Wednesday
November 14, 1990
Part VI
Environmental
Protection Agency
Department of Energy Waste Isolation
Pilot Plant; Notice of Final No-Migration
Determination
Printed on Recycled Paper
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47709 > "Federal 'Register / Vol. 55. No.220* / Wednesday/Noveniber 14, 1990 / Notices '
ENVIRONMENTAL PROTECTION
AGENCY
tFRL-3860-1]
Conditional No-Migration
Determination for the Department of
Energy Waste Isolation Pilot Plant
(WIPP)
AGENCY: Environmental Protection
t Agency.
ACTION: Notice of final no-migration
determination.
SUMMARY: In response to a petition from
the Department of Energy (DOE), the
Environmental Protection Agency (EPA)
is today making a determination of no
migration for placement of hazardous
waste at DOE's Waste Isolation Pilot
Plant (WIPP), located near Carlsbad,
New Mexico. Today's determination
imposes several conditions on such
placement and is for a maximum often
years. As a result of this determination,
DOE may place a limited amount of
untreated hazardous waste subject to
the land disposal restrictions of the
Resource Conservation and Recovery
Act (RCRA) in the WIPP for the •
purposes of testing and experimentation.
DOE submitted a petition to EPA for a
no-migration determination iri March
1989; EPA proposed to grant the petition
in April 1990. After a careful review of
public comments on the proposal, EPA
has concluded that DOE has
demonstrated, to a reasonable degree of
certainty, that hazardous constituents
will not migrate from the WIPP disposal
unit during the testing period proposed .
by DOE, and that DOE has otherwise
met the requirements of 40 CFR 268.6 for
the WIPJP. The approved petition •
requires DOE to remove the hazardous
wastes from the underground repository;
if it cannot demonstrate the long-term
acceptability of the disposal site by the
end of the test period.
EFFECTIVE DATE: November 14,1990.
ADDRESSES: The public docket for this
determination is available for public
inspection in Room M2427, U.S..
Environmental Protection Agency, 401M
Street SW, Washington, DC, 20400,
Monday through Friday, excluding
Federal holidays. Members of-the public-
may make an appointment; to review
docket materials by calling (202) 475-
9327. Copies of docket materials may be
• made at no cost, with a maximum of 100
pages of material from any one
regulatory docket, Additional copies .are.
$0.15 per page.
FOR FURTHER INFORMATION CONTACT:
General questions about the regulatory
requirements under RCRA should be
directed to the RCRA/Superfund Hotline
.at 800^24-9346 (toll free) or 202-382-
3000 (local). V'" '•-' ; :
Specifi&questions about the issues-
discussed in this notice should be .
directed to Matthew Hale, Office of
Solid Waste (OS-341), U.S. .
Environmental Protection Agency,.401M
Street SW, Washington, DC 20460, at
202-382-4746. . , .:•';,...
SUPPLEMENTARY INFORMATION: "
Preamble Outline • ' ' .
I. Background , . • -..'
A. RCRA Land Disposal Restrictions
B. Regulatory Status of Mixed Waste •
C. WIPP Project '• - ' -
D. Regulatory Status of the WIPP
II. DOE Petition jand EPA Proposed
Determination ''.''.•'
HI. Summary of EPA Determination
IV. Discussion of EPA Determination and
. Conditions Of Determination ".'•''.-.
A. No-Migratibn Finding /•''
B. Conditions pf Determination ; •' '
1. Limitation to Testing and '.',,•
Experimentation '••"'*...,.
2. Limitation on Volume ' >.'.
3. Waste Retrieval r . •.
4. Waste Retrievability
5^ Carbon Ads.orption Device • .
6. Air Monitoring Plan ; ' . ;
7. Waste Analysis
8.-Reporting Requirements . '-*•
V. Discussion-of Majorlssues ' ,.-••••:•
A. Appropriateness of "Exemption" for • ,
DOE - .;">'•• '.'v '
B. Timing of EPA Decision
C. Scope of Determination
D. EPA Oversight over the Test Phase
E. Site Suitability ; .
P. Conditional Determination
• G. Definition {>f No Migration .
;. H. Definition t?f-Unjt:JBdundary ;
: • I. Waste Characterisation : *••''•'•
' J. RetrievabilitJ L ' •
, K. Human Intrusion
, VI. Conditions, of No-Migration. ,
Determination - • ,
•I.-Background- •
A. RCRA Land Disposal.Restrictions ,/.
The Hazardous and Solid Waste - .* i
Amendments j(HSWA) of 1984, which .
amend the Resource Conservation and
Recovery Act (RCRA), imposed •,;
substantial He"w requirements on the
land disposal,of hazardous waste. In' '•.;
particular, the amendments prohibit ;the
continued land disposal of hazardous
wastes, unless either (1) the wastes, meet
. treatment standards specified by EPA,
or (2) the Administrator determines that
the prohibition is not required in order -
to protect human health and-the » •
environment. [This latter determination
must be based on a demonstration by
the owner/op'erator of the facility , .
receiving the [waste "that there-will be
no migration bf hazardous constituents
from the disposal unit or injection zone'- ••
as long as the wastes remain -,. ...'-.:-
hazardous." {RCRA sections 3004(d)(l),
(e)(l), and (g)(5),) The Department of
Energy (DOE) has chosen to comply
With the land disposal restrictions for
certain transuranic (TRU) wastes to be
shipped for testing and-experimentation
;at its Waste Isolation Pilot Plant (WJPP)
by pursuing the second option.. Today's
notice approves, with conditions, DOE's
petition for the WIPP site.
EPA first promulgated standards and
procedures for review of no-migration
.petitions under 40 GFR 268.6 in
November 1986. These regulations^
; which apply to land disposal units other ...
.than underground injection wells, codify
the statutory standard-for no-migration
'.findings, specify the information
required in no-migration petitions, and
.establish"EPA's procedures for
"approving of denying petitions
(November 7,1986, 51 FR 40572). EPA
; .amended these regulations on August
17,1988 (53 FR 31138) to add further
procedural requirements and
standards.* EPA is now developing
additional no-migration standards to
•clarify or expand on certain parts of the
current regulations. The Agency expects
•'-to propose these standards-in the near
future. In conjunction with this proposal,
' EPA has also developed draft no-
migration guidance, a copy of which is
.' available in the docket for this
rulemakirig. • .
To date, EPA has received 31 no-
. migration petitions submitted in
accordance with 40 CFR 268.6. Today's
notice, which addresses disposal of
mixed radioactive and hazardous waste
in a mined -salt bed, is the Agency's first
decision on any of these petitions under
§ 268.6. The other § 268.6 petitions, ;
which primarily address land treatment
'•'-' operations," are currently under Agency
• review. In addition, EPA has received
approximately 65 no-migration petitions
for underground injection wells under 40
•" CFR part 148. Of these, 30 have been
'approved, 26 are still under review, and
a number of others have been
.withdrawn.
-.•B. Regulatory Status of Mixed Wastes
' -Tjie hazardous wastes that are subject
to today's notice are "mixed wastes."
Mixed wastes are defined as a mixture
of hazardous wastes regulated under .'
' Subtitle C of RCRA and radioactive
' w&stes regulated under the Atomic
Energy Act (AEA). Because section 1004
of RCRA excludes "source," "special
nuclear," and "byproduct materials," as
defined under the Atomic Energy Act,
?QnJu)y26,1988, EPA also promulgated .
standards under 40 CFR part 148 for no-migration
" determinations for underground injecti6n wells (53
.FR 28122). - - • .'-.-•
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Federal Register / Vol. 55, No. 220 / Wednesday, November 14, 1990 /Notices
from the definition of RCRA "solid
waste," there has been some confusion
in the past as to the scope of EPA's
authority over mixed waste under
RCRA. EPA clarified this question in a
Federal Register notice on July 3,1986.
EPA's clarification stated that the -
section 1004 exclusion applies only to
the radioactive portion of mixed waste,
not to the hazardous constituents. -
Therefore, a mixture of "source,"
"* "special nuclear," or "byproduct
materials" and a RCRA hazardous
waste must be managed as a hazardous
waste, subject to the requirements of
RCRA subtitle C (that is, RCRA
standards for the management of
hazardous waste). EPA's oversight
under RCRA, however, extends only to
the hazardous waste components of the
mixed waste, not to the source, special
nuclear, or byproduct materials
themselves. The exempted radionuclides
are instead addressed under the AEA.2
DOE subsequently confirmed and
clarified this interpretation in the
Federal Register on May 1,1987.
Sections I.D and V.A of this notice
further discusses the relationship
between the. AEA standards and the no-
migration finding.
EPA's July 3,1986 interpretation went
into effect immediately in states not
authorized to administer the RCRA
hazardous waste program—that is, in
the ten states and territories where EPA
directly regulates hazardous waste
under the Federal RCRA regulations. At
the same time, the July 3,1986 notice
informed authorized states that they
were required to apply for and receive
authorization from EPA to regulate
mixed waste under RCRA. To date,
twenty-three states and territories
(including New Mexico, where the WIPP
is located) have obtained authority to
regulate mixed waste under the state
RCRA hazardous waste programs. Thus,
mixed wastes are currently regulated as
hazardous under Federal RCRA
requirements in thirty-three states and
territories. ...
C. WIPP Project . _ •
Today's notice'addresses mixed
waste that DOE intends to ship for
testing and experimentation to the WIPP
site near Carlsbad, New Mexico, during
a preliminary test phase. At the site, the
waste will be placed in a mined
underground repository, located in a salt
bed approximately 2,150 feet below the
2 This interpretation, however, does not preclude
EPA from requiring data on radionuclide content of
wastes where necessary to carry out EPA's
authorities under RCRA—for example, to ensure
protection of personnel carrying out RCRA
inspection or oversight sampling.
earth's surface. Over an approximately
five-year period, DOE plans to test and
evaluate the behavior of the waste in
the repository, as well as the
characteristics of the surrounding
formation, to determine the site's
acceptability for the long-term disposal
of radioactive waste. Today's no- .
migration determination requires DOE
to remove the waste from the repository
if the site proves to be unacceptable for
long-term disposal.
Over the long-term, the WIPP
repository has been designed as a
permanent disposal site for transuranic
(TRU) radioactive wastes resulting from
nuclear weapons production at ten DOE
sites around the country.3 TRU wastes
are defined as wastes contaminated
with alpha-emitting radio'nuclides with
an atomic number greater than 92 (that
is, heavier than uranium) hi
concentrations of greater than 100
nanocuries per gram of waste. In
addition, TRU wastes by definition have
half-lives of more than twenty years,
although the actual half-lives of
radionuclides in waste to be placed in
the WIPP are often hundreds or
thousands of years. The TRU wastes
targeted for the WIPP consist of a
variety of materials, including tools,
equipment, protective clothing, rags,
graphite, glass, and other material
contaminated during the production and
reprocessing of plutonium; contaminated
organic and inorganic sludges;
contaminated process and laboratory
wastes; and contaminated items from
decontamination and decommissioning
activities at DOE facilities. As TRU
wastes, these wastes are distinguished
from high-level radioactive waste, such
as used reactor fuel, and low-level
radioactive waste. Other disposal
strategies are being developed for high-
level and low-level radioactive wastes.
The land in the area of the WIPP is
owned by the Federal government and
administered by the Bureau of Land
Management. The four-mile by four-mile
plot of land overlying the repository has
been temporarily withdrawn from public
use by the Department of Interior; it is
now under the control of DOE. Before
DOE can bring waste to the site,
however, either Congress or the
Department of Interior must take new
3 The DOE facilities that intend to send TRU
waste to the WIPP are Idaho National Engineering
Laboratory, Idaho Falls, Idaho; Rocky Flats Plant,
Golden, Colorado; Los Alamos National Laboratory,
Los Alamos, New Mexico; Argonne National
Laboratory, Argonne Illinois; Savannah River Plant,
Aiken, South Carolina; Oak Ridge National
Laboratory, Oak Ridge, Tennessee; Hanford
Reservation, Richland, Washington; Mound Plant,
Miamisburg, Ohio; Lawrence Livermore Natidnal
Laboratory, Livermore, California; and Nevada Test
Site, Mercury, Nevada.
land withdrawal action. The repository
is designed to hold TRU wastes that are
currently stored at the DOE generating
facilities, as well as new TRU wastes
that will be generated over the next 25
years. The underground waste disposal
area of the WIPP, when completed, will
cover 100 acres, with a total design
capacity of 6.45 million cubic feet (or
approximately 850,000 drums of waste).
To date, 15 acres of underground
disposal rooms have been mined.
- Although DOE has conducted
extensive studies of the WIPP site and
the repository performance,
uncertainties still remain. For example,
concerns have been raised over the
possibility that gas generated
underground at the WIPP could, over the
long term, build up to unacceptable
pressures, leading to possible releases
from the repository. To address this and
other questions, DOE plans to conduct
testing and experimentation over the
next several years. This testing will
include in-situ experiments with actual
TRU wastes underground, as well as
other investigations. These in-situ tests
would initially involve wastes
amounting to approximately 0.5 percent
of the total repository capacity. From
these tests, DOE hopes to gather data
that will allow it to'demonstrate
compliance with EPA's'standards'for
disposal of radioactive materials (40
CFR part 191 subpart B) and long-term
no-migration of RCRA hazardous
constituents, as well as in identifying
any engineering modifications that may
be necessary to meet these standards.
DOE is also considering the need for an
"operations demonstration" during the
test period. The purpose of this
demonstration, which might involve up
to an additional three to eight percent of
the total WIPP capacity, would be to
show DOE's operational readiness to
ship waste to the WIPP and to place it
underground. (Today's approval does
not cover placement of wastes for the
purposes of the "operations
demonstration." DOE would have to
submit for EPA's consideration an
amendment to its no-migration petition;
any EPA decision on such an
amendment would be proposed in the
Federal Register, with opportunity for
public comment.)
As a condition to today's approved
petition, DOE must remove all .
hazardous wastes from the repository if
it is unable to meet EPA standards for
permanent disposal of hazardous and
radioactive wastes at the conclusion of
the test period.4 However, if the WIPP
* Under 40 CFR 268.6(a)(S), petitioners seeking a
no-migration demonstration must provide sufficient
Continued
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47702
Federal Register /Vol. 55. No. 220
proves acceptable as a permanent ;
repository, and if DOE successfully
petitions EPA for a long-term no-
migration determination, DOE will then
be able to begin full-scale disposal of
waste at the site; Drums, metal boxes,
and metal canisters of waste will be
snipped to the WIPP from the generating
sites and placed in underground rooms.
Under current plans, the rooms will be
backfilled with crushed salt and sealed.
After an operating period of
approximately 25 years, DOE plans to
seal the shafts of the mine with cement-
clay plugs and compacted salt and
decommission the facility. After
decommissioning, the salt of the Salado
Formation will creep inward and is
expected to encapsulate the waste
within 60 to 200 years,
Access to the WIPP site will be
restricted. The Department of Interior
temporarily withdrew the lands on the
WIPP site from public use in 1983,
allowing DOE to begin construction of
the facility. Before DOE can bring waste
to the site, however, either Congress or
the Department of Interior must take
new land withdrawal action. In
addition, DOE and the State of New
Mexico have agreed to prohibit in
perpetuity all subsurface mining,
drilling, and resource exploration
unrelated to the WIPP project at the
WIPP site. As a further protection, the
Federal government has acquired the
entire surface and subsurface estate at
the WIPP site. Finally, to discourage
drilling in the vicinity of the repository
in the distant future, DOE intends to
place permanent warning markers at the
site.
D. Regulatory Status of the WIPP
The WIPP is located in the State of
New Mexico, which received
authorization for mixed waste on July
25,1990. (See 55 FR 28397, July 11,1990.)
As an "existing" hazardous waste
management facility at the time of New
Mexico's authorization for mixed waste,
the WIPP is eligible for RCRA interim
status. Facilities "in existence" (which
include facilities under construction) at
the time a waste is identified as •
hazardous under RCRA can obtain
interim status if their owner/operators
submit a part A application to EPA or
the appropriate state. If DOE submits an'
application to New Mexico and secures
interim status, it will be legally
authorized to receive mixed Waste at the
Information to assure the Administrator that the
disposal unit will comply with other applicable
Federal. Stale, and local laws. Therefore, if the
WIPP cannot comply with radioactive disposal
standards undcr-40 CFR part 191. it would not
satisfy the conditions for a long-term no-migration
dolcrmimilion.
WIPP—subject of course to the land
disposal restrictions. The WIPP must
also comply with the1 RCRA interim
status standards, codified at 40 CFR part
265, and eventually obtain a RCRA
permit under'40 CFR parts 264 and 270.
The interim status requirements of
part 265 establish general facility
standards! For example, the WIPP is
required under these standards to have
a waste analysis plafr for its mixed
waste, a contingency plan describing
procedures that DOE will take in the
case of an emergency, and a closure
plan describing how the facility will be
closed. In addition, the State of New
Mexico has recently'requested that DOE
submit 'to it the RCRA partB permit'
application for the WIPP; this
application must be submitted no later
than six months after the State's
request, or by February 28,1991. The
RCRA permit for the WIPP (if granted)
will establish detailed operating,
closure, arid post-closure conditions in
accordance with 40 CFR part 264,
subpart X. (As a geological repository,
the WIPP is regulated under the RCRA
category of subpart JX "miscellaneous
units.") The permit's scope would
extend to all facility! activities related to
mixed waste. ;
Several commenters on EPA's
proposed decision oh the WIPP
expressed confusion over the
relationship between a no-migration
decision by EPA and a RCRA permit
issued by the State. In explanation, EPA
notes that its no-migration
determination is relatively narrow in
scope, only addressing the question of
whether hazardous Constituents will or
will not migrate from the underground
repository. To ensure no-migration,
EPA's determination imposes certain
conditions (e.g., a volume limitation and
retrievability of waite); these conditions
will be enforced by EPA. On the other
hand, the State RCRA permit is
significantly broader than a no-
migralion finding, since it will impose
the full technical arid general facility
standards of 40 CFR part 264, and it will
apply to the above-ground operations as
well as operations Underground. The
permit may include certain requirements
already imposed under EPA's no-
. migration determination, or it may
establish more stringent requirements, if
the State of New Mexico determines
that they are necessary. The State
permit will be issued under State
procedures, which include public notice,
comment, and an opportunity for a
public hearing. The!conditions of the
permit will be enforced by the State.
As discussed earlier, EPA's authority
under RCRA over waste destined for the
WIPP extends only to mixed hazardous ,
and radioactive waste, and it is further
limited to the hazardous components of
the mixed waste. The potential release
of radioactive material from the WIPP is
addressed under the Atomic Energy Act
(AEA). EPA has promulgated standards
under the AEA limiting releases
associated with the disposal of
radioactive wastes. These standards,
which are codified at 40 CFR part 191,
consist of two parts: Subpart A dealing
with releases during the operational
phase of a permanent disposal facility,
and subpart B, dealing with long-term ;
releases after decommissioning. Under
these regulations, a facility is not
defined as a disposal site until it has
been designated as a permanent
resposjtory and removal is not
contemplated; since this decision will
not be made for the WIPP until after the
test phase, the WIPP is not legally
subject to the part 191 standards. Under
an agreement with the State of New
Mexico, however, DOE has agreed to
comply with the subpart A standards,
beginning with the initial receipt of
waste at the WIPP—that is, before the
facility has been designated as a
permanent repository. The subpart
standards also do not yet apply to the
WIPP because they have been remanded
to'EPA by the U.S. Court of Appeals at
the First Circuit, and therefore are not in
effect at this time. DOE, however, has
agreed with the State of New Mexico to
demonstrate compliance with the
remanded standards (if final standards
have not been developed) before a final
decision is made to dispose of waste
permanently in the repository. This
decision will be made on the basis of
data gathered during the test phase at
the WIPP.
Finally, EPA emphasizes that today's
finding addresses only the specific
question of whether hazardous
constituents will or will not migrate
from the WIPP as long as the waste
remains hazardous. Issues raised by the
transportation of waste to the WIPP site,
or by handling and possible treatment of
' waste before it reaches the WIPP, are
beyond the scope of EPA's legal
authority in evaluating no-migration
petitions, and thus are not addressed in
this notice.
II. DOE Petition and EPA Proposed
Determination
The mixed waste DOE intends to ship
to the WIPP for testing includes solvent-
contaminated wastes, which became
subject to the land disposal restrictions
on November"8,1986, and characteristic
wastes (containing heavy metals such as
lead), which became subject to the land
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Federal Register f
55, No. 22O / Wediiesday* Movembep 14,. MSI
disposal restriction® on August &i 1890^.
(However, It' should be noted that EPA
granted a two>-yeaF national capacity.'
variance to mixed1 eharaeferis.tis wastes.
deferring'the effective date-of the
disposal prohibitionnratil; May 8i.iaS2
{June 1,1S90,55 FR 22520).); In addition,
some mixed wastes are likely to include
wastes that are hazardous under EPAx'a
new toxieity characteristics rule (;5& FR
11798^ although the- Agency has not yet
promulgated fend disposal1' restrictions
for these waste?.
To- comply withr the fond disposal
restrictions, DOE has sought to
demonstrate to EPA, in a non^nigration
petition submitted in March 1989! that
placement of these wastes untreated5 in
the WIPP repository will not lead to
migration of hazardous constituents
beyond the disposal unit boundary-., fit .
response to EPA concerns, DOE
provided additional supporting material.
after its initial submission,, including
addenda in October 1989 and January
1990. DOE's final petition was bound
into eight volumes in March, 1S9Q |DOE/
WIPP 88-003, Revision 1} and is,
included in. the docket for this
rulemakingi.
After careful review of DOE's petition
as well as information from; numerous
other sources, EPA proposed in the
Federal Register of April S, 1990 to grant
DOE's petition with eertate conditions.
(See 55 FR 13668 for a more detailed1
discussion of the information provided
by DOE and of the basis for EP&'s
proposed decision.) Under EPA'a
proposal, DOE would be allowed; to
place untreated mixed, waste in. the-. -
WIPP repository within- the scope of the
testing aad experimentation activities •
described in the petition^ EPA's; proposal
would not have allowed' DOET to coiwfc.ct
its proposed operations demonstration,
nor would it have aHawed DOE, to-
•ctiuduet two pilot-room tests, which had
originally been; suggested bjp EPA, if the
testing failed to show thai the WIPP
could meet the no-migration; standard's:
for; the loEgterm, disposal a£ mixed; ,. , ,
waste, DOE would be- required t&.'" .
remove the waste from the underground;
repository. The proposal also included
the following conditions: £1} The waste
must be placed to the- WIPP tat a .
retrievabtefoBmt |2J DOE must provide
annual written reports on the test phase-
progress! to EPA;, £$! a carbow absorption,
device capable of achievtog,a 9-5 per.eeB*
efficiency, must be installed ia the
discharge system of the bin experiment
rooms; f4)j BOB-must implement a .
specific air. monitoring plan; {5J0QE
must certify, thai it has. seeurest control
of the sarfaee and subsurface estate at.
the.-WIPP site-before wastes ears- be
placed in t&e repository;. <* and f6f during
the test phase, DOE: must provide-
detailed waste characterization and .
analyses on the waste emplaced in the
WIPP.
EPA provided'a-SO-day public
•comment period on-its proposed :
determf nation and held' pubKc hearings
in Carlsbad, Albuqqerqtte, and Santa Fe,
New Mexico, during the comment
period'. The Agency received 103 written
comments GIT its proposal from both1
individuals' and organizations, and more
than 300 people testified at the three
hearings. Today's decision is based on a-
carefuJreviewofthe public's comments;
and clarifying: information provided by
DOE, as well as EPA's further
evaluation of the suitability of tfte site
based on a field visit to foe WWP site on
July28,199&. • '-
IJL Summatg of EPA. Detersninatiott
After a review of DOE's- petition,
supporting informatibn; and publie •
coroiaent,. EPA finds that DOE has
demonstrated! to-a reasonable degree of
certainty, that hazardous constituents
will not migrate- front the WIPP
repository as a result of its planned test
activities, as required by.the statute and'
regulations at 40 CFR 268ift This
determination is based on the condition;
that DOE only place hazardous waste-
within' the scope of the test phase
operations described' in its no-migratioB
petition and its performance assessment
test pfan. Consistent with the
determination, EPA i» approving DOE's
no-migration petition for Use WIPP for
the test phase operations, subject iff the-
conditions laid out irc section-. VT of this
notice; H should be noted1 that tifte
proposed operations'demonstration and'
pilot roora tests--cannot be coHducted:
under the terms- of today's decision.
. Before these activities eoufd'be carried5
out, DOE xvouFd1 have to submit an • ' '
amendment to its no-migration petifion,.
which EPA would evaluate; EPA would:
then propose- a decision for comment.
before a final decision would be made. '..
'EPA's action today allows DOE to-
place untreated' mixed waste subject ta
the RCRA land disposal resMctions in
^ the WIPP for testing and?
experimentation to determine whether1
the site is appropriate for the fong-term;
disposal of mixed waste (that is,,
whether disposal at the site wiE: .
conform with standards- for t&e '
permanent disposal of hazardous.
wastes); Only the waste specified by
DO&ia is petition may be placed in the
WlPPuwier ti&fis determfriatioa.8'TBte
quastity/ 0f waste Slat may be piacerf in
the WIPPia BmJted1 to 8v50G dhimsv ort
percent of tfte facility's SnaF capacity/.
DOE may not begin permanent disposal
of the mixed waste subject to the RCRA
land disposal: prohibitions at the site
and must remove att waste from the
underground repository if it cannot
demonstrate no migration of hazardoas
constituents esrerthe long terro. pas
additros to ERA^s Eeqairemen* that
hazardoua ,v/aste be removed from, the
respositary, DOE has also committed tot
carry out such a removal in a; consent
agreement with-the State of New
Mexfco.J
In iBakiHy its no-migration finding;
EPA Goncentnafed ow whether, release*
of non-radioactive hazardous:
constituents fronr the repository mfgh*
occur during: the test phase, to doing sot
EPA addressed afI possible routes of
release, bat focused in particular on tfte
potential for volatile organic
constituents.released during testing to
migrateeut of the WEPP umtftroagfetfee
ventilation exhaust shaft. Because of'the
nature of fee tests-that will be
conducted to the WJPP and their..
relatively short duratioiii EPA has:
concluded that releases of hazardous -
constituents from the unit through brine,
salt, or other geological media ;a
implausible during the test phase.
The ratrievability of waste placed in
the WIPP during the test phase is; centrait
to EPA's finding. TheEefojEe».EKft,haa
reviewed bo& fee technical feasibility
of retrieval and the praetlcabihty of
DOB's-retrieval pfasLEPAhasi •-' ;
concluded, fea* retrieval of wastes i;om
the WIPP cans be accomplished safely4
and that DOE's commitsneat to
retrieving; the wastes and taking: it
above ground,, if it proves necessary, is
satisfactory^ Finally^ EPA considered tost
general design, construction* aad mine
maintenanee program at the WIPP and;
has concluded that the mine is well-
designed and will remain stable daring
8 In its no-migta lion petition, DOE Mfentified
listed saJvenfa anti EP'iExtractraH Procedure):
characteristic wastea as hazardous, under RGRA, in
addition, some of the waste described1 fii DOES
petition- may now be hazardous under the EPA'ff
recentljt premnlg»(ed 'Eoxicity Gharacteristies. PEC]
rule (55 FR 11798), El'A has not i^tppomulfiated .
treatment standards fotTC wastes;, however, it ia
? DOE re«:RSly secured the.ksLou!9!aBding:
nline^a^Eease afthe WlPFsilfe, thereby satisfyfhg
this condition-. Affa- rastiJIv.^^ has-eliminate^tfeia
coniJHfoin In. its feiaMetermioa'acm:
standards-have been proroulgatBd,TG waatea .
piaead in tha. WIPP wiil be subject tuthe.biMl,
disposal restrictions. Because EPA.'a review, of .
DOE's petition considered* potentiat migration- of
hazarrfpus constttwents from at! of ttie- waste DOE
identified aaschedateditur the WIPR.todajf'ffaa- ,
migratior. determination applies ta wastes thataf*
hazardoiia. under the TC rule, as weli as, solvents:
and EPofiaractertsttcs- wastes, a» tong as the waste*
were included in the petition.
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47704
•Federal Register / Vol. 55, No. 220 ./Wednesday. November 14, 1990 /Notices
the test period and well beyond..The
specific conditions of today's finding are
discussed in the following section and
listed in summary form in section VI of
this notice.
Although EPA's granting of DOE's
petition is specifically based on a
finding of no-migration of hazardous
constituents from the unit during the test
phase, EPA has thoroughly reviewed
available information'on the expected
long-term performance of the WIPP
repository. Given the geological stability
of the area; the depth, thickness, and
very low permeability of the salt
formation in which the repository has
been mined; and the properties of rock
salt as an encapsulating medium, EPA
believes that the WIPP is a promising
site for the permanent disposal of mixed
waste. To be sure, a number of
uncertainties related to the long-term
performance of the WIPP remain—for
example, the extent and effects of gas
' generation, the. effects of brine inflow
into the repository, and the influence of
a "disturbed rock zone" around the
mined repository. DOE will be
Investigating these uncertainties in the
test phase at the WIPP, and it will
review whether technical modifications
to the repository design or the waste are
necessary to ensure compliance with the
regulatory standards.
It should be remembered that today's
decision is only for the disposal of
mixed waste during the test phase for
testing and experimentation to
determine whether the site is
appropriate for the long-term, disposal of
mixed wastes. Before DOE may move
from the test phase to full-scale
operations, it must petition EPA again
and demonstrate no migration over the
long term—that is, it must successfully
address current uncertainties about
long-term WIPP performance.
Information gathered by DOE during the
test phase will be central to such a
demonstration. Any EPA decision to
approve (or deny) a no-migration
petition for permanent disposal at the
conclusion of the test phase will be
made with full opportunity for public
comment, as prescribed in 40 CFR
268.6{g).
Further technical details regarding
EPA's final decision are provided in a ' •
background document. In addition,
major issues raised by public
commenters are discussed in section V
of today's notice, as well as in a
response to comments document. Both
the background document and the
response to comments document-are
available in the public docket for this
action.
IVr Discussion of EPA Determination
and Conditions of Determination
A No-Migration Finding
To make a no-migration
determination, sections 3004 (d)(l),
(e)(l), and (g){5) of RCRA require EPA to
find that "there will be no migration of
hazardous constituents from the
disposal unit or injection zone as long as
the wastes remain hazardous." As EPA
explained in the preamble to its
proposed decision, it interprets this
requirement to mean that constituents
listed in appendix VIII of 40 CFR part
261 cannot migrate at hazardous levels
from the disposal unit during the time.
that hazardous waste is present in the
unit. If the hazardous waste Within the
unit becomes non-hazardous or if it is
removed from the unit, further migration
from the unit ceases to be an issue. In
the case of the WIPP, DOE will have to
remove all hazardous waste from the
underground repository if it cannot
demonstrate the long-term acceptability
of the site; therefore, the effective period
of EPA's finding is the test phase. Thus,
EPA's decision today is based on the
conclusion that the Appendix VIII
constituents will not migrate at
hazardous levels from the underground
repository during the test phase and that
DOE will remove all hazardous waste
from the unit if testing cannot show that
the site meets long-term no-migration
standards.
EPA's no-migration finding for the
WIPP test phase.falls into several
categories: Migration of hazardous
constituents under anticipated test
conditions in the repository; short-term
stability of the repository; feasibility of
. retrieval; possible effect of accidents
and spills; and effectiveness of controls
against human intrusion during the test
phase. These aspects of EPA's
determination are discussed below.
'. No migration of hazardous
'constituents beyond the unit boundary.
In the proposal, EPA explained in some
detail its definition of the unit boundary
for the WIPP'and its standards for
determining whether, a constituent
migrating from the unit is "hazardous." •
The proposed unit boundary was the
Salado Formation at the WIPP site,
bounded by the four-mile by four-mile
land withdrawaji area, except that, for
'air emissions during operations, the unit
boundary was the point where the air
exhaust ventilation shaft met the
surface. EPA's definition of the unit
boundary in today's decision is largely
unchanged from the proposal; however,
in response to public comment, it has
slightly modified the unit definition as it
applies to air emissions. In the final
decision, the unjt referes to that portion
of the Salado Formation that falls within
the WIPP land withdrawal area:
specifically, any movement of
constituents above "hazardous" levels
into overlying or underlying formations,
or beyond the lateral boundaries of the
land withdrawal area would constitute
migration. This unit boundary would
apply to migration via air emissions
during operations as well as via ground
water of other routes after closure of the
unit. (This issue is discussed in more
detail in section V.H of today's notice.)
EPA's definition of "hazardous" levels
of migration remains unchanged from
the proposal. As. discussed below in
section V.G, EPA is relying on "health-
based levels" to define migration—that
is, levels that would be hazardous to a
person exposed at the unit boundary for
an entire lifetime.
The no-migration standard applies to
all possible routes of release from the
unit. EPA, however, has concluded that
migration of hazardous constituents out
of the unit during the test period is
implausible by any route other than air.
Waste will be containerized during the
test period, and even if it were released
from a container, there is no possibility
that waste could migrate from the unit
by ground water or directly through the
salt rock within the test period. No
commenters questioned this conclusion,
which EPA discussed in the proposal.
Potential for Migration via Air
Emissions. For air emissions during the
test period, EPA's finding is based on a
careful review of possible releases from
the bin-scale and alcove-tests DOE is
planning to conduct during the test
period. For reasons described below,
EPA has concluded that any releases
from the alcove-scale tests will be
negligible. Therefore, it has focused its .
attention on the bin-scale tests. In these
tests, headspace gases will be vented '
into the bin discharge system whenever
the bins become pressurized through a •
pressure relief valve installed on each
bin. The gases will then be passed on to
the exhaust shaft. Because the purpose
of the experiments is to gather data on '
the gas generation potential for the •
various types of wastes intended for
disposal at the WIPP, the rate of gas
generation and thus the amount of
hazardous constituents expected to be:
released can only be estimated- Because
of this uncertainty, DOE has proposed
and EPA's decision today requires the
inclusion of a carbon canister in the bin
gas discharge system to remove any
volatile organic constituents released
from the .bins. This carbon adsorption
control device must be designed to
achieve a control .efficiency of at least
95 percent. As explained in its proposal,
-------
Federal Register f
Nte-...2aa /'
, fe-vember
ffefes.
EPA has taken this- eonteot device Htfo
air emissions^
For its as
coneesfratiosB-ofi'gdktsle oj^aaier
con
at DOE'is Rocky Flats Bask arafc stored
at the I^aba> National1 Engjaeezisg: •
Laborafesj;. As dessm&edi.Bfc &e WJFP
able: t& pmvide- little er »a icfapniatiea
oasas "
contra! naeasaEessfer these data.
Therefope^ EPA views the anal^tieat
being semfesuantitati.ife, Nevertheless,,
even if these data undeEestiraate. tha ,
constituent CQiussntratians % as, muck .
as. an, order of magnitude,, tEe
noncentrattQa o£ eonstitueuta at the unit
boundary are stiE expected to be belaw
heaMt-&ased;levefe, •
The" results of EE&'a assessment aJK
' showoi in Tidfe 1 beSam along, wit&,
levelsairegaMorj? eoiiGeyou , ..'-.'.
, EPA eaasasvatrweljt assumed that
both
24(t EPA. tfeesa3si:m«d -aa. average gaa
. geHBJcatfQn.Eate?a£5,m6le&pei cfruza-per;
year» a figmse tBat EKJEe&aracteiaizes, aa
represeafiHg. tB.e ^ipec bouiai of tie-
range of erexfif>re gas. generation rates-
'
Waste. Tests; January 19865, S/SNffa^-
0462J: Eacft bm ssn heltf t&e eqni^aleaft
,of six .drum vqlinnesiaf waste. '. ••'. '""".•
Therefore; EKJE's; upper fionnd* ^s
g^ne^ati^^f^:: rate- is erpinsafenf te a' total
gas geHeratjoir rate frwn- aH24a
experfiHentaP 6ms afoiff caMcr meters
per day. BOFftas- specifier? tlie general
veirtstettesr pate tfifs^te ftsr pe^esRoiy
as 4^09QSG^we fee* permrasfe,. wisiefc
. is eqaJvafeBttetTmiffisiyeniifenieteFa
per day. "ffijseirf&e- w^ame rfairf*
exhsasteJ a*aie»e!»&»u»esftali.awf fis
.available to mfeeiwiftaRy gases-'refease
from tlie bin- dfee&arge- systeRr. TRe-
resuftfesy offirtien- faeferat ffie e*6ansf
arid.rockfeffi darfi^^ ratfeettesf pfr
for
Pi teeafetrfate Ae
inspected while thef tests arenndeiwayi
.„ __ _ r^ e peart ceSeehtrafons;
(with the carbes adsorption contra!
sev«* efders 0f magaiftsde; feefowr aay
other level dE'iegHlatery eoaeenr. TE
figure* fepiesefrf fee bfer-scafe tests-
alone; howesrer,
wiBrstew &&wie foef'tate ef Creep' GP
FinaHjfv D€)l'inteBdfeipfflrtlcrf% tebac
seejrsE afee^c* voSr cra^etf salt to- •
. t .
provided5 date to- shew ;ffia*e«Bn whe»
testafeeyes wSlfeeffKetf wiffi
off' walls- Between' ibeliscftfiB'- antd1 tifte-
• romee wsdfe,. sw ^feat twsm- Gfoanre- does?
nof Hnpfege- COT jflte- feacfeffiTetf' drums'.
These modifiiBalSiEHis-easare^fte • ' '
suceessfel ratpfeval of t&e dram^ &DRI •
the alcoves, at tfee coRefiisfenv of tfte test
i. ifft pFOTfe
,
tSw con eerrtraf Ions &*• fte «»dteasf- shaft
weriSf be1 two1 to- ef^ft eidteEs- of
expressed* concern tfeaf
feaastlfe,
e&efew^BB-teveisroFregQfefery IPAeaaaof asstraieirenKroaPfeiitSH«FT
coraeefBr. .... • • mfgratipir finding^ "Eltese coanaenters
Because.the alcove; experiments "
the' exhaust shaft front tSft £Sbeve fcm» •
-ff fiactorof 'a* feas* fiiree- to
than" this wiee1 t&e afeoAfFestaie- sesfeitf af
the start of the>.exper&BeRfe,
EPA reeognfees1 Aa8 ffier aeftiaf &6r gas
of the tesf afco#es
removal — an rssaedisEiissediin the •
prevfsHKseetftrre. FfBa^t^Sieg argued*
that reftieval fronr bacRfiHed alcoves
has not been- dfemonstEatetf anj tftat
'
moles* per draai per-yeiK: HfoWever; even
if t&era*e-wer«rs%nificairtfyMgfier,
sdai'y -'
underground during retrfevaF.ma^ have
inlterent.Trstcs'. • ?•- •• * . "
HRff has eoncfuafetf titeet POE"a Wkste
Retrieval; Ptan^ ito eontfnWaSfoni wlthf
mock reMevafc; demonstrates fftat :
for
95 pejee&f 'eiltcierrey', ifierefbrei EKS. '
findmft^ D0E'&*s' efeHKHissfratedl'to a
F&astwia&fe disgree of eertamtj,;,t!tat
hazardous- eons^Beirt* wiff noi* m^afe
beyoratf; ffierrepos jtoty batrndkr^1
the
tongten»,,salterBepwfiCb6
e site. Bi tfie:
,
ntajiBr aspect^ of theretriessal procesa
are addressed in tfte plaA, including- -,
radiofegfeaE andtftazardbiis w-asfe
cdnfaminatBstf eontoF,. dhinr anrfbfn
handffng; overpaeRiDg;proced\iresibr .
corrode^ ortJama^d'drumsi.Greaft HP/ of
centamftiatibHi.andlback^retrfevaJ'.
Whife refease orfea&age of hazardous . .
eoristftuents ftom eoHtaiheKS.wi0fii:ffie;'
ce
In the short femr, Roweves; saR? creep —
which can lead te localized feaetnrihg;
and Foefc faff— r mtrst &e mitiga fed to
egvuruiinenf.
Bcien greatfy
e.' Such events are adequately
addressed by- emergency sesponse '
pEocedafes dteffnerffot t&e WlFtT. The ', •
specifics' of t&e various, emergeBejf
response procedures are'
: fs-.tfee
experiment!^ arear. Tte meist' sfgmfcant
roofs afaffttest
fBoms-wB &e-r
• alone slrdiiMpiaerFent excessive cracfeng-
the Waste ^^.,i,-
while EPA- agrees :-vmflx Gemmenf era tfiat
a fire ois; expfostoft wpnldE mafie. retrfesfaiE
more dJffieu^th&Agjgncy fs'Triiposihg: •
additional conditions to' m£afln6;e l&e • . ;
• potehfitatfor/sucfi aa. event; {See. sestfoa,
V.I.T of roxfay's notfce for a defaiTed'
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47706
Federal Register / Vol. 55, No. 220-/ Wednesday," November 14, 1990 / Notices
description of this point.) Thus.'
adequate safeguards have been imposed
and will be implemented in the event of
an accidental release of hazardous
constituents.
It should be noted that the Waste
Retrieval Plan is backed by successful
mock retrieval demonstrations, although
EPA recognizes that mock retrieval
demonstrations performed thus far at:
the WIPP did not include removal of
waste from the alcoves themselves.
Other aspects of the removal process, .
however, were simulated in the retrieval
demonstration. Mock retrieval
experiments on backfilled alcoves and
on bins will be performed before any
waste is placed in the WIPP. .
EPA agrees with commenters that
shuffling of the waste during the
retrieval process could increase the risk
of a release; however, safe movement of
the waste containers is technically
feasible, and EPA has concluded that
DOE's routine container-management
procedures are adequate. Furthermore,
any removal activities will be conducted
under the oversight 6t the State of New .
Mexico, either during RCRA interim
status or under permit conditions, which
will ensure an appropriate level of care.
Finally, the Environmental Evaluation
Group, an independent group
established by Congress to provide
review of the WIPP project, provides
oversight over waste management and
safety aspects.of WIPP operations,
including removal. •
. A number of commenters raised the
possibility of drum corrosion during the
test phase, which, c'puld lead to spillage'
and complicate retrieval. EPA has
concluded, however, that the potential
for significant drum corrosion during the
test phase is limited .and will not
substantially affect the retrieval of
wastes. While it is true that salt is very
corrosive, the rate of corrosion of the
drums being stored in the repository is
expected to be low. This'is because
several key factors affecting the rate of
drum corrosion allow for favorable drum
storage conditions. In particular, the rate
of corrosion is affected by the
composition of the brine contacting the
drums. That is, corrosion proceeds most
rapidly if the brine is unsaturated and
contains dissolved oxygen. However..
the brine in the WIPP repository is both1
saturated with salt and contains low
levels of dissolved oxygen;.therefore,
drum corrosion would be inhibited. .
Moreover, the rate of corrosion is -
directly affected fay the amount of brine
contacting the drums. Sjnce the
repository is expected to remain dry
during the'test period and'thus there,w.ill
be minimal drum-brine contact, EPA
does not expect the drums to corrode
significantly. For ithese reasons, EPA has
concluded that the useful drum life in
the WIPP will exceed the period of this
determination, including retrieval time,
and it sees no reason to question DOE's
statement that the drums will maintain
integrity, for twenty years.
In addition, EPA notes that containers
at the WIPP will be subject to
monitoring and inspection procedures
required under RCRA 40 CFR part 265
(and, once a permit has been issued,
under 40 CFR part 264]. These
requirements will be adminstered by the
New Mexico Environmental •
Improvements Division, with EPA
oversight. If any questionable drums
were identified, mitigative measures-—
such as overpacking—could be
undertaken. To be sure, drums that are
sealed in the alcoves during the alcove
tests cannot be routinely inspected.
However, under DOE's test plan, these
tests are expected to last approximately
five years. Thus, inspection would be
possible well within the useful life of the
drum. '
Finally, as EPA discusses in this and
the following section, spillage from
drums (however unlikely) can be
contained and cleaned up, and corroded
drums can be overpacked. Thus, EPA
disagrees with commenters that drum
corrosion might prevent the safe
removal of drums from the -WIPP, if
removal-proves necessary..
Limited effect of accidents and spills.
Numerous commenters argued that
accidents or spills at the WIPP site
would complicate retrieval of wastes or
might lead to migration. EPA agrees that
accidents or spills, might complicate
retrieval, but it ha's nevertheless
concluded that the cleanup of spills and
the removal of contaminated material
from the WIPP is technically feasible.
The'WIPJP Retrieval Plan outlines DOE's
planned approach to the removal of .
contaminated maferial; in addition, the
feasibility of .safe Removal of such
material was demonstrated in DOE's
mock retrievals. Moreover, neither EPA
nor public commenters identified .any ' -
spill situations that by themselves
would lead to a release from the
repository.
EPA has addressed the possibility of
fire or explosion in the WIPP by new
waste characterization requirements in
today's decision. Under these
requirements, DOE must test every
container shipped to the WIPP for
flammable gases. If flammable gases are
identified, the waste cannot be placed in
the repository. .Therefore, under the
terms of.EPA's determination, explosion
or fire in the WIPP is not a credible
event. (After DOE has developed a
greater body of data .on wastes shipped
to the WIPP, it is likely that waste
characterization requirements
addressing flammability can be relaxed.
However, this could only take place
through a modification of the
determination, with opportunity for
public comment.)
Effectiveness of controls against
human intrusion. During the period
covered by today's determination, DOE
will maintain active control over the
WIPP site, and unauthorized access will
be prohibited. Furthermore, the site will
be operating under RCRA interim status
and permit conditions, administered by
the State of New Mexico, and therefore
will have to comply with the RCRA
security requirements. These
requirements include prevention of
Unknown entry of persons or livestock
to- the active portion of the facility.
Finally, DOE has secured all mineral
leases at the WIPP site, eliminating the
possibility of the disturbance of the
repository as a result of mining or •
drilling. For these reasons, the Agency
has concluded that migration resulting
from human intrusion will not occur
during the term of the determination.
B. Conditions of Determination
1: Limitation to Testing and
Experimentation
In EPA's proposed finding, it limited
activities involving mixed waste at the
WIPP repository to the testing and
experimentation described in DOE's
petition and referenced documents. The
Agency has retained this condition in its
final determination. Consequently, DOE
will be restricted to. its planned test
, phase activities, as described in the,
"WIPP Test Phase Plan: Performance
Assessment," Revision O (DOE/WIPP
89-011, April 1990). Before DOE could
conduct activities beyond the scope of
this test plan, it would have to petition
EPA to modify its no-migration finding.
Several commenters on the proposal
expressed uncertainty about what
specific activities would fall under the
definition of "testing and
experimentation"; in addition, the
commenters asked for clarification of
when DOE would have to notify EPA of
changes from activities described in the
performance assessment test plan.
With respect to the first point, DOE
could conduct in the repository only
those tests-or experiments designed to
provide data to demonstrate the long- .
term acceptability of the WIPP; Thus,
DOE's planned "operations
demonstration" has been explicitly
excluded from the allowed activities; :
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Federal Register / Vol. 55, No. 220 / Wednesday/November 14. 1990 / Notices 47707
other nontesting activities would
similarly be excluded. For clarification,
. EPA has modified this condition, which
originally read "placement of waste for
the primary purpose of conducting an
operations demonstrated is prohibited
under this variance *• * *," by dropping
the word "primary." Several
commenters suggested that the inclusion
of the word "primary" amounted to an
invitation to DOE to conduct a full-scale
operations demonstration with the
excuse that some testing was also going
on. This was not EPA's intention, and
therefore it has modified the condition
accordingly. EPA, however, stresses that
it does not understand this condition as
preventing DOE from incidentally
testing some operational aspects of its
system when it places waste
underground for permissible testing.
Such activity, in EPA's view, would not
constitute an "operations •
demonstration" in the sense that DOE as
well as DOE critics have used the
phrase up to this point. In addition, EPA
recognizes that some mixed wastes
might be generated'underground as 8.
result of legitimate experimentation or
air monitoring in the WIPP repository.
These wastes, which might no longer
have any experimental purposes, could
.nevertheless be stored in the repository
until a final determination on the site
was made. Because the materials were
originally placed in the WIPP for
permissible testing, continued storage of
the wastes in the repository would be
consistent with the terms of EPA's
decision.
With respect to the second point, tests
and experiments 'conducted under
today's determination would have to be
consistent with the activities described
in DOE's performance assessment test
plan and its no-migration petition. For
example, where substantially different
wastes or waste containers are used,
where waste volumes were increased
above 0.5 percent (but less than one
percent), or where tests outside DOE'sr
planned three-phase bin and alcove-- '
scale tests are contemplated, DOE
would be required to notify EPA and, if
the changes might affect the basis of ...
EPA's finding, seek a modification to
that finding. The only exception to this
would be those wastes that are
described in DOE's no-migration, ••
petition that are modified through
various treatment technologies; because
the composition of these wastes, if
changed, would contain fewer toxic
constituents, the Agency does not
believe it would have to be notified
before the wastes could be placed in the
repository. EPA does note, However,
that the pilot-room tests originally
suggested by EPA and now ' :
contemplated by DOE, would be
excluded under today's decision,
because they go substantially beyond
the program described in DOE's test
plan and furthermore are inconsistent
with other conditions of the :
determination (e.g., the volume limit and
retrievability of wastes). , ,
2. Limitation on Volume
. In its proposed determination, EPA
did not set a specific limit on the amount
of mixed waste that DOE could place in
the repository, during the test phase.
Instead, EPA argued that, because of the
• experimental nature of the test phase,
DOE needed a reasonable degree of
flexibility in carrying out its '
experimental program. Although several
commenters supported EPA's approach,
many opposed'it, arguing that it was
open-ended and allowed DOE to expand
the scope of the test phase indefinitely.
Although EPA continues to believe that
its no-migration finding, as proposed;
significantly restricts the nature of DOE
activities during the test phase, the
Agency nonetheless understands the
concerns of the commenters. Therefore,
it has decided to place a volume
limitation of 8,500 drums or 1 percent of
the total projected WIPP volume on
wastes that can be placed in the
repository under this determination.
In setting a volume limit, EPA notes •
that DOE's "WIPP Test Phase Plan"
called for bin and alcove-scale testing of
waste amounting to 0.5 percent of the
projected WIPP capacity, while in
Congressional testiiaony, DOE indicated
that bin, alcove, and pilot-room tests
might require waste amounting to
approximately 2 percent of the WIPP
capacity. Because EPA has determined
that the pilot-room tests, as currently
planned, could not be conducted under
the proposed no-migration finding, it
believes that the 2 percent volume limit
would be inappropriate. At the same • .
time, EPA also believes that limiting
DOE to the amounts specified in the
current test plan might not provide
sufficient flexibility for DOE to modify
those plans, particularly in response to
comments from reviewing organizations.
Consequently, EPA has decided to .
impose a limit of 1 percent of total WIPP
. capacity (or 8,500 drums); a figure that
provides some flexibility to DOE and at
the same time gives the public
assurance of an opportunity to comment
if significant increases over DOE's
proposed waste volumes are needed.
EPA emphasizes that it is not basing
the 1 percent limit on any technical
determination of how much waste
would be necessary for DOE to carry
out an adequate testing program. Rather,
EPA in effect is defining a limit that it
would consider to be a significant
departure from the activities described
in DOE's. no-migration petition and its
final test plan. Before DOE could exceed
that limit, it would have to repetition
EPA, and any EPA approval of an
expanded test program would have to
undergo public comment. EPA also
emphasizes that the 1 percent figure
represents an upper limit on the amount
of waste that may be placed in the WIPP
under today's determination. This limit
would not override the condition that
waste could be placed in the WIPP only
for testing and experimentation within
the scope of DOE's test plan. Waste
would not be allowed in the repository
for purposes other than testing and
experimentation, even if the volume of
waste involved did not exceed the:l
percent limit. • ;
Many commenters also suggested that
EPA shorten the proposed ten-year
expiration date for petition approval.
EPA has not adopted this suggestion,
because, as it discussed in the proposed
decision, it believes such a limit might
artificially constrain legitimate testing.
EPA does not believe the difference
between five years (the projected length
of DOE's test phase) and ten years is
significant hi terms of the likelihood of
release of hazardous constituents from
the repository. Furthermore, it has
concluded that this difference in time
will npt significantly effect
retrieyability; However, EPA,
acknowledges that the timing and '."'-..
procedures for removal of waste if DOE
is not able to demonstrate the long-term
acceptability of the WIPP at the;close of
the ten-year period was not clear in the
proposed finding. Therefore, the Agency
has amended the conditions of the
finding to address this concern. This
issue is discussed below.
3. Waste Retrieval
The requirement that DOE retrieve
wastes from the repository if it cannot
demonstrate the long-term acceptability
of the site remains unchanged from, the
proposal. As discussed above in section
IV.A,'EPA has found such retrieval to be .
feasible within the general parameters
of the plans,submitted with the petition. .
In addition, EPA has added a clause
spelling out in more detail the timing of
retrieval. Under this requirement, DOE
must submit to EPA a specific retrieval
schedule no later than six months after
it is determined that the WIPP cannot
meet the long-term disposal standards,
or six months before the expiration of
the petition approval (i.e., 10 years after
petition approval), whichever comes
first. This schedule would have to detail
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477D8 Federal Register / VoL 55. No. 220 /'IWednesday, November 14, 1990 /
retrieval procedures and include a
schedule for the removal of the waste as
rapidly as technically feasible. Before
retrieval took place, the plan would be
subject to public comment and EPA
approval
4.WasteRetrievability
DOE is required to place all waste in
the repository in a readily retrievable
manner. This condition is unchanged
from the proposal. By "readily
retrievable," EPA means adoption of the
specific measures identified in DOE's
petition to maintain room stability {i.e.,
room sizing, rock bolting), the use of
easily retrieved waste containers'(eg.,
boxes, bins, and drums), and the
absence of backfilling—except in alcove
tests where standoff walls will be used.
(EPA notes that testing in pilot-scale
rooms, which the Agency originally
suggested and DOE is now considering,
would not be allowed under this
condition, because—as currently
planned—they would involve backfilling
of waste in the pilot rooms without
standoff walls. DOE would have to seek
a modification of the no-migration
finding, with opportunity for public.
comment, before conducting such tests.)
5. Carbon Adsorption Device
Today's decision requires DOE to
install a carbon adsorption control
device in the bin discharge system of
each room designed to achieve a 95
percent control efficiency. The Agency
believes a 95 percent control efficiency
is readily achievable. (See 55 FR 25454.) •
The design must be based on a total
design gas volume consisting of a design
gas generation value of at least 5 moles
per drum per year from the bins and the
volume of gas used to purge the bin
exhaust manifold. EPA also wishes to
clarify that the design value for the
frequency of carbon replacement must
be verified by testing and modified as
needed to prevent breakthrough from
occurring. The testing must consist of
measurements of the adsorption
capacity of carbon for the bin exhaust
gases, as described in the petition. EPA
is also requiring DOE to maintain design
records, including any test data, and
operating records in the facility,
operating record, as described in the ' •
notice of the proposed decision. (See 55
FR 13063, Section IV.J.) Records must be
maintained for the term of today's
determination (Le., ten years from
today'a date), or three years after the
creation of the records, whichever is
longer. In addition, the records must be
maintained during the course of any
enforcement action for which they are
relevant
EPA is not requiring DOE to perform
testing to verify the control efficiency of
the carbon bed. However, DOE must
monitor the bin exhaust manifold to
show that no migration above health-
based levels occurs at the unit
boundary. This must be further
confirmed by monitoring at the exhaust
. shaft. Although the 5 moles per drum per
•year design value for gas generation is
believed to be conservative, the overall
'average rate of gas generation fromTRU
wastes is not known with certainty; this
is the purpose of the bin and alcove
tests. Hie control [efficiency actually
achieved will be higher or lower
depending on the.rale at which gas is
generated during the tests. However,
even if gas generation rates were to be
as high as 25 moles per drum per year,
the design would Still achieve the no-
migration standard.
6. Air Monitoring plan
EPA is requiring air monitoring for
activities conducted under today's no-
migration finding to confirm that there is
no migration of hazardous constituents
above health-based levels beyond the
unit boundary. As described in its notice
of proposed decision (55 FR 13068), EPA
has concluded that the only possible
migration pathway during the test phase
is through the exhaust shaft. Therefore,
in accordance with the requirements of
40 CFR 268.6(c), tile Agency is requiring
DOE to implement the air monitoring
plan submitted with its petition, subject
to the clarifications, modifications, and
reporting requirements described in the
notice of proposed ilecision, except as
noted below.
In its proposed decision, EPA solicited
comment on whether additional
monitoring should be conducted in the
underground repository with portable
explosimeters to detect any buildup of
methane, hydrogen, or other flammable
gases. No comments were received in
favor of portable explosimeters.
Therefore, EPA has decided not to
require their use. At the same time,
however,' EPA has determined that only
by testing individual waste containers to
be placed in the WIPP can it be assured
that no- fire or explosion hazard exists.
Thus, EPA is including an additional
condition requiring such testing, as •
described in section IV.B.7.a of today's
notice. |
EPA also solicited comment on
whether to allow a reduction in
monitoring frequency from weekly to
monthly. EPA received no comments on
this question and has decided to retain a
weekly minimum monitoring frequency.
Furthermore, EPA solicited comment on
whether other constituents, in addition
to the five constituents proposed, should
be targeted for routine quantitation. No
comments were received on this
question; therefore, EPA has decided to
retain the five target constituents listed
in the notice of proposed decision, with
provisions for targeting additional
constituents, as described in the
proposal.
In the proposal; EPA spelled out a
variety of quality assurance and quality
control requirements, making mention of
the "Report on Minimum Criteria to
Assure Data Quality," Since that time,
EPA has revised this report and has •
retitled it "Quality Assurance and
Quality Control" (August 1990), a copy
of which has been placed in the docket
to .this rule. Therefore, EPA is requiring
DOE to follow the requirements of the
revised report, in addition to adhering to
the specific quality control requirements
described in the DOE monitoring plan
and EPA's notice of proposed decision.
EPA wishes to clarify that it intends the
"method limit of quantitation," the term
used in the notice of its proposed
decision, to be synonymous with the
term "method detection limit," or MDL,
used in the report, "Quality Assurance
and Quality Control" In addition, EPA
is requiring DOE to maintain
documentation of all aspects of quality
assurance and quality control, as
described in Jhe revised report, in the
WIPP facility operating record; this
documentation must be available for
inspection by the Agency. The records
must be maintained for the term of
today's determination or three years
after they are created, whichever is
longer. In addition, the records must be
maintained during the course of any
enforcement action for which they are •
. relevant •
Initial monitoring results underground
at the WIPP have revealed significant
background levels of 1,1,1-
trichloroetfaane and carbon
tetrachloride.7 The levels measured can
interfere with the evaluation of accuracy
if the approach described in the notice
of proposed decision is used. Therefore,
EPA is changing the method by which
relative accuracy is determined. Instead
of computing accuracy based on a
matrix spike alone (as the relative
difference between the concentration
recovered from the sampler and the
concentration of the targeted analyte as
determined from the known
concentration in the audit gas cylinder],
the computation should be adjusted for
7 Significant levels of methylene chloride were
also detected in back&nund samples. However,
laboratory contamination it the most likely
explanation for the measured levels of methylene
chloride.
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Federal Register / Vol. 55, No. 220 ;/ Wednesday, November 14, 1990 / Notices
47709
the actual background concentration
measured in a matrix duplicate at the
time the matrix spike is collected.
Therefore, DOE must'collect and
analyze both a matrix spike and a
concurrent matrix duplicate, •
EPA further solicited comment on
what specific quality assurance (QA)
objectives it should require for data
acceptability. DOE requested that EPA
allow less accurate measurements at
concentrations near the detection limit.
The data provided by DOE, however,
gave no basis for establishing an
alternative QA objective for accuracy,
due to high background levels. Because
of this, and because EPA is.not requiring
data that are below the method
detection limit (MDL) to be used in the
evaluation of relative accuracy (the
MDL is generally considerably higher •
than the limit of sensitivity of the
analytical procedure), EPA has
concluded that the plus or minus 10
percent requirement can be achieved.
Therefore, no change is being, made to
the QA objectives established in the
notice of proposed decision.
Finally, EPA proposed to require
calibration of the ventilation exhaust
fans on a quarterly basis. In its
comments on the proposal, DOE
interpreted this to mean a full dynamic
calibration, .which it argued is needed
only on a yearly basis. EPA means to
require only a check on the fan
calibration on a quarterly basis, using
the methods' described in the notice of
proposed decision. EPA agrees that a
full calibration is needed only on a
yearly basis.
Several commenters expressed
concern that EPA is allowing monitoring
at the top of the exhaust shaft instead of
at the entrance to the shaft. They argued
that EPA should require DOE to monitor
the entrance and exit of the shaft to
demonstrate EPA's statement that there
will be no difference between
measurements. EPA disagrees with :
these commenters. Even if, as suggested
by one commenter, the integrity of the
concrete shaft liner, were compromised,
it is inconceivable that any depletion of
concentrations of hazardous
constituents could be detected, given the
large volume of air that the exhaust
shaft is designed to handle during
operation. EPA's overriding concern
regarding the specific location of the
exhaust.shaft monitoring station is that
it be situated so as to enable ready
access for operation and maintenance
purposes. Indeed, EPA views ready
accessibility as one of a number of
important quality assurance objectives.
. Therefore, EPA .continues to accept
monitoring at the top of the exhaust
shaft.
7. Waste Analysis
a. Flammability. EPA received a .
number of comments that flammable
gases could build up in waste
containers, creating a fire and explosion
hazard. After reviewing these comments
and new information made available
during the public comment period, EPA
has concluded that, while a fire or
explosion is unlikely, the possibility of
accidental ignition of flammable gases
in waste containers cannot be ruled out.
Were a fire or explosion to occur, as a
result of accidental ignition of
flammable gases in die void space of a
waste container, retrieval.could be much
more difficult, should retrieval become
necessary. Moreover, .such an event
could itself cause migration above
hazardous levels beyond the
uniboundary.
For these reasons, EPA believes that
no waste container should be emplaced
in the underground repository if it
contains flammable mixtures of gases in
any layer of confinement, or mixtures of
gases that could become flammable
when mixed with air. To assure a
sufficient margin of safety, EPA defines
any mixture as potentially flammable if
it exceeds 50 percent of the lower
explosive limit (LEL) of the mixture in
air.
To ensure that individual waste .,
containers have met the prohibition on,
flammable gases, the Agency is
requiring that every waste container be
tested for hydrogen, methane, and .
volatile organic compounds (VOCs) as a
class. Given the heterogeneity of the
waste package, the Agency is also
requiring that headspace sampling be
representative of the entire void space
of the waste container. EPA expects that
all layers of confinement in a container
will have to be sampled until DOE can
demonstrate to the Agency, based on
the data collected, that sampling of all
layers is either unnecessary or can be
safely reduced. The testing of wastes
that exhibit high rates of radiolysis
should be performed-a relatively short
time before the container is actually
emplaced underground. Otherwise,
hydrogen levels could build up to
flammable levels following sample
collection and analysis. Therefore, DOE
must determine, and document, the
length of time that headspace gases can
be expected to remain below flammable
levels (i.e., 50 percent of the mixture-
LEL) after sampling has been performed,
for both newly generated and
retrievably stored wastes, and to ensure
that the waste containers are emplaced
in the WIPP within that time.
If testing reveals the presence of •
significant levels of flammable VOCs,
DOE must perform an explicit flame test
to determine if a flammable mixture.can
be formed with air; Significant levels of
flammable VOCs are defined as
measured concentrations (excluding
methane) of 500 parts per million or
greater. If testing shows that VOCs are
insignificant, i.e., below 500 parts per
million, DOE may determine the lower
, explosive; limit of the mixture from the
lower explosive limits of methane and
hydrogen using the Le Chatelier formula,
as described in Section V.I.a of today's
notice.. '
All testing must satisfy the quality
assurance and quality control'
requirements described in EPA's report
"Quality Assurance and Quality
Control" (August 1990) and must meet
quality assurance objectives of plus or
minus 10 percent on precision and
accuracy. DOE must also maintain
records.on all testing performed and,
other documentation needed to comply
with this condition at the generating site
or in the WIPP facility operating record.
These records must be available for
•inspection by EPA, and must include
documentation of all aspects of quality
assurance and quality control, as
described in the above-referenced
document. Records must be maintained
for the term of today's decision, or three
years after they are generated,
whichever is longer. They also must be
retained for the duration or any
enforcement action related to this part
of today's decision. , .
b. RCRA Constituents—-Short-term
characterization. In response to
comments regarding the accuracy of the
waste composition estimates-provided
by DOE in its no-migration petition, EPA
is modifying its proposal to require that
DOE analyze headspace gases in
containers that are shipped to the WIPP
and compare the results of this analysis
to the estimated values provided in the
no-migration petition. Since it was the
values in the petition that EPA ,
evaluated in today's decision, DOE must
ensure that the analytical data derived
from the actual test-phase wastes are
similar to the petition estimates. Wastes
that are not compositionally similar may •
not be placed in the WIPP.
(1) Bin-scale tests. DOE must compare
actual measurements of headspace
concentrations of volatile organics in
each of the drums containing wastes to
be used in the bin-scale tests to the
headspace concentrations reported in
DOE's petition. The comparisons must
be made in terms of both maximum and
mean concentrations; (EPA considers
only headspace concentrations to be
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* ' '
47710 Federal Register / Vol. 55. No. 220 / Wednesday, November 14, 1990 / Notices
necessary because migration through air
was determined to be the only viable
route of migration during the test phase.)
The comparison of the maximum
concentrations is designed to ensure
that the wastes to be emplaced in the
WIPP are in fact similar to the wastes
described in the petition. In its proposed
decision, EPA noted concerns with the
precision and accuracy of some of the
analytical data in the petition and took
this uncertainty into account during its
evaluation. To address concerns over
the quality of its data, DOE will be
conducting an extensive
characterization program on wastes to
be shipped to the WIPP for the bin-scale
and alcove tests under greatly improved
quality assurance/quality control (QA/
QC) procedures. (See e.g., DOE's Pre-
Test Waste Characterization Plan,
Revision 6, in the docket to today's
decision.) Because of improved data
quality. EPA expects these new data to
differ somewhat from those contained in
the petition. However, the Agency
believes that the measured maximum
concentrations identified in individual
drums in DOE's pretest waste
characterization program should be
generally comparable to the maximum
values reported in the petition.
There are no established criteria for
quantitatively defining "comparability"
in this context. EPA, however, has
concluded that, if the measured
headspace concentration in a given
drum are no more than a factor of two
over the maximum reported for the drum
in the petition, the wastes are
reasonably comparable. In selecting a •
factor of two, EPA notes that some
differences between the new data and
that contained in the petition are
expected. This is because me new data
will represent a larger sample and
analytical results may be more accurate.
(As noted in EPA's proposal, the
precision and accuracy of the analytical
data in the petition were not always
well documented.) For these reasons,
EPA has concluded that It is reasonable
to expect some concentrations will be
measured that will exceed the maximum
values reported in the petition. EPA,
however, also believes that the data
should not be significantly different and
concludes that a factor of two __
represents a reasonable expectation. ' «
Accordingly, DOE may place the
contents of individual drums into bins
for the bin-scale tests if the'measured
headspace concentrations do not exceed
the reported maximums by more than a
factor of two.8 Testing and vertification
must be completed before the waste is
shipped to the WIPP. If the measured
concentration of any of the pertinent
hazardous constituents in a drum
headspace exceeds |b.e allowable
maximum, the contents of the drum from
'which the sample was'collected cannot
be shipped to or emplaced in the WIPP,
unless DOE subsequently treats the
waste so as to reduce headspace.
concentrations to below the maximum
levels. Alternatively; DOE may petition
EPA to modify the conditions of its
determination. Any such modification
would require public comment. Further,
DOE must maintain records of all
relevant test data atlthe generating site
or the-WIPP for the tprm of today's'
determination, or flujee years after the
data are generated, whichever is longer.
In addition, records ftmst also be
retained for the duration of any
enforcement action for which they are
relevant.
The maximum allowable
concentrations for hazardous
constituent by waste type (the maximum
•reported concentrations multiplied by
two) are presented in Table 2,
.—MAXIMUM HEADSPACE
CONCENTRATIONS
Iln volume percent]
Constituent
t.
Carbon j
tetrachloride j
Methylene
chloride ..... J
1.1.1-
Ttich1oroethane.J
Trichtoroethy)Bne_.j
1.1,2-Trichtoro-
trifluorosthane...-
Type:
i '
O.OS !
,0.44
• t .
1.88
•0^38 ,
0.05
JT
0.16
0.84;
5.68
0.34:
1.62,
Type
O.S8 i
0.50
2.12
O.28
5.74;
Type
IV
8.18
1.42
14.96
0.28
20.80
EPA's no-migration finding for air
releases was based lipon the mean
headspace concentrations of volatile
constituents reported by DOE.
Accordingly, EPAias concluded that
comparison of the new, pre-test.
characterization data with the mean
concentrations reported in the petition is
also necessary to ensure that EPA's
estimates of volatile emissions are valid
for the actual test-phase wastes. In .
determining a reasonable factor for this
comparison, EPA considered the "safety
margin" indicated by; the no-migration
demonstration. For tbe constituents of
concern, this safety margin ranges from
approximately eleven to well over
sixteen million, varyipg by constituent.
EPA has no reason to believe that the
* A» with tho condition related to flammabllity
discuited onnrfouiljr. DOE must demonstrate that
(ample* collected /or these analyses are
headspace concentrations for 1,1,1-
trichloroethane arid l,l,l-trichloro-l,2,2-
trifluoroethane (with safety factors of
six and seven orders of magnitude,
respectively) could be high enough to
alter the no-migration finding. For the
other constituents (carbon tetrachloride,
methylene chloride, and
trichloroethylene), the safety factors are .
lower (one, two, and two orders of
magnitude, respectively). EPA, therefore,
has concluded that DOE must compare
the new headspace data for these
constituents to the mean values reported
in the petition.8 To ensure that the no-
migration finding remains valid for these
constituents,' EPA is requiring that the
mean values for the test phase wastes
cannot exceed ten times the mean
values reported in the petition.
•EPA is confident that the factor of ten
(back-calculated from the modeling for
carbon tetrachloride) is sufficiently
conservative for all three of the
constituents. Even though no additional
safety factor has been added for carbon
tetrachloride, EPA notes that the .
modeling upon which the calculation
was based contains several
conservative assumptions (e.g., that both
test rooms are filled to capacity). EPA
also notes that, during the test phase,
emissions will be monitored and it will
be clear well in advance if emission
levels are approaching the no-migration
limits, and corrective measures could be
taken. Therefore, EPA is comfortable
with a safety factor of ten for the
comparison of the mean values.
DOE must compare the predicted
mean values (multiplied by ten) against
the average of the measured
concentrations of the headspaces of all
drums of a single waste type used to
make up each bin. That is, the mean
from the population of drums going to
each bin (by waste type) must be
compared with the reported mean for
that waste type. If the calculated mean
exceeds the reported mean by more than
a factor of ten, that bin cannot be
emplaced at the WIPP under today's
decision. Testing and verification must
be completed before the waste is
shipped to or emplaced in the WIPP. As
with comparisons of maximum
concentrations, DOE most maintain
records of all relevant test data at the
generating site or at the WIPP facility
for the term of today's determination, or
for three years after generation,
whichever is longer.
The allowable average concentrations
for each waste type in drums to be used
representative of the entire headspace within the
drum, including the headspace within inner bags.
0 See footnote 8.
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Federal Register / Vol. 55, No. 22O / Wednesday, November 14, 19SO / Notices
47711
in a single bin are presented in Table
3.10
TABtE 3.—MEAN HEADSPACE
CONCENTRATIONS
tin volume percent!
Constituent
Carbon
tetraehfowte
Methytene
chloride..™™
Trichloroethy|ena_.
Type
0.24
0.39
0.25
T
0.26
0.42
0.28
T
0.30
0.33
0.29
T
6.90
O.93
0.38
(2} Alcove tests. EPA has found
emissions from the alcove tests to be
inconsequential in comparison to the
bin-scale tests. Accordingly, EPA is not
requiring testing of the headspaee of
drams used in the alcove tests to
demonstrate comparability with
reported concentrations in DOE*s
petition. * * Before any drums can be
shipped to the WIPP for alcove tests,
however, DOE roust verify (by waste
type), through results of the bin-scale
tests conducted up to, that point, that the
measured mean concentrations for
specific hazardous constituents do not
.exceed the reported mean values by
more than a factor of ten. (See Table 3.)
(This condition would hot require DOB
to conduct all bin-scale tests before the
alcove tests could proceed; however,
based on discussions with DOE, EPA ,
believes that most of the bin-scale tests
will be conducted before the alcove;
tests begin.} EPA is also not requiring
DOE to test the drums to determine
maximum concentrations for specific
hazardous constituents, because it ;
believes that sufficient data will; have i
been compiled from tests conducted in .
bin-scale drums to determine if there is
a concern. In this regard, EPA notes that
the drums for both, the bin-scale and the
alcove tests will be randomly selected
from the population of each appropriate
waste type. Therefore, there is no reason
to believe that the wastes usedin the
alcove tests will be any more or less -
accurately characterized by the data in
.the petition than will be the wastes used
in the bin-scale tests. For this reason,
10 The allowable concentrations are the reported
mean concentrations foreash waste type multiplied
by ten. In calculating the mean headspaee
concentrations, EPA used one-bait the detection
limit indicated in the no-migration petition to '
represent concentrations where the constituent .was
not detected. . " ' '
•' la Although today's decisions doe?not require:
DOE tocharaeterize RCRA constituents in the
drums to be used in the afcove testa, DOS has
informed EPA that it intends to test same statistical
number of drums that are to be used in the alcove
test. In addition, as discussed earlier, DOE tviR be
requited to test the headspaee of drums used in the
alcove testa fortlamroability.
EPA has concluded that the data
collected from the drums selected for the
bin-scale tests can be appropriately
extrapolated to the drums, for the alcove
tests.
c. RCRA Constituents—Long-term
characterization. In its proposed
decision, EPA expressed some concern
over the limited waste characterization
data provided by DOE hi support of its
petition. While EPA concluded that the
data were sufficient for the no-inigration
demonstration for the test phase, it also
believed that further characterization
was required, before any finding could
be made for the operational and post-
closure phases. EPA believes that this
farther characterization will be
necessary both to further confirm DQE*s
estimates of waste composition and to
ensure that the wastes are sufficiently'
similar to allow the results of test-phase
experimentation to be extrapolated to
the wastes that DOE wishes to emplaee
at the WIPP in the operational phase.
That is, the Agency wished to ensure
that the test-phase wastes are
accurately represented by the estimates
and are representative of the remainder
of the wastes.12 In addition, more
accurate source term data may prove
necessary, EPA believes, in long-term
modeling exercises. Toward these ends,
the Agency proposed to require DOE to
report all characterization data that will
be collected*
After carefully reviewing public
comments, EPA continues to believe
that the data provided by DOE in its
petition are sufficient for its finding with
respect to the WIPP test phase, ivhere
air emissions are the major concern
(especially given the standards on
headspaee concentrations and
fiammabslity imposed in today's
decision}. The additional waste
characterization data under .
development by DOE during the test
phase will be important for any review
of a subsequent no-migration petition for
operational and post-closure periods,
where groundwater migration and other
issues may arise; however, the data are
not needed for today's decision.
. iz By "representative," EPA is referring to those
factors that should contribute to migration of
hazardous constituents. The purpose of the test- -
phase experiments is to evaluate gas-generation
processes and providesdatabase of information •
• that can be used to predict gas generation potential.
of the waaies that are planned to be emptaced
during the operational phase. Thus, the issue of
whether the test-phase wastes are "representative"- •
deals with whether the results olE the test-phase-•
experiments can be extrapolated to the remaining
wastes. To that end. DOE's approach is based upon
an "envelope" or "bounding" concept wherein ' .
wastes whose characterization (for gas-generation :
potential)is within that envelope would be
considered "represented" by the test-phase wastes.
Accordingly, EPA has not included • *
detailed requirements-for .•waste . •
characterization of the test-phase • •
wastes (beyond the headspaee
concentrations and flammability limits)
or of wastes generated at the ten DOE
sites as a condition for today's final
decision. However, DOB is developing
waste characterization plans, including '
sample collection, preservation, and
analytical procedures, to demonstrate
the extent to which Ihe test phase
wastes are representative of Ihe other
wastes from the ten sites, and to confirm
•the actual levels of RCRA .constituents
in headspaee gases and sludges. If
certain wastes that are generated at the.
ten sites are not represented (as defined
in footnote 12J by the wastes that were
tested during the test phase, they conld'
not be shipped to the WIPP without
further Agency evaluation, including the
possibility for. public comment or
treatment of the waste.
Over the past several months, EPA—-
and the state of New Mexico—has
reviewed a number of documents
concerning DOE's pre-test waste
characterization plans. EPA will
continue to provide comments to DOE to
assist DOE in' evaluating whether the
waste characterization data that DOE
will be collecting are sufficient to make
a long-term finding for the WIPP. If
adequate data are not collected, EPA
will not be 'in a position to approve any
no-migration petition for the operational
and post^closure phases, if DOE submits
such a petition. Af a minimum, the
wastes .should be analyzed for the
following constituents: •
Acetone
Benzene
Brottiofonn
BotanoJ
Nitrobenzene1
13A2-Tetraehlbioethane
Tetrachioroethytene
Toluene
2-Butanone'
Carbon tetraehloride .
Chloroform ,
Chlorobenzene
Cyciehexane " ,
1,1-Dichloroethane
1,2-Dichloroethane
1,2-Dichloroethene
cis-l,2-DiEhIoroethane
Ethyl benzene'
Ethyl ethe>
Formaldehyde
Hydrazine
Methanol
Methytene .chloride
4-Methjif-2-pentanene
M.l-Tricbknnethane
Trichloioetbylene ...
!,13-TrichoForo-lA2- '
trifTuoroethane
1,3,5-Trimethylbenzene
o-Xylerie
p-Xytene
Cadmium
Chromium
Lead
Murcury
Selenium .
Sihref • . • •
Testing for these constituents; should •
include'headspaee analysis of all waste
types for the,.org,anic compounds, as
well as total analysis of the sludges for.
both the organic compounds-and= the
.metals.1? Since these date are not •
' 1:> As .indicated in Section l.Doft
the state of New Mexicoia responsible for enforcing
Continued
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47712
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Federal Register •/ Vol. 55. No. 220 / Wednesday. November 14, 1990 / Notices
necessary for today's finding, but rather
will be evaluated as part of a
subsequent review of a petition for the
operational and post-closure periods (if •
DOE chooses to aubmit such a petition).
EPA has concluded that the specifics of
this testing should not constitute a
condition in today's decision.
8. Reporting Requirements
Reporting requirements associated
with EPA's final no-migration
determination are unchanged from the
proposal—that is, annual written reports
are required on the status of DOE's
performance assessment during the test
phase—except that the final
determination requires that DOE send
reports to EPA's Region VI office in
Dallas, Texas, as well as to the EPA *
Office of Solid Waste at EPA
headquarters. Because Region VI will
have direct enforcement authority over
the WIPP, EPA believes that it is
important for reports to go directly to
the regional office as well as to EPA
headquarters.
V. Discussion of Major Issues
,EPA received more than 400
comments on its proposal, some
supporting EPA's proposed decision and
others opposing it. Commenters raised a
wide variety of issues, including the
general scope of EPA's review and its
proposed decision; the suitability of the
site; the consistency of EPA's proposed
approach with the statutory no-
migration standards; adequacy of waste
characterization; the feasibility and
likelihood of retrieval; the impact of
possible human intrusion; and many
other issues. The major issues raised by
the public are discussed below as well
as in other sections of this notice. These
and the other issues raised by
commenters are also discussed in detail
in a Response to Comment document
prepared by EPA. This document is
available in the public docket to this
decision.
A. Appropriateness of "Exemption"for
DOE
A number of commenters criticized
EPA for proposing to grant to DOE what
they regarded as an "exemption" from
the hazardous waste regulations for its •
WIPP operations. They questioned why
EPA would grant an "exemption" or
"variance" to DOE for radioactive
wastes, given the risks of this material.
Numerous commenters also questioned
RCRA Interim status standards at the WIPP and for
Issuing a RCRA permit to the facility. In carrying out
these responsibilities, the State may require
additional or more stringent waste characterization
requirements.
DOE's record at other sites, and argued
that DOE shbuld be required to comply
with all applicable regulations—without
special "exemptions" or "variances"—
before it was allowed to place waste in
the WIPP repository for any purposes.
EPA stresses that it is not granting an
"exemption" to DOE from the hazardous
waste regulations. This action, however,
is a "variance" only in a very narrow
sense. HSWA establishes two routes by
which a regulated party may dispose of,
waste in compliance with the land
disposal restrictions: It may pretreat
wastes according to specified treatment.
standards, or it may dispose of the
waste in a unit that meets the stringent
no-migrationjstandard. DOE has chosen
the second route of complying with
these restrictions—an option that is in
some respects the more stringent of the
two. For exaipple, if DOE were to
choose treatment as its approach, DOE
would no longer be required to
demonstrate jthat no hazardous
constituents would migrate from the
WIPP before pie treated waste (which
might still rerhain hazardous) could be
placed underground. In any case, EPA
reemphasizes that its action today in no
way exempts: DOE from the hazardous
waste regulations; instead, it is a
determination by EPA that the.
placement of untreated mixed waste in
the WIPP during the test phase complies
with the statutory and regulatory
restrictions oh land disposal under
RCRA. Furthermore, it should be noted
that the WIPP must also comply with the
other hazardous wastes standards of
RCRA, as well as other applicable
standards. Other standards applicable
to the WIPP are described in Section I.D
of this notice.
EPA recognizes the concerns of many
commenters over acknowledged
problems at other DOE sites. EPA,
however, does not believe that problems
at other sites should rule out approval of
a no-migration petition for the WIPP.
The issue at hand is whether there will
be any migration of hazardous
constituents from the WIPP disposal
unit. EPA has carefully and
independently reviewed all the
information from other sources. As a
consequence of this review, EPA has
concluded that DOE has demonstrated,
to a reasonable degree of certainty, that
hazardous constituents will not migrate
from the disposal unit, under the
conditions prescribed in Section VI of
this notice. |
B. Timing of EPA Decision
A number of commenters expressed
concern about what they considered to
be EPA's undue haste in proposing to
grant DOE's no-migration petition for
the WIPP, and they criticized EPA's
tentative schedule for a final decision.
They suggested that EPA may have
taken undue shortcuts in the regulatory
.process, or that DOE's petition was
given an insufficient level of technical
review.
EPA disagrees with these
commenters. The Agency deliberated on
DOE's original petition for more than a
year before its proposed no-migration
determination for the WIPP in April
1990, and it spent an additionalfive
months in the review of public
comments before reaching a final
decision. In the course of this review,
EPA conducted a complete and thorough
evaluation of DOE's petition, material •
provided by DOE in support of its
petition, independent studies of the
WIPP, arid public comments on the
proposed no-migration determination. In
addition, EPA staff conducted three
investigatory visits to the WIPP site. The
results of EPA's review are summarized
in today's notice and in the Agency's
proposed decision in April 1990.
Technical details are provided in EPA's
Response to Comments Document and
its Background Document, both of which
are available in the docket for this
rulemaking.
EPA acknowledges that it placed a
high priority on the review of DOE's
WIPP petition. The Agency disagrees,
however, that it took any undue
shortcuts in the review or omitted any
significant procedural steps. EPA's
decision was made in full accord with
the procedures for no-migration
determinations, codified at 40 CFR 269.6;
and with EPA's procedures for site- •
specific decisions under RCRA. EPA
modeled its procedures for handling the
WIPP no-migration petition (as well as •
other no-migration petitions now under
review) on its procedures for handling
RCRA delisting petitions. These
procedures ensure a thorough and
complete Agency review, with public
notice and full opportunity for public
comment.
C. Scope of Determination •
In its proposed no-migration
determination for the WIPP, EPA noted
that it did not consider the release and
possible risks associated with
radioactivity; rather, its review ;
addressed the release of hazardous
constituents from the disposal unit. EPA
pointed out in its proposal that the
statutory language on no-migration
referred to the release of hazardous
constituents, which do not include
radionuclides, and risks of radioactivity
from the materials DOE is placing in the
WIPP fall within the scope of the Atomic
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Federal Register /Vol. 55, No. 22O / Wednesday, November 14, 199O / Noticer
47713
Energy Act rather than RCKA. The
Agency further noted tbafrisks . ,-
associated with transportation lay
outside the scope of its no-migration ;
review. Finally. EPA did not seek to
determine, whether the approach
proposed by DOE—that is. deep
geologic disposal of TRU wastes at the
WIPP site—was the best possible
alternative for handling that waste.
Despite EPA's explanation of the scope
of its no-migration review, numerous
commenters raised issues related to
radioactivity, transportation, and
alternatives to the WIPP. EPA
understands that concerns of these
commenters; however, its continues to.
believe these concerns lie outside the i
scops of its legal authority and are • ;:
better-addressed in ether forums. ;.;
Radioactivity was a major concern of
many eoinmenters. A number, in ;•,
particular, argued that, since EPA's ~
charge is to protect human health and ;
the environment, it must address the ; •
release of radionuclides in any
evaluation of the non-migration
potential of -waste from-the WIPP. EPA,
however, believes feat the potential for .
radioactive releases from source, special
nufctear, and byproduct material is not
within the scope of :the non-migration
determination. First, as EPA explained
, in its proposed no-migration finding for
the WIPP. the Agency's authority 'over"
mixed wastes under RCRA. extends only
to the hazardous components of the
waste, not to the radionuclides
exempted from RCRA. (EPA explained
this positios more fully in its mixed
waste clarification notice of July 3,1986,
5.3 FR 37945, See;a!so.Section LB, above).
Second, release of'radionuclides is not
within the specific mandate'of the no-
migration language in RCRA or the
regulatory standards codified at 40 CPR
268.6. Under the statute, EPA may not
find a method of disposal protective of
human health unless "* * - * it has been
demonstrated to.the Administrator, to a
reasonable degree of certainty, that
there will be no migration of hazardous
constituents from the disposal unit * * *
for as long as. the waste remains ,
hazardous." Hazardous constituents are
a term of art under the statute, referring
to compounds listed in 48 CFR part 201,
appendix VIII. No type of radionuclide
is listed in the appendix. Moreover, EPA
regulations at 40 CFR,r26#.6 do riot
contemplate evaluation of the
radioactive risks of .a given ,qmt.
EPA acknowledges that it has a
general authority and responsibility
under RCRA and other acts to protect.
human .health and the environment and
that this standard is an overriding
consideration in any no-migration; •" . v
decision, including a decision regarding
the WIPP. The Agency believes, . .
however, that the standards issued by'..
:EPA under the-Atomic Energy Act and1
the Clean Air Act are the proper ' •
standards for protection of homah
health -and the environment for radiation
risks at the-WIPP site. Air emissions !
from the WIPP during the-test phase will '
have to comply with the Clean Air Act
standards for radioactive releases in 40
CFR part 61 and (under agreement with'
the State of New Mexico) with AEA
standards issued tinder 40 CFR part 191
subpart A. In chapter 6 of its Final
Safety Analysis Report, DOE calculated
radionuclide emissions from the WIPP
according to EPA-approved models to
document compliance with Clean Air •
•Act and AEA standards. DOE is also
preparing a NESHAP notice of
anticipated start-up to file with EPA, in
accordance with Clean Air Act
standards*. Finally, long-term releases of
radionuclides will be controlled under
AEA disposal standards codified at 4(>
CFR part 191 subpart B. These
regulations, which were specifically :
designed to address potential •
radioactive releases, are the appropriate
authority for addressing any s'ueh: •
releases at fee WIPP site. '
. EPA also aeknowledges^pulilie '
concerns about transportation safety
and agrees that it is important for.DOE •
to take every necessary measure to
ensure the safety of shipments to the
WIPP. The question of transportation
. risks, however, lies outside the scope of.
EPA's no-migration authority, and
therefore the Agency has not addressed
them in its review* Instead, overall . •
issues of transportation safety for the -• •
WIPP project are addressed-ander the
National Environmental Policy Act
(NEPA) through the Environmental
Impact Statement process and by the -
Nuclear Regulatory Commission, which
by agreement with DOE has oversight
over shipping containers-and-the waste
form during transportation.
Finally, EPA has reviewed comments
suggesting that alternatives other than
the WIPP—for example-, Iqngrterm . •',:•..
storage of TRU wastes at'the sites of ;'••
generation—should be chosen for ;
management of TRU wastes. The
Agency continues to believe that deep
geological burial is ,a promising strategy
for the disposal of radioactive waste.
But, in any case, the question of whether
acceptable alternatives to the WIPP: • ••
exist, or whether other approaches
might be preferable, lies outside the
scope of ERA's review.Under the • -.'
statute, DOE may place untreated mixed
waste in the WIPP repository if it can
meet the .statutory standards for-nb •
migration:- Alternative approaches to' •'.
deep geological burial are more•- •••• • / - - •
. appropriately addressed luiderthe---' '"> -
NEPA process. " -.' -'H;. , .-.--.• ..•• •
' D..EPA Oversight Over the Test PKnse,
Several commenters of EPA's - •,
. proposed determination argued that
EPA should assert direct oversight over" .
the testing and experimentation during
the test phase. For example, some
commenters argued that, before any'
waste was placed in the repository, EPA
should rttake a finding that in-sita testing
• at the repository was both necessary
and sufficient. Others identified what •
they considered to be flaws in DOE*8
test pJans—e.g., sealing the alcoves in
the alcove-scale tests—and argued that
EPA should--not allow waste tab*
placed in the repository before those
flaws were addressed. ;
Although EPA believes that DOE has.
generally laid out A reasonable test
program for the WIPP.it disagrees with •
• commenters who argue that the Agency
must find, as part pi today's .. •
determinatMHi, that DOE's test plans are
necessary and sufficient; Thequestion -
before EPA & whether there will be any
migration of hazardous coTistitirents '•
beyond the unit boundary for as long as' .
' the waste remains hazardous, riot
. whether alternatives to in-site-testing
are available,' or 'whether DOE'S testing"
program has shortcomings. If DOE can- :
demonstrate-no migration for the-test
pha se, which EPA concludes it has
done,-then,it has met the-statutory • ; .'. ,
standard for placement of untreated
hazardous wastes in the WIPP.
At the same time, the results of the
test phase wiB be critical in review of a
no-migration petition for longr-term ' • '.
disposal at the WIPP, if DOE chooses to
submit one. EPA^ therefore, has put DOE
on^notice1 that data from the bin and
alcove tests, must be of good quality. For
example, if the adequacy of alcove seals
cannot be demonstrated, any data .
derived from the alcove tests will be of .
questionable value. Similarly, it is
•essential for the long-term finding that
DOE adequately characterize test waste
for RCRA constituents. Toward this-endv.
EPA.has described in somedetail in
section I V.B.7 of this notice the types'
and quality of data on waste
characterization it expeets-to .see is any
petition forlong-term-disposal. > . ', :'•'••;
Howeven for the.reasdns discussed • •
above* the Agency-has concluded that il
is' not appropriate to address the scope '
•-or details of DOE*s.test plans in today's. -.
decision-^except insofar-as they involve •
possible migration of waste from-the : -
disposal unit or the retxieyabilityof the
•waste." . • ' ' - •''•:•'•'. ••"•'•• •'•' " v .
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Federal Register / Vol. 55. No. 220 / Wednesday. November 14, 1990 / Notices
E. Site Suitability
In reaching its proposed
determination, EPA reviewed more than
300 studies of the WIPP site, not only by
DOE and its contractors, but also by
independent researchers and groups
such as the U.S. Geological Survey and
the Environmental Evaluation Group.
The overwhebning^conclusion that EPA
drew from these studies is that the WIPP
has been located in a remarkably stable
formation, and that it is a promising site
for the permanent disposal of •
radioactive waste. Although there
remain some questions about the site,
which DOE will be addressing during
the test phase, EPA expressed its
conclusion that the site was sufficiently
well characterized for the test phase to
proceed. Thus, EPA agreed with the .
National Academy of Sciences and
DOE's Blue Ribbon Panel that it makes
sense to begin testing in the WIPP
repository as soon as regulatory
requirements are satisfied.
Several commenters on the petition,
however, raised issues associated with
the suitability of the WIPP site.
Commenters, for example, expressed
concern about the possibility of karst
formation In the vicinity of the WIPP
site and the general role of dissolution
processes in the area; the assumed
existence of a pressurized brine pool
below the repository; and the rate of
brine inflow into the repository. These
issues are discussed briefly below and
ore addressed in more detail in EPA's
Response to Comment document for this
rulemaking.
A number of commenters expressed
concern that the WIPP landscape had
the characteristics of a karst terrain. A
karst terrain is a kind of topography that
is typically formed over limestone,
dolomite, or gypsum through dissolution
processes; it is usually characterized by
closed depressions or sinkholes; caves,
and underground drainage. The
Implication for the WIPP, according to
commenters, is that contamination from
the repository if it reached the overlying
Rustler formation, could be transported •
rapidly to the accessible environment.
Commenters also suggested that ground
water in overlying karst formations
might attack the repository shaft seals,
after closure, and enter the Salado
Formation—the salt bed in which the ;
WIPP repository has been constructed.
This might lead to dissolution of the
halite, allowing a potential pathway for
migration past the unit boundary.
The,commenters argument that the
WIPP area is karstic is based primarily
on the presence of several
acknowledged and alleged dissolution
features in the WIPP area. These include
sinkholes in.Nash J}raw, several
kilometers from the WIPP site;
dissolution featured identified in the
WIPP 33 drill hole, just outside the site
boundary; and "Barrows Bathtub," a
depression about one kilometer from the
proposed underground disposal area.
Such features; according to commenters,
demonstrate that the WIPP site is found
in a mature karst area and that wastes
can be expected to leak from the WIPP
shortly after closure.
As a result of commenters' concerns,
EPA reevaluated the question of karst in
reaching its final decision. This
reevaluation included a field
investigation of the WIPP site, in the
company of one of the commenters. The
tour covered the most important
features that the commenters believed
were karstic in the vicinity of the WIPP.
The closest of these was approximately
one kilometer from the surface buildings
at the facility. On the basis of this
review, EPA has concluded that karst is
not now an issue at. the WIPP, and is
unlikely to become ;one for many
thousands of years; if ever.
EPA recognizes the presence of some
localized; surface dissolution features in
the general area of |the WIPP,
particularly in Nash Draw. This is not
surprising/given th4t the geologic units
within the area are 'composed of rock
that would be susceptible to dissolution
under the correct hydrologic and
geochemical conditions. However,
evidence suggests that these are ancient
features and that current rates of
dissolution are extremely slow. For
example, dissolution rates at the Nash
Draw have been estimated at one-third
of a foot every one thousand years, rates
that would not threaten the WIPP
repository for millions of years. In
addition,' the widespread occurrence of
caliche—a surface feature indicating
arid conditions and limited surface
dissolution-^-rin the WIPP area suggest
the stability of the surface landscape
over at least the last 10,000 years. At the
same time, borings.drilled at and near
the WIPP site have failed to encounter
solution channels indicative of a karst
environment. Finally, it should be noted
that the Salado Formation lies 260
meters below the surface, shielded by
relatively impermeable rocks. Thus, the
repository horizon is isolated from any
ongoing dissolution, process. The fact
that the Salado Fpnnation in the area of
the WIPP has remained largely
unaffected by dissolution processes over
its 225-million-year history is evidence'
of its stability. .•.-.;- • .
' Numerous commenters -also expressed
concern about thte presence and possible
effects of pressurized brine in the
Castile formation underlying the Salado.
One bore hole in the immediate vicinity
of the repository—WIPP 12—
encountered a large brine pocket in the
Castile. Geophysical measurements
suggest that this pocket extends
underneath the repository itself,
Commenters expressed the concern that
this brine might, in the long run, threaten
the WIPP through dissolution processes
or, if a bore hole were drilled at some
future date through.the repository into
the brine pocket, pressurized brine
might force contamination to the
surface.
After reviewing the comments and
other data in the record, EPA continues
to believe that the brine pockets in the
Castile formation—although they
contain a substantial amount of fluid—
do not offer a significant threat to the
repository. Castile deformation, which
led to the formation of the brine pockets,
was initiated millions of years ago in
association with major tectonic tilting of
strata in the Delaware Basin. The region
is tectonically inactive' at-present,
implying that new development of major
Castile features is not occurring. In
addition, the brine pool is completely
saturated with respect to halite and
therefore has no potential to dissolve
the surrounding host rock. Since the
Castile and Salado Formations are
hydrologically distinct, there is no
credible hydrologic connection between
the two formations. Finally, because of
restrictions on access, there is no
realistic possibility of a borehole
reaching brine pockets below the
repository during the, test period.
Therefore, this issue does not arise for
today's determination. DOE's
performance assessment, however, is
addressing the possible effects of such a.
borehole after repository closure.
A number of commenters also
expressed concern about the effects of
brine inflow into the repository and the
validity of permeability values used for
the Salado Formation. EPA has
reviewed the information pertinent to
this discussion and believes that, while
a good understanding of brine inflow
into the repository exists, additional
studies must be conducted to .
understand the true nature of brine ,
inflow and to quantify inflow, in a
manner more indicative of facility
conditions. These tests will be
performed during the WIPP test phase.
They will be important in any decision
on the long-term acceptability of the
WIPP site. Brine inflow, however, will
not be a problem during the test phase
and thus is not an issue for today's
decision. '
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Federal Register / Vol. 55, No. 220 / Wednesday, November 14, 1990'/ Notices
47715
Finally, commenters expressed
concern that DOE's petition and EPA's
proposed decision did not fully address
the long'term closure scenario expected
at the repository. Commenters cited
data predicting high rates of gas '
generation and argued that this gas
might delay or prevent creep closure of
the repository. As a worst case, gas •
generation exceeding lithostatic ,
pressure might fracture surrounding salt
or threaten the seal system of the ;
repository. In fact, DOE, EPA, and other
groups have recognized that the issue of
gas generation, and its relation to ,
repository performance, must be
adequately addressed before permanent
disposal of waste takes place at the
WIPP. The major purpose of DOE's in-
situ tests in the WIPP with actual,
wastes is to explore the issue of gas
generation. Today's decision will allow
these tests to proceed. The Agency
believes that the end of the test phase is
the appropriate time for it to 'make a
determination'of whether the repository
is or is not suited for long-term disposal,
since the results of the experiments "
performed, during the test phase will
help quantify gas generation "rates; :as
well as identify different initigatlve .
measures if the rates prove
unacceptable. • ,'.,..
F. Conditional Determination
Several commenters took issue with
EPA's "conditional" approach in its
proposed decision. EPA's proposed?
' determination was based, on: (1) The .
finding that hazardous constituents '
would not migrate from the disposal unit
during the test period, and (2) the
requirement that DOE remove the waste
at the conclusion of the test period
unless it could demonstrate that there
would be no migration over the long-
term. According to commenters, this
approach is inconsistent with the
statute, which requires a finding that
hazardous gpnstituents will not migrate
from the unit as-long as the waste
remains hazardous. The commenters
argued that, under the statutory
standard, DOE should be required to
demonstrate that hazardous,waste
permanently place in the repository :
would not migrate from the unit before
DOE could place any waste ,• • .-, ;•
underground, even temporarily. EPA,
however, continues to believe that its
proposed approach is consistent with
the statute and has not amended its • ;;
finding.
As commenters point out, RCRA
specifies that'hazardous constituents .
must not migrate from the unit .for as
long as the waste remains hazardous.
The phrase, "from'the unit" is a key
element of this standard. If the waste is
removed from the unit at the end of the
test period, migration of hazardous
constituents from the uiu't after that time
is clearly impossible, because there are :
no longer any hazardous constituents in
the unit to migrate. Consequently, in the
case of temporary placement, for -
example during the WIPP test phase, the
appropriate question is whether
hazardous constituents will migrate •
during the-period of temporary
placement. (As discussed elsewhere in
today's notice, EPA has concluded that
hazardous constituents will not migrate
from the unit during the test phase.) At
the same time, of course, it is important
to see that removal at the'end of the test
period is reasonably assured. EPA judge
DOE's no-migration petition-for the .-
WIPP on these grounds. (See Section ' ,
V.G for discussion of this point.) . .
One group of commenters argued
further that, if EPA were to continue
with its "conditional!' approach, it,
should review DOE's test plan to ensure
that in-situ testing at the WIPP was .
necessary to demonstrate Iong4erjtn no
migration and that the specific tests to
be .conducted would be sufficient.'; ' /. •.
Although EPA has commented on; DOE's,
test plan, EPA disagrees, with these ..
commenters on the type of EPA review
that is necessary. On the, basis of its. ,.
review, EPA has concluded that DdE's
test plan is well designed and the testing
will yield important information on,the ,-•
long-term performance of tlble repository.
EPA, hdweveivhas not an4 b.felieve.s tha.t
it shduld not formally analyze: DOE's in-
situ testing at the WIPP to determine
whether it is necessary of sufficient, and.
it does not believe such an analysis is
within the scope of a no-migration •
review. As long as DOE can
demonstrate that hazardous constituents
will not migrate from the disposal Unit, it
is legally entitled to place prohibited
waste in the WIPP, There is'ndthing in
the statute that further compels a •
petitioner to demonstrate that placement
in the unit is "necessary."
G. Definition of No Migration
Sections 3004 (d}(l). (e)(l), and (g)(5)
of RCRA state that land disposal is •' f .•
prohibited, unless "it has been ••
demonstrated to the Administrator, to a
reasonable degree of certainty, that
there will be no migration of hazardous ••
constituents from the disposal unit or
injection zone as long as.the waste
• remains hazardous." In its proposed no-
migration decision on the WIPP, EPA
adopted the same interpretation of this
standard as it had in its no-migration '•••
regulations for underground injection
wells; that is, the Agency interpreted the
standard to prohibit the migration of .
hazardous constituents in
concentrations 'high enough to render
the waste hazardous.-(See 53 FR 28122, •
July 26,1988.) Critics of this approach .-
argued that Congress clearly meant that
not a single molecule of a hazardous •
constituent couid migrate from the. unit,
as long as the waste remaining in the
unit was'hazardous. Under this . -• > ,;'
standard, DOE's WIPP nojmigration- ,
petition.could not have been approved,
because at least some molecules of
volatile organics listed as hazardous
constituents will migrate via-the air '
route during operations—--although most
likely-at several orders of .magnitude • -•
below levels of detection! .'•'••
In today's decision, EPA is retaining
its proposed definition of "rib migratibn":
of hazardous constituents. As explained
in detail in the preamble to the* proposed
decision, EPA believes that this. ' '
approach is fully consistent with the ' -
language of the statute and is protective
of human health and the environment.,
EPA=also notes that its interpretation of
"no migration" was recently/upheld in-a
decision on the underground injection
Well rules by die U.S. Court of Appeals
for the District of Columbia.5 (NRD.C v.
£P4'No. Slip. Op. (D.C. Cir. 1990)0 ¥ ';„.'
this decision, the Court accepted EPA's
argument that "no migration of •
hazardous constituents *;'.*• * for as long",
•as the waste remains hazardous" may
be read tp:mean no migration of-. ,y
constirttents above hazardous (or
health-based) levels. As .a. result, EPA ,;.'.;
has decided to retain the .same standard
in its finai decision on the WIPP' : .. ,,
petition. , ,
H. befinition of Unit Boundary .
In today's finding, EPA Has slightly.. ,
modified its-definition of-the disposal • .
unit boundary in response to;publio ,
comments. In the propos£l,.EPA defined ,
the unit boundary (or point of ,
compliance) for. .groundwater migration.
as the Salado Formation, laterally ,
bounded by the limits of the four-mile by
four-mile land withdrawal area. For air
emissions during operations of the, .
WIPP, EPA defined the unit boundary as
the point where the air shaft metthe/ -
surface.,L • , . , -.,.:•'/ .;•-.' ,-: ;. •
Numerous Sommeriters expressed .-•-
; concern about the extent -of .the unit •-.. •
boundary for groundwater, arguing that;
it might; allow broad areas of •• ••• •
contamination underground;- they. ; ••' ,
objected to EPA arguing that there
Would be no migration from the unit
even if the hazardous constituents ^'••'-. •
moved tip to two miles laterally.- Several
commenters suggested that the unit
boundary in no case should be greater
than the mined repository,-and should •
probably be less. One group of
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^ Federal Register /. Vol. 55. No. 220 / .Wednesday, November ifl, 1990 / Notices
commenters also pointed to what they
believed was an inconsistency between
the unit boundary for air and for
groundwater. They argued that the unit
boundary should be the same in both
cases and that the unit boundary for air,
therefore, should be no farther than the
top of the Salado. After reviewing these
comments, EPA has decided to retain its
definition of the lateral boundary of the '
unit (i.en the boundary of the land
withdrawal area within the Salado
Formation), but to define the boundary
for air emissions as the top of the Salado
Formation.
*EPA has rejected commenters
suggestion that the unit boundary be
defined as the mined area (or some
smaller area). As the. Agency explained
in detail in its proposed finding, it
believes that, in the context of a
geological repository, some credit
should be given for the surrounding
formation in which a-waste is placed.
The purpose of placing waste in a
geologic repository is to isolate it from
the general environment; it is not to
prevent any movement of waste,
however slight, within that formation. In
fact, some lateral movement of waste
into the surrounding formation can be
an inevitable, and desirable, aspect of
repository performance—as it is in the
case of the WIPP. A no-migration
standard that prohibited any lateral
movement would run counter to the
concept of a geological repository,
without providing for any additional
environmental protection or protecting
against any meaningful release.
In taking this general position, EPA
believes that it is being consistent with
the Intent of Congress, for example-as
expressed in the Senate Report on the
1984 HSWA amendments: "In
determining appropriate confinement
from which migration shall not be
allowed to occur, the term disposal unit
or injection zones should be construed
* '* * !n terms of the overall integrity of
the disposal practice, keeping in mind,
in particular, the potential for
contamination of ground-water or
surface water resources" (S. Rep. No.
284 98th Cong. 1st Seas, at 15). Wastes
confined to the boundaries of the unit,
as defined in EPA's final determination,
would remain more than 1,000 feet from
the nearest unconfined ground water.
EPA also notes that its position is
consistent with the recent court decision
on its no-migration rules for
underground injection walls. (NRDCy.
EPA No. Slip. Op. (D.C. Cir. 1990).) In
this decision, the court supported EPA's
position that the term injection zone
(which for underground injection wells
is analogous to the unit) includes
confining material surrounding ,the
porous formation into which the waste
is actually injected. Similarly, EPA
believes it is. appropriate to consider at
least a portion of the confining salt at
the WIPP as ipart of the unit.
Ciritics of fiPA's proposed definition
of the WIPP unit suggested no
alternative boundaries, other than
somewhere within the furthest extent of
the mined area. As discussed above,
EPA has rejected this alternative. In the
absence of any rationale for an
intermediate;boundary between the'
mined area and the proposed boundary,
EPA has decided to retain the proposed
approach. EPA emphasizes that the
WIPP unit, vulder this definition, is fully
isolated from the surrounding
environment! If waste remains within
the unit bouridary, no meaningful
movement of waste will have occurred,
and no contamination of ground-water
resources will result. Further, although
there will undoubtedly be some lateral
migration of contaminated material
along markerj beds within the salt
formation,,all projections indicate that
this migration will be very limited, in no
way approaching the boundaries of the
unit. (The mojjt likely route of migration,
instead, would be up the closed shafts to
overlying formations.) Therefore,
extensive underground'movement of
waste is not expected, regardless of the
definition of unit
In the, case of air migration, EPA
recognizes thatits. proposed definition
caused some confusion. To address
commenters' concerns, EPA has
amended the Unit definition for air
during operations, placing the boundary
at the top of the Salado Formation. The
issue of where DOE should monitor to
demonstrate compliance at that point,
however, is a ^different question. (See
section IV.B.6 for a discussion of this
point!) ' -
/. Waste Characterization
i
1. Flammabilijty
In evaluating the potential for release
of hazardous constituents in its
proposed decision, EPA considered the
potential for fjre and explosion at the
WEPP. The Agency noted that the Waste
Acceptance Criteria (WIPP-WAC)
prohibits explosives and compressed
gases in TRU Wastes and requires that
pyrophoric materials be rendered safe
by mixing them with chemically stable
materials, such as concrete or glass, or
be processed to render them
nonhazardous. In addition, the Nuclear
Regulatory Commission requires that all
waste containers, be equipped with one
or more carbon composite filters
designed to prevent pressure buildup or
the accumulation of flammable gases
prior to shipment to the 'WIPP, as
specified in "TRUPACT-II Authorized
Methods for Payload Control"
(TRAMPAC).1* EPA suggested that
these requirements, in conjunction with
the maintenance of general ventilation
in the underground repository, make the
possibility of fire or explosion extremely
unlikely.13
EPA continues to believe that a fire or
explosion is unlikely. It acknowledges,
however, the concerns of commenters
that flammable gases could build up in
waste containers, creating a fire and
explosion hazard. The Agency has
reanalyzed the available information
and has concluded that the accidental
ignition of flammable'gases in waste
containers cannot be ruled out, given the
available data on waste
characterization. At the same time, EPA
has concluded that spontaneous
combustion within as individual waste
container, i.e., without an ignition
source, is not credible.16
Were a fire or explosion to occur as a
result of accidental ignition of
flammable gases in the void space of a
waste container, retrieval could become
more difficult, should retrieval be
necessary. Moreover, such an event
could itself cause migration of
hazardous constituents above health-
based levels beyond the unit boundary.
For these reasons, EPA has concluded
that no waste container should be
emplaced in the underground repository
,if it contains flammable mixtures of
gases in any layer of confinement, or
mixtures of gases that could become
flammable when'mixed with air. To
assure a sufficient margin of safety, EPA
considers any mixture to be potentially
flammable if it exceeds SO percent of the
lower explosive limit (LEL) of the
mixture in air.
EPA, consequently, is requiring DOE
to ensure that individual waste
containers have met the prohibition of
flammable gases. DOE must implement
this provision by testing each waste
drum or individual container for
hydrogen, methane, and volatile organic
compounds (VOCsJ as a class. EPA is
14 The Agency notes that TRAMPAC also sets
limits on the thermal wattage, i.e., decay heat of
individual waste containers to control the rate of
generation of hydrogen gas by radlolysis (DOE,
Safety Analysis Report for the TRUPACT-II
Shipping Package, Appendix 1.3.7. revision 2, June
1989).
15 The Agency notes that the WIPP-WAC also
place restrictions on the total quantity of fissile
material in a waste container to ensure criticality
16 See the conclusions in the Sandia National
Laboratory memorandum from Siezak and Lappin to
Marcer and Fredrickson, January 5,1990.
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Federal Register / Vol. 55. No. 220 / Wednesday. November 14, 1990 / Notices
establishing this condition because it
does not judge available process
knowledge to be sufficiently reliable or
accurate to allow a determination on the
flammability hazard of individual waste
packages.
EPA recognizes that headspace testing
of every drum or individual container on
a continuing basis may pose a
significant burden on DOE. Without •
sufficient data, however, EPA feels
compelled to require that DOE conduct
testing, given the potential
consequences of a fire or explosion.
Once sufficient data have been
collected, however, EPA will consider
the extent to which continued testing is
necessary. Test data may well show
that flammable gases are only present at
levels well below the lower explosive
limit, either for certain wastes (e.g.,
TRUCON content code or item
description code) or from particular. .
generating sites. If the test data in fact
show that no fire or explosion hazard
exists, DOE should submit the data to
EPA and request that the testing
requirement be modified accordingly.
Any change in the terms of this
condition will be made under the
procedures of 40 CFR 268.6(e),.which
include public notice and opportunity
for comment.
EPA is also requiring that headspace
sampling be representative of the entire
void space of the waste container.
Initially, the Agency believes that each •
individual layer of confinement within
the Container will have to be sampled,
given the limited data available for .
inner bags. EPA, however, expects that
once DOE accumulates enough data, it
may be able to 'show that for most
package configurations in which bags
are twisted and taped, similar levels of
. flammable gases will be found in all
layers of confinement.17 However, it is
anticipated that the occurrence of
detectable quantities of free liquids, as
determined by real-time radiography of,
visual inspection, will continue to
indicate the need to sample the layer in
which it occurs, unless DOE can
demonstrate otherwise.
EPA also believes that testing of
wastes that exhibit high rates of
radiolysis should be conducted within a
relatively short time period of when, the
container is actually placed
underground. Otherwise, hydrogen
levels could build up to flammable
levels following sample collection and
analysis. DOE has accumulated
considerble data on radiolysis rates for
various materials in TRU wastes. DOE
used such data in its application to the
Nuclear Regulatory Commission for a
certificate of compliance for the
TRUPACT-H shipping package to
determine the length of time a waste
drum must, aspirate (i.e., vent) before it
can be shipped after retrieval from
storage.18 Similarly, EPA is requiring
DOE to determine, and document, the
length of time during which headspace
gases can be expected to remain below
flammable levels (i.e., 50 percent of the
mixture LEL) after sampling has been
performed, for both newly generated
and retrievably stored wastes, and to
ensure that waste containers! are
emplaced at the WIPP within that time.
If testing reveals the presence of
significant levels of flammable VOGs,
an explicit flame test must be performed
to determine if a flammable mixture can
be formed with air. American Society
for Testing and Materials (ASTM)
Method E 681-85, "Concentration Limits
of Flammability of Chemicals," or •
equivalent, are.acceptable test methods.
Significant levels of flammable VOCs
are indicated by measured
concentrations (excluding methane) of
500 parts per million of greater, as
propane, as determined by gas • "...
chromatography.and flam'e ionizatibn
detection (GC/FID) or of 500 parts.per
million or greater, by volume, as
determined by gas chroma.tpgraphy and
mass spectrometry (GC/MS.) i9 If
testing shows that VOCs are
insignificant, i.e., below 500 parts per
million,' the lower explosive limit of the
mixture may be determined from the
lower explosive limits of methane and
hydrogen using the Le Chatelier formula
as follows: If LELi, and LELa are the
lower explosive limits of hydrogen and
methane, resepctively, and Ci and Cz
are the measured concentrations of
hydrogen and methane, respectively,
expressed as volume percent, then if the
fraction, Ci/LEL> and Gz/LELa sum to 0.5
or greater, die mixture is considered to
be flammable when mixed with air.20
»' EPA notes that DOE intends to open up and
. disassemble the drums selected for the bin-scale
tests for visual inspection. Therefore, this
requirement should hot increase radiation exposure
to workers.
18 DOE, TRUPACT-II Content Codes (TRUCON},
DOE-WIPP 89-004, Revision 3, July 1989, and DOE,
Safety Analysis Report for the TRUPACT-II .
Shipping Package, Appendix 1.3.7, Revision Z, June
1989.
18 For purposes Of determining concentration
levels using GC/MS, only noncdmbustible
compounds may be excluded from the sunj total of
non-methane VOC. e.g., carbon tetrachloride; -
tetrachloroethylene, chloroform, and bromoform.
20 The lower explosive limits of hydrogen and .
methane are 4.0 and 5.0 percent, respectively, in air
(Bureau of Mines, "Fiammability Characteristics of
Combustible Gases and Vapors," Bulletin 627,13.65).
2. RGRA Constituents .
In its proposal, EPA expressed some
concern with the quality of the .waste
characterization data provided by DOE
in support of its petition. However, given
the nature of the wastes, the safety . ,
margins between predicted emission:.; :
levels and health-based levels, arid
required controls on air emissions, EPA: -
concluded that the information provided
by DOE (based primarily upon process
knowledge) was sufficient to
demonstrate, to a reasonable degree of ;
certainty, no migration of hazardous
constituents during the test phase, Many
commenters, nevertheless, criticized the
quality, and completeness of DOE's
waste characterization information and •
DOE's approach to waste • :
characterization. Several commenters '
noted the critical role played by waste
characterization in the prediction of no ,
migration arid stressed that-EPA needed
accurate waste descriptions, supported
:by detailed analysis, to evaluated
potential 'evironmental impacts of waste
disposal. In-responding to these
coiiiments, EPA has differentiated
between short-term issues (relevant to
today's decision for the test phase) and
• longrterm issues (relevant to a' decision -,
for the operational and post-closure .
phases, should DOE submit a petition :
for these phases). .-'•!•'•'
a. Short-term issues. Many of the ;
commenters expressed concern with the •:
Agency's acceptance of waste;
characterization data based-primarily '.,
upon process knowledge. Commenters
stated that, in the case of the WIPP,
waste characterization requirements
have not been met.
/5 EPA disagrees with the commenters'
position that DOE's waste
characterization information is
insufficent for-a no-migration
determination for the test phase. DOE's
analysis of the wastes'incuded an
evaluation of the materials and
processes from which .the wastes were
generated as.well as actual chemical • •
analysis of the wastes. In the former
case-, DOE provided flow diagrams and
narrative descriptions of the processes
that generated all,128 of the identified
waste Content Codes as well as an
identification of the RCRA hazardous
constituents used in the process. DOE
also provided estimated concentrations
for each of the hazardous-constituents -
expected in the wastes. This was ......
designed to be a conservative '• • •
characterization, in which it was
assumed that any hazardous
constituents that were used in a process
would be present in the resulting waste
stream,-regardless of known physical
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Register / Vol. 55. No. 220 /Wednesday. November 14, 1990 / Notices
processes that would reduce the
likelihood that the constituents would in
fact be present (e.g., volatilization). EPA
notes that no comments were received
indicating that wastes from the.
processes described by DOE would be
expected to be compositionally different
from the DOE-estimated compositions.
The bulk of the analytical data
presented by DOE to corroborate the
conclusions of the above-described
characterization were focused on the
only viable route of release during the
test phase—namely, through the air. For
this characterization, DOE provided
results from over 200 headspace
analyses, representing all four of the
identified waste types; these samples
were analyzed for numerous gases,
including nine organics. Other analyses
for which results were reported included
Toxlcity Characteristic and Extraction
Procedure leaching tests, total volatiles,
and total metals. While these analyses
were not typically conducted on all four
of the waste types, EPA notes that these
tests are not directly relevant for
characterizing the most likely route of
release during the period that is subject
to today's decision (i.e., the test phase).
Additionally, EPA in its proposal
considered the "safety margin"
indicated by calculations of air
emissions. That is, even if the
concentrations of hazardous
constituents were significantly
underestimated, the no-migration
standard would still be met during the
test phase.*1 Additional assurances are
provided by the air monitoring systems
that will be operated to allow detection
of emissions. Based upon the safety
margin indicated by these factors;-the
Agency concludes that the level of
waste characterization is acceptable for
the test phase. Nevertheless, to ensure
that the wastes to be used in the
binscale tests are similar in composition
to those described in the no-migration
petition. EPA is requiring that DOE test
the headspace of the wastes shipped to
the WIPP (as a measure of the waste
constituents' propensity to migrate
through air) and compare the results to
the values provided in DOE's no-
migration petition. This comparison
must be conducted and the waste must
be found to be compositionally similar
before the waste can be sent to and
emplaced in the WIPP; if the waste is
not similar to the estimated
•concentrations provided in the no-
migration petition, the waste cannot be
shipped to the WIPP unless it is
11 The safety factor assumes that an explosivity
hazard U not present. To ensure against such a
hazard. EPA placed «n additional condition on the
dectilan (XCB icctlon IVJ3.7J.
modified compositionally, such that it is
compositionally similar. The details of
this comparison are described in section
IV.B.7.b of today's notice.'
Other commenters stated that, to the
extent that DOE has provided any
laboratory analysis of wastes intended
for the WIPP, if is solely headspace
analysis (i.e., ahalysis of the
constituents' concentrations in,the air
under the lid of the drum) used as a
surrogate for th'e waste in the drum.
These commenters maintained that
headspace analysis, while extremely
useful for homogeneous phases, is
limited, at best^ for analyzing
heterogeneous (wastes such as those
intended for th£ WIPP. In the opinion of
these commenters, headspace analysis
is unreliable as a surrogate for direct
analysis of liquids and solids in drums
due to uneven partitioning of
constituents.
The Agency recognizes that there are
limitations on the utility of headspace
analysis as a surrogate for analysis of
waste composition. Certainly headspace
analysis is not Appropriate for all
evaluations for; all waste types. In some
cases, however,, headspace analysis is
the most relevant measurement. For
purposes of the test-phase
determination, headspace analysis is
primarily used ui the evaluation of gas
generation and explosivity hazards.
Since it is the composition of the gas
that is of conceal, analysis of the
headspace (/.a, the actually evolved
gas) is the mos| appropriate parameter
to consider. If concentrations in the
waste were used for the explosivity
evaluation, the [composition of the
evolved gas would be modeled, or
predicted, rather than actually ,
measured. [ • -
EPA agrees with the commenters'
concerns regarding the validity of a
single headspace sample (under the lid)
as representative of potentially evolved
gases from heterogeneous wastes. This
is especially problematic when the
drums contain several inner layers of
confinement, as do the drums that will
be emplaced in; the WIPP. Specifically,
questions exist as to whether the
headspace benfeath the lid is
compositionally different from the
headspace in the inner layers, .EPA is
addressing this issue hi the context of
the testing condition related to
headspace analysis. In that condition,
EPA is requiring that DOE take
representative samples of the headspace
(which may require, in some cases, for
DOE to take samples from inner bags)
and analyze them to confirm its
assertion that the headspace beneath
the lid is, in fact, representative of the
total evolved gas within the drums.
EPA also agrees that headspace
analysis is not a suitable surrogate for
direct analyses of the waste for '
purposes of evaluations where the total
composition is a factor. However, for
volatile organic constitutents, EPA
believes that headspace analysis can be
a useful tool for determining whether the
constituents are'present. That is, if a
volatile constituent is present in the
waste, it is reasonable to assume that it
will also be present in the headspace.
Accordingly, results from headspace
analyses were used to confirm the
presence of volatile hazardous
constituents, not to quantify their
concentrations in the wastes.
Several commenters argued that
DOE's quality assurance/quality control
of waste characterization data was
deficient. Others noted that DOE had
been unable to provide adequate
sampling plans and sample handling
procedures for analytical work. EPA
raised similar concerns with DOE's
procedures, but, for the reasons
described in the proposal and further
elaborated upon above, the Agency has
concluded that the data are sufficient for
the test phase demonstration. At the
same time, EPA advises DOE that it
expects additional analytical data to
support a long-term demonstration,
where significantly greater quantities of
waste are involved and routes of
possible migration are not limited to
release of volatiles to the air during
operations.
b. Long-term issues. EPA notes that
the "safety margin" for the long-term
showing {i.e., the operational and post-
closure phases) has not been
determined. For. that reason, the Agency
believes that additional waste
characterization data are needed to
reduce the uncertainties before a
decision on a long-term no-migration
determination can be made. EPA,
however, has decided not to make such
testing a condition of today's decision,
because the collection of such data is
not relevant to the decision during the
test phase; EPA, however, expects DOE
to develop and implement waste
characterization plans, including
appropriate sample collection,
preservation, and analytical procedures,
that will allow a demonstration of the
extent to which the test phase wastes
are representative of the other wastes
from the ten generating sites and that
allows greater precision in estimating
potential for long-term migration (e.g.,
through routes such as ground water). If
such data are not collected, EPA will not
be in a position to approve a no- •
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Federal Register / Vol. 55, No. 220 / Wednesday. November 14, 1990./ Notices 47719
migration petition for the operational
and post-closure phases, if DOE submits
such a petition. EPA's expectations
related to these data are presented in
Section IV.B.7.b of today's notice.
Many commenters expressed
concerns regarding the extent to which
the wastes that will be used for the test
phase are representative of the other
wastes that DOE wishes to emplace at
the WIPP during the operational phase.
It was stated by many commenters that,
for the test phase, adequate waste
characterization is vital to assure that
tests will be performed on
representative wastes. Commenters
pointed out that almost 70 percent of the
wastes proposed for storage do not yet
exist. They asked what controls and
safeguards were in place to ensure that
these future wastestreams are
adequately represented by existing
wastes.
The Agency agrees with commenters'
concern that the use of representative
wastes in the test phase will be critical
to the success of any DOE no-migration
petition for the later (operational and
post-closure) phases. More specifically,
the test-phase wastes must be
sufficiently representative of the other
wastes that DOE wishes to emplace at
the WIPP to allow extrapolation of data
from the test-phase experiments to the
behavior of the other wastes.22 This
issue is, in fact, the basis for the
selection of wastes that will be used in
the test phase experiments. The
selection process will be based upon
those parameters that contribute to gas
generation and is designed to identify
wastes that represent the spectrum of
expected values for those parameters.
Since waste selection and
characterization, as part of the design of
the experiments, is the responsibility of
DOE, EPA believes that it is DOE's
responsibility to establish and
implement procedures to demonstrate
that the wastes are, in fact, sufficiently
representative.
Many commenters also argued that
EPA's proposed decision did not clearly
establish whether all waste analysis
data would be provided to EPA prior to
emplacement of any waste or whether
the data would be provided
incrementally as waste is being
emplaced. These commenters stated
that they had serious concerns if the
Agency is proposing to allow DOE to
22 It should be noted that, if one or more wastes
that are generated at any of the DOE sites are not
"represented" by the test wastes, these wastes
could not be sent to the WIPP without further
evaluation. However, this would not invalidate the
testing for all other wastes that are generated at the
ten DOE sites and are represented by the test
wastes.
provide waste analysis data
simultaneously with waste
emplacement. They argued that waste
analysis should be provided to the
Agency not only before the waste is put
into the 'ground, but before EPA can
make a decision about a no-migration
variance. They believed that this
condition would allow EPA
independently to asses the quality of the
data. In the opinion of some
commenters, delivering waste analysis
information while the waste was "riding
the Carlsbad elevators" would
essentially render EPA's independent
technical review of the data
inconsequential.
EPA is not requiring that DOE submit
the analytical data on the test waste for
EPA review before the test wastes are
emplaced. Much of the analytical work .
to be conducted by DOE is related to the
eventual demonstration of no-migration
over the long term. Since EPA will
evaluate these data as part of any
subsequent petition for the later phases,
EPA disagrees with the commenters'
statement that this evaluation will be
"inconsequential." Rather, it will be a
critical element of that evaluation.
EPA, however, is requiring DOE
during the test phase to .evaluate
headspace data before waste is placed
in the repository, as described earlier.
For example, DOE must evaluate the
explosivity-related testing before
shipping test wastes to the WIPP.
Similarly, DOE must compare the
analytical results of newly conducted
headspace analyses to the waste
characterization data in the no-
migration petition before the waste is
emplaced in the underground repository.
Because the standards for both the
flammability and the RCRA constituent
analyses are objective and
straightforward, EPA does not believe
that Agency review of the data before
placement is necessary.
The flammability and RCRA
constituent requirements, described in
detail in section IV.B.7, will address
many of the commenters' concerns with
the accuracy of the data. These
requirements will also ensure that the
wastes emplaced during the test phase
are. in fact, the wastes characterized by
DOE in the petition and evaluated by
the Agency and the public.
/. Retriev.ability
Commenters also raised concerns
about whether waste would ever be
retrieved from the WIPP if it were
placed in the repository, regardless of
the technical feasibility of retrieval.
Some questioned DOE's commitment to
retrieval, even if the WIPP site proved
unacceptable. Others argued that, even
if DOE were willing to remove the '
waste, no other site would accept it, and
therefore the waste would not be
retrieved. Several commenters.argued
that DOE should identify a permitted
site ready to receive retrieved waste
before any waste should be allowed
underground.
EPA believes that it has placed
adequate safeguards in today's
determination to ensure that DOE in fact
removes the hazardous waste from the
repository, if it cannot demonstrate the
repository's long-term acceptability.
Condition 3 in Section VI of today's
determination explicitly requires
retrieval of wastes if DOE cannot
demonstrate compliance with the
standards of 40 CFR Part 268 before the
expiration of the petition approval.
Failure on the part of DOE to remove
wastes under these circumstances
would constitute a violation of the terms
of EPA's determination, leading to
possible enforcement action by EPA. In
addition, citizens could sue DOE under
section 7002 to enforce retrieval of
waste from the repository.
Because of this condition, EPA has not
found it necessary to require DOE to
identify a specific site where waste
retrieved from the WIPP would be
stored, or to require that a permit be
granted for storage of retrieved waste
before any waste is placed underground.
Furthermore, EPA questions whether
any such condition would be useful,
given that wastes would probably not
be removed (if removal proved
necessary) for a five-to-ten year period.
Current predictions on the best storage
site for the waste up to ten years in the
future would be at best open to
question, and valuable permitting.
resources would be expended on a site
that might never receive the waste.
K. Human Intrusion
Commenters generally accepted that
DOE could maintain institutional
controls over the test period to preclude
human intrusion. One group of
commenters, however, argued that EPA
must consider the possible effects of
human intrusion in the distant future
before allowing the placement of any
waste for testing. These commenters
expressed particular concern about
potential mineral resources at the WIPP
site, and the possibility that knowledge
of the site would disappear after
decommissioning. Other commenters.
argued that permanent markers should
be erected at the WIPP site once the
facility is closed, and information
regarding the type and location of the
markers should be published.
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..EPAgenerally believes,that the issue
of human intrusion is a long-term
question, .not relevant to the short-term
operation of the WlPP during the test
and operational phases. In the short--
term, DOE management of the site and
, RCRA permit controls will ensure . •
limited access. Long-term issues would
be addressed at the time a petition is
considered for permanent disposal. For
this reason, EPA disagrees with
commenters who argue that it must
consider human intrusion in the distant
future before allowing any testing at the
WIPP. • '
, More generally, EPA believes that, in
the context of RCRA no-migration
decisions, it should address the question
of human intrusion by considering the
likelihood of the intrusion, and imposing
controls to make such intrusions
unlikely. EPA agrees that permanent
markers will be necessary (in fact, they
are required under 40 CFR part 191
subpart B) and that information on the
markers should be published. These
issues will be addressed in any no-
migration decision allowing permanent
disposal.
In its final determination, EPA has
removed one proposed condition related
to human intrusion. In the proposal, EPA
required that "DOE certify to EPA that it
has secured control of the entire surface.
and subsurface estate at the WIPP site,"-
This condition is now moot,'because
DOE has now secured control over Jail'
oil and gas and mineral leases at the
site. EPA has placed documentation of •
this fact in the record for this
rulemaking. Thus, because the condition
has been satisfied, EPA has dropped it
from its final determination.
VI. Conditions of No-Migration
Determination '
As a condition of granting DOE's no-
migration petition, EPA is requiring that
the following conditions by met by DOE:
(1) No wastes subject to this
determination may be placed in the
WIPP repository for purposes other than
testing or experimentation to determine
the long-term acceptability of the WIPP;
In accordance with 40 CFR 288.6(e],
DOE must notify EPA before it conducts
any testing or experimentation not
within the scope of the "WIPP Test
Phase Plan: Performance Assessment,"
April 1990 (DOE/WIPP 89-011, Revision
O), as further explained in Section
IVJ3.1 of this notice. Placement of waste
for thp purpose of conducting an
operations demonstration is prohibited.
(2) Wastes placed in the repository
may not exceed 8,500 drums or 1 percent
of the total capacity of the repository, as
currently planned.
(3) All wastes placed in the WIPP
must be remoWd if DOE cannot
demonstrate compliance with the
standards of $0 CFR 268.6, before the
expiration of this petition approval, with
respect to permanent disposal of mixed
waste in the repository. DOE must
submit-a detailed schedule for retrieval
of the waste, jhncluding times for
completing rejtriev.al as quickly as
reasonably feasible, no later than six
months after a determination that the
repository cannot meet standards for
long-term disposal under 40 CFR 268.6 or
six months before the expiration of this
petition approval,'whichever occurs '
first. . I . ".-.•.
(4) All wastes placed in the WIPP
must be placed in a readily retrievable
manner, as described in section iV.B.4 of
thisnotice.
(5) DOE mu'st install and operate a
carbon adsorption device designed, to
achieve a control efficiency of 95
percent in the; discharge, system of the
bin experiment rooms. DOE must
monitor the control device outlet :
airstream in accordance with the •
monitoring plan described in section
rv.K of EPA's [proposed decision (55 FR ,
13089) as amended by section IV.B.7 of
today's notice^ and it must maintain
design and operating records as , . :
described in section IV.J of EPA's
proposed decision, as amended by -
sectionTV.B.6!of today's notice. Records
must be maintained at the WIPP facility
for the term of this determination or for
three years after they'are created, ' •
whichever is longer. Records must also
be maintained during the course of any
enforcement actions for which they are
relevant; .'[-.. - '•. '•....
(6) DOE must implement the air
monitoring plan described in section
IV.K of EPA's (proposed decision (55 FR
13089). as amended in section IV.B.7 of
today's notice, Records,must be
maintained at the, WIPP facility for the
term of this determination or for three
years after they are created, whichever
is longer. Records must be maintained
during the course of any enforcement
action for .which they are relevant..
(7) Conditions relating to waste
analysis: : ;
(a) DOE must ensure that each waste
container emplaced underground at the '
WIPP has no layer of confinement which
contains flammable mixtures of, gases or
mixtures of gases that could become
flammable when mixed with air. This
prohibition must be implemented by ;
analytical testing of a representative
'sample of headspace'gases from each
waste drum of individual container, as
described in- sedtion IV.B.7.a and V.F.l.a
of today's notice.
(b) DOE must analyze representative
samples of the headspaces of containers
to be usedjn the bin-scale test and
compare these results to the estimated
compositions provided in its petition for
each waste type, as detailed in IV.B.7.b
of today's notice. If the waste is not
compositionally similar, as defined in
Tables 2 and 3 in IV.B.7.b, that waste
cannot be shipped to the WIPP until the
waste has been treated or modified such
that it is compositionally similar to the
estimates provided'in the no-migration
petition. In addition, as prescribed in
IV.B.7.b, DOE must demonstrate the
comparability of bin-scale wastes to
wastes described in DOE's petition
before placing waste in the WIPP for the
alcove tests.
.(c) Waste analysis records must be
maintained for the term of .this
determination or for three years after
generation, whichever is longer. Records
must also be maintained during the
course of any enforcement action for
which they are relevant. The records
may be maintained at .the generating site
or at the WIPP facility^ ''.
(8) DOE must provide to the EPA
Office of Solid Waste and EPA Region .
VI annual written reports on the status
of DOE's performance assessment
during the test phase. These reports
must include: A description of the tests
to date and their results, modifications
to the test plan, a summary of DOE's
current understanding of the repository's
performance, waste characterization
data from pre-test waste *
characterization, and an annual
summary of air monitoring data required
in Item 6 above. , . .
Beyond these specific conditions, the
wastes placed by DOE in the WIPP and
DOE's activities under this Variance
. must be consistent with those described
in the petition. Under § 268.6(e), DOE
must notify EPA of "any changes in
conditions at the unit and/or
environment that significantly depart
from the conditions described in the
Variance .and affect the potential for
migration of hazardous' constituents
from the unit* * * ."If the change is
planned, EPA must be notified in writing
30 days in advance of the change; if it is
unplanned^-EPA must be notified within •
ten days. , :
Under § 2G8.6(f), if DOE determines
that there has been migration of
hazardous constituents from the
repository in violation of part 268, it
must suspend receipt of prohibited
wastes at the unit and notify, EPA
within ten days of the determination.
Within 60 days, EPA is required to
determined whether DOE may continue
to receive prohibited waste in the unit
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and whether the variance should be
revoked.
Finally, under § 268.6(h), the term of
today's petition approval runs for ten
years, that is until November 14, 2000.
Dated: October 31,1990.
Don R. Clay,
Assistant Administrator for Solid Waste and
Emergency Response. ' •
{FR Poo. 90-26836 Filed 11-13-90; 8:45 am]
BILLING CODE 6560-50-M .
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