Tuesday
 August 11, 1992
Part JII


Environmental

Protection Agency

40 CFR Parts 268 and 271
Land Disposal Restrictions "Wo
Migration" Variances; Proposed Rule

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35940
Federal  Register / Vol. 57,  No. 155  /  Tuesday,  August 11,  1992 / Proposed Rules
ENVIRONMENTAL PROTECTION
AGENCY

40 CFR Parts 268 and 271

IFRL-3763-4]
BIN 2050-AC44

Land Disposal Restrictions "No
Migration" Variances
AGENCY: Environmental Protection
Agency.
ACTION: Proposed rule and notice of
availability.

SUMMARY: The Environmental Protection
Agency (EPA or the Agency) is
proposing its interpretation of the "no
migration" variance to the
Congressionally mandated restrictions
on land disposal of hazardous waste,
and also is proposing a minor
modification to the Land Disposal
Restrictions regulations to reflect this
interpretation. The Environmental
Protection Agency also is proposing new
procedural and substantive
requirements for petitioning the Agency
and demonstrating that there will be "no
migration" from a land disposal unit, as
well as the Agency's criteria for
evaluating such "no migration"
petitions. Additionally, the Agency is
proposing under the authority of RCRA
Section 3004{n), standards that would
limit organic air emissions from land
treatment, landfill,  and waste pile units
that, having successfully demonstrated
"no migration" and received the
variance, are allowed to dispose
hazardous wastes that do not meet the
Best Demonstrated Available
Technology (BOAT) treatment
standards, which are normally required
prior to land disposal. In this action the
Agency also is announcing the
availability of a draft guidance manual
for petitioners making the no migration
demonstration entitled No Migration
Variances to the Hazardous Waste Land
Disposal Prohibitions: A Guidance
Manual for Petitioners (U.S. EPA. Draft,
July, 1992). These actions are in
response to amendments to the
Resource Conservation and Recovery  .
Act (RCRA), enacted through the
Hazardous and Solid Waste ,    .
Amendments of 1984 (HSWA).
DATES: Comments  on the proposed rule
must be received on or before
September 25,1992.
ADDRESSES: Comments should be
addressed to the docket clerk at the •
following address: U.S. Environmental
Jrotection Agency, RCRA Docket (Room
2427) (OS-305). 401 M Street, SW..
Washington, DC 20460. One original and
two copies should  be sent and identified
                        at the top by regulatory docket reference
                        number F-92-NMVP-JFFFFF. The Docket
                        is open from 9 a.m. to 4 pjn., Monday
                        through Friday, excluding Federal
                        holidays. The public must make an
                        appointment to review docket materials,
                        and should call the docket clerk at (202)
                        260-9327 for appointments. The public
                        may copy, at no cost, a maximum of one
                        hundred pages of material from any one
                        regulatory docket. Additional copies are
                        $0.15 per page.
                           Copies of the guidance manual for no
                        migration petitioners |can be obtained
                        from the National Technical Information
                        Service (NTIS), U.S. Department of
                        Commerce, Springfield, Virginia 22161,
                        at (703) 487-4600: No Migration
                        Guidance (NTIS #PB|92-207 695).
                        FOR FURTHER INFORMATION CONTACT:
                        For general information about this
                        proposed rulemaking, contact the RCRA
                        Hotline, Office of Solid Waste (OS-305),
                        U.S. Environmental Protection Agency,
                        401M Street SW., Washington, DC
                        20460, (800) 424-9346j(tollfree) or (703)
                        920-9810 in the Washington, DC,
                        metropolitan area.
                           For information on aspects of this
                        proposed rule pertaining to No
                        Migration, contact Dave Reeves, Office
                        of Solid Waste (OS-343), U.S.
                        Environmental Protection Agency, 401M
                        Street SW., Washington, DC 20460, (202)
                        260-4892.          '
                           For information on aspects of this
                        proposed rule pertaining to control of
                        organic air emissions from no migration -
                        units under RCRA Section 3004(n),
                        contact Kent C. Hustyedt. Office of Air
                        ' Quality Planning and Standards (MD-  -
                        13), U.S. Environmental Protection
                        Agency, Research Triangle Park, North
                        Carolina, 27711. (919) 541-5395.       :
                        SUPPLEMENTARY INFORMATION:
                                           l
                        Preamble Outline     j
                        I. Authority         [
                        II. Background       !    .             •
                        III. Summary of Proposed Rule
                        A. Interpretation of the|Statutoiy Language
                        B. Hazardous Levels  \
                           1. Consideration of Ambient      ••. .
                            Concentrations         •     .'
                        C. Point of Complianceior No-Migratjon,.. •
                        D. Petitions to Demonstrate No Migration ..'
                        E. Conditional Requirements of a No
                            Migration Variance
                           1. Land Treatment Units      '
                           2. Temporary Storage Units    '  ;•   . ••••
                           3. Other Demonstrations
                           4. Monitoring for New Units
                         F. Additional Demonstrations for the Air ...
                            Medium        >      .
                           1. OSHA Standards      .  • '
                           2. NESHAP for Benzene        "  .
                           3.3004{n) Standards!           '    "'.;
                           a. Introduction '            ' ..-,-    '  •
                           b. Background     ]         "•'•  :'   •
                           c. Regulatory Approach      -.'...-
                           d. Proposed Requirements    .
IV. State Authorizations
V. Regulatory Requirements
VI. References

I. Authority

  These regulations are issued under the
authority of sections 1006,2002(a), 3001,
3004, 3005, and 3015 of the Solid Waste
Disposal Act, as amended by the
Resource Conservation and Recovery
Act of 1976, as amended by the
Hazardous and Solid Waste
Amendments of 1984, (42 U.S.C. 6905,
6912(a), 6921, 6924, 6925, and 6935).

II. Background

  Sections 3004 (d), (e), and (g) of RCRA
provide that land disposal of hazardous
waste that does not meet Best
Demonstrated Available Technology
(BOAT) treatment standards is
prohibited, unless the Administrator
determines that prohibition of one or
more disposal methods is not required to
protect human health and the
environment for as long as the wastes
remain hazardous. This determination
must take into account such factors as
long-term uncertainties of land disposal,
the goal of proper management of
hazardous wastes, and the persistence,
toxicity, mobility, and bioaccumulative
potential of the wastes and their
constituents. These provisions indicate
that in order to satisfy this standard, a
hazardous waste management facility
owner or operator must demonstrate in
a petition to the Agency to a reasonable
degree of certainty, that there will be no
migration of hazardous constituents
from the disposal unit (or injection zone)
for as long as the wastes remain
hazardous. This is known as the "no
migration" variance. Throughout this
preamble, when the term "no migration"
is used, it is intended to mean "no
migration of hazardous constituents
from the disposal unit or injection zone
for as long as the wastes remain
hazardous," as written in the statute and
as interpreted in the regulatory language
proposed at 40 CFR part 268 in today's
notice.
  . The Agency codified this language in
existing regulations under 40 CFR 268.6
on November 7,1986 (51FR 40572).
These regulations were corrected on
June 4,1987 (52 FR 21010). Paragraph (k)
of 268.6 was added on August 8,1987 (52
FR 25160) requiring that liquid
, hazardous wastes containing PCB's in
' concentrations above 500 ppm cannot be
 the subject of a no migration variance.
 40 CFR 268.6 was further amended on
 August 17,1988 (53 FR 31138) to add
 additional procedural requirements for
• no migration petitions and for
 compliance with the terms of a variance,

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                  Federal Register  / Vol. 57. No. 155 / Tuesday. August 11. 1992 / Proposed Rules
                                                                         35941
   once granted. These additional
   requirements are as follows: (1)
   Demonstrating compliance with other
   applicable Federal State, and local
   laws; (2) submittal of monitoring plans
   for land disposal units; (3) reporting
   changes in operating conditions from the
   ones described in the variance
   application, and, (4) reporting detection
   of migration of hazardous constituents,
   and suspending receipt of prohibited
   hazardous wastes. Final regulations for
   underground injection of hazardous
   waste published in the Federal Register
   on July 26,1988 (53 FR 28118) further
   clarified EPA's interpretation of "no
   migration" as it applies to underground
   injection of hazardous waste. It should
   be noted that today's proposed
   rulemaking is not intended to supersede
   these standards already promulgated for
   underground injection wells.

   III. Summary of Proposed Rule

  A. Interpretation of the Statutory
  Language •

    Today's notice explains the Agency's
  interpretation of the "no migration"
  statutory standard expressed in sections
  3004 (d), (e), and (g) of RCRA and
  proposes minor amendments to section
  288.6(a) to reflect this interpretation.
  Sections 3004 (d), (e), and (g) of RCRA
  provide that land disposal of hazardous
  waste that does not meet BOAT
  treatment standards is prohibited.
  unless the Administrator determines
  that the prohibition of one or more
  disposal methods is not required to
  protect human health and the
  environment for as long as the wastes
  remain hazardous, taking into account
  such factors as long-term uncertainties
  of land disposal, the goal of proper
  management of hazardous wastes, and
  the persistence, toxicity, mobility, and
  bioaccumulative potential of the wastes
  and their constituents. These provisions
  indicate that in order to satisfy this
  standard, an interested person must
 demonstrate to the Agency "to a
 reasonable degree of certainty, that
 there will be no migration of hazardous
 constituents from, the disposal unit or
- injection zone for as long as the wastes
 remain hazardous." EPA interprets this
 statutory language to require that
 petitioners demonstrate that hazardous
 waste constituents will not migrate from
 the land disposal unit (i.e. landfill, -
 surface impoundment, waste pile,
 injection zone, land treatment unit, salt
 dome formation, salt bed formation,
 underground mine, cave, vault, or
 bunker) in hazardous concentrations  for
 as long as the wastes remain hazardous.
 These concentrations must be met at  the
 unit boundary for all environmental
   media: Ground water, surface water,
   soil, and air. The statute explicitly
   provides that the standard applies to
   migration from a unit or injection zone:
   "*  *  * there will be no migration of
   hazardous constituents from the
   disposal unit or injection zone * * *"
   (RCRA Sections 3004 (d), (e), and (g))
   Therefore, the Agency proposes that
   consideration of attenuation of
  hazardous waste constituents beyond
  the boundary of the disposal unit or
  injection zone would not be acceptable
  as a basis for successfully making a
  petition demonstration.
    The Agency thus would grant
  petitions where owners or operators
  demonstrate (to a reasonable degree of
  certainty) that hazardous waste
  constituents will not migrate at
  hazardous levels, or, put another way,
  where only non-hazardous levels of
  waste constituents migrate. This
  interpretation of the statute was
  recently upheld in NRDC \. EPA, 907
  F.2d 1146 (D.C, Cir. 1990). In the NRDC
  case, the court noted that under EPA's
  interpretation, "hazardous constituents
  may migrate so long as the wastes
  immediately surrounding them at the
  border are no longer hazardous, or
  putting it slightly differently, so long as
  they do not migrate in high enough
  concentrations to be hazardous waste."
 Id at 1159-1160. The court examined
 EPA's interpretation and affirmed EPA's
 decision finding that Congress had made
 no clear determination in section 3004
 that hazardous constituents must not
 migrate regardless of the hazard and
 that EPA's policy choice was
 reasonable. 907 F.2d at 1162.
   Based on this interpretation of the
 statutory language provided above, the
 Agency proposes to clarify and amend
 § 268.6(a) to define the term "no
 migration of hazardous constituents
 from the disposal unit or injection zone"
 (or simply, "no migration") to mean that
 concentrations of hazardous
 constituents do not and shall not exceed
 Agency-approved health-based or
 environmental-based levels, in any
 environmental medium, at the boundary
 of the unit or injection zone. Under this
 approach, possible migration pathways
 for each medium are as follows:
 Concentrations of hazardous
 constituents in ground water in the
 vicinity of the unit could not exceed the
 appropriate ingestion health-based
 levels for drinking water. Surface water
 concentrations, both in surface water
 bodies 'in the vicinity of the unit and in
storm runoff from the unit, likewise
could not exceed appropriate health-
based levels for drinking water or
   ambient water quality criteria.1
   Similarly, concentrations in soil
   (including, but not limited to silt, loam.
   sand, gravel, and in some cases, rock)
   outside the unit could not exceed health-
   based levels for ingestion. Finally, air
   emissions of hazardous constituents
   from the unit, either in the form of
   particulates or volatilized organics,
   could not exceed the appropriate health-
   based levels for inhalation exposure.
   (Health-based levels for each medium
  are discussed in more  detail in Section B
  of this preamble.)
    In addition, the Agency proposes to
  modify § 268.6(a)(4) to require
  monitoring of all environmental media,
  i.e., ground water, surface water, soil,
  and air. Where petitioners can
  conclusively demonstrate that
  monitoring of any medium is
  unnecessary or technically infeasible or
  impractical, the Agency may determine
  on a site-specific basis to waive the
  monitoring requirement for one or more
  media. The point of compliance for both
  modeling and monitoring measurements
  will be at (or as near as possible to) the
  unit boundary (without compromising
  the integrity of the unit). For the air
 medium, compliance will be measured
 at the downwind edge of the unit
 boundary at a height of 1.5 meters. (The
 point of compliance for demonstrating
 "no migration" is discussed in more
 detail in Section C of this preamble.)

 B, Hazardous Levels

   The Agency will be using EPA-
 approved health-based levels for ground
 water, surface water, soil, and air to
 designate "hazardous levels of
 hazardous constituents." The Agency
 currently is using peer-reviewed health
 and environmental effects data hi
 several areas including clean closure,
 delisting, and proposed  trigger levels for
 corrective action. Such data  for each
 medium of concern are based, for the
 most part, on the drinking water
 Maximum Contaminant Levels (MCLs),
 surface water quality criteria (Ambient
 Water Quality Criteria 45 FR 79318,
 November 18,1980; 49 FR 5831, February
 15,1984; 50 FR 30784. July 29,1985),
 verified Reference Doses (RfDs) for
 systemic toxicants developed by the
 Agency's Risk Assessment Forum, and

  * Note, however, that where the petitioning unit
 has complied with permit design requirements to
 prevent run-on or run-off from a 24-hour, 25-year
 storm, and a storm of even greater magnitude
 results in run-on or run-off from the unit the Agency
 would consider this an exceptional or unpredictable
 event EPA therefore would consider allowing
continued operation of the unit under the no
migration variance once any damage that affects the
unit's operation has been corrected.

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Federal Register /  Vol. 57, No. 155 / Tuesday, August 11, 1992  /  Proposed Rules
Risk-Specific Doses (RSDs) for
carcinogens developed by the Agency's
Carcinogen Assessment Group. These
dose levels are used with standard
exposure assumptions for each medium
(ground water, surface water, soil, and
air) to obtain allowable health and
environmental levels. The maximum
residual risk level would be the same for
Class A and B carcinogenic constituents,
1X10"'. For Class C carcinogens the
maximum residual risk level would be
1X10"*. Detailed information on  the
exposure assumptions and lists of the
applicable concentration levels for
ground water, surface water, soil, and
air for some hazardous constituents are
contained in the RCRA Facility
Investigation (RFI) Guidance (U.S. EPA,
Interim Final, May, 1989), and in  the
proposed Subpart S Corrective Action
Rule (55 FR 30798; July 27,1990).
Additional Information on health-based
levels is available on EPA's Integrated
Risk Information System (IRIS, On-line
database, U.S. EPA, 1991), EPA's
"Carcinogenic Risk Assessment
Verification Endeavor (CRAVE) Risk
Estimate for Carcinogenicity" (U.S. EPA,
1990), and in the Superfund Public
Health Evaluation Manual (U.S. EPA,
1986).
  EPA proposes to use appropriate
levels such as those described in the
above references for approving or
disapproving a no migration petition.
Maximum Contaminant Levels (MCLs)
for drinking water and Ambient Water
Quality Criteria (AWQC) would receive
first priority for use as appropriate
levels, where they exist Reference
Doses and Risk-Specific Doses would be
used secondarily in the absence of
MCLs and AWQCs.
  The Agency realizes, however, that
Agency-approved levels do not exist for
every hazardous constituent in
Appendix VHL In addition, the Agency
acknowledges that existing health and
environmental effects data available for
some hazardous constituents have not
been formally promulgated by EPA. In
most cases, EPA believes it will be
possible to develop reasonable
estimates, based on beat professional
judgement, or to eliminate minor
constituents from consideration because
only trace levels exist in the waste.
Where health-based levels are not
available or cannot be estimated, and
where more than very minor trace levels
of a hazardous constituent are present
in the waste, EPA believes background
or analytical detection limits should be
used. (EPA notes that it has adopted the
above approach to setting health-based
levels in the RCRA delisting program
and the proposed Subpart"S corrective '
                        action rule.) No migration petitioners
                        also may wish to propose their own
                        levels for constituents of concern, using
                        reasonable worst-case assumptions.
                        Petitioners should submit to the Agency
                        data of sufficient Quantity and quality
                        for the Agency to determine the
                        environmental and health effects of the
                        constituent. Thus, |there will be
                        opportunity for notice and comment on
                        each such level within the context of
                        each petition. Data submitted for the
                        purposes of determining an appropriate
                        level should follov> established EPA
                        protocols to ensurp the acceptability of
                        the test data. (For jexample, following
                        the toxicity testing guidelines of 40 CFR
                        Parts 797 and 798 (50 FR 39252,
                        September 27,1985), would be
                        considered prima facia evidence  of the
                        acceptability of th|e data.) Petitioners
                        who choose to propose their own levels
                        for constituents should consider that
                        Agency review of such information may
                        require additional time and could delay
                        a determination on their no migration
                        petitions.
                          The Agency believes that human
                        health-based levels will be protective of
                        both human health and the environment.
                        Nevertheless, the Agency may
                        determine that a unit boundary level for
                        a constituent should be lowered from
                        the human health-based standard in
                        order to protect against detrimental
                        environmental effects around the unit
                        (e.g., those that may pose a threat to
                        endangered species, or sensitive
                        ecosystems).
                          The Agency realizes that many of the
                        peer-reviewed human health-based
                        levels are below an analytical detection
                        limit. In these cases, where modeling is
                        possible, the petitioner must
                        demonstrate that no migration will occur
                        above the human health-based levels
                        using modeling arid analysis. As stated
                        in 40 CFR 268.6, any models must be
                        verified and calibrated to the site. In
                        demonstrating compliance with the
                        •terms of the petition during the life of
                        the unit the petitioner will, of necessity,
                        use analytical detection limits as the
                        basis for compliance. Use of analytical
                        detection limits should be based  upon
                        methodology prescribed in Test
                        Methods for Evaluating Solid Wastes,
                        Physical/Chemical Methods,  (EPA
                        Publication No. SW-846,1986, third
                        edition), with the lowest possible
                        detection level indicated therein  for
                        each hazardous constituent
                          Finally, the Agency considered, but is
                        not proposing as a general rule to take
                        into account the effects of additivity of
                        hazardous constituents within a single
                        environmental medium in setting the
                        levels that the petitioner must meet to
 demonstrate no migration. Similarly, the
 Agency also considered but rejected an
 approach that would assess additivity
 across two or more media (e.g., ground
 water and air). Guidelines for using
 additivity in assessing the risks posed
 by multiple contaminants are contained
 in "Guidelines for the Health Risk
 Assessment of Chemical Mixtures" (51
 FR 34014. September 24,1988). The
 Agency does not currently intend to use
 this approach, because it believes that a
 determination of additive effects of two
 or more chemicals or across two or more
 media would be exceedingly difficult,
 would involve too many uncertainties,
 and would 'be unnecessarily
 conservative. For example, a constituent
 ingested via the ground water exposure
 route may have a different mechanism
 of action and different target organ(s)
 from those of the same constituent when
 inhaled; similarly, two different
 chemicals ingested by the same route
 might have different target organs.
 Furthermore, the exposure routes
 considered under this rule are projected
 and hypothetical, rather than actual,
 exposures. Therefore, EPA. believes that
 consideration of additivity for two or
 more hypothetical exposure routes is
 generally unnecessary, especially given
 the conservatism of its exposure
 assumptions in the current approach. (In
 some cases, however—e.g^ where actual
 rather than hypothetical long-term
 exposure is involved—EPA may take a
 more conservative approach, and
 consider additivity, where technically   •
 feasible.) The Agency believes that
 assessing effects of different
 constituents individually within one
 hypothetical exposure medium is both
 consistent with the statutory no
 migration standard and fully protective
 of human health and the environment.

 1. Consideration of Ambient
 Concentrations

   As discussed above, the Agency
 believes the statutory concern is  over
 the hazardousness of contaminants that
 may cross the unit boundary. EPA has
 previously interpreted the unit boundary
 as the point of compliance for no
 migration petitions and specifically
 rejected an approach that would have
• considered attenuation factors for
 movement of contaminated groundwater
 outside the unit boundary. [51 FR 40838,
 November 7,1986.] Similarly, EPA does
 not believe ambient or background
 concentrations of constituents outside
 the unit boundary should be considered
 in evaluating migration out of the unit
 With these factors in mind, the Agency
 is considering three options for
 addressing no migration in situations

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                Federal Register  /  Vol. 57.  No. 155 / Tuesday.  August 11, 1992 / Proposed Rules
                                                                       35943
  where ambient contaminant
  concentrations exist.
    In the first option, existing
  concentrations in ground water would
  only affect no migration variances to the
  extent they indicate that a unit may
  already be contributing to those levels
  through contamination. EPA would not
  accept possible dilution of releases-
  when they flow into the aquifer as the
  basis for a less stringent standard on the
  level of concentration allowed to leave
  the unit. Nor would it make the standard
  more stringent because the receiving
  ground water is already above ambient
  levels. Rather, the no migration
  determination would continue to be
  based upon whether the concentrations
  of the constituents migrating from the
  unit itself exceed hazardous (i.e.. health-
  based) levels.
   For example, assume ground water
  upgradient from the petitioning unit has
  a concentration of 10 mg/1 of hazardous
  constituent A and the health-based level
  for constituent A is 5 mg/1 for drinking
  water. The ho migration standard EPA
  proposes to apply in this case would
  nonetheless require that any release
  from the unit not contain concentrations
 of constituent A above 5 rng/L
 Depending on the leachate
 concentration, the volume of leachate
 that reaches the ground water, and the
 degree of mixing that occurs between
 the leachate and the underlying ground
 water, a monitoring well located
 downgradient from the petitioning unit
 could contain varying concentrations of
 hazardous constituent A. The Agency
 recognizes that the aforementioned
 variables raise some uncertainty in
 estimating leachate concentrations •
 released from the unit on the basis of
 upgradient and downgradient ground
 water measurements.
  There are also instances, however,
 where migration of any level of
 constituent A from a unit might add the
 same amount, to the ambient background
 concentration of a given environmental
 medium.  An example 4s volatilization of
 hazardous constituents from liquid or
 solid material in the unit to ambient air
 outside the unit In this situation, unlike
 that of fluids, every molecule added
from the unit to the air-will
incrementally increase the
concentration in the air at the unit
boundary above pre-existing
background levels. Again, EPA's
proposed approach is not to consider the
pre-existing background levels hi the air
but, instead, to focus on the incremental
increases at the point of compliance that
are attributable to migration from the
unit The  Agency recognizes that this
approach allows total concentrations at
  the unit boundary above the pre-existing
  background such that the sum may, in
  fact, be above health-based levels.
    Inherent In any determination of
  background levels is a consideration of
  statistical variability. This variability
  results from the sampling distribution of
  the measurements, as well as the
  sampling and analysis variability, and
  variability due to spatial and temporal
  factors. General RCRA ground water
  monitoring guidance recommends the
  use of confidence intervals for
  comparison to a fixed compliance
  standard. For all options presented hi
  this section, the Agency is proposing a
  similar approach where a 95%
  confidence interval is constructed
  around the mean background
  concentration. (For normal distributions,
  this confidence interval calculation is as
  follows:
  X±t (o.«.n-,> s/Vn

  Where x is the mean, t is
  obtained from the Student's t-
 Distribution, S is the standard deviation
 of sample values, and n is the sample
 size.) For more information on statistical
 variability and construction of
 confidence intervals, see the "Guidance
 Document  on the Statistical Analysis of
 Ground-Water Monitoring Data at
 RCRA Facilities," (EPA/530-SW-89-
 0026: April 1989; NTIS: PB89-151-O47).
   For the first option, discussed above,
 EPA proposes that the upper limit of this
 confidence level be med to define
 background (i.e., ambient levels), and
 that Agency-approved health-based
 levels would be added to the upper
 confidence limit in determining no
 migration limits at downgradient points
 of measurement. Any downgradient
 measurement that exceeds this sum
 would be considered migration.
   A second option in situations of
 existing ambient concentrations is not to
 allow the contribution at the unit
 boundary from background levels and
 the contribution from the unit, together,
 to exceed the health-based standard
 This second option would be more
 stringent than the first option; in effect, .
 it also would be a type of locational
 requirement For example, in relatively
 pristine areas a unit could meet the no
 migration demonstration as long as the
 resulting level at the unit boundary is
 below the applicable health-based
 standards. In areas where pre-existing
 background concentrations are elevated,-
 the unit would be less likely to meet the
no migration standard. If background
concentrations are already above the
health-based levels, a unit could not
meet the no migration demonstration.
The ultimate determination of
compliance would be the downgradient
  measurement which, very simply, could
  not exceed the health-based level used
  as the no migration standard.
    A third option in situations where
  background levels of a hazardous  ,
  constituent exist would be to set some
  de minimis level of allowable
  constituent addition from the unit. For
  example, where the ambient air is
  already above the health-based level,
  the unit could release an additional level
  of constituents measured at the unit
  boundary, but the contribution from the
  unit must not increase the overall risk
  level beyond a small (statistically
  insignificant) increment. In contrast to
  Option 1, the amount of allowable
 increase would not be set by reference
 to existing health-based levels, but by
 establishing a level for this purpose
 only. The Agency proposes for this third
 option that the de minimis level be
 determined based on the statistical
 variability associated with the
 background concentrations. For
 example, the background concentration
 would be determined as discussed
 previously, by constructing a 95%
 confidence interval around the mean
 concentration of the background sample
. measurements.
   In this third option, the upper limit of
 the confidence interval constructed from
 background sample measurements
 would be used for no migration
 purposes. Measured values
 downgradient would be compared to
 this upper limit to evaluate whether a
 statistically significant increase above
 background  concentrations had
 occurred. Where any downgradient
 sample measurement was found to fall
 above the upper 95% confidence  limit, it
 would be statistically significant and
 migration would be considered to have
 occurred.
   EPA solicits comments on these three
 or any other approaches. In particular,
 we are seeking input from commenters
 as to the relative burden that may be
 imposed, either on petitioners or the
 reviewing Agency, in implementing any
 one of the three options. Also, are there-
 exceptional technical difficulties
 associated with implementing a specific
option? The Agency requests comments
from the public on whether the de
minimis approach (Option 3) is more
difficult to implement than the other
options, for instance, due to the lack of
standard monitoring protocols for air.

C. Point of Compliance for No Migration
  The statutory standard requires that
there will be no migration of hazardous
constituents  from the unit or injection    i
zone.- As discussed above, the Agency  j
interprets this to mean that hazardous  j

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35944
Federal Register  /  Vol. 57, No. 155 / Tuesday, August 11. 1992 / Proposed Rules
constituents will not migrate at
hazardous levels from the unit (or
injection zone). Thus, the point of
compliance for making this
demonstration is the unit boundary (or
the boundary of the injection zone; see
53 FR 28118, July 28,1988 for a
discussion of "injection zone"). For land
disposal units, a "hazardous waste
management unit" as defined in 40 CFR
200.10, is a "contiguous area of land on
or in which hazardous waste is placed,
or the largest area in which there is a
significant likelihood of mixing
hazardous waste constituents in the
same area."
  For the purposes of demonstrating no
migration from the unit, the Agency
believes that, where an engineered
barrier (e.g., a liner)  exists for surface
impoundments, landfills, waste piles, or
land treatment units, the unit boundary
consists of the outermost extent of the
engineered barrier of the unit The
outermost extent of the engineered
barrier also constitutes the point of
compliance for each medium. For
example, in demonstrating no migration
from the unit via ground water or
subsurface soil, the unit boundary would
consist of the outer liner present in a
surface impoundment, landfill, land
treatment unit, or waste pile. In
demonstrating no migration from such a
unit via surface water runoff or surface
soil, the outer limits  of any dikes,
ditches, or berms present at the edge of
the "hazardous waste management unit"
constitute the point of compliance. In
demonstrating no migration from the
unit via the air pathway, the outer
extent of any engineered barrier over
the unit (roof, dome, etc.) would
constitute the point of compliance.
   While engineered barriers form a
useful way to delineate the boundary of
a hazardous waste management unit,
the Agency recognizes that these
engineered components do not always
exist. For example, most units are not
enclosed to protect from migration via'
air. In this case, the Agency proposes
that the downwind edge of the unit at a
height of 1£ meters  conntitutes the point
of compliance for demonstrating no
migration via air. (A height of 1.5 m
corresponds with a typical inhalation
height This height also 5s proposed
because it would facilitate monitoring of
partkulate emissions, which cannot be
 accurately monitored close to the soil
 surface without effectively vacuuming
 large and small particles into the
 apparatus.) For air demonstration
 purposes, any berms, dikes, or ditches
 that surround the area of waste
 placement define the "edge" of the unit
 (However, for determining the point of
                        compliance for the air medium or other
                        media, the Agency does not intend to
                        allow the inclusion of unreasonable
                        buffer zones betweejn the area of waste
                        placement and a perimeter dike, benn,
                        or ditch.)
                          In cases where units are unlined (e.g.,
                        a unit obtaining an exemption from liner
                        requirements under § 264.221  (b) or (d)),
                        the petitioner and the petition reviewer
                        must use best professional judgement to
                        set the unit boundary. Unlined land
                        treatment units have a subsurface point
                        of compliance at the base of the
                        maximum treatment zone (not exceeding
                        a depth of 5 feet from the initial soil
                        surface), or immediately outside of any
                        liner that may exist'Finally, for some
                        miscellaneous units such as those
                        regulated under subpart X (e.g., geologic
                        repositories), the  unit boundary should
                        be decided on a sitej-specific basis. In all
                        cases where a no migration petition is
                        filed, however, the Agency will
                        demarcate the  unit boundary  and point
                        of compliance for demonstrating and
                        evaluating no migration via all media in
                        a suitably stringent manner.
                          Although engineered barriers are used
                        to define the unit boundary, EPA
                        believes (and Congress in the legislative
                        history indicated) tijat engineered
                        barriers such as liners cannot be
                        assumed to be adequate to prevent
                        migration of hazardous wastes from a
                        land disposal unit or injection zone.  S.
                        Rep. No. 284,89th Cong. 2d. Sess. at  15.
                        Consequently, EPA proposes  that,
                        except for temporary storage  units, the
                        no migration demonstration must rely
                        upon other assurances to demonstrate
                        no migration of waste  from the unit. (For
                        temporary storage units,  the no
                        migration demonstration may be based
                        upon removal of the waste prior to
                        failure of the engineered barrier.) This
                        approach, of course, does not exempt an
                        owner or operator ivho has a no
                        migration variance from parts 264 and
                        265 design requirements  for liners and
                        other engineered barriers.
                        D. Petitions to Demonstrate No
                        Migration        j
                           The Agency intends to limit the
                        approval of petitions for a no migration
                        demonstration to those that can
                        demonstrate compliance with the
                        conditions outlined in today's
                        interpretation to a reasonable degree of
                         certainty. The Agency also recognizes
                         that site-specific factors can  be relevant
                         to consideration of a petition and to a no
                         migration determination. Owners and
                         operators who believe they have land
                         disposal units that will qualify for
                         approval, should submit petitions to the
                         Administrator. At the date of issuance
                         of this notice, EPA has already received
a number of petitions and is reviewing
them under existing regulations and
guidance.
  For underground injection wells,
separate requirements exist for the
development and review of no migration
petitions as outlined in the rule
promulgated July 26,1988 (53 FR 28118).
  Specific existing requirements for the
development and processing of no
migration petitions for land disposal
units are Outlined in 40 CFR 268.6, The
Agency believes that a petition to
demonstrate no migration should
include (but is not limited to) two
essential components in its approach: (1)
Sufficient site-specific, theoretical, long-
term projections about the unit, waste,
and environmental conditions to insure
that migration at hazardous levels will
not occur from the unit to any medium
(or, for temporary units, as long as the
waste remains in the unit); and (2)
current data derived from monitoring,
sampling, and analysis of the unit,
waste, and environmental conditions
that both confirm the models and
describe current conditions.
  The assumptions and input data used
in site-specific modeling projections
should be based on site conditions.
Models, input data, and relevant
documentation should be available to
EPA upon request and without
restriction. EPA is discouraging the use
of proprietary models, as the models
selected will have to be closely
scrutinized to determine their
reasonableness and accuracy, and will
be subject to public comment
  Furthermore, in today's proposed
amendment to 40 CFR 268.6{a)(4), no
migration variances will require, as  a
condition of their approval, monitoring
of all environmental media (ground
water,-surface water, soil, and air) to
detect migration of hazardous
constituents from the unit at the earliest
practicable time. In certain cases the
Administrator may determine, based
.upon waste- and site-specific
 characteristics, that monitoring of one or
 more media is unnecessary at an
 individual site, because migration to
 that medium (those media) clearly is not
 a realistic concern (e.g., ambient
 air monitoring at some types of
 underground geologic repositories).
 Similarly, the Administrator may
 determine that conventional monitoring
 of one or more media immediately at the
 unit boundary is technically infeasible
 or impractical However, in most cases
 of technical ^feasibility or
 impracticality. the Agency still will
 require some type of monitoring or
 modified monitoring as near as possible
 to the unit boundary without

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                Federal Register / Vol. 57. No. 1S5 / Tuesday. August 11, W92  / Proposed Rules         35945
  compromising the integrity of the unit.
  (For more information on no migration
  monitoring in situations of technical
  infeasibility or impracticality, see the
  "Land Disposal Restrictions for First
  Third Scheduled Wastes; Final Rule" (53
  FR 31189. August 17,1988). The Agency
  also may determine in certain situations
  that modeling of a particular medium
  likewise is unnecessary or infeasible
  [e.g.. air modeling for a covered waste
  pile). 'However, where an engineered
  control such as a  cover exists for which
  modeling is infeasible, the Agency may
  require the petitioner to assess the
  performance of the engineered system in
  lieu of modeling. Petitioners who believe
  that one of these situations applies to
  their unit should include in the petition
  information that clearly demonstrates
  why modeling or monitoring of any
  medium is unnecessary or technically
  infeasible. [For more discussion  of
  monitoring requirements and monitoring
  plans that should  be included in a no
  migration petition, see the Land
  Disposal Restrictions for First Third
  Scheduled Wastes, Final Rule, August
  17.1988, 53 FR 31139).
   The Agency proposes to add new
 petition provisions at 40 CFR
 § 268.6{c)(3) to require that, for existing
 units that are receiving hazardous waste
 prior to submittal of the no migration
 petition, monitoring data for ground
 water, surface water, soil, and air be
 included as part of the petition. The
 Agency recognizes, however, that
 monitoring data may be difficult to
 collect, or may be nonexistent, for new
 units. Therefore, the Agency also is
 proposing additional petition
 requirements at 40 CFR § B8.6(cK3) such
 that for both existing and new units,
 variance approval  is conditioned-upon
 Agency review and approval of
 monitoring data, gathered subsequent to
 unit operation, which confirms no
 migration. IWhere  subsequent
 monitoring data reveals migration, the
 Agency would revoke the variance.)
 However, at its discretion, EPA
 additionally may require that monitoring
 data for one or more media be submitted
 for a new tmit prior to granting of the
 variance, as part c-Tthe petition, -where
 sach data are reasonably available (for
 example, monitoring data already
 generated as a result of the field test
 plot forthe land treatment
 demonstration required -under 40 CFR
 264272).
  The Agency proposes mat in most
 cases, in addition to initial monitoring to
 demonstrate no migration, detection
monitoring to -confirm no migration for  •
ground water, surface water, and soil be
 conducted at regular intervals (for
  example, semiannually for ground-water
  monitoring to coincide with part 264
  subpartP monitoring). However, for the
  air medium EPA is proposing a slightly
  different monitoring approach. Except
  for those units where the Agency has
  determined that air modeling or
  monitoring is unnecessary or technically
  infeasible, petitioners would be  required
  to conduct a one-time, reasonable
  worst-case ambient monitoring program
  to confirm modeling estimates and to
  provide a correction factor for the
  modeling where necessary. (Air
  monitoring under reasonable worst-case
  conditions is proposed, because  it would
  facilitate detection of hazardous
  constituents, which may be at low
  concentrations near detection limits.)
  Subsequent to granting of the variance,
  however, rather than performing regular
  ambient air monitoring during the
  operation of the tmit, the Agency
  proposes that the owner-or operator
 regularly sample the waste stream
 entering the unit to confirm that the
 modeled annual quantity of a hazardous
 constituent is not exceeded. The  Agency
 proposes this approach because it
 believes that ambient air monitoring
 performed at the unit boundary may
 involve too many uncertainties and too
 much variability to be reliable in
 detecting migration. EPA requests
 comments on the proposed approach for
 air monitoring. Additional guidance for
 making the no migration demonstration
 for all environmental media is provided
 in the guidance manual made available
 in today's notice entitled No-Migration
 Variances to fee Hazardous Waste Land
 Disposal Prohibitions:, A Guidance
 Manual for Petitioners. (U.S. EPA, Draft.
 July, 1992).
  No migration variances may be issued
 for existing facilities having interim
 status or part B permits under SCRA. or
 for new facilities seeking a permit.
 Because much of the information  that
 must be included in a RCRA partB
 application must also accompany the
 petition for a ""no migration" variance,
 facility owners and operators are
 encouraged to submit petitions with the
 relevant part B data summarized and  •
 referenced, with copies of critical partB
 materials attached as needed. Petitions
 should be-submitted to EPA
 Headquarters. Petitions will be
 reviewed'by EPA Headquarters with
 assistance 'from Regional and State
personnel.
  Variances will be effective only after
issuance; submittal of a petition will not
exempt a 'facility from complying with
applicable land disposal prohibitions.
Variances wfll be valid for up to 10
years, but not longer than me term of the
  facility's RCRA permit, and they will
  automatically expire upon expiration.
  termination, or denial of a RCRA permit,
  or when the volume of waste for which
  the variance was issued is reached.
  Owners and operators desiring to renew
  expired variances must repetition the
  Agency. Petitions to renew must
  undergo the same notice and comment
  procedure as did the original petition.
    EPA also is proposing today to amend
  § 268.6(f)(3)  such that, subsequent to
  notification from the owner or operator.
  if the Administrator determines that
  migration is  occurring or has occurred
  from the unit, the Administrator will
  revoke the variance. This approach is
  based upon the belief that, with the
 exception of the air medium, once a
 single verified migration event has been
 detected, the no migration
 demonstration has failed. (Note also the
 exception in the case of run-on or runoff
 resulting from an unpredictable future
 event, as identified previously in this
 preamble at footnote 1.) Variance
 holders have 10 days in which to re-
 sample to verify detection of migration
 from their unit Verified migration
 events require suspension of receipt of
 waste at the unit and notification of
 EPA. For more information on detection
 of hazardous constituent migration and
 verification, see the "Land Disposal
 Restrictions for First Third Scheduled
 Waste; Final Rule" (S3 FR 31189-31190;
 August 17.1988).
  For the air medium the Agency
 proposes to base the no migration
 standard upon an annual average air
 concentration. EPA proposes to interpret
 migration to the air medium as
 exceeding the health-based level for a
 hazardous constituent on an annual
 average basis, not on a single verified
 event.The Agency believes this
 approach is protective, since air health-
 based levels are based upon long-term
 exposure assumptions, and are not
 appropriate for use in an acute air
 exposure scenario. Furthermore, air
 concentrations are highly dependent
 upon dispersive and temporal factors,
 and therefore differ from the ground
 water, surface water, and soil media,
 where these factors are less significant. •
 Acute air exposure scenarios would be
 addressed under § •288.6(a){5), which
 requires compliance with other Federal,
 State, and local laws, and which would
 require compliance wife OSHA short-
 term air exposure standards at 29 CFR
part 1910 as a condition of the variance,
EPA requests comments on this
approach.
  Thfe Agency also today is proposing
additional provisions at § 268.8(r)
providing that the Agency -will revoke -a

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35946      ' Federal Register  /  Vol. 57. No. 155 / {Tuesday. August 11, 1992 / Proposed Rules
unit's no migration variance if, on the
basis of any information, the Agency at
any time determines that migration from
the unit has occurred, or that such a
variance is no longer protective of
human health and the environment.
  The Agency should caution potential
petitioners that the burden of proof in
demonstrating no migration will be
substantially greater for facilities with a
history of continuing mismanagement of
hazardous waste and serious
compliance problems, as evidenced by
State or EPA monitoring and inspection
reports. (Minor infractions in
compliance should not affect EPA's
review of a petition.] This does not
mean such facilities will be required to
meet a more stringent standard, but that
more information and analysis may be
necessary, both in the petition and
during operation under the variance, to
confirm to the Agency's satisfaction that
migration is not occurring and will not
occur in the future. For example, more
frequent waste stream analysis, or even
sampling by an independent party could
be required under the terms of the
variance. Given that EPA must find "to a
reasonable degree of certainty" that the
test is satisfied, it obviously is
reasonable for EPA to regard such  .
facilities with special scrutiny.
  Similarly, for a unit that has
experienced releases [migration) in the
past, the owner or operator petitioning
for a variance will be under a greater
burden of proof to demonstrate both: (1)
That the same type of release will not
occur in the future, and (2) that past and
future releases can be separated for
modeling and monitoring purposes. The
second item could be particularly
relevant for the ground water medium,
for example, where contamination
already detected in ground water could
continue to appear in monitoring wells
after a variance has been granted. It
would be difficult to prove whether the
contamination was from a past or
present release. Likewise, for a unit
located in a waste management area
where releases have occurred from
other units, it also could be difficult to
differentiate between releases,
particularly if the other units contained
the same hazardous constituents as the
unit for which a variance is sought
   In either case, the owner or operator
is discouraged from submitting a no
migration petition unless he or she can
conclusively demonstrate not only that
future migration will not occur, but also
that past releases detected through
monitoring either are not from the unit
for which a variance is sought, or that
they will not obscure or interfere with
 the ability of monitoring devices to
detect future releases. If there is
uncertainty, the assumption will be that
the release is from the unit for which a
variance is sought, and the variance
likely will be denied or, if already
granted, revoked.;

E. Conditional Requirements of a No
Migration Variance

  EPA proposes that for certain land
disposal units, no migration variances
may be granted based upon conditional
requirements. These conditions will be
specified in the variance, and are as
follows:         '
                I
1. Land Treatment Units.

  Land treatment units, under 40 CFR
264.272, are required to complete, and
receive Agency approval of, a Land
Treatment Demonstration. This Land
Treatment Demonstration focuses on
waste application rates and degradation
rates, and it requires the owner or
operator to demonstrate that hazardous
constituents in the waste may be
applied and completely degraded,
transformed, or immobilized, without
overloading the soil degradational
capacity or causing migration of
hazardous constituents outside of the
treatment zone. Because the no
migration variance will be granted
based upon certain basic monitoring and
modeling data, the Land Treatment
Demonstration need not be complete in
order to receive a no migration variance.
Therefore, EPA today is proposing new
requirements at § 26&6Q) providing that,
for land treatment units, the variance
will be conditioned upon completion of
the Land Treatment Demonstration  .
within two years after the date of
granting of the no migration variance, or
the variance will be revoked. This
provision is intended to ensure
completion of the Land Treatment
Demonstration in a timely fashion, while
nevertheless recognizing that the land
treatment unit must operate in order to
generate the relevant information and
data. However, it should be clarified
that this provison is not intended to
provide any time extension of the
requirement to have an approved no
migration variance prior to land disposal
of prohibited hazardous waste. Land
treatment units would all be required to
have an approved no migration variance
prior to receipt of prohibited waste,
regardless of whether the Land
Treatment Demonstration is complete or
not Furthermore, petitioners with
 incomplete Land Treatment
 Demonstrations would also have to
 meet all of the same information
 requirements to fulfill no migration
 petition criteria.
  The Agency also proposes to add new
requirements for land treatment units at
§ 268.6(k) in order to assure that the no
migration standard will continue to be
met after the conclusion of the post-
closure care period. The first situation of
concern would occur if accumulations
within the unit of nondegradable
hazardous constituents exceed health-
based levels for ingestion at closure and
during the post-closure care period. If
this occurs, the no migration standard
could be exceeded via an ingestion, air
dispersion, or surface runoff pathway.
To ensure that migration would not
occur, the Agency is proposing to
require either that the unit be capped
with clean soil at the end of the post-
closure care period, or that hazardous
constituents be removed at closure to
concentrations below health-based
levels. (If the petitioner were to choose
the clean soil cap option, then a
vegetative cover would have to be
established on the unit, as required by
§ 264.280(c)(2). In addition, the petitioner
would not be relieved of the existing
requirement to provide a vegetative
cover during the closure and post-
closure care period.) The Agency
proposes that the clean soil cap be
installed at the end of the post-closure
care period, rather than at closure, in
order to allow the biodegradation
process to continue without being
smothered and inactivated by anaerobic
conditions resulting from the soil cover.
  The second situation of concern
would occur if, at closure and at the end
of the post-closure care period, non-
degradable hazardous constituents
present in the unit are capable of
leaching at levels exceeding health-
based levels. To ensure no migration,
EPA is proposing that where the unit
contains nondegradable hazardous
constituents above health-based levels
at closure, the facility owner must
perform a leaching test or modeling
procedure that the Agency determines is
valid for the particular types of
constituents present to determine their
teachability. If modeling or test results
 show a potential for migration from the
unit above the health-based levels, then
 at closure the petitioner must remove
 hazardous constituents to below health-
 based levels.
   All existing closure and post-closure
 requirements under parts 264 and 265
 are still applicable, and would in no
 way be superseded by today's proposed
 requirements at § 268.6(k). Rather,
 today's proposed variance conditions
 would add to existing parts 264 and 265
 requirements. In particular, it should be
 noted that land treatment units (and
 other land disposal units) that will close

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                Federal Register /  Vol. 57. No. 155 / Tuesday, August  11. 1992 ) Proposed Rules
                                                                       35947
  with hazardous constituents in place at
  concentrations above health-based
  levels must comply with 40 CFR
  264.119(b) requirements for a deed
  notice that the site has been used for
  hazardous waste management, and
  consequently that future use is
  restricted EPA expects that this
  provision will prevent future human
  intrusion into the site after the post-
  closure care period has ended.
  2. Temporary Storage Units
    Under Section 3004(k) of RCRA, land
  disposal is defined as placement
  (including temporary storage)  of
  prohibited wastes in any land-based
  unit. Placement of prohibited wastes in
  a Iand4>ased unit can occur only after
  the unit owner or operator has been
  granted a no migration variance. Land-
  based units include: Landfills,  surface
  impoundments, -waste piles, injection
  wells, land treatment units, salt dome
  formations, salt bed formations.
  underground mines, caves, vaults, and
  bunkers. Use of a non-land-based unit to
  manage prohibited waste does not
  require a no migration variance. Non-
  land-based tinits include: Incinerators,
  tanks, and container storage areas.
 However, undergo CFR 268.50, certain
 restrictions are placed on the use of
 tanks and containers for storage of
 prohibited wastes: These units can be
 used to store such wastes only for the
 purpose of accumulating waste to
 facilitate its proper recovery, treatment.
 or disposal. Readers are advised to
 review the requirements of 40 CFR
 268.50.
  There rosy be circumstances under
 which owners or operators wish to store
 prohibited wastes in land-based units.
 As stated, doing so will require & no
 migration variance. The Agency
 indicated in Ike preamble to regulations
 promulgated an November 7,1S86 (51 £»
 40572) its ielief that an indoor waste
 pile with a concrete liner, used  for
 temporary storage, might be a good
 candidate for a tto migration variance.
 EPA wishes to caution potential
 petitioners that it does not consider ail
 types of land-based units, nor all waste
 types, to be^good candidates for a no
 migration variance for temporary land-
 based storage. Tie petition for such a
 unit would nave to demonstrate teat
 there would be no migration for as long
 as the -wastes remain in the unit
 (assuming they remain hazardous for
 that time). A number of factors.
 including {but not limited to] the
characteristics of thetmit-and the waste,
the  duration of storage, -and locational
factors, will be considered by the
Agency in making a decision on a no
migration petition for temporary land-
  based storage. As mentioned previously
  in this preamble the Agency proposes
  that, for land-based storage purposes,
  the containment of -hazardous waste
 •within engineered barriers (meeting
 minimum technology requirements) will
 be considered in making the no
 migration demonstration, provided that
 wastes are to be removed after a
 reasonably short storage period that
 may be conservatively projected to be
 well before the failure of the engineered
 barrier system.'
   The Agency today proposes to add
 provisions § 268.6 (1)(1) and (1)(2) to
 require the following as conditions of a
 no migration variance for temporary
 land-based storage units:
   a. Clean closure. As part of the
 variance, the unit's closure plan must
 provide for clean closure, both
 technically and with adequate financial
 assurance, within a specified time
 period. The Agency proposes this
 approach to assure that no hazardous
 waste or hazardous constituent
 concentrations above health-based
 levels remain after closure that could
 migrate from the unit in the future.
   b. Management of wastes at closure.
 The variance also must require that, at
 closure, the waste removed from the
 unit be managed in accordance with fee
 prohibitions on land disposal, including
 meeting the treatment standards where
 appropriate. This provision is proposed
 to ensure that hazardous waste from a
 temporary land-based no migration
 storage unit is not merely transferred to
 another land-based storage or disposal
 unit in an effort to circumvent the
 treatment requirements.
 3. Other Demonstrations
  In certain cases, conditional variances
 may also be appropriate for
 performance assessments in units other.
 than land -treatment and temporary
 storage. For example, B petitioner
 seeking a variance for a subpart Xnnit
 such as A geologic repository may need
 to test waste in-situ to determine that
 migration will not occur over the long
 term. In this .case, the petition would
 have to show that waste would not
 migrate during ihe period of the
 demonstration. No migration variances
 for such test demonstrations would be
 issued unless the Agency believes that a
 subpart X-unit has a reasonable chance
 of successfully demonstrating no
 migration over the long term.
Furthermore, the petition also must
 assure that all waste would he removed
 if the test demonstration failed..
4. Monitoring for'New Units
  As discussed earlier in this preamble.
 the Agency is proposing at $ 28&8{c)(3)
  that approval of a no -migration variance
  for a new unit shall be conditioned upon
  Agency review and approval of
  monitoring data, gathered subsequent to
  unit operation; these data must show
  that no migration of hazardous
  constituents is occurring. The Agency is
  proposing this approach because it
  recognizes that monitoring data on
  potential releases usually will not be
  available for new units. (However,
  where any monitoring data are available
  for a new unit, as a result of field test
  plots, etc., such data may be required as
  part of a no migration petition.)
  Similarly, an existing unit must also
  continue to demonstrate no migration
  through monitoring data collected during
 its operation. Approval of the no
 migration variance for an existing unit
 likewise is conditioned upon such
 operational monitoring data confirming
 no migration. The Agency requests
 comments on this approach.

 F. Additional Demonstrations for the Air
 Medium

   In addition to demonstrating no
 migration of hazardous constituents
 from the unit petitions also are required,
 undercurrent regulations at 40 CFR
 26a£. to demonstrate compliance with
 other laws. For the air medium, this
 requirement necessitates that petitioners
 provide a certification of compliance
 with OSHA workplace air standards
 and the benzene NESHAP. and, once
 promulgated, provide data
 demonstrating compliance with die
 RCRA Section 3004{n) standards for
 controlling air emissions from hazardous
 waste treatment storage, and disposal
 facilities.

 1. OSHA Standards

  OSHA workplace air standards may
 be found at 29 CFR part 1910. These   '
 standards include short-term (1-hour
 and an 6-hour average) air
 concentrations which must not be
 exceeded, or .protective breathing
 apparatus must be worn by workers.

 2. NESHAP for Benzene

  Similarly, successful petitions also
 must include a certification of
 compliance with the National Emission
 Standards for Hazardous Air Pollutants
 (NESHAP) for benzene at 40 CFR part
 61, published March 7,1990.55 FR 8292.
 Tiiis regulation .requires certain facilities
that manage greater than 10 Mg/yr of
 benzene in their waste to control certain
 waste streams, normally those with
greater than 20 ppmw benzene in the
waste. Facilities subject to the benzene
NESHAP control requirements would be
required to treat the waste to lower

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35348        'Federal  Register / Vol. 57. No. 155  / Tuesday. August 11. 1992 / Proposed Rules
benzene concentrations to a maximum
of 10 ppmw prior to land disposing in an
open (uncovered) unit.

3.3004(n) Standards
  a. Introduction. The EPA is proposing
today to amend 40 CFR 268.6 to include
an additional condition that the
applicant for a no migration variance
must satisfy. This condition would
require that the applicant demonstrate
in the no migration petition that the
particular land treatment unit, landfill,
or waste pile meets certain organic air
emission standards proposed by EPA
under 40 CFR part 264 subpart CC in a
separate rulemaking, and would be
imposed pursuant to RCRA section
3004(n) as well as sections 3004(d), (e),
and (g). Specifically, as a condition for a
no migration variance to dispose a
waste having a volatile organic
concentration equal to or greater than a
certain action level, proposed as 500
ppmw,2 in a land treatment unit, landfill,
or waste pile, an owner or operator
would need to install and operate on the
land disposal unit a cover or enclosure
connected through a closed vent system
to a control device. As an alternative to
using the control equipment, the owner
or operator could elect  to treat the waste
(by a meano other than by waste
dilution) to reduce the volatile organic
concentration to a level less than the
proposed 500 ppmw action level before
land disposal occurs.
  b. Background. Section 3004(n) of
RCRA directs EPA to "* * * promulgate
regulations for the monitoring and
control of air emissions from hazardous
waste treatment, storage, and disposal
facilities (TSDF), including but not
limited to open tanks, surface
impoundments, and landfills, as
necessary to protect human health and
the environment." To implement the
Congressional directive of RCRA section
3004(n), EPA decided to use a phased
approach so that standards could be
implemented for certain TSDF emission
sources as quickly as possible. In .
rulemakings separate from today's
proposal, EPA first promulgated air
emission standards for certain
hazardous waste treatment processes
(i.e., distillation, fractionation, thin-film
evaporation, solvent extraction, steam
  « This level Is not -el finalized.On July 22.1991
 (58 FR 33490). EPA proposed a level of 500 parts per
 million by weight (ppmw) as the action level for
 organic air emissions from TSDFs. This proposed
 level It subject to change as a mult of public
 comment* on the proposed rule. However, for the
 remainder of this discussion, the action level shall
 be referred to is the proposed SCO ppmw level. See
 elsewhere in this preamble for more discussion of
 EPA considerations In proposing this 500 ppmw
 action level.
stripping, and air stripping) to coincide
with the development of regulations
under RCRA section 3004(m) restricting
the land disposal of untreated
hazardous wastes (55 FR 25454; June 21,
1990). These final air emission standards
apply to certain TS)[)F treatment unit
process vents (Subpart AA in 40 CFR
parts 264 and 265) and TSDF equipment
leaks  (Subpart BB in 40 CFR parts 264
and 265). For the second phase EPA has
proposed standards, to be added to 40
CFR parts 264 and J265 as Subpart CC,
that would require lowners and
operators of TSDF subject to the RCRA
Subtitle C permitting requirements to
install and operatej organic emission
controls on certain! tanks, surface
impoundments, containers, and
miscellaneous units (56 FR 33490; July
22,1991). These proposed standards are
referred to in the remainder of this
section as the "Subpart CC rulemaking."
  The TSDF air emission standards
established by the [first and second
phase rulemakingS; under RCRA section
3004(n) will control emissions of not
only air toxics but jalso organic
compounds that react photochemically
with other chemical compounds in the
atmosphere to form ambient ozone.
Elevated ambient ozone concentrations
are a major air pollution problem in
most  large cities in the United States.
The EPA estimates that more than 100
million people live in areas in which
ambient ozone concentrations exceed
acceptable health-based levels defined
by the national ambient air quality
standards. Ozone is a pulmonary irritant
that can impair normal human
respiratory functions and can aggravate
pre-existing respiratory diseases.
Exposure to ozone also increases the  •
susceptibility to bacterial infections. In
addition, ozone can reduce the yields of
citrus, cotton, potatoes, soybeans, '
wheat, spinach, and other crops as well
as damage conifer forests, and cause a
reduction in the fruit and seed diets of
wildlife. Thus, EPA believes that organic
emissions from land disposal units and
 other TSDF sources must be limited to
 levels that not only will adequately
protect the public from the risk resulting
 from exposure to air toxics (by
 demonstration of no migration of
 hazardous constituents from the •
 disposal unit), but also will adequately
 protect human health and the
 environment from exposure to elevated-
 levels of ambient ozone.
   The EPA considered and decided not
 to include land treatment units, landfills,
 and waste piles in the Subpart CC
 rulemaking. Estimates of existing
 nationwide organic emissions  from land
 treatment units, landfills, and waste
 piles (based on data for the year 1985)
 are approximately 113,000 megagrams
 per year (Mg/yr). To characterize
 organic air emissions from TSDF
 sources to determine the applicability of
 the Subpart CC rulemaking, it first was
 necessary for EPA to make certain
 assumptions  about how the hazardous
 waste management industry would
 respond to the land disposal restrictions.
 The EPA assumed that all hazardous
 waste would be treated to meet the
 BOAT treatment standards prior to
 placement of the waste in a land
 disposal unit. Furthermore. EPA
 assumed that compliance with the
•BOAT treatment standards would
 remove or destroy organics in the waste
 and, consequently, reduce the organic
 content of the wastes placed in land
 disposal units. Based on these
 assumptions, EPA estimated that
 nationwide organic emissions from land
 treatment units, landfills,  and waste
 piles would be reduced to
 approximately 2,000 Mg/yr. Because the
 estimate results indicated that a large
 reduction in organic emissions would  be
 achieved by treating wastes to BOAT
 levels prior to land disposal, EPA
 decided to defer developing standards
 for land treatment units, landfills, and
 waste piles to a time when the
 protectiveness of the land disposal
 restrictions with respect to TSDF air
 .emissions could be better assessed.
   Since this decision was made, EPA
 has developed and clarified in this
 notice procedural and substantive
 requirements in 40 CFR part 268 for
 petitioning EPA and demonstrating that
 there will be no migration of hazardous
 constituents from a land  disposal unit.
 In accordance with the no migration
 petition requirements specified under 40
 CFR 268.6, an owner or operator of a
 particular TSDF would be allowed upon
 approval from EPA to dispose in a land
 treatment unit landfill, or waste pile
 specific hazardous wastes that are
 untreated or otherwise do not meet the
 BOAT treatment standards. Because  the
 possibility now exists that some
 hazardous wastes may not be treated to
 meet BOAT treatment standards prior to
 disposal in land treatment units,
 landfills, and waste piles, EPA
 reassessed the need to apply air
 emission controls to these units for the
 purpose of limiting emissions of those
 organic compounds which react
 photochemically in the atmosphere to
, form ambient ozone (referred to here as
  "ozone precursors").
    As previously discussed in this
  preamble, a condition for approval of a
  no migration variance is a
  demonstration by the applicant that  no

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                                                                       35949
   migration of hazardous constituents will
   occur from the disposal unit into the air
   for as long as the waste remains
   hazardous. However, air emissions from
   land treatment units, landfills, and
   waste piles contain individual organic
   compounds which have been identified
   as ozone precursors but have not been
   listed as hazardous constituents. For a
   land treatment unit, landfill, or waste
   pile operated under a no migration
  varance in accordance with
  requirements established under
  authority of RCRA sections 3004 (d), (e),
  and (g), the owner or operator would
  demonstrate no migration of only those
  ozone precursors which are also listed
  as hazardous constituents but not all
  ozone precursors. Consequently,
  significant quantities of ozone
  precursors could be emitted from a land
  disposal unit granted a no migration
  variance. Therefore, EPA concluded that
  organic emission standards are needed
  for land treatment units, landfills, and
  waste piles operated under a no
  migration variance to provide ambient
  ozone protection.
   c. Regulatory approach. Section
  3004(n) of RCRA provides EPA with
  broad authority to control air emissions
  from TSDF sources as necessary to
  protectpublic health and the
 environment. This authority allows
 control of all types of ozone precursors
 to provide ambient ozone protection,
 and, thus, is the authority EPA is using
 to propose the organic emission
 standards for TSDF land treatment
 units, landfills, and waste piles operated
 under a no migration variance. Because
 these standards will be narrowly
 applied to these units, the standards are
 being proposed as part of the no
 migration variance rules in 40 CFR 268.6
 even though they are under the authority
 of RCRA section 3004{n). In addition, as
 noted in a recent opinion, EPA retains
 residual authority to  control non-
 hazardous constituents under the
 section 3004 (d). (e). and (g) variance
 process by virtue of the general
 protectiveness finding contained in the
 opening clause of those provisions.
NRDC v. EPA No. 88-1657 (D.C. Cir.
June 29,1990).      -
   The need to apply air emission
controls to a particular TSDF waste
management unit can be determined by
the emission potential of the particular
hazardous waste that is placed in the
unit For the subpart CC proposal, EPA
evaluated possible formats and decided
that the concentration of volatile
organics in the waste is an appropriate
indicator of the emission potential for a
TSDF waste management unit The
volatile organics concentration
  {expressed in parts per million by
  weight {ppmw) as measured by the
  proposed EPA reference method 25D) is
  the total quantity of organics in a liquid
  or solid state that is likely to volatilize
  and, consequently, could be emitted to
  the atmosphere if not controlled.
  Therefore, the concentration of volatile
  organics in the waste is an appropriate
  indicator of the emission potential for a
  TSDF land treatment unit, landfill, or
  waste pile.
    The EPA evaluated different volatile
  organic concentration action levels for
  the subpart CC proposal (i.e., 0 ppmw,
  500 ppmw, 1.500 ppmw, and 3,000
  ppmw) above which waste would need
  to be managed In units equipped with a
  cover vented to a control device or, for
  some quiescent sources, only a cover.
  Based on an evaluation of the options, a
  volatile organic concentration action
  level of 500 ppmw was proposed for the
  subpart CC organic emission standards
  for TSDF tanks, surface impoundments,
  and containers. For standards such as
  these that apply to interrelated sources
  to be effective, they must have uniform
  coverage of applicability from the point
  of waste generation through the point
 where the organics in the waste are
 either recycled, removed, or destroyed.
 When only a cover is applied to a tank,
 surface impoundment, or container, the
 volatilization of the organics in the
 waste is inhibited, but the organics are
 neither removed or destroyed. When a
 cover vented to a control device is
 applied to a tank, surface impoundment.
 or container, only that portion of the
 organics in the waste which are actually
 emitted from the waste management
 unit and vented to the control device are
 removed or destroyed. Organics still
 remain in the waste and can potentially
 be emitted from subsequent waste
 management units located downstream
 of the controlled waste management
 unit Until organics in the waste are
 removed, recycled, or destroyed, they
 will still be emitted to the atmosphere
 from uncontrolled downstream waste
 management units. Selecting a higher or
 lower action level for land disposal
 units than was selected for the storage
 and treatment-units that would be
 regulated by the subpart CC rulemaking
 would alter the effectiveness of the
 proposed standards. A higher action
 level would allow a portion of the
 organics retained in the waste by the
use of suppression controls (l.e., covers)
 on the upstream waste management
units to be emitted from the
uncontrolled land disposal unit A lower
action level would require that controls
be used on land disposal units receiving
wastes from upstream waste.
  management units using no controls.
  Therefore, to maintain the effectiveness
  of the proposed subpart CC standards
  and avoid improper application of
  controls, it is necessary to apply the
  same action level through disposal of
  the waste. Thus, EPA also is proposing
  in today's rule a volatile organic
  concentration action level of 500 ppmw
  for land treatment units, landfills, and
  waste piles, to be consistent with the
  proposed approach for subpart CC. In
  the final rule, this value may change to
  maintain consistency with the final
  subpart CC rule.
    To establish the specific control
  requirements for a land treatment unit.
  landfill, or waste pile, EPA first
  reviewed the different emission control
  methods that can be used to reduce
  organic emissions from these land
  disposal units. These methods include
  using: (1) A cover to suppress the
  release of organics from the waste; (2) a
  closed vent system and control device in
  combination with the cover to capture
  and control the organic emissions
 released from the waste; or (3) treatment
 of the waste to remove or destroy the
 organics in the waste prior to placement
 of the waste in a land disposal unit.
   Organic emissions can be suppressed
 by applying a cover that directly
 contacts or encloses the waste medium
 thereby creating a physical barrier over
 the waste surface which inhibits the
 volatilization of organics. The EPA has
 already proposed standards under the
 Subpart CC rulemaking that would
 require the application of covers to
 surface impoundments. Since surface
 impoundments can be many acres in
 size, and even larger than land
 treatment units, landfills, and waste
 piles, the certain covers suitable for
 surface impoundments could be
 installed on these land disposal units.as
 well. The covers can be fabricated from
 either rigid material panels that are
 essentially impervious to organic
 permeation or from flexible, synthetic
 membrane sheets that have a high
 resistance to permeation of many types
 of organic compounds frequently
 contained in wastes managed at TSDF.
 Also, with proper installation and
 maintenance, leakage from cover seams
 and fittings can be limited to very low
 levels. Thus, covers are appropriate for
 controlling organic emissions from
 certain types of waste management
 units holding the waste for relatively
 short periods of time such as for
 temporary storage of the waste.
However, waste that is placed in a land
disposal unit remains in the unit for
many years. Consequently, if the
organics are not removed or destroyed

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'  Federal Register / Vol.  57, No. 155 / Tuesday. August 11. 1992  /  Proposed Rules
prior to placement in the land disposal
unit, the potential still remains that the
organics in the waste will be released to
the atmosphere over the long term as the
organics in the waste slowly escape by
permeation of the cover material or
through small leaks in cover seams and
fittings. Therefore, using only a cover
would not effectively control organic
emissions from a land disposal unit.
  To effectively reduce organic
emissions from a covered land disposal
unit, the cover needs to be vented to a
control device. Using this control
combination, the organic vapors
released from the waste are captured in
the enclosed space beneath the cover
and then the captured gas stream is
vented to a control device where the
organics are removed or destroyed. A
variety of control devices are available
that are capable of achieving high
organic emission control efficiencies.
Organic removal control devices such as
carbon adsorbers and condensers
extract the organics from the gas stream
and recover the organics for potential
recycling or reuse. Organic destruction
control devices such as vapor
incinerators destroy the organics in the
gas stream by oxidation of the organic
compounds, primarily to carbon  dioxide -
and water. The type of control device
best suited for reducing emissions from
a particular covered land treatment unit,
landfill, or waste pile depends on the
size of the unit and the characteristics of
the organic vapor stream vented from
the unit. To achieve the maximum
potential control device organic
emission reduction efficiency, the vent
system used to convey the organic ,
vapors from the covered unit to a
control device must be closed so that no
organic vapors can escape directly to
the atmosphere prior to the gas stream
entering the control device. A closed
vent system consists of piping,
connections, and, in some cases, a flow
inducing device (e.g.. a fan or blower) to
transport the gas stream to the control
device.
  An alternative to  using a cover vented
to a control device would be to treat the
waste by a means other than by waste
dilution that reduces the volatile organic
concentration to a level less than the
proposed 500 ppmw. In this case, the
owner or operator could select from a
number of treatment processes that are
effective in reducing the organic content
of the waste below  the proposed 500
ppmw action level but would not
necessarily meet the specific BDAT
treatment standards applicable  to the
waste. Treating the waste in this manner
may offer significant cost savings to a
TSDF owner or operator compared to  -
                          the cost of installing and operating a
                          cover vented to a Control device on the
                          affected land disposal unit, and thus
                          may be the preferred way to comply
                          with standards,  j
                            Given the need to limit organic
                          emissions from TSDF land disposal
                          units, and the suitability of applying the
                          air emission controls selected for
                          surface impoundments to other types of
                          land disposal units, EPA is  proposing
                          today to include an additional condition
                          for obtaining a noimigration variance.
                          This condition would require that each
                          land treatment unit, landfill, or waste
                          pile receiving the Waste be  managed in
                          compliance with the air emission
                          standards for certain surface
                          impoundments as [specified in the 40
                          CFR 264 subpart CC proposal. To
                          comply-with these standards, the owner
                          or operator would either install and
                          operate the specified air emission
                          control equipment, or elect to treat the
                          waste before land disposal by a means
                          other than by waste dilution to reduce
                          the volatile organic concentration to a
                          level less than die proposed 500 ppmw.
                          The remainder of [this section
                          summarizes'the specific proposed
                          requirements of 40 CFR part 264 subpart
                          CC that EPA proposes  to include in 40
                          CFR 268.6 as a condition for obtaining a
                          no migration variance.
                             d. Proposed requirements. The
                          proposed control equipment
                          requirements are to install, operate, and
                          maintain either a cover or enclosure,
                          connected through a "closed vent system
                          to a control device. These requirements
                          would apply to any land treatment unit,
                          landfill, or waste pile granted a no
                          migration variance, including units for
                          which a variance'had already been
                          granted. The cover (i.e. flexible
                          membrane cover, air-supported
                          structure, or any other type selected by
                          the owner or operator) and all openings
                          on the cover are to be  designed and
                          operated with no detectable emissions
                         ' as determined by Reference Method 21
                          specified in 40 CFR part 60 appendix A.
                          All openings in the cover such as
                          hatches and access doors would need to
                          be sealed (e.g., gasketed, latched] and
                          kept closed at all times except when
                          necessary to use [the opening for waste
                          loading, inspection, or sampling or for
                          equipment inspection, maintenance, or
                          repair. The closed vent system would be
                          required to be designed, installed
                          operated, and maintained  so that there
                          are no detectable emission as
                          determined by monitoring the system
                          using Reference, Method 21. Each control
                          device would be [required to reduce the
                          organics in the gas stream vented to it
                          by at least 95 percent or, if an enclosed
combustion device is used, to a total
organic concentration of 20 ppm by
volume as compounds determined by
Reference Method 18 specified in 40
CFR part 60 appendix A. To document
that a control device achieves this
performance level, the owner or
operator would be required to use either
detailed design specifications for the
control device or results of control
device performance testing.
  Determination  that a waste contains
less than the proposed 500 ppmw would
be made by either direct measurement
or knowledge of the waste at the point
of waste generation. Direct
measurement of the waste volatile
organic concentration would be
performed using the proposed EPA
Reference Method 25D ( 56 FR 33490;
July 22,19S1). Knowledge of the waste
would constitute documentation that
conclusively shows that the waste
volatile organic concentration is below
the specified limit under all conditions.
For example, a company that generates
a hazardous waste as a result of
manufacturing a product could provide
EPA with evidence that no organic
chemicals are used in the manufacturing
process. The waste determinations
would need to be performed initially
and repeated at least annually and,
additionally, whenever the process or
operation generating the waste has
changed in such a manner that the
volatile organic concentration may be
increased.
   The proposed standards would
require the owner or operator to include
certain emission control equipment
items as part of the weekly inspections
the owner or operator is already
conducting to comply with existing
RCRA standards (e& 40 CFR 264.273 for
land treatment units, 40 CFR 264.303 for
landfills. 40 CFR 264.254 for waste piles).
For example, covers would need to be
checked once per week by the facility
workers to ensure that equipment is
being used properly (e.g. covers are
closed and latched except when
workers require access to the unit) and
the equipment is being maintained in
good condition (e.g. no holeo or gaps
have developed in covers).
   Continuous monitoring of control
device operation would be required.
This would involve the use of
 instrumentation to measure and record
 operating parameters that indicate
 whether the control device is operating
 correctly or is malfunctioning.
 Semiannual leak detection monitoring
 using Reference Method 21 would also
 be required for, certain cover
 components to ensure gaskets and seals
 are in good condition, and for closed

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               Federal Register / Vol.  57, No. 155 / Tuesday,  August 11,  1992 / Proposed Rules
                                                                      35951
 vent systems to ensure all fittings
 remain leak-tight.
   The proposed recordkeeping
 requirements would require the owner
 or operator to record certain information
 documenting emission control
 equipment performance and
 maintenance in the on-site facility
 operating logs or files. This information
 would be available for review by EPA
 enforcement personnel during an on-site
 compliance inspection. The information
 to be collected and recorded would
 include: the results of all waste
 determinations for volatile organic
 concentration and organic vapor
 pressure; design specifications for
 closed vent systems and control devices;
 and emission control equipment
 inspection and monitoring records.
   The proposed reporting requirements
 would require the owner or operator to
 submit a report to EPA only when: (1) A
 control device malfunction is not
 corrected within 24 hours of detection;
 or (2) a waste placed in an open land
 disposal unit exceeds the proposed 500
 ppmw volatile organic concentration. If
 either of these events (referred to here
 as "exceedances") occur, the owner or
 operator would be required to maintain
 a record of the exceedance. For waste
 exceedances, the owner or operator
 would be required to submit a report to
 EPA within 30 days after the waste
 determination explaining why the waste
 was not managed in accordance with
 the requirements of the standards. For
 control device exceedances, the owner
 or operator would be required to submit
 a report to EPA on a semiannual basis
 describing any exceedances that
 occurred during the past 6-month period
 and explaining why each exceedance
 occurred.

 IV. State Authorization

A. Applicability of Rules in Authorized
States
  Under section 3008 of RCRA, EPA
may authorize qualified States  to
administer and enforce the RCRA -
program within the State. (See 40 CFR
part 271 for the standards and      '   .
requirements for authorization.)   .  .  ,
Following authorization, EPA retains
enforcement authority under sections
3008,7003, and 3013 of RCRA, although
authorized States have independent
enforcement authority.
  Prior to the Hazardous and Solid
Waste Amendments of 1984 (HSWA). a
State with final authorization
administered its hazardous waste
program entirely in lieu of EPA
administering the Federal program in  -
that State. The Federal requirements no
longer applied in the authorized State.
 and EPA could not issue permits for any
 facilities in the State which the State
 was authorised to permit. When new,
 more stringent Federal requirements
 were promulgated or enacted, the State
 was obliged to enact equivalent
 authority within specified time frames.
 New Federal requirements did not take
 effect in an authorized State until the
 State adopted the requirements as State
 law.
   In contrast, under  section 3006{g) of
 RCRA, 42 U.S.C. 6928{g). new
 requirements and prohibitions imposed
 by HSWA take effect in authorized
 States at the same time that they take
 effect in nonauthorized States. EPA is
 directed to carry out those requirements
 and prohibitions in authorized States,
 including the issuance of permits, until
 the State is granted authorization to do
 so. While States must still adopt
 HSWA-related provisions as State law
 to retain final authorization, the HSWA
 requirements apply in authorized States
 in the interim.

 B. Effect on State Authorizations
  Today's propoed no migration rule,
 which also limits organic emissions from
 land treatment landfill, and waste pile
 units operating under a no migration
 variance, is proposed pursuant to
 sections 3004 (d), (e), fe), and (n) of
 RCRA (42 U.S.C. 6924 (d), (e). (g). and
 (n)), provisions added by HSWA
 Therefore, the Agency is proposing to
 add the requirements to Table 1 in 40
 CFR 271.10). which identifies the
 Federal program requirements that are
 promulgated pursuant to HSWA and
 take effect in all States, regardless of
 authorization status.  States may apply
 for either interim or final authorization
 for the HSWA provisions identified in
Table 1, as discussed in this section of
 the preamble.
  As noted above, EPA will implement
today's rule in the authorized States
until they modify their programs to
adopt these rules and the modification is
approved by EPA Because this rule is
proposed pursuant to HSWA, a State
submitting a program modification may
apply to .receive either interim or final
authorization under section 3006(g)(2)  or
section 3006(b), respectively, on the
basis of requirements that are
substantially equivalent or equivalent to
EPA's. The procedures and schedule for
State program modifications for either
interim or final authorization are
described hi 40 CFR 271.21. It should be
noted that all HSWA interim
authorizations will expire January 1,
1993 (see 40 CFR 271.24(c)).
  40 CFR 271.2l(e)(2) requires that
States that have final authorization must
modify their programs to reflect Federal
 program changes, and must
 subsequently submit the modifications
 to EPA for approval. The deadlines by
 which a State-must modify its program
 to adopt this proposed regulation will be
 determined by the date of promulgation
 of the final rule, in accordance with 40
 CFR 271.21(e). These deadlines can be
 extended in certain cases (40 CFR
 2ri.21(e)(3}). Once EPA approves the
 modification, the State requirements
 become Subtitle C RCRA requirements.
   A State that submits its official
 application for final authorization less
 than 12 months after the effective date
 of these standards is not required to
 include standards equivalent to these
 standards in its application. However,
 the State must modify its program by the
 deadlines set forth in 40 CFR 271.21(e).
 States that submit official applications
 for final authorization 12 months after
 the effective date of these standards
 must include standards equivalent to
 these standards in their applications. 40
 CFR 271.3 sets forth the requirements a
 State must meet when submitting its
 final authorization application.
  In addition to meeting the
 requirements in 40 CFR part 271, a State
 seeking authorization for today's rules
 must demonstrate the ability to capably
 implement the base RCRA program, as
 well as the additional HSWA elements.
 EPA's assessment of a State's capability
 will reflect an evaluation of the State's
 entire authorized program. The
 assessment will examine not only
 whether a State-is effectively
 implementing the base program, but also
 how that State may implement
 additional program areas.
  States with authorized RCRA
 programs (but which are not yet
 authorized for the requirements in
 today's rule) may already have
 requirements under State law similar to
 those in today's rule. These State
 regulations have not been assessed
 against the Federal regulations being
 proposed today to determine whether
 they meet the tests for authorization,.
 Thus, a State is not authorized to
 implement these requirements in lieu of
EPA until the State program
 modification is approved..Of course.
 States with existing standards may
 continue to administer and enforce their
 standards as a matter of State law. In
 implementing the Federal program, EPA
will work with States under cooperative
 agreements to minimize duplication  of
 efforts. In many cases, EPA will be able
 to defer to the States in their efforts  to
implement their programs, rather than
 take .separate, actions under Federal
authority.

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Federal Register / Vol. 57, No. 155  / Tuesday, August 11,  1992 / Proposed Rules
  As of the date of this proposal, no
Slates have received authorization to
act on HSWA no migration petitions
pursuant to the initial codification of
sections 3004(d). (e), and (g) at 40 CFR
268.8 (51FR 40572, November 7,1988).
The November 7,1986 Codification Rule
explains that a State's authorization
status may change in response to further
implementation of HSWA, i.e., when
EPA publishes regulations which further
define initially codified rules. Had any
States been authorized for no migration
under the November 7,1986 Codification
Rule, they would no longer be
authorized under RCRA to implement
these no migration rules when finally
promulgated. (No migration regulated as
a matter of State law is, of course, not
affected.) This is because today's rules
are more stringent than the initial
codification of no migration
requirements and, as explained above,
the authorized State's regulations have
not been assessed against the new
standards. A State previously
authorized for no migration may, of
course, apply for and receive
authorization for today's requirements.
  States are not required to adopt the
existing no migration regulation
(§ 268.6), since it is a variance provision,
and not adopting results  in a more
stringent State program. However, any
State  that has adopted the no migration
regulation (§ 268.6) and is seeking
authorization under part 271, must adopt
the revisions to § 268.6 proposed in
today's rule, since these revisions result
in § 268.6 being more stringent.
  Similarly, as of the date of this
proposal, no States have received
authorization to act on HSWA section
3004(n) air emission standards for
hazardous waste landfill, waste pile, or
land treatment units, proposed today at
§ 268.6(b)(6). States may also apply for
and receive authorization for today's
proposed 3004(n) requirements.
V. Regulatory Requirements
A. Regulatory Impact Analysis
  Executive Order 12291 requires EPA
to determine whether a new regulation
will be "major" and, if so, that a
Regulatory Impact Analysis be
conducted. A major rule* is defined as a
regulation that is likely to result in:
  1. An annual effect on the economy of
SI00 million or more;
  2. A major increase in costs or prices
for consumers, individual industries,-
Federal, State, or local government
agencies or geographic regions; or
  3. Significant adverse effects on
competition, employment, investment,
productivity, innovation, or the ability of
United States-based enterprises to
                        compete with foreign-based enterprises
                        in domestic or export markets.
                          The Agency has determined that
                        today's proposed rjule is not a major
                        rule, because it does not meet the above
                        criteria. Today's action is an
                        interpretation of existing statutory and
                        regulatory languagje and will not impose
                        further resource burdens on the
                        regulated community, other than the
                        voluntary and already existing costs of
                        compiling the no migration petitions
                        themselves. In fact, no migration
                        variances granted by the Agency
                        provide relief from the costs of meeting
                        BDAT treatment standards prior to land
                        disposal, as required under the land
                        disposal restrictions. Therefore, since
                        this proposed rule is part of the overall
                        program for no migration variances for
                        land disposal of prohibited hazardous
                        waste, reduced costs to the regulated
                        community result. The national cost
                        savings for units receiving a no
                        migration variance, which allows land
                        disposal of prohibited hazardous waste,
                        are estimated to be substantial when
                        compared with the costs to owners and
                        operators of meeting the BDAT
                        treatment standards for the same
                        wastes. The Agency requests comments
                        today on the estimated costs to the
                        regulated community of preparing no
                        migration petitions consistent with the
                        existing procedural requirements as
                        proposed to be amended, and also
                        comments on the estimated cost savings
                        to be realized from receipt of a variance.
                          The Office of Management and Budget
                        (OMB) has reviewed today's proposed
                        rule as required by Executive Order
                        12291.           |

                        B. Regulatory Flexibility Act

                          I certify that within the scope of the
                        Regulatory Flexibility Act, these
                        regulations will not have a significant
                        economic impact on a substantial
                        number of small entities. The regulations
                        pertain to an optional variance, and
                        impose no new regulatory or economic
                        requirements on small businesses.

                        C. Paperwork Redaction Act

                           The information collection
                        requirements in this proposed rule have
                        been approved by the Office of
                        Management and Budget (OMB) under
                        the Paperwork Reduction Act 44 U.S.C.
                        3501  et. seq. and have been assigned
                        OMB control number 2050-0062.

                        VI. References   ; ,
                           (1) VS. EPA. 19914 Integrated Risk
                        Information System (IRIS). On-line. Office of
                        Health and Environmental Assessment,
                        Environmental Criteria and Assessment
                         Office, Cincinnati, OH.
  (2) U.S. EPA, 1990. Carcinogenic Risk
Assessment Verification Endeavor (CRAVE)
Risk Estimate for Carcinogenicity. Office of
Health and Environmental Assessment,
Environmental Criteria and Assessment
Office, Cincinnati, OH.
  (3) U.S. EPA, 198ft Superfund Public Health
Evaluation Manual.
  (4) U.S. EPA, Draft, July, 1992. No-Migration
Variances to the Hazardous Waste Land
Disposal Prohibitions: A Guidance Manual
for Petitioners.
  (5) U.S. EPA, 198ft Test Methods for
Evaluating Solid Wastes, Physical/Chemical
Methods, EPA SW-846, Third Edition.
  (6) US. .EPA, May, 1989. No Migration Cost
Analysis.

List of Subjects

40 CFR Part 268

  Hazardous waste, Reporting and
recordkeeping requirements.

40 CFR Part 271

  Administrative practice and
procedure. Confidential business
information. Hazardous materials
transportation, Hazardous waste,
Indians—lands, Intergovernmental
relations, Penalties, Reporting and
recordkeeping requirements, Water
pollution control, Water supply.
  Dated: July 12,1992.
William K. Reilly,
Administrator.

  For the reasons set out in the
preamble, 40 CFR part 268 is proposed
to be amended as follows:

PART 268—LAND DISPOSAL,
RESTRICTIONS

  The authority citation for part 268
continues to read as follows:
  Authority: 42 U.S.C. 6905,6912(a). and 6924.

Subpart A—General

  2. In 40 CFR part 238, subpart A, it is
proposed to amend § 268.6 by revising
paragraph (a) introductory text; by
adding  a semicolon at the end of
paragraph (a)(3) in place of the period,
by removing "and," at the end of
paragraph (b)(4) and by adding a
semicolon at the end of paragraph (b)(5)
in place of the period; by revising
paragraphs (a)(4) and (f)(3); by
redesignating paragraphs (c)(3) through
(c)(5) as paragraphs (c)(4) through (c)(6),
and paragraphs (j) through (n) as
paragraphs (m) tiirough (q), respectively;
by removing the words ", and" at the
.end of newly designated paragraph
(c)(4) and adding in their place a period;
and by adding new paragraphs (b)(6), '
(c)(3). (j), (k). (1), and (r) to read as
follows:

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                  Federal Register /  Vol. 57. No. ISS  /  Tuesday. August 11. 1992 / Proposed Rules
                                                                        35953
   §268.6  Petitions to allow land disposal of
   a waste prohibited under subpart C of part
   268.
     (a) Any person seeking an exemption
   from a prohibition under subpart C of
   this part for the disposal of a restricted
   hazardous waste in a particular unit or
   units must submit a petition to the
   Administrator demonstrating, to a
   reasonable degree of certainty, that
   there will be no migration of hazardous
   constituents from the land disposal unit
   or injection zone for as long as the
   wastes remain hazardous. For the
   purposes of this demonstration, "no
   migration'of hazardous constituents
   from the land disposal unit  or injection
   zone" (or simply, "no migration") shall
   be interpreted to mean that
   concentrations of hazardous
   constituents released from the unit do
   not and shall not exceed Agency-
   approved health-based (or
 .  environmental-based, where the Agency
   determines to be appropriate) levels at
   the unit boundary and beyond. A
   petition must demonstrate that no
   migration is occurring or shall occur to
   the ground water, surface water, soil, or
   air media. The demonstration must
   include the following components:
   **'**»
    (4) A monitoring plan that detects any
  migration of hazardous constituents
  from the unit to the ground water,
  surface water, soil, or air at the earliest
  practicable time, unless the
  Administrator determines that
  monitoring of one or more media is
  unnecessary or technically infeasible or
  impractical;
  *****
.   (b) * * *
   (6) Each land treatment unit, landfill,
 or waste pile receiving the hazardous
 waste(s) in accordance with a variance
 granted under this section must be '
 managed in compliance with the air
 emission standards for Surface
 impoundments in §§ 264.1081,264.1082,
 264.1084{b)(l), 284.1086. 264.1087,
 264.1088, and 264.1089 of this chapter.1
   (c)  * * *
   (3) For an existing unit at the time a
 no migration petition is submitted for
 that unit, the monitoring data collected
 according to the monitoring plan
 specified under paragraph (c)(l) of this
  1 Theie sections were proposed at 56 FR 33490,
 July 22.1901. EPA will finalize these sections before
 the No Migration final rule is published.
  section must be submitted to the
  Administrator prior to granting of the
  variance, as part of the petition, for his
  review arid consideration. For new and
  existing units, granting of a variance
  under this section shall be conditioned
  upon Agency review and approval of
  monitoring data, gathered subsequent to
  unit operation, that confirm no migration
  of hazardous constituents from the unit.
  For a new unit, the Agency may require
  that monitoring data for one or more
  media, where reasonably available, be
  submitted to the Administrator prior to
  granting of the variance, as part of the
  petition, for his review and
  consideration.
  *     «    *    *    *

    ffl * *  *    .
    (3) Following receipt of the
  notification the Administrator will
  determine, within 60 days of receiving
  notification, whether the owner or
  operator can  continue to receive
  prohibited waste in the unit and
  whether the variance is to be revoked.
  Should the Administrator determine that
  migration of hazardous constituents
  from the unit  is occurring or has
  occurred (i.e.. that a release from the
  unit exceeds Agency-approved health-
  based or environmental-based levels),
  the Administrator shall revoke the
 variance. The Administrator shall also
 determine whether further examination
 of any migration is warranted under
 applicable provisions of part 284 or part
 265 of this chapter.
 *****

   0) For land treatment units that have
 not completed the land treatment
 demonstration required under 40 CFR
 264.272, granting of a variance under this
 section shall be conditioned upon
 completion of  the land treatment
 demonstration .on or before the date two
 years after the date of granting of this
 variance, or the Administrator shall
 revoke the variance.
  (k) For land  treatment units where
 concentrations of hazardous
 constituents in the treatment zone
 exceed Agency-approved health-based
 levels for soil ingestion at closure, the
 facility owner or operator must perform
 a modeling procedure or a test
procedure, which the Agency
determines is valid for each type of
hazardous constituent present, to
demonstrate leachability Dependent on
the results of these analyses, the unit's
  closure and post-closure plans must
  require either
     (1) Capping with clean soil at the end
  of the post-closure care period, if the
  procedures show no reasonable
  potential for migration of hazardous
  constituents from the unit at
  concentrations exceeding Agency-
  approved health-based levels; or
    (2) Removal of hazardous constituents
  at closure, to concentrations at or below
  Agency-approved health-based levels
  for soil ingestion, if hazardous
  constituents may potentially be released
  from the unit at concentrations
  exceeding Agency-approved health-
  based levels.
    (1) For land disposal units that are
  used to temporarily store prohibited
  waste, a variance granted under this
  section shall be conditioned upon the
  following requirements:
    (1) The unit's closure plan must
  provide for clean closure, both
  technically and with adequate financial
  assurance, within a specified time
  period; and
   (2) At closure, the waste must be
 managed in accordance with the
 requirements of this part.
 *****

   (r) On the basis of any information,
 should the Administrator at any time
 determine that migration of hazardous
 constituents from the unit is occurring or
 has occurred (i.e., that a release from the
 unit exceeds Agency-approved health-
 based or environmental-based levels),
 or that a variance previously granted
 under this section is for any other
 reason no longer protective of human
 health and the environment, the
 Administrator shall revoke the variance.
 *****

 PART 271—REQUIREMENTS FOR
 AUTHORIZATION OF STATE
 HAZARDOUS WASTE PROGRAMS
  1. The authority citation for part 271
 continues to read as follows:
  Authority: 42 U.S.C. 6905,6912(a), and 6928.

  2. Section 271.1(j) is proposed to be
 amended by adding the following entry
 to Table 1 in chronological order by date
 of publication in the Federal Register to
read as follows:

271.1  Purpose and scope.
*    *    *    *     *

  (0 *  *  *

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35954
Federal Register / Vol.  57,  No.  155 / Tuesday, August 11, 1992 / Proposed Rules
               TABLE 1.—REGULATIONS IMPLEMENTING THE HAZARDOUS AND SOUD WASTE AMENDMENTS OF 1984
        Promulgation date
                       Title of regulation
                                                                  Federal Register reference
                                                                                                      Effective date
tlnsort date of final pubficabon],.
               Land Disposal Restrictions "No Migra-1 tlnsert page citation of final rule.].
                 ton" Variances.
	 [Insert effective date of final rule.]
|FR Doc. 02-18561 Filed 6-10-92; 8:45 am]
BILUNO CODE AM040-M

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