequent (weekly) inspections and instrumentation 

monitoring is advisable (such as during initial filling of an impoundment). However, as a general 

requirement throughout the life of an impoundment, it is unnecessary. Instead, Duke Energy 

favors a general required inspection and equipment inspection frequency of once a month for 

dams with a dam hazard potential rating of “high” and quarterly for impoundments with a dam 

hazard potential rating of “significant.” The rule should also provide that the general required 

equipment inspection frequency should be variable based on site-specific conditions and upon 

the recommendation of an independent professional engineer.

Duke Energy agrees with the proposed language in 40 C.F.R. § 257.83(e), which provides that 

the “qualified person” performing periodic inspections be “trained to recognize specific signs of 

structural instability and other hazardous conditions by visual observation.” This allows for those 

who will be performing inspections to have training which is specific to the facility they are 

inspecting, as well as the frequency and thoroughness of the inspections they will be performing. 

For example, an individual performing a routine monthly inspection would not require the depth 

of education, experience, and training that an individual performing an annual inspection would 

require.

EPA Response: The final rule requires weekly general inspections and monthly instrumentation 

inspections to be conducted for all CCR surface impoundments. Periodic inspections of all CCR 

units are a necessary practice to ensure that the overall structural integrity of the CCR unit is 

maintained and that actual and potential structural weaknesses and other hazardous conditions 

are quickly identified and remediated throughout the active life of the unit. All CCR surface 

impoundments pose some risk of release—whether from a catastrophic failure or from a more 

limited structural failure, such as occurred at Duke Energy’s Dan River plant. Periodic 

inspections are a generally accepted, prudent engineering practice that will significantly reduce 

the risks of such failures; during the Impoundment Assessment Program, EPA discovered that 

many facilities routinely conduct some sort of periodic inspection and monitoring, although the 

frequency varied widely between facilities. The final rule merely codifies this practice, by 

establishing a consistent minimum. EPA is therefore requiring that all CCR surface 

impoundments be inspected by a qualified person both weekly (for visual signs of a potentially 

adverse condition) and monthly (for instrumentation monitoring). Consistent with the proposed 

rule, EPA is also requiring annual inspections for all CCR surface impoundments that exceed the 

specified size threshold of: (1) a height of five feet and a storage capacity of 20 acre-feet; or (2) a 

height of 20 feet, must also be inspected no less than annually by a qualified professional 

engineer. These inspection requirements are generally being promulgated as proposed, with 

minor technical clarifications. 
27

The final inspection requirements have been drawn heavily from guidelines established by 

FEMA for dam safety, under which maintaining structural integrity involves continuous 

evaluation of the unit, based on periodic inspections. To be most effective, FEMA suggests, and 

EPA concurs, that inspections be varied with respect to both the time interval between 

inspections and the level of detail of the inspection. FEMA guidance, in part, suggests that 

inspections can be categorized as either: visual observations to identify abnormal conditions (i.e., 

informal inspections); field inspections by a professional engineer (i.e., intermediate 

inspections); and a technical review to determine if the unit meets current and accepted design 

criteria and practices (i.e., formal inspection). 3 In general, FEMA recommends that inspections 

focusing on visual observations should be conducted often (e.g., weekly) while more substantive 

technical evaluation should be conducted every year to every five years depending on the 

engineering analyses required. (See also the preamble discussion on the requirements specified 

in §§ 257.73 and 257.74 of this rule, in particular the discussion addressing the five year time 

interval for structural stability and factor of safety reassessments.) 

For the reasons discussed above, EPA has concluded, consistent with FEMA guidelines, that 

routine inspections of all CCR units are necessary to ensure that the units are safely operated and 

that issues that could disrupt the safety and continuing operation of these units are promptly 

identified and remediated. Accordingly, the final rule requires both weekly inspections and 

monthly instrumentation inspections to be conducted at all CCR surface impoundments to 

confirm that they are operating safely. These inspections must be conducted by a qualified 

person trained to recognize specific signs of structural instability and other hazardous conditions 

by visual observation and if, applicable monitor instrumentation. EPA is also retaining the 

annual inspection requirement for CCR surface impoundments exceeding the specified size 

threshold established in this rule. This inspection must be conducted and certified by a qualified 

professional engineer. Units exceeding this size threshold pose a higher degree of risk of release 

of CCRs to the environment than other types of CCR surface impoundments (e.g., incised or 

“small” CCR units) and as such warrant additional regulatory control and oversight. 

In a departure from the proposed rule, EPA is requiring the monitoring of all instrumentation 

supporting the operation of the CCR unit to be conducted by a qualified person no less than once 

per month. This is a change from the proposal which required instrumentation to be monitored 

no less than every seven days. 

In considering the frequency of monitoring of instrumentation, the Agency was influenced by a 

number of factors including the FEMA guidelines suggested by the commenters, in addition to 

FERC guidance. FEMA guidance identifies that instrumentation monitoring frequency must be 

established “in order to give a timely warning of possible adverse conditions. Furthermore, 

FERC hydropower dam guidance, details that, for high- and significant hazard potential dams, 

the types of monitoring instrumentation which EPA observed most frequently at CCR surface 

impoundments during the Assessment Effort, i.e., reservoir level devices, drain flow devices, 

 

3 See “Federal Guidelines for Dam Safety” Federal Emergency Management Agency. (Reprinted April 

2004).
28

seepage/leakage flow devices, should be monitored at a frequency of not more than “monthly to 

quarterly.” Given the nature of the material in CCR units, EPA has taken a conservative 

approach in requiring that instrumentation monitoring be conducted monthly for all CCR surface 

impoundments, including low hazard potential CCR surface impoundments in addition to highand significant hazard potential CCR surface impoundments.4

 Also weighing heavily in EPA’s 

decision were the observations made as part of the Assessment Program, which revealed that 

many CCR units are equipped with only “basic” measuring devices such as piezometers and pool 

elevation and freeboard instrumentation and not the more sophisticated (i.e., sensitive) measuring 

devices for measuring pressure, seepage, internal movement, slope movement; and vibration. 

These findings strongly suggested to the Agency that, given the status of current instrumentation 

employed at CCR facilities, weekly monitoring would be excessive, impractical, and—of 

greatest significance--unlikely to indicate any measurable changes in structural stability in such a 

short time frame. EPA, therefore, agrees that a monthly time frame is a more appropriate 

interval for detecting discernible or significant changes in the operation of the CCR unit. EPA 

has not, however, differentiated between high, significant, and low hazard potential CCR surface 

impoundments in the requirement that instrumentation be monitored monthly, as commenters 

suggested. Through the Assessment effort, EPA identified that typically low hazard potential 

CCR surface impoundments were monitored less frequently than high- or significant hazard 

potential CCR surface impoundments by the owner or operator. Additionally, these low hazard 

potential CCR surface impoundments less commonly were equipped with sophisticated 

monitoring instrumentation, including remote monitoring instrumentation which would allow the 

owner or operator to monitor the unit from a remote location. Based on these observations, along 

with the limited burden that instrumentation monitoring places on the owner or operator, the rule 

requires all CCR surface impoundments with instrumentation to be monitored monthly.

Comment Number: EPA-HQ-RCRA-2009-0640-06398-7

Organization1:Duke Energy

Commenter1: Mike Stroben

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Other Sections: 5.6.4

Comment Excerpt Text:

Duke Energy also supports the development of structural integrity standards for CCR surface 

impoundments. Since the ash release at the Tennessee Valley Authority’s Kingston Fossil Fuel 

Plant in December of 2008, EPA has been conducting comprehensive structural integrity 

assessments of the CCR surface impoundments at many coal-fired electric generating facilities 

across the country, including Duke Energy facilities. None of the inspections at Duke Energy 

facilities has resulted in any of the impoundments receiving an “unsatisfactory” rating, meaning 

 

4 https://www.ferc.gov/industries/hydropower/safety/guidelines/eng-guide/chap9.pdf
29

that not a single impoundment is considered unsafe or requires immediate or emergency 

remedial action.

EPA Response: EPA has adopted in today’s final rule specific structural stability requirements intended to 

ensure adequate dam safety of CCR surface impoundments, throughout the design, construction, 

operation, maintenance, and closure of the CCR unit. Today’s final rule includes design requirements for 

structural stability and operating requirements for hydraulic and hydrologic capacity, inspection 

requirements, air criteria, and recordkeeping.

Comment Number: EPA-HQ-RCRA-2009-0640-06844-2

Organization1:Intermountain Power Agency (IPA)

Commenter1: James A. Hewlett

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Other Sections: 8.6

Comment Excerpt Text:

Evaluation of Potential Risks 

In the preamble to the proposed rules, the EPA stated that part of the decision to revisit its 

regulatory determination for CCR under the Bevill amendment was driven by the failure of a 

surface impoundment at Tennessee Valley Authority (TVA) Kingston fossil plant in December 

2009 and by the revision of risk assessment methodology based on new information. As a result 

of these revisions, the EPA co-proposed regulations of the CCR under RCRA Subtitle C. 

At the TVA Kingston plant, the release of 5.4 million cubic yards of coal ash (mixed with 327 

million gallons of water) covered about 300 acres of land surface and water bodies. Due to the 

potential harm to the environment, the utility, local and federal environmental agencies 

immediately began sampling and analysis of the ash itself, surface water, groundwater, drinking 

water, and air. The Tennessee Department of Health reviewed all analytical results to ensure that 

public health was protected. 

On September 7,2010, the Tennessee Department of Health released the Final Report of Public 

Health Assessment which was prepared under a cooperative agreement with the U.S. Department 

of Health and Human Services Agency for Toxic Substances and Disease Registry. 

The report found minimal health risks from the coal ash spill at TVA's Kingston facility and 

noted that the significant risk is the safety risk of engulfment by the ash to people in the path of 

the ash release. It appears that it was not the "toxicity" or the environmental "hazard" of CCR 

specific waste found in that impoundment that caused the ecological disaster, but the sheer size 

of the release. The ecological damage would have been severe even if the material released was 

simply mud.
30

Potential risks from CCR, including dam safety, can be properly addressed by federal 

nonhazardous and equally protective Subtitle D regulations. Previously, EPA has agreed that 

hazardous waste regulation will result in unnecessary regulation. In its final Regulatory . 

Determination issued on May 22,2000, EPA concluded that hazardous waste regulation was not 

warranted for coal ash. The Agency found that the inflexible nature of the federal hazardous 

waste program would result in excess costs and unduly burdensome regulations for coal ash. 

Most recently, EPA has found that the coal ash being recovered from the Kingston release site 

can be safely disposed of in a RCRA Subtitle D non-hazardous waste facility. Rather than 

regulating coal ash under Subtitle C, the EPA should work with other federal and state agencies 

by focusing on developing dam integrity programs to enhance surface impoundment safety.

EPA Response: EPA has adopted in today’s final rule specific technical criteria intended to ensure 

adequate dam safety of CCR surface impoundments, throughout the design, construction, operation, 

maintenance, and closure of the CCR unit under RCRA Subtitle D standards. Today’s final rule includes 

design requirements for structural stability and operating requirements for hydraulic and hydrologic 

capacity, inspection requirements, air criteria, and recordkeeping. EPA has based the structural stability 

requirements of the final rule on a number of dam safety programs and guidance, including that of 

FEMA, USACE, and MSHA.

Comment Number: EPA-HQ-RCRA-2009-0640-06987-11

Organization1:Entergy Services, Inc.

Commenter1: Joseph Hantz

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Other Sections: 7.1.2

Comment Excerpt Text:

Furthermore, Entergy believes that the intent of EPA’s proposed regulation of CCRs, to ensure 

protection of human health and the environment, can be adequately achieved through Subtitle D 

by issuing national minimum criteria and establishing dam and impoundment safety 

requirements to address the structural integrity of surface impoundments to prevent catastrophic 

releases, and that Arkansas and Louisiana’s existing regulations are a testimony to the ability of 

state programs to do so.

EPA Response: EPA has adopted in today’s final rule specific technical criteria intended to ensure 

adequate dam safety of CCR surface impoundments, throughout the design, construction, operation, 

maintenance, and closure of the CCR unit under RCRA Subtitle D standards. Today’s final rule includes 

design requirements for structural stability and operating requirements for hydraulic and hydrologic 

capacity, inspection requirements, air criteria, and recordkeeping.
31

Comment Number: EPA-HQ-RCRA-2009-0640-07534-18

Organization1:Aquaterra Environmental Solutions, Inc.

Commenter1: Scott Waltrip

Commenter Type: Other Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Other Sections: 3.4.1.4

Comment Excerpt Text:

Parts 264 and 265 Depth and volume thresholds 

Parts 264 and 265 give several regulatory requirements that hinge on the depth and volume 

limitations of subsections 264.1303(b) and 265.1303(b) for surface impoundments. They are: 

§§264.1303 and 265.1303 Require design plans for surface impoundments exceeding the 

limitations 

§§265.1304 and 265.1304 Require weekly inspections for surface impoundments exceeding the 

limitations; the subsections also require annual P.E. inspection/certification 

§§265.1305 and 265.1305 Require approved closure plans for surface impoundments exceeding 

the limitations 

We have addressed design plans elsewhere in our comments. However, please clarify whether 

owners of smaller impoundments have to meet the closure requirements, or whether they simply 

do not have to submit closure plans for approval. Also, please clarify whether owners of smaller 

impoundments have to inspect the facilities at all, or whether they may inspect at some other 

intervals. 

EPA Response: Although the commenter is referring to requirements for inspections of the CCR unit 

proposed under the Subtitle C proposed rule, EPA has adopted similar requirements for inspections under 

today’s Subtitle D final rule. This rule requires all CCR surface impoundments to be examined by a 

qualified person at least once every seven days for any appearance of actual or potential structural 

weakness or other conditions that are disrupting or that have the potential to disrupt the operation or 

safety of the CCR unit. The results of the inspection by a qualified person must be recorded in the 

facility’s operating record. Additionally, EPA is requiring the monitoring of all instrumentation 

supporting the operation of the CCR unit to be conducted by a qualified person no less than once per 

month. The results of the monitoring of all instrumentation by a qualified person must be recorded in the 

facility’s operating record. Furthermore, the rule requires owners or operators of any CCR surface 

impoundments exceeding the MSHA size threshold (i.e., a height of five feet or more and a storage 

volume of 20 acre-feet or more; or a height of 20 feet or more) to conduct annual inspections of the CCR 

unit throughout its operating life. The owner or operator of existing CCR surface impoundments must 

ensure that the initial annual inspection by a qualified professional engineer is completed and documented 

with a report no later than three months after the effective date of the rule. The report which the qualified 

professional engineer has documented must be placed in the facility’s operating record and placed on the 

facility’s publicly accessible internet site. An annual inspection is considered complete when the 

inspection report has been placed in the facility’s operating record. Units which do not meet or exceed the 
32

size threshold of today’s final rule are not required to be inspected annually or assessed quiquennially by 

a qualified professional engineer. The owner or operator of all CCR surface impoundments, regardless of 

size, must comply with the hazard potential assessment requirements, hydrologic and hydraulic capacity 

requirements, and the weekly inspection requirements.

Comment Number: EPA-HQ-RCRA-2009-0640-08218-30

Organization1:Maryland Department of the Environment (MDE)

Commenter1: Shari T. Wilson

Commenter Type: State Government

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Other Sections: 5.6

Comment Excerpt Text:

Maryland does not have experience with wet-ash impoundments, as there are currently none in 

Maryland. However, as there are impoundments adjacent to Maryland waters, Maryland supports 

EPA’s effort to insure the safety of these structures. 

EPA Response: EPA has adopted in today’s final rule specific technical criteria intended to ensure 

adequate dam safety of CCR surface impoundments, throughout the design, construction, operation, 

maintenance, and closure of the CCR unit under RCRA Subtitle D standards. Today’s final rule includes 

design requirements for structural stability and operating requirements for hydraulic and hydrologic 

capacity, inspection requirements, air criteria, and recordkeeping.

Comment Number: EPA-HQ-RCRA-2009-0640-08787-43

Organization1:Association of State and Territorial Solid Waste Management Officials 

(ASTSWMO)

Commenter1:Stephen A. Cobb (Al)

Commenter Type: State Government

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Other Sections: 3.4.1.3.2 3.4.1.3.1

Comment Excerpt Text:

ASTSWMO notes that the NPDES permit program appropriately focuses on effluent discharge 

limits and monitoring. Facility design and structural integrity would be a significant and 

unrelated addition to the NPDES permit program. Any surface impoundment integrity should be 

linked to the facility design requirements under RCRA Subtitle D. 

State dam safety authority, dam safety expertise, and associated regulatory programs are often 

not housed within State solid waste disposal program or water pollution programs. Likewise, 

State dam safety programs are not limited to disposal facilities and broadly regulate dams and 

levees with the guidance of several federal agencies. ASTSWMO understands that that the 

Association of State Dam Safety Officials (ASDSO) will be submitting comments and urges 
33

EPA to fully consider their comments, including incorporation of federal dam safety guidelines 

rather than MSHA dam safety guidelines. 

EPA Response: EPA, in promulgating the final rule, has taken into consideration several dam safety 

guidance and regulations, including those of FEMA, FERC, US Army Corps of Engineers, US Fish and 

Wildlife, US Bureau of Reclamation, and MSHA. EPA has fully considered ASDSO’s comments on the 

proposed rule. EPA has adopted in today’s final rule specific technical criteria intended to ensure 

adequate dam safety of CCR surface impoundments, throughout the design, construction, operation, 

maintenance, and closure of the CCR unit under RCRA Subtitle D standards based primarily of federal 

dam safety guidelines such as FEMA Federal Guidelines for Dam Safety. Today’s final rule includes 

design requirements for structural stability and operating requirements for hydraulic and hydrologic 

capacity, inspection requirements, air criteria, and recordkeeping.

EPA has chosen not to promulgate structural integrity standards based upon the NPDES permit program, 

agreeing with commenters that this would constitute a significant and unrelated addition to the program.

Comment Number: EPA-HQ-RCRA-2009-0640-09705-1

Organization1:

Commenter1:Robert B. Titus

Commenter Type: Private Citizen

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Other Sections: 4.1.1

Comment Excerpt Text:

With this letter l am requesting that Coal Combustion Waste (CCW) be regulated under the 

current provisions of the RCRA Subtitle D. It is my opinion that Subtitle D strikes the correct 

balance between protecting public health while providing the utility industry with affordable 

rules by which to dispose of waste by products. 

However, I do believe that coal ash impoundment construction standards must be upgraded. 

Increased inspection and monitoring of existing and proposed impoundments should be 

implemented as well.

EPA Response: EPA has adopted in today’s final rule specific technical criteria intended to ensure 

adequate dam safety of CCR surface impoundments, throughout the design, construction, operation, 

maintenance, and closure of the CCR unit under RCRA Subtitle D standards based primarily on federal 

dam safety guidelines such as FEMA Federal Guidelines for Dam Safety. Today’s final rule includes 

design requirements for structural stability and operating requirements for hydraulic and hydrologic 

capacity, inspection requirements, air criteria, and recordkeeping.
34

Comment Number: EPA-HQ-RCRA-2009-0640-09885-32

Organization1:Progress Energy, Inc.

Commenter1: Caroline Choi

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

Development of structural integrity standards for CCR surface impoundments

Progress Energy agrees with EPA’s proposal to incorporate the surface impoundment integrity 

and inspection obligations into the RCRA program modeled largely on the standards for coal 

slurry impoundments regulated by the Mine Safety and Health Administration (MSHA). While 

MSHA standards regulate a broader array of materials with differing physical properties than 

CCRs, the MSHA rules provide a good starting point for developing comparable standards for 

CCR impoundments.

However, it is important to ensure that the same applicability criteria triggering the obligation to 

record impoundment information in the company’s operating record apply in triggering the 

related obligation to conduct surface impoundment inspections

EPA Response: EPA has adopted in the final rule surface impoundment structural stability and inspection 

obligations under a RCRA Subtitle D approach modeled partially on the standards for coal slurry 

impoundments regulated by the Mine Safety and Health Administration (MSHA). However, EPA has 

revised language in the final rule to also incorporate, in large part, standards and guidance developed by 

other federal and state agencies charged with the oversight of dams and other impounding structures. EPA 

considered guidance and regulation from such agencies as FEMA, US Army Corps of Engineers, FERC, 

US Bureau of Reclamation, and US Fish and Wildlife, in addition to MSHA. EPA agrees with 

commenters that the MSHA rules provided a good starting point for developing structural integrity and 

inspection requirements for CCR surface impoundments.

EPA acknowledges that there may have been an error in extending the applicability criteria of 

recordkeeping to inspection requirements in the proposed rule. In the proposed rule, the preamble 

generally stated that the proposed regulatory requirements addressing stability (which included 

inspections) applied only to those CCR surface impoundments exceeding the specified size threshold 

established by the MSHA regulations, the regulatory text required inspections for all CCR units.

The final rule requires weekly general inspections to be conducted for all CCR surface impoundments. 

Periodic inspections of all CCR units are a necessary practice to ensure that the overall structural integrity 

of the CCR unit is maintained and that actual and potential structural weaknesses and other hazardous 

conditions are quickly identified and remediated throughout the active life of the unit. All CCR surface 

impoundments pose some risk of release—whether from a catastrophic failure or from a more limited 

structural failure, such as occurred at Duke Energy’s Dan River plant. Periodic inspections are a 

generally accepted, prudent engineering practice that will significantly reduce the risks of such failures; 

during the Impoundment Assessment Program, EPA discovered that many facilities routinely conduct 

some sort of periodic inspection and monitoring, although the frequency varied widely between facilities. 
35

The final rule merely codifies this practice, by establishing a consistent minimum. EPA is therefore 

requiring that all CCR surface impoundments be inspected by a qualified person weekly (for visual signs 

of a potentially adverse condition).

Comment Number: TRANS-CHI-0018-5

Organization1:ALCOA Power Generating, Inc.

Commenter1:Scott Darling

Commenter Type: Other Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

ALCOA does agree that there is a need to ensure that surface impoundments are safe in 

catastrophic failure and we recommend that inspections of surface impoundments by certified 

professional engineers knowledgeable with dams and ash ponds be conducted annually.

EPA Response: EPA has adopted in today’s final rule specific inspection requirements for annual 

inspection and quinquennial assessments (i.e., hazard potential assessments, structural stability 

assessments, safety factor assessments). Both the annual inspections and the quinquennial assessments 

must be conducted and certified by a qualified professional engineer.

Section 4.4.6.1 - Existing criteria for endangered species and surface water

Total Number of Submissions: 1

Total Number of Comments: 1

Comment Number: EPA-HQ-RCRA-2009-0640-09349-19

Organization1:Santee Cooper

Commenter1: Jay Hudson

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

40 CFR 257.82 (35245) regulates discharges to surface waters, both point and non-point. 

However, the NPDES permit process adequately regulates industrial point source discharges 

from industrial treatment ponds. Duplicate or overlapping regulatory requirements should be 

avoided.
36

EPA Response: EPA agrees with commenters that the NPDES permit process adequately regulates 

industrial point source discharges from CCR units. EPA has removed the surface water requirements 

proposed under 40 CFR 257.82 from today’s final rule. CCR surface impoundments are still subject to the 

existing NPDES permit requirements for discharges to surface water.

Section 4.4.6.2 - Run-on and run-off controls

Total Number of Submissions: 23

Total Number of Comments: 23

Comment Number: EPA-HQ-RCRA-2009-0640-06252-14

Organization1:Minnkota Power Cooperative, Inc. (Minnkota)

Commenter1:John T. Graves

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

EPA should amend its run-on control requirements for CCR surface impoundments. Current runon controls were designed for Municipal Solid Waste landfills and are not appropriate for the 

way impoundments at many power plants are designed. 

EPA Response: EPA agrees with the commenter that it would be inappropriate to extend the runon controls for MSW landfills to CCR surface impoundments. In evaluating the arguments 

against the requirements to prevent flow onto the CCR surface impoundment, the Agency was 

strongly influenced by guidance developed by FEMA for selecting and accommodating 

hydraulic and hydrologic inflow and outflow as well as the application of this guidance to the 

CCR surface impoundments evaluated as part of EPA’s Assessment Program.5 A review of 

FEMA guidance confirmed commenters’ contentions that managing flow both to and from dams 

and impoundments was a widely used practice, and a preferable management strategy for 

accommodating storm water flows. This was further confirmed by observations made during 

EPA’s Assessment Program; EPA frequently observed units designed to detain or retain storm 

water inflows of an upstream catchment area to manage CCR, and/or to receive storm water 

inflow as part of the facility’s overall storm water management system. Moreover, EPA relied 

on the same FEMA guidance to assess the adequacy of the hydrologic and hydraulic capacity of 

the CCR surface impoundments. In conducting these assessments, EPA considered a number of 

factors including operating freeboard, catchment area, hydrologic structures’ inflow and outflow 

ratings, design precipitation event, spillway presence and capacity, and unit operating procedures 

 

5 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.
37

to make this determination. The adequacy of the capacity was determined using FEMA 

guidance for selecting and accommodating inflow design floods (IDF) for dams. (Note: The use 

of the terminology related to “inflow design flood” for CCR surface impoundments rather than 

“run-on” and “run-off” is more directly applicable to the hydraulic and hydrologic capacity of 

CCR surface impoundments to adequately manage both the inflow and outflow from a design 

flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

and run-off requirements for CCR surface impoundments to require owners or operators of all 

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

Comment Number: EPA-HQ-RCRA-2009-0640-06254-16

Organization1:Sunflower Electric Power Corporation

Commenter1:Paul E. Reynolds

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

EPA should amend its run-on control requirements for CCR surface impoundments. Current runon controls were designed for Municipal Solid Waste landfills and are not appropriate for the 

way impoundments at many power plants are designed. 

EPA Response: EPA agrees with the commenter that it would be inappropriate to extend the runon controls for MSW landfills to CCR surface impoundments. In evaluating the arguments 

against the requirements to prevent flow onto the CCR surface impoundment, the Agency was 

strongly influenced by guidance developed by FEMA for selecting and accommodating 

hydraulic and hydrologic inflow and outflow as well as the application of this guidance to the 

CCR surface impoundments evaluated as part of EPA’s Assessment Program.6 A review of 

FEMA guidance confirmed commenters’ contentions that managing flow both to and from dams 

and impoundments was a widely used practice, and a preferable management strategy for 

 

6 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.
38

accommodating storm water flows. This was further confirmed by observations made during 

EPA’s Assessment Program; EPA frequently observed units designed to detain or retain storm 

water inflows of an upstream catchment area to manage CCR, and/or to receive storm water 

inflow as part of the facility’s overall storm water management system. Moreover, EPA relied 

on the same FEMA guidance to assess the adequacy of the hydrologic and hydraulic capacity of 

the CCR surface impoundments. In conducting these assessments, EPA considered a number of 

factors including operating freeboard, catchment area, hydrologic structures’ inflow and outflow 

ratings, design precipitation event, spillway presence and capacity, and unit operating procedures 

to make this determination. The adequacy of the capacity was determined using FEMA 

guidance for selecting and accommodating inflow design floods (IDF) for dams. (Note: The use 

of the terminology related to “inflow design flood” for CCR surface impoundments rather than 

“run-on” and “run-off” is more directly applicable to the hydraulic and hydrologic capacity of 

CCR surface impoundments to adequately manage both the inflow and outflow from a design 

flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

and run-off requirements for CCR surface impoundments to require owners or operators of all 

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

Comment Number: EPA-HQ-RCRA-2009-0640-06300-12

Organization1:Southern Company on behalf of itself and its four subsidiaries: Alabama 

Power Company, Georgia Power Company, Gulf Power Company, and Mississippi Power 

Company

Commenter1: Chris M. Hobson

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

3. Proposed Run-On Control Requirements Are Inappropriate for Surface Impoundments. 

Surface impoundments are designed to collect, store, and manage precipitation. They are not 

intended, and should not be required, to “prevent flow onto the active portion of the CCB landfill 

or surface impoundment,” as suggested in proposed 257.81(a)(1). [Footnote 50: Id. at 35245.] A 

general run-on standard such as that proposed by EPA is both unnecessary and nonsensical in the 

context of the typical ash impoundments at Southern Company’s subsidiary utilities. Such 

impoundments are generally open ponds designed to manage, not avoid, precipitation. Rather, to 
39

the extent EPA’s standards allow for continued operation of surface impoundments, any 

regulatory standard should seek to ensure that the impoundment can manage severe precipitation 

events (i.e., a 100-year storm) through some combination of storage and discharge without 

overtopping or otherwise malfunctioning

EPA Response: EPA agrees with the commenter that it would be inappropriate to extend run-on 

controls to CCR surface impoundments. In evaluating the arguments against the requirements to 

prevent flow onto the CCR surface impoundment, the Agency was strongly influenced by 

guidance developed by FEMA for selecting and accommodating hydraulic and hydrologic inflow 

and outflow as well as the application of this guidance to the CCR surface impoundments 

evaluated as part of EPA’s Assessment Program.7 A review of FEMA guidance confirmed 

commenters’ contentions that managing flow both to and from dams and impoundments was a 

widely used practice, and a preferable management strategy for accommodating storm water 

flows. This was further confirmed by observations made during EPA’s Assessment Program; 

EPA frequently observed units designed to detain or retain storm water inflows of an upstream 

catchment area to manage CCR, and/or to receive storm water inflow as part of the facility’s 

overall storm water management system. Moreover, EPA relied on the same FEMA guidance to 

assess the adequacy of the hydrologic and hydraulic capacity of the CCR surface impoundments. 

In conducting these assessments, EPA considered a number of factors including operating 

freeboard, catchment area, hydrologic structures’ inflow and outflow ratings, design precipitation 

event, spillway presence and capacity, and unit operating procedures to make this determination. 

The adequacy of the capacity was determined using FEMA guidance for selecting and 

accommodating inflow design floods (IDF) for dams. (Note: The use of the terminology related 

to “inflow design flood” for CCR surface impoundments rather than “run-on” and “run-off” is 

more directly applicable to the hydraulic and hydrologic capacity of CCR surface impoundments 

to adequately manage both the inflow and outflow from a design flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

and run-off requirements for CCR surface impoundments to require owners or operators of all 

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

Comment Number: EPA-HQ-RCRA-2009-0640-06313-98

Organization1:Earthjustice et. al.

 

7 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.
40

Commenter1: Lisa Evans

Commenter Type: Advocacy Group

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Other Sections: 3.5.2.3

Comment Excerpt Text:

Installation of run-on and run-off controls should be required for all existing CCR landfills 

within 6 months of the effective date of the final rule. Six months will be ample time to design 

and install such controls. Such controls have been an integral part of the design and management 

of all Subtitle C and Subtitle D landfills. 

Storm water controls are permitted and implemented for construction projects across the United 

States on a daily basis in order to comply with storm water discharge permits. Such permits 

routinely require 7-10 days to obtain and controls, including diversion structures, silt barriers, 

and detention structures are constructed over a period of weeks to months. Thus there is no 

reason to allow more than six months to implement run-on/run-off controls at CCR sites. 

EPA Response: EPA disagrees with the commenter that run-on and run-off controls should be 

required for all existing CCR landfills within 6 months of the effective date of the rule. The runon and run-off (RORO) controls of the final rule require that the owner or operator prepare the 

initial run-on and run-off control system plan within one year of the effective date of the rule. 

Run-on and run-off control system plan reporting may require design, construction, and postconstruction implementation. In instances where run-on and run-off capacity is insufficient, 

installing additional capacity may involve construction of diversion structures such as swales or 

ditches. Many of these efforts may require several months of design and construction, 

compounded by the fact that much of the work cannot be completed in cold-weather or heavyrain seasons.

Comment Number: EPA-HQ-RCRA-2009-0640-06352-16

Organization1:Dayton Power & Light Company (DP&L)

Commenter1: JoAnne Rau

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

C. The proposed subtitle D regulations at 40 CFR §257.81(a)(I) require a "control system to 

prevent flow onto the active portion of the CCR landfill or surface impoundment" during peak 

discharge events. A more appropriate way to address this would be to require that the surface 

impoundment be designed to accommodate peak discharge events rather than to prevent the run-
41

on from occurring. Since most impoundments already are so designed, this would prevent them 

from having to comply with an unnecessary requirement to prevent run-on

EPA Response: EPA agrees with the commenter that it would be inappropriate to extend run-on 

controls to CCR surface impoundments. In evaluating the arguments against the requirements to 

prevent flow onto the CCR surface impoundment, the Agency was strongly influenced by 

guidance developed by FEMA for selecting and accommodating hydraulic and hydrologic inflow 

and outflow as well as the application of this guidance to the CCR surface impoundments 

evaluated as part of EPA’s Assessment Program.8 A review of FEMA guidance confirmed 

commenters’ contentions that managing flow both to and from dams and impoundments was a 

widely used practice, and a preferable management strategy for accommodating storm water 

flows. This was further confirmed by observations made during EPA’s Assessment Program; 

EPA frequently observed units designed to detain or retain storm water inflows of an upstream 

catchment area to manage CCR, and/or to receive storm water inflow as part of the facility’s 

overall storm water management system. Moreover, EPA relied on the same FEMA guidance to 

assess the adequacy of the hydrologic and hydraulic capacity of the CCR surface impoundments. 

In conducting these assessments, EPA considered a number of factors including operating 

freeboard, catchment area, hydrologic structures’ inflow and outflow ratings, design precipitation 

event, spillway presence and capacity, and unit operating procedures to make this determination. 

The adequacy of the capacity was determined using FEMA guidance for selecting and 

accommodating inflow design floods (IDF) for dams. (Note: The use of the terminology related 

to “inflow design flood” for CCR surface impoundments rather than “run-on” and “run-off” is 

more directly applicable to the hydraulic and hydrologic capacity of CCR surface impoundments 

to adequately manage both the inflow and outflow from a design flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

and run-off requirements for CCR surface impoundments to require owners or operators of all 

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

Comment Number: EPA-HQ-RCRA-2009-0640-06398-39

Organization1:Duke Energy

Commenter1: Mike Stroben

Commenter Type: Electric Utility Company

 

8 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.
42

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

Duke Energy agrees with EPA that run-on and runoff controls are necessary for most surface 

impoundments and landfills. However, Duke Energy also points out that there are certain 

exceptions that EPA needs to recognize in the proposed regulatory language. For example, 40 

C.F.R. § 257.81 requires a "control system to prevent flow onto the active portion of the CCR 

landfill or surface impoundment" during peak discharge events. While this requirement may be 

appropriate for CCR landfills and surface impoundments that are constructed with above-ground 

dikes on all sides, it is a wholly inappropriate requirement for CCR surface impoundments that 

have been specifically designed to retain stormwater from an adjoining watershed, including 

those impoundments that have been formed by damming a ravine. Such impoundments have 

already received regulatory review/approval, have been designed with capacity and outlets that 

are sufficient to deal with the water flow into the impoundment from the natural watersheds 

during peak discharge events, and have operated safely.

Duke Energy recommends that EPA eliminate the proposed prohibition of run-on into 

impoundments. Instead, EPA should require that impoundment designs appropriately address the 

additional flow contributed by stormwater which discharges into the impoundment during peak 

discharge events. In this manner, impoundments that have been designed as described above, and 

which have been engineered to address peak discharge events, will not be confronted with a 

restriction that is both unnecessary and effectively impossible to satisfy.

EPA Response: EPA agrees with the commenter that it would be inappropriate to extend run-on 

controls to CCR surface impoundments. In evaluating the arguments against the requirements to 

prevent flow onto the CCR surface impoundment, the Agency was strongly influenced by 

guidance developed by FEMA for selecting and accommodating hydraulic and hydrologic inflow 

and outflow as well as the application of this guidance to the CCR surface impoundments 

evaluated as part of EPA’s Assessment Program.9 A review of FEMA guidance confirmed 

commenters’ contentions that managing flow both to and from dams and impoundments was a 

widely used practice, and a preferable management strategy for accommodating storm water 

flows. This was further confirmed by observations made during EPA’s Assessment Program; 

EPA frequently observed units designed to detain or retain storm water inflows of an upstream 

catchment area to manage CCR, and/or to receive storm water inflow as part of the facility’s 

overall storm water management system. Moreover, EPA relied on the same FEMA guidance to 

assess the adequacy of the hydrologic and hydraulic capacity of the CCR surface impoundments. 

In conducting these assessments, EPA considered a number of factors including operating 

freeboard, catchment area, hydrologic structures’ inflow and outflow ratings, design precipitation 

event, spillway presence and capacity, and unit operating procedures to make this determination. 

 

9 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.
43

The adequacy of the capacity was determined using FEMA guidance for selecting and 

accommodating inflow design floods (IDF) for dams. (Note: The use of the terminology related 

to “inflow design flood” for CCR surface impoundments rather than “run-on” and “run-off” is 

more directly applicable to the hydraulic and hydrologic capacity of CCR surface impoundments 

to adequately manage both the inflow and outflow from a design flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

and run-off requirements for CCR surface impoundments to require owners or operators of all 

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

Comment Number: EPA-HQ-RCRA-2009-0640-06529-43

Organization1:NiSource Corporate Services

Commenter1: Dale A. Helmers

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

Run-On (40 C.F.R. § 257.81)

While this requirement may be appropriate for CCR landfills, it is not appropriate for CCR 

surface impoundments that are part of a facility’s stormwater management program. The use of 

these impoundments to manage stormwater is integral to ongoing operations. Prohibiting CCR 

surface impoundments from receiving run-on will require construction of new impoundments 

without providing measureable environmental benefits. This requirement should be deleted

EPA Response: EPA agrees with the commenter that it would be inappropriate to extend run-on 

controls to CCR surface impoundments. In evaluating the arguments against the requirements to 

prevent flow onto the CCR surface impoundment, the Agency was strongly influenced by

guidance developed by FEMA for selecting and accommodating hydraulic and hydrologic inflow 

and outflow as well as the application of this guidance to the CCR surface impoundments 
44

evaluated as part of EPA’s Assessment Program.10 A review of FEMA guidance confirmed 

commenters’ contentions that managing flow both to and from dams and impoundments was a 

widely used practice, and a preferable management strategy for accommodating storm water 

flows. This was further confirmed by observations made during EPA’s Assessment Program; 

EPA frequently observed units designed to detain or retain storm water inflows of an upstream 

catchment area to manage CCR, and/or to receive storm water inflow as part of the facility’s 

overall storm water management system. Moreover, EPA relied on the same FEMA guidance to 

assess the adequacy of the hydrologic and hydraulic capacity of the CCR surface impoundments. 

In conducting these assessments, EPA considered a number of factors including operating 

freeboard, catchment area, hydrologic structures’ inflow and outflow ratings, design precipitation 

event, spillway presence and capacity, and unit operating procedures to make this determination. 

The adequacy of the capacity was determined using FEMA guidance for selecting and 

accommodating inflow design floods (IDF) for dams. (Note: The use of the terminology related 

to “inflow design flood” for CCR surface impoundments rather than “run-on” and “run-off” is 

more directly applicable to the hydraulic and hydrologic capacity of CCR surface impoundments 

to adequately manage both the inflow and outflow from a design flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

and run-off requirements for CCR surface impoundments to require owners or operators of all 

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

Comment Number: EPA-HQ-RCRA-2009-0640-06532-38

Organization1:Southern Illinois Power Cooperative

Commenter1: Leonard F. Hopkins

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

Run-On (40 C.F.R. § 257.81)

 

10 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.
45

While this requirement may be appropriate for CCR landfills, it is not appropriate for CCR 

surface impoundments that are part of a facility’s stormwater management program and run-on is 

specifically called for under the facility’s stormwater pollution prevention plan. The use of these 

impoundments to manage stormwater is integral to ongoing operations. Prohibiting CCR surface 

impoundments from receiving run-on will require construction of new impoundments without 

providing measureable environmental benefits. This requirement should be deleted

EPA Response: EPA agrees with the commenter that it would be inappropriate to extend run-on 

controls to CCR surface impoundments. In evaluating the arguments against the requirements to 

prevent flow onto the CCR surface impoundment, the Agency was strongly influenced by 

guidance developed by FEMA for selecting and accommodating hydraulic and hydrologic inflow 

and outflow as well as the application of this guidance to the CCR surface impoundments 

evaluated as part of EPA’s Assessment Program.11 A review of FEMA guidance confirmed 

commenters’ contentions that managing flow both to and from dams and impoundments was a 

widely used practice, and a preferable management strategy for accommodating storm water 

flows. This was further confirmed by observations made during EPA’s Assessment Program; 

EPA frequently observed units designed to detain or retain storm water inflows of an upstream 

catchment area to manage CCR, and/or to receive storm water inflow as part of the facility’s 

overall storm water management system. Moreover, EPA relied on the same FEMA guidance to 

assess the adequacy of the hydrologic and hydraulic capacity of the CCR surface impoundments. 

In conducting these assessments, EPA considered a number of factors including operating 

freeboard, catchment area, hydrologic structures’ inflow and outflow ratings, design precipitation 

event, spillway presence and capacity, and unit operating procedures to make this determination. 

The adequacy of the capacity was determined using FEMA guidance for selecting and 

accommodating inflow design floods (IDF) for dams. (Note: The use of the terminology related 

to “inflow design flood” for CCR surface impoundments rather than “run-on” and “run-off” is 

more directly applicable to the hydraulic and hydrologic capacity of CCR surface impoundments 

to adequately manage both the inflow and outflow from a design flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

and run-off requirements for CCR surface impoundments to require owners or operators of all 

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

 

11 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.
46

Comment Number: EPA-HQ-RCRA-2009-0640-06722-18

Organization1:Arkansas Electric Cooperative Corporation (AECC)

Commenter1: Jonathan Oliver

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

EPA should amend its run-on control requirements for CCR surface impoundments. Current runon controls were designed for Municipal Solid Waste landfills and are not appropriate for the 

way impoundments at many power plants are designed. 

EPA Response: EPA agrees with the commenter that it would be inappropriate to extend run-on 

controls to CCR surface impoundments. In evaluating the arguments against the requirements to 

prevent flow onto the CCR surface impoundment, the Agency was strongly influenced by 

guidance developed by FEMA for selecting and accommodating hydraulic and hydrologic inflow 

and outflow as well as the application of this guidance to the CCR surface impoundments 

evaluated as part of EPA’s Assessment Program.12 A review of FEMA guidance confirmed 

commenters’ contentions that managing flow both to and from dams and impoundments was a 

widely used practice, and a preferable management strategy for accommodating storm water 

flows. This was further confirmed by observations made during EPA’s Assessment Program; 

EPA frequently observed units designed to detain or retain storm water inflows of an upstream 

catchment area to manage CCR, and/or to receive storm water inflow as part of the facility’s 

overall storm water management system. Moreover, EPA relied on the same FEMA guidance to 

assess the adequacy of the hydrologic and hydraulic capacity of the CCR surface impoundments. 

In conducting these assessments, EPA considered a number of factors including operating 

freeboard, catchment area, hydrologic structures’ inflow and outflow ratings, design precipitation 

event, spillway presence and capacity, and unit operating procedures to make this determination. 

The adequacy of the capacity was determined using FEMA guidance for selecting and 

accommodating inflow design floods (IDF) for dams. (Note: The use of the terminology related 

to “inflow design flood” for CCR surface impoundments rather than “run-on” and “run-off” is 

more directly applicable to the hydraulic and hydrologic capacity of CCR surface impoundments 

to adequately manage both the inflow and outflow from a design flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

and run-off requirements for CCR surface impoundments to require owners or operators of all 

 

12 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.
47

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

Comment Number: EPA-HQ-RCRA-2009-0640-06827-12

Organization1:Oklahoma Gas and Electric Company (OG&E)

Commenter1: Kenneth E. Raymond

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

E. Run-On Control Requirements for CCR Surface Impoundments are Unnecessary

Another faulty aspect of the Subtitle D option is the imposition of run-on controls for surface 

impoundments. These provisions require a control system to prevent the flow of storm water into 

a CCR surface impoundment during peak rainfall events. While this requirement may be 

appropriate for CCR landfills, it is inappropriate for surface impoundments that have been 

specifically designed and constructed to account for storm water from such rainfall events.

To address this issue, OG&E suggests iliat the Agency require CCR surface impoundments to be 

designed to appropriately address peak rainfall events for their particular locations rather than 

requiring that run-on into the impoundments must be prevented. By doing so, surface 

impoundments that have been already been designed and constructed to address such rainfall 

events will not be confronted with a restriction that is both unnecessary and effectively 

impossible to meet

EPA Response: EPA agrees with the commenter that it would be inappropriate to extend run-on 

controls to CCR surface impoundments. In evaluating the arguments against the requirements to 

prevent flow onto the CCR surface impoundment, the Agency was strongly influenced by 

guidance developed by FEMA for selecting and accommodating hydraulic and hydrologic inflow 

and outflow as well as the application of this guidance to the CCR surface impoundments 

evaluated as part of EPA’s Assessment Program.13 A review of FEMA guidance confirmed 

commenters’ contentions that managing flow both to and from dams and impoundments was a 

widely used practice, and a preferable management strategy for accommodating storm water 

flows. This was further confirmed by observations made during EPA’s Assessment Program; 

EPA frequently observed units designed to detain or retain storm water inflows of an upstream 

catchment area to manage CCR, and/or to receive storm water inflow as part of the facility’s 

overall storm water management system. Moreover, EPA relied on the same FEMA guidance to 

assess the adequacy of the hydrologic and hydraulic capacity of the CCR surface impoundments. 

In conducting these assessments, EPA considered a number of factors including operating 

 

13 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.
48

freeboard, catchment area, hydrologic structures’ inflow and outflow ratings, design precipitation 

event, spillway presence and capacity, and unit operating procedures to make this determination. 

The adequacy of the capacity was determined using FEMA guidance for selecting and 

accommodating inflow design floods (IDF) for dams. (Note: The use of the terminology related 

to “inflow design flood” for CCR surface impoundments rather than “run-on” and “run-off” is 

more directly applicable to the hydraulic and hydrologic capacity of CCR surface impoundments 

to adequately manage both the inflow and outflow from a design flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

and run-off requirements for CCR surface impoundments to require owners or operators of all 

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

Comment Number: EPA-HQ-RCRA-2009-0640-06863-36

Organization1:Avista Corp.

Commenter1: Darrell Soyars

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

EPA Should Amend Its Run-On Control Requirements For CCR Surface Impoundments 

One complication of copying the proposed CCR Subtitle D regulations from the MSWLF 

program is that some of the particular operating requirements for MSWLF landfills cannot be 

directly applied to CCR surface impoundments. As discussed above, this is true in the case of 

attempting to apply the MSWLF closure time periods to CCR disposal units. Another important 

example of this is the section of the proposed requirement for surface impoundments and 

landfills requiring the establishment of specific operating controls for water run-on and run-off. 

Id. at 35245 (proposed 40 C.F.R. § 257.81). The run-on portion of these controls requires a 

“control system to prevent flow onto the active portion of the CCR landfill or surface 

impoundment” during peak discharge events. Id. (proposed 40 C.F.R. § 257.81(a)(1)). While this 

requirement may be appropriate for CCR landfills (as it is for MSWLFs), it is wholly 

inappropriate for surface impoundments that have been specifically designed as holding basins 

for stormwater or that have been formed by damming a ravine and have been designed with 

outlets that are sufficient to deal with the water flow from the natural watersheds into the 

impoundment during peak discharge events. 

Avista suggests that EPA address the inapplicability of this requirement for these types of 
49

surface impoundments by instead requiring that CCR impoundments be designed to 

appropriately address peak discharge events, rather than specifying that run-on into the 

impoundment be prevented. In this manner, impoundments that have been designed as described 

above and have been engineered to address peak discharge events will not be confronted with a 

restriction that is both unnecessary and effectively impossible to meet. 

EPA Response: EPA agrees with the commenter that it would be inappropriate to extend run-on 

controls to CCR surface impoundments. In evaluating the arguments against the requirements to 

prevent flow onto the CCR surface impoundment, the Agency was strongly influenced by 

guidance developed by FEMA for selecting and accommodating hydraulic and hydrologic inflow 

and outflow as well as the application of this guidance to the CCR surface impoundments 

evaluated as part of EPA’s Assessment Program.14 A review of FEMA guidance confirmed 

commenters’ contentions that managing flow both to and from dams and impoundments was a 

widely used practice, and a preferable management strategy for accommodating storm water 

flows. This was further confirmed by observations made during EPA’s Assessment Program; 

EPA frequently observed units designed to detain or retain storm water inflows of an upstream 

catchment area to manage CCR, and/or to receive storm water inflow as part of the facility’s 

overall storm water management system. Moreover, EPA relied on the same FEMA guidance to 

assess the adequacy of the hydrologic and hydraulic capacity of the CCR surface impoundments. 

In conducting these assessments, EPA considered a number of factors including operating 

freeboard, catchment area, hydrologic structures’ inflow and outflow ratings, design precipitation 

event, spillway presence and capacity, and unit operating procedures to make this determination. 

The adequacy of the capacity was determined using FEMA guidance for selecting and 

accommodating inflow design floods (IDF) for dams. (Note: The use of the terminology related 

to “inflow design flood” for CCR surface impoundments rather than “run-on” and “run-off” is 

more directly applicable to the hydraulic and hydrologic capacity of CCR surface impoundments 

to adequately manage both the inflow and outflow from a design flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

and run-off requirements for CCR surface impoundments to require owners or operators of all 

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

 

14 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.
50

Comment Number: EPA-HQ-RCRA-2009-0640-07047-26

Organization1:Great River Energy

Commenter1: Erik Silvola

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

EPA applied run-on controls to surface impoundments in the proposal. This is appropriate for 

landfills but not impoundments. Many facilities use CCR impoundments for a number of duties 

including stormwater management. The proposal should be amended to allow stormwater 

management in properly designed impoundments as this is key for many plants and especially 

zero liquid discharge facilities.

EPA Response: EPA agrees with the commenter that it would be inappropriate to extend run-on 

controls to CCR surface impoundments. In evaluating the arguments against the requirements to 

prevent flow onto the CCR surface impoundment, the Agency was strongly influenced by 

guidance developed by FEMA for selecting and accommodating hydraulic and hydrologic inflow 

and outflow as well as the application of this guidance to the CCR surface impoundments 

evaluated as part of EPA’s Assessment Program.15 A review of FEMA guidance confirmed 

commenters’ contentions that managing flow both to and from dams and impoundments was a 

widely used practice, and a preferable management strategy for accommodating storm water 

flows. This was further confirmed by observations made during EPA’s Assessment Program; 

EPA frequently observed units designed to detain or retain storm water inflows of an upstream 

catchment area to manage CCR, and/or to receive storm water inflow as part of the facility’s 

overall storm water management system. Moreover, EPA relied on the same FEMA guidance to 

assess the adequacy of the hydrologic and hydraulic capacity of the CCR surface impoundments. 

In conducting these assessments, EPA considered a number of factors including operating 

freeboard, catchment area, hydrologic structures’ inflow and outflow ratings, design precipitation 

event, spillway presence and capacity, and unit operating procedures to make this determination. 

The adequacy of the capacity was determined using FEMA guidance for selecting and 

accommodating inflow design floods (IDF) for dams. (Note: The use of the terminology related 

to “inflow design flood” for CCR surface impoundments rather than “run-on” and “run-off” is 

more directly applicable to the hydraulic and hydrologic capacity of CCR surface impoundments 

to adequately manage both the inflow and outflow from a design flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

 

15 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.
51

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

and run-off requirements for CCR surface impoundments to require owners or operators of all 

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

Comment Number: EPA-HQ-RCRA-2009-0640-08220-16

Organization1:PowerSouth Energy Cooperative

Commenter1: Dr. Keith Stephens

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

EPA should amend its run-on control requirements for CCR surface impoundments. Current runon controls were designed for Municipal Solid Waste landfills and are not appropriate for the 

way impoundments at many power plants are designed. 

EPA Response: EPA agrees with the commenter that it would be inappropriate to extend run-on 

controls to CCR surface impoundments. In evaluating the arguments against the requirements to 

prevent flow onto the CCR surface impoundment, the Agency was strongly influenced by 

guidance developed by FEMA for selecting and accommodating hydraulic and hydrologic inflow 

and outflow as well as the application of this guidance to the CCR surface impoundments 

evaluated as part of EPA’s Assessment Program.16 A review of FEMA guidance confirmed 

commenters’ contentions that managing flow both to and from dams and impoundments was a 

widely used practice, and a preferable management strategy for accommodating storm water 

flows. This was further confirmed by observations made during EPA’s Assessment Program; 

EPA frequently observed units designed to detain or retain storm water inflows of an upstream 

catchment area to manage CCR, and/or to receive storm water inflow as part of the facility’s 

overall storm water management system. Moreover, EPA relied on the same FEMA guidance to 

assess the adequacy of the hydrologic and hydraulic capacity of the CCR surface impoundments. 

In conducting these assessments, EPA considered a number of factors including operating 

freeboard, catchment area, hydrologic structures’ inflow and outflow ratings, design precipitation 

event, spillway presence and capacity, and unit operating procedures to make this determination. 

The adequacy of the capacity was determined using FEMA guidance for selecting and 

accommodating inflow design floods (IDF) for dams. (Note: The use of the terminology related 

 

16 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.
52

to “inflow design flood” for CCR surface impoundments rather than “run-on” and “run-off” is 

more directly applicable to the hydraulic and hydrologic capacity of CCR surface impoundments 

to adequately manage both the inflow and outflow from a design flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

and run-off requirements for CCR surface impoundments to require owners or operators of all 

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

Comment Number: EPA-HQ-RCRA-2009-0640-08270-5

Organization1:Cliffs Natural Resources Inc. (Cliffs)

Commenter1: David Z. Skolasinski

Commenter Type: Other Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Other Sections: 4.1.3 4.6.1 4.6.1.2 4.4.8.1 4.4.8.2 4.4.8.4 4.4.5.1.1 4.4.5.1.2

Comment Excerpt Text:

Cliffs Supports EPA's Proposed "Subtitle D Prime" Approach With Modification 

Cliffs supports EPA' s effOlis to implement a federal Subtitle D non-hazardous waste regulatory 

program for the disposal of CCRs at surface impoundments and landfills. Cliffs, however, is 

concerned about various aspects of the Subtitle D regulatory approach provided in the final rule. 

One impOliant concern is the automatic closure of CCR surface impoundments at utilities under 

the proposed Subtitle D regulatory program that are currently operating in a manner that is fully 

protective of human health and the environment. 

Cliffs suppOlis EPA's alternative "Subtitle D prime" approach because it would ensure the 

development of fully protective controls for the disposal of CCRs at landfills and surface 

impoundments. The "Subtitle D prime" approach would provide the environmental safeguards 

EP A is seeking while not imposing unnecessary regulatory costs on the utility sector that in turn 

increases the cost of electricity to electrical rate payers including Cliffs' mines. 

Under the "Subtitle D prime" approach, it would include all of the elements of the proposed 

Subtitle D regulatory program except that it "would not require the closure or installation of 

composite liners in existing surface impoundments; rather these surface impoundments could 

continue to operate for the remainder of their useful life." 75 Fed. Reg. at 35,210. Thus, the 
53

"Subtitle D prime" approach avoids a major flaw contained in the Subtitle D regulatory approach 

that would close down all surface impoundments irrespective of their environmental 

performance. Under the "Subtitle D prime" approach, existing CCR surface impoundments 

would continue to be subject to applicable groundwater monitoring standards and corrective 

action requirements. 

Certain modifications to the "Subtitle D prime" approach should be made, however, if EP A 

adopts this approach in the final rule. These modifications relate to several of the requirements 

found in the Subtitle D regulatory program proposed. First, EPA should not adopt a specific 

timeframe for closure but require surface impoundments and landfills to close according to a 

closure plan approved by a state or developed and certified by a registered professional. Second, 

EP A should not impose location restrictions on existing surface impoundments and landfills 

because EPA has provided no evidence in the record to substantiate structural stability issues in 

these restricted areas. 

Third, EPA should amend its run-on control requirements for surface impoundments by instead 

just requiring that these units be designed to appropriately address peak discharge events. 

Fom1h, in terms of groundwater monitoring, EPA should allow the state or a registered 

professional to delete constituents not reasonably expected to be in the waste or establish an 

alternative list of indicator parameters consistent with the groundwater monitoring programs 

applicable to municipal and non-municipal solid waste landfills. 

Fifth, EPA should allow registered professionals to make compliance ce11ifications even if they 

are employees of the owner/operator of the disposal unit. Finally, EPA should allow for alternate 

liner systems, because in some regions of the country the proposed composite liner system is 

simply unnecessary to ensure groundwater protection and in other instances an alternate liner 

system (i.e. geosynthetic clay liners) would be more appropriate that the one proscribed in the 

proposed rule. 

EPA Response: Regarding the comment’s third point, EPA agrees with the commenter that it 

would be inappropriate to extend run-on controls to CCR surface impoundments. In evaluating 

the arguments against the requirements to prevent flow onto the CCR surface impoundment, the 

Agency was strongly influenced by guidance developed by FEMA for selecting and 

accommodating hydraulic and hydrologic inflow and outflow as well as the application of this 

guidance to the CCR surface impoundments evaluated as part of EPA’s Assessment Program.17

A review of FEMA guidance confirmed commenters’ contentions that managing flow both to 

and from dams and impoundments was a widely used practice, and a preferable management 

strategy for accommodating storm water flows. This was further confirmed by observations 

made during EPA’s Assessment Program; EPA frequently observed units designed to detain or 

retain storm water inflows of an upstream catchment area to manage CCR, and/or to receive 

storm water inflow as part of the facility’s overall storm water management system. Moreover, 

EPA relied on the same FEMA guidance to assess the adequacy of the hydrologic and hydraulic 

 

17 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.
54

capacity of the CCR surface impoundments. In conducting these assessments, EPA considered a 

number of factors including operating freeboard, catchment area, hydrologic structures’ inflow 

and outflow ratings, design precipitation event, spillway presence and capacity, and unit 

operating procedures to make this determination. The adequacy of the capacity was determined 

using FEMA guidance for selecting and accommodating inflow design floods (IDF) for dams. 

(Note: The use of the terminology related to “inflow design flood” for CCR surface 

impoundments rather than “run-on” and “run-off” is more directly applicable to the hydraulic 

and hydrologic capacity of CCR surface impoundments to adequately manage both the inflow 

and outflow from a design flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

and run-off requirements for CCR surface impoundments to require owners or operators of all 

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

Comment Number: EPA-HQ-RCRA-2009-0640-08841-29

Organization1:Deseret Generation and Transmission Co-operative

Commenter1: Howard Vickers

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

EPA should amend its run-on control requirements for CCR surface impoundments. Current runon controls were designed for Municipal Solid Waste landfills and are not appropriate for the 

way impoundments at many power plants are designed. 

EPA Response: EPA agrees with the commenter that it would be inappropriate to extend run-on 

controls to CCR surface impoundments. In evaluating the arguments against the requirements to 

prevent flow onto the CCR surface impoundment, the Agency was strongly influenced by 

guidance developed by FEMA for selecting and accommodating hydraulic and hydrologic inflow 

and outflow as well as the application of this guidance to the CCR surface impoundments 
55

evaluated as part of EPA’s Assessment Program.18 A review of FEMA guidance confirmed 

commenters’ contentions that managing flow both to and from dams and impoundments was a 

widely used practice, and a preferable management strategy for accommodating storm water 

flows. This was further confirmed by observations made during EPA’s Assessment Program; 

EPA frequently observed units designed to detain or retain storm water inflows of an upstream 

catchment area to manage CCR, and/or to receive storm water inflow as part of the facility’s 

overall storm water management system. Moreover, EPA relied on the same FEMA guidance to 

assess the adequacy of the hydrologic and hydraulic capacity of the CCR surface impoundments. 

In conducting these assessments, EPA considered a number of factors including operating 

freeboard, catchment area, hydrologic structures’ inflow and outflow ratings, design precipitation 

event, spillway presence and capacity, and unit operating procedures to make this determination. 

The adequacy of the capacity was determined using FEMA guidance for selecting and 

accommodating inflow design floods (IDF) for dams. (Note: The use of the terminology related 

to “inflow design flood” for CCR surface impoundments rather than “run-on” and “run-off” is 

more directly applicable to the hydraulic and hydrologic capacity of CCR surface impoundments 

to adequately manage both the inflow and outflow from a design flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

and run-off requirements for CCR surface impoundments to require owners or operators of all 

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

Comment Number: EPA-HQ-RCRA-2009-0640-08850-12

Organization1:Lansing Board of Water & Light (BWL)

Commenter1: Lansing Board of Water & Light (BWL)

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

The Lansing Board of Water & Light Requests Clarification on Proposed Run-On and Run-Off 

Controls. 277.81(a)(1) requires a control system to prevent flow onto the active portion of the 

 

18 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.
56

CCR landfill or surface impoundment during the peak discharge from a 24-hour, 25-year storm 

must be designed, constructed, and maintained. While we can see logically how this can be done 

for a landfill, how does this work for a surface impoundment? It is an impoundment. 

EPA Response: EPA agrees with the commenter that it would be inappropriate to extend run-on 

controls to CCR surface impoundments. In evaluating the arguments against the requirements to 

prevent flow onto the CCR surface impoundment, the Agency was strongly influenced by 

guidance developed by FEMA for selecting and accommodating hydraulic and hydrologic inflow 

and outflow as well as the application of this guidance to the CCR surface impoundments 

evaluated as part of EPA’s Assessment Program.19 A review of FEMA guidance confirmed 

commenters’ contentions that managing flow both to and from dams and impoundments was a 

widely used practice, and a preferable management strategy for accommodating storm water 

flows. This was further confirmed by observations made during EPA’s Assessment Program; 

EPA frequently observed units designed to detain or retain storm water inflows of an upstream 

catchment area to manage CCR, and/or to receive storm water inflow as part of the facility’s 

overall storm water management system. Moreover, EPA relied on the same FEMA guidance to 

assess the adequacy of the hydrologic and hydraulic capacity of the CCR surface impoundments. 

In conducting these assessments, EPA considered a number of factors including operating 

freeboard, catchment area, hydrologic structures’ inflow and outflow ratings, design precipitation 

event, spillway presence and capacity, and unit operating procedures to make this determination. 

The adequacy of the capacity was determined using FEMA guidance for selecting and 

accommodating inflow design floods (IDF) for dams. (Note: The use of the terminology related 

to “inflow design flood” for CCR surface impoundments rather than “run-on” and “run-off” is 

more directly applicable to the hydraulic and hydrologic capacity of CCR surface impoundments 

to adequately manage both the inflow and outflow from a design flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

and run-off requirements for CCR surface impoundments to require owners or operators of all 

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

Comment Number: EPA-HQ-RCRA-2009-0640-09239-71

Organization1:Prairie State Generating Company, LLC (PSGC)

Commenter1: Keith Bastian

 

19 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.
57

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

Run-On (40 C.F.R. § 257.81)

While this requirement may be appropriate for CCR landfills, it is not appropriate for CCR 

surface impoundments that are part of a facility's stormwater management program. The use of 

these impoundments to manage stormwater is integral to ongoing operations. Prohibiting CCR 

surface impoundments from receiving run-on will require construction of new impoundments 

without providing measure able environmental benefits. This requirement should be deleted.

EPA Response: EPA agrees with the commenter that it would be inappropriate to extend run-on 

controls to CCR surface impoundments. In evaluating the arguments against the requirements to 

prevent flow onto the CCR surface impoundment, the Agency was strongly influenced by 

guidance developed by FEMA for selecting and accommodating hydraulic and hydrologic inflow 

and outflow as well as the application of this guidance to the CCR surface impoundments 

evaluated as part of EPA’s Assessment Program.20 A review of FEMA guidance confirmed 

commenters’ contentions that managing flow both to and from dams and impoundments was a 

widely used practice, and a preferable management strategy for accommodating storm water 

flows. This was further confirmed by observations made during EPA’s Assessment Program; 

EPA frequently observed units designed to detain or retain storm water inflows of an upstream 

catchment area to manage CCR, and/or to receive storm water inflow as part of the facility’s 

overall storm water management system. Moreover, EPA relied on the same FEMA guidance to 

assess the adequacy of the hydrologic and hydraulic capacity of the CCR surface impoundments. 

In conducting these assessments, EPA considered a number of factors including operating 

freeboard, catchment area, hydrologic structures’ inflow and outflow ratings, design precipitation 

event, spillway presence and capacity, and unit operating procedures to make this determination. 

The adequacy of the capacity was determined using FEMA guidance for selecting and 

accommodating inflow design floods (IDF) for dams. (Note: The use of the terminology related 

to “inflow design flood” for CCR surface impoundments rather than “run-on” and “run-off” is 

more directly applicable to the hydraulic and hydrologic capacity of CCR surface impoundments 

to adequately manage both the inflow and outflow from a design flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

and run-off requirements for CCR surface impoundments to require owners or operators of all 

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

 

20 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.
58

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

Comment Number: EPA-HQ-RCRA-2009-0640-09349-18

Organization1:Santee Cooper

Commenter1: Jay Hudson

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

The regulations should clarify that configurations at existing facilities may already meet these 

requirements, and that the regulations do not mandate new construction in all cases. For 

example, many impoundments are completely contained within the confines of the embankment 

dam and do not have an outside watershed contributing to the pond volume. In addition, the 

NPDES permit process for wastewater treatment ponds routinely requires impoundments to 

safely contain and allow treatment of the 24-hr, 25-year storm event.

EPA Response: EPA agrees with the commenter that it would be inappropriate to extend run-on 

controls to CCR surface impoundments. In evaluating the arguments against the requirements to 

prevent flow onto the CCR surface impoundment, the Agency was strongly influenced by 

guidance developed by FEMA for selecting and accommodating hydraulic and hydrologic inflow 

and outflow as well as the application of this guidance to the CCR surface impoundments 

evaluated as part of EPA’s Assessment Program.21 A review of FEMA guidance confirmed 

commenters’ contentions that managing flow both to and from dams and impoundments was a 

widely used practice, and a preferable management strategy for accommodating storm water 

flows. This was further confirmed by observations made during EPA’s Assessment Program; 

EPA frequently observed units designed to detain or retain storm water inflows of an upstream 

catchment area to manage CCR, and/or to receive storm water inflow as part of the facility’s 

overall storm water management system. Moreover, EPA relied on the same FEMA guidance to 

assess the adequacy of the hydrologic and hydraulic capacity of the CCR surface impoundments. 

In conducting these assessments, EPA considered a number of factors including operating 

freeboard, catchment area, hydrologic structures’ inflow and outflow ratings, design precipitation 

event, spillway presence and capacity, and unit operating procedures to make this determination. 

The adequacy of the capacity was determined using FEMA guidance for selecting and 

accommodating inflow design floods (IDF) for dams. (Note: The use of the terminology related 

to “inflow design flood” for CCR surface impoundments rather than “run-on” and “run-off” is 

 

21 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.
59

more directly applicable to the hydraulic and hydrologic capacity of CCR surface impoundments 

to adequately manage both the inflow and outflow from a design flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

and run-off requirements for CCR surface impoundments to require owners or operators of all 

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

EPA would note that for CCR surface impoundments which already meet these requirements, i.e., 

do not receive contributory flow from adjoining catchment areas, the CCR unit must comply with the 

hydrologic and hydraulic requirements of the rule by ensuring that the CCR unit has sufficient capacity to 

accommodate direct precipitation from the corresponding design precipitation event.

Comment Number: EPA-HQ-RCRA-2009-0640-09427-16

Organization1:San Miguel Electric Cooperative, Inc. (San Miguel)

Commenter1: Joseph G. Eutizi

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

EPA should amend its run-on control requirements for CCR surface impoundments. Current runon controls were designed for Municipal Solid Waste landfills and are not appropriate for the 

way impoundments at many power plants are designed.

EPA Response: EPA agrees with the commenter that it would be inappropriate to extend run-on 

controls to CCR surface impoundments. In evaluating the arguments against the requirements to 

prevent flow onto the CCR surface impoundment, the Agency was strongly influenced by 

guidance developed by FEMA for selecting and accommodating hydraulic and hydrologic inflow 

and outflow as well as the application of this guidance to the CCR surface impoundments 

evaluated as part of EPA’s Assessment Program.22 A review of FEMA guidance confirmed 

 

22 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.
60

commenters’ contentions that managing flow both to and from dams and impoundments was a 

widely used practice, and a preferable management strategy for accommodating storm water 

flows. This was further confirmed by observations made during EPA’s Assessment Program; 

EPA frequently observed units designed to detain or retain storm water inflows of an upstream 

catchment area to manage CCR, and/or to receive storm water inflow as part of the facility’s 

overall storm water management system. Moreover, EPA relied on the same FEMA guidance to 

assess the adequacy of the hydrologic and hydraulic capacity of the CCR surface impoundments. 

In conducting these assessments, EPA considered a number of factors including operating 

freeboard, catchment area, hydrologic structures’ inflow and outflow ratings, design precipitation 

event, spillway presence and capacity, and unit operating procedures to make this determination. 

The adequacy of the capacity was determined using FEMA guidance for selecting and 

accommodating inflow design floods (IDF) for dams. (Note: The use of the terminology related 

to “inflow design flood” for CCR surface impoundments rather than “run-on” and “run-off” is 

more directly applicable to the hydraulic and hydrologic capacity of CCR surface impoundments 

to adequately manage both the inflow and outflow from a design flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

and run-off requirements for CCR surface impoundments to require owners or operators of all 

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

Comment Number: EPA-HQ-RCRA-2009-0640-09885-24

Organization1:Progress Energy, Inc.

Commenter1: Caroline Choi

Commenter Type: Electric Utility Company

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

EPA should amend its run-on control requirements for CCR surface impoundments

One complication of copying the proposed CCR Subtitle D regulations from the MSWLF 

program is that some of the particular operating requirements for MSWLF cannot be directly 

applied to CCR surface impoundments. An important example of this is the proposed 

requirement for surface impoundments and landfills to establish specific operating controls for 

water run-on and run-off. The run-on portion of these controls requires a “control system to 

prevent flow onto the active portion of the CCR landfill or surface impoundment” during peak 
61

discharge events. While this requirement may be appropriate for CCR landfills (as it is for 

MSWLFs), it is wholly inappropriate for surface impoundments that have been specifically 

designed as holding basins for storm water or that have been formed by damming a ravine and 

designed with outlets that are sufficient to deal with the water flow from the natural watersheds 

into the impoundment during peak discharge events.

Progress Energy suggests that EPA address the inapplicability of this requirement for these types 

of surface impoundments by requiring that CCR impoundments be designed to appropriately 

address peak discharge events, rather than specifying that water run-on into the impoundment be 

prevented. In this manner, impoundments that have been designed as described above and have 

been engineered to address peak discharge events will not be confronted with a restriction that is 

both unnecessary and effectively impossible to meet

EPA Response: EPA agrees with the commenter that it would be inappropriate to extend run-on 

controls to CCR surface impoundments. In evaluating the arguments against the requirements to 

prevent flow onto the CCR surface impoundment, the Agency was strongly influenced by 

guidance developed by FEMA for selecting and accommodating hydraulic and hydrologic inflow 

and outflow as well as the application of this guidance to the CCR surface impoundments 

evaluated as part of EPA’s Assessment Program.23 A review of FEMA guidance confirmed 

commenters’ contentions that managing flow both to and from dams and impoundments was a 

widely used practice, and a preferable management strategy for accommodating storm water 

flows. This was further confirmed by observations made during EPA’s Assessment Program; 

EPA frequently observed units designed to detain or retain storm water inflows of an upstream 

catchment area to manage CCR, and/or to receive storm water inflow as part of the facility’s 

overall storm water management system. Moreover, EPA relied on the same FEMA guidance to 

assess the adequacy of the hydrologic and hydraulic capacity of the CCR surface impoundments. 

In conducting these assessments, EPA considered a number of factors including operating 

freeboard, catchment area, hydrologic structures’ inflow and outflow ratings, design precipitation 

event, spillway presence and capacity, and unit operating procedures to make this determination. 

The adequacy of the capacity was determined using FEMA guidance for selecting and 

accommodating inflow design floods (IDF) for dams. (Note: The use of the terminology related 

to “inflow design flood” for CCR surface impoundments rather than “run-on” and “run-off” is 

more directly applicable to the hydraulic and hydrologic capacity of CCR surface impoundments 

to adequately manage both the inflow and outflow from a design flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

 

23 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.
62

and run-off requirements for CCR surface impoundments to require owners or operators of all 

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

Comment Number: EPA-HQ-RCRA-2009-0640-10483-50

Organization1:Utility Solid Waste Activities Group (USWAG) et al.

Commenter1: James R. Roewer

Commenter Type: Trade Association

Classification: Substantive

Comment Category:

Current Task: Examine Context Assigned/Due:

Comment Excerpt Text:

C. EPA Should Amend Its Run-On Control Requirements For CCR Surface Impoundments

One complication of copying the proposed CCR Subtitle D regulations from the MSWLF 

program is that some of the particular operating requirements for MSWLF landfills cannot be 

directly applied to CCR surface impoundments. As discussed above, this is true in the case of 

attempting to apply the MSWLF closure time periods to CCR disposal units. Another important 

example is the proposed requirement for surface impoundments and landfills to establish specific 

operating controls for water run-on and run-off. Id. at 35245 (proposed 40 C.F.R. § 257.81). The 

run-on portion of these controls requires a “control system to prevent flow onto the active 

portion of the CCR landfill or surface impoundment” during peak discharge events. Id. 

(proposed 40 C.F.R. § 257.81(a)(1)). While this requirement may be appropriate for CCR 

landfills (as it is for MSWLFs), it is wholly inappropriate for surface impoundments that have 

been specifically designed as holding basins for stormwater or that have been formed by 

damming a ravine and have been designed with outlets that are sufficient to deal with the water 

flow from the natural watersheds into the impoundment during peak discharge events.

USWAG suggests that EPA address the inapplicability of this requirement for these types of 

surface impoundments by instead requiring that CCR impoundments be designed to 

appropriately address peak discharge events, rather than specifying that run-on into the 

impoundment be prevented. In this manner, impoundments that have been designed as described 

above and have been engineered to address peak discharge events will not be confronted with a 

restriction that is both unnecessary and effectively impossible to meet.

EPA Response: EPA agrees with the commenter that it would be inappropriate to extend run-on 

controls to CCR surface impoundments. In evaluating the arguments against the requirements to 
63

prevent flow onto the CCR surface impoundment, the Agency was strongly influenced by 

guidance developed by FEMA for selecting and accommodating hydraulic and hydrologic inflow 

and outflow as well as the application of this guidance to the CCR surface impoundments 

evaluated as part of EPA’s Assessment Program.24 A review of FEMA guidance confirmed 

commenters’ contentions that managing flow both to and from dams and impoundments was a 

widely used practice, and a preferable management strategy for accommodating storm water 

flows. This was further confirmed by observations made during EPA’s Assessment Program; 

EPA frequently observed units designed to detain or retain storm water inflows of an upstream 

catchment area to manage CCR, and/or to receive storm water inflow as part of the facility’s 

overall storm water management system. Moreover, EPA relied on the same FEMA guidance to 

assess the adequacy of the hydrologic and hydraulic capacity of the CCR surface impoundments. 

In conducting these assessments, EPA considered a number of factors including operating 

freeboard, catchment area, hydrologic structures’ inflow and outflow ratings, design precipitation 

event, spillway presence and capacity, and unit operating procedures to make this determination. 

The adequacy of the capacity was determined using FEMA guidance for selecting and 

accommodating inflow design floods (IDF) for dams. (Note: The use of the terminology related 

to “inflow design flood” for CCR surface impoundments rather than “run-on” and “run-off” is 

more directly applicable to the hydraulic and hydrologic capacity of CCR surface impoundments 

to adequately manage both the inflow and outflow from a design flood.) 

EPA has concluded that it was inappropriate to propose to prohibit all run-on discharge or 

inflow from storm water to CCR surface impoundments. EPA has also concluded that run-on 

and run-off criteria are inappropriate for CCR surface impoundments, and that a more 

appropriate standard involves determining the hydrologic and hydraulic capacity of a unit, 

measured by its inflow design flood or IDF. Therefore, EPA is amending the proposed run-on 

and run-off requirements for CCR surface impoundments to require owners or operators of all 

CCR surface impoundments to design, construct, operate, and maintain hydraulic and hydrologic 

capacity to adequately manage flow both into and from a CCR surface impoundment during and 

after the peak discharge resulting from the inflow design flood, based on the Hazard Potential 

Classification of the CCR surface impoundment.

 

24 EPA referred to FEMA’s “Federal Guidelines for Dam Safety: Selecting and Accommodating Inflow 

Design Floods for Dams” in evaluating the adequacy of the CCR surface impoundment’s hydrologic and 

hydraulic capacity during its assessment effort.