Thursday
  March 19, 1987
 Part  III



 Environmental

 Protection Agency

40 CFR Parts 264, 265, and 270
Proposed Amendments for Landfill,
Surface Impoundment, and Waste Pile
Closures; Proposed Amendment to Rule

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  8712
Federal  Register  /  Vol. 52.  N'o. 53  /  Thursday.  March 19. 1987 /  Proposed  Rules
  ENVIRONMENTAL PROTECTION
  AGENCY

  40 CFR Parts 264,265, and 270

  ISW-FRL-3C92-21

  Proposed Amendments for Landfill,
  Surface Impoundment, and Waste Pile
  Closures; Proposed Rule

  AGENCY: U.S. Environmental Protection
  Agency (EPA).
  ACTION: Proposed Amendment to rule.

  SUMMARY: The Agency is proposing to
  supplement the currently authorized
  options found in 40 CFR Parts 264 and
  265 for closing and providing post-
  closure care for landfills, surface
  impoundments, and waste piles that are
  used to treat,  store, or dispose of
 hazardous wastes. Under the
 supplemental option proposed today, the
 Agency and authorized States may
 establish appropriate closure and post-
 closure requirements on a site-specific
 basis. The requirements would be
 established by analyzing detailed data
 concerning the waste and site
 characteristics, and assessing all
 potential pathways by which hazardous
 constituents may migrate and pose
 threats to human health and the
 environment. The public will be
 provided an opportunity to comment
 fully in permit hearings on the
 appropriateness of the site-specific
 closure and post-closure requirements
 for individual  facilities before they are
 made final.
  The purpose of this proposed
 regulatory amendment is to allow
 increased technical flexibility for
 situations not adequately addressed by
 the broad nationwide closure standards
 now in effect. However, as with the
 existing standards, any alternative
 requirements established under the
 proposed regulatory amendments must
 be designed to protect human health and
 the environment.
 DATE: Written  comments should be
 submitted on or before May 18,1987. An
 original and two copies of ydiir
 comments on this proposal should be
 mailed to the Docket Clerk, Office of
 Solid Waste (WH-582J, U.S.
 Environmental Protection Agency, 401M
 Street. SW.. Washington, DC 20460 and
 should be identified as follows: F-87-
 ACP-FFFFF.
 ADDRESS: The  official docket for this
 regulation including comments received
 by the Agency is located in Room
 MLG100. U.S. Environmental Protection
 Agency. 401 M Street. SW.. Washington,
DC 20460, and  is available for viewing
from 9:00 a.m. to 3:30 p.m., Monday
                        through Friday, excluding holidays. Call
                        Mia Zmud at 475-9327 or Kate Blow at
                        382-4675 for appointments.
                        FOR FURTHER INFORMATION CONTACT
                        RCRA Hotline at 800-424-9346 (in
                        Washington, DC. call 382-3000) or for
                        technical information contact Ossi
                        Meyn. Office of Solid Waste  (WH-
                        565E), U.S. Environmental Protection
                        Agency. Washington. DC 20460,
                        telephone (202) 382^1654.
                        SUPPLEMENTARY INFORMATION:

                        I. Authority
                         These regulations are issued under the
                        authority of sections 1006, 2002(a), 3004,
                        3005, and 3007 of the Solid Waste
                        Disposal Act (SWDA). as amended by
                        the Resource Conservation and
                        Recovery Act of 1976 (RCRA), as
                        amended (42 U.S.C. 6905, 6912(a). 6924.
                        and 6925).

                        II. Background
                         Subtitle C of RCRA creates a "cradle-
                        to-grave" management system intended
                        to ensure that hazardous waste is safely
                       treated, stored, or disposed. First,
                       Subtitle C requires the Agency to
                       identify hazardous waste. Second, it
                       creates a manifest system designed to
                       track the movement of. hazardous waste,
                       and requires hazardous waste
                       generators and transporters to employ
                       appropriate management practices as
                       well as procedures to ensure the
                       effective operation of the manifest
                       system. Third, owners and operators of
                       treatment storage, and disposal
                       facilities must comply with standards
                       that "may be necessary to protect
                       human health and the environment" that
                       are established by the Agency under
                       section 3004 of RCRA. Ultimately, these
                       standards will be implemented through
                       permits that are issued by authorized
                       States or the Agency to owners and
                       operators of hazardous waste treatment.
                       storage, and disposal facilities. Until
                       these permits are  issued, existing
                       facilities are controlled under the
                       interim status regulations of 40 CFR Part
                       265 that were largely promulgated on
                       May 19.1980. Interim status waste
                       facilities are waste management
                       facilities in existence on November 19,
                       1980 (or on the effective date of
                       statutory or regulatory changes under
                       the Hazardous and Solid Waste
                       Amendments (HSWA) of 1984).
                        In regulations promulgated on July 26,
                       1982 [47 FR 32274], the Agency
                       established permitting standards in 40
                       CFR Part 264 covering the treatment,
                       storage, and disposal of hazardous
                       wastes in surface  impoundments, waste
                       piles, land treatment  units, and landfills.
                       Owners and operators of such facilities
  must meet these standards to receive a
  RCRA permit.

  III. Discussion of Today's Amendments

   At present, the regulations afford one,
  and. for some units, two options for
  closing landfills, surface impoundments.
  and waste piles. In the case of surface
  impound and landfill units, one  may
  close by placing a highly impermeable
  cap over the unit (and in the case of a
  surface impoundment, the unit must be
 dewatered and the wastes stabilized)
  and conducting a 30-year (or other
 appropriate period) post-closure
 program of monitoring and maintaining
 the cap; monitoring, maintaining,
 collecting and removing liquids in the
 leachate collection system if present:
 and monitoring the ground water. Where
 monitoring data indicates ground-water
 contamination, corrective action may be
 required pursuant to Part 264 Subpart F
 (for permitted facilities) or section
 3008(h) of HSWA (for interim status
 facilities). This option is available to
 waste piles only after all wastes have
 been removed or decontaminated and it
 is not practical to remove contaminated
 subsoils.
   A second option, available to surface
 impoundments and waste piles, is to
 remove or decontaminate all waste
 residues, contaminated design and
 operating system components (e.g.
 liners, leachate collection systems, and
 dikes), contaminated subsoils, and
 structures contaminated with waste and
 leachate. If this is successfully
 accomplished, no post-closure
 monitoring or other post-closure  care is
 required. This type of closure is more
 fully discussed in the final amendments
 to 5 265.228 published elsewhere in
 today's  Federal Register.
  These two closure options evolve  out
 of the Agency's approach for minimizing
 the post-closure release of hazardous
 constituents into the environment. The
 first option, leaving waste in place but
 installing a low permeability cap,
 derives  from the Agency's overall
 liquids management strategy for  land
 disposal units. As described in the
preamble to the minimum technology
regulations (47 FR 32274. July 26,1982
and 51 FR 10708, March 28.1986). the
Agency's general strategy for such units
is to  impose design and operational
requirements  to minimize leachate
generation (e.g.. caps and prohibition on
liquids in landfills)  and then to require
removal of the leachate  before liquids
can migrate into the environment.
Consistent with this control strategy, the
"disposal" closure option requires very  "
low permeability caps at closure  in
order to minimize post-closure

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   infiltration of liquid through the unit and
   the need for post-closure monitoring and
   corrective action.
     The second closure option, closure by
   removal, eliminates the potential for
   leachate production after closure by
   removing the source of contamination.
   The goal at closure is  to remove or
   decontaminate all materials on site that
   could potentially contribute to future
   contamination problems.
     While each  closure  option adopts a
   different strategy to achieve protection
   of human health and the environment.
   the goal of both closure as a disposal
   unit and closure by removal is to
   minimize or eliminate  potential threats
   to human health and the environment
   and the need for future corrective action
   at the site.
    The Agency  now has several years of
   experience in reviewing and approving
   closure plans under RCRA. Moreover,
  the Agency has gained considerable
  experience  in effecting remedial actions
  under the Comprehensive
  Environmental  Response Compensation
  and Liability Act (CERCLA)  that are in
  many ways analogous to RCRA
  closures. Based on this experience. EPA
  believes that in many circumstances a
  "hybrid" approach that combines the
  strategies of closure by removal and
  closure as a disposal unit may be
  equally or more effective than either the
  pure "disposal" or "removal" closure
  option. Rather than designing all caps to
  minimize infiltration and allowing the
  waste to remain in place, this "hybrid"
  approach would consist of the removal
  of the majority of contaminated
  materials and would allow covers and
 post-closure monitoring to be designed
 based on the exposure pathway of
 concern. For example, if the constituents
 remaining in the soil were highly
 immobile and would not migrate to the
 ground water, the cover could be
 designed to prevent direct contact and
 inhalation  of constituents (the pathways
 of concern), rather than  to minimize
 infiltration. This allows the method of
 closure to be tailored to  the specific
 circumstances under which the unit is
 being closed. It also creates~an incentive
 to remove waste from the unit rather
 than leaving waste in place and relying
 on control strategies such as capping to
 minimize migration of constituents.
   A  few examples may help to explain
 now closure requirements may be
 altered to suit the site-specific
 conditions of the unit undergoing
 closure. Generally, situations in which
 alternate closure requirements may be
 appropriate are when: (1) Substantial
 removal of waste and waste residues
will occur (but some minimal residual
contamination is  left in the unit); (2)
   residual contamination has low mobility
   and toxicity; (3) pathways of potential
   exposures to contaminants are limited:
   and (4) longrterm monitoring/care will
  *be provided;?The following examples
   should not be interpreted as scenarios
   that will in all cases qualify for the
   alternate closure requirements nor the
   only possible scenarios. However, these
   examples illustrate the point that site-
   specific conditions may in some cases
   call for site-specific closure
   requirements.
    The following is an example of a
   closing unit, located in an arid region
   where infiltration is very low and
   evapotranspiration significantly exceeds
   precipitation, for which site-specific
   requirements are appropriate. The unit
   contains residual levels of relatively
   immobile contaminants; conservative
  estimates of attenuation of residual
  contaminants in the unsaturated zone
  show that the waste constituents will
  never migrate to the ground water.
  which is 100 feet below  the unit. The
  owner or operator is able to show,
  based on waste and site conditions, that
  the residual wastes pose no surface
  water or atmospheric threat, and that
  direct contact with the waste is the only
  potential exposure pathway of concern.
  In this situation, a cover designed to
  prevent infiltration would be
  unnecessary, but a cover designed to
  protect against the direct contact threat
  would be required to fully protect
  human health and the environment at
  this site.
   Indeed, the Agency has already
 acknowledged through rulemaking that
 a unit existing in such an environment
 may warrant reduced requirements.
 Such a unit is eligible for an exemption
 under 5 264.90{b)(4) and § 284.221(b)
 from the ground-water monitoring
 requirements and single-liner
 requirements for surface impoundments
 if an owner or operator can demonstrate
 that no potential migration of liquid
 from the unit into ground water is
 possible during the active life and post-
 closure care period. The minimum
 technology requirements in the 1984
 amendments to the Solid Waste
 Disposal Act allow for a similar waiver
 in section 3004(o)(2) from the statutory
 requirements. A unit in a low
 precipitation, high evapotranspiration
 environment with a deep water table
 may well be able to make such a
 demonstration of no migration.
   Another situation that may warrant
 specific consideration is where an
owner or operator may have removed
all wastes and liner systems from a unit
but residual waste constituents still
remain in the unsaturated soil. If the
waste constituents in the unsaturated
   soil exceed Agency established health
   and environmental effect levels, then tl
   unit may not meet the closure by
   removal test in § § 264.228 and 265.228
   (See the discussion of the "remove or
   decontaminate" standard in the
   preamble to § 265.228 elsewhere in
   today's Federal Register). However.
   when these residual concentrations are
   sufficiently low, fate and transport
   calculations based on waste constituen'
   characteristics and site hydrogeologrc
   and locational conditions may show tha
   the waste residuals in the unsaturated
   soils will never produce ground-water
   contamination above an Agency
   established exposure level  (see
   discussion below for explanation of
   Agency-established exposure levels).
   Since in this example the ground water
  will remain potable, the cap design for
  the unit does not have to prevent
  infiltration. Furthermore, if the owner or
  operator can show that the waste
  residuals pose no atmospheric, surface
  water, direct contact, or ingestion threat
  then capping the unit may not be
  necessary to protect human health and
  the environment from the residual
  contamination. However, ground-water.
  vadose zone or soil monitoring is
  generally necessary to confirm or verify
  the fate and transport predictions.
   Today's proposal specifies a set of
  factors that the Regional Administrator
  (or State) must consider when
  establishing alternate closure
  requirements under 5§ 284.310(c) and
  285.310(c). The Agency expects to limit
  the use of the alternate closure option to
  situations where residual hazardous
 constituents are present in low
 concentrations, are of low toxicity. and
 have low mobilities, where migration of
 the  waste residuals to any medium is
 unlikely, and where long-term
 monitoring is guaranteed. The factors
 used in the Regional Administrator's
 analysis are designed to ensure that
 wastes and waste residues will not pose
 a threat to human health and the
 environment through any potential
 exposure pathway. These potential
 pathways include expos- -& to ths wszts
 constituents through direct contact,
 ground water, surface water,  and
 atmospheric routes. Basically, the
 following topics must be examined: (l)
 The  potential for the waste or waste
 constituents to migrate from the closing
 unit. (2) the toxicity of the waste or
 waste constituents that migrate from the
 unit, (3) the health and environmental
 effects associated with potential
 exposure to the waste or waste
constituents that migrate from the unit.
and (4) the uncertainty in each of the
above analyses.

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   8714
Federal  Register / Vol. 52.  Xo. 53  /  Thursday.  March 19. 1987 y  PronnAPH  Rules
     The factors the Regional
   Administrator would consider when
   establishing alternative closure
   requirements under §§ 264.310(c) and
   265.310(c) are similar in many ways to
   factors the Regional Administrator
   considers when setting alternate
   concentration limits (ACLs) under
   § 264.94. The basic  test of both of these
   alternate programs  is the same: The
   alternate requirements must protect
   human health and the environment. The
   factors related to ground-water and
   surface-water impacts are the same for
   the alternate closure requirements as for
   the setting of ACLs. The main difference
   between the two procedures is that in
   the proposed closure demonstration the
   Regional Administrator may take into
   account attenuation in the unsaturated
   zone and may require different types of
   monitoring. In addition, where ACLs
   address only ground-water
   contamination, the proposed closure
  analysis would also  address surface
  water and the potential exposure
  pathways of direct contact and
  atmospheric releases.
    The closure demonstration submitted
  by facility owners and operators should
  rely on Agency-recommended exposure
  limits that have undergone peer review
  by the Agency. These include water
  quality standards and criteria (Ambient
  Water Quality Criteria: 45 FR 79318,
  November 2& 1980.49 FR 5831. February
  15,1984: 50 FR 30784, July 29,1985).
  health-based limits based on verified
  reference doses (RfDs) developed by the
  Agency's Risk Assessment Forum
  (Verified Reference Doses of USEPA.
  EACO-CIN-475, January 1988) and
  Carcinogenic Potency Factors (CPF)
  developed by the Agency's Carcinogen
 Assessment Group (Table-11. Health
 Assessment Document for
 Tetrachloroethylene(Perchloroethylene)
 USEPA. OHEA/6008-82/005F. July 1985),
 or site-specific Agency-reviewed public
 health evaluations, issued by the
 Agency for Toxic Substance and
 Disease Registry of the Center for
 Disease Control. Department of Health
 and Human Services.
   The Agency is currently compiling-	
 toxicity information on many of the
 hazardous constituents contained in
 Appendix VIII of 40 CFR Part 261. The
 facility owners and operators should
 check with the Office of Solid Waste,
 Characterization and Assessment
 Division. Technical Assessment  Branch
 (202) 382-4781 for the latest toxicity
 information. If no Agency-recommended
 exposure limits exist for a hazardous
 constituent then the facility owner or
operator must either remove the
constituent down to background levels.
                        submit data of sufficient quality for the
                        Agency to determine the environmental
                        and health effects of the constituent, or
                        follow landfill closure and post-closure
                        requirements. All data submitted by the
                        owner or operator on environmental and
                        health effects of a constituent should.
                        when possible, follow the toxicity
                        testing guidelines of 40 CFR Parts 797
                        and 798 (50 FR 39252. September 27.
                        1985). The Agency does not believe
                        there are many situations where
                       exposure limits will be developed by
                       owners or operators, since  testing
                       required by 40 CFR Parts 797 and 798 to
                       produce reliable toxicity estimates is an
                       expensive  and time-consuming effort.
                         For purposes of fate and transport
                       modeling, it is necessary to identify
                       points of exposure. In calculations that
                       may be used to estimate the potential
                       impacts of releases of hazardous
                       constituents from closing units, points of
                       exposure would be assumed as below.
                       The points  of exposure were chosen
                       because the Agency believes that they
                       are realistic and conservative estimates
                       of where either environmental or human
                       receptors would likely be exposed to the
                       contaminants released from the unit.
                       Furthermore, the Agency feels that they
                       are conservative enough to be protective
                      of human health and the environment in
                      all situations that would be encountered
                      during the alternate closure scenario.
                      For closure  under the proposed alternate
                      requirements of §§ 284.310(c) and
                      265.310(c). the potential point of
                      exposure for analysis of the direct
                      contact and atmospheric routes is at or
                      within the unit boundary. The potential
                      point of exposure for surface water is at
                      the edge of the closest on-site surface
                      water runoff pathway (including ditches
                      and intermittent streams) or actual
                      surface water body that is affected by
                      the unit The potential point of exposure
                      for ground water is the first aquifer
                      found at the unit boundary. Generally
                      the ground-water protection standard
                      should be met in this first saturated zone
                      at the unit boundary, if a cap and long-
                      term management will be required. The
                     ground-water protection standard
                     should also be met at the first aquifer
                     directly beneath the unit if no cap or
                     long-term management will be required
                       The Agency is soliciting comments on
                     the concept of allowing the defined
                     points of exposure to be moved beyond
                     the unit boundary. For example in some
                     situations, effective measurement of
                     leakage may be better determined away
                     from the unit. In such case, it may be
                     equally protective to assume a point of
                     exposure away from the unit boundary.
                       Comments are requested on the
                     following points:
     (1) Under what conditions may the
   points of exposure be extended, and
     (2) What criteria must be met in
   specifying the extended points of
   exposure.
     If any adjustments are made to the
   points of exposure, then long-term
   monitoring will be necessary to verify
   that no unacceptable levels of
   contaminants are migrating to or past
   the points of exposure.
    The regulations require an owner or
   operator requesting approval of
   alternate site-specific closure
   requirements to submit site-specific
   supporting data. The data and data
   analysis submitted by the owner or
   operator must be of sufficient quality for
   the Regional Administrator to assess  the
  factors for each of the exposure
  pathways listed in §5 264.310(c) and
  265.310{c). In addition, the following
  information must be submitted by the
  owner or operator (1) A description of
  closure activities designed to meet the
  closure performance standard. (2) any
  data, models, and assumptions used to
  support fate and transport predictions,
  (3) design and operating plans of any
  proposed monitoring system used Ur
  verify fate and transport predictions,
  and (4) a plan which identifies   '
  subsequent contingency closure -;'
  activities that may be needed if the
  alternate requirements are not
  successful and shows how these closure
  activities will be conducted. The specific
  information requirements are codified at
  55 265.310(c)(2) and 270.21(e)(2).
   Any unit undergoing closure under the
 alternate requirements will need
 verification monitoring systems to
 confirm fate and transport predictions of
 hazardous constituents through any of
 the exposure pathways. Because of the
 uncertainties inherent in any form of
 modeling, the Agency plans to rely on
 monitoring to ensure that actual
 migration rates and concentrations of
 hazardous constituents are consistent
 with those projected as the basis of any
 alternate closure option. The verification
 moniioring may include, but is not
 limited to the following: (1) Leachate
 collection and analysis, (2) unsaturated
 zone monitoring, (3) air monitoring. (4)
 surface water runoff analysis, and (5)
 ground-water monitoring. For example.
 if the migration of hazardous
 constituents through the unsaturated
 zone is expected to be attenuated, then
 soil pore monitoring should be
 performed to verify this projection.
  The Agency is asking for comments
on whether to provide flexibility in
specifying ground-water well  locations
(point of exposure for the ground-water
pathway) for units that have

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                  Federal  Register / Vol.  52. Mo. 5,1
                                                                     March  19. 1087  / Proposed Rules
   institutional or physical obst.iclcs (e.g.
   linriod pipelines, natural geologic
   features) which prevent the installation
   of (hnvngraclient monitoring wells
   ilirectly ;it the unit boundary. Comments
   an: requested on the criteriii by which
   •nljustments can lie made to the
   placement of ground-water monitoring
   wells. The Agency believes that the
   distance the ground-water monitoring
   wells can be moved in order to avoid
   physical or institutional obstacles
   should be limited (perhaps to less than
   50 feet) so that early detection of
   leakage from  the unit could be detected.
    The verification monitoring program
   for ground water may vary from the
  ground-water monitoring programs in
   § § 264.97 and 264.100 in terms of well
  placement, sampling protocols, and
  duration (Note:  § 264.117 already grants
  the Regional Administrator authority to
  modify the length of time that ground-
  water monitoring must be performed
  based on site-specific factors). The
  program, however, must be sufficient to
  verify the accuracy of fate and transport
  predictions and  ensure that the alternate
  closure requirements are indeed meeting
  the closure performance standard. The
  Agency may, for example, require
  monitoring between the unit and the
  potential point of exposure to ensure
  that actual concentrations of
 constituents in air or water never
 exceed Agency approved levels or so
 that actual travel times of constituents
 can be compared with those predicted
 by the model. If observed constituent
 concentrations or migration rates differ
 from expected values, the Regional
 Administrator may invoke
 § 2S4.310(c)(3) or 5 265.310(c)(3) to
 require further model validation.
 additional closure activities or ground-
 water corrective  action to ensure
 compliance with  the requirements of
 §S 264.111 and 265.111.
   Alternate closure requirements will
 not be established under § 265.310(c) on
 the basis that adverse effects on human
 health and the environment will simply
 be delayed for some period of time.
 Thus, the owner or operator-would not
 be allowed to meet alternate closure
 requirements by arguing that a ground-
 water plume of contamination would not
 reach potential ground-water users (e.g..
 not migrate beyond the area of the unit
 or property boundary) for some period
 of time. The same concept applies for all
 the potential pathways for exposure:
 temporary prevention of adverse
 impacts is not grounds for alternate
 closure requirements under §§ 264.310(c)
and 265.310(c).
  The Agency believes that the
alternative proposed  in §§ 264.310(c)
   -ind 265.310(c) generally will not be
   applicable to landfill and surface
   impoundment units closing with
   sioraficant quantities of waste remaining
   ifrpia'ce. Under fhose circumstances, the
   possibility of a successful alternate
   closure is minimal since the potential for
   harm to human health and the
   environment posed by high
   concentrations of hazardous waste will
   be demonstrated by most valid fate and
   transport modeling processes. Likewise.
   facilities with units located in areas
   vulnerable to flooding and/or seismic
  activity will most  likely be unable to
  make successful demonstrations for
  alternate closure requirements.
    The Agency is soliciting comments on
  whether all wastes that were placed in
  the unit should be removed before an
  owner or operator can close under
  §§ 264.310{c) and 265.310(c). Could some
  wastes be allowed to remain in the unit
  if they are stabilized, have been treated.
  or if there are engineering controls (e.g.
  slurry walls)? Should geological
  characteristics, such as fractured
  bedrock or Karst topography be
  considered? In addition what location
  factors besides flooding and/or seismic
  activity should be assessed before
  allowing closure under the alternate
  approach?
   The Agency is also requesting
  comments on how ground-water use
 should be considered in alternate
 closure considerations. The Agency is
 proposing to consider ground-water use
 when deciding on exposure assumptions
 for alternative closures
 (§§ 264.310(c)(i)(G) and 265.310(c)(i)(G)).
 For this purpose, ground water that is
 potentially potable, e.g. has less than
 10.000 parts per million Total Dissolved
 Solids (TDS), will be considered to be a
 potential drinking water resource and
 drinking water exposure  to possible
 contaminants will be considered. If the
 ground water is nonpotable (greater
 than 10.000 parts per million TDS). then
 drinking water exposure is unlikely and
 ground-water concerns may be
 secondary to other environmental
 exposures (direct contact, surface water,
 or atmospheric exposures).
   The Agency is proposing to require
 closure approaches  under §§ 264.310(c)
 and 265.310(c) to meet specific
 performance standards. The general
 closure performance standards of
 §§ 264.111 and 265.111 require the  owner
 or operator to close  the facility in a
 manner that: (1) Minimizes the need for
 further maintenance, and (2) controls,
 minimizes or eliminates, (to the extent
 necessary to prevent threats to human
 health and the environment), post-
closure escape of hazardous waste,
   hazardous waste constituents, leachate.
   contaminated rainfall, or waste
   decomposition products to the ground or
   surface waters or to the atmosphere.
   Today's proposed regulation includes
   more specific performance requirements
   for closure under |§ 264.310(c) and
   265.310(c) to ensure that the site-specific
   closure requirements will be as effective
   in protecting human health and the
  environment as the final cover required
  by the closure option under
  §§ 264.310(b) and 265.310(b).
    The owner or operator should submit
  a request for permit modification for an
  alternate closure at least one year
  before the expected closure date. He
  must then  modify the closure and
  postclosure plan, filed with the permit
  application, to  conform to the alternate
  set of closure and post-closure
  requirements, established by the
  Regional Administrator.
    While the proposed rule allows an
  owner or operator to apply for approval
  of alternative closure one year before
  the expected closure date, the Agency is
  asking for comments on whether or not
  EPA should allow the owner or operator
  to request such a closure approach
  during the initial permit application
  stage. Because it may be difficult for an
  owner or operator to anticipate all of the
  waste and site factors that would be
  crucial in completing closure under the
 alternative approach, the Agency has
 chosen to require the approval of one of
 the two standard closure options (i.e.,
 landfill closure or "clean closure") to
 assure that the intended closure is
 protective and supported by adequate
 financial responsibility. A modified
 closure plan, incorporating alternative
 closure could be submitted for Agency
 approval at the end of the operating
 period of the unit, when more definite
 information on waste and site factors
 would be available to the unit's owner
 or operator. The Agency is requesting
 comments on approval of alternative
 closure during the permitting process or
 prior to one year before the expected
 closure date. Commenters should
 address the Agency's concerns with
 respect to the uncertainties regarding
 alternative closure.
   A final and very important area where
 the Agency seeks public comment is the
 issue of whether a unit should be
 allowed to close under the proposed
 alternative if hazardous constituents
 have already migrated to ground water
 above Agency approved levels. The
Agency is presently considering four
options for defining closure alternatives
for units with existing ground-water
contamination.

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 8716
Federal Register / Vol.  52, No. 53 / Thursday.  March 19. 1987  / Proposed Rules
   Option I: Units with ground-water
 contamination above Agency-approved levels
 would be considered ineligible for the
 alternate closure option and must instead
 close as a landfill.
   Option II: Units where levels of
 constituents in ground water are above
 Agency approved levels would be considered
 eligible to close under § 264.3iO(c) or
 § 2CS,310(c) only if owners or operators
 undertake ground-water remediation during
 the closure period in order to meet Agency-
 approyed levels.
   Option III: Units with ground-water
 contamination would be allowed to close
 under § 264.310(c) or { 265.310(c) without
 immediately addressing ground-water
 contamination originating from that unit, but
 the facility would not be allowed to certify
 final facility closure until all ground-water
 contamination had been addressed.
   Option IV: Units with ground-water
 contamination would be allowed to close
 under § 264.310(c) or J 265.310(c) but must
 conduct corrective action during the post-
 closure period.
   The following paragraphs discuss
 each of these options.

 Option I: No  Contamination
   The alternate closure option would
 only be available to units without
 ground-water contamination at the time
 of closure. Availability for the alternate
 closure under this option would be
 essentially the same as for "clean"
 closures under the existing regulations.
 However, in contrast to "clean" closures
 which require levels of constituents in
 the unsaturated zone to be below
 Agency-approved levels, Option I of the
 alternate closure rule would allow
 modeling through the unsaturated zone
 to show that levels of constituents
 unacceptable in the leachate would be
 attenuated to safe levels before reaching
 the ground water. As described
 elsewhere in  today's Federal Register,
 the current regulations normally force
 units with ground-water contamination
 into the landfill option because
 contaminated ground water and soils
 cannot be completely excavated during
 the limited time allowed for closure.
   A drawback to taking this approach is
 that there may be situations where__
 capping an old unit (i.e.. doting as a ~
 landfill) may  provide no incremental
 environmental benefit even though there
 is  an existing ground-water problem. For
 example, the  mobile and toxic fractions
 of a waste .may have already migrated
 away from the unit at the time of
closure, or the owner or operator may be
 able to remove a sufficient volume of
 waste so that he can demonstrate that
 the level of contamination remaining in
the soil will not contribute further to the
existing ground-water problem. In such
situations, the installation of an
impervious cap may serve no useful
                        purpose in preventing further ground-
                        water degradation and will not help
                        clean up the existing problem. In fact, a
                        cap may complicate or prohibit certain
                        corrective actions by adding additional
                        material that must be excavated or by
                        interfering with a pump and treatment
                        program that relies on "flushing"
                        contaminants through the aquifer.
                        Recognizing this, the Agency is also
                        considering options II. Ill and IV below.
                        Option II: Clean up Ground Water To
                        Meet Ground-Water Protection
                        Standard
                          Under this option, units with ground-
                        water contamination would have to
                        meet Agency-approved health-based
                        levels in the ground water before
                        certifying closure under the alternate
                        closure option [§§ 264.310(c) or
                        265.310(cj]. However, owners or
                        operators would be allowed to
                        undertake corrective action as a closure
                        activity in order to  meet the ground-
                        water protection standard of § 264.92 in
                        the ground water.
                          To make this option available, the
                        Agency would have to amend Subpart G
                        §§ 264.113(b) and 265.113(c) to authorize
                        the Regional Administrator to extend
                        the closure period in certain limited
                        circumstances, including the need to
                        incorporate long-term corrective action
                        into the closure process. The drawback
                        of this approach is that if corrective
                        action were incorporated into the
                        closure process, final closure
                        certifications would be delayed
                        (possibly for many years) because
                        owners or operators would not be
                        allowed to certify unit closure until any
                        contamination emanating from that unit
                        had been cleaned up. The benefit of this
                        approach is assurance that ground-
                        water problems are addressed without
                        imposing costly requirements (such as
                        impervious caps) in situations where
                        they arguably provide no environmental
                        benefit and may, in fact, impede
                        corrective action.
                        Option III: Facility Closure Contingent
                        on Ground-Water Clean-up.
                          In option III units with existing
                        ground-water contamination would be
                        allowed to close under the alternate
                        closure option without necessarily
                        addressing the plume originating from
                        that unit, but final facility closure would
                        be dependent on addressing all ground-
                        water problems at that site. In effect
                        this option would disassociate an owner
                        or operator's responsibility to address
                        soil contamination at a particular unit
                        from his obligation to clean up ground
                        water at his facility. Capping decisions
                        for individual units  would be based on
                        direct contact and inhalation concerns
 and the need to prevent additional
 contamination of ground water. If
 existing ground-water contamination
 warrants immediate attention.
 corrective action could be compelled
 through a section 3008(h) order, a post-
 closure permit, or appropriate State
 Authority. If. however, the
 contamination from the closing unit
 commingles with ground-watei
 contamination from other units (and the
 plume is not posing an immediate
 threat), it may make more sense to
 address the ground-water problem as a
 whole rather than trying to address the
 individual contribution from each unit
 through separate actions. As with the
 landfill option, the owner or operator
 closing a unit under $ 264.310(c) and
 § 265.310(c) would know that although
 the unit has been closed, they still have
 outstanding corrective action
 requirements. The owner or operator
 would remain subject to a facility-wide
 responsibility for future ground-water
 clean-up, not just responsibility for
 addressing the contribution from  the
 individual closing unit

 Option IV: Clean up Ground Water  '
 During the Post-Closure Care Period.

  This option would allow a unit to be
 closed under § 264.310(c) or § 265.310(c),
 although ground-water contamination
 was evident at the time of certification
 of closure. The owner or operator of the
 closed unit would be responsible for
 performing corrective action during the
 post-closure period to meet the ground-
 water protection standard of § 264.92.
 The post-closure permit would include
 provisions for performing corrective
 action, including indentification of
 remedial methods, chemical
 constituents, target concentrations
 levels and ground-water monitoring. The
 owner or operator would continue to be
 responsible for meeting the
 requirements of § 264.117 or § 265.117.
 The advantage of the option would be to
 allow completion of all other closure
 activities (e.g., installation of a cover
 system), to begin all other post-closure-
 care activities (e.g., monitoring an_
 maintaining the leachate collection, leak
 detection, and cover system), and
 complete all corrective action, which
 may involve a much longer period of
 time than was envisioned for routine
 closure activities. The rule as proposed
 today does not reflect any of the four
 options. Based on public comment, the
 Agency will select an approach and
 make modifications to the rule as
 proposed to make clear the Agency's
position on how existing ground-water
contamination will affect the specific
closure options.

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   A. Applicability of Ruins in Authorized
   States

    Under section 3006 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, the Agency
   retains enforcement authority under
   snctions 3008, 7003 and 3013 of RCRA,
   although authorized States have primary
   enforcement responsibility.
    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 authorized 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. 6926(g). new
  requirements and prohibitions imposed
  by the HSWA 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
 applies in authorized States in the
 interim.

 B. Effect on State Authorizations'
   Today's rule proposes standards that
 would not be effective in authorized
 States since the requirements would not
 be imposed pursuant to the Hazardous
 and Solid Waste Amendments^ 1984.
 Thus, the requirements will be
 applicable only in those States that do
 not have interim or final authorization.
 In authorized States, the requirements
 will not be applicable until the States
 revises its program to adopt equivalent
 requirements under State law.
   40 CFR 271.21(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. [For proposals: The deadline
by which the 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 § 271.21 (e). (Note to
   regulation writefvSee attached chart to
   determine the appropriate date)]. These
   deadlines can be extended in certain
   cases (40 CFR 271.21(e)(3)j. Once EPA
   approves the modification, the State
   requirements become Subtitle C RCRA
   requirements.
    States with authorized RCRA
   programs may already have
   requirements 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 carry out these
  requirements in lieu of EPA until the
  State program modification is submitted
  to EPA and approved. Of course. States
  with existing standards may continue to
  administer and enforce their standards
  as a matter of State law.
   States that submit their official
  application for final authorization less
  than 12 months after the effective date
  of these standards are not required to
  include standards equivalent to these
  standards in their application. However,
  the State must modify its program by the
  deadlines set forth in § 271.21(e). States
  that  submit official applications for final
 authorization 12 months after the
 effective date of those standards must
 include standards equivalent to these
 standards in their application. 40 CFR
 271.3 sets forth the requirements a State
 must meet when submitting its final
 authorization application.
 V. Regulatory Impact

   Under Executive Order 12291. the
 Agency must determine whether a
 regulation is "major" and. therefore,
 subject to the requirement of a
 Regulatory Impact Analysis. The
 Agency does not believe that these
 changes will result in an annual effect
 on the economy of $100 million or more;
 a major increase in costs or prices for
 consumers, individual industries,
 Federal, State, or local government
 agencies, or geographic regions: or
 significant adverse effects on
 competition, employment, investment,
 productivity, innovation, or in domestic
 or export markets. In addition, the
 proposed changes allow another closure
 option which, in many cases, will be less
 expensive to implement than the
existing standard. Therefore, the Agency
 believes that today's rule is not a major
rule under Executive Order 12291.
  This regulation was submitted to the
Office of Management and Budget for
   review as required by-Executive Order
   12291.

   VI. Regulatory Flexibility Act

     Under the Regulatory Flexibility Act
   (5 U.S.C. 601, et seq.), the Agency must
   prepare a regulatory flexibility analysis
   for all regulations that may have a
   significant impact on a substantial
   number of small entities. The Agency
   conducted such an analysis on the land
   disposal regulations and published a
 -  summary of the results in the Federal
   Register, Vol. 48, No. 15, on January 21.
   1983. The additional burdens imposed
   by this regulation are not significant. In
   fact, this regulation will likely reduce
   economic burden by allowing for
  another  closure option.

  VII. Paperwork Reduction Act

    The information collection
  requirements in this proposed rule have
  been submitted for approval to the
  Office of Management and Budget
  (OMB) under the Paperwork Reduction
  Act of 1980,44 U.S.C. 3501 et seq.
  Submit comments on these requirements
  to the Office of Information and
  Regulatory Affairs, Officeiof
  Management and Budget (OMB), 726
  Jackson Place. NW., Washington, DC
  20503. marked "Attention: Desk Officer
  for EPA". The final rule will respond to
  any OMB or public comments on the
  information collection requirements.
  List of Subjects

 40 CFR Part 264

   Hazardous waste, Insurance.
 Packaging and containers. Reporting
 and recordkeeping requirements.
 Security measures. Surety bonds.
 4O CFR Part 265

   Hazardous waste. Insurance,
 Packaging and containers. Reporting
 and recordkeeping requirements,
 Security measures, Surety bonds. Water
 supply.

 40 CFR Part 270

   Administrative practice and
 procedure. Confidential business
 information. Hazardous materials-
 transportation. Hazardous waste.
 Reporting and recordkeeping
 requirements. Water pollution control.
 Water supply.
  Dated: March 8,1987.
 Lee M. Thonus,
Administrator.
  Therefore, it is proposed that 40 CFR
Chapter I be amended as follows:

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  8718
Federal  Register / Vol. 52. No.  53 / Thursday. March 19.  1987 / Proposed  Rules
  PART 264— STANDARDS FOR
  OWNERS AND OPERATORS OF
  HAZARDOUS WASTE TREATMENT,
  STORAGE, AND DISPOSAL
  FACILITIES

    1. The authority citation for Part 264
  continues to read as follows:

   Authority: Sees. 1008. 2002(a). 3004. and
  JIX15 of the Solid Waste Disposal Act. as
  .imondud by the Resource Conservation and
  Rpcovnry Act, as amended (42 U.S.C. 690S.
  09I2(a). 6924. and 6925).

   2. In § 264.90 by adding paragraph
 §2*4.90  AppWcabHtty.
 *    *    *    *    *
   (e) • ' '
   (4) May be modified or replaced by an
 alternate monitoring program.
 incorporated in an approved closure
 plan, designed to verify the adequacy of
 a closure undertaken pursuant to
 § 254.310{c).
   3. In § 264.228 by removing paragraph
 (b) and redesignating paragraph (c) as
 paragraph (b) and revising paragraph
 (a) (2) to read as follows:

 §264.220  Closure and poct-dowrt cart.
   (a) ' ' •
   (2)(i) Eliminate free liquids by
 removing liquid wastes and solidifying
 the remaining wastes and waste
 residues;
   (ii) Stabilize remaining waste to a
 bearing capacity sufficient to support
 final coven and
   (iii) Comply with the requirements of
 § 264.310.
   4. In § 264.310 by revising it to read as
 follows:

 §264.310  Closure and poct-dosur* cam.
   (a) At final closure of the landfill and
 upon closure of any cell, the owner or
 operator must perform closure and
 postclosure care in accordance with the
 requirements of either paragraph (b) or
 (c) of this section.
  (b)(l) The owner or operator must
 cover the landfill or cell with a final
 cover designed and constructed to: _____
  (i) Provide long-term minimization of
 migration of liquids through the closed
 landfill:
  (ii) Function with minimum
 maintenar.ee:
  (iii) Prornote drainage and minimize
 erosion or abrasion of the coven
  (iv) Accommodate settling and
 subsidence so that the cover's integrity
 is maintained: and
  (v) Have a permeability less than or
 equal to the permeability of any bottom
liner system or natural subsoils present.
  (2) After final closure, the owner or
operator must comply with all post-
                        closure requirements contained in
                        §§ 264.117 through 264.120, including
                        maintenance and monitoring throughout
                        the post-closure care period (specified in
                        the permit under § 264.117). The owner
                        or operator must:
                          (i) Maintain the integrity and
                        effectiveness of the final cover.
                        including making repairs to the cap as
                        necessary to correct the effects of
                        settling, subsidence, erosion, or other
                        events.
                          (ii) Continue to operate the leachate
                        collection and removal system until
                        leachate is no longer detected;
                          (iii) Maintain and monitor the ground-
                        water monitoring system and comply
                        with all other applicable requirements of
                        Subpart F of this part;
                          (iv) Prevent run-on and run-off from
                        eroding and otherwise damaging the
                        final coven and
                          (v) Protect and maintain surveyed
                        benchmarks used in complying with
                        S 264.309. or
                          (c) The owner or operator must
                        comply with an alternate set of closure
                        and post-closure requirements that are
                        established by the Regional
                        Administrator by modifying the permit
                        at the time of closure and that are
                        specific to the unit being closed.
                         The Regional Administrator shall
                       authorize alternate requirements under
                       this paragraph only if he or she finds.
                       based upon consideration of the factors
                       set forth in paragraph (c)(l) of this
                       section and the data submitted by the
                       owner or operator under paragraph(c)(2)
                       of this section, that the requirements
                       will assure the achievement of the
                       closure performance standard in
                       9 264.111 and will be at least as effective
                       in protecting human health and the
                       environment as the final cover required
                       under paragraph (b) of this section.
                       These requirements shall include, an
                       appropriate closure/post-closure
                       verification monitoring program for
                       exposure pathways of concern at the
                       site. This monitoring program must be
                       sufficient to verify the accuracy of any
                       fate and transport calculations used in
                       the design of the closure system being
                       proposed.
                        (1) In determining whether to
                       authorize alternate closure requirements
                       under this paragraph the Regional
                       Administrator will consider the
                       following factors:
                        (i) Potential adverse effects on
                       ground-water quality, considering:
                        (A) The physical and chemical
                       characteristics of the waste in the unit(s)
                       to be closed, including its toxicity and
                       bioaccumulation potential and its
                       mobility and persistence.
    (B) The hydrogeological
  characteristics of the facility and
  surrounding land:
    (C) The characteristics of the
  unsaturated zone that may affect the
  fate and transport of waste constituents
  from the unit(s) to be closed:
    (D) The direction and rate of ground-
  water flow:
    (E) The proximity and withdrawal
  rates of ground-water users:
    (F) The current and future uses of
 ground water in the area:
    (G) The existing quality of ground
 water, including other sources of
 contamination and their cumulative
 impact on the ground-water quality;
   (H) The potential for health risks
 caused by human exposure to waste
 constituents;
   (I) The potential damage to wildlife,
 crops, vegetation, and physical
 structures caused by exposure to waste
 constituents;
   (I) The persistence and permanence of
 the potential adverse effects: and
   (ii) Potential adverse effects on
 surface water quality, considering:
   (A) The physical and chemical   -
 characteristics of the waste and waste
 constituents in the unit(s) to be doted;
 including its toxicity and        ;
 bioaccumulation potential and its
 mobility and persistence.
   (B) The topographic characteristics of
 the facility and surrounding land
 including run-off and run-on patterns;
   (C) The quality of ground-water and
 the direction of ground-water flow;
   (D) The patterns of precipitation and
 evapotranspiration of the region:
   (E) The proximity of the unit(s) to be
 closed to surface waters;
   (F) The current and future uses of
 surface waters in the area and any
 water quality standards established for
 those surface waters;
   (G) The existing quality of surface
 water, including other sources of
 contamination and the cumulative
 impact on surface water quality;
  (H) The potential for health risks
 caused by human exposure to waste
 constituents;
  (I) The potential damage to wildlife.
 crops, vegetation, and physical
 structures caused by exposure to waste
 constituents; and
  (}) The persistence and permanence of
 the potential adverse effects, and
  (iii) Potential adverse effects caused
 by direct contact to the waste and waste
constituents considering:
  (A) The physical and chemical
characteristics of the waste and waste
constituents in the unit(s) to be closed:
including its toxicity and

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   bioaccumulation potential and its
   mobility and persistence.
     (B) The current and future uses of the
   area;
     (C) The potential for human exposure
   to waste constituents:
     (D) The potential for health risks
   caused by exposure to waste
   constituents;
    {E) The potential damage to wildlife.
   crop vegetation, and physical structures
   caused by exposure to waste
   constituents;
    (F) The persistence and permanence
   of the potential adverse effects: and
    (iv) Potential adverse effects caused
   by release to the atmosphere of waste or
   waste constituents considering:
    (A) The physical and chemical
  characteristics of the waste and waste
  constituents in the unit(s) to be closed:
  including its toxicity and
  bioaccumulation potential and its
  mobility and persistence.
    (B) The current and future uses of the
  area:
    (C) The potential for human exposure
  to waste constituents;
    (D) The potential for health risks
  caused by exposure to waste
  constituents;
    (E) The potential damage to wildlife.
  crop vegetation, and physical structures
  caused by exposure to waste
  constituents;
   (F) The persistence and permanencsr^-
  of the potential adverse effects.
   (v) The engineered characteristics of
  the unit(s) to be closed that affect
 ground-water, surface water, direct
 contact, or atmospheric exposure
 pathways.
   (2) An owner or operator submitting
 closure and post-closure plans to
 conduct closure and post-closure care
 under this paragraph must submit data
 that is of sufficient quality for the
 Regional Administrator to assess the
 factors listed in subparagraph (1) of this
 paragraph. At a minimum, the
 information required by § 270.21(e)(2)
 must be submitted to the Regional
 Administrator.
   (3) If. at any time during the post-
 closure care period, the Regional
 Administrator determines that any of
 the assumptions underlying fate and
 transport calculations used to justify the
 closure systems are incorrect or that the
 alternate requirements have not ensured
 compliance with § 284.111. the Regional
 Administrator may impose such
 additional requirements, including those
 set forth in paragraph (b) of this section.
as may be necessary to ensure
compliance with $ 264.111.
   PART 265—INTERIM STATUS
   STANDARDS FOR OWNERS AND
   OPERATORS OF HAZARDOUS WASTE
   TREATMENT, STORAGE, AND
   DISPOSAL FACILITIES

     5. The authc-rity citation for Part 265
   continues to read as follows;
    Authority: Sees. 1006. 2002(aJ. 3004. 3005.
   and 3015. Solid Waste Disposal Act. as
   amended by the Resource Conservation and
   Recovery Act a* amended (42 U.S.C. 6905.
   6912(a). 6924. 6925. and 6935).

    6.  in 9 265.90 by adding paragraph
  §265.9O  Applicability.
  *****
    (c) * * *
    (3) May be modified or replaced by an
  alternate ground-water monitoring
  program, incorporated in an approved
  closure plan, designed to verify the
  adequacy of a closure undertaken
  pursuant to § 265.310(c).
  *****          •    '
    7. In J 26S.228 by removing paragraph
  (b) and designating paragraph (c) as
  paragraph (b) and revising paragraph*
  (a)(2) to read as follows:

           Closure and poet-closure.
          '               •*»* 5 **
    (2)(i) Eliminate free liquids by
 receiving liquids wastes or solidifying
 the remaining wastes and waste
, residues;
-   fiiJSfisbilize remaining waste to a  * ss
 bearing capacity sufficient to support
 final coven and
   (iiij comply with requirements of
 § 265.310.
 •    *    •     •     *
   8. In 1285.310 by revising it to read as
 follows:

 §265.310 Closure and oost-ctoeure care.
   (a) At final closure of the landfill or
 upon closure of any cell, the owner or
 operator must perform closure and post-
closure care in accordance with the
requirements or either paragraphs (b) or
(c) of this section.
   (b)(l) The owner or operator must
cover the landfill or cell with a final
cover designed and constructed to:
   (i) Provide long-term minimization of
migration of liquids through the closed
landfill;
  (ii) Function with minimum
maintenance:
  (iii) Promote drainage and minimize
erosion or abrasion of the cover.
  (iv) Accommodate settling and
subsidence so that the cover's integrity
is maintained: and
  (v) Have a permeability less than or
equal to the permeability of any bottom
liner system or natural subsoils present.
     (2) After final closure, the owner or
   operator must comply with all post-
   closure requirements contained in
   §§ 265.117 through 265.120. including
   maintenance and monitoring throughout
   the post-closure care period. The owner
   or operator must:
     (i) Maintain the integrity and
   effectiveness of the final cover.
   including making repairs to the cap as
   necessary to correct the effects of
   settling, subsidence, erosion, or other
   events.
     (ii) Maintain and monitor the ground-
   water monitoring system and comply
   with ail other applicable requirements of
•   Subpart F of this part;
    (iii) Prevent run-on and run-off from
   eroding or otherwise damaging the final
   coven and
    (iv) Protect and maintain surveyed
  benchmarks used in complying with
   § 265.309. or
    (c) The owner or operator must
  comply with an alternate set of closure
  and post-closure requirements  that are
  established by the Regional
  Administrator at the time of closure and
  that are specific to the unit being closed.
  The Regional Administrator shall
  authorize alternate requirements under
  this paragraph only if he,pr  she finds.
  based upon considerations of factors set
  forth in paragraph (c)(l) of this  section
  and the data submitted by the owner or
  operator under paragraph (c)(2) of this
 '8e«tioa>tfeatth» requirements will
  assure the achievement of the closure
  performance standard in 5 265.111 and
  will beat least as effective in protecting
  human health and the environment as
  the final cover required under paragraph
 (b) of this section. These requirements
 shall include, an appropriate closure/
 postclosure verification monitoring
 program for exposure pathways of
 concern at the site. This monitoring
 program must be sufficient to verify the
 accuracy of any fate and transport
 calculations used in the design of the
 closure system being proposed.
   (1) In determining whether to
 authorize alternate closure requirements
 under this paragraph the Regional
 Administrator will consider the
 following factors:
   (i) Potential adverse effects on
ground-water quality, considering:
   (A) The physical and chemical
characteristics of the waste in the unit(s)
to be closed, including its toxicity and
bioaccumulation potential and its
mobility and persistence.
   (B) The hydrogeological
characteristics of the facility and
surrounding land:
  (C) The characteristics of the
unsaturated zone that may affect the

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  87T.O
Federal  Register / Vol. 52. \o.  53 / Thursday.  March. 19. 1987  /  Proposed Rules
  fate and transport of waste constituents
  from (he unit(s) to be closed.
    (D) The direction and rate of ground-
  water flow:
    (PC) The proximity and withdrawal
  rates of ground-water users:
    (F) The current and future uses of
  ground water in the area;
    (G) The existing quality of ground
  water, including other sources of
  contamination and their cumulative •
  imp.ict on the ground-water quality:
    (II) The potential for health risks
  (•dused by human exposure to waste
  constituents;
    (I) The potential damage to wildlife.
  crops, vegetation, and physical
  structures caused by exposure to waste
  constituents:
    (J) The persistence and permanence of
  the potential adverse effects: and
    (ii) Potential adverse effects on
  surface water quality, considering:
    (A) The physical and chemical
  characteristics of the waste and waste
  constituents in the unit(s) to be closed:
  including its toxicity and
  bioaccumulation potential and its
  mobility and persistence.
   (B) The topographic characteristics of
  the facility and surrounding land.
  including runoff and runon patterns;  •
   (C) The quality of ground-water and
 the direction of ground-water flow;
   (D) The patterns of precipitation and
 evapotranspiration of the region:
   (E) The proximity of the unit(s) to be
 closed to surface waters;
   (F) The current and future uses of
 surface waters in the area and any
 u uter quality standards established for
 those surface waters;
   (G) The existing quality of surface
 water, including other sources of
 contamination  and the cumulative
 impact on surface water quality:
  (H) The potential for health risks
 caused by human exposure to waste
 constituents;
  (I) The potential damage to wildlife.
 crops, vegetation, and physical
 structures caused by exposure to waste
 constituents: and
  (J) The persistence and permanence of
 the potential adverse effects, and
  (iii) Potential adverse effects caused
 by direct contact to the waste and waste
 constituents considering:
  (A) The physical and chemical
 characteristics  of the waste and waste
 constituents in  the unit(s) to be closed:
 including its toxicity and
 bioaccumulation potential and its
 mobility and persistence.
  (B)  The current and future uses of the
area:
  (C)  The potential for human exposure
to wnste constituents:
                          (D) The potential for health risks
                        caused by exposure to waste
                        constituents;
                          (E) The potential damage to wildlife.
                        crop vegetation, and physical  structures
                        caused by exposure to waste
                        constituents;
                          (F) The persistence and permanence
                        of the potential adverse effects: and
                          (iv) Potential adverse effects caused
                        by release to the atmosphere of waste or
                        waste constituents considering:
                          (A) The physical and chemical
                        characteristics of the waste and waste
                        constituents in the unit(s) to be closed:
                        including its toxicity and
                        bioaccumulation potential and its
                        mobility and persistence.
                          (B) The current and future uses of the
                        area;
                          (C) The potential for human exposure
                        to waste constituents;
                          (D) The potential for health risks
                        caused by exposure to waste
                        constituents;
                          (E) The potential damage to wildlife.
                        crop vegetation, and physical structures
                        caused by exposure to waste
                        constituents.
                         (F) The persistence and permanence
                       of the potential adverse effects.
                         (v) The engineered characteristics of
                       the unit(s) to be closed that affect
                       ground water, surface water, direct
                       contact, or atmospheric exposure
                       pathways.
                         (2) An owner or operator submitting
                       closure and post-closure plans to
                       conduct closure and post-closure care
                       under this paragraph must submit data
                       that is of sufficient quality for the
                       Regional Administrator to assess the
                       factors listed in paragraph (c)(l) of this
                       section. At a minimum, the following
                       information must be submitted to the
                       Regional Administrator:
                         (i) A description of all closure
                       activities proposed to meet the closure
                       performance standard of § 265.111
                       including:
                         (A) Detailed design and construction
                       plans for any proposed cover;
                         (B) Methods for any proposed
                       removal, treatment, or immobilization of
                       waste, waste residues, surrounding and
                       underlying contaminated soil and/or
                       ground water necessary to meet the
                       closure performance standard in
                       § 265.111;
                        (C) Sampling methods to verify the
                       levels of constituents remaining in
                       waste residue, soil, and/or ground water
                       after any proposed removal and a
                       schedule for submitting these data to the
                       Administrator and
                        (0) Design plans for any proposed
                       engineered barriers.
                        (ii)  A proposed modeling approach,
                       where required, for predicting the fate
  and concentration of hazardous
  constituents or waste degradation
  products at the point(s) of exposure. The
  model(s) used must be appropriate for
  simulating the environmental conditions
  at the site. Data and documentation to
  support any fate and transport
  predictions must include but not be
  limited to:
   (A) The physical and chemical
  characteristics of the waste or waste
  residue including the maximum
  concentration and characteristics of
  each Appendix VIII constituent that
  could reasonably be derived from the
  original waste(s) placed in the unit(s):
   (B) The concentration of Appendix
  VIII constituents that could be expected
  in leachate produced by the remaining
  waste, waste residue, and/or
 contaminated soil;
   {C} Estimated quantity of waste
 residue and contaminated soil expected
 to remain on site;
   (D) Hydrogeologic properties of the
 saturated and unsaturated zone that
 may affect the fate and transport of
 hazardous constituents;
   (E) A method and justification foe any
 proposed grouping of constituents for
 the purpose of fate and transport
 analysis;                    »
   (F) An evaluation of the performance
 of any engineered components of the
 unit or any proposed closure activities
 and an explanation of how these control
 strategies figure into fate and transport
 predictions;
   (G) The capabilities, assumptions, and
 limitations of any proposed model(s)
 including rationales for selected input
 criteria, methods and QA/QC for
 obtaining necessary data, and a
 comparison  of the model's assumptions
 to actual site characteristics; and
  (H) The concentration in ground water
 of all Appendix VIII constituents that
 could reasonably be derived from the
 waste.
  (iii) Design and operatinq plans for a
 proposed monitoring system to verify
 the accuracy of any fate and transport
 predictions,  including:
  (A) A proposed period of operation:
 and
  (B) Levels in each medium of concern
 that will prompt notifications of the
 Regional Administrator.
  (iv) A topographic map showing a
 distance of 1000 feet around the facility
at scale of 2.5 centimeters (1 inch) equal
 to not more than 61.0 meters (200 feet).
Contours must be shown on the map.
The contour interval must be sufficient
 to clearly show the pattern of surface
 water flow in the vicinity of and from
each operational unit of the facility (for
example, contours with an interval of 1.5

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                   Federal  Register / Vol. 52. No.  53 / Thursday,  March 19.
   meters (5 feet), if relief is greater than
   6.1 meters (20 feet), or an interval of 0.6
   meters (2 feet), if relief is less than 6.1
   meters (20 feet)). Owners and operators
   of HWM facilities located in
   mountainous areas should use large
   contour intervals to adequately show
   topographic profiles of facilities. The
   map shall clearly show the following:
     (A) Map scale and date;
     (B) 100-year floodplain area:
     (C) Surface waters including
   intermittent streams:
     (D) Surrounding land uses (residential.
   commercial, agricultural, recreational);
     (E) A wind rose (i.e.. prevailing
   windspeed and direction);
     (F) Orientation of the map (north
   arrow);
     (G) Legal boundaries of the HWM
   facility site;
     (H) Access control (fences, gates);
    (I) Injection and withdrawal wells
  both on-site and off-site:
    (J) Buildings: treatment, storage, or
  disposal operations: or other structure
  (recreation areas, runoff control
  systems, access and internal roads,
  storm, sanitary,  and process sewerage
  systems, loading and unloading areas,
  fire control facilities, etc.):
   (K) Barriers for drainage or flood
  control;
   (L) Location of operational and closed
  units within the HWM facility site.
  where hazardous waste is or was
  treated, stored, or disposed (include
  equipment cleanup areas); and
   (M) Location of faults and other
  geologic seismic  zones.
   (3) If, at any time during the post-
 closure care period, the Regional
 Administrator determines that any of
 the  assumptions  underlying fate and
 transport calculations used to justify the
 closure systems are incorrect or the
 alternate requirements have not ensured
 compliance with  § 265.111, the Reqional
 Administrator may impose such
 additional requirements including those
 set forth in paragraph (b) of this section
 as may be necessary to ensure
 compliance with  § 285.111.

 PART 270-EPA-ADMINISTERED
 PERMIT PROGRAMS: THE
 HAZARDOUS WASTE PERMIT
 PROGRAM

   9.  The authority citation for Part 270 is
 revised to read as follows:
  Authority: Sees. 1006, 2002, 300*. 3005.3007
 3019. and 7004. Solid Waste Disposal Act as
amended by the Resource Conservation and
Recovery Act of 1976. as amended {42 U.S.C
8905.6912.6924. 6925. 6927. 6939. and 6974).
  10. § 270.17 is amended by revising
paragraph (g) to read as follows:
   § 270.17  Specific Part 8 information
   requirements for surface impoundments.
   •   _..    .    .     ,

     (g);A description of how hazardous
   was,te residues a.nd contaminated
   materials willibe removed from the unit
   at closure, aslrequired under
   § 264,228(a)(l). For any wastes not to be
   removed from the  unit upon closure, the
   owner or operator must submit detailed
   plans and an engineering report
   describing compliance with § 264.310(b).
   This information should be included in
   the closure plan and, where applicable.
   the post-closure plan submitted under
   § 270.14(b)(13). The owner or operator
   may apply at the time of closure for
   alternate closure'requirements under
   § 264.310(c) by requesting a permit
  modification and submitting the
  information required in § 270.21(e)(2).
  *    •    «    «     <
    11. 5 270.18 is amended by revising
  paragraph (h) to read as follows:

  §270.18  Specific Pert B Information
  requirements for waste piles.
  *    •    *     •    »
    (h) A description of how  hazardous
  waste residues and contaminated
  materials will be removed from the
  waste pile at closure, as required under
  § 264.258(a). For any waste not to be
  removed from the waste pile upon
  closure, the owner or operator must
  submit detailed plans and an
  engineering report describing
  compliance with § 264.310(b). This
  information should be included in the
  closure plan and, where applicable, the
  post-closure plan submitted under
  § 270.14(b)(13). The owner or operator
 may apply at the time of closure for
 alternate closure requirements under
 S 264.310(c) by requesting a  permit
 modification and submitting the
 information required in § 270.21(e)(2).
   12. In § 270.21 by revising  paragraph
 (e) to read as follows:

 9270.21  Specific Part B Information
 requirements for landfills.
 •   *     *    »     .
   (e)(l) Detailed plans and an
 engineering report describing the final
 cover which will be applied to each
 landfill or landfill cell at closure in
 accordance with S 264.310(b)(l), and a
 description of how each landfill will be
 maintained and monitored after closure
 in accordance with § 264.310(fa)(2). This
 information should be included in the
closure and post-closure plans
submitted under § 270.14(b)(13).
  (2) For owners and operators
requesting permit modifications at the
time of closure to perform closure and
post-closure care under §  264.310{c).  the
following additional information:
  1987 / Proposed  Rules
      ^^^"^^^^^"*M"^^

      (i) A description of all closure
   activities proposed to'meet the closure
   performance standard of § 264.111
   including:
     (A) Detailed design and construction
   plans for any proposed cover:
     (B) Methods for any proposed
   removal, treatment, or immobilization of
   waste, waste residues, surrounding and
   underlying contaminated soil and/or
   ground water necessar/ to meet the
   closure performance standard in
   § 264.111;
    (C) Sampling methods to verify the
   levels of constituents remaining in
   waste residue, soil, and/or ground-water
   after any proposed removal and a
   schedule for submitting these data to the
   Administrator; and
    (D) Design plans for any proposed
  engineered barriers.
    (ii) A proposed modeling approach for
  predicting the fate and concentration of
  hazardous constituents or waste
  degradation products at the point(s) of
  exposure. The model(s) used must be
  appropriate for simulating the
  environmental conditions at the site.
  Data and documentation to support any
  fate and transport predictions must
  include but not be limitedto:
   (A) The physical and chemical
  characteristics of the waste or waste
  residue including the maximum
  Concentration and characteristics of
  each Appendix VIII constituent that
  could reasonably be derived  from the
  original waste(s) placed in the unit(s):
   (B) The  concentration of Appendix
  VIII constituents that could be expected
  in leachate produced by the remaining
  waste, waste residue, and/or
 contaminated soil;
   (C) Estimated quantity of waste
 residue and contaminated soil expected
 to remain on site;
   (D) Hydrogeologic properties of the
 saturated and unsaturated zone that
 may affect the fate and transport of
 hazardous constituents:
   (E) A method and justification for any
 proposed grouping of constituents for
 the purpose of fate and transport
 analysis:
   (F)  An evaluation of the performance
 of any engineered components of the
 unit or any proposed closure activities
 and an explanation of how these control
 strategies figure into fate and transport
 predictions:
  (G) The capabilities, assumptions, and
 limitations  of any proposed model(s)
 including rationales for selected input
criteria, methods and QA/QC  for
obtaining necessary data, and a
comparison of the model's assumptions
to actual site characteristics: and

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8722
Federal Register  /  Vol. 52. N'o. 53  /  Thursday.  March 19,  1987 / Proposed Rules
  (M) The concentration in ground-
water of all Appendix VIII constituents
(hHt could reasonably be derived from
the waste.
  (Hi) Design and operating plans for a
proposed monitoring system to verify
thi: accuracy of any fate and transport
predictions, including:
  (A) A proposed period of operation:
and
  (B)  Contaminent levels in each
medium of concern that will prompt
noiification of the Regional
Administrator.
                           Note.—The following information, relevant
                         to evaluating closure demonstrations under
                         § 264.310(c), is required elsewhere in Part 270:
                           General facility location and design
                         information as required in 3 2ro.14(b)(ll) and
                         § 270.14{b](19):
                           Description of any plume of contamination
                         including the maximum concentration of all
                         Appendix VIII constituents.
                         *****

                           13. In § 270.41 by revising paragraph
                         (a)(5)(i) to read as follows:
§ 270.41  Major modification or revocation
and refasuanc* of permits.

  (a)'**
  (5) * * *
  (i) When modification of a closure
plan is required  under § 264.112(b) or
I 264.118(b), or when an owner or
operator requests authorization to
perform closure  and post-closure care
under § 264.310(c).
*•**•*

[FR Doc. 87-5576 Filed 3-18-87; 8:45 am|
•CLUNG COM (SfO-CO-M

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