Thursday
June 13, 1991
Part SI
40 CFR Part 261
Special Wastes From Mineral Processing
pining Waste Exclusion); FinsE
Regulatory Determination and Final Rule
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27300 Federal Register / Vol. 56, No. 114 / Thursday, June 13', *1991 / Rules and Regulations
ENVIRONMENTAL PROTECTION
AGENCY
IEPA/OSW-FR-91-018; FRL-3956-1]
40 CFR Part 261
RIN 2050-AC41
Final Regulatory Determination for
Special Wastes From Mineral
Processing (Mining Waste Exclusion)
AGENCY: Environmental Protection
Agency.
ACTION: Final regulatory determination
and final rule.
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) for 20 special wastes from
the processing of ores and minerals.
EPA has concluded that regulation
under Subtitle C of RCRA is
inappropriate for all 20 of the special
wastes that were studied. EPA plans to
address 18 of the wastes under subtitle
D, possibly in the program being
developed for mining wastes. For the
remaining two wastes (phosphogypsum -
and process waste water from
phosphoric acid production), EPA plans
to proceed with the development and
promulgation of a program under the
Toxic Substances Control Act (TSCA)
that will address their management,
including possible regulations
concerning waste minimization/
pollution prevention for these wastes. In
addition. EPA plans to use existing
authorities under either RCRA Section
7003 or CERCLA section 106 to address
any site-specific ground-water
contamination problems that are
believed to pose substantial and
imminent endangerment to human
health or the environment. EPA has also
decided to postpone consideration of a
possible ban on the utilization of one of
the special wastes, slag from elemental
phosphorus production in construction
and/or land reclamation.
The rationale and salient facts used
by the Agency to arrive at these
decisions are provided below.
EFFECTIVE DATE July 15,1991.
FOR FURTHER INFORMATION CONTACT:
For further Information on the regulatory
determination, contact the RCRA/
Supcrfund hotline at (800) 424-9346 (toll
free) or (703) 928-9810. or Bob Hall at
(703) 308-8412.
SUPPLEMENTARY INFORMATION:
Table of Contents
i. Background
A. Statutory Authority
D History of the Mining Waste Exclusion
C. Overview of the Report to Congress
D. Supplemental Analysis and Notice of
Data Availability
II. Factors Considered in Making the
Regulatory Determination
HI. Regulatory Determination for the 20
Special Wastes from Mineral Processing
IV. Decision to Postpone^ Consideration of a
Possible Ban on Elemental Phosphorus
Slag Utilization
V. Regulatory Flexibility Analysis
VI. Agency Initiatives
VII. Regulatory Determination Docket
Appendix AAnalysis of and Response to
Public Comments on the Report to
Congress
Appendix BAnalysis of and Response 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(p) of RCRA,
the Administrator must determine
whether or not subtitle C regulation of
the special study wastes is warranted.
Wastes-for which the exclusion is
retained will continue to be subject to
regulation under RCRA Subtitle D as
solid wastes.
B. History of the Mining Waste
Exclusion
In October, 1980, RCRA was amended
by adding section 3001(b)(3)(A)(ii) to
exclude "solid waste from the
extraction, beneficiation, and processing
of ores and minerals" from regulation as
hazardous waste under subtitle C of
RCRA, pending completion of a study
and a Report to Congress required by
section 8002 (f) and (p) and a
determination by the EPA Administrator
either to promulgate regulations under
subtitle C or that such regulations are
unwarranted and that the exclusion
should continue (as required by section
3001(b)(3)(C)). EPA modified its
hazardous waste regulations in
November 1980 to reflect this "Mining
Waste Exclusion," and issued a
preliminary, arid quite broad,
interpretation of the scope of its
coverage. In particular, EPA interpreted
the exclusion to include "solid waste
from the exploration, mining, milling,
smelting and refining of ores and
minerals" (45 FR 76618, November 19,
1980).
In 1984, EPA was sued for failing to
submit the Report to Congress and make
the required regulatory determination by
the statutory deadline (Concerned
Citizens ofAdamstown v. EPA No. 84-
3041", D.D.C., August 21,1985). In
responding to this lawsuit, the Agency
explained that it planned to propose a
narrower interpretation of the scope of
the Mining Waste Exclusion, so that it
would encompass fewer wastes, and
proposed to the Court two schedules:
One for completing the section 8002
studies of extraction and beneficiation
wastes and submitting the Report to
Congress addressing these wastes, and
one for proposing and promulgating a
reinterpretation for mineral processing
wastes. In so doing, the Agency, in
effect, split the wastes that might be
eligible for exclusion from regulation
into two groups: Mining (mineral
extraction and beneficiation) wastes,
and mineral processing wastes. The
Court agreed to this approach and
established a schedule for the two tasks.
On December 31,1985, EPA published
the required Report to Congress on solid
wastes from mineral extraction and
beneficiation, and on July 3,1986 (51 FR
24496) published a determination that
regulation of such wastes under subtitle
C of RCRA was not warranted. Since
the determination was made, the
Agency has been developing a tailored
regulatory approach for these wastes
under RCRA subtitle D.
In keeping with its Court-ordered
directive to reinterpret the Mining
Waste Exclusion for mineral processing
wastes, in October, 1985, EPA proposed
to narrow the scope of the Exclusion for
mineral processing wastes to include
only a few specific waste streams (see
50 FR 40292, October 2,1985). However,
the Agency did not specify the criteria
that it used to identify these wastes, or
to distinguish them from other wastes
that were not identified as being eligible
for the exclusion. In response to this
proposal, many companies and industry
organizations "nominated", wastes that
they believed were eligible for the
regulatory exemption. Faced with an
inability at that time to articulate
criteria that could be used to distinguish
exempt from non-exempt wastes and the
approaching Court-ordered deadline for
final action, EPA withdrew its proposal
on October 9,1986 (51 FR 36233).
In July, 1988, the court in
Environmental Defense Fund v. EPA,
852 F.2d 1316 (D. C. Cir. 1988), cert.
denied, 109 S. Ct. 1120 (1989) held that
EPA's withdrawal of its 1985 proposal
was arbitrary and capricious, and
ordered EPA to reinterpret the scope of
the Exclusion for mineral processing
wastes. In particular, EPA was directed
by the Court to restrict the scope of the
Exclusion as it applied to mineral
processing wastes to include only "large
volume, low hazard" wastes. In a series
of rulemaking notices, EPA has, during
the past three years, established the
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1991 I Ruleg and Regulations 27301
boundaries of the Mining Waste : , .
Exclusion for mineral processing wastes,
has articulated the criteria that were
used to define "mineral processing," and
has evaluated whether individual
wastes are large volume and low hazard
and, thusj eligible for the, temporary
exclusion provided by RCRA section
3001(b)(3)(A)(ii). This rulemaking
process was completed with the
publication of final rules on September
1,1989 (54 FR 36592) and January 23, -
1990 (55 FR 2322]. With the completion
of these notices, the Agency established
that the temporary exemption from ..
subtitle C requirements "established by
the Exclusion for mineral processing
wastes and, therefore, the scope of the
Report to Congress, was limited to 20.
specific mineral processing wastes. = -
EPA then prepared and submitted a
detailed and comprehensive Report to
Congress addressing the 20 special
mineral processing wastes; in
compliance with the Court-ordered
deadline. In addition to the explicit
consideration of the eight study factors
listed at section 8002(p) of RCRA; the
Agency included in the Report a
proposed regulatory status for each of
the 20 special wastes. Thus, the Report.
serves both as an information source
and as a tentative indication of the
Agency's final determination.
Accordingly, arid in compliance with
statutory directive, the Report, the data
and analyses that underlie it, and the
comments received on it have served as
the primary basis for the regulatory
decisions that are articulated in today's
notice.
EPA did not complete the regulatory
determination within the six month
statutory deadline. As a result, the
Environmental Defense Fund filed a new
RCRA citizen's suit, which was settled
by consent decree. EDFv. EPA, No. 91-
0429 (D.D.C. Mar. 4,1991). Under the
terms of the.consent decree, EPA must
issue the regulatory determination no
later than May 20,1991. Today's
decision is issued in compliance with
that decree. -,' '
C. Overview of the Report to Congress
1. Scope of the Report
The scope of the Report to Congress
was limited to 20 mineral processing
wastes, representing 12 mineral
commodity sectors. These wastes are
generated by 91 facilities located in 29
states. The 20 wastes covered by the '
Report to Congress, organized by sector,
follow: .
Sector
Alumina
Chromium (Sodium
Chromate/
dichromate).
Coal gasification.....
Copper...............
Elemental
Phosphorus.
Ferrous Metals
Hydrofluoric acid-
Lead....
Magnesium..
Phosphoric acid...
Titanium -
tetrachloride.
Zinc. ....
Waste(s)
Red tind brown muds from
bauxite reffning.
Treated residue from roasting/
leaching of chrome ore.
Gasifier ash from coal gasifi-
cation. .
Process wastewater from coal
gasification.
Slag from primary processing.
Calcium sulfate wastewater
v treatment plant sludge/from
primary processing.
Slag tailings from primary
processing.
Slag from primary production.
Iron blast furnace APC dust/
sludge. .
Iron blast furnace slag. .
Basic oxygen furnace and
open hearth furnace APG
dust/sludge.
Basic oxygen furnace and'
open hearth furnace slag:
Fluordgypsum.
Process wastewater.
Slag from primary processing.
Process wastewater from pri-
mary magnesium processing
by,the anhydrous' process.
Phosphogypsum. , ..
Process wastewater.....
Chloride process waste solids.
Slag from primary processing.
2. Study .Factors
The RTC addressed the following
eight study factors required by section
8002(p)pf RCRA:
. "1. The sources and volumes of such;
materials generated per year; ;'" ' ,
2. Present disposal and utilization
practices; '
3. Potential danger 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 has
been proved; ,
5. Alternatives to current disposal
methods; ,
6. The costs of such alternatives;
7. The impacts of these alternatives on
the use of phosphate rock, uranium ore,
and other natural resources; and
8. The current and .potential.utilization'.
of such materials. '
In addition, the statute suggests that
the Administrator may review 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. .
The Agency's approach in preparing
.this Report was to combine certain
study factors, for purposes of analysis
and exposition, into seven sections. The
first section provides a brief overview of
the industry, including the types of - :,
production processes used and the
number and location of operating
facilities that generate one or more of
the mineral processing special wastes.
The second section summarizes .'"
information on waste characteristics,
generation, and current management
practices (study factors 1 and 2),while
the third section provides a discussion
of potential for and. documented cases of
danger to human health or the
environment (study factors 3 and 4). the,
fourth section (as suggested generally by
section 8002(p} of RCRA), summarizes
applicable federal and state regulatory -
controls. The fifth section discusses ;,
alternative waste management practices
and potential utilization of the wastes
(study factors 5 and 8), while the sixth
section discusses costs and impacts of
alternative practices (study 'factors 6
arid 7). The seventh and final section
summarizes and analyzes the findings of.
EPA's evaluation of the above study ',.'.
factors. ; ; .-..-. :'
3. Preliminary Findings in the Report to
Congress ',-'.-- ' .- -
The; Report to Congress presented
EPA's preliminary findings regarding the
20 special wastes frommineral ,
processing, based on two separate
approaches: (1) The application of the
RCRA section 8002(p) study factors arid
(2) the application of the RCRA section
8002(p) study factors and additional
considerations. A summary of the
Agency's findings, .prior to receipt and
analysis of public comments, regarding
the appropriate regulatory status of the
20 mineral processing special wastes
.covered in the RTC is provided below.
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27302 Federal Register / Vol. 5(3, No. 114 / Thursday, June 13, 1091 / Joules and Regulations
REPORT TO CONGRESS TENTATIVE RECOMMENDATIONS !
Waste stream
B*d cod Brown Muds from Bauxite Refining v , _
Troilod RdskkM from Roasting/Leaching of Chrome Ore
Gwitiar Ash Item Coal Gasification '. :.
Process Was'ewalor from Coal Gasification _ 1
Stag from Primary Copper Processing .............................. ."....
Stag T«ttfngs from Primary Copper Processing ~ ...
Steg from Etomontal Phosphorus Production.. « . . . .
Iron Blast Furnace Stag. _ ;
Basic Oxygon Fumaco and Open Hearth Furnace Slag from Carbon Steel Prod.
FloofOflyptum from Hydrofluoric (HF) Add Production.. « .. . * <
Process Wastowator from MaQneslum Processing. ..
Stag from Primary Zlrtc Processing.............. « ' . . . ....
Phosphogypsum from Phosphoric Add Production , ...
Process Wastowatdf from Phosphoric Add Production : ;.... '.....
A!r Pottotton Control Dust/Sludge from Iron Blast Furnaces ,.
Air Pollution Control Dur.t/Sludgo from Baste Oxygen Furnaces and Open Hearth Furnaces from Carbon Steel Production,
3*g from Primary Lead Processing .;....
Calcium Sutfatd Wastcwator Treatment Plant Siudge from Primary Copper Processing \ .
Process Wastowator from HF Add Production . . ... '. .
Chkxkia Process Waste Solids from Titanium Tetrachloride Production «i .'....
Approach 1 (using 8002(p)
study factors)
Full subtitle
c
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
C
D,
Subtitle C-
minus
D
D
D
D
D
D
D
D
D
D
b
D
D
D
.P ' ' .
D
C
C
C
C
Approach 2
(using
8002(p)
study
factors and
additional
consider-
ations),
:D .
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
D
1 Source: USEPA. 1990. Roport to Congress on Special Wastes from Mineral Processing, Vol. I, pp. 11-17.
a. Approach 1: Application of the RCRA
Section 8002(p) Study Factors
1, Wastes EPA Tentatively
Recommended to Remain Under RCRA
Subtitle D
Using the study factors listed in RCRA
section 8Q02(p), EPA examined: (1) The
potential for and documented danger to
human health and the environment; (2)
the need for additional regulations; and
(3) the costs and impacts of subtitle C
regulation for the 20 special wastes.
EPA's analysis did not merely evaluate
whether the wastes should be treated as,
hazardous in light of the criteria under
subtitle C for other wastes, but took into
account Congress' desire to examine
"special wastes" in a different light.
EPA's analysis suggested that regulation
under subtitle C of RCRA would be
Inappropriate for the following 16
mineral processing wastes:
* Red and brown muds from bauxite
refining;
Treated residue from roasting/
leaching of chrome ore;
* Gasifier ash from coal gasification;
Process wastewater from coal
gasification;
Slog from primary copper
processing;
Slag tailings from primary copper
processing;
Sing from elemental phosphorus
production;
* Iron blast furnace slag;
* Basic oxygen furnace and open
hearth furnace slag from carbon steel
production;
Air pollution control dust/sludge
from iron blast furnaces; .
Air pollution control dust/sludge .
from basic oxygen furnaces and open
hearth furnaces from carbon steel . ,
production;
Fluorogypsum from hydrofluoric
acid production;
Process wastewater from primary .
magnesium processing by the anhydrous
process;
Process wastewater from
phosphoric acid production;
Phosphogypsum from phosphoric
acid production; and
Slag from primary zinc processing.
Three of these sixteen wastes (treated
residue from roasting/leaching of
chrome ore; process wastewater from
coal gasification; and slag tailings from
primary copper processing) were found
not to pose an actual or potential danger
to human health and the environment.
The thirteen remaining wastes were
identified as having some actual or
potential hazard associated with current
management practices or plausible
mismanagement scenarios, and so were
further evaluated.
EPA found that the potential risk
associated with slag from primary zinc
processing, process wastewater from
primary magnesium processing by the
anhydrous process, air pollution control
(APC) dust/sludge from iron blast
furnaces and from basic oxygen and
open hearth furnaces used to make
carbon steel, red and brown muds from
bauxite refining, elemental phosphorus
slag, and gasifier ash from coal
gasification, was comparatively low; ;
that is, the Agency found that
management of these materials'did not ,
present a substantial hazard to human
health or the environment. In particular,,
no documented damages attributable to .
these wastes were identified..In
addition, State regulations are in effect .
for the one primary magnesium facility
and revised/strengthened regulations
have been proposed for the primary zinc
processing facility. EPA also found that
several facilities recycle rather than
dispose of ferrous metal production APC
dust. Therefore; the Agency found that
subtitle C regulation was-not
appropriate..In the case of elemental
phosphorus slag, the Agency found that
while there appeared to be some
significant hazards associated with use :
of the material in construction :
applications (that is, off-site utilization),
the best means of dealing with this
problem was through the use of
authorities provided by RCRA section
3001(b)(3)(B)(iii) (which allows for
special controls from phosphate rock
mining and mineral processing wastes)
rather than through imposition of the
subtitle C hazardous waste management'
standards.
EPA identified four wastes that did
not exhibit-a hazardous characteristic
(with the exception of one sample of
copper slag at one facility) but for which
documented cases of adverse
environmental impacts that affected
surface water were identified at at least
one facility:
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Federal^, Registgr /
Tfiursflay, Ijuqg. 13, :i991 '/ Rules and Regulations
=* Iron blast:furnace slag; , : ;,.
>» Slag from primary copper
processing; :, "'*
« Basic :oxygen furnace and open
hearth furnace slag from earboir steel
production; and ; :
» 'Huorogypsum from hydrofluoric
acid production. '-''"'.', f
For all four wastes, however, these: ;
surface water release^ (one of which
. occurred via ground water) have been
and/or are being addressed under
existing regulatory,authorities at .the
§tate.and/or federal level. Therefore, the
'Ageiicy concluded tfia.t regulatiomof'
thesej fourvwastes as hazardpus W.pJild,^
. riot pipvide additional protection to " '
.,human-health or the environment '*"
j Justifying; theleh'mination of the special -
. status pf these wastes; thus, (subtitle C:
; regulation was not considered '-.;
appropriate. : , . ; -''.-. : :!, >
Phosphogypsum and phosphoric aeid
. process wastewater were also of ' " '..:-
; concern because damage'case
, information indicated that both closed
sand currently -active phosphogypsum
s under subtitle C. ; ; -; ; ;, , ; . ,
ti. Approach 2:"Applicatfpn
'
- Sections 3001(bK3)and«002(p) of -?;
(RCRA-arid the decision iji :-';."' '< ;,;? ; .
"Environm'etital Defense Fiiird v,'JE!PA,'
852;Ft2d'l309,(D;C. Cu\ l!988) makeit ; ;
clear'that the Agency may and should
consider the "specific -factors of section
; 8002(p) (l)-(8)iri making its decision
regarding the appropriate regulatory
Status of special Wastes. In addition, the
Agency stated in the Report that in '
making its regulatory determination, it
might be appropriate to consider other
factors relating .to the broader goals and
objectives of the Agencj and RCRA, '
such as developing and maintaining
strong state mining and mineral '."-
processing waste regulatory programs
and facilitating implementation of
federal prbgrariis. . :
Accordingly, EPA stated in the Report
to Congress that in order to facilitate ".'-'
both development and maintenance of /
strong state programs and ;''."
implementation of any federal
regulations that niay be necessary for
mmeral processing wastes, it might be ;
4fhe SubtitleC-J^inus scenario th&t was ;
corisidered in the RTC is hypothetical and was :
assumed only for .the purpose of cost estimation; It
does not necessarily represent what EPA wpuld ..
consider an appropriate regulatory program. , -.
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27304 Federal Register / Vol. 56, No. 114 / Thursday, June 13,1991 /Rules and Regulations
appropriate to regulate all 20 of the
special wastes under subtitle D of
RCRA. In addition, the Report stated
that some mining and mineral
processing wastes might be excluded
from any further federal regulation
under RCRA.
In light of these considerations, the
results of Approach 2 indicated that it
might be appropriate for the waste
streams identified under Approach 1 for
potential subtitle C (full C or C-Minus)
regulation not be subject to the
hazardous waste management
standards, but instead to be retained
within the Mining Waste Exclusion. If
such a finding was appropriate, EPA
stated that it would need to be
conditioned on the premise that major
slops be taken to control releases from
the facilities generating these waste
streams. Some corrective measures are
already being taken under a variety of
Agency authorities (e.g., RCRA,
Superfund, CWA) and more can and
would be undertaken. EPA also asserted
that the states must act to address the
most immediate problems posed by
these wastes, as well as any of the other
mineral processing special wastes that
have been found in the Report to pose
significant actual or potential hazard to
human health or the environment. To
assist in this effort, EPA pledged to
provide technical and other resource
support to the involved states to
Improve their programs. If near term
actions did not result in adequate
control of such wastes, EPA would then
take action to reconsider its regulatory
determination and could designate
certain waste streams as subtitle C
hazardous wastes.
4. Public Comment Process
With publication of the Report to
Congress, EPA initially established a 60-
dny public comment period that ended
on September 28,1090. In response to
requests from several commenters,
however, EPA extended the comment
period to October 19,1990. In addition, a
public hearing on the Report was held in
Washington, DC on October 17,1990.
EPA received 91 sets of written
comments prior to the close of the
comment period and eight late
comments. All individual comments and
a transcript from the public hearing are
available for public inspection in the
docket (Docket No. F-90-RMPA-FFFFF).
The docket also contains a summary of
all the comments presented at the
hearings 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 analyses were
conducted on five wastes that were
addressed in the Report to Congress,
including gasifier ash and process
wastewater from coal gasification, basic
oxygen furnace and open hearth furnace
air pollution control dust/sludge, and
phosphogypsum and process
wastewater from phosphoric acid
production. A Notice of Data
Availability (NODA), which announced
the availability of this information, was
published in the Federal Register on
January 7,1991.
A 30-day public comment period was
provided, which closed on February 6,
1991. As in the case of the Report to
Congress, EPA received requests that it
extend the comment period. However,
EPA did not extend this comment period
because of the need to proceed with the
regulatory determination process as
expeditiously as possible and because
the Agency believed that the comment
period provided was adequate. In
addition, EPA took steps to ensure that
commenters could make the maximum
use of the time available. For example,
EPA made the supplemental data
publicly available as soon as possible,
immediately following Agency
signature, rather than waiting until the
NODA was published in the Federal
Register. Also, at the request of industry,
EPA delayed the start of the public
comment period until after the holidays.
Included in the new data was
information on phosphoric acid process
wastewater and phosphogypsum
concerning generation and management
of these wastes, the engineering
feasibility and cost of alternative waste
management practices, waste
characteristics, ground water monitoring
data, and state regulations. The Agency
specifically solicited comments on the
engineering feasibility and accuracy of
cost estimates for the alternative waste
management practices presented as part
of the new data.
The Agency received 22 written
comments addressing the NODA. All of
the comments are available for public
inspection in Docket No. F-91-RM2A-
FFFFF. Agency responses to the
comments are provided in the docket
and appendix B to this regulatory
determination.
II. Factors Considered in Making the
Regulatory Determination
The RCRA statute, as amended,
directs EPA to make a regulatory
determination for the special study
wastes based upon its Report to
Congress and comments received from
interested parties. The statute contains
the following eight study factors: :
1. The 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
disposal and reuse of such materials;
4. Documented cases in which danger
to human health or the environment has
been proved;
5. Alternatives to current disposal
methods;
6. The costs of such alternatives;
7. The impact of those alternatives on
the use of phosphate rock and uranium
ore, and other natural resources; and
8. The current and potential utilization
of such materials.
In addition, RCRA section 8002(p).
suggests that EPA review studies and
actions of other federal and state
agencies, and invite participation from
concerned parties, including industry
and other federal and state agencies in
an attempt to avoid duplication of effort.
EPA has complied with the
Congressional mandate in developing
the required Report to Congress and
soliciting and incorporating comments
received from affected parties. In
making today's regulatory
determination, the Agency has relied
upon the analysis of the eight study
factors described as "Approach I" in the
RTC, modified slightly in response to
public comments. EPA believes that this
approach is most consistent with
Congressional intent. To the extent that
the Agency were otherwise to conclude
that subtitle C regulation was warranted'
based upon consideration of all of these
factors and information, EPA believes,
upon further reflection, that it is
unnecessary'and probably inappropriate
to look outside the Report to Congress,
public comments, and supplemental
technical information, as outlined for
Approach 2 in the RTC, to justify-a
different determination.
In addition, as discussed in more
detail in appendix A to this preamble,
EPA believes that the so-called
"additional factors" upon which
Approach 2 was based are, in large part,
already embodied within the contours of
'the inquiry that Congress intended for
EPA to make in the Report and
regulatory determination. The Report
identifies (1) the development and
maintenance of strong state mining and
mineral processing regulatory programs,
and (2) the facilitation of an integrated
federal mining regulatory program as the
key considerations under Approach 2,
: Section 8002(p)(5) instructs EPA to
corisider "alternatives to current
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/ Federal Register /Vol.- 56» No.; 114 / THursday, June 13j 1991 /rRules and; Regulations' .,'.. 27305
disposal methods^' as a factor in , -
developing the Report and regulatory
determination. Certainly, consideration ,
of alternative state regulatory schemes,
in addition1 to federal schemes, is ..... .-.
contemplated by this section. Also,
facilitation of a potential integrated '
federal mining program was actually
considered by EPA in its cost estimates
(reflected inithe "Subtitle D-Plus -..-
scenario"). ;.. ' ;-:-.
Nonetheless, EPA-does not believe
;thatit should .rely on "possible" .''-.. : .
improved state programs-to determine . .
that subtitle C is not warranted unless
EPAis confident that such'programs are .
being developed and can address the-
problems associated with mineral '
processing;wastes that may pbse a ' ; ;
significant risk. Thus, EPA believes, that
section 8002(p) requires that EPA not
consider these factors in a way that
would supplant any decision the Agency
makes under the decision making
methodology outlined in Approach 1.
In any event, EPA notes that the issue
. is effectively moot; As discussed below,
EPA has determined, on the basis of
Approach l,;that subtitle C is not ; ;
appropriate for any of the 20 wastes
analyzed. Thus; even if EPA were to
employ Approach 2 as outlined in the
Report, it would not change any of the
decisions made today. '
In "Approach 1," the Agency '
evaluated the RCRA section 8002(p)
study factors by first assessing the need
for additional regulatory controls (or
absence thereof), then evaluating the
options for appropriate requirements
that could be applied to each individual
waste .stream for which additional
controls might be in order, and, finally,
estimating the associated costs and
impacts. In applying the .decision
criteria, EPA believes that the factors
that are most important in establishing
the-regulatory, status of the special
wastes should be given major emphasis.
Therefore, potential risks posed and
documented damages caused by the
wastes, the need for additional
regulations, and the costs and impacts
that would be associated with more
stringent regulatory controls are the
focus of the three steps in the analytical
process. The reason for"this is that in the /
absence of a realistic showing of a ''.-.
potential risk and/or dpcumented'
damages from current management (or
in appropriate cases, plausible
mismanagement), EPA believes that
Congress would not intend to eliminate
the special status of these wastes by
imposing hazardous waste regulation
under, RCRA Subtitle C; if greater
regulatory controls may be appropriate
because of significant: potential' 6r , ;
documented.danger, the costs and,
impacts of regulatory controls are the
critical factors .in determining.whether a,
given alternative would conform to ,
Congress'expressed goals for these
wastes (adequate protection of human
health and the environment and . ,
continued operation of the affected
.industries). : , , ,
.The overall decision making process v
as described in the RTC was left ;
basically intact for. the purpose of this
regulatory determination. However, a
number.of specific changes have,been
ma.de to the individual decision criteria .
in response to public comments; these '-
changes are detailed below, and address
the specific questions: considered'in this
step-:wise process, as well as how the
answers to these questions interact
when deciding whether to go frpm.one
step to the next.. -.. .
The modified step-wise process thai
the Agency applied to the available
information is outlined below.
Step 1. Does management of this waste.
pose human health/environmental"
problems ? Might curren t practices cause
problems in the future? ,
Critical to the Agency's decision
making process is whether the special
Waste either has caused or may cause '.-
human health or environmental damage,;
To resolve these issues, EPA has posed
the following key questions: " ''-.
1. Has the waste, as currently
managed, caused documented human '
health impacts or environmental .
damage? ' '. '.
2. Does EPA's analysis indicate that
the waste may pose a significant risk to
human health or the environment at any
of the sites that generate it (or in off-site
use), under either current management
practices or plausible mismanagement
scenarios? , ,.
3. Does the waste exhibit any of the
characteristics of hazardous waste? "
In the RTC, EPA concluded that
further evaluation was necessary if the
answer to any of these three questions '
was yes. However, numerous',
commenters argued that several of the
damage cases included in the RTC do
not represent today's conditions, for a
variety of reasons, that the risk ' - .-
assessment conducted for the RTC tends'
to overstate risk, and, that the-leachate
concentrations measured using the EP '--
leach test overestimate actual leachate ;
concentrations. Although EPA disagrees
with many of the specific points made
by commenters in support of these
arguments, as discussed in appendix A ;
to this preamble,, the Agency believes
that a more flexible decision ftiaking'. -; -
approach is warranted in response to
the general concerns expressed.. " ;
Concluding that further evaluation i§ ;
'necessary if the answer to just-one of . ;
the above questions is yes; without- ::;.
taking into account the overall certainty
and cortservativeness of that answer , ,
' relative to the answers to the other
. questions, Could unnecessarily lead the
Agency into Step 2 of the decision
making process; .-...- -.' ,;. ; .
'" "Fherefofe, for this regulatory .
determination, EPA answered each of ,
these questions and then considered the
Combined answers as a whole in
deciding whether further Devaluation was
: necessary; A fundamental concept in
this approach was that no"one question
is more significant iii reaching a
decision regarding potential hazard than
the others, as the' answer to one :
question could offset, somewhat, the \
ansv/er to another. That is, rather than
following a very rigid approach of
proceeding to jS.tep 2 if the answer to just
one question was yes, the Agency
considered how the answers traded off,
taking into account each answer's
supporting weight of evidence and : .':
certainty. '.-, ',, '.' ,
For example, the scenario for a gives
waste couldbe that (1) there was not a
.- documented danlage case that could be,.
attributed to the waste with reasonable.
certainty (i.e., the answer to question 1
, was^no); (2) the reasonably conservative
risk analysis/provided a sound basis for
concluding that the potential for human
health and environmental problems was
.low under current management ;
practices or plausible mismanagement '
scenarios (i.e., the answer to question 2
was no); and (3) the waste exhibited the
toxicity characteristic using the EP leach
test (i.e., the answer.to question 3 was
, yes), but only rarely and never for
samples analyzed using the Synthetic
Precipitation Leaching Procedure (SPLP).
Under this scenario, EPA would have
reached an .overall low hazard
conclusion because the balance of the
information, supporting the answers to
questions 1 and .2 effectively outweighs,
. in the Agency's judgment, the answer to
question 3. '''.---- ' .;
By following this approach, the .'
Agengy considered all of the relevant
information in making its decision on
the'pptential for each waste-to pose
human health and'environmental -'
; problems. If this analysis led the Agency
to conclude thai there is a reasonable
potential for:problems, then-EPA "
concluded 'that further evaluation was
necessary. If the conclusion was thMt the
potential for problems is low, then the
Agency determined :that regulation of
the waste under RCRA subtitle C is not
'appropriate. EPA believes that this
"balancing" approach 'to the analysis'-in »
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27306 Federal Register / Vol. 56, No. 114 / Thursday, June 13, 1991 / Rules and Regulations
Step 1 allows EPA to determine with
more precision the actual hazards posed
by those wastes, consistent with the
intent of the Bevill Amendment 852 F.2d
at 1314. EPA also notes that this
analysis does not precisely match the
approach EPA uses to list or identify
non-special wastes as hazardous, but is
more conservative in the direction of not
imposing regulation unless the potential
risk justifies elimination of special
status.
Step 2. Is more stringent regulation
necessary and desirable?
If the waste has caused or may
potentially cause human health or
environmental impacts as determined in
Step 1, then EPA concluded that an
examination of alternative regulatory
controls was appropriate. Given the
context and purpose of the study, the
Agency focused on an evaluation of the
likelihood that such impacts might
continue or arise in the absence of more
stringent regulation, and whether
subtitle C would be an efficient
mechanism for controlling these
impacts. Specifically, the Agency posed
three 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 waste?
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?
Due to changes made in response to
public comments, these questions differ
from the questions presented for Step 2
in the RTC, In two ways. First, the
Agency eliminated a question
concerning the likelihood of new '
facilities opening in the future and
generating and managing a special
waste in a different environmental
setting than those examined in the RTC.
The Agency acknowledges that this is a
relevant issue and considered it in the
Report to Congress for each industry
and waste that was studied. However,
EPA agrees with public commenters that
an analysis of this issue relies largely on
conjecture about the potential
conditions that might exist at a new
facility, if one were to open. Therefore,
the Agency believes that the potential
for problems at hypothetical new
facilities is less important than the other
factors considered in the decision
making process, and did not consider
the question explicitly in developing the
regulatory determination.
Second, several commenters argued
that subtitle C regulation, even with
Section 3004(x) flexibility, would impose
numerous prescriptive standards that
would not necessarily be needed to
control the problems at a given facility
or across a commodity sector. While
EPA disagrees with many of the specific
points made by these commenters in
support of their arguments, as presented
in the appendices to this preamble, the
Agency agrees that the suitability of
subtitle C controls relative to the
magnitude and extent of the problem(s)
defined in Step 1 is an important issue in
the decision making process and the
approach is also consistent with EPA's
previous approach to making regulatory
determinations under the Bevill
Amendment, which focused on whether
subtitle C, even with the use of Section
3004[x), might be too "cumbersome and
uncertain" to accomplish the goals of
effective regulation of the risks from
special wastes, or put another way,
whether subtitle C is the right
"template" for regulating the special
wastes at issue. 852 F.2d at 1313,1315.
Therefore, the Agency added the third
question listed above for the purpose of
developing today's regulatory
determination.
EPA considered the answers
developed for these questions together
with the answers to the questions
addressed in Step 1 to reach an overall
conclusion on the need for further
evaluation. If current practices or
existing regulatory controls were found
to be adequate, or Subtitle C would not
be an effective regulatory alternative,
and if the potential for actual future
impacts was considered low (e.g.,
existing facilities in remote locations,
low likelihood of actual risk, adequate
federal or state regulatory controls
already exist), then the Agency
concluded that the waste should not be
regulated under Subtitle C. Otherwise,
further examination of regulatory
alternatives was considered necessary.
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,
EPA believed that a waste might be a
candidate for regulation under subtitle
C, then the Agency estimated and
evaluated the costs and impacts of two
regulatory alternatives that are based
upon subtitle C, and one regulatory
alternative that reflects one possible
approach that might be taken under
RCRA subtitle D ("Subtitle D-Plus").
Two evaluations were performed. The
first focused on the magnitude,
distribution, and significance of the
incremental costs of regulation under
full Subtitle C as compared to the
Subtitle D-Plus scenario for each
potentially affected facility. The second
focused on incremental costs and
impacts associated with regulation
under a modified subtitle C ("Subtitle C-
Minus") scenario, that incorporates
waste management standards based
upon site-specific risk potential, as
compared to Subtitle D-Plus. The key
questions in the Agency's decision
making process for both comparisons
were as follows:
1, Are predicted economic impacts
associated with the full subtitle C (or
Subtitle C-Minus in the case of the
second comparison) scenario significant
for any of the affected facilities?
2. Are these impacts substantially
greater than those that would be
experienced under the Subtitle D-Plus
scenario?
3. What is the likely extent to which
compliance costs could be passed
through to product markets or input
costs could be reduced, i.e., to what
extent could regulatory cost burdens be
shared?
4. In the event that costs are
significant, could a large proportion of
domestic capacity or product
consumption be affected?
5. What effects would hazardous
waste regulation have upon the viability
of the beneficial use or recycling of the
special waste?
In EPA's judgment, an ability to pass
through costs or an absence of
significant impacts suggested that
subtitle C regulation (or Subtitle C-
Minus in the case of the second
comparison) might be appropriate for
wastes that pose significant risk. In
cases in which the subtitle C (or Subtitle
C-Minus) scenario would impose
widespread and significant impacts on
facilities, result in reductions in
domestic capacity or supply, and/or
deter the safe and beneficial use of the
waste, EPA concluded that regulation
under some other regulatory authority,
including Subtitle D or TSCA, might be
more appropriate.
III. Regulatory Determination for the 20
Special Wastes From Mineral Processing
The following discussion presents
EPA's conclusions regarding the
appropriate regulatory status of each of
the special wastes frdm mineral
processing, based on information
obtained by analyzing the statutory
study factors in the manner outlined
above. The information summarized
here incorporates information received
during the public comment period and
additional refinement of the data.
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Federal Register f Vol. 56, No. 114^ /L Thursday, June 13. 1991 / 'Rtile s and Regulations 27307
presented in EPA's July 1990 Report to
Congress and January 1991 NOD A. :,
EPA has decided that regulation under
subtitle C is inappropriate for all 20 of
the mineral processing wastes. For nine
of the wastes, no comments were
received that objected to EPA's
tentative determination in the Report to
Congress that regulation under subtitle
C for these wastes is unwarranted.
These nine wastes include:
(1) Red and brown muds from bauxite
refining; :,
(2) Treated residue from roasting/
leaching of chrome ore;
(3) Gasifier ash from coal gasification;
(4) Process wastewater from coal ;
gasification;
(5) Fluorogypsum from hydrofluoric
: acid production; ,
(6) Iron blast furnace slag;
(7) Basic oxygen furnace and open
hearth furnace slag from carbon steel
production;
(8) Slag tailings from primary copper
processing; and
(9) Process wastewater from primary
magnesium processing by the anhydrous
process;
- For the remaining eleven wastes, EPA
eceived at least one comment arguing
that subtitle C regulations should be
promulgated. EPA's determination
rationale for each of these wastes
follows. . ^ '-'--'
Slag From Primary Copper
Processing. An examination of available
information regarding copper slag leads
to the following findings regarding the
three key questions outlined above for
Step I in the Agency's decision making
process.
First, copper slag rarely, if ever,
exhibits a hazardous waste
characteristic. Only one sample out of
70 exceeded-EP-toxicity regulatory
levels, for cadmium and lead. The
Agency agrees with commenters that the
accuracy of the one sample is
questionable, because the cadmium
concentrations in the EP leachate
extract are inconsistently high compared
to concentrations in the total sample
analysis,
Second, although one commenter "
pointed out that the slag contains a
number of constituents in
concentrations that exceed the
conservative risk screening criteria used
in the Report to Congress, these
concentrations by themselves do not
demonstrate that the slag poses a
significant hazard. An examination of
the slag management practices and
environmental conditions at the 10
active primary copper facilities
indicates that copper slag currently
generated at these facilities poses an
overall low risk to human health and the
environment. This is largely due to the
fact that most of the active facilities are
.located in areas with low-risk
environmental and exposure
characteristics (e.g., very low
precipitation and net recharge, large
depths to ground water, large distances
to surface water, and great distances to
potentially exposed populations). As .
; pointed out by several commenters, with
whom EPA agrees, the Agency's risk
modeling for copper slag was very
conservative (tending'to overestimate
risks) and supports a conclusion that the
slag poses low risks as currently
managed.
Finally, following careful review of
the information and public comments on
the copper slag damage cases, EPA
believes that the damages documented
in the RTC for copper slag resulted from
unusual circumstances that generally do
not represent current management
practices. For example, the damages at
Commencement Bay (Puget Sound) were
caused by the use of copper slag, as well
as other wastes, as fill in a wetland or
tideflats area. The nearby copper facility
that generated the slag is now inactive,
and the ten active primary copper
processing facilities are generally
concentrated in arid areas where it is
very unlikely that slag could be
disposed of m a wetland. Similarly, at
the inactive copper facilities hi Midvale,
i UT and El Paso, TX, environmental
contamination has been caused by the
co-management of slag from copper,
lead, and/or zinc processing since the
late 1800's. Based on the available
damage case information, survey
responses, and public comments, EPA
believes that these cases do not reflect
the industry norm today. In addition,
EPA presently does not have damage
case information that suggests that
current copper slag management
practices are causing problems.
Based on these findings, EPA
'concludes that current management of
copper slag does not appear to pose
significant human health or
environmental hazards, and current slag
management practices-appear unlikely
to cause problems in the future. As a
result, Federal regulation under subtitle
C is not appropriate.. Given this finding,
EPA did not evaluate the questions
addressed in Steps 2 and 3 of the
decision making methodology.
Slag From Elemental Phosphorus
Production. Addressing the questions in.
Step 1 of the decision making process,
the information included in the RTC and
provided in public comments leads to
the following major findings for
elemental phosphorus slag. . ,
First, elemental phosphorus slag does
not exhibit any of the four ,
characteristics of hazardous waste. One
commenter contends that the slag is
intrinsically dangerous because it is
radioactive and contains toxic
. constituents. EPA agrees that the
radionuclide content may pose a direct
radiation threat when the slag is used
off-site. (See further discussion oh this
issue later in this section and in section
IV.) However, the slag contains few
chemical constituents that exceed the
RTC's conservative risk screening
criteria by a significant margin, and
none exceed regulatory levels that .
would qualify the slag for subtitle C
controls. ''".,
Second, current on-site slag ;
management practices and ,._
environmental conditions at the five
active elemental phosphorus facilities
generally pose a low risk via the ground-
water and surface water exposure
pathways. Significant risks via these
pathways are limited by the low
concentrations of potentially harmful
constituents in slag leachate and the
generally large size of slag particles that
limit stormwater erosion potential. In
addition, the potential for the slag piles
to cause significant impacts to surface
water is precluded by the relatively
great distance (more than 500 meters) to
the nearest water body at two facilities,
the use of stormwater run-off controls at
the slag piles at two facilities, and the
large flow and assimilative capacity (30
cubic meters per second or 1,058 cubic
feet per second) of the creek closest to
the fifth facility. As the RTC and one ,
commenter point out, one Of the sites is
located within a mile of a wetland; one
' site overlies an area of karst terrain, and
one facility is located in a. National
Forest. While these facts are pertinent^
the Agency believes, based on all the
evidence, that existing management
practices for elemental phosphorus slag
should not significantly threaten these
environments through the ground-water
and surface water pathways, given the
small potential for releases to these
media. ' '
Moreover, although one commenter
points out that ground-water
contamination has been observed at
three of the five active facilities,.
available information on the
documented damages at elemental
phosphorus facilities indicates that the.
ground-water contamination is due to
other wastes and waste management
practices (e.g., historic unlined ponds
used to store process wastewater). This
supports the above.finding that on-site
management of the slag does not pose a
significant ground-water risk. ,-, , ; ...
On^site management at three .
facilities, however, may pose a : ,.
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27308 Federal Register / Vol. 56, No. 114 / Thursday, June 13, 1991 / Rules and iRegulations
moderate risk via the air exposure
pathway due to the chromium, cadmium,
and uranium-238 concentrations in the
stag. Although the vitrified nature and
generally large size of particles tends to
limit wind erosion,,there is some
evidence that dust from slag piles may
be blown into the air and potentially
lead to exposures. As noted in the RTC
and reiterated by one commenter, three
of the facilities are located in fairly
densely populated areas and three are
located in agricultural areas where
airborne deposition and subsequent
food chain exposures are possible.
Based on these findings, EPA
concludes that current on-site
management practices for elemental
phosphorus slag do not appear to pose a
significant ground-water or surface
water risk and are not likely, to cause
significant problems through these
pathways in the future. However, there
is some potential for airborne releases
and resulting impacts; because of the
Agency's desire to fully evaluate all
potential risks, the Agency proceeded to
Step 2 of its decision making process to
evaluate \vhether more stringent
regulation is necessary and desirable.
In this step, EPA made three basic
findings:
The relatively low to moderate risk
from the on-site management of
elemental phosphorus slag is expected
to continue in the future in the absence
of subtitle C regulation given current
waste management practices and
environmental conditions at the five
active facilities. The slag characteristics
and existing management practices at
the five active facilities are unlikely to
change significantly.
None of the states where elemental
phosphorus slag is generated
specifically apply fugitive dust control
requirements to slag piles. However,
adequate authority and mechanisms
already exist under the Clean Air Act to
control this dust. For example, the
National Ambient Air Quality Standards
include a standard for the airborne
concentration of particulate matter, and
the dust could be controlled under the
National Emission Standards for
1 iBzardous Air Pollutants, if necessary.
* Regulation under subtitle C would
Impose significant and specific
requirements (e.g., liners, caps, ground-
water monitoring) that are directed at
controlling releases/risks that do not
appear to exist or are otherwise
controlled and, thus, are not appropriate
given the special status of the waste.5
Based on these combined findings
from Steps 1 and 2, EPA concludes that
regulation of elemental phosphorus slag
under subtitle C is not appropriate under
the circumstances. (Accordingly, EPA
did not proceed to Step 3 of its decision
making process.) EPA plans to further
examine the potential impacts of fugitive
dust emissions from elemental
phosphorus slag piles and will
determine whether controls for these
releases are needed, and if so, whether
they can be developed under the Clean
Air Act.
The Agency is uncertain about the
potential gamma radiation exposures
and risks associated with off-site use of
elemental phosphorus slag in
construction and land reclamation. As
discussed in more detail in section IV of
this preamble, the Agency has
postponed any decisions about the
significance of this risk and the need for
additional control of off-site uses
pending more extensive review. In
response to comments, EPA
acknowledges that the RTC is in error in
its statement that radon emissions from
elemental phosphorus slag pose
significant risks, as other EPA studies
clearly show that the slag is not a
significant source of radon emissions.
However, the fact that radon gas
emissions from elemental phosphorus
slag are inconsequential does not
eliminate concern about the potential for
direct exposure to gamma radiation
emitted from the sl&g.
Slag From Primary Zinc Processing,
Regarding the questions raised in Step 1
of the Agency's decision making
process, a careful review of the RTC
information and public comments on
zinc slag leads to the following three
conclusions.
Based on available data, zinc slag
frequently exhibits EP-toxicity, as 25 of
37 samples contained lead in
concentrations that exceed the EP-
toxicity regulatory level by a factor of
between 5 and 13. Using the,SPLP test,
however, lead concentrations never
exceeded the EP toxicity regulatory
level, although the SPLP test has been
shown on occasion to underestimate the
amount of leachable lead in a sample.
At the same time, based on a review
of existing waste management practices
and predictive modeling results, EPA
believes that zinc slag; as currently
managed at the sole active facility in
Monaca, PA, poses an overall low risk
to human health and the environment.
For example, the Agency predicts that
metals leached from zinc slag at the
Monaca facility would.be largely bound
To be regulated under subtitle C the waste
would have to be listed as a hnzardotis waste
became it does not exhibit any of the four
characteristics that would otherwise classify it as a
hazardous waste.
to subsurface soil and would not reach ,
the deep useable aquifer within 200 ,
years. Even if a shallower aquifer, exists
at the site as the RTC and one '
commenter suggest, any shallow ground
water that may become contaminated
with slag leachate is likely to discharge,
without being withdrawn for human use,
into the adjacent Ohio River via the
steep bluff adjoining the site. The Ohio
River is very large at this point, and EPA
modeling predicts that it can readily
assimilate any chronic loading of
contaminants that may occur, and any ;
such release would be controlled
through permitting under the Clean
Water Act.
A portion of the zinc slag is also sold
for use at off-sjte locations as road
gravel or, construction aggregate, and
another portion is stockpiled until it can
be sold for off-site use as a source of-
iron. Given the high concentrations of
lead measured in EP leach tests of zinc
slag, EPA recognizes that possible off-
site use locations may be more
conducive to releases and risks than the-
existing processing facility in Monaca,
PA, although the Agency has no
evidence that such risks are occurring or
would occur. In fact, the Agency did not
discover any damages attributable to
such slags used off-site.
Third, EPA did not discover any
damage cases attributed to zinc slag at
the Monaca facility. Damage case
studies at inactive sites did demonstrate
the potential for surface water
contamination via stormwater run-off
from zinc slag'piles, however. While ,
these cases demonstrate the potential
for problems if zinc slag is not properly
controlled, they do not by themselves
indicate that more stringent controls are
needed for slag at the one active facility.
In fact, the lack of documented damage
associated with the active facility
supports the'conclusion that zinc slag as
currently managed at that facility poses
a low risk. One commenter argued that .
the lack of damage case data from the
active facility may be: a reflection of the
inadequacy of the facility's :
environmental monitoring system, and
not the absence of actual damage.
However, the Agency believes that slag
at the Monaca facility does not pose a ;
threat, principally because the slag
composition at the Monaca facility is
not considered comparable to that of the
inactive facilities, i.e., it arises from
feedstocks having a different chemical
composition. It should also be noted that
with respect to the commenter's specific
point, the facility has been in operation
for over 50 years and there are no
available monitoring data that show any '
-------
- 1991 /'
27309
evidence of damages resulting from the
management of zinc slag.
The Agency considered these findings,
. by themselves, to be insufficient to -
support a final regulatory determination.
Although qn-site risks and damages at
the sole active facility are low, the
elevated EP leachate concentrations (as
well as difficulties in interpreting the
low SPLP leachate concentrations) and
the prospect of zinc slag being managed
at off-site locations that may present a
problem prompted the Agency to
proceed to Step 2 of its decision making
.process to determine whether more
stringent regulation is necessary and
desirable. In answer to the questions
addressed in Step 2, the Agency found:
that: . ;
The waste management practices
and environmental conditions that
currently limit the pptential-for ......
significant threats to human health and
the environment at the Monaca facility
are expected to continue in the future in
the absence of subtitle C regulation.
Similarly, management practices at off-
site locations would not be expected to
.change significantly. The characteristics
of the slag are also unlikely to change in
the future. , ...
EPA's recently promulgated
. stormwater regulations (55 FR 47990,
November 16,1990) under the Clean
Water Act will minimize the potential
for adverse impacts of stormwater run-
off from zinc slag piles in the future. >_
The only potential problem
associated with these-slags that EPA
has identified is with their off-site use or
disposal. However, the Agency has no
evidence .that such use or disposal is
resulting in environmental damage.
Control under subtitle C would impose
significant and specific requirements
(e.g., liners, closure and post-closure
care) that are directed at controlling
releases/risks that.do not appear to
exist or are otherwise controlled and,
thus, are not appropriate given the
special status of the waste.
Finally, the Agency notes that the State
of Pennsylvania has proposed
regulations that would impose more
stringent environmental controls on the
on-site management and off-site use of
zinc slag, although the exact nature and
extent of these controls cannot be
predicted with certainty. The proposed
rule would require generators to certify
that they have attempted to reuse arid/
or recycle the slag before disposal and
would require permits to contain ;:. .
provisions for liners, leachate collection
systems, monitoring wells, and disposal
of leachate.
Based on these combined findings
from Steps 1 and 2, EPA concluded that
regulation of zinc slag under subtitle C is
inappropriate under the circumstances.
(As a result, the Agency did not proceed
to evaluate the questions addressed in ,
Step 3 of its decision making process.) ',.-.'
Air Pollution Control (APC) Dust/
Sludge From Iron Blast Furnaces.
Addressing the questions in Step 1 of the
decision making process, the
information provided in the RTC and in
public comments on the RTC leads to
the following findings for this waste.
First, EPA found that lead
concentrations measured in iron blast
furnace APC dust/sludge leachate using
the EP leach test only occasionally
exceeded the EP-toxicity regulatory -
level (4 out of 70 samples from 3 out of 16
facilities with data). In addition, the
waste is recycled (completely at one
facility and partially_at another) at two
of the three facilities where the waste
was found to be EP-toxics Although lead,
concentrations determined by SPLP
analyses never exceeded the EP toxicity
regulatory level, the Agency has
difficulty interpreting these
measurements because the SPLP test
has been shown on occasion to
underestimate the amount ^of leachable
lead in a sample. .'
At the same time, based on an
examination of the site specific
conditions at 15 of the 26 facilities that
generate this waste, current
management practices and
environmental conditions are highly
variable, with the potential for
contaminant releases existing at some
sites. For example, there is potential for
ground-water contamination at five
facilities that manage at least some of
the dust/sludge in surface
impoundments, although the low EP
leachate concentrations at these
facilities (none exceeded the EP-toxicity
regulatory levels) would appear to
suggest that any such contamination
would not likely be significant. The.
dust/sludge also consists of small
particles that are amenable to release
and transport via stormwater and wind
erosion when the waste is managed in
exposed piles. Due to site-specific
management practices and
environmental conditions, there appears
to be some potential for migration into
surface water at four facilities and a '
potential for airborne releases and
exposures at seven facilities.
One commenter argued that risks ,
posed by this waste could be
substantially higher than reported,
because, as the commenter-pointed; out,
the RTC did not consider the site- -.;.,-
specific conditions at all active facilities,
inactive facilities that could be *
reactivated in the future, and potential
new facilities. While the commenter ''-'
raises a good point, the Agency notes
that the sample of facilities examined in
the RTC represents more than half (15)
of the 26 active facilities and seven of
the ten states where active facilities are
located. Furthermore, the conditions '
examined in the RTG represent a wide
diversity of management practices and
environmental conditions. Specifically,
all known management practices for the
dust/sludge were represented by the 15
sample facilities, including disposal
methods (landfills and ponds) and
temporary storage methods (storage
pads and transfer, areas), such as might
be present at facilities that recycle the
waste or send-it off-site for disposal.
Some of these units are equipped with
engineered controls to prevent releases
(e.g., liners and run-off controls), while
others are not. In terms of
environmental conditions, the facilities
examined represent a variety of depths
to ground water, net recharge rates,
distances to surface water, -and
proximities to potential receptors. As a
consequence, the Agency believes that
,the facilities examined reasonably ",-
represent the conditions that might exist
at the.other facilities. EPA thus believes
that the hazards that Were evaluated
reflect the diversity and nature of
hazards posed by iron blast furnace- --.-.
APC dust/sludge at the other facilities.
Finally, despite the Agency's :
theoretical conclusions about the
potential for iron blast furnace APC
dust/sludge to be released into the
environment at some facilities, EPA did
not find any damage cases attributable
to this waste, which EPA believes to be
significant when evaluating the actual
hazards posed by special wastes. One
commenter alleged that there are such
documented damage cases, but that EPA
did not discover them because it did not
review files for inactive sites and other
key information sources, However, as
stated in the Agency's responses to
comments on the RTC's analytical
methodology (see appendix A of this
preamble), the Agency maintains the ,
view that its damage case investigation
- effort for these and other wastes was
comprehensive and thorough. The
Agency closely evaluated the specific
information sources referenced ,by the
commenter and, though the information
clearly shows'environmental problems
at ferrous metal production facilities,
EPA does not believe that the damages
can be attributed to the special wastes
studied in the Report to Congress. For
example, surface water and ground-
water impacts were found related to
"slag landfills'* at.two facilities, :but the
landfills contained a number of co-.
disposed wastes, including sludges, fly
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27310 Federal Register / Vol. 56, No. 114 / Thursday, June 13, '1991 /^ Rules
ash. waste acid, end coke plant tars, all
of which may have contributed to the
observed impacts.
In summary, this waste exhibits
hazardous waste characteristics only
rarelyonly three facilities out of 16
with data generate dust/sludge that
exhibits the toxicity characteristic, and
even then the data suggest that the
waste exhibits the characteristic only
occasionally. Moreover, the waste is
recycled (completely at one facility and
partially at another) at two of the three
facilities where it occasionally exhibits
the toxicity characteristic. The Agency
recognizes that existing waste
characteristics, management practices,
and environmental conditions could
lead to releases at selected facilities.
However, the low EP leachate
concentrations at most facilities and the
lack of documented cases of damage
attributable to the dust/sludge indicate
that the potential effects of such
releases are not of sufficient magnitude
to warrant removal of the special status
of these wastes. In addition, EPA's
recently promulgated stormwater
regulations (55 FR 47990, November 16,
1990) under the Clean Water Act will
minimize the potential for adverse
impacts of stormwater runoff from the
dust/sludge. Based on these findings,
EPA concludes that regulation of this
waste under subtitle C is inappropriate
under the circumstances. (Accordingly,
the Agency did not evaluate the
questions addressed in Steps 2 and 3 of
its decision making process.)
Basic Oxygen Furnace and Open
Hearth Furnace Air Pollution Control
(APC) Dust/Sludge From Carbon Steel
Production. Based on a review of
information in the RTC, supplemental
analysis, and public comments on steel
APC dust/sludge, EPA's responses to
the questions in Step 1 of the decision
making process are basically the same
as (hose outlined above for iron blast
furnace APC dust/sludge. Specifically:
» Steel APC dust/sludge appears to
be EP-toxic only rarely. Of seven
samples analyzed from five facilities,
the concentration of selenium exceeded
the EP-toxlcity regulatory level in only
one sample, and in this one case, only
by a factor of 1.5. Selenium
concentrations as determined by SPLP
analyses did not exceed the EP-toxicity
level.
Based on an examination of the
site-specific conditions at 11 facilities
that generate the dust/sludge, current
management practices and
environmental conditions are highly
variable, with the potential for
contaminant releases existing at certain
facilities. Like the iron blast furnace
APC dust/sludge, however, there
appears to be only a minor potential for
ground-water contamination at a few
facilities that manage the steel APC
dust/sludge in impoundments. The steel
APC dust/sludge consists of small
particles that would be amenable to
release and transport via stormwater
and wind erosion if the waste is not
properly controlled.
EPA did not identify a single case of
documented damage that can be
attributed to steel APC dust/sludge. .
Based on these findings, EPA
concludes that subtitle C regulation for
steel APC dust sludge is inappropriate
under the circumstances that exist.
(Therefore, the Agency did not employ
Steps 2 and 3 of its decision making .
methodology.) The basic rationale for
this conclusion is the same as that for
iron blast furnace APC dust/sludge.
That is, the dust/sludge rarely if ever
exhibits a characteristic of hazardous ;
waste. Although existing management
practices and environmental conditions .
have the potential for environmental
releases at certain facilities (although no
evidence exists that such contamination
has occurred or would occur), the
waste's low contaminant concentrations
and lack of damage cases indicate that
the potential for adverse effects is not of
sufficient magnitude to warrant removal
of the special status of the waste. Thus, '
to the extent that additional controls
may be justified, and state management
controls are deemed to be inadequate,
EPA may pursue appropriate controls
for steel APC dust/sludge management
under the Subtitle D program being
developed for mineral extraction and
beneficiation wastes.
Calcium Sulfaie Wastewater
Treatment Plant Sludge From Primary
Copper Processing. In the Report to
Congress, EPA tentatively recommended
subtitle C regulation for this waste
under Approach IB. However, EPA
received data in comments indicating
that only one facility now generates and
disposes of this sludge. In addition, as
outlined in section II of this preamble,
the Agency modified Step 2 of its
decision making methodology in
response to public comments to
deemphasize consideration of potential
threats that could exist at any new
facilities that open in the future in favor
of the other Step 2 factors, in light of the
speculative nature of EPA's predictions
regarding industry expansion. The
possibility of expansion was an
important factor contributing to the
RTC's Subtitle C recommendation for
this waste. EPA, therefore, has
reconsidered the RTC tentative
recommendation, focusing only on the
remaining active generator (located in
Garfield, UT). .
Addressing the three questions
considered in Step 1 of the decision ,
making process:
The sludge at the Garfield facility is
EP-toxic for arsenic (7 out of 7 samples
average 44 times the regulatory level),
cadmium (6 of 7 samples average 3 times
the regulatory level), and selenium (7 .of
7 samples average 5 times the regulatory
level). SPLP leach test concentrations,
however, were below the subtitle C
regulatory levels for all of the samples
analyzed.
One commenter argued that calcium
sulfate sludge poses a large risk that ,
should be controlled under subtitle C;
however, based on a review 'of existing
management practices and: the arid'
setting of the Garfield facility, EPA
believes that the hazards associated
with calcium sulfate sludge at this site
are low. Predictive modeling that
accounts for the low net recharge and
high evaporation rate, depth to ground
water, and clayey subsurface at the site "
indicates that the potential for ground-
water contamination is very low.'
Similarly, the potential for significant
surface water contamination is '
negligible given the great distance of the'
sludge management units to the nearest -
surface water body (over 2 miles to the
Great Salt Lake), and windblown
dusting is significantly limited by the
surface crust that forms on the dried
sludge.
* No cases of documented damage
caused by the sludge at the one active
facility were discovered by EPA.
Even though the site-specific risk
findings and lack of damage cases
indicate that management of the sludge '
does not pose human health or
environmental problems, the high
intrinsic hazard of the sludge compelled
EPA to consider additional factors
before reaching a final regulatory
determination. Therefore, EPA
proceeded to Step 2 of its decision
making process to examine whether
more stringent regulation is necessary
and desirable.
In Step 2, EPA found that current
practices at the Garfield facility appear
adequate to limit contaminant releases ;
and associated risks in the future in the >
absence of subtitle C regulation. The
sludge is well managed at present and
the potential for releases appears to be
precluded by the environmental
conditions at this site. Specifically,
potential releases to ground water are
significantly limited by the site's very
arid setting (liquids discharged to
impoundments along with the sludge are
expected to quickly evaporate and little
precipitation and recharge is available
to carry contaminants to the
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Federal Register /Vplj 56, No,' 114 /; Thursday, ,Juae:,13, 1991 /; Rules -and
subsurface), clayey subsurface, and '..-
depth to ground water (8. meters, to the
,water table and 90 meters. to the
uppermost useable aquifer). Because .the
nearest Surface water near the sludge
units, the Great Salt Lake, is over two
miles away,',significant releases to '
surface watp also should not be a
problem. Finally, the potential for :-
.significant/releases to air is limited,
because a surface crust forms on the
dried sludge, largely. preventing the. ; ,
wind from blowing dust into the air, and
because the'dried sludge is exposed to
the wind only temporarily .before it js ;
'Stabilized and. buried in ah on-sitd':
' ' '
.. ,. .. .. .
- EPA also found in Step 2 that existing
state regulatory programs provide, only
limited controls over the- management :6f:
. cataium sulfate sludge. Some-'' , "' ; ;".-:"';'' ';'
comme'riters argued that the RTG's'- :
analysis of state regulations
significantly understates ' the regulatory
requirements' applicable to copper
processing wastes. Howeveivupon,';
further con'sideration pf-ayailable
inforriiation and communication! with-
state officials; EPA ebncmdes'that-the
states have been regulating 'copper'
^processing, wastes, including calcium
sulfate sludge; 6nly;tp a- limited extent. /
However, as discussed b'elo.w, the . :
Agency does not believe, ba'sed'oh ..
available; inforihatroh,. that this limited
: Wgulatidn has resulted ^iit1^^ * :i;.;;-;^ '
' envirpnme'ntal'probleins. ."' ''' >' '; ' "'.
Finallyi .EPA also cpncluded in Step 2 -
...that Subtitle G. regulation of calcjuin
sulfate wastewater treatrnent, plant ''.
sludge wpiild jmpose signifiaant and; ..."
specific requirements .(e.g.; liners, caps,
grouncU water monitoring) that are ..'..
directed at controlling releases/risks
that do not appear to exist or are ,'
otherwise. controlled and, thus, are not '
appropriate given the special status of
the waste; . -.- .--, .--..-
Based ort these combined findings
from Steps 1 and 2, EPA concluded that
existing sludge management practices at
the one facility in question currently
limit the potential for damages. >
Therefore, considering all of these
findings together,. EPA concludes that
subtitle C regulation of;calcium sulfate
sludge is inappropriate given the . r
.existing circumstances. (Accordingly,
EPA did not evaluate -the.questions ].
addr.essed.in Step 3 of its decision- , ; .
making methodology.) EPA may address
the generation and management of this ".
sludge under the subtitle D program
under development for the mining' ;
industry.
; This subtitle D determination differs,
from the RTC's tentative . ; - r '",,
recommendation fpr two reaspns. First, ;
potential human .health^ and, ,; ;
environmental problems at pne copper: /,.
processing .facility were droppe,d from > i
consideration because public comments
indicate that the .facility no longer .:
generates and disposes of calcium ;
sulfate sludge. Second, the Agency. *
agreed with commenters that concerns
expressed in the RTC about ppt.ential
problems at new facilities rthat may open
in the future are somewhat speculative.
Therefore, EPA did not place as much
weight on .these concerns in making the
regulatory determination as-it did in the
RTC;.." '" - -1.',:'"1-.1-.;";:;;;';:".,;."
Chloride Process Waste Splidsfcom .:
Titahiuin Tjktfachioride Pfodu6tJoin. Jtt' "
- the RTC, EPA tentatively recommended ,'
subtitle G Regulation for this waste '.'.' / '.';
under Approach.IB.'Hoivever, '.-'"' ".'''
radditipnal 4aia submitt.ed in publjfc , '''-:
"comments and reanalysis' of the' &TC :
data indicate that the waste is not EP- -"
toxic for lead'as indicated in.'thig RTC 6
and,.therefore, is EP-toxic only for
chromium. In addition, this waste would .,'
currently be exempt from "subtitle C
regulation by 40 GFR 261^{b){6), which
exempts wastes that are hazardous only
because they exhibit the EP toxicity J . ;
, characteristic fbr chrpmiuih, conlain- -"
only trivalent chromium, and are; ; ;
managed iii non-oxidizing environments;,
For these reaspns, EPA decidedtfa. . '
reevaluate:the RTG's tentative - :. .;,
conclusions.'.'''.'' .','- ' '<:* '-;.:'!;'-'.:.'--- ,.{',,::-
Cdriside'rjng the three questipjisvin '<-,?-''.
Step 1. of the Ageiiicy's decision makiiig-1:
process; the Agency has made;the-;.!
following findings. First, the Waste is.;", f,
characteristically hazardous only as a ;
Tesult of-its chromium .contents whic'h is
currently exempted from regulation
, under subtitle C of RGRA by ''':'
§ 261i4(b)(6){i)(A). In addition, chromium
concentrations in the waste solids.
measured using the SPLP leach 'test aire
below the EP-toxicity regulatory levels,
as indicated.by further analysis of the
RTC data and information submitted in
comments. ''-' : .
Second, based on an examination of
existing conditions at the nine active .
titanium tetrachloride facilities, EPA
found that current management ofthe
waste solids may allow contaminants to
migrate in the -environment at certain
sites, but thatthe, potential for this - . ...
'migration to cause significant impacts is
low. For example, there appears to be a
potential for leachate from -this"waste-to"'-.
reach -ground-water at half of the sites,
0 The sole sample found to contain lead above the
EP-tpJdc level was determined to ,be for the waste
acids and entrained solids discharged to an pri-site' ".'
impoundment; not the titanium waste :solids.(the
special waste) that settle (o the bottom of the'
impoundment. EPA has determined, therefore! that
this sample is not appropriate for use in '.. -. :
characterizing the waste solids. ';. ' ' :
but predictive modeling at the ''most ;
. sensitive". siterindieates that -.--. ;
-, contaminant concentrati.ons at the .:."'.
property boundary would be below
drinking water standards: Similarly, the
Agency's mpdeling predicts that :
cpncen tra tiohs of contaminants in . :
surface waters near the sites would be
well below human health and
environmental protection benchmarks,
and that:the risks associated with the -'.'
inhalation of windblown dust from the /
waste solids piles would be negligible..
One commenter argued that the risks
posed by- this waste.are sufficiently high .
to warraht regulation under subtitle G. :
. ,Jn.particular, theicommenter argued that
chemical c.pheentrations (e.g., of ' '
,- .chromium, lead,: radium, and arsenic) in,
,;fhej waste Solids,could be muchiigher--."-'
;'tlian the.few.s^mples examined i'ii the ,;:
, iRTC, that the wastes threaten fragile :
ecosystems hear several of the facilities,
and that drinking water threats could "'"'-.'
, exist,if priyate wells were installed '
^closer to existing facilities. While'EP^. .
agrees therei is always a ppssibility'that'
the waste coiild contain higher chemical
cpncentratioris than those reported,-the
Agency used 17 samples from 7;fabilities
arid; believes the resulting ',':'; >:'".'"--.'..-
chara'cterizatitin of the.was'te'is'-,';'"-'
adequate. The Agency also recognizes , "
."that several sites.are located-near :, .
*t '.'fragite'! ecp^ysfems: Sjx pf the hihe : '::
,^^actiye; facilities. afe^^iQcatep; witEiini;i;6pO' '
meters (i,iiule) of a: Wetland, one is- ' "r -
.located witliin 2,600.njeters:qf'ah. ' ' -' ;
endangered species habitat, and three "
are: loeated Within 1,600 meters of a- . ;
Natidhai;Parki Wildh'fe Refuge,* or ^
Recreation Area. .Howevef, the Agency's'
conservative modeling predicts that it is :
very unlikely that contaminants ,- ,
released from the'waste solids- ;,,
management Junits could migrate to
these areas in harmful concentrations.
Finally, EPA's ground-water modeling
for the "worst-caise" facility predicts
that contaminant concentrations.at the
property boundary are below health- '..
based and ground-water protection ' ;
criteria. Therefore, it does not appear
, that releases to ground water would
pose a serious threat to the ;
environments surrounding each plaut. ,
Third, EPA found no documented ,'
cases.of damage attributable to titanium
tetrachloride yyaste'solids. No evidlence ',
, of damages was uncovered in the RTC's
comprehensive review pf all nine active
and two inactive titanium facilities, and ,
no.new damage ease information was
.submitted in public comments. .
.Based on these findings, EPA : . !;: :
concludes that regulation of titanium. V
tetrachloride waste solids under RCRJ8; .
Subtitle G is inappropriate under-the
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*27312 federal Register / Vol. 56, No. 114 / Thursday, June 13, 1991 / Rules and Regulations
circumstances. (Accordingly, the Agency
did not evaluate Steps 2 and 3 of the
decision making methodology;) Current
on-aite management practices do not
appear to pose a significant risk. In
addition, management practices are
likely to be improving because the
waste is currently comanaged with
waste acids from titanium tetrachloride
production, a waste that recently
became subject to subtitle C controls.
EPA plans to follow closely the changes
in management practices that are
expected to result from the change in
regulatory status of the waste acids,
changes that in some cases may result in
management of the waste solids in units
subject to subtitle C requirements. At
those facilities where the waste is not
managed in units regulated under ,
subtitle C, EPA believes that releases
that may occur can be adequately
addressed under subtitle D given the
special status of these wastes. In
addition, in the final Toxicity
Characteristic rulemaking, EPA
Indicated that it would re-evaluate the
trivalent chromium exemption in
I 261.4(b)(6) (55 FR11812, March 29,
1990). If EPA finds that this exemption is
not protective of human health and the
environment and if an examination of
titanium tetrachloride waste
management shows any continuing or
new problems, the Agency will
reconsider this subtitle D determination
for chloride process waste solids from
titanium tetrachloride production.
Today's subtitle D determination is
warranted and differs from the RTC's
tentative recommendation primarily due
to changes in the data base used to
characterize the waste, such that the
waste only exhibits the toxicity
characteristic of hazardous \vaste for
chromium and is exempt from subtitle C
regulation. As discussed above,
consideration of changes in management
practices for waste solids that are
expected as a result of the classification
of waste acids from titanium
tutrachloride production as a hazardous
waste supports a subtide D decision. In
addition, if the decisionmaking process
had been carried to Step 2, the fact that
the Agency modified Step 2 of its
decisionmaking methodology (in
response to public comments) to
decmphasize consideration of potential
threats that could exist at any new
facilities that open in the future, would
also have contributed to the change
from the subtitle C tentative
recommendation in the RTC to today's
subtitle D regulatory determination.
Stag from Primary Lead Processing. In
the Report to Congress, EPA tentatively
recommended subtitle C regulation for
lead slag under decision making
Approach IB. Further Agency analyses
in response to public comments,
however, provided a clearer picture of
the three damage cases presented in the
Report and the risks associated with one
facility's practice of shipping its slag off-
site for disposal. EPA, therefore,
reconsidered the RTC's tentative
recommendation to account for this
additional information.
Addressing Step 1 in the Agency's
decision making process, which
evaluates whether management of the
waste poses human health or
environmental problems, EPA made four
basic findings. First, lead slag is EP-
toxic using results of the EP leach test;
EP-toxicity leach tests show that lead
exceeded the regulatory level at all five
active facilities in a total of 27 out of 101
samples; the maximum lead
concentrations exceeded the regulatory
level fay a factor of 19. Cadmium
concentrations exceeded the regulatory
level at two facilities, by as much as a
factor of seven. Arsenic, mercury, and
selenium concentrations also exceeded
the regulatory levels at the one facility
that is only a refinery (the other
facilities are either combined smelters
and refineries or, in the case of one
facility, only a smelter). No samples
analyzed using the SPLP test contained
contaminants in concentrations above
the EP-toxicity regulatory levels;
however, the SPLP test has been shown
on occasion to underestimate the
concentration of leachable lead in a
sample.
Second, current practices for
managing lead slag at the five active
lead processing facilities appear to limit
the potential for significant impacts
caused by the slag. The potential for
lead slag to cause significant surface
water contamination at all but one
facility is limited by the use of control
systems that retain and treat storrnwater
run-off from slag piles prior to discharge,
or by an expected small contaminant
loading that is well within the
assimilative capacity of nearby water
bodies and is subject to control under
the Clean Water Act. Risk modeling
indicates that stormwater erosion of a
lead slag pile at one facility could result
in surface water contamination.
However, due to releases to ground
water from unlined wastewater ponds at
this facility, the site is presently being
cleaned up under the Superfund
program, and any potential surface
water impacts associated with erosion
from the slag pile will be addressed as
part of the site's overall Superfund
response. EPA's recently promulgated
stormwater regulations'(55 FR 47990,
November 16,1990) under the Clean
Water Act will also minimize the
potential for adverse impacts of
stormwater runoff from lead slag.
The Agency's modeling indicates that
it is possible for some contaminants to
leach from lead slag piles at two of the
active facilities and migrate into
underlying ground water. However,
increased on-site concentrations of
constituents in ground water are .. .
expected to be well within applicable
drinking water standards. Air pathway
modeling also indicates that it is very
unlikely for lead slag piles to cause
harmful concentrations of contaminants
in the air at the nearest residences. One
commenter contends that lead slag
should be regulated under subtitle C
because windblown dust from slag piles
could pose a significant risk by resulting
in an accumulation of contaminated
dust in residential areas where people
could be exposed directly. However, a
Remedial Investigation/Feasibility
Study at the facility in East Helena, MT
has shown that slag management is a
very minor contributor to windblown
particulate matter and accumulated dust
in the site environs.7 As much as 95
percent of the lead particulate matter
measured in air near the East Helena
facility was found to come from ore
processing areas and other sources, not
the slag piles.
Third, there is a greater potential for
human health and environmental risk at
two off-site municipal landfills where
lead slag from one facility is disposed,
although the Agency has no evidence
that such management does present a
substantial hazard. Although the total
quantity of slag that is shipped to these
off-site landfills represents only 3
percent of the total quantity of slag that
is generated, the slag that is shipped off-
site is the highly concentrated refinery
slag that is consistently EP-toxic for
mercury, lead, cadmium, arsenic, and/or
selenium.
Fourth, historical slag management
practices have clearly caused ground-
water contamination at one site, but
steps have since been taken to help
prevent this contamination from
occurring in the future. The RTC
reported damage cases at two other lead
facilities, but close examination of the
RTC data and information submitted in
public comments has eliminated one of
the damage cases and called the other
one into question. Specifically, EPA's
ongoing Superfund evaluation at the
lead facility in East Helena, MT has
7 Comprehensive Remedial Investigation/
Feasibility StudyASARCO Incorporated, East
Helena, Montana, March 30,1990.
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uneJ' 13' 199*
*d /Regulations : :«? 27313
demonstrated thai ground-water :
-contamination.'at that site has been
caused by two on-site wastewater;
impoundments. Contribution'.io the
problem from the lead slag pile is
thought to be limited, though further
study is planned. At the other .site,
located in Boss, MO, observed ground-
water contamination is notclearly
attributable to slag, as it too may have
been paused .by nearby'wastewater
impoundments. The Agency's risk
modeling predicts that grounds-water
contamination from the slag pile at this
site is unlikely.
Based on these findings^ EPA
concludes that the potential for lead slag
' to cause significant impacts is limited by
the current management practices arid
conditions at the five active facilities,
but there is some potential for adverse
impacts that may be caused fay the off-
site disposal of relatively small
quantities of lead slag from one facility.
Therefore, EPA proceeded to Step 2 of
its decision making process to evaluate
whether more stringent regulation is
necessary and desirable. In this step' of
the process, EPA found that: ;' "
" ' Curreiit practices at the off-site
landfills that'are receiving lead slag for
disposal may not be adequate; to limit
contaminant release and associated
risk. As mentioned above, these are
municipal landfills that may or may not
be adequately equipped to contain
contaminant migration from lead slag.
In Nebraska, where all of the .
present off-site disposalof slag takes
place, the slag could continue to be
managed at off-site locations in the "
future with riiininial state regulation.
The other states where primary lead
processing occurs have varying degrees
of regulatory control. The State of
Missouri, for example, where three
facilities are located, has recently
developed strengthened permitting,
closure, mairitenanpe, and financial
assurance requirements for facilities
that manage mineral processing wastes..
In addition, stormwater run-off from
lead slag piles into nearby surface
waters is subject to control under the
' Clean Water Act in all three states
where the slag is currently managed.
.. Because subtitle C regulation would
subject the slag to strict hazardous '_v
waste management standards, it would ^
prevent the disposal of slag in municipal
landfills. However, a subtitle C,
- determination for this wasjte would also
impose significant and specific
requirements for on-site management
(e.g., liners, closure and postclosure
care, ground-water monitoring) that are
directed at controlling releas.es/risks
that dp not. appear-to exist or are,!..:.:.
otherwise contrplled at thefive active
lead processing facilities and, ;thus, are v
not Appropriate given the special status
of the waste. In particular, the Agency
does hot believe that it is appropriate to
subject the entire industry to stringent
subtitle C controls when any potential
problems appear to be associated
primarily with only, 3 percent of the lead
slag that is currently produced.
Based on the combined findings from
Steps 1 and 2, EPA concludes that
regulation of the waste under subtitle C
is inappropriate.under the
circumstances. (Accordingly, EPA did
not proceed to evaluate the questions " ,
addressed in Step 3 of its decision
making process.};The Agency, therefore,
will work to ensure that both on-site and
off-site slag management-practices are:
adequately protective under subtitle D
and under the Clean Water Act. In
particular, EPA will investigate further
the offsite disposal practices Used by the
Omaha facility to determine the extent..
to which slag is currently co-disposed
with municipal waste. If the , :
management, of this waste d0es prove to
be problematic, EPA may, for example,, .
classify co-disposal of the slag with ;.
municipal wastes as open dumping
under RCRA section 4004. Open ' V.-
dumping is a prohibited practice under ;.
criteria promulgated under sectiop 4004.
This determination differs from the
RTC's, tentative recommendation
primarily because the Agency closely
reexamined the three lead slag damage
cases discussed in the Report to
Congress in response to public
comments. As outlined above, this
examination determined that controls
have already been established at one
site to address the problem, that another
case appears to be mainly if not entirely
due to wastes other than lead slag, and
that attribution of the third case to slag
management practices is questionable.
^Therefore, an important factor in ;
tentatively recommending Subtitle C T
regulation in the RTC: has been removed.
Process Wastewater From, the:
Production of Hydrofluoric Acid. EPA
tentatively recommended subtitle C
regulation for hydrofluoric, (HF) acid
process wastewater-under Approach 1A
;and IB in the Report to Congress.
Additional daUt,submitted in public,
comments and follow-up with the State
of Louisiana, however, confirm that the
documented damages cited in the Report '
are attributable to phosphoric acid ,
wastewaters, and not HF process :
wastewater as reported in the RTC. EPA
also found that two of the three active , ;
HF acid production facilities neutralize
their wastewater. Accordingly, EPA has
reconsidered the RTC's tentative: . .; '.
recommendation. ;-.->,;:-...':. .^;-;- .-,>..-,.,'.
: ; Reconsidering the three questions > .-.
addressed in Step 1 of the Agency's
decision, making process, the Agency,;:_
reaches three basic, findings. First, all
nine samples of-process wastewater
'analyzed (from two of three active-
facilitiesj-exhibited the hazardous waste
characteristic of corrosivity. However,
no constituent concentrations exceeded
EP-toxicity regulatory levels (all eight- -
inorganic constituents with EP-toxicity
regulatory levels were measured in :
concentrations that were no more than
0.6 times the regulatory levels).
Second, as the RTC and one
commenter who argued for subtitle G
regulation pointed out, ther'e is a
relatively high potential for.process.
wastewater to migrate into shallow
ground water at the three active ;
facilities. However, EPA does not
believe that this migration will pose
significant health risks, either because
the shallow ground water is not likely to-
be used at close downgradient distances
or because the waste management units
are equippedwith controls (e.g., a,
monitoring well.network and slurry . , '- .
walls) to detect and help contain , :
ground-water contamination. : ......
One commenter identified a number
of factors:that would, according to the
. commenter, tend to .make risks higher ;,
than presented in the RTC (e.g., the
presence of shallow ground water, the.
current lack of liners beneath existing
impoundments, the potential for changes
in population and land use patterns
leading to higher risks in the future, the,
wastewater's.corrosivity,,and the close
proximity of each existing facility to
wetlands). All of these factors were
considered in the RTC and contribute to
EPA's concern that shallow ground
water near existing units may be
affected. However, EPA does not agree
that the RTCf understates the potential
impacts associated with this . . :
contamination, because the
concentrations of'Contaminants in the
wastewater are-generally low. No
constituepts in the wastewater were ,
measured in concentrations above the
subtitle C regulatory levels, and few ; -
exceeded the highly conservative risk ..
screening criteria used in the RTC by
more than a factor of 10. .Therefore,
although the ground-water may become
contaminated taboye levels of concern in
the immediate vicinity of waste .
, management! units, contaminants are not
expected to migrate downgradient to
potential human or ecological exposure
points. ..' .'."" . ,;'.'
; Third, new data provided in ,.- . . '
comments appear to indicate that , . --
shallow ground water at one. of the ',' ,
activeifaeilitie.s has been!pontamin.ated,;.
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27314 Federal Register / Vol. 56, No. 114 / Thursday, June 13, 1991 / Rules and Regulations
with sulfate, total dissolved solids
(TDS), and fluoride.8 Concentrations of
sulfate and TDS in a few wells
surrounding wastewater management
units exceed upgradient concentrations
and secondary drinking water standards
(designed to prevent an unpleasant
taste). Fluoride concentrations in the
ground water exceed background
concentrations but do not exceed the
health-based drinking water criterion.
Contamination above the sulfate and
TDS standards appears to have
migrated at least 50 meters
downgradient from the units. No
significant effect on pH has been
observed, however, even though the
very low pH of the wastewater would
appear to pose the greatest threat. In
addition, no data are available on the
concentrations of metals and other
constituents with subtitle C regulatory
levels, but any contamination by these
constituents is expected to be minor
because concentrations in the
wastewater are low, as discussed
above. No other cases of documented
damage attributable to HF acid process
\vastewaterare known to exist.
Based on these findings, EPA
concluded that additional waste
management controls for HF acid
process wastewater might be
appropriate, and proceeded to Step 2 of
Its decision making process. In this step
of tho process, the Agency found that:
Current practices at two of the three
active facilities are probably adequate
to limit contaminant release and
associated risk. One of the two manages
the wastewater in a surface
impoundment bounded by a slurry wall
and conducts ground-water monitoring,
while the other neutralizes the
wastewater prior to using it for gypsum
transport.
It does not appear that existing
state controls adequately address the
management of this waste at all
facilities. Of the three states where
active facilities arc located (LA, TX, and
KY), Louisiana appears to be most
comprehensive in its regulation of
hydrofluoric acid process wastewater.
The other two states impose less
stringent requirements, though Kentucky
recently proposed new solid waste
regulations that may address process
wastewater more directly.
Though the corrosivity of the
wastewater is a potential concern, it
docs not appear to pose a significant
problem at the three active facilities
based on available ground-water
monitoring data. In addition, the
concentrations of RCRA Appendix VIII
constituents in the waste are low
enough that they are not expected to
result in exceedances of applicable
standards in ground water. Regulation
under subtitle C would also impose
significant and specific requirements
(e.g., liners, financial responsibility) that
are not appropriate given the special
status of the waste.
Based upon the combined findings of
Steps 1 and 2, EPA concludes that
regulation of process wastewater from
hydrofluoric acid production under
subtitle C is inappropriate. Although the
waste exhibits the hazardous waste
characteristic of corrosivity, the low pH
of the wastewater does not appear to
pose significant human health or
environmental hazards at the three
active facilities. Moreover, the only
constituents which were found in the
wastewater at significant levels (e.g.,
sulfates, fluoride) are not listed in
appendix VIII of part 261. Thus, aside
from corrosivity, subtitle C would not
identify or list this waste as hazardous
under subtitle C. Consequently, to the
extent that state programs'are
determined to be inadequate, the
Agency plans to pursue methods within
the developing subtitle D mining wastes
program to control risks posed by this
waste. (Accordingly, EPA did not
proceed to evaluate the questions
addressed in Step 3 of its decision
making process.)
This determination differs from the
RTC's tentative recommendation
primarily because the Agency closely
reexamined the reported damage case in
response to public comments. As
outlined above, this examination
demonstrated that the damages
described in the RTC are_actiiE.-lly
attributable to a differenf waste, rather
than to HF acid process wastewater.
Therefore, the primary reason for
tentatively recommending subtitle C
regulation in the RTC has been removed.
Phosphogypsum and Process
Wastewater from Phosphoric Acid
Production. The Report to Congress
considered two special wastes from
phosphoric acid production:
Phosphogypsum and process
wastewater. E?A believes that it is
appropriate to address these two wastes
together in this regulatory
determination. Although the wastes do
not necessarily have to be co-managed,
all of the active phosphoric acid
facilities presently manage the gypsum
and wastewater together in one system,
consisting of a phosphogypsum stack
and associated impoundments.9
Therefore, it is not possible to make a
determination for one waste without, in
practice, affecting the status of the other
waste at all of the operating facilities. In
addition, though the two wastes have
distinct physical and chemical
properties, it is very difficult to attribute
environmental problems in the vicinity
of the waste management units to one
waste or the other. Moreover, given the
existing co-management of the wastes, it
is also appropriate to evaluate the two
'wastes together from the standpoint of
alternative management practices and
cost/economic impacts.
In the Report to Congress, EPA
tentatively recommended Subtitle D-
Plus regulation for both phosphogypsum
and process wastewater. Since
publishing the RTC, EPA has conducted
a supplemental analysis of management
technologies and state regulations for
the two wastes, and received and,
evaluated public comments on the RTC
and supplemental analysis. In addition,
in response to public comments, EPA
has more closely evaluated existing
ground-water monitoring data for the
active phosphoric acid facilities and
analyzed the potential costs associated
with the corrective action provisions in
RCRA sections 3004(u) and 3008(h). EPA
therefore reconsidered the RTC's
tentative recommendation to account for
. this additional information.
Addressing Step 1 in the Agency's
decision making process, which
evaluates whether management of the
wastes poses human health or
environmental problems, EPA made
three findings.
First, both the gypsum and'process
wastewater exhibit a characteristic of
hazardous waste, but the gypsum
appears to do so only rarely Out of 11
facilities with data on the composition
of phosphogypsum, only the gypsum at
the facility in Rock Springs, WY exhibits
the characteristic of EP-toxicity. Two
out of two samples of phosphogypsum
from this facility contained
concentrations of chromium that exceed
the toxicity characteristic regulatory
level, by a factor of six, on average, This
appears to be a characteristic restricted
to gypsum derived from the processing
of certain phosphate rock mined in Utah
and processed at the Rock Springs
facility. Available data indicate that the
concentrations of chromium and other
EP constituents in gypsum at facilities in
Louisiana and Florida, which process.
rock from Florida, and facilities in Idaho
and North Carolina, which process
locally derived rock, are usually one to
This Information Joes not constitute a
merited damage case.
8 The gypsum is slurried to the stack using
process wastewater and large quantities of the
wastewater are held in the interstitial pore spaces
within a phosphogypsum stack. . .
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Federal Regiister / Vol. 56> No. J^14/ Thursday, June 13. 1991 / Rules and Regulations 27315
two orders of magnitude below the
regulatory levels.
In contrast, the process wastewater
routinely exhibits the hazardous waste
characteristic of corrpsivity (i.e., it has a
pH of less than 2). Out of 15 facilities
with data, all process wastewater
samples examined at six facilities had a
pH less than 2 and most samples
examined at six other facilities had a pH
below 2. All of the pH values available
for the other three plants with data are
greater than or equal to 2. Process
wastewater at three out of six facilities
with data also exhibits the toxicity "
characteristic. A total of 19 of 19
wastewater samples from the three
facilities contained cadmium
concentrations that exceed the
regulatory level (by a factor of four on
average), and two out of two samples
from one of the facilities also contained
chromium concentrations that exceed .
the regulatory level (by a factor of two,
on average).
Second, existing practices for
managing phosphogypsum and pro-cess
wastewater appear to pose substantial
risks of environmental contamination
and impacts through the ground-water
and surface water pathways.
Considering the hydraulic head created
by gypsum stacks and process
wastewater impoundments and the net
recharge, depth to ground water, and
subsurface permeability at the 20 active
facilities, EPA believes that there is a
moderate to high potential for ground-
water contamination across the
industry. This potential for ground-water
contamination is limited significantly at
the one Wyoming facility, which has
equipped its waste management units
with synthetic liners and a seepage
collection ditch, but the units at most
other facilities are either unlined or only
lined with the clay and silt that
naturally exist in the area. EPA's
concern about potential ground-water
contamination at the 11 facilities in
Central Florida is compounded by the
presence of underlying karst in the deep
Floridan Aquifer; karst is prone to form
caverns or solution cavities,that can
serve as contaminant migration
pathways! Available data indicate that
the background ground-water quality is
suitable for drinking 10 and that there is
10 Background data for the surficial aquifers
indicate that shallow ground water at the sites is
generally drinkable, but low yields at the Florida
sites limit uses primarily to irrigation and livestock
watering. Lower aquifers, where present, are
generally of equal or better quality, and appear to
be either current or potential public drinking water
supplies. ' , ., .' .
either a private or public well, where
potential human exposures could occur,
' within 1,600 meters (1 mile) .
downgradient of the waste management
units at 14 of the 20 active facilities. In
addition, 15 of the active facilities are
located within 1,600 meters of a wetland
and 16 facilities have waste
management units within 500 meters
(less than a third of a mile) of a surface
water body where contamination could
pose ecological threats. Phosphogypsum ,
does not appear to pose a significant air
pathway risk. Radon emissions to the, .
air from gypsum stacks are controlled
under the Clean Air Act ata level
designed to ensure "acceptable" risk
within an "ample margin of safety" (see
54 FR 51654, December 15,1989).
Windblown dust releases from gypsum
stacks also appear to be effectively
precluded by the crus.t that forms on the
dried gypsum solids. ,
Third, a close examination of
available monitoring data reveals that
there are numerous cases of
documented ground-water
contamination across the industry. For
example, out of 16 facilities with data,
the phosphogypsum stacks and/or
process wastewater ponds at 13
facilities appear to have caused
groundwater contamination that
exceeds background levels and primary
(i.e., health-based) drinking water
standards. Contamination by .
constituents with toxicity characteristic
regulatory levels is seldom evident more
than 500 meters from the waste
management units, but other
contaminants with health-based limits
(gross alpha radiation, radium, and
sodium) have migrated in potentially
harmful concentrations over greater
distances. Based on a review of the
monitoring data and plant
configurations, EPA believes that
contamination above primary drinking
water standards has migrated or is
likely to migrate beyond the facility
property boundary (unless corrective
measures are implemented) at 12 of 15
facilities with data.
Based on these findings, EPA
concluded that management of
- phosphogypsum and process .
wastewater poses potential health and
environmental problems. Therefore, EPA
proceeded to Step 2 of its decision
making process to examine whether
more stringent regulation is necessary or
desirable. In this step, EPA found that:
* Current phosphogypsum and
process wastewater management
practices are of ten not adequate to limit
contaminant release and associated
risk. As discussed above, current
management practices generally consist
of disposal or storage in large unlined
piles and ponds, typically in areas that
are conducive to ground-water
contamination. ,
Current state and federal
regulations generally do not appear
adequate to control current and likely
future ground-water contamination.
Although Florida is in the process of
developing strengthened regulations, the
State presently permits the special
waste units to contaminate ground
water, usually as far as, but sometimes
beyond, the facility property boundary.
Given the intrinsic hazards of the
wastes, the widespread potential for
contaminant release and migration, and
the potential for human and ecological
exposures in the vicinity of active ;
facilities, EPA believes a more stringent
regulatory approach is needed.
EPA believes that regulation under
subtitle C would impose significant and
specific requirements that are directed
at controlling the types of releases/risks
that have been documented for
phosphoric acid production wastes
across the industry.
Based on the combined findings from
Steps 1 and 2, EPA concluded that
existing management practices create
the potential for environmental
problems and that more stringent
regulation is both necessary and
desirable. EPA therefore seriously
considered subtitle. C regulation for the
phosphoric acid wastes and proceeded
to Step 3 of its decision-making process
to evaluate the operational and
economic consequences of a subtitle C
determination.
In Step 3 of the decisioji-makirig
process, EPA examined the costs and
impacts of the three regulatory scenarios
examined in the RTG and the
Supplemental Analysis, and used the
insights gained thereby in deciding
whether the economic impacts of
subtitle C (or C-Minus) regulation might
cause extensive and significant
economic dislocations within the
phosphoric acid production industry.
Cost impacts were reevaluated
subsequent to release of the RTC and
were based upon an integrated
management strategy for controlling
risks posed by the two special wastes in
combination. This departure from the
Agency's initial approach was required
by new knowledge gained through
additional plant visits and analysis;
these findings are summarized in the
Supplemental Analysis and discussed
further in comment response documents.
Extensive comments received on the
Supplemental Analysis have cast doubt
upon the engineering feasibility^of some
of the waste managemert alternatives
-------
27316
\
Federal Register / Vol. 56, No. 114 / Thursday, June 13, 1991 / Rules and Regulation?
presented in that document.
Consequently, the Agency has based its
cost analysts in support of today's
regulatory determination on the use of
lined phosphogypsum stacks and
cooling ponds (Engineering Alternative 3
in the Supplemental Analysis). The
technology required to implement this
alternative has been amply
demonstrated (i.e., is feasible), though
the costs involved are higher than those
of some of the other alternatives
evaluated in the Supplemental Analysis.
Because EPA is not confident at present
that full subtitle C compliance is
technically feasible for existing
phosphoric acid plants, principally
because of the predicted operational
effects of the large-scale lime
neutralization required for compliance
(the only Engineering Alternatives that
would comply with promulgated Subtitle
C Land Disposal Restrictions (LDRs) for
corrosive wastes rely on lime
treatment), the cost and impact analyses
conducted for today's notice focus
exclusively on the Subtitle C-Minus and
D-Plus scenarios.
EPA has estimated that the total
industry-wide cost of compliance with
the Subtitle C-Minus scenario (assuming
implementation of Engineering
Alternative 3) would be approximately
$465 million annually, with an additional
$15 million to $60 million required
annually for corrective action,
depending upon the analytical
assumptions employed. Estimated
nnmializod compliance costs for the
Subtitle D-Plus scenario are
approximately one-third lower, at about
$330 million for the industry in total;
corrective action costs under this
scenario could range from $13 million to
$48 million annually. These costs
represent from 10.0 to 21.6 percent of the
value of shipments (VOS) under Subtitle
C-Minus, and from 8.2 to 15.2 percent of
the VOS under Subtitle D-Plus
(excluding corrective action costs),
depending upon the facility involved.
Costs of this magnitude exceed typical
operating margins in the affected
Industry, could not be passed through,
and hence, could not be sustained over
an extended period.
As required by Section 8002(p)(7),
EPA has also conducted an analysis of
the impacts associated with the costs of
regulatory compliance. Based upon the
results of this analysis, the Agency has
concluded that the costs and impacts of
regulatory compliance under the Subtitle
C-Minus and D-Plus scenarios would be
highly significant for most phosphoric
acid facilities, with C-Minus costs being
particularly difficult to withstand. These
costs would create economic hardship
for and threaten the continued economic
viability of many of the facilities in the
industry. Consequently, the Agency has
decided that while the management of
phosphoric acid production wastes
requires additional controls, hazardous
waste controls under RCRA are too
inflexible and costly for the industry to
implement and remain economically
viable. Even a less rigorous approach
under the auspices of RCRA Subtitle D
could impose costs and impacts that the
domestic industry would find difficult to
withstand. Therefore, the Agency has
serious reservations regarding the
economic feasibility of a traditional
waste management program designed .
within the contours of the RCRA statute.
Given these facts and the need for
action to address the risks posed by
phosphoric acid production processes
and associated wastes, EPA believes
that a different approach is required.
The Agency has therefore developed a
two-pronged approach to address these
wastes. First, the Agency will rely upon
existing authorities under RCRA Section
7003 and CERCLA Section 106 to
respond effectively to emergency
situations that arise. In addition, EPA
will accelerate the collection of facility-
specific information, consider the risks
posed by these facilities, and take
appropriate action to contain or ,
stabilize wastes at facilities that present
a risk to human health and the '
environment. In this manner, EPA
believes that it can respond
appropriately to any problems that arise
while developing a program that is both
adequately protective of human health
and the environment and economically
feasible and achievable for affected
industry.
Second, EPA believes that a
regulatory program specifically designed
to address the complex issues
associated with phosphoric acid
industry special wastes can be
developed under authorities afforded by
the Toxic Substances Control Act
(TSCA). Like RCRA, TSCA provides a
mechanism to address threats posed to
human health and the environment and,
unlike RCRA Subtitle C, does not
contain prescriptive requirements.
TSCA provides the additional and
significant advantage of being broader
in scope, and explicitly,allows EPA to
address various parts of the production
and waste generation process itself.
Therefore, EPA plans to proceed with
examination of this problem under
TSCA to consider how to develop .a
program that will address phosphoric
acid production practices and processes
to reduce the risks posed by ...,.:
phosphogypsum and process ;
wastewater. , . ,
The TSCA regulatory investigation
already underway will focus on
developing risk management strategies
to reduce or eliminate risks posed by
phosphoric acid production wastes. EPA
is eyaluating the chemicals and the
processes involved in phosphoric acid
production-and the resulting wastes to
determine how TSCA authorities can
best be used to reduce the toxicity and/ ,
or volume of these wastes. The Agency
will analyze the efficacy and feasibility
of some of fhe alternatives to current
practices that were described in the
Supplemental Analysis, with an
emphasis on developing sound methods.
(in both a technical and economic sense)
of reducing the toxicity and/or the ,
volume of the special wastes. EPA will
assess pqllutiqn prevention
opportunities based on a phosphoric
acid life-cycle analysis, the
Supplemental Analysis, and other
information obtained during the TSCA
investigation. The investigation will also ,
address the risk reduction potential and
associated costs for identified regulatory
options, such as restrictions on
manufacturing,, processing, or disposal.
Depending op the results of this
assessment, site specific risk reduction.
strategies may be. considered as most
appropriate. As specific wastes or
toxicity reduction techniques are
identified, EPA will work with the
industry to implement the most.
promising alternatives as quickly as
possible. EPA believes that by
developing a tailored program under
TSCA, the Agency will be able to more
fully explore, promote, and enforce
several promising pollution prevention ,
and/or source reduction ideas (e.g.,
more efficient raw product,filtration,
fluosilicic acid recovery) than would be
possible under a RCRA program.
In addition, EPA plans to further
explore and evaluate containment
strategies of various kinds, so that
whatever wastes are generated will not
result in contaminant releases to the
environment. If information obtained or
findings developed during the TSCA
investigation are such that RCRA could
better handle this matter, the Agency
will revisit today's regulatory
determination, and.determine whether
subtitle C regulation of the phosphoric
acid .special wastes remains
inappropriate. , . .
IV. Decision To Postpone Consideratip
of a Possible Ban on Elemental
Phosphorus Slag Utilization
fa the RTC, EPA found that the ,
radionuclide content and potential for .
-------
June 13» 1991' 7 Rules and Regulations 27317
radiation risk is a concern-for slag from
elemental phosphorus production. The
primary basis for this finding was EPA's
Idaho Radionuclide Study,11 which
estimated that average life-time cancer
risks range from 4xlO~4 to ixlO~3 in
' Soda Springs arid Pocatello, Idaho as a
result of the use of .elemental
phosphorus slag in a wide range of off-
site construction applications^ Based on
these findings,,EPA stated in the RTC
that it planned to use the authority of
RGRA section 3001(b)(3)(B)(iii) to ban
the use of the slag in construction and/
or land reclamation when the Agency
issued its regulatory determination for
mineral processing wastes. EPA -
solicited comments on the appropriate
regulatory language that should be used
and how such a ban should be
implemented. "
In response, five commenters
questioned the validity of the Idaho
Radionuclide Study. The commenters
argued that the study was not conducted
according to required procedures, has
not been sufficiently peer-reviewed,
contradicts epidemiological studies that
show that cancer risks in Idaho are low,
and suffers from several technical flaws.
For example, according to the , .
commenters, the data collection
methodology was inadequate to support
valid risk estimation, the study relies on
a zero threshold low-dose risk model
that is not supported by experimental
evidence, and the study relies on aerial
radiation measurements that exaggerate
actual radiation levels. The commenters
argued, therefore, that the Idaho study
cannot-be used as a basis for a decision
to ban off-site uses of the slag.
Since the release of the RTC, the
Idaho Radipnuclide Study and
supporting data have been distributed
for review by industry, EPA's Science
Advisory Board (SAB], and the Agency
for Toxic Substances and Disease
Registry. A public hearing on the study
was also held in Soda Springs, ID on
August 21,1990. Because of the concerns .
raised, EPA has postponed its final
determination on the validity of the
study's conclusions until the Agency
.decides how to incorporate SAB's
findings and after the Agency's review
of information provided, at the public
hearing is completed. In addition, the
Agency is postponing its consideration
of a possible ban on elemental
phosphorus slag utilization until it .
completes its review of the technical
basis for such an action. EPA will
propose a supplemental notice at the
appropriate time.
V. Regulatory Flexibility Analysis
The Regulatory Flexibility Act (RFA)
of 1980 (Pub. L. 96-354), which amends
the Administrative Procedures Act,
requires Federal regulatory agencies to
consider "small entities" throughout the
regulatory process. The RFA requires in
section 603 an initial screening analysis
to be performed to determine whether a
substantial number of small entities will
"be significantly affected by a regulation.
If so, regulatory alternatives that
eliminate or mitigate the impacts must
be considered.
EPA conducted a detailed analysis of
the facilities and companies that
generate the 20 special Wastes from
mineral processing during the :
preparation of the Report to Congress.
The Agency established at that time that
no companies that meet the definition of
"small business" generate any of the
special mineral processing wastes. Also,
EPA has not received any information in
public comment on the Report that
would contradict this finding, and
therefore concludes that today's action
will not adversely affect small mineral
processing companies. Consequently, an
explicit Regulatory Flexibility Analysis.
is not required.
VI. Agency Initiatives
To follow up oh the findings that have
resulted in today's regulatory
determination, EPA plans to continue
severalinitiatives that directly relate to
some of the mineral processing wastes
addressed in this regulatory
determination. These initiatives include
the following four activities:
(1) Evaluation of the radiation
exposures and risks associated with the
off-site use of elemental phosphorus .
1 'EPA, 1890, Idaho Radionuclide Study, Office of
Research and Development Las Vegas Facility, Las
Vegas, NV, EPA/520/6-80/008, April 1990... . :
(2) Review of hazards posed by
wastes containing diffuse naturally
occurring radioactive material (NORM);
(3) development of a management
program under RCRA Subtitle D for ..,.,'
mineral extraction and faeneficiation
wastes; and
(4) Development of a program .under
TSCA addressing the phosphoric acid
industry.
As discussed in section IV of this
preamble, in April 1990, EPA released
the, Idaho Radionuclide Study, which
provided an assessment of the direct
radiation exposures and risks
associated with the use of elemental
phosphorus slag in construction in Soda
Springs and Pocatello, Idaho; A public
hearing on the study was held in Soda
Springs, ID on August 21,1990. EPA has
also requested its Science Advisory
Board (SAB) and other scientific
organizations to review .the study's
underlying data, methodology, .and ..
conclusions. The SAB is scheduled to
issue its findings this year. When
available, EPA will review these .
findings. together with other scientific. :
and public inputs to define needs for
further study. Final conclusions from
this study will be used to -help evaluate
the need for any added controls on the
off-site use of elemental phosphorus
.
In a separate study,. EPA is presently
evaluating the characteristics, risks, and
regulatory control options under TSGA
for diffuse NORM wastes. The scope of
this study is much broader than the
Idaho Radionuclide Study, and includes
phosphate and elemental phosphorus
wastes, metal mining and mineral
processing wastes (including wastes
from bauxite and aluminum, copper,
zinc, tin, titanium, and zirconium and
hafnium processing), and a variety of
other wastes (e.g., coal ash, oil and gas
production scale, water treatment
sludges, and certain consumer items).
The purpose of the study is to determine
whether the routine management of;
these wastes pose a sufficient
radiological hazard to warrant
. additional regulatory controls. EPA
plans to complete the study in the
summer of 1991, at which time the
Agency will begin to evaluate whether
any added controls are necessary to
limit the radiation hazards, what,
authorities exist for such controls/and -
what the form and substance of a
NORM waste program might be. As
appropriate, EPA Will evaluate -
authorities and opportunities to address .
NORM wastes under RCRA, the Toxic
Substances ControlAct, and other ..
programs,
EPA is in the process of developing a
RCRA Subtitle D program for mineral
extraction and beneficiation wastes.
EPA plans to include those mineral
processing wastes determined here to
warrant regulation under subtitle D
under the regulatory "umbrella" for
extraction and beneficiation wastes,
making it the extraction, beneficiation,
and mineral processing wastes program.
As the development of this program
proceeds, the Agency may find it
necessary to control certain mineral
processing wastes, such as waste acids,
that have little in common with the
majority of extraction and beneficiation
wastes under a .separate regulatory
program. .
Finally, as discussed in the regulatory
determination for the phosphoric acid ,
wastes, EPA plans to proceed with an
examination of phosphogypsum and
process wastewater management under
TSCA. EPA; will consider how to . -,.'
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27318 Federal Register /Vol. 58, No. 114 / Thursday, June 13. 1991 /Rules-and
develop a program under TSCA,
Including pollution prevention
opportunities, that will address
phosphoric acid production practices
and processes to reduce the risks posed
by those two wastes.
VIL Regulatory Determination Docket
The EPA RCRA docket is located at:
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)
475-9327 for appointments.
Documents related to this regulatory
determination are available for
inspection at the docket.
y at of Subjects in 40 CFR Part 261
Hazardous waste, Waste treatment
and disposal. Recycling, Reporting and
rccordkceping requirements. Manifests.
Dated; May 20,1991.
William K. Rcllly,
Administrator.
PART 261IDENTIFICATION AND
LISTING OF HAZARDOUS WASTES
1. The authority citation for part 261
continues to read as follows:
Authority. 42 U.S.C. 0005,6912{a), 6921,
6023, and 6938.
2. Section 261.4 is amended by
revising the last sentence of the
introductory text of paragraph (b)(7j to
read as follows:
§ 261.4 Exclusions.
(b) * * '
(7) * * * For the purpose of
§ 261.4(b)(7), solid waste from the
processing of ores and minerals includes
only the following wastes:
* * * * *
Note: The Following Appendices Will Not
Appear in the Code of Federal Regulations.
Appendix AAnalysis of and Response
to Public Comments on the Report to
Congress
EPA received numerous public
comments on the Report to Congress,
including comments on the overall
methodology used to evaluate the eight
study factors and comments on the.
specific analysis and discussion of each
of the 20 wastes. All of the comments
are available for inspection in Docket
No. F-90-RMPA-FFFFF. EPA has
carefully considered each of these
comments in developing this regulatory
deteimination and includes in this
appendix responses to certain major
comments that have a particularly
significant bearing on the Agency's final
determination. All other comments and
detailed responses are included in a
supporting comment response
background document, available for
inspection in the RCRA docket.
I. Report to Congress Methodology
The Agency received a number of
comments on the Report's scope (i.e., the
particular wastes studied) as well as the
approach that EPA used to evaluate five
of the study factors: (1) Waste
characteristics, generation, and current
management practices; (2) potential
danger to human health and the ;
environment; (3) documented danger to -
human health and the environment; (4)
compliance costs; and (5) economic
impacts. Commenters did not raise. '
significant methodological issues .
concerning the Agency's evaluation of
Federal and State waste management
controls or waste management
alternatives and potential utilization.
A. Scope . : . ,.
Several commenters took exception to
the Report's overall scope, with some
stating that the scope was too narrow ,
and some stating that the scope was too
broad. The commenters that argued that
the scope was too narrow said that EPA
improperly narrowed the scope of the
mining waste exclusion, leaving several
mineral processing wastes potentially
subject to subtitle C regulation when
they should have been studied further in
the Report to Congress. For example,
one commenter said that certain wastes
that exhibit a hazardous waste
characteristic, such as coal tar wastes
from historic town gas manufacturing,
constituted exempt mineral processing
wastes and should have been studied in
the Report. The commenters'that
believed the scope was too broad said
that EPA wrongly studied materials that
are not solid wastes and thus not
subject to RCRA regulation, such as
some slags.
EPA believes the argument that the
scope of the Report was too narrow is
not an issue pertaining to the Report to
Congress, but rather pertains to the
scope of the Agency's final rulemakings
interpreting the scope of the exclusion
for mineral processing wastes. As EPA
explained in the preambles to the rales
as well as the Report to Congress, two
final rules established the scope of the
exemption for mineral processing, and
EPA did not solicit further comment on
this issue in the RTC. EPA also notes -
that the coal tar wastes mentioned in
the comment are no longer generated
(the last plant that manufactured gas for
municipal use using coal closed in the
1970's) in high volumes (if they ever
were), and the Bevill Amendment
applies only to currently generated
waste and historical stockpiles of ,,
currently generated waste. Moreover,
the coal tar wastes remaining froni,.
historic town gas manufacturing are
substantially different from the coal gas
wastes studied in the Report to
Congress, as the coal tar wastes have a .
different chemical makeup and were
generated by different processes.
With respect to the argument that the
scope of the Report is too broad, EPA
acknowledges that some of the' ;.
materials examined in the Report are
not always solid wastes, depending on
how they are. managed in particular
instances. In fact, if they are not defined
as solid wastes Under EPA's regulations^
the Agency agrees that regulation under
RCRA is not appropriate. However, the
Agency believes that all of the materials
examined are managed as a solid waste,
as ^defined by RCRA regulations, at least
part of the .time at some facilities. ' ".-.
Therefore, all of the.se wastes were .
appropriate for study in the mineral '
processing report. . '' '
B. Waste Characteristics, Generation, .
and Current Management Practices
One commenter argued that EPA's
consideration of waste characteristics in
the RTC did not .recognize the variability1
in .composition of a given waste from:.: , -.
one facility to the next. According to the"
commenter, this variability provides .. i
support for a determination that subtitle
: C regulation is unwarranted because .
regulation under other state and federal
authorities provides the flexibility
necessary to address the geographic
variability in waste characteristics
(which subtitle C does not). For
example, data for phosphogypsum and
process wastewater from phosphate
rock processing clearly demonstrate,
according to the commenter, the
variability of characteristics of these :
wastes and the relationship between
that variability .and the geographic
origin of the phosphate rock being
processed. The commenter went on to
contend that the RTC used waste
characterization data only to determine
whether a waste contains constituents
at concentrations of potential concern,
ignoring the critical aspect of geographic
variability. . i
EPA disagrees with this comment.
Waste characteristics and the . ,
variability in chemical concentrations
from one facility to the next were
critical elements in the risk and cost ;.
analyses, as: well as in the Agency's
final decision making. Specifically, the
. variability in waste composition was
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-federal Register / ygi. 56, No. 114 / Jhursday, June; 13, ,1991 / Rules and Regulations 27319
explicitly highlighted in the analysis of
each waste's intrinsic hazard, and the
facilities that were examined in the cost
.arid economic impact portion's of the
analysis were selected as a fimctiori of ' '
whether' their wastes exhibit a ' , :",' :v
. hazardous waste characteristic. If " ?
subtitle C, regulation for a given waste
: warranted serious consideration based
on an analysis of the study factors, EPA
closely examined on a facility-by- '
facility .basis the; frequency and
magnitude with which the waste ':'' . ;'. ;
exhibits a hazardous waste
characteristic in order to-reach a final ''.
regulatory, determination., . -".. . .
C. Potential Danger to Human Health "
the Environment , ' ..1. '.';"-. -
..
1. Leaching Procedures. Four ; ,
.commenters addressed 'the ,
appropriateness of different, laboratory.
leach tests used to measure; contaminant
concentrations in leachate from mineral ;
processing waste samples. .Three of the
, commenters objected to the RTC's use.. ,
of data generated from the Extraction
Procedure, (EP) leach test. These
commenters stated that EP Jeachate
concentrations overestimate actual
leachate concentrations because the EP' ~
test mimics' ah implausibje ;._
.mismanagement scenario^ in which ".' -
mineral processing wastes are co- *.
disposed with municipal solid waste in a
. municipal landfill and exposed to-an
organic leaching medium. In general, r
thesevcomrnenters believed that
analyticaLresults from'a distilled 'water "
leaching procedure or the Synthetic
Precipitation Leaching Procedure (SPLP)
would provide a more realistic- -
assessment of the leaGhabiltty of metals '
, from mineral processing wastes under "
actual field conditions. In contrast,
another commenter suggested that use
'of the EP leach test data is re'asohable .-.'.
because, among other reasons, co-
r disposal with municipal wastes cannot /
be ruled out for some mineral processing
wastes that are disposed off-site, arid '
..because at the time' the RTCwas being :
prepared,-. the EP leach test was the
required procedure for determining
whether a mineral processing waste
would be regulated as EP, toxic if the
Bevill exemption was removed. .-; . ;
The Agency believes that the RTG's
use of EP leach test data for mineral
processing w;aste characterization and
risk assessment is reasonable for three
main reasons. First, use of the EP
leachate data is a reasonably
conservative approach. While several '
constituents were found Jo be present in
higher concentrations in EP leachate
than SPLP leachate for some samples
that were tested using both procedures,
results for the two tests are often similar
(and for liquid wastes, they are identical
since liquids are not leached, but simply-
compared djrectly to the appropriate
regulatory cpncentratibh levels). There .
are also cases where EJP leachate
concentrations:were found to be less '.-"
than SPLP leac.hate concentrations^ For '
example, the results of an IJPA study 1 .
analyzing the validity of the SPLP test
showed that the SPLP test has been
shown on occasion to underestimate the
amount of leachable lead in a sample.2
Other constituents, that are commonly
present in higher concentrations in EP
leachate'than SPLP leachate include
iron, zinc, aluminum, cadmium,' copper,
and.nickel. In contrast, arsenic, ''.;"
vanadium, molybdenum, and barium are
1 commonly found in higher
cpneehtrations in SPLP leachate than EP.'.
leachate. In addition to the fact that EP
leachate concentrations'appear
reasonably conservative relative to the
SPLP concentrations, the Agency
believes use of the'EP leachate data is ,
reasonable because mineral processing
wastes may be plausibly mismanaged in
, a municipal landfill in certain cases. For:.'
example, lead slag.from one of,the. ,
primary lead .processing plants, and , ;
steel (basic oxygen furnace-and open
hearth furnace) air. pollution control .'
. dus;t/sludge froni one plant:are,presently;
shipped off-site for disposal in k ; '.::'
municipal landfiH. Given the existing
regulatory regime, it is:not incphceivable.
that; other mineral proce,ssing \vastes ...'.."-
from other facilities could he disposed iii
a similar manner in the>future. '. '.; - /;
. Second, as'npted by one of the
commenters; the;EP leach test at the
time; the RTC was being prepared was
the legally required procedure for ;
'determining whether the mineral
processing wastes under study exhibit J
the hazardous waste characteristic of EP
toxicity. The test that hasv replaced the
EP test, the Toxicity Characteristic :"
Leaching Procedure, assumes the same' '-
mismanagement scenario and will also
be used to .determine the toxicity of
wastes for regulatory purposes.
Third, the vast majority of available
leaehate data for mineral processing
wastes are from EP leach tests. The
amount of data from other laboratory ,:
leach tests or from samples of actual
1 Performance Testing of Method 1312QA
SupporJ for RCRA Testing, U.S. Environmental
Protection Agency, Environmental Monitoring
Systems Laboratory, tas Vegas, NV, March 1989.
Pocket No. F^-eg-MWRP-FOOQa. .
2 Given recent data that indicate that lead is a
health hazard at significantly lower levels than ,
previously believed (U.S. Department of Health and
Human Services, Toxicological Profile for Lead,
Agency for Toxic Substances and Disease Registry,
June 1990), EPA believes it is especially important
that it not rely solely on a procedure that may, .-'-.
underestimate lead leachability. " '
leachate collected ,in the field, is.
insufficient to support a cprhprehensive
evaluation. :/; :. ;" .'!.. ,-'^'-''.:''
The, Agency recognizes, that there are
some uncertainties associated with ,, -.
usingEE'leachate data to estimate.the ..,'
concentrations of metals in leachate ;
generated from the mineral processing :.
wastes as they are currently managed.
As a result, the differences between. ; ;
measured EP and: SPLP leachate .-.-...
concentrations were factored, into, the , ,
Agency's decision making for this
regulatory determination. Also; EPA
'- acknowledges that the RTC's use of EP;
leachate data differs from the approach
used in the Agency's previous : ;
rulemakings on. mineral processing : '-
wastes .'{reinterpreting the scope of the -
Mining VVaste. Exclusion), but believes .-:
the reasons outlined-above provide a
sound basis for using the EP data in the
analysis leading to" the regulatory . ;
determination. In the previous,
rulemakings, the Agency used limited
SPLP data in order tip establish which
wastes qualified as "low hazard" and ':
thus-were eligible for detailed study in
the RTC (i.e., use of the SPLP data was a
reasonable approach for selecting the"
wastes to be studies, because waste's:
that exhibit hazardous characteristics '.'"':,
undier the SPLP-test are clearly not low >.
hazard).,For purposes of actually" ' ':
conducting a risk assessment, however,
relying 'primarily -on the EP leachate
data is.'a reasbiiable, though moi'e ;
conseryatiye'appr'pach. The overall-
'consfervativehess of EPA's risk-, >; r '
assessment js discussedlfurther faelow. ,
-2.;OverallConseryQtiveness.'Fiye '-' :: ;
commenters stated that the risk ., .r
assessment;methodplogy in general t-
--' relies; oh overly conservative:- -
assumptions ma't grossly^ overestimate"... :
'risk_anddgnore cbhtradictory reaWife - .
information.'The commenters saiid the
risk.screening criteria used to evaluate :
the intrinsic hazard of each waste . , ~
stream's composition are ultra- .
conservative, as they are based on
worst-Gase assumptions regarding an
unbroken chain of events that allow ".'.'"
contaminant release, migration through
the environment, and exppsure to . ;:
reqeptprs. : , '.-, .,.,-... ."..;.
; While the Agency,agrees,that there
are elements of. the risk assessment .
methodology that tend tp overestimate '
actual risks, these overestimates are , ;
offset somewhat by other elements of
the methodology that tend to , "
underestimate actual risks. The Agency '
acknowledges that most of the-risk , :;
screening criteria are ednservative, as
stated throughout the RTC. However, :.
the Agency used these criteria only for "-
the purpose pf analysing the intrinsic-
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27320 Federal Register'/ Vol. 56, No. 114 / Thursday, June 13, 1991 / Rules and Regulations
hazard of each waste stream. EPA
interpreted an exceedance of the criteria
only as an indication that the risks of a
given waste should be evaluated in
more detail, not by itself as proof that
the waste poses a significant risk. If a
waste contained constituents in
concentrations above the screening
criteria, the analysis was supplemented
with additional evaluation of conditions
at actual facilities, and then further, if
this evaluation indicated that there were
potential problems, the Agency
conducted risk modeling in order to
develop final risk conclusions. The RTG
then proceeded to evaluate the risk
conclusions together with the damage
case conclusions before reaching an
overall finding on the hazards
associated with each waste.
Overall, EPA believes that the risk
assessment, while conservative, was
reasonable in that EPA factored the
uncertainties created by key
assumptions in the risk assessment
methodology into the regulatory
decision making process for each waste
stream. The approach that EPA used to
evaluate potential human health and
environmental problems is outlined in
section II of this preamble and applied
in section III, which presents the
rationale for the final regulatory
determination for specific wastes.
3. Madding Inadequacies. One
commenter argued that the Agency's
risk modeling was inadequate and
significantly underestimated risks
because it did not adequately consider a
number of specific factors. Important
factors that the commenter alleged were
left out or considered incorrectly include
site-specific soil-water distribution
coefficients (Kd's), the transport of
metals in ground water by colloids,
metal-organic complexing during
ground-water transport, ground-water
flow through karst terrains, storm
events, evaporation and subsequent
concentration of metals in small surface
water bodies, and the transport of
contaminated storm-water runoff to
surface water bodies.
In general, EPA acknowledges these
modeling limitations but believes most
of them were unavoidable, forced in part
by necessary limitations in the scope/
complexity of the risk assessment, as
well as by limitations in the state of
ground-water modeling as a science. For
example, the Agency agrees that Kd
values are highly site-specific, but
believes that modeling each site using
actual Kd's would have required
prohibitively extensive field
measurements and verification. As a
result, the Agency used the nex* best
approachEPA used its best
professional judgment to select
representative Kd values for each site
and each contaminant, based on a
review of data in the literature and an
examination of available data on the
soil composition at.each site. In
addition, with the possible exception of
a few experimental models, the Agency,
is unaware of any reliable techniques
for modeling the migration of colloids or
the flow of ground water through karst.
Overall, the Agency believes that its risk
modeling approach accounts for the
factors noted by the commenter in the
best way possible, considering the
study's time limitations. When
significant factors could not be
considered in the quantitative modeling
exercise, they were considered in a
qualitative manner so as to not
compromise the overall completeness of
the risk analysis.
4. Lack of Consideration of Off-Site
Use/Disposal and Future Changes. One
commenter argued that the risk
assessment was deficient because it did
not consider the risks associated with
off-site use or disposal of the mineral
processing wastes. This same
commenter said the risk assessment is
also fundamentally flawed because it
analyzes risks only in terms of existing
conditions at each facility that generates
the mineral processing wastes, not
accounting for possible future changes
in water use patterns or population
distributions.
While the Agency acknowledges 'that
it did not rigorously mo'del the risks
associated with off-site use/disposal or
possible future locations of new
facilities, it disagrees that the RTC did
not consider these factors.3 Based on a
review of the past disposal practices
and potential utilization of each waste,
only about half of the mineral
processing wastes are candidates for
off-site use or disposal, including copper
slag, elemental phosphorus slag, all four
of the ferrous metal production wastes,
fluorogypsum, lead slag,
phosphogypsum, and zinc slag. In the
case of elemental phosphorus slag, the
RTC relied on monitoring and risk
modeling conducted by EPA's Office of ,
Radiation Programs to evaluate the
potential radiation hazards associated
with off-site uses; as discussed in
section VI of this preamble, EPA is in
the process of re-examining the validity
of this off-site modeling for elemental
phosphorus slag. For the other wastes,
' As discussed elsewhere, EPA did examine
potential changes in exposure scenarios at existing
facilities. For example, the Agency's risk modeling
examined potential groundwater exposure points at
locations closer to the facility than known current
well locations (e.g., at the facility boundary].
EPA evaluated the observed and
potential hazards associated with off-
site use or disposal in the context of the
wastes' damage case record and ,
intrinsic hazard analysis, and factored
the results of this evaluation into the
overall hazard findings in each waste-
specific chapter of the RTC. For
example, before reaching conclusions
about the hazards posed by iron blast
furnace slag, a waste that has been
shipped off-site for disposal and a
variety of uses for decades, EPA
Searched for and evaluated any
evidence of environmental damage
caused by the off-site management
practices. The conservative risk
screening criteria used to evaluate each
waste's intrinsic toxicity also were
developed using hypothetical scenarios
that might occur if the wastes were
mismanaged (e.g., scenarios in which an
inactive waste pile is not closed or
maintained and people are allowed to
come into direct contact with the waste].
Therefore, the Agency believes that both
off-site activities and possible future
changes have been accounted for in the
overall hazard conclusion for each
waste stream. EPA also notes, however,
that, as a general matter, the use of site-
specific risk modeling and evaluation is
appropriate for high-volume special
wastes which are typically managed on-
site.
5. Treatment of Radionuclides in the
Report to Congress. One commenter
claimed that EPA's treatment of
radionuclides is different with respect to
the four wastes tentatively proposed for
removal from the Mining Waste
Exclusion and the sixteen other wastes.
The commenter argued that EPA has
determined that some radionuclide risk
exists for some of the sixteen wastes but
instead of recommending subtitle C
regulation, EPA merely expressed that it
plans to further investigate the potential
for exposure and associated radiation
risk. This commenter added that if
further investigation is warranted before
regulatory action is taken on some
wastes, the same principle should apply
to all the wastes.
EPA could not evaluate the risks
associated with radioactive constituents
for all of the wastes studied in the RTC
because the necessary data were not
available. In addition, there presently
are no controls for risks from
radioactive materials under RCRA
subtitle C, as there is not a hazardous
waste characteristic test for
radioactivity and no radionuclides or
radioactivity levels are listed in ,
appendix VIII to 40 CFR part 261
(Hazardous Constituents). As a result,
concerns about residual radioactivity
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Federal Register /Vol. 56, No. 114/ Thursday, June 13, 1991 / Rules /and Regulations 27321
would not be resolved by rempyal of the
Mining Waste Exclusion, because such
an action would not result in subtitle C
regulation unless the waste exhibits a
RCRA hazardous characteristic.; : ,. ;
To the extent that data'were available
on the radionuclide concentration in
various wastes, EPA believes that it
evaluated the data and made filial
regulatory determinations for the wastes
in a consistent manner. That is, EPA
uniformly compared available
radionuclide concentration data for the
wastes to risk screening criteria and
developed conclusions on the intrinsic
hazard of the wastes accordingly. The
Agency then evaluated potential
radiation risk as an" element in the .". . ;
'overall risk assessment for each waste, -
and cPmbined the risk assessment
.conclusions with the other RCRA ; .
section 80D2(pj study factors in
accordance with the decision making
methodology outlined in section II of
this preamble in order tp reach a final
regulatory determination. Therefore,
radiation risk was but one element in an
overall evaluation process, and EPA :
consistently followed that process to
reach appropriate determinations "for
each waste. To the extent/that
radioactivity appears to be a concern for
a,given waste, EPA believes that.
potential radiation risks should be
addressed along with the waste's other
potentialthreats within the regulatory
framework determined to be appropriate
(subtitle D in all cases). In addition, EPA
is examining potential radiation risks I
associated with these and other
materials in studies currently underway.
D. Documented Danger to Human-'
Health and the Environment ,
One cpmmenter contends that many
of the damage cases cited in the RTC
are not attributable to Bevill processing
wastes. The commentet also stated that:
other damage cases cited by EPA
resulted from historical management
practices that have long since been
discontinued by the mineral processing
industry. A number of commenters made
this assertion regarding specific mineral
commodity sectors and wastes as well.
The Agency reexamined the RTC data
and evaluated the information submitted
in comments arid eliminated some of the
- damage cases covered in the RTC for
the purpose of this regulatory
determination (see the comment- ;
response background document in the
' docket for details). For example, EPA
has eliminated the damage cases for
lead slag at the ASARCO facility in East
Helena, MT and for hydrofluoric acid
process wastewater at the Allied facility
in Geismar, LA because available
'information indicates that the
contamination documented in the RTC
is attributable to other wastes:
: Furthermore, as discussed in the RTC,
inclusion in the RTC of documented
contaminant releases to the,
environment due to discontinued waste
management practices does not
necessarily demonstrate that releases
from current management practices will
occur. The Agency believes, however,
that damage case information on past
waste management practices is useful in
demonstrating the potential for
environmentaland human health
impacts, for two primary reasons. First,
these damage cases provide information
on combinations of management
practices arid site conditions that have
resulted, in environmental problems,
which is useful for anticipating and
avoiding future problems. Second,
damage cases associated with past
practices, like those associated with
ongoing practices, are useful in
demonstrating the kinds of impacts that
can result when hazardous constituents
are released from the wastes. If damage-
case-information on past waste
management practices was available,
EPA evaluated the particular
circumstances involved to determine if
the case represents conditions that are
likely to exist today; If, in EPA's
judgment, a historical damage case did
not apply to current management
practices, it was used to supplement the
risk conclusions in-the sense that it ;
could demonstrate how problems can *
occur in mismanagement scenarios, but '.
it was not given the-full status of a .
damage case in making the regulatory
determination. However, if a historical
damage case was found to represent .
today's management practices, it was
considered equally with any damage
cases for current management practices
in developing the regulatory
determination.
One commenter claimed that the
Agency did not meet the standard set by,
Congress that damage cases should ,
relate to the individual waste stream ;
being studied. The comriienter added
that although relating damage to a ;
specific stream may be difficult, it is
essential if an analysis is tb.be '
meaningful. ",
EPA disagrees with this comment. As
mentioned previously, the Agency
reexamined the RTC data and evaluated
the information submitted in comments
and eliminated some of the damage
cases covered in the RTC because the -
damages could notbe attributed to a
given waste stream being studied. In
some of the cases that were retained for
the.purpose of this regulatory -
determination attribution to a sole
waste: stream was not possible; because
wastes were co-managed, for example.
However, the Agency believes ihat at ;.
least one of the special'wastes being -;'
studied was contributing to the damages
described in cases used for the ,
regulatory determination. This view is
based, on EPA's review of available data
on waste management practices and site
conditions as reflected in state of EPA ;
regional regulatory files. '
One commenter argued that contrary ''.
to the Agency's position, the absence of
damagecases is not a'reliable indicator,
of the absence of potential hazard from '
the wastes studied in the Report. The ."
commenter stated that the lack of , ;
damage,cases can be attributed to .two ',
factors: Deficiencies arid flaws in EPA's:
methodology for identifying damage ,' :
cases, and inadequacies within state ;
programs for identifying damage cases.
The Agency has reviewed these '.
comments arid maintains the view that ',
its damage case investigation effort'was
comprehensive and thorough. Many
sources were utilized to obtain
information oh facilities, including the
National Priorities List (NPL) and other
lists; federal, state, andjocal regulatory
agencies; public interest or citizen's. '
groups; and professional and trade
associations. In addition, EPA followed ';
up:on general and specific examples
cited in comments and has not found ".'
any additional damage cases. For , : ,,-,
.example, EPA:has revlewed'the
evidence suggested by one cpmriientef
linking 'observed damages to ferrous "
metal production wastes, and concludes
that'any such dariiages are not
attributable to any of the four ferrous
metal productiori wastes studied in the ;
Report. The Agency acknowledges that
although damages may have occurred at
some facilities not identified in the :-\
Report, documentation of these damages
was not available or non-existent. This
is precisely why the RTC's findings
about the hazards of each waste stream
are based on both ari.arialysis of
damage cases and risks in the absence
of any known damages. Moreover, EPA "
believes that the lack of dpcumented
damages for a given waste stream does
not necessarily signify a lack of hazard
from that waste streanv but believes
that the attribution of damage cases to a:
waste-stream is the most concrete
evidence of such a hazard.
E. Estimation of Compliance Costs
_.l. Incorrect Cost Estimates. Several,
commenters claimed that EPA had
seriously underestimated the total
compliance costs associated with
subtitle G regulations by failing to '
consider several pertinent: elements,
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27322 Federal Register / Vol. 56, No. 114 / Ttursday, June 13, 1991 / Rules and Regulations
Including: The cumulative financial
Impact of federal and state regulations
(including the recent Bevill
rutemakings); hydrogeological
investigations that may include the
construction of systems of ground-water
monitoring wells; location requirements
at facilities within a 100-year flood
plain; land disposal restriction
requirements; neutralization; recycling;
remedial work to control releases; and
closure activities. One commenter, on
the other hand, asserted that EPA
overstated the cost associated with
compliance by assuming that more
facilities exhibit hazardous waste
characteristics than are indicated by
available data. For example, the
commenter stated that the Agency
incorrectly assumed that wastewater at
every facility would be regulated as
hazardous, even though the wastewater
may not actually exhibit hazardous
waste characteristics at each operating
plant.
The Agency generally disagrees with
those commenters who argued that EPA
underestimated compliance costs
associated with subtitle C regulation. As
part of its analysis, EPA did, in fact,
address many of the cited compliance
cost elements. In the Report to Congress,
EPA accounted for ground-water
monitoring systems, neutralization of
wastes, location standards, land
disposal restrictions (in some cases),
and closure requirements. The
cumulative impact of previous
rulemnkings is not relevant to the issue
of whether the special mineral
processing wastes studied in the Report
to Congress can be managed under
RCRA subtitle C without excessive
additional costs being incurred by the
regulated community. That is, the costs
and impacts of regulating non-special
mineral processing wastes under
subtitle C have no relevance to today's
regulatory determination. EPA
acknowledges that, at certain facilities,
corrective action requirements could
result in potentially'significant costs for
some wastes and, thus, has given further
consideration to the associated costs
(further discussion of this issue is
presented below).
On the other hand, EPA acknowledges
that compliance costs may be overstated
in certain instances in which wastes
were assumed to exhibit a hazardous
characteristic when in fact they may
not. The Agency used this conservative
assumption to overcome data limitations
(i.e., a lack of EP-toxicity test data for
some facilities) and to demonstrate the
estimated magnitude of compliance
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Federal Register / Vol.. 56,, No. 114 / Thursday, June 13. 1991-7-Rules-.'and Regulations' 27323
design accordingly, and calculating the
total cost of the necessary land disposal
'unit(s) for the wastes in question. In
conducting the supplementary analysis
of the phosphoric acid sector, the
Agency also-factored land disposal
restriction costs (lime treatment) into
the total costs for phosphogypsum
disposal.
BDATs were riot applied, and costs,
therefore, were not calculated, for
copper, lead, and zinc slags because of
an assumption that slags, when
generated, are similar to wastes that
have been treated by vitrification [a
BDAT). For this reason, stabilization
was presumed to be an unnecessary
management method for these wastes.
(If stabilization is required, costs would
increase, but this would not have
affected the Agency's regulatory
determination.) Transportation costs
were not factored in for on-site
management because data in EPA's
possession and personal observations
made during site visits to a substantial
number of the facilities considered in
the Report demonstrate that many, if not
most, potentially affected facilities own
land of adequate size contiguous with or
close to their existing waste
management units to construct new
units of sufficient capacity.
4. Costs Associated With Replacing
Waste Management Units. Some
.commenters argued that EPA failed to
consider the costs associated with
replacing subtitle C hazardous waste
disposal facilities in the future (i.e.; after
the first operation is closed in year 15).
These commenters suggested that such
costs, when discounted to the present,
are significant (i.e., on the order of 25
percent of the total compliance costs).
EPA acknowledges this comment to
be true. A 15-year life without
replacement of equipment or facilities
was assumed for simplicity during the
. analysis. Data provided by facility
operators in response to the 1989
SWMPF Survey and the Agency's
understanding of relevant mineral
commodity markets suggest that an
assumed 15-year operating life is not
unreasonable for some facilities. In
other cases, however, it is unclear
whether this is or is not a valid
assumption. In those cases, the
remaining life of the facilities cannot be
predicted with accuracy. EPA
acknowledges that in situations in " . : "
which the facilities would continue to
operate and would require new waste
management units periodically,
annualized compliance costs would
. increase over those reported in the RTC,
evi?n by 25 percent or more. In any
event, such an increase does not effect
today's regulatory determination.
5. Accuracy of Cost Estimates^ EPA
received several comments regarding
the accuracy of its cost estimates. While
many commenters argued that EPA
provided inaccurate cost estimates for
regulating the 20 special wastes, one
commenter contends that, although EPA
ignores many of the costliest elements of
the subtitle C program, the Agency's
economic analysis accurately
demonstrates the high cost impacts of
regulating Bevill wastes under subtitle
c. - - - . :-.' .
In its analysis, EPA employed an
engineering design model and detailed
cost analyses to develop realistic cost
estimates of subtitle C regulation. After
review of the comments and upon
further analysis, EPA continues to stand
by its cost estimates (as modified) as-
adequate and appropriate for their
intended use as input to the regulatory .
determination, even though some cost
considerations were excluded from the
analysis for most wastes" (e.g., corrective
action). Furthermore, EPA notes that
high costs alone are not determinative of
/appropriate regulatory status. Rather,
: the financial impact of such costs is the
real measure-of economic feasibility.
Section F below provides additional
comments on economic impacts.
&. Maximum Flexibility.
One commenter asserted that EPA
should calculate subtitle C-Minus
compliance costs on the basis of a
realistic level of flexibility under RCRA,
section 3004(x) rather than on the
maximum level of flexibility. Unless the
maxinjum flexibility rules can be
guaranteed, contends this_commenter,
firms may be faced with the unpalatable
choice of investing in "maximum
flexibility" waste disposal facilities in
year one, only to find that they need
"full subtitle C" facilities in year three.
As was clearly stated in the RTC, the
purpose of EPA's evaluation of three
regulatory scenarios was to demonstrate
the range of potential compliance costs,
not to articulate a new regulatory
program (which was beyond the scope
of the RTC). The Agency believes that, ,
using a hypothetical subtitle C-Minus
scenario is appropriate for considering
the feasibility of subtitle C regulation of
special mineral processing wastes,
because of the significant technical
challenges that stringent regulation of
special wastes (by definition) may pose.
Moreover, the Agency believes that the
"realistic" level of flexibility that may in
fact be appropriate needs to be
determined based on a detailed
evaluation of site-specific conditions, '
which was .not possible within the
context of the RTC because of data ''..-
limitations.
7. Relative Costs of subtitle C, C-
Minus, arid subtitle-D-Plus, Several
comments were submitted to EPA
regarding the relative costs of the
subtitle C, C-Mihus, and subtitle D-Plus
regulatory scenarios. Many of those who
commented, recognizing the different
cost implications of each scenario,
encouraged a subtitle D determination,
while others argued that because the
differences in estimated costs among the
scenarios for certain wastes are
insignificant, a subtitle C determination
should be promulgated. One commenter
argues that with little cost difference, a
subtitle C determination would offer
greater environmental protection
advantages. Another commenter stated
that the differences between subtitle C-
Minus and subtitle D-Plus regulation are
likely to be,especially apparent with
respect to corrective -action costs (which
EPA did not include) because inclusion
of the processing wastes under subtitle'
C-Minus may exposathe facilities to the
same corrective action requirements
(and costs) as those under full subtitle
C. This same commenter added that
non-hazardous wastes should not be
regulated under subtitle G (through
application of corrective action) simply
because such regulation is projected by
EPA to be/only slightly more costly than '
subtitle D regulations.
EPA responds that the cost of
alternative management practices is but
one of the study factors that EPA is
required to consider; therefore, the
regulatory determination is not being
made on the basis of the comparative
cost difference between subtitle C and D
programs alone. The Agency does
recognize that similar corrective action
requirements might be applied under .
both subtitle C and C-Minus, and has
examined the associated costs (as
discussed above).
In addition, EPA notes that the
regulatory scenarios that were used to
estimate potential compliance costs
:were developed with consideration of
'the environmental protection that they
would afford. Thus, it is not the case
that subtitle C regulation necessarily '.
would provide more environmental
protection that the other scenarios
considered. For example, in some cases,
adequately protective design and :
operating standards for new waste
management units under subtitle C-
Minus and D-Plus have been defined by
EPA to be identical. ,
F. Estimation of Economic Impacts
^.Inaccurate Use of Price Data. One
commenter identified a specific concern
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27324 Federal Register / Vol. 58, No. 114 / Thursday. June 13, 1991 /'Rutes and Re|uljaUona
wilh EPA's use of estimated mineral
prices in 1095, with no explanation as to
how they were derived other than that
they were reported by an EPA
subcontractor. This commenter claimed
that EPA did not verify its data by
contracting industry sources.
Contrary to the commenter's claim,
the Agency used industry experts
retained for this purpose to estimate
projected 1995 prices. Industry and
affected facility input and review prior
to the publishing of the RTC were not
possible because of procedural
constraints. Affected parties were,
however, encouraged to review the RTC
estimates during the public comment
period. In response to comments
received, EPA has in fact made
corrections to the prices reported in the
RTC for refined lead and merchant
grade phosphoric acid, which had
resulted from calculation and
transcription errors; estimated impacts
on the corresponding facilities and
sectors have been revised in support of
today's regulatory determination. As no
alternative long-term price projections
wore suggested by commenters for feg
remaining primary mineral commodnSis,
estimated long-term real prices remain
as reported in the RTC.
Furthermore, the Agency notes two
points that reduce the importance of the
uso or accuracy of the 1995 projected
prices. First, while the prices are
important in assessing the overall
magnitude of the economic impacts,
their accuracy will not greatly affect the
difference between or relative impacts
of subtitle C versus D regulation; that is,
the magnitude of the impacts will be
affected to a far greater extent than the
relative differences between scenarios.
Sucond, if the prices as used are
potentially underestimated (in many
CRSC3, estimated 1995 prices are lower
than current prices), the impacts in the
RTC are overestimated because the
estimated value of shipments (price
multiplied by production quantity)
would be smaller and the cost as a
percentage of value of shipments,
therefore, larger. This is the case for the
majority of the sectors, and is consistent
with EPA's objective of performing a
conservative and defensible analysis.
Only in the titanium tetrachloride sector
were prices projected to increase
significantly, raising the possibility that
EPA's estimated value of shipments was
overstated and the impacts on that
sector were, therefore, underestimated.
However, given the strength of that
sector (as evidenced by the planned
construction of several new domestic '
plants), EPA believes that the long-term
, projection of prices for that sector are
reasonable and that impacts are not
significantly understated.
2. Impact on Industry. Several '
commenters argued that industries
producing primary copper, lead, zinc,
and elemental phosphorus would be
adversely affected by a subtitle C
regulatory determination because the
regulations would generate additional
and substantial annual fixed costs that
would have to be met regardless of
market conditions. Several of these
commenters argued that these costs are
likely to remain fixed even in periods of
slack demand, contributing to depressed
profits during such periods. A few of
these commenters further argued that a
decreased profit margin would make the
market less desirable to investors,
thereby discouraging the overall
economic growth of the industry.
EPA recognizes that increased costs
that cannot be passed along reduce
profits at all times, irrespective of
market conditions. The costs of
adequate environmental protection are,
however, simply a component of the
total cost of doing business. In trying to
evaluate future trends and market
conditions, the Agency did conduct
qualitative analyses of sectors for which
it believed the industry was subject to
potentially significant compliance costs,
and included the results of these
analyses in the RTC. For example, the
impacts discussions for the copper,
ferrous metal, lead, phosphoric acid,
titanium tetrachloride, and zinc sectors
included examinations of both the
present and future general competitive ,
position of domestic producers, and the
potential for compliance cost pass-
through (discussed more fully below).
EPA believes that its discussion of
future trends and market conditions has
adequately addressed the concerns
regarding long-term impacts.
3. Pass-Through Potential. Several
commenters indicated that EPA should
not assume that the mineral processing
industry can pass on the costs of new
regulatory requirements to the product
consumer in the form of higher prices. A
few of these commenters noted that the
world market sets the commodity prices;
if American producers raise their prices,
consumers will look to international
markets, where products could be
obtained'at lower prices. These
commenters agreed that higher pricing
on mineral processing products could be
devastating to the industry.
EPA understands that higher prices in
any market can cause adverse impacts
on the affected industry. EPA believes,
however, that the commenters'
suggestions that all mineral processors
in all commodity sectors are "price <
takers" having no ability to pass on cost
increases and therefore having to
absorb them iriternally, is demonstrably
untrue. '
In general, the pass-through of
compliance costs follows the path of
least market resistance. Where all
facilities in the affected sector face
similar compliance costs and produce
commodities for which there are few'
alternative supply sources or'substitute
materials, there is a high likelihood that
moderate "compliance costs can be
passed forward in the form of higher
product prices. On the other hand,
where only a small proportion of
facilities in a sector are affected, or
alternative supplies or substitute
materials are abundant, the opposite
may be true. Similar possibilities exist in
input and labor markets where the
regulated sector may be able to
negotiate wage or price concessions in
order to remain in. operation or continue
operating at current levels. In all cases,
the ability to pass through compliance
costs depends on the initial incidence of
compliance costs within the affected
sector and the concentration and
interdependency of buyers and sellers in
relevant input and product markets. In
the RTC, EPA discussed the market
factors that, in combination, determine
1 the extent to which regulatory
compliance costs can be passed through
for each affected commodity sector. In
general, EPA found little substantive
information or data in the comments
received that suggested that the
Agency's preliminary findings with
respect to pass-through potential were
incorrect.'
//. Decision making Methodology far the
Regulatory Determination
One commenter argued that EPA's
second approach, which recommends
that the Agency not regulate any of the
wastes studied in the RTC as hazardous
because of the potential for improved
state mineral processing programs, is
not authorized by the statute, is
factually insupportable, and unlawful,
adding that the authority for EPA's
second approach does not arise from the
study factors in section 8002(p) of RCRA
and that EPA's regulatory determination
must be directed by the specific
provisions of the Bevill Amendment.
This commenter further argued that
states cannot regulate mineral
processing wastes adequately without a
national hazardous waste designation,
stating that there are no federal
programs for nonhazardous waste in
place and no statutory authority to
ensure that state, nonhazardous waste
programs adequately regulate mineral'
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Federal Register / Vol. 56. No. 114 /Thursday, June 13, 1991 / Rules aud Regulations 27325
processing wastes. This same
commenter stated that EPA's assertions
in the RTC about the success of .
individual state mineral processing
waste management control efforts are
uncertain and impossible to assess at
the present, and therefore cannot
support the use of EPA's second
approach. In addition, this commenter
stated that by delaying regulatory action.
with EPA's second approach, EPA
would substantially undermine the two
principal objectives of RCRA: Overall
protection of human health and the
environment and the minimization of
generation and land disposal of -
hazardous waste. Finally< the /.'-
commenter argued that if the Agency
decides to consider factors beyond the
eight listed in section 8002(p), then it
must consider all objectives and goals of
the RCRA statute, not just a select few.
On the other hand, several
commenters encouraged EPA to apply
Approach 2 to its regulatory
determination, stating that the '.:
development and maintenance of strong
state programs and federal regulations
under other statutory authorities is, in
fact, mandated by RCRA. These
commenters further argued that the
flexibility offered by Approach 2 for
regulation of the mineral processing
industry is essential to its continued
strength and growth, which the Bevill
Amendment was enacted to ensure.
Other commenters argued that the
"other factors" discussed for Approach
2 were, in fact, embodied in the study
factors and should be considered in
Approach!.
As was stated; in sectipn II of this
preamble, EPA generally agrees that its
regulatory determination should be
based on the eight study factors outlined
in section 8002(p) of RCRA, as embodied
in the Report to Congress, as well as the
public comments and additional
information received in response to the
Report (and "developed by EPA to
supplement the Report in response to
comments). EPA also agrees that, to the
extent that the Agency were otherwise
to conclude that subtitle C regulation
was \varranted based upon
consideration of all of these factors and
information, that it would be improper
to look outside the Report to Congress,
public comments, and supplemental
technical information to justify a
different determination. Therefore, EPA
has decided not to employ Approach 2 .
as outlined in the Report to Congress in
making today's regulatory
determination, and has instead
employed an Approach 1 methodology
^modified slightly, as discussed in the
main text). ''-.
EPA also agrees somewhat with
commenters who asserted that the so-
called "additional factors" upon which
Approach 2 was, based are, in large part,
already embodied within the contours of
the inquiry that Congress intended for
EPA to make in the Report and
regulatory determination. The Report
identifies (1) the development and
maintenance of strong state mining and
mineral processing regulatory programs,
and (2) .the facilitation of an integrated
federal mining regulatory program as the
key considerations under Approach 2.
Section 8002(p)(5) instructs EPA to
consider "alternatives to current
disposal methods" as a factor in
developing the Report and regulatory
determination. Certainly, consideration ..
of alternative state regulatory schemes,
in addition to federal schemes, is
contemplated by this section. In
additiont facilitation of a potential
integrated federal mining program was
actually considered by EPA in its cost
estimates {reflected in the "subtitle D-
Plus scenario").
Nonetheless, EPA does not believe
that it should rely on possible improved
state programs to determine that subtitle
C is not warranted unless EPA is
confident that such programs are being
developed and can address the
problems, associated with mineral
processing wastes that may pose a
significant risk. Thus EPA disagrees that
section 8002[p) requires EPA to consider
these factors in any way that would'
supplant a decision the Agency makes
under the decision making methodology
outlined in Approach 1.
In any event, EPA notes that the issue
is effectively moot As discussed in, the
section HI of this preamble, EPA has
been able to make its regulatory
determination for all 20 wastes on the
basis of a slightly modified Approach 1
alone. Subtitle C was found not to be
warranted for any of the wastes
analyzed. Thus, even if EPA were to
employ Approach 2 as originally
conceived in the Report, it would not
change'any of the decisions made today.
///. Wastes for Which Regulation Under
RCRA Subtitle!) is Generally Supported
Nine of the twenty special mineral
processing wastes studied in the Report
to Congress were found to pose few if
any risks to public health or the
environment. EPA tentatively
recommended a subtitle D regulatory
determination for these wastes in its
Report and continues to believe that
subtitle C regulation is -unwarranted.
The Agency received no comments on
the Report suggesting a contrary
position. The nine wastes include: (1)
Red and brown muds froin bauxite
refining; (2) gasifier ash from coal
gasification; (3) process wastewater
from coal gasification; (4) slag tailings
from primary copper processing; (5)
fluorogypsum from hydrofluoric acid
production; (6) treated residue from
roasting/leaching of chrome ore; (7)
process wastewater from primary ;
magnesium processing by the anhydrous
process; (8) basic oxygen furnace and
open hearth furnace slag from carbon
steel production; and (9) iron blast
furnace slag. Therefore, the Agency is
today finalizing its decision, as proposed
in the RTC, for these nine wastes.
IV. Wastes for Which the Regulatory
Determination is Contested
EPA received numerous comments
regarding the Report's recommended
regulatory determination for 11 wastes:
(1) Slag from primary copper processing;
(2) slag from elemental phosphorus .'.
production; (3) air pollution control
dust/sludge from iron blast furnaces; (4)
air pollution control dust/sludge from
basic oxygen furnaces and open hearth
furnaces from carbon steel production;
(5) phosphogypsum from phosphoric
acid production; (6) process wastewater.
from phosphoric acid production; (7)
slag from primary zinc production; (8)
calcium sulfate-wastewater treatment
plant sludge from primary copper -'.. .
processing; (9) process wastewater from
hydrofluoric acid production; (10) slag
from primary lead production; and (11)
chloride process waste solids from
titanium tetrachloride production. As
discussed in section I.C.3 of this
preamble, the Report tentatively
recommended, based on decision
making Approach 1, that the first seven
of these wastes, be regulated under
subtitle D, while the last four be
regulated under either subtitle C or D,
depending on the scenario modeled.
The comments focused on the Report's
analysis of the section 8002(p) study
factors for each of these wastes, as well
as.the Report's tentative conclusions.
EPA received at least one comment
arguing that subtitle C regulation of each
of the'll wastes is warranted. The
Agency has considered each of the
comments, it received, sometimes
conducting additional analyses in
response, and all of the comments and
additional information have been taken
into account in developing this final
regulatory determination. EPA's
responses to these comments are ia the
supporting comment-response
background, document.
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27326 Federal Register / Vol. 56, No'. 114 / Thursday. June 13, J991 /Rules and Regulations
Appendix BAnalysis of and Response
to Public Comments on the Notice of
Data Availability
/. Engineering Feasibility and Cost of
Alternative Management Practices for
Phosphogypsum and Process
Wastewater From Phosphoric Acid
Production
A. Subtitle C-Minus and D-Plus
Scenarios as the Basis for the
Regulatory Determination
Twenty commenters questioned the
appropriateness of using the Subtitle C-
Minus and D-Plus scenarios as a basis
for the regulatory determination. .
Specifically, the commenters contend
that because these two scenarios are
hypothetical and because regulatory
requirements for the scenarios have not
been established, the two scenarios
cannot be used as a basis for a
regulatory determination, and costs
estimated for these two scenarios
cannot be used to make a decision, as to
whether or not regulation under the
existing subtitle C program is
warranted. Furthermore, the .;: .
commenters believed that the Agency
assumption (and cost estimates resulting
from that assumption) that certain sub-
sconnrios for management of process
wastewater and/or phosphogypsum
would be identical under a C-Minus '
scenario and a D-Plus scenario is
illogical. The commenters concluded
that EPA must make its decision ,
between the subtitle C and subtitle D, ',
programs and not on variations (i.e., C-
Minus and D-Plus) of the two programs.'
EPA disagrees with these comments.
Section 3004{x) of RCRA allows the
Administrator to modify certain subtitle
C requirements, at his discretion, so as
to "take into account the special
characteristics" of the wastes in
question. Such modifications are
"hypothetical" and have not been
"established" to the extent that to date,
none of the special wastes to which
section 3004(x) applies have been
regulated under RCRA subtitle C. As
discussed at length in the RTC, the
Subtitle C-Minus scenarios articulated
in the RTC and in the Supplemental
Analysis represent realistic (though
maximal) application of the regulatory
flexibility provided by the statute. The
Agency has provided cost estimates for
Implementation of section 3004(x)
flexibility because it believes that a
tailored subtitle C program is less costly
and may be less burdensome to industry
ao as to address the risks posed by
phosphoric acid industry special wastes.
The Agency recognizes that the contours
of a prospective subtitle D program for
mineral processing wastes have yet to
be established. Nonetheless, EPA
believes that for analytical purposes, it
was appropriate to consider one
possible approach to such a program, to
estimate the costs and impacts that
would result from implementation
thereof, and to compare these estimates
to those of the other regulatory
scenarios, in order to develop an
understanding of the potential
differences between environmentally
protective approaches to special wastes
management under the provisions of the
two potentially applicable portions of
the RCRA statute. Finally, the fact .that,
in the Agency's view, adequately ,
protective tailored approaches to waste!
management under subtitle C and '
subtitle D are very similar in terms of
requirements and their costs does not in
any way invalidate EPA's analysis. .
Rather, this suggests only that: (1)
Current management controls are.
inadequate in some cases (as discussed
at length in the RTC and elsewhere in ;
today's notice, (2) that even under a
Subtitle D program, certain site
conditions and waste management '
practices (such as are found at many
phosphoric acid plants) would require
fairly stringent controls and changes in
current practice to adequately protect
the environment, and (3) that the
flexibility afforded by section 3004(x)..
can be employed to, develop ' ' ,
management standards that are .', ,
achievable while also ensuring
protection of human health and the
environment. ' ' .
B. Technical Feasibility of Engineering
Alternatives , '
The Agency received comments on
several aspects of the feasibility of the
engineering alternatives (discussed in
the NODA). Several of the comments
are summarized below; the remainder
are addressed in the supporting
comment response background
document.
J. Use of Undemonstrated
Technologies. Several commenters
objected to EPA's presentation of
engineering alternatives that incorporate
certain technologies that are considered
by the industry to be undemonstrated,
unproven, and/or experimental. The
. commenters contend that waste,
management scenarios that utilize
undemonstrated technologies cannot be
used as alternatives to current waste
management practices under the
definition of section 8002(p) of RCRA.
The commenters contend that each of
the "Subtitle C compliance scenarios"
(Engineering Alternatives 1, 2, and 7)
incorporate one or more technologies
that are not currently'demonstrated in
the industry as feasible. These
technologies include the following:...
Segregation (hydraulic separation)
of waste management units for process
wastewater and phosphogypsum
(Alternatives 1, 2, and 7);
Neutralization of phosphogypsum
slurry, disposal of limed gypsum on
existing stacks, and return of transport
water to the production process
(Alternatives i, 2, and 7);
Recovery of fliiosilicic acid from the
reaction stage of phosphoric acid
production (Alternatives 2 and 7); and
* Use of cooling towers and indirect: ,
cooling via heat exchangers to effect a
closed-loop cooling system in lieu of a
process wastewater cooling pond.
As an example of undemonstrated
'. technology, the commenters stated that
even though lime neutralization of
process wastewater is used at some
plants before NPDES-permitted
discharge, neutralization of all, process
wastewater and subsequent recycle to
the production process has not been
successfully demonstrated at an existing
plant. Because this technology and the
Other technologies are undemonstrated
in the industry in the manner in which
they are, intended to be used in the
engineering alternatives, the ;
comiiienters argued that the subtitle C
engineering alternatives cannot be used
'' as a*basis for a regulatory determination
to regulate the industry under subtitle C.
EPA largely disagrees wifh these ..- : ;
comments. T,he commenters' proposed ,
.definition.of'"demonstrated" is extreme
and qontrary to long-standing Agency
policy. While EPA agrees that there
must be an expectation that a given
technology will perform adequately if it-
is to serve as the basis for a regulatory
decision, the Agency does not agree that
; current use of the technology in the
industry being examined is necessary. In ,
fact, it is very often the case that
technologies and techniques that have
been developed elsewhere for different
purposes are used by the Agency for
achievement of new pollution control
standards. This type of "technology
transfer" is at the very heart of such
programs as Clean Water Act Effluent
Guidelines development and
establishment of Best Demonstrated :
.Available Technology (BOAT)
requirements under the RCRA Subtitle" C.
Land Disposal Restrictions.
With regard to the specific-
technologies that comprise engineering
alternatives 1, 2, and 7, EPA believes
that most, if not all, of these
technologies have been demonstrated in
other industrial applications and that
their technical feasibility .is not in
question. The fact that they are not in
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Federal Register / Vol. 56, No. 114 / Thursday^ June 13, 1991 /' Rules and Regulations 27327
use in the phosphoric acid industry is '
more reflective of an absence of strong
regulatory controls and associated
financial incentives than'of the ' '
feasibility or availability ;of the v
technologies memselyes. Specifically,
EPA ha,s at least anecdotal evidence
that closed loop cooling and recovery of
FSA from the reactor/flash cooler '
system have been successfully :- '''.'
employed in other industries and in
foreign phosphoric acid plants, | "*; !
respectively. *. .
.- Moreover, EPA .wishes'-to.jrnpjkg clear '.
that it believes that the cbmmenters
have misinterpreted the Agency's! :'.:.'.
response to the- statutory requirement! to
examine "alternatives to current . . ,,
. disposarmeth;ods";andi"the costs bf ,
such alternatiy.es" (RCiRA! section :'-." .
8002(p), study factors 5 and 6]. As-.".-.'
pointed out by the commenters, in the
RTC,,EPA discussed a number of .;
alternatives to curr.ent waste . .',.'....."
, management practices, .focusing on, ,
techniques that have been applied'pn a
commercial scale, to reduce, the quantity
and/or toxicity of the special wastes
considered in. the Report. The intent of ,
this'd.iscussion;was to achieve partial
fulfillment of.study factors5 and 8 :
, (poientiaLytiiization) by focusing on ~ .
pmyen'means of source reduction and
waste.minimization as an alternative to/
. oii'Site waste management. For most of :
the 20 special wastes considered in the
RTC,.opportunities for recycling'and
cpmrnerpial-use are, quite limited, for
various reasons. In;contrast, EPA's ;
" approach to responding to the'remaindet
of study factor 5 as well as study factor,
6 was to articulate and estimate the '.--''
j; cost? of on-site waste management. ' .','.'
under alternative regulatory scenarios.
The Agency believes that this context
was and is the most relevant to the;key
decisions to be made (Subtitle C vs. *;
Subtitle D regulation) based upon the
findings of the RTC and subsequent
analysis. Thus, there is no direct linkage
between EPA's criterion for discussion
: of a waste management alternative or
opportunity for utilization'and the' - -
development and analytical ,...;'
implementation of the regulatory -'':-
scenarios presented in the RTC and the ~
Supplemental Analysis. Accordingly, .
EPA categorically rejects the '"-"'
commenters'assertion that a given'
technology, device, and/or practice must
currently be in use within the domestic
phosphoric acid industry in order for it
to be considered "technically feasible."
The Agency further ^rejects the / '
commenters' suggestion that EPA's own!
methodology as articulated in the 3RT.C '
compels such an approach, Lbecause ' f
commen,ters have misconstrued the
Agency's analytical methods'and
underlying riationale. L'
The Agency;acknowledges -that there
are significant uncertainties regarding
the operational consequences of the .';
lime treatment of phosjihogypsum. Once
again, hoyirever., comnienters have based
their arguments upon ah inaccurate
interpretation of EPA's analysis. The
treatment of phosphogypsum '.'..
contemplated in engineering alternatives
1, 2, and 7 assumes that/the water being
used to slurry the.gypsum from the filter
to the neutralization mixing basin would
be treated process wastevfaieT^noi the
"pond water" that is currently managed
. at actiye:facilities. '' ' l' '. -;'. ' '
Consequently, the laboratory test
result? reported by the.cbmmenters in ' . .
support of their argument are, in the ' :
Agency's view, of questionable
relevance,,and by no means
demonstrate that treated gypsum would.
present significant disposal and other
operational problems. '._'''
Finally, EPA Relieves ;that the -;_'.'
importance'of the. issue pf segregation of
the gypsum management and cooling
w.ater.areas within a facility's waste
management system has been
overstated by trie commenters. In the
Supplemental Analysis, EPA discussed ,
a number of different approaches for
. separately addressing contamipants .,-';..
contained in phosphogypsum slurry and
contaminants condensed into cooling
waters.,In no case1 did EPA state {or ,,,
even suggest) that a cpmplete.hydrauiic ;
separation between gypsum.
management units and cooling ponds -
w,buld be either necessary or
appropriate, even under a full subtitle C.l
scenario. Indeed, the Supplemental
Analysis recognizes that jeachate will
cbntinue to be genera ted for many years
from any existing gypsum stack; To the
1 extent that this leachate or gypsum :
transport water (which would have been
rendered non-hazardous under . :
engineering alternatives 1, 2, and 7) '
might enter the cooling water pond,
treatment or product recovery would
occur through removal of this water to
the treatment system or filter,
respectively. In either casei "co-
mingling" of.separate hazardous wastes
would not occur, obviating the need for '
complete hydraulic separation and any
associated undesirable effects on plant
water balance. :
. 2. Feasibility of Lime .Neutralization.
Several commenters expressed doubt
over the engineering feasibility pf lime
neutralization of both process
wastewater and phosphogypsum,1 for
seyeral reasons, including the limited
availability of lime to meet the demand
that would be created and the formation
of a silica gel that would interfere with ;
Waste management and production
process operations.
Several cpmrhenters argued that the
demaird for lime imposed by any of the
engineering alternatives that incprporate
lime neutralization would place a severe
burden on the United States lime :
production industry. The commenters
stated that implementation of '
Engineering Alternative 1 (lime
neutralization of all w'aste streams) '
would require the southeastern Jime
industry to triple its present capacity in
the first-year of implementation of the -,.-
alternative to ;meet the additional . ' i
demand. In addition,to expressing their
uncertainty over whether this demand !
could be met, the commenters also , ,
expressed'concern over .potential . ".':..
environmentaUmpacts that the demand -
woiild^create, including increased ,
generation of carbon dioxide, increased
fuel; consumptiori, and the need for ''..
additipnal'limestone strip mines.
, In response -to this comment, EPA has
conducted additional analysis to ''-.
determine whether implementation of
Alternative 1 would impart significant -v
impacts oil lime-supply,'demand, and
capacity within the relevant regions of
the country. A description of this :
"analysis and the results thereof may be ,'
found in the1 docket. * These results
suggest several conclusions:. ' ,:':
First, EPA agrees that adoption of -:
engine'erihg alternative 1 by the fentire;
doirjestic industry Would significaritlyj ,;:
increase-the demand -forJime in th.e
regibns of the cbuntry in which the"
active phosphoric acid plants are "
located, requiring an increase iri lirne- .
prpductibn. In the western states (Idaho
andr Wyoming), -this increase could " ',
probably be met through- greater ;
utilization pf existing lime productioiti
capacity. In the south, uniform adbptjoti'..'
of engineering alternative'l would .'..;.-
create demand'in.excess bf regional. ,
supply, requiring shipments from other
parts of the country (e.g., .Ohio, :
Pennsylvania), installation of additional;
lime capacity, and/or imports of lime
(probably from Mexico). fc > .
Second, the analysis of incremental
lime demand presented by the
cpmmenters significantly overstates the
impacts of new regulatory requirements, .
for several reasons. The estimates of ;
lime demand presented by the
cpmmenters are substantially higher
than EPA's'Estimates: Because the
1ICF In.corpOi'afed. 1991.Technical Background
Document: Data and Analyses in Support of the'-..''.
Regulatory Determination for Special Wastes from.
Phosphoric Acid Production^ Prepared for the Office.
of Solid Waste,;US EPA. , .
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27328 Federal Register / Vol. 56. No. 114 / Thursday. June 13, 1991 / Rules and Regulations
reasons for this difference have not been
adequately explained in the materials
submitted to the Agency, EPA continues
to believe that its lime consumption
estimates for engineering alternative 1
ore valid. Moreover, in comparing
demand with supply, commenters were
quite selective in terms of which states
and lime plants were defined as being
located within the same region as the
phosphoric acid plants. EPA believes
that lime produced in Virginia,
Kentucky, Illinois, Indiana, Missouri,
and Texas is also available (in a
logistical and economic sense) to the
potentially affected phosphoric acid
facilities, particularly those located hi
Louisiana, Texas, and North Carolina.
Therefore, the gap between potential
demand and existing supply is
substantially narrower than that
suggested by the commenters.
Third, the Agency acknowledges that
implementation of any alternative that
substantially increased the demand for
lime would result in increased energy
consumption and releases of carbon
dioxide, a "greenhouse" gas, to the
atmosphere. Because many lime and
limestone producers are operating at
levels substantially below their
capacity, however, EPA is not convinced
that opening of additional limestone
mines would necessarily be required to
any significant degree as a result of
implementation of the engineering
alternatives, though additional
production from existing mines would
clearly be needed.
Finally, and most importantly, the
comments focus on a worst-case
scenario under which every plant would
lime treat all of Us special wastes.
Under a tailored subtitle C (C-Minus)
program, this is but one option among
many. EPA believes that most facility
operators, when provided with the
incentive to comply in a least-cost
manner, would develop alternatives to
lime treating all of their wastes, thus
greatly reducing the amount of lime
required and the importance of this
issue.
Commenters also stated that a
colloidal silica gel would be created
during the neutralization of process
wastewater and phosphogypsum. The
commenters argued that this gel is likely
to remain in suspension in both the
gypsum transport water and the cooling
pond process wastewater, which may
pose significant problems in the
operation of plant equipment when
these waters are returned to the
production process. In particular,
several commenters stated that the gel
would potentially "blind" (clog) the
phosphogypsum filter when the treated
gypsum transport water is returned to
the filter and reused as filter washwater,
resulting in decreased efficiency,
increased downtime, and lost
production. Commenters also indicated
that they were unaware of any
demonstrated technology to remove the
gel from the phosphogypsum filters.
EPA is not convinced that the
catastrophic operational effects
predicted by the commenters would
occur on a widespread and continuing
basis if lime treatment of the special
wastes were to be instituted,
particularly if FSA recovery were to be
practiced. Commenters have assumed
that the engineering alternatives
contemplated by EPA would involve
continual treatment of process
wastewater and phosphogypsum as they
are currently generated, when in fact the
alternatives were developed to address
management of new waste streams
having different chemical characteristics
resulting from treatment and/or product
recovery. Therefore, the appropriate
question is whether lime treatment of
process wastewater that has not
reached a high equilibrium
concentration of chemical contaminants
would result in significant gel formation,
not whether lime treatment of currently
generated "pond water" would create
such operational problems. ,
Nevertheless, EPA does have some
concerns about the efficacy of a lime
treatment strategy. For example, the
Agency recognizes that for a period of
tune (perhaps one to two years),
treatment of existing pond water would
occur. To the extent that gel formation
took place, operational difficulties might
be significant. Because, however,
implementation of today's decision does
not require that lime treatment be
implemented, EPA does not believe that
resolution of this issue (which would
require additional research) is necessary
prior to a determination of the
appropriate regulatory status of the
special wastes from phosphoric acid
production.
3. Feasibility of Separate
Management of Phosphogypsum and
Process Wastewater. Commenters
expressed concern over the technical
difficulty inherent in separately
managing phosphogypsum and process
wastewater so that no hydraulic
communication between the two
"circuits" is permitted. Because the
integrated management of these two
wastes is employed at all existing
facilities and is, according to the
commenters, essential to maintaining a
negative water balance (i.e., zero
discharge through NPDES outfalls), the
commenters believed that the separate
management of these two wastes is an
undemonstrated technology that cannot
be used to support a regulatory
determination. One commenter
performed a computer modeling study to
predict his facility's water balance
under Engineering Alternatives 1 and 7
and predicted that separate
management of process wastewater and
phosphogypsum at the facility would
require treatment and discharge of .
excess process wastewater.
Commenters indicated that the potential
increase in discharge created by
segregated management would be
contrary to the objectives of the Clean
Water Act effluent guidelines as well as
NPDES requirements for the industry.
Furthermore, the commenters pointed
out that the Agency addressed neither
the feasibility nor the cost of
implementing separate management of
the wastes.
As discussed above, the Agency has
never suggested that it would require
complete hydraulic separation of the
areas dedicated to gypsum disposal and
process water cooling. In addition, the
computer simulation results submitted
by the commenter assume no changes or
adjustments in the operation of the
plant, an assumption that is contrary to
standard industry practice. Plants
continually monitor water balance and
modify their water management
activities as needed to comply with
discharge limits and operational
requirements. EPA has received no
convincing evidence that suggests that a
new water balance could not be
developed for affected plants, though
admittedly, new equipment and piping'
might be necessary in some situations.
Accordingly, EPA believes that the
potential impacts on plant water
balance and associated regulatory
significance of the issue as suggested by
the commenters are substantially
overstated.
4. Land Required To Implement
Subtitle C Compliance Alternatives.
Some commenters contend that
adequate amounts of land are
unavailable to implement the subtitle C
compliance alternatives (Alternatives 1,
2, and 7); hence, the commenters stated
that implementation of these
alternatives under subtitle C is
infeasible. The commenters contend that
the implementation of these alternatives
would require the construction of new
waste management and treatment units
and expansion of existing waste
management units on land that is in
addition to acreage already occupied at
the facilities. Specifically, the
commenters stated that in order to
implement Alternative I (lime
-------
27329
neutralization of all waste streams), ,
"additional land would be required for:
(1) Extra filter.capacity; (2) lime .
. receiving and.slaking facilities;, (3) a 50-
acre gypsum transport water pond; (4)
an additional 50 acres of cooling ponds;
(5) a cooling water neutralization basin;
(6) a larger stack; and (7) cooling water
sludge ponds. Many of the facilities that
commented claimed that they did not
have enoughJand available to
accommodate all of these units,,and
many of these facilities reported that
they could not purchase adjacent
property of sufficient size.
EPA continues to believe that the
availability and cost of land needed for
regulatory compliance are not critical
issues. As discussed in more detail
below, the Agency believes that the
commenters' estimates of the size of
new required waste management units
are significantly overstated. Also,"
additional land required for many of the
items listed by the commenters (e.g.,
extra filter capacity, lime receiving and
slaking facilities, neutralization basin) is
quite modest in extent, particularly
within the context of the vast scale of a
domestic phosphoric acid plant (all of
which are hundreds'or thousands of
acres in size). Moreover, to the extent
that substantial new acreage is required
.for additional waste management units,
land could be acquired that was not
adjacent to the facility, i.e., the units .
could be sited at some distance from the
plant. EPA believes that the incremental
costs of managing the phosphoric acid
wastes in this manner would be modest
because the wastes are already piped
(in slurry and liquici form) considerable
distances'(hundreds of yards) at some
plants. Therefore, the Agency believes
that "extending the pipeline," even for
several miles, is not a significant issue,
from either a feasibility or cost
standpoint. ,
G. Costs of Engineering Alternatives
The Agency received comments on
several aspects of the estimated costs of
the engineering alternatives. Several of
these comments are summarized below;
the remainder are addressed in the
supporting comment response
background document. ,
1. Operating Year. Commenters
argued that EPA significantly
'understated the costs of the engineering
alternatives by basing its calculation of
annual incremental compliance costs
per ton of P2O5 output on a 365-day
production year. The commenters
contend that it is not possible for
phosphoric acid facilities to operate 365
days in a year and that, due to
necessary maintenance, facilities
Derate,, on average, 330.days per year.
: Data submitted by individual facility
operators in EPA's 1989 National Survey
,of Special Wastes from Mineral
Processing Facilities demonstrate that
: most phosphoric acid plants operated
for more than 350 days in 1988.
Nonetheless, EPA recognizes that
individual production lines within a
given plant are subject to considerable
down, time for maintenance and. repairs.
Because the model plant used to
evaluate the engineering alternatives in
the Supplemental Analysis wajs based,
oh a,single production line, the Agency
has revised its cost estimates to reflect
the commenter's suggestion that a 330,
, day operating year _be employed.
2. Capital Cost for Neutralization . ;
Sludge Ponds. Commenters argued that
EPA seriously understated the capital
cost of installing sludge disposal
impoundments necessary to manage the
calcium fluoride sludge that would be
generated by lime neutralization of the
cooling water component of process
wastewater. The reasons given by the -
commenters are:
(1) EPA's capital cost: was sufficient
for only one year of sludge storage;
(2) The capital cost does not include
, the post of acreage needed tp provide
adequate residence time for settling of
solids in the treated cooling water; and
(3) Lining of the impoundment was not
included and would be required.
EPA generally disagrees with this .-.'
comment. The Agency recognizes that it
did not provide complete information
.concerning engineering design
assumptions in the Supplemental
Analysis; this omission occurred
because of extreme time constraints.
EPA believes that many of the
commenters' .concerns arise from
incorrect (though, in many cases,
reasonable) inferences that they have
made based upon the limited ".
information that was available to them.
First, the sludge settling/disposal
impoundments referred.to by the
commenter were indeed designed to
accommodate a 15 year accumulation of
process wastewater treatment sludge.
For engineering alternative 1, the
impoundment was designed to contain
118,271,000'cubic feet of sludge
(generation rate of 7.8 million cubic feet
or 180 acre-feet per year). Using the
same cost engineering model as
employed for the RTC, EPA estimated
that this impoundment would cover 64
acres (80 acres total, allowing for site
preparation activities), and have a depth
of 42 feet (14 foot dug outdepth, 28 foot
berm height). ,
Furthermore, as clearly stated in the
Supplemental Analysis, the Agency
believes that the volume, of the sludge
disposal impoundment (the vast ,
majority of which would be available in
the early years of operation) coupled
with the large volume of the existing
cooling pond, would provide adequate :
residence time for solids removal
(settling) from the treated process
wastewater stream. Commenters have
provided no evidence or a rationale
supporting their contention that EPA's
assumptions,in this regard might be.
.invalid; EPA concludes, therefore, that
its approach as described in the ,
Supplemental Analysis was and is
reasonable. Therefore, the Agency
believes that the commenters'
suggestion that the actual area required
for treated process wastewater and
sludge management (1,272 acres versus:
EPA's estimate of 80 acres) is ' .' ':'
significantly in error. '.".-,-..
Finally, EPA does acknowledge that
there is a distinct possibility that the '
sludge settling impoundments required
under Alternative 1 would require "
composite liners, at feast for facilities '
located in the-State of Florida. Florida ,
ground-Water protection standards . -,:';
(which incorporate federal MCLs) allow
: individual permit Writers, at their
discretion, to require the installation of
liners under new units to ensure : , .
adequate protection of the ground-Water
resource. Because the concentrations of
lime-treated process wastewater
contaminants such as sulfate and
sodium are likely to be an order of
magnitude or more above MGLs (they,
are not removed to any significant ,
extent by lime treatment 2), EPA has
concluded that liners would probably be
required as a permit condition for any
CaF2 sludge disposal impouiidment(s)
that would be built in Florida as part of
a regulatory compliance strategy.
Therefore, to the extent that such
impoundments would actually be
constructed in response to new
regulations, EPA has underestimated the
associated compliance" costs in the
Supplemental Analysis. ' ,
. 3. Cost of Separate Management of
Phosphogypsum arid Process '[ .
Wastetvater. The industry commenters
stated that EPA failed to consider the
capital costs arid operating and
maintenance costs involved with
separately managing the cooling water
and phosphogypsUm slurry circuits. The
commenters further contend that
separate management of these waste
streams would necessitate a major
retrofit of, current waste management
units at existing production facilities.
* As-depicted in the Supplemental Analysis,
Exhibit 1, p. 12, and as suggested by numerous
additional data submitted io the docket
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27330 Federal Register / Vol. 56, No. 114 / Thursday, June 13. 1991 / Rules and Regulation^
The commenters estimated that the cost
necessary to separate the gypsum and
cooling water circuits (capital cost] at
EPA's model plant would be at least $10
million.
As discussed above, the Agency has
never stated that it would require
complete hydraulic separation of the
areas dedicated to gypsum disposal and
process water cooling. Accordingly, EPA
docs not believe that a plant retrofit to
achieve separation of these areas would
be necessary or required.
D. Economic Impacts of Alternative
Waste Management Practices
In general, all of the industry
commenters considered Implementation
of the various alternatives under subtitle
C to be economically intractable. Based
on their analysis of the economic
impacts they believe would be imposed
by the implementation of engineering
alternative 1, the commenters concluded
that: (1) Implementation of the
alternative would eliminate the
industry's export markets; (2) it is
possible that foreign producers could
penetrate the domestic market; and (3)
incremental compliance costs could not
be reasonably passed on to suppliers,
workers, or consumers. The commenters
believed that these conclusions would
apply equally to impacts posed by
engineering alternatives 2 and 7.
EPA recognizes that implementation
of engineering alternatives 1, 2, and 7
under a subtitle C framework would .
impose cost impacts that might be
difficult for members of the domestic
industry to withstand. The real issue,
however, is the magnitude and
distribution of the impacts that might be
imposed by tailored subtitle C
standards. Under the Subtitle C-Minus
scenario presented in both the RTC and
the Supplemental Analysis/facilities
could achieve compliance by adopting
strategies to either contain or reduce/
eliminate contaminants in their special
wastes. Presumably, they would do so in
a manner that minimized costs, given
their own operational strategies and
site-specific conditions. Therefore, the
cost estimates provided in the
Supplemental Analysis should be
viewed as upper-bound estimates; it is
likely that actual costs and associated
impacts would be lower (at least on a
per ton P2O5 basis) than those estimated
for the model plant.3 This fact, coupled
with diminished relevance of the cost
impacts of full subtitle C regulation,
suggests that many of the claims made
by commenters are overstated.
//. Other Wastes Addressed in the
Notice of Data Availability
EPA received no comments on the
additional information regarding gasifier
ash and process wastewater from coal
gasification. However, the Agency did
receive two comments addressing the
supplemental analysis of basic oxygen
furnace dust/sludge from carbon steel
production. The Agency has taken the
comments into account in developing
this final regulatory determination.
EPA's detailed responses to the
comments are available for inspection in
the docket.
[FR Doc. 91-12563 Filed 6-12-91; 8;45 am]
BILLING CODE SSGO-SO-M
3 While this is true, estimated costs under the
Subtitle D-Plus scenario are also very high.
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