Monday
August 9, 1093
Part V
Environmental
Protection Agency
40 CFR Part 261
Final Regulatory Determinatioh on Four
Large-Volume Wastes From the
Combustion of Coal by Electric Utility
Power Plants; Final Rule
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42466 Federal Register /Vol. 58, No. 151 7 Monday, August 9, 1993 / Rules and Regulations
ENVIRONMENTAL PROTECTION _
AGENCY
40 CFR Part 261
[530-2-93-009; FRL-4689-S]
Final Regulatory Determination on
Four Larga-Volume Waatea From the
Combustion of Coal by Electric Utility
Powor Plants
AGENCY: Environmental Protection
Agency.
ACTtON; Final regulatory determination.
SUMMARY: Today's action presents the
Agency's final regulatory determination
required by Section 3001(b)(3)(C) of the
Resource Conservation and Recovery
Act (RCRA) on four large-volume fossil-
fuel combustion (FFC) waste streams—
fly ash, bottom ash, boiler slag, and flue
gas emission control waste—studied in
the Agency's February 1988, Report to
Congress; Wastes from the Combustion
of Coal by Electric Utility Power Plants
(RTC). EPA has concluded that
regulation under Subtitle C of RCRA is
Inappropriate for, the four waste streams
that were studied because of the limited
risks posed by them and the existence
of generally adequate State and Federal
regulatory programs. The Agency also
believes that the potential for damage
from these wastes is most often
determined by site- or region-specific
factors and that the current State
approach to regulation is thus
appropriate. Therefore, the Agency will
continue to exempt these wastes from
regulation as hazardous wastes under
RCRA Subtitle C. However, EPA
believes that industry and the States
should continue to review the
appropriate management of these
wastes. EPA will consider these wastes
during the Agency's ongoing assessment
of industrial non-hazardous wastes
under RCRA Subtitle D.
EPA plans to make a final regulatory
determination on the remaining FFC
waste streams (beyond the four listed
above) subject to Section 3001(b)(3) of
RCRA by April 1,1998.
EFFECTIVE DATE: September 2,1993.
FOR FURTHER INFORMATION CONTACT: For
further information on the regulatory
determination, contact the RCRA/
Superfund hotline at (800) 424-9346 or
(703) 412-9810, or Patti Whiting at (703)
308-8421.
SUPPLEMENTARY INFORMATION:
Tabla of Content!
1. Background
A. Statutory Authority '-."...
B. History of the Combustion Waste
Exclusion
COvondaw of tho Report to Congress >
1. Scope of the Report
2. Study Factors
3. Preliminary Findings
a. Large-Volume Wastes
b. Low-Volume Wastes
• c. Waste Utilization
4. Public Comment Process
D. Supplemental Analysis and Notice of
Data Availability
H Scope of the Regulatory Determination
A. As-Generated Large-Volume Wastes
B. As-Managed Large-Volume Wastes
III. Factors Considered in Making the
Regulatory Determination
IV. Regulatory Determination for Four Large-
Volume Coal-Fired Utility Wastes
V. Regulatory Flexibility Act
VI. Regulatory Determination Docket
Appendix A—Analysis of and Responses to
Public Comments on the Report to
Congress
Appendix B—Analysis of and Responses to
Public Comments on the Notice of Data
Availability
I. Background
A. Statutory Authority
Today's notice is issued under the
authority of Section 3001(b)(3)(C) of
RCRA, which requires that after .
completion of the Report to Congress
mandated by Section 8002 (n) of RCRA,
the Administrator must determine
whether Subtitle C regulation of fossil
fuel combustion wastes is warranted.
B. History of the Combustion Waste
Exclusion
In December 1978, EPA proposed the
first regulations to implement Subtitle C
of RCRA. At that time, the Agency
recognized that certain large-volume
wastes, including wastes from the
combustion of fossil fuels, might •
warrant special treatment. However, the
Agency had very little information
regarding the nature of and risks posed
by these large-volume wastes.
Additionally, the Agency had no data
on the costs and effectiveness of
technologies for managing these wastes.
In light of these uncertainties, EPA
proposed a limited set of regulations for
the management of these wastes (43 FR -
58946, 59015, December 18,1978).
On May 19,1980, EPA promulgated
the initial regulations implementing
Subtitle C. By then, however, Congress
was debating RCRA^authorization and
both Houses had passed bills restricting
EPA's authority to regulate large-volume
wastes under Subtitle C of RCRA.
Anticipating the enactment of
legislation amending RCRA Section
3001, EPA excluded fossil fuel
combustion wastes from these
regulations (45 FR 33084, 33089, May
19,1980).
In October 1980, Congress passed the
Solid Waste Disposal Act Amendments.
Among other things, the amendments
temporarily exempted from regulation
as hazardous wastes certain large-
volume wastes generated primarily from
the combustion of coal or other fossil
fuels (RCRA Section 3001(b)(3)(A)(i)).
These large-volume wastes include fly
ash waste, bottom ash waste, boiler slag
waste, and flue gas emission control (or
flue gas desulfurization) waste. In RCRA
Section.8002(n), Congress directed EPA
to conduct a detailed and
comprehensive study based on eight
study factors (discussed in detail below)
and to submit a Report to Congress on
"the adverse effects on human health
and the environment, if any, of the
disposal and utilization of fly ash waste,
bottom ash waste, slag waste, flue gas
emission control waste, and other
byproduct materials generated primarily
from the combustion of coal or other
fossil fuels."
Finally, in RCRA Section
3001(b)(3)(C), Congress directed that
within 6 months of submitting the
report, EPA must, after public hearings .
and opportunity for comment, decide
whether regulation of the management
of the temporarily exempt FFC wastes as
hazardous wastes under Subtitle C is
warranted. Once the decision is made,
the Administrator must publish the
Agency's regulatory determination in
the Federal Register.
In 1981, EPA provided an
interpretation of the RCRA regulations
regarding the exclusion of fossil-fuel
combustion wastes from regulation
under Subtitle Ci. EPA stated that,
pending the results of the Report to
Congress, the Agency would interpret
the following to be exempt from RCRA
Subtitle C pending further study: (1) Fly
ash, bottom ash, boiler slag, and flue gas
emission control wastes resulting from:
the combustion solely of coal, oil, or
natural gas, the combustion of any
mixture of these fossil fuels, and the
combustion of any mixture of coal and
other fuels 2 where coal makes up at
least 50 percent of the mixture, and (2)
wastes-produced in conjunction with
the combustion of fossil fuels that are
necessarily associated with the
production of energy and that have been
and are mixed with and co-disposed or
co-treated with fly ash, bottom ash,
boiler slag, or flue gas emission control
wastes from coal combustion.
RCRA was amended again in 1984 by
the Hazardous and Solid Waste
Amendments (HSWA) (Pub. L. No. 98-
616, 98 Stat. 3221). These amendments
. i Letter from G. Dietrich, U.S. EPA, to P,. Emler,
Utility Solid Waste Activities Group, January 13,
1981, Report to Congress: Wastes from the
Combustion of Coal by Electric Utility Power
Plants, February 1988, Appendix A.,
2 See discussion below on page 10.
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Federal Register / Vol. 58> No. 151 /Monday; August 9, 1993 / Rules and Regulations 42467
added Section 3004(x), which gave EPA
the flexibility to promulgate regulations
under Subtitle C that considered the
unique characteristics of some large-
volume wastes, including FFC wastes.
Specifically, if EPA determined that
some or all of the wastes from fossil-fuel
combustion should: be regulated as
hazardous waste, it could modify
certain HSWA requirements to take into
account the special characteristics of the
wastes, the practical difficulties of
implementing the standards, and site-
specific characteristics, as long as the
modifications still protected human
health and the environment.
In February 1988, EPA submitted its
Report to Congress: Wastes from the
Combustion of Coal by Electric Utility
Power Plants, as required under RCRA
Section 8002(n). Because coal-fired
electric utilities generate a large
majority of all fossil-fuel combustion
wastes, the RTG focused on wastes
generated by coal-fired electric utilities.
The document does not address wastes
generated by utilities burning other
fossil fuels or wastes from non-utility
boilers burning any type of fossil fuel
(the Agency deferred study of these j
waste streams until a later date). The
report provided the Agency's analysis of
available data considering the eight
study factors listed in Section 8002(n) of
RCRA and presented the Agency's
tentative determination regarding large-
volume-wastes from coal-fired electric •
utilities. Following the release of the
RTC, the Agency provided a notice and
comment period that extended through
May 16,1988, and held a public hearing
in Denver, Colorado,, on April 26,1988.
Appendix A summarizes the comments
received on the RTC. ,
Because of Other priorities, the
Agency did not publish the regulatory
determination for fossil-fuel combustion
wastes within the timeframe established
in Section 3001(b)(3)CC), As a result, a
suit was filed on behalf of the Bull Run
Coalition (an Oregon citizens group),
with the Edison Electric Institute
intervening as plaintiffs.^ On June 30,
1992, the Agency entered into a Consent
Decree that established a schedule for
the Agency to complete the regulatory
determinations for all fossil-fuel
combustion wastes. The Consent Decree
divides FFC wastes into two categories:
(1) Fly ash, bottom ash, boiler slag, and
'flue gas emission control waste from the
combustion of coal by electric utilities
^and, (2) all remaining wastes subject to
RCRA Sections'3001(b) and 8002(n).
Separate schedules are provided in the
• 'Frank Gearhatt. eta/, v. Willidmk Beilly etaJ„
No. 91-2435 (D.D.C.}
Consent Decree for each category of
waste. • \ • • • '"./'. ..:•.;•• " -. :-•'--'. ..
Inaccordance with the requirements
of the Consent Decree, the Agency
notified the parties to the litigation on
December 1,1892, that a regulatory
determination for fly ash, bottom ash,
slag, and flue gas emission control waste
from the; combustion of coal by electric
utilities would be made by August 2,
1993. For the remaining FFC wastes, the
Agency indicated that further study was
required and that a regulatory
determination would be completed for
these wastesby April 1,1998.
In preparing the regulatory "•
determination, EPA collected and
reviewed recent information on wastes
from coal-fired electric utility power
plants. On February 12,1993, EPA
, published a Notice of Data Availability
in the Federal Register, soliciting
comments on these data (58 FR 827,3),
In the notice, EPA also requested
comments on a proposed methodology
to be used in making the final regulatory
determination. This three-step
analytical approach was recently used
in making the June 13,1991, regulatory
determination for special wastes from
mineral processing (56 FR 27300).
Comments on the newly available data
and on the proposed methodology are
.discussed in Appendix B of today's
notice.
Today's decision is based on the RTC
and the data and analyses that underlie
the report, comments on the RTC,
supplemental information gathered after
the RTC, and comments, on that newly
available information.
C, Overview of the Report to Congress
1. Scope of the Report
EPA published the RTC m 1988, The
RTC documents EPA's study of special
wastes from coal-fired utilities
temporarily excluded from regulation
under RCRA Subtitle C, EPA did not
include within the1 scope of the RTG oil-
. and gas-fired utility wastes, as well as
industrial FFC wastes. The study
presents EPA's understanding of the
generation, management, .disposal, and
reuse of wastes from coal combustion
for electricity generation.
2. Study Factors •
The RTG addressed the following,
eight study factors required under
Section 8002(n) of RCRA:
1. Sources and volumes of such /
materials generated per year,
2. Present disposal and utilization ;
practices, .'.'". ~- •_
3. Potential danger, if any, to human
health and the environment from the
disposal and reuse of such materials,
4. Documented cases in which danger to?
; human health or the environment"
from surface runoff or leachate has
, beenprqyed, • - .:""•":
5. Alternatives to current disposal
methods, ' -•-.-',' •••-., . .,
6. Costs of such alternatives, .-..>.<
7. Impact of those alternatives on the ,-
use of coal and other natural
resources', and , , ;
8. Current and potential utilization of
such materials.-
In preparing the RTC, EPA addressed
these eight study factors as. they apply
to coal-fired combustion wastes
generated by electric utilities. The RTC
is divided into six sections that address
these factors. The first section provides
an overview of the U.S. electric utility
industry, including the structure,
economic and environmental
regulations, and describes the
importance of coal to the electric utility ,
industry. The second section examines
the amounts and,types of wastes
generated. The third section discusses
current waste management and disposal
practices used by the electric utility
industry and possible alternatives to
these practices. The fourth section
reviews the potential arid documented
impacts of these wastes on human
health and the environment, and the
fifth section evaluates costs associated,
with current waste disposal practices
and additional costs that could be
incurred under a variety of alternative
waste management practices. The final
section summarizes the RTC's tentative
' findings and provides recommendations
for a regulatory determination,
3. Preh'minary Findings .
Using the RTC findings, EPA
developed three preliminary '.-'.'-
recommendations for such wastes. A
summary of these recommendations is ;
provided below. .'•".•-.;
'\a. Large-volume, wastes. The RTC •
found that while the majority of the
materials present in the four large '..-_•'..
volume wastes—fly ash, bottom ashr
boiler slag, and flue dust—are not of '
major concern (e.g,, more than 95
percent of the ash is composed of oxides
of silicon, aluminum, iron, and
.calcium), trace constituents in the
wastes, including arsenic, barium,
cadmium, chromium, lead, mercury,
and selenium, may present risks to
human health and.the environment.
However, the data also indicates that
these wastes generally do not exhibit the
RGRA hazardous waste characteristics.
In particular, a review of the extiacjtiqn,; .
procedure (EP) test data indicated that
metals are generally not found in :
leachate at levels above the hazardous •
waste toxicity characteristic. Only three
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$2468 . Federal Register / Vol. 58, No. 151 / Monday, August 9, 1993,1. Rules ^d Regulations
metals—cadmium, chromium, and
arsenic—were detected in any ash or
sludge samples above toxicity
characteristic levels and then only
infrequently.
In addition, the report tentatively
concluded that current waste
management practices appear to be
adequate for protecting human health
and the environment. For example,
while groundwater monitoring data
showed that waste management units
can cause releases of pollutants to
underlying groundwater, the frequency
and magnitude of exceedences of
Primary Drinking Water Standards
(PDWSs) were found to be relatively
low—about 5 percent of all samples
showed exceedences of PDWS, with
exceedences less than 20 times the
applicable standard in all cases.
Additionally, human populations
generally are not directly.exposed to
groundwater in the vicinity ofcoal-fired
utility waste management sites; public
drinking water intakes are usually at
least several kilometers from the sites.
Furthermore, the RTC indicated that
as of 1988, coal-fired electric utilities
spent about $800 million per year for
the disposal of coal combustion wastes.
If all utility large-volume wastes from
coal combustion were regulated as
hazardous wastes, the cost of disposal
practices, excluding corrective action
costs or higher recycling costs, could
increase to $3.7 billion per year. Costs
would approach $5 billion annually if
all existing facilities were capped and
closed and new facilities were
constructed with liners, leachate
collection systems, flood protection, and
groundwater monitoring. Based on these
findings, the RTC tentatively concluded
that regulation of these wastes under
Subtitle C was not warranted.
b. Low-Volume Wastes. The RTC
identified a number of wastes other than
the large-volume wastes that are
typically generated in lower volumes by
coal-fired electric utilities. These "low-
volume wastes" include, but are not
limited to, boiler blowdown, coal pile
runoff, cooling tower blowdown,
demineralizer regenerant and rinses,
metal and boiler cleaning wastes,
pyrites, and sump effluents. The report
indicated that several low-volume
wastes may exhibit the hazardous waste
characteristics of corrosivity and EP
toxicity.
Data in the RTC showed that waste
streams produced during equipment
maintenance (e.g., boiler chemical
cleaning wastes) occasionally exceeded
hazardous waste toxicity characteristics
for chromium and lead. Boiler chemical
cleaning wastes were also, in limited
instances, found to exhibit the
characteristic of corrosivity. No
exceedences of toxicity characteristics
were observed for other low-volume
wastes, but available data were limited.
In addition, the Agency concluded that
data on these low-volume wastes that
are co-disposed with the four large.-
volume waste streams were insufficient
to determine the potential contribution
of particular wastes to environmental
risk and that additional study of low-
volume wastes was warranted. Because
of these findings, the Agency indicated
that it was considering removing the
exemption for low-volume wastes.
c. Waste utilization. EPA noted in the
RTC that waste utilization practices
appeared to be conducted in an
environmentally safe manner. The
Agency encouraged the utilization of
coal combustion wastes as one method
for reducing the amount of these wastes
requiring disposal and supported
voluntary efforts by industry to
investigate new possibilities for
utilizing coal combustion wastes..
4. Public Comment Process
With the publication of the RTC, EPA
established a comment period that
ended May 16,1988 (See 53 FR 9976,
March 28,1988). In addition, the
Agency held a public hearing on the
RTC in Denver, Colorado, on April 26,
1988 (53 FR 14839). A second hearing
was scheduled but subsequently
cancelled. EPA received 24 sets of "
written comments prior to the close of
the comment period. All individual
comments and a transcript from the
public hearing are available for public
inspection in the RTC docket (Docket
No. F-88-PATA-FFFFF). The docket
also contains a summary of all the
comments presented at the hearing or
submitted in writing. EPA's responses to
those comments are provided in the
docket, as well as in Appendix A to this
regulatory determination.
D. Supplemental Analysis and Notice of
Data Availability
Supplemental data were collected and
analyzed for the large-volume and some
low-volume wastes addressed by the
RTC. A Notice of Data Availability
(Notice), which announced the
availability of this information, was
published in the Federal Register on
February 12,1993. In the Notice, EPA
also made available for comment the
proposed methodology to be used in ,
making a final regulatory determination
for fly ash, bottom ash, slag, and flue gas
emission control wastes. The Agency
provided a 45-day public comment
period, which closed on March 29,
1993.
The supplemental data provided in
the Notice were obtained by EPA from
various EPA offices and other Federal
agencies, State agencies, and the electric
utility industry. In addition, literature
searches were performed to identify
recently published materials on fly ash,
bottom ash, boiler slag, and flue gas '
emission control waste generated by
coal-fired electric utilities. Information
in the Notice included:
• Published and unpublished
materials obtained from State arid
Federal agencies, utilities and trade
industry groups, and other
knowledgeable parties on the volumes
and characteristics of fly and bottom
ash, slag, and flue gas emission control
waste.. , , .
• Published and unpublished
materials on management practices
(including co-disposal and reutilization)
associated with fly and bottom ash, slag,
and flue gas emission control waste.
• Published and unpublished
.materials on the potential,
environmental impacts associated with
fly and bottom ash, slag, and flue gas
emission control waste management.'
• Published and unpublished
materials on trends in utility plant
operations that may affect waste
volumes and characteristics. Specific
information was sought on innovations
in scrubber use and the potential
impacts of the 1990 Clean Air Act
Amendments on waste volumes and
characteristics.
• Energy Information Agency (EIA),
Department of Energy, 1990 data on
utility operations and waste generation
obtained from EIA's Form 767 database.
These data are submitted to EIA
annually by electric utilities.
• Site visit reports and accompanying
facility submittals for five power plants
visited by EPA during fall of 1992.
• Materials obtained from public files
maintained by State regulatory agencies
in Virginia, North Dakota, Texas,
Indiana, Colorado, Wisconsin, Ohio,
' and Pennsylvania. These materials focus
on waste characterization and
. environmental monitoring data, along
'with supporting background
information.
EPA received 14 written comments
addressing the Notice. All of the
comments are available for public
inspection in Docket No. F-93-FFCA-
FFFFF. EPA's response to the comments
are provided in the docket and in
Appendix B to this regulatory
determination.
II. Scope of the Regulatory
Determination
This section describes the wastes that
are and are not affected by this
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- -Federal Register / Vol. 58, No. 151 /Monday, .August 9, 1993 /Rules and Regulations ' 42469
regulatoryxletermination. The
. discussion addresses the affected .--
generators, the status of wastes
- generated from those utilities that co-
bum fossil fuels with non-coal fossil.
fuels or other materials, and the effect
of co-management of the four large-
volume wastes with low-volume coal
combustion wastes on the regulatory
status of the large-volume wastes.
The Consent Decree divided the
universe of fossil-fuel combustion
wastes into two categories: large-volume
wastes from coal-fired electric utilities
referenced in RCRA Section 3001(b}(3)
(fly ash, bottom ash, boiler slag, and flue
gas emission control wastes) and :
"remaining wastes" (these wastes must
still be studied according to RCRA
Section 8002(n)). Each category has
separate schedules for making the
regulatory determination. Today's
action only affects fly ash, bottom ash,
boiler slag, and flue gas emission
control waste from coal-fired electric
utilities. All remaining wastes are
outside the scope of this determination.
Because a waste stream which is
categorized as a large-volume waste as
generated may become a remaining
waste as a result of the manner in which
it is managed, this section explains the
universe of as-generated and as-
managed large-volume wastes affected
by today's action.
A. .As-Generated large-Volume Wastes
The universe of wastes affectedrby
this action is limited to the large-volume
wastes generated by coal'fired units at;
steam electric utility power plants in the
United States, including independent .
power producers not engaged hi any
other industrial activity (this latter
group'was included because the Agency
has no reason to believe that its wastes
and practices are any different than
those of larger power plants). These
wastes are subject to the regulatory
determination only when managed
separately from other FFC wastes. "
Further, the population is limited to
wastes from those facilities for which.
coal is almost the sole fossil-fuel feed.
Information on electric utilities
collected since publication of the Report
to Congress demonstrates that nearly all
coal-fired boilers occasionally burn
small amounts of natural gas and/or
fossil-fuel oil for boiler startup or flame
stabilization. While oil ash is a
remaining waste outside the scope of
today's action, the Agency believes,
based on published literature and
information collected during site visits,
that the burning of oil for startup and
flame stabilization results in a de
minimis contribution to the total
volume of combustion by-products
generated by the boiler during normal
• operations. Similarly, natural gas
combustion for boiler startup or flame
stabilization results in de minimis ash
formation relative to the volume of by-
products generated from coal
combustion. Accordingly, the total
volume of fly ash, bottom ash, slag, and
flue gas emission control waste
generated by a coal-fired plant that
burns oil or natural gas in small
^quantities for start-up or flame '
stabilization shall be considered a large-
volume waste subject to this
determination. ,
The information collected following
publication of the RTC also indicates
that some operators occasionally burn
materials other than coal in utility
boilers, some of which are considered
hazardous wastes under RCRA
(operators may do so and their residues
continue to remain exempt under the
Bevill exemption as long as 50 percent
of the feed is coal and the residue passes
the BIF two-part test if they burn
hazardous waste). This practice maybe
conducted for the purposes of disposal
or energy recovery. Wastes from the co-
burning of materials were not studied in
the RTC, and very limited information
regarding their generation,
characteristics, and management has
been collected to date. The Agency
recognizes that the burning of such
materials, when practiced in an
environmentally sound manner, can be
'•' an effective waste management or ;
energy recovery strategy. However, EPA
has insufficient data to determine the^
amount of material burned or the
potential influence of burning such
materials on the characteristics of the
four large-volume wastes. The Agency
intends to study the co-burning issue
further at a later date, as appropriate.
Thus,, the-large-volume wastes which. '
result from any such burning (with the
exception of co-burning with hazardous
waste) are outside the scope of this
determination. The following paragraph
discusses the special case of co-burning
hazardous waste and coal.
The residues from those facilities that
burn hazardous wastes are subject to the
Boiler arid Industrial Furnace (BIF) rule
under RCRA (40 CFR 266.112).« Under
the BIF rule, facilities must conduct
site-specific sampling and analysis of
«Tha 19S1 interpretation at footnote I abova
states that the residues from co-burning enjoy tho
temporary exemption only when the non-coal
material in the faed-is burned for its fuel value, this
condition, however, was removed for co-burners of
hazardous waste in the BIF rule (see preamble
discussions at 56 FR 7196-7200, Feb. 21,1991). For
the same reasons cited during that rulemaking, and
as a matter of consistency, the Agency no longer
imposes such a condition when {he non-coal -
material is not a hazardous waste.
waste-derived residues to document that
ihazardpus waste burning has not.v;
significantly increased concentrations of
hazardous constituents in the residues;
Because this testing ensures that such
,wastes are similar to those studied in
the RTG, thus making further study of
these Wastes unnecessary, residues that
pass the test are within die scope of
today's regulatory determination.
Finally, for the purposes of this
action, large-volume wastes from coal-
fired electric utilities do not include
wastes generated from fluidized bed
combustion (FBC) boiler units. FBC is a
relatively new combustion technology
that allows for the removal of sulfur' :•
without an end-pf-pipe scrubber. The
wastes generated; by this technology
were not studied in the RTC, and only
limited information regarding their
characteristics and management has
been collected to date. The information
that is available has not provided EPA
with enough evidence to conclude that
waste generated from FBC units is
substantially similar to conventional
boiler wastes. Some sources maintain
that FBCrunits that bum solely coal as
ajfossil-fuel source generate fly ash and
spent bed material that is substantially
different from conventional boiler
wastes.5 This is because In FBCr coal is
burned in the presence of limestone. ,
The differences in the FBC wastes are
defined by a presence of sulfur
compounds and high amounts of
residual alkalinity. On the other hand,
industry representatives believe that the
wastes are very-similar to;the fly ash
waste and flue gas emission control
wastes studied in the RTC. -: -
The information does indicate that the
u§e of FBC technology in the electric
utility industry may be increasing.
Because of the current lack of data, the
potential of the co-firing of limestone to
have a significant effect on the
characteristics of the wastes produced,
and the potential for increased
utilization of the technology, the,
Agency has decided to defer a decision
on these wastes until further
information from the growing number of
facilities can be examined. Therefore,
the Agency considers these wastes
"remaining wastes," which are outside
the scope of today's regulatory
determination. . •••.•'•
B As-Managed Large-Volume Wastes
As described above, large-volume
wastes include fly ash, bottom ashr slag,
and flue gas emission control wastes
•, s United States Environmental Protection Agency,
Office of Research and Development, Fhridized-Bed
Combustion Technology Overview, EPA-600/7-81-
074,April 1981. . -•:. . : ' :
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42470 Federal Register / Vol. 58, No. 151 / Monday, August 9, 1993 / Rules and Regulations
from coal-fired electric utility boilers.
However, the Consent Decree defines
lares-volume wastes that are "mixed
with, co-disposed, co-treated, or
otherwise co-managed with other wastes
generated in conjunction with the
combustion of coal or other fossil-fuels
* * *" as remaining wastes. As a result,
a waste that may be categorized as large-
volume as generated may become a
remaining waste by virtue of the
circumstances of its management.
Remaining wastes are outside the scope
of this regulatory determination.
(Although these wastes are not covered
by today's regulatory determination,
these wastes remain exempt from RCRA
Subtitle C until April 1,1998, at the
latest.)
The RTC found that the level of "co-
mixing, co-treatment, co-disposal or co-
management" practiced at utility waste
disposal sites varies considerably. At
one extreme, many or most liquid
wastes generated at the plant may be
handled along with ash in a single
impoundment system. At the other
extreme, all large-volume wastes may be
discharged to units receiving no other
materials of any kind. In practice, most
utility disposal sites operate somewhere
between these extremes, with large-
volume wastes discharged into units
receiving certain other materials.
Depending on the specific materials
commingled in a particular management
unit, the resulting mixture may be a
remaining waste and hence fail outside
of the scope of today's action.
The Agency recognizes that many
plant operators use process waters (e.g.,
non-contact cooling water and low-
pressure service water) in ash handling
or FGD systems, Because of the
continuous use of these process waters,
the Agency does not consider them to be
wastes. In any event, the use of these
process waters as foedwater for emission
control systems or for ash transport
generally will not increase the
environmental risks associated with the
wastes relative to the risks derived from
utilization of fresh water for the same
purposes. Discouraging such practices
may lead to an increased usage of fresh
water for the same purposes, thereby
increasing the total volume of water
exposed to the large-volume wastes as
well as the total volume of waste
generated. The Agency feels that this
would be an undesirable outcome of
today's action. For these reasons, the
Agency does not consider the practice of
using these non-contact process waters
hi ash sluicing systems or as makeup
water for FGD systems to constitute co-
managoment. The four large-volume
wastes, therefore, that are transported/
mixed with these process waters do not
become "remaining wastes." Instead,
they are within the scope of this
Regulatory Determination. These waters
are limited to ash hopper seal water, ash
hopper cooling water, and other non- .
contact cooling waters.
The Agency emphasizes that co-
management of low-volume wastes and
large-volume wastes makes the
combined waste stream a remaining
waste. Given below is a list of
management practices that result in
combined waste streams that are
remaining wastes; This list, which is not
exhaustive, includes those activities
observed or believed to occur at
operating FFC waste disposal facilities
that involve the "mixing, co-treatment,
co-disposal, or co-management" of_
large-volume wastes with low-volume
wastes. Remaining wastes as managed
include:
• Discharge of boiler blowdown to a
large-volume waste impoundment,
« Discharge of demineralizer
regenerant to a large-volume waste
impoundment,
• Discharge of metal cleaning wastes
to a large-volume waste impoundment,
• Discharge of boiler chemical
cleaning wastes to a large-volume waste
impoundment,
• Discharge of plant wastewater
treatment effluent to" a large-volume
waste impoundment,
• Discharge of coal mill rejects to a
large-volume waste impoundment,
• Disposal of oil ash in a large-
volume waste landfill or impoundment,
• Disposal of plant wastewater
treatment sludge in a large-volume
waste landfill,
o Disposal of coal mill rejects in a
large-volume waste landfill, and
e Reuse of metal cleaning
wastewatera in a FGD feedwater system.
EPA recognizes that it may not have
provided a clear understanding of what
constitutes co-management since
offering the 1981 interpretation of the
exemption cited above. Therefore, the
Agency may propose a definition of co-
management in the future. This is
important because low-volume wastes
are within the Bevill Exemption only if
they are co-managed with large volume
waste. Low-volume wastes that are
independently managed are not and
have never been within the scope of the
Bevill Exemption.o
ED. Factors Considered in Making the
Regulatory Determination
RCRA, as amended, directs EPA to
make a regulatory determination
generally based upon the RTC and
"Industry comments on both the RTC and Notice
generally agreed with this interpretation.
comments received from interested
parties. The statute contains the eight
study parameters identified hi Section
I.C.2., Study Factors. In addition, RCRA
Section 8002(n) suggests that EPA
review relevant studies and other
actions of other Federal and State
agencies and invite participation by
other concerned parties, including
industry and other Federal and State
agencies, with a view toward avoiding
duplication of effort.
EPA complied with the congressional
mandate in developing, in 1988, the
required RTC. In conducting this study,
EPA relied upon the analysis of the
eight study factors noted above! The
Agency has expanded the data base
through the collection of additional data
referenced in the February 12,1993,
Notice. The Notice also made available,
in the RCRA docket, the three-step
methodology the Agency was
considering using in making this
regulatory determination. This basic
analytical approach was used in making
the regulatory determination for mineral
processing wastes (56 FR 27300, June
13,1991). EPA modified the
methodology in this case/however, so
that it best fit the available information
on the nature and management of the
coal-fired electric utility wastes at issue
in this determination. The method
involves answering a series of questions
covering the potential hazards of the
wastes, the existing management and
regulatory controls that affect the
hazards that may be presented, and the
potential impacts of regulating the
wastes as hazardous under RCRA
Subtitle C. This approach allows EPA to
make a systematic evaluation of the
information presented in the RTC and
other information collected pursuant to
the Notice. EPA has solicited and
incorporated comments on the RTC, the
data described in the Notice, and the
three-step methodology in making
today's regulatory determination. EPA
believes that this approach is consistent
with congressional intent. ~
EPA received no comments that
disagreed with any aspect of the three-
step methodology. Therefore, no
changes have been made in the
approach. The decision process outlined
below presents a series of questions and
sub-questions that were addressed in
the order posed. If the Agency
determined the response to Step 1 for a
waste to be affirmative (e.g., "Yes,
management of this waste does pose
human health/environmental problems,
or might cause problems in the future"),
then the analysis proceeded to Step 2
for the waste and constituent(s) of
concern, If, however, the answer to Step
1 was negative, then the analysis
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Federal Register
> fetes* an
indicate that the waste could pose
significant risk to human health or the .;•
environment at any sites, that generate it
(or in offsite use), under either current
management practices or plausible "•
mismanagement scenarios?
Substep 3. Does the waste exhibit any
of the characteristics of hazardous
waste?1" : , • . ••"-, : -"•''
As described above, the Agency first
determined whether each waste may
pose human health/environmental
problems by examining whether the
waste has caused documented human
health or environmental damages in the
past, whether each waste* as managed,,
may pose signiScantrisk to human
health or the environment, and whether
each waste exhibits any of the
characteristics of hazardous waste. If
each of the questions in Step 1 resulted!
in a negative response, no further
review would be performed for that ,
waste, and the Agency would determine
that regulation under Subtitle C of "
RCRA is not warranted. However, as
.with the Regulatory Determination for
Mineral Processing Special Wastes (56
FR 27305,June 13;,1991)K an affirmative
response to any one of the three sub-
questions above did not necessarily
trigger further analysis, under Step 2 of
the methodology. Rather, the Agency
answered each, of the three, questions
separately and then considered the
combined responses as a whole in
•deciding whether further evaluation was
necessary. In that consideration, the
certainty and weight of evidence ,
supporting an affirmative response to
one question was. taken into account in
the Agency's decision to proceed to Step
2. If the Agency determined that
additional review was warranted for a
particular waste, additional review
under Step 2* was limited to those waste
characteristics or waste management
practices for which significant potential:
; for risk was identified fn Step 1.
The* first question the Agency
addressed under Step? 1 was whether
coal combustion waste has: caused .
documented human health1 impacts or
' environmental damage. Tb; determine .
this,, the Agency first considered
existing damage case information
presented: in the RTC, EPA examined
additional' damage case information to
determine whether there; was further
evidence of negative impacts: to-human
health or the environment. The Agency ;
requires that each relevant ease--satisfy
at least one-of the following three ,
conditions: scientific investigation
concluding that damages occurred,
administrative ruling concluding that
damages occurred, or court decision' or
6ut-o£court settlement concluding that
damages-occurred. Ideally, damages
would dearly be the result of the large-
volume coal, combustion wastes.
In the Agency's analysis, damage to .
human health or. the environment was;
considered as follows: Threat to human
health included both acute and chronic
effects (e.g,, exeeedences of primary
drinking water standards, directly
observed health effects,, such as elevated
blood contaminant levels or loss of HfeJ
associated with management of coal-
fired electric utility wastes, while
danger to the environment included j (1)
Impairment of natural resources- (e.g..
.contamination of any; source of drinking
water reasonably/ expected to be used),
(2) ecological, effects resulting in
impairment of the structure' or function
of natural ecosystems and habitats* and
(3) effects on wildlife resulting in
impairment of terrestrial or aquatic.
fauna (e.g., reduction in species
diversity/ or density, impairment of
reproduction). , '.
To address the second question—
"could the waste pose significant risk to
human health and the environment
under either current management
practices; or plausible! mismanagement
scenarios* the Agency performed a two-
part assessment of the potential foe risk
presented by/the waste,
: First, the Agency conducted & risk
screen of intrinsic hazard of the wastes;,
comparing, waste characterization data
with conservativesCTeening criteria
developed for four exposure pathways?
groundwater, surface water, inhalation P
and ingestion,Thepurpose:of tfierisk
screen was to identifyifhe waste
constituents and exposure: pathways1.
that have: the potential to present threats
to "human health and the environment.
Exceedences of the screening criteria
' .indicate the need for further study•, but
do not in themselves "demonstrate that
the wastes pose a significant hazard.
Second, for each waste" constituent.
found to exceed the screening Criteria,
the Agency evaluated the potential for
release, transport, and exposure of that
constituent for specific pathways. The
three exposure^ pathways evaluated for
human' health-risk were1 groundwater
ingestion, particulate inhalation, and
sTbilingestion. The fourth pathway,,
surface water, was evaluated for ^ •
ecological risk., The Agency solicited:
comment in the Notice on excluding;
from1 consideration another pathway;
radiation exposure, because of
insufficient information to perform;the
required analysfs; No comments or-
supplemental data were received '
regarding the proposed exclusion.
Therefore,; EFA did not consider '•'....
radiation exposure in the analysis;
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42472 Federal Register / Vol, 58, No. 151 / Monday, August 9, 1993 / Rules and Regulations
To address the third question of Step
1, the Agency reviewed available waste
characterization data to determine
whether fly and bottom ash, slag, and
FGD sludge exhibit any of the hazardous
characteristics. In evaluating toxicity
data, the Agency considered both
Extraction Procedure (EP) arid Toxicity
Characteristic Leaching Procedure
CTCLP) data, since much of the currently
available data on toxicity predates the
use of the TCLP.
Several commenters on the RTC
claimed that the EP toxicity test is not
a valid indication of hazards associated
with utility wastes since the test was
designed to mimic conditions in acidic
municipal landfills rather than
homogeneous monofills used by electric
utilities. Those commenters concluded
that data from the EP test significantly
overstate potential risks.
As discussed further hi Appendix A
to this preamble, EPA has developed the
methodology to take into account the
eight study factors (Section 8002(n)) set
forth in the Bevill Exemption to
determine whether hazardous waste
regulation is warranted for FFC wastes.
While waste characterization data,
including both the results of EP toxicity
testing and those of other leaching
procedures (TCLP, ASTM. etc.), are
considered in the decision, they are not
the sole basis for determining whether
to regulate fossil-fuel combustion wastes
under RCRA Subtitle C. The
methodology focuses on the risks posed
by fossil-fuel combustion wastes as
managed (and some ash is currently
managed in Subtitle D landfills). EPA
therefore believes that consideration of
EP toxicity data, in conjunction with the
results of other leaching studies and
data on the actual environmental
impacts of waste management practices,
is appropriate.
EPA receive^ limited additional data
from commenters to the Notice. The few
EP and TCLP results provided were
consistent with other samples collected
for the purposes of the RTC and the
Notice. None of the additional data
supplied during the comment period
exceeded the hazardous waste criteria.
Step 2. Is more stringent regulation
necessary or desirable?
If the Agency determined in Step 1
that the management of fly or bottom
ash, slag, or FGD sludge from coal-fired
utilities has caused or may potentially
cause human health or environmental
impacts, then the Agency would
proceed to Step 2. In evaluating the
need for more stringent controls to
address the potential risks associated
with the management of these wastes,
EPA asked the following questions:
1. Are current practices adequate to
limit contaminant release and
associated risk?
2. Are current Federal and State
regulatory controls adequate to
address the management of the
wastes?
3. Will Subtitle C effectively address
problems associated with the waste
without imposing significant
unnecessary controls that are
inconsistent with the special status
of the waste?
In Step 2, the Agency looked at waste
management practices and existing
regulations to examine the potential for
release and exposure under current
practices. If current management
practices or existing regulatory controls
were found to be adequate or if Subtitle
C was found to be an ineffective or
inappropriate regulatory alternative,
then the Agency would determine that
the waste should not be regulated under
Subtitle C. If, on the other hand, current
practices or existing regulatory controls
were found to be inadequate in
controlling potential and actual risks
and if Subtitle C would be effective, the
Agency would proceed to Step 3.
Step 3. What would be the operational
and economic consequences of a
decision to regulate a special waste
under Subtitle C?
If, based upon the previous two steps,
the Agency found that a waste presents
significant risk despite current
management practices and existing
regulatory controls and that Subtitle C
regulation would be effective and
appropriate in reducing those risks
without imposing unnecessary controls,
the Agency would then evaluate the
costs and impacts associated with
regulating this waste under Subtitle C
and, possibly, other regulatory
scenarios. Costs and impacts would be
evaluated in terms of the estimated
affected population of generators, the
ability of generators to pass on costs of
compliance to customers or suppliers,
the effect of regulation on domestic
energy supply and capacity, and the
effect of regulation on beneficial use of
the affected waste.
With cases in.which the Subtitle C
scenarios would impose widespread
and significant impacts on facilities,
reduce domestic capacity or supply,
and/or deter safe and beneficial use of
the waste, EPA might conclude that
regulation under Subtitle C is
inappropriate. However, EPA might
determine that regulation of the waste
under Subtitle C is warranted if, in the
Agency's judgement, the reduction in
risk that would result from such
regulation would justify the operational
and economic consequences to the
industry and the economy as a whole.
The Agency invited commenters to the
Notice to submit information regarding
cost data.
IV. Regulatory Determination for Four
Large-Volume Coal-Fired Utility Wastes
The following discussion presents
EPA's conclusions regarding the
regulatory status of large-volume coal-
fired utility wastes under RCRA. The
determination as to whether regulation1
of such wastes under Subtitle C is
warranted is based upon the February
1988 Report to Congress, comments on
the Report to Congress including
comments received at the public hearing
held in Denver on April 26,1988, the
information collected for the February
12,1988, Notice, and comments
received on the Notice.
Based on all of the available
.information, EPA has concluded that
regulation of the four large-volume
fossil-fuel combustion wastes as
hazardous waste under RCRA Subtitle C
is unwarranted. Below are the Agency's
responses to each step of the decision
methodology.
Step 1. Does the management of this
waste pose human health/
environmental problems? Might current
practices cause problems in the future?
The Agency has determined that the
answer to this question is yes.
Substep 1. Has the waste, as currently
managed, caused documented human
health impacts or environmental
damage?
Response: The Agency has
determined that the waste has caused
documented impacts, but at a very
limited number of sites.
In accordance with the methodology
described above, EPA first addressed
whether the management of this waste
currently poses human health/
environmental problems and whether
current practices could cause problems
in the future. In its examination of
potential/actual cases in which danger
to human health or the environment
could be attributed to the management
of fossil-fuel combustion wastes, the
RTC included information from several
studies that documented occasional
exceedences of primary and secondary
drinking water standards in
groundwater underlying fossil-fuel
waste management sites. To supplement
the RTC data, EPA conducted State file
reviews in States selected for their
geographical representation and large
coal-fired electricity generation
capacity. Overall, both efforts indicate
that the extent of actual damage cases/
environmental harm associated with
large volume FFC waste management
appears limited.
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Federal Register / VqL 58, No, 151 / Monday, August 9, 1993;/ Rules and Regulations 42473,
EPA used the "test of proof'
developed to support the Report to
Congress on Mineral Processing Wastes
to evaluate the potential damage cases.
As described in Chapter 2 of that report,
the test of proof requires that a case
satisfy at least one of three conditions:
scientific investigation concluding that
damages occurred, administrative ruling,
concluding that damages occurred, or
court decision or dut-of-court settlement
concluding that damages occurred. For
the six damage cases described below,
scientific investigation was the measure
of proof satisfied, since, the data, most
supported application of this measure.
In applying the test, EPA first
considered whether actual
documentation exists that shows thai
human health or environmental harm,
occurred (e.g., contaminated
ground water in a water supply well,
observed impacts on wildlife). Only a
limited number of large-volume FFC
waste management sites actually meet
this criterion and can be considered
proven damage cases. These cases
include the two sites identified in the
RTC, as well as four additional sites
identified during recent data collection
efforts. EPA notes; that of these six, cases,
only one case can: clearly be: attributed ,
to fly ash management alone. The
remaining: five cases are. associated with :
the co-management of the large-volume
wastes with other wastes. Because co-
management of large and low-volume
wastes is the predominant waste
management practice, limited
information exists on independently
managed large-volume wastes.
The RTC described a site that
involved A dike failure that caused an
accidental release from a fly ash
disposal lagoon to a river. This case
resulted^ in substantial damage to river
organisms; The other case described in
the RTC involved co-management. In
this case, a release occurred from a fly
ash and petroleum coke waste disposal
site that resulted in the contamination
of drinking water wells with selenium
and vanadium; This site is ranked on
the CERCLA (Superfund) National,
Priority List Site.
EPA's more recent data collection
efforts; resulted, in the identification of
four additional sites that are considered
proven cases of damage (see the
Supplemental Analysis of Potential
Risks to Human Health and the
Environment from Large-Volume Coal
Combustion Waste, found in Docket no>
F-93-FFCA-FFFFFJ^ Each case involves
co-management of wastes at older,
unlined waste management units. These
incidents involved ground water
. contamination and/or vegetative, '
damages due to releases from waste
management units.
In summary, there is minimal
documentation of impacts on drinking
water sources in the vicinity of coal-
fired utilities'. In addition, it is
important to note that the damage case
sites were chosen for study because of
known releases and cannot necessarily
be extrapolated to the general' universe.
Also, most releases have been from
unlined units at older sites that in many
States are now subject to more stringent
design and operating criteria.'
Furthermore, actual cases of harm to
human health or the environment may
be limited to a few sites, often with
other contributing, factors, including
additional pollutant sources attributed
to the co-management with other FFC
and non-FFC wastes. The review of such
cases of co-management will be reserved
for the "remaining waste" study. * .
The FFC waste damage case/
environmental data collected to date
indicate, therefore, that although the
extent appears limited, damage to the
environment has occurred. Although the
releases are often confined to the
vicinity of the units and have not
reached environmental/human
receptors, the potential for exposure
necessitates further analysis in Substep
2V which examines the potential risks
posed by these wastes.
Substep 2. Does EPA's analysis
indicate that the waste could pose:
significant risk to human health or the
environment at any sites that generate
coal combustion wastes, under either
current management practices or
plausible mismanagement scenarios?
Responses: Groundwater
contamination and surface water
contamination through groundwater
recharge are possible under some
plausible conditions (unlined units).
Available information on the ,
environmental conditions of the sites
indicates ecological and natural
resource damages are of most concern,,
because potential for human exposure is
limited.
The RTC containsconsiderable
information on the four large-volume
coal combustion wastes (fly ash, bottom
ash, slag, and flue gas desulfurization
(FGD) sludge). Information includes
waste characteristics and management
practices, environmental factors
affecting human exposure potential at
disposal sites, and evidence of •
ecological damage at coal combustion
7 The percentage of units required to meat more
stringent design and operating criteria' will increase
as older units reach capacity (assuming a typical
lifetime fo 15 years) and new units come on-line
(and are subject to these more stringent
requirements}., -,
sites. In addition, EPA collected -
supplemental •information from various
• EP& offices and, other Federal agencies,,
State agencies, and the. electric utility'
industry on waste characterization,
management, and potential impacts.. -;
This supplemental information
included groundwater monitoring data
for 43 coal combustion waste sites
collected from State regulatory agencies
and from EPA site visit reports- All data
used in this supplemental analysis are
available for public, inspection in the
docket No. F-93-FFGA-FFFFF. A
bibliography of the sources used in the
risk analysis is found in Appendix A of
the Supplemental Analysis of Potential
Risks to Human Health and the
Environment from Large-Volume Coal
Combustion Waste, also found in Pocket
no, F^-93HFFGA-EFFFF.
The first step; of the methodology was
to evaluate constituents of concern ;
(identified by waste characterization :
data) using a risk screen. A risk screen
analysis is a process which applies a
conservative and simplified ' '
methodology to the constituents.and .
pathways to determine if they are of
concern. The risk screen compared
waste characterization data with
screening-level criteria1. "The screening;
criteria were developed to identify : :
wastes, constituents, and pathways
requiring further analysis; thai is, wastes
captured by the screen mayor may not
be; of concern. Criteria for 23
constituents: (primarily metals)were
developed for groundwater, surface ,
water, ingestion, and inhalation
exposure pathways using a methodology
similar to that used in the mineral
processing regulatory determination. (In;
the, cases where the Agency regulatory
levels had changed since the mineral
processing RTC, the screening criteria
were also updated.) •- ;
Groundwater exposure criteria were
developed using the MCLs set by the ,
Agency to protect drinking, water. If no;
primary MCL had been established for
a particular parameter, then a health-
based level (HBL) was calculated using,
Agency cancer slope factors or non-
cancer reference doses (RfDs) from
IRIS.* In instances where the calculated
'HBL was: less than corresponding MCL,
both values were considered in the
screening. - , •
Screening; criteria based on primary
MCLs were derived! by multiplying the
MCL by a factor of 10 to simulate
scenarios where only limited dilution of
waste? leachate occurs prior to exposure,
HBLs were derived: from IRIS» drinking
»U.S. Environmental Protection Agency. . •
Integrated Rist Information System (IRIS). (IRIS, ' •
November 1992 update). ;
" '' '' ''
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'42474 Federal Register / Vol. 58, No. 151 7 Monday, August 9, 1993 / Rules and Regulations
water or oral cancer slope factors (CSFs)
representing a IxlO-s lifetime cancer
risk, or RfDs. Calculation of the HBLs
relied on the following conservative
assumptions; the maximally exposed 70
kg individual drinking 2 liters of water
per day, 365 days per year, for a lifetime
duration of 70 years. (The 70-year
exposure duration was chosen to
maintain comparability with the MCLs;
this approach is consistent with that
taken in the mineral processing
regulatory determination.) These
assumptions yield the following general
equations:
HBLcsr-(n)g/l) - (lxlO-')(70 y){70 kg)/{(CSF
(mg/kg/d)-«X2l/d)(70y)}
HBum (rng/1) - (RED rng/kg/day)(70 kg)/(2 V
day)
As with the MCL-based criteria, the
HBLs were multiplied by a factor of 10
to simulate a scenario where only
limited dilution of waste leacnate
occurs prior to exposure. Groundwater
exposure criteria were compared with
waste EP Toxlcity and TCLP analysis
results for each of the four waste steams.
The surface water exposure criteria
were selected to represent potential
harm to aquatic organisms exposed to
surface water releases of wastes or waste
leachate, The criteria were derived by
multiplying the freshwater chronic
Ambient Water Quality Criteria (AWQC)
for non-human effects by a factor of 100
to simulate a scenario where only
limited dilution occurs. Surface water
exposure criteria were compared with
waste EP Toxicity and TCLP analysis
results for the four waste streams.
The ingestion screening criteria were
derived from IRIS oral RfDs and oral
CSFs, assuming incidental ingestion of
solid waste materials. Exposure
assumptions are an ingestion rate of 200
mg/day from ages 1 to 6, and 100 mg/
day from ages 7 to 31 (resulting in an
average of 0.114 g soil/day), an adult
receptor weight of 70 kg and an
exposure of 350 days/year for 30 years.
For CSF-derived values, a life-time
.averaging 70 years was assumed. These
assumptions were then used to calculate
the concentration of a constituent in a
waste that would result in an exposure
equivalent to the RID or the
concentration corresponding to a
lifetime cancer risk of IxlO-s. The
equations for RID- and CSF-based
criteria are shown below.
Criterion.^) (mg/g)« RfD (mg/kg/d) {(70
kg)(365 d/y)(30 y)}/ {(350 d/y)(30
y){0.114 g soil/d)}
Criterionejsj (mg/g)« {10-»/CSF (mg/kg/
dH}(70 kg](365 d/y)(70 y)}/ {(350 d/
y){30yX0.1l4gsoil/d)}
No dilution factor was employed in
deriving the criteria for solid samples.
The exposure pathway assumes
exposure to participate whole waste
material. Ingestion exposure criteria
were compared with waste total •
constituent analysis results for the four
.•waste steams.
The exposure assumptions used in
deriving inhalation exposure criteria
include: 50 ug/m3 airborne dust
concentration;^ adult inhalation
volume of 20 m3/d; 70 kg body weight;
exposure frequency of350 days per
year; exposure duration of 30 years; and,
for CSF-derived values, 70 year lifespan
(or averaging time) and 1x10-* risk of
cancer. Note that 50 ug/m3x20 mVd
results in a soil exposure rate of 1 mg/ -
d. The equations used to derive the
criteria from both inhalation RfDs and
inhalation CSFs are shown below:
g/g) = RfD (mg/kg/d) {(70
kg)(365 d/y)(30 y)}/ {(350 d/y)(30
y)(0.001 g soil/d)}
CriteriacsH (mg/g) = {IxlO-'/CSF (mg/kg/d)-'}
{(70 kg)(36S d/y)(70 y)}/ {(350 d/y)(30
yKO.OOl g soil/d)}
Again, no dilution factor was
employed in deriving the criteria for
solid samples. The exposure pathway
assumes exposure to particulate whole
waste material. Inhalation exposure
criteria were compared with waste total
constituent analysis results for the four
waste steams.
The screening criteria described above
were then compared to EP, TCLP, and
total constituent data from the RTC and
subsequent data collection efforts. For
all waste constituents that exceeded a
screening-level criterion at more than 10
percent of the sites sampled, or
exceeded the criteria by more than a
factor of 10, further analysis was
conducted. A summary of screening
criteria exceedences, reported by waste
type and by exposure pathway, can be
found in Appendix C of the
Supplemental Analysis of Potential
Risks to Human Health and the
Environment from Large- Volume Coal
Combustion Waste.
The 'results of the risk screening
suggest that of the large-volume wastes,
fly ash and FGD sludge are of most
concern. The risk screen also identified
groundwater, surface water, and
inhalation as exposure pathways
needing further analysis. The
constituents needing further analysis
included arsenic, cadmium, chromium,
lead, mercury, nickel, Ph, selenium, and
silver.,
The Agency then evaluated the
release, transport, and exposure
potential of those constituents, wastes,
and pathways for which the risk screen
1050 Jig/m3 is the National Ambient Air Quality
Standard for annual exposure to participates.
indicated that further analysis was
necessary. When available, monitoring
data were used to determine the
potential for human and environmental
exposure. In'other cases, information on
the physical setting of coal combustion
waste sites and'on the waste
management practices was used to
evaluate exposure potential. In the case
of the inhalation pathway, the potential
•for human health risk was evaluated
using an atmospheric fate and transport
model. For the inhalation pathway, the
potential for human health" risk, when
evaluated using an atmospheric fate and
transport model, was found to be
negligible. For more information on the
air pathway analysis, please consult the
Supplemental Analysis of Potential
Risks to Human Health and the
Environment from Large-Volume Coal
Combustion Waste. Further analyses of
the groundwater and surface water
pathway are summarized below.
Groundwater monitoring data were
used in both the groundwater and.
surface water exposure pathway
analyses. A summary table of the
groundwater monitoring sites is in
Appendix D of the Supplemental
Analysis of Potential Risks to Human
Health and the Environment from Large-
Volume Coal Combustion Waste found
in the docket. When interpreting the
groundwater monitoring data, the
Agency took several factors into
account.
First, many of the sites may have co-
managed their coal combustion wastes
with other wastes, such as boiler
cleaning solution or pyrites. The extent
to which these other wastes may have
contributed to groundwater
contamination could not be
conclusively determined, because it was
difficult to assess in many cases
whether co-management had occurred
and without this information, it was not
possible to separate the effects of the
large-volume.wastes from the other
wastes. However, at least two site
operators asserted that they believed
that co-managed wastes, and not the
large-volume wastes, were the cause of
groundwater contamination. The
Agency took the presence of co-
managed wastes into account when
evaluating the risk from the large-
volume coal combustion wastes.
Second, some of the sites have other
possible sources of contamination
nearby. To the extent that they can be
. determined, these sources are noted in
the summary table referenced above.
Finally, in the case of some
contaminants (e.g., iron), naturally
occurring levels may be quite high.
- Again, to the extent that naturally
occurring constituents can be
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Federal Register / TM. S8» No;, 151 1 Mcrada^ August 9, 1993; / Rufes and Rbgulaltons 42/475
determined to be adding to •
downgradient concentrations, this is
noted in the summary table. '
With these considerations in mind,
the Agency determined that available
data from coal combustion waste.
landfills, and surface impoundments
demonstrated the existence of potential
for human, exposure to groundwater .
contamination,; because coal combustion
waste constituents identified in the risk
screen as needing-further study were
found to be leaching onsite in excess of
the primary MCLs. Subsequent analyses
of coal, combustion waste sites suggest,
however; that potential for actual
human exposure is very limited.
For example, nine sites of the fbrty-
,nihe sites with groundwater monitoring
data had contaminants above the MCL
that appeared to stem from, coal . '
combustion units. (Another ten sites
had upgradient concentrations equal to,
downgradient concentrations, other
possible sources of groundwater
contamination, or (in two cases! a Iac^
of upgradrent information, preventing
any conclusions about the effects of the
coal combustion units on groundwater
contemihation.} Constituents with
exceedences include arsenic, barium,
cadmium, chromium, fluoride, lead,
mercury, nickel, and selenium. Of the
nine sites,, none were completely lined,,
although one site had a clay-lined
disposal unit with: air under-draih
emptying into a series of unlined ponds.
All nine sites have-older {pre-1975)
units, four consisting of surface
impoundments, four consisting of
landfills, and one with both types of -
units. Fly ash was the principal waste
disposed offer all units. Four sites of the
nine alscr are* known to have accepted
co-managed' wastes (pyrites;, boiler
cleaning wastes, demineralizer
regenerant, oil ash, etc.), and the others
may have as well.
Potential fbrliuman exposure to
groundwater contaminants from coal
combustion wastes is limited because of
the location of most coal combustion
sites. Based on a random study (found
in the RTC) of one hundred sites, only
29: percent of the sites have any
population withhrl kilometer, and only
3* percent of the sites have public
drinking water systems within R
kilometers. Although infiltration and
transportation of contaminants in
groundwater varies with site- or
regional-specific factors (such as depth
to groundwater, hydraulic conductivityt
_ soil type, and net recharge), exposure to
coal combustion waste groundwater
contaminants 5 kilometers from the
source of contamination is not expected
to occur., Of the public: drinking water
systems within 5 kilometers of coal
combustion: waste sites; just, under half
(47 percent); are expected to treat the
groundwater for hardness' (i.e., these1
systems have groundwater with over
240 ppmCaCOs),, which, would tend to
remove co-contaminant metals aswell.
Coal combustion units also tend to be
near surface water bodies. The same)
RTC study revealed, that 58 percent of
the.sitesare within 500. meters of.as '
surface water body; The volume and
flow rate of surface water would terid to
dilute and divert the contaminant
plume.
In addition, groundwater
contamination appears to be attributable
to pastmanagementpractices. As the
Agency's groundwajerr monitoring data
outlines: above, all. of the nine: sites with
a clear indication of groundwater
contamination are older (pre-1975]),
unlined units. (In contrast; of the 13>
lined sites, only one had exceedences of
an MCL, and that site had equal
concentrations upgradient and
'downgradient J
/Finally,: some of the groundwater
contamination may be attributable to co-
management with, other wastes, such as
pyrites* boilercleaningwasteland
demineralizer, regenerant. Because of the
prevalence of co-management (several
public comments; on the ETC reported
thatthepredominant industrypractice
is to co-dispose of low-volume wastes in
ash or flue gas emission control waste
ponds).thelarge-volume waste may not
"be the sole contributor to; the
groundwater contamination. "Ewo of the;
nine sites report that co-management is
the cause of the contamination.
In conclusion, hazardous constituents
in coal combustion waste (particularly
in fly ash and flue gas emission control,
waste) have the potential to leach into
groundwater under, certainconditions* '
Contaminants of concerns include
arsenic,cadmium, chromium, lead,,.
mercury, and selenium. Available data
suggest* however, that contamination
stems from older,/urilined units :
representing past practices, and that the
"units are not typically located near
populations and drinking water
systems. In addition, the sites within 5.
kilometers of public drinking water
systems, abouthalf have groundwater
wjth over 240 ppm C&Coy and are
therefore expected to treat the water for
hardness, thus, removing; co,-
contaminant metals as well.
Furthermore, at least some of the
groundwater contamination is
attributable to other wastes managed
with the large-volume coal combustion.
wastes; Thus^ potential for human
exposure solely; from the large-volume
coal combustion waste, front current
management practices is limited.
An examination of the surface water
pathway reveals that, although direct
discharge of untreated coal combustion
waste tosurfacewateriffnot likely
because of Clean Water Act controls, a
few of the coal combustion waste
constituents have the potential in some
instances, to affect nearby vegetation
and aquatic organisms by migration
through shallow groundwater to nearby'
surface waters} This7 was observed'at one
site where migratibnf of borore to a;
nearby wetland was, determined by the;
State to be the cause of vegetative
damage. In many cases, natural
attenuation processes" are expected to;
dilute the contaminants below levels' of
concern;For example, if'contaminants
reach surface waters, the volume of
surface water and its high flow rate
could dilute the contaminants; For those
sites whosenearby water bodies may
have a low flow rate fe-g;, lakes,,
swamps; or marshes), however, coaE
combustion waste may cause local
environmental damages, as was
observed at the above site;.
Even when contaminated
groundwater does not affect human
health, and the environment,, it may be
considered to have caused impacts that
limit future use of that groundwater. In,
particular,, available: data suggest that
the groundwater at a number of coal
combustion, waste sites is contaminated
,above secondary MCLs. (SMCLs) by such
secondary parameters as iron,
manganese, sulfate, and total dissolved
solids,;although these effects may be
localized through dilution arid
attenuation. The SMCLs are guidelines
generally setto be protective of such
aesthetic considerations as taste,; odor,;
potentfal to stain: laundry, and human:
cosmetic effects such as tooth and skin
•staining,, ' ,--
In addition to being disposed of in
landfills and surface impoundments,;
coal combustion ash is often
beneficially used both onsite and offsite.
EPA continues:taencourage flie .. .-:-
beneficial use of doal combustion
wastes. Because most offsite
applications tend to immobilize the coal
combustion waste (e.g., fly ash used to
make concrete),, adverse impacts; appear
to be unlikely; HbweveriJf fly ash is;
apph" ed directly to agricultural; soil,,
there is some concern; with, metals:- ,
uptakeby food crops and cattle feed. In
addition, boron: in the; coal ash is; readily,
mobilized and has; a phytotoxic effect on
plants. Although coal ash Is? not •
frequently used in agriculture,; any
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42476
Federal Register / Vol. 58, No. 151 / Monday, August 9, 1993 / Rules and Regulations
agricultural use of coal combustion
•waste should be carefully evaluated."
Substep 3; Does the waste exhibit any
of the characteristics of hazardous
waste?
Response: The Agency has
determined that these wastes exhibit the
characteristics of hazardous waste
infrequently, from 0 to 7 percent of the
samples depending on waste type.
The RTC concludes that although coal
combustion waste may leach
contaminants (arsenic, cadmium,
chromium, lead, and mercury) above
toxidty characteristic regulatory levels,
such exceedences are infrequent and the
average concentrations of constituents
are below characteristically toxic levels.
A full bibliography of the sources of EP
and TCLP data and a summary of the
results are given in Appendices A and
B of the Supplemental Analysis of
Potential Risks to Human Health and
the Environment from Large-Volume
Coal Combustion Waste.
The results of Step 1 of the analysis
indicate that the wastes rarely exhibit
any characteristics of hazardous waste
and the waste pose very limited risk to
human health or the environment under
certain scenarios, such as unlined units
sited over shallow groundwater with
nearby drinking water wells.
Furthermore, since most releases have
occurred at unlined older sites, EPA
recognized that a review of current
waste management practices and
regulatory control governing these
practices was appropriate as outlined in
Step 2 of the methodology, which
assesses the need for more stringent
regulation.
Step 2: Is more stringent regulation
necessary or desirable? The Agency has
determined that the answer is no. EPA
regulation is not necessary or desirable.
In evaluating the need for more
stringent controls to address the
potential risks associated with the
management of these wastes, EPA first
evaluated the adequacy of current
industry waste management practices in
limiting contaminant release and
associated risk. The Agency then
viewed the adequacy of current State
and Federal regulatory controls
addressing these wastes. For the
purposes of this analysis, EPA
supplemented the data supplied in the
RTC with site visits, a 1992 EPA study
under which the Agency obtained and
reviewed State regulations applicable to
FFC waste management, the Department
of Energy's 1991 report entitled Coal
» QunctociztOon of Coal Creek Station Fly Ash
for Utilization Potential, Energy and Environmental
fU*»tca C«ptBr,Pabtmiry 1993 (SM Docket No. F-
93-FFCA-FFFFF).
Combustion Waste Disposal: Update of
State Regulations and Cost Data,
dialogue with industry and State
representatives, the Electric Power
Research Institute's Facility Design and
Installation Manual (1991), State file
searches, and literature reviews.
Substep 1. Are current practices
adequate to limit contaminant release
and associated risk?
Response: The Agency has
determined that industry practices are
moving toward increased use of control
measures (liners, covers, etc.) and
groundwater monitoring.
The Agency's data on current
practices indicate that industry is
moving toward an increased use of
control measures (e.g., liners, covers)
and groundwater monitoring. For
example, the RTC noted that before
1975, less than 20 percent of units
(surface impoundments and landfills) in
the United States for which data were
available had installed some form of
liner. More recent data (EEI's Power
Statistics Database, 1989) suggest that 13
to 29 percent of surface impoundments
for which data are available, have some
form of liner and that 41 to 43 percent
of landfills have some form of liner. As
the damage case and groundwater
monitoring information suggests, most
of the releases have occurred at older,
unlined units. EPA has observed during
site visits that newer units are generally
lined. Furthermore, most newer utility
waste management facilities have
groundwater monitoring systems, and
many also have leachate collection
systems. Despite the positive trends in
management of FFC wastes, some of
these units may be sited with
inadequate controls. Therefore, in
addition to viewing industry
management practices, EPA collected
and evaluated information on the extent
of current State and Federal regulation
of coal-fired utility waste management.
Substep 2. Are current Federal and
State regulatory controls adequate to
address the management of the waste?
Response: Effluent limitations in the
Clean Water Act regulations for steam
electric power plants under 40 CFR part
423 require no discharge from new fly
ash ponds. State programs are generally
adequate and are improving, with most
State's now requiring permits and
minimum design and operating criteria
that would address likely risks.
Additionally, Federal authorities exist
to address site-specific problems posing
threats to human health and the
environment under RCRA Section 7003
and CERCLA Sections 104 and 106.
The RTC included information on
coal-fired electric utility waste
regulation in all 50 States. In updating
this information, EPA conducted a
review of States that were selected
according to the high levels of ash
generated in those States. This .approach
resulted in a study universe of 17 States
that generate approximately 70 percent
of all coal ash in the United States.
The data show that States have
generally implemented more stringent
regulations for FFC waste since 1983
(when the State regulation review was
conducted for the RTC). Under
developing State industrial solid waste
management programs, coal-fired
utilities are more frequently being
required to meet waste testing
standards, and waste management units
often must comply with design and
operating requirements (e.g., liners and
groundwater monitoring standards).
Of the 17 States for which EPA
updated the RTC data, 14 regulate coal-
fired utility wastes as solid wastes,
explicitly exempting them from
hazardous waste regulation;*2 16 States
require offsite FFC waste management ,
units to have some type of operating
permit, with design and operating
criteria varying by State; 12 have
mandatory liner requirements, while
three States provide for discretionary
authority to impose liner requirements
on a site-specific basis; 12 impose
mandatory groundwater monitoring
requirements on FFC waste disposal
sites; and 16 impose final cover
requirements, hi addition, some States
have been working to reduce the threat
of groundwater and surface water
contamination, by discouraging the use
of wet management in ponds as a
disposal practice (through permitting
requirements and location restrictions).
On the Federal level, National Pollutant
Discharge Elimination System permits ,
under the Clean Water Act regulate all
direct discharges to surface water.
Effluent limitations under 40 CFR part
423 govern steam electric power
generating point sources and require no
(zero) discharge to surface waters from
new source fly ash transport waters (40
CFR 423.15(g)). '
Considering industry's trend toward
more protective waste management
practices, the fact that State regulatory ,
programs are generally adequate, and
because Federal authorities exist that
can address these wastes, EPA has
concluded that current management
practices and regulatory controls are
adequate for managing the four large-
volume FFC wastes.
"Of the remaining three States, two States
establish requirements based on waste
characteristics and one exempts these wastes bom
their solid and hazardous waste management
program. ,
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Federal Register / VpL 58, No; 151 7 Monday, August 9, 1993 /Rules and Regulations' 42477
Substep 3. Would Subtitle C
effectively address the problems , -
associated with the waste without
imposing significant unnecessary
controls?
Response: The Agency has
determined that it is unlikely that
Subtitle C would effectively address the
problems associated with the four large-
volume fossil-fuel combustion wastes
without imposing unnecessary controls.
After reviewing industry practices
, and current State and Federal...
regulation, EPA reviewed the alternative
scenario of regulating the four large-
volume FFC wastes under Subtitle C.
First, it was recognized that coal
combustion wastes rarely exceed the
RCRA characteristics for hazardous
waste, and therefore, that most coal
" combustion wastes would not be subject
to Subtitle C controls unless they were
listed as hazardous wastes.
Furthermore, it was noted that even if ,
these wastes were listed as hazardous, ,
and therefore, regulated under Subtitle ~
C, such an approach would be
inappropriate for these wastes. A
Subtitle C system would require coal
combustion units to obtain a Subtitle C
permit (which would unnecessarily
duplicate existing State requirements)
and would establish a series of waste
unit design and operating requirements
for these wastes, which would generally
be in excess of requirements to protect
human health and the environment. For
example, if such wastes were placed in
the Subtitle C universe, all ash disposal
units would be required to meet specific
liner and monitoring requirements.
Since FFC sites vary widely in terms of
topographical, geological,
climatological, and hydrological
characteristics (e.g., depth to --
groundwater, annual .rainfall, distance
to drinking water sources, soil type) and
the wastes' potential to leach into the
groundwater and travel to exposure
points is linked to such factors, it is
more appropriate for individual States
to have flie flexibility necessary to tailor
• specific controls to the site or region
specific risks posed by these wastes.
EPA also reviewed the comments
received in response to the 1988 RTG
and the Notice. Comments received on .
the RTC showed unanimous support for
EPA's initial recommendation that
large-volume combustion wastes do not
warrant regulation under RCRA Subtitle
C. Specifically, the commenters felt that
current Subtitle D criteria, together with
existing State regulations, have proved
' adequate to protect human health and ;
the environment. Furthermore, of the,
respondents to the Notice who
addressed the recommendation that
large-volume combustion wastes do not
warrant regulation under Subtitle C, all
agreed that the supplemental data
support this recommendation.
For these reasons, EPA concludes that
Subtitle C is inappropriate to address
the problems associated with these
wastes and that the site or region
specific State approach is appropriate
for addressing the limited human health
and environmental risks involved with
the disposal df FFC wastes. The Agency
encourages States to continue to
develop and implement site-specific
approaches to these wastes. EPA
believes that industry and the States
should continue to .review the
appropriate management of these
wastes. EPA will also consider these
wastes during the Agency's ongoing
assessment of industrial non-hazardous
wastes under RCRA Subtitle D. Should
the characteristics of the waste streams
change as a result of implementation of
any provisions of the Clean Air Art as
amended in 1990, the Agency .may
choose to reexamine the exemption.
Step 3. What would be the operational
and economic consequences of a
decision to regulate a special waste
under Subtitle C?
Although the analysis never reached
this point, EPA's preliminary :
examination of potential costs under
Subtitle C indicates that'annual costs of
full Subtitle C controls Would range
between $100 and $500 million per
year. This assumes that these wastes
Would be listed as hazardous in RCRA
part 261, subpart D. However, if these
wastes were not listed, the wastes.
would often not be subject to Subtitle C,
since they rarely test characteristically
hazardous pursuant to part 261, subpart
C. Subtitle C controls include ,.
groundwater monitoring, liners,
leachate collection, closure/covers, dust
control, financial assurance, location
restrictions, and corrective action.
V. Regulatory Flexibility Act :
The Regulatory Flexibility Act (RFA)
of 1980 (Pub.L. 96-354), requires
FederaLregulatory agencies to consider..
the impact of rulemaking on "small
entities." If a rulemaking will have a
significant impart on small entities,
agencies must consider regulatory
alternatives that minimize economic
impart. :
Today's decision'does not affect any
small entity. Rather, it continues to
exempt the four large-volume wastes
from coal-fired electric utilities from
regulation as hazardous wastes.
Accordingly, this action will not add .
any economic burdens to any affected _
entities, small or large. Therefore, a
regulatory flexibility analysis is not
required. Pursuant to SectionB05(b) of
the RFA; 5" UJSLC.' 605(b), the
Administrator certifies that this rule
Will not have a significant impact on
small entities.
VI. Regulatory Determination pocket
Documents related to this regulatory -
determination are available for '
inspection at the docket.
The EPA RCRA docket is located at
the following address: United States
Environmental Protection Agency; EPA
RCRA Docket, room M2427, 401 M
Street SW., Washington, DC 20460.
The docket is open from 9 a.m. to 4
p.m., Monday through Friday,' except for
Federal holidays. The public must make .
an appointment to review docket '•'.>••
materials. Call the docket clerk at (202)
260-9327 to make an appointment.
Dated: August 2, 1993. ,
Carol M. Browner, • •
Administrator. .;• " ,
Appendix A — Analysis of and
Responses to Public Comments on the
Report to Congress
The 1988 Report to Congress: Wastes
from the Combustion of Coal by Electric
Utility Power Plants cOncluded-with
three recommendations. Comments on
the RTC were largely organized in ;•'--
response to those recommendations.
The summarized comments and EPA's
response to those comments follow each
recommendation, printed in bold below.
(1) EPA has concluded that coal
combustion waste streams generally do
not exhibit hazardous characteristics
under current RCRA regulations. EPA
does not intend to regulate under
Subtitle C fly ash, bottom ash, boiler
slag, arid flue gas emission control
wastes.
All respondents agreed with and
supported the RTC's first
recommendation that high-volume
combustion wastes do not warrant
regulation under Subtitle C. They
concluded-that current Subtitle D
criteria, together with existing State
regulations, have proved adequate to >
protect human health arid the '•.-.. ,
environment.
Several commenters claimed that the
EP toxipity test is not a valid indication
of the hazards associated with utility
wastes since the test was designed to
mimic conditions in acidic municipal
landfills rather than homogeneous
monbfills used by electric utilities. They
claim, therefore, that data from the EP
test significantly overstate potential
" ' ' '
. .
As noted in the RTC and by several
commenters, the Bevill Exemption
requires EPA to consider eight factors
(Section 8002(n)) in detenr ining ',.
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42478 Federal Register / Vol. 58, No. 151 / Monday," August 9, 1993 /Rules and Regulations
whether hazardous waste regulation is
warranted for fossil-fuel combustion
wastes. To that end, EPA has developed
the methodology identified in the
Notice that takes into account all of
these factors. While waste
characterization data, including the
results of EP toxicity testing as well as
other leaching procedures (TCLP,
ASTM, and batch/column) are
considered in the decision, they are not
the sola basis for determining whether
to regulate FFC wastes as hazardous.
The methodology specifically focuses
on the risks posed by FFC wastes as
they are actually managed.
EPA acknowledges that EP toxicity
test results may not always represent the
leaching potential of hazardous
constituents from FFC wastes. However,
some ash is (or could be) managed in
offsite Subtitle D landfills. Furthermore,
EPA has found significant variability in
the leaching characteristics of FFC
wastes, depending on the fossil-fuel
source and boiler operating conditions.
Therefore, EPA believes that
consideration of EP toxicity data, in
conjunction with the results of other
leaching studies and data on the actual
environmental impacts of waste
management practices, is appropriate.
Finally, EPA's data show that EP
toxicity test results for the four large-
volume wastes are not inconsistent with
leach tests conducted using ASTM,
batch/column, and TCLP methods (see
February, 1988 RTC).
(2) EPA is concerned that several
other wastes from coal-fired utilities
may exhibit the hazardous
characteristics of corrosivity or EP
toxicity and merit regulation under
Subtitle C. EPA intends to consider
whether these waste streams should be
regulated under Subtitle C of RCRA
based on further study and information
obtained during the public comment
period.
Nineteen of the twenty-two
respondents commented on the RTC's
second recommendation to study low-
volume wastes further and consider
regulating these wastes under RCRA
Subtitle C. All 19 respondents disagreed
with the recommendation to regulate
any low-volume wastes under Subtitle
C.
Several commenters claimed that
insufficient data existed to support a
Regulatory Determination for low-
volume wastes. EPA concurs with these
comments. The Agency intends to study
co-managed low-volume wastes further
to obtain sufficient data to make a
Regulatory Determination. Low-volume
wastes managed independently are
outside the scope of the Bevill
Exemption.
Many comments maintained that
Subtitle C regulation is not warranted
for low-volume wastes co-managed with
large-volume coal combustion wastes.
Some commenters claimed that .the
predominant industry practice is to co-
dispose of low-volume wastes in ash or
FGD sludge ponds (several commenters
referenced the 1985 Radian study and
the 1982 Envirosphere report). Such co-
management was claimed to be
practical, effective, and environmentally
sound. The report acknowledges that
this practice may reduce the potential
hazard of low-volume wastes, by
neutralization or dilution. Commenters
emphasized that no adverse
environmental impacts from the co-
disposal of high-volume and low-
volume wastes have been shown in
studies by the electric utility industry
and EPA and that none were cited in the
RTC.
EPA acknowledges that the RTC
contained very limited information on
the extent and potential environmental
impacts of co-management of low-
volume wastes with ash, slag, and FGD
wastes. In fact, although the Agency has
information verifying that co-
management does occur, there is limited
information clarifying the amounts and
types of co-management. Indeed, this
was the reason EPA reached no tentative
conclusions regarding these practices.
Comprehensive studies were available
for fewer than five of the hundreds of
existing co-management sites. EPA's
efforts to compile more recent data
continue to show limited information
on the effects of co-management.
However, some information suggests
that at several large-volume waste
management sites where groundwater
impacts have been detected (see data in
the RCRA Docket), the operators have
suggested that the cause of the
contamination is co-management with
low-volume wastes. Of specific concern
are pyrites and chemical boiler cleaning
wastes. Further, the Agency has
observed that the general trend in the
industry is to segregate certain low-
volume wastes (i.e., pyrites, boiler
cleaning wastes, and demineralizer
regenerant) from ash, slag, and FGD
sludge.
The Agency believes that additional
data collection for the low-volume
wastes co-managed with the large-
volume wastes described in the report is
required and is deferring a final
Regulatory Determination for co-
managed wastes, pending completion of
further studies. Co-managed low-
volume wastes remain exempt from
hazardous waste regulation, however,
until such a determination is made; As
required under the Bevill Exemption,
the Agency emphasizes that the
decision'on remaining wastes will be
based on all Section 8002(n) study
factors, not on waste characterization
data alone.
As discussed in the scope section of
this determination, the Agency does not
consider process waters (e.g., non-
contact cooling water and low-pressure
service water) used in ash handling or
FGD systems to be wastes; Also, the
continuous use of these process waters
as feedwater for emission control
systems or for ash transport generally
will not increase the environmental
risks associated with the wastes relative
to the risks derived from utilization of
fresh water for the same purposes.
Discouraging such practices may lead to
an increased usage of fresh water for the
same purposes, thereby increasing the
total volume of water exposed to the
large-volume wastes as well as the total
volume of waste generated. The Agency
believes that this would be an
undesirable outcome of today's action.
For these reasons, the Agency does not
consider the practice of using these non-
contact process waters in ash sluicing
systems or as makeup water for FGD
systems to constitute co-management.
One commenter thought that the
limitations applied to discharges of
pollutants from ash disposal facilities
under the National Pollutant Discharge
Elimination System adequately protect
the environment and that additional
regulations would be redundant.
The Agency does, not concur with the
commenter that meeting NPDES permit
limits at surface water discharge points
alone is necessarily adequate to ensure
groundwater protection. For example,
FFC waste management units may not
have surface water-discharges, and,
therefore, might not be required to have
NPDES permits. Even if NPDES-
permitted, these units may generate
leachate that could affect underlying
groundwater. Although some States may
use Federal NPDES permit requirements
to protect groundwater resources, the
Clean Water Act and the NPDES
program generally focus on protecting
surface water quality.
One commenter referred to a 1976
study conducted by an electric utility
company in which both bench
(laboratory) and field tests were
conducted. The purpose of the study
was to derr onstrate to EPA, for purposes
of meeting the effluent limitations of a
NPDES permit, that co-disposal of two
boiler cleaning wastes with ash in ash
ponds provided treatment equivalent to
that available from a dedicated waste
treatment facility. The bench tests
showed 99 percent treatment for metals.
The commenter maintained that the
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42479
few-volume wastes were effectively
treated without any increase in risk
from the high-volume wastes (and the
waste management unit) into which
they were added.
SPA acknowledges that the referenced
study does demonstrate that a level of
Ph.adjustment can be achieved over a
period of time so that NPDES permit
limits can be met. However, the study
does not address protection of the
grouridwater underlying the
impoundment. Further, the study
provides data for only two types of
boiler cleaning solution mixed with ash
from a single plant. Because of the
variability in types of boiler cleaning
solutions and ash characteristics and the
relative paucity of data on low-volume
wastes and co-management in general
(and the consequent uncertainty related
to the environmental impacts of co-
management), the Agency believes that
further study is required..
Several commenters claimed that EPA
appeared to have selectively included
data from EP test results for boiler
cleaning wastes and other low-volume
waste streams in the RTC (Exhibits 5-
5 and 5-6). Exhibit 5-5 (talcen from the
! 1985 Radian study) presents test results
for two treated and three untreated -. ;
boiler cleaning waste streams. The
commenters noted that the Radian study
sets forth data for four .untreated and _--••
four treated waste streams. None of the
results for the streams omitted in the
report exceeds the EP toxicity limits, to
the extent that only the untreated waste
streams for which ah exceedence was
shown are included in the report, the
qommenters maintained that
observations on those results are
overstated. ..
In addition, the commenters felt that
the report was similarly selective in "
reporting "EP Toxicity Test Results for
Liquid Low-Volume Wastes" (taken
from the 1987 Radian study) shown in
Exhibit 5^B. Where the original data
included 17 boiler cleaning wastes and
7 waterside rinse tests, the report
included only 10 boiler cleaning wastes
and 3 waterside wastes in Exhibit 5-6.
Additionally, by omitting the "less
than" sign next to many of the values,
there was concern that the report gives
a false impression that a reading is a
positive value, when actually the value
was below the detection limit. It was
. also pointed out that this omission
factors into the calculation of the
geometric mean for the samples.
EPA acknowledges the comments. .
The intent was not to overstate or
•overemphasize the frequency or
magnitude of observed concentrations of
constituents in leachate. Rather, EPA
was attempting simply to present data
that illustrated the concentrations that
could be observed, hi its Regulatory
Determination on the wastes, EPA
considered all data (including non-
detects), rather than only selected
observations. . ;
One commenter noted that the boiler
cleaning wastewaters from the initial
acid wash stage and subsequent rinses
should not be considered separately
because they are typically combined
and managed together as a single waste
stream. The commenter noted that the
report shows these fluids as separate
waste streams and includes data for
each stream in Exhibit 5-6. If the data
were collected on these fluids as a
'unified stream, the commenter claimed
that the resulting boiler cleaning waste
would likely not, exceed any of the
current limits for EP toxicity.
The commenter went on to say that
even if certain boiler cleaning wastes
may, in certain circumstances, test
hazardous as generated, this fact should
not trigger Subtitle C regulation. The
commenter emphasized that co-
disposed boiler cleaning waste does not
present a hazard and that this critical
fact is^acknowledged in the RTC.
The Agency has found that some
utilities do manage the wastes generated
during different stages of the waterside
boiler tube cleaning operations
separately, at least for some period of
time. Therefore, the Agency believes'
that it is appropriate to consider waste
characterization data for the distinct
streams (as well as for combined
streams). As noted previously, the
Agency does not believe that the RTC
and other currently available ''.-'.-
information provide sufficient data to
complete a Regulatory Determination for
boiler chemical cleaning wastes, co-
managed with large-volume wastes at
this time.
One commenter cited data on 17 .
untreated waterside boiler cleaning
wastes (whfch include ethylene-
diamine-triacetic acid (EDTA),
hydroxyacetic-fonnic acid, and
ammoniated bromate and hydrochloric
acid). Only one sample (or 5.8 per cent)
showed an exceedence of the EP limits,
for total lead with a concentration of
6.67 mg/1. The average lead
concentration for all 17 samples was
1.43 mg/1 with a median value of 0.5
mg/1. None of the 17 waterside boiler
cleaning waste samples was corrosive.
. Another, commenter cited company -
data for 69 samples of waterside boiler;
cleaning wastes (which include EDTA,
hydroxyacetic-fonnic acid, and citric
acid). Among these samples, only 15 (or
22 percent) showed exceedences of the
EP limits. Thirteen of these exceedences
were for total chromium and two were
for total lead. The average total .,
chromium concentration for all 69
samples was 3.41 mg/1 with a median
Value of 2.08 mg/1. The average total
lead concentration was 1.23 mg/1 xwith
a median value of 0.56 mg/1. The -
commenter emphasized that these
values were all considerably less, than
those cited in the RTC. .
In addition, the company tested
several of the same waterside Boiler
cleaning wastes for hexavalent
chromium under the EP toxicity test
procedure. Of the 16 samples so tested,
only 1 showed a concentration of
hexavalent chromium above the
detection limit of 0.02 mg/1. Two of the
16 tested samples, exceeded 5.0 mg/1 for
total chromium concentrations. All 17
of the other samples showed
concentrations of hexavalent chromium
below the detection limit.: '
EPA acknowledges these comments
and would welcome the opportunity to
review any additional data. The
averages for lead and chromium cited by--
the commenters are indeed lower than
those cited in the RTC. However,
because some boiler cleaning chemicals
appear to exhibit hazardous waste
characteristics and the data on the
impacts of their management with large- .'
volume wastes are limited, the Agency
believes further study is necessary
before a final regulatory determination
is made. •
; Several commenters claimed that the
costs of managing low-volume wastes
under Subtitle G would be very high.
Some commenters felt that such
management would necessitate
transporting these wastes offsite,
thereby posing risks of environmental
releases without significant
environmental benefit, Other '
commenters observed that continuing to
manage these wastes onsite would
• require that the disposal facilities
become treatment, storage, or disposal
facilitiesi '.•••'.. .
, As noted previously, EPA is deferring
-a final determination on low-volume :
wastes co-managed with the four large-
volume wastes, pending additional data
collection. As necessary and-in . ,
accordance with the Section 8002(n)
study factors, EPA will consider the
potential cost impacts in making a
determination for these wastes. Low-
volume wastes managed independently •
are not and never have been within the
scope of the Bevill Exemption.
The Agency also recognizes that '
transporting hazardous wastes may pose
risks of environmental releases.
However, regulations have been
developed to ensure that hazardous
wastes are transported hi a manner
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42480 Federal Register / Vol. 58, No. 151 / Monday. August 9, 1993 / Rules and Regulations
sufficient to protect human health and
the environment (see 40 CFR § 263).
Many commenters stated that when
low-volume wastes are co-managed with
high-volume wastes, the Bevill
Amendment forbids EPA from
regulating them until the Agency
addresses each of tha Section 8002(n) (
factors in its study and bases its
determination on all of those factors.
These commenters maintained that EPA
may not rely solely on tha outcome of
a waste characteristic test as the basis of
its Regulatory Determination regarding
these wastes and this management
process. They went on to say that the
record assembled in tha Report to
Congress presents no evidence of
environmental risk associated either
with this co-management practice or
with the co-disposed wastes and
contains no information or findings as
to many of the remaining Section
8002(n) factors.
For the reasons died above, the data
are insufficient to assess fully the
potential risks associated with present
co-disposal practices. As discussed,
EPA does not intend to rely solely on
waste characterization data as the basis
of its Regulatory Determination for
remaining wastes. The Agency
acknowledges that many of the 8002(n)
study factors have not been considered
for low-volume wastes co-managed with
high-volume wastes. EPA plans to
address these study factors before we
make * final regulatory determination
on thes« wastes.
(3) EPA encourages the utilization of
coal combustion wastes as one method
for reducing the amount of these wastes
that need to be disposed to the extent
that such utilization can be done in an
environmentally safe manner.
While all respondents agreed with the
RTC'c third recommendation
encouraging coal combustion waste
utilization, several qualifying comments
were received.
One commenter noted that, while the ,
RTC is correct in requiring that
utilization to be done in an
environmentally safe manner, Congress
needs to be equally concerned that
waste utilization is done in a
structurally safe manner. This
commenter claimed that the RTC's
assertion, "all types of coal ash are
appropriate for usa as construction
materials, as cement additives, and for
several other uses," is entirely
erroneous. Tha commenter stated that
the RTC contradicts this statement
further on by delineating some of the
reasons why some fly ashes are not
appropriate for use in construction. All
materials used in engineering
construction work are required to
comply with appropriate ASTM
standards. Regarding utilization in
concrete, the commenter felt that the
RTC must cite the appropriate ASTM
Standard C618.
EPA acknowledges and agrees with
the comment However, it is not within
EPA's authority to mandate structural
requirements, except where they may
affect the potential for environmental
impacts.
In a recommendation on utilization,
one commenter pointed out that the
RTC encourages this practice "to the
extent that it can be done in an
environmentally safe manner." The
commenter cited the report's statement
that "current waste utilization practices
appear to be done in an environmentally
safe manner." The commenter claims
that there is no delineation between
practices that are environmentally safe
and ones that are not environmentally
safe.
To date, and using the limited data
available, the Agency has not found any
environmental damages associated with
the utilization of large-volume coal-fired
utility wastes. However, the Agency
agrees with the commenter that
utilization of coal combustion wastes
should be done in a manner fully
protective of the environment and
consistent with existing Federal and
State regulations. •
Several commenters disagreed with
the RTC where it stated that the
potential for significantly increasing the
amount of waste utilization may be
limited. Given current utilization
techniques, the report predicts that the
major portion of coal combustion wastes
will continue to be land disposed. Some
commenters felt that reluctance toward
waste utilization is largely due to the
stigma of classifying the by-products as
"waste" and that EPA should remove
"beneficially used coal ash" from the
definition of "solid waste".
Some commenters also noted that in
enacting RCRA, Congress intended that
EPA take a more active role in resource
conservation and recovery. They
thought EPA should give stronger
support for additional use and market
development with the emphasis placed
on large-volume utilization. It was noted
that some States have exempted ash for
reuse from their solid waste programs
and recommended that the Agency
support State efforts to authorize the use
of coal combustion by-products.
These commenters claimed that
considerable attention was directed to
limited cases of adverse impact in the
RTC. They maintained that EPA should
acknowledge in its Regulatory
Determination that a selective ash
characterization program coupled with
good engineering practice would ensure
environmental acceptability of large-
volume ash applications. The Agency
should take a leadership role by issuing
procurement guidelines related to the
use of coal ash in high-volume
applications within the transportation
and construction industries. Such high-
volume applications would include the
'use of coal ash as structural fills, road
embankments, and backfills.
The Agency notes that Congress
specifically mandates in RCRA Section
8002(n) that the Agency consider the
cases of adverse impact. The Agency
encourages utilization of coal
combustion byproducts and supports
State efforts to promote utilization in an
environmentally beneficial manner.
EPA notes that the Agency has issued a
procurement guideline to encourage the
use of fly ash in cement and concrete in
Federal projects (see 48 FR 4230,
January 28,1984). The Agency prefers to
ie individual states are in
the best position to determine what
types of utilization are appropriate for
their environmental settings.
Appendix B—^Analysis of and
Responses to Public Comments on the
Notice of Data Availability
Chi February 12,1993, the Agency
issued a Notice of Data Availability.
(Notice) requesting comment on
additional data on fossil-fuel
combustion (FFC) wastes. These data
are intended to update and supplement
the materials presented in the 1988
Report to Congress on Wastes from the
Combustion of Coal by Electric Utility
Power Plants (RTC). Da addition, the
Notice solicited comment on the
proposed methodology to be used in
completing the August 1993 regulatory
determination. ' '
Comments were received from 14
parties. Several commenters also
submitted additional published
materials on FFC waste characteristics
and management/treatment techniques.
The Agency considered these materials
in completing the regulatory
determination^ as appropriate.
The following discussion briefly
summarizes the comments received on
the additional data and the proposed
methodology. The Agency's responses
are also provided. The comments and
responses have been grouped according
to general topic areas.
Methodology; Several commenters
supported the use of EPA's proposed
three-step methodology for completing
the FFC waste regulatory determination.
No commenters disagreed with any
aspect of the methodology.
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Federal Register / Vol. 58^ No. 151 / Monday, August 9, 1993 /Rules and Regulations 42481
Fly Ash, Bottom Ash, Boiler Slag, and
FGD Waste: Nearly all respondents • ';
indicated that the Notice documents
supported the 1988 RTC's
recommendation that large-volume
combustion wastes dp not warrant
regulation under Subtitle C. No
coniriferiters'disagreed with this
.^commendation.
The Agency concurs with the
commenters that the information .
' contained in the docket does not
• contradict the data presented in the
RTG. The Notice documents update and
supplement the RTC by providing
additional data on waste characteristics,
environmental monitoring, and ~
environmental impacts.
Several commenters noted that State
regulation of FFC waste management
has become more stringent since the
1988 RTC. More stringent solid waste
regulations? including waste testing
requirements and design-and
performance-based standards, were
specifically cited.
The Department of Energy and the -
EPA have recently completed separate ~
studies of the current level of State
regulation of FFC wastes. Proceeding .
from the findings of these studies, the.
Agency concurs with the commenters ,
that State requirements have generally
become more stringent since 1983
(when the data cited in the 1988 RTC
were collected). EPA supplemented the
1983 data for all 50 States with an
updated analysis of 17 States •
representing all geographic regions of .
• the United States an.d generating
approximately 70 percent of the
Nation's coal ash. As noted in.the
preamble to the regulatory ;
determination, this study showed that
States are imposing additional controls
to ensure the proper management of
these wastes. •
One commenter felt that there is the
potential for groundwater degradation
from these coal combustion residues as
a result of their leaching potential,
although regulation of these'wastes
under Subtitle C is not appropriate. The
inherent high permeability of materials
landfilled without the benefit of,
stabilization or liners could allow a
large volume of percolation to occur,
resulting in potential groundwater
contamination. The commenter urged:
the Agency to eliminate questionable
coal combustion waste impoundments
and suggested that regulations similar to
40 CFR part 258 (requirements for
municipal solid waste landfills) would
be appropriate for FFb Waste'
management units. .
While the Agency believes that design
and operating requirements similar to
part 258 may be appropriate for some
FFG waste management units, the risks
posed by FFC waste management are
site-specific. Although groundwater •:
contamination has occurred at certain
coal combustibn waste sites,
contamination has been due to a limited
number of constituents, which are likely
to attenuate and dilute to safe levels
before reaching an exposure point,iThis
is in contrast to municipal solid waste
landfills that are subject to 40 CFR part
258. The leachate at these sites often ,
contains elevated levels of a wide range
of toxic pollutants,-and numerous
damages have been observed. Therefore, .,
' the Agency believes that the level of .
protection provided by the part 258
criteria may not need to be universally
applied to allEFC waste management
units. It is therefore appropriate to allow
the States to retain the flexibility to
tailor requirements to site-specific or
regional factors rather than establish
broad Federal minimum requirements.
It should be noted that many States have
adopted regulatory requirements for
FFC waste management units
comparable to the part 258 criteria. EPA
will consider these wastes as part of the
Agency's ongoing assessment .of
industrial non-hazardous wastes under
RCRA Subtitle D.
Low-Volume Wastes and Co- •. •:- • •
Management: Five of the,fourteen
respondents supported permanently
retaining the exemption for low-volume
coal-fired utility Wastes co-managed^
with large-volume wastes. These
commenters indicated that the 1988
RTC and Notice data show that co-
management'is an environmentally
sound management practice. One
commenter specifically cited two .'.-.. -....
Electric Power Research Institute (EPRI)
studies completed since 1988 as
demonstrating that co-managed wastes
should be'excluded. .
, EPA's efforts to compile more recent
data continue to show limited
information on the effects of co-
management. However, some :
information included in the Notice
docket suggests that at several large- "
volume waste management sites where
groundwater impacts have been -
detected, the operators have suggested
that the cause of the contamination is
co-management with low-volume
wastes. Of specific concern to the
Agency is co-management of ash, slag,
and FGD waste with pyrites and/or'. •_
chemical boiler cleaning wastes.
The Agency does not believe that the
two recent co-management studies cited
by the commenter are conclusive or
sufficiently representative of the entire „'
universe of co-management sites. For
'example, at one site, EPRI findings " •
indicate that a release is occurring
because of pyrite co-disposal. The -•'"'.,':
release is localized by site-specific
conditions (i.e., alkaline soils) that may
not be found at every facility. Similarly,
a release is also occurring at the second
site. While migration of constituents
with primary drinking water standards
is limited, boron and sulfate have been
detected in downgradient wells.
Low-volume wastes, co-managed with
large-volume wastes remain exempt
pending additional study. Separately
managed low-volume wastes are outside
the scope of the exemption, as noted by
one commenter representing a large part
of the industry. The same commenter in
responding to the RTC cited RCRA
Section 3001(b)(3)(i) and a January 13,
1981, letter from G. Dietrich. U.S. EPA, ,
to P. Emler, Utility Solid Waste
Activities Group, as indicating that the
Bevill Exemption applies, only to low-
volume wastes when they are co-
managed with the four large-volume."
However, the Agency cautions that
the limited data available to date
indicate that co-management of some
large-volume wastes with pyrites and
chemical boiler cleaning wastes can
cause adverse environmental impacts. ,
Pending the study of low-volume wastes
co-managed with large-volume wastes,
the Agency will continue to rely on its
authorities pursuant to RCRA Section
7003 as well as its Superfund -.
authorities under CERGLA Sections 104 "
and 106, to address any human health •
and environmental threats associated
with the co-management of these
wastes. - ' . .,-
Several commenters emphasized that
low-volume wastes are typically cp- •
managed with ash, slag, and FGD •
wastes. .'..-.'"- ' ;
The Agency has observed that the
general trend in the industry is to
segregate certain low-volume wastes,
(e.g., boiler chemical cleaning wastes)
from ash, slag, and FGD wastes. At some
plants, low-volume wastes, such as
pyrites and chemical boiler cleaning
wastes, are now being disposed of
separately. As indicated above, the
Agency believes that additional study is
required to evaluate the risks posed by ,
co-management of the low-volume
•wastes with the large-volume wastes.
Reutilization: One commenter noted
that in enacting RCRA, Congress
intended that EPA take an active role in
resource conservation and recovery. The
commenter indicated that some States
have developed overly stringent
regulatory requirements that have
"Comments dated May 16,1988, received from
USWAG on the RTC and comments dated March • -
29,1993, received from USWAG on the Notice (sea
Docket numbers F-^BB-^PATA-FFFFF and F-93- ••'
FFCA-FFFFF). - ;: .--.-'•
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42412 FexJer«l Regfrter A Vol. 58, No. 151 /Monday. August 9> 199S / Rules and Regulations
discouraged reuse of FFC wastes.
Several commenters recommended that,
in the Regulatory Determination, EPA
should recognize coal combustion
byproduct* as beneficial resources
rathec than a* waste materials.
Because, according to the RTC, the
majority of coal combustion byproducts
are currently managed at waste* rather
than re-used (because, in part, of market
condition* as well a* regulatory status),
the Agency believe* it is appropriate to
consider them waste materials.
However, the Agency continues to
encourage reutilization of coal
combustion byproducts and supports
State efforts to promote reutilization in
an environmentally beneficial manner.
In term* of exempting coal combustion
wastes from the definition of solid
waste, because this determination is
confined to the issue of whether to
regulate those waste* as hazardous, this
request I* outside the scope of today's
action. The Agency, however, is
currently engaging in an effort to revise
the definition of solid waste. In April
1993. EPA's Definition of Solid Waste
Task Force held a public meeting in
Washington, DC The task force plans to
hold a series of monthly open meetings
from July through November 1993,
which will provide a forum for the
public to provide input on the
definition of solid waste.
Comments Related to Specific
Documents:
Two commenters suggested that three
documents in the docket addressing the
Gavin Power Plant were added in error
and should not be considered in the
regulatory determination because they
deal with the investigation of
groundwater constituents (volatile
organic compounds (VOCs)) that are
unrelated to the management of coal
combustion byproducts.
The Agency recognizes that the source
of the VOC contamination at the Gavin
site is unlikely to have been coal
combustion wastes. These documents
were Included in the docket only to
provide a complete understanding of
groundwater conditions, including
background levels, at the site.
Site Visit Reports: One commenter
provided comments on EPA's site visit
report for the Cayuga Power Station, PSI
Energy, Incorporated. The commenter's
specific remarks and the Agency's
responses are summarized below:
One commenter noted that the Cayuga
site visit report incorrectly assumes that
ail data in Table 5 are from
downgradient wells. The commenter
suggest* that the maximum arsenic and
vanadium values above background
were actually detected in an ash well
(PZ-14), rather than with a soil core
system. Because of this, the commenter
concludes that no adverse impact on
groundwater has occurred.
In response, CPZ-14 is specifically
identified in EPRI's Report on the
Cayuga site (see Comanagoment of Coal
Combustion By-product and Low-
Volume Wastes: Midwestern Sites, EPRI
Report EN-7545J as a downgradient
well, and arsenic and vanadium were
found above background levels in the
sediments immediately underlying the
ash pond. The Agency acknowledges
that any release of these constituents is
limited because they were not found in
other wells. It should further be noted
that other constituents, including sulfate
and boron, have consistently been found
above background levels in several
downgradient wells.
One commenter stated that the
Cayuga site visit report overemphasizes
the lack of background groundwater
monitoring data, because the actual
downgradient groundwater data show
no adverse impacts.
The report only indicates which
parameters appear to be above
background levels and notes that the
limited background data make any data
analysis difficult. The site visit report
does not comment on whether the data
show any adverse impacts associated
with the ash management unit.
One commenter noted that total
constituent and hydroxylamine
extraction coal ash data presented in the
EPRI study and the Cayuga site visit
report should not be used to consider
the actual leaching potential.
These data were included in the site
visit report because they were the only
waste characterization data available for
the Cayuga site (no other leaching
studies were performed). The Agency
recognizes that the hydroxylamine
extraction test provides a "worst case"
estimate of the potential for constituent
mobilization and would likely
overestimate actual teachability. The
Agency emphasizes that the proposed
three-step methodology not only
considers waste characterization
information, but also the actual risks
posed by a waste in its "as managed"
state.
One commenter noted that the new
groundwater monitoring data included
in the Notice docket show few "
exceedences of primary drinking water
standards. Most exceedences of primary
drinking water standards occurred at
older sites that are atypical of current
sites. Exceedences of Secondary
Drinking Water Standards occur more
frequently, but the percentage of sites
involved is still low. The commenter
noted that exceedences of SDWSs are
not violations of a Federal standard
requiring enforcement or of most State
standards, since SDWSs are guidelines.
Further, exceedences would likely not
occur if the relevant point of
compliance were set further from the
site (e.g., 150 meters downgradient as in
the municipal solid waste landfill
rules). Finally, the commenter indicated
that many elevated constituent levels
could be attributable to natural or other
non-coal ash related sources (data were
cited from several sites). Another
commenter suggested that, the data show
that the potential exists for groundwater
degradation through migration of
constituents with SDWSs (e.g., iron,
sulfates, chlorides, and other soluble
salts).
The Agency disagrees that the new
docket materials show alow percentage
of exceedences of both PDWSs and
SDWSs. Of the 49 individual sites with
groundwater monitoring information
(summarized in Appendix D of the ,
Supplemental'Analysis of Potential
Risks to Human Health and the
Environment from Large-Volume Coal
Combustion Waste, found in the
docket), 19 had at least one exceedence
of a PDWS, and 42 had at least one
exceedence of a SDWS,
The Agency concurs that some of
these exceedences of PDWSs could be
due to contamination from other sources
and that dilution and attenuation would
tend to reduce contaminant
concentration below levels of concern at
receptors. While the Agency recognizes
that SDWS exceedences are not always
considered violations, elevated levels of
secondary parameters can cause adverse
impacts. Therefore, the Agency has
considered the mobility of these
parameters in determining the risks
posed by FFC waste management.
Acknowledging the results of this
analysis, the Agency concurs that many
newer units have been designed to
prevent releases (i.e., with liners),
releases are frequently localized by site-
specific conditions such that
contaminants do not reach receptors,
and exceedences are sometimes caused
by natural or non-coal ash related
sources (often for chlorides, iron, and
manganese}. Finally, although much of
• the data is from older sites, many of
these sites are currently active;
therefore, they cannot be regarded as
categorically atypical.
(FR Doc. 93-18975 Filed 8-6-93; 8:45 am)
BILLING CODE 6560-5O-P
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