[Federal Register Volume 72, Number 167 (Wednesday, August 29, 2007)]
[Notices]
[Pages 49714-49719]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-17138]


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ENVIRONMENTAL PROTECTION AGENCY

[EPA-HQ-RCRA-2006-0796; FRL-8462-2]
 RIN 2050-AE81


Notice of Data Availability on the Disposal of Coal Combustion 
Wastes in Landfills and Surface Impoundments

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of Data Availability.

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SUMMARY: This notice announces the availability of new information and 
data contained in three documents that the Agency is requesting public 
comments on concerning the management of coal combustion wastes (CCW) 
in landfills and surface impoundments. The Agency is seeking public 
comments on how, if at all, this additional information should affect 
the Agency's decisions as it continues to follow-up on its Regulatory 
Determination for CCW disposed of in landfills and surface 
impoundments. The three documents that the Agency is requesting comment 
on include: a joint U.S. Department of Energy (DOE) and EPA report 
entitled, Coal Combustion Waste Management at Landfills and Surface 
Impoundments, 1994-2004; a draft risk assessment conducted by EPA on 
the management of CCW in landfills and surface impoundments; and EPA's 
damage case assessment. The Agency solicits comments on the extent to 
which the damage case information, the results of the risk assessment, 
and the new liner and ground water monitoring information from the DOE/
EPA report should affect the Agency's decisions. EPA is also requesting 
direct comment on the draft risk assessment document to help inform a 
planned peer review. In addition, the Agency has included in the Docket 
to this Notice of Data Availability (NODA) a rulemaking petition 
submitted by a number of citizens' groups and several approaches, one 
prepared by the electric utility industry and the other prepared by a 
number of citizens' groups, regarding the management of CCW. The Agency 
will consider all the information provided through this notice, the 
comments and new information submitted on this notice, as well as the 
results of a subsequent peer review of the risk assessment as it 
continues to follow-up on its Regulatory Determination for CCW disposed 
of in landfills and surface impoundments.

DATES: Submit comments on or before November 27, 2007.

ADDRESSES: Submit your comments, identified by Docket ID No. EPA-HQ-
RCRA-2006-0796, by one of the following methods:
     www.regulations.gov: Follow the on-line instructions for 
submitting comments.
     E-mail: Comments may be sent by electronic mail (e-mail) 
to [email protected], Attention Docket ID No. EPA-HQ-RCRA-2006-0796. 
In contrast to EPA's electronic public docket, EPA's e-mail system is 
not an ``anonymous access'' system. If you send an e-mail comment 
directly to the Docket without going through EPA's electronic public 
docket, EPA's e-mail system automatically captures your e-mail address. 
E-mail addresses that are automatically captured by EPA's e-mail system 
are included as part of the comment that is placed in the official 
public docket, and made available in EPA's electronic public docket.
     Fax: Comments may be faxed to 202-566-0272. Attention 
Docket ID No. EPA-HQ-RCRA-2006-0796.
     Mail: Send two copies of your comments to Notice of Data 
Availability on the Disposal of Coal Combustion Wastes in Landfills and 
Surface Impoundments, Environmental Protection Agency, Mailcode: 5305T, 
1200 Pennsylvania Ave., NW., Washington, DC 20460. Attention

[[Page 49715]]

Docket ID No. EPA-HQ-RCRA-2006-0796.
     Hand Delivery: Deliver two copies of your comments to the 
Notice of Data Availability on the Disposal of Coal Combustion Wastes 
in Landfills and Surface Impoundments Docket, EPA/DC, EPA West, Room 
3334, 1301 Constitution Ave., NW., Washington, DC 20460. Attention 
Docket ID No. EPA-HQ-RCRA-2006-0796. Such deliveries are only accepted 
during the Docket's normal hours of operation, and special arrangements 
should be made for deliveries of boxed information.
    Instructions: Direct your comments to Docket ID No. EPA-HQ-RCRA-
2006-0796. EPA's policy is that all comments received will be included 
in the public docket without change and may be made available online at 
http://www.regulations.gov, including any personal information 
provided, unless the comment includes information claimed to be 
Confidential Business Information (CBI) or other information whose 
disclosure is restricted by statute. Do not submit information that you 
consider to be CBI or otherwise protected through www.regulations.gov 
or e-mail. The www.regulations.gov Web site is an ``anonymous access'' 
system, which means EPA will not know your identity or contact 
information unless you provide it in the body of your comment. If you 
send an e-mail comment directly to EPA without going through 
www.regulations.gov, your e-mail address will be automatically captured 
and included as part of the comment that is placed in the public docket 
and made available on the Internet. If you submit an electronic 
comment, EPA recommends that you include your name and other contact 
information in the body of your comment and with any disk or CD-ROM you 
submit. If EPA cannot read your comment due to technical difficulties 
and cannot contact you for clarification, EPA may not be able to 
consider your comment. Electronic files should avoid the use of special 
characters, any form of encryption, and be free of any defects or 
viruses. For additional information about EPA's public docket, visit 
the EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm. For additional instructions on submitting comments, go to 
the SUPPLEMENTARY INFORMATION section of this document.
    Docket: All documents in the docket are listed in the 
www.regulations.gov index. Although listed in the index, some 
information is not publicly available, e.g., CBI or other information 
whose disclosure is restricted by statute. Certain other material, such 
as copyrighted material, will be publicly available only in hard copy. 
Publicly available docket materials are available either electronically 
in www.regulations.gov or in hard copy at the Notice of Data 
Availability on the Disposal of Coal Combustion Wastes in Landfills and 
Surface Impoundments Docket, EPA/DC, EPA West, Room 3334, 1301 
Constitution Ave., NW., Washington, DC. This Docket Facility is open 
from 8:30 a.m. to 4:30 p.m., Monday through Friday, excluding legal 
holidays. The Docket telephone number is (202) 566-0270. 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.

FOR FURTHER INFORMATION CONTACT: Alexander Livnat, Office of Solid 
Waste (5306P), U.S. Environmental Protection Agency, Ariel Rios 
Building, 1200 Pennsylvania Avenue, NW., Washington, DC 20460-0002, 
telephone (703) 308-7251, e-mail address [email protected]. For 
more information on this rulemaking, please visit http://www.epa.gov/epaoswer/other/fossil/index.htm/.

SUPPLEMENTARY INFORMATION:

I. What Should I Consider as I Prepare My Comments for EPA?

    1. Tips for Preparing Your Comments. When submitting comments, 
remember to:
     Identify the rulemaking by docket number and other 
identifying information (subject heading, Federal Register date and 
page number).
     Follow directions--The agency may ask you to respond to 
specific questions or organize comments by referencing a Code of 
Federal Regulations (CFR) part or section number.
     Explain why you agree or disagree; suggest alternatives 
and substitute language for your requested changes.
     Describe any assumptions and provide any technical 
information and/or data that you used.
     If you estimate potential costs or burdens, explain how 
you arrived at your estimate in sufficient detail to allow for it to be 
reproduced.
     Provide specific examples to illustrate your concerns, and 
suggest alternatives.
     Explain your views as clearly as possible.
     Make sure to submit your comments by the comment period 
deadline identified.
    2. Docket Copying Costs. The first 100-copied pages are free. 
Thereafter, the charge for making copies of Docket materials is 15 
cents per page.

II. How Should I Submit CBI to the Agency?

    Do not submit information that you consider to be CBI 
electronically through http://www.regulations.gov or by e-mail. Send or 
deliver information identified as CBI only to the following address: 
RCRA CBI Document Control Officer, Office of Solid Waste (5305W), U.S. 
EPA, 1200 Pennsylvania Avenue, NW., Washington, DC 20460, Attention 
Docket ID No. EPA-HQ-RCRA-2006-0796. You may claim information that you 
submit to EPA as CBI by marking any part or all of that information as 
CBI (if you submit CBI on disk or CD ROM, mark the outside of the disk 
or CD ROM as CBI and then identify electronically within the disk or CD 
ROM the specific information that is CBI). Information so marked will 
not be disclosed, except in accordance with procedures set forth in 40 
CFR Part 2.
    In addition to one complete version of the comment that includes 
any information claimed as CBI, a copy of the comment that does not 
contain the information claimed as CBI must be submitted for inclusion 
in the public docket and EPA's electronic public docket. If you submit 
the copy that does not contain CBI on disk or CD ROM, mark the outside 
of the disk or CD ROM clearly that it does not contain CBI. Information 
not marked as CBI will be included in the public docket and EPA's 
electronic public docket without prior notice. If you have any 
questions about CBI or the procedures for claiming CBI, please contact: 
LaShan Haynes, Office of Solid Waste (5305W), U.S. Environmental 
Protection Agency, Ariel Rios Building, 1200 Pennsylvania Avenue, NW., 
Washington, DC 20460-0002, telephone (703) 605-0516, e-mail address 
[email protected].

III. Disposal of CCW in Landfills and Surface Impoundments

A. Background

    In May 2000, EPA published its Final Regulatory Determination on 
Wastes From the Combustion of Fossil Fuels (65 FR 32214). The Agency 
concluded that these wastes do not warrant regulation under Subtitle C 
of RCRA and, therefore, retained the hazardous waste exemption of RCRA 
section 3001(b)(3)(C). We also determined, however, that national 
regulations under Subtitle D of RCRA were appropriate for coal 
combustion wastes (referred to as CCW throughout this

[[Page 49716]]

notice) when disposed of in landfills or surface impoundments.\1\
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    \1\ In addition, EPA determined that regulations under Subtitle 
D of RCRA and/or modifications to the existing regulations 
established under authority of the Surface Mining Control and 
Reclamation Act (SMCRA) were appropriate when these wastes are used 
to fill surface or underground coal mines. As recommended in a 
recent National Academy of Sciences Report entitled, ``Managing Coal 
Combustion Residues in Mines,'' National Research Council of the 
National Academies, 2006, EPA will be collaborating with the U.S. 
Department of Interior, Office of Surface Mining (OSM) to develop 
national standards for the placement of CCW in coal mines. A 
separate notice was issued by OSM regarding this effort (see 72 FR 
12026, March 14, 2007; available at http://a257.g.akamaitech.net/7/257/2422/01jan20071800/edocket.access.gpo.gov/2007/pdf/E7-4669.pdf).
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    Specifically, EPA's determination to develop regulations under 
Subtitle D of RCRA was based on a factual record developed prior to 
1995 which led to the following considerations: (i) The constituents 
present in these wastes include metals, such as arsenic, cadmium, 
chromium, lead and mercury, that could present a danger to human health 
and the environment under certain conditions; (ii) while testing of the 
CCW using the toxicity characteristic leaching procedure (TCLP) rarely 
exceeds the hazardous waste toxicity characteristic (or TC), the Agency 
identified eleven documented cases of proven damages \2\ to human 
health and/or the environment by improper management of these wastes in 
landfills and surface impoundments; (iii) at the time the Regulatory 
Determination was made, between 40 and 70 percent of CCW disposal sites 
lacked controls, such as liners and/or ground water-monitoring; and 
(iv) while there had been substantive improvements in state regulatory 
programs, the Agency also identified gaps in state oversight. In 
deciding to pursue Subtitle D in lieu of Subtitle C regulation, the 
decisive factors which guided the Agency's thinking at that time 
included the improving trends in disposal and utilization practices, 
and the current and potential utilization of the wastes, which the 
Agency believes it should encourage.
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    \2\ Per the May 2000 Regulatory Determination, 65 FR 32224 and 
Section 1.4.4 of the 1999 Report to Congress, proven damage cases 
are those with (i) documented exceedances of primary MCLs or other 
health-based standards measured in ground water at sufficient 
distance from the waste management unit to indicate that hazardous 
constituents have migrated to the extent that they could cause human 
health concerns, and/or (ii) where a scientific study demonstrates 
there is documented evidence of another type of damage to human 
health or the environment (e.g., ecological damage), and/or (iii) 
where there has been an administrative ruling or court decision with 
an explicit finding of specific damage to human health or the 
environment. In cases of co-management of CCWs with other industrial 
waste types, CCWs must be clearly implicated in the reported damage.
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B. Additional Information on Management of CCW in Landfills and Surface 
Impoundments

    Since EPA issued the 2000 Regulatory Determination, which was based 
on information collected prior to 1995, additional information and data 
have become available that we believe should be considered as part of 
the Agency's evaluation regarding the development of regulations under 
Subtitle D of RCRA for CCW. Therefore, today's Notice of Data 
Availability (NODA) is soliciting public comment on how, if at all, the 
following additional information and data should affect the Agency's 
decisions as it continues to follow-up on its Regulatory Determination 
for CCW disposed of in landfills and surface impoundments: (1) A joint 
U.S. Department of Energy (DOE) and EPA report entitled, Coal 
Combustion Waste Management at Landfills and Surface Impoundments, 
1994-2004; (2) a draft risk assessment conducted by EPA on the 
management of CCW in landfills and surface impoundments; and (3) EPA's 
recently completed damage case assessment. EPA is also seeking direct 
comment on the draft risk assessment document to help inform a planned 
peer review. In addition, the Agency is also including in the docket to 
today's NODA a February 2004 Petition for Rulemaking submitted by the 
Clean Air Task Force and the Hoosier Environmental Council, jointly 
with a number of citizens' groups to Prohibit the Placement or Disposal 
of CCW into Groundwater and Surface Water; and two suggested approaches 
for managing CCW in landfills and surface impoundments. One approach is 
a Voluntary Action Plan that was formulated by the electric utility 
industry through their trade association, the Utility Solid Waste 
Activities Group (USWAG).\3\ The second approach is a proposed 
framework prepared by a number of citizens' groups \4\ for federal 
regulation of CCW disposed of in landfills and surface impoundments 
under Subtitle D of RCRA generated by U.S. coal-fired power plants. The 
Agency is making these documents available in the Docket to allow all 
interested parties to be aware of the various documents that EPA will 
consider as it continues to follow up on its Regulatory Determination 
for CCW disposed of in landfills and surface impoundments.\5\
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    \3\ USWAG members include approximately 80 utility companies, 
the Edison Electric Institute (EEI), the Natural Rural Electric 
Association (NRECA), the American Public Power Association (APPA), 
and the American Gas Association (AGA) and represent more than 85% 
of total U.S. electric generating capacity.
    \4\ The proposed framework was jointly prepared by Earthjustice, 
Clean Air Task Force, Environmental Integrity Project, Sierra Club, 
Natural Resources Defense Council, Waterkeeper Alliance, Hoosier 
Environmental Council, Public Citizen, Jefferson Action Group, Dine 
CARE, Army for a Clean Environment, Plains Justice, Appalachian 
Center for the Economy and the Environment, People in Need of 
Environmental Safety, Valley Watch, West Virginia Highlands 
Conservancy, Montana Environmental Information Center, San Juan 
Citizens Alliance, Clean Wisconsin, Residents Against the Power 
Plant, Ohio Valley Environmental Coalition, Neighbors for Neighbors, 
Delaware Riverkeeper Network, Healthlink, Wenham Lake Watershed 
Association, Coal River Mountain Watch, Dakota Resource Council and 
Save Us From Future Environmental Risks.
    \5\ In addition, the Agency is also placing in the docket to 
today's NODA comments that the Clean Air Task Force and the Hoosier 
Environmental Council submitted to EPA as Attachment 1 to a July 12, 
2005 letter to Thomas P. Dunne, then Acting Assistant Administrator 
for the Office of Solid Waste and Emergency Response (OSWER) on the 
electric utility industry's Voluntary Action Plan.
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    These documents are available for review and downloading through 
the docket for today's action (see the ADDRESSES section above for 
instructions on accessing this information from the docket). The 
remainder of this notice briefly describes the various documents that 
are being made available for review and/or comment.
1. DOE/EPA Report
    In reaching its determination in May 2000 to develop national 
Subtitle D regulations under RCRA for the management of CCW in 
landfills and surface impoundments, the Agency generally relied on 
information and data on industry practices that were available prior to 
1995. For information on industry practices, the Agency based its 
Regulatory Determination on information contained in a report prepared 
by the Electric Power Research Institute (EPRI) \6\ addressing waste 
management units that were constructed between 1985 and 1995. The 
Agency, however, recognized that the electric utility industry was 
changing its management practices. Therefore, in 2005, DOE and EPA 
conducted a joint study to collect more recent information on CCW 
management practices by the electric power industry. Specifically, this 
report presents information and data on CCW disposal practices and 
state regulatory requirements at landfills and surface impoundments 
that were permitted, built, or laterally expanded between January 1, 
1994, and December

[[Page 49717]]

31, 2004.\7\ The scope of the study excluded waste units that manage 
CCW in active or abandoned coal mines.
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    \6\ Coal Combustion By-Products and Low-Volume Wastes Co-
management Survey, Draft Report, EPRI, June 1997.
    \7\ A draft of this report was peer reviewed by the Association 
of State and Territorial Solid Waste Management Officials (ASTSWMO), 
the Utility Water Act Group (UWAG), and the Clean Air Task Force 
(CATF). Comments received on the draft report, which are included in 
the docket to today's NODA, have been considered and addressed by 
DOE and EPA in the final report entitled, Coal Combustion Waste 
Management at Landfills and Surface Impoundments, 1994-2004.
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    Data in the report on recent and current disposal practices were 
derived from a survey conducted by USWAG of its members. In addition, 
EPA supplemented and checked the accuracy of this information by 
directly contacting state agencies, as well as a limited number of 
individual electric utilities.
    In summary, the report shows an increase in the number of CCW 
disposal units with respect to liner design and ground water monitoring 
since 1994. Based on 100% member-response to USWAG's survey, plus EPA's 
fact-finding efforts, the report identified 56 new CCW management 
units, of which 38 are landfills, and 18 are surface impoundments. This 
number, however, does not reflect the total number of new CCW disposal 
units that were permitted, built or laterally expanded between 1994 and 
2004. The study utilized proxy data to derive an estimate of the total 
number of new units. The first proxy was the tonnage of CCW available 
for disposal in States that have coal-fired power plant capacity, and 
the second was the coal-fired generating capacity of electric utilities 
owning the identified disposal units. The estimated net disposable CCW 
\8\ in the 19 states where new units were identified was then compared 
with the total net disposable CCW in all states with coal-fired 
electric generating capacity. Using this approach, it was estimated 
that the number of identified new CCW management units represents 
between 64% and 71%, respectively, of the total number of new units 
established between 1994 and 2004.
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    \8\ Net disposable CCW is the total CCW generated minus CCW 
beneficially used.
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    The report identified that the use of liners and ground water 
monitoring at new landfills and surface impoundments built since 1994 
has increased with 98% having liners and 91% having ground water 
monitoring. This compares with liners installed in 75% of landfills and 
60% of surface impoundments built between 1985 and 1995; and with 
ground water monitoring installed at 88% of landfills and 65% of 
surface impoundments that were established between 1985 and 1995. In 
addition, the frequency of dry handling in landfills appears to have 
increased, compared to wet handling in surface impoundments; 
approximately two-thirds of the new units are landfills, while the 
other one-third are surface impoundments. The Agency solicits comments 
and information on the amount or percentage of CCW that is expected to 
be managed in the future in landfills as opposed to surface 
impoundments. The percentage of composite liners has also increased for 
landfills from about 10%, as reported in the 1999 Report to Congress 
(RTC) \9\ to 53% for new units constructed between 1994 and 2004, and 
for surface impoundments, from 2% as reported in the 1999 RTC to 50% 
for new units constructed between 1994 and 2004. The number of unlined 
units currently in operation in the U.S. is not known. The DOE/EPA 2006 
Report also provides information from a review of eleven States' CCW 
programs, including the regulatory designation of CCW for disposal, 
permitting requirements, liner requirements, ground water-monitoring 
requirements, and leachate collection requirements.
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    \9\ Wastes from the Combustion of Fossil Fuels, Volume 2: 
Methods, Findings and Recommendations, EPA-R-99-010, 1999 available 
at http://www.epa.gov/epaoswer/other/fossil/volume_2.pdf.
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    The Agency requests comments with supporting data on how the 
findings of the DOE/EPA report should affect the Agency's decision 
regarding the regulation of CCW in landfills and surface impoundments 
under RCRA Subtitle D.
2. EPA's Risk Analysis Data
    As part of the rulemaking process for making the May 2000 
Regulatory Determination for CCW, EPA prepared a draft quantitative 
risk assessment. However, because time constraints precluded the Agency 
from addressing public comments on the draft study, EPA did not use the 
draft risk assessment in making its Regulatory Determination; rather it 
relied on the damage cases identified. Between 2000 and 2006, EPA 
addressed pubic comments and updated the risk assessment for the 
management of CCW in landfills and surface impoundments.
    The purpose of the risk assessment is to identify CCW constituents, 
waste types, liner type, receptors, and exposure pathways with 
potential risks and to provide information that EPA can use as it 
continues to follow-up on its Regulatory Determination for CCW disposed 
of in landfills and surface impoundments. The risk assessment was 
designed to develop national human and ecological risk estimates that 
are representative of onsite CCW management settings throughout the 
United States.\10\
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    \10\ Because the main technical aspects of the CCW risk 
assessment were completed in calendar year 2003, the newly collected 
information from the DOE/EPA report on the 56 new waste management 
units has not been incorporated into the database utilized for the 
risk assessment.
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    To assess the risks posed by the onsite management of CCW, this 
risk assessment estimates the release of CCW constituents from 
landfills and surface impoundments, estimates the concentrations of 
these contaminants in environmental media surrounding coal-fired 
utility power plants, and estimates the risks that these concentrations 
pose to human and ecological receptors. The risk assessment does not 
address risks that may be due to direct discharges of CCW pollutants to 
surface waters, which are covered under the National Pollutant 
Discharge Elimination System (NPDES) program.
    The risk analysis includes a full-scale Monte Carlo analysis; 
however, constituent screening results also are presented as part of 
the problem formulation discussion, along with a summary of the 
screening methodology. The full-scale analysis is designed to 
characterize five waste management scenarios that are defined by two 
waste management options (CCW disposal at power plant sites in 
landfills and surface impoundments) and three waste types, as follows:
     Conventional CCW, including fly ash, bottom ash, boiler 
slag, and flue gas desulfurization (FGD) sludge, which are typically 
co-disposed in landfills and surface impoundments;
     CCW co-disposed with coal refuse in landfills and surface 
impoundments, which can result in more acidic disposal conditions than 
conventional CCW monofills; and,
     Fluidized-bed combustion (FBC) wastes, including fly ash 
and bed ash. FBC wastes differ from conventional wastes because the 
limestone mixed during fluidized bed combustion tends to make the FBC 
waste more alkaline. FBC wastes are only disposed of in landfills in 
the United States and therefore, the Agency did not model the 
management of FBC wastes in surface impoundments.
    These three waste types provide a good representation of waste 
disposal practices and the waste chemical conditions that impact the 
release of CCW constituents from landfills and surface impoundments.
    To identify the CCW constituents and exposure pathways to be 
addressed in this risk analysis, the Agency relied on

[[Page 49718]]

a 2003 CCW database assembled over several years to characterize whole 
waste and waste leachate from CCW disposal sites across the country. 
The 2003 CCW constituent database includes all of the CCW 
characterization data used by EPA in its previous risk assessments 
supplemented with additional data collected from public comments, data 
from EPA regions and state regulatory agencies, industry submittals, 
and literature searches.
    Also, as noted in footnote 10, because the main technical aspects 
of the CCW risk assessment were completed in 2003, the newly collected 
information from the more recent DOE/EPA report on the 56 new waste 
units established between 1994 and 2004 was not part of the database 
used in characterizing the CCW landfills and surface impoundments 
modeled in the risk assessment. The risk assessment reflected 
management of CCW in both lined and unlined units as part of a Monte 
Carlo probabilistic risk analysis. Information on lined and unlined 
units was derived from facility data from a 1995 industry survey.
    Specific findings of the risk assessment, from the Monte Carlo 
analyses of both lined and unlined units, include:
     The 90th and 50th percentile risks for those units (both 
landfill and surface impoundments) that had a composite liner were 
below a cancer risk of 10-\5\ and an HQ of 1 for all constituents, 
waste management scenarios, and exposure pathways modeled in the CCW 
risk assessment.
     For humans exposed via the ground water to drinking water 
pathway, arsenic and thallium show risks to human health above the risk 
criteria for unlined and clay-lined CCW landfills. Arsenic poses a 90th 
percentile cancer risk of 5 x 10\-4\> for unlined units and 2 x \10-4\ 
for clay-lined units (The 90th percentile arsenic cancer risk from this 
risk assessment of landfilled CCW falls within the range that EPA 
established for the arsenic MCL (i.e., 1 to 6 excess cancers in a 
population of 10,000 individuals)). Thallium shows a 90th percentile 
noncancer HQ of 3 for unlined units only. The 50th percentile results 
for this pathway are at or below the risk criteria for all 
constituents. \11\ Other landfill constituents did not show a noncancer 
risk above an HQ of 1 or risk level of 1 chance in 100,000 excess 
cancer risk.
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    \11\ The risk analysis presents the correspnding 50th percentile 
results from the Monte Carlo analyses.
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     Risks are higher for surface impoundments for the 
groundwater-to-drinking-water pathway, with a 90th percentile arsenic 
cancer risk of 9x10-3 for unlined units and 3x10-
3 for clay-lined units. For unlined units, five additional 
constituents have noncancer HQs ranging from 3 to 5 for the 90th 
percentile, including boron, lead, cadmium, cobalt, and molybdenum. Two 
constituents (boron (2) and molybdenum (3)) have HQs greater than 1 for 
clay-lined surface impoundments. The 50th percentile cancer risk 
results for arsenic are 3x10-4 in unlined units and 9x10-
5 in clay lined surface impoundments.
     For arsenic, arrival times of the peak concentrations at a 
receptor well are relatively long for CCW landfills, with travel times 
ranging from hundreds to thousands of years. Arrival times are much 
shorter for surface impoundments, with time to peak concentrations 
being less than 100 years for most of the model runs.
     For humans exposed via the groundwater-to-surface-water 
(fish consumption) pathway, selenium (HQ = 2) and arsenic (cancer risk 
= 2x10-5) show 90th percentile risks for unlined surface 
impoundments above the risk criteria. All other waste management 
scenarios and all 50th percentile results show risks at or below the 
risk criteria for the fish consumption pathway.
     Liners appear to reduce risks from all constituents for 
landfills and surface impoundments. The risks from clay-lined units (as 
modeled in the risk assessment) were reduced by about half when 
compared to unlined units. Composite liners appear to be effective in 
mitigating CCW risks from landfills and surface impoundments.
     For ecological receptors exposed via surface water, the 
90th percentile risks for unlined and clay-lined landfills exceed an HQ 
of 1 for boron (200) and lead (4). For surface impoundments, 90th 
percentile risks for six constituents: boron (2000), lead (20), arsenic 
(10), selenium (10), cobalt (5), and barium (2) exceed an HQ of 1. The 
only exceedance from the 50th percentile risk results is HQ of 4 for 
boron in surface impoundments.
     For ecological receptors exposed via sediment, 90th 
percentile risks for lead, arsenic, and cadmium exceeded an HQ of 1 for 
both landfills (HQs from 2 to 20) and surface impoundments (HQs from 20 
to 200). All 50th percentile results show ecological risks at or below 
the risk criteria for the sediment pathway.
    The Agency is making the risk analysis document available in the 
Docket to allow interested parties to submit comments on the analytical 
methodology, data, and assumptions used in the analysis and to submit 
additional information for the Agency to consider. In addition, the 
risk assessment will undergo independent scientific peer review by 
experts outside of the EPA following closure of the public comment 
period. Public comments will be made available to the peer reviewers 
for their consideration during the review process. The peer review will 
focus on technical aspects of the analysis, including the construct and 
implementation of the Monte Carlo analysis, the selection of models to 
estimate the release of constituents found in CCW from landfills and 
surface impoundments, and their subsequent fate and transport in the 
environment, and the characterization of risks resulting from potential 
exposures to human and ecological receptors.
3. EPA Damage Case Assessment
    For the May 2000 Regulatory Determination, the Agency determined 
there were approximately 300 CCW landfills and 300 CCW surface 
impoundments used by 440 coal-fired utilities. EPA recently completed 
an assessment of possible environmental damages from CCW landfills and 
surface impoundments. Under the Bevill Amendment for the ``special 
waste'' categories, EPA was statutorily required to examine 
``documented cases in which danger to human health or the environment 
has been proved.'' The criteria used to determine whether danger to 
human health and the environment has been proved are briefly described 
in footnote 2 to this NODA and more fully explained in the May 2000 
Regulatory Determination at 65 FR 32224.
    EPA has gathered or received information on 135 possible damage 
cases. Sixteen of these were submitted since publication of the 2000 
Regulatory Determination. EPA re-evaluated the old damage cases and 
evaluated the new cases, and they are available in the docket to 
today's action and subject to comment as part of the NODA. After 
reviewing these 135 damage cases, EPA identified 24 proven damage 
cases. Sixteen were determined to be proven damages to ground water and 
eight were determined to be proven damages to surface water and covered 
by the National Pollutant Discharge Elimination System (NPDES) under 
the Clean Water Act.\12\ The overwhelming majority of the damage cases 
reflect management in unlined units--that is, all but one of the 24 
proven damage cases involved unlined CCW

[[Page 49719]]

management units,\13\ including six cases involving disposal of CCW in 
unlined sand and gravel pits. Additionally, 43 cases were determined to 
be potential damages to ground water or surface water.\14\ Four of the 
potential damage cases were attributable to oil combustion wastes.
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    \12\ Of the 24 damage cases, 11 were presented and discussed in 
the May 2000 Regulatory Determination.
    \13\ The lone damage case from a lined unit was the result of a 
liner failure in a surface impoundment.
    \14\ Per the May 2000 Regulatory Determination, 65 FR 32224, 
potential damage cases are those with (1) documented exceedances of 
primary MCLs or other health-based standards only directly beneath 
or in very close proximity to the waste source, and/or (2) 
documented exceedances of secondary MCLs or other non-health-based 
standards on-site or off-site.
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    Six of the alleged damage cases were minefills which, while under 
the scope of the 2000 Regulatory Determination, are outside the scope 
of this NODA that deals exclusively with surface disposal.\15\ The 
remaining 62 alleged damage cases subject to detailed assessment were 
not considered damage cases due to either (1) lack of any evidence of 
damage, or (2) lack of evidence that damages were uniquely associated 
with CCW.
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    \15\ See Footnote 1 regarding OSM's ANPR (72 FR 12026).
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    Of the 16 proven cases of damages to ground water, the Agency has 
been able to confirm that corrective actions have been completed in six 
cases and are ongoing in nine cases. The Agency has not received 
information regarding the one remaining case. Corrective action 
measures at these CCW management units vary depending on site specific 
circumstances and include formal closure of the unit, capping, the 
installation of new liners, ground water treatment, ground water 
monitoring, and combinations of these measures.
    For a more detailed description, see the document CCW--Damage--
Case--Assessments.pdf in the docket to today's action. Detailed 
information on many of these sites is also available in the docket for 
the 1999 Report to Congress, Docket ID  EPA-HQ-RCRA-1999-0022. 
The Agency solicits comments and supporting information on the extent 
to which the damage case information should affect the Agency's 
decisions regarding the regulation of CCW in landfills and surface 
impoundments under RCRA Subtitle D.
4. Additional Documents
    In addition to the reports identified under (1) to (3) above, the 
Agency is also including in the docket to today's NODA a February 2004 
Petition for Rulemaking submitted by the Clean Air Task Force and the 
Hoosier Environmental Council, jointly with a number of citizens' 
groups to Prohibit the Placement or Disposal of CCW into Groundwater 
and Surface Water; and two suggested approaches for managing CCW in 
landfills and surface impoundments. One approach is a Voluntary Action 
Plan that was formulated by the electric utility industry through their 
trade association, USWAG, regarding the management of CCW. The second 
approach is a proposed framework prepared by a number of citizens' 
groups for federal regulation of CCW disposed of in landfills and 
surface impoundments under Subtitle D of RCRA generated by U.S. coal-
fired power plants.

C. Conclusion

    The Agency solicits comments on the extent to which the damage case 
information, the results of the risk assessment, and the new liner and 
ground water monitoring information should affect the Agency's 
decisions. The Agency will consider all the information provided 
through today's notice, the comments and new information submitted on 
this notice, as well as the results of the peer review of the risk 
assessment as it continues to follow-up on its Regulatory Determination 
for CCW disposed of in landfills and surface impoundments.

    Dated: August 23, 2007.
Susan Parker Bodine,
Assistant Administrator, Office of Solid Waste and Emergency Response.
 [FR Doc. E7-17138 Filed 8-28-07; 8:45 am]
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